JP2020139612A - Roller bearing and method of manufacturing the same - Google Patents

Abstract

To provide a roller bearing capable of inhibiting a cage or a roller from being broken when the roller is incorporated, and a method of manufacturing the same.SOLUTION: In a method of manufacturing a roller bearing, firstly, a cage is prepared. A plurality of rollers for being incorporated in the cage are prepared. The plurality of rollers are incorporated in the cage. A step of preparing the cage includes a step of thermally treating a cage body part constituting the cage. The step of thermally treating the cage body part is carried out in a state in which the plurality of rollers are incorporated in the cage body part, after the plurality of rollers are incorporated.SELECTED DRAWING: Figure 1

Description

The present invention relates to a roller bearing and a method for manufacturing the roller bearing, and more particularly to a roller bearing composed of only a cage and a plurality of rollers and a method for manufacturing the roller bearing.

Planetary bearings included in so-called automatic transmissions and large-end bearings for engine connecting rods are roller bearings that consist only of a cage and multiple rollers (hereinafter, these are sometimes referred to as rollers with cages). There is). The roller bearing rotates while revolving. Therefore, there is a concern that the outer diameter surface of the cage constituting the roller bearing may be worn. In recent years, the viscosity of the lubricating oil contained in the member in which the roller bearing is used has been reduced and the amount has been reduced. As a result, there is a concern that the outer diameter surface of the above-mentioned cage will be further worn. For this reason, the usage environment for roller bearings is becoming more and more severe for roller bearings.

As a countermeasure for this, for example, as in JP-A-2004-218761 (Patent Document 1), it is conceivable to set the hardness of the surface of the cage to Hv400 or more and 700 or less.

Japanese Unexamined Patent Publication No. 2004-218761

Here, when manufacturing a roller bearing, a plurality of rollers are incorporated in the cage. At this time, the plurality of rollers are pushed into the cage by utilizing the elastic deformation of the column portion due to the contact of the plurality of rollers with the column portion forming the cage. As in JP-A-2004-218761, if the rollers are installed with the surface hardness of the cage increased to cope with severe lubrication conditions, scratches may occur on the rollers or the rollers in the cage may be damaged. There is a risk of causing problems in the parts that come into contact.

The present invention has been made in view of the above problems. An object of the present invention is to provide a roller bearing and a method for manufacturing the roller bearing, which prevents a failure of the cage during roller assembly.

In the method for manufacturing a roller bearing according to the present invention, a cage is first prepared. Multiple rollers to be incorporated into the cage are prepared. Multiple rollers are incorporated into the cage. The step of preparing the cage includes a step of heat-treating the cage main body constituting the cage. The step of heat-treating the cage main body is performed in a state where the plurality of rollers are incorporated into the cage main body after the plurality of rollers are incorporated.

The roller bearing according to the present invention includes a cage and a plurality of rollers. Multiple rollers are incorporated into the cage. A plurality of cages extending in the extending direction so as to connect a pair of annular portions arranged at intervals in the extending direction and one annular portion and the other annular portion of the pair of annular portions. Including the pillar part of. An oxide film is formed on the surface of a plurality of rollers.

According to the present invention, the step of heat-treating the cage main body is performed after the step of incorporating a plurality of rollers. Therefore, damage to the cage main body and the plurality of rollers in the process of incorporating the plurality of rollers can be suppressed.

It is a flowchart which shows the manufacturing process of the cage which comprises the roller bearing of this embodiment. It is the schematic which shows the steel material used in the manufacturing process of the cage in this embodiment. It is the schematic which shows the process (S100) of FIG. It is the schematic which shows the process (S200) of FIG. It is the schematic which shows the process (S400) of FIG. It is the schematic which shows the process (S500) of FIG. It is the schematic which shows the process (S550) of FIG. It is the schematic which shows the roller bearing finally obtained by the step (S600) of FIG. It is a flowchart which shows the manufacturing process of the roller which comprises the roller bearing of this embodiment. It is a flowchart which shows the manufacturing process of the cage which comprises the roller bearing of the comparative example. It is a schematic diagram which shows the process (S650) of FIG. It is a vertical cross-sectional view of the two-cycle engine using the roller bearing of this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First, a method for manufacturing a roller bearing according to the present embodiment will be described with reference to FIGS. 1 to 9.

