CONTINUOUSLY VARIABLE GEAR TRANSMISSION

• US 20170284519A1
• Filed: 06/19/2017
• Published: 10/05/2017
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: Enviolo BV
• Original Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Inventors: Kolstrup, Anders
• Granted Patent: US 11,598,397 B2
• Time in Patent Office: Days
• CPC Class Codes: F16H 15/28 with external friction surface
• CPC Class Codes: F16H 15/40 in which two members co-operative by means of balls, or rollers of uniform effective diameter, not mounted on shafts

Abstract

A continuously variable gear is described having an input shaft, a plurality of traction balls distributed radially around the axis, each traction ball is mounted on an axle passing there through, the axles are tiltable in the radial grooves in the housing and support plate. To control the position of the traction balls, the axles are guided in curved slots of a turnable iris plate. To control the axial placement of the traction balls, there is a rotatable input disc positioned adjacent to the traction balls, a rotatable output disc positioned adjacent to the traction balls opposite the input disc, and a pre-spanning ring around the traction balls such that each of the traction balls is making three-point contact with the input disc, the output disc and the pre-spanning ring, the contact surface of the pre-spanning ring having a specific curvature larger than the radius of the traction balls.

Claims

1. An apparatus for facilitating control of the ratio of a continuously variable transmission (CVT), the apparatus comprising:

a first member having a first plurality of radial grooves arranged angularly about an axis, the first plurality of radial grooves engaging a first end of ball axles of a plurality of traction balls of the CVT, wherein the first member is non-rotatable;

a second member having a second plurality of radial grooves arranged angularly about the axis, the second plurality of radial grooves engaging a second end of the ball axles; and

an actuator for rotating the first and second members relative to one another such that during operation of the CVT the first plurality of radial grooves can be angularly misaligned relative to the second plurality of grooves through a plane lying through the shaft, wherein an angular misalignment of the first and second plurality of radial grooves corresponds to a tilting of the ball axles in the first and second pluralities of radial grooves.

2. The apparatus of claim 1, wherein the first member comprises a stationary member, and wherein the second member is rotated relative to the first member.

3. The apparatus of claim 2, wherein the second member comprises a support plate configured for rotation relative to the first member.

4. The apparatus of claim 1, wherein the first member comprises a housing member.

5. The apparatus of claim 4, wherein the second member comprises a support plate.

6. The apparatus of claim 5, further comprising an actuator housing and an actuator arm, the actuator housing coupled to the support plate, and the actuator arm coupled to a mechanism for tilting the plurality of traction balls of the CVT.

7. The apparatus of claim 1, further comprising an input disc in contact with the plurality of traction balls, and wherein a clockwise rotation of the input disc and a clockwise rotation of the second plurality of radial grooves results in the ball axles being tilted in a first direction in the radial grooves.

8. The apparatus of claim 7, wherein the second plurality of grooves is further characterized in that a counterclockwise rotation of the second plurality of grooves results in the ball axles being tilted in a second direction in the radial grooves.

9. The apparatus of claim 1, further characterized by a support plate having a minor rotational play around its ideal aligned position.

10. A method for facilitating control of a speed ratio of a continuously variable transmission (CVT) having a shaft, a plurality of traction balls arrayed angularly about a longitudinal axis of the shaft, each traction ball including a ball axle about which the traction ball rotates, and a pre-spanning ring contacting the plurality of traction balls, the method comprising:

providing a first plurality of radial grooves for engaging a first end of each of the ball axles, the first member being non-rotatable;

providing a second plurality of radial grooves for engaging a second end of each of the ball axles; and

arranging the first and the second plurality of radial grooves relative to one another such that during operation of the CVT the first plurality of radial grooves can be misaligned relative to the second plurality of radial grooves through a plane lying through the shaft, wherein an angular misalignment of the first and the second plurality of radial grooves corresponds to a tilting of the ball axles in the first and second pluralities of radial grooves.

11. The method of claim 10, wherein the first plurality of radial grooves is part of a housing.

12. The method of claim 11, wherein the second plurality of radial grooves is part of a support plate.

13. The method of claim 12, further comprising providing an actuator housing and an actuator arm, the actuator housing being coupled to the support plate, and the actuator arm being coupled to a mechanism for tiling the plurality of traction balls.