JPH0545801B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a roller spline used, for example, in a guide section of a machine tool or a guide section of an industrial robot, and particularly relates to a roller holding structure.

(Prior Art) As a conventional roller spline, there is one shown in FIG. 16, for example. This roller spline uses rollers instead of the balls of the so-called Angirayu-type ball spline to increase the load capacity. That is, spline shaft 1
00, an outer cylinder 101 is slidably assembled via a number of rollers 102. This outer cylinder 101
is provided with a circulation path 103 that circulates the roller 102 between a load area and a no-load area,
The outer cylinder 101 is capable of infinite sliding on the spline shaft 100.

This circulation path 103 includes a loaded roller rolling path 104 on which a roller 102 in the load range, which is interposed between the spline shaft 100 and the outer cylinder 101, rolls, and
A hole is drilled in the solid part of the load roller rolling path 104.
and a no-load roller rolling path 105 connecting both ends of the roller.

(Problems to be Solved by the Invention) However, in a spline using such a roller, it is a problem to prevent the skew of the roller 102 (runout of the rotating shaft).

In the case of the above conventional example, the bearing plate 1
06 is provided with a groove 107, and the inner wall of this groove 107 guides and holds both end surfaces of the roller 102. However, the skew of the roller 102 is most problematic because the roller 102 is skewed through a direction change path (not shown). This is the point in time when the roller enters the loaded roller rolling path 104 from the no-load area.

FIG. 17 shows a state in which the roller 102 changes direction from the no-load area α of the passage 108 to the loaded area β. During this direction change of the roller 102, if the roller 102 enters the load area β from the no-load area α in a skewed state as schematically shown in FIGS. 18 and 19, the roller 102
One end 102a of the roller 2 collides with the loaded roller rolling surface 104 in the load range β first, which impedes the smooth operation of the roller 102 and also causes the end of the roller 102 that has entered the load range β Edge load occurs in the portion 102a, damaging the roller 102 and the loaded roller transfer surface 104, resulting in deterioration of durability. Furthermore, vibrations and changes in rolling resistance occur during roller circulation, which impede smooth movement.

On the other hand, in this conventional example, the spline shaft 1
00, three protrusions 109,... are equally distributed, and a total of six rows of rollers 10 are arranged to sandwich each protrusion 109,...
2,... are arranged to improve torque transmission. Therefore, for example, as shown in the figure, the protrusion 10
9,... are arranged in a triangular shape, the roller rolling surfaces 104 of the rollers 102,... that abut the two lower protrusions 109,... are inclined with respect to the horizontal direction.

When the spline shaft 100 bends downward due to a load from above in this state, the parallelism between the roller rolling surface 104 on the outer cylinder 101 side and the roller rolling surface on the spline shaft 100 side shifts, and the roller 102 The contact state becomes uneven, and a problem similar to skew occurs. In order to solve the problem caused by the bending of the spline shaft 100, the spline shaft 100
It is necessary to increase the bending rigidity of the shaft, but this would increase the shaft diameter and increase the size of the force device configuration.

The present invention has been made to solve the problems of the prior art described above, and its main purpose is to prevent the occurrence of roller skew as much as possible, to ensure smooth alignment and circulation of the rollers, and to improve durability. Our goal is to provide excellent roller splines.

