U.S. patent application number 12/935544 was filed with the patent office on 2011-06-23 for double-clutch transmission for vehicles.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS, INC.. Invention is credited to Axel Geiberger, Mikael B. Mohlin, Mathias Remmler, Markus Rockenbach.
Application Number | 20110146443 12/935544 |
Document ID | / |
Family ID | 40671915 |
Filed Date | 2011-06-23 |
United States Patent
Application |
20110146443 |
Kind Code |
A1 |
Mohlin; Mikael B. ; et
al. |
June 23, 2011 |
DOUBLE-CLUTCH TRANSMISSION FOR VEHICLES
Abstract
A double-clutch transmission (DCT)includes, but is not limited
to an inner input shaft inside an outer input shaft. Two clutches
of the DCT are connected to the input shafts respectively. The DCT
has three layshafts that are parallel to the input shafts. One or
more pinions are fixed onto the layshafts respectively. Seven
forward gearwheel groups and one reverse gearwheel group of the DCT
are arranged on the shafts. Each one of the gearwheel groups
comprises a fixed gearwheel on one of the input shafts, meshing
with an idler gearwheel on one of the layshafts. In particular, a
third fixed gearwheel meshes with a third idler gearwheel and a
fifth idler gearwheel. Especially, the DCT includes, but is not
limited to a park-lock.
Inventors: |
Mohlin; Mikael B.; (Kungalv,
SE) ; Geiberger; Axel; (Mainz, DE) ; Remmler;
Mathias; (Mauchenheim, DE) ; Rockenbach; Markus;
(Schweppenhausen, DE) |
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS,
INC.
Detroit
MI
|
Family ID: |
40671915 |
Appl. No.: |
12/935544 |
Filed: |
March 31, 2009 |
PCT Filed: |
March 31, 2009 |
PCT NO: |
PCT/EP2009/002355 |
371 Date: |
February 21, 2011 |
Current U.S.
Class: |
74/665D |
Current CPC
Class: |
F16H 2003/0931 20130101;
Y10T 74/1907 20150115; F16H 2200/0086 20130101; F16H 3/093
20130101; F16H 2003/0826 20130101; Y10T 74/19233 20150115; F16H
3/006 20130101; Y10T 74/19112 20150115; F16H 2200/0056 20130101;
Y10T 74/19228 20150115; Y10T 74/19065 20150115; F16H 2003/0822
20130101 |
Class at
Publication: |
74/665.D |
International
Class: |
F16H 37/06 20060101
F16H037/06; F16H 3/093 20060101 F16H003/093 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2008 |
EP |
08006486.8 |
Mar 31, 2008 |
EP |
08006569.1 |
Mar 31, 2008 |
EP |
08006606.1 |
Mar 31, 2008 |
EP |
08006607.9 |
Mar 31, 2008 |
EP |
08006608.7 |
Mar 31, 2008 |
EP |
08006609.5 |
Mar 31, 2008 |
EP |
08006610.3 |
Mar 31, 2008 |
EP |
08006611.1 |
Mar 31, 2008 |
EP |
08006612.9 |
Mar 31, 2008 |
EP |
08006613.7 |
Mar 31, 2008 |
EP |
08006614.5 |
Mar 31, 2008 |
EP |
08006615.2 |
Mar 31, 2008 |
EP |
08006616.7 |
Mar 31, 2008 |
EP |
08006617.8 |
Mar 31, 2008 |
EP |
08006618.6 |
Mar 31, 2008 |
EP |
08006619.4 |
Mar 31, 2008 |
EP |
08006620.2 |
Mar 31, 2008 |
EP |
08006621.0 |
Mar 31, 2008 |
EP |
08006622.8 |
Mar 31, 2008 |
EP |
08006623.6 |
Mar 31, 2008 |
EP |
08006624.4 |
Mar 31, 2008 |
EP |
08006625.1 |
Mar 31, 2008 |
EP |
08006626.9 |
Mar 31, 2008 |
EP |
08006627.7 |
Mar 31, 2008 |
EP |
08006628.5 |
Mar 31, 2008 |
EP |
08006629.3 |
Mar 31, 2008 |
EP |
08006630.1 |
Mar 31, 2008 |
EP |
08006631.9 |
Mar 31, 2008 |
EP |
08006632.7 |
Mar 31, 2008 |
EP |
08006633.5 |
Mar 31, 2008 |
EP |
08006634.3 |
Mar 31, 2008 |
EP |
08006635.0 |
Mar 31, 2008 |
EP |
08006636.8 |
Mar 31, 2008 |
EP |
08006637.6 |
Mar 31, 2008 |
EP |
08006638.4 |
Mar 31, 2008 |
EP |
08006639.2 |
Mar 31, 2008 |
EP |
08006640.0 |
Mar 31, 2008 |
EP |
08006641.8 |
Mar 31, 2008 |
EP |
08006642.6 |
Mar 31, 2008 |
EP |
08006643.4 |
Mar 31, 2008 |
EP |
08006644.2 |
Mar 31, 2008 |
EP |
08006645.9 |
Mar 31, 2008 |
EP |
08006646.7 |
Mar 31, 2008 |
EP |
08006647.5 |
Mar 31, 2008 |
EP |
08006648.3 |
Mar 31, 2008 |
EP |
08006649.1 |
Claims
1. A double-clutch transmission, comprising: an inner input shaft
and an outer input shaft, at least a portion of the inner input
shaft surrounded by the outer input shaft; a first clutch disc
connected to the inner input shaft and a second clutch disc
connected to the outer input shaft; a first layshaft, a second
layshaft and a third layshaft spaced apart from the input shafts
and arranged in parallel to the input shafts, at least one of the
layshafts comprising a pinion for outputting a drive torque,
gearwheels arranged on the first layshaft, on the second layshaft,
on the third layshaft, on the inner input shaft and on the outer
input shaft, the gearwheels comprising a first gearwheel group, a
second gearwheel group, a third gearwheel group, a fourth gearwheel
group, a fifth gearwheel group, a sixth gearwheel group, a seventh
gearwheel group, and a reverse gearwheel group for providing seven
sequentially increasing forward gears and one reverse gear
respectively, the first gearwheel group comprising a first fixed
gearwheel on the outer input shaft, meshing with a first idler
gearwheel on one of the layshafts, the third gearwheel group
comprising a third fixed gearwheel on the outer input shaft,
meshing with a third driven gearwheel on one of the layshafts, the
fifth gearwheel group comprising a fifth fixed gearwheel on the
outer input shaft, meshing with a fifth idler gearwheel on one of
the layshafts, the seventh gearwheel group comprising a seventh
fixed gearwheel on the outer input shaft, meshing with a seventh
idler gearwheel on one of the layshafts, the second gearwheel group
comprising a second fixed gearwheel on the inner input shafts,
meshing with a second idler gearwheel on one of the layshafts, the
fourth gearwheel group comprising a fourth fixed gearwheel on the
inner input shafts, meshing with a fourth idler gearwheel on one of
the layshafts, the sixth gearwheel group comprising a sixth fixed
gearwheel on the inner input shafts meshing with a sixth idler
gearwheel on one of the layshafts, the reverse gearwheel group
comprising a fixed driving gearwheel on one of the input shafts
meshing with a reverse gearwheel on one of the layshafts, the
reverse gearwheel meshes with a reverse idler gearwheel on the
layshaft that comprises the pinion, each of these gearwheel groups
comprising a coupling device which is arranged on one of the
layshafts to selectively engage one of the gearwheels for providing
one of the seven sequentially increasing forward gears and the one
reverse gear, and the third fixed gearwheel further meshing with
the fifth idler gearwheel, wherein the double-clutch transmission
further comprises a fixed gearwheel on one of the layshafts that
carries the pinion as a final drive for providing a park-lock.
2. The double-clutch transmission according to claim 1, wherein the
first forward gear and the reverse gear are driven via different
input shafts.
3. The double-clutch transmission according to claim 1, wherein the
second forward gear and the reverse gear are driven by different
input shafts.
4. The double-clutch transmission according to claim 1, wherein the
reverse gear group comprises a reverse gear wheel and a second
reverse gear wheel on a same reverse gear idler shaft, the reverse
gear wheel and the second reverse gear wheel meshes with two
gearwheels on the two layshafts.
5. The double-clutch transmission according claim 1, wherein a
distance between one of the layshafts with gearwheels of higher
gear ratios and the inner input shaft is lesser than a distance
between the other layshaft with gearwheels of lower gear ratios and
the inner input shaft.
6. The double-clutch transmission according to claim 1, wherein the
idler gearwheels of the first gear, the third gear, the fifth gear
and the seventh gear are driven by the hollow input and the idler
gearwheels of the second, fourth, and the sixth gears are driven by
the solid input shaft.
7. The double-clutch transmission according to claim 1, wherein at
least two coupling devices are configured to engage two of the
idler gearwheels simultaneously to pre-select a gear for gear
shift.
8. The double-clutch transmission device according to claim 1,
wherein at least two of the first idler gearwheel, the second idler
gearwheel, the third driven gearwheel, and the fourth idler
gearwheel are provided on the same layshaft.
9. The double-clutch transmission device according to claim 1,
wherein at least two of the fifth idler gearwheel, the sixth idler
gearwheel, and the seventh idler gearwheel are provided on the same
layshaft.
10. The double-clutch transmission according to claim 1, further
comprising bearings for supporting the layshafts, at least one of
the bearings provided next to one of the pinions.
11. A gearbox, comprising: an inner input shaft and an outer input
shaft, at least a portion of the inner input shaft surrounded by
the outer input shaft; a first clutch disc connected to the inner
input shaft and a second clutch disc connected to the outer input
shaft; a first layshaft, a second layshaft and a third layshaft
spaced apart from the input shafts and arranged in parallel to the
input shafts, at least one of the layshafts comprising a pinion for
outputting a drive torque. gearwheels arranged on the first
layshaft, on the second layshaft, on the third layshaft, on the
inner input shaft and on the outer input shaft, the gearwheels
comprising a first gearwheel group, a second gearwheel group, a
third gearwheel group, a fourth gearwheel group, a fifth gearwheel
group, a sixth gearwheel group, a seventh gearwheel group, and a
reverse gearwheel group for providing seven sequentially increasing
forward gears and one reverse gear respectively, the first
gearwheel group comprising a first fixed gearwheel on the outer
input shaft, meshing with a first idler gearwheel on one of the
layshafts, the third gearwheel group comprising a third fixed
gearwheel on the outer input shaft, meshing with a third driven
gearwheel on one of the layshafts, the fifth gearwheel group
comprising a fifth fixed gearwheel on the outer input shaft,
meshing with a fifth idler gearwheel on one of the layshafts, the
seventh gearwheel group comprising a seventh fixed gearwheel on the
outer input shaft, meshing with a seventh idler gearwheel on one of
the layshafts, the second gearwheel group comprising a second fixed
gearwheel on the inner input shafts, meshing with a second idler
gearwheel on one of the layshafts, the fourth gearwheel group
comprising a fourth fixed gearwheel on the inner input shafts,
meshing with a fourth idler gearwheel on one of the layshafts, the
sixth gearwheel group comprising a sixth fixed gearwheel on the
inner input shafts meshing with a sixth idler gearwheel on one of
the layshafts, the reverse gearwheel group comprising a fixed
driving gearwheel on one of the input shafts meshing with a reverse
gearwheel on one of the layshafts, the reverse gearwheel meshes
with a reverse idler gearwheel on the layshaft that comprises the
pinion, each of these gearwheel groups comprising a coupling device
which is arranged on one of the layshafts to selectively engage one
of the gearwheels for providing one of the seven sequentially
increasing forward gears and the one reverse gear, and the third
fixed gearwheel further meshing with the fifth idler gearwheel,
wherein the double-clutch transmission further comprises a fixed
gearwheel on one of the layshafts that carries the pinion as a
final drive for providing a park-lock; and an output gearwheel on
an output shaft that meshes with the pinion for outputting the
drive torque to a torque drain.
