U.S. patent application number 12/935883 was filed with the patent office on 2011-03-03 for double-clutch transmission for vehicles.
This patent application is currently assigned to GM GLOBAL TECHNOLOGY OPERATIONS, INC.. Invention is credited to Axel Geiberger, Mikael B. Mohlin, Mathias Remmler, Markus Rockenbach.
Application Number | 20110048168 12/935883 |
Document ID | / |
Family ID | 40671915 |
Filed Date | 2011-03-03 |
United States Patent
Application |
20110048168 |
Kind Code |
A1 |
Mohlin; Mikael B. ; et
al. |
March 3, 2011 |
DOUBLE-CLUTCH TRANSMISSION FOR VEHICLES
Abstract
A double-clutch transmission (DCT) includes, but is not limited
to two input shafts that are connected to two clutch discs
respectively. The DCT also has three parallel layshafts. One or
more of the layshafts includes, but is not limited to a pinion as a
final drive. The DCT also includes, but is not limited to seven
gearwheel groups for providing seven sequentially increasing
forward gears. Each gearwheel group includes, but is not limited to
a fixed gearwheel on one of the input shafts, meshing with an idler
gearwheel on one of the layshafts. A third fixed gearwheel meshes
with a third gear idler gearwheel and a fifth gear idler gearwheel.
Especially, a reverse gearwheel group of the DCT includes, but is
not limited to a reverse 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. A second fixed gearwheel
meshes with a second gear idler gearwheel and a fourth gear idler
gearwheel.
Inventors: |
Mohlin; Mikael B.;
(Kungaelv, SE) ; Geiberger; Axel; (Mainz, DE)
; Remmler; Mathias; (Mauchenheim, DE) ;
Rockenbach; Markus; (Schweppenhausen, DE) |
Assignee: |
GM GLOBAL TECHNOLOGY OPERATIONS,
INC.
Detroit
MI
|
Family ID: |
40671915 |
Appl. No.: |
12/935883 |
Filed: |
March 31, 2009 |
PCT Filed: |
March 31, 2009 |
PCT NO: |
PCT/EP2009/002356 |
371 Date: |
September 30, 2010 |
Current U.S.
Class: |
74/665S |
Current CPC
Class: |
F16H 2003/0826 20130101;
F16H 2200/0056 20130101; Y10T 74/19112 20150115; Y10T 74/19233
20150115; Y10T 74/19228 20150115; Y10T 74/19065 20150115; F16H
2003/0822 20130101; F16H 3/093 20130101; F16H 3/006 20130101; F16H
2200/0086 20130101; Y10T 74/1907 20150115; F16H 2003/0931
20130101 |
Class at
Publication: |
74/665.S |
International
Class: |
F16H 3/093 20060101
F16H003/093; F16H 3/00 20060101 F16H003/00 |
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 being surrounded by the outer input shaft; a first clutch
disc connected to the inner input shaft and a second clutch disc
connected to the outer input shaft; a first layshaft, a second
layshaft and a third layshaft spaced apart from the input shafts
and arranged in parallel to the input shafts; at least one of the
layshafts comprises a pinion; gearwheels arranged on the first
layshaft, on the second layshaft, on the third layshaft, on the
inner input shaft and on the outer input shaft, the gearwheels
comprising a first gearwheel group, a second gearwheel group, a
third gearwheel group, a fourth gearwheel group, a fifth gearwheel
group, a sixth gearwheel group, a seventh gearwheel group for
providing seven sequentially increasing forward gears, the first
gearwheel group comprising a first fixed gearwheel on the outer
input shaft, meshing with a first gear idler gearwheel on one of
the layshafts for providing a first forward gear, the third
gearwheel group comprising a third driving gearwheel on the outer
input shaft, meshing with a third driven gearwheel on one of the
layshafts for providing a third forward gear, the fifth gearwheel
group comprising a fifth fixed gearwheel on the outer input shaft,
meshing with a fifth gear idler gearwheel on one of the layshafts
for providing a fifth forward gear, the seventh gearwheel group
comprising a seventh fixed gearwheel on the outer input shaft,
meshing with a seventh gear idler gearwheel on one of the layshafts
for providing a seventh forward gear, the second gearwheel group
comprising a second fixed gearwheel on the inner input shafts,
meshing with a second gear idler gearwheel on one of the layshafts
for providing a second forward gear, the fourth gearwheel group
comprising a fourth fixed gearwheel on the inner input shafts,
meshing with a fourth gear idler gearwheel on one of the layshafts
for providing a fourth forward gear, the sixth gearwheel group
comprising a sixth fixed gearwheel on the inner input shafts,
meshing with a sixth gear idler gearwheel on one of the layshafts
for providing a sixth forward gear, 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 third fixed gearwheel further
meshing with the fifth gear idler gearwheel, wherein the gearwheels
further comprises a reverse gearwheel group that comprises a
reverse 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, the reverse gearwheel group further comprises a
coupling device on one of the layshafts to engage the reverse gear
idler gearwheel for providing the reverse gear, and the second
fixed gearwheel further meshes with the fourth gear idler
gearwheel.
2. The double-clutch transmission according to claim 1, wherein the
first forward gear and the reverse gear are provided by the
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 that are driven by the different input shafts
respectively.
4. The double-clutch transmission device according to claim 1,
comprising a park-lock.
5. The double-clutch transmission device according to claim 4,
wherein the park-lock comprises a fixed gearwheel on one of the
layshafts that has the pinion as a final drive.
6. The double-clutch transmission device according to claim 1,
further comprising: two pinions mounted on two of the layshafts
respectively.
7. The double-clutch transmission device according to claim 1,
wherein at least two of the first gear idler gearwheel, the second
gear idler gearwheel, and the third gear idler gearwheel are
mounted on the same layshaft.
8. The double-clutch transmission device according to claim 1,
wherein at least two of the fourth gear idler gearwheel, the fifth
gear idler gearwheel, 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 the pinion.
10. The double-clutch transmission according to claim 8, wherein at
least one of the bearings is provided next to one of the driven
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 disc connected to the inner
input shaft and a second clutch disc connected to the outer input
shaft; a first layshaft, a second layshaft and a third layshaft
spaced apart from the input shafts and arranged in parallel to the
input shafts; at least one of the layshafts comprises a pinion;
gearwheels arranged on the first layshaft, on the second layshaft,
on the third layshaft, on the inner input shaft and on the outer
input shaft, the gearwheels comprising a first gearwheel group, a
second gearwheel group, a third gearwheel group, a fourth gearwheel
group, a fifth gearwheel group, a sixth gearwheel group, a seventh
gearwheel group for providing seven sequentially increasing forward
gears, the first gearwheel group comprising a first fixed gearwheel
on the outer input shaft, meshing with a first gear idler gearwheel
on one of the layshafts for providing a first forward gear, the
third gearwheel group comprising a third driving gearwheel on the
outer input shaft, meshing with a third driven gearwheel on one of
the layshafts for providing a third forward gear, the fifth
gearwheel group comprising a fifth fixed gearwheel on the outer
input shaft, meshing with a fifth gear idler gearwheel on one of
the layshafts for providing a fifth forward gear, the seventh
gearwheel group comprising a seventh fixed gearwheel on the outer
input shaft, meshing with a seventh gear idler gearwheel on one of
the layshafts for providing a seventh forward gear, the second
gearwheel group comprising a second fixed gearwheel on the inner
input shafts, meshing with a second gear idler gearwheel on one of
the layshafts for providing a second forward gear, the fourth
gearwheel group comprising a fourth fixed gearwheel on the inner
input shafts, meshing with a fourth gear idler gearwheel on one of
the layshafts for providing a fourth forward gear, the sixth
gearwheel group comprising a sixth fixed gearwheel on the inner
input shafts, meshing with a sixth gear idler gearwheel on one of
the layshafts for providing a sixth forward gear, 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 third fixed gearwheel
further meshing with the fifth gear idler gearwheel, wherein the
gearwheels further comprises a reverse gearwheel group that
comprises a reverse 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, the reverse gearwheel group further
comprises a coupling device on one of the layshafts to engage the
reverse gear idler gearwheel for providing the reverse gear, the
second fixed gearwheel further meshes with the fourth gear idler
gearwheel; and an output gearwheel on an output shaft that meshes
with the pinion for outputting a drive torque to a torque
drain.