Another objective is to increase the load capacity against radial loads.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, an outer cylinder is slidably fitted in the axial direction to a spline shaft via a roller, and the outer cylinder is fitted with: In a roller spline in which a circulation path is provided for circulating the roller between a loaded area and a non-load area, and the outer cylinder is movable infinitely along the spline axis, on one side in the width direction of the circulation path, A guide wall that guides one end surface of the roller is formed, and a guide member that guides and holds the other end surface of the roller is provided on the other side of the circulation path over the entire circulation path. The spline shaft is formed by guiding and holding both end surfaces, and has four protrusions extending in the axial direction and having a rectangular cross section extending in the axial direction on the outer periphery of the spline shaft, and is equally spaced vertically and horizontally, and forming grooves corresponding to the protrusions on the inner periphery of the outer cylinder. A total of eight roller circulation paths are provided on both sides of each of the protrusions, and a load area is arranged between both sides of each protrusion and the opposing surfaces of the inner wall of the groove so as to sandwich each protrusion. A roller rolling path of The roller rolling surfaces of the upper and lower roller rolling paths are provided on the same plane, and the roller rolling surfaces formed on the opposing surfaces of the protrusions and grooves that constitute the upper and lower roller rolling paths are configured to extend vertically, and the upper and lower roller rolling surfaces are arranged on the same plane. The rolling surfaces of the rollers are provided on the same surface.

The guide member provided in the loaded roller rolling path of the roller circulation path may be provided with an engaging claw portion that engages with the roller edge to prevent the roller from falling off.

(Function) In the roller spline configured as described above, the roller circulates from the load area to the no-load area as the spline shaft and the outer cylinder move relative to each other. Over the entire area of this circulation path, both end surfaces of the roller are guided and held by the guide wall and the guide member, and the posture of the roller is forcibly kept constant.

Further, by providing an engaging pawl portion on the guide member, the roller can be prevented from falling off and can also be used as a roller retainer.

Furthermore, if four protrusions are provided on the outer periphery of the spline shaft on the top, bottom, left and right sides, and eight rollers are arranged to sandwich both sides of each protrusion, even if the spline shaft is bent by a load from above, it will not bend. The direction is the vertical direction, and the distance between the loaded roller rolling surfaces of the loaded roller rolling paths formed on both the upper and lower side surfaces of the left and right protrusions changes while remaining parallel, so that uneven contact of the rollers does not occur. Further, at this time, the interval between the load roller rolling paths formed on both sides of the upper and lower protrusions does not change. Moreover, since each of the roller rolling paths constituting the upper, lower, left, and right roller rolling paths has a planar configuration extending in the horizontal and vertical directions, each roller rolling surface can be processed with high precision.

Further, since the upper and lower roller rolling surfaces and the left and right roller rolling surfaces are arranged on the same plane, it is possible to simultaneously grind the roller rolling surfaces located on the same plane.

(Example) The present invention will be explained below based on the illustrated example. In FIGS. 1 to 14 showing a roller spline according to an embodiment of the present invention, reference numeral 1 indicates the entire roller spline, and a general spline shaft 2
0, an outer cylinder 30 that is slidably fitted in the spline shaft 20 in the axial direction, and a number of rollers B interposed between the outer cylinder 30 and the spline shaft 20.

The spline shaft 20 has a substantially rectangular cross section, and has protrusions 21 symmetrically and evenly distributed on each of the four sides (top, bottom, left and right). The protrusions 21 have a flat rectangular shape with a protrusion height smaller than their width, and loaded roller rolling surfaces extending in the axial direction in parallel to each other are formed on both sides of each protrusion 21. Furthermore, each corner of the spline shaft 20 is chamfered 22 .

On the other hand, the outer cylinder 30 is a cylindrical member, and the outer cylinder main body 31
It is constructed by assembling side covers 32, 32 on both ends of the roller B, and is provided with a circulation path C that circulates the roller B from the load area to the no-load area.

As shown in FIGS. 2 and 3, the circulation path C includes a loaded roller rolling path 4 that axially transfers and guides the roller B1 in the loaded area interposed between the outer cylinder 30 and the spline shaft 20, and A no-load roller rolling path 5 that guides the roller B2 in the no-load area, which is provided parallel to the running path 4 at a position spaced apart from the spline shaft 20, connects both ends of the loaded and no-load roller rolling paths 4 and 5. It is composed of direction changers 6, 6 which form one loop.

