Continuously variable transmission

• US 9,869,388 B2
• Filed: 11/21/2014
• Issued: 01/16/2018
• Est. Priority Date: 07/05/2007
• Status: Active Grant

• 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.
• Primary Examiner(s): LEWIS, TISHA D
• Application Number:
  US14/550,702
• Publication Number:
  US 20150080165A1
• Time in Patent Office: 1,152 Days
• CPC Class Codes: F16H 15/28 with external friction surface
• CPC Class Codes: F16H 15/50 Gearings providing a continuous range of gear ratios
• CPC Class Codes: F16H 61/664 Friction gearings
• CPC Class Codes: F16H 61/6648 controlling of shifting being influenced by a signal derived from the engine and the main coupling
• CPC Class Codes: F16H 63/067 mechanical actuating means

Abstract

Inventions are directed to components, subassemblies, systems, and/or methods for continuously variable transmissions (CVT). In one aspect, a control system is adapted to facilitate a change in the ratio of a CVT. A control system includes a control reference nut coupled to a feedback cam and operably coupled to a skew cam. In some cases, the skew cam is configured to interact with carrier plates of a CVT. Various inventive feedback cams and skew cams can be used to facilitate shifting the ratio of a CVT. In some transmissions described, the planet subassemblies include legs configured to cooperate with the carrier plates. In some cases, a neutralizer assembly is operably coupled to the carrier plates. A shift cam and a traction sun are adapted to cooperate with other components of the CVT to support operation and/or functionality of the CVT.

Claims

1. A skew-based control system for controlling a continuously variable transmission (CVT) having a plurality of tiltable planets, comprising:

a control reference source configured to provide a control reference indicative of a desired operating condition of the CVT;

a summing junction operable to compare the control reference to a feedback value;

a skew dynamics module operable to

receive a result of the comparison of the control reference to the feedback value, and

return a rate of change in the tilt angle for the plurality of tiltable planets; and

an integrator for determining a tilt angle for the plurality of tiltable planets based on the rate of change in the tilt angle for the plurality of tiltable planets, wherein the system is configured to change the tilt angle of the plurality of tiltable planets.

2. The system of claim 1, wherein the CVT comprises a traction sun, the plurality of tiltable planets operably coupled to a carrier plate and to the traction sun, and wherein the control reference comprises a position reference of the traction sun.

3. The system of claim 1, wherein the control reference comprises one of a desired skew angle, a desired tilt angle, a speed ratio, and a torque ratio.

4. The system of claim 1, further configured to generate a control error based on the comparison of the desired operating condition with a current operating condition.