12. A power train device, comprising: an inner input shaft and an
outer input shaft, at least a portion of the inner input shaft
surrounded by the outer input shaft; a first clutch disc connected
to the inner input shaft and a second clutch disc connected to the
outer input shaft; a first layshaft, a second layshaft and a third
layshaft spaced apart from the input shafts and arranged in
parallel to the input shafts; at least one of the layshafts
comprises a pinion; gearwheels arranged on the first layshaft, on
the second layshaft, on the third layshaft, on the inner input
shaft and on the outer input shaft, the gearwheels comprising a
first gearwheel group, a second gearwheel group, a third gearwheel
group, a fourth gearwheel group, a fifth gearwheel group, a sixth
gearwheel group, a seventh gearwheel group for providing seven
sequentially increasing forward gears, the first gearwheel group
comprising a first fixed gearwheel on the outer input shaft,
meshing with a first gear idler gearwheel on one of the layshafts
for providing a first forward gear, the third gearwheel group
comprising a third driving gearwheel on the outer input shaft,
meshing with a third driven gearwheel on one of the layshafts for
providing a third forward gear, the fifth gearwheel group
comprising a fifth fixed gearwheel on the outer input shaft,
meshing with a fifth gear idler gearwheel on one of the layshafts
for providing a fifth forward gear, the seventh gearwheel group
comprising a seventh fixed gearwheel on the outer input shaft,
meshing with a seventh gear idler gearwheel on one of the layshafts
for providing a seventh forward gear, the second gearwheel group
comprising a second fixed gearwheel on the inner input shafts,
meshing with a second gear idler gearwheel on one of the layshafts
for providing a second forward gear, the fourth gearwheel group
comprising a fourth fixed gearwheel on the inner input shafts,
meshing with a fourth gear idler gearwheel on one of the layshafts
for providing a fourth forward gear, the sixth gearwheel group
comprising a sixth fixed gearwheel on the inner input shafts,
meshing with a sixth gear idler gearwheel on one of the layshafts
for providing a sixth forward gear, 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 third fixed gearwheel further
meshing with the fifth gear idler gearwheel, wherein the gearwheels
further comprises a reverse gearwheel group that comprises a
reverse 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, the reverse gearwheel group further comprises a
coupling device on one of the layshafts to engage the reverse gear
idler gearwheel for providing the reverse gear, the second fixed
gearwheel further meshes with the fourth gear idler gearwheel; and
an output gearwheel on an output shaft that meshes with the pinion
for outputting a drive torque to a torque drain; and at least one
power source for generating a driving torque.
13. The power train device according to claim 12, wherein the power
source comprises a combustion engine.
14. The power train device according to 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/EP2009/002356, filed Mar. 31, 2009, which was published under
PCT Article 21(2) and which claims priority to European Application
No. 08006645.9, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006638.4, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006639.2, filed Mar.
31, 2008, and which claims priority to European Application No.
08006640.0, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006641.8, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006642.6, filed Mar.
31, 2008, and which claims priority to European Application No.
08006635.0, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006643.4, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006644.2, filed Mar.
31, 2008, and which claims priority to European Application No.
08006486.8, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006606.1, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006607.9, filed Mar.
31, 2008, and which claims priority to European Application No.
08006608.7, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006646.7, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006616.7, filed Mar.
31, 2008, and which claims priority to European Application No.
08006617.8, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006609.5, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006610.3, filed Mar.
31, 2008, and which claims priority to European Application No.
08006611.1, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006612.9, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006621.0, filed Mar.
31, 2008, and which claims priority to European Application No.
08006622.8, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006623.6, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006624.4, filed Mar.
31, 2008, and which claims priority to European Application No.
08006569.1, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006637.6, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006615.2, filed Mar.
31, 2008, and which claims priority to European Application No.
08006636.8, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006625.1, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006626.9, filed Mar.
31, 2008, and which claims priority to European Application No.
08006627.7, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006628.5, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006629.3, filed Mar.
31, 2008, and which claims priority to European Application No.
08006630.1, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006631.9, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006619.4, filed Mar.
31, 2008, and which claims priority to European Application No.
08006620.2, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006618.6, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006614.5, filed Mar.
31, 2008, and which claims priority to European Application No.
08006613.7, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006634.3, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006633.5, filed Mar.
31, 2008, and which claims priority to European Application No.
08006632.7, filed Mar. 31, 2008, and which claims priority to
European Application No. 08006649.1, filed Mar. 31, 2008, and which
claims priority to European Application No. 08006648.3, filed Mar.
31, 2008, and which claims priority to European Application No.
08006647.5, filed Mar. 31, 2008, which are all hereby incorporated
in their entirety by reference.
TECHNICAL FIELD
[0002] The present application relates to a double-clutch
transmission for vehicles, such as cars.
BACKGROUND
[0003] A double-clutch transmission comprises two input shafts that
are connected to and actuated by two clutches separately. The two
clutches are often combined into a single device that permits
actuating any of the two clutches at a time. The two clutches
transmit driving torque from an engine to the two input shafts of
the double-clutch transmission.
[0004] U.S. Pat. No. 6,634,247 B2 discloses a six-gear double
clutch transmission with an electric unit. The double clutch
transmission has not been widely used in the cars for street
driving. Problems that hinder the wide application of double clutch
transmissions comprise of providing a compact, reliable and
fuel-efficient double clutch transmission. Therefore, there exists
a need for providing such a double clutch transmission that is also
affordable by consumers.
SUMMARY
[0005] The present application provides a double-clutch
transmission that comprises an inner input shaft and an outer input
shaft. The outer input shaft surrounds a portion of the inner input
shaft. The outer input shaft surrounds the inner input shaft in a
radial direction. The radial direction indicates regions that
surround a longitudinal axis of the inner input shaft. The outer
input shaft can be a hollow input shaft and the inner input shaft
can be a solid input shaft. Alternatively, the inner input shaft
can also be a hollow input shaft.
[0006] A first clutch disc is non-rotatably connected to the inner
input shaft and a second clutch disc 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] The DCT has a first layshaft, a second layshaft and a third
layshaft that are spaced apart from the input shafts and arranged
in parallel to the input shafts. That is, longitudinal axes of
these shafts are parallel to each other, including overlapping
axes. One of more of the layshafts comprises a pinion as a final
drive. The pinion can mesh with an output gear wheel on an output
shaft 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 a 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 first layshaft, on
the second layshaft, on the third layshaft, on the inner input
shaft and on the outer input shaft. 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, a seventh gearwheel group for providing seven
sequentially increasing forward gears. A gear of the DCT can refer
to an output speed of the output gear wheel. 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 a first gear to a seventh gear.
Gear ratios of the DCT decrease from the first gear to the seventh
gear correspondingly. For example, in a car having a DCT of seven
gears, 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 0.32:1. The seven gears provide an
increasing order of output speeds of the transmission for driving a
car with the DCT.
[0009] The first gearwheel group comprises a first fixed gearwheel
on the outer input shaft, meshing with a first gear idler gearwheel
on one of the layshafts for providing a first forward gear. The
third gearwheel group comprises a third fixed gearwheel on the
outer input shaft, meshing with a third idler gearwheel on one of
the layshafts for providing a third forward gear. The fifth
gearwheel group comprises a fifth fixed gearwheel on the outer
input shaft, meshing with a fifth gear idler gearwheel on one of
the layshafts for providing a fifth forward gear. The seventh
gearwheel group comprises a seventh fixed gearwheel on the outer
input shaft, meshing with a seventh gear idler gearwheel on one of
the layshafts for providing a seventh forward gear.
[0010] The second gearwheel group comprises a second fixed
gearwheel on the inner input shafts, meshing with a second gear
idler gearwheel on one of the layshafts for providing a second
forward gear. The fourth gearwheel group comprises a fourth fixed
gearwheel on the inner input shafts, meshing with a fourth gear
idler gearwheel on one of the layshafts for providing a fourth
forward gear. The sixth gearwheel group comprises a sixth fixed
gearwheel on the inner input shafts, meshing with a sixth gear
idler gearwheel on one of the layshafts for providing a sixth
forward gear.
[0011] One or more gearwheel groups comprises 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. The third
fixed gearwheel further meshes with the fifth gear idler
gearwheel.
[0012] Especially, the gearwheels further comprises a reverse
gearwheel group that comprises a reverse 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. The reverse
gearwheel group further comprises a coupling device on one of the
layshafts to engage the reverse gear idler gearwheel for providing
the reverse gear. The second fixed gearwheel further meshes with
the fourth 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 or different clutches
respectively. One double meshing feature is provided by the third
fixed gearwheel that meshes with the third gear idler gearwheel and
the fifth gear idler gearwheel. Another double meshing feature is
provided by the second fixed gearwheel that meshes with the second
gear idler gearwheel and the fourth 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] In the application, the first forward gear and the reverse
gear can be provided by the 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.