In this example, one row of rollers B is interposed on both sides of each protrusion 21 provided on the spline shaft 20, forming a total of eight circulation paths C. 1
Two circulation paths C provided on both sides of the two protrusions 21,
C is located on one plane perpendicular to the diameter line N passing through the center of the protrusion 21 of the spline shaft 20, and if this virtual plane is called a circulation path forming surface, each protrusion 21,... The circulation path forming surfaces drawn in the figure are parallel to each other, intersect at right angles, and are arranged in a substantially rectangular shape. The protrusions 21, . . . are provided vertically and horizontally, and the circulation paths C, . . . are arranged horizontally and vertically.

Next, the outer cylinder main body 31 will be explained in detail.

The inner peripheral shape of the outer cylinder body 31 is similar to the spline shaft 2.
It is formed in a rectangular cross-sectional shape corresponding to 0, and first grooves 33, ... corresponding to the protrusions 21 formed protrudingly formed on the outer periphery of the spline shaft 20 are provided on four sides of the top, bottom, left and right sides, and each protrusion 21 has a rectangular cross section. An accommodating groove 36 for accommodating the roller B1 in the load area is provided on the inner wall of the first groove 33 facing both sides. This accommodation groove 36
is the inner peripheral flat surface 37 of the outer cylinder main body 31 and the first groove 3
3 is notched in the axial direction to have an L-shaped cross section, and the above-mentioned protrusion 21 of the accommodation groove 36
A loaded roller rolling surface 42 is provided on the side surface opposite to the roller rolling surface 41 formed in the roller. These loaded roller rolling surfaces 41 and 42 constitute a loaded roller rolling path 4.

The width of this loaded roller rolling path 4 is approximately roller B1.
The inner end wall of the housing groove 36 is equal to the length of the roller B.
It serves as a guide wall 10 that guides the end face on one side. This guide wall 10 guides the entire end surface of the roller B.

On the other hand, the other end surface of the loaded roller rolling path 4 is
It is guided and held by a holder 9 as a guide member.

The cage 9 has a pair of holding pieces 93 that are perpendicular to each other.
93 with an L-shaped cross section, and both of the load roller rolling paths 4, 4 of the two circulation paths C, C provided between the protrusions 21, 21 adjacent to each other on both sides of the plate member. It is designed to guide and hold the rollers B1 and B1. In addition, the holding piece parts 93, 93
An engaging claw portion 94 is provided on the side edge of the roller B1 to prevent the roller B1, . . . from falling off by engaging with the edge of the rollers B1, B1. This cage 9 has each holding piece 93, 93 attached to a flat surface portion 3 on the inner circumference of the outer cylinder body 31.
7 and 37 by fixing members 8 and 8, it is firmly fixed to the outer cylinder main body 31.

As shown in FIG. 6, the fixing member 8 is a rivet-like member having a head 82 at one end of a shaft portion 81 and a caulked portion 823 at the other end. The shaft portion 81 is inserted through the retainer 9, and the caulking portion 83 is caulked in alignment with a stopper hole 91 having a dish-shaped cross section provided in the retainer 9, thereby fixing the retainer. Of course, other fixing methods such as screwing may be used.

Further, a second groove 34 for forming a no-load rolling path 5 is provided at a corner of the inner circumference of the outer cylinder main body 31, facing the chamfered portion 22 of the corner of the spline shaft 20, extending over the entire axial length. It is set up across the street. This second
The concave groove 34 is cut in a wide rectangular cross-section in the circumferential direction, and is partitioned into two by a rod-shaped guide member 7 interposed in the center, forming two no-load roller rolling paths 5, 5. has been done.

That is, a groove 34a having a triangular cross section is provided on both circumferential side walls of the second groove 34, and one side of the triangular groove 34a has an unloaded roller rolling surface 51 parallel to the loaded roller rolling surface 42. The other side is a guide wall 11 that is perpendicular to the no-load roller rolling surface 51, and guides and holds substantially the entire end surface of the roller B.