12. A power train device, comprising: an inner input shaft and an
outer input shaft, at least a portion of the inner input shaft
surrounded by the outer input shaft; a first clutch disc connected
to the inner input shaft and a second clutch disc connected to the
outer input shaft; a first layshaft, a second layshaft and a third
layshaft spaced apart from the input shafts and arranged in
parallel to the input shafts, at least one of the layshafts
comprising a pinion for outputting a drive torque, gearwheels
arranged on the first layshaft, on the second layshaft, on the
third layshaft, on the inner input shaft and on the outer input
shaft, the gearwheels comprising a first gearwheel group, a second
gearwheel group, a third gearwheel group, a fourth gearwheel group,
a fifth gearwheel group, a sixth gearwheel group, a seventh
gearwheel group, and a reverse gearwheel group for providing seven
sequentially increasing forward gears and one reverse gear
respectively, the first gearwheel group comprising a first fixed
gearwheel on the outer input shaft, meshing with a first idler
gearwheel on one of the layshafts, the third gearwheel group
comprising a third fixed gearwheel on the outer input shaft,
meshing with a third driven gearwheel on one of the layshafts, the
fifth gearwheel group comprising a fifth fixed gearwheel on the
outer input shaft, meshing with a fifth idler gearwheel on one of
the layshafts, the seventh gearwheel group comprising a seventh
fixed gearwheel on the outer input shaft, meshing with a seventh
idler gearwheel on one of the layshafts, the second gearwheel group
comprising a second fixed gearwheel on the inner input shafts,
meshing with a second idler gearwheel on one of the layshafts, the
fourth gearwheel group comprising a fourth fixed gearwheel on the
inner input shafts, meshing with a fourth idler gearwheel on one of
the layshafts, the sixth gearwheel group comprising a sixth fixed
gearwheel on the inner input shafts meshing with a sixth idler
gearwheel on one of the layshafts, the reverse gearwheel group
comprising a fixed driving gearwheel on one of the input shafts
meshing with a reverse gearwheel on one of the layshafts, the
reverse gearwheel meshes with a reverse idler gearwheel on the
layshaft that comprises the pinion, each of these gearwheel groups
comprising a coupling device which is arranged on one of the
layshafts to selectively engage one of the gearwheels for providing
one of the seven sequentially increasing forward gears and the one
reverse gear, and the third fixed gearwheel further meshing with
the fifth idler gearwheel, wherein the double-clutch transmission
further comprises a fixed gearwheel on one of the layshafts that
carries the pinion as a final drive for providing a park-lock; an
output gearwheel on an output shaft that meshes with the pinion for
outputting the drive torque to a torque drain; and at least one
power source for generating a driving torque.
13. The power train device according to claim 12, wherein the power
source comprises a combustion engine.
14. The power train device of claim 12, wherein the power source
comprises an electric motor.
15. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. National-Stage entry under 35
U.S.C. .sctn.371 based on International Application No.
PCT/EP2009/002355, filed Mar. 31, 2009, which was published under
PCT Article 21(2) and which claims priority to European Application
No. 08006645.9, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006638.4, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006639.2, filed Mar.
31, 2008, and which claims priority to European Application No.
08006640.0, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006641.8, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006642.6, filed Mar.
31, 2008, and which claims priority to European Application No.
08006635.0, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006643.4, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006644.2, filed Mar.
31, 2008, and which claims priority to European Application No.
08006486.8, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006606.1, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006607.9, filed Mar.
31, 2008, and which claims priority to European Application No.
08006608.7, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006646.7, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006616.7, filed Mar.
31, 2008, and which claims priority to European Application No.
08006617.8, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006609.5, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006610.3, filed Mar.
31, 2008, and which claims priority to European Application No.
08006611.1, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006612.9, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006621.0, filed Mar.
31, 2008, and which claims priority to European Application No.
08006622.8, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006623.6, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006624.4, filed Mar.
31, 2008, and which claims priority to European Application No.
08006569.1, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006637.6, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006615.2, filed Mar.
31, 2008, and which claims priority to European Application No.
08006636.8, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006625.1, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006626.9, filed Mar.
31, 2008, and which claims priority to European Application No.
08006627.7, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006628.5, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006629.3, filed Mar.
31, 2008, and which claims priority to European Application No.
08006630.1, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006631.9, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006619.4, filed Mar.
31, 2008, and which claims priority to European Application No.
08006620.2, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006618.6, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006614.5, filed Mar.
31, 2008, and which claims priority to European Application No.
08006613.7, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006634.3, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006633.5, filed Mar.
31, 2008, and which claims priority to European Application No.
08006632.7, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006649.1, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006648.3, filed Mar.
31, 2008, and which claims priority to European Application No.
08006647.5, filed Mar. 31, 2008, which are all hereby incorporated
in their entirety by reference.
TECHNICAL FIELD
[0002] The present application relates to a double-clutch
transmission for vehicles, such as cars.
BACKGROUND
[0003] A double-clutch transmission comprises two input shafts that
are connected to and that are actuated by two clutches separately.
The two clutches are often combined into a single device that
permits actuating any of the two clutches at a time. The two
clutches transmit driving torque from an engine to the two input
shafts of the double-clutch transmission.
[0004] U.S. Pat. No. 6,634,247 B2 discloses a six-gear double
clutch transmission with an electric unit. The double clutch
transmission has not been widely used in the cars for street
driving. Problems that hinder the wide application of double clutch
transmission comprise of providing a compact, reliable, and
fuel-efficient double clutch transmission. Therefore, there exists
a need for providing such a double clutch transmission that is also
affordable by consumers.
SUMMARY
[0005] The present application provides a double-clutch
transmission (DCT) that comprises an inner input shaft and an outer
input shaft. The inner input shaft can be either solid or hollow.
The outer input shaft encloses a portion of the inner input shaft
in a radial direction. The radial direction of the shaft indicates
a direction that points away from a central longitudinal axis of
the shaft following a radius direction of the shaft.
[0006] The DCT comprises a first clutch that is non-rotatably
connected to the inner input shaft and a second clutch that is also
non-rotatably connected to the outer input shaft. For example, the
first clutch is fixed to the inner input shaft and the second
clutch is fixed to the outer input shaft. Alternatively, the
non-rotatable connection can be provided by a universal joint.
[0007] The DCT also comprises a first layshaft, a second layshaft,
and a third layshaft that are radially spaced apart from the input
shafts. The layshafts are essentially parallel to the input shafts.
One or more of the layshafts comprise a pinion or pinions for
outputting a drive torque to a vehicle. Examples of the vehicle
include a car or a motorcycle. Pinions of the DCT comb with an
output gearwheel respectively such that the output gearwheel
transmits torques from the pinions to an output shaft for driving
the vehicle.
[0008] The DCT has gearwheels arranged on the first layshaft, on
the second layshaft, on the third layshaft, on the inner input
shaft, and on the outer input shaft. The gearwheels includes a
first gearwheel group, a second gearwheel group, a third gearwheel
group, a fourth gearwheel group, a fifth gearwheel group, a sixth
gearwheel group, a seventh gearwheel group and a reverse gearwheel
group for providing seven sequentially increasing forward gears and
one reverse gear respectively. Typically, a gearwheel is typically
mounted to its carrying shaft coaxially. The fact that a gearwheel
and its carrying shaft having the same rotational axis ensures
uniform gear meshing of the gearwheel with its neighboring
gearwheel on a parallel shaft.
[0009] The sequentially increasing gears describe an escalating
order that members of the order follow each other. Gears of a car
are typically arranged in a sequentially increasing manner from
first gear to seventh gear. For example, in a vehicle can have a
transmission with a first gear having a gear ratio of 2.97:1. A
second gear has a gear ratio of 2.07:1. A third gear has a gear
ratio of 1.43:1. A fourth gear has a gear ratio of 1.00:1. A fifth
gear has a gear ratio of 0.84:1. A sixth gear has a gear ratio of
0.56:1. Lastly, a seventh gear has a gear ratio of 0.45:1. The
seven gears provide an increasing order of output speed of the
transmission for driving the vehicle.
[0010] The first gearwheel group comprises a first fixed gearwheel
on the outer input shaft, meshing with a first idler gearwheel on
one of the layshafts. Similarly, the third gearwheel group
comprises a third fixed gearwheel on the outer input shaft, meshing
with a third driven gearwheel on one of the layshafts. The fifth
gearwheel group comprises a fifth fixed gearwheel on the outer
input shaft, meshing with a fifth idler gearwheel on one of the
layshafts. The seventh gearwheel group comprises a seventh fixed
gearwheel on the outer input shaft, meshing with a seventh idler
gearwheel on one of the layshafts.
[0011] The second gearwheel group comprises a second fixed
gearwheel on the inner input shafts, meshing with a second idler
gearwheel on one of the layshafts. The fourth gearwheel group
comprises a fourth fixed gearwheel on the inner input shafts,
meshing with a fourth idler gearwheel on one of the layshafts. The
sixth gearwheel group comprises a sixth fixed gearwheel on the
inner input shafts, meshing with a sixth idler gearwheel on one of
the layshafts. The reverse gearwheel group comprises a fixed
driving gearwheel on one of the input shafts, meshing directly or
indirectly with a reverse idler gearwheel on one of the layshafts,
wherein the layshaft includes or carries the pinion.
[0012] The direct meshing can be provided by two gearwheels that
are physically in contact with each other. The indirect meshing can
be provided by one or more intermediate gearwheels that mesh with
the fixed driving gearwheel and the reverse gearwheel.
[0013] Each of these gearwheel groups comprises a coupling device,
which is arranged on one of the layshafts to selectively engage one
of the gearwheels to its carrying shaft for selecting one the seven
sequentially increasing forward gears and the one reverse gear. The
carrying shaft is a shaft that carries the weight of the gearwheel.
The third fixed gearwheel meshes with both the third idler
gearwheel and the fifth idler gearwheel.
[0014] Two coupling devices for engaging two gearwheels can form a
coupling unit. The coupling unit is also called a double-sided
coupling unit or a double-sided synchronizer.
[0015] The DCT provides seven forward gears and one reverse gear. A
dual-clutch of the DCT enables gear switching between odd and even
ratios to be swift and efficient because the gearwheels for the odd
gears and even gears are driven by different clutches respectively.
A double-meshing feature is provided by the third fixed gearwheel
on the outer input shaft meshing with the third idler gearwheel and
the fifth idler gearwheel. The double-meshing feature makes the DCT
to be compact and lightweight at low cost because one fixed
gearwheel is reduced from the input shafts. The reverse gear
enables a vehicle with the DCT to be more maneuverable.
[0016] The double-clutch transmission can further comprise a
park-lock gearwheel that is fixed onto one of the layshafts for
providing a park-lock. The layshaft with the park-lock also carries
the pinion for engaging and for locking a differential of the DCT.
The differential comprises the output gearwheel on the output
shaft. The park-lock enables a vehicle with the park-lock to park
at a place in a secure manner, even on a slope. The park-lock is
easy to implement as it is placed on the layshaft that carries the
pinion.
[0017] The double clutch transmission can provide two coupling
devices that engage two of the idler gearwheels of the seven gears
respectively at the same time. The process of multiple engagements
of the two idler gearwheels on different layshafts is known as
pre-selection of gears. Especially, the two idlers of two
consecutive gears that are driven by different input shafts of the
DCT can be both engaged for shifting from one of the two gears to
the other. For example, idler gearwheels of the third gear and the
fourth gear of the DCT are both engaged to their weight-carrying
layshaft by their neighboring coupling devices when only one of the
input shafts receives an input torque. Since incoming torque from
any of the input shafts is constantly delivered to an idler
gearwheel of the two consecutive gears, there is little or no
interruption in torque flow during the gearshift. Therefore, the
double-clutch transmission provides continuous and more efficient
torque transmission, as compared to the gearshift process in single
clutch transmissions.