[0015] In the application, the DCT can comprise a second reverse
gearwheel group that comprises a fixed gearwheel on one of the
input shafts, meshing 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 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] The reverse gearwheel group can provide a first reverse gear
and a second reverse gear that are driven by the different input
shafts respectively. 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. 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.
[0017] The double-clutch transmission device can comprise a
park-lock. The park-lock can comprise a fixed gearwheel on one of
the layshafts that has the pinion as a final drive. 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.
[0018] The double-clutch transmission device can comprise two
pinions that are mounted on two of the layshafts respectively. The
two pinions 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.
[0019] According to the application, two or more of the first gear
idler gearwheel, the second gear idler gearwheel, and the third
gear idler gearwheel are mounted on the same layshaft. Putting
idler gearwheels of low gears, such as idler gearwheels of the
first, second and third gears, on the same shaft require the
layshaft to be strong and sturdy. Remaining layshafts of the
double-clutch transmission can thus be made slim at low cost for
carrying gearwheels of high gears, except the layshaft carrying
reverse gear idler gearwheel. For example, two or more the fourth
gear idler gearwheel, the fifth gear idler gearwheel, the sixth
gear idler gearwheel and the seventh gear idler gearwheel are
mounted on the same layshaft.
[0020] The double-clutch transmission can further comprise bearings
for supporting the layshafts. One or more of the bearings is
provided next to the pinion. The pinion that outputs torque of its
carrying layshaft is better supported by immediately adjacent
bearing for reducing deflection the layshaft under load. The
supporting bearing thus can improve torque transmission efficiency
and reduce cost of the DCT.
[0021] One or more the bearings are provided next to one of the
driven 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.
[0022] In the application, these can be a gearbox that comprises
the double-clutch transmission and an output gearwheel on an output
shaft. The output gearwheel meshes with the pinion for outputting a
drive torque to a torque drain. The output gearwheel can even 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.
[0023] The application provides a power train device with the
gearbox. One or more of power source generates 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.
[0024] 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.
[0025] The power source can comprise an electric motor. Electric
motor used in a hybrid car, or in an electrical car enables
reduction of pollution, as compared to typical combustion using
petrol. The electric motor can even recuperate brake energy in a
generator mode.
[0026] The application also provides 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
[0027] The present invention will hereinafter be described in
conjunction with the following drawing figures, wherein like
numerals denote like elements, and
[0028] FIG. 1 illustrates a front view of a first embodiment of a
double clutch transmission of the application;
[0029] FIG. 2 illustrates the path of torque flow of a first gear
transmission ratio;
[0030] FIG. 3 illustrates the path of torque flow of a second gear
transmission ratio;
[0031] FIG. 4 illustrates the path of torque flow of a third gear
transmission ratio;
[0032] FIG. 5 illustrates the path of torque flow of a fourth gear
transmission ratio;
[0033] FIG. 6 illustrates the path of torque flow of a fifth gear
transmission ratio;
[0034] FIG. 7 illustrates the path of torque flow of a sixth gear
transmission ratio;
[0035] FIG. 8 illustrates the path of torque flow of a seventh gear
transmission ratio;
[0036] FIG. 9 illustrates the path of torque flow of a first
reverse gear transmission ratio;
[0037] FIG. 10 illustrates the path of torque flow of a second
reverse gear transmission ratio;
[0038] FIG. 11 illustrates an assembly of a double-sided coupling
device with its neighboring gearwheels for engagement;
[0039] FIG. 12 illustrates an assembly of a single-sided coupling
device with its neighboring gearwheel for engagement;
[0040] FIG. 13 illustrates an assembly of an idler gearwheel that
is rotatably supported by a shaft on a bearing;
[0041] FIG. 14 illustrates an assembly of a fixed gearwheel that is
supported on a shaft;
[0042] FIG. 15 illustrates a cross-section through a detail of a
crankshaft of an internal combustion engine according to embodiment
of the double-clutch transmission;
[0043] FIG. 16 illustrates a front view of a further embodiment of
a double clutch transmission of the application;
[0044] FIG. 17 illustrates an expanded side view of the double
clutch transmission of FIG. 16;
[0045] FIG. 18 illustrates a front view of a further embodiment of
a double clutch transmission of the application;
[0046] FIG. 19 illustrates an expanded side view of the double
clutch transmission of FIG. 18;
[0047] FIG. 20 illustrates a front view of a further embodiment of
a double clutch transmission of the application;
[0048] FIG. 21 illustrates an expanded side view of the double
clutch transmission of FIG. 20;
[0049] FIG. 22 illustrates an alternative expanded side view of the
double clutch transmission of FIG. 16; and
[0050] FIG. 23 illustrates an alternative front view of a further
embodiment of a double clutch transmission in FIG. 19.
DETAILED DESCRIPTION
[0051] The following detailed description is merely exemplary in
nature and is not intended to limit or the application and uses.
Furthermore, there is no intention to be bound by any theory
presented in the preceding background or summary or the following
detailed description.
[0052] In the following description, details are provided to
describe the embodiments of the application. It shall be apparent
to one skilled in the art, however, that the embodiments may be
practiced without such details.
[0053] FIGS. 1-15 provide detailed description of an embodiment of
a double clutch transmission (DCT) of the application. FIGS. 1-15
comprise similar parts that have similar reference numbers.
Relevant description of the similar parts is incorporated where
necessary.
[0054] FIG. 1 illustrates a front view of an embodiment of a double
clutch transmission 1 of the application. The DCT 1 comprises a
reverse pinion 55 on a reverse gear shaft 38, a relatively large
output gearwheel 12 on an output shaft 14, an upper pinion 41 on an
upper layshaft 40, an inner input shaft 20 inside an outer input
shaft 22, and a lower pinion 51 on a lower layshaft 50. The inner
input shaft 20 is a solid input shaft 20 (i.e. K1) and the outer
input shaft is a hollow input shaft 22 (i.e. K2). The solid input
shaft 20 and the hollow input shaft 22 share the same longitudinal
axis of rotation. The three pinions 41, 51, 55 are fixed to right
ends of the upper layshaft 40, the lower layshaft 50 and the
reverse gear shaft 38 respectively. The output gearwheel 12 is also
fixed to the output shaft 14 along its longitudinal axis. The three
pinions 41, 51, 55 mesh with the output gearwheel 12 separately at
different positions of the output gearwheel 12.
[0055] The reverse gear shaft 38, the upper layshaft 40, and the
lower layshaft 50 are parallel to the coaxial input shafts 20, 22
with predetermined distances in-between. The distances are provided
in radial directions of these shafts respectively, which is better
seen in FIG. 2. Other gearwheels are mounted on these shafts that
mesh with each other according to predetermined manners. These
manners are better seen in some of the following figures.
[0056] 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 10. The cutting plane A-A passes through the rotational
axes of the reverse gear shaft 38, the upper layshaft 40, the input
shafts 20, 22, the lower layshaft 50, and the output shaft 14. One
of the goals of FIGS. 2 to 10 is to further illustrate structure
and torque flows of the DCT 1.
[0057] FIG. 2 illustrates the expanded view of the DCT that shows
the manners of the gearwheels mounting, which corresponds to FIG.
1.
[0058] According to FIG. 2, the DCT 1 comprises the following
shafts, from top to bottom, the reverse gear shaft 38, the upper
layshaft 40, the hollow input shaft 22, the solid input shaft 20,
the lower layshaft 50, and the output shaft 14. The solid input
shaft 20 is partially disposed inside the hollow input shaft 22.
The solid input shaft 20 also protrudes outside the hollow input
shaft 22 at two ends. The hollow input shaft 22 is mounted onto the
solid input shaft 20 by a pair of solid shaft bearings 71 that are
disposed between the solid input shaft 20 and the hollow input
shaft 22 at two ends of the hollow input shaft 22. As a result, the
two input shafts 20, 22 are coupled together such that the solid
input shaft 20 is free to rotate inside the hollow input shaft 22.
The hollow input shaft 22 surrounds a right portion of the solid
input shaft 20, and a left portion of the solid input shaft 20 is
exposed outside the hollow input shaft 22. The assembly of the
input shafts 20, 22 is supported by the solid shaft bearing 71 at a
protruding end of the solid shaft 20 on the left and by the hollow
shaft bearing 72 on the hollow input shaft 22 on the right.
