阅读说明：本技术 旋转体支承用轴、旋转体支承用轴的制造方法及滚子轴承 (Shaft for supporting rotating body, method for manufacturing shaft for supporting rotating body, and roller bearing ) 是由 鹤见纮一郎 于 2019-07-09 设计创作，主要内容包括：本发明提供一种旋转体支承用轴、旋转体支承用轴的制造方法及滚子轴承。圆柱状的旋转体支承用轴支承作为旋转体的行星齿轮,在该旋转体支承用轴的外周面形成有供多个滚子滚动的滚道面,该旋转体支承用轴具有以从轴向的两端面沿轴向凹陷的方式形成的中空部,两端面的中空部中的至少一个中空部的开口被作为密封构件的塞子密封,所述旋转体支承用轴具备：油流入路,用于向被塞子密封的中空部内供给润滑油；及油流出路,从滚道面向被密封的中空部贯通旋转体支承用轴,用于将中空部内的润滑油向滚道面供给。(The invention provides a shaft for supporting a rotating body, a method for manufacturing the shaft for supporting the rotating body, and a roller bearing. A cylindrical rotating body supporting shaft supporting a planetary gear as a rotating body, the rotating body supporting shaft having a hollow portion formed so as to be recessed in an axial direction from both end surfaces in the axial direction, an outer peripheral surface of the rotating body supporting shaft having a raceway surface on which a plurality of rollers roll, an opening of at least one hollow portion of the hollow portion of both end surfaces being sealed by a plug as a sealing member, the rotating body supporting shaft comprising: an oil inflow path for supplying lubricating oil into the hollow portion sealed by the plug; and an oil outflow path that penetrates the sealed hollow portion from the raceway surface to the rotating body support shaft, and supplies the lubricating oil in the hollow portion to the raceway surface.)

1. A cylindrical shaft for supporting a rotating body, the shaft having a rolling surface on which a plurality of rollers roll, the shaft being formed on an outer peripheral surface thereof,

the rotating body supporting shaft has a hollow portion formed so as to be recessed in the axial direction from both end surfaces in the axial direction,

an opening of at least one of the hollow portions of the two end faces is sealed by a sealing member,

the shaft for supporting a rotating body includes:

an oil inflow path for supplying lubricating oil into the hollow portion sealed by the sealing member; and

and an oil outflow path that penetrates the sealed hollow portion from the raceway surface to the shaft for supporting a rotating body, and supplies the lubricating oil in the hollow portion to the raceway surface.

2. The shaft for supporting a rotating body according to claim 1,

the hollow portion has a first hollow portion that opens to one axial direction, a second hollow portion that opens to the other axial direction, and a communication portion that communicates the first hollow portion with the second hollow portion,

the rotating body supporting shaft includes a first plug as the sealing member that seals an opening of the first hollow portion, and a second plug as the sealing member that seals an opening of the second hollow portion.

3. A method for manufacturing a cylindrical shaft for supporting a rotating body, the shaft for supporting a rotating body having a raceway surface on which a plurality of rollers roll formed on an outer peripheral surface thereof, the method comprising:

a hollow portion processing step of forming a hollow portion recessed in the axial direction from both end surfaces in the axial direction by performing reverse extrusion processing on both end portions in the axial direction, respectively;

a sealing step of sealing an opening of at least one of the hollow portions of the two end surfaces with a sealing member; and

and an oil passage forming step of forming an oil inflow passage for supplying lubricating oil into the hollow portion sealed by the sealing member and an oil outflow passage for supplying lubricating oil in the hollow portion to the raceway surface, the oil outflow passage penetrating the shaft for supporting a rotating body from the raceway surface to the sealed hollow portion.

4. A roller bearing comprising:

a cylindrical rotor support shaft; and

a plurality of rollers provided between the shaft for supporting a rotating body and the rotating body, and a retainer for retaining the plurality of rollers,

the rotating body supporting shaft is configured such that a raceway surface on which the plurality of rollers roll is formed on an outer circumferential surface, the rotating body is supported via the plurality of rollers, and,

the shaft for supporting a rotating body has a hollow portion formed so as to be recessed in an axial direction from both end surfaces in the axial direction, an opening of at least one of the hollow portions in the both end surfaces is sealed by a sealing member, and,

the rotating body supporting shaft has an oil inflow path for supplying lubricating oil into the hollow portion sealed by the sealing member, and an oil outflow path for supplying lubricating oil in the hollow portion to the raceway surface through the rotating body supporting shaft from the raceway surface.

