Continuously variable transmission
First Claim
1. A method for controlling a continuously variable accessory drive (CVAD) with a continuously variable transmission (CVT) coupled to a prime mover and a load, the CVT having a plurality of traction planets, each traction planet adapted to rotate about a tiltable axis, the method comprising:
- a) receiving a desired output speed for the CVT;
b) determining a command signal for a skew actuator, 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;
c) applying the command signal to the skew actuator, wherein applying the command signal to the skew actuator causes the first carrier member to rotate about the longitudinal axis to apply a skew condition to tilt the axes of the plurality of traction planets, wherein the tilt angle determines an output speed of the CVT;
d) measuring the output speed of the CVT;
e) comparing the measured output speed to the desired output speed; and
f) repeating step b) through step e) until the measured output speed is substantially equal to the desired output speed.
3 Assignments
0 Petitions
Accused Products
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.
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Citations
10 Claims
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1. A method for controlling a continuously variable accessory drive (CVAD) with a continuously variable transmission (CVT) coupled to a prime mover and a load, the CVT having a plurality of traction planets, each traction planet adapted to rotate about a tiltable axis, the method comprising:
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a) receiving a desired output speed for the CVT; b) determining a command signal for a skew actuator, 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; c) applying the command signal to the skew actuator, wherein applying the command signal to the skew actuator causes the first carrier member to rotate about the longitudinal axis to apply a skew condition to tilt the axes of the plurality of traction planets, wherein the tilt angle determines an output speed of the CVT; d) measuring the output speed of the CVT; e) comparing the measured output speed to the desired output speed; and f) repeating step b) through step e) until the measured output speed is substantially equal to the desired output speed. - View Dependent Claims (2, 3, 4)
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5. A continuously variable transmission (CVT) system for use in a continuously variable accessory drive (CVAD), comprising:
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an input driver for receiving power from an input shaft coupled to an external source; a first traction ring coupled to the input driver for receiving power; a variator assembly coupled to the first traction ring for receiving power from the first traction ring; a second traction ring coupled to the variator assembly for receiving power from the variator assembly; a planetary gear assembly coupled to the second traction ring and further coupled to an output shaft; and a controller operable to; a) receive a desired output speed for the CVT; b) determine a command signal for a skew actuator, 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; c) apply the command signal to the skew actuator, wherein applying the command signal to the skew actuator causes the first carrier member to rotate about the longitudinal axis to apply a skew condition to tilt the axes of the plurality of traction planet assemblies, wherein the tilt angle determines an output speed of the CVT; d) measure the output speed of the CVT; e) compare the measured output speed to the desired output speed; and f) repeat step b) through step e) until the measured output speed is substantially equal to the desired output speed. - View Dependent Claims (6, 7, 8, 9, 10)
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Specification