[0059] 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 solid input shafts 20. The radial direction is perpendicular to
the common longitudinal axes of the input shafts 20, 22. There are
two gearwheels fixed on the left exposed portion of the solid input
shaft 20. These gearwheels are a fixed wheel second gear 30 and a
fixed wheel sixth gear 32 from right to left sequentially. The
fixed wheel second gear 30 also serves as a fixed wheel fourth gear
31. Each of the fixed wheel second gear 30 and the fixed wheel
sixth gear 32 is mounted onto the solid input shaft 20 coaxially.
On the hollow input shaft 22, which is mounted on the right portion
of the solid input shaft 20, there are attached with a fixed wheel
third gear 25, a fixed wheel seventh gear 27, and a fixed wheel
first gear 24 from left to right. The fixed wheel third gear 25
also serves as a fixed wheel fifth gear 26. Each of the fixed wheel
third gear 25, the fixed wheel seventh gear 27, and the fixed wheel
first gear 24 is fixed onto the hollow input shaft 22
coaxially.
[0060] The upper layshaft 40 is provided above the input shafts 20,
22. There are gearwheels, coupling devices and bearings provided on
the upper layshaft 40, which includes, from right to the left, an
upper pinion 41, a layshaft bearing 73, a idler first gear 60, a
double-sided coupling device 80, a idler third gear 62, an idler
second gear 61, a single-sided coupling device 81, and a layshaft
bearing 73. The idler first gear 60, the idler third gear 62, and
the idler second gear 61 are mounted on the upper layshaft 40 by
bearings respectively such that these gearwheels are free to rotate
around the upper layshaft 40. The double-sided coupling device 80
can move along the upper layshaft 40 to engage any of the idler
first gear 60 and the idler third gear 62 to the upper layshaft 40.
Similarly, the single-sided coupling device 81 can move along the
upper layshaft 40 to engage the idler second gear 61 to the upper
layshaft 40. The idler first gear 60 meshes with the fixed wheel
first gear 24. The idler third gear 62 meshes with the fixed wheel
third gear 25. The idler second gear 61 meshes with the fixed wheel
second gear 30.
[0061] The reverse gear shaft 38 is provided further above the
upper layshaft 40. A reverse gear idler wheel 37, a double-sided
coupling device 84, a second reverse gear idler wheel 35 and a
park-lock gearwheel 39 are mounted onto the reverse gear shaft 38
at a left side of the reverse pinion 55 from right to left. One
idler shaft bearing 74 is mounted at a left end of the reverse gear
shaft 38 next to the park-lock gearwheel 39. Another idler shaft
bearing 74 is installed on the reverse gear shaft 38 between the
reverse gear idler wheel 37 and the reverse pinion 55. The reverse
gear idler wheel 37 and the second reverse gear idler wheel 35 are
mounted on the reverse gear idle shaft 38 by bearings such that the
reverse gear idler wheel 37 and the second reverse gear idler wheel
35 are free to rotate around the reverse gear shaft 38. The
park-lock gearwheel 39 is fixed onto the reverse gear shaft 38
coaxially. The reverse gear idler wheel 37 meshes with the idler
first gear 60. The second reverse gear idler wheel 35 meshes with
the idler second gear 61.
[0062] The park-lock gearwheel 39 comprises a park-lock on the
reverse gear shaft 38. The park-lock is the park-lock gearwheel 39
which is provided with a ratchet device, with a click device having
a rack element, a pawl or similar. The park-lock keeps the reverse
gear shaft 38, the reverse pinion 55 and the output shaft 14 from
rotating, which stops a vehicle with the DCT 1 from running when
parked. Detailed structure of the park-lock is not shown in FIG.
2.
[0063] The DCT 1 with the park-lock is controlled by a gearshift
lever located in a driving compartment and movable by a vehicle
operator between positions corresponding to transmission gear
ranges such as Park, Reverse, Neutral, Drive, and Low. A linear
actuation cable is attached at its first end to the gearshift
lever, and movement of the gearshift lever alternatively pushes or
pulls on the cable to move a transmission mode select lever
attached to the other end of the cable. The mode select lever is
mechanically connected to a shift valve within a DCT housing, and
movement of the shift valve effects shifting between different
gears.
[0064] When the gearshift lever is placed in the Park position, two
related mechanical actuations take place within the DCT 1. First,
the mode select lever is moved to disengage the input shafts 20, 22
from an engine. Second, the park-lock pawl is moved into locking
engagement with the park-lock gearwheel 39 on the reverse gear
shaft 38 to thereby lock the output shaft 14 against rotation. A
linear actuation cable that actuates the mode select lever moves
the lock pawl.
[0065] The lower layshaft 50 is provided below the input shafts 20,
22. There are a number of gearwheels, coupling devices and bearings
mounted on the lower layshaft 50, which include, from right to the
left, the lower pinion 51, a layshaft bearing 73, an idler seventh
gear 66, a double-sided coupling device 83, an idler fifth gear 64,
an idler fourth gear 63, a double-sided coupling device 82, an
idler sixth gear 65, and a layshaft bearing 73. The lower pinion 51
is fixed onto the lower layshaft 50 at its longitudinal axis. The
idler seventh gear 66, the idler fifth gear 64, the idler fourth
gear 63 and the idler sixth gear 65 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.
The double-sided coupling devices 83 can move along the lower
layshaft 50 such that it can engage either the idler seventh gear
66 or the idler fifth gear 64 to the lower layshaft 50. The
double-sided coupling device 82 can also move along the lower
layshaft 50 such that it can engage either the idler sixth gear 65
or the idler fourth gear 63 to the lower layshaft 50 respectively.
The idler seventh gear 66 meshes with the fixed wheel seventh gear
27. The idler fifth gear 64 meshes with the fixed wheel fifth gear
26. The idler fourth gear 63 meshes with the fixed wheel fourth
gear 31. The idler sixth gear 65 meshes with the fixed wheel sixth
gear 32.
[0066] In other words, there are four double-meshing features
provided in the DCT 1. A first double-meshing feature comprises
that the idler first gear 60 meshes with both the reverse gear
idler wheel 37 and the fixed wheel first gear 24. A second
double-meshing feature comprises that the fixed wheel third gear 25
meshes with both the idler third gear 62 and the idler fifth gear
64. A third double-meshing feature comprises that the fixed wheel
second gear 30 meshes with the idler second gear 61 and the idler
fourth gear 63. A fourth double meshing feature comprises that the
idler second gear 61 meshes with both the second reverse gear idler
wheel 35 and the fixed wheel second gear 30.
[0067] A distance 56 between the input shafts 20, 22 and the upper
layshaft 40 is measured from a common longitudinal axis of the
input shafts 20, 22 to a longitudinal axis of the upper layshaft
40. Similarly, a 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.
[0068] The output shaft 14 is further provided further below the
lower layshaft 50. Two output shaft bearings 75 are installed at
two opposite ends of the output shaft 14 respectively for
supporting. The output gearwheel 12 is fixed onto the output shaft
14 coaxially in the middle. The output gearwheel 12 meshes with the
reverse pinion 55, the lower pinion 51 and the upper pinion 41.
[0069] 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" or "synchronizer" for
engaging or disengaging gearwheels on its carrying shaft. The
double-clutch transmission (DCT) is alternatively termed as a
double-clutch, a double clutch transmission or a dual clutch
transmission (DCT).
[0070] The fixed wheel first gear 24 is also known as the first
fixed gearwheel 24. The fixed wheel third gear 25 is also known as
the third fixed gearwheel 25. The fixed wheel fifth gear 26 is also
known as the fifth fixed gearwheel 26. The fixed wheel seventh gear
27 is also known as the seventh fixed gearwheel 27. The fixed wheel
second gear 30 is also known the second fixed gearwheel 30. The
fixed wheel fourth gear 31 is also known as the fourth fixed
gearwheel 31. The fixed wheel sixth gear 32 is also known as the
sixth fixed gearwheel 32. The second reverse gear idler wheel 35 is
also known as the second reverse idler gearwheel 35. The reverse
gear idler wheel 37 is also known as the reverse idler gearwheel
37. The idler first gear 60 is also known as the first 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 fixed 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 output gear wheel 12, the park-lock gearwheel 39,
the upper pinion 41, the lower pinion 51, the reverse pinion 55,
the fixed wheel first gear 24, the fixed wheel third gear 25, the
fixed wheel fifth gear 26, the fixed wheel seventh gear 27, the
fixed wheel second gear 30, the fixed wheel fourth gear 31, the
fixed wheel sixth gear 32 are also known as fixed gearwheels or
gear wheels. The upper pinion 41, the lower pinion 51, and the
reverse pinion 55 are alternatively known called final drive
pinions or final drives. The park-lock on the park-lock 39 can
alternatively be provided on any of the layshafts 38, 40, 50 that
has a final drive pinion. Any of the input shafts 20, 22 or
layshafts 38, 40, 50 can be supported by more than two
bearings.