Technical Field

The present invention relates to a rotor support shaft that supports a rotor via rollers, a method of manufacturing the rotor support shaft, and a roller bearing.

Background

A shaft for supporting a rotating body is known, which supports the rotating body such as a gear or a roller via a roller. For example, in the planetary gear mechanism, a shaft for supporting a rotating body is used which supports a planetary gear via a roller.

As the shaft for supporting the rotating body, there is a structure in which a hollow portion is formed so as to extend in the axial direction. The hollow portion is formed for reducing the weight of the shaft for supporting the rotating body, and is also used as a part of a lubricant supply path to the roller (see, for example, japanese patent application laid-open No. 2007-198459).

The hollow portion of the shaft for supporting a rotating body is formed by cutting using a drill or the like or forging, but from the viewpoint of manufacturing cost, it is desirable to form the hollow portion by forging. However, when the hollow portion is formed by forging, the work hardening may progress during the forming of the hollow portion, and the forming may not progress. In particular, when the hollow portion is small in diameter and deep, such a problem is likely to occur. When work hardening occurs, the forming can be performed again by annealing and softening, but the manufacturing takes time and labor, and the manufacturing cost also increases.

Disclosure of Invention

An object of the present invention is to provide a rotor support shaft that can be easily manufactured by forging, a method of manufacturing the rotor support shaft, and a roller bearing.

A cylindrical shaft for supporting a rotating body according to an aspect of the present invention is a shaft for supporting a rotating body, the shaft for supporting a rotating body having a cylindrical shape and a raceway surface on which a plurality of rollers roll being formed on an outer peripheral surface of the shaft for supporting a rotating body, the shaft for supporting a rotating body having a hollow portion formed so as to be recessed in an axial direction from both end surfaces in the axial direction, an opening of at least one of the hollow portions in the both end surfaces being sealed by a sealing member, the shaft for supporting a rotating body including: an oil inflow path for supplying lubricating oil into the hollow portion sealed by the sealing member; and an oil outflow path that penetrates the sealed hollow portion from the raceway surface to the shaft for supporting a rotating body, and supplies the lubricating oil in the hollow portion to the raceway surface.

Drawings

The foregoing and other features and advantages of the invention will be apparent from the following description of the preferred embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the several views.

Fig. 1 is an exploded perspective view showing a planetary gear mechanism to which a rotor support shaft according to an embodiment of the present invention is applied.

Fig. 2 is a cross-sectional view of a planetary gear using a rotor support shaft according to an embodiment of the present invention.

Fig. 3 is a flowchart showing the procedure of a method for manufacturing a shaft for supporting a rotating body according to an embodiment of the present invention.

Fig. 4A, 4B, 4C, and 4D are explanatory views for explaining the hollow portion processing step.

Fig. 5 is a cross-sectional view of a planetary gear using a rotor support shaft according to a modification of the present invention.

Detailed Description

An embodiment of the present invention will be described with reference to fig. 1 to 5. The embodiments described below are described as preferable specific examples for carrying out the present invention. Although there are some portions that specifically exemplify various technical matters that are technically preferable, the technical scope of the present invention is not limited to the specific aspects.

Fig. 1 is an exploded perspective view showing a planetary gear mechanism to which a rotor support shaft according to the present embodiment is applied. Fig. 2 is a sectional view of a planetary gear unit using the rotor support shaft according to the present embodiment.

The planetary gear mechanism 11 includes a sun gear 12, an internal gear 13, a plurality of (3 in the present embodiment) planetary gear units 14, and a carrier 16. The sun gear 12 has external teeth 121 on the outer peripheral surface. The internal gear 13 has internal teeth 131 on the inner peripheral surface. The planetary gear unit 14 is disposed between the sun gear 12 and the internal gear 13 and meshes with the external teeth 121 and the internal teeth 131. The planetary gear units 14 are each rotatably (autorotatably) fixed to the carrier 16.

The planetary gear mechanism 11 is used in a transmission for changing the speed of rotation of an output shaft (crankshaft) of an engine, which is a drive source of an automobile, for example. The planetary gear mechanism 11 fixes 1 element of 3 elements of the sun gear 12, the internal gear 13, and the carrier 16 and inputs a torque to the other 1 element, thereby transmitting the input torque to the remaining 1 element while decelerating or increasing the speed. The sliding of each part of the planetary gear mechanism 11 is lubricated by lubricating oil (transmission oil).

