Infinitely variable transmissions, continuously variable transmissions, methods, assemblies, subassemblies, and components therefor
First Claim
1. A method of changing the ratio of a variator of a continuously variable or infinitely variable transmission (CVT/IVT), the variator comprising a plurality of spherical rollers arranged about a central axis and interposed between a first traction ring and a second traction ring, each spherical roller being rotatable about an axle, the method comprising the steps of:
- determining a desired speed ratio for the transmission;
sending a control signal to a hydraulic control valve operably coupled to a plurality of hydraulic pistons, wherein the plurality of planet axles of the variator are operably coupled to at least one of the plurality of hydraulic pistons; and
supplying a hydraulic pressure from the hydraulic control valve to at least one of the plurality of hydraulic pistons based on the control signal, wherein one or more of the hydraulic pressure and the rate at which hydraulic pressure is applied actuates a change in a tilt angle of at least one of the planet axles to the desired speed ratio.
3 Assignments
0 Petitions
Accused Products
Abstract
Inventive embodiments are directed to components, subassemblies, systems, and/or methods for infinitely variable transmissions (IVT) having a variator provided with a plurality of tilting spherical planets. In one embodiment, a variator is provided with multiple planet arrays. In another embodiment, a hydraulic system is configured to control the transmission ratio of the IVT. Various inventive idler assemblies and planet-pivot arm assemblies can be used to facilitate adjusting the transmission speed ratio of an IVT. Embodiments of a transmission housing and bell housing are adapted to house components of an IVT and, in some embodiments, to cooperate with other components of the IVT to support operation and/or functionality of the IVT. Various related devices include embodiments of, for example, a control feedback mechanism, axial force generation and management mechanisms, a control valve integral with an input shaft, and a rotatable carrier configured to support planet-pivot arm assemblies.
563 Citations
15 Claims
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1. A method of changing the ratio of a variator of a continuously variable or infinitely variable transmission (CVT/IVT), the variator comprising a plurality of spherical rollers arranged about a central axis and interposed between a first traction ring and a second traction ring, each spherical roller being rotatable about an axle, the method comprising the steps of:
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determining a desired speed ratio for the transmission; sending a control signal to a hydraulic control valve operably coupled to a plurality of hydraulic pistons, wherein the plurality of planet axles of the variator are operably coupled to at least one of the plurality of hydraulic pistons; and supplying a hydraulic pressure from the hydraulic control valve to at least one of the plurality of hydraulic pistons based on the control signal, wherein one or more of the hydraulic pressure and the rate at which hydraulic pressure is applied actuates a change in a tilt angle of at least one of the planet axles to the desired speed ratio. - View Dependent Claims (2, 3, 4)
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5. A method of shifting a continuously or infinitely variable transmission having a variator, the variator comprising a plurality of spherical rollers arranged about a central axis and interposed between a first traction ring and a second traction ring, each spherical roller being rotatable about an axle, the method comprising the steps of:
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hydraulically coupling a control valve to a control piston; coupling the control piston to a feedback spring; sending a pilot pressure indicative of a desired tilt angle of the of planet axles to the control valve, wherein the pilot pressure range is a function of a spring rate of the feedback spring, a total deflection range of the feedback spring, and an area of the control piston; and actuating a tilting of at least one planet axle based at least in part on the pilot pressure, whereby tilting the planet axle changes the speed ratio of the transmission. - View Dependent Claims (6, 7, 8)
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9. A method of shifting an infinitely variable transmission comprising a plurality of spherical rollers arranged about a central axis and interposed between a first traction ring and a second traction ring, each spherical roller being rotatable about an axle coupled at both ends to a pivot arm of a plurality of pivot arms, the method comprising the steps of:
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operably coupling a feedback mechanism to the plurality of pivot arms; operably coupling a pressure regulator to the feedback mechanism; delivering one or more indications of a state of the plurality of pivot arms from the feedback mechanism to the regulator; receiving a control signal at the pressure regulator; regulating a hydraulic pressure with the pressure regulator, the hydraulic pressure based at least in part on the combination of the control signal and the one or more indications of the state of the plurality of pivot arms; and actuating a transmission ratio adjustment by using the hydraulic pressure to move the plurality of pivot arms. - View Dependent Claims (10, 11)
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12. A shifting mechanism for a continuously or infinitely variable transmission (C/IVT) having a variator, the variator comprising a plurality of spherical rollers arranged about a central axis and interposed between a first traction ring and a second traction ring, each spherical roller being rotatable about an axle, the shifting mechanism comprising:
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a control valve configured to be housed in a cavity of an input shaft of the C/IVT; a control piston in fluid communication with the control valve; and a pivot pin hub operationally coupled to the control piston, the pivot pin hub operably coupled to a pivot arm of the C/IVT. - View Dependent Claims (13, 14, 15)
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Specification