U.S. patent application number 12/935885 was filed with the patent office on 2011-06-30 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 Rockkenbach.
Application Number | 20110154945 12/935885 |
Document ID | / |
Family ID | 40671915 |
Filed Date | 2011-06-30 |
United States Patent
Application |
20110154945 |
Kind Code |
A1 |
Mohlin; Mikael B. ; et
al. |
June 30, 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. A first clutch
disc and a second clutch disc of the DCT are connected to the two
input shafts respectively. Pinions are fixed onto three parallel
layshafts of the DCT respectively. The gearwheels on the layshafts
include, but are not limited to seven gearwheel groups. Each of the
gearwheel group includes, but is not limited to a fixed gearwheel
that meshes with an idler gearwheel. A fourth fixed gearwheel on
the outer input shaft meshes with the fourth gear idler gearwheel
and the sixth gear idler gearwheel. In particular, a fifth fixed
gearwheel on the inner input shaft meshes with a fifth gear idler
gearwheel and the seventh gear idler gearwheel. The gearwheels
further includes, but is not limited to a reverse gearwheel group
that includes, but is not limited to a fixed gearwheel on one of
the input shafts, meshing with a reverse gear idler gearwheelon one
of the layshafts.
Inventors: |
Mohlin; Mikael B.;
(Kungaelv, SE) ; Geiberger; Axel; (Mainz, DE)
; Remmler; Mathias; (Mauchenheim, DE) ;
Rockkenbach; Markus; (Schweppenhausen, DE) |
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS,
INC.
Detroit
MI
|
Family ID: |
40671915 |
Appl. No.: |
12/935885 |
Filed: |
March 31, 2009 |
PCT Filed: |
March 31, 2009 |
PCT NO: |
PCT/EP2009/002305 |
371 Date: |
February 24, 2011 |
Current U.S.
Class: |
74/665D |
Current CPC
Class: |
F16H 3/093 20130101;
F16H 2003/0822 20130101; Y10T 74/19233 20150115; F16H 2200/0056
20130101; F16H 2003/0826 20130101; F16H 3/006 20130101; Y10T
74/19065 20150115; F16H 2003/0931 20130101; Y10T 74/19228 20150115;
F16H 2200/0086 20130101; Y10T 74/19112 20150115; Y10T 74/1907
20150115 |
Class at
Publication: |
74/665.D |
International
Class: |
F16H 3/093 20060101
F16H003/093; F16H 37/06 20060101 F16H037/06 |
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 connected
to the inner input shaft and a second clutch 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 and a seventh
gearwheel group for providing seven sequentially increasing gears,
the first gearwheel group comprising a first fixed gearwheel on the
inner input shaft, meshing with a first gear idler gearwheel on one
of the layshafts, the third gearwheel group comprising a third
driving gearwheel on the inner input shaft, meshing with a third
driven gearwheel on one of the layshafts, the fifth gearwheel group
comprising a fifth fixed gearwheel on the inner input shaft,
meshing with a fifth gear idler gearwheel on one of the layshafts,
the seventh gearwheel group comprising a seventh fixed gearwheel on
the inner input shaft, meshing with a seventh gear idler gearwheel
on one of the layshafts, the second gearwheel group comprising a
second fixed gearwheel on the outer input shafts, meshing with a
second gear idler gearwheel on one of the layshafts, the fourth
gearwheel group comprising a fourth fixed gearwheel on the outer
input shafts, meshing with a fourth gear idler gearwheel on one of
the layshafts, the sixth gearwheel group comprising a sixth fixed
gearwheel on the outer input shafts, meshing with a sixth gear
idler gearwheel on one of the layshafts, and each gearwheel group
comprising a coupling device which is arranged on one of the
layshafts to selectively engage one of the gearwheels for selecting
one of the seven gears, and the fourth fixed gearwheel further
meshing with the sixth gear idler gearwheel, wherein the fifth
fixed gearwheel further meshes with the seventh gear idler
gearwheel, and the gearwheels further comprises a reverse gearwheel
group that comprises a fixed gearwheel on one of the input shafts,
meshing with a reverse gear idler gearwheel on one of the layshafts
for providing a reverse gear, and the reverse gearwheel group
further comprises a coupling device which is arranged on the
layshaft mounted with the reverse gear idler gearwheel to
selectively engage the reverse gear idler gearwheel.
2. The double-clutch transmission device according to claim 1,
further comprising: the first forward gear and the reverse gear are
provided by different input shafts.
3. The double-clutch transmission according to claim 1, wherein the
reverse gearwheel group provides a first reverse gear and a second
reverse gear.
4. The double-clutch transmission device according to claim 1,
further comprising a reverse gear shaft, a reverse gearwheel and a
reverse pinion, the reverse gearwheel and the reverse pinion
mounted on the reverse gear shaft.
5. The double-clutch transmission device according to claim 1,
further comprising a park-lock.
6. The double-clutch transmission device according to claim 1,
wherein the first gear idler gearwheel is provided on one of the
layshafts while the fourth idler gearwheel, the fifth idler
gearwheel, the sixth idler gearwheel and the seventh idler
gearwheel are provided on the remaining layshafts.
7. The double-clutch transmission according to claim 1, wherein at
least two of the second gear idler gearwheel, the third driven
gearwheel, the fourth gear idler gearwheel and the fifth gear idler
gearwheel are mounted on the same layshaft.
8. The double-clutch transmission according to claim 1, wherein the
sixth gear idler gearwheel and the seventh gear idler gearwheel are
mounted on the same layshaft.
9. The double-clutch transmission according to claim 1, further
comprising bearings for supporting the layshafts, at least one of
the bearings being provided next to each of the pinions.
10. The double-clutch transmission according to claim 9, wherein at
least one of the bearings is provided next to one of the idler
gearwheels of low gears.
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 connected to the inner input
shaft and a second clutch 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 and a seventh gearwheel group for providing seven
sequentially increasing gears, the first gearwheel group comprising
a first fixed gearwheel on the inner input shaft, meshing with a
first gear idler gearwheel on one of the layshafts, the third
gearwheel group comprising a third driving gearwheel on the inner
input shaft, meshing with a third driven gearwheel on one of the
layshafts, the fifth gearwheel group comprising a fifth fixed
gearwheel on the inner input shaft, meshing with a fifth gear idler
gearwheel on one of the layshafts, the seventh gearwheel group
comprising a seventh fixed gearwheel on the inner input shaft,
meshing with a seventh gear idler gearwheel on one of the
layshafts, the second gearwheel group comprising a second fixed
gearwheel on the outer input shafts, meshing with a second gear
idler gearwheel on one of the layshafts, the fourth gearwheel group
comprising a fourth fixed gearwheel on the outer input shafts,
meshing with a fourth gear idler gearwheel on one of the layshafts,
the sixth gearwheel group comprising a sixth fixed gearwheel on the
outer input shafts, meshing with a sixth gear idler gearwheel on
one of the layshafts, and each gearwheel group comprising a
coupling device which is arranged on one of the layshaft to
selectively engage one of the gearwheels for selecting one of the
seven gears, and the fourth fixed gearwheel further meshing with
the sixth gear idler gearwheel, wherein the fifth fixed gearwheel
further meshes with the seventh gear idler gearwheel, and the
gearwheels further comprises a reverse gearwheel group that
comprises a fixed gearwheel on one of the input shafts, meshing
with a reverse gear idler gearwheel on one of the layshafts for
providing a reverse gear, and the reverse gearwheel group further
comprises a coupling device which is arranged on the layshaft
mounted with the reverse gear idler gearwheel to selectively engage
the reverse gear idler gearwheel; and an output gearwheel on an
output shaft, the output gearwheel meshing with the pinions.
