JP7565165B2 - Cages, bearings, reducers - Google Patents

Description

The present invention relates to retainers, bearings, and reducers.

Industrial robots, machine tools, and the like sometimes use reducers equipped with needle bearings. In needle bearings, a number of rolling elements (rollers) held in apertures (openings) in a cage are sandwiched between an inner race and an outer race to form a bearing. The cage has multiple apertures (openings) arranged in the circumferential direction relative to the central axis of the bearing. The cage has pillars formed between adjacent apertures (openings).

As the power density of the RV reducer increases, the roller filling rate of the needle bearings used in the crankshaft section tends to increase. This tendency to increase the roller filling rate is particularly noticeable in eccentric oscillating reducers.

Patent No. 2628674

However, as the roller filling rate increases, the number of apertures (openings) in the cage through which the rollers are inserted increases. This reduces the distance between adjacent apertures (openings) in the circumferential direction of the central axis, and reduces the circumferential dimension of the column portion. This can reduce the strength of the cage.

In reducers used in robots, etc., skewers occur in the rollers of needle bearings, which can cause the rollers to tilt.
When the rollers of the needle bearing are tilted, they collide with the contour of the window (opening) of the cage in a tilted state. As a result, the rollers collide with the end face side along the central axis of the contour of the window (opening) and the column side which is circumferential to the central axis. This causes stress concentration in the base R part of the column part which is the corner of the contour of the window (opening) of the cage.

Here, in a cage with reduced strength, problems can occur such as stress concentration causing breakage near the cage's aperture.

The present invention aims to provide a structure that can improve the strength of needle bearing retainers, and to provide retainers, bearings, and reducers that can prevent damage caused by skewers with a simple configuration.

A cage according to one aspect of the present invention includes:
A bearing retainer that retains a plurality of cylindrical rollers having an axis parallel to a central axis around the central axis,
a side peripheral portion that has a rectangular open space in which the rollers are housed along the periphery of the central axis and that forms a cylindrical surface around the central axis;
annular end surface portions disposed radially from both ends of the side circumferential portion in a direction along the central axis;
a restricting portion that is integrally formed as a mutually opposing protrusion on an entire circumference of a radial end portion of the end face portion with respect to the central axis line, and that protrudes to a position closer to the end face of the roller in a direction along the central axis line than a contour end face of the side peripheral portion that defines a contour of the opening space;
having
The end surface portions are all disposed radially outward with respect to the central axis line of the side peripheral portion,
The axis of the roller is located radially outward from the side peripheral portion with respect to the central axis, and the restricting portion is located radially outward from the axis of the roller with respect to the central axis,
The rollers are arranged at equal distances from each other in a circumferential direction of the central axis,
a distance between adjacent rollers in a circumferential direction of the central axis at a position where a radial position with respect to the central axis is equal to a pitch circle including the axis of the roller is smaller than a distance between adjacent open spaces in a circumferential direction of the central axis at a position where a radial position with respect to the central axis is equal to the cylindrical surface of the side peripheral portion ,
This has solved the above problem.
A cage according to one aspect of the present invention includes:
A bearing retainer that retains a plurality of cylindrical rollers having an axis parallel to a central axis around the central axis,
a side peripheral portion that has a rectangular open space in which the rollers are housed along the periphery of the central axis and that forms a cylindrical surface around the central axis;
annular end surface portions disposed radially from both ends of the side circumferential portion in a direction along the central axis;
a restricting portion that is integrally formed as a mutually opposing protrusion on an entire circumference of a radial end portion of the end face portion with respect to the central axis line, and that protrudes to a position closer to the end face of the roller in a direction along the central axis line than a contour end face of the side peripheral portion that defines a contour of the opening space;
having
The end surface portions protrude radially inward with respect to the central axis from both end portions of the side circumferential portion in a direction along the central axis,
The axis of the roller is located radially inward with respect to the central axis of the roller relative to the side peripheral portion,
The restricting portion is located radially inward with respect to the central axis line of the roller,
The cylindrical surface formed by the side peripheral portion has a diameter larger than a pitch circle diameter of the roller arrangement,
The rollers are arranged at equal distances from each other in a circumferential direction of the central axis,
a distance between adjacent rollers in a circumferential direction of the central axis at a position where a radial position with respect to the central axis is equal to a pitch circle including the axis of the roller is smaller than a distance between adjacent open spaces in a circumferential direction of the central axis at a position where a radial position with respect to the central axis is equal to the cylindrical surface of the side peripheral portion ,
This has solved the above problem.

A cage according to one aspect of the present invention includes:
A bearing retainer that retains a plurality of rolling elements around a central axis,
a side peripheral portion in which a plurality of the rolling elements are housed along the periphery of the central axis;
an end surface portion having an annular plate shape and disposed at an end of the side peripheral portion in a radial direction of the central axis; and a reinforcing portion disposed on the end surface portion.
Equipped with
It is possible.
According to a retainer of one aspect of the present invention, when a skew force causes the rolling elements to tilt relative to the central axis and abut against the side peripheral portion, the strength of the side peripheral portion is improved by the reinforcing portion, thereby preventing damage to the retainer.

A cage according to one aspect of the present invention includes:
In the above cage,
The reinforcing portion is formed in a circular ring shape.
It is possible.

A cage according to one aspect of the present invention includes:
In the above cage,
The reinforcing portion is a thick portion that is integrally formed with the end surface portion and is thicker than the thickness of the end surface portion in a direction along the central axis.
It is possible.

A cage according to one aspect of the present invention includes:
In the above cage,
the reinforcing portion and the end of the rolling element are capable of coming into contact with each other in a direction along the central axis.
It is possible.

A cage according to one aspect of the present invention includes:
In the above cage,
The side peripheral portion has the end surface portions at both ends in a direction along the central axis.
It is possible.

A cage according to one aspect of the present invention includes:
In the above cage,
The reinforcing portion is formed on an opposing surface of the end surface portion.
It is possible.

A cage according to one aspect of the present invention includes:
In the above cage,
The end surface portion and the reinforcing portion can be integrally molded by pressing.

A cage according to one aspect of the present invention includes:
A bearing retainer that retains a plurality of rolling elements around a central axis,
a side peripheral portion having a rectangular open space in which a plurality of the rolling elements are housed along the periphery of the central axis;
an annular end surface portion disposed from an end portion of the side peripheral portion in a direction along the central axis toward a radial direction of the central axis;
a restricting portion protruding from the side peripheral portion at a position closer to the rolling element than an end surface that defines a contour of the opening space;
having
This has solved the above problem.

According to a cage according to one aspect of the present invention, when the rolling elements are tilted relative to the central axis due to a skew force, they come into contact with the restricting portion and do not come into direct contact with the open space. This prevents stress from concentrating on the corners of the open space contour of the side periphery. Therefore, damage to the cage can be prevented.

A cage according to one aspect of the present invention includes:
In the above cage,
The restriction portion is integrally formed with the end surface portion,
the restricting portion is formed integrally with the end surface portion and is disposed at a position adjacent to the rolling element along the central axis direction from an inner periphery of the end surface portion,
It is possible.

