JPH041377Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the improvement of a roller spline bearing using rollers that can move forward and backward only in the axial direction.It is highly accurate, has no play in the rotational direction, is easy to assemble, and has adjustable preload. The purpose of the present invention is to provide a roller spline bearing with a high level of performance.

For example, conventional roller spline bearings include
An example of use in an expansion joint is shown in USP 2,983,120, and as shown in Figures 13 to 16,
The protrusion 31 of the shaft 30 is movable in the axial direction within the groove 34 on the inner surface of the outer cylinder 41 of the joint part 33 via a large number of rollers 32 surrounding the protrusion 31 within the guide 42. As shown in FIG. 17, a protrusion 37 protruding from the inner cylinder surface 36 of the outer cylinder 35 slides into a groove 40 recessed in the shaft 39 via a large number of rollers 38 surrounding the protrusion 37. The rollers 32 or 38 can be moved back and forth in the axial direction, and the rollers 32 or 38 can endlessly circulate around the protrusion 31 or 37, respectively.
Which is the driving force or acceleration side during rotational drive?
The group of rollers 32 or 38 on either side of the protrusion 31 or 37 will carry the rotational load depending on whether it is on the braking or deceleration side or the direction of rotation. There was a practical problem. That is, since it is assumed that there is a gap between the shaft 30 or 39, the rollers 32 or 38, and the outer cylinder 35 or 41, the accuracy as a roller spline is low, and the life span is shortened due to the occurrence of rotational vibration. Since there is no retainer for the rollers 32 or 38, the rollers 32 or 38 tend to fall off when assembling or removing the shaft 30 or 38 and the outer cylinder 35 or 41, making it difficult to assemble or remove the rollers. 32 or 38
In addition, it is not possible to apply preload to remove the gap between the shaft 30 or 39 and the outer cylinder 35 or 41, and the raceway surface on which the rollers 32 or 38 contact and roll, especially the outer cylinder 35 or 41. Since the raceway surface on the 41 side could not be ground, the raceway surface accuracy such as raceway surface roughness, parallelism and flatness was poor, and the performance could not be used for high precision applications as a spline bearing.

In a roller spline bearing using rollers, the raceway surface on which the rollers can roll provided on the inner surface of an outer cylinder is fitted in the inner cylinder surface of the outer cylinder separately from the outer cylinder in the axial direction. A tapered jib is formed on the inner surface of the bearing plate, and a tapered jib is fitted between the back surface of the bearing plate and the outer cylinder so as to be movable in the axial direction. It is attached via side plates fixed to both ends of the cylinder, and the preload between the raceway surfaces on the shaft side and the outer cylinder side can be adjusted by moving the tapered jib back and forth. The object of the present invention is to provide a roller spline bearing with high precision and adjustable preload, which does not have the above-mentioned drawbacks, and its configuration will be explained below with reference to the drawings.

In a first embodiment shown in FIG. 1, a roller spline bearing 1 includes an outer cylinder 2 and a shaft 3 fitted into the outer cylinder 2 so as to be freely retractable.
Side plates 4, 4 are attached to both ends of the shaft 3 in the forward and backward direction, and a shaft raceway surface 5 is formed on the outer peripheral surface of the shaft 3 in the axial direction. As shown in FIG. 2, in this embodiment, four shaft raceway surfaces 5 are formed. The outer cylinder raceway surface 7 provided on the inner cylinder surface 6 of the outer cylinder 2 is provided on the inner surface of a bearing plate 8 that is separate from the outer cylinder 2. The bearing plate 8 is a rod-shaped body and A fitting groove 9 recessed in the inner cylinder surface 6 of the
It is inserted in the axial direction.

In this embodiment, the rollers 10 interposed between the shaft raceway surface 5 and the opposing outer cylinder raceway surface 7 have substantially the same diameter and height, and have a square cross-section at the center of rotation;
As shown in FIGS. 3 and 6, a cross roller arrangement is used in which adjacent rollers 10 are arranged with their rotational axes 90 degrees apart from each other, so that the rollers 10 do not come into contact or roll. Both raceway surfaces 5 and 7 facing each other are formed into right-angled V-shaped grooves.