[0018] According to the application, different input shafts can
provide the first forward gear and the reverse gear. For example,
the outer input shaft can drive the first gearwheel group and the
inner input shaft can drive the reverse gearwheel group. Since the
first forward gear and the reverse gear are provided on two
different input shafts, the two clutches of the DCT can enable
efficient switching between the two input shafts to provide a
rocking motion. In this, a driving scheme that the DCT engages one
of the two input shafts alternatively drive the vehicle back and
forth rapidly using the first gear and the reverse gear without
much loss in momentum. The swaying back and forth of the vehicle
pulls the vehicle out of mud.
[0019] The reverse gearwheel group can also comprise a further
reverse gear for providing second reverse gear, in addition to the
previously mentioned first gear. The further reverse gear meshes
with a further fixed driving gearwheel that is provided on one of
the input shafts. One of the two reverse gears can provide a
powerful and slower reverse gear whilst the other reverse gear can
provide a faster reverse gear with less strength. The two reverse
gears at different speeds enable some special vehicles, such as a
Leopard II Main Battle Tank, to increase their maneuverability and
operation efficiency.
[0020] Furthermore, different input shafts can drive the two
reverse gears for providing the two reverse gears. This scheme
makes the interchange between the two reverse gears to be fast,
just by alternatively engaging one of the two clutches of the DCT.
In a special case, the two reverse gears are driven either by the
same inner input shaft or by the same outer input shaft. For easier
design and implementation, the two reverse gears can be provided on
the same layshaft. In certain implementation, the second forward
gear and the further reverse gear are driven by different input
shafts for providing a rocking motion to pull out a vehicle that is
stuck in mud.
[0021] The DCT can also comprise an eighth gearwheel group for
providing an eighth forward gear. The eighth gearwheel group
comprises a fixed eighth fixed gearwheel on one of the input
shafts, meshing with an eighth idler gearwheel on one of the
layshafts. The eighth gear is useful for some high-end cars that
have more powerful engine for achieving high speed driving. More
gears also mean more choices for a driver.
[0022] The sixth fixed gearwheel can further mesh with the eighth
idler gearwheel. In other words, the DCT can provide two
double-meshing features. One double meshing feature includes the
eighth idler gearwheel meshing with the sixth idler gearwheel via
the sixth fixed gearwheel, which also serves as the eight fixed
gearwheel. The two double meshing features save or reduce two
driving gearwheels on the input shafts such that the weight, cost
and size of the DCT is reduced. Furthermore, since the two
double-meshing features are provided on the inner input shaft and
the outer input shaft separately, gear changing between the idler
gearwheels of these double-meshing features can be performed
efficiently by engaging any of the input shafts using the double
clutch.
[0023] In the application, the DCT has a distance between one of
the layshafts with gearwheels of low gears and the inner input
shaft is greater than a distance between the other layshaft with
gearwheels of high gears and the inner input shaft. The layshaft
with gearwheels of low gears can be any of the layshafts. Since
gearwheels of low gears, for example first, second, or third gear,
can be larger than the gearwheels of high gears, such as fifth,
sixth, seventh, or eighth gear, the layshaft with the gearwheels of
high gears can be brought closer to the input shafts such that the
DCT can be made more compact.
[0024] In the application, the DCT can have two pinions are mounted
on two of the layshafts respectively. In a further alternative,
each of the three layshafts can have a pinion on it for outputting
a torque of its carrying layshaft. A gearwheel or pinion-carrying
shaft is a shaft that bears the weight of the gearwheel. The pinion
can be used as a fixed gearwheel for providing the park-lock. In
fact, any one of the pinions on the layshafts can be made into or
be adapted to the park-lock.
[0025] Two or more of the first idler gearwheel, the second idler
gearwheel, the third driven gearwheel, and the fourth idler
gearwheel can be provided on the same layshaft. These gearwheels of
low gears transmit larger torques and thus require a thicker
layshaft, as compared to the layshaft carrying the gearwheels of
high gears. The thicker layshaft can be more fully utilized when
more gearwheels of the low gears are installed on it. For example,
the first idler gearwheel, the second idler gearwheel, and the
third idler gearwheel can be mounted on the upper layshaft.
[0026] Similarly, two or more of the fifth idler gearwheel, the
sixth idler gearwheel, the seventh idler gearwheel, and the eighth
idler gearwheel can be provided on the same layshaft. Gearwheels of
higher gears are advantageous to be installed on the same shaft
because the shaft can be made slim for the reduction of cost and
size of the double-clutch transmission. For example, the fifth
idler gearwheel, the sixth idler gearwheel, and the seventh idler
gearwheel can be provided on the same layshaft. More gearwheels of
high gears mounted on the same shaft provide further opportunity
for installing gearwheels of low gears on another shaft. The other
shaft can thus be made short for carrying less number of
gearwheels.
[0027] The DCT can further comprise bearings for supporting the
layshafts and the input shafts. One or more of the bearings can be
provided next to the pinions. Since each of the pinions output
torque of its carrying shaft, support from its neighboring bearing
can help with reducing the carrying shaft's deflection unload,
minimizing the carrying shaft's size and improving the pinion's
meshing accuracy for better efficiency.
[0028] One or more of the bearings can be provided next to one of
the driven gearwheels of low gears. Bearings that support a shaft
are more advantageously provided next to gearwheels of low gears.
The supporting shaft can be made slim and have less deflection when
the bearings are next to the gearwheels of low gears. For example,
the bearing can be located immediately adjacent to the first idler
gearwheel or the second idler gearwheel. The driven gearwheels of
low gears, such as first, second, or third gear, carries heavier
load and torque, which need stronger support from the bearings at
their vicinity.
[0029] In the application, there can be provided a gearbox an
output gearwheel on an output shaft that meshes with the pinion of
the DCT for outputting the drive torque to a torque drain. The
torque drain can be a differential of a drive train. In a motor
vehicle, the term drive train is also known as power train or power
plant that refers to the group of components that generate power
and deliver it to the road surface, water, or air. This includes
the engine, transmission, drive shafts, differentials, and the
final drive. The final drive can be drive wheels, continuous track
like with tanks or Caterpillar tractors, propeller, etc. Sometimes
the "power train" is used to refer to simply the engine and
transmission, including the other components only if they are
integral to the transmission. In a carriage or wagon, running gear
designates the wheels and axles in distinction from the body.
[0030] According to the application, a power train device with the
gearbox is provided. The power train device comprises one or more
power source for generating a driving torque. The power source is
preferred to be onboard with the power train such that a vehicle
with the power train device can be more mobile.
[0031] The power source can comprise a combustion engine. The
vehicle having the combustion engine and the double-clutch
transmission is easy to manufacture. The combustion engine can
consume less petrol for environmental protection. Furthermore, a
combustion engine for other types of fuel can have even less
polluting emission, such as hydrogen fuel.
[0032] The power source can further comprise an electric motor.
Electric motor used in a hybrid car, or in an electrical car
enables reduction of pollution, as compared to typical combustion
using petrol. The electric motor can even recuperate brake energy
in a generator mode.
[0033] In the application, there can be provided a vehicle that
comprises the power train device. The vehicle having the power
train device is efficient in energy usage by using the
double-clutch transmission.
[0034] The double clutch transmission enables pre-selection of
gears for smooth gear transmission. Two coupling devices can engage
the idler gearwheel of the current gear and the idler gearwheel of
the next sequential gear at the same time. This allows the next
sequential gear to be connected rapidly and thus in a more smooth
manner. In particular, the two idlers of two consecutive gears that
are driven by different input shafts of the DCT can be both engaged
simultaneously. For example, idler gearwheels of the third gear and
the fourth gear of the DCT can be both engaged to their
weight-carrying layshaft by their respectively coupling devices
when one of the input shafts receives an input torque. One engaged
idler gearwheel is driven directly by the input torque whilst the
other engaged idler gearwheel is driven via the pinion by the input
torque. In this manner, little or no interruption in torque flow
during gearshift. Therefore, the double-clutch transmission
provides continuous and more efficient torque transmission, as
compared to other gearshift process.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The present invention will hereinafter be described in
conjunction with the following drawing figures, wherein like
numerals denote like elements, and
[0036] FIG. 1 illustrates a front view of an embodiment of a double
clutch transmission of the application;
[0037] FIG. 2 illustrates the path of torque flow of a first gear
transmission ratio;
[0038] FIG. 3 illustrates the path of torque flow of a second gear
transmission ratio;
[0039] FIG. 4 illustrates the path of torque flow of a third gear
transmission ratio;
[0040] FIG. 5 illustrates the path of torque flow of a fourth gear
transmission ratio;
[0041] FIG. 6 illustrates the path of torque flow of a fifth gear
transmission ratio;
[0042] FIG. 7 illustrates the path of torque flow of a sixth gear
transmission ratio;
[0043] FIG. 8 illustrates the path of torque flow of a seventh gear
transmission ratio;
[0044] FIG. 9 illustrates the path of torque flow of a reverse gear
transmission ratio;
[0045] FIG. 10 illustrates an assembly of a double-sided coupling
device with its neighboring gearwheels for engagement;
[0046] FIG. 11 illustrates an assembly of a single-sided coupling
device with its neighboring gearwheel for engagement;
[0047] FIG. 12 illustrates an assembly of an idler gearwheel that
is rotatably supported by a shaft on a bearing;
[0048] FIG. 13 illustrates an assembly of a fixed gearwheel that is
supported on a shaft;
[0049] FIG. 14 illustrates a cross-section through a detail of a
crankshaft of an internal combustion engine according to embodiment
of the double-clutch transmission;
[0050] FIG. 15 illustrates a front view of a further embodiment of
a double clutch transmission of the application;
[0051] FIG. 16 illustrates an expanded side view of the double
clutch transmission of FIG. 16;
[0052] FIG. 17 illustrates a front view of a further embodiment of
a double clutch transmission of the application;
[0053] FIG. 18 illustrates an expanded side view of the double
clutch transmission of FIG. 17;
[0054] FIG. 19 illustrates a front view of a further embodiment of
a double clutch transmission of the application;
[0055] FIG. 20 illustrates an expanded side view of the double
clutch transmission of FIG. 19;
[0056] FIG. 21 illustrates a front view of a further embodiment of
a double clutch transmission of the application; and
[0057] FIG. 22 illustrates an expanded side view of the double
clutch transmission of FIG. 21.
[0058] FIG. 23 illustrates an alternative front view of the
expanded side view of the double clutch transmission in FIG.
18.
DETAILED DESCRIPTION
[0059] The following detailed description is merely exemplary in
nature and is not intended to limit or the application and uses.
Furthermore, there is no intention to be bound by any theory
presented in the preceding background or summary or the following
detailed description.
[0060] In the following description, details are provided to
describe the embodiments of the application. It shall be apparent
to one skilled in the art, however, that the embodiments may be
practiced without such details.
[0061] FIGS. 1 to 9 and FIGS. 11 to 15 provide detailed description
of an embodiment of a double clutch transmission (DCT) of the
application.
[0062] FIG. 1 illustrates a front view of an embodiment of a double
clutch transmission 1 of the application. The DCT 1 comprises a
reverse gear idler shaft 38, a relatively large output gearwheel 12
on an output shaft 14, an upper pinion 41 on an upper layshaft 40,
a solid input shafts 20, a hollow input shaft 22, and a lower
pinion 51 on a lower layshaft 50.
[0063] The input shaft 20 is also called K1. The input shaft 22 is
also called K2. The solid input shaft 20 and the hollow input shaft
22 share the same longitudinal axis of rotation and are
non-rotatably connected to two clutches 8, 10 of a double clutch 6,
separately. The clutches 8, 10 and the double clutch 6 are shown in
FIG. 15.
