Device for guiding a moveable conical pulley disc of a CVT variator

1. A device for guiding a movable conical pulley disc ( 3 ) relative to a fixed conical pulley disc ( 2 ) along a variator shaft ( 1 ) of a continuously variable belt transmission, the movable conical pulley disc ( 3 ) being supported by the variator shaft ( 1 ) and being axially movable along the variator shaft ( 1 ) via first and second bearing surfaces ( 4 , 5 ) of the variator shaft ( 1 ), and at least one independent transfer element is provided between the movable conical pulley disc ( 3 ) and the variator shaft ( 1 ) to facilitate transfer of torque therebetween;

wherein the variator shaft ( 1 ) has at least one axial guide groove ( 7 ) and the movable conical pulley ( 3 ) has at least one corresponding axial guide groove ( 8 ) and a single independent transfer element is located within each corresponding pair of guide grooves ( 7 , 8 ) for coupling the movable conical pulley ( 3 ) to the variator shaft ( 1 ), the single independent transfer element is an elongate cylindrical pin ( 6 )having a length extending over a range of motion of the movable conical pulley ( 3 ), and the movable conical pulley ( 3 ) is independently axially movable with respect to both the variator shaft ( 1 ) and each elongate cylindrical pin ( 6 );

first and second abutments ( 18 , 19 ) restrict axial movement of the at least one independent cylindrical pin ( 6 ) along the guide groove ( 7 ) of the variator shaft ( 1 ); and

the first abutment ( 18 ) is formed by a step in the variator shaft ( 1 ) and the second abutment ( 19 ) is formed by an element separate from the variator shaft ( 1 ).

2. The device according to claim 1 , wherein the at least one independent cylindrical pin ( 6 ) and the guide groove ( 7 ) of the variator shaft ( 1 ) are formed so that rotation of the at least one independent cylindrical pin ( 6 ), relative to the variator shaft ( 1 ), is minimized.

3. The device according to claim 2 , wherein the at least one independent cylindrical pin ( 6 ) is flattened to minimize rotation thereof relative to the variator shaft ( 1 ) during operation of the continuously variable belt transmission.

4. The device according to claim 1 , wherein the second abutment ( 19 ) is formed by a surface of a piston ( 9 ) supported by the variator shaft ( 1 ).

5. The device according to claim 1 , wherein the second abutment ( 19 ) is formed by a ring which fits in a radial groove of the variator shaft ( 1 ).

6. The device according to claim 1 , wherein securing elements restrict axial movement of the at least one independent cylindrical pin ( 6 ) in the guide groove ( 8 ) of the movable conical pulley ( 3 ), and the securing elements are rings which fit into corresponding radial grooves of the movable pulley ( 3 ).

7. The device according to claim 1 , wherein two independent cylindrical pins ( 6 ), which fit into corresponding guide grooves ( 7 , 8 ) of the variator shaft ( 1 ) and the movable conical pulley ( 3 ), are respectively provided for transferring torque between the movable conical pulley ( 3 ) and the variator shaft ( 1 ).

8. The device according to claim 1 , wherein three independent cylindrical pins ( 6 ), which fit into corresponding guide grooves ( 7 , 8 ) of the variator shaft ( 1 ) and the movable conical pulley ( 3 ), are respectively provided for transferring torque between the movable conical pulley ( 3 ) and the variator shaft ( 1 ).

9. A device for a continuously variable transmission for guiding an axially movable conical pulley disc ( 3 ) along a variator shaft ( 1 ) relative to a fixed conical pulley disc ( 2 ), comprising:

the movable conical pulley disc ( 3 ),

the variator shaft ( 1 ), and

at least one independent transfer element having a length extending over a range of motion of the movable conical pulley ( 3 ) and located between the movable conical pulley disc ( 3 ) and the variator shaft ( 1 )to facilitate transfer of torque therebetween; wherein

the variator shaft ( 1 ) has at least one axial shaft guide groove ( 7 ) and the movable conical pulley ( 3 ) has at least one corresponding axial pulley guide groove ( 8 ),

each transfer element is located within a corresponding pair of guide grooves ( 7 , 8 ) for coupling the movable conical pulley ( 3 ) to the variator shaft ( 1 ), and for each transfer element,