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 connected to
the inner input shaft and a second clutch 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 and a seventh
gearwheel group for providing seven sequentially increasing gears,
the first gearwheel group comprising a first fixed gearwheel on the
inner input shaft, meshing with a first gear idler gearwheel on one
of the layshafts, the third gearwheel group comprising a third
driving gearwheel on the inner input shaft, meshing with a third
driven gearwheel on one of the layshafts, the fifth gearwheel group
comprising a fifth fixed gearwheel on the inner input shaft,
meshing with a fifth gear idler gearwheel on one of the layshafts,
the seventh gearwheel group comprising a seventh fixed gearwheel on
the inner input shaft, meshing with a seventh gear idler gearwheel
on one of the layshafts, the second gearwheel group comprising a
second fixed gearwheel on the outer input shafts, meshing with a
second gear idler gearwheel on one of the layshafts, the fourth
gearwheel group comprising a fourth fixed gearwheel on the outer
input shafts, meshing with a fourth gear idler gearwheel on one of
the layshafts, the sixth gearwheel group comprising a sixth fixed
gearwheel on the outer input shafts, meshing with a sixth gear
idler gearwheel on one of the layshafts, and each gearwheel group
comprising a coupling device which is arranged on one of the
layshaft to selectively engage one of the gearwheels for selecting
one of the seven gears, and the fourth fixed gearwheel further
meshing with the sixth gear idler gearwheel, wherein the fifth
fixed gearwheel further meshes with the seventh gear idler
gearwheel, and the gearwheels further comprises a reverse gearwheel
group that comprises a fixed gearwheel on one of the input shafts,
meshing with a reverse gear idler gearwheel on one of the layshafts
for providing a reverse gear, and the reverse gearwheel group
further comprises a coupling device which is arranged on the
layshaft mounted with the reverse gear idler gearwheel to
selectively engage the reverse gear idler gearwheel; an output
gearwheel on an output shaft, the output gearwheel meshing with the
pinions; 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/EP2009/002305, 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 (DCT) comprises two input
shafts that are connected to and 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 are connected to two input shafts of the DCT
separately for providing driving torques.
[0004] Volkswagen has presented a DCT named DSG DQ200. The DSG
DQ200 is an attempt of having a seven-speed DCT in the cars for
street driving. The DCT still has not been widely. Problems that
hinder the wide application of DCT comprise of providing a compact,
reliable and fuel-efficient DCT. Therefore, there exists a need for
providing such a DCT 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 is partially inside the outer
input shaft. In other words, the outer input shaft encloses the
inner input shaft in a radial direction. The radial direction
indicates regions that surround a longitudinal axis of the inner
input shaft.
[0006] The DCT has a first clutch disc that is non-rotatably
connected to the inner input shaft. The DCT also has a second
clutch disc that is non-rotatably connected to the outer input
shaft. The non-rotatable connections ensure that a connection
between two joined shafts causes simultaneous rotation of the two
shafts. For example, the two shafts can be fused together to make
the non-rotatable connection. Alternatively, the non-rotatable
connection can be provided by a universal joint.
[0007] There are a first layshaft, a second layshaft and a third
layshaft radially spaced apart from the input shafts. These
layshafts are arranged in parallel to the input shafts.
Longitudinal axes of these shafts are parallel to each other,
including overlapping. One or more of the layshafts comprise a
pinion for outputting a drive torque to a drive train of a vehicle.
The drive train can alternatively be referred as powertrain or
powerplant that comprises the group of components for generating
power and delivering it to the road surface, water, or air. The
drive train can include an engine, a transmission, drive shafts,
differentials, and final drive. The final drive can be drive
wheels, continuous track like with tanks or caterpillar tractors,
propeller, etc. Sometimes "drive train" refers simply to the engine
and the transmission, including the other components only if they
are integral to the transmission.
[0008] Gearwheels of the DCT are arranged on the three layshafts
and on the input shafts. These gearwheels comprise a first
gearwheel group, a second gearwheel group, a third gearwheel group,
a fourth gearwheel group, a fifth gearwheel group, a sixth
gearwheel group and a seventh gearwheel group for providing seven
sequentially increasing gears. The sequentially increasing gears
describe an escalating order that members of the order follow each
other. Gears of a car can be arranged in a sequentially increasing
manner from first gear to seventh gear. For example, in a car
having a DCT, a first gear has 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;
and a seventh gear has a gear ratio of 0.42:1. The seven gears
provide an increasing order of output speed of the transmission for
driving the car.
[0009] The first gearwheel group comprises a first fixed gearwheel
on the inner input shaft that meshes with a first gear idler
gearwheel on one of the layshafts. The third gearwheel group
comprises a third driving gearwheel on the inner input shaft that
meshes with a third driven gearwheel on one of the layshafts. The
driving gearwheel can be a gearwheel fixed on its carrying shaft or
an idler gearwheel that is free to rotate around its carrying
shaft. Similarly, the driven gearwheel can also be a gearwheel
fixed on its carrying shaft or an idler gearwheel that is free to
rotate around its carrying shaft. A carrying shaft of a gearwheel
is a shaft that is mounted with the gearwheel for carrying the
weight and transmits torque of the gearwheel.
[0010] The fifth gearwheel group comprises a fifth fixed gearwheel
on the inner input shaft that meshes with a fifth gear idler
gearwheel on one of the layshafts. The seventh gearwheel group
comprises a seventh fixed gearwheel on the inner input shaft that
meshes with a seventh gear idler gearwheel on one of the layshafts.
The second gearwheel group comprises a second fixed gearwheel on
the outer input shafts that meshes with a second gear idler
gearwheel on one of the layshafts. The fourth gearwheel group
comprises a fourth fixed gearwheel on the outer input shafts that
meshes with a fourth gear idler gearwheel on one of the layshafts.
The sixth gearwheel group comprises a sixth fixed gearwheel on the
outer input shafts that meshes with a sixth gear idler gearwheel on
one of the layshafts.
[0011] Each gearwheel group comprises a coupling device that is
arranged on one of the layshafts to selectively engage one of the
gearwheels to one of the layshafts for selecting one of the seven
gears. The fourth fixed gearwheel meshes with both the fourth gear
idler gearwheel and the sixth gear idler gearwheel.
[0012] Especially, the fifth fixed gearwheel meshes with both the
fifth gear idler gearwheel and the seventh gear idler gearwheel.
The gearwheels of the DCT further comprise a reverse gearwheel
group that comprises a fixed gearwheel on one of the input shafts.
The fixed gearwheel of the reverse gearwheel group meshes with a
reverse gear idler gearwheel on one of the layshafts. The reverse
gearwheel group further comprises a coupling device that is
arranged on the layshaft mounted with the reverse gear idler
gearwheel to selectively engage the reverse gear idler
gearwheel.
[0013] The DCT provides seven forward gears through a dual clutch.
The DCT makes gear switching between odd and even ratios to be
swift and efficient because the gearwheels of the odd and even
gears are driven by different clutch discs respectively. One double
meshing feature is provided by the fourth fixed gearwheel that
meshes with the fourth gear idler gearwheel and the sixth gear
idler gearwheel. Another double meshing feature is provided by the
fifth fixed gearwheel that meshes with the fifth gear idler
gearwheel and the seventh gear idler gearwheel. The two double
meshing features make the DCT to be compact and lightweight at low
cost because two fixed gearwheels are avoided on the input
shafts.
[0014] 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 neighbouring 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 Manual
Transmissions.
[0015] In the application, the DCT can further comprise a second
reverse gearwheel group that comprises a fixed gearwheel on one of
the input shafts that meshes with a second reverse gear idler
gearwheel on one of the layshafts. The meshing can be provided
directly between the two gearwheels or indirectly via other
gearwheels. The second reverse gearwheel group can further comprise
a coupling device which is arranged on the layshaft mounted with
the second reverse gear idler gearwheel to selectively engage the
second reverse gear idler gearwheel for proving a second reverse
gear. The second reverse gear can be driven by one of the input
shafts that is different from the other reverse gear. The second
reverse gear enables dual speeds for reversing a vehicle, which can
be useful driving different applications of a multi-purpose
vehicle. For example, the first reverse gear can be used as a
faster reverse operation, whilst the second reverse gear can be
used as a slower and silent reverse operation, or vice versa.
[0016] According to the application, different input shafts can
provide the first forward gear and the second reverse gear. The DCT
can put the first forward gear and the second reverse gear on two
different input shafts. Dual clutches of the DCT enables that the
switching between the two input shafts can be achieved quickly. As
a result, a driving scheme that the DCT engages the two input
shafts alternatively can drive the vehicle back & forth
rapidly. This scheme is useful for moving the vehicle out of a
muddy puddle because the vehicle can simply be driven back &
forth to get out the puddle. Less loss of momentum of the
gearwheels and the layshafts of the DCT can be achieved.
Alternatively, the back and forth movements can be provided by a
second forward gear and a first reverse gear on different input
shafts.
[0017] The reverse gearwheel group can provide a second reverse
gear, in addition to the previously mentioned first gear. One of
the two reverse gears provides a powerful and slower reverse gear.
In contrast, the other reverse gear provides 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.
[0018] The two reverse gears can be driven by different input
shafts. 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.
[0019] In the application, the DCT can comprise a reverse gear
idler shaft or a reverse gear layshaft, a reverse gearwheel and a
reverse pinion. The reverse gearwheel and the reverse pinion can be
both mounted on the reverse gear idler shaft or the or the reverse
gear layshaft. Distance of reverse torque transmission has been
reduced by arranging the reverse gearwheel and the reverse pinion
on the same shaft. The reverse gear thus has improved transmission
efficiency.