A cage according to one aspect of the present invention includes:
In the above cage,
The end surface portion and the restricting portion may be integrally formed by pressing.

A cage according to one aspect of the present invention includes:
In the above cage,
an end portion of a contour of the open space as viewed in a radial direction of the central axis and an end portion of the rolling element visible from the open space in a direction along the central axis are spaced apart from each other;
It is possible.

A cage according to one aspect of the present invention includes:
In the above cage,
The side peripheral portion has the end surface portions at both ends in the central axis direction.
It is possible.

A cage according to one aspect of the present invention includes:
In the above cage,
The restricting portion is formed on an opposing surface of the end surface portion.
It is possible.

A bearing according to another aspect of the present invention comprises:
an outer race having an outer rolling surface that is formed in a circular ring shape and faces inward in a radial direction;
an inner race arranged coaxially with the outer race and having an inner rolling surface facing outward in the radial direction;
A plurality of the rolling elements rolling on the inner rolling surface and the outer rolling surface;
Any of the above cages for holding a plurality of the rolling elements;
having
It is possible.

A reducer according to another aspect of the present invention includes:
an outer cylinder having an inner peripheral surface on which internal teeth are formed and arranged in a circumferential direction;
an eccentric oscillating gear having external teeth that mesh with the internal teeth of the external cylinder; a crankshaft connected to a drive source to oscillate the eccentric oscillating gear;
a carrier that supports the crankshaft and rotates relative to the outer cylinder;
Equipped with
The crankshaft can be supported on the carrier by the above-mentioned bearing.

The present invention provides a structure that can improve the strength of the retainer in a needle bearing, and has the effect of providing a retainer, bearing, and reducer that can prevent damage caused by a skewer with a simple configuration.

1 is a front view, partially cross-sectionally taken in the direction of a central axis, showing a first embodiment of a cage and a bearing according to the present invention; 1 is a cross-sectional view showing a first embodiment of a cage according to the present invention, taken in a direction coinciding with a central axis. 1 is a side view showing a first embodiment of a cage according to the present invention, viewed in a direction perpendicular to a central axis line. FIG. 2 is a schematic enlarged view showing the specifications of a cross section in a direction coinciding with a central axis in the first embodiment of the cage according to the present invention. 5 is a cross-sectional view showing a second embodiment of a retainer, a bearing, and a reducer according to the present invention, taken in a direction coinciding with the central axis. FIG. FIG. 11 is a cross-sectional view showing a third embodiment of a cage according to the present invention, taken in a direction coinciding with the central axis.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a cage, a bearing, and a reducer according to the present invention will be described below with reference to the drawings.
Fig. 1 is a front view, partially cross-sectionally taken along the central axis, showing a cage and a bearing in this embodiment. Fig. 2 is a side cross-sectional view taken along the central axis of the cage in this embodiment. Fig. 3 is a side view, viewed from the outside in a direction perpendicular to the central axis, showing the cage in this embodiment. Fig. 4 is a schematic view taken along the central axis showing the dimensions of the cage in this embodiment.
In the figure, reference numeral 1 denotes a cage.

As shown in Figs. 1 to 3, the cage 1 according to this embodiment is used in a bearing that holds a plurality of rolling elements (rollers) 2 around a central axis F3.
As shown in Figures 1 to 3, the retainer 1 of this embodiment comprises a side peripheral portion 1a having an opening space 1p that serves as a cutout window in which a plurality of rolling elements (rollers) 2 are housed along the periphery of a central axis F3, annular plate-shaped end surface portions 1b and 1c arranged radially from both end portions 1a1 and 1a2 in the direction of the central axis F3 of the side peripheral portion 1a toward the radial direction of the central axis F3, and reinforcing portions 1d and 1e arranged on the end surface portions 1b and 1c.

In other words, the cage 1 has a side circumferential portion 1a that forms a substantially cylindrical surface with a diameter larger than the pitch circle diameter of the roller arrangement, flange-like end surface portions 1b, 1c that protrude radially inward from both ends 1a1, 1a2 in the direction of the central axis F3 of this annular side circumferential portion 1a, multiple open spaces 1p that are formed in a line in the circumferential direction on the cylindrical surface of the side circumferential portion 1a to form pillar portions between each other and are multiple pockets into which the rollers 2 fit, and protrusions (ridges) 1d, 1e that serve as regulating portions (reinforcing portions) that position the end surfaces of the rollers 2 in the direction of the central axis F3.

As shown in Figures 1 to 3, the rolling elements (rollers) 2 have a generally cylindrical outer shape. The rolling elements (rollers) 2 have an axis F4 that is parallel to the central axis F3. The multiple rolling elements (rollers) 2 are arranged around the central axis F3 so that their axes F4 are parallel to one another. The multiple rolling elements (rollers) 2 are arranged so that they are equidistant from one another in the circumferential direction of the central axis F3. The cage 1 holds the multiple rolling elements (rollers) 2 in this state so that they can rotate while moving in the circumferential direction of the central axis F3.

The peripheral side portion 1a forms a substantially cylindrical surface around the central axis F3. The peripheral side portion 1a has a width dimension T1a (see FIG. 4) in the direction along the central axis F3 that is substantially the same all around the central axis F3. The peripheral side portion 1a has a thickness dimension Ta (see FIG. 4) in the direction along the central axis F3 that is substantially the same all around the central axis F3.

The side peripheral portion 1a has a distance from the central axis F3, i.e., a radial dimension, which is approximately equal over the entire length along the central axis F3.
The shape of the peripheral side portion 1a is not limited to the shape described above, but can be modified according to the shape of the bearing to be accommodated.
A plurality of open spaces 1p are formed in the circumferential direction of the side peripheral portion 1a. The open spaces 1p are provided in the circumferential direction of the side peripheral portion 1a. The open spaces 1p are positions for storing rollers (rolling elements) 2.

As shown in FIGS. 1 to 3, the open space 1p has a generally rectangular contour when viewed from the radially outer side of the side circumferential portion 1a.
The open space 1p is formed such that the dimension Tp (see FIG. 4) in the direction along the central axis F3 is larger than the length dimension T2 (see FIG. 4) of the roller (rolling element) 2 in the direction along the central axis F3.
The open space 1p is formed such that the dimension in the circumferential direction about the central axis F3 is larger than the length dimension of the rollers (rolling elements) 2 in a direction perpendicular to the central axis F3.

The peripheral side portion 1a has a flange-shaped end surface portion 1b at the end portion 1a1 in the direction of the central axis F3, which protrudes radially inward relative to the central axis F3. The peripheral side portion 1a also has a flange-shaped end surface portion 1c at the end portion 1a2 in the direction of the central axis F3, which protrudes radially inward relative to the central axis F3.

