JP2575926B2 - Linear guide device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a linear guide device used for a linear motion section of a machine tool or an industrial robot, for example.

[Prior Art] Linear sliding bearings that guide linear motion between two objects by using rolling elements such as balls or rollers that endlessly circulate have been widely used in the industry in recent years. Various structures have been proposed.

As one aspect thereof, a ball bearing for linear sliding disclosed in JP-A-62-2000015 has been proposed. Specifically, as shown in FIG. 22, a load ball groove c for rolling the ball b is formed on both opposing outward side surfaces of the bearing block a (hereinafter, block), and on both sides of the block a. A ball rolling groove opposed to the load ball groove c is provided on the pair of track bases d, and the block a is formed by a pair of balls b sandwiched between the load ball groove c and the ball rolling groove. This guides linearly along the way d.

Japanese Patent Application Laid-Open No. 62-200016 proposes a linear guide device to which the above-described linear sliding ball bearing is applied. Specifically, as shown in FIG. 23, the screw shaft f of the feed screw mechanism is screwed into the center of the block a in the bearing, and the block a is attached to the track base d based on the rotation of the screw shaft f. It is to promote along.

By the way, in the above-described linear sliding ball bearing and the linear guide device, like other bearings, a preload is applied to the rolling element for the purpose of preventing the backlash of the block from the raceway and achieving high-precision motion. Required to be used.

Therefore, in the related art, the preload is applied and the magnitude of the preload is adjusted by appropriately selecting the diameter of the ball to be inserted between the block and the raceway according to the required preload amount.

[Problems to be Solved by the Invention] However, in the preload applying method performed by selecting the ball diameter, it is necessary to remove the block from the way and replace all balls every time the applying or adjusting work is performed. And the work is very troublesome.

In addition, it cannot be confirmed whether or not the proper preload has been applied unless the block in which the ball has been selected is actually incorporated into the way. It is necessary to repeat the operation several times, and in this respect, the operation of applying the preload is very troublesome.

In addition, in the above-described linear guide device, since the feed screw shaft is screwed to the block, it is very difficult to remove the block from the way once the device is assembled, and it is difficult to change the preload amount. It also has the disadvantage that it is not easy.

The present invention has been made in view of the above-described object, and an object of the present invention is to provide a linear guide device capable of applying and adjusting a preload in a state where a block is assembled to a track. is there.

Means for Solving the Problems In order to achieve the above object, the linear guide device of the present invention has a pair of upper and lower load ball grooves on each of which opposing outward facing side surfaces, on each of which a ball rolls. A bearing block having a ball circulation path communicating and connecting both ends of the ball groove, a starting table having a ball transfer groove for holding the ball in combination with the load ball groove, and guiding the bearing block; In a linear guide device comprising a feed screw shaft which is disposed in parallel with the groove and is screwed to the bearing block, the bearing block has a slit-shaped space parallel to a side surface of the block in which the load ball groove is formed. And an adjustment hole communicating the side surface of the block and the slit-shaped space is formed in the center between the pair of upper and lower load ball grooves, and The adjusting screw is screwed, and a through hole with which the feed screw shaft is screwed is arranged in the axial direction of the adjusting hole, and the adjusting screw is projected into the slit-shaped space, and according to a fastening amount of the adjusting screw. The opening width of the slit-shaped space is changed.

In such technical means, there are roughly two methods for providing the above-mentioned slit-like space in a bearing block (hereinafter, block). In other words, one method is to cut and form a slit-like space directly on the block, and the other is to form the block into a bearing race (hereinafter, referred to as a bearing race).
(Lace) and a block main body, and a slit-shaped space is formed between the race and the block main body.
In this case, in the former, the block is elastically deformed,
In the latter case, the opening width of the slit-shaped space can be adjusted, while in the latter case, the opening width can be adjusted by moving the race formed with the loaded ball grooves with respect to the block body.

Further, as the above-mentioned way, it is not necessary to be integrated as long as the way can linearly guide the block from both sides via balls, and the way provided on both sides of the block may be different. Absent.

Further, the contact angle between the ball and the loaded ball groove or the ball rolling groove may be appropriately changed in design, and the number of the balls may be appropriately selected according to the required maximum load or the like.

[Operation] The above technical means works as follows.

