JPS63158319A - Ball bearing for linear sliding - Google Patents

Abstract

PURPOSE:To prevent the slip-off of a ball without using a ball retainer by forming the ball rolling surfaces faced to the groove opening direction on the inner bottom surface of each loading ball groove. CONSTITUTION:As for each bearing race 3, loading ball grooves 10a and 10b opened in the convergence direction along the longitudinal direction are formed on the front surface side, and the opening width (l) of each loading ball groove 10a, 10b is formed less than the diameter (d) of a ball 6. Further, ball rolling grooves 11a and 11b faced to the action direction of the load acting onto the ball 6 rolling in the loading ball grooves 10a and 10b from the bearing race 3 side are formed. Therefore, the ball is prevented from slipping off in the case when a rail is cut off from the bearing body, without using a ball retainer.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a straight line for linearly guiding a movable body to be moved in a sliding part of a machine tool such as an NC machine or an industrial robot. Regarding dynamic ball bearings.

[Prior Art] Conventionally, this type of straight II IH dynamic ball bearing has a pair of load ball grooves that extend in the front-rear direction on the inner surface of both sleeves and face in a direction that converges with each other, and each of these load ball grooves has a A bearing body having a substantially gate-shaped cross section and a corresponding non-load ball hole is attached to both front and rear end surfaces of this bearing body, and a ball endless track is formed by connecting each of the above-mentioned load ball grooves and the non-load ball hole in communication. a pair of lid bodies formed therein; a track rail having a pair of raceway surfaces facing oppositely to the ball rolling surfaces of the bearing race along the front-rear direction of both left and right shoulders and facing in a direction in which they are mutually expanded; and the track rail; Rolls while applying a load between each raceway surface of the rail and each load ball groove of each bearing race,
It consists of a large number of balls that guide the bearing body along the track rail, and a ball retainer that is installed between the pair of lids and prevents the balls rolling along the load ball groove from falling off. Two straight lines connecting each ball contact point in the upper and lower pair of load ball grooves located in the oil section on one side and each ball contact point in the upper and lower pair of raceway surfaces located on one side of the track rail intersect on the track rail side. There are known types that expand on the oil side.

[Problems to be Solved by the Invention] However, in these conventional linear sliding ball bearings, the load ball grooves formed on the inner surface of each oil section of the bearing body and located below do not make contact with the balls. The direction is diagonally upward from the opening direction of each load ball groove, and it is not possible to apply a grindstone from the contact direction of these balls to grind them. There was a problem in that the raceway surface could not be ground with high precision and smooth sliding motion could not be achieved.

Additionally, in order to prevent the balls from falling off when the track rail is separated from the bearing body, a pole retainer is installed between the pair of lid bodies, but such a pole retainer can connect to the bearing body without coming into contact with the track rail. Must be located within the gap between the track rail and
It is usually formed by press forming a thin plate and has a complex shape, so it requires high accuracy in forming and mounting, and even a slight deformation causes the ball to slide into the pole retainer. This often resulted in contact, causing noise and impeding smooth sliding movement. In addition, the use of such a pole retainer inevitably requires work to attach the pole retainer between a pair of lid bodies, and this ball retainer attachment work has been a major obstacle in automating bearing assembly. .

Therefore, the inventor of the present invention has developed a method that allows for easy and highly accurate grinding of load ball grooves, as well as a method that prevents each ball from falling off when the track rail is separated from the bearing body, without using a pole retainer. The present invention was arrived at as a result of various research on linear sliding ball bearings.

[Means for Solving the Problems] That is, the present invention provides a body main body having a substantially gate-shaped cross section and having fitting grooves along the front and back directions on the inner surface of both sleeve portions, and a body main body having a substantially gate-shaped cross section and a body main body that has fitting grooves along the front and back directions on the inner side of both sleeves, and a pair of bearing races that have facing ball raceway surfaces and are fitted into respective fitting grooves of the body body, and each ball raceway surface is provided on the body body and/or each bearing race. a bearing body having a no-load ball passage corresponding to the above, and a pair of bearing bodies that are attached to both front and rear end surfaces of the body main body and that connect each of the ball rolling surfaces and the no-load ball passage to form a ball endless track. a track rail having a lid body, a pair of raceway surfaces facing oppositely to the ball rolling surfaces of each of the bearing races along the front-rear direction of both left and right shoulders and facing in a mutually expanding direction; Consisting of a large number of balls that roll while applying a load between each raceway surface and each ball rolling surface of each of the above-mentioned bearing races, and guide the bearing body along the raceway, each of the above-mentioned bearing races has Load ball grooves with a substantially circular cross section are formed that open in a direction that converges with each other along the front and rear directions, and the opening width of each of these load ball grooves is made smaller than the diameter of the ball at least, and the inner bottom of each load ball groove is This is a linear sliding ball bearing with a ball rolling surface facing toward the groove opening direction.

