# US 7,610,825 B2 · Multi-speed transmission with countershaft gearing

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- Number: US 7,610,825 B2
- Document ID: US7610825B2
- Status: Granted
- Kind: B2
- Application number: 11/678,051
- Filed: 2007-02-22
- Published: 2008-08-28
- Granted: 2009-11-03
- Earliest claimed: 2007-02-22
- Assignees: GM Global Technology Operations LLC
- Inventors: James D. Hendrickson; Tejinder Singh; Henryk Sowul
- Web page: https://patentgrep.com/patent/US7610825B2

## CPC

- F16H 3/006: {power being selectively transmitted by parallel flow paths, e.g. dual clutch transmissions}
- F16H 3/093: with two or more countershafts
- F16H 2003/0931: {each countershaft having an output gear meshing with a single common gear on the output shaft}
- F16H 2200/0056: the gear ratios comprising seven forward speeds
- Y10T 74/19228: Multiple concentric clutch shafts
- Y10T 74/19233: Plurality of counter shafts
- Y10T 74/19288: Double clutch and interposed transmission
- F16H: GEARING
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A transmission is provided having a dual clutch, to achieve torque flow through a countershaft gearing arrangement. The countershaft gearing arrangement includes a plurality of co-planar gear sets having gears that are selectively connectable to a plurality of countershafts. At least one transfer gear set transfers torque from the counter shafts to an output shaft. The output shaft is connected to a final drive unit that has a final drive unit output shaft that is transverse to an input member connected at one end to a torque converter and at the other end to the dual clutch.

## Claims

### Claim 1

A powertrain comprising:
a transmission input member;
a power source for generating a torque in the input member;
a first intermediate shaft;
a second intermediate shaft;
a clutch selectively engagable to couple the transmission input member with one of the first and second intermediate shafts;
a first and a second countershaft;
a transmission housing having a front and rear wall for supporting the first and second intermediate shaft and the first and second countershaft;
a first set of gears connected for common rotation with the first intermediate shaft and intermeshing with a first selectable set of gears to form a first plurality of co-planar gear sets, wherein each of the gears of the first selectable set of gears is connectable for common rotation with one of the first and second countershafts for selectively transferring the torque to the countershafts when the clutch is engaged;
a second set of gears connected for common rotation with the second intermediate shaft and intermeshing with a second selectable set of gears to form a second plurality of co-planar gear sets, wherein each of the gears of the second selectable set of gears is connectable for common rotation with one of the first and second countershafts for selectively transferring the torque to one of the countershafts when the clutch is engaged;
an output shaft disposed radially outward of the second intermediate shaft; and
a first transfer gear coupled to one of the first and second countershafts for transferring torque from the first and second countershaft to the output shaft, and
wherein one of the second plurality of co-planar gear sets that produces a first and third gear ratio is adjacent the rear wall of the transmission housing.

### Claim 2 (depends on 1)

The powertrain of claim 1, wherein the first set of gears further comprises two gears.

### Claim 3 (depends on 1)

The powertrain of claim 1, wherein the second set of gears further comprises three gears.

### Claim 4 (depends on 1)

The powertrain of claim 1, further comprising a first idler gear rotatable about a first idler axis and intermeshing with at least one of the selectable sets of gears of the first set of gears.

### Claim 5 (depends on 4)

The powertrain of claim 4, further comprising a second idler gear rotatable about the idler axis and intermeshing with the first transfer gear.

### Claim 6 (depends on 1)

The powertrain of claim 1, further comprising a second transfer gear connected for common rotation with one of the first and second countershafts and intermeshing with an output gear connected for common rotation with the output shaft for transferring torque from the countershaft to the output shaft.

### Claim 7 (depends on 6)

The powertrain of claim 6, wherein the first and second transfer gears are disposed in a single plane.

### Claim 8 (depends on 1)

The powertrain of claim 1, further comprising a plurality of synchronizers for selectively connecting the first and second set of selectable sets of gears to at least one of the countershafts.

### Claim 9 (depends on 1)

The powertrain of claim 1, further comprising eight synchronizers for selectively connecting the first and second set of selectable sets of gears to at least one of the countershafts.

### Claim 10 (depends on 1)

The powertrain of claim 1, further comprising a final drive unit wherein the final drive unit has an output shaft that is perpendicular to the input member.

### Claim 11 (depends on 1)

The powertrain of claim 1, wherein the clutch is a dual clutch having a first hub connected to the first intermediate shaft and a second hub connected to the second intermediate shaft.

### Claim 12 (depends on 11)

The powertrain of claim 11, wherein the first hub is remote from the second hub and wherein an output shaft of the final drive unit that is perpendicular to the input member is disposed between the first and second hub.

### Claim 13 (depends on 1)

The powertrain of claim 1, wherein the clutch is disposed between the first and second plurality of co-planar gear sets.

### Claim 14 (depends on 1)

The powertrain of claim 1, wherein the clutch is a friction clutch.

### Claim 15 (depends on 1)

The powertrain of claim 1, wherein a first plurality of co-planar gear sets further comprises two co-planar gear sets.

### Claim 16 (depends on 1)

The powertrain of claim 1, wherein a second plurality of co-planar gear sets further comprises three co-planar gear sets.

### Claim 17 (depends on 1)

The powertrain of claim 1, wherein one of the second plurality of co-planar gear sets transfers the torque to achieve a fifth forward gear ratio.