[0064] The two pinions 41, 51 are fixed to the upper layshaft 40
and the lower layshaft 50 respectively at their longitudinal axes
of rotation. The output gearwheel 12 is also fixed to the output
shaft 14 at its rotation axis. The two pinions 41, 51 mesh
separately with the output gearwheel 12 at different positions of
the output gearwheel 12.
[0065] The reverse gear idler shaft 38, the upper layshaft 40, the
input shafts 20, 22, and the lower layshaft 50 are parallel to each
other with predetermined distances in-between. The distances are
provided in radial directions of these shafts, which are better
seen in FIG. 2. Other gearwheels are mounted on these shafts that
mesh with each other according to predetermined manners. The
manners of these gearwheels' mounting and meshing are better seen
in some of the following figures.
[0066] Functionally, the gearwheel 12 acts as a ring gear of a
differential that is used as a carrier of differential gears. The
carrier is contained in a housing. Driving shafts for wheels of a
car, which are not shown in the figure, can be connected to
corresponding tapered gears of the differential. Therefore, the
output shaft 14 acts essentially as an axis of the
differential.
[0067] FIG. 1 further shows a cutting plane A-A for illustrating an
expanded cross-section view through the DCT 1, which is shown in
FIGS. 2 to 9. The cutting plane A-A passes through the rotational
axes of the reverse gear idler shaft 38, the upper layshaft 40, the
input shafts 20, 22, the lower layshaft 50, and the output shaft
14. One of the goals of FIGS. 2 to 9 is to illustrate further
structure and torque flows of the DCT 1.
[0068] FIG. 2 illustrates the expanded view of the DCT that shows
the manners of the gearwheels mounting, which corresponds to FIG.
1.
[0069] According to FIG. 2, the DCT 1 comprises the following
shafts, from top to bottom, the reverse gear idler shaft 38, the
upper layshaft 40, the hollow input shaft 22, the solid input shaft
20, the lower layshaft 50, and the output shaft 14. The solid input
shaft 20 is partially disposed inside the hollow input shaft 22.
The solid input shaft 20 also protrudes outside the hollow input
shaft 22 at two ends. The hollow input shaft 22 is mounted onto the
solid input shaft 20 by a pair of solid shaft bearings 71 that are
disposed between the solid input shaft 20 and the hollow input
shaft 22 at two ends of the hollow input shaft 22. As a result, the
two input shafts 20, 22 are coupled together such that the solid
input shaft 20 is free to rotate inside the hollow input shaft 22.
The hollow input shaft 22 surrounds a right portion of the solid
input shaft 20, and a left portion of the solid input shaft 20 is
exposed outside the hollow input shaft 22. The assembly of the
input shafts 20, 22 is supported by a solid shaft bearing 71 at a
protruding end of the solid shaft 20 on the left and by a hollow
shaft bearing 72 on the hollow input shaft 22 on the right.
[0070] According to FIG. 2, the outer input shaft 22 surrounds a
portion of the solid input shaft 20 in a radial direction of the
solid input shaft 20. There are four gearwheels mounted on the left
exposed portion of the solid input shaft 20. These gearwheels are a
fixed wheel second gear 30, a fixed wheel reverse gear 34, a fixed
wheel fourth gear 31, and a fixed wheel sixth gear 32 from left to
right sequentially. All of the fixed wheel second gear 30, the
fixed wheel reverse gear 34, the fixed wheel fourth gear 31, and
the fixed wheel sixth gear 32 are mounted onto the solid input
shaft 20 coaxially. On the hollow input shaft 22, which is mounted
on the right portion of the solid input shaft 20, there is attached
with a fixed wheel third gear 25, a fixed wheel seventh gear 27,
and a fixed wheel first gear 24 from left to right. The fixed wheel
third gear 25 also serves as a fixed wheel fifth gear 26. The fixed
wheel second gear 30 is fixed onto the hollow input shaft 22
coaxially.
[0071] The upper layshaft 40 is provided above the input shafts 20,
22. There are gearwheels and coupling devices provided on the upper
layshaft 40, which includes, from right to the left, the upper
pinion 41, an idler seventh gear 66, a double-sided coupling device
80, an idler fifth gear 64, an idler sixth gear 65, a double-sided
coupling device 81, and an reverse gear idler wheel 37. One
layshaft bearing 73 is positioned at a left end of the upper
layshaft 40 and another layshaft bearing 73 is positioned between
the upper pinion 41 and the idler seventh gear 66. The idler
seventh gear 66, the idler fifth gear 64, the idler sixth gear 65,
and the reverse gear idler wheel 37 are mounted on the upper
layshaft 40 by bearings respectively such that these gearwheels are
free to rotate around the upper layshaft 40. The double-sided
coupling device 80 is configured to move along the upper layshaft
40 to engage or disengage the idler seventh gear 66 or the idler
fifth gear 64 to the upper layshaft 40. Similarly, the double-sided
coupling device 81 is configured to move along the upper layshaft
40 to engage the idler sixth gear 65 or the reverse gear idler
wheel 37 to the upper layshaft 40. The idler seventh gear 66 meshes
with the fixed wheel seventh gear 27. The idler fifth gear 64
meshes with the fixed wheel fifth gear 26. The idler sixth gear 65
meshes with the fixed wheel sixth gear 32.
[0072] The reverse gear idler shaft 38 is provided further above
the upper layshaft 40. A first reverse gear wheel 35 is fixed onto
the reverse gear idler shaft 38 in the middle. An idler shaft
bearing 74 supports each end of the reverse gear idler shaft 38
such that the first reverse gear wheel 35 and the reverse gear
idler shaft 38 are free to rotate together. The upper layshaft 40,
the reverse gear idler shaft 38, and the input shafts 20 are
positioned at vertexes of a triangle such that the first reverse
gear wheel 35 meshes with the fixed wheel reverse gear 34 and with
the reverse gear idler wheel 37.
[0073] The lower layshaft 50 is provided below the input shafts 20,
22. There are a number of gearwheels and coupling devices mounted
on the lower layshaft 50, which include, from right to the left,
the lower pinion 51, an idler first gear 60, a double-sided
coupling device 83, an idler third gear 62, an park-lock 42, an
idler fourth gear 63, a double-sided coupling device 82, and an
idler second gear 61. One layshaft bearing 73 is provided between
the lower pinion 51 and the idler first gear 60. Another layshaft
bearing 73 is provided next to the idler second gear 61 at the left
end of the lower layshaft 50. The lower pinion 51 is fixed onto the
lower layshaft 50 at its rotational axis. The idler first gear 60,
the idler third gear 62, the idler fourth gear 63, and the idler
second gear 61 are mounted on the lower layshaft 50 by bearings
separately such that these gearwheels become idlers, being free to
rotate around the lower layshaft 50.
[0074] The double-sided coupling devices 83 is configured to move
along the lower layshaft 50 such that it can engage either the
idler first gear 60 or the idler third gear 62. Similarly, the
double-sided coupling devices 82 is configured to move along the
lower layshaft 50 such that it can engage either the idler fourth
gear 63 or the idler second gear 61 to the lower layshaft 50
respectively. The idler first gear 60 meshes with the fixed wheel
first gear 24. The idler third gear 62 meshes with the fixed wheel
third gear 25. The idler fourth gear 63 meshes with the fixed wheel
fourth gear 31. The idler second gear 61 meshes with the fixed
wheel second gear 30.
[0075] The park-lock 42 includes a fixed gear wheel that is fixed
to the lower layshaft 50. The park-lock 42 locks the lower layshaft
50 when parking a vehicle that has the double-clutch transmission
1. The park-lock is provided with a ratchet device, with a click
device having a rack element, a claw or similar. The park-lock 42
keeps the lower layshaft 50 and the output shaft 14 from rotating,
which thereby stops the vehicle from moving when it is a parked.
Functions of the park-lock 42 are easy to implement as it is placed
the lower layshaft 50 that carries the pinion 51. In a generic
sense, the park-lock 42 can be placed on any layshaft that carries
the pinion.
[0076] The DCT 1 with the park-lock is controlled by a gearshift
lever located in a driving compartment and movable by a vehicle
operator between positions corresponding to transmission gear
ranges, such as Park, Reverse, Neutral, Drive, and Low. A linear
actuation cable is attached at its first end to the gearshift
lever, and movement of the gearshift lever alternatively pushes or
pulls on the cable to move a transmission mode select lever
attached to the other end of the cable. The mode select lever is
mechanically connected to a shift valve within a DCT housing, and
movement of the shift valve effects shifting between different
gears.
[0077] When the gearshift lever is placed in a park position, two
related mechanical actuations take place within the DCT 1. First,
the mode select lever is moved, depending on a clutch system, to
disengage or to engage the input shafts 20, 22 from an engine.
Second, a park-lock pawl is moved into locking engagement with the
ratchet device of the park-lock 42 on the lower layshaft 50 to
thereby lock the output shaft 14 against rotation. A linear
actuation cable that actuates the mode select lever moves the lock
pawl.
[0078] In other words, there are two double-meshing features
provided in the DCT 1. A first double-meshing feature comprises
that the fixed wheel third gear 25 meshes with both the idler third
gear 62 and the idler fifth gear 64. A second double meshing
feature comprises that the first reverse gear wheel 35 meshes with
both the reverse gear idler wheel 37 and the fixed wheel reverse
gear 34.
[0079] In addition, FIG. 2 shows a distance 56 that extends between
the input shafts 20, 22 and the upper layshaft 40 and a distance 58
that extends between the input shafts 20, 22 and the lower layshaft
50.
[0080] The distance 56 the input shafts 20, 22 and the upper
layshaft 40 is measured from a common longitudinal axis of the
input shafts 20, 22 to a longitudinal axis of the upper layshaft
40. The gearwheels 64, 65, 66 that reflect high gears are provided
on the upper layshaft 40. Similarly, the distance 58 is measured
from the common longitudinal axis of the input shafts 20, 22 to a
longitudinal axis of the lower layshaft 50. The gearwheels 60, 61,
62, 63 that reflect low gears are provided on the lower layshaft
50. Since the high gears are smaller than the low gears, the
distance 56 is longer than the distance 58.
[0081] The output shaft 14 is further provided below the lower
layshaft 50. Two output shaft bearings 75 at two opposite ends of
the output shaft 14 respectively for supporting. The output
gearwheel 12 is fixed onto the output shaft 14 coaxially. The
output gearwheel 12 meshes with the lower pinion 51 and the upper
pinion 41.
[0082] In the present specification, the expressions "mesh" and
"comb" with respect to geared wheels or engaged gearwheels are
provided as synonyms. The solid input shaft 20 is alternatively
termed as an inner input shaft 20, while the hollow input shaft 22
is alternatively termed as an outer input shaft 22. The solid input
shaft 20 is replaced alternatively by a hollow shaft and is
disposed inside the hollow input shaft 22. The term "coupling
device" is alternatively termed as "shifting mechanism" or
"synchronizer" for engaging or disengaging gearwheels on its
carrying shaft. The double-clutch transmission (DCT) can be
alternatively termed as a double clutch, or a dual clutch
transmission.
[0083] The fixed wheel first gear 24 is also known as the first
fixed gearwheel 24. The fixed wheel third gear 25 is also known as
the third fixed gearwheel 25. The fixed wheel fifth gear 26 is also
known as the fifth fixed gearwheel 26. The fixed wheel seventh gear
27 is also known as the seventh fixed gearwheel 27. The fixed wheel
second gear 30 is also known the second fixed gearwheel 30. The
fixed wheel fourth gear 31 is also known as the fourth fixed
gearwheel 31. The fixed wheel sixth gear 32 is also known as the
sixth fixed gearwheel 32. The first reverse gear wheel 35 is also
known as a first reverse idler gearwheel 35. The reverse gear idler
wheel 37 is also known as the reverse idler gearwheel 37. The idler
first gear 60 is also known as the first idler gearwheel 60. The
idler second gear 61 is also known as the second idler gearwheel
61. The idler third gear 62 is also known as the third fixed
gearwheel 62. The idler fourth gear 63 is also known as the fourth
idler gearwheel 63. The idler fifth gear 64 is also known as the
fifth idler gearwheel 64. The idler sixth gear 65 is also known as
the sixth idler gearwheel 65. The idler seventh gear 66 is also
known as the seventh idler gearwheel 66.
