Seal member of ball joint

Patent metadata

Field	Value
Publication number	US-11085486-B2
Application number	US-201815928993-A
Country	US
Kind code	B2
Filing date	Mar 22, 2018
Priority date	Mar 31, 2017
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

Provided is a seal member or a ball joint capable of satisfactorily maintaining sealing performance between a ball portion of a ball shank and a ball receiving portion of a holder for a long time even when the ball shank is used under a condition that the ball shank is pivoted repeatedly with respect to the holder at a large pivot angle and at high speed. The seal member includes: a base portion having an annular ring shape and is to be fixed to the holder; a retaining portion formed on an inner peripheral side of the base portion integrally with the base portion and is recessed into a conical shape toward the holder; and a lip portion formed along an inner peripheral edge of the retaining portion so as to be held in sliding contact with a spherical surface of the ball portion of the ball shank.

First claim

The invention claimed is:

1. A seal member of a ball joint, which is to be used in a ball joint including a ball shank and a holder coupled to each other in a freely pivotable manner, and is configured to seal a gap between a ball portion of the ball shank and a ball receiving portion of the holder, the seal member comprising:
a locking portion, which has an annular ring shape, and fixed to the holder by being fastened to a radially outer peripheral edge of the ball receiving portion;
a flange portion having a plate like annular shape formed on a radially inner side of the locking portion integrally with the locking portion, and extending from the locking portion and covering an axially outermost to surface of the ball receiving portion;
a retaining portion having a thickness smaller than a thickness of the flange portion, the retaining portion being formed on an inner peripheral side of the flange portion integrally with the flange portion, and is recessed into a conical shape toward the holder; and
a lip portion, which is formed along an inner peripheral edge of the retaining portion so as to be held in sliding contact with a spherical surface of the ball portion of the ball shank.

2. The seal member of a ball joint according to claim 1 , wherein the lip portion extends from the retaining portion toward a center of the seal member so as to decrease an inner diameter of the seal member.

3. The seal member of a ball joint according to claim 1 , further comprising a coupling portion, which is formed between the retaining portion and the lip portion, and has a thickness smaller than a thickness of each of the retaining portion and the lip portion.

4. The seal member of a ball joint according to claim 1 , further comprising a reinforcing member, which has a disc shape and is provided in a connection portion between the flange portion and the retaining portion.

5. A ball joint, comprising: a ball shank, which includes a ball portion formed at a distal end of a shank portion thereof, a holder having a ball receiving portion, which is coupled to the ball portion of the ball shank so as to allow the ball shank to be freely pivotable; and a seal member, which is configured to seal a gap between the ball receiving portion of the holder and the ball portion of the ball shank, the seal member including:
a locking portion, which has an annular ring shape, and fixed to the holder by being fastened to a radially outer peripheral edge of the ball receiving portion;
a flange portion having a plate like annular shape formed on a radially inner side of the locking portion integrally with the locking portion, and extending from the locking portion and covering an axially outermost top surface of the ball receiving portion;
a retaining portion having a thickness smaller than a thickness of the flange portion, the retaining portion being formed on an inner peripheral side of the flange portion integrally with the flange portion, and is recessed into a conical shape toward the holder; and
a lip portion, which is formed along an inner peripheral edge of the retaining portion so as to be held in sliding contact with a spherical surface of the ball portion of the ball shank.

Assignees

• Fanuc Corp
• Thk Co Ltd

Inventors

• Wu Yunfeng
• Kashiwagura Satoshi

Classifications

• F16C2322/59

  Manipulators, e.g. robot arms · CPC title

• F16J15/3204

  with at least one lip · CPC title

• F16C11/0676 Primary

  allowing operational relative movement of joint parts due to sliding between parts of the sealing means · CPC title

• F16J15/3284

  characterised by their structure; Selection of materials · CPC title

• F16C11/0623 Primary

  Construction or details of the socket member · CPC title