The roller 10 has a load area 11 formed between the shaft raceway surface 5 and the outer cylinder raceway surface 7, and a return hole with a square cross section that is bored in the outer cylinder 2 parallel to the load area 11. 12, and the roller 10 can circulate in a circulation path formed by direction change paths 13, 13 provided in both side plates 4 so that the roller 10 can change direction smoothly between the load area 11 and the return hole 12. It is said that

In this embodiment, four circulation paths are provided.

On the back surface opposite to the inner surface of each bearing plate 8, between the bottom of the two fitting grooves 9 of the outer cylinder,
As shown in FIG. 3, a tapered jib 14 having a substantially rectangular rod shape slightly inclined in the axial direction is fitted into the fitting groove 9 so as to be movable forward and backward in the axial direction (horizontal direction in the figure).

As shown in FIGS. 2 and 3, the taper jib 14 is provided with a threaded hole 15 for a bolt in the axial direction for preload adjustment on one end surface (the left end in FIG. 3), and a screw hole 15 is provided on the side plate 4. The tip of the preload adjustment bolt 16 screwed in at 29 is screwed into the preload adjustment bolt screw hole 15. Therefore, by rotating the preload adjustment bolt 16, the tapered jib 14 can move forward and backward in the axial direction while its inner and outer surfaces are in sliding contact with the back surface of the bearing plate 8 and the bottom of the fitting groove 9. There is. The preload adjustment bolt 16 is a known differential screw. For example, in FIG.
Screw hole 1 for preload adjustment bolt, which is the threaded part with 4
5 is set to 0.5 mm, when the preload adjustment bolt 16 is rotated one turn counterclockwise, the taper jib 14 moves to the left by 0.5 mm based on the principle of a known differential screw, and the thickness of the taper jib 14 in the figure is If the bearing plate 8 is tapered so that it becomes thicker from the left side to the right side, the bearing plate 8 is pushed downward, so that a preload can be applied to the rollers in the axial groove.

In addition, in this embodiment, as shown in FIGS. 2 to 6, a thin inner wall is provided on the entire inner surface 6 of the outer cylinder 2 and the inner peripheral surface 18 of the side plate 4 having the same inner diameter as the inner cylinder surface 6. A cylindrical retainer 17 is fitted. The retainer 17
In this case, when the outer cylinder 2 is assembled to the shaft 3, it does not come into sliding contact with the rollers 10 rolling in the load area 11, and when the outer cylinder 2 is removed from the shaft 3, the rollers 10 When fitted into the outer cylinder 2, in a position facing each outer cylinder raceway surface 7, so that the outer cylinder does not deviate,
A long hole 19 is bored in the axial direction. The long hole 19
The width of the hole 19 is smaller than the diagonal length of the square axial cross section of the roller 10, and both ends of the elongated hole 19 are connected to the side plate when the retainer 17 is fitted, as shown in FIGS. 4 to 6. It also serves as a locking hole into which a protrusion 20 protrudingly provided on the inner circumferential surface 18 of No. 4 is locked.

The retainer 17 is formed of a resilient cylindrical thin plate made of plastic or the like, and is inserted into the inner cylindrical surface 6 while being elastically deformed during assembly, and the end of the elongated hole 19 is fitted into the protrusion 20. urge At this position, the retainer 17 is positioned and fixed both in the axial direction of the outer cylinder 2 and in the circumferential direction. As shown in FIG. 2, the longitudinal edge of the elongated hole 19 has an outward opening angle of 90°, and slides into contact with the rollers 10 in the load area 11 when operated as a roller spline bearing. It is said that the shape does not.

In the second embodiment shown in FIG. 7, six circulation paths each consisting of a load area return hole and a two-way switching path are provided, and the other configurations are the same as in the first embodiment described above. .

An appropriate number of circulation paths can be provided depending on the size of the bearings, differences in loads, etc.

In both the first and second embodiments described above, the retainer 17 or 17a is provided, and the rollers 10 are in contact with the outer cylinder raceway surface 7 of the bearing plate 8.
When the outer cylinder 2 or 2a is removed from the shaft 3 or 3a, it is prevented from deviating from the outer cylinder 2 or 2a.

