JP2816331B2 - Roller bearing for linear motion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing for linear motion, and more particularly, to a reciprocating motion of a linear motion portion in which a ball is closely contacted with an inner peripheral surface of a sleeve and an outer peripheral surface of a linear motion portion which linearly moves in a retainer. The present invention relates to a rolling bearing for linear motion that performs a rolling motion with the rolling motion.

[0002]

2. Description of the Related Art Conventionally, a rolling bearing A for linear motion of this type has a collet portion 200 'at the tip of a hand-held grinding device for grinding and polishing a work (workpiece) as shown in FIG. It is used in various fields such as a guide for linearly reciprocating a moving shaft (linear motion part) 4. The specific structure is such that a ball mounting hole 42 is formed in a metal cylindrical retainer 2.
Are scattered, and a ball body 12 slightly smaller than the ball mounting hole 42 is loaded into the cylindrical retainer 2 so as to protrude from the inside and outside of the retainer 2, and the cylindrical retainer 2 is attached to the sleeve 1. Has been assembled. Since the ball 12 is loaded into the ball mounting hole 42 with grease applied to the ball 12, even if the ball mounting hole 42 is slightly larger than the ball 12, the ball 12 can be loaded from the ball mounting hole 42. It does not fall. When the rolling bearing A for linear motion is used in a hand-held grinding device for grinding and polishing as described above, an O-ring 3 provided on the outer peripheral surface of the sleeve 1 is provided on the inner peripheral surface of the housing 5. Housing 15
It is set in the accommodating portion 15 so as to be pressed against the bottom. In this linear motion rolling bearing A, the ball body 12 is in close contact with the inner peripheral surface of the sleeve 1 and the outer peripheral surface of the linear motion portion 4 that linearly moves in the retainer 2, and the linear motion portion 4 is reciprocated with the linear motion portion 4. Rolling motion in the ball mounting hole 42 so as to support the same position, it is possible to provide a feature excellent in straight running accuracy.

[0003]

In such a linear motion rolling bearing A, the retainer 2 is assembled to the sleeve 1 by press fitting. That is, the flange 400 is provided around the end of the retainer 2, the retainer 2 is pressed into the sleeve 1, and the retainer 2 is fixed to the sleeve 1 by the pressure contact between the flange 400 and the inner peripheral surface of the sleeve 1. . But,
Since the assembling method depends on the processing accuracy, the retainer 2 may come out of the sleeve 1 due to the vibration (repetitive vibration of the pressing force and the returning power) at the time of the reciprocating sliding of the linear motion part 4, and it is used for a long time. There is a problem of poor reliability above. Also, depending on the loading state of the ball 12 into the ball mounting hole 42, the ball 12 rolling in the ball mounting hole 42 with the reciprocating motion of the linear motion part 4 collides with the front and rear edge of the ball mounting hole 42 and is rubbed. Metal powder is generated from the retainer, and this may become a movement resistance of the linear motion part 4 or hinder accurate linear motion.

SUMMARY OF THE INVENTION The present invention has been made in view of the conventional circumstances, and an object thereof is to provide a linear motion rolling bearing in which a retainer is firmly fixed to a sleeve and the linear motion portion has a high linearity. Is to do.

[0005]

According to a first aspect of the present invention, a ball mounting hole is provided scattered on a retainer fitted in a sleeve, and the ball mounting hole is provided in the ball mounting hole. A ball body smaller than the hole is loaded so as to protrude from the inside and outside of the retainer, and the ball body is brought into close contact with the inner peripheral surface of the sleeve and the outer peripheral surface of the linear motion part that linearly moves in the retainer, with the reciprocating motion of the linear motion part. In a rolling bearing for linear motion in which a rolling motion is performed, a plurality of parallel grooves are provided at regular intervals in a width direction on a retainer component plate in an unfolded state formed of wear-resistant plastic, and a plurality of band plate portions are formed by the parallel grooves. A mounting hole for the ball body is formed in each band plate portion, and a locking portion is integrally formed so as to protrude from one and the same side of both end portions of the desired band plate portion. The retaining portion is formed on the inner surface of the sleeve in a form in which the retainer component plate loaded with the ball body is formed into a substantially cylindrical shape by using the elastic deformation of the groove bottom of the parallel groove with the locking portion facing outward, and the locking portion is formed on the inner surface of the sleeve. The gist is that it is plugged and locked.
A second aspect of the present invention is that the locking portion is a convex portion or a concave portion, and the locked portion is a concave portion or a convex portion in which the convex portion or the concave portion is inserted and locked. .