On the other hand, the guide member 7 inserted in the second groove 34 is a rod-shaped member having a drum-shaped cross section with both sides constricted in a triangular shape. The triangular grooves 34a, 34a on both sides of the groove bottom 34 are in full contact with the groove bottom 34b of the second groove 34.
It is positioned at the corner of the boundary between

Further, the narrower flat surface 72 of the flat surfaces 71 and 72 of the guide member 7 is pressed and held against the groove bottom side by the bent portion 92 of the retainer 9.

On the side faces of the wide flat surface 71 on both sides of the guide member 7, no-load roller rolling surfaces 52, 52 are formed parallel to and facing the no-load roller rolling surfaces 51, 51. The side surface on the narrower flat surface 72 side faces parallel to the guide wall 11 on the outer cylinder main body 31 side, and guides and holds substantially the entire end surface of the roller B2.

On the other hand, the side cover 32 is connected and fixed to both ends of the outer cylinder main body 31 with bolts 12, and connects the loaded roller rolling path 4 and the non-load roller rolling path 5 provided on the outer cylinder main body 31 side. This constitutes a turning path 6.

The side cover 32 has an inner periphery formed in a rectangular cross-section like the outer cylinder main body 31, and is provided with direction change paths 6 at eight locations corresponding to the circulation paths C, . . . of the rollers. The direction change path 6 is an arc-shaped or U-shaped path, and has a semicircular groove 61 whose diameter is the maximum span between the loaded roller rolling path 4 and the unloaded roller rolling path 5, which are arranged in parallel on the outer diameter side. The inner diameter side is formed by an insertion piece 62 that is formed separately and has a semicircular cross section. This insertion piece 62 is longer than the groove width of the outer diameter side circular arc groove 61, and can be inserted into the outer diameter side circular groove 61 by fitting one end of the insertion piece 62 into a positioning recess 63 provided on the side wall of the circular groove 61. They are positioned concentrically.

The direction change path 6 formed in this manner is open at one side in the road width direction, and the end surface of the roller B is exposed. This side surface on the opening side is covered by the holding piece part 91 of the cage 9 described above, and also in the direction change path 6, the end surface of the roller B is covered by the guide wall 13 provided on the side cover 32 side and the guide member It is guided and held by a retainer 9.

In this way, the roller B is loaded onto the loaded roller rolling path 4.
The end face of the direction change path 6 is held by a retainer 9, while the no-load roller rolling path 5
The end face is guided and held by the guide member 7, and the entire circulation path C is forcibly guided and held. Of each load roller rolling path 4, load roller rolling surfaces 41 and 42 formed on opposing surfaces of the protrusions 21 and the accommodation groove 36 as a groove, which constitute the left and right loaded roller rolling paths 4, extend in the horizontal direction. Planar configuration with left and right roller rolling surfaces 41, 42
are placed on the same surface. On the other hand, roller rolling surfaces 41 and 42 formed on opposing surfaces of the protrusions 21 and the housing grooves 36 serving as grooves constituting the upper and lower loaded roller rolling paths 4 have a planar configuration extending in the vertical direction, and , upper and lower roller rolling surfaces 41 and 42 are provided on the same surface. With this configuration, the roller rolling surfaces 41 and 42 of the spline shaft 20 and the outer cylinder 30 can be processed with high precision, and the four rollers B1 can be uniformly contacted and receive large torque. I can do it.

In addition, since the upper and lower roller rolling surfaces 41, 42 and the left and right roller rolling surfaces 41, 42 are arranged on the same plane, the roller rolling surfaces 41, 42 located on the same plane in the upper, lower, left, and right directions Simultaneous grinding is possible, making machining extremely easy and highly accurate.

Note that 300 is a keyway carved on the outer periphery of the outer cylinder main body 31.

Next, the operation of the roller spline having the above configuration will be explained.

