JP2001059520A - Integral box type linear bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate oiling by housing a plurality of balls in an axial direction freely to circulate, inserting an exposed ball cage into a penetrating hole or a groove of a housing for attaching a guided material, and holding both ends thereof with and end member. SOLUTION: A housing part 3 for holding a ball cage 12 in a housing 1 is disposed, and is constituted of a groove having a C-shaped cross section or a penetrating hole. The cage 12 is provided with a plurality of a endless groove shaped ball circulating paths 13 including a ball exposing hole elliptically opened in an inner circumference in an axial direction, on an outer periphery in order to house a plurality of balls B. For preventing separation from the housing 1 of the cage 12 as well as preventing flow-out of oil outward, both ends of the cage 12 are held with a ring shaped end member 20. An oil groove 5 is disposed along a circumferential direction of one end side of an inner wall of the housing part 3, an oiling hole 6 is penetrated from a side surface of the housing 1 to the oil groove 5, and communicates with a circulating path 13. It is thus possible to carry out oiling for all trains of the ball in one location, and it is also possible to improve workability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear bearing used for a linear guide in various machine tools, industrial machines and the like, and more particularly to a rationalization of the structure of a linear ball bearing and an improvement of a lubrication mechanism.

[0002]

2. Description of the Related Art Conventionally, a linear ball bearing in which a ball is in rolling contact with a shaft has been favorably used as a linear bearing because of its small static and dynamic friction coefficients. Here, a linear ball bearing is a structure in which a plurality of balls to be moved in the axial direction are accommodated in a freely circulating manner, and a cylindrical ball retainer exposed from an inner peripheral ball exposure hole is inserted into an outer cylinder. The bearing moves linearly with respect to the shaft inserted in the bearing through the rolling of the ball. The linear ball bearing has been used in a box-shaped housing for mounting a member to be linearly guided with respect to the shaft.

[0003]

As described above, in the prior art, when it is desired to linearly guide an object with respect to an axis, a housing for mounting the object to be guided is prepared.
It had to house linear ball bearings in it. For this reason, at least two members, a housing and a linear ball bearing, must be prepared, so that the number of parts and the assembling time are required, and there is a problem that the whole becomes large. Further, there is also a trouble that the positional accuracy between the housing and the linear ball bearing must be maintained accurately.

[0004] By the way, lubrication is necessary for smooth movement of the ball in the bearing, and a lubrication hole for that needs to be provided in the bearing itself. The ball retainer is provided on the end face of the bearing by using an end member for clamping and fixing both ends of the ball retainer inserted in the bearing.
In this case, the end face of the bearing is close to the shaft,
In a device using a bearing, a built-in guided object (moving member) is usually configured to perform maintenance from a direction orthogonal to a moving direction, and thus there is a problem that it is difficult to perform a refueling operation.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and accommodates a plurality of balls to be moved in the axial direction in a freely circulating manner.
The ball cage exposed from the ball exposure hole on the inner periphery is inserted into a housing portion formed of a through hole or a groove of a box-shaped housing having means for attaching an object to be guided linearly to the shaft, and Are sandwiched by end members fixed to the housing.

In the above bearing, an oil groove communicating with the ball circulation path of the ball retainer inserted in the housing portion in the bearing is provided along the circumferential direction of the inner wall of the housing portion, and the oil groove is formed from the side of the housing. A second invention is disclosed as a second invention in which a bearing in which an oil supply hole is penetrated is provided.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a view showing an example of the linear bearing of the present invention. The greatest feature of the present invention is that the linear bearing and the housing for mounting the guided object are integrated. Here, as the bearing, a type in which the lower end is opened in a C-shape to hold a shaft (not shown) is taken as an example, but it is a matter of course that the type may surround the shaft. is there.

Reference numeral 1 in the figure denotes a housing. The housing 1 is a box type on which an object to be guided (not shown) can be placed on the upper surface, and a screw hole 2 for attaching the object to be guided is provided.
Is provided. This housing 1 has a ball retainer 12
There is provided a housing portion 3 for housing and holding (see FIG. 2). As described above, in this embodiment, it is assumed that the lower end of the bearing is opened in a C-shape, so that the housing portion 3 is configured as a C-shaped groove,
The inner peripheral wall has a shape corresponding to the outer peripheral shape of the ball retainer 12. When the bearing is of a type that surrounds the shaft, the housing portion is configured as a through hole.