According to the above technical means, when the retainer constituting plate in the deployed state is formed into a substantially cylindrical shape by elastic deformation of the groove bottom of the parallel groove with the locking portion facing outward, the elastic recovery of the groove bottom is achieved. The action causes a reaction force to return to the deployed state and causes the locking portion to be securely locked to the locked portion formed on the inner surface of the sleeve by the reaction force. In addition, even if the ball body rolls with the reciprocating motion of the linear motion part and collides with the front and rear hole edges of the ball mounting hole and rubs, the impact is absorbed by the elastic deformation of the wear resistant plastic retainer. In addition, the characteristics of its own wear resistance work together to suppress the generation of shavings. When attaching the retainer to the sleeve, the retainer component plate is inserted into the sleeve inner space in a substantially cylindrical form having a smaller diameter than the sleeve inner space,
Release the hand with the locking part positioned so as to correspond to the locked part, and lock with the return force (reaction force) to the deployed state generated on the retainer component plate by the elastic restoring action generated at the groove bottom. The part is inserted and locked in the locked part.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings. 1 shows an embodiment of a hand-held grinding device having a linear motion rolling bearing, wherein reference symbol A denotes a linear motion rolling bearing, and B denotes a hand-held grinding device.

As shown in the drawing, a linear motion rolling bearing A includes a sleeve 1 and a retainer 2 for supporting a fine-diameter ball body 12 fitted in the sleeve 1 and projecting in and out in a dispersed manner and rotatably. An O-ring 3 is provided around the outer peripheral surface of the sleeve 1.

The retainer 2 is inserted into the sleeve inner space 11 in a form in which a retainer constituting plate 2 'formed of a plastic having excellent wear resistance such as polyacetal or polyphenylene sulfide is wound into a substantially cylindrical shape. It has become.

More specifically, as shown in FIG. 3, the retainer constituting plate 2 'is provided with parallel grooves 22 at regular intervals from the same one side in the width direction thereof in the unfolded state.
A ball mounting hole 42 is formed in each of the band plate portions 32, and a locking portion 52 is integrally formed on one end of the band plate portion 32 at one end with a parallel groove 22 at one end thereof. ing.

The ball mounting hole 42 has a diameter slightly larger than that of the ball body 12 to be loaded.

In the present embodiment, the locking portion 52 is a convex portion, and more specifically, the convex portion is convex from the same single side where the parallel grooves 22 at both ends of the odd-numbered or even-numbered band plate portion are recessed. Part is protruding.

The mounting hole 42 can be rotated with grease so that a ball body (fine diameter) 12 for slidingly moving a linear motion part 4 to be described later is protruded inward and outward in a stage prior to mounting on the sleeve 1. To be loaded.

The sleeve 1 is provided with annular recesses as the locked portions 21 at both ends of the inner peripheral surface corresponding to the locking portions 52 formed on the retainer constituting plate 2 ', and is provided around the outer peripheral surface. The O-ring 3 is locked on the concave step portion 31.