[0071] In the drawings of the present application, dash lines
indicate either alternative positions of illustrated parts or
combing relationship between gearwheels.
[0072] 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
of 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.
[0073] 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 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 respectively in
a compact manner.
[0074] The application provides a compact structure of a parallel
transmission. The parallel transmission includes two input shafts
20, 22, each of which can be non-rotatably coupled to a shaft via
its own clutch 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.
[0075] The DCT 1 according to the application is particularly well
suited for transverse installation in front-wheel drive vehicles,
in which the front differential, for example, is positioned below
the pinions 41, 51, 55. A short overall length of the power train
for transmitting torques can be achieved.
[0076] The application provides at least three relatively small
pinions 41, 51, 55 on intermediately arranged layshafts 38, 40, 50
that comb with one relatively big output gearwheel 12. The output
gearwheel 12 in turn is fixed onto the output shaft 14. This
arrangement provides a compact and lightweight DCT 1.
[0077] The application further enables 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.
[0078] It is further not only of advantage to provide the even
gearwheels fixed onto one input shaft, but also fix the odd gears
onto 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 gear. For example,
the power-shift operation from the third gear to the fourth gear
causes the solid input shaft 20 and the hollow input shaft 22 being
engaged alternatively, which is energy efficient and fast.
[0079] Some idler gearwheels of the low gears (e.g. 1st, 2nd, &
3rd gears) provided on the same layshaft are advantageous. In FIG.
2, the idler first gear 60, the idler second gear 61, and the idler
third gear 62 are installed on the same upper layshaft 40. In
contrast, idler gearwheels of high gears (e.g. 4th, 5th, 6th, &
7th gears) provided on another layshaft. According to FIG. 2, the
idler fourth gear 63, the idler fifth gear 64, the idler sixth gear
65, and the idler seventh gear 66 are provided on the same lower
layshaft 40. The lower layshaft 50 has higher rotational speed with
smaller diameter for lower torque transmission, as compared to that
of the upper layshaft 40. This arrangement eliminates the need of
providing multiple layshafts with large size for carrying those
heavily duty idler gearwheels 60, 61, 62 of low gears (e.g. 1st,
2nd, & 3rd gears) on many shafts respectively. These
arrangements offer the feasibility of making the DCT 1 lightweight
and compact at less cost.
[0080] The layshaft bearings 73, 74 of the DCT 1 are next to the
pinions 38, 41, 51. The layshaft bearings 73, 74 offer strong
support to the pinions 38, 41, 51 carrying layshafts 38, 40, 50 for
reducing unwanted shaft deflection. Excessive shaft deflection can
lower gear transmission efficiency or cause gearwheels' early worn
out. The idler shaft bearings 74 next to the reverse gear idler
wheel 37 also provide strong support to the reverse gear shaft 38.
In a like manner, the output shaft bearings 75 at two opposite ends
of the output shaft 14 offer sturdy support to the output shaft
14.
[0081] In fact, it is also beneficial to provide the idler first
gear 60, the idler second gear 61, and the reverse gear idler wheel
37 close to the bearings 73, 74, 75 for supporting. As shown in
FIG. 2, the layshaft bearing 73 is immediately adjacent to the
idler first gear 60 for giving strong support to the upper layshaft
40. The pinions 38, 41, 51 and especially these gearwheels of low
gears (e.g. 1st and 2nd gears) undergo heavier load than those of
the higher gears (e.g. 6th & 7th gears) because their drive
ratio is higher for the lower gears and reverse gears. Therefore, a
carrying shaft of low gears (e.g. upper layshaft 40) must take up
stronger driving torques and carry heavier gearwheels with larger
sizes. If those loads are taken up close to the supporting bearings
of the shafts, their load-carrying shafts' bending will be
reduced.
[0082] 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 hollow input shaft 22 from the double-clutch 6 of the DCT 1.
A torque of the first gear is transmitted from the hollow input
shaft 22, via the fixed wheel first gear 24, via the idler first
gear 60, via the double-sided coupling device 80, via the upper
layshaft 40, via upper pinion 41, via the output gearwheel 12, to
the output shaft 14. The double-sided coupling device 80 is engaged
the idler first gear 60 to the upper layshaft 40 when transmitting
the torque of the first gear, which provides the first gear of the
DCT 1. The number of tooth engagements or engaged gear pairs for
the torque transfer of the first gear is two.
[0083] 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 solid input shaft 20 from the double-clutch 6 of
the DCT 1. A torque of the second gear is transmitted from the
solid input shaft 20, via the fixed wheel second gear 30, via the
idler second gear 61, via the single-sided coupling device 81, via
the upper layshaft 40, via the upper pinion 41, via the output
gearwheel 12, to the output shaft 14. The single-sided coupling
device 81 engages the idler second gear 61 to the upper layshaft 40
when transmitting the torque of the second gear, which provides the
second gear of the DCT 1. The number of tooth engagements or
engaged gear pairs for the torque transfer of the second gear is
two.
[0084] 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 hollow input shaft 22 from the double-clutch of the
DCT 1. A torque of the third gear is transmitted from the hollow
input shaft 22, via the fixed wheel third gear 25, via the idler
third gear 62, via the double-sided coupling device 80, via the
upper layshaft 40, via the upper pinion 41, via the output
gearwheel 12, to the output shaft 14. The double-sided coupling
device 80 engages the idler wheel third gear 62 to the upper
layshaft 40 when transmitting the torque of the third gear, which
provides the third gear of the DCT 1. The number of tooth
engagements or engaged gear pairs for the torque transfer of the
third gear is two.
[0085] 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 solid input shaft 20 from the double-clutch 6 of
the DCT 1. A torque of the fourth gear is transmitted from the
solid input shaft 20, via the fixed wheel fourth gear 31, via the
idler fourth gear 63, via the double-sided coupling device 82, via
the lower layshaft 50, via the lower pinion 51, via the output
gearwheel 12, to the output shaft 14. The double-sided coupling
device 82 engages the idler fourth gear 63 to the lower layshaft 50
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.
[0086] 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 hollow input shaft 22 from the double-clutch 6 of the DCT 1.
A torque of the fifth gear is transmitted from the hollow input
shaft 22, via the fixed wheel fifth gear 26, via the idler fifth
gear 64, via the double-sided coupling device 83, via the lower
layshaft 50, via the lower pinion 51, via the output gearwheel 12,
to the output shaft 14. The double-sided coupling device 83 engages
the idler fifth gear 64 to the lower layshaft 50 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.
[0087] 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 solid input shaft 20 from the double-clutch 6 of the DCT 1.
A torque of the sixth gear is transmitted from the solid input
shaft 20, via the fixed wheel sixth gear 32, via the idler sixth
gear 65, via the double-sided coupling device 82, via the lower
layshaft 50, via the lower pinion 41, via the output gearwheel 12,
to the output shaft 14. The double-sided coupling device 82 engages
the idler sixth gear 65 to the lower layshaft 50 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.
[0088] 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 hollow input shaft 22 from the double-clutch 6
of the DCT 1. A torque of the seventh gear is transmitted from the
hollow input shaft 22, via the fixed wheel seventh gear 27, via the
idler seventh gear 66, via the double-sided coupling device 83, via
the lower layshaft 50, via the lower pinion 51, via the output
gearwheel 12, to the output shaft 14. The double-sided coupling
device 83 engages the idler seventh gear 66 to the lower layshaft
50 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.
[0089] FIG. 9 illustrates the path of torque flow of a first
reverse gear transmission ratio. In FIG. 9, an input torque of the
first 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 hollow input
shaft 22 from the double-clutch 6 of the DCT 1. A torque of the
first reverse gear is transmitted from the hollow input shaft 22,
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 84, via the reverse gear idle shaft 38, via the reverse
pinion 55, via the output gearwheel 12, to the output shaft 14. The
double-sided coupling device 84 engages the reverse gear idler
wheel 37 to the reverse gear idle shaft 38 when transmitting the
torque of the first reverse gear, which provides the first reverse
gear of the DCT 1. The number of tooth engagements or engaged gear
pairs for the torque transfer of the first reverse gear is
three.