<Manufacturing method of roller bearings>
The roller bearing of the present embodiment is a roller bearing (roller with a cage) composed of only a cage and a plurality of rollers. FIG. 1 is a flowchart showing a manufacturing process of a cage constituting the roller bearing of the present embodiment. With reference to FIG. 1, in the method for manufacturing a roller bearing of the present embodiment, a so-called weld cage is manufactured. That is, after performing necessary processing such as forming a pocket using a strip-shaped steel plate or the like, the steel plate is rolled into a tubular shape, and one end and the other end in the rounded direction are welded. As described above, a tubular cage is formed.

FIG. 2 is a schematic view showing a steel material used in the manufacturing process of the cage according to the present embodiment. With reference to FIG. 2, the cage included in the roller bearing of the present embodiment is formed of a steel plate as a material. Since this steel sheet is initially strip-shaped, it is in a state called strip steel 1.

FIG. 3 is a schematic view showing the step (S100) of FIG. With reference to FIG. 1, a forming step (S100) is performed on the prepared steel strip 1. Specifically, with reference to FIG. 3, the central portion of the strip steel 1 in the width direction is bent in a substantially V shape so that the upper side of the drawing is recessed. In other words, the strip steel 1 is bent in a substantially V shape so as to be convex toward the side opposite to the main surface on the illustrated side, that is, toward the lower main surface in FIG. Here, the V-shape is a shape that is bent so that a step is provided in the cage main body so that the outer diameter surface side becomes a convex shape when the strip steel 1 is bent into a tubular shape as described later. is there. That is, when the strip steel 1 is viewed from the front side (lower left side in FIG. 3) in the extending direction of the strip steel 1 in FIG. 3, the strip steel 1 is processed so as to have a concave shape in the central portion in the left-right direction. .. Such processing is performed by pressing the steel strip 1 from the side that later becomes the outer diameter surface to the side that later becomes the inner diameter surface with a generally known press.

FIG. 4 is a schematic view showing the step (S200) of FIG. With reference to FIG. 1, a pocket punching process (S200) is performed on the strip steel 1 that has undergone the forming step. Specifically, with reference to FIG. 4, the strip steel 1 penetrates from one main surface of the rectangular main surface constituting the strip shape of the strip steel 1 to the other main surface on the opposite side. The pocket 3 which is such an opening is formed. The pocket 3 preferably has a rectangular shape when the rectangular main surface of the strip steel 1 is viewed in a plan view. It is preferable that the pocket 3 is formed so as to extend in a manner intersecting with the steel strip 1 by extending long in the width direction intersecting the extending direction of the main surface of the steel strip 1. The steel strip 1 has a shape that is bent by the forming step (S100). A pocket 3 is formed in the steel strip 1 having such a shape. The pocket 3 formed for this purpose is bent so as to have a concave shape at the central portion in the extending direction.

With reference to FIG. 1, a cutting step (S300) is then performed on the strip steel 1. This is a step of cutting the strip steel 1 by a required length in the extending direction of the strip steel 1 extending from the upper right side to the lower left side of FIG. Specifically, the strip steel 1 is cut off so that when the strip steel 1 is bent into a tubular shape, the length of the annular circumference forming the cylinder remains.

FIG. 5 is a schematic view showing the step (S400) of FIG. With reference to FIG. 1, a bending step (S400) is performed on the strip steel 1 that has undergone the forming step (S100), the pocket punching step (S200), and the cutting step (S300). Specifically, the strip steel 1 is bent so as to have a tubular shape, for example, a cylindrical shape so that its extending direction forms an annular shape. By being bent in this way, the steel strip 1 can form a cage main body portion that constitutes the cage main body. Further, one end portion 1E in the direction in which the steel strip 1 is bent to form an annular shape of the cage main body portion and the other end portion 1F on the opposite side thereof face each other so as to be adjacent to each other. Further, in the widthwise end portion of the strip steel 1, that is, in the region on the widthwise end side of the strip steel 1 than the end portion of the pocket 3 in the extending direction of the pocket 3 of the cage main body formed. As the annular portion 5, a pair of annular portions of one annular portion 5A and the other annular portion 5B on the opposite side are formed. One annular portion 5A and the other annular portion 5B are arranged at intervals from each other in the extending direction of the cage main body portion.

