JP2003239959A - Linear motion guide device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear motion guide device which prevents breakage of a holding piece and the reduction of rolling property of a ball due to foreign matters entering between the ball and the holding piece, and improves reliability. <P>SOLUTION: This linear motion guide device is provided with a ball rolling groove 13A only on an outer face of a guide rail 11 opposing to the ball 15 and has no relief groove for a ball cage. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motion guide device used as a means for linearly guiding a work table or the like of a machine tool.

[0002]

2. Description of the Related Art Conventionally, as a linear motion guide device of this type,
For example, the one disclosed in JP-A-12-213538 is known. The linear motion guide device disclosed in this publication is
The guide rail 11 (see FIG. 8) and a slider that relatively moves in the longitudinal direction of the guide rail 11 are provided, and the ball rolling grooves 13A,
13B is formed along the longitudinal direction of the guide rail 11. These ball rolling grooves 13A and 13B are opposed to the ball rolling grooves formed in the slider, and a large number of balls 15 made of a steel material are provided between these ball rolling grooves.
(See FIG. 3) are arranged in a line.

The ball 15 is a ball row 2 as shown in FIG.
0 is formed, and a holding piece 21 made of synthetic resin is provided between the balls 15. This holding piece 2
1 is formed in a disk shape, and concave spherical surfaces 2 are provided on both end surfaces thereof.
2 is formed. In such a linear motion guide device, a compression force is applied to the ball row 20 by the holding pieces 21 provided between the balls 15. As a result, the span between the balls 15 is maintained at an appropriate value, so that it is possible to improve operability and reduce noise.

[0004]

However, in the above-described linear motion guide device, foreign matter such as dust is formed in the ball rolling groove 13A of the guide rail 11 and the escape groove 23 for the ball cage (FIG. 8). (Refer to FIG. 2), it may enter between the ball 15 and the holding piece 21, and the holding piece 2 may be damaged by foreign matter entering between the ball 15 and the holding piece 21.
1 may be damaged or the ball 15 may be less likely to roll.

The present invention has been made in view of the above problems, and an object thereof is to prevent foreign matter such as dust from entering between the ball and the holding piece and to improve reliability. It is to provide a linear motion guide device that can be improved.

[0006]

To achieve the above object, the invention of claim 1 provides a guide rail having a ball rolling groove formed along the longitudinal direction, and the ball rolling of the guide rail. A slider having a ball rolling groove facing the moving groove, a plurality of balls arranged in a line between the ball rolling grooves of the slider and the guide rail, and formed between the guide rail and the slider. And a holding piece interposed between the balls, wherein the guide rail has an outer surface facing the ball and the ball rolling groove. It is characterized by having only a clearance groove and not having a clearance groove for a ball retainer.

According to a second aspect of the present invention, in the linear motion guide device according to the first aspect, a corner and / or a corner of a portion of the guide rail that comes into contact with the side seal has a R chamfer or C of 0.5 mm or more. Characterized by chamfering. According to the first aspect of the present invention, foreign matter such as dust does not enter between the ball and the holding piece through the clearance groove for the ball retainer. Therefore, the foreign matter that enters between the ball and the holding piece may damage or damage the holding piece. It is possible to prevent the rolling property of the ball from decreasing and improve the reliability.

According to the second aspect of the present invention, foreign matter such as dust does not enter between the ball and the holding piece through the gap between the lip portion of the side seal and the outer peripheral surface of the guide rail.
The reliability can be further increased.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a linear motion guide device according to a first embodiment of the present invention. In FIG. 1, 1
Reference numeral 1 denotes a guide rail, and 12 denotes a slider that relatively moves in the longitudinal direction of the guide rail 11, and ball rolling grooves 13A and 13B are formed on the left and right side surfaces of the guide rail 11, respectively. These ball rolling grooves 13A and 13B are formed along the longitudinal direction of the guide rail 11, and the ball rolling groove 13 formed in the central portion of the side surface of the guide rail 11.
A has a Gothic arch-shaped cross section along the width direction of the guide rail 11. In addition, the ball rolling grooves 13A, 1
3B is opposed to a ball rolling groove 14 (see FIG. 2) formed in the slider 12, and both ball rolling grooves 13A, 14
A large number of balls 15 made of a steel material, such as SUJ2, are arranged in a line between 13 and 13B and 14. The ball rolling groove 13B is formed at the upper edge of the side surface of the guide rail 11.

The slider 12 has a slider body 121 having a substantially gate-shaped cross section along the width direction of the guide rail 11,
The slider body 121 includes end caps 122 and 123 attached to the front and rear end surfaces of the slider body 121. The slider body 121 has a plurality of screw holes 16 for bolting the slider 12 to a work table of a machine tool. A ball return passage 17 (see FIG. 2) for returning the ball 15 to the initial position is formed corresponding to the ball rolling groove 14. The ball rolling groove 14 is formed on the inner surface of the slider body 121.

The ball return passage 17 has a ball rolling groove 13 therein.
End caps 122, 12 formed on the slider body 121 in parallel with the ball rolling path formed between A, 14 and 13B, 14 and closing the open end of the ball rolling path.
In FIG. 3, an arc-shaped connecting passage (not shown) that connects the ball rolling passage and the ball returning passage 17 is provided.
Is formed corresponding to.