When the adjustment amount of the adjusting screw screwed into the adjusting hole of the bearing block is adjusted, the opening width of the slit-shaped space from which the adjusting screw protrudes changes, and the load ball groove of the bearing block and the raceway facing the bearing block are adjusted. The distance between the ball and the ball rolling groove is adjusted, and the preload of the ball rolling on the load ball groove can be adjusted.

At this time, the feed screw shaft screwed into the bearing block is located on the axis of the adjustment hole, and the adjustment hole is located at the center between the upper and lower load ball grooves formed on the side surface of the bearing block. ing. Therefore, the force by which the adjusting screw pushes and expands the slit-shaped space acts perpendicularly to the feed screw axis, and the reaction force acts equally on the balls rolling in the upper and lower loaded ball grooves. For this reason, even if the fastening amount of the adjustment screw increases, the bearing block does not become eccentric in the vertical direction with respect to the feed screw shaft.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show a first embodiment of the linear guide device of the present invention, which is roughly divided into a bearing block B (hereinafter, block) into which a screw shaft 8 of a feed screw mechanism is screwed. It comprises a track 1 for guiding the block B, and a plurality of balls 2 for transferring a load between the block B and the track 1 while applying a load.

Further, as shown in FIG. 3, the block B fixedly supports a pair of bearing races 4a, 4b (hereinafter, races) formed with two load ball grooves 41a, 41b, and the races 4a, 4b. The race 4a includes a block main body 3, a pair of lids 5 engaging with both front and rear end surfaces of the block main body 3, and a pair of ball retainers 6 engaging the side surfaces of the races 4a and 4b. A slit-shaped space 10 is formed between the block 4 and the block main body 3, and the slit-shaped space 10 is formed by an adjusting screw 7 (opening width adjusting means) screwed into the race 4a.
The width of the opening can be adjusted.

As shown in FIGS. 4 to 7, the block body 3 has a fixing portion 3b for fixing the races 4a and 4b protruding from a ball nut portion 3a to which the screw shaft 8 is screwed. The ball nut portion 3a is tapped with a bolt hole 38 for fixing the table 9, while the fixing portion 3b
The threaded hole 32 with which the race fixing bolt 31 is engaged is tapped. As shown in FIG. 8, the ball nut portion 3a has a screw shaft 8 formed in a part of a through hole 33 provided slightly larger than the screw shaft 8 so as to correspond to a spiral ball rolling groove 81. A ball circulation path is formed by forming a return tube 36 and fixing the holding member 35 with the return tube 36. Note that a preload is applied to the ball 37 sandwiched between the screw shaft 8 and the block body 3 in order to increase the accuracy of the movement of the block B.

The races 4a and 4b are substantially rectangular members formed to have the same length as the block main body 3, and are fixed and supported by fixing portions of the block main body 3 by fixing bolts 31 penetrating through holes. Then, as shown in FIGS. 9 to 11, the upper load ball groove 41 is formed on the side surface along the longitudinal direction.
a and the lower loaded ball groove 41b are formed in a curved surface with a radius of curvature larger than the radius of the ball 2, and the no-load rolling holes 43a, for circulating the ball 2 rolling through the loaded ball grooves 41a, 41b. 43b is drilled. In this embodiment, the upper load ball grooves 41a are provided obliquely upward, and the lower load ball grooves 41b are provided obliquely downward at an angle of 45 ° from the horizontal. Therefore, the block B formed by fixing the pair of races 4a and 4b to the block main body 3 can uniformly apply loads in four directions perpendicular to the moving direction.

The race 4a is formed with an adjusting hole 44 into which the adjusting screw 7 is screwed so as to connect the load ball groove side to the back side. Therefore, when the race 4a is fixed to the block main body 3, the adjusting screw 7 comes into vertical contact with the ball nut portion 3a of the block main body 3, and the race 4a and the ball 4 A slit-shaped space 10 is formed between the slit-shaped space 10 and the nut portion 3a, and the opening width of the slit-shaped space 10 can be adjusted.

