JP2008291975A - Linear motion guide bearing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear motion guide bearing unit having an improved lubricity over a long period of time. <P>SOLUTION: In a slider 2 of the linear motion guide bearing unit, rolling-element return raceway 16 is formed in order to send rolling elements 3 from the terminal to the starting point of a rolling-element rolling-contact raceway 14. The rolling-element return raceway 16 comprises a linear raceway 13 parallel to the rolling-element rolling-contact raceway 14, and a curved raceway 15 for communication of the linear raceway 13 with the rolling-contact raceway 14. A tubular member 21 made of resin is inserted in a linear hole 20 made in the slider 2, a plurality of strip walls 21a which are extended longitudinally are protruded radially inside from the inner peripheral face of the tubular member 21, radially tip-ends 21b of the strip walls 21a constitute linear raceways 13. Annular walls 21c are protruded radially inward respectively from the inner peripheral faces in the vicinity of both ends in the longitudinal direction of the tubular member 21. A lubricant reservoir for holding the lubricant is made up of a recess 23 formed by being surrounded by both the annular walls 21c and the strip walls 21a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a linear motion guide bearing device.

An example of the configuration of a conventional linear guide bearing device will be described.
The linear motion guide bearing device includes a guide rail having a substantially square cross section extending in the axial direction, and a slider having a substantially U-shaped cross section attached to the guide rail. The rolling element rolling grooves of 2 rows, 4 rows, etc. are formed in the axial direction.
The slider includes a slider body and end caps attached to both end portions in the axial direction. The slider body has a rolling element rolling groove facing the rolling element rolling groove of the guide rail on the inner surface of both sleeve parts, and a straight path that penetrates the thick part of the sleeve part in the axial direction. ing. And the rolling element rolling path is formed by the both rolling element rolling grooves which oppose.

  On the other hand, the end cap has a curved path that allows the rolling element rolling path to communicate with a straight path parallel thereto. The straight road and the curved roads at both ends constitute a rolling element return path for sending the rolling elements from the end point of the rolling element rolling path to the start point. A road is formed. A large number of rolling elements made of, for example, steel balls are loaded in the rolling element circulation path.

The slider attached to the guide rail moves smoothly along the guide rail through the rolling of the rolling element in the rolling element rolling path. During the movement, the rolling element moves in the rolling element circulation path in the slider. Roll infinitely while rolling.
In such a conventional linear motion guide bearing device, the lubricant is automatically supplied to a large number of rolling elements rolling in the rolling element return path over a long period of time. May be arranged.

For example, Patent Document 1 discloses a linear motion guide bearing device in which a linear path of a rolling element return path is formed in a synthetic resin sleeve fitted into a circular hole penetrating the slider body. ing. That is, a return hole forming a straight path is formed in the synthetic resin sleeve. And the oil groove connected to the front-and-rear both end surfaces of a sleeve is recessedly provided in the internal peripheral surface of a return hole.
Patent Document 2 discloses a linear motion guide bearing device in which a tube is inserted into a linear hole formed in a slider. That is, the inner peripheral surface of the tube forms a straight path in the rolling element return path. And a part or all of a tube is comprised with the lubricant containing polymer.

Further, Patent Document 3 discloses a linear motion guide bearing device in which a sleeve-like return path member is inserted into an insertion hole formed in a slider body. That is, the inner peripheral surface of the return path member constitutes a straight path in the rolling element return path. The return path member is composed of a sintered resin member having a porous structure, and lubricating oil or grease is held in the porous structure.
JP-A-4-194413 Japanese Patent Laid-Open No. 10-78032 JP 2003-90338 A

However, the linear motion guide bearing device disclosed in Patent Document 1 has excellent lubricity because the oil groove does not have a structure for holding the lubricant and the lubricant in the oil groove may leak to the outside. May not be maintained over a long period of time, and it was necessary to replenish the lubricant as needed.
Further, in the linear motion guide bearing device disclosed in Patent Literature 2, the tube is made of a lubricant-containing polymer, and in the linear motion guide bearing device disclosed in Patent Literature 3, the return path member is sintered with a porous structure. Since it is comprised with the resin member, intensity | strength was not high and there existed a possibility of damaging by the contact of a rolling element. Further, since the lubricant contained in these members is not so large, there is a possibility that excellent lubricity cannot be maintained for a longer period of time.
Accordingly, an object of the present invention is to solve the above-described problems of the prior art and to provide a linear motion guide bearing device having excellent lubricity over a long period of time.

