System and method for shifting a transmission

Patent metadata

Field	Value
Publication number	US-12545228-B2
Application number	US-202217931412-A
Country	US
Kind code	B2
Filing date	Sep 12, 2022
Priority date	Sep 29, 2021
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

A method and system for shifting a transmission that includes one or more mechanical clutches without clutch plates is described. In one example, a torque output of an electric machine is adjusted in response to a request to shift a transmission so that forces that hold the mechanical clutch in an engaged position may be reduced.

First claim

The invention claimed is:

1 . A method for shifting a transmission, comprising:
adjusting a torque of an electric machine responsive to a driver demand via a controller while not shifting a gear of the transmission, wherein the electric machine is the only electric machine coupled to the transmission; and adjusting the torque of the electric machine via the controller responsive to a gear shift request, the torque adjusted according to a torque map that reduces forces that act to keep a clutch engaged to a gear in response to the gear shift request, where the torque map adjusts the torque of the electric machine according to a temperature of the transmission, including: at a lower transmission temperature, the torque of the electric machine is temporarily reduced from the torque responsive to the driver demand to a first torque that reduces the forces, and, at a higher temperature, the torque of the electric machine is temporarily reduced from the torque responsive to the driver demand to a second torque, lower than the first torque, that reduces the forces.

2 . The method of claim 1 , where the torque map adjusts the torque of the electric machine according to a vehicle speed.

3 . The method of claim 2 , where the torque map adjusts the torque of the electric machine according to a transmission break-in effects.

4 . The method of claim 1 , further comprising adjusting a position of a mechanical clutch in response to the gear shift request.

5 . The method of claim 4 , where the position of the mechanical clutch is adjusted to release a first gear and engage a second gear.

6 . The method of claim 1 , where an output shaft of the electric machine is coupled to an input shaft of the transmission via a gear and without a clutch.

7 . A propulsion system, comprising:
an electric machine configured as the only torque source of the propulsion system; a transmission including a mechanical clutch configured to selectively engage one or more gears of the transmission; and a controller including executable instructions stored in non-transitory memory that cause the controller to adjust a torque of the electric machine to a first mapped torque in response to a request to upshift the transmission to a numerically higher gear, the first mapped torque being a torque that reduces a force acting to hold the mechanical clutch in an engaged position, where the first mapped torque is a function of a transmission temperature and a vehicle speed, and where the first mapped torque decreases as the transmission temperature increases.

8 . The propulsion system of claim 7 , where the first mapped torque is also a function of break-in effects of the transmission, and where the brake-in effects include a reduction in torque to rotate components of the transmission.

9 . The propulsion system of claim 7 , where the first mapped torque increases as the vehicle speed increases.

10 . The propulsion system of claim 7 , further comprising a clutch actuator and additional instructions to adjust a position of the clutch actuator in response to the request to shift the transmission.

11 . The propulsion system of claim 7 , further comprising additional executable instructions that cause the controller to adjust the torque of the electric machine to a second mapped torque in response to a request to downshift the transmission to a numerically lower gear.

12 . A method for shifting a transmission, comprising:
adjusting a torque of an electric machine responsive to a driver demand via a controller while not shifting a mechanical clutch of the transmission, wherein the electric machine is the only electric machine of a powertrain comprising the transmission and the electric machine; adjusting the torque of the electric machine via the controller responsive to a first torque map that reduces forces that act to keep a clutch engaged to a first gear in response to a gear upshift request; and adjusting the torque of the electric machine via the controller responsive to a second torque map that reduces forces that act to keep the clutch engaged to a second gear in response to a gear downshift request, where torque values output from the second torque map are different from torque values output from the first torque map.

13 . The method of claim 12 , where the torque values in the first torque map and the torque values in the second torque map change according to a transmission temperature.

14 . The method of claim 13 , where the torque values in the first torque map and the torque values in the second torque map change according to vehicle speed.

15 . The method of claim 12 , where the torque values in the first torque map and the torque values in the second torque map reduce the torque of the electric machine as a distance that a vehicle that includes the transmission is driven increases.

16 . The method of claim 12 , where an output shaft of the electric machine is directly coupled to the transmission via a gear and without a clutch.

Assignees

• Dana Heavy Vehicle Sys Group

Inventors

• Allen James
• Houser Jordan M
• Reichert Jared
• Ziskovsky Darren J
• David Jeffrey M

Classifications

• B60W2510/107

  Temperature · CPC title

• B60W2710/083

  Torque · CPC title

• B60W2710/022

  Clutch actuator position · CPC title

• B60W2540/10

  Accelerator pedal position · CPC title

• B60W30/19

  Improvement of gear change, e.g. by synchronisation or smoothing gear shift · CPC title