Vehicle transmission and method of assembling vehicle transmission

Patent metadata

Field	Value
Publication number	US-10533616-B2
Application number	US-201715726545-A
Country	US
Kind code	B2
Filing date	Oct 6, 2017
Priority date	Feb 12, 2014
Publication date	Jan 14, 2020
Grant date	Jan 14, 2020

Abstract

A vehicle transmission includes a transmission shaft, a friction element assembly mounted on the transmission shaft, a piston assembly for actuating the friction element assembly, a snap ring for retaining the friction element assembly and a mounting groove formed in the transmission shaft. The snap ring is installed into the mounting groove by expanding the snap ring and then allowing the snap to contract and enter the mounting groove. The mounting groove is located such that the snap ring could exit the mounting groove upon expansion of the snap ring due to a centrifugal force. Accordingly, various arrangements are provided to prevent the snap ring from leaving the mounting groove after installation.

First claim

The invention claimed is:

1. A method of assembling a transmission of a motor vehicle having a transmission shaft, a piston assembly including a protrusion, and a transmission member with an assembly notch formed in the transmission member and configured to receive the protrusion when the piston assembly is in an assembly position and with an operational notch formed in the transmission member and configured to receive the protrusion when the piston assembly is in an operational position, wherein said assembly and operational notches are disposed in a circumferential manner, said method comprising:
mounting the piston assembly of a clutch or brake assembly on the transmission shaft;
moving the piston assembly to the assembly position;
mounting a friction element assembly of the clutch or brake assembly on the transmission shaft;
placing a snap ring near a mounting groove formed in the transmission shaft;
securing the friction element assembly with the snap ring by allowing the snap ring to contract and enter the mounting groove;
moving the piston assembly from the assembly position to the operational position, wherein the piston assembly is configured to actuate the friction element assembly, after securing the friction element assembly with the snap ring; and
preventing the snap ring from expanding out of the mounting groove with the friction element assembly when the piston assembly is in the operational position.

2. The method of claim 1 , wherein moving the piston assembly to the operational position includes rotating the piston assembly.

3. The method of claim 1 , wherein:
moving the piston assembly to the assembly position includes placing the piston assembly into the assembly notch formed in the transmission member; and
mounting the friction element assembly includes moving the friction element assembly to uncover the mounting groove.

4. The method of claim 3 , wherein moving the piston assembly from the assembly position to the operational position includes placing the piston assembly into the operational notch formed in the transmission member and moving the friction element assembly to cover the snap ring in the mounting groove.

5. The method of claim 4 , wherein preventing the snap ring from expanding out of the mounting groove includes placing an arresting surface of a pressure plate of the friction element assembly so that the snap ring cannot expand sufficiently to exit the mounting groove.

6. The method of claim 1 , further comprising:
placing the transmission in a vehicle.

7. A transmission of a motor vehicle comprising:
a transmission shaft;
a transmission member;
a mounting groove formed in the transmission shaft; and
a clutch or brake assembly including:
a friction element assembly mounted on the transmission shaft;
a piston assembly including a protrusion configured to actuate the friction element assembly; and

a snap ring configured to be expanded and installed into the mounting groove to secure the friction element assembly, wherein the piston assembly is configured to be moved from an assembly position to an operational position after the friction element assembly is secured with the snap ring, and the friction element assembly is configured to prevent the snap ring from expanding out of the mounting groove when the piston assembly is in the operational position:
an assembly notch formed in the transmission member and configured to receive the protrusion when the piston assembly is in the assembly position; and
an operational notch formed in the transmission member and configured to receive the protrusion when the piston assembly is in the operational position, wherein said assembly and operational notches are disposed in a circumferential manner.

8. The transmission of claim 7 , wherein the friction element assembly includes a pressure plate configured to prevent the snap ring from expanding out of the mounting groove when the piston assembly is in the operational position.

9. The transmission of claim 7 , wherein, in the assembly position, the friction element assembly uncovers the mounting groove, and, in the operational position, the friction element assembly covers the mounting groove.

10. The transmission of claim 7 , wherein the clutch or brake assembly is configured such that moving the piston assembly to the operational position includes rotating the piston assembly.

11. The transmission of claim 7 , wherein the snap ring is situated in the mounting groove, and the mounting groove is located such that the snap ring can exit the mounting groove upon expansion of the snap ring, when the piston assembly is not in the operating position.

12. The transmission of claim 7 , further comprising, in combination, a vehicle in which the vehicle transmission is mounted and drivingly connected to wheels of the vehicle.

13. A clutch or brake assembly for a transmission of a motor vehicle comprising:
a friction element assembly;
a piston assembly configured to actuate the friction element assembly; and

a snap ring configured to be expanded and installed into a mounting groove formed in a transmission shaft to secure the friction element assembly, wherein the piston assembly is configured to be moved from an assembly position to an operational position after the friction element assembly is secured with the snap ring, and the friction element assembly is configured to prevent the snap ring from expanding out of the mounting groove when the piston assembly is in the operational position; wherein the piston assembly includes a protrusion, and the piston assembly is configured such that:
the protrusion is received in an assembly notch formed in a transmission member when the piston assembly is in the assembly position; and
the protrusion is received in an operational notch formed in the transmission member when the piston assembly is in the operational position and said notches are disposed in a circumferential manner.

14. The clutch or brake assembly of claim 13 , wherein the friction element assembly includes a pressure plate configured to prevent the snap ring from expanding out of the mounting groove when the piston assembly is in the operational position.

15. The clutch or brake assembly of claim 13 , wherein, in the assembly position, the friction element assembly uncovers the mounting groove, and, in the operational position, the friction element assembly covers the mounting groove.

16. The clutch or brake assembly of claim 13 , wherein the clutch or brake assembly is configured such that moving the piston assembly to the operational position includes rotating the piston assembly.

Assignees

• Ford Global Tech Llc

Inventors

• Heuver Bradley Ronald
• Young Marv
• Garbacik Carl

Classifications

• F16D2121/12

  for releasing a normally applied brake, the type of actuator being irrelevant or not provided for in groups F16D2121/04 - F16D2121/10 · CPC title

• F16D13/683

  for clutches with multiple lamellae · CPC title

• F16D13/70

  Pressure members, e.g. pressure plates, for clutch-plates or lamellae; Guiding arrangements for pressure members {(clutch flywheels comprising two or more masses with a rotational damper F16F15/12)} · CPC title

• F16H57/0025 Primary

  with gearing elements rigidly connected to a shaft, e.g. securing gears or pulleys by specially adapted splines, keys or methods · CPC title

• Y10T29/49464

  Assembling of gear into force transmitting device · CPC title