1 to 3, the end surface portions 1b and 1c are annular plates (annular plate shapes) extending in a direction perpendicular to the central axis F3. The end surface portions 1b and 1c have substantially the same contour shape when viewed from the central axis F3. The end surface portions 1b and 1c are formed so as to be perpendicular to the side peripheral portion 1a.
The end surface portions 1b, 1c have substantially equal outer diameters over the entire circumference around the central axis F3. The end surface portions 1b, 1c have substantially equal inner diameters over the entire circumference around the central axis F3.
The end surface portions 1b, 1c have substantially equal radial dimensions over the entire circumference around the central axis F3.
The radial dimension of the end surface portions 1b, 1c with respect to the central axis F3 is set to be larger than the radial dimension about the axis F4 of the roller (rolling element) 2. The radial dimension of the end surface portions 1b, 1c with respect to the central axis F3 may be smaller than the radial dimension of the roller (rolling element) 2 with respect to the axis F4.

The end surface portion 1b has a thickness dimension Tb (see FIG. 4) in a direction along the central axis F3 that is substantially constant over the entire circumference around the central axis F3. The end surface portion 1b has a thickness dimension Tb (see FIG. 4) in a direction along the central axis F3 that is substantially constant over the entire length along the radial direction of the central axis F3.
The end surface portion 1c has a thickness dimension Tc (see FIG. 4) in a direction along the central axis F3 that is substantially constant over the entire circumference around the central axis F3. The end surface portion 1c has a thickness dimension Tc (see FIG. 4) in a direction along the central axis F3 that is substantially constant over the entire length along the radial direction of the central axis F3.

The thickness dimension Tb (see FIG. 4) of the end surface portion 1b and the thickness dimension Tc (see FIG. 4) of the end surface portion 1c are both formed to be equal. The thickness dimension Tb (see FIG. 4) of the end surface portion 1b and the thickness dimension Tc (see FIG. 4) of the end surface portion 1c are both set to be equal to the thickness dimension Ta (see FIG. 4) of the peripheral portion 1a.

As shown in Figures 1 to 3, end face portion 1b has a protrusion (ridge) 1d that serves as a restricting portion or reinforcing portion formed at the radially inner end portion relative to center axis F3, facing end face portion 1c. End face portion 1c has a protrusion (ridge) 1e that serves as a restricting portion or reinforcing portion formed in correspondence with protrusion (ridge) 1d, at the radially inner end portion relative to center axis F3, facing end face portion 1b. Protrusions (ridges) 1d, 1e are formed on the opposing surfaces of end face portion 1b and end face portion 1c.

The protrusions (ridges) 1d, 1e, which serve as restricting or reinforcing portions, are each formed continuously in an annular shape around the central axis F3. The protrusions (ridges) 1d, 1e, which serve as restricting or reinforcing portions, are formed as thick portions that are thicker than the thicknesses of the end face portions 1b, 1c in the direction along the central axis F3.
A protrusion (ridge) 1d serving as a restricting portion or a reinforcing portion is formed integrally with the end surface portion 1b. A protrusion (ridge) 1e serving as a restricting portion or a reinforcing portion is formed integrally with the end surface portion 1c.

The protrusion (ridge) 1d, which serves as a restricting or reinforcing part, has a width dimension Td (see FIG. 4) along the radial direction of the central axis F3 that is substantially the same all around the central axis F3. The protrusion (ridge) 1e, which serves as a restricting or reinforcing part, has a width dimension Te (see FIG. 4) along the radial direction of the central axis F3 that is substantially the same all around the central axis F3.

The width dimension Td (see FIG. 4) of the protrusion (ridge) 1d serving as a restricting portion or a reinforcing portion and the width dimension Te (see FIG. 4) of the protrusion (ridge) 1e serving as a restricting portion or a reinforcing portion are both formed to be equal.
The width dimension Td (see Figure 4) of the convex portion (protrusion) 1d which serves as a regulating portion or a reinforcing portion, and the width dimension Te (see Figure 4) of the convex portion (protrusion) 1e which serves as a regulating portion or a reinforcing portion are both formed to be equal to the thickness dimension Ta (see Figure 4) of the side peripheral portion 1a.

The protrusions (ribs) 1d serving as restricting or reinforcing portions can be seen from the opening space 1p when viewed from the radially outer side relative to the central axis F3. In other words, the protrusions (ribs) 1d serving as restricting or reinforcing portions protrude toward the center of the opening space 1p beyond the end face (contour end face) 1p1 that defines the contour of the opening space 1p in the direction along the central axis F3.
The protrusions (ribs) 1e serving as restricting or reinforcing portions can be seen from the opening space 1p when viewed from the radially outer side relative to the central axis F3. In other words, the protrusions (ribs) 1e serving as restricting or reinforcing portions protrude toward the center of the opening space 1p beyond the end face (contour end face) 1p1 that defines the contour of the opening space 1p in the direction along the central axis F3.

In the direction along the central axis F3, the distance Tde (see FIG. 4) between the protrusions (protrusions) 1d and 1e is smaller than the distance Tp (see FIG. 4) between a pair of opposing parallel sides on the contour of the open space 1p in the direction along the central axis F3. Similarly, in the direction along the central axis F3, the distance Tde (see FIG. 4) between the protrusions (protrusions) 1d and 1e is set to be approximately equal to or slightly larger than the length T2 (see FIG. 4) of the rolling element (roller) 2 in the direction along the central axis F3.
The difference between the distance Tde (see FIG. 4) and the distance Tp (see FIG. 4) is set so that it is equal to the total length of one side extending in the circumferential direction with respect to the central axis F3 in the rectangular contour of the open space 1p.

The difference between the distance Tde (see FIG. 4) and the length T2 (see FIG. 4) is set so as to be equal to the total length of one side of the opening space 1p, which has a rectangular contour in the circumferential direction relative to the central axis F3.
The end faces of the mutually opposing convex portions (protrusions) 1d and 1e are parallel to each other in a direction perpendicular to the central axis F3. The end faces of the mutually opposing convex portions (protrusions) 1d and 1e are subjected to surface treatment such as smoothing and deburring.

The end faces of the protrusions (ribs) 1d and 1e maintain the same distance Tde (see FIG. 4) in the radial direction relative to the central axis F3. In other words, the end faces of the protrusions (ribs) 1d and 1e maintain the same distance Tde (see FIG. 4) in the thickness direction.
The end faces of the protrusions (ribs) 1d and 1e maintain the same distance Tde (see FIG. 4) in the circumferential direction about the central axis F3. That is, the end faces of the protrusions (ribs) 1d and 1e maintain the same distance Tde (see FIG. 4) in the circumferential direction about the central axis F3.

The end faces of the protrusions (ridges) 1d and 1e can be located closer to the central axis F3 than the axis F4 in the radial direction relative to the central axis F3. Alternatively, the end faces of the protrusions (ridges) 1d and 1e can be located including the axis F4 in the radial direction relative to the central axis F3.

