Linear motion guide unit

Patent metadata

Field	Value
Publication number	US-11067123-B2
Application number	US-201916720079-A
Country	US
Kind code	B2
Filing date	Dec 19, 2019
Priority date	Dec 19, 2019
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

A linear motion guide unit has sleeves which form return passages and are formed of a high temperature resistant resin material which allows use in a high temperature environment. In the linear motion guide unit, spaces serving as grease pools are formed in the sleeves inserted into insertion holes of a carriage. The sleeves are formed of a thermoplastic resin whose heat distortion temperature is higher than 80° C. Each sleeve is formed by combining split circular members obtained by dividing a cylindrical member into two pieces along the longitudinal direction, and a plurality of grooves which become spaces are formed on the inner circumferential surfaces of the sprit circular members through cutting orthogonal to a parting plane between the split circular members.

First claim

What is claimed is:

1. A linear motion guide unit comprising:
an elongated guide rail having a first raceway groove formed along each of opposite sides extending in a longitudinal direction; and a slider which slides on the guide rail in the longitudinal direction,
wherein the slider comprises:
a carriage which has a second raceway groove extending to face the first raceway groove of the guide rail and an insertion hole extending along the second raceway groove;
a sleeve which is inserted into the insertion hole so as to form a return passage;
a pair of end caps which are attached to opposite end surfaces of the carriage and each of which has a turnaround passage communicating with the return passage and a load-carrying race formed between the first raceway groove and the second raceway groove; and
a plurality of rolling elements which roll through a circulation passage formed by the load-carrying race, the return passage, and the paired turnaround passages, and
wherein the sleeve is not porous and formed of a thermoplastic resin selected from a group consisting of polyimide resin, polyamide-imide resin, ABS resin, polyethylene terephthalate (PET) resin, polyamide resin, polyacetal resin, polytetrafluoroethlylene (PTFE) resin, polyphenylenesulfide resin, and polyether ether ketone (PEEK) resin, and has a space serving as a grease pool.

2. A linear motion guide unit according to claim 1 , wherein the polyamide resin which is the thermoplastic resin is polyamide 66 resin.

3. A linear motion guide unit according to claim 1 , wherein the sleeve is formed by combining semi-circular members obtained by dividing a cylindrical member into at least two pieces along its longitudinal direction, and, in order to form the space serving as the grease pool, a plurality of grooves or a plurality of slits are formed in the semi-circular members through cutting orthogonal to a parting plane between the semi-circular members.

4. A linear motion guide unit according to claim 1 , wherein the end caps are formed of a thermoplastic resin whose heat distortion temperature is higher than 80° C.

5. A linear motion guide unit according to claim 4 , wherein the heat distortion temperature of the end caps falls within a range of 80° C. to 300° C.

Assignees

• Nippon Thompson Co Ltd

Inventors

• TAKEMURA Ayana
• Itabashi Shigemasa

Classifications

• F16C2322/39

  General buildup of machine tools, e.g. spindles, slides, actuators · CPC title

• F16C2208/70

  Polyesters, e.g. polyethylene-terephthlate [PET], polybutylene-terephthlate [PBT] · CPC title

• F16C2208/60

  Polyamides [PA] · CPC title

• F16C2208/58

  Several materials as provided for in F16C2208/30 - F16C2208/54 mentioned as option · CPC title

• F16C33/6651

  in recesses or cavities provided in retainers, races or rolling elements · CPC title