Continuously variable transmission

• US 8,496,554 B2
• Filed: 03/21/2012
• Issued: 07/30/2013
• Est. Priority Date: 10/14/2008
• 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: Pohl, Brad P, Thomassy, Fernand A., Lohr, Charles B, McBroom, Scott T
• Primary Examiner(s): PANG, ROGER L
• Application Number:
  US13/426,269
• Publication Number:
  US 20120238386A1
• Time in Patent Office: 496 Days
• Field of Search: 475/183, 475/158, 475/189, 475/190, 475/192, 475/196, 475/197, 476/38, 180/53.1, 180/53.8
• US Class Current: 475/189
• 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 continuously variable accessory drive (CVAD) comprising:

a continuously variable transmission (CVT) coupled to an accessory device and having a longitudinal axis, the CVT comprising;

a plurality of traction planets, each traction planet adapted to rotate about a tiltable axis;

a first carrier member comprising a plurality of radially offset slots formed in the first carrier member and arranged angularly about the longitudinal axis; and

a second carrier member comprising a plurality of radial slots formed in the second carrier member and arranged angularly about the longitudinal axis, the second carrier member being coupled to the first carrier member, the first and second carrier members operably coupled to each traction planet, wherein the first carrier member is configured to rotate relative to the second carrier member about the longitudinal axis; and

a skew actuator operably coupled to the CVT, the skew actuator adapted to apply a skew condition to the CVT to tilt the axes of the traction planets, wherein the skew actuator comprises a hydraulic piston.

2. The CVAD of claim 1, wherein the skew actuator further comprises a hydraulic control valve in fluid communication with the hydraulic piston.

3. The CVAD of claim 2, wherein the skew actuator further comprises 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.

4. The CVAD of claim 1, further comprising an output arranged along the longitudinal axis of the CVT, the output configured to couple the CVAD to the accessory device.

5. The CVAD of claim 4, further comprising an alternator coupled to the output.

6. The CVAD of claim 4, further comprising a pump coupled to the output.

7. The CVAD of claim 1, wherein the CVT is configured to receive an input power from a pulley driven by a prime mover.