The retainer 12 has a well-known tubular shape or a partially open tubular shape having a plurality of endless groove-shaped ball circulation paths 13 including a ball exposure hole 14 opened to the inner periphery in the shape of a long hole in the axial direction. In a state where a plurality of balls B are accommodated in the ball circulation path, the ball B is inserted into and fixed to the accommodation section 3 of the housing 1 so that the inside of the ball circulation path covered by the inner peripheral wall surface of the accommodation section of the housing is formed. Infinitely circulates (see FIGS. 5 and 6). In this case, the interpolated cage 12
At the same time to prevent the
In order to prevent the later-described oil from flowing out, it is necessary to hold both ends of the retainer by a ring-shaped end member fitted into the inner periphery of the housing portion 3 of the housing.

Reference numeral 20 in the figure denotes an end member (see FIGS. 1 and 7). The end member 20 is formed in a C-shaped ring shape in which the inner peripheral end 22 is in sliding contact with the outer periphery of the shaft. Here, the inner peripheral end is squeezed into a skirt shape, so that the inner peripheral end is biased by the inner peripheral end. To prevent oil from leaking out. This end member 2
On the ball holder side of No. 0, there is provided a fitting edge 21 which can be fitted into the annular step 16 provided at the end of the ball holder 12, and is fitted to both ends of the ball holder 12, and in a state where it is sandwiched. It is provided by fitting an outer peripheral end into a fitting groove 4 engraved in an annular shape on the inner circumference of the housing portion 3 of the housing.
In this embodiment, the main body of the end member 20 is made of metal, and the end portion 20 is slidably contacted with the outer periphery of the shaft and the fitting edge portion 21 is formed.
Has a composite structure made of highly elastic plastic.

Reference numeral 5 in the figure denotes an oil groove. The oil groove 5 is provided along a circumferential direction on one end side of the inner wall of the housing portion 3 of the housing 1, and an oil supply hole 6 penetrates from the side surface of the housing toward the oil groove. The oil groove 5 communicates with the ball circulation path 13 of the ball retainer 12 inserted in the accommodation section 3. In this case, the oil groove 5 is provided between the outer periphery of each ball circulation path of the ball retainer and the inner wall of the accommodation section. By providing a recess 15 for creating a gap in the entire length direction, it serves as a communicating means with the oil groove (see FIGS. 5 and 6).

[0012]

The linear bearing of the present invention having the above configuration has the following specific effects. Since the housing for mounting the guided object and the linear ball bearing are integrated, the number of parts can be reduced, assembling labor can be reduced, and the manufacturing cost can be reduced. For the same reason, the size of the housing can be reduced, so that a linear bearing optimal for a device having a limited mounting space is realized. As a result of the housing also serving as a bearing case,
It is possible to open the oil supply hole on the side of the housing,
Refueling workability is improved. The oil groove communicating with the ball circulation path of the ball cage is provided along the circumferential direction of the inner wall of the housing part, so that lubrication can be performed in all rows with one oil supply, and the workability of oil supply is good. Become.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a linear bearing according to the present invention during assembly.

FIG. 2 is a perspective view of a main part of the housing.

FIG. 3 is a front view of the housing.

FIG. 4 is a sectional view of the housing.

FIG. 5 is a side view of the ball retainer.

FIG. 6 is a front view of the same ball retainer.

FIG. 7 is a partially cutaway side view of a main part in the middle of assembly;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 3 Housing part 5 Oil groove 6 Oil supply hole 12 Ball retainer

Claims (2)

[Claims] 1. A plurality of balls to be moved in the axial direction are accommodated in a freely circulating manner, and an object to be guided to be linearly guided with respect to a shaft is mounted on a ball retainer exposed from a ball exposing hole on an inner periphery. An integrated box-type linear bearing, wherein the ball holder is inserted into a receiving portion formed of a through hole or a groove of a box-shaped housing having means, and both ends of the ball retainer are sandwiched by end members fixed to the housing. 2. An oil groove communicating with a ball circulation path of a ball retainer inserted in the housing portion is provided along a circumferential direction of an inner wall of the housing portion, and an oil supply hole is formed from a side surface of the housing toward the oil groove. The integral box-type linear bearing according to claim 1, which is penetrated.