JPH0652085B2 - Linear sliding bearing - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear sliding bearing used for linear guides of various machine tools, robots, precision tables and the like.

[0002]

2. Description of the Related Art As a conventional linear sliding bearing of this type, for example, there are bearings shown in FIGS. That is, 100 is an orbital base, and this orbital base 1
The bearing main body 101 is slidably attached to 00 through the ball 102. Ball 102 is rail 10
0 and the ball rolling surfaces 103 and 104 provided so as to face the bearing body 101 are arranged side by side in a row, and as the bearing body 101 moves, the balls 102, ... The bearing body 101 is lightly moved by rolling between.

[0003]

However, in such a conventional example, the ball rolling surfaces 104, 104 formed on the bearing body 101 are parallel to the ball rolling surfaces 103, 103 provided on the raceway 100. Since it is formed in a straight line, when a moment load M as indicated by an arrow in the figure is applied to the bearing body 101, the ball row 1 is moved as shown in FIG.
Balls 102A and 102A located at the ends of 02 and 102
The concentrated load F will be applied to. So the ball 10
Even if the preload is applied to 2A and 102A, the load more than the preload may be applied.
A and 102A are deformed to cause so-called yawing in which the bearing body 101 is inclined in the horizontal direction with respect to the way 100, which hinders smooth running. Further, the balls 102A, 102A and the ball rolling surface 10
There is also a problem that 3,104 may be damaged, and durability is deteriorated and product life is shortened even if not damaged.

The present invention has been made to solve the above-mentioned problems of the prior art, and the purpose thereof is to:
(EN) Provided is a linear sliding bearing capable of preventing a concentrated load from being generated on a part of a rolling element when a moment load is applied, thereby ensuring smooth running and extending a product life.

[0005]

In order to achieve the above object, according to the present invention, a bearing body having a substantially groove-shaped cross section is slidably mounted on a raceway. Rolling surfaces for guiding the load balls are formed on the facing surfaces of the outer circumference of the raceway and the inner circumference of the bearing body, and
In a linear sliding bearing formed by interposing a number of rolling elements arranged endlessly between the two rolling surfaces, both rolling surfaces for the load balls are arranged in one row on one side of the raceway, and the left and right sides in total. To 2
The bearing body is formed with a strip, and a clearance portion deeper than the rolling surface is formed at an axially intermediate portion of the rolling surface on the bearing body side of the two rolling surfaces. A kerf extending vertically in a plane orthogonal to the moving direction of the bearing body is provided at a portion corresponding to the relief portion.

[0006]

When a moment load is applied to the bearing body, the rolling surface of the bearing body inclines with respect to the rolling surface of the raceway, and the distance between the rolling surfaces tends to become narrow at one end. The bearing body bends around the kerf portion having low rigidity, and an increase in the load acting on the rolling element interposed between the narrowing rolling surfaces is suppressed. Also, the rolling surface of the bearing body bends toward the rolling surface side of the raceway by the amount of bending at the kerf, but this deflection is escaped by the relief part provided on the rolling surface, so the rolling surface The increase in load acting on the rolling elements located in the middle part is also suppressed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments. 1 to 6 showing an embodiment of the present invention,
Reference numeral 1 denotes an entire linear sliding bearing, which is roughly composed of a raceway 2 and a bearing body 4 which is movably assembled to the raceway 2 via balls B as rolling elements.

In this embodiment, a single load ball rolling surface 52, 72 is provided on each side surface of the track 2, and both sides of the bearing block 41 having a groove-shaped cross section constituting the bearing body 4 are provided. The load ball rolling surfaces 52, 172 corresponding to the load ball rolling surfaces 52, 72 are provided on the inner side surfaces of the skirts 10, 11, and a large number are provided between the load ball rolling surfaces 52, 152; 72, 172 facing each other. Ball B
₁ , B ₁ , ... Are endlessly interposed. As the bearing body 4 moves, the loaded ball rolling surfaces 52, 15
2; Balls B ₁ , B ₁ , ... Rolling between 72 and 172 are formed on the side covers 42, 42 at both ends of the bearing block 41 via ball direction changing grooves 42 a, 42 a, and the skirt portion 10 of the bearing block 41. , B by escaping into the ball escape holes 19 and 21 formed in the ball B ₁ ,
It is designed to circulate ...