The cage 1 in this embodiment includes a side peripheral portion 1a along the circumferential direction around the central axis F3, a plurality of opening spaces 1p provided around the side peripheral portion 1a to house the rollers (rolling elements) 2, flange-shaped end surface portions 1b, 1c extending radially inward from the ends 1a1, 1a2 along the central axis F3 of the side peripheral portion 1a, and protruding portions (reinforcing portions, restricting portions) 1d, 1e protruding from the radially inner ends of the end surface portions 1b, 1c along the central axis F3 toward the center of the contour of the opening space 1p in the direction along the central axis F3, and the protruding portions (reinforcing portions, restricting portions) 1d, 1e protrude toward the center of the contour of the opening space 1p beyond the side 1p1 of the rectangular contour of the opening space 1p in the direction along the central axis F3.

Next, we will explain how to form the retainer in this embodiment.

In the present embodiment, the cage 1 is integrally formed from a plate material by pressing. At this time, the cage 1 is formed by bending the peripheral side portion 1a and the end surface portions 1b and 1c so that the radial cross section relative to the central axis F3 is substantially U-shaped, and the circumferential ends relative to the central axis F3 are connected to form an annular shape.
Furthermore, in the end face portions 1b and 1c, the inner peripheral ends with respect to the central axis F3 are bent in a direction facing each other and approaching each other to form protrusions (reinforcing portions, restricting portions) 1d and 1e.

Furthermore, the end faces of the protrusions (reinforcement portions, restriction portions) 1d and 1e are subjected to surface treatment such as deburring.
In this manner, the cage 1 is formed so that its radial cross section with respect to the central axis F3 has a C-shape that is nearly rectangular.

The order of folding, the order of surface treatment, etc. can be set appropriately based on ease of processing, etc., and is not limited to the above order.

The state of the cage 1 and rollers (rolling elements) 2 in this embodiment will be explained.

Here, consider a case where the rollers (rolling elements) 2 in the cage 1 are inclined so that the axis F4 is inclined relative to the central axis F3.
Here, the cage 1 is used as a bearing. Therefore, as shown in Fig. 1, an outer race Or is located on the outside of the cage 1 in the radial direction relative to the central axis F3. Also, as shown in Fig. 1, an inner race Ir is located on the inside of the cage 1 in the radial direction relative to the central axis F3.
Therefore, it is only necessary to consider the state in which the rollers (rolling elements) 2 are inclined in the circumferential direction with respect to the central axis F3.

Thus, in the cage 1 of this embodiment, when the rollers (rolling elements) 2 are tilted so that the axis F4 is inclined relative to the central axis F3, the protrusions (reinforcement parts, regulating parts) 1d and 1e first come into contact with the end faces of the rollers (rolling elements) 2. In this state, the rollers (rolling elements) 2 do not come into contact with the sides of the rectangular contour of the opening space 1p. Therefore, due to the contact of the rollers (rolling elements) 2, no stress is generated in the side peripheral part 1a near the contour of the opening space 1p. In particular, the rollers (rolling elements) 2 do not come into contact near the corners of the rectangular contour of the opening space 1p, and no stress concentration occurs.

Furthermore, when the roller (rolling element) 2 is tilted in this way and first comes into contact with the convex portions (reinforcement portion, restriction portion) 1d, 1e, the end surface portions 1b, 1c are deformed so that the convex portions (reinforcement portion, restriction portion) 1d, 1e move away from each other in the direction of the central axis F3. In other words, the end surface portions 1b and 1c are deformed so as to move away from each other. At this time, the end surface portions 1b and 1c are deformed so that the inner peripheral sides on which the convex portions (reinforcement portion, restriction portion) 1d and the convex portions (reinforcement portion, restriction portion) 1e are formed move away from each other in the direction along the central axis F3. In contrast, the deformation of the end surface portions 1b and 1c is suppressed on the outer peripheral side connected to the side peripheral portion 1a.

This makes it possible to prevent stress concentration on the side periphery 1a. Also, when the roller filling rate is increased, damage can be prevented even in the side periphery 1a, which has become thinner and has reduced strength. Furthermore, the life of the cage 1 can be extended.

Also consider the case where a skew force acts on the cage 1, so that the axis F4 does not tilt, but the roller (rolling element) 2 moves along the central axis F3.

In this way, in the cage 1 of this embodiment, when the rollers (rolling elements) 2 move along the central axis F3 without tilting the axis F4, the protrusions (reinforcement parts, regulating parts) 1d and 1e first come into contact with the end faces of the rollers (rolling elements) 2. In this state, the rollers (rolling elements) 2 do not come into contact with the sides of the rectangular contour of the opening space 1p. Therefore, the contact of the rollers (rolling elements) 2 does not generate stress in the side periphery 1a near the contour of the opening space 1p.

Furthermore, when the roller (rolling element) 2 moves in this manner and first comes into contact with the convex portion (reinforcement portion, restriction portion) 1d or the convex portion (reinforcement portion, restriction portion) 1e, the end surface portion 1b or the end surface portion 1c is deformed so that the convex portions (reinforcement portion, restriction portion) 1d, 1e move away from each other in the direction of the central axis F3. In other words, the end surface portion 1b and the end surface portion 1c are deformed so as to move away from each other. At this time, the end surface portion 1b and the end surface portion 1c are deformed so that the inner peripheral side on which the convex portion (reinforcement portion, restriction portion) 1d and the convex portion (reinforcement portion, restriction portion) 1e are formed moves away from each other in the direction along the central axis F3. In contrast, the deformation of the end surface portion 1b and the end surface portion 1c is suppressed on the outer peripheral side connected to the side peripheral portion 1a.

As a result, the cage 1 of this embodiment can prevent stress concentration on the peripheral side portion 1a, prevent breakage, and extend the life of the cage 1. Therefore, since it is not necessary to increase the curvature R at the corners of the contour of the open space 1p to maintain strength, the gap between the cage 1 and the rolling elements 2 can be reduced, and the cage 1 can be made more compact.
Furthermore, the retainer 1 of this embodiment has a simple structure that can be integrally molded by bending four rows, which reduces the number of manufacturing steps and the number of parts required, making it possible to manufacture the retainer at low cost.

In the cage 1 of this embodiment, the dimensions shown in FIG. 4 can be set so as to satisfy the respective relationships as shown below.
T2≦Tde
Tde < Tp
Tp < Tbc
Tbc < T1a
Td = Te = Tb = Tc = Ta

Next, we will explain the bearings in this embodiment.

As shown in FIG. 1, a bearing 1A in this embodiment has the above-mentioned cage 1 and a plurality of rolling elements (rollers) 2, an outer race Or, and an inner race Ir.
The bearing 1A rotates about a central axis F3.
The outer race Or has an outer rolling surface that is formed in an annular shape and faces radially inward with respect to the central axis F3.

The inner race Ir is disposed coaxially with the outer race Or and has an inner rolling surface that faces radially outward with respect to the central axis F3.
In FIG. 1, only the positions of the rolling surfaces of the outer race Or and the inner race Ir are shown.
A plurality of rolling elements (rollers) 2 roll on an inner rolling surface and an outer rolling surface.

As described above, the bearing 1A in this embodiment can prevent stress concentration in the retainer 1 and suppress damage. Therefore, it is possible to prevent damage to the bearing 1A, extend its life, and reduce its size.