[0020] 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 comprises a
final drive pinion for engaging and 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 and beneficial for the vehicle and passengers'
safety.
[0021] In the application, the DCT can comprise two pinions mounted
on two of the layshafts respectively, instead of the one pinion.
The two pinions on the layshafts can mesh or comb with one
relatively big output gearwheel on an output shaft. The output
gearwheel can be integrated into a transmission differential device
without providing an intermediate output shaft of the transmission
gearbox. This allows a very dense packaging situation for the
DCT.
[0022] According to the application, the first gear idler gearwheel
can be provided on one of the layshafts. In contrast, the fourth
idler gearwheel, the fifth idler gearwheel, the sixth idler
gearwheel and the seventh idler gearwheel can be provided on the
remaining layshafts.
[0023] According to application, two or more of the second gear
idler gearwheel, the third driven gearwheel, the fourth gear idler
gearwheel and the fifth gear idler gearwheel can be mounted on the
same layshaft. Putting idler gearwheels of high gears on the same
shaft can make their weight and torque carrying layshaft to be slim
for low cost.
[0024] In the application, the sixth gear idler gearwheel and the
seventh gear idler gearwheel can be mounted on the same layshaft.
In a sever-gear DCT, idlers of the six and seventh gears carry the
least torques so that their weight and torque carrying layshaft can
be made very slim for light weight and low cost.
[0025] In the application, the DCT comprises bearings for
supporting the layshafts. One or more of the bearings can be
provided next to some or all of the pinions. The pinion that
outputs torque of its carrying layshaft is better supported by
immediately adjacent bearing for reducing the deflection and load
the layshaft. The supporting bearing thus can improve torque
transmission efficiency and reduce cost of the DCT.
[0026] According to the application, one or more of the bearings
can be provided next to one of the idler gearwheels of low gears.
Gearwheels of low gears transmit larger torques as compared to the
gearwheels of high gears. Close support of the bearings help to
reduce excessive deflection and weight related cost of their
carrying shafts.
[0027] According to the application, there can be gearbox that
comprises the DCT and an output gearwheel on an output shaft. The
output gearwheel can mesh with each of the pinions. The output
gearwheel provides a single source of torque output so that the
construction of the DCT is made simple and neat.
[0028] In the application, there can be a power train device with
the gearbox. The power train device can comprise one or more power
source for generating a driving torque. The power train device
usually has the gearbox and the power source onboard so that a
vehicle with the power train device can be mobile without being
physically attached to an external stationary power source.
[0029] In the application, the power source can comprise a
combustion engine. The power train with the combustion engine and
the DCT is easy to manufacture. The combustion engine can consume
less petrol for environmental protection. Furthermore, a combustion
engine usable for other types of fuel can have even less polluting
emission, such as hydrogen fuel.
[0030] According to the application, the power source can
alternatively comprises 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.
[0031] According to the application, there can be a vehicle that
comprises the power train device. The vehicle having the power
train device is efficient in energy usage by using the DCT.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The present invention will hereinafter be described in
conjunction with the following drawing figures, wherein like
numerals denote like elements, and
[0033] FIG. 1 illustrates a front view of a first embodiment of a
double clutch transmission of the application;
[0034] FIG. 2 illustrates the path of torque flow of a first gear
transmission ratio;
[0035] FIG. 3 illustrates the path of torque flow of a second gear
transmission ratio;
[0036] FIG. 4 illustrates the path of torque flow of a third gear
transmission ratio;
[0037] FIG. 5 illustrates the path of torque flow of a fourth gear
transmission ratio,
[0038] FIG. 6 illustrates the path of torque flow of a fifth gear
transmission ratio;
[0039] FIG. 7 illustrates the path of torque flow of a sixth gear
transmission ratio;
[0040] FIG. 8 illustrates the path of torque flow of a seventh gear
transmission ratio;
[0041] FIG. 9 illustrates the path of torque flow of a first
reverse gear transmission ratio;
[0042] FIG. 10 illustrates the path of torque flow of a second
reverse gear transmission ratio;
[0043] FIG. 11 illustrates an assembly of a double-sided coupling
device with its neighbouring gearwheels for engagement;
[0044] FIG. 12 illustrates an assembly of a single-sided coupling
device with its neighbouring gearwheel for engagement;
[0045] FIG. 13 illustrates an assembly of an idler gearwheel that
is rotatably supported by a shaft on a bearing;
[0046] FIG. 14 illustrates an assembly of a fixed gearwheel that is
supported on a shaft;
[0047] FIG. 15 illustrates a cross-section through a crankshaft of
an internal combustion engine according to embodiment of the
DCT;
[0048] FIG. 16 illustrates a front view of a further embodiment of
a double clutch transmission of the application;
[0049] FIG. 17 illustrates an expanded side view of the double
clutch transmission of FIG. 16;
[0050] FIG. 18 illustrates a front view of a further embodiment of
a double clutch transmission of the application;
[0051] FIG. 19 illustrates an expanded side view of the double
clutch transmission of FIG. 18;
[0052] FIG. 20 illustrates a front view of a further embodiment of
a double clutch transmission of the application;
[0053] FIG. 21 illustrates an expanded side view of the double
clutch transmission of FIG. 20;
[0054] FIG. 22 illustrates a front view of a further embodiment of
a double clutch transmission of the application; and
[0055] FIG. 23 illustrates an expanded side view of the double
clutch transmission of FIG. 22.
DETAILED DESCRIPTION
[0056] The following detailed description is merely exemplary in
nature and is not intended to limit 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.
[0057] 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
practised without such details.
[0058] FIGS. 1-15 provide detailed description of an embodiment of
a double clutch transmission (DCT) of the application.
[0059] FIG. 1 illustrates a front view of an embodiment of a double
clutch transmission 1 of the application. The DCT 1 comprises a
relatively large output gearwheel 12, an upper idler layshaft 40,
two input shafts 20, 22 and two pinions 51, 55. The two input
shafts 20, 22 are a solid input shaft 20 (i.e. K1) and a hollow
input shaft 22 (i.e. K2). The solid input shaft 20 and the hollow
input shaft 22 share the same rotational axis and are non-rotatably
connected to two clutch discs 8, 10 of a double clutch 6,
separately. The two pinions are the lower pinion 51 and the reverse
pinion 55. The two pinions are fixed to a lower layshaft 50 and a
reverse gear layshaft 38 at their rotational axes respectively. The
output gearwheel 12 is fixed to an output shaft 14 at its rotation
axis. The two pinions mesh with the output gearwheel 12 separately
at different positions of the output gearwheel 12.
[0060] The upper idler layshaft 40, the lower layshaft 50, the
input shafts 20, 22, and the reverse gear layshaft 38 are parallel
to each other at predetermined distances. The distances are
provided in radial directions of these shafts, which is better seen
in FIG. 2. Other gearwheels are mounted on these shafts
respectively meshing with each other according to predetermined
manners. The manners of these gearwheels' mounting and meshing are
better seen in some of the following figures.
[0061] 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 output gearwheel 12, the reverse pinion 55, the input
shafts 20, 22, the lower pinion 51 and the upper idler layshaft 40.
One of the goals of FIGS. 2 to 9 is to further illustrate structure
and torque flows of the DCT 1.
[0062] FIG. 2 illustrates the expanded view of the DCT that shows
the manners of the gearwheels mounting, which corresponds to FIG.
1.
[0063] According to FIG. 2, the DCT 1 comprises the following
shafts, from top to bottom, the upper idler layshaft 40, the lower
layshaft 50, the hollow input shaft 22, the solid input shaft 20,
the reverse gear layshaft 38 and the output shaft 14. The solid
input shaft 20 is partially disposed inside the hollow input shaft
22, and the solid input shaft 20 also protrudes outside the hollow
input shaft 22 at its 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.
[0064] According to FIG. 2, a portion of the solid input shaft 20
is surrounded by the outer input shaft 22 in a radial direction of
the input shafts 20, 22. There are three gearwheels and a coupling
device mounted on the left exposed portion of the solid input shaft
20. These gearwheels and the coupling device are a fixed wheel
fifth gear 26, a single-sided coupling device 85, an idler wheel
third gear 25 and a fixed wheel first gear 24 from left to right
sequentially. The fixed wheel fifth gear 26 also serves as a fixed
wheel seventh gear 27. All of the fixed wheel first gear 24, the
idler wheel third gear 25 and the fixed wheel fifth gear 26 are
fixed 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 are attached with a fixed wheel second gear 30 and
a fixed wheel fourth gear 31 from right to left. The fixed wheel
fourth gear 31 also serves as a fixed wheel sixth gear 32. Both the
fixed wheel second gear 30 and the fixed wheel fourth gear 31 are
fixed to the hollow input shaft 22 coaxially.