When the spline shaft 20 and the outer cylinder 30 move relative to each other, the rollers B of the respective circulation paths C, . At that time, Laura B
Since the end face of the circulation path C is guided and held by the retainer 9 and the guide member 7 over the entire area of the circulation path C, skew is prevented from occurring over the entire area. especially,
Roller B is transferred from the direction change path 6 to the loaded roller rolling path 4.
When the roller B enters, the shaft of the roller B is held in a position perpendicular to the traveling direction by the holding piece 91 of the cage 9, so that the end of the roller B is placed on the roller rolling surface of the loaded roller rolling path 4. There is no uneven contact between the parts, and the durability of the roller rolling surface can be maintained.

In addition, the 8 rows of rollers B,... are connected to the spline shaft 20.
Since the four protrusions 21 provided on the upper, lower, left and right sides are arranged so as to sandwich them, the radial load applied to the outer cylinder 30 from the upper, lower, left and right sides can be equally supported.

Furthermore, even if the spline shaft 20 is bent under radial load, each loaded roller rolling path 4,...
The roller rolling surfaces 41 and 42 are kept parallel, and no unbalanced load is generated at the end of the roller B.

For example, if we consider a case where the spline shaft 20 bends vertically due to a load from above, each roller rolling surface 41 of the loaded roller rolling path 4 disposed above and below the protrusions 21, 21 projecting left and right. , 42 are parallel, and the distance between the roller rolling surfaces 41 and 42 is only narrowed in the parallel state. Therefore, the load rollers B1, . . . are maintained in a uniform contact state in the axial direction.

This is due to loads from the left and right sides, causing the spline shaft to
0 is bent left and right, similarly, the distance between the respective transfer surfaces 41 and 42 of the load roller rolling path 4 arranged on the left and right sides of the vertically protruding protrusion 21 is only narrowed in the parallel state, and the roller B1 will be maintained in a uniform contact state.

FIG. 15 shows another embodiment of the present invention, in which the same components as in the above embodiment are designated by the same reference numerals. In this embodiment, cages 9' and 9' are Each roller circulation path C is a separate member. The rest of the structure and operation are the same as those of the above embodiment, so the explanation thereof will be omitted.

In each of the above embodiments, a cylindrical roller is used, but a barrel-shaped roller may also be used. Further, although this example shows a roller with a chamfered edge, it goes without saying that the present invention can also be applied to a roller without a chamfered edge.

(Effects of the Invention) The present invention has the above-described structure and operation, and since the roller is guided and held on both end faces throughout the entire load range and non-load range, the skew prevention effect can be enhanced. can. Further, since the end face of the roller is held by the guide member disposed opposite the guide wall, the circulation path can be formed easily and accurately.

Furthermore, if the guide member is provided with an engaging pawl portion that prevents the roller from falling off, it can also be used as a retainer for the roller, and the structure can be simplified.

Furthermore, if the configuration is such that four protrusions are evenly distributed around the outer circumference of the spline shaft and the outer cylinder is fitted through eight roller rows, the load capacity against loads from the top, bottom, left, and right can be increased. In addition, even if the spline shaft is bent, the direction of the bending is the direction that narrows the roller rolling surfaces of each load roller rolling path in parallel, so that uneven contact of the rollers is eliminated and durability can be improved. In addition, since each roller rolling surface constituting the upper, lower, left, and right roller rolling paths has a planar configuration that extends in the horizontal and vertical directions, each roller rolling surface can be processed with high precision, and the four rollers can be machined with high precision. It is possible to receive large torque by uniformly contacting the parts.

In addition, since the upper and lower roller raceway surfaces and the left and right roller raceway surfaces are arranged on the same plane, simultaneous grinding of the roller raceway surfaces located on the same plane is possible, making machining extremely easy and Can be performed with high precision.

