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AssigneeVan Doorne's Transmissie B.V.
InventorsArjen Brandsma, Paulus Maria Smeets, Gerardus Johannes Maria Lamers
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A continuously variable transmission, provided with two adjustable pulleys, each pulley comprising a pair of mutually displaceable essentially frusto-conical pulley sheaves having a radial dimension provided on a pulley shaft, each sheave having a sheave face, whereby the sheave faces of a pulley are mutually oriented at a pulley angle, and with an endless flexible belt for transmitting torque comprising two lateral side faces, which are mutually oriented at a belt angle ( alpha ) such that the flexible belt tapers radially inwardly and which are intended for interacting with the sheave faces of a pulley under the influence of a clamping force to be exerted on the flexible belt by the sheaves. The belt angle is marginally, but notionally, larger than the pulley angle (beta) of at least one pulley for at least a substantial part of the radial dimension of the pulley sheaves.
A continuously variable transmission, in particular for motor vehicles, provided with two adjustable pulleys, each comprising a pair of mutually displaceable essentially frusto-conical pulley sheaves having a radial dimension provided on a pulley shaft, each sheave having a sheave face, whereby the sheave faces of a pulley are mutually oriented at a pulley angle, and with an endless flexible belt for transmitting torque comprising two lateral side faces, which are mutually oriented at a belt angle such that the flexible belt tapers radially inwardly and which are intended for interacting with the sheave faces of a pulley under the influence of a clamping force to be exerted on the flexible belt by the sheaves, characterised in that, the belt angle is marginally, but notionally, larger than the pulley angle of at least one pulley for at least a substantial part of the radial dimension of the pulley sheaves.
A continuously variable transmission according to any one of the preceding claims, characterised in that the pulley angle decreases in a radially outward direction along at least a substantial part of the radial dimension of the pulley sheaves.
A continuously variable transmission according to any one of the preceding claims, characterised in that the pulley angle decreases in a radially outward direction, such that when a clamping force is applied during operation of the CVT, the pulley angle substantially corresponds to the belt angle, at least at a radial position of interaction between the lateral side faces and the sheave faces, independently from the actual radial position of such interaction for a substantial part of the radial dimension of the sheaves.
A continuously variable transmission according to 6, characterized in that the said clamping force is a maximum clamping force applied during operation of the CVT.
A continuously variable transmission according to any one of the preceding claims, characterised in that the belt angle substantially corresponds to the pulley angle at a radially innermost position of interaction between the lateral side faces and the sheave faces and in that the belt angle is marginally, but notionally, larger than the said pulley angle by a value in the range from 1/30th of a degree to ⅓rd of a degree at a radially outermost position of the said interaction.
A continuously variable transmission according to any one of the preceding claims, characterised in that the belt angle is marginally, but notionally, larger than the said pulley angle by a value in the range from {fraction (1/20)}th of a degree to ⅙th of a degree at a radially innermost position of interaction between the lateral side faces and the sheave faces.
A continuously variable transmission according to any one of the preceding claims, characterised in that the pulley angle of at least one pulley and/or the belt angle is asymmetrically with respect to an orthogonal of an axial direction of the pulley shafts.
A continuously variable transmission according to any one of the preceding claims, characterised in that at least one sheave face is provided with a curvature having an essentially constant radius of curvature, such that the said sheave face is concave as seen in tangential cross section.
Endless flexible drive belt, in particular a push-type drive belt intended for application in a continuously variable transmission according to any one of the preceding claims.
Dependencies are inferred from the claim text.