Hereinafter, a second embodiment of the retainer, bearing, and reducer according to the present invention will be described with reference to the drawings.
5 is a cross-sectional view taken along the axial direction, showing the cage, bearings, and reducer in this embodiment. In the figure, reference numeral 100 denotes the reducer. This embodiment differs from the first embodiment described above in terms of the reducer, and other configurations corresponding to those in the first embodiment described above are given the same reference numerals and will not be described.

5 , the reducer 100 according to this embodiment includes a tubular housing 200, a gear unit (external teeth member) 300, and three crank assemblies 400. The tubular housing 200 houses the gear unit 300 and the three crank assemblies 400.
In this embodiment, the reducer 100 is an eccentric oscillating reducer.

The housing tube 200 includes a case (outer cylinder) 210, a carrier part (carrier) 220, and two main bearings 230. The carrier part 220 is disposed within the case (outer cylinder) 210. The two main bearings 230 are disposed between the case (outer cylinder) 210 and the carrier part 220. The two main bearings 230 enable relative rotational motion between the case (outer cylinder) 210 and the carrier part 220. The output part of the reducer 100 in this embodiment is exemplified by one of the case (outer cylinder) 210 and the carrier part 220.

5 shows a central axis (main axis) F0 of the reducer 100, which is defined as the central axis of rotation of the two main bearings 230. When the case (outer cylinder portion) 210 is fixed, the carrier portion 220 rotates around the main axis F0. When the carrier portion 220 is fixed, the case (outer cylinder portion) 210 rotates around the main axis F0. In other words, one of the case (outer cylinder portion) 210 and the carrier portion 220 can rotate around the main axis F0 relative to the other of the case (outer cylinder portion) 210 and the carrier portion 220.
In this embodiment, the direction along the central axis (main axis) F0 of the reducer 100, which serves as the central axis of rotation of the two main bearings 230, is referred to as the axial direction.

A flange portion (mounting flange) 215 is provided around the outer periphery of the cylindrical case (outer cylinder portion) 210. A plurality of mounting holes 216 are formed at intervals around the periphery of the flange portion 215. The flange portion 215 is used, for example, as a spigot when mounting the reducer 100 to a fitting portion.

The case (outer cylinder portion) 210 includes an outer cylinder 211 and a number of internally toothed pins (internal teeth) 212. The outer cylinder 211 defines a cylindrical internal space in which the carrier portion 220, the gear portion 300, and the crank assembly 400 are housed. Each internally toothed pin 212 is a columnar member extending approximately parallel to the main axis F0. Each internally toothed pin 212 is fitted into a groove portion formed in the inner wall of the outer cylinder 211. Therefore, each internally toothed pin 212 is appropriately held by the outer cylinder 211.

The multiple internal tooth pins 212 are arranged at approximately regular intervals around the main axis F0. The semi-circumferential surface of each internal tooth pin 212 protrudes from the inner wall of the outer cylinder 211 toward the main axis F0. Therefore, the multiple internal tooth pins 212 function as internal teeth that mesh with the gear portion 300.

The carrier part 220 includes a base part (first member) 221, an end plate part (second member) 222, a positioning pin 223, and a support bolt (fixing bolt) 224. The carrier part 220 has an overall cylindrical shape. A through hole 229 that is concentric with the main axis F0 is formed in the carrier part 220.

The base (first member) 221 includes a substrate 225 and three shafts 226. Each of the three shafts 226 extends from the substrate 225 toward the end plate (second member) 222. A screw hole 227 and a reamer hole 228 are formed in the tip surface of each of the three shafts 226. The positioning pin 223 is inserted into the reamer hole 228. As a result, the end plate (second member) 222 is precisely positioned relative to the base (first member) 221.

The support bolts 224 are fastened to the screw holes 227. As a result, the end plate portion (second member) 222 is appropriately fixed to the base portion (first member) 221.
The base portion (first member) 221 and the end plate portion (second member) 222 are fixed to each other by the support bolts 224 so as to provide a predetermined preload. The end plate portion (second member) 222 is called a hold.

The gear portion 300 is disposed between the base plate portion 225 and the end plate portion (second member) 222. The three shaft portions 226 pass through the gear portion 300 and are connected to the end plate portion (second member) 222.

The gear section 300 includes two gears 310 and 320. Gear 310 is disposed between the base plate section 225 and gear 320. Gear 320 is disposed between the end plate section (second member) 222 and gear 310.

Gear 310 is substantially the same in shape and size as gear 320. Gears 310 and 320 move around inside outer cylinder 211 while meshing with internal tooth pin 212. Therefore, the centers of gears 310 and 320 move around main axis F0.

The rotation phase of gear 310 is shifted by approximately 180° from the rotation phase of gear 320. While gear 310 meshes with half of the multiple internally toothed pins 212 of case (outer cylinder portion) 210, gear 320 meshes with the remaining half of the multiple internally toothed pins 212. Therefore, gear portion 300 can rotate case (outer cylinder portion) 210 or carrier portion 220.

In this embodiment, the gear section 300 includes two gears 310, 320. Alternatively, the gear section may include more than two gears. Alternatively, the gear section may include a single gear.

Each of the three crank assemblies 400 includes a crankshaft 410, four bearings 421, 422, 423, and 424, and a transmission gear (external teeth) 430. The transmission gear 430 may be a general spur gear. In the reducer 100 of this embodiment, the transmission gear 430 is not limited to a specific type.

The transmission gear 430 directly or indirectly receives the driving force generated by a driving source (e.g., a motor). The reducer 100 can appropriately set the transmission path of the driving force from the driving source to the transmission gear 430 depending on the usage environment and usage conditions. Therefore, this embodiment is not limited to a specific drive transmission path from the driving source to the transmission gear 430.

5 shows a crank axis (transmission shaft) F2. The transmission shaft F2 is substantially parallel to the main shaft F0. The crankshaft 410 rotates around the transmission shaft F2.
The crankshaft 410 includes two journals (crank journals) 411, 412 and two eccentric portions (eccentric bodies) 413, 414. The journals 411, 412 extend along the transmission axis F2. The central axes of the journals 411, 412 coincide with the transmission axis F2. The eccentric portions 413, 414 are formed between the journals 411, 412. Each of the eccentric portions 413, 414 is eccentric from the transmission axis F2.

The journal 411 is inserted into the bearing 421. The bearing 421 is disposed between the journal 411 and the end plate portion (second member) 222. Thus, the journal 411 is supported by the end plate portion (second member) 222 and the bearing 421. The journal 412 is inserted into the bearing 422. The bearing 422 is disposed between the journal 412 and the base portion (first member) 221. Thus, the journal 412 is supported by the base portion (first member) 221 and the bearing 422.
In this embodiment, the bearing 421 is a needle bearing, and a plurality of rollers 431 are arranged around the journal 411. The bearing 422 is a needle bearing, and a plurality of rollers 432 are arranged around the journal 412.