[0065] The lower layshaft 50 is provided above the solid input
shaft 20 and the hollow input shaft 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 fourth gear 63, a single-sided coupling device 82, a
park-lock gearwheel 39, an idler third gear 62, a double-sided
coupling device 81 and an idler fifth gear 64. One layshaft bearing
73 is provided between the lower pinion 51 and the idler fourth
gear 63. Another layshaft bearing 73 is provided next to the idler
fifth gear 64 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 fourth gear 63, the idler third gear 62 and the
idler fifth gear 64 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. In contrast, the
park-lock gearwheel 39 is a gear wheel that is fixed onto the lower
layshaft 50. The double-sided coupling devices 81 is configured to
move along the lower layshaft 50 such that it can either engage a
gearwheel on its left or right to the lower layshaft 50
respectively. The single-sided coupling device 82 is configured to
move along the lower layshaft 50 to engage or disengage the idler
fourth gear 63. The idler fourth gear 63 meshes with the fixed
wheel fourth gear 31. The idler third gear 62 meshes with the idler
wheel third gear 25. The idler fifth gear 64 meshes with the fixed
wheel fifth gear 26.
[0066] The upper idler layshaft 40 is provided further above the
lower layshaft 50. There are provided gearwheels and coupling
devices on the upper idler layshaft 40, which includes, from right
to the left, an idler second gear 61, a single-sided coupling
device 86, a single-sided coupling device 80, an idler first gear
60 and a fixed wheel auxiliary gear 28. One idler shaft bearing 74
is positioned at a left end of the upper idler layshaft 40 and
another idler shaft bearing 74 is positioned at right end of the
upper idler layshaft 40. The idler second gear 61 and the idler
first gear 60 are mounted on the upper idler layshaft 40 by
bearings respectively such that these gearwheels are free to rotate
around the upper idler layshaft 40. The fixed wheel auxiliary gear
28 is fixed onto the upper idler layshaft 40. The single-sided
coupling device 80 is configured to move along the upper idler
layshaft 40 to engage or disengage the idler first gear 60 to the
upper idler layshaft 40. The single-sided coupling device 86 is
configured to move along the upper idler layshaft 40 to engage or
disengage the idler second gear 61 to the upper idler layshaft 40.
The idler second gear 61 meshes with the fixed wheel second gear
30. The idler first gear 60 meshes with the fixed wheel first gear
24. The fixed wheel auxiliary gear 28 meshes with the idler wheel
third gear 25.
[0067] The reverse gear layshaft 38 is provided below the input
shafts 20, 22. There are gearwheels and coupling devices provided
on the reverse gear layshaft 38, which includes, from right to the
left, the reverse pinion 55, an idler sixth gear 65, a single-sided
coupling device 84, a reverse gear idler wheel 37, a double-sided
coupling device 83 and an idler seventh gear 66. The idler sixth
gear 65, the reverse gear idler wheel 37 and the idler seventh gear
66 are mounted on the reverse gear layshaft 38 via bearings
separately such that these gearwheels become idlers, being able to
freely rotate around the reverse gear layshaft 38. A layshaft
bearing 73 is positioned between the reverse pinion 55 and the
idler sixth gear 65. Another layshaft bearing 73 is positioned at a
left end of the reverse gear layshaft 38. The single-sided coupling
device 84 is configured to move along the reverse gear layshaft 38
for engaging or disengaging the idler sixth gear 65 to the reverse
gear layshaft 38. The double-sided coupling device 83 is configured
to move along the reverse gear layshaft 38 for engaging or
disengaging any one of the reverse gear idler wheel 37 and the
idler seventh gear 66 to the reverse gear layshaft 38. The idler
sixth gear 65 meshes with the fixed wheel sixth gear 32. The
reverse gear idler wheel 37 meshes with the idler first gear 60.
The idler seventh gear 66 meshes with the fixed wheel seventh gear
27.
[0068] The lower layshaft 50 comprises a fixed park-lock gearwheel
39 for locking the upper layshaft 50 when parking a vehicle with
the double-clutch transmission 1. The park-lock is a wheel which is
provided with a ratchet device, with a click device having a rack
element, a claw or similar. The park-lock keeps the lower layshaft
50 and the output shaft 14 from rotating, which stops a vehicle
with the DCT 1 from running when parked. When using the park-lock,
the park-lock gearwheel 39 on the lower layshaft 40 can be easily
engaged to lock the output shaft 14, via the lower layshaft 50, via
the lower pinion 51, via the output gearwheel 12, and stopping the
output shaft 14 from rotating. The lower pinion 51 is a final drive
pinion, which is similar to the reverse pinion 55. Detailed
structure of the park-lock is not shown in FIG. 2.
[0069] In other words, there are three double-meshing features
provided in the DCT 1. A first double-meshing feature comprises
that the fixed wheel fourth gear 31 meshes with both the idler
fourth gear 63 and the idler sixth gear 65. A second double meshing
feature comprises that the fixed wheel fifth gear 26 meshes with
both the idler fifth gear 64 and the idler seventh gear 66. A third
double-meshing feature comprises that the idler first gear 60
meshes with both the fixed wheel first gear 24 and the reverse gear
idler wheel 37.
[0070] A distance 56 between the input shafts 20, 22 and the upper
idler layshaft 40 is greater than a distance 58 between the input
shafts 20, 22 and the lower 30 layshaft 50. The distance 56 between
the input shafts 20, 22 and the upper idler layshaft 40 is measured
from a common longitudinal axis of the input shafts 20, 22 to a
longitudinal axis of the upper idler layshaft 40. Similarly, the
distance 58 between the input shafts 20, 22 and the lower layshafts
50 is measured from the common longitudinal axis of the input
shafts 20, 22 to a longitudinal axis of the lower layshaft 50. The
difference exists because the gearwheels of lower speeds 60, 61 on
the upper idler layshaft 40 is larger than the gearwheels 62, 63,
64 on the lower layshaft 50 so that the upper idler layshaft 40 is
brought to be closer to the input shafts 20, 22 than the lower
layshaft 50.
[0071] The output shaft 14 is provided below the reverse gear
layshaft 38 in FIG. 2. Two output shaft bearings 75 at two opposite
ends of the output shaft 14 respectively for supporting. The output
gearwheel 12 is mounted on the output shaft 14 coaxially. The
output gearwheel 12 is also fixed on the output shaft 14 and meshes
with the lower pinion 51.
[0072] 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 alternatively replaced by a hollow shaft and disposed
inside the hollow input shaft 22. The term "coupling device" is
alternatively termed as "shifting mechanism" for engaging or
disengaging gearwheels on a shaft. The double-clutch transmission
(DCT) 1 is alternatively termed as double-clutch, double clutch
transmission or dual clutch transmission (DCT). The inner clutch
disc 8 also known as an inner clutch 8. The outer clutch disc 10 is
additionally known as an outer clutch 10.
[0073] The fixed wheel first gear 24 is also known as the first
fixed gearwheel 24. The idler wheel third gear 25 is also known as
the third idler 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
auxiliary gear 28 is also known as the auxiliary fixed gearwheel
28. 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 reverse gear idler wheel
37 is also known as the reverse gear idler gearwheel 37. The idler
first gear 60 is also known as the first gear idler gearwheel 60.
The idler second gear 61 is also known as the second gear idler
gearwheel 61. The idler third gear 62 is also known as the third
gear idler gearwheel 62. The idler fourth gear 63 is also known as
the fourth gear idler gearwheel 63. The idler fifth gear 64 is also
known as the fifth gear idler gearwheel 64. The idler sixth gear 65
is also known as the sixth gear idler gearwheel 65. The idler
seventh gear 66 is also known as the seventh gear idler gearwheel
66. The coupling devices are alternatively known as synchronizers.
Any of the input shafts 20, 22 or layshafts 38, 40, 50 can be
supported by more than two bearings.
[0074] In the drawings of the present application, dash lines
indicate either alternative positions of the illustrated parts or
combing relationship between the gearwheels.
[0075] The application provides the DCT 1 that permits gearshift
operations with less loss of driving torque. This is because the
gearshift operations can be achieved by selectively connecting one
of the two clutch discs 8, 10 of the DCT 1. Therefore, an
associated additional main drive clutch can be avoided. Selective
connections between the two clutch discs 8, 10 also enable the
realization of an automatic transmission that can be operated
without interruptions in propulsive power. The propulsive power
comprises momentum derived from the rotating gearwheels and shafts
inside the DCT 1. Such a transmission is similar in design to a
mechanical manual transmission and it has correspondingly very low
friction losses. The DCT 1 further provides a parallel manual
transmission that can be used for transverse installation in a
front-wheel drive vehicle.