In another embodiment of the bearing plate shown in FIGS. 8 and 9, instead of separately providing the cages 17 and 17a, both openings in the outer cylinder raceway surface 7b, which are right-angled V-shaped grooves of the bearing plate 8b, are provided. The inner end surface 23 is perpendicular to the outer cylinder raceway surface 7b adjacent to the end edge.
is a bearing plate 8b having protruding holding ends 21, 21 formed therein, and by using the bearing plate 8b, retainers 17, 17a are not used in the first and second embodiments described above. It is possible to use a roller spline bearing.

Due to the presence of the holding end 21, as shown in FIG. 8, the rollers 10 in the load range do not deviate from the outer cylinder 2 even when the outer cylinders 2, 2a are removed from the shafts 3, 3a.

Bearing plate 8 shaped as shown in Fig. 8
As shown in FIG. 9, by using a grindstone 22 whose width is narrower than one side of the axial square cross section of the roller 10 from the direction shown in the figure, the outer cylinder raceway surface 7b and the holding end are formed in an accurate and highly precise shape. It is possible to perform a grinding finish on the inner end surface 23 of 21.

In the third embodiment shown in FIG. 10, unlike the first and second embodiments described above, the rollers 10 that roll adjacently have their rotation axes in the same direction, instead of using cross rollers. . Convex tracks 24, 24 are protrudingly provided on the circumferential surface of the shaft 3c, and a shaft raceway surface 5c, which is a right-angled V-shaped groove, is formed on both sides of the convex raceway 24, and a right-angled V-shaped groove surface of the shaft raceway surface 5c. One side is a convex rail 24
The track side surface 25 of The load area 11c is formed by the shaft raceway surface 5c and the outer cylinder raceway surface 7c, which is a right-angled V-shaped groove of the bearing plate 8c. A tapered jib 14c that can move forward and backward in the axial direction is provided on the back surface of the bearing plate 8c opposite to the raceway side surface 25 in a position parallel to the raceway side surface 25.

Therefore, the bearing plate 8c and the tapered jib 14c are provided at symmetrical positions on both sides of the convex rail 24, so that the load area 11c, the return hole 12, and the rollers 10 rolling in the load area 11c and the return hole 12 can change direction smoothly. An even number of circulation paths consisting of possible bidirectional change paths are always provided symmetrically to the convex rail 24. In the illustrated example, there are three convex rails 24 and six circulation paths are provided.

Note that the reference example shown in FIG. 11 shows a configuration in which the taper jib 14c is omitted in the third embodiment described above, but in this case, the return hole 12 may be provided at the position where the taper jib 14c is missing. The load area 11, the return hole 12, and the bidirectional change path can all be provided at positions where the rotational axes of the rolling rollers 10 can be held in parallel, but preload cannot be applied between the rollers and the raceway surface. In order to apply the bearing plate to the raceway side 2 of the convex raceway 24
If it cannot move forward and backward in five directions and requires preload, the only option is to incorporate rollers with a larger diameter.

As shown in FIG. 12, the outer cylinder 2 is processed by drilling the bearing plate insertion groove pilot hole 26 and return hole pilot hole 27 at predetermined positions, and then broaching a right-angled groove at the required angle. By boring the center hole 28, the bearing plate fitting groove 9, return hole 12, and inner cylindrical surface 6 are completed. Figure 2, Figure 7, Figure 1
The return holes 12 shown in FIG. 0 and FIG. Then, a right-angled groove is broached so that each of the four corners of the square axial center section of the roller 10 is supported.
As for drilling the return hole 12, the diameter of the return hole pilot hole is as shown in FIGS. 2, 7, 10,
As shown in FIG. 11, it is preferable that the length is greater than the length of one side of the square cross section of the roller 10. Since the return hole 12 is located in the no-load area of the roller 10, it is sufficient that the roller 10 rolling in the return hole 12 is supported by each of the four corners of the square cross section by right-angled grooves. Drilling process is extremely easy and rolling rollers 1
The gap between the roller spline bearing and the lower return hole becomes a space for holding lubricant and a space for removing foreign matter, which helps maintain and improve the life and accuracy of the roller spline bearing. The present invention is a roller spline bearing that uses rollers, and has a configuration described in the claims of the utility model registration. A bearing plate is inserted into the bearing plate, and the taper jib fitted into the back surface of the bearing plate is slid forward and backward in the axial direction by the rotation of a single preload adjustment bolt screwed in the axial direction. The plate is moved uniformly over its entire length in the direction perpendicular to the sliding surface of the tapered jib, making it possible to uniformly adjust the preload on the rollers rolling in the negative pressure area over the entire length, and in the direction of rotation of the shaft. On the other hand, it is possible to obtain a highly rigid roller spline bearing that has no backlash at all, and even when the load changes in the direction of rotation of the shaft, the occurrence of relative displacement between the shaft and the outer cylinder is extremely small, resulting in improved accuracy. A high degree of coupling is possible, and since the preload adjustment bolt is threaded in the axial direction, the entire roller spline bearing can be formed compactly in the axial direction.In addition, the outer cylinder raceway surface is a separate bearing plate from the outer cylinder. This makes it possible to grind the outer cylinder raceway surface and meet the necessary conditions for the raceway surface.
In other words, it has become possible to ensure sufficient surface roughness, hardness, dimensional accuracy, etc., and the various effects of improving the accuracy of the roller spline bearing and extending its life have been achieved.

