JPH0139940Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention arranges a large number of rolling elements so as to be able to circulate endlessly between a long track member and a sliding member that is covered with the track member. This invention relates to a track guide rolling bearing in which a sliding member is movable longitudinally relative to the member by rolling of rolling elements.

Conventional technology In this type of rolling bearing, the amount of height displacement (straightness) of the top surface of the sliding member from the reference surface when the sliding member is moved with the raceway member fixed (based on the reference).
is an important factor for the dynamic performance of bearings.

In order to keep this amount of displacement small, it was first necessary to improve the precision of each member of the bearing, but the remarkable development of machine tools in recent years has had a considerable effect.

Problems to be solved by the invention However, another problem was that the number of rolling elements in the raceway groove changed when the bearing was sliding. This mechanism will be explained with reference to A and B in FIG. 4. The bearing model shown here is a diagram showing the state of the rollers in the raceway groove of a roller bearing for infinite linear motion in which the rollers are arranged in a cross-roller manner infinitely circulating in the V-shaped raceway groove. Figure A shows the rollers in the raceway groove in a certain state, and the number of rollers with their end faces facing the front is 4, a, b, c, and d.
It's a book. FIG. 4B shows a view in which the sliding member is moved slightly to the right, that is, the roller is moved slightly to the right from this state. The roller d comes off the raceway groove and enters the no-load area, and no new rollers have yet entered the load area from the no-load area, so the number of rollers with their end faces facing the front in the load area is a, b, c, which is a decrease of one.

In this way, the number of rollers located in the load area in the raceway groove increases or decreases as the sliding member slides, and at a certain point the load that was supported by four rollers is now supported by three rollers. It will be paid and paid.

In this way, the number of rollers in the raceway groove increases or decreases depending on the sliding position, and this phenomenon is caused by the rolling elements in the raceway groove sharing the load applied to the bearing, as shown in Figure 5A. The position of the sliding member moves up and down with respect to the sliding distance (displacement amount of S1).

This is because the position O of the top surface of the sliding member when the load was shared by the four rollers a, b, c, and d is different from the position O of the top surface of the sliding member when the load was shared by the three rollers a, b, and c. This means that elastic compression deformation occurs at the positions where a, b, and c are in contact with the rollers, and the position of the upper surface has lowered to position P, and the length of S1 is 1 in the case of a small bearing. It ranges from several microns to several tens of microns in the case of extremely large bearings.

This problem is considered to be unavoidable in bearings in which rolling elements endlessly circulate on the raceway, and there has been particular reluctance to solve this factor.

Therefore, although the straightness of the bearing has been improved to some extent, it is still not a satisfactory bearing for use in equipment that particularly requires running accuracy, such as the detection part of a measuring instrument. Ta.

Purpose of the invention In view of the current state of track guide bearings explained above,
In this invention, even if the number of rolling elements to bear the load in the main rolling element raceway groove changes, the load that was shared by the reduced number of rolling elements can be transferred to another secondary rolling element raceway groove. It is an object of the present invention to provide a relatively simple track guide bearing that has a structure in which the rolling elements within the sliding member share the load, minimizes changes in the position of the upper surface of the sliding member, and maintains good straightness.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a raceway member in which two raceway grooves for rolling elements are formed on both sides in the longitudinal direction of an elongated shape, and a raceway of this raceway member. A recess for wrapping the groove portion is formed in the axial direction, and each recess has two grooves on the inner wall corresponding to the raceway groove of the raceway member.
A track guide comprising a sliding member in which a strip raceway groove for rolling elements is formed, and a large number of rolling elements that fit between the raceway grooves of this track member and the raceway grooves of the sliding member and can roll freely. In the rolling bearing, one of each of the two rolling element raceway grooves is formed shorter than the other on the inner wall of the sliding member, and there is a gap between the shorter rolling element raceway groove and the rolling element. The clearance is equal to or slightly larger than the clearance between the longer rolling element raceway groove and the rolling element; The structure is such that the elastic compressive deformation size that occurs when the number of rolling elements is reduced or the size smaller than that is adopted.