The eccentric part 413 is inserted into a bearing 423. The bearing 423 is disposed between the eccentric part 413 and the gear 310. The eccentric part 414 is inserted into a bearing 424. The bearing 424 is disposed between the eccentric part 414 and the gear 320.
In this embodiment, the bearing 423 is a needle bearing, and a plurality of rollers 433 are arranged around the eccentric portion (eccentric body) 413. The bearing 424 is a needle bearing, and a plurality of rollers 434 are arranged around the eccentric portion (eccentric body) 414.

When a driving force is input to the transmission gear 430, the crankshaft 410 rotates around the transmission axis F2. As a result, the eccentric parts 413 and 414 rotate eccentrically around the transmission axis F2. The gears 310 and 320 connected to the eccentric parts 413 and 414 via the bearings 423 and 424 oscillate within a circular space defined by the case (outer cylinder part) 210. The gears 310 and 320 mesh with the internal tooth pin 212, causing a relative rotational motion between the case (outer cylinder part) 210 and the carrier part 220.

In the reducer 100 according to this embodiment, the bearing 421 can be configured to correspond to the bearing 1A in the first embodiment. In this case, the crank axis (transmission shaft) F2 corresponds to the central axis F3 in the first embodiment. The roller 431 corresponds to the rolling element (roller) 2 in the first embodiment. The journal 411 corresponds to the inner race Ir in the first embodiment. The end plate portion (second member) 222 corresponds to the outer race Or in the first embodiment.

Similarly, in the reducer 100, the bearing 422 can be configured to correspond to the bearing 1A in the first embodiment. In this case, the crank axis (transmission shaft) F2 corresponds to the central axis F3 in the first embodiment. Also, the roller 432 corresponds to the rolling element (roller) 2 in the first embodiment. The journal 412 corresponds to the inner race Ir in the first embodiment. The end plate portion (second member) 222 corresponds to the outer race Or in the first embodiment.

Similarly, in the reducer 100, the bearing 423 can be configured to correspond to the bearing 1A in the first embodiment. In this case, the roller 433 corresponds to the rolling element (roller) 2 in the first embodiment. The eccentric portion (eccentric body) 413 corresponds to the inner race Ir in the first embodiment. The gear 310 corresponds to the outer race Or in the first embodiment.

Similarly, in the reducer 100, the bearing 424 can be configured to correspond to the bearing 1A in the first embodiment. In this case, the roller 434 corresponds to the rolling element (roller) 2 in the first embodiment. The eccentric portion (eccentric body) 414 corresponds to the inner race Ir in the first embodiment. The gear 320 corresponds to the outer race Or in the first embodiment.

In the reducer 100 according to this embodiment as well, the above-described retainer 1 is housed in each of the bearings 421 to 424 .
This makes it possible to achieve the same effects as those of the above-described embodiment.

Furthermore, in this embodiment, the two main bearings 230 can be configured to correspond to the bearing 1A in the first embodiment.

Hereinafter, a third embodiment of a cage and a bearing according to the present invention will be described with reference to the drawings.
FIG. 6 is a cross-sectional view taken along the axial direction, showing the cage and bearing in this embodiment.
This embodiment differs from the first and second embodiments described above in terms of the arrangement of the end surface portions. Other corresponding components are given the same reference numerals and descriptions thereof may be omitted.

In the cage 1 of this embodiment, both end face portions 1b and 1c are positioned radially outward from the central axis F3 of the peripheral portion 1a.

The peripheral side portion 1a has a flange-shaped end surface portion 1b at the end portion 1a1 in the direction of the central axis F3, which protrudes radially outward relative to the central axis F3. The peripheral side portion 1a also has a flange-shaped end surface portion 1c at the end portion 1a2 in the direction of the central axis F3, which protrudes radially outward relative to the central axis F3.

As shown in Fig. 6, the end surface portions 1b and 1c are annular plates (annular plate shapes) extending in a direction perpendicular to the central axis F3. The end surface portions 1b and 1c have substantially the same contour shape when viewed in the direction along the central axis F3. Both the end surface portions 1b and 1c are formed so as to be perpendicular to the side peripheral portion 1a.
The end surface portions 1b, 1c have substantially equal outer diameters over the entire circumference around the central axis F3. The end surface portions 1b, 1c have substantially equal inner diameters over the entire circumference around the central axis F3.
The end surface portions 1b, 1c have substantially equal radial dimensions over the entire circumference around the central axis F3.
The radial dimension of the end surface portions 1b, 1c with respect to the central axis F3 is set to be larger than the radial dimension about the axis F4 of the roller (rolling element) 2. The radial dimension of the end surface portions 1b, 1c with respect to the central axis F3 may be smaller than the radial dimension of the roller (rolling element) 2 with respect to the axis F4.

The end surface portion 1b has a thickness dimension Tb in a direction along the central axis F3 that is substantially constant over the entire circumference around the central axis F3. The end surface portion 1b has a thickness dimension Tb in a direction along the central axis F3 that is substantially constant over the entire length along the radial direction of the central axis F3.
The end surface portion 1c has a thickness dimension Tc in a direction along the central axis F3 that is substantially constant over the entire circumference around the central axis F3. The end surface portion 1c has a thickness dimension Tc in a direction along the central axis F3 that is substantially constant over the entire length along the radial direction of the central axis F3.

The thickness dimension Tb of the end surface portion 1b and the thickness dimension Tc of the end surface portion 1c are both formed to be equal. The thickness dimension Tb of the end surface portion 1b and the thickness dimension Tc of the end surface portion 1c are both set to be equal to the thickness dimension Ta of the peripheral portion 1a.

As shown in FIG. 6, end surface portion 1b has a protrusion (ridge) 1d that serves as a restricting portion or reinforcing portion formed at the radially outer end portion relative to center axis F3, facing end surface portion 1c. End surface portion 1c has a protrusion (ridge) 1e that serves as a restricting portion or reinforcing portion formed in correspondence with protrusion (ridge) 1d, at the radially outer end portion relative to center axis F3, facing end surface portion 1b. Protrusions (ridges) 1d, 1e are formed on the opposing surfaces of end surface portion 1b and end surface portion 1c.

The protrusions (ridges) 1d, 1e, which serve as restricting or reinforcing portions, are each formed continuously in an annular shape around the central axis F3. The protrusions (ridges) 1d, 1e, which serve as restricting or reinforcing portions, are formed on the outer edges as thick portions that are thicker than the thicknesses of the end face portions 1b, 1c in the direction along the central axis F3.
A protrusion (ridge) 1d serving as a restricting portion or a reinforcing portion is formed integrally with the end surface portion 1b. A protrusion (ridge) 1e serving as a restricting portion or a reinforcing portion is formed integrally with the end surface portion 1c.

The protrusion (ridge) 1d, which serves as a restricting or reinforcing part, has a width dimension Td along the radial direction of the central axis F3 that is substantially the same all around the central axis F3. The protrusion (ridge) 1e, which serves as a restricting or reinforcing part, has a width dimension Te along the radial direction of the central axis F3 that is substantially the same all around the central axis F3.

