SYNCHRONIZER ACTUATION ASSEMBLY

• US 20120017716A1
• Filed: 07/22/2010
• Published: 01/26/2012
• Est. Priority Date: 07/22/2010
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (Motors Liquidation Co. GUC Trust)
• Inventors: Neelakantan, Vijay A., Olson, Bret M., Wittkopp, Scott H.
• Granted Patent: US 8,578,803 B2
• Time in Patent Office: Days
• US Class Current: 74/473.11
• CPC Class Codes: F16H 2061/2838 Arrangements with single drive motor for selecting and shifting movements, i.e. one motor used for generating both movements
• CPC Class Codes: F16H 2061/2884 Screw-nut devices
• CPC Class Codes: F16H 61/30 Hydraulic or pneumatic motors or related fluid control means therefor
• CPC Class Codes: F16H 63/18 the final actuating mechanism comprising cams
• CPC Class Codes: Y10T 74/19279 Cam operated
• CPC Class Codes: Y10T 74/20018 Transmission control
• CPC Class Codes: Y10T 74/20024 Fluid actuator

Abstract

A synchronizer actuation assembly for actuating at least one synchronizer member includes a barrel cam, at least one shift fork, a hydraulic piston assembly, and a motion converter. The barrel cam includes at least one cam groove that circumscribes the barrel cam and defines at least a neutral position and a first engaged position. The at least one shift fork has a first end portion disposed in the at least one cam groove and a second forked end portion. The hydraulic piston assembly includes a housing and a piston disposed in the housing. The motion converter includes a translatable input member engaged with the piston of the hydraulic piston assembly, a rotatable output member rotatably coupled with the barrel cam, and a direction selection mechanism. The translatable input member is selectively rotatably coupled with the rotatable output member in a first rotational direction or a second rotational direction.

Claims

1. A synchronizer actuation assembly for actuating at least one synchronizer member, the synchronizer actuation assembly comprising:

a barrel cam including at least one cam groove that circumscribes the barrel cam and defines at least a neutral position and a first engaged position, wherein the barrel cam is rotatable in a first rotational direction and a second rotational direction;

at least one shift fork having a first end portion and a second end portion, wherein the first end portion is disposed in the at least one annular groove of the barrel cam and the second end portion is forked for controlling the synchronizer member;

a hydraulic piston assembly including a housing and a piston, wherein the piston is disposed in the housing and is positionable between a first position and a second position; and

a motion converter including a translatable input member engaged with the piston of the hydraulic piston assembly, a rotatable output member rotatably coupled with the barrel cam, and a direction selection mechanism, wherein the translatable input member is selectively rotatably coupled with the rotatable output member, and wherein the direction selection mechanism has a first state and a second state, and

wherein a movement of the piston rotates the barrel cam in the first rotational direction when the direction selection mechanism is in the first state, and wherein a movement of the piston rotates the barrel cam in the second rotational direction when the direction selection mechanism is in the second state.

2. The synchronizer actuation assembly of claim 1, wherein the housing of the hydraulic piston assembly includes a fluid port in hydraulic communication with a hydraulic circuit.

3. The synchronizer actuation assembly of claim 1, wherein the hydraulic piston assembly includes a biasing member that urges the piston to the first position.

4. The synchronizer actuation assembly of claim 3, wherein the biasing member is a spring disposed between the housing and the piston of the hydraulic piston assembly.

5. The synchronizer actuation assembly of claim 1, wherein the barrel cam has a plurality of equally spaced angular positions, and wherein each of the angular positions has a unique arrangement of an axial position of the at least one cam groove, and wherein the axial position of each of the at least one cam groove is selected from a neutral position, a first engaged position, and optionally a second engaged position for synchronizing gears in a vehicle transmission.

7. The synchronizer actuation assembly of claim 1, wherein the motion converter includes a selective direction one-way clutch.

8. The synchronizer actuation assembly of claim 7, wherein the translatable input member of the selective direction one-way clutch is an actuation member having a first end portion in translatable engagement with the piston and a second end portion engaged with a first race of the selective direction one-way clutch, and wherein the rotatable output member is a second race of the selective direction one-way clutch.

9. The synchronizer actuation assembly of claim 7, wherein the hydraulic piston assembly includes a first fluid port and a second fluid port each selectively hydraulically connectable with one of a fluid pressure source and a fluid exhaust, and wherein the first fluid port is proximate to a first end of the housing and the second fluid port is proximate to a second end of the housing of the hydraulic piston assembly.

10. The synchronizer actuation assembly of claim 1, wherein the motion converter includes a selective direction spiral ratchet assembly, and wherein the rotatable output member is a rotatable member having a pair of spiral grooves extending along a length of the rotatable member in opposing rotational directions.