Function Since the present invention has the above-mentioned configuration, the load is supported by the longer rolling element raceway groove and the rolling element, and the number of rolling elements in the load area decreases as the sliding member slides. death,
When the aforementioned elastic compression deformation occurs, the load that was being shared by the reduced rolling element is borne by the shorter rolling element raceway groove and the rolling element fitted into it. , the change in the position of the top surface of the sliding member is significantly small, and good straightness is maintained.

Embodiment The drawings show an embodiment of the present invention. FIG. 1 is a perspective view showing the first embodiment, FIG. 2 is a sectional view perpendicular to the sliding direction of FIG. 1, and FIG. Figure 1 is a perspective view showing the side plate and casing, Figure 4 is a model of the arrangement of cylindrical rollers in the raceway groove, Figure 5 is a model of the amount of vertical displacement of the sliding member when the bearing is slid, Figure 6 shows a second embodiment using a ball.

In the figure, 1 is a sliding member, 2 is a track member, 3 is a casing, and 4 is a side plate. As shown in FIGS. 1 to 3, V-shaped raceway grooves 2a and 2b are formed on both sides of the raceway member 2, one on each of the upper and lower sides. The upper raceway groove size is formed smaller than the lower raceway groove size. Similar raceway grooves 3a and 3b are also formed at both inner wall positions of the recess of the sliding member 3 corresponding to the raceway grooves 2a and 2b of the raceway member 2.

The cylindrical rollers 6a, 6b of the AF surface inserted between the raceway grooves 2a, 2b of the raceway member 2 and the raceway grooves 3a, 3b of the sliding member 1 are inserted into the raceway groove 3 in the casing 3.
After passing through paths a and 3b, the vehicle is scooped up by arc-shaped turning paths 4a and 4b that are continuous therewith and continues forward. Next, it moves to return paths 5a and 5b formed parallel to the raceway groove and continuous with the other end of the direction change path. In this way, the upper and lower cylindrical rollers 6a, 6b are configured to endlessly circulate in each raceway groove.

In the illustrated example, most of the load on the bearing is borne by the large diameter rollers 6a in the lower raceway grooves 2a, 3a, and the small diameter rollers 6a in the upper raceway grooves 2b, 3b.
b is formed so as to share the reduction in load capacity when the number of large diameter rollers 6a in the lower raceway grooves 2a, 3a is reduced.

In other words, when there is no clearance between the lower raceway grooves 2a and 3a and the large diameter cylindrical roller 6a (including the preloaded state), there is a clearance α ( (including zero clearance).

The above-mentioned clearance α is due to the fact that the number of cylindrical rollers 6a that share the load within the lower raceway grooves 2a and 3a decreases from the state shown in FIG. 4A to the state shown in FIG. Roller 6a and raceway groove 2 in contact with it
The dimension is equal to or smaller than the dimension reduced when elastic compression deformation occurs in a and 3a.

Therefore, when the upper surface of the sliding member 3 should be lowered due to a decrease in the number of cylindrical rollers 6a that share the load within the lower raceway grooves 2a and 3a, the upper raceway groove 2
Since the small diameter rollers 6b in b and 3b compensate for the load sharing capacity corresponding to the decrease in the cylindrical rollers 6a, the downward movement of the upper surface of the sliding member 3 can be significantly reduced.

This state is illustrated in FIG. 5B, in which the upper surface of the sliding member 3 is held down from position O to position Q, and its length S2 is determined by the upper raceway grooves 2b, 3b and the small diameter roller 6b. Figure 5 A when not provided
This is significantly smaller than the descending length S1.

Since the upper raceway grooves 2b, 3b and the small diameter rollers 6b only share the reduction in load capacity due to the reduction in the cylindrical rollers 6a as described above, their lengths are as follows.
It is sufficient that the raceway grooves 2b, 3b and the small diameter roller 6b are smaller than the lower raceway grooves 2a, 3a and the cylindrical roller 6a.