  In order to solve the above-described problems, the present invention has the following configuration. That is, the linear motion guide bearing device according to the first aspect of the present invention includes a guide rail having a rolling element rolling groove extending in the axial direction on the outer surface, and a rolling element rolling facing the rolling element rolling groove of the guide rail. A plurality of sliders mounted on the guide rail having a groove and capable of relative movement in the axial direction, and a rolling element rolling path formed between the rolling element rolling grooves. A rolling element return path that feeds the rolling element from an end point to a starting point of the rolling element rolling path is formed in the slider, and the rolling element return path is the rolling element rolling path. In a linear motion guide bearing device comprising: a linear path parallel to the curved path; and a curved path communicating with the linear path and the rolling element rolling path, the linear hole provided in the slider has a resin tubular shape. The member is inserted, and from the inner peripheral surface of the tubular member, the longitudinal direction A plurality of extending strip-like wall bodies protrude radially inward, and the straight path is constituted by the radial tip portions of these strip-like wall bodies, and the inner peripheral surface in the vicinity of both longitudinal ends of the tubular member The annular wall bodies project radially inward, and a lubricant reservoir for containing the lubricant is formed by the recesses formed by being surrounded by both the annular wall bodies and the belt-like wall body. It is characterized by that.

The linear motion guide bearing device according to claim 2 of the present invention is the linear motion guide bearing device according to claim 1, wherein the tubular member is an integrally formed resin member.
Furthermore, a linear motion guide bearing device according to a third aspect of the present invention is the linear motion guide bearing device according to the first aspect, wherein the tubular member is formed by combining a plurality of resin parts. Furthermore, the linear motion guide bearing device according to claim 4 of the present invention is the linear motion guide bearing device according to claim 3, wherein the plurality of resin parts have substantially the same shape, and the tubular member extends in the longitudinal direction. It is the shape divided | segmented by the plane which follows.

  The linear motion guide bearing device of the present invention has excellent lubricity over a long period of time.

An embodiment of a linear motion guide bearing device according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of a linear guide bearing device according to the present invention. 2 is a front view of the linear motion guide bearing device of FIG. 1 viewed from the axial direction (however, the end cap is omitted), and FIG. 3 is the AA line of FIG. It is sectional drawing.
First, the configuration of the linear motion guide bearing device of the present embodiment will be described. On a guide rail 1 having a substantially square cross section extending in the axial direction, a slider 2 having a substantially U-shaped cross section is assembled so as to be relatively movable in the axial direction.

Rolling element rolling grooves 10 and 10 each formed of a concave groove having a substantially arc-shaped cross section extending in the axial direction are formed at the ridge line portion where the upper surface of the guide rail 1 and both side surfaces 1a and 1a intersect. Rolling element rolling grooves 10 and 10 each having a substantially semicircular cross section extending in the axial direction are formed at intermediate positions on both side surfaces 1a and 1a of the guide rail 1.
The slider 2 includes a slider body 2A and end caps 2B and 2B that are detachably attached to both end portions in the axial direction. Further, both end portions of the slider 2 (end surfaces of the end caps 2B). ) Are provided with side seals 5 and 5 for sealing the opening of the gap between the guide rail 1 and the slider 2.

Furthermore, rolling element rolling grooves 11, 11 having a substantially semicircular cross section facing the rolling element rolling grooves 10, 10 of the guide rail 1 are formed at the corners of the inner surfaces of both sleeve portions 6, 6 of the slider body 2 </ b> A. Formed at the center of the inner surface of the sleeves 6 and 6 are rolling element rolling grooves 11 and 11 having a substantially semicircular cross section facing the rolling element rolling grooves 10 and 10 of the guide rail 1. Yes.
The rolling element rolling grooves 10, 10, 10, 10 of the guide rail 1 and the rolling element rolling grooves 11, 11, 11, 11 of both sleeve portions 6, 6 have a substantially circular cross section. 14, 14, 14, and 14 are formed, and these rolling element rolling paths 14 extend in the axial direction. The number of rolling element rolling grooves 10 and 11 provided in the guide rail 1 and the slider 2 is not limited to two rows on one side, and may be one row on one side or three rows or more, for example.