In the present invention, the body main body constituting the bearing body may be made of ordinary steel, but it can also be made of lightweight materials such as extruded aluminum or synthetic resin moldings.

Also, regarding the bearing race, at least along the front-rear direction, the upper load ball groove should open diagonally downward, and the lower load ball groove should open diagonally downward. A pair of upper and lower load ball grooves each having a substantially circular cross section are formed and open in directions converging with each other so that the grooves open obliquely upward;
The opening width of each of these load ball grooves is at least smaller than the diameter of the ball, and a ball rolling surface facing toward the opening direction of the groove is formed at the inner bottom of each load ball groove. This ball rolling surface is preferably formed to have a width slightly smaller than the opening width of the load ball groove, and with its center of curvature passing through the center of the opening width, so that it is separated from the opening of the load ball groove. It is preferable to insert a grindstone of a predetermined width and apply the grindstone perpendicularly to the ball rolling surface so that the ball rolling surface can be precisely and precisely ground. Generally speaking, the bearing race may be attached to the fitting groove of the body main body using conventionally known fixing means such as screws or adhesives, but in consideration of automation of assembly, it is preferably fixed by press fitting. It is better to do so.

Furthermore, the no-load ball passage formed in the bearing body may be configured with no-load ball holes bored along both sleeves of the body main body or along the front-rear direction of each bearing race, and the above-mentioned The approximately semicircular no-load ball groove formed in the fitting groove on the inner surface of both sleeves of the body body and the approximately semicircular no-load ball groove formed on the back side of each bearing race are aligned with each other. may be formed.

[Function] The linear sliding ball bearing of the present invention has a bearing body composed of a main body and a bearing race, and the bearing race has a substantially circular cross section that opens in a direction converging with each other along the front-rear direction of the bearing race. The opening width of each load ball groove is made smaller than the diameter of the ball at least, and a ball rolling surface facing toward the opening direction of the groove is formed at the inner bottom of each load ball groove. Therefore, it is possible to grind the ball rolling surface with high precision, and it is also possible to prevent the balls from falling off when the track rail is separated from the bearing body without using a ball retainer.

[Example] Hereinafter, the linear sliding ball bearing of the present invention will be specifically described based on the example shown in the accompanying drawings.

1 to 4, a linear sliding ball bearing according to an embodiment of the present invention is shown. This straight line 1 learning ball bearing includes a bearing body 1 composed of a body body 2 having a substantially gate-shaped cross section and a pair of bearing races 3, and a pair of lid bodies 4 attached to both front and rear end surfaces of the body body 2. It is composed of a track rail 5, and a large number of balls 6 that roll while applying a load between the track rail 5 and the bearing body.

In the present invention, as shown in FIGS. 4 to 8, the body main body 2 is made of a lightweight material such as an aluminum extrusion molded material or a synthetic resin molded product, and both sleeve portions 7 are provided on the inner side in the front and back direction. Fitting grooves 8 are formed along the respective fitting grooves, and a pair of upper and lower no-load ball holes 9 are bored along the front-rear direction.

Further, each of the bearing races 3 is attached to each fitting groove 8 of the body main body 2 by means of press fitting, and each of these bearing races 3 is attached to each of the fitting grooves 8 of the body main body 2.
As shown in the figure, load ball grooves 10a and 10b, each of which has a substantially circular cross section, are formed on the front side thereof and open in directions converging with each other along the front-rear direction.
The opening width p of a and 10b is at least the diameter d of the ball 6.
Roughly speaking, the bottom of the ball has a ball facing toward the direction of the groove opening, that is, the direction of the load acting on the balls 6 rolling in the load ball grooves 10a, 10b from the bearing race 3 side. Rolling surface 11a, 11b
is formed.

Furthermore, the lid body 4 is shown in FIGS. 1 to 3, FIG.
13, each end of each load ball groove 10a, 10b formed on the bearing body 1 side and each end of each non-load ball hole 9 corresponding to each of these load ball grooves 10a, 10b. A pair of upper and lower ball circulation paths 12a and 1 on one side for forming a ball endless track by communicating and connecting the
2b, and is composed of a lid main body 4a and four lid pieces 4b.

That is, the lid main body 4a has a pair of upper and lower slots 13a, which are curved so that they approach each other at the center in the vertical direction on one side of the inner surface and move away from each other at both ends, and have a substantially semicircular shape in the depth direction. 13b, and a mounting groove 14 for fitting and mounting the lid pair piece 4b is formed approximately in the center of the dark edge of each of these slots 13a, 13b, and the lid piece 4b is , the lid body 4
It has circumferential grooves 15a and 15b which are fitted into the mounting groove 14 of a and form ball circulation paths 12a and 12b together with the respective slots 13a and 13b.

