Boot for constant velocity universal joint

Patent metadata

Field	Value
Publication number	US-2021123481-A1
Application number	US-201816493879-A
Country	US
Kind code	A1
Filing date	Mar 14, 2018
Priority date	Mar 16, 2017
Publication date	Apr 29, 2021
Grant date	—

Abstract

A boot for a constant velocity universal joint includes large- and small-diameter mounting portions to be mounted to an outer joint member and a shaft, respectively, with boot clamps, a bellows portion integrally coupling the large- and small-diameter mounting portions to each other, and a cylindrical shoulder portion formed at a bellows portion-side end of the large-diameter-side mounting portion, and connected to the bellows portion through two auxiliary crest portions and one auxiliary trough portion between the auxiliary crest portions. A radial distance between each of the auxiliary crest portions and the auxiliary trough portion is shorter than a radial distance between a crest portion and a trough portion. A diameter passing through a center of the radial distance between each of the auxiliary crest portions and the auxiliary trough portion is larger than a diameter of the cylindrical shoulder portion.

First claim

1 . A boot for a constant velocity universal joint, comprising:
a large-diameter-side mounting portion, which is to be mounted on an outer peripheral surface of an outer joint member of the constant velocity universal joint, and is to be fixed to the outer peripheral surface of the outer joint member through fastening with use of a boot clamp; a small-diameter-side mounting portion, which is to be mounted on an outer peripheral surface of a shaft, and is to be fixed to the outer peripheral surface of the shaft through fastening with use of a boot clamp; a bellows portion configured to integrally couple the large-diameter-side mounting portion and the small-diameter-side mounting portion to each other; and a cylindrical shoulder portion, which is formed at a bellows portion-side end of the large-diameter-side mounting portion, and is connected to the bellows portion through two auxiliary crest portions and one auxiliary trough portion between the two auxiliary crest portions, wherein a radial distance (H 1 ) between each of the auxiliary crest portions and the auxiliary trough portion is set shorter than a radial distance (H 2 ) between a crest portion and a trough portion of the bellows portion, wherein a diameter (D 1 ) passing through a center (Ho) of the radial distance (H 1 ) between each of the auxiliary crest portions and the auxiliary trough portion is set larger than a diameter (D 3 ) of the cylindrical shoulder portion, and wherein the boot has such a deformation mode that, when the constant velocity universal joint forms a high operating angle, the auxiliary crest portions overlap each other in a radial direction of the boot on the outer peripheral surface of the outer joint member.

2 . The boot for a constant velocity universal joint according to claim 1 , wherein curvature radii of the crest portion and the trough portion of the bellows portion, which are closest to the small-diameter-side mounting portion, on a longitudinal cross section are larger than curvature radii of the other crest portions and the other trough portions on the longitudinal cross section.

3 . The boot for a constant velocity universal joint according to claim 1 , wherein the cylindrical shoulder portion comprises an arc-shaped portion projecting radially inward from the bellows portion-side end of the large-diameter-side mounting portion and a straight-shaped portion extending in connection to the arc-shaped portion.

4 . The boot for a constant velocity universal joint according to claim 1 , wherein the boot for a constant velocity universal joint is made of a thermoplastic polyester-based elastomer.

5 . The boot for a constant velocity universal joint according to claim 2 , wherein the cylindrical shoulder portion comprises an arc-shaped portion projecting radially inward from the bellows portion-side end of the large-diameter-side mounting portion and a straight-shaped portion extending in connection to the arc-shaped portion.

6 . The boot for a constant velocity universal joint according to claim 2 , wherein the boot for a constant velocity universal joint is made of a thermoplastic polyester-based elastomer.

7 . The boot for a constant velocity universal joint according to claim 3 , wherein the boot for a constant velocity universal joint is made of a thermoplastic polyester-based elastomer.

8 . The boot for a constant velocity universal joint according to claim 5 , wherein the boot for a constant velocity universal joint is made of a thermoplastic polyester-based elastomer.

Assignees

• Ntn Toyo Bearing Co Ltd

Inventors

• Yoshinaga Shingo

Classifications

• F16D3/845 Primary

  allowing relative movement of joint parts due to the flexing of the cover · CPC title

• F16D3/2237

  where the grooves are composed of radii and adjoining straight lines, i.e. undercut free [UF] type joints · CPC title

• F16J15/525 Primary

  fixed to a part of a transmission performing a wobbling or a circular translatory movement · CPC title

• F16J3/043

  with particular means for limiting wear · CPC title

• F16J15/52

  by means of sealing bellows or diaphragms (connection of valves to inflatable elastic bodies B60C29/00) · CPC title