A side seal 18 (see FIG. 1) for sealing the gap formed between the guide rail 11 and the slider 12 is attached to the end caps 122, 123. The side seal 18 has a lip portion 19 made of a soft material such as rubber.
9 is a guide rail 11 including ball rolling grooves 13A and 13B
It is slidably elastically contacted to the outer peripheral surface of.

The ball 15 is a ball row 2 as shown in FIG.
0 is formed, and a holding piece 21 made of synthetic resin is provided between the balls 15. This holding piece 2
Reference numeral 1 is a disk shape, and concave spherical surfaces 22 are formed on both end surfaces of the holding piece 21. The guide rail 11 has ball rolling grooves 13A and 13B on the outer surface facing the ball 15.
And a clearance groove 23 (FIG. 8) for the ball cage.
(See) has no structure.

FIG. 4 shows the ball rolling grooves 13A and 13B formed in the guide rail 11. As shown in FIG. 4, the corners of the portions which come into contact with the side rails 18, for example, the ball rolling groove 13A. , 13B both side edges 13a, 13b
Has a radius of 0.5 mm or more and is chamfered.
As described above, the guide rail 11 has a structure in which only the ball rolling grooves 13A and 13B are provided on the outer surface facing the ball 15, so that foreign matters such as dust can escape from the escape groove for the ball cage and the ball 15 and the holding piece 21. Between the ball 15 and the holding piece 21, foreign matter entering between the ball 15 and the holding piece 21 may damage the holding piece 21 or the ball 1.
It is possible to prevent the rolling property deterioration of No. 5 from occurring and improve the reliability.

Further, when the both side edges 13a, 13b of the ball rolling grooves 13A, 13B are chamfered with a radius of 0.5 mm or more, the rigidity of the lip portion corresponding to the shape is increased, and the lip of the side seal 18 is increased. Part 19 and guide rail 11
It is possible to prevent a gap from being formed between the ball 15 and the holding piece 21 from the gap between the lip portion 19 of the side seal 18 and the ball rolling grooves 13A and 13B. Since it does not get in, it is possible to increase reliability.

The present invention is not limited to the above embodiment. For example, in the above-described first embodiment, the ball rolling groove 1 is formed on each of the left and right side surfaces of the guide rail 11.
Although 3A and 13B are formed, the present invention is also applied to a linear motion guide device in which only the ball rolling grooves 13A are formed on the left and right side surfaces of the guide rail 11 as in the second embodiment shown in FIG. be able to. Further, in the above-described first embodiment, the ball rolling groove 13B is provided on the upper side edge portion of the side surface of the guide rail 11, but as in the third embodiment shown in FIG.
The ball rolling groove 13B may be provided on the upper surface of the guide rail 11. Further, in the above-described first embodiment, the ball rolling groove 13A having a cross section along the width direction of the guide rail 11 formed in a Gothic arc shape is provided in the central portion of the side surface of the guide rail 11, but as shown in FIG. Rolling groove 1 with different cross-section
3A may be provided at the center of the side surface of the guide rail 11. Figure
In the case of 7, there is a corner A under the ball rolling groove 13A, and the corner A is rounded with a radius of 0.5 mm or more. Although the corners or corners of the guide rails 11 that come into contact with the side seals 18 are R-chamfered with a radius of 0.5 mm or more in the above-described embodiment, a 0.5-mm C-chamfer may be used instead of the R-chamfered. Good.

[0017]

As described above, according to the linear motion guide device of the invention of claim 1, foreign matter such as dust does not enter between the ball and the holding piece through the escape groove for the ball cage. Therefore, it is possible to prevent the damage of the holding piece, the deterioration of the rolling property of the ball and the like due to the foreign matter entering between the ball and the holding piece, thereby improving the reliability.

According to the linear guide device of the second aspect of the present invention, foreign matter such as dust does not enter between the ball and the holding piece through the gap between the lip portion of the side seal and the outer peripheral surface of the guide rail. , More reliable.

[Brief description of drawings]

FIG. 1 is a perspective view of a linear motion guide device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the linear motion guide device shown in FIG.

FIG. 3 is a diagram showing a ball row formed by the balls shown in FIG.

4 is a diagram showing a part of the guide rail shown in FIG. 1. FIG.

FIG. 5 is a diagram showing a second embodiment of the present invention.

FIG. 6 is a diagram showing a third embodiment of the present invention.

FIG. 7 is a diagram showing a fourth embodiment of the present invention.

FIG. 8 is a diagram showing a guide rail of a conventional linear motion guide device.

[Explanation of symbols]

11 Guide rail 12 sliders 13A, 13B, 14 Ball rolling groove 15 balls 17 Ball return passage 18 Side seal 19 Lip part 20 ball rows 21 Holding piece

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Claims (2)

[Claims] 1. A guide rail having a ball rolling groove formed along the longitudinal direction, a slider having a ball rolling groove facing the ball rolling groove of the guide rail, a slider and the guide rail. A large number of balls arranged in a line between both ball rolling grooves, a side seal for sealing a gap formed between the guide rail and the slider, and a holding piece interposed between the balls. And a guide rail having only the ball rolling groove on an outer surface facing the ball, and not having a clearance groove for a ball retainer. Linear motion guide device. 2. The linear motion according to claim 1, wherein a corner and / or a corner of a portion of the guide rail that comes into contact with the side seal is chamfered by R or C chamfering of 0.5 mm or more. Guidance device.