[0076] The DCT 1 according to the application can be connected
similar to a known manual transmission, such as a parallel manual
transmission. In the know 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 also 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 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.
[0077] The application provides a compact structure of a parallel
transmission. The parallel transmission includes two input shafts,
each of which can be non-rotatably coupled 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.
[0078] 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 51, 55. A short overall length of the power train for
transmitting torques can be achieved.
[0079] The application provides at least two relatively small
pinions 51, 55 on intermediately arranged layshafts 50, 38 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.
[0080] 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.
[0081] 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 clutch discs 8,
10 in the process of increasing or decreasing gears. For example,
the power-shift operation from the first 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.
[0082] Some gearwheels of the low gears (e.g. 1st & 2nd gears)
provided on the same layshaft are advantageous. In FIG. 2, the
idler first gear 60 and the idler second gear 61 are installed on
the same upper idler layshaft 40. Furthermore, the idler third gear
62, the idler fourth gear 63 and the idler fifth gear 64 are
installed on the same upper layshaft 50. This arrangement enables
one thick lower layshaft for carrying a number of heavy-duty
gearwheels 62, 63, 64, and avoids providing too many thick
layshafts in the DCT 1. Therefore, the DCT 1 can be made light with
less cost.
[0083] The layshaft bearings 73 of the DCT 1 are next to the
pinions 51, 55. The layshaft bearings 73 offer strong support to
the pinion carrying layshafts 50, 38 for reducing shaft deflection,
which can lower gear transmission efficiency or cause gearwheels
early worn out. The idler shaft bearing 74 next to the idler second
gear 61 also provide strong support to the idler second gear 61 and
the upper idler layshaft 40.
[0084] In other words, it is beneficial to provide the gearwheels
of the first gear, of the second gear and of the pinions 51, 55
close to the bearings for supporting. The pinions 51, 55 and
gearwheels of these gearwheels of low gears (e.g. 2nd gear, 4th
gear etc) undergo bigger forces than those of the higher gears
because the drive ratio is larger for the lower gears and reverse
gears. Therefore, their shafts must take up stronger driving
forces. If those forces are taken up close to the support points of
the shafts a reduced shaft bending will occur.
[0085] 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 (not shown).
According to FIG. 2, the input torque of the first gear is received
by the solid input shaft 20 from the double-clutch 6 of the DCT 1.
A torque of the first gear is transmitted from the solid input
shaft 20, via the fixed wheel first gear 24, via the idler first
gear 60, via the single-sided coupling device 80, via the upper
idler layshaft 40, via the fixed wheel auxiliary gear 28, via the
idler wheel third gear 25, via the idler third gear 62, via the
double-sided coupling device 81, via the lower layshaft 50, via the
lower pinion 51, via the output gearwheel 12, to the output shaft
14. The single-sided coupling device 80 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 double-sided coupling
device 81 is engaged to the idler third gear 62 when transmitting
the first gear. The number of tooth engagements or engaged gear
pairs for the torque transfer of the first gear is four.
[0086] 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 (not
shown). According to FIG. 3, the input torque of the second gear is
received by the hollow input shaft 22 from the double-clutch 6 of
the DCT 1. A torque of the second gear is transmitted from the
hollow input shaft 22, via the fixed wheel second gear 30, via the
idler second gear 61, via the single-sided coupling device 86, via
the upper idler layshaft 40, via the fixed wheel auxiliary gear 28,
via the idler wheel third gear 25, via the idler third gear 62, via
the double-sided coupling device 81, via the lower layshaft 50, via
the lower pinion 51, via the output gearwheel 12, to the output
shaft 14. The single-sided coupling device 86 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 double-sided
coupling device 81 is engaged to the idler third gear 62 when
transmitting the second gear. The number of tooth engagements or
engaged gear pairs for the torque transfer of the second gear is
four.
[0087] 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 (not
shown). According to FIG. 4, the input torque of the third gear is
received by the solid input shaft 20 from the double-clutch of the
DCT 1. A torque of the third gear is transmitted from the solid
input shaft 20, via the single-sided coupling device 85, via the
idler wheel third gear 25, via the idler third gear 62, via the
double-sided coupling device 81, 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 81 is engaged to the idler
third gear 62 when transmitting the torque of the third gear, which
provides the third gear of the DCT 1. The single-sided coupling
device 85 is engaged to the idler wheel third gear 25 when
transmitting the third gear. The number of tooth engagements or
engaged gear pairs for the torque transfer of the third gear is
two.
[0088] 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 (not
shown). According to FIG. 5, the input torque of the fourth gear is
received by the hollow input shaft 22 from the double-clutch 6 of
the DCT 1. A torque of the fourth gear is transmitted from the
hollow input shaft 22, via the fixed wheel fourth gear 31, via the
idler fourth gear 63, via the single-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 single-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.
[0089] 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 (not shown).
According to FIG. 6, the input torque of the fifth gear is received
by the solid input shaft 20 from the double-clutch 6 of the DCT 1.
A torque of the fifth gear is transmitted from the solid input
shaft 20, via the fixed wheel fifth gear 26, via the idler fifth
gear 64, via the double-sided coupling device 81, 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 81 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.
[0090] 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 (not shown).
According to FIG. 7, the input torque of the sixth gear is received
by the hollow input shaft 22 from the double-clutch 6 of the DCT 1.
A torque of the sixth gear is transmitted from the hollow input
shaft 22, via the fixed wheel sixth gear 32, via the idler sixth
gear 65, via the single-sided coupling device 84, via the reverse
gear layshaft 38, via the reverse pinion 55, via the output
gearwheel 12, to the output shaft 14. The single-sided coupling
device 84 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.
[0091] 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 (not
shown). According to FIG. 8, the input torque of the seventh gear
is received by the solid input shaft 20 from the double-clutch 6 of
the DCT 1. A torque of the seventh gear is transmitted from the
solid input shaft 20, via the fixed wheel seventh gear 27, via the
idler seventh gear 66, via the double-sided coupling device 83, via
the reverse gear layshaft 38, via the reverse pinion 55, via the
output gearwheel 12, to the output shaft 14. The double-sided
coupling device 83 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.
[0092] FIG. 9 illustrates the path of torque flow of a first
reverse gear transmission ratio. In FIG. 9, an input torque of the
reverse gear is received from the crankshaft 2 of a combustion
engine (not shown). According to FIG. 9, the input torque of the
first reverse gear is received by the solid input shaft 20 from the
double-clutch 6 of the DCT 1. A torque of the reverse gear is
transmitted from the solid input shaft 20, via the fixed wheel
first gear 24, via the idler first gear 60, via the reverse gear
idler wheel 37, via the double-sided coupling device 83, via the
reverse gear layshaft 38, via the reverse pinion 55, via the output
gearwheel 12, to the output shaft 14. The double-sided coupling
device 83 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.
[0093] FIG. 10 illustrates the path of torque flow of a second
reverse gear transmission ratio. In FIG. 9, an input torque of the
second reverse gear is received from the crankshaft 2 of a
combustion engine (not shown). According to FIG. 9, the input
torque of the second reverse gear is received by the hollow input
shaft 22 from the double-clutch 6 of the DCT 1. A torque of the
second reverse gear is transmitted from the hollow input shaft 22,
via the fixed wheel second gear 30, via the idler second gear 61,
via the single-sided coupling device 86, via the upper idler
layshaft 40, via the single-sided coupling device 80, via the idler
first gear 60, via the reverse gear idler wheel 37, via the
double-sided coupling device 83, via the reverse gear layshaft 38,
via the reverse pinion 55, via the output gearwheel 12, to the
output shaft 14. When transmitting the torque of the second reverse
gear, the single-sided coupling device 86 engages the idler second
gear 61 to the upper idler layshaft 40, the single-sided coupling
device 80 engages the idler first gear 60 to the upper idler
layshaft 40, and the double-sided coupling device 83 engages the
reverse gear idler wheel 37 to the reverse gear layshaft 38. The
number of tooth engagements or engaged gear pairs for the torque
transfer of the reverse gear is four.
[0094] FIG. 11 illustrates an assembly 100 of a double-sided
coupling device 102 with its neighbouring gearwheels 101, 103 for
engagement. The assembly 100 comprises a shaft 104 with the two
coaxially mounted idler gear 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. 11.