Here, on the back side of the portion of the bearing block 41 where the loaded ball rolling surfaces 152, 172 are provided, that is, on the outer side surfaces of the left and right skirt portions 10, 11,
Notches or slits 232 and 242 extending linearly in the vertical direction are engraved in a plane orthogonal to the central axis of the track rail 2. The positions of the slits 232 and 242 are on the outer side surfaces of the skirts 10 and 11, and are described below in the relief portion 2.
It is formed in the part corresponding to 52,272.

On the other hand, the load ball rolling surfaces 152, 172 on the bearing body side are formed in a straight line in the longitudinal direction, but in order to release the displacement when a moment load is applied to the bearing body 4 at the center thereof. Escape section 252, 27
Two are provided. The length of the escape portions 252 and 272 is
In the present embodiment, the number of the load balls B ₁ ... Densely arranged on the load ball rolling surfaces 152, ... Is 12, which is about three in the center. That is, when the bearing block 41 is viewed from the side surface, the escape portions 252 and 272 are formed on both sides of the slits 232 and 242 by the length of one ball B ₁ on both sides thereof. Escape part 252, 27
Reference numeral 2 is composed of a curved surface having an arcuate cross section which is deepened by one step in a shape similar to the general surface of the loaded ball rolling surfaces 152, 172, and both longitudinal ends thereof do not hinder smooth rolling of the balls B ₁ ,. Formed on a gently sloping surface.

Further, both longitudinal ends of each of the loaded ball rolling surfaces 152, 172 are crowned, and the loaded ball rolling surfaces 52, 72 provided on the track base 2 toward both ends thereof.
A gentle slope is provided in the direction in which the distance between and increases.

Thus, the left and right bending rigidity of the bearing body 4, in the present embodiment, both skirt portions 10, of the bearing block 41 in which the load ball rolling surfaces 152, 172 are formed,
The bending rigidity of 11 is somewhat reduced by the amount of forming the slits 232 and 242, and when a moment M _B in the left-right direction acts on the bearing body 4 as shown in FIG. 4,
The skirt portions 10 and 11 are easily deformed around the slits 232 and 242. Further, the displacement of the loaded ball rolling surfaces 152, 172, ... Due to the deformation of the slits 232, 242 of the bearing body 4 is eliminated by the relief portion 25.
2, 272 escape by the central load ball B ₁ , ...
To prevent overloading.

Further, in this embodiment, each load ball B
_A support pressure is increased by applying a preload to the load balls ₁ , ₂ , ..., Even in the relief portions 252, 272 formed on the load ball rolling surfaces 152, 172 of the bearing body 4, each load ball B ₁ ,
The depths of the relief portions 252 and 272 are selected so that a preload is applied to.

In the linear sliding bearing having the above structure, the bearing main body 4 has the loaded ball rolling surfaces 52 and 15 respectively.
2; Lightly moves along the track 2 via the load balls B ₁ , ... Interposed between 72 and 172. During the movement of the bearing body 4, the load balls B ₁ , ... Are circulated through the ball escape holes 19, 21 through the ball direction changing grooves 42a, 42a ,.

As shown in FIG. 4, when a lateral moment load M _B is applied to the bearing body 4,
Loaded ball rolling surfaces 152, 1 provided on the bearing body 4
Considering 72, as shown schematically in FIG. 5, the ends of the left and right load ball rolling surfaces 152, 172 that are inclined with respect to the load ball rolling surfaces 52, 72 of the track 2 and are located diagonally. The parts P and Q approach the loaded ball rolling surfaces 52 and 72 of the track 2, and the contact surface pressures of the loaded balls B ₁₁ and B _{11 at} the positions P and Q of the ends increase. Then, by the reaction force of the load balls B ₁₁ , B ₁₁ , both skirt portions 10 of the bearing block 41,
The load ₁₁ applied to the load balls B ₁ and B ₁ is deformed in a direction of bending around the slits 232 and 242, and the load is shared by the plurality of load balls B ₁₁ , B ₁₂ , B ₁₃ , and B ₁₄ to be substantially even. It will be taken charge of and the surface pressure will be the load ball rolling surface 1
52,172 do not join. In addition, each load ball B ₁₁ ,
Since B ₁₄ is preloaded, if the moment load is set within the preload range, the load balls B ₁₁ , ... B ₁₄ will not be deformed and the rigidity will be maintained. On the other hand, when the skirt portions 10 and 11 of the bearing body 4 are deformed, the loaded ball rolling surface 15 corresponding to the slits 232 and 242 positions.
2, 172 are slightly loaded ball rolling surfaces 52, 7 of the way 2
Although it is displaced to the 2 side, the amount of the displacement is the escape portions 252, 272.
Escaped by the central load balls B ₁₅ , B ₁₆ , B
₁₇ is not overloaded.