The sun gear 12 has a shaft 120 fixed to a central portion thereof and is arranged concentrically with the internal gear 13 and the carrier 16. Each planetary gear unit 14 has a planetary gear 140 and a roller bearing 15. The planetary gear 140 meshes with the external teeth 121 and the internal teeth 131. The roller bearing 15 includes a rotor support shaft 1 of the present invention, and supports the planetary gear 140 as a rotor, and the rotor support shaft 1 is inserted through a shaft hole 141 penetrating a center portion of the planetary gear 140.

The rotor support shaft 1 is formed in a substantially cylindrical shape. The outer peripheral surface of the rotor supporting shaft 1 serves as a raceway surface 2 on which the rollers 150 roll. The rotating body supporting shaft 1 supports the planetary gear 140 as a rotating body via the roller 150. Both axial end portions of the rotor supporting shaft 1 are fixed to shaft fixing holes 161 formed in the carrier 16.

In the present embodiment, the carrier 16 is formed with a pin insertion hole 162 that communicates with the shaft fixing hole 161 and opens radially outward. A pin hole 3 is formed in the rotor supporting shaft 1 at a position facing the pin insertion hole 162, and the rotor supporting shaft 1 is fixed to the carrier 16 by inserting the pin 17 into the pin insertion hole 162 and the pin hole 3. In the present embodiment, the case where the rotor supporting shaft 1 is fixed to the carrier 16 using the pin 17 is shown. However, the present invention is not limited to this, and the rotor supporting shaft 1 may be fixed to the carrier 16 by fastening (deforming and expanding) the end portion of the rotor supporting shaft 1.

The roller bearing 15 smoothes the rotation of the planetary gear 140 with respect to the rotor supporting shaft 1 by the plurality of rollers 150 rolling on the outer peripheral surface (raceway surface 2) of the rotor supporting shaft 1 and the inner peripheral surface 141a of the shaft hole 141 of the planetary gear 140. The roller bearing 15 supports the rotation of the planetary gear 140 while receiving a centrifugal force generated by the revolution of the planetary gear unit 14 about the shaft 120. The roller bearing 15 is also referred to as a radial needle bearing. The roller bearing 15 includes a rotor supporting shaft 1, a plurality of cylindrical rollers 150, and an annular retainer 151 that retains the plurality of rollers 150. The rollers 150 are arranged so that the axial direction thereof coincides with the axial direction of the cage 151, and are arranged at equal intervals in the circumferential direction of the cage 151.

For example, when the internal gear 13 is fixed and the shaft 120 rotates, the rotation of the sun gear 12 rotating together with the shaft 120 is decelerated and output to an output shaft, not shown, spline-fitted to the center hole 160 of the carrier 16. At this time, the planetary gear 140 revolves around the rotation axis O of the shaft 120 and rotates around the central axis C of the rotor support shaft 1.

As the shaft 1 for supporting a rotating body, for example, a steel material can be used. A material composed of SUJ2 (high carbon chromium bearing steel material) or S45C (carbon steel for machine structural use) may be preferably used. Here, the rotor supporting shaft 1 made of SUJ2 having relatively low formability was used. The outer diameter of the rotor support shaft 1 is, for example, about 30mm, and the length of the rotor support shaft 1 is, for example, about 50 mm. Hereinafter, a direction parallel to the central axis C of the rotor support shaft 1 is referred to as an axial direction.

The rotor supporting shaft 1 is formed in a substantially cylindrical shape as a whole, and a hollow portion 4 is formed in a central portion (axial center portion) of a cross section perpendicular to the axial direction so as to be recessed in the axial direction from both end surfaces in the axial direction. That is, the hollow portion 4 is formed so as to be open at both axial end surfaces extending in the axial direction. In the present embodiment, the hollow portion 4 is formed to penetrate the rotor support shaft 1 in the axial direction.

The hollow portion 4 has a first hollow portion 41 that opens to one axial direction (left side in fig. 2), a second hollow portion 42 that opens to the other axial direction (right side in fig. 2), and a communication portion 43 that communicates the first hollow portion 41 and the second hollow portion 42. That is, the hollow portion 4 is formed with the first hollow portion 41, the communicating portion 43, and the second hollow portion 42 in this order from one side to the other side in the axial direction. The first hollow portion 41 and the second hollow portion 42 have substantially the same diameter. The diameter of the communication portion 43 is smaller than the diameters of the first hollow portion 41 and the second hollow portion 42. The diameters and depths (lengths in the axial direction from the end portions) of the first hollow portion 41 and the second hollow portion 42 can be appropriately set according to the required oil permeability of the lubricating oil, the workability of the shaft 1 for supporting a rotating body, and the like.

