Continuously variable transmissions and methods therefor

Abstract

Inventive embodiments are directed to components, subassemblies, systems, and/or methods for continuously variable transmissions (CVT) having a variator provided with a plurality of tilting, traction planets and traction rings. In one embodiment, a variator is coupled to a rangebox to provide multiple operating modes. In another embodiment, a hydraulic system is configured to control the transmission ratio of the variator and the rangebox. Various inventive shift-cam-and-sun subassemblies can be used to facilitate shifting of the transmission ratio of a CVT. Embodiments of a transmission housing and bell housing are adapted to house components of a CVT and, in some embodiments, to cooperate with other components of the CVT to support operation and/or functionality of the CVT. Various related devices include embodiments of, for example, a pivot arm, a control feedback mechanism, axial force generation and management mechanisms, a control valve integral with an input shaft, a pivot pin hub, and a rotatable carrier configured to support planet-pivot arm assemblies. FIG. 72 shows a torque-split ball-type rolling traction CVT with a ball-type rolling traction variator (1200) and planetary gearset (1400) which is followed by a rangebox (1600).

Description

RELATED APPLICATIONS[0001]This application claims the benefit of, and herby incorporates by reference herein in its entirety, U.S. Provisional Application 60 / 889,512, filed on Feb. 14, 2007.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The disclosed invention relates generally to mechanical power modulation and transmission. More specifically, the invention concerns continuously variable units and transmissions, subassemblies, components, and methods for use therewith.[0004]2. Description of the Related Art[0005]In the relevant technology various types of continuously variable transmissions (CVT) are known. The particular type of CVT which pertains to the present disclosure is typically known as a ball-type rolling traction CVT. Although ball-type rolling traction CVTs have gained some acceptance in certain industrial applications, the technology has generally been unable to overcome technical and economic hurdles to gain a wider adoption across multiple fields of ...

AI Technical Summary

Benefits of technology

[0007]The systems and methods herein described have several features, no single one of which is solely responsible for its desirable attributes. Without limiting the scope as expressed by the claims that follow, its more prominent features will now be discussed briefly.

Problems solved by technology

Although ball-type rolling traction CVTs have gained some acceptance in certain industrial applications, the technology ha

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