Linear motion guide unit

Patent metadata

Field	Value
Publication number	US-9528549-B2
Application number	US-201514670681-A
Country	US
Kind code	B2
Filing date	Mar 27, 2015
Priority date	May 30, 2014
Publication date	Dec 27, 2016
Grant date	Dec 27, 2016

Abstract

A porous compact impregnated with lubricant fits into a lengthwise hole in the carriage to apply the lubricant around balls rolling through a return passage to realize maintenance-free lubrication. The carriage has a flat upper portion which has threaded holes lying midway between the widthwise opposed bulges to fasten counterparts to the carriage. The carriage has widthwise opposed corners where the flat upper portion merges the respective bulges. The corners each have therein a lengthwise hole in which the cylindrical porous compact impregnated with lubricant is inserted to extend across the overall length of corners. The bulges of the carriage have threaded holes which are used to fasten the end caps to the fore and aft ends of the carriage.

First claim

What is claimed is:

1. A linear motion guide unit comprising: a guide rail having first raceway groove extending lengthwise on each longitudinal side of the guide rail, and a slider that fits over or conforms to the guide rail for movement relative to the guide rail,
the slider being composed of a carriage having a second raceway groove lying in opposition to the first raceway groove on each longitudinal side of the guide rail to define a load-carrying race between the first raceway groove and the second raceway groove and a return passage extending in parallel with load-carrying race, an end cap secured to each opposite end of the carriage and each end cap comprising a turnaround passage to connect the load-carrying race with the return passage, and a plurality of balls for rolling elements disposed to roll through a circulating circuit which is made up of the load-carrying race, return passages, and turnaround passages;
wherein the carriage is made up of a flat upper portion spreading above and in opposition to a top surface of the guide rail and side bulges lying on widthwise opposite sides of the upper portion to extend downward alongside of the longitudinal sides of the guide rail and further having the second raceway grooves on inside surfaces thereof, and
wherein the flat upper portion of the carriage has threaded holes lying midway between the widthwise opposed bulges to fasten counterparts to the carriage, the carriage having widthwise opposed corners where the flat upper portion merges with the respective bulges, the corners each have therein a lengthwise hole in which a cylindrical porous compact impregnated with lubricant is inserted to extend across a length of the corner, and the bulges of the carriage have threaded holes which are used to fasten the end caps to the fore and aft ends of the carriage.

2. The linear motion guide unit constructed as defined in claim 1 , wherein the end cap is composed of an end cap major part and a spacer, an end cap major part having sidewise opposed shoulders having surfaces to come into abutment against the bulges of the carriage, the shoulders each having a first spigot end cap major part having a first spigot part to constitute in part a cylindrical spigot which are to fit into a lengthwise hole in the carriage, the end cap major part further having an outside circular part of the turnaround passage continuing the first spigot part, and the spacer having a second spigot part coming into abutment against an end surface apart from the shoulders of the end cap major part to provide a rest of the spigots and formed with an inside circular wall of the turnaround passage.

3. The linear motion guide unit constructed as defined in claim 2 , wherein the end cap major part is composed of the shoulders, the upper portion extending between the shoulders with lying in opposition to the upper side of the guide rail, and bulges extending downwards from widthwise opposed ends of the upper portion along the longitudinal sides of the guide rail, and wherein the end surface of the upper portion to come into abutment against the spacer has a lowered surface which is retracted backward than the surfaces of the shoulders by a thickness of the spacer.

4. The linear motion guide unit constructed as defined in claim 3 , wherein a side surface to define the shoulder of the end cap major part provides a locating surface lying perpendicular to a sliding direction relative to the spacer when the spacer is arranged on the end surfaces of the upper portion and the bulges of the end cap major part.

5. The linear motion guide unit constructed as defined in claim 4 , wherein after the spacer is installed between the shoulders in a recessed surface below the shoulder, the cylindrical spigot of the first spigot part and the second spigot part mated with each other fits into the lengthwise hole in the carriage while the surfaces of the shoulders are formed flush with the end surface of the carriage.

6. The linear motion guide unit constructed as defined in claim 5 , wherein the spacer, after fastened across the overall length thereof to the end surface with the exception of sidewise opposed shoulders of the end cap major part, is exposed outside across the overall surfaces of upper surface, side surface and bottom surface of the spacer.

7. The linear motion guide unit constructed as defined in claim 2 , wherein the first spigot on the end cap major part has about two-third circumference of the cylindrical spigot and the second spigot on the spacer has about one-third circumference of the cylindrical spigot.

8. The linear motion guide unit constructed as defined in claim 2 , wherein a screw to fasten the end caps to the fore and aft ends of the carriage is driven into a counterbore lying on the outermost end surfaces of the end cap major part so as not to rise above the outermost surface of the end cap major part.

9. The linear motion guide unit constructed as defined in claim 2 , wherein the carriage on one end thereof has a dent which is used to identify a direction while manufacturing the carriage and wherein the carriage, the end cap major part and the spacer are painted in different colors.

10. The linear motion guide unit constructed as defined in claim 1 , wherein the cylindrical porous compact is made of a powdery synthetic resinous material of polyethylene or polypropylene which is molded at an elevated temperature while compacted into a porous or cellular structure in which the pores are open to each other through interstices among the fused particles, and lubricant retained in the pores or cells in the porous structure gets oozed out of pores or cells by a stress or impact of the plurality of balls rolling through the return passages and applied around the plurality of balls while rolling through the return passages.

11. The linear motion guide unit constructed as defined in claim 1 , which is a miniature style composed of the guide rail of around 3 mm in width and the slider of around 8 mm in width.

Assignees

• Nippon Thompson Co Ltd

Inventors

• Kikuchi Shunsuke

Classifications

• F16C29/0611

  of the return passages, i.e. the passages where the rolling elements do not carry load · CPC title

• F16C33/6648

  in a porous or resinous body, e.g. a cage impregnated with the liquid · CPC title

• F16C29/064 Primary

  with two rows of balls, one on each side of the rail · CPC title

• F16C29/005

  Guide rails or tracks for a linear bearing, i.e. adapted for movement of a carriage or bearing body there along · CPC title

• F16C29/0609

  of the ends of the bearing body or carriage where the rolling elements change direction, e.g. end caps · CPC title