In the present embodiment, the openings of both ends of the hollow portion 4 of the rotor supporting shaft 1 are sealed by plugs 5 as sealing members. The hollow portion 4 is used as a part of a lubricant supply path to the roller 150, but the openings of the hollow portion 4 are sealed by the plugs 5, respectively, whereby leakage of lubricant from the openings can be suppressed. In the present embodiment, the 2 plugs 5 are provided, which are the first plug 51 for sealing the opening of the first hollow portion 41 and the second plug 52 for sealing the opening of the second hollow portion 42. As the sealing member for sealing the opening of the hollow portion 4, a bolt-like member having a screw groove formed on the outer peripheral surface may be used in addition to the plug 5.

The first and second plugs 51 and 52 are formed in the same shape, and each integrally has a bottom wall 5a and a short cylindrical tube 5 b. The cylindrical portion 5b axially protrudes from the radially outer end of the bottom wall 5 a. The first and second plugs 51 and 52 are press-fitted and fixed into the first and second hollow portions 41 and 42 from the bottom wall 5a side. The opening-side end of the first hollow portion 41 and the opening-side end of the second hollow portion 42 have diameter- enlarged portions 41a and 42a whose diameters are enlarged stepwise. Steps 41b and 42b are formed at the boundaries between the diameter- enlarged portions 41a and 42a and the other portions of the first and second hollow portions 41 and 42. The interference between the first and second stoppers 51 and 52 and the steps 41b and 42b prevents the first and second stoppers 51 and 52 from being pressed excessively when the first and second stoppers 51 and 52 are pressed. The opening-side end portions of the diameter-expanded portions 41a and 42a are tapered so as to be expanded in diameter as they approach the openings. This facilitates insertion of the first and second plugs 51, 52 into the enlarged diameter portions 41a, 42 a.

As the first and second plugs 51 and 52, a cold-rolled steel sheet such as SPCC can be used. The first and second plugs 51 and 52 are also affected by the compatibility with the lubricating oil used or the temperature at which the lubricating oil is used, but a material composed of a resin or a material composed of a resin added to the core may be used. The outer diameter, height, and plate thickness of the first and second plugs 51, 52 may be set as appropriate according to the shape of the end hole, and the first plug 51 and the second plug 52 may have different sizes.

The rotor support shaft 1 further includes an oil inflow passage 6 and an oil outflow passage 7. The oil inflow passage 6 supplies lubricating oil into the hollow portion 4 (defined from the external space) sealed by the first and second plugs 51, 52. The oil outflow passage 7 penetrates the rotor support shaft 1 from the raceway surface 2 to the sealed hollow portion 4, and supplies the lubricant oil in the hollow portion 4 to the raceway surface 2.

One end of the oil inflow passage 6 communicates with an oil passage 163 for supplying lubricating oil formed in the carrier 16, and the other end communicates with the second hollow portion 42 sealed by the second plug 52. In the present embodiment, the oil inflow passage 6 is formed so as to extend in a direction inclined with respect to the axial direction and the radial direction (the communication portion 43 side in the radial direction and the axial direction) so as to avoid the second plug 52. The end of the oil inflow passage 6 on the side of the oil passage 163 is formed with a large diameter portion 6a having a larger diameter than the oil passage 163. Therefore, even when the carrier 16 and the rotor support shaft 1 are misaligned during assembly or the like, the outlet of the oil passage 163 can be made to face the oil inflow passage 6, thereby suppressing leakage of the lubricating oil. The position, the inclination angle, and the inner diameter of the oil inflow passage 6 are not particularly limited, and may be set as appropriate. For example, in the case where the second plug 52 needs to be avoided, such as when the second plug 52 is provided at a position axially outward of the outlet of the oil passage 163, the oil inflow passage 6 may be formed to extend in the radial direction.

