JPH0139941Y2 - - Google Patents

Description

[Detailed description of the invention] ● Industrial application field This invention relates to a linear way unit that can move a rail and a casing linearly to any position by combining a rolling bearing for linear motion and a ball screw. It's an improvement.

● Conventional technology This type of conventional bearing unit was developed in Japanese Patent Application Laid-Open No.
As shown in Publication No. 137616, the casing has an inverted U-shaped cross section with an endless circulation path for balls including raceway grooves on both ends of the inner circumferential surface, and raceway grooves are located at the outer positions corresponding to the raceway grooves. In a linear way unit that is assembled with a rail member having a U-shaped cross section through balls, a ball screw used for driving is located inside the rail member, a screw shaft is fixed to the rail member, and the outer cylinder The structure was such that the part was fixed to the casing.

Problems to be solved by the invention In the prior art described above, the ball screw and the bearing part that moves linearly are formed near the same plane, which increases the width of the linear way unit and the width of the device in which it is assembled. had no choice but to grow.

Further, since the casing or the rail member has a U-shaped cross section, there is a space between the left and right balls, and the bearing has a disadvantage in that its rigidity against loads in the left and right direction is weak. As a result, even if an appropriate preload is applied, the amount of preload decreases during use.

● Purpose of the invention The purpose of the invention is to solve these drawbacks and provide a columnar linear way unit that is small, has high bearing rigidity, and is easy to manufacture.

●Means for solving the problem The present invention has the following configuration in order to solve the conventional drawbacks.

The present invention includes a casing member in which an endless circulation path for balls including a raceway groove is formed on the upper part of the inner surface of a hollow columnar shape, and a raceway groove formed in the upper part of the outer surface corresponding to the raceway groove, and a hollow column in the casing member. In a columnar linear way unit that moves linearly by assembling a long rail member inserted into a section via a ball, the space between the track grooves of the rail member is a solid part, and the solid part A generally V-shaped wide cutout groove is formed in the lower part of the casing member in the longitudinal direction, and an outer cylinder of a ball screw is fixed to the center of the bottom surface of the casing member so as to protrude inside.
The screw shaft of the ball screw is rotatably fixed to the rail member.

Function The present invention has the above-mentioned configuration, and the casing member has a hollow columnar shape with a closed cross section, so it has high rigidity against lateral pressure, and the rail member also has a solid portion between the raceway grooves on both sides. Since the rigidity against lateral pressure is high, deformation due to lateral loads during use is difficult to occur, and preload is well maintained, improving bearing accuracy and linear motion accuracy.

In addition, since the outer cylinder of the ball screw and the screw shaft are arranged in the V-shaped notch groove below the solid part between the raceway groove of the casing member and the raceway groove of the opposing rail member, the entire linear way unit The width dimension of is small.

Embodiment The drawing shows an example of the implementation of the present invention, in which a hollow square columnar casing member C includes an upper casing 1, a lower casing 2, and a bearing plate 6.
It is made by combining. A mounting portion 1a protrudes from the upper casing 1 to be fixed to other members.

A bearing plate 6 is inserted and fixed between the left and right upper and lower casings 1 and 2, and a raceway groove 6a is formed in the longitudinal direction of the inner wall surface of the bearing plate 6. The position of the raceway groove 6a is the casing member C.
A return hole 6b for returning the ball 7 is formed inside the bearing plate 6.

At both ends of the bearing plate 6 in the longitudinal direction, a direction change path 6 is provided that is continuous with the raceway groove and the return hole.
A side plate 6c, on which d is formed, is fixed to form an endless circulation path for the ball 7.

A rail 4 having raceway grooves 4a formed at positions corresponding to the raceway grooves 6a of the bearing plate 6 is attached to the rail mounting surface 5a of the bed 5 to constitute a rail member R.

The above-mentioned rail member R has a solid portion 5c between the raceway grooves 4a on both sides, and a section below the solid portion 5c is formed in a substantially inverted V-shape. That is, the lower surface is formed with a notch groove 5b extending downward in the longitudinal direction. The outer cylinder 9 of the ball screw 3 is positioned in the space between the notch groove 5b of the bed 5 and the center of the bottom surface of the lower casing 2, and is fixed to the lower casing 2.

Although not shown, the screw shaft 8 of the ball screw 3 is rotatably fixed by members attached to both ends of the bed 5.

This columnar linear way unit has the following two functions.

The first function is to fix the casing member C,
By rotating the screw shaft 8, the rail member R moves left and right, so it can be used for a robot arm, etc.

The second function is that by fixing the end of the rail member R and rotating the screw shaft, the casing member C can be moved left and right.

As for the method of fixing the lower casing 2 and the outer cylinder 9 of the ball screw 3, a general method is shown in which circlips are attached to both ends.

Although the present invention mainly uses balls as the rolling elements, it is also possible to use rollers.

In this way, in the present invention, the rails 4 having the raceway grooves 4a of the rolling elements are fixed to the left and right sides of the solid part 5c of the bed 5, and the casing member C is formed into a hollow column with a closed cross section, so that the rigidity between the rolling elements is reduced. The unit is designed to increase the preload and accurately maintain an appropriate preload even during use.Furthermore, since the ball rows and ball screws are formed above and below, the width of the entire unit can be reduced.

Furthermore, the height of the unit will not increase significantly as the space is utilized effectively.

Although the illustrated embodiment shows an example of a casing member formed in the shape of a hollow rectangular prism, it is also possible to use a casing member or a rail member formed in the shape of a hollow cylinder.

Effects The present invention has the configuration and operation described above, and the casing member forms a closed cross section, and the rail member has a solid portion between the raceway grooves on both sides, so it is resistant to lateral pressure. It has great rigidity,
Preload is also maintained well, and bearing accuracy and linear motion accuracy are improved.

In addition, since the ball screw member is disposed in the approximately inverted V-shaped notch groove below the solid part between the raceway grooves of the rail member, the width dimension of the linear way unit as a whole can be reduced. It also has

[Brief explanation of the drawing]

The drawings show an example of implementation; FIG. 1 is a longitudinal sectional view perpendicular to the length direction, FIG. 2 is a partially cutaway side view, and FIG. 3 is a perspective view of the bed of the rail member. C: Casing member, 5b: Notch groove, R: Rail member, 5c: Solid part, 1: Upper casing,
6: Bearing plate, 1a: Mounting part, 6a:
Raceway groove, 6b: return hole, 2: lower casing, 3: ball screw, 4: rail, 4a: raceway groove, 5: bed, 5a: rail mounting surface, 6c: side plate, 6d: direction change path, 7: ball, 8: Screw shaft, 9: Outer cylinder.

Claims (1)

[Claims for Utility Model Registration] (1) A casing member in which an endless circulation path for balls including raceway grooves is formed in the upper part of the inner surface of a hollow columnar shape, and a raceway groove in the upper part of the outer surface corresponding to the raceway groove. A long rail member is formed and inserted into the hollow part of the casing member, and is assembled via balls to form a columnar linear way unit that moves linearly. is a solid part, and a wide notch in the shape of an inverted V is formed in the lower part of the solid part in the longitudinal direction, and an outer cylinder of the ball screw is formed in the center of the bottom surface of the casing member. is fixed to protrude inside, and the screw shaft of the ball screw is rotatably fixed to the rail member and disposed in the substantially inverted V-shaped notch groove. unit. (2) The columnar linear way unit according to claim 1, wherein the raceway groove portion of the casing member or the rail member is formed separately. (3) The casing member or the rail member is 4
A columnar linear way unit as set forth in claim 1 of the utility model registration, characterized in that it has a prismatic shape.