FIG. 6 shows a second embodiment of the present invention. While the first embodiment has a configuration in which adjacent rollers are orthogonally arranged so that a single row of raceway grooves and rollers can apply loads in all directions, the raceway grooves in the second embodiment are Gothic arch grooves. This ball bearing is a ball bearing for raceway guidance that can apply loads in all directions through four points of contact between a row of raceway grooves and balls. While the first embodiment uses cylindrical rollers as the rolling elements, this example has the same configuration except that balls are used.

Additionally, these are examples in which the large-diameter rolling elements are placed closer to the frontage end of the recess of the sliding member, and the advantage of these is that the mounting hole of the sliding member can be formed further inside. Although it is possible to narrow the width of the bearing, the arrangement of the upper and lower rolling elements may be reversed if necessary.

Furthermore, to prevent the upper and lower rolling elements from rolling,
It is also possible to use a small diameter ball as the upper small diameter roller.

Effects The present invention has the configuration and operation described above, and even if the number of rolling elements that must bear the load in the raceway groove for the main rolling element is reduced, the reduced number of rolling elements can share the load. The load that had previously been applied can be shared by the rolling elements in the raceway groove for the secondary rolling element, which is shorter than the main raceway groove, and the gap between the secondary raceway groove and its rolling element is smaller than that of the primary raceway groove and its rolling element. The gap is equal to the gap between the main raceway groove and the rolling element, or the dimension of the elastic compression deformation that occurs when the rolling element decreases, or the dimension is shorter than that when the sliding member slides. This has the effect of significantly reducing the amount of vertical displacement of the upper surface and achieving smooth, highly accurate linear motion that maintains stable and good straightness.

In addition, even if raceway grooves are provided on the upper and lower levels, almost all the load is borne by the long raceway groove on one side and the rolling elements, so there is no increase in sliding resistance and smooth sliding can be maintained. It's also effective.

Moreover, when the number of rolling elements that share the load in the main raceway groove decreases, the supplementary raceway groove is short and small, making it possible to make the entire bearing relatively compact, which reduces component costs and processing costs. It also has the effect of keeping the costs low.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a perspective view of the first embodiment, FIG. 2 is a sectional view perpendicular to the sliding direction of FIG. 1, and FIG. 3 is a diagram of the first embodiment. Figure 4 shows a model of the arrangement of cylindrical rollers in the raceway groove. Drawing A shows a state in which there are many load-sharing rolling elements, and figure B shows progress in sliding and load-sharing. Figure C shows a state in which the number of rolling elements has decreased.
Figure 5 shows the arrangement of the rolling elements in the short raceway groove in state B, Figure 5 shows the vertical displacement model of the sliding member when the bearing slides, and Figure A shows the conventional model. FIG. 6 is a sectional view similar to FIG. 2 showing a second embodiment using a ball. 1: Sliding member, 2: Raceway member, 2a: Raceway groove for cylindrical rollers of raceway member, 2b: Raceway groove for small diameter rollers of raceway member, 3: Casing, 3a: Raceway groove for cylindrical rollers of sliding member, 3b : Raceway groove for small diameter rollers of sliding members.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A raceway member having two raceway grooves for rolling elements formed on each side in the longitudinal direction of a long piece, and a recess for enclosing the raceway groove portion of this raceway member. a sliding member formed in the axial direction and having two rolling element raceway grooves formed on the inner wall corresponding to the raceway grooves of the raceway member in the recess thereof; and the raceway groove of the raceway member and the sliding member. In a track guiding rolling bearing comprising a large number of rolling elements that are fitted between the raceway grooves and can roll freely, one of each of the two rolling element raceway grooves on the inner wall of the sliding member has: It is formed shorter than the other, and the clearance between the shorter rolling element raceway groove and the rolling element is equal to or slightly larger than the clearance between the longer rolling element raceway groove and the rolling element. The dimensions are the dimensions of the elastic compressive deformation that occurs when the number of rolling elements is reduced between the longer rolling element raceway groove and the rolling elements, or smaller dimensions. shaft. (2) The shorter rolling element raceway groove, the rolling element raceway groove of the raceway member facing the groove, and the rolling elements fitted in both grooves are the same as the longer rolling element raceway groove. A rolling bearing for track guide according to claim 1, which is smaller in size than the rolling elements.