FIG. 6 is a schematic view showing the step (S500) of FIG. With reference to FIGS. 1 and 6, a joining step in which one end 1E of the strip steel 1 bent in the step (S400) and the other end 1F are joined (welded here). (S500) is done. As a result, the strip steel 1 is formed as a tubular cage main body 4. The cage main body 4 includes a plurality of pillars 6 as the cage main body 4 between a pair of pockets 3 adjacent to each other in a direction intersecting the extending direction of the plurality of pockets 3. One annular portion 5A is formed on one end side of each of the extending directions of the plurality of pillar portions 6, and the other annular portion 5B is formed on the other end side in the extending direction. That is, the plurality of pillar portions 6 extend in the extending direction of the cage main body portion 4 so as to connect one annular portion 5A and the other annular portion 5B.

The main body surface 7 as the surface of the cage main body 4 has an outer diameter surface 7A, an inner diameter surface 7B, and a pair of annular end faces (axial end faces) 7C and 7D. The pre-heat treatment cage 10A having the above configuration is formed. The outer diameter surface 7A is a portion of the main surface of the steel strip 1 facing the outside of the pre-heat treatment cage 10A in the tubular cage main body 4. The inner diameter surface 7B is a portion of the main surface of the steel strip 1 facing the inside of the pre-heat treatment cage 10A in the tubular cage main body 4. The annular end face 7C is an end face in the width direction of the steel strip 1 on the one side of the annular portion 5A. The annular end face 7D is the widthwise end face of the steel strip 1 on the other annular portion 5B side.

FIG. 7 is a schematic view showing the step (S550) of FIG. With reference to FIGS. 1 and 7, a roller incorporating step (S550) is performed in which a plurality of rollers 8 are incorporated into the cage main body 4 formed by the welding step (S500) of FIG. The roller 8 is preferably a so-called needle-shaped roller whose width in the extending direction is longer than the width of the cross section intersecting in the extending direction, but the roller 8 is not limited to this and may be a cylindrical roller. The roller 8 is incorporated into the cage main body 4 of the pre-heat treatment cage 10A by moving in the direction M indicated by the arrow in the drawing. One roller 8 is incorporated in each pocket 3.

FIG. 8 is a schematic view showing a roller bearing finally obtained by the step (S600) of FIG. With reference to FIGS. 1 and 8, the heat treatment step (S600) is then performed. Specifically, after the step of incorporating the plurality of rollers 8 (S550), the cage main body 4 is heat-treated with the plurality of rollers 8 incorporated into the cage main body 4. In other words, after the step of incorporating the plurality of rollers 8 (S550), the cage main body 4 is heat-treated together with the plurality of rollers 8. As the heat treatment, one of a soft nitriding treatment, a carburizing and quenching treatment, and a carburizing and nitriding treatment is performed. However, it is more preferable that the carburizing nitriding treatment is performed here.

The hardness of the surface of the cage body 4 after the step (S600) of heat-treating the cage body 4 is preferably Hv650 or more and 800 or less. Among them, the hardness of the surface of the cage main body 4 is more preferably Hv650 or more and 750 or less, and further preferably Hv650 or more and 700 or less.

After the step (S600) of heat-treating the cage main body 4, the nitrogen concentration in the surface layer of the cage main body 4, that is, the region adjacent to the surface of the cage main body 4 is 0.3% by mass or more. preferable. Here, the surface layer (region adjacent to the surface) is a region closest to the surface, and specifically, for example, a region having a depth of 5 μm or less from the surface (or a depth of 4 μm or less from the surface). is there. Among them, the nitrogen concentration is more preferably 0.3% by mass or more and 1.0% by mass or less.

After the step (S600) of heat-treating the cage main body 4, the nitrogen concentration in the surface layer of the plurality of rollers 8, that is, the region adjacent to the surface of the plurality of rollers 8 is preferably 0.3% by mass or more. Similar to the cage body 4, the surface layer (region adjacent to the surface) of the roller 8 is the region closest to the surface, and specifically, for example, the depth from the surface is within 5 μm (or). It is a region where the depth from the surface is within 4 μm). Among them, the nitrogen concentration is more preferably 0.3% by mass or more and 1.0% by mass or less.

As described above, the cage main body 4 becomes the cage 10B after the heat treatment. In this way, a roller bearing 100C having a structure in which a plurality of heat-treated rollers 8 are incorporated is formed in the heat-treated cage 10B. In the roller bearing 100C, an oxide film is formed (that is, arranged) not only on the surface of the cage 10B after the heat treatment but also on the surface of the plurality of rollers 8.