When the retainer 2 is assembled to the sleeve 1, as shown in FIG. 4, the retainer constituting plate 2 'is formed into a substantially cylindrical shape having a diameter smaller than the diameter of the sleeve inner space 11 and having a size at which the ends overlap. Groove bottom 22a in parallel groove 22
It is wound using the elastic deformation function of the part, and inserted into the sleeve 1 in that state. And the locking part 52 is the sleeve 1
When the user releases his / her hand at a position corresponding to the locked portion 21 formed on the inner peripheral surface, the retainer 2 returns to the expanded state due to the elastic restoring action of the groove bottom 22a, and the locking portion 52 is moved by the reaction force.
Is retained by the locked portion 21 and the retainer 2 is assembled (FIG. 2). When the retainer constituting plate 2 ′ is assembled to the sleeve 1, each of the balls 12 lightly abuts on the inner peripheral surface of the sleeve 1. The width (L) and the width of each band (l) are set in advance.

In this embodiment, the diameter of the ball 12 is set to 1.
The diameter of the ball mounting hole 42 is about 2 mm.

A linear motion rolling bearing A constituted by assembling a retainer 2 to a sleeve 1 is set in a housing portion 15 formed in a housing 5 of a hand-held grinding device B as shown in FIG. The hand-held grinding apparatus B shown in the present embodiment is for polishing and grinding a work by linearly reciprocating a polishing / grinding tool such as a grindstone attached to a chuck portion.

The hand-held grinding device B has an outer case 35 fitted on the outer periphery of the inner case 25, a tip cap 45 at the front end of the inner case 25, and a rear end cap 55 at the rear end of the inner case 25. The housing 5 is formed by screwing, and an air supply control unit 6 is provided at a rear end of the housing 6.

The air supply control unit 6 is provided with the rear end cap.
The opening 55 is closed with a stopper lid 16 which can be moved forward and backward, and an air supply part 16a for connecting a supply hose (not shown) for compressed air to the axis of the stopper lid 16 is provided in a penetrating manner. Part 16
a, the compressed air supplied through the air supply passage 16b is supplied to the nozzle body 26 provided on the front side of the lid 16 by controlling the compressed air supplied from the air supply passage 16b. It has a conventionally well-known structure.

The nozzle body 26 is provided on the front side of the plug lid 16 in a state where airtightness is maintained, and a nozzle port 26a extending inside the housing 6 is brought close to the outer periphery of the turbine 7 described later. Further, the compressed air supplied into the housing 5 from the nozzle port 26a is exhausted to the outside through an exhaust path 36 provided in the stopper 16.

The turbine 7 is configured to rotate around a drive shaft 8 which is supported in a state of crossing the inside of the housing 5. The turbine 7 has a large number of blades 17 protruding from the outer periphery thereof inclining in one direction, and is rotated by compressed air supplied from the nozzle port 26a.

A drive shaft 8 which is a support shaft of the turbine 7 is rotatably supported at both ends by bearings 18.
The tubular body 9 is fixed so as to sandwich the cylindrical body 9.

The cylindrical body 9 is rotatably fitted inside a rear end of a connecting rod 100 having a chuck portion 200 for gripping a grinding / polishing tool 300 at the front end.

The chuck portion 200 has a ball body in a sliding space 62 in the retainer 2 in the rolling bearing A for linear motion.
A sliding shaft (hereinafter, referred to as a linear motion portion) 4 which is slidably guided by being pressed against 12 and a collet portion 200 'fixed to the tip thereof. The grinding / polishing tool 300 gripped with a stroke twice as much as the eccentricity (about 0.35 mm) of the cylindrical body 9 generated by the rotation of the drive shaft 8 by screwing the leading end of the connecting rod 100. It is designed to reciprocate linearly.

In the hand-held grinding apparatus having the above-described structure, the ball body 12 is brought into close contact with the inner peripheral surface of the sleeve 1 and the outer peripheral surface of the sliding portion (linearly moving portion) 4 which linearly moves in the retainer 2, and slides. The reciprocating motion of the moving part (linear motion part) causes the ball to roll in the ball mounting hole 42 with a stroke twice as much as the eccentric amount (about 0.35 mm). At that time, the ball mounting hole
Ball during rolling exercise depending on the loading situation for 42
Even if 12 collides with the front or rear hole edge of the ball mounting hole 42 and is rubbed, the retainer 2 itself absorbs the friction by elastic deformation and opposes its own wear resistance to generate shavings. Can be suppressed.