[0095] FIG. 12 illustrates an assembly 110 of a single-sided
coupling device 112 with its neighbouring 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.
12.
[0096] FIG. 13 illustrates an assembly 120 of an idler gearwheel
121 that is rotatably supported by a shaft 122 on a bearing 123.
The idler gearwheel 121 is coaxially mounted onto the shaft 122 via
the bearing 123. The bearing 123 enables the idler gearwheel 121 to
be freely rotated around the shaft 122. Symbols that represent the
assembly 120 are provided at the right hand side of the FIG.
13.
[0097] FIG. 14 illustrates an assembly 130 of a fixed gearwheel 132
that is supported on a shaft 131. The fixed gearwheel 132 is
coaxially mounted 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.
[0098] A number of fixed gearwheels are rigidly connected to the
input shafts 20, 22 and other shafts 14, 38, 40, 50. A symbol as
used in the previous figures for such a fixed gearwheel is provided
on the left side in FIG. 14. The more commonly used symbol for such
a fixed gearwheel is provided on the right side in FIG. 14.
[0099] FIG. 15 illustrates a cross-section through a crankshaft 2
of an internal combustion engine according to the embodiment of the
DCT 1. According to FIG. 15, a crankshaft 2 of an internal
combustion engine, which is not shown here, is non-rotatably
connected to the 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 non-rotatably connected to the clutch disc 8, and
extends all the way through the hollow shaft 22. Similarly, the
hollow input shaft 22 is non-rotatably connected to the other
clutch disc 10.
[0100] The clutch housing 4 has a larger outer diameter around the
inner clutch disc 8 than that around the outer clutch disc 10.
Correspondingly, the inner clutch disc 8 has a larger outer
diameter than that of the outer clutch disc 10 inside the clutch
housing 4. The fact that the larger inner clutch disc 8 on the
solid input shaft 20 drives the first gear makes the DCT 1
robust.
[0101] 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 the another
efficiently. The gear switching can be achieved by switching
between the two input shafts, between gearwheels of double meshing
features, or both.
[0102] For example, the DCT 1 can provide odd gears (i.e. 1st, 3rd,
5th & 7th gears) by driving the gearwheels of the DCT 1 using
the solid input shaft 20. Alternatively, the DCT 1 can provide even
gears (i.e. 2nd, 4th & 6th gears) by driving the gearwheels of
the DCT 1 using the hollow input shaft 22. Gear switching between
the odd and even can simply be obtained by alternating between the
two input shafts 20, 22.
[0103] 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 fourth gear or the sixth gear without
stopping their shared driving gearwheel, the fixed wheel fourth
gear 31. The selection can be achieved by engaging either the
driven idler fourth gear 63 or the driven idler sixth gear 65.
Similarly, the gear switching between the fifth gear and the
seventh gear can be simply engaging any one of the running
gearwheels, namely the idler fifth gear 64 and the idler seventh
gear 66.
[0104] Combining the switching technique between the input shafts
20, 22 or between the driven gearwheels of one double meshing,
flexibility of gear changes can be further enhanced. For example,
the gear switching from the fourth to the seventh can be provided
by disengaging the hollow input shaft 22, followed by engaging the
solid input shaft 20 and the idler seventh gear 66.
[0105] The double-meshing features reduce the number of driving
gearwheels, which is commonly engaged by driven gearwheels of their
double-meshing feature. For example, the driving fixed wheel fourth
gear 31 and the driving fixed wheel sixth gear 32 become one single
gearwheel that is shared by the driven idler fourth gear 63 and the
driven idler sixth gear 65. The driving fixed wheel fifth gear 26
and the driving fixed wheel seventh gear 27 become one single
gearwheel that is shared by the driven idler fifth gear 64 and the
driven idler seventh gear 66. As a result, the number of gearwheels
on the input shafts 20, 22 has been reduced and less space is
required on the input shafts 20, 22 so that the DCT 1 can be made
cheaper and lighter.
[0106] The park-lock gearwheel 39 gives an useful safety feature
for a car with the DCT 1. The park-lock keeps the lower layshaft
50, the output shaft 14 and the output shaft 14 from rotating,
which stop a vehicle with the DCT 1 from running when parked.
[0107] In providing gear meshing or combing for torque
transmission, less number of gear tooth engagement (i.e. gear
engagement) is preferred. The less number of gear tooth engagement
provides lower noise and more efficient torque transmission.
[0108] The DCT 1 drives the gearwheel groups of the first gear and
the second 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 by using the first gear and the second reverse gear for
that operation. 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 clutch discs 8, 10 of the DCT 1.
Alternatively, the vehicle can change between the second gear and
the first reverse gear to move back and forth quickly by
alternatively engaging between the inner input shaft and the outer
input shaft.
[0109] FIGS. 16-17 illustrate a further embodiment of the
application. The embodiment includes parts that are similar to the
parts of previously described embodiment. The similar parts are
labelled with the same or similar part reference number.
Descriptions related to the similar parts are hereby incorporated
by reference.
[0110] FIG. 16 illustrates a front view of a further embodiment of
a double clutch transmission 1 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. 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.
[0111] FIG. 16 further comprises a cutting plane A-A for
illustrating the cross-section through the gearbox which is shown
in FIG. 17. 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. One of the goals of FIG. 17 is to
further illustrate the structure and the torque flows through the
embodiment of the gearbox 1.
[0112] FIG. 17 illustrates an expanded side view of the double
clutch transmission 1 of FIG. 16. The expanded side view
illustrates structure and various torque flows for the several
gears of the double clutch transmission gearbox 1. The double
clutch transmission gearbox 1 comprises the following shafts, from
top to bottom, a top layshaft 90, the upper layshaft 40, a solid
input shaft 20, a 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.
[0113] 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 first
gear 24, an idler third gear 62, a single-sided coupling device 86,
and a fixed wheel fifth gear 26, which is at the same time a fixed
wheel seventh gear 27, and a solid shaft bearing 71.
[0114] The hollow input shaft 22 comprises, from the right end to
the left end, a hollow shaft bearing 72, a fixed wheel second gear
30, and a fixed wheel fourth gear 28, which serves also as a fixed
wheel sixth gear 29.
[0115] The upper layshaft 40 comprises, from the right end to the
left end, the upper pinion 41, a layshaft bearing 73, an idler
fourth gear 63, combing with the fixed wheel fourth gear 28, a
single-sided coupling device 80, a park-lock gearwheel 39, a fixed
wheel third gear 25, combing with the idler third gear 62, a
single-sided coupling device 81, an idler fifth gear 64, combing
with the fixed wheel fifth gear 26, and a layshaft bearing 73.
[0116] The top layshaft 90 comprises, from the right end to the
left end, a layshaft bearing 73, an idler second gear 61, combing
with the fixed wheel second gear 30, a single-sided coupling device
84, a single-sided coupling device 87, an idler first gear 60,
combing with the fixed wheel first gear 24, a fixed top wheel 92,
combing with the idler third gear 62, and a layshaft bearing
73.
[0117] The lower layshaft 50 comprises, from the right end to the
left, a lower pinion 51, an idler shaft bearing 74, an idler sixth
gear 65, combing with the fixed wheel sixth gear 29, a single-sided
coupling device 83, a reverse gear idler wheel 37, combing with the
idler first gear 60, a double-sided coupling device 82, an idler
seventh gear 66, combing with the fixed wheel seventh gear 27, and
an idler shaft bearing 74.
[0118] Torque flow of the first gear according to FIG. 17, starts
from the solid input shaft 20, via the fixed wheel first gear 24,
via the idler first gear 60, via the single-sided coupling device
84, via the top layshaft 90, via the fixed top wheel 92, via the
idler third gear 62, via the fixed wheel third gear 25, via the
upper layshaft 40, and to the upper pinion 41.
[0119] Torque flow of the second gear according to FIG. 17 starts
from the hollow input shaft 22, via the fixed wheel second gear 30,
via the idler second gear 61, via the single-sided coupling device
84, via the top layshaft 90, via the fixed top wheel 92, via the
idler third gear 62, via the fixed wheel third gear 25, via the
upper layshaft 40, to the upper pinion 41.
[0120] Torque flow of the third gear according to FIG. 17 starts
from the solid input shaft 20, via the single-sided coupling device
86, via the idler third gear 62, via the fixed wheel third gear 25,
via the upper layshaft 40, to the upper pinion 41.
[0121] Torque flow of the fourth gear according to FIG. 17 starts
from the hollow input shaft 22, via the fixed wheel fourth gear 28,
via the single-sided coupling device 80, via the upper layshaft 40,
to the upper pinion 41.
