Continuously variable transmission

• US 8,870,711 B2
• Filed: 07/29/2013
• Issued: 10/28/2014
• Est. Priority Date: 10/14/2008
• Status: Expired due to Fees

• Current Assignee: Enviolo BV
• Original Assignee: Fallbrook Intellectual Property Company LLC (Fallbrook Technologies Incorporated)
• Inventors: Pohl, Brad P., Thomassy, Fernand A., Lohr, Charles B., McBroom, Scott T.
• Primary Examiner(s): PANG, ROGER L
• Application Number:
  US13/953,533
• Publication Number:
  US 20130310214A1
• Time in Patent Office: 456 Days
• Field of Search: 477/37, 475/183, 475/185, 475/189, 475/190, 475/192, 475/196, 475/197, 476/38, 180/53.1, 180/53.8
• US Class Current: 477/37
• CPC Class Codes: F02B 67/04 of mechanically-driven auxiliary apparatus
• 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
• CPC Class Codes: F16H 15/42 in which two members co-operate by means of rings or by means of parts of endless flexible members pressed between the first mentioned members
• 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 2059/704 Monitoring gear ratio in CVT's
• CPC Class Codes: F16H 2061/6641 Control for modifying the ratio control characteristic
• CPC Class Codes: F16H 59/40 Output shaft speed
• CPC Class Codes: F16H 61/0021 Generation or control of line pressure
• CPC Class Codes: F16H 61/0204 for gearshift control, e.g. control functions for performing shifting or generation of shift signal
• CPC Class Codes: F16H 61/664 Friction gearings
• CPC Class Codes: F16H 61/6646 controlling shifting exclusively as a function of speed
• CPC Class Codes: F16H 63/065 hydraulic actuating means
• CPC Class Codes: F16H 63/067 mechanical actuating means
• CPC Class Codes: F16H 63/42 Ratio indicator devices
• CPC Class Codes: Y02T 10/60 Other road transportation technologies with climate change mitigation effect
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Inventive embodiments are directed to components, subassemblies, systems, and/or methods for continuously variable accessory drives (CVAD). In one embodiment, a skew-based control system is adapted to facilitate a change in the ratio of a CVAD. In another embodiment, a skew-based control system includes a skew actuator coupled to a carrier member. In some embodiments, the skew actuator is configured to rotate a carrier member of a CVT. Various inventive traction planet assemblies can be used to facilitate shifting the ratio of a CVT. In some embodiments, the traction planet assemblies include legs configured to cooperate with the carrier members. In some embodiments, a traction planet assembly is operably coupled to the carrier members. Embodiments of a shift cam and traction sun are adapted to cooperate with other components of the CVT to support operation and/or functionality of the CVT. Among other things, shift control interfaces for a CVT are disclosed.

Claims

1. A skew actuator for a continuously variable accessory drive (CVAD) having a skew control system, the skew actuator comprising:

a hydraulic piston coupled to the CVAD, the hydraulic piston operably coupled to a first carrier member of the CVAD, the first carrier member comprising a plurality of radially offset slots formed in the first carrier member and arranged angularly about a longitudinal axis of the CVAD;

a hydraulic control valve in fluid communication with the hydraulic piston; and

a spool actuator coupled to the hydraulic control valve, the spool actuator configured to adjust the hydraulic control valve based at least in part on a desired skew condition of the CVT.

2. The skew actuator of claim 1, wherein the hydraulic control valve comprises a housing and a spool, the housing configured to translate with respect to the spool.

3. The skew actuator of claim 1, further comprising a pump in fluid communication with the hydraulic control valve.

4. The skew actuator of claim 3, further comprising an accumulator in fluid communication with the pump.

5. The skew actuator of claim 1, wherein the hydraulic control valve is a four-way directional control valve.

6. A skew control system for a continuously variable accessory drive (CVAD) having a plurality of traction planets, the skew control system comprising:

a sensor configured to receive data from the CVAD;

a skew actuator configured to communicate with a control module, the skew actuator further configured to apply a skew condition to each of the traction planets in a CVAD, wherein the skew actuator is operably coupled to a first carrier member of the CVAD, the first carrier member comprising a plurality of radially offset slots formed in the first carrier member and arranged angularly about a longitudinal axis of the CVAD;

a skew controller in communication with the control module, the skew controller configured to determine a skew actuator command signal based at least in part on a signal from the sensor, wherein the skew actuator command signal is configured to control an output speed of the CVAD.

7. The skew control system of claim 6, wherein the sensor is configured to communicate with an accessory device.

8. The skew control system of claim 6, wherein the skew actuator comprises a servo motor.

9. The skew control system of claim 6, wherein the skew actuator comprises a hydraulic control valve.

10. The skew control system of claim 9, wherein the hydraulic control valve is a four-way directional control valve.

11. The skew control system of claim 6, wherein the skew actuator comprises a lever.

12. A method of assembling a device for modulating power to an accessory device, the method comprising the steps of:

providing a continuously variable transmission (CVT) having a plurality of traction planets arranged angularly about a longitudinal axis, the CVT having a skew-based control system adapted to apply a skew condition to each of the traction planets;

providing a skew actuator coupled to the CVT, wherein the skew actuator is operably coupled to a first carrier member of the CVT, the first carrier member comprising a plurality of radially offset slots formed in the first carrier member and arranged angularly about a longitudinal axis of the CVT;

configuring the skew actuator to communicate with a skew controller, wherein the skew controller is adapted to control a speed ratio of the CVT or the speed of the accessory device; and

operably coupling the CVT to the accessory device.

13. The method of claim 12, wherein operably coupling the CVT to the accessory device comprises coupling a main shaft of the CVT to a driven shaft of the accessory device.

14. The method of claim 12, further comprising the step of operably coupling the CVT to a prime mover.