The oil outflow passage 7 is formed to extend in the radial direction at the axial center portion of the rotor support shaft 1. In the present embodiment, the oil outflow passage 7 is formed such that one end communicates with the communication portion 43 and the other end opens to the raceway surface 2. However, the present invention is not limited to this, and one end of the oil outflow path 7 may communicate with the first hollow portion 41 or the second hollow portion 42. The oil outflow passage 7 may extend in a direction slightly inclined with respect to the radial direction. The arrangement of the opening portion of the oil outflow passage 7 on the roller 150 side can be appropriately set according to the positional relationship with the roller 150, the oil permeability, and the like.

The lubricant oil is supplied from the oil passage 163 to the rotor supporting shaft 1 by the centrifugal force generated when the carrier 16 rotates, and is introduced into the hollow portion 4 through the oil inflow passage 6. The lubricant oil introduced into the hollow portion 4 is supplied to the raceway surface 2 through the oil outflow passage 7 by a centrifugal force generated when the carrier 16 rotates, and lubricates the rollers 150.

Fig. 3 is a flowchart showing the procedure of the method for manufacturing the shaft for supporting a rotating body according to the present embodiment. As shown in fig. 3, in the method for manufacturing a shaft for supporting a rotating body according to the present embodiment, first, in step S1, a preparation step of preparing a base material of the shaft 1 for supporting a rotating body is performed. When the shaft 1 for supporting a rotating body is formed of a relatively low-formability material such as SUJ2, a cylindrical base material having a size relatively close to the product size (having an outer diameter slightly larger than the product size) can be prepared.

Then, in step S2, a hollow portion processing step of forming the hollow portion 4 by forging processing is performed. In the present embodiment, in the hollow portion processing step, both end portions in the axial direction of the base material are subjected to backward extrusion processing, respectively. Thus, the hollow portion 4 is formed so as to be recessed in the axial direction from both end surfaces in the axial direction.

Specifically, first, as shown in fig. 4A, the base material 101 is set to the bottomed cylindrical lower die 100. As shown in fig. 4B, the first hollow portion 41 is formed by backward extrusion processing by pushing the punch 102 into the center of one end of the base material 101. Then, as shown in fig. 4C, the base material 101 is set on the lower die 100 with the end on which the first hollow portion 41 is not formed as the opening side. The second hollow portion 42 is formed by backward extrusion processing by pushing a punch 102 into the center of the other end of the base material 101. Here, a case where the backward extrusion processing is performed on one end of the base material 101 and then the backward extrusion processing is performed on the other end of the base material will be described. However, the present invention is not limited to this, and both ends of the base material 101 may be simultaneously subjected to the backward extrusion processing. In the molding of the second hollow portion 42, in order to avoid deformation of the first hollow portion 41, the second hollow portion 42 may be molded with a spacer inserted into the first hollow portion 41.

Then, as shown in fig. 4D, the communication portion 43 is formed by penetrating the wall between the first hollow portion 41 and the second hollow portion 42 by machining (drilling) with the drill 103. Thereby, the first hollow portion 41 and the second hollow portion 42 communicate with each other via the communication portion 43, forming the hollow portion 4. Further, the communication portion 43 is not limited to the machining by the drill 103, and may be formed by blanking, for example. The communicating portion 43 may be processed by an oil passage forming step in step S3 described later. By this step, a workpiece subjected to the hollow portion processing step can be obtained.

After the hollow portion processing step of step S2 is performed, an oil passage forming step is performed on the workpiece subjected to the hollow portion processing step in step S3. In the oil passage forming step, the oil inflow passage 6, the oil outflow passage 7, and the pin hole 3 are formed by machining (drilling) using a drill. By this step, a workpiece subjected to the oil passage forming step can be obtained.

Then, in step S4, a hardening step is performed on the workpiece subjected to the oil passage forming step. In the hardening step, the workpiece subjected to the oil passage forming step is quenched and annealed, or carburized, and quenched and annealed at a carburizing temperature. In the hardening step, carbonitriding may be performed, quenching and annealing may be performed from the carbonitriding temperature, or annealing and high-frequency heating may be combined. At least the surface of the roller 150 is hardened so that the hardness thereof is in the range of 58HRc to 64 HRc. By this step, a work subjected to the hardening step can be obtained.

Then, in step S5, a finishing process is performed on the workpiece subjected to the hardening process. In the finishing process, the workpiece subjected to the hardening process is formed into the size, shape, and surface roughness of the drawing, and thus a desired portion is cut or polished. By this step, a workpiece subjected to the finishing step can be obtained.