[0122] Torque flow of the fifth gear according to FIG. 17 starts
from the solid input shaft 20, via the fixed wheel fifth gear 26,
via the idler fifth gear 64, via the single-sided coupling device
81, via the upper layshaft 40, to the upper pinion 41.
[0123] Torque flow of the sixth gear according to FIG. 17 starts
from the hollow input shaft 22, via the fixed wheel sixth gear 29,
via the idler sixth gear 65, via the single-sided coupling device
83, via the lower layshaft, to the lower pinion 51.
[0124] Torque flow of the seventh gear according to FIG. 17 starts
from the solid input shaft 20, via the fixed wheel seventh gear 27,
via the idler seventh gear 66, via the double-sided coupling device
82, via the lower layshaft 50, to the lower pinion 51.
[0125] Torque flow of the first reverse gear according to FIG. 17
starts from the solid input shaft 20, via the fixed wheel first
gear 24, via the idler first gear 60, via the reverse gear idler
wheel 37, via the double-sided coupling device 82, via the lower
layshaft 50, to the lower pinion 51.
[0126] Torque flow of the second reverse gear according to FIG. 17
starts from the hollow input shaft 22, via the fixed wheel second
gear 30, via the idler second gear 61, via the single-sided
coupling device 84, via the top layshaft 90, via the single-sided
coupling device 87, via the idler first gear 60, via the reverse
gear idler wheel 37, 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.
[0127] FIGS. 18-19 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
labelled with the same or similar part reference number.
Descriptions related to the similar parts are hereby incorporated
by reference.
[0128] FIG. 18 shows a front view of the gearbox 1 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 a reverse pinion 55 which
is provided on a reverse gear shaft 38. 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.
[0129] FIG. 18 further comprises a cutting plane A-A for
illustrating the cross-section through the gearbox which is shown
in FIG. 19. 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. One of the goals of FIG. 19 is to
further illustrate the structure and the torque flows through the
embodiment of the gearbox 1.
[0130] FIG. 19 illustrates a simplified cross-section through the
double clutch transmission gearbox 1 of FIG. 18. It illustrates
structure and various torque flows for the several gears of the
double clutch transmission gearbox 1. The double clutch
transmission gearbox 1 comprises the following shafts, from top to
bottom, the upper layshaft 40, the lower layshaft 50, the solid
input shaft 20, the hollow shaft 22, and the reverse gear shaft
38.
[0131] 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.
[0132] 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 first
gear 24, an idler third gear 62, a single-sided coupling device 82,
a fixed wheel fifth gear 26, which is at the same time a fixed
wheel seventh gear 27, and a solid shaft bearing 71.
[0133] The hollow input shaft 22 comprises, from the right end to
the left end, a hollow shaft bearing 72, a fixed wheel second gear
30, and a fixed wheel fourth gear 31, which serves also as a fixed
wheel sixth gear 32.
[0134] The upper layshaft 40 comprises, from the right end to the
left end, a layshaft bearing 73, an idler second gear 61, combing
with the fixed wheel second gear 30, a single-sided coupling device
86, a single-sided coupling device 84, an idler first gear 60,
combing with the fixed wheel first gear 24, a fixed wheel third
gear 28, combing with the idler third gear 62, and a layshaft
bearing 73.
[0135] The reverse gear shaft 38 comprises, from the right end to
the left end, the reverse pinion 55, an idler shaft bearing 74, an
idler sixth gear 65, combing with the fixed wheel sixth gear 32, a
double-sided coupling device 83, a reverse gear idler wheel 37,
combing with the idler first gear 60, a single-sided coupling
device 85, an idler seventh gear 66, combing with the fixed wheel
seventh gear 27, and an idler shaft bearing 74.
[0136] The lower layshaft 50 comprises, from the right end to the
left end, the lower pinion 51, a layshaft bearing 73, an idler
fourth gear 63, combing with the fixed wheel fourth gear 31, a
single-sided coupling device 80, a park-lock gearwheel 39, a fixed
wheel third gear 25, combing with the idler third gear 62, a
single-sided coupling device 81, an idler fifth gear 64, combing
with the fixed wheel fifth gear 26, and a layshaft bearing 73.
[0137] Torque flow of the first gear according to FIG. 19 starts
from the solid input shaft 20, via the fixed wheel first gear 24,
via the idler first gear 60, via the single-sided coupling device
84, via the upper layshaft 40, via the fixed wheel third gear 28,
via the idler third gear 62, via the fixed wheel third gear 25, via
the lower layshaft 50, to the lower pinion 51.
[0138] Torque flow of the second gear according to FIG. 19 starts
from hollow input shaft 22, via the fixed wheel second gear 30, via
the idler second gear 61, via the single-sided coupling device 86,
via the upper layshaft 40, via the fixed wheel third gear 28, via
the idler third gear 62, via the fixed wheel third gear 25, via the
lower layshaft 50, to the lower pinion 51.
[0139] Torque flow of the third gear according to FIG. 19 starts
from the solid input shaft 20, via the double-sided coupling device
82, via the idler third gear 62, via the fixed wheel third gear 25,
via the lower layshaft 50, to the lower pinion 51.
[0140] Torque flow of the fourth gear according to FIG. 19 starts
from hollow input shaft 22, via the fixed wheel fourth gear 31, via
the idler fourth gear 63, via the single-sided coupling device 80,
via the lower layshaft 50, to the lower pinion 51.
[0141] Torque flow of the fifth gear according to FIG. 19 starts
from solid input shaft 20, via the fixed wheel fifth gear 26, via
the idler fifth gear 64, via the single-sided coupling device 81,
via the lower layshaft 50, to the lower pinion 51.
[0142] Torque flow of the sixth gear according to FIG. 19 starts
from the hollow input shaft 22, via the fixed wheel sixth gear 32,
via the idler sixth gear 65, via the double-sided coupling device
83, via the reverse gear shaft 38, to the reverse pinion 55.
[0143] Torque flow of the seventh gear according to FIG. 19 starts
from the solid input shaft 20, via the fixed wheel seventh gear 27,
via the idler seventh gear 66, via the single-sided coupling device
85, via the reverse gear shaft 38, to the reverse pinion 55.
[0144] Torque flow of the first reverse gear according to FIG. 19
starts from the solid input shaft 20, via the fixed wheel first
gear 24, via the idler first gear 60, via the reverse gear idler
wheel 37, via the double-sided coupling device 83, via the reverse
gear shaft 38, to the reverse pinion 55.
[0145] Torque flow of the second reverse gear according to FIG. 19
starts from the hollow input shaft 22, via the fixed wheel second
gear 30, via the idler second gear 61, via the single-sided
coupling device 86, via the upper layshaft 40, via the single-sided
coupling device 84, via the idler first gear 60, via the reverse
gear idler wheel 37, via the double-sided coupling device 83, via
the reverse gear shaft 38, to the reverse pinion 55, via the output
gearwheel 12, to the output shaft 14.
[0146] FIGS. 20-21 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
labelled with the same or similar part reference number.
Descriptions related to the similar parts are hereby incorporated
by reference.
[0147] FIG. 20 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 a reverse pinion 55, which
is provided on a reverse gear shaft 38. 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.
[0148] FIG. 20 further comprises a cutting plane A-A for
illustrating the cross-section through the gearbox which is shown
in FIG. 21. 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. One of the goals of FIG. 21 is to
further illustrate the structure and the torque flows through the
embodiment of the gearbox.
[0149] FIG. 21 illustrates a simplified cross-section through the
double clutch transmission gearbox 1 of FIG. 20. They illustrate
its structure and various torque flows for the several gears of the
double clutch transmission gearbox 1.
[0150] The double clutch transmission gearbox 1 comprises the
following shafts, from top to bottom, an upper layshaft 40, the
lower layshaft 50, the solid input shaft 20, the hollow shaft 22,
and the reverse gear shaft 38. 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.
[0151] 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 first
gear 24, an idler third gear 62, a single-sided coupling device 84,
a fixed wheel fifth gear 26, which is at the same time a fixed
wheel seventh gear 27, and a solid shaft bearing 71.
[0152] The hollow input shaft 22 comprises, from the right end to
the left end, a hollow shaft bearing 72, a fixed wheel reverse gear
35, a fixed wheel fourth gear 31, which serves also as a fixed
wheel sixth gear 32, and a fixed wheel second gear 30.
[0153] The upper layshaft 40 comprises, from the right end to the
left end, an idler shaft bearing 74, an idler reverse gear 67,
combing with the fixed wheel reverse gear 35, a single-sided
coupling device 86, a single-sided coupling device 85, an idler
first gear 60, combing with the fixed wheel first gear 24, a fixed
wheel third gear 28, combing with the idler third gear 62, and an
idler shaft bearing 74.