Furthermore, the slider 2 has straight paths 13, 13, 13, penetrating in the axial direction parallel to the rolling element rolling paths 14 at the upper and lower portions of the thick portions of the sleeve portions 6, 6 of the slider body 2 A. 13 is provided.
On the other hand, as shown in FIG. 3, the end caps 2B and 2B having a substantially U-shaped cross section have rolling element rolling paths 14 and linear paths 13 parallel to the rolling element rolling paths 14 on the contact surface (back surface) with the slider body 2A. A semi-doughnut-shaped curved path 15 that communicates with each other. The straight path 13 and the curved paths 15 and 15 at both ends constitute a rolling element return path 16 that sends the rolling element 3 from the end point of the rolling element rolling path 14 to the starting point. The rolling element return path 16 and the rolling element. The rolling path 14 forms a substantially annular rolling element circulation path. A large number of rolling elements 3 made of, for example, steel balls are slidably loaded in the rolling element circulation path.

When the slider 2 assembled to the guide rail 1 is moved in the axial direction along the guide rail 1, the rolling element 3 loaded in the rolling element rolling path 14 rolls in the rolling element rolling path 14. It moves in the same direction as the slider 2 with respect to the guide rail 1 while moving. When the rolling element 3 reaches one end (end point) of the rolling element rolling path 14, the rolling element 3 is scooped up from the rolling element rolling path 14 by the tongue 17 provided in the end cap 2 </ b> B and sent to the curved path 15.
The rolling element 3 having entered the curved path 15 makes a U-turn and is introduced into the straight path 13, and reaches the opposite curved path 15 through the straight path 13. Here, the U-turn is made again to return to the rolling element rolling path 14, and such circulation in the rolling element circulation path is repeated infinitely.

  The straight path 13 of such a linear motion guide bearing device is configured as follows. The slider main body 2A is formed with a linear hole 20 having a circular cross section that is parallel to the rolling element rolling path 14 and penetrates in the axial direction, and a resin tubular member 21 is inserted into the linear hole 20. (See FIG. 4, which is a perspective view showing only the tubular member 21 and the slider body 2A). End caps 2B are attached to both end portions of the slider body 2A in the axial direction, and the end portions of the tubular member 21 abut against the end cap 2B and the axial movement of the tubular member 21 is restricted. The axial position of the tubular member 21 is fixed without providing a means for fixing the directional position.

  Next, the tubular member 21 will be described in detail with reference to FIGS. FIG. 5 is a plan view and a perspective view of the tubular member 21 divided into two by a plane along the longitudinal direction for convenience of explanation. A plurality (four in FIG. 4) of strip-shaped wall bodies 21a are formed on the inner peripheral surface of the tubular member 21 along the longitudinal direction. That is, from the inner peripheral surface of the tubular member 21, a strip-like wall body 21a extending in the longitudinal direction protrudes radially inward. And the linear path 13 is comprised by the radial direction front-end | tip part 21b of these several strip | belt-shaped wall bodies 21a, and the rolling element 3 moves to an axial direction along the radial direction front-end | tip part 21b of the strip | belt-shaped wall body 21a. ing.

  Further, annular wall bodies 21 c are formed in the vicinity of both ends in the longitudinal direction of the inner peripheral surface of the tubular member 21. That is, the annular wall 21c along the inner peripheral surface protrudes radially inward from the inner peripheral surface of the tubular member 21. And the recessed part 23 enclosed by the two annular wall bodies 21c and the two strip | belt-shaped wall bodies 21a is formed. Lubricants such as lubricating oil and grease are accommodated in the recesses 23 and function as a lubricant reservoir for lubricating the rolling elements 3 passing through the straight path 13. That is, when the rolling element 3 passing through the straight path 13 comes into contact with the lubricant in the recess 23, the lubricant is supplied to the rolling element 3.

  Since the lubricant is accommodated in the recess 23 surrounded by the two annular wall bodies 21c and the two belt-like wall bodies 21a, a large amount of lubricant can be held in the linear motion guide bearing device. Thereby, while being able to maintain the outstanding lubricity over a long period of time, the frequency | count of replenishment of the lubricant to a linear guide bearing apparatus can be decreased. Further, since the lubricant is held in the recess 23, there is almost no possibility that the lubricant leaks to the outside of the linear motion guide bearing device. For this reason, excellent lubricity can be maintained over a long period of time, the number of times the lubricant is supplied to the linear motion guide bearing device can be reduced, and the periphery of the linear motion guide bearing device is contaminated with the lubricant. There is almost no risk of doing so.