On the other hand, the lid 5 is made of synthetic resin and is fixed to the front and rear end surfaces of the block body 3 with fixing bolts (not shown). As shown in FIGS. Are formed, while the races 4a, 4
A ball turning circuit 52 is provided for connecting and connecting the load ball grooves 41a and 41b formed in b with the corresponding no-load rolling holes 43a and 43b. This ball swirling circuit 52 has a load ball groove.
Semicircular guide piece 5 having a guide surface 54 continuous with 41a, 41b
3 (see FIGS. 15 and 16) is formed by fitting a ball guide groove 55 formed in the lid 5. Therefore, by attaching the lid body 5 to the block body 3, a ball circulation path that connects and connects both ends of the load ball grooves 41a and 41b is formed.

The ball retainer 6 is a rod-shaped member having a substantially trapezoidal cross section as shown in FIGS.
When attached to the races 4a, 4b, the gap between the protruding end 61 and the side surface of the races 4a, 4b is formed to be smaller than the diameter of the ball 2, and when the block B is removed from the track base 1, the ball 2
Is prevented from falling from the load ball grooves 41a and 41b. Reference numeral 62 denotes a through hole formed corresponding to the adjustment hole 44 of the race 4a, and reference numeral 63 denotes a mounting hole through which a mounting screw 64 to the race 4a (4b) passes.

The track base 1 is formed in a substantially U-shaped cross section in which a pair of support portions 1b for supporting the block B rise from both ends of a fixed portion 1a fixed to a bed or the like. A concave groove 11 is formed on the inner side surface of each support portion 1b, and upper and lower ball rolling grooves 12a facing the upper load ball groove 41a and the lower load ball groove 41b are formed at upper and lower corners of the concave groove 11, respectively. , 12b are formed. Further, a through hole 13 corresponding to the adjustment hole 44 of the race 4a is formed at one position in the longitudinal direction of the support portion 1b.
The adjustment screw 7 to be screwed into is rotated. Reference numeral 14 denotes a bolt hole through which a bolt (not shown) for fixing the track base 1 passes.

In such a configuration, the linear guide device of the present embodiment assembles the block B from the block main body 3, the races 4a and 4b, the lid 5, the ball retainer 6, and the plurality of balls 2, and the ball nut of the block main body 3. A table 9 for mounting a movable body to be linearly guided is attached to the portion 3a, and a driving means (not shown) such as a stepping motor is connected to one end of a screw shaft 8 screwed to the ball nut portion 3a. The block B is used by propelling the block B along the way 1 a predetermined distance in accordance with the rotation amount of the screw shaft 8. In FIG. 1,
Reference numeral 15 denotes a seal for preventing foreign matter from entering between the track base 1 and the block B.

The application and adjustment of the preload to the ball 2 in the use thereof is performed through a through hole formed in the support portion 1b of the track base 1.
Block B at the position where 13 and adjustment hole 44 of race 4a match
Is stopped, and the operation is performed as follows.

That is, when the adjusting screw 7 engaged with the adjusting hole 44 is rotated to change the opening width of the slit-shaped space 10 formed by the race 4a and the block main body 3, the load of the square races 4a and 4b is accordingly changed. The gap between the ball grooves 41a, 41b and the ball rolling surfaces 12a, 12b of the track base 1 is adjusted, and the load ball grooves 41a, 4b are adjusted.
An arbitrary preload is applied to the ball 2 rolling on 1b.

Therefore, by changing the amount of rotation of the adjusting screw 7,
The preload amount can be freely adjusted without removing the block B from the track base 1.

However, in this embodiment, the slit-shaped space that can be adjusted
The opening width of 10 is the gap between the through hole 42 formed in the race 4a and the fixing bolt 31. Therefore, the diameter of the through hole 42 must be larger than the diameter of the fixing bolt 31 in order to increase the adjustment width of the preload amount.

In FIG. 1, the adjustment screw 7 is screwed into only one of the races 4a to form a slit-shaped space 10 between the race 4a and the block body 3, but the adjustment screw 7 is also formed in the other race 4b. May be screwed together to form a slit-shaped space 10 between the races 4a, 4b and the block body 3. In this manner, the slit-shaped spaces 10 are formed on both sides of the block body, and the opening widths of these slit-shaped spaces 10 are evenly changed by the adjusting screws 7, so that the adjusting screws 7 press the block body 3 evenly from both sides. As a result, there is no fear that the block body 3 is displaced with respect to the track base 1 to apply a load to the screw shaft 8, and the feeding accuracy of the block B is ensured.

In FIG. 1 showing this embodiment, the opening width of the slit-shaped space 10 is exaggerated in order to facilitate understanding of the above description.

FIG. 20 shows a cross section of a second embodiment of the linear guide device of the present invention.

In this embodiment, a slit-shaped space 10 is formed by cutting in a substantially rectangular block body 3 having load ball grooves 41a and 41b formed on both side surfaces, and a slit-shaped space is formed in the same manner as in the first embodiment. An adjustment hole 44 communicating with the space 10 was formed by tapping from the side.

Therefore, in this embodiment, when the adjustment bolt 7 is screwed into the adjustment hole 44, elastic deformation such that the slit-shaped space 10 expands is generated in the block main body 3, and the load ball grooves 41a, 41
The gap between b and the ball rolling grooves 12a, 12b is adjusted, and an arbitrary preload is applied to the ball 2 rolling in the loaded ball grooves 41a, 41b.

Also in this embodiment, the slit-shaped space 10 may be formed on both sides of the through hole 33 through which the screw shaft 8 passes, and the effect is the same as that of the first embodiment.

The other components such as the lid 5, the ball retainer 6, and the rail 1 other than those described above are the same as those of the first embodiment, so that the description will be omitted.

[Effects of the Invention] As described above, according to the linear guide device of the present invention, application and adjustment of the preload to the ball are performed by changing the opening width of the slit-shaped space formed in the bearing block. Therefore, the operation can be performed without removing the bearing block from the way. Moreover, since the bearing block does not become eccentric in the vertical direction with respect to the feed screw shaft even when the ball is preloaded, it is possible to apply the preload to the ball while maintaining the light movement of the bearing block. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the linear guide device of the present invention, FIG. 2 is a perspective view, FIG. 3 is an exploded perspective view showing the structure of a bearing block, and FIGS. Front view, side view, bottom view, plan view and sectional view showing the block body, FIGS. 9 and 10 are plan and side views showing a bearing race, and FIG. 11 is a sectional view taken along line II of FIG. , FIG. 12 and FIG. 13 are front and rear views showing the lid, and FIG.
FIG. 15 is a front view and a plan view showing a guide piece, FIG. 17 is a side view showing a ball retainer, and FIG. 18 is a sectional view taken along the line III-III of FIG. , Figures 19 and 20
FIG. 12 is a perspective view and a cross-sectional view showing a way, and FIG. 12 is a cross-sectional view showing a second embodiment of the linear guide device of the present invention.
FIG. 23 is a sectional view showing a conventional linear sliding ball bearing and a linear guide device, respectively. [Description of Symbols] B: Bearing block, 1: Track, 2: Ball, 3: Block body, 4a, 4b: Bearing race, 7:
Adjusting screw (opening width adjusting means), 8: screw shaft, 10: slit space, 12a, 12b: ball rolling groove, 41a, 41b ...
Load ball groove

Claims (3)

(57) [Claims] 1. A bearing block having a pair of upper and lower load ball grooves on each of opposing outward facing side surfaces on which balls roll, and a ball circulation path connecting and connecting both ends of the load ball grooves. A raceway for guiding the bearing block, the raceway having a ball rolling groove for sandwiching the ball in combination with the groove, and a feed screw disposed in parallel with the load ball groove and screwed to the bearing block In the linear guide device including a shaft, the bearing block forms a slit-shaped space parallel to the block side surface on which the load ball groove is formed, and has an adjustment hole communicating the block side surface and the slit-shaped space. An adjusting screw is screwed into the center between a pair of upper and lower load ball grooves, and a through hole into which the feed screw shaft is screwed is adjusted. A straight line that is arranged on the axis of the hole, and changes the opening width of the slit-shaped space in accordance with the amount of fastening of the adjusting screw, thereby adjusting the preload of the ball rolling in the load ball groove. Guide device. The bearing block comprises a pair of bearing races in which the load ball groove and the ball circulation path are formed, and a block main body that holds these bearing races and is screwed to the feed screw shaft. The linear guide device according to claim 1, wherein the slit-shaped space is formed between the bearing race and the block body. 3. The linear guide device according to claim 1, wherein the slit-like space is formed in the bearing block by cutting, and the opening width of the slit-like space changes by elastic deformation of the bearing block. .