Then, in step S6, a sealing process is performed on the workpiece subjected to the finishing process. In the sealing step, the plugs 5, which are sealing members, seal both openings of the hollow portion 4 on both end surfaces of the workpiece subjected to the finishing step. In the sealing step, the first plug 51 is press-fitted from the opening of the first hollow portion 41, the second plug 52 is press-fitted from the opening of the second hollow portion 42, and both openings of the hollow portion 4 are sealed by the plugs 5. As described above, the rotor support shaft 1 can be obtained.

In the present embodiment, the case where the hollow portion 4 penetrates the rotor support shaft 1 in the axial direction is described. However, the hollow portion 4 may be opened to both end surfaces in the axial direction, and may not penetrate the rotor support shaft 1 in the axial direction as shown in fig. 5. In other words, the communicating portion 43 may be omitted, and the hollow portion 4 is constituted by the first hollow portion 41 and the second hollow portion 42. In the example of fig. 5, the oil inflow passage 6 and the oil outflow passage 7 communicate with the second hollow portion 42. The second hollow portion 42 forms a part of the lubricating oil supply passage. Therefore, the first plug 51 may be omitted as long as only the opening of the second hollow portion 42, which is a part of the lubricating oil supply path, is sealed by the second plug 52. In this case, the inner peripheral surface 44 of the first hollow portion 41 on the side where the first plug 51 is omitted may be a cylindrical surface having a single inner diameter.

As described above, the rotor supporting shaft 1 of the present embodiment includes the hollow portion 4 formed to be recessed in the axial direction from both end surfaces in the axial direction. The opening of at least one hollow portion 4 of the hollow portions 4 of the both end faces is sealed by a plug 5. The rotor support shaft 1 includes an oil inflow passage 6 and an oil outflow passage 7. The oil inflow passage 6 supplies lubricating oil into the hollow portion 4 sealed by the plug 5. The oil outflow passage 7 penetrates the rotor support shaft 1 from the raceway surface 2 to the sealed hollow portion 4, and supplies the lubricant oil in the hollow portion 4 to the raceway surface 2.

Thus, the hollow portion 4, which is lightweight and used as a part of the lubricating oil supply passage, can be formed by performing reverse extrusion processing on both axial end portions. As a result, the amount of plastic deformation per one working can be suppressed to be smaller than in the case where the backward extrusion is performed only on one end portion in the axial direction. Thus, the rotor support shaft 1 can be manufactured easily and at low cost by forging. That is, according to the present embodiment, even when the small-diameter and deep hollow portion 4 is formed, the conventional annealing step other than work hardening is not required, and the manufacturing labor, time, and manufacturing cost can be significantly reduced.

Since the amount of plastic deformation per one working is reduced, the load applied to the forging die (the lower die 100 or the punch 102) can be suppressed, and therefore the life of the forging die can be extended. Further, as compared with the case where the backward extrusion processing is performed only on one end portion in the axial direction as in the related art, the deeper hollow portion 4 can be formed more finely, and the size range of the applicable hollow portion 4 can be expanded.

The present invention has been described above based on the embodiments, but these embodiments do not limit the invention of the claims. Note that all combinations of the features described in the embodiments are not essential to the means for solving the problem of the invention.

The present invention can be suitably modified and implemented within a range not departing from the gist thereof. For example, in the above-described embodiment, the rotating body supporting shaft 1 used in the planetary gear mechanism 11 has been described. However, the use of the rotating body supporting shaft 1 is not limited thereto, and it can be used for supporting various rotating bodies such as rollers and links via the rollers 150.

In the above-described embodiment, the case where the rotor support shaft 1 is manufactured by cold forging has been described, but the present invention is not limited to this, and may be applied to warm forging or hot forging.

Further, a cylindrical outer ring (cage) may be used between the planetary gear 140 and the plurality of rollers 150 in the above-described embodiment. In this case, the entirety of the rotor supporting shaft 1, the rollers 150, the cage 151, and the outer ring constitutes a roller bearing. In this roller bearing, for example, the planetary gear 140 as a rotating body is disposed on the outer peripheral side of the outer ring, whereby the same configuration as that of the planetary gear unit 14 in the above-described embodiment can be realized. In this roller bearing, the member disposed on the outer peripheral side of the outer ring does not need to be a rotating body, and the outer ring may be disposed in a holding hole of a non-rotating member such as a housing to fix the rotating body to the rotating body supporting shaft 1.

According to the present invention, it is possible to provide a rotor support shaft that can be easily manufactured by forging, a method of manufacturing the rotor support shaft, and a roller bearing.