### Claim 18 (depends on 17)

The powertrain of claim 17, wherein the one of the second plurality of co-planar gear sets that transfers the torque to achieve the fifth forward gear ratio is disposed adjacent a structural wall of the housing of the powertrain.

### Claim 19 (depends on 17)

The powertrain of claim 17, wherein the one of the second plurality of co-planar gear sets that achieves the fifth forward gear ratio includes a single drive gear and a single driven gear.

### Claim 20 (depends on 1)

The powertrain of claim 1, wherein one of the second plurality of co-planar gear sets transfers the torque to achieve a seventh forward gear ratio.

### Claim 21 (depends on 20)

The powertrain of claim 20, wherein the one of the second plurality of co-planar gear sets that achieves the seventh forward gear ratio includes a single drive gear and a single driven gear.

### Claim 22 (depends on 21)

The powertrain of claim 21, wherein the one of the second plurality of co-planar gear sets that transfers the torque to achieve the seventh forward gear ratio is disposed adjacent a structural wall of the housing of the powertrain.

### Claim 23 (depends on 1)

The powertrain of claim 1 wherein a first of the first plurality of co-planar gear sets include a first selectable gear and a first gear intermeshed with a second selectable gear, and wherein a second of the first plurality of co-planar gear sets include a first gear intermeshed with a first selectable gear and a second selectable gear, wherein the first gears are coupled to the first intermediate shaft, the first selectable gears are selectively connectable to the first countershaft, and the second selectable gears are selectively connectable to the second countershaft.

### Claim 24 (depends on 23)

The powertrain of claim 23 wherein the first selectable gears of the first and second co-planar gear sets are selectively connectable to the first countershaft by a first synchronizer assembly having a pair of synchronizers and the second selectable gears of the first and second co-planar gear sets are selectively connectable to the second countershaft by a second synchronizer assembly having a pair of synchronizers.

### Claim 25 (depends on 24)

The powertrain of claim 24 wherein the first co-planar gear set includes a reverse gear rotatable about an idler axis, and wherein the reverse gear is intermeshed with the first selectable gear of the first co-planar gear set in order to provide a reverse gear ratio.

### Claim 26 (depends on 25)

The powertrain of claim 25 further comprising a reverse transfer gear rotatable about the idler axis and connected for common rotation with the reverse gear, the reverse transfer gear intermeshed with the first transfer gear.

### Claim 27 (depends on 26)

The powertrain of claim 26 wherein a third of the second plurality of co-planar gear sets include a first gear intermeshed with a first selectable gear and a second selectable gear, wherein the first gear is coupled to the second intermediate shaft, the first selectable gear is selectively connectable to the first countershaft, and the second selectable gear is selectively connectable to the second countershaft.

### Claim 28 (depends on 27)

The powertrain of claim 27 wherein a fourth and a fifth of the second plurality of co-planar gear sets each include a first gear intermeshed with a first selectable gear, wherein the first gears are coupled to the second intermediate shaft and the first selectable gears are selectively connectable to at least one of the first and second countershafts.

### Claim 29 (depends on 28)

The powertrain of claim 28 wherein the first selectable gear of the fourth co-planar gear set is selectively connectable to the first countershaft and the first selectable gear of the fifth co-planar gear set is selectively connectable to the second countershaft.

### Claim 30 (depends on 29)

The powertrain of claim 29 wherein the first selectable gears of the third and fourth co-planar gear sets are selectively connectable to the first countershaft by a third synchronizer assembly having a pair of synchronizers and the second selectable gear of the third co-planar gear set and the first selectable gear of the fifth co-planar gear set are selectively connectable to the second countershaft by a fourth synchronizer assembly having a pair of synchronizers.

### Claim 31 (depends on 28)

The powertrain of claim 28 wherein the first selectable gear of the fourth co-planar gear set is selectively connectable to the second countershaft and the first selectable gear of the fifth co-planar gear set is selectively connectable to the second countershaft.

### Claim 32 (depends on 31)

The powertrain of claim 31 wherein the first selectable gear of the third co-planar gear set is selectively connectable to the first countershaft by a third synchronizer assembly having a single synchronizer, the second selectable gear of the third co-planar gear set and the first selectable gear of the fourth co-planar gear set are selectively connectable to the second countershaft by a fourth synchronizer assembly having a pair of synchronizers, and the first selectable gear of the fifth co-planar gear set is selectively connectable to the second countershaft by a fifth synchronizer assembly having a single synchronizer.

### Claim 33 (depends on 28)

The powertrain of claim 28 wherein the first selectable gear of the fourth co-planar gear set is selectively connectable to the first countershaft and the first selectable gear of the fifth co-planar gear set is selectively connectable to the first countershaft.

### Claim 34 (depends on 33)

The powertrain of claim 33 wherein the second selectable gear of the third co-planar gear set is selectively connectable to the second countershaft by a third synchronizer assembly having a single synchronizer, the first selectable gear of the third co-planar gear set and the first selectable gear of the fourth co-planar gear set are selectively connectable to the first countershaft by a fourth synchronizer assembly having a pair of synchronizers, and the first selectable gear of the fifth co-planar gear set is selectively connectable to the first countershaft by a fifth synchronizer assembly having a single synchronizer.