[Brief explanation of the drawing]

Fig. 1 is a side view of the first embodiment, Fig. 2 is an elevational view of the same showing a cross section taken along the line - in Fig. 1 in the right half, and Fig. 3 is a side view of the outer cylinder showing a partial cross section of the axial center of the above. , FIG. 4 is an enlarged internal view of a portion of the cage, FIG. 5 is an enlarged internal view of a protruding portion of the upper side plate, FIG. 6 is an enlarged internal view of a portion of the cage assembly, and FIG. 7 is a side plate of the second embodiment. 8 is an elevational view of another embodiment of the bearing plate, FIG. 9 is an explanatory diagram of the same raceway surface processing as above, FIG. 10 is a sectional view of the side plate mounting surface of the third embodiment, and FIG. The figure is a cross-sectional view of the side plate mounting surface of a reference example.
Fig. 2 is an explanatory diagram of the outer cylinder processing, Fig. 13 is a side view including an axial cross section of the conventional example, Fig. 14 is a sectional view taken along the line - - in Fig. 13, Fig. 15 is a perspective view of the same guide, and Fig. 16 is FIG. 17 is a perspective view of the roller arrangement as above, and a sectional view of another conventional example. 1... Roller spline bearing, 2, 2a... Outer cylinder, 3, 3a, 3c... Shaft, 4... Side plate, 5, 5
c...Shaft raceway surface, 6...Inner cylinder surface, 7, 7b, 7c
... Outer cylinder raceway surface, 8, 8b, 8c ... Bearing plate, 9 ... Fitting groove, 10 ... Roller, 14,
14c...Taper jib, 16...Preload adjustment bolt, 25...Race side.

Claims (1)

[Scope of utility model registration request] In a roller spline bearing using rollers that can move forward and backward only in the axial direction, the outer cylinder raceway surface on which the rollers can roll, which is provided on the inner surface of the outer cylinder, is separate from the outer cylinder and has an inner cylinder surface of the outer cylinder. A groove is formed on the inner surface of a bearing plate that is fitted in the axial direction into a fitting groove formed in the outer cylinder, and a groove that is slightly inclined in the axial direction is formed between the back surface of the bearing plate and the bottom of the fitting groove of the outer cylinder. A rectangular rod-shaped tapered jib is fitted in the fitting groove so as to be movable in the axial direction, and the tapered jib is capable of slidingly contacting the back surface of the bearing plate and the bottom of the fitting groove over the entire surface of the tapered jib. ,
A single preload adjustment bolt that can move the taper jib forward and backward in the axial direction is screwed into one end of the taper jib in the axial direction through side plates fixed to both ends of the outer cylinder, and the single preload adjustment bolt By sliding the taper jib in the axial direction by rotating the adjustment bolt, the bearing plate can move forward and backward uniformly over its entire length in the direction perpendicular to the sliding surface, and the bearing plate is able to move forward and backward in the direction perpendicular to the sliding surface on both the shaft side and the outer cylinder side. A roller spline bearing characterized in that a preload between the bearing plates can be uniformly adjusted over the entire length of the bearing plate.