Furthermore, since the tubular member 21 is made of a resin having higher strength than the lubricant-containing polymer and the sintered resin, there is almost no possibility that the tubular member 21 is damaged by the contact of the rolling elements 3. In addition, the kind of resin which comprises the tubular member 21 is not specifically limited, What is necessary is just to have the intensity | strength required.
Further, the contact between the metal rolling element 3 and the metal slider body 2A is eliminated, and the rolling element 3 comes into contact with the resin tubular member 21, so that noise generated when the linear motion guide bearing device is driven is reduced. The In addition, if a resin separator is interposed between the rolling elements 3 and the rolling elements 3, the contact between the rolling elements 3 is eliminated, so that noise is further reduced. The type of resin constituting the separator is not particularly limited, but an elastomeric resin is particularly preferable.

  Further, if the inner diameter of the linear hole 20 into which the tubular member 21 is inserted is slightly larger than the outer diameter of the tubular member 21, and a gap is provided between the linear hole 20 and the tubular member 21, the linear motion guide is provided. When the bearing device is driven, the tubular member 21 finely moves due to vibration accompanying the movement of the rolling elements 3. In the case where the lubricant is lubricating oil, the lubricating oil in the recess 23 is shaken by the fine movement and adheres to the rolling element 3, so that stable lubricity can be obtained.

The tubular member 21 may be an integrally molded resin member or a member formed by combining a plurality of resin parts. In the latter case, the plurality of resin parts may all have the same shape or different shapes. Further, the number of resin parts constituting the tubular member 21 may be two, or three or more. An example is shown in FIG. That is, the tubular member 21 is configured by combining two substantially identical resin parts 25 and 25 having a shape (a semicircular cross section) obtained by dividing the tubular member 21 into two planes along the longitudinal direction. A method for fixing the two resin parts 25 and 25 in combination is not particularly limited, but the hole 26 and the protrusion 27 to be engaged are provided on the mating surfaces of the two, and the protrusion 27 is formed in the hole 26. The method of fitting in is mentioned.
Moreover, the accommodation of the lubricant in the recess 23 which is a lubricant reservoir may be performed after combining the resin parts 25 and 25 into the tubular member 21, or may be performed before the combination as shown in FIG. Good. In this case, the lubricant is grease.

It is a perspective view showing one embodiment of a linear guide bearing device concerning the present invention. It is the front view which looked at the linear motion guide bearing apparatus of FIG. 1 from the axial direction. It is the sectional view on the AA line of FIG. It is the perspective view which showed only the tubular member and the slider main body among linear motion guide bearing apparatuses. It is the top view and perspective view of what divided the tubular member in the plane along a longitudinal direction. It is the front view of the substantially identical shape resin parts which comprise a tubular member, and the front view of the tubular member which combines this resin part. It is a perspective view which shows the state which accommodated the lubricant in the recessed part of the resin-made parts which comprise a tubular member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Guide rail 2 Slider 2A Slider main body 2B End cap 3 Rolling body 10 Rolling body rolling groove 11 Rolling body rolling groove 13 Straight path 14 Rolling body rolling path 15 Curved path 16 Rolling body return path 20 Linear hole 21 Tubular member 21a Band-shaped wall 21b Radial tip 21c Annular wall 23 Recess 25 Resin part

Claims (4)

A guide rail having a rolling element rolling groove extending in the axial direction on the outer surface, a rolling element rolling groove facing the rolling element rolling groove of the guide rail, and attached to the guide rail so as to be relatively movable in the axial direction. And a plurality of rolling elements movably loaded in rolling element rolling paths formed between the rolling element rolling grooves, and rolling the rolling elements to the rolling element rolling elements. A rolling element return path to be sent from the end point of the road to the start point is formed in the slider, and the rolling element return path includes a linear path parallel to the rolling element rolling path, the linear path, and the rolling element rolling path. A linear guide bearing device configured with a curved path communicating with
A resin tubular member is inserted into a linear hole provided in the slider, and a plurality of strip-like wall bodies extending in the longitudinal direction protrude radially inward from the inner peripheral surface of the tubular member. The straight path is configured by the radial tip of the body,
From the inner peripheral surface in the vicinity of both ends in the longitudinal direction of the tubular member, the annular wall body protrudes inward in the radial direction, and a recess formed by being surrounded by both the annular wall body and the belt-like wall body, A linear guide bearing device comprising a lubricant reservoir for containing a lubricant.   The linear guide bearing device according to claim 1, wherein the tubular member is an integrally formed resin member.   The linear guide bearing device according to claim 1, wherein the tubular member is formed by combining a plurality of resin parts.   The linear motion guide bearing device according to claim 3, wherein the plurality of resin parts have substantially the same shape, and the tubular member is divided by a plane along the longitudinal direction.

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