[0090] Alternative paths for transmitting some of the
above-mentioned torque flow paths of the DCT 1 are possible to be
provided.
[0091] FIG. 10 illustrates the path of torque flow of a second
reverse gear transmission ratio, which provides an alternative to
the first reverse gear. In FIG. 10, a second reverse gear idler
wheel 36 and a single-sided coupling device 85 have been added onto
the reverse gear idle shaft 38 at its left end. The second reverse
gear idler wheel 36 meshes with the idler sixth gear 65. In FIG.
10, an input torque of the second reverse gear is received from the
crankshaft 2 of a combustion engine (not shown). According to FIG.
10, the input torque of the second reverse gear is received by the
solid input shaft 20 from the double-clutch 6 of the DCT 1. A
torque of the second reverse gear is transmitted from the solid
input shaft 20, via the fixed wheel second gear 30, via the idler
second gear 61, via the second reverse gear idler wheel 35, via the
double-sided coupling device 84, via the reverse gear idle shaft
38, via the reverse pinion 55, via the output gearwheel 12, to the
output shaft 14. The double-sided coupling device 84 engages the
second reverse gear idler wheel 35 to the reverse gear shaft 38
when transmitting the torque of the second reverse gear, which
provides the second reverse gear of the DCT 1. The number of tooth
engagements or engaged gear pairs for the torque transfer of the
second reverse gear is three.
[0092] FIG. 11 illustrates an assembly 100 of a double-sided
coupling device 102 with its neighboring gearwheels 101, 103 for
engagement. The assembly 100 comprises a shaft 104 with the two
coaxially mounted idler gears 101, 103 on two bearings
respectively. The coupling device 102 is provided between the idler
gear 101 on the left and the idler gear 103 on the right. The
coupling device 102 is configured to move along the shaft 104 to
selectively engage any of the idler gears 101, 103 at one time. In
other words, the idler gears 101, 103 can alternatively be brought
into non-rotating engagement with the shaft 104 by the coupling
device 102. Symbols for showing the assembly 100 is provided at the
right hand side of FIG. 11.
[0093] FIG. 12 illustrates an assembly 110 of a single-sided
coupling device 112 with its neighboring gearwheel 113 for
engagement. The assembly 110 comprises a shaft 114 with the one
coaxially mounted idler gear 113 on a bearing. The coupling device
112 is provided next to the idler gear 113 on the left side. The
coupling device 112 is configured to move along the shaft 114 to
engage or disengage the idler gears 113. In other words, the idler
gear 113 can be brought into non-rotating engagement with the shaft
114 by the single-sided coupling device 112. Symbols for showing
the assembly 110 are provided at the right hand side of FIG.
12.
[0094] 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.
[0095] 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 131. 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.
[0096] A number of fixed gearwheels are rigidly connected to the
input shafts 20, 22 and other shafts 14, 38, 40, 50 in a manner
that is similar to the assembly 130. A symbol as used in the
previous figures for such a fixed gearwheel is provided on the left
side in FIG. 14. The more commonly used symbol for such a fixed
gearwheel is provided on the right side in FIG. 14.
[0097] FIG. 15 illustrates a cross-section through a detail of a
crankshaft 2 of an internal combustion engine according to the
embodiment of the DCT 1. According to FIG. 15, the crankshaft 2 of
the internal combustion engine, which is not shown here, is
non-rotatably connected to a housing 4 of a double clutch 6. The
double clutch 6 includes an inner clutch disc 8 and an outer clutch
disc 10, which can be brought into non-rotating engagement with the
housing 4 via control elements that are not illustrated here. The
solid input shaft 20 can be non-rotatably connected to the inner
clutch disc 8, and extends all the way through the hollow shaft 22.
Similarly, the hollow input shaft 22 can be non-rotatably connected
to the outer clutch disc 10. The inner clutch disc 8 is also known
as the inner clutch, whilst the outer clutch disc 10 is also known
as the outer clutch.
[0098] 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.
[0099] The above-mentioned nine torque flow paths not only provide
viable solutions to generate nine gears of the DCT 1, but also
offer possibilities of switching from one gear to another
efficiently. The gear switching can be achieved by switching
between the two input shafts, between gearwheels of a double
meshing feature, or in combination of both.
[0100] 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 hollow input shaft 22. The DCT 1 also can provide even gears
(i.e. 2nd, 4th & 6th gears) by driving the gearwheels of the
DCT 1 using the solid input shaft 20. Gear switching between the
odd and the even can simply be obtained by alternating between the
two input shafts 20, 22.
[0101] One double meshing feature provides efficient and fast gear
switching between gears of two driven gearwheels that comb with a
shared driving gearwheel. For example, the DCT 1 provides the
convenience of selecting the third gear or the fifth gear without
stopping their shared driving gearwheel, namely the fixed wheel
third gear 25. The selection can be achieved by engaging either the
driven idler third gear 62 or the driven idler fifth gear 64.
[0102] The double-meshing feature of the fixed wheel third gear 25
reduces the number of driving gearwheels, which is commonly engaged
by the driven gearwheels idler third gear 62 and the driven
gearwheel idler fifth gear 64. For example, the fixed wheel third
gear 25 and the fixed wheel fifth gear 26 as driving gear wheels
become one single gearwheel that is shared by the idler third gear
62 and the idler fifth gear 64. As a result, the number of
gearwheels on the hollow input shaft 22 has been reduced and less
space is required on the hollow input shaft 22 so that the DCT 1
can be made cheaper and lighter.
[0103] The other double-meshing feature of the fixed wheel fourth
gear 31 also reduces the number of driving gearwheels, which is
commonly engaged by the driven gearwheel idler second gear 61 and
the driven idler fourth gear 63. For example, the driving fixed
wheel fourth gear 31 and the driving fixed wheel second gear 30
become one single gearwheel that is shared by the idler fourth gear
63 and the idler second gear 61. As a result, the number of
gearwheels on the solid input shaft 20 has been reduced and less
space is required on the solid input shaft 20 so that the DCT 1 can
be made cheaper and lighter.
[0104] The park-lock gearwheel 39 comprises a park-lock on the
reverse gear shaft 38 that carries a final drive pinion 55. 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 reverse gear shaft 38, the reverse pinion 55,
the output gear wheel 12, and the output shaft 14 from rotating,
which stops a vehicle with the DCT 1 from running when parked.
Detailed structure of the park-lock is not shown.
[0105] 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.
Examples of the less gear tooth engagement are provided in FIGS.
2-10.
[0106] The DCT 1 drives the gearwheel groups of the first gear and
the second reverse gear by different input shafts 20, 22. A vehicle
with the DCT 1 can move between a slow forward mode and a slow
backward mode by engaging and disengaging the respective clutch
discs 8, 10, which are connected to the two input shafts 20, 22
respectively. The DCT 1 enables the vehicle to move back and forth
quickly with little loss of the transmission power or gearwheels
momentum. This scheme helps in many situations in which a wheel of
the vehicle 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. Alternatively, the
vehicle cam move back and forth by switching between the second
forward gear and the first reverse gear.
[0107] The DCT 1 provides two reveres gears so that a vehicle can
be maximized in engine output capacity. The DCT 1 can also be more
fuel efficient when having the two reverse gears. The DCT 1 with
the two reverse gears is especially useful for maneuverability of
some specialized vehicles, such as main battle tanks.
[0108] Moreover, the fact that two reverse gears are provided by
two different input shafts respectively are convenient because any
of the two reverse gears can be swiftly chosen by engaging one of
the clutch discs 8, 10 of the DCT 1.
[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
labeled with the same or similar part reference number.
Descriptions related to the similar parts are hereby incorporated
by reference.
[0110] FIG. 16 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
shaft 38, a solid input shaft 20, and a hollow output shaft 22 are
provided in parallel with the layshafts 40, 50. In some variants of
the application, at least one a further layshaft with a further
pinion can be provided but this is not shown here. Such a further
pinion would then also mesh or comb with the output gearwheel
12.
[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.
[0112] FIG. 17 illustrates a simplified cross-section through the
double clutch transmission gearbox 1 of FIG. 16. It illustrates
structure and various torque flows for the several gears of the
double clutch transmission gearbox 1.
[0113] The double clutch transmission gearbox 1 comprises the
following shafts, from top to bottom, the reverse gear shaft 38,
the upper layshaft 40, the solid input shaft 20, the hollow shaft
22, the lower layshaft 50 and the output shaft 14.
[0114] 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 both ends.
[0115] 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 serve also as solid shaft bearing 71, a fixed wheel second
gear 30, which serves also as a fixed wheel fourth gear 31, a fixed
wheel sixth gear 32, and a solid shaft bearing 71.