The width dimension Td of the protrusions (ridges) 1d serving as restricting portions or reinforcing portions and the width dimension Te of the protrusions (ridges) 1e are both formed to be equal.
A width Td of the protrusion (ridge) 1d, which serves as a restricting portion or reinforcing portion, and a width Te of the protrusion (ridge) 1e are both formed to be equal to a thickness Ta of the side peripheral portion 1a.

The protrusion (ridge) 1d, which serves as a restricting or reinforcing part, can be seen from the opening space 1p when viewed from the inside in the radial direction relative to the central axis F3 toward the outside. In other words, the protrusion (ridge) 1d, which serves as a restricting or reinforcing part, protrudes in a direction closer to the end surface 1c than the side 1p1, which is the edge of the outline of the opening space 1p in the direction along the central axis F3. In other words, the protrusion (ridge) 1d protrudes toward the center of the opening space 1p in the direction along the central axis F3, further than the end surface 1p1, which is the outline of the opening space 1p.

The protrusions (ridges) 1e that serve as the restricting or reinforcing parts can be seen from the opening space 1p when viewed from the inside in the radial direction relative to the central axis F3 toward the outside. In other words, the protrusions (ridges) 1e that serve as the restricting or reinforcing parts protrude toward the center of the opening space 1p beyond the end face 1p1 of the rectangular contour of the opening space 1p in the direction along the central axis F3.

In the direction along the central axis F3, the distance Tde between the protrusions (protrusions) 1d and 1e is smaller than the distance Tp between a pair of parallel sides facing each other on the contour of the open space 1p in the direction along the central axis F3. Similarly, in the direction along the central axis F3, the distance Tde between the protrusions (protrusions) 1d and 1e is set to be approximately equal to or slightly larger than the length T2 of the rolling element (roller) 2 in the direction along the central axis F3.
The difference between the distance Tde and the distance Tp is set so that it is equal to the total length of one side extending in the circumferential direction with respect to the central axis line F3 in the rectangular contour of the open space 1p.

The difference between the distance Tde and the length T2 is set so as to be equal over the entire length of an end face 1p1 of one side of the rectangular contour of the open space 1p in the circumferential direction relative to the central axis F3.
The end faces of the opposing convex portions (protrusions) 1d and 1e are parallel to each other in a direction perpendicular to the central axis F3. The end faces of the opposing convex portions (protrusions) 1d and 1e are subjected to surface treatments such as smoothing, flattening, and deburring. The end faces of the convex portions (protrusions) 1d and 1e are smoothed and flattened to a greater extent than the end faces 1p1 of the opening spaces 1p so as to reduce friction with the end faces of the rollers 2.

The end faces of the protrusions (ribs) 1d and 1e maintain the same distance Tde over the entire radial length relative to the central axis F3. In other words, the end faces of the protrusions (ribs) 1d and 1e maintain the same distance Tde over the thickness direction.
The end faces of the protrusions (ribs) 1d and 1e maintain the same distance Tde all around the circumference in the circumferential direction about the central axis F3. That is, the end faces of the protrusions (ribs) 1d and 1e maintain the same distance Tde in the circumferential direction about the central axis F3.

The end faces of the protrusions (ridges) 1d and 1e can be positioned farther away from the central axis F3 than the axis F4 is in the radial direction relative to the central axis F3. Alternatively, the end faces of the protrusions (ridges) 1d and 1e can be positioned including the axis F4 in the radial direction relative to the central axis F3.

The retainer 1 in this embodiment includes a side peripheral portion 1a along the circumferential direction around the central axis F3, a plurality of opening spaces 1p provided around the side peripheral portion 1a to serve as storage positions for rollers (rolling elements) 2, flange-shaped end surface portions 1b, 1c extending radially outward from ends 1a1, 1a2 along the central axis F3 of the side peripheral portion 1a, and protruding portions (reinforcing portions, restricting portions) 1d, 1e protruding in a direction along the central axis F3 from the radially outer peripheral ends of the end surface portions 1b, 1c along the central axis F3 toward the center of the contour of the opening space 1p, and the protruding portions (reinforcing portions, restricting portions) 1d, 1e protrude toward the center of the contour of the opening space 1p beyond the sides of the rectangular contour of the opening space 1p in the direction along the central axis F3.

Next, we will explain how to form the retainer in this embodiment.

In the present embodiment, the cage 1 is integrally formed from a plate material by pressing. In this case, the cage 1 is formed by bending the peripheral side portion 1a and the end face portions 1b, 1c so that the radial cross section relative to the central axis F3 is substantially U-shaped, and the circumferential ends relative to the central axis F3 are connected to form an annular shape.
Furthermore, in the end surface portions 1b and 1c, the outer peripheral end portions with respect to the central axis F3 are bent in a direction facing each other and approaching each other to form protrusions (reinforcing portions, restricting portions) 1d and 1e.

Furthermore, the end faces of the protrusions (reinforcement portions, restriction portions) 1d, 1e are subjected to surface treatment such as deburring so as not to impede the rotation of the rollers (rolling elements) 2 when they come into contact with each other.
In this manner, the cage 1 is formed so that its radial cross section with respect to the central axis F3 has a C-shape that is nearly rectangular.

The order of folding, the order of surface treatment, etc. can be set appropriately based on ease of processing, etc., and is not limited to the above order.

The state of the cage 1 and rollers (rolling elements) 2 in this embodiment will be explained.

Here, consider a case where the rollers (rolling elements) 2 in the cage 1 are inclined so that the axis F4 is inclined relative to the central axis F3.
Here, the cage 1 is used as a bearing. Therefore, an outer race Or is located outside the cage 1 in the radial direction relative to the central axis F3, as shown in Fig. 1 of the first embodiment. Similarly, an inner race Ir is located inside the cage 1 in the radial direction relative to the central axis F3.
Therefore, a state in which the roller (rolling element) 2 is tilted in the circumferential direction with respect to the central axis F3 is considered.

In the cage 1 of this embodiment, when the rollers (rolling elements) 2 are inclined such that the axis F4 is inclined relative to the central axis F3, the protrusions (reinforcement parts, regulating parts) 1d and 1e first come into contact with the end faces of the rollers (rolling elements) 2. In this state, the rollers (rolling elements) 2 do not come into contact with the side end faces 1p1 of the rectangular contour of the opening space 1p. Therefore, due to the contact of the rollers (rolling elements) 2, no stress is generated in the side peripheral part 1a near the contour of the opening space 1p. In particular, the rollers (rolling elements) 2 do not come into contact near the corners of the rectangular contour of the opening space 1p, and no stress concentration occurs.

Furthermore, when the roller (rolling element) 2 is tilted in this way and first comes into contact with the convex portions (reinforcement portion, restriction portion) 1d, 1e, the end surface portions 1b, 1c are deformed so that the convex portions (reinforcement portion, restriction portion) 1d, 1e move away from each other in the direction of the central axis F3. In other words, the end surface portions 1b and 1c are deformed so as to move away from each other. At this time, the end surface portions 1b and 1c are deformed so that the outer peripheral sides on which the convex portions (reinforcement portion, restriction portion) 1d and the convex portions (reinforcement portion, restriction portion) 1e are formed move away from each other in the direction along the central axis F3. In contrast, the deformation of the end surface portions 1b and 1c is suppressed on the inner peripheral side connected to the side peripheral portion 1a.