To attach these lids 4, step bolt holes 16 are bored in both the front and rear ends of the main body 2, as shown in FIG. 7, and each lid 4 is installed as shown in FIG. Stepped insertion holes 17 corresponding to the stepped bolt holes 16 are opened in the steps, and as shown in FIG. A bushing 18 is interposed, a mounting bolt 19 is inserted through a stepped insertion hole 17 on the lid body 4 side, and this mounting bolt 19 is screwed into a stepped bolt hole 16 on the body main body 2 side.

As shown in FIGS. 4 to 6 and 15, the track rail 5 has a pair of track surfaces 21a and 21b formed along the front and back directions of both left and right shoulders of the track rail 5, which face each other in a direction in which they widen. Each of these raceway surfaces 21a and 21b connects each load ball groove 10a of each bearing race 3 fitted into each fitting groove 8 on the inner side of both sleeves 7 of the body main body 2 with the ball 6 in between. , 10b, and when the bearing body 1 slides along the track rail 6, the ball rolling surfaces 11a, 11b on the side of the bearing body 1 and the track. Track surface 21a on the rail 5 side.

21b, each ball 6 applies a load.

Next, FIGS. 16 and 17 show straight lines I according to other embodiments.
This shows a ball bearing for an imperial edict, and unlike the case of the above embodiment, a pair of upper and lower no-load ball grooves 22a having a substantially semicircular shape are formed in each fitting groove 8 of the body main body 2,
22b, and a pair of upper and lower no-load ball grooves 23a having a substantially semicircular shape formed on the back side of each bearing race 3,
23b are aligned with each other to form a no-load ball passage for circulating the no-load balls.

[Effects of the Invention] The linear motion ball bearing of the present invention allows load ball grooves to be easily and precisely ground, and furthermore,
This prevents the balls from falling off when the track rail is separated from the bearing body without using a ball cage, and also prevents the balls from coming into contact with the surrounding area of the load ball groove during tank movement. , there is no increase in surrounding motion resistance or generation of noise.

[Brief explanation of the drawing]

Fig. 1 is a front view showing a linear sliding ball bearing according to an embodiment of the present invention, Fig. 2 is a side view of Fig. 1, Fig. 3 is a plan view of Fig. 1, and Fig. 4 is a plan view of Fig. 1. FIG. 5 is a partial enlarged sectional view showing the main part of FIG. 4, FIG. 6 is a partial sectional view taken along the Vl-Vl line in FIG. Figure 7 is a front view of the main body, Figure 8 is the 7th
Figure 9 is a side view of the bearing race; Figure 9 is a perspective view of the bearing race;
Figure 0 is a back view of the lid, Figure 11 is XI-XI of Figure 10.
A line cross-sectional view, FIG. 12 is an xm-xn line cross-sectional view of FIG. 11,
Figure 13 is a perspective view of the lid piece that constitutes the lid;
The figure is a partial sectional view showing the installation state when the lid body is attached to the body body, Figure 15 is a partial perspective view of the track rail, and Figure 16 is a partial perspective view of the track rail.
This figure is a sectional view similar to FIG. 4 showing another embodiment, and FIG. 17 is a perspective view showing the bearing race of FIG. 16. Explanation of symbols (1) Bearing body, (2) Body main body, (3) Bearing race, (4) Lid, (5) Track rail, (6 )...Hall, (7
)...Oil part, (8)...Fitting groove, (9)...No load ball hole, (10a) (10b)...Load ball groove, (11a) (Ilb) -* - 7L/Rolling surface, (12
a) (12b)... Ball circulation path, (21a) (2
1b)... Raceway surface, (1... Opening width of load ball groove, (d)... Ball diameter.

Claims (1)

[Claims] A body main body having a substantially gate-shaped cross section having fitting grooves along the front and back directions on the inner surface of both sleeves, and a ball rolling surface facing in a direction converging with each other along the front and back directions, and each fitting of the body main body a pair of bearing races fitted in grooves, and the body main body and/or each bearing race has an unloaded ball passage corresponding to each ball rolling surface; and the body main body. A pair of lids are attached to both the front and rear end surfaces of the body, and form a ball endless track by connecting each of the ball rolling surfaces and the no-load ball path, and each of the above-mentioned lids are attached to the front and rear ends of the left and right shoulders. A track rail having a pair of raceway surfaces facing oppositely to the ball rolling surfaces of the bearing races and facing in directions in which they expand each other, and each raceway surface of the track rail and each ball rolling surface of each of the bearing races. It consists of a large number of balls that roll while applying a load between them and guide the bearing body along the track rail, and each of the bearing races has a roughly circular cross section that opens in a direction that converges with each other along the front and back direction. The opening width of each load ball groove is made smaller than the diameter of the ball at least, and a ball rolling surface facing toward the opening direction of the groove is formed at the inner bottom of each load ball groove. A ball bearing for linear sliding that is characterized by: