JPH0416296B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a linear guide device, and more specifically, to an X-axis guide device in a machine tool such as an NC machine.
This invention relates to a linear guide device that is frequently used in sliding parts of various general industrial machines such as Y/Z axes, automatic tool changers, automatic welding machines, injection molding machines, and industrial robots.

[Prior Art] Conventionally, as this type of linear guide device, a guide shaft having a ball rolling groove along the axial direction, a loaded ball groove forming an endless track for the balls rolling in the rolling groove, and no load ball groove are used. A linear guide device is known that includes a bearing body having a load ball groove, and a movable body that is attached to the bearing body and performs linear reciprocating motion along the guide shaft via the balls. .

[Problems to be Solved by the Invention] However, in this type of conventional linear guide device, the bearing main body and the movable body are directly fixed to each other by mounting means such as mounting bolts. Accuracy errors such as deviations in the bearing itself, deviations in the flatness of the guide raceway surface including the guide shaft, and errors in the level place an unreasonable load on the ball part of the bearing body, which prevents smooth linear movement of the movable body. Not only is this impossible, but it also has the disadvantage of shortening its lifespan. Further, if the table attached to the movable body becomes misaligned, an unreasonable internal load is similarly applied to the bearing body, resulting in a problem of decreased linear motion accuracy and shortened service life.

[Means for Solving the Problems] This invention was made in view of the above circumstances, and in order to solve the above technical problems, a gap for deformation absorption and relaxation is provided between the bearing body and the movable body. In addition, this gap allows relative displacement between the bearing body and the movable body, thereby absorbing accuracy errors of the guide shaft and improving linear motion accuracy of the movable body. The present invention aims to provide a linear guide device.

That is, the present invention provides a bearing having a guide shaft having a ball rolling groove along the axial direction, and a loaded ball groove and an unloaded ball groove that form an endless track for the balls rolling in the rolling groove. In a linear guide device consisting of a main body and a movable body that is attached to the bearing body and performs linear reciprocating motion along the guide shaft via the ball, there is a space between the bearing body and the movable body. At the same time, an arcuate convex surface is formed on the bearing body side and/or the movable body side surface of the spacing seat, and the spacing seat forms a contact with the bearing body and/or the movable body. A mounting bolt having an arc-shaped concave surface in sliding contact with the arc-shaped convex surface on the contact surface, and threadedly connects the bearing body to the bearing body by passing through the movable body and the spacing seat between the bearing body and the movable body. Provided is a linear guide device, characterized in that the guide shaft is coupled to the guide shaft so that installation errors of the guide shaft can be absorbed and alleviated by relative displacement between the bearing body and the movable body due to elastic deformation of the mounting bolt. This is what I am trying to do.

In this invention, an arc-shaped convex surface is formed on a surface of the spacer that faces the bearing body and/or the movable body, and a circular convex surface is formed on the surface of the bearing body and/or the movable body that comes into contact with the spacer. An arcuate concave surface is formed in sliding contact with the arcuate convex surface, and in this case, the arcuate convex surface is formed by a spherical convex surface or an arcuate convex surface, and the arcuate concave surface is also correspondingly formed by a spherical concave surface or, It is formed by an arcuate grooved surface. Further, the arcuate convex surface or spherical convex surface formed on the bearing body side and/or the movable body side may be directly formed integrally with the bearing body and the movable body, but if formed with a separate member such as a washer, it will be easier to process. preferable.

[Effect] The above technical means works as follows.

A gap is formed between the bearing body and the movable body to absorb and alleviate deformation, and since the mounting bolt has elastic deformation, it is possible to prevent excessive loads from being placed inside the bearing body due to accuracy errors in the guide shaft, etc. When this happens, the relative displacement between the bearing body and the movable body due to the elastic deformation of the bolt (specifically, due to the sliding action between the arcuate convex surface of the spacer and the arcuate concave surface of the bearing body and/or the movable body) (displacement), errors in accuracy of the guide shaft are absorbed and alleviated between the bearing body and the movable body.

[Examples] Examples of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view showing an example of a linear guide device of the present invention. As shown in the figure, the rolling groove 1a
A bearing body 2 has a loaded ball groove 22 and an unloaded ball groove 21 that form an endless track for balls 4 rolling on the bearing body 2. The main part is composed of a movable body 3 that performs linear reciprocating motion.

As shown in FIGS. 2 to 4, the bearing body 2 is formed into a substantially U-shape with a groove 24 provided on the lower surface, and is slidably fitted onto the upper part of the guide shaft 1. Further, on the left and right inner surfaces of the groove 24, load ball rolling grooves 1a, 1a, which are rolling grooves for the balls 4 formed on both sides of the upper part of the guide shaft 1, are provided.
Two load ball grooves 22, 22 each having an arcuate cross section are formed facing each other, and a non-load ball groove 21 is bored along the guide shaft direction on the back side of each load ball groove 22. (See Figure 6).
A large number of balls 4 are arranged in the load ball groove 22 in a state where they are aligned by respective ball holders 5 (see FIGS. 6 and 7). Furthermore, guide grooves 6a for guiding the balls 4 between the loaded ball groove 22 and the non-load ball groove 21 are provided on both end surfaces of the bearing body 2 in the sliding direction.
A pair of side lids 6 are attached. In this case, the side cover 6 is made of hard synthetic resin or the like, and is attached to the front and rear end surfaces of the bearing body 2 with bolts 6b. Note that the reference numeral 7 is a grease nipple attached to the side cover 6.

On the other hand, the upper surface of the bearing body 2 and the movable body 3
A spacing seat 10 is interposed between the bottom surface of the spacer and the lower surface of the spacer to actively form a gap 8 for deformation absorption and relaxation between the two. Through hole 3a bored in body 3
The bearing body 2 and the movable body 3 are connected with the gap 8 maintained by screwing a mounting bolt 9 that passes through the bearing body 2 into a screw hole 23 provided in the upper part of the bearing body 2. . in this case,
The spacer 10 includes a disc-shaped base 12 and a spherical convex surface 1 protruding from the lower surface of the disc-shaped base 12.
3, and a through hole 11 penetrating the central part of the disc-shaped base 12 and the spherical convex surface 13 (the fifth
), a spherical concave surface 14 is formed on the abutment surface of the spacing seat 10 of the bearing body 2, and the spherical concave surface 14 is in sliding contact with the spherical convex surface 13, and the spherical convex surface 13 and the spherical concave surface 14 are in sliding contact. The bearing body 2 and the movable body 3 are connected by a mounting bolt 9. In this case, the dimensions of the gap 8 are set within the allowable range of elastic deformation of the mounting bolt 9. Therefore, when the bearing body 2 receives an external load due to an accuracy error in the guide shaft 1, for example, the mounting bolt 9
is elastically deformed, and due to the relative displacement between the bearing body 2 and the movable body 3, the above-mentioned external load can be absorbed and relaxed. Directional precision errors can be absorbed and alleviated, and the linear motion precision of the bearing body 2 and the movable body 3 can be improved.

The guide shaft 1 is fixed to a fixed base 31 such as a bed with fixing bolts 30 passing through mounting holes (not shown) drilled at appropriate intervals.

8 to 11 show a second embodiment of the present invention, in which accuracy errors, etc. in a direction perpendicular to the guide shaft direction are absorbed and alleviated. That is, the arcuate convex stripe 1 is formed on the lower surface of the rectangular base 15.
The so-called semicylindrical spacing seat 1 formed with 6
This is a case in which the bearing body 2 and the movable body 3 are interposed between the bearing body 2 and the movable body 3 with the bearing body 2 parallel to the guide shaft 1, and connected by a mounting bolt 9. In this case, an arcuate concave surface 17 is formed on the upper surface of the bearing body 2, and is in sliding contact with the arcuate convex surface 16 of the spacer 10. Therefore, the sliding action between the spacer 10 and the arcuate grooved surface 17 can absorb and alleviate accuracy errors in the direction orthogonal to the guide shaft direction. In this case, as shown in Figure 11,
By forming a relatively large crowning 25 on the end side of the load ball groove 22, accuracy errors in the direction of the guide shaft can be absorbed and alleviated.

12 to 14 show a third embodiment of the present invention, in which accuracy errors in the direction of the guide shaft are absorbed and alleviated. That is, similar to the second embodiment, the spacer 10 formed in a semicylindrical shape is interposed between the bearing body 2 and the movable body 3 in a state perpendicular to the guide shaft 1, and the mounting bolt 9 is inserted. This is the case when they are connected. In this case, a spacing seat 1 is placed on the upper surface of the bearing body 2.
Arc-shaped grooved surface 1 slidingly in contact with arc-shaped convex surface 16 of 0
7 is formed. Therefore, the spacing seat 1
The sliding action between the arcuate convex surface 16 and the arcuate concave surface 17 can absorb and alleviate accuracy errors in the guide shaft direction. In this case, due to accuracy errors in the direction orthogonal to the guide shaft direction, the balls 4 interposed between the guide shaft 1 and the bearing body 2 are circumscribed by four rows of angular contacts, resulting in an automatic adjustment structure with a degree of freedom. Therefore, accuracy errors in the direction orthogonal to the guide shaft 1 are absorbed and alleviated (see FIG. 14).

The other parts in the second and third embodiments are the same as those in the first embodiment, so the same parts are given the same reference numerals and the explanation thereof will be omitted.

In each of the above-mentioned embodiments, a spherical recess 14 or an arcuate grooved surface 17 that comes into sliding contact with the spherical convex surface 13 or the arcuate convex surface 16 provided on the spacer 10 is formed on the upper surface of the bearing body 2. Although the case has been described, it is not limited to the case in which the spherical concave surface 14 or the arcuate concave surface 17 is formed only on the bearing body 2, and the spherical convex surface 13 or the arcuate convex surface 16 of the spacing seat 10 is directed upward. A spherical concave surface 14 or an arcuate concave surface 17 is formed on the lower surface of the movable body 3 (see FIG. 15), or a spherical convex surface 13 or an arcuate convex surface 17 is formed on the upper and lower surfaces of the spacer 10. A spherical convex surface 13 is formed on both the upper surface of the bearing body 2 and the lower surface of the movable body 3, respectively.
Or a spherical concave surface 14 in sliding contact with the arcuate convex surface 16
Alternatively, it may be formed with an arcuate grooved surface 17. By providing sliding contact portions on the upper and lower surfaces in this manner, accuracy errors can be absorbed and alleviated even more smoothly.

Furthermore, although the above embodiments have been described in which the spherical concave surface 14 or the arcuate concave surface 17 is formed on the upper surface of the bearing body 2 and/or the lower surface of the movable body 3, it is not always necessary to use this structure. A washer 19 having a concave surface 14 or a concave arc surface 17 may be disposed on the upper surface of the bearing body 2 and/or the lower surface of the movable body 3. By using the washer 19 in this way, the bearing The linear guide device can be easily assembled without performing any processing on the main body 2 itself or the movable body 3 itself (see FIGS. 16 and 17).

[Effects of the Invention] As explained above, according to the linear guide device of the present invention, a gap is formed between the bearing body and the movable body by interposing the spacing seat, and the spacing is maintained between the bearing body and the movable body. An arcuate convex surface is formed on the surface of the seat facing the bearing body and/or the movable body, and an arcuate concave surface is formed on the contact surface of the bearing body and/or the spacer of the movable body, so that the arcuate convex surface and the circular convex surface are formed. The bearing body and the movable body are connected by a mounting bolt that passes through the movable body and the spacing seat and is screwed to the bearing body, resulting in the following effects. is obtained.

(1) Due to the gap between the bearing body and the movable body due to the spacing seat, and the sliding contact between the arcuate convex surface of the spacing seat and the arcuate concave surface of the bearing body and/or the movable body, the mounting bolt becomes elastic. This allows the guide shaft to have precision errors in its axial direction, such as axial straightness and mounting height, and precision errors in the direction orthogonal to this axis, that is, horizontality. Since the accuracy error (torsion degree) is absorbed and alleviated, the accuracy of the linear motion of the movable body is significantly improved.

(2) By absorbing and mitigating the above-mentioned errors, it is possible to prevent unreasonable internal loads that occur during device assembly or use, so the linear movement of the movable body can be performed with high precision and smoothly, increasing the service life. I can figure it out.

(3) Since a spacing seat is interposed between the bearing body and the movable body, and it is only necessary to connect them with mounting bolts, the installation work is simple and high precision is not required for installation. .

(4) There are few components and it can be manufactured at low cost.

[Brief explanation of drawings]

Fig. 1 is a schematic perspective view showing a first embodiment of the present invention, Fig. 2 is a plan view showing a bearing main body in the first embodiment, and Fig. 3 is a main part of the bearing main body in the first embodiment. 4 is a cross-sectional view of FIG. 3, FIG. 5 is a perspective view of the spacing seat in the first embodiment, FIG. 6 is a sectional view taken along line - of FIG. 4, and FIG. is a view taken in the direction of the arrow in FIG. 6, FIG. 8 is a plan view of the bearing body in the second embodiment, FIG. 9 is a cross-sectional view taken from FIG. 8, and FIG. A perspective view, FIG. 11 is a sectional view of the bearing body in the second embodiment, FIG. 12 is a plan view showing the bearing body in the third embodiment, and FIG. 13 is a sectional view of main parts in the third embodiment.
Figure 14 is a cross-sectional view of Figure 11, and Figure 15 is a cross-sectional view of Figure 11.
17 are sectional views of main parts showing fourth to sixth embodiments of the present invention. Description of symbols 1... Guide shaft, 1a... Rolling groove, 2
...Bearing body, 3...Movable body, 4...Ball, 8...Gap, 9...Mounting bolt, 11...
Through hole, 13... Spherical convex surface, 14... Spherical concave surface, 16... Arc-shaped convex surface, 17... Arc-shaped grooved surface, 19... Washer, 21... No-load ball groove, 22... ...Load ball groove.

Claims (1)

[Scope of Claims] 1. A guide shaft having a ball rolling groove along the axial direction, and a loaded ball groove and a non-load ball groove forming an endless track for the balls rolling in the rolling groove. In a linear guide device consisting of a bearing body and a movable body that is attached to the bearing body and performs linear reciprocating motion along the guide shaft via the balls, there is a gap between the bearing body and the movable body. In addition to interposing a spacing seat that forms a gap between the bearing body and/or the movable body, an arcuate convex surface is formed on the bearing body side and/or the movable body side surface of the spacing seat, and the distance between the bearing body and/or the movable body. The abutment surface is provided with an arcuate concave surface that slides in contact with the arcuate convex surface, and the bearing body and the movable body are mounted by passing through the movable body and the spacing seat and screwed to the bearing body. A linear guide device, characterized in that the linear guide device is connected by a bolt so that mounting errors of the guide shaft can be absorbed and alleviated by relative displacement between the bearing body and the movable body due to elastic deformation of the mounting bolt. 2. The linear guide device according to claim 1, wherein the arc-shaped convex surface is formed by a spherical convex surface, and the arc-shaped concave surface is formed by a spherical concave surface. 3. The linear guide device according to claim 1, characterized in that the arcuate convex surface is formed by an arcuate convex stripe, and the arcuate concave surface is formed by an arcuate concave stripe. 4. The linear guide device according to any one of claims 1 to 3, wherein the arcuate concave surface on the bearing body side and/or on the movable body side is formed of a washer.