This makes it possible to suppress the occurrence of stress concentration in the side periphery 1a. Furthermore, when the roller filling rate is increased, damage can be prevented even in the side periphery 1a, which has become thinner and has reduced strength. Furthermore, the life of the cage 1 can be extended.

Also consider the case where a skew force acts on the cage 1, so that the axis F4 does not tilt, but the roller (rolling element) 2 moves along the central axis F3.

In this way, in the cage 1 of this embodiment, when the rollers (rolling elements) 2 move along the central axis F3 without tilting the axis F4, the convex portions (reinforcement portions, regulating portions) 1d, 1e first come into contact with the end faces of the rollers (rolling elements) 2. In this state, the rollers (rolling elements) 2 do not come into contact with the end faces 1p1 of the rectangular contour sides of the opening space 1p. Therefore, the contact of the rollers (rolling elements) 2 does not generate stress in the side peripheral portion 1a near the contour of the opening space 1p.

Furthermore, when the roller (rolling element) 2 moves in this manner and first comes into contact with the convex portion (reinforcement portion, restriction portion) 1d or the convex portion (reinforcement portion, restriction portion) 1e, the end surface portion 1b or the end surface portion 1c is deformed so that the convex portions (reinforcement portion, restriction portion) 1d, 1e move away from each other in the direction of the central axis F3. In other words, the end surface portion 1b and the end surface portion 1c are deformed so as to move away from each other. At this time, the end surface portion 1b and the end surface portion 1c are deformed so that the outer peripheral side on which the convex portion (reinforcement portion, restriction portion) 1d and the convex portion (reinforcement portion, restriction portion) 1e are formed moves away from each other in the direction along the central axis F3. In contrast, the deformation of the end surface portion 1b and the end surface portion 1c is suppressed on the inner peripheral side connected to the side peripheral portion 1a.

As a result, the cage 1 of this embodiment can suppress the occurrence of stress concentration in the peripheral side portion 1a, prevent damage, and achieve a longer life. Therefore, the radius of the curve formed at the corner of the rectangular contour of the opening space 1p can be reduced, and the gap between the cage 1 and the rolling elements 2 can be reduced, resulting in a more compact design.

In addition, the cage 1 of this embodiment has a simple structure that can be integrally molded by bending along four edges, which reduces the number of manufacturing steps and the number of parts required, making it possible to manufacture the cage at low cost.

This embodiment can achieve the same effects as the above-mentioned embodiment.

Examples of applications of the present invention include reducers and drive devices (power transmission devices) that use needle bearings in conjunction with each other.

1 ... retainer 1A ... bearing 1a ... side peripheral portion 1a1, 1a2 ... end portion 1b, 1c ... end surface portion 1d, 1e ... convex portion (reinforcement portion, restriction portion)
1p...opening space 1p1...end face F3...center axis F4...axis 2...roller (rolling element)

Claims (6)

A bearing retainer that retains a plurality of cylindrical rollers having an axis parallel to a central axis around the central axis,
a side peripheral portion that has a rectangular open space in which the rollers are housed along the periphery of the central axis and that forms a cylindrical surface around the central axis;
annular end surface portions disposed radially from both ends of the side circumferential portion in a direction along the central axis;
a restricting portion that is integrally formed as a mutually opposing protrusion on an entire circumference of a radial end portion of the end face portion with respect to the central axis line, and that protrudes to a position closer to the end face of the roller in a direction along the central axis line than a contour end face of the side peripheral portion that defines a contour of the opening space;
having
The end surface portions are all disposed radially outward with respect to the central axis line of the side peripheral portion,
The axis of the roller is located radially outward from the side peripheral portion with respect to the central axis, and the restricting portion is located radially outward from the axis of the roller with respect to the central axis,
The rollers are arranged at equal distances from each other in a circumferential direction of the central axis,
a distance between adjacent rollers in a circumferential direction of the central axis at a position where a radial position with respect to the central axis is equal to a pitch circle including the axis of the roller is smaller than a distance between adjacent open spaces in a circumferential direction of the central axis at a position where a radial position with respect to the central axis is equal to the cylindrical surface of the side peripheral portion ,
Retainer. A bearing retainer that retains a plurality of cylindrical rollers having an axis parallel to a central axis around the central axis,
a side peripheral portion that has a rectangular open space in which the rollers are housed along the periphery of the central axis and that forms a cylindrical surface around the central axis;
annular end surface portions disposed radially from both ends of the side circumferential portion in a direction along the central axis;
a restricting portion that is integrally formed as a mutually opposing protrusion around an entire circumference of a radial end portion of the end face portion with respect to the central axis line, and that protrudes to a position closer to the end face of the roller in a direction along the central axis line than a contour end face of the side peripheral portion that defines a contour of the opening space;
having
The end surface portions protrude radially inward with respect to the central axis from both end portions of the side circumferential portion in a direction along the central axis,
The axis of the roller is located radially inward with respect to the central axis of the roller relative to the side peripheral portion,
The restricting portion is located radially inward with respect to the central axis line of the roller,
The cylindrical surface formed by the side peripheral portion has a diameter larger than a pitch circle diameter of the roller arrangement,
The rollers are arranged at equal distances from each other in a circumferential direction of the central axis,
a distance between adjacent rollers in a circumferential direction of the central axis at a position where a radial position with respect to the central axis is equal to a pitch circle including the axis of the roller is smaller than a distance between adjacent open spaces in a circumferential direction of the central axis at a position where a radial position with respect to the central axis is equal to the cylindrical surface of the side peripheral portion ,
Retainer. 3. The cage according to claim 1 or 2,
The end surface portion and the restriction portion are integrally formed by pressing. 3. The cage according to claim 1 or 2,
An end portion of the contour of the opening space as viewed in a radial direction of the central axis and an end portion of the roller visible from the opening space in a direction along the central axis are spaced apart from each other.
Retainer. an outer race having an outer rolling surface that is formed in a circular ring shape and faces inward in a radial direction;
an inner race arranged coaxially with the outer race and having an inner rolling surface facing outward in the radial direction;
A plurality of the rollers rolling on the inner rolling surface and the outer rolling surface;
The cage according to claim 1 or 2, which holds a plurality of the rollers;
having
Bearing. an outer cylinder having an inner peripheral surface on which internal teeth are formed and arranged in a circumferential direction;
an eccentric oscillating gear having external teeth that mesh with the internal teeth of the external cylinder; a crankshaft connected to a drive source to oscillate the eccentric oscillating gear;
a carrier that supports the crankshaft and rotates relative to the outer cylinder;
Equipped with
6. A reducer, wherein the crankshaft is supported by the carrier through the bearing according to claim 5.

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