[0084] In the drawings of the present application, dash lines
indicate either alternative positions of the illustrated parts or
combing relationship between the gearwheels.
[0085] The DCT 1 permits gearshift operations with less loss of
driving torque. This is because the gearshift operations can
selectively connect of one of the two clutches 8, 10 of the DCT 1.
Therefore, an associated additional main drive clutch can be
avoided. The selective connections between the two clutches 8, 10
also enable a realization of an automatic transmission that can be
operated without interruptions in propulsive power. The propulsive
power comprises momentum derived from rotating gearwheels and
rotating shafts inside the DCT 1. Such a transmission is also
similar in design to a mechanical manual transmission. The DCT 1
further provides a parallel manual transmission that can be used
for transverse installation in a front-wheel drive vehicle.
[0086] The DCT 1 according to the application can be connected
similar to a known manual transmission, such as a parallel manual
transmission. In the known manual transmission, a drive shaft for
the front axle of a vehicle extends outward from its DCT case, and
parallel to the output shaft 14 of the main DCT 1. The arrangement
of the known manual transmission provides little space left for
actuation of the manual transmission and clutch and for an optional
electric motor. The optional electric motor can act as a starter
device for a combustion engine, as an energy recuperation device
for brake operation or as an additional drive means in hybrid
vehicles. Having such little space presents a number of
difficulties that are solved or are at least alleviated by the
application. The application provides a DCT 1 that has two clutches
for connecting to an electrical motor and the manual transmission
in a compact manner.
[0087] The application provides a compact structure of a parallel
transmission. The parallel transmission includes two input shafts
20, 22, each of which can be coupled non-rotatably via its own
clutch to a shaft that is powered by a drive engine of a vehicle.
The DCT 1 of the application further provides the output shaft 14
that is parallel to the input shafts 20, 22.
[0088] The DCT 1 according to the application is particularly well
suited for transverse installation in front-wheel drive vehicles,
in which the front differential, for example, is positioned below
the pinions 41, 51. A short overall length of the power train for
transmitting torques can be achieved.
[0089] The application provides at least two relatively small
pinions 41, 51 on intermediately arranged layshafts 40, 50 that
comb with one relatively big output gearwheel 12. The output
gearwheel 12 in turn is fixed onto the output shaft 14. This
arrangement provides a compact and lightweight DCT 1.
[0090] The application further allows a design in which the output
gearwheel 12 is integrated into a transmission differential device
without providing an intermediate output shaft of the DCT 1. This
allows a very dense packaging situation for the DCT 1.
[0091] It is further not only of advantage to provide fixed wheels
for the even gearwheels on one input shaft and fixed gearwheels for
the odd gears on another input shaft. This arrangement provides the
above-mentioned power-shift operation in a smooth and efficient
manner when gearshift is performed sequentially. This is because
the DCT 1 can alternatively engage one of the two clutches 8, 10 in
the process of increasing or decreasing gear. For example, the
power-shift operation from the third gear to the fourth gear causes
the solid input shaft 20 and the hollow input shaft 22 being
engaged alternatively, which is energy efficient and fast.
[0092] Some gearwheels of the low gears, for example a first,
second, third or fourth gear, provided on the same layshaft are
advantageous. In FIG. 2, the idler first gear 60, the idler second
gear 61, the idler third gear 62, and the idler fourth gear 63 are
installed on the same lower layshaft 50. In contrast, gearwheels of
high gears, for example fifth, sixth, or seventh gear, provided on
another layshaft. According to FIG. 2, the idler fifth gear 64, the
idler sixth gear 65, and the idler seventh gear 66 are provided on
the upper layshaft 40. This is because the lower layshaft 50 has
lower rotational speed with larger size for higher torque
transmission, as compared to that of the upper layshaft 40. This
arrangement eliminates the need of providing multiple layshafts
with larger size for carrying those heavily loaded idler gearwheels
60, 61, 62, 63 of the low gears, for example first, second, third,
or fourth gear, on different shafts. Furthermore, the reverse gear
idler shaft 38 with even lower rotational speed, heavier load and
lesser number of gearwheels can be made shorter and thicker. These
arrangements offer the feasibility of making the DCT 1 lightweight
with less cost.
[0093] The layshaft bearings 73 of the DCT 1 are next to the
pinions 41, 51. The layshaft bearings 73 offer strong support to
the pinions carrying layshafts 40, 50 for reducing shaft
deflection. Excessive shaft deflection can lower gear transmission
efficiency or cause gearwheels early worn out. The idler shaft
bearing 74 next to the reverse gear idler shaft 38 also provides
strong support to the first reverse gear wheel 35. In a like
manner, the output shaft bearing 75 at two ends of the output shaft
14 offer sturdy support to the output shaft 14.
[0094] In other words, it is beneficial to provide the idler first
gear 60, the idler second gear 61, the reverse gear idler wheel 37,
and the pinions 41, 51 close to the bearings for supporting. The
pinions 41, 51 and especially these gearwheels of low gears, for
example first and second gears, undergo heavier load than those of
the higher gears because the drive ratio is higher for the lower
gears and reverse gears. Therefore, a carrying shaft of low gears,
for example lower layshaft 50, must take up higher driving forces.
If those forces are taken up close to the support points of the
layshaft, shaft bending will be reduced.
[0095] FIG. 2 illustrates the path of torque flow of a first gear
transmission ratio. In FIG. 2, an input torque of the first gear is
received from a crankshaft 2 of a combustion engine, which is not
shown in the figure. According to FIG. 2, the hollow input shaft 22
of the double-clutch 6 of the DCT 1 receives the input torque of
the first gear. A torque of the first gear is transmitted from the
hollow input shaft 22, via the fixed wheel first gear 24, via the
idler first gear 60, via the double-sided coupling device 83, via
the lower layshaft 50, via lower pinion 51, and via the output
gearwheel 12 to the output shaft 14. The double-sided coupling
device 83 is engaged to the idler first gear 60 when transmitting
the torque of the first gear, which provides the first gear of the
DCT 1. The number of tooth engagements or engaged gear pairs for
the torque transfer of the first gear is two.
[0096] FIG. 3 illustrates the path of torque flow of a second gear
transmission ratio. In FIG. 3, an input torque of the second gear
is received from the crankshaft 2 of the combustion engine, which
is not shown in the figure. According to FIG. 3, the solid input
shaft 20 of the double-clutch 6 of the DCT 1 receives the input
torque of the second gear. The torque of the second gear is
transmitted from the solid input shaft 20, via the fixed wheel
second gear 30, via the idler second gear 61, via the double-sided
coupling device 82, via the lower layshaft 50, via the lower pinion
51, via the output gearwheel 12, to the output shaft 14. The
double-sided coupling device 82 is engaged to the idler second gear
61 when transmitting the torque of the second gear, which provides
the second gear of the DCT 1. The number of tooth engagements or
engaged gear pairs for the torque transfer of the second gear is
two.
[0097] FIG. 4 illustrates the path of torque flow of a third gear
transmission ratio. In FIG. 4, an input torque of the third gear is
received from the crankshaft 2 of the combustion engine, which is
not shown in the figure. According to FIG. 4, the hollow input
shaft 22 of the double clutch of the DCT 1 receives the input
torque of the third gear. The torque of the third gear is
transmitted from the hollow input shaft 22, via the fixed wheel
third gear 25, via the idler third gear 62, via the double-sided
coupling device 83, via the lower layshaft 50, via the lower pinion
51, via the output gearwheel 12, to the output shaft 14. The
double-sided coupling device 83 is engaged to the idler wheel third
gear 62 when transmitting the torque of the third gear, which
provides the third gear of the DCT 1. The number of tooth
engagements or engaged gear pairs for the torque transfer of the
third gear is two.
[0098] FIG. 5 illustrates the path of torque flow of a fourth gear
transmission ratio. In FIG. 5, an input torque of the fourth gear
is received from the crankshaft 2 of the combustion engine, which
is not shown in the figure. According to FIG. 5, the solid input
shaft 20 of the double-clutch 6 of the DCT 1 receives the input
torque of the fourth gear. The torque of the fourth gear is
transmitted from the solid input shaft 20, via the fixed wheel
fourth gear 31, via the idler fourth gear 63, via the double-sided
coupling device 82, via the lower layshaft 50, via the lower pinion
51, via the output gearwheel 12, to the output shaft 14. The
double-sided coupling device 82 is engaged to the idler fourth gear
63 when transmitting the torque of the fourth gear, which provides
the fourth gear of the DCT 1. The number of tooth engagements or
engaged gear pairs for the torque transfer of the fourth gear is
two.
[0099] FIG. 6 illustrates the path of torque flow of a fifth gear
transmission ratio. In FIG. 6, an input torque of the fifth gear is
received from the crankshaft 2 of a combustion engine, which is not
shown in the figure. According to FIG. 6, the hollow input shaft 22
of the double-clutch 6 of the DCT 1 receives the input torque of
the fifth gear. The torque of the fifth gear is transmitted from
the hollow input shaft 22, via the fixed wheel fifth gear 26, via
the idler fifth gear 64, via the double-sided coupling device 80,
via the upper layshaft 40, via the upper pinion 41, via the output
gearwheel 12, to the output shaft 14. The double-sided coupling
device 80 is engaged to the idler fifth gear 64 when transmitting
the torque of the fifth gear, which provides the fifth gear of the
DCT 1. The number of tooth engagements or engaged gear pairs for
the torque transfer of the fifth gear is two.
[0100] FIG. 7 illustrates the path of torque flow of a sixth gear
transmission ratio. In FIG. 7, an input torque of the sixth gear is
received from the crankshaft 2 of a combustion engine, which is not
shown in the figure. The solid input shaft 20 of the double-clutch
6 of the DCT 1 receives the input torque of the sixth gear. The
torque of the sixth gear is transmitted from the solid input shaft
20, via the fixed wheel sixth gear 32, via the idler sixth gear 65,
via the double-sided coupling device 81, via the upper layshaft 40,
via the upper pinion 41, via the output gearwheel 12, to the output
shaft 14. The double-sided coupling device 81 is engaged to the
idler sixth gear 65 when transmitting the torque of the sixth gear,
which provides the sixth gear of the DCT 1. The number of tooth
engagements or engaged gear pairs for the torque transfer of the
sixth gear is two.
[0101] FIG. 8 illustrates the path of torque flow of a seventh gear
transmission ratio. In FIG. 8, an input torque of the seventh gear
is received from the crankshaft 2 of a combustion engine, which is
not shown in the figure. According to FIG. 8, the hollow input
shaft 22 of the double-clutch 6 of the DCT 1 receives the input
torque of the seventh gear. The torque of the seventh gear is
transmitted from the hollow input shaft 22, via the fixed wheel
seventh gear 27, via the idler seventh gear 66, via the
double-sided coupling device 80, via the upper layshaft 40, via the
upper pinion 41, via the output gearwheel 12, to the output shaft
14. The double-sided coupling device 80 is engaged to the idler
seventh gear 66 when transmitting the torque of the seventh gear,
which provides the seventh gear of the DCT 1. The number of tooth
engagements or engaged gear pairs for the torque transfer of the
seventh gear is two.
