Assemblies and methods for clamping force generation

• US 9,618,100 B2
• Filed: 03/24/2014
• Issued: 04/11/2017
• Est. Priority Date: 05/07/2008
• Status: Expired due to Fees

• Current Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Original Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Inventors: Lohr, Charles B
• Primary Examiner(s): Fenstermacher, David M
• Application Number:
  US14/223,218
• Publication Number:
  US 20140206499A1
• Time in Patent Office: 1,114 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. An axial force generator for use with a continuously variable transmission (CVT) having a set of spherical power rollers arranged angularly about a main axis and in contact with a support member, the set of spherical power rollers being between and in contact with a first traction ring and a second traction ring, the main axis defining a longitudinal axis, the axial force generator comprising:

a permanent magnet bearing;

a first mechanical load cam coupled to the first traction ring and to the permanent magnet bearing; and

an electromagnetic bearing for receiving a rotational power, wherein the permanent magnet bearing is adapted to provide a force between the spherical power rollers, the first and second traction rings, and the support member.

2. The axial force generator of claim 1, further comprising a spring for preloading the axial force generator.

3. The axial force generator of claim 1, wherein the electromagnetic bearing is coupled to the first traction ring.

4. The axial force generator of claim 1, wherein the first mechanical load cam is adapted to receive a rotational power.

5. The axial force generator of claim 1, further comprising a second mechanical load cam coupled to the second traction ring and a torque coupling.

6. The axial force generator of claim 1, further comprising a control system configured to receive signals from the CVT and determine a clamping force based on the received signals.

7. An axial force generator for use with a continuously variable transmission (CVT) having a set of spherical power rollers arranged angularly about a main axis and in contact with a support member, the set of spherical power rollers being between and in contact with a first traction ring and a second traction ring, the main axis defining a longitudinal axis, the axial force generator comprising:

a housing rotatable about the longitudinal axis;

a permanent magnet bearing; and

an electromagnetic bearing for receiving a rotational power, wherein the permanent magnet bearing is adapted to provide a force between the spherical power rollers, the first and second traction rings, and the support member.

8. The axial force generator of claim 7, further comprising a control system configured to receive signals from the CVT and determine a clamping force based on the received signals.

9. An axial force generator for use with a continuously variable transmission (CVT) having a set of spherical power rollers arranged angularly about a main axis and in contact with a support member, the set of spherical power rollers being between and in contact with a first traction ring and a second traction ring, the main axis defining a longitudinal axis, the axial force generator comprising:

a permanent magnet bearing; and

an electromagnetic bearing for receiving a rotational power, wherein the permanent magnet bearing is adapted to provide a force between the spherical power rollers, the first and second traction rings, and the support member, and wherein the second traction ring is substantially non-rotatable about the longitudinal axis.

10. The axial force generator of claim 9, further comprising a control system configured to receive signals from the CVT and determine a clamping force based on the received signals.

11. An axial force generator for use with a continuously variable transmission (CVT) having a set of spherical power rollers arranged angularly about a main axis and in contact with a support member, the set of spherical power rollers being between and in contact with a first traction ring and a second traction ring, the main axis defining a longitudinal axis, the axial force generator comprising:

a permanent magnet bearing;

an electromagnetic bearing for receiving a rotational power, wherein the permanent magnet bearing is adapted to provide a force between the spherical power rollers, the first and second traction rings, and the support member; and

a control system configured to receive signals from the CVT and determine a clamping force based on the received signals.

12. A method of controlling an axial force in a continuously variable transmission (CVT) using the axial force generator of claim 11, the method comprising:

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

determining a clamping force based on the received signal; and

configuring the axial force generator to provide the determined clamping force.

13. The method of claim 12, wherein the axial force generator is configured to optimize the operating efficiency of the CVT.

14. The method of claim 12, wherein the clamping force is a constant clamping force.

15. The method of claim 12, wherein the clamping force is a minimum clamping force.

16. The method of claim 12, wherein the signal comprises a signal indicative of one or more of torque, temperature, and component speed.

17. The method of claim 12, wherein determining the clamping force based on the received signal comprises using an algorithm to determine an optimum clamping force.

18. The method of claim 12, wherein configuring the axial force generator to provide the determined clamping force is performed dynamically.

19. The method of claim 12, wherein the axial force generator is configured to provide a predetermined clamping force.