[0116] The hollow input shaft 22 comprises, from the right end to
the left end, a hollow shaft bearing 72, a fixed wheel first gear
24, a fixed wheel seventh gear 27, and a fixed wheel third gear 25,
which serves also as a fixed wheel fifth gear 26.
[0117] The upper layshaft 40 comprises, from the right end to the
left end, the upper pinion 41, a layshaft bearing 73, an idler
first gear 60, an attached idler first gear 60' which is attached
to the idler first gear 60, a double-sided coupling device 80, an
idler third gear 62, an idler second gear 61, a single-sided
coupling device 81, a park-lock gearwheel 39, and a layshaft
bearing 73. The idler first gear 60 meshes with the fixed wheel
first gear 24. The idler third gear 62 meshes with the fixed wheel
third gear 25. The idler second gear 61 meshes with the fixed wheel
second gear 30. The double-sided coupling device 80 is configured
to move the along the upper layshaft 40 for engaging either
attached idler first gear 60' or the idler third gear 62 to the
upper layshaft 40. The single-sided coupling device 81 is also
configured to move along the upper layshaft 40 for engaging or
disengaging the idler second gear 61 to the 40.
[0118] The reverse gear shaft 38 comprises, from the right end to
the left end, the reverse pinion 55, a reverse gear idler wheel 37,
a double-sided coupling device 85, a second reverse gear wheel 36
as an idler, and an idle shaft bearing 74. The reverse gear idler
wheel 37 meshes with the attached idler first gear 60'.
[0119] The lower layshaft 50 comprises, from the right end to the
left end, the lower pinion 51, a layshaft bearing 73, an idler
seventh gear 66, a double-sided coupling device 83, an idler fifth
gear 64, an idler fourth gear 63, a double-sided coupling device
82, an idler sixth gear 65, and a layshaft bearing 73. The idler
seventh gear 66 meshes with the fixed wheel seventh gear 27. The
idler fifth gear 64 meshes with the fixed wheel fifth gear 26. The
idler fourth gear 63 meshes with the fixed wheel fourth gear 31.
The idler sixth gear 65 meshes with both the second reverse gear
wheel 36 and the second reverse gear wheel 36.
[0120] Torque flow of the first gear according to FIG. 17 starts
from the hollow input shaft 22, via the fixed wheel first gear 24,
via the idler first gear 60, via the attached idler first gear 60',
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.
[0121] Torque flow of the second gear according to FIG. 17 starts
from the solid input shaft 20, via the fixed wheel second gear 30,
via the idler second gear 61, via the single-sided coupling device
81, via the upper layshaft 40, via the upper pinion 41, via the
output gear wheel 12, to the output shaft 14.
[0122] Torque flow of the third gear according to FIG. 17 starts
from the hollow input shaft 22, via the fixed wheel third gear 25,
via the idler third gear 62, via the double-sided coupling device
80, via the upper layshaft 40, via the upper pinion 41, via the
output gear wheel 12, to the output shaft 14.
[0123] Torque flow of the fourth gear according to FIG. 17 starts
from the solid input shaft 20, via the fixed wheel fourth gear 31,
via the idler fourth gear 63, via the double-sided coupling device
82, via the lower layshaft 50, via the lower pinion 51, via the
output gear wheel 12, to the output shaft 14.
[0124] Torque flow of the fifth gear according to FIG. 17 starts
from the hollow input shaft 22, via the fixed wheel fifth gear 26,
via the idler fifth gear 64, via the double-sided coupling device
83, via the lower layshaft 50, via the lower pinion 51, via the
output gear wheel 12, to the output shaft 14.
[0125] Torque flow of the sixth gear according to FIG. 17 starts
from the solid input shaft 20, via the fixed wheel sixth gear 32,
via the idler sixth gear 65, via the double-sided coupling device
82, via the lower layshaft 50, via the lower pinion 51, via the
output gear wheel 12, to the output shaft 14.
[0126] Torque flow of the seventh gear according to FIG. 17 starts
from the hollow input shaft 22, via the fixed wheel seventh gear
27, via the idler seventh gear 66, via the double-sided coupling
device 83, via the lower layshaft 50, via the lower pinion 51, via
the output gear wheel 12, to the output shaft 14.
[0127] Torque flow of the first reverse gear according to FIG. 17
starts from the hollow input shaft 22, via the fixed wheel first
gear 24, via the idler first gear 60, via the attached idler first
gear 60', via the reverse gear idler wheel 37, via the double-sided
coupling device 85, via the reverse gear layshaft 38, via the
reverse pinion 55, via the output gear wheel 12, to the output
shaft 14.
[0128] Torque flow of the second reverse gear according to FIG. 17
starts from the solid input shaft 20, via the fixed wheel sixth
gear 32, via the idler sixth gear 65, via the second reverse gear
wheel 36, via the double-sided coupling device 85, via the reverse
gear layshaft 38, via the reverse pinion 55, via the output gear
wheel 12, to the output shaft 14.
[0129] 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
labeled with the same or similar part reference number.
Descriptions related to the similar parts are hereby incorporated
by reference.
[0130] FIG. 18 shows a front view of the gearbox of the
application. A relatively big output gear wheel 12 on an output
shaft 14 meshes with a lower pinion 51 which is provided on a lower
layshaft 50. The output gearwheel 12 further meshes with an upper
pinion 41 which is provided on an upper layshaft 40. A reverse gear
idler shaft 38, a solid input shaft 20, a hollow input shaft 22 are
provided in parallel with the two layshafts 40, 50. In some
variants of the application, at least one a further layshaft with a
further pinion can be provided but this is not shown here. Such a
further pinion would then also mesh or comb with the output gear
wheel 12.
[0131] 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 structure and torque flows through the
embodiment of the gearbox 1.
[0132] 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.
[0133] The double clutch transmission gearbox 1 comprises the
following shafts, from top to bottom, the reverse gear idler shaft
38, the upper layshaft 40, the solid input shaft 20, the hollow
input shaft 22, the lower layshaft 50, and the output shaft 14.
[0134] The above-mentioned shafts are provided parallel to each
other at predetermined mutual distances inside gearbox 1. The
hollow shaft 22 is arranged concentrically around the solid input
shaft 20. The solid input shaft 20 protrudes outside the hollow
input shaft 22 at the right end.
[0135] 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 fourth
gear 31, which is at the same time a fixed wheel second gear 30, a
fixed wheel sixth gear 32, and a solid shaft bearing 71.
[0136] The hollow input shaft 20 comprises, from the right end to
the left end, a hollow shaft bearing 72, a fixed wheel first gear
24, a fixed wheel seventh gear 27, and a fixed wheel third gear 25
which is at the same time a fixed wheel fifth gear 26.
[0137] The upper layshaft 40 comprises, from the right end to the
left end, the upper pinion 41, a layshaft bearing 73, an idler
first gear 60, combing with the fixed wheel first gear 24, a
attached idler first gear 60' which is attached to the idler first
gear 60, a double-sided coupling device 80, an idler third gear 62,
combing with the fixed wheel third gear 25, an idler second gear
61, combing with the fixed wheel second gear 30, a single-sided
coupling device 81, a park-lock gearwheel 39, and a layshaft
bearing 73.
[0138] The lower layshaft 50 comprises, from the right end to the
left end, a lower pinion 51, a layshaft bearing 73, an idler
seventh gear 66, combing with the fixed wheel seventh gear 27, a
double-sided coupling device 83, an idler fifth gear 64, combing
with the fixed wheel fifth gear 26, an idler fourth gear 63,
combing with the fixed wheel fourth gear 31, a double-sided
coupling device 82, an idler sixth gear 65, combing with the fixed
wheel sixth gear 32, and a solid shaft bearing 71.
[0139] The reverse gear shaft 38 comprises, from the right end to
the left end, an idle shaft bearing 74, a reverse gear idler wheel
37, combing with the attached idler first gear 60', a second fixed
wheel reverse gear 35, combing with the fixed wheel reverse gear
34, and an idle shaft bearing 74.
[0140] Torque flow first gear according to FIG. 19 starts from the
hollow input shaft 22, via the fixed wheel first gear 24, via the
idler first gear 60, via the attached idler first gear 60' 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.
[0141] Torque flow second gear according to FIG. 19 starts from the
solid input shaft 20, via the fixed wheel second gear 30, via the
idler second gear 61, via the single-sided coupling device 81, via
the upper layshaft 40, via the upper pinion 41, via the output gear
wheel 12, to the output shaft 14.