[0102] FIG. 9 illustrates the path of torque flow of a reverse gear
transmission ratio, which is a first reverse gear. In FIG. 9, an
input torque of the reverse gear is received from the crankshaft 2
of a combustion engine, which is not shown in the figure. According
to FIG. 9, the solid input shaft 20 of the double-clutch 6 of the
DCT 1 receives the input torque of the reverse gear. The torque of
the reverse gear is transmitted from the solid input shaft 20, via
the fixed wheel reverse gear 34, and via the first reverse gear
wheel 35. The torque is then transmitted via the reverse gear idler
wheel 37, via the double-sided coupling device 81, via the upper
layshaft 40, via the upper pinion 41, and via the output gearwheel
12 to the output shaft 14. The double-sided coupling device 81 is
engaged to the reverse gear idler wheel 37 when transmitting the
torque of the reverse gear, which provides the reverse gear of the
DCT 1. The number of tooth engagements or engaged gear pairs for
the torque transfer of the reverse gear is three.
[0103] FIG. 10 illustrates an assembly 100 of a double-sided
coupling device 102 with its neighboring gearwheels 101, 103 for
engagement. The assembly 100 comprises a shaft 104 with the two
coaxially mounted idler gears 101, 103 on two bearings
respectively. The coupling device 102 is provided between the idler
gear 101 on the left and the idler gear 103 on the right. The
coupling device 102 is configured to move along the shaft 104 to
selectively engage any of the idler gears 101, 103 at one time. In
other words, the idler gears 101, 103 can alternatively be brought
into non-rotating engagement with the shaft 104 by the coupling
device 102. Symbols for showing the assembly 100 is provided at the
right hand side of FIG. 10.
[0104] FIG. 11 illustrates an assembly 110 of a single-sided
coupling device 112 with its neighboring gearwheel 113 for
engagement. The assembly 110 comprises a shaft 114 with the one
coaxially mounted idler gear 113 on a bearing. The coupling device
112 is provided next to the idler gear 113 on the left side. The
coupling device 112 is configured to move along the shaft 114 to
engage or disengage the idler gears 113. In other words, the idler
gear 113 can be brought into non-rotating engagement with the shaft
114 by the single-sided coupling device 112. Symbols for showing
the assembly 110 are provided at the right hand side of FIG.
11.
[0105] FIG. 12 illustrates an assembly 120 of an idler gearwheel
121 that is supported rotatably by a shaft 122 on a bearing 123.
The idler gearwheel 121 is mounted coaxially onto the shaft 122 via
the bearing 123. The bearing 123 enables the idler gearwheel 121 to
be rotated freely around the shaft 122. Symbols that represent the
assembly 120 are provided at the right hand side of the FIG.
12.
[0106] FIG. 13 illustrates an assembly 130 of a fixed gearwheel 132
that is supported on a shaft 131. The fixed gearwheel 132 is
mounted coaxially onto the shaft 131 such that the gearwheel 132 is
fixed to the shaft 132. The fixed gearwheel 132 and the shaft 131
are joined as one single body such that torque of the fixed
gearwheel 132 is transmitted to the shaft 131 directly, and vice
versa.
[0107] A number of fixed gearwheels are connected rigidly to the
input shafts 20, 22 and other shafts 12, 38, 40, 50 in a manner
that is similar to the assembly 130. A symbol as used in the
previous figures for such a fixed gearwheel is provided on the left
side in FIG. 13. The more commonly used symbol for such a fixed
gearwheel is provided on the right side in FIG. 13.
[0108] FIG. 14 illustrates a cross-section through a detail of a
crankshaft 2 of an internal combustion engine according to the
embodiment of the DCT 1. According to FIG. 14, the crankshaft 2 of
the internal combustion engine, which is not shown here, is
non-rotatably connected to a housing 4 of a double clutch 6. The
double clutch 6 includes an inner clutch disc 8 and an outer clutch
disc 10, which can be brought into non-rotating engagement with the
housing 4 via control elements that are not illustrated here. The
solid input shaft 20 is connected non-rotatably to the inner clutch
disc 8, and extends all the way through the hollow shaft 22.
Similarly, the hollow input shaft 22 is connected non-rotatably to
the other clutch disc 10.
[0109] An outer diameter around the inner clutch disc 8 is larger
than an outer diameter around the outer clutch disc 10.
Correspondingly, an outer diameter of the inner clutch disc 8 is
larger than an outer diameter of the outer clutch disc 10.
[0110] Alternative paths for transmitting some of the
above-mentioned torque flow paths of the DCT 1 are possible to be
provided.
[0111] The above-mentioned nine torque flow paths not only provide
viable solutions to generate nine gears of the DCT 1, but also
offer possibilities of switching from one gear to another gear
efficiently. The gear switching can be achieved by switching
between the two input shafts, between gearwheels of double meshing
features, or both.
[0112] For example, the DCT 1 can provide odd gears, such as a
first, third, fifth, or seventh gear, by driving the gearwheels of
the DCT 1 using the hollow input shaft 22. The DCT 1 also provides
even gears, such as second, fourth, or sixth gear, by driving the
gearwheels of the DCT 1 using the solid input shaft 20. Gear
switching between the odd and even can be obtained simply by
alternating between the two input shafts 20, 22.
[0113] One double meshing feature provides efficient and fast gear
switching between gears of two driven gearwheels that comb with a
shared driving gearwheel. For example, the DCT 1 provides the
convenience of selecting the third gear or the fifth gear without
stopping their shared driving gearwheel, the fixed wheel third gear
25. The selection can be achieved by engaging either the driven
idler third gear 62 or the driven idler fifth gear 64.
[0114] The double-meshing feature of the fixed wheel third gear 25
reduces the number of driving gearwheels, which is commonly engaged
by the driven gearwheels idler third gear 62 and the driven
gearwheel idler fifth gear 64. For example, the driving fixed wheel
third gear 25 and the driving fixed wheel fifth gear 26 become one
single gearwheel that is shared by the idler third gear 62 and the
idler fifth gear 64. As a result, the number of gearwheels on the
hollow input shaft 22 has been reduced and less space is required
on the hollow input shaft 22 such that the DCT 1 can be made
cheaper and lighter.
[0115] The park-lock 42 gives a useful safety feature for a car
with the DCT 1. As the park-lock 42 is placed on the lower shaft 50
that carries the final drive pinion 51, the park-lock 42 can easily
keep the lower layshaft 50 and the output shaft 14 from rotating. A
vehicle with the DCT 1 is then hindered from moving when the
vehicle is in a park mode.
[0116] In providing gear meshing or combing for torque
transmission, less number of gear tooth engagement, that is gear
engagement, is preferred. The less number of gear tooth engagement
provides lower noise and more efficient torque transmission.
Examples of the less gear tooth engagement are provided in FIGS.
2-10.
[0117] The DCT 1 drives the gearwheel groups of the first gear and
the reverse gear by different input shafts 20, 22. This provides
the ability to drive a vehicle change between a slow forward and a
slow backward by engaging and disengaging the respective clutches
8, 10 that are connected to the two input shafts 20, 22. The DCT 1
enables the vehicle to move back and forth quickly with little loss
of the transmission power or gearwheels momentum. This helps in
many situations in which a wheel of a vehicle with the DCT 1 is
stuck in a hostile environment such as a snow hole or a mud hole.
The vehicle can then be swayed free just by switching between the
two clutches 8, 10 of the DCT 1.
[0118] FIGS. 16 to 17 illustrate a further embodiment of the
application. The embodiment includes parts that are similar to the
parts of previously described embodiments. The similar parts are
labeled with the same or similar part reference number.
Descriptions related to the similar parts are hereby incorporated
by reference.
[0119] FIG. 15 shows a front view of the gearbox of the
application. A relatively big output gearwheel 12 meshes with a
lower pinion 51, which is provided on a lower layshaft 50. The
output gearwheel 12 further meshes with an upper pinion 41, which
is provided on an upper layshaft 40. A reverse gear idler shaft 38,
a solid input shaft 20, and a hollow input shaft 22 are provided to
be parallel to the upper layshaft 40 and the lower layshaft 50. In
some variants of the application, at least one a further layshaft
with a further pinion can be provided but this is not shown here.
Such a further pinion would then also mesh or comb with the output
gearwheel 12.
[0120] FIG. 15 further comprises a cutting plane A-A for
illustrating the cross-section through the gearbox 1, which is
shown in FIG. 16. For an embodiment, which has more than two
layshafts or an additional idler shaft, a cutting plane, which
leads through all shafts, is applied similarly. FIG. 16 illustrates
a simplified cross-section through the double clutch transmission
gearbox 1 of FIG. 15. It illustrates the structure and various
torque flows for the several gears of the double clutch
transmission gearbox 1.
[0121] According to FIG. 16, the double clutch transmission gearbox
1 comprises the following shafts, from top to bottom, the reverse
gear idler shaft 38, the upper layshaft 40, the solid input shaft
20, the hollow shaft 22, and the lower layshaft 50. The
above-mentioned shafts are provided parallel to each other at
predetermined mutual distances inside the gearbox 1. The hollow
shaft 22 is arranged concentrically around the solid shaft 20. The
solid input shaft 20 protrudes outside the hollow input shaft 22 at
a right end.
[0122] The solid input shaft 20 comprises, from the right end to
the left end, a solid shaft bearing 71, a hollow shaft bearing 72
that serves also as a solid shaft bearing 71, a fixed wheel sixth
gear 32, a fixed wheel fourth gear 31, a fixed wheel second gear
30, and a solid shaft bearing 71.
[0123] The hollow input shaft 22 comprises, from the right end to
the left end, a hollow shaft bearing 72, a fixed wheel first gear
24, a fixed wheel seventh gear 27, and a fixed wheel third gear 25,
which serves also as a fixed wheel fifth gear 26.
[0124] The upper layshaft 40 comprises, from the right end to the
left end, an upper pinion 41, a layshaft bearing 73, an idler
seventh gear 66, a double-sided coupling device 80, an idler fifth
gear 64, an idler sixth gear 65, a double-sided coupling device 81,
and a reverse gear idler wheel 37, and a layshaft bearing 73. The
idler seventh gear 66 combs with the fixed wheel seventh gear 27.
The idler fifth gear 64 combs with the fixed wheel fifth gear 26.
The idler sixth gear 65 combs with the fixed wheel sixth gear
32.
[0125] The reverse gear idler shaft 38 comprises, from the right
end to the left end, an idle shaft bearing 74, a first reverse gear
wheel 35, combing with the fixed wheel first gear 24, a second
reverse gear wheel 36, combing with the reverse gear idler wheel
37, and an idle shaft bearing 74.
[0126] The lower layshaft 50 comprises, from the right end to the
left end, a lower pinion 51,a layshaft bearing 73, an idler first
gear 60, a double-sided coupling device 83, an idler third gear 62,
a park-lock 42, an idler fourth gear 63, a double-sided coupling
device 82, an idler second gear 61, and a layshaft bearing 73. In
particular, the idler first gear 60 combs with the fixed wheel
first gear 24. The idler third gear 62 combs with the fixed wheel
third gear 25. The idler fourth gear 63 combs with the fixed wheel
fourth gear 31. The idler second gear 61 combs with the fixed wheel
second gear 30.
[0127] Several torque flows for different gears are possible.
[0128] A torque flow of the first gear can start from the hollow
input shaft 22, via the fixed wheel first gear 24, via the idler
first gear 60, via the double-sided coupling device 83, via the
lower layshaft 50, via the lower pinion 51, and via the output gear
wheel 12 to the output shaft 14.
[0129] Similarly, a torque flow of the second gear can start from
the solid input shaft 20, via the fixed wheel second gear 30, via
the idler second gear 61, via the double-sided coupling device 82,
via the lower layshaft 50, via lower pinion 51, and via the output
gear wheel 12 to the output shaft 14.