a first end the transfer element is located adjacent a first abutment ( 18 ) formed by a step in the variator shaft ( 1 ) at a first end of the corresponding axial guide groove ( 7 ),

a second and opposite end of the corresponding pair of guide grooves ( 7 , 8 ) are open to receive the corresponding transfer element during assembly of the device, and

the second end of the corresponding pair of guide grooves are closeable by a second abutment ( 19 ) formed in an element separate from the variator shaft ( 1 ) to restrict axial sliding movement of the transfer element along the guide grooves ( 7 , 8 ) as the movable conical pulley ( 3 ) slides axially along the variator shaft ( 1 ).

10. The device according to claim 9 , wherein the at least one independent transfer element is cylindrical pin ( 6 ) and the at least one independent cylindrical pin ( 6 ) and the guide groove ( 7 ) of the variator shaft ( 1 ) are formed so that rotation of the at least one independent cylindrical pin ( 6 ), relative to the variator shaft ( 1 ), is minimized.

11. The device according to claim 10 , wherein the at least one independent cylindrical pin ( 6 ) is flattened to minimize rotation thereof relative to the variator shaft ( 1 ) during operation of the continuously variable belt transmission.

12. The device according to claim 9 , wherein securing elements restrict axial movement of the at least one independent transfer element, which comprises at least one independent cylindrical pin ( 6 ) in the guide groove ( 8 ) of the movable conical pulley ( 3 ), and the securing elements are rings which fit into corresponding radial grooves of the movable pulley ( 3 ).

13. The device according to claim 9 , wherein the at least one independent transfer element, which comprises two independent cylindrical pins ( 6 ), which fit into corresponding guide grooves ( 7 , 8 ) of the variator shaft ( 1 ) and the movable conical pulley ( 3 ), are respectively provided for transferring torque between the movable conical pulley ( 3 ) and the variator shaft ( 1 ).

14. The device according to claim 9 , wherein the at least one independent transfer element comprises three independent cylindrical pins ( 6 ), which fit into corresponding guide grooves ( 7 , 8 ) of the variator shaft ( 1 ) and the movable conical pulley ( 3 ), are respectively provided for transferring torque between the movable conical pulley ( 3 ) and the variator shaft ( 1 ).

15. A device for guiding a movable conical pulley disc ( 3 ) relative to a fixed conical pulley disc ( 2 ) along a variator shaft ( 1 ) of a continuously variable belt transmission, the movable conical pulley disc ( 3 ) being supported by the variator shaft ( 1 ) and being axially movable along the variator shaft ( 1 ) via first and second bearing surfaces ( 4 , 5 ) of the variator shaft ( 1 ), and at least one independent transfer element is provided between the movable conical pulley disc ( 3 ) and the variator shaft ( 1 ) to facilitate transfer of torque therebetween;

wherein the variator shaft ( 1 ) has at least one axial guide groove ( 7 ) and the movable conical pulley ( 3 ) has at least one corresponding axial guide groove ( 8 ) and a single transfer element is located within each corresponding pair of guide grooves ( 7 , 8 ) for coupling the movable conical pulley ( 3 ) to the variator shaft ( 1 ), the single transfer element is an elongate independent cylindrical pin ( 6 ) having a length extending over a range of motion of the movable conical pulley ( 3 ), and the movable conical pulley ( 3 ) is independently axially movable with respect to both the variator shaft ( 1 ) and each elongate independent cylindrical pin ( 6 ), one end of each elongate independent cylindrical pin ( 6 ) is located for abutment with a first abutment ( 18 ), formed by a step in the variator shaft ( 1 ), while an opposite end of each elongate independent cylindrical pin ( 6 ) is located for abutment with a second abutment ( 19 ), formed by a surface of a piston ( 9 ) supported by the variator shaft ( 1 ), to restrict axial sliding movement of the independent cylindrical pin ( 6 ) along the guide grooves ( 7 , 8 ) as the movable conical pulley ( 3 ) slides axially along the variator shaft ( 1 ), and the variator shaft ( 1 ) has an axially fluid supply line which extends axially along a portion of the variator shaft ( 1 ) and only a single radial bore extends through the variator shaft to a pressure chamber.