Belt for continuously variable transmission and manufacturing method of the same

Abstract

A belt for a continuously variable transmission (CVT) including an endless body and a plurality of V blocks attached to the endless body. The V blocks include a plurality of types of blocks having different thicknesses and are divided into a plurality of V block groups. The V block groups have different ratios of the plurality of types of V blocks, to provide a belt whose noise level is low and dispersed.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] Apparatuses and methods consistent with the present invention relate to a belt for a continuously variable transmission which is wound across a primary pulley and a secondary pulley each composed of a pair of sheaves and, more specifically, to a belt for a continuously variable transmission whose noise is reduced by using V blocks having different thickness for the large number of V blocks that abut against the pulleys. [0003] 2. Description of Related Art [0004] A belt type continuously variable transmission (hereinafter abbreviated as CVT) is generally used for power transmission systems of cars and the like. Belts for the CVTs typically include V blocks that are continuously attached to an endless body. In terms of the endless body, there is a push-type endless body that uses a ring composed of a plurality of laminated metal plates that transmits power by exerting a compression force on the V blocks, and a pull-t...

AI Technical Summary

Benefits of technology

[0009] It is an aspect of the invention to provide a belt for a CVT that disperses a peak of the frequency and lowers noise by forming a plurality of block groups having different ratios of blocks with different thicknesses.

[0017] Since the belts for a CVT of the present invention are composed of a plurality of V block groups having a different combination ratio of V blocks, they can disperse noise further when compared to the traditional randomly mixed belt and can reduce a rasping noise which is otherwise disturbing to human ears. The belt may be readily assembled by randomly arranging the V blocks in the V block groups. The noise may be reduced further by arranging the V blocks in the V block groups with a predetermined order that even further reduces the noise level.

[0018] The belt may be readily assembled with fewer types of V blocks and its cost lowered by forming the V block groups with two types of V blocks having different thicknesses and by forming the series of belts using two V block groups.

[0019] The number of different types of V blocks used may be equalized, thus improving efficiency in assembly and yield by equalizing the number of V blocks in the series or by inverting the ratios of the combinations of the V blocks in the two V block groups.

[0020] As will be appreciated, the invention may be suitably applied to a belt whose endless body is a metal ring, such that the V blocks are attached successively to reduce noise.

[0021] Further, the inventive belt manufacturing method enables an optimum arrangement of V blocks, causing less of a noise level, which can be analyzed through computer simulation, for example.

Problems solved by technology

Although the belt in which the blocks, having different thickness, are attached at random (hereinafter referred to as a randomly mixed belt) can lower the frequency peak by dispersing the noise, its effect is not enough and a noise is still produced that irritates human ears.

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