[0130] A torque flow of the third gear can start from the hollow
input shaft 22, via the fixed wheel third gear 25, via the idler
third gear 62, via the double-sided coupling device 83, via the
lower layshaft 50, via the lower pinion 51, and via the output gear
wheel 12 to the output shaft 14.
[0131] A torque flow of the fourth gear can start from the solid
input shaft 20, via the fixed wheel fourth gear 31, via the idler
fourth gear 63, via the double-sided coupling device 82, via the
lower layshaft 50, via the lower pinion 51, and via the output gear
wheel 12 to the output shaft 14.
[0132] A torque flow of the fifth gear can start from the hollow
input shaft 22, via the fixed wheel fifth gear 26, via the idler
fifth gear 64, via the double-sided coupling device 80, via the
upper layshaft 40, via the upper pinion 41, and via the output gear
wheel 12 to the output shaft 14.
[0133] A torque flow of the sixth gear can start from the solid
input shaft 20, via the fixed wheel sixth gear 32, via the idler
sixth gear 65, via the double-sided coupling device 81, via the
upper layshaft 40, via the upper pinion 41, and via the output gear
wheel 12 to the output shaft 14.
[0134] A torque flow of the seventh gear can start from the hollow
input shaft 22, via the fixed wheel seventh gear 27, via the idler
seventh gear 66, via the double-sided coupling device 80, via the
upper layshaft 40, via the upper pinion 41, and via the output gear
wheel 12 to the output shaft 14.
[0135] A torque flow of the reverse gear can start from the hollow
input shaft 22, via the fixed wheel first gear 24, and via the
first reverse gear wheel 35. The torque is then transmitted via the
reverse gear idler shaft 38, via the second reverse gear wheel 36,
via the reverse gear idler wheel 37, via the double-sided coupling
device 81, via the upper layshaft 40, via the upper pinion 41, and
via the output gear wheel 12 to the output shaft 14.
[0136] FIGS. 17 and 18 illustrate a further embodiment of the
application. The embodiment includes parts that are similar to the
parts of previously described embodiments. The similar parts are
labeled with the same or similar part reference number.
Descriptions related to the similar parts are hereby incorporated
by reference.
[0137] FIG. 17 shows a front view of a gearbox 1 of the
application. A relatively big output gearwheel 12 on an output
shaft 14 meshes with a lower pinion 51, which is provided on a
lower layshaft 50. The output gearwheel 12 further meshes with an
upper pinion 41, which is provided on an upper layshaft 40. A
reverse gear idler shaft 38, a solid input shaft 20, and a hollow
input shaft 22 are provided parallel to the upper layshaft 40 and
the lower layshaft 50. In some variants of the application, at
least one a further layshaft with a further pinion can be provided
but this is not shown here. Such a further pinion would then also
mesh or comb with the output gearwheel 12.
[0138] FIG. 17 further comprises a cutting plane A-A for
illustrating the cross-section through the gearbox 1, which is
shown in FIG. 18. For an embodiment, which has more than two
layshafts or an additional idler shaft, a cutting plane, which
leads through all shafts, is applied similarly.
[0139] FIG. 18 illustrates a simplified cross-section through the
double clutch transmission gearbox 1 of FIG. 18. It illustrates its
structure and various torque flows for the several gears of the
double clutch transmission gearbox 1.
[0140] The double clutch transmission gearbox 1 comprises the
following shafts, from top to bottom, the upper layshaft 40, the
solid input shaft 20, the hollow input shaft 22, the lower layshaft
50, and the reverse gear idler shaft 38.
[0141] The above-mentioned shafts are provided parallel to each
other at predetermined mutual distances inside gearbox 1.
[0142] The hollow shaft 22 is arranged concentrically around the
solid input shaft 20. The solid input shaft 20 protrudes outside
the hollow input shaft 22 at the right end.
[0143] The solid input shaft 20 comprises, from the right end to
the left end, a solid shaft bearing 71, a hollow shaft bearing 72,
which serves also as a solid shaft bearing 71, a fixed wheel sixth
gear 32, a fixed wheel fourth gear 31, a fixed wheel second gear
30, a solid shaft bearing 71, and a fixed wheel reverse gear
34.
[0144] The hollow input shaft 22 comprises, from the right end to
the left end, a hollow shaft bearing 72, a fixed wheel first gear
24, a fixed wheel seventh gear 27, and a fixed wheel third gear 25
which serves also as a fixed wheel fifth gear 26.
[0145] The upper layshaft 40 comprises, from the right end to the
left end, an upper pinion 41, a layshaft bearing 73, an idler first
gear 60, combing with the fixed wheel first gear 24, a double-sided
coupling device 80, an idler third gear 62, combing with the fixed
wheel third gear 25, an idler fourth gear 63, combing with the
fixed wheel fourth gear 31, a double-sided coupling device 81, an
idler second gear 61, combing with the fixed wheel second gear 30,
and a layshaft bearing 73.
[0146] The lower layshaft 50 comprises, from the right end to the
left end, a lower pinion 51, a layshaft bearing 73, an idler
seventh gear 66, a double-sided coupling device 83, an idler fifth
gear 64, an idler sixth gear 65, a park-lock 42, a double-sided
coupling device 82, a second reverse gear wheel 36, and a solid
shaft bearing 73. In particular, the idler seventh gear 66 combs
with the fixed wheel seventh gear 27. The idler fifth gear 64 combs
with the fixed wheel fifth gear 26. The idler sixth gear 65 combs
with the fixed wheel sixth gear 32.
[0147] The reverse gear idler shaft 38 comprises, from the right
end to the left end, an idle shaft bearing 74, a first reverse gear
wheel 35, combing with the second reverse gear wheel 36 and combing
with the fixed wheel reverse gear 34, an idle shaft bearing 74.
[0148] Several torque flows are possible.
[0149] A torque flow of the first gear to FIG. 18 can start from
the hollow input shaft 22, via the fixed wheel first gear 24, via
idler first gear 60, via the double-sided coupling device 80, via
the upper layshaft 40, via the upper pinion 41, and via the output
gear wheel 12 to the output shaft 14.
[0150] Similarly, a torque flow of the second gear can start from
the solid input shaft 20, via the fixed wheel second gear 30, via
the idler second gear 61, via the double-sided coupling device 81,
via the upper layshaft 40, via the upper pinion 41, and via the
output gear wheel 12 to the output shaft 14.
[0151] A torque flow of the third gear can start from the hollow
input shaft 22, via the fixed wheel third gear 25, via the idler
third gear 62, via the double-sided coupling device 80, via the
upper layshaft 40, via the upper pinion 41, and via the output gear
wheel 12 to the output shaft 14.
[0152] A torque flow of the fourth gear can start from the solid
input shaft 20, via the fixed wheel fourth gear 31, via the idler
fourth gear 63, via the double-sided coupling device 81, via the
upper layshaft 40, via the upper pinion 41, and via the output gear
wheel 12 to the output shaft 14.
[0153] A torque flow of the fifth gear can start from the hollow
input shaft 22, via the fixed wheel fifth gear 26, via the idler
fifth gear 64, via the double-sided coupling device 83, via the
lower layshaft 50, via the lower pinion 51, and via the output gear
wheel 12 to the output shaft 14.
[0154] A torque flow of the sixth gear can start from the solid
input shaft 20, via the fixed wheel sixth gear 32, via the idler
sixth gear 65, via the double-sided coupling device 82, via the
lower layshaft 50, via the lower pinion 51, and via the output gear
wheel 12 to the output shaft 14.
[0155] A torque flow of the seventh gear can start from the hollow
input shaft 22, via the fixed wheel seventh gear 27, via the idler
seventh gear 66, via the double-sided coupling device 83, via the
lower layshaft 50, via the lower pinion 51, and via the output gear
wheel 12 to the output shaft 14.
[0156] A torque flow of the reverse gear can start from the solid
input shaft 20, via the fixed wheel reverse gear 34, via the first
reverse gear wheel 35, via the second reverse gear wheel 36, via
the double-sided coupling device 82, via the lower layshaft 50, via
the lower pinion 51, and via the output gear wheel 12 to the output
shaft 14.
[0157] FIGS. 19 to 20 illustrate a further embodiment of the
application. The embodiment includes parts that are similar to the
parts of previously described embodiments. The similar parts are
labeled with the same or similar part reference number.
Descriptions related to the similar parts are hereby incorporated
by reference.
[0158] FIG. 19 shows a front view of the gearbox of the
application. A relatively big output gearwheel 12 meshes with a
lower pinion 51, which is provided on a lower layshaft 50. The
output gearwheel 12 further meshes with an upper pinion 41, which
is provided on an upper layshaft 40. There is also a reverse pinion
55 on a reverse gear solid shaft 38. A reverse gear hollow shaft 39
is mounted onto the reverse gear solid shaft 38 by two reverse gear
hollow shaft bearings 76 at opposite ends such that the reverse
gear hollow shaft 39 can freely rotate around the reverse gear
solid shaft 38. The reverse pinion 55 also meshes with the output
gear wheel 12. A solid input shaft 20 and a hollow input shaft 22
are provided in parallel with the reverse gear solid shaft 38, the
upper layshaft 40, and the lower layshaft 50. In some variants of
the application, at least one a further layshaft with a further
pinion can be provided but this is not shown here. Such a further
pinion would then also mesh or comb with the output gearwheel
12.
[0159] FIG. 19 further comprises a cutting plane A-A for
illustrating the cross-section through the gearbox, which is shown
in FIG. 20. For an embodiment, which has more than two layshafts or
an additional idler shaft, a cutting plane that leads through all
shafts is applied similarly.
[0160] FIG. 20 illustrates a simplified cross-section of the double
clutch transmission gearbox 1 of FIG. 19. It illustrates structure
and various torque flows for the several gears of the double clutch
transmission gearbox 1.
[0161] The double clutch transmission gearbox 1 comprises the
following shafts, from top to bottom, the reverse gear idler shaft
38, a reverse gear hollow shaft 39, the upper layshaft 40, the
solid input shaft 20, the hollow input shaft 22, the lower layshaft
50 and an output shaft 14.
[0162] The above-mentioned shafts are provided parallel to each
other at predetermined mutual distances inside gearbox 1. The
hollow shaft 22 is arranged concentrically around the solid input
shaft 20. The solid input shaft 20 protrudes outside the hollow
input shaft 22 at the right end.
[0163] The solid input shaft 20 comprises, from the right end to
the left end, a solid shaft bearing 71, a hollow shaft bearing 72
that serves also as a solid shaft bearing 71, a fixed wheel fourth
gear 31, a fixed wheel second gear 30, a fixed wheel sixth gear 32,
and a solid shaft bearing 71.
[0164] The hollow input shaft 20 comprises, from the right end to
the left end, a hollow shaft bearing 72, a fixed wheel seventh gear
27, and a fixed wheel third gear 25, which serves also as a fixed
wheel fifth gear 26.
[0165] The upper layshaft 40 comprises, from the right end to the
left end, the upper pinion 41, a layshaft bearing 73, an idler
first gear 60, a double-sided coupling device 80, an idler third
gear 62, an attached idler third gear 62', an idler second gear 61,
a single-sided coupling device 81, a layshaft bearing 73. The idler
third gear 62 combs with the fixed wheel third gear 25. The idler
second gear 61 combs with the fixed wheel second gear 30. The idler
third gear 62 is attached or is fused to the idler third gear 62'
such that they become one integral body.
[0166] The reverse gear idler shaft 38 comprises, from the right
end to the left end, the reverse pinion 55, an idler shaft bearing
74, a reverse gear hollow shaft 39, a park lock 42, a single-sided
coupling device 85, and an idler shaft bearing 74.
[0167] The reverse gear hollow shaft 39 comprises, from the right
end to the left end, a second reverse gear wheel 36, combing with
the idler first gear 60, and a first reverse gear wheel 35, combing
with the attached idler third gear 62'.