[0154] The reverse gear shaft 38 comprises, from the right end to
the left end, a reverse pinion 55, a layshaft bearing 73, an idler
sixth gear 65, combing with the fixed wheel sixth gear 32, a
double-sided coupling device 83, a reverse gear idler wheel 37,
combing with the idler first gear 60, a double-sided coupling
device 82, an idler seventh gear 66, combing with the fixed wheel
seventh gear 27, and an idler shaft bearing 74.
[0155] The lower layshaft 50 comprises, from the right end to the
left end, the lower pinion 51, a layshaft bearing 73, an idler
fourth gear 63, combing with the fixed wheel fourth gear 31, a
double-sided coupling device 80, an idler second gear 61, combing
with the fixed wheel second gear 30, a park-lock gearwheel 39, a
fixed wheel third gear 25, combing with the idler third gear 62, a
single-sided coupling device 81, an idler fifth gear 64, combing
with the fixed wheel fifth gear 26, and a layshaft bearing 73.
[0156] Torque flow of the first gear according to FIG. 21 starts
from solid input shaft 20, via the fixed wheel first gear 24, via
the idler first gear 60, via the single-sided coupling device 85,
via the upper layshaft 40, via the fixed wheel third gear 28, via
the idler third gear 62, via the fixed wheel third gear 25, via the
lower layshaft 50, to the lower pinion 51.
[0157] Torque flow of the second gear according to FIG. 21 starts
from hollow input shaft 22, via the fixed wheel second gear 30, via
the idler second gear 61, via the double-sided coupling device 80,
via the lower layshaft 50, to the lower pinion 51.
[0158] Torque flow of the third gear according to FIG. 21 starts
from solid input shaft 20, via the single-sided coupling device 84,
via the idler third gear 62, via the fixed wheel third gear 25, via
the lower layshaft 50, to the lower pinion 51.
[0159] Torque flow of the fourth gear according to FIG. 21 starts
from the hollow input shaft 22, via the fixed wheel fourth gear 31,
via the idler fourth gear 63, via the double-sided coupling device
80, via the lower layshaft 50, to the lower pinion 51.
[0160] Torque flow of the fifth gear according to FIG. 21 starts
from the solid input shaft 20, via the fixed wheel fifth gear 26,
via the idler fifth gear 64, via the single-sided coupling device
81, via the lower layshaft 50, to the lower pinion 51.
[0161] Torque flow of the sixth gear according to FIG. 21 starts
from the hollow input shaft 22, via the fixed wheel sixth gear 32,
via the idler sixth gear 65, via the double-sided coupling device
83, via the reverse gear shaft 38, to the reverse pinion 55.
[0162] Torque flow of the seventh gear according to FIG. 21 starts
from the solid input shaft 20, via the fixed wheel seventh gear 27,
via the idler seventh gear 66, via the double-sided coupling device
82, via the reverse gear shaft 38, to the reverse pinion 55.
[0163] Torque flow of the first reverse gear according to FIG. 21
starts from the solid input shaft 20, via the fixed wheel first
gear 24, via the idler first gear 60, via the reverse gear idler
wheel 37, via the double-sided coupling device 83, via the reverse
gear shaft 38, to the reverse pinion 55.
[0164] Torque flow of the second reverse gear according to FIG. 21
starts from the hollow input shaft 22, via the fixed wheel reverse
gear 35, via the idler reverse gear 67, via the single-sided
coupling device 86, via the upper layshaft 40, via the single-sided
coupling device 85, via the idler first gear 60, via the reverse
gear idler wheel 37, via the double-sided coupling device 83, via
the reverse gear shaft 38, to the reverse pinion 55.
[0165] FIGS. 22-23 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
labelled with the same or similar part reference number.
Descriptions related to the similar parts are hereby incorporated
by reference.
[0166] FIG. 22 shows a front view of the gearbox 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 carries a number of gearwheels that meshes with
gearwheels on the upper layshaft 40 and input shafts 20, 22
according to a predetermined manner. The input shafts 20, 22, the
upper layshaft 40 and the lower layshaft 50 are parallel to each
other, and the two input shafts 20, 22 are coaxial. 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.
[0167] FIG. 22 further comprises a cutting plane A-A for
illustrating the cross-section through the gearbox which is shown
in FIG. 23. 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. One of the goals of FIG. 23 is to
further illustrate the structure and the torque flows through the
embodiment of the gearbox.
[0168] FIG. 23 illustrates a simplified cross-section through the
double clutch transmission gearbox 1 of FIG. 22. They illustrate
its structure and various torque flows for the several gears of the
double clutch transmission gearbox 1.
[0169] The double clutch transmission gearbox 1 comprises the
following shafts, from top to bottom, the reverse gear idler shaft
38, an upper layshaft 40, the hollow shaft 22, the solid input
shaft 20, the lower layshaft 50, and the output shaft 14. 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.
[0170] 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 fifth
gear 26, which also serves as a fixed wheel seventh gear 27, a
fixed wheel third gear 25, a fixed wheel first gear 24, and a solid
shaft bearing 71.
[0171] The hollow input shaft 22 comprises, from the right end to
the left end, a hollow shaft bearing 72, a fixed wheel second gear
30, which also serves as a fixed wheel third reverse gear 34, a
fixed wheel fourth gear 31, which serves also as a fixed wheel
sixth gear 32, a hollow shaft bearing 72, which also serves as a
solid shaft bearing 71.
[0172] The upper layshaft 40 comprises, from the right end to the
left end, the upper pinion 41, a layshaft bearing 73, an idler
reverse gear 37, a double-sided coupling device 80, an idler fourth
gear 63 meshing with the fixed wheel fourth gear 31, an idler fifth
gear 64 meshing with the fixed wheel fifth gear 26, a double-sided
coupling device 81, an idler third gear 62 meshing with the fixed
wheel third gear 25, a park-lock gearwheel 39, and a layshaft
bearing 73.
[0173] The reverse gear idler shaft 38 comprises, from the right
end to the left end, an idler shaft bearing 74, a fixed wheel first
reverse gear 35, a fixed wheel second reverse gear 36, and an idler
shaft bearing 74. The fixed wheel first reverse gear 35 meshes with
the fixed wheel third reverse gear 34. The fixed wheel second
reverse gear 36 meshes with the idler reverse gear 37.
[0174] The lower layshaft 50 comprises, from the right end to the
left end, the lower pinion 51, a layshaft bearing 73, an idler
second gear 61 combing with the fixed wheel second gear 30, a
double-sided coupling device 83, an idler sixth gear 65 combing
with the fixed wheel sixth gear 32, an idler seventh gear 66
combing with the fixed wheel seventh gear 27, a double-sided
coupling device 82, an idler first gear 60 combing with the fixed
wheel first gear 24, and a layshaft bearing 73.
[0175] Torque flow of the first gear according to FIG. 23 starts
from the solid input shaft 20, via the fixed wheel first gear 24,
via the idler first gear 60, 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.
[0176] Torque flow of the second gear according to FIG. 23 starts
from the hollow input shaft 22, via the fixed wheel second gear 30,
via the idler second gear 61, 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.
[0177] Torque flow of the third gear according to FIG. 23 starts
from the solid input shaft 20, via the fixed wheel third gear 25,
via the idler third gear 62, via the double-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.
[0178] Torque flow of the fourth gear according to FIG. 23 starts
from the hollow input shaft 22, via the fixed wheel fourth gear 31,
via the idler fourth gear 63, 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.
[0179] Torque flow of the fifth gear according to FIG. 23 starts
from the solid input shaft 20, via the fixed wheel fifth gear 26,
via the idler fifth gear 64, via the double-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.
[0180] Torque flow of the sixth gear according to FIG. 23 starts
from the hollow input shaft 22, via the fixed wheel sixth gear 32,
via the idler sixth gear 65, 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.
[0181] Torque flow of the seventh gear according to FIG. 23 starts
from the solid input shaft 20, via the fixed wheel seventh gear 27,
via the idler seventh gear 66, 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.
[0182] Torque flow of the reverse gear according to FIG. 23 starts
from the hollow input shaft 22, via the fixed wheel third reverse
gear 34, via the fixed wheel first reverse gear 35, via the reverse
gear idler shaft 38, via the fixed wheel second reverse gear 36,
via the idler reverse gear 37, 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.
[0183] 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 practise. Thus, the scope of the
embodiments should be determined by the claims, rather than by the
examples given.
[0184] 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.
* * * * *