ASSEMBLIES AND METHODS FOR CLAMPING FORCE GENERATION

• US 20170211698A1
• Filed: 04/07/2017
• Published: 07/27/2017
• Est. Priority Date: 05/07/2008
• Status: Abandoned Application

• Current Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Original Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Inventors: Lohr, Charles B.
• Application Number:
  US15/482,259
• Publication Number:
  US 20170211698A1
• Time in Patent Office: Days
• CPC Class Codes: F16H 15/50 Gearings providing a continuous range of gear ratios
• CPC Class Codes: F16H 15/503 in which two members co-operate by means of balls or rollers of uniform effective diameter, not mounted on shafts
• CPC Class Codes: F16H 15/52 in which a member of uniform effective diameter mounted on a shaft may co-operate with different parts of another member
• CPC Class Codes: F16H 59/14 Inputs being a function of torque or torque demand
• CPC Class Codes: F16H 59/38 of gearing elements
• CPC Class Codes: F16H 61/6645 controlling shifting exclusively as a function of speed and torque
• CPC Class Codes: F16H 61/6649 characterised by the means for controlling the torque transmitting capability of the gearing
• CPC Class Codes: F16H 63/304 the final output mechanisms comprising elements moved by electrical or magnetic force band brake actuating mechanisms F16H63/3003

Abstract

Mechanisms and methods for clamping force generation are disclosed. In one embodiment, a clamping force generator system includes a permanent magnet bearing coupled to a traction ring and to a torque coupling. The traction ring can be provided with an electromagnetic bearing rotor and the torque coupling can be provided with an electromagnetic bearing stator. In some embodiments, a mechanical load cam, a permanent magnet bearing, and an electromagnetic bearing cooperate to generate a clamping force between the traction rings, the power rollers, and the idler. In other embodiments, a series of permanent magnet bearings and a mechanical bearing configured to produce a clamping force. In one embodiment an electromagnetic bearing is coupled to a control system and produces a specified clamping force that is associated with a torque transmitted in the transmission during operation. In some embodiments, a mechanical load cam produces a clamping force proportional to torque, while a permanent magnet bearing provides a minimum clamping force.

Claims

1. A method of controlling an axial force in a continuously variable transmission (CVT) having a plurality of spherical power rollers in contact with a first traction ring, a second traction ring, and a support member, the method comprising the steps of:

receiving, by a control system, a signal associated with an operating condition of the CVT;

determining a clamping force based on the received signal; and

configuring an axial force generator to provide the determined clamping force, the axial force generator comprising a permanent magnet bearing and an electromagnetic bearing for receiving a rotational power.

2. The method of claim 1, wherein configuring the axial force generator comprises optimizing the operating efficiency of the CVT.

3. The method of claim 1, wherein the clamping force is a constant clamping force.

4. The method of claim 1, wherein the clamping force is a minimum clamping force.

5. The method of claim 1, wherein the signal is indicative of one or more of torque, temperature, and component speed.

6. The method of claim 1, wherein determining the clamping force based on the received signal comprises using an algorithm to determine an optimum clamping force.

7. The method of claim 1, wherein configuring the axial force generator to provide the determined clamping force is performed dynamically.

8. The method of claim 1, further comprising configuring the axial force generator to provide a predetermined clamping force.

9. A system for controlling an axial force in a continuously variable transmission (CVT) having a plurality of spherical power rollers in contact with a first traction ring, a second traction ring, and a support member, the system comprising:

a controller configured for

receiving a signal associated with an operating condition of the CVT,

determining a clamping force based on the received signal, and

communicating an indication of the determined clamping force to an axial force generator comprising a permanent magnet bearing and an electromagnetic bearing for receiving a rotational power, wherein the axial force generator is configured to provide the determined clamping force.

10. The system of claim 9, wherein the axial force generator is configured to optimize the operating efficiency of the CVT.

11. The system of claim 9, wherein the clamping force is a constant clamping force.

12. The system of claim 9, wherein the clamping force is a minimum clamping force.

13. The system of claim 9, wherein the signal is indicative of one or more of torque, temperature, and component speed.

14. The system of claim 9, wherein the controller is configured to determine the clamping force based on the received signal using an algorithm to determine an optimum clamping force.

15. The system of claim 9, wherein the axial force generator is configured to provide the determined clamping force dynamically.

16. The system of claim 9, wherein the axial force generator is further configured to provide a predetermined clamping force.