[0168] The lower layshaft 50 comprises, from the right end to the
left end, the lower pinion 51, a layshaft bearing 73, an idler
seventh gear 66, a double-sided coupling device 83, an idler fifth
gear 64, an idler fourth gear 63, a double-sided coupling device
82, an idler sixth gear 65, and a layshaft bearing 73. The idler
seventh gear 66 combs with the fixed wheel seventh gear 27. The
idler fifth gear 64 combs with the fixed wheel fifth gear 26. The
idler fourth gear 63 combs with the fixed wheel fourth gear 31. The
idler sixth gear 65 combs with the fixed wheel sixth gear 32.
[0169] Torque flow of the first gear according to FIG. 20 starts
from the hollow input shaft 22, via the fixed wheel third gear 25,
via the idler third gear 62, via the attached idler third gear 62',
via the first reverse gear wheel 35. The torque flow is then
transmitted via the reverse gear hollow shaft 39, via the second
reverse gear wheel 36, via the idler first gear 60, via the
double-sided coupling device 80, via the upper layshaft 40, via the
upper pinion 41, and via the output gear wheel 12 to the output
shaft 14.
[0170] Torque flow of the second gear according to FIG. 20 starts
from the solid input shaft 20, via the fixed wheel second gear 30,
via the idler second gear 61, via the single-sided coupling device
81, via the upper layshaft 40, via the upper pinion 41, via the
output gear wheel 12, to the output shaft 14.
[0171] Torque flow of the third gear according to FIG. 20 starts
from the hollow input shaft 22, via the fixed wheel third gear 25,
via the idler third gear 62, via the double-sided coupling device
80, via the upper layshaft 40, via the upper pinion 41, via the
output gear wheel 12, to the output shaft 14.
[0172] Torque flow of the fourth gear according to FIG. 20 starts
from the solid input shaft 20, via the fixed wheel fourth gear 31,
via the idler fourth gear 63, via the double-sided coupling device
82, via the lower layshaft 50, via the lower pinion 51, via the
output gear wheel 12, to the output shaft 14.
[0173] Torque flow of the fifth gear according to FIG. 20 starts
from the hollow input shaft 22, via the fixed wheel fifth gear 26,
via the idler fifth gear 64, via the double-sided coupling device
83, via the lower layshaft 50, via the lower pinion 51, via the
output gear wheel 12, to the output shaft 14.
[0174] Torque flow of the sixth gear according to FIG. 20 starts
from the solid input shaft 20, via the fixed wheel sixth gear 32,
via the idler sixth gear 65, via the double-sided coupling device
82, via the lower layshaft 50, via the lower pinion 51, via the
output gear wheel 12, to the output shaft 14.
[0175] Torque flow of the seventh gear according to FIG. 20 starts
from the hollow input shaft 22, via fixed wheel seventh gear 27,
via the idler seventh gear 66, via the double-sided coupling device
83, via the lower layshaft 50, via the lower pinion 51, via the
output gear wheel 12, to the output shaft 14.
[0176] Torque flow of the reverse gear according to FIG. 20 starts
from the hollow input shaft 22, via the fixed wheel third gear 25,
via the idler third gear 62, and via the attached idler third gear
62'. The torque is then transmitted via the first reverse gear
wheel 35, via the reverse gear hollow shaft 39, via the
single-sided coupling device 85, via the reverse gear idle shaft
38, via the reverse pinion 55, via the output gear wheel 12, to the
output shaft 14.
[0177] FIGS. 24 and 25 illustrate a further embodiment of the
application. The embodiment includes parts that are similar to the
parts of previously described embodiments. The similar parts are
labeled with the same or similar part reference number.
Descriptions related to the similar parts are hereby incorporated
by reference.
[0178] FIG. 21 shows a front view of the gearbox of the
application. A relatively big output gearwheel 12 meshes with a
lower pinion 51, which is provided on a lower layshaft 50. The
output gearwheel 12 further meshes with an upper pinion 41, which
is provided on an upper layshaft 40. There is also a reverse pinion
55 on a reverse gear solid shaft 38. A reverse gear hollow shaft 39
is mounted onto the reverse gear solid shaft 38 by two reverse gear
hollow shaft bearings 76 at opposite ends such that the reverse
gear hollow shaft 39 can freely rotate around the reverse gear
solid shaft 38. The reverse pinion 55 also meshes with the output
gear wheel 12. A solid input shaft 20 and a hollow input shaft 22
are provided in parallel with the reverse gear solid shaft 38, the
upper layshaft 40, and the lower layshaft 50. In some variants of
the application, at least one a further layshaft with a further
pinion can be provided but this is not shown here. Such a further
pinion would then also mesh or comb with the output gearwheel
12.
[0179] FIG. 21 further comprises a cutting plane A-A for
illustrating the cross-section through the gearbox, which is shown
in FIG. 21. It illustrates structure and various torque flows for
the several gears of the double clutch transmission gearbox 1. For
an embodiment, which has more than two layshafts or an additional
idler shaft, a cutting plane, which leads through all shafts, is
applied similarly.
[0180] The double clutch transmission gearbox 1 comprises the
following shafts from top to bottom, the reverse gear idler shaft
38, the reverse gear hollow shaft 39, the upper layshaft 40, the
solid input shaft 20, the hollow input shaft 22, the lower layshaft
50, and the output shaft 14.
[0181] The above-mentioned shafts are provided parallel to each
other at predetermined mutual distances inside gearbox 1. The
hollow shaft 22 is arranged concentrically around the solid input
shaft 20. The solid input shaft 20 protrudes outside the hollow
input shaft 22 at the right end.
[0182] The solid input shaft 20 comprises, from the right end to
the left end, a solid shaft bearing 71, a hollow shaft bearing 72,
a fixed wheel fourth gear 31, a fixed wheel second gear 30, a fixed
wheel sixth gear 32, and a solid shaft bearing 71. The hollow shaft
bearing 72 serves also as a solid shaft bearing 71. The fixed wheel
sixth gear 32 also serves as a fixed wheel eighth gear 32'.
[0183] The hollow input shaft 20 comprises, from the right end to
the left end, a hollow shaft bearing 72, a fixed wheel seventh gear
27, and a fixed wheel third gear 25, which is at the same time a
fixed wheel fifth gear 26.
[0184] The upper layshaft 40 comprises, from the right end to the
left end, the upper pinion 41, a layshaft bearing 73, an idler
first gear 60, a double-sided coupling device 80, an idler third
gear 62, and an attached idler third gear 62'. Further, the upper
layshaft 40 includes an idler second gear 61, a double-sided
coupling device 81'', an idler sixth gear 65', and a layshaft
bearing 73. The idler third gear 62 combs with the fixed wheel
third gear 25 whilst the idler sixth gear 65' combs with the fixed
wheel sixth gear 32.
[0185] The reverse gear idler shaft 38 comprises, from the right
end to the left end, the reverse pinion 55, an idler shaft bearing
74, the reverse gear hollow shaft 39, a single-sided coupling
device 85, and an idler shaft bearing 74.
[0186] The reverse gear hollow shaft 39 comprises, from the right
end to the left end, a second reverse gear wheel 36, combing with
the idler first gear 60, a first reverse gear wheel 35, combing
with the attached idler third gear 62'.
[0187] The lower layshaft 50 comprises, from the right end to the
left end, the lower pinion 51, a layshaft bearing 73, an idler
seventh gear 66, a double-sided coupling device 83, an idler fifth
gear 64, an idler fourth gear 63, a double-sided coupling device
82, a park-lock 42, an idler eighth gear 67, and a layshaft bearing
73. In particular, the idler seventh gear 66 combs with the fixed
wheel seventh gear 27. The idler fifth gear 64 combs with fixed
wheel fifth gear 26. The idler fourth gear 63 combs with the fixed
wheel fourth gear 31. The idler eighth gear 67 combs with the fixed
wheel eighth gear 32'.
[0188] Torque flow of the first gear according to FIG. 22 starts
from the hollow input shaft 22, via the fixed wheel third gear 25,
via the idler third gear 62, and via the attached idler third gear
62'. The torque flow is then transmitted via the first reverse gear
wheel 35, via the reverse gear hollow shaft 39, via the second
reverse gear wheel 36, via the idler first gear 60, via the
double-sided coupling device 80, via the upper layshaft 40, via
upper pinion 41, and via the output gear wheel 12 to the output
shaft 14.
[0189] Similarly, torque flow of the second gear according to FIG.
22 starts from the solid input shaft 20, via the fixed wheel second
gear 30, via the idler second gear 61, via the single-sided
coupling device 81, via the upper layshaft 40, via the upper pinion
41, via the output gear wheel 12, to the output shaft 14.
[0190] Torque flow of the third gear according to FIG. 22 starts
from the hollow input shaft 22, via the fixed wheel third gear 25,
via the idler third gear 62, via the double-sided coupling device
80, via the upper layshaft 40, via the upper pinion 41, and via the
output gear wheel 12 to the output shaft 14.
[0191] Torque flow of the fourth gear according to FIG. 22 starts
from the solid input shaft 20, via the fixed wheel fourth gear 31,
via the idler fourth gear 63, via the double-sided coupling device
82, via the lower layshaft 50, via the lower pinion 51, and via the
output gear wheel 12 to the output shaft 14.
[0192] Torque flow of the fifth gear according to FIG. 22 starts
from the hollow input shaft 22, via the fixed wheel fifth gear 26,
via the idler fifth gear 64, via the double-sided coupling device
83, via the lower layshaft 50, via the lower pinion 51, and via the
output gear wheel 12 to the output shaft 14.
[0193] Torque flow of the sixth gear according to FIG. 22 starts
from the solid input shaft 20, via the fixed wheel sixth gear 32,
via the idler sixth gear 65', via the double-sided coupling device
81'', via the upper layshaft 40, via the upper pinion 41, and via
the output gear wheel 12 to the output shaft 14.
[0194] Torque flow of the seventh gear according to FIG. 22 starts
from the hollow input shaft 22, via the fixed wheel seventh gear
27, via the idler seventh gear 66, via the double-sided coupling
device 83, via the lower layshaft 50, via the lower pinion 51, and
via the output gear wheel 12 to the output shaft 14.
[0195] Torque flow of the eighth gear according to FIG. 22 starts
from the solid input shaft 20, via the fixed wheel eighth gear 32',
via the idler eighth gear 67, via the double-sided coupling device
82, via the lower layshaft 50, via the lower pinion 51, and via the
output gear wheel 12 to the output shaft 14.
[0196] Torque flow of the reverse gear according to FIG. 22 starts
from the hollow input shaft 22, via the fixed wheel third gear 25,
via the idler third gear 62, via the attached idler third gear 62',
via the first reverse gear wheel 35, via the reverse gear hollow
shaft 39, and via the single-sided coupling device 85. The torque
flow is afterward sent via the reverse gear idle shaft 38, via the
reverse pinion 55, and via the output gear wheel 12 to the output
shaft 14.
[0197] Although the above description contains much specificity,
these should not be construed as limiting the scope of the
embodiments but merely providing illustration of the foreseeable
embodiments. Especially the above stated advantages of the
embodiments should not be construed as limiting the scope of the
embodiments but merely to explain possible achievements if the
described embodiments are put into practice. Thus, the scope of the
embodiments should be determined by the claims, rather than by the
examples given.
[0198] While at least one exemplary embodiment has been presented
in the foregoing summary and detailed description, it should be
appreciated that a vast number of variations exist. It should also
be appreciated that the exemplary embodiment or exemplary
embodiments are only examples, and are not intended to limit the
scope, applicability, or configuration in any way. Rather, the
foregoing summary and detailed description will provide those
skilled in the art with a convenient road map for implementing an
exemplary embodiment, it being understood that various changes may
be made in the function and arrangement of elements described in an
exemplary embodiment without departing from the scope as set forth
in the appended claims and their legal equivalents.
* * * * *