In this embodiment, the rolling bearing A for linear motion is described as a guide for a sliding shaft (linear motion part) for linearly moving the grinding and polishing tool 300 in the hand-held grinding device B. The present invention can equally be used in any technical field as long as it guides the reciprocating motion of the linear motion part. Further, in the present embodiment, the locked portion 21 is described as an annular concave portion, but the locked portion 21 may have a concave portion only at a position corresponding to the convex portion which is the locking portion 52. It is. In addition, the locking portion 52 is a concave,
The locked portion 21 may be a convex portion.

[0027]

As described above, according to the present invention, the retainer constituting plate wound in a substantially cylindrical shape by the elastic deformation function of the groove bottom in the parallel groove returns to the deployed state by the elastic restoring action of the groove bottom in the parallel groove. Since the locking portion is inserted into the locked portion formed on the inner surface of the sleeve by using the reaction force to move, the retainer is firmly fixed to the sleeve, and the retainer is assembled to the sleeve. The retainer does not come off the sleeve due to the vibration (repetitive vibration of the pressing force and the returning power) generated by the reciprocal sliding as in the conventional press-fitting which depends on the processing accuracy. In addition, since the retainer formed in a so-called mat shape (in a state of being developed into a flat plate shape) is formed into a substantially cylindrical shape and is assembled to the sleeve, for example, the retainer is integrally formed into a cylindrical shape using a plastic material. There is no need to attach a removable auxiliary mold for forming the mounting hole of the ball body as a molding die, so that the molding cost can be reduced. In addition, when the ball body rolls in the ball mounting hole in accordance with the reciprocating motion of the linear motion part, it may collide with the front or rear edge of the ball mounting hole depending on the loading state of the ball mounting hole. Since the retainer itself is elastically deformed and absorbs and resists the rubbing force due to its own abrasion resistance, shaving powder such as a metal material is not generated, and excellent straight running accuracy is maintained. be able to.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a hand-held grinding device equipped with a linear motion rolling bearing according to an embodiment.

FIG. 2 is an enlarged sectional view taken along line (2)-(2).

FIG. 3 is a perspective view of a retainer constituting plate.

FIG. 4 is an enlarged cross-sectional view taken along the line (2)-(2), showing an assembled state of the retainer.

FIG. 5 is a partial longitudinal sectional view of a conventional hand-held grinding device equipped with a linear motion rolling bearing.

[Explanation of symbols]

A: Rolling bearing for linear motion 1: Sleeve 2: Retainer 4: Linear motion part 62: Sliding space 2 ': Retainer component plate 22: Parallel groove 32: Strip plate part 12: Ball body 52: Locking part 21: Coated Locking part 42: Ball mounting hole

Claims (2)

(57) [Claims] A ball mounting hole is scattered on a retainer fitted inside a sleeve, and a ball body smaller than the hole is loaded into the ball mounting hole so as to protrude from inside and outside of the retainer. A linear motion rolling bearing that is in close contact with the inner peripheral surface and the linear motion part that linearly moves in the retainer, and that rolls with the reciprocating motion of the linear motion part. A plurality of parallel grooves are provided at regular intervals in the width direction of the retainer constituting plate, and the parallel grooves are divided into a plurality of band portions, and the mounting holes for the ball body are formed in each of the band portions. An engaging portion is integrally formed so as to protrude from the same one side of both end portions of the band plate portion, and a retainer component plate in which the ball is loaded in the mounting hole is formed with a parallel groove with the engaging portion facing outward. bottom A rolling bearing for linear motion, wherein a locking portion is inserted and locked into a locked portion formed on the inner surface of the sleeve in a substantially cylindrical shape utilizing the elastic deformation of the rolling bearing. 2. The method according to claim 1, wherein the locking portion is a convex portion or a concave portion,
2. The rolling bearing for linear motion according to claim 1, wherein the locked portion is a concave portion or a convex portion whose convex portion or concave portion is inserted and locked.