[0142] Torque flow third gear according to FIG. 19 starts from the
hollow input shaft 22, via the fixed wheel third gear 25, via the
idler third gear 62, via the double-sided coupling device 80, via
the upper layshaft 40, via the upper pinion 41, via the output gear
wheel 12, to the output shaft 14.
[0143] Torque flow fourth gear according to FIG. 19 starts from the
solid input shaft 20, via the fixed wheel fourth gear 31, via the
idler fourth gear 63, via the double-sided coupling device 82, via
the lower layshaft 50, via the lower pinion 51, via the output gear
wheel 12, to the output shaft 14.
[0144] Torque flow fifth gear according to FIG. 19 starts from the
hollow input shaft 22, via the fixed wheel fifth gear 26, via the
idler fifth gear 64, via the double-sided coupling device 83, via
the lower layshaft 50, via the lower pinion 51, via the output gear
wheel 12, to the output shaft 14.
[0145] Torque flow sixth gear according to FIG. 19 starts from the
solid input shaft 20, via the fixed wheel sixth gear 32, via the
idler sixth gear 65, via the double-sided coupling device 82, via
the lower layshaft 50, via the lower pinion 51, via the output gear
wheel 12, to the output shaft 14.
[0146] Torque flow seventh gear according to FIG. 19 starts from
the hollow input shaft 22, via the fixed wheel seventh gear 27, via
the idler seventh gear 66, via the double-sided coupling device 83,
via the lower layshaft 50, via the lower pinion 51, via the output
gear wheel 12, to the output shaft 14.
[0147] Torque flow a reverse gear according to FIG. 19 starts from
the solid input shaft 20, via the fixed wheel reverse gear 34, via
the first reverse gear wheel 35, via the reverse gear idler shaft
38, via the single-sided coupling device 85, via the reverse gear
idler wheel 37, via the attached idler first gear 60' 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.
[0148] 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
labeled with the same or similar part reference number.
Descriptions related to the similar parts are hereby incorporated
by reference.
[0149] FIG. 20 shows a front view of the gearbox 1 of the
application. A relatively big output gear wheel 12 on an output
shaft 14 meshes with a lower pinion 51 which is provided on a lower
layshaft 50. The output gear wheel 12 further meshes with an upper
pinion 41 which is provided on an upper layshaft 40. The output
gear wheel 12 also 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.
[0150] FIG. 20 further comprises a cutting plane A-A for
illustrating the cross-section through the gearbox 1 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 structure and torque flows through the
embodiment of the gearbox 1.
[0151] FIG. 21 illustrates a simplified cross-section through the
double clutch transmission gearbox 1 of FIG. 20. It illustrates
structure and various torque flows for the several gears of the
double clutch transmission gearbox 1.
[0152] The double clutch transmission gearbox 1 comprises the
following shafts, from top to bottom, the reverse gear shaft 38,
the upper layshaft 40, the solid input shaft 20, the hollow input
shaft 22, the lower layshaft 50, and the output shaft 14. The
above-mentioned shafts are provided parallel to each other at
predetermined mutual distances inside gearbox 1. The hollow shaft
22 is arranged concentrically around the solid input shaft 20. The
solid input shaft 20 protrudes outside the hollow input shaft 22 at
its two ends.
[0153] 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 fourth
gear 31 which serves also as a fixed wheel second gear 30, a fixed
wheel sixth gear 32, and a solid shaft bearing 71.
[0154] The hollow input shaft 20 comprises, from the right end to
the left end, a hollow shaft bearing 72, a fixed wheel seventh gear
27, and a fixed wheel third gear 25, which also serves as a fixed
wheel fifth gear 26.
[0155] The upper layshaft 40 comprises, from the right end to the
left end, the upper pinion 41, a layshaft bearing 73, an idler
first gear 60, a double-sided coupling device 80, an attached idler
third gear 62', an idler third gear 62, combing with the fixed
wheel third gear 25, an idler second gear 61, combing with the
fixed wheel second gear 30, a single-sided coupling device 81, and
a layshaft bearing 73.
[0156] The reverse gear shaft 38 comprises, from the right end to
the left end, the reverse pinion 55, an idler shaft bearing 74, a
first reverse gear wheel 35 on the reverse gear hollow shaft 39,
combing with the idler first gear 60, a second reverse gear wheel
36 on the reverse gear hollow shaft 39, combing with the attached
idler third gear 62', a single-sided coupling device 85, and an
idler shaft bearing 74.
[0157] The lower layshaft 50 comprises, from the right end to the
left end, the lower pinion 51, a layshaft bearing 73, an idler
seventh gear 66, combing with the fixed wheel seventh gear 27, a
double-sided coupling device 83, an idler fifth gear 64, combing
with the fixed wheel fifth gear 26, an idler fourth gear 63,
combing with the fixed wheel fourth gear 31, a double-sided
coupling device 82, an idler sixth gear 65, combing with the fixed
wheel second gear 30, a 34, and a solid shaft bearing 71.
[0158] Torque flow first gear according to FIG. 21 starts from the
hollow input shaft 22, via the 25, via the idler third gear 62, via
the attached idler third gear 62', via the double-sided coupling
device 80, via the upper layshaft 40, via the upper pinion 41, via
the output gearwheel 12, to the output shaft 14.
[0159] Torque flow second gear according to FIG. 21 starts from the
solid input shaft 20, via the fixed wheel second gear 30, via the
idler second gear 61, via the single-sided coupling device 81, via
the upper layshaft 40, via the upper pinion 41, via the output
gearwheel 12, to the output shaft 14.
[0160] Torque flow third gear according to FIG. 21 starts from the
hollow input shaft 22, via the fixed wheel third gear 25, via the
idler third gear 62, via the attached idler third gear 62', via the
double-sided coupling device 80, via the upper layshaft 40, via the
upper pinion 41, via the output gearwheel 12, to the output shaft
14.
[0161] Torque flow fourth gear according to FIG. 21 starts from the
solid input shaft 20, via the fixed wheel fourth gear 31, via the
idler fourth gear 63, via the double-sided coupling device 82, via
the lower layshaft 50, via the lower pinion 51, via the output
gearwheel 12, to the output shaft 14.
[0162] Torque flow fifth gear according to FIG. 21 starts from the
hollow input shaft 22, via the fixed wheel fifth gear 26, via the
idler fifth gear 64, via the double-sided coupling device 83, via
the lower layshaft 50, via the lower pinion 51, via the output
gearwheel 12, to the output shaft 14.
[0163] Torque flow sixth gear according to FIG. 21 starts from the
solid input shaft 20, via the fixed wheel sixth gear 32, via the
idler sixth gear 65, via the double-sided coupling device 82, via
the lower layshaft 50, via the lower pinion 51, via the output
gearwheel 12, to the output shaft 14.
[0164] Torque flow seventh gear according to FIG. 21 starts from
the hollow input shaft 22, via the fixed wheel seventh gear 27, via
the idler seventh gear 66, via the double-sided coupling device 83,
via the lower layshaft 50, via the lower pinion 51, via the output
gearwheel 12, to the output shaft 14.
[0165] Torque flow first reverse gear according to FIG. 21 starts
from the hollow input shaft 22, via the fixed wheel third gear 25,
via the idler third gear 62, via the attached idler third gear 62',
via the second reverse gear wheel 36, via the reverse gear hollow
shaft 39, via the single-sided coupling device 85, via the reverse
gear shaft 38, via the reverse pinion 55, via the output gearwheel
12, to the output shaft 14.
[0166] FIG. 22 illustrates an alternative expanded side view of the
double clutch transmission of FIG. 16. FIG. 22 comprises parts that
are similar to that of FIGS. 16-17. The similar parts have similar
or same part reference numbers. Descriptions of the similar or the
same parts are hereby incorporated.
[0167] FIG. 23 illustrates an alternative front view of a further
embodiment of a double clutch transmission in FIG. 19. FIG. 23
comprises parts that are similar to that of FIGS. 18-19. The
similar parts have similar or same part reference numbers.
Descriptions of the similar or the same parts are hereby
incorporated.
[0168] Although the above description contains much specificity,
these should not be construed as limiting the scope of the
embodiments but merely providing illustration of the foreseeable
embodiments. Especially the above stated advantages of the
embodiments should not be construed as limiting the scope of the
embodiments but merely to explain possible achievements if the
described embodiments are put into practice. Thus, the scope of the
embodiments should be determined by the claims, rather than by the
examples given.
[0169] 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.
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