Further, when a moment load in the direction of the arrow in the figure is applied to each of the load balls B ₁ , ..., The relief portions 252, 2
Of the areas A and B arranged on both sides of the area C of 72, the force acting on the load balls B ₁₁ , ..., B ₁₄ in the area A increases, and the preload of the load balls B ₁₆ ,, ... B _{111 in} the area B slightly decreases. . On the other hand, if the direction of the moment load changes, A, B
The forces acting on the loaded balls B ₁₁ , B ₁₄ ; B ₁₈ , ... B ₁₁₁ are reversed between the regions, but the relative displacement amount is small. Therefore, the amount of displacement of the entire bearing body 4 is small even when subjected to a moment load, and a single bearing can ensure accurate linear movement.

In this embodiment, the case of acting as a moment load in the lateral direction of the bearing body 4 has been described, but when an unbalanced load is applied to the front and rear of the bearing body 4 as shown in FIG. 6 (M _{A in the} figure). Can also be applied. In that case, a slit may be provided on the upper surface of the bearing body 4.

Although only one slit 232, 242 is provided in the above description, a plurality of slits 232, 242 may be provided side by side.

[0019]

The present invention has the above-described structure and operation. Even if a moment load is applied to the bearing body, the inclination of the rolling surface of the bearing body depends on the bending of the bearing body centering on the kerf. The rolling element located at the end of the rolling element row is released and no concentrated load is generated. In addition, the bending of the bearing body on the rolling element rolling surface side is released by the relief portion provided on the ball rolling surface, and concentrated load is not generated on the rolling elements located in the central portion of the loaded ball row. Therefore, even if a moment load is applied to the bearing body, the rolling elements are not deformed by the concentrated load as in the conventional case, and smooth running of the bearing body can be guaranteed. Further, there is no fear that the rolling elements and the rolling surface of the balls will be damaged, the durability can be improved, and the product life can be extended.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a linear sliding bearing showing an embodiment of the present invention.

FIG. 2 is a side view of the linear sliding bearing.

FIG. 3 is a partially cutaway plan view of the linear sliding bearing.

FIG. 4 is a plan view showing a state in which a moment load is applied to the bearing shown in FIG.

FIG. 5 is a plan view schematically showing a load state of each load ball when the moment load of FIG. 4 is applied.

FIG. 6 is a side view of the bearing of FIG. 1 in a state in which a front and rear moment load is applied.

FIG. 7 is a partially cutaway front view of a conventional linear sliding bearing.

8 is a plan cross-sectional view of the bearing of FIG.

9 is a plan view schematically showing a state in which a moment load is applied to the bearing of FIG.

[Explanation of symbols]

2 Raceway 4 Bearing body 52,72 Loaded ball rolling surface (raceway side) 152,172 Loaded ball rolling surface (bearing body side) 232 Slit (cut groove) 242 Slit (cut groove) 252,272 Relief part B Ball B ₁ Load ball

Claims (1)

[Claims] 1. A bearing main body having a substantially groove-shaped cross section is slidably mounted on a raceway, and a load ball is guided to a surface facing the outer circumference of the raceway and the inner circumference of the bearing body. In the linear sliding bearing, each of which has a rolling surface for rolling, and in which a number of rolling elements arranged endlessly are interposed between the rolling surfaces. The raceway is formed in one row on one side of the way, and two strips are formed on the left and right in total. Also, of the two raceways described above, the axially intermediate part of the raceway on the bearing body side is more than the raceway. A deep relief portion is formed, and a kerf extending vertically in a plane orthogonal to the moving direction of the bearing body is provided at a portion of the outer periphery of the bearing body corresponding to the relief portion. Bearing for linear sliding.