[Brief explanation of the drawing]

1 is a longitudinal sectional view of a roller spline according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the roller circulation path in FIG. 1, FIG. 3 is a sectional view taken along the line - The figure is a perspective view of the spline shown in Figure 1.
5 is a partial perspective view showing the side cover of the roller spline shown in FIG. 1 disassembled, FIG. 6 is a sectional view showing a part of the roller spline shown in FIG.
The figure is an exploded partial side sectional view of the side cover in Figure 1, Figure 8 is a sectional view taken along the - line in Figure 1, Figure 9 is a sectional view taken along the - line in Figure 1, and Figure 10 is a sectional view taken along the - line in Figure 1. A side view of the spline shaft; FIG. 11 is a partial perspective view of FIG. 10; FIG. 12 shows the side cover of FIG. 1; FIG. , FIG. 13 shows the cage shown in FIG. 1, in which FIG. 13A shows a front view, FIG. 1B shows a vertical sectional view, FIG. Figure a is a perspective view, figure b is a side view, figure c is a front view,
FIG. 15 is a vertical cross-sectional view of a roller spline according to another embodiment of the present invention, FIG. 16 is a vertical cross-sectional view of a conventional roller spline, and FIG. 17 is a schematic cross-section of a direction changing portion of the spline shown in FIG. 18 and 19 are schematic explanatory diagrams of the state in which skew occurs. Explanation of symbols: 1...roller spline, 20...spline shaft, 21...projection, 22...chamfer, 30...
Outer cylinder, 31...Outer cylinder body, 32...Side cover, 33...First
Concave groove, 34...Second concave groove, 34a...Triangular groove, 34b
...Groove bottom, 35...Through hole, 36...Accommodating groove, 37...Flat surface, 4...Loaded roller rolling path, 41, 42...Loaded roller rolling surface, 5...Unloaded roller rolling path, 51,
52... No-load roller rolling surface, 6... Direction change path, 6
DESCRIPTION OF SYMBOLS 1...Circular groove, 62...Insertion piece, 63...Positioning recess, 7...Guide member (guide member), 71, 72...
flat surface, 8...fixing member, 9...retainer (guide member),
91... Stopping hole, 92... Bent part, 93... Holding piece part,
94... Engaging claw, 10, 11, 13... Guide wall, 12
...Bolts, B1, B2...Rollers, C...Circulation path.

Claims (1)

[Claims] 1. An outer cylinder is slidably fitted in the spline shaft via a roller in the axial direction, and a circulation path is provided in the outer cylinder to circulate the roller between a load area and a no-load area. In the roller spline in which the outer cylinder is infinitely movable along the spline axis, a guide wall is formed on one side in the width direction of the circulation path to guide one end surface of the roller, and a guide wall is formed on one side in the width direction of the circulation path. On the other side, a guide member for guiding and holding the other end surface of the roller is provided over the entire circulation path, and is configured to guide and hold both end surfaces of the roller over the entire circulation path, and extends in the axial direction around the outer circumference of the spline shaft. Four protrusions with a rectangular cross section are equally distributed on the top, bottom, left and right, grooves corresponding to the protrusions are formed on the inner periphery of the outer cylinder, and a total of eight roller circulation paths are formed, one pair on each side of each protrusion. A roller rolling path in the load area is provided between both sides of each protrusion and the opposing surfaces of the inner wall of the groove, and is arranged to sandwich each protrusion. The roller transfer surface formed on the opposing surface of the protrusions and grooves constituting the rolling path has a planar configuration extending in the horizontal direction,
and the left and right roller rolling surfaces are provided on the same plane, while the roller rolling surfaces formed on the opposing surfaces of the protrusions and grooves forming the upper and lower roller rolling paths are configured in a plane extending in the vertical direction, A roller spline characterized in that the upper and lower roller rolling surfaces are provided on the same surface. 2. The roller spline according to claim 1, wherein the guide member provided in the loaded roller rolling path of the roller circulation path is provided with an engaging claw portion that engages with a single edge of the roller to prevent the roller from falling off.