11. The synchronizer actuation assembly of claim 10, wherein the selective direction spiral ratchet assembly includes a first nut and a second nut each selectively rotatably coupled to the translatable input member, and wherein the first nut is rotatably fixed with a first of the spiral grooves and the second nut is rotatably fixed with a second of the pair of spiral grooves, and wherein the translatable input member is rotationally stationary.

6. The synchronizer actuation assembly of claim 6, wherein a rotation angle between each of the angular positions is selected to correspond to a single translation of the piston between the first position and the second position.

12. A synchronizer actuation assembly for actuating at least one synchronizer member, the synchronizer actuation assembly comprising:

a barrel cam including at least one cam groove that circumscribes the barrel cam and defines at least a neutral position and a first engaged position, wherein the barrel cam is rotatable in a first rotational direction and a second rotational direction;

at least one shift fork having a first end portion and a second end portion, wherein the first end portion is disposed in the at least one annular groove of the barrel cam and the second end portion is forked;

a hydraulic piston assembly including a housing and a piston, wherein the piston is disposed in the housing and is positionable between a first position and a second position; and

a selective direction one-way clutch including an actuation member, a direction selector mechanism, a first race, and a second race, wherein a first end portion of the actuation member is in translatable engagement with the piston and a second end portion of the actuation member is engaged with the first race, and wherein the second race is rotatably coupled to the barrel cam, and wherein the direction selector mechanism has a first state and a second state for selectively rotatably coupling the first race with the second race, and

wherein a movement of the piston rotates the barrel cam in the first rotational direction when the direction selection mechanism is in the first state, and wherein a movement of the piston rotates the barrel cam in the second rotational direction when the direction selection mechanism is in the second state.

13. The synchronizer actuation assembly of claim 12, wherein the direction selector mechanism includes a pawl selectively engaged with a toothed gear, and wherein in the first state the pawl transmits torque between the first race and the second race in the first rotational direction and allows rotation between the first race and the second race in the second rotational direction, and wherein in the second state the pawl transmits torque between the first race and the second race in the second rotational direction and allows rotation between the first race and the second race in the first rotational direction.

14. The synchronizer actuation assembly of claim 12, wherein the hydraulic piston assembly includes a biasing member that urges the piston to the first position.

15. The synchronizer actuation assembly of claim 14, wherein the biasing member is a spring disposed between the housing and the piston of the hydraulic piston assembly.

16. The synchronizer actuation assembly of claim 12, wherein each of the at least one cam groove includes a plurality of angular positions equally spaced around the circumference of the barrel cam, and wherein each of the angular positions corresponds to one of the neutral position, the first engaged position, and a second engaged position for synchronizing gears in a vehicle transmission.

17. The synchronizer actuation assembly of claim 16, wherein a rotation angle between each of the angular positions is selected to correspond to a single translation of the piston between the first position and the second position.

18. The synchronizer actuation assembly of claim 12, wherein the hydraulic piston assembly includes a first fluid port and a second fluid port each selectively hydraulically connectable with one of a fluid pressure source and a fluid exhaust, and wherein the first fluid port is proximate to a first end of the housing and the second fluid port is proximate to a second end of the housing of the hydraulic piston assembly.

19. A synchronizer actuation assembly for actuating at least one synchronizer member, the synchronizer actuation assembly comprising:

a barrel cam including at least one cam groove that circumscribes the barrel cam and defines at least a neutral position and a first engaged position, wherein the barrel cam is rotatable in a first rotational direction and a second rotational direction;

at least one shift fork having a first end portion and a second end portion, wherein the first end portion is disposed in the at least one annular groove of the barrel cam and the second end portion is forked;

a hydraulic piston assembly including a housing and a piston, wherein the piston is disposed in the housing and is positionable between a first position and a second position; and

a selective direction spiral ratchet assembly including a translatable input member, a direction selector mechanism, and a rotatable output member having a pair of spiral grooves extending along a length of the rotatable member in opposing rotational directions, and

wherein a movement of the piston rotates the barrel cam in the first rotational direction when the direction selection mechanism is in the first state, and wherein a movement of the piston rotates the barrel cam in the second rotational direction when the direction selection mechanism is in the second state.

20. The synchronizer actuation assembly of claim 19, wherein the selective direction spiral ratchet assembly includes a first nut and a second nut each selectively rotatably coupled to the translatable input member, and wherein the first nut is rotatably fixed with a first of the spiral grooves and the second nut is rotatably fixed with a second of the pair of spiral grooves, and wherein the translatable input member is rotationally stationary.