FIG. 9 is a flowchart showing a manufacturing process of rollers constituting the roller bearing of the present embodiment. A plurality of rollers are prepared to form the roller bearing 100C. With reference to FIG. 9, in the manufacturing process of the roller of the present embodiment, first, a coil material cutting step (S10) is performed. Specifically, the coil material as a material for forming the rollers is cut by a required amount (S10). For example, in the case of a needle-shaped roller, a coil material having a width corresponding to the width of a cross section intersecting the extending direction of the roller to be formed is prepared. Further, the coil material is cut in the length direction so as to have a dimension corresponding to the length in the extending direction of the needle-shaped roller.

Next, the end face forming step (S20) is performed. Specifically, the end face of the cut coil material in the length direction is formed so as to have the shape of the end face of the roller to be formed. Next, the heat treatment step (S30) is performed at a plurality of rollers. As a result, similar to the cage main body 4 described above, the individual members to be rolled are also heat-treated. Next, a grinding step (S40) is performed on the surfaces of the plurality of rollers that have been heat-treated, and a polishing step (S50) is performed. As a result, the surface of the heat-treated surface is scraped. Therefore, in the completed state, the oxide film formed on the surface of the roller 8 is removed in the heat treatment step (S30) of FIG. The step of incorporating the plurality of rollers 8 into the cage (retainer main body 4) is performed after the step of grinding the surface of the rollers 8. In this way, the roller 8 is incorporated into the preheat treatment cage 10A when it is not covered with the oxide film. However, in the finally formed roller bearing 100C (see FIG. 8), an oxide film is formed on the surfaces of the plurality of rollers 8. This is because, after the step of heat-treating the cage main body 4 by the heat treatment step (S600) of FIG. 1, a plurality of rollers 8 are also heat-treated, and an oxide film is formed on their surfaces.

<Comparative examples and their issues>
Next, with reference to FIGS. 10 to 11, a method for manufacturing a roller bearing as a comparative example without using the present embodiment will be described. FIG. 10 is a flowchart showing a manufacturing process of a cage constituting a roller bearing of a comparative example. With reference to FIG. 10, a so-called weld cage is also manufactured in the roller bearing manufacturing method of the comparative example. Since the manufacturing method shown in FIG. 10 is basically the same as the manufacturing method shown in FIG. 1, the description of the same parts will not be repeated. However, as shown in FIG. 10, in the comparative example, the roller assembling step (S650) is performed after the heat treatment step (S600) is performed on the cage main body 4. In this respect, the manufacturing method of FIG. 10 is different from the manufacturing method of FIG. 1 in which the heat treatment step (S600) is performed after the roller incorporating step (S550).

FIG. 11 is a schematic view showing the process (S650) of FIG. With reference to FIGS. 10 and 11, a plurality of rollers 8 are incorporated into the cage main body 4 of the post-heat treatment cage 10C after the heat treatment step (S600) is completed. It should be noted that no oxide film is formed on the surface of the roller 8 incorporated here. At this time, similarly to the step of FIG. 7, the roller 8 is incorporated into the cage main body 4 of the cage 10C after the heat treatment by moving in the direction M indicated by the arrow in the drawing. Note that FIG. 11 shows each member formed by the comparative example. Therefore, in FIG. 11, for example, a reference number in which one 0 is added next to the reference number in FIGS. 7 and 8 is added to the same member as each member formed by the present embodiment of FIGS. 7 and 8. Is attached. For example, the member corresponding to the roller "8" in FIG. 7 is described as the roller "80" in FIG.

With reference to FIG. 10 again, the roller bearing 100D is formed by incorporating the plurality of rollers 8 into the cage 10C after the heat treatment.

As shown in FIG. 9, the oxide film on the surface of the roller 8 is removed by a grinding step and a polishing step after the heat treatment. Therefore, no oxide film is formed on the surfaces of the plurality of rollers 8 of the roller bearing 100D. This point is structurally different from the roller bearing 100C of FIG. 8 in which an oxide film is formed on the surface of the roller 8. Further, the post-heat treatment cage 10C in FIG. 11 is harder than the pre-heat treatment cage 10A. Therefore, when the rollers 8 are incorporated into the cage 10C after the heat treatment, the roller stopper portion of the cage 10C after the heat treatment may be cracked or chipped, or the surface of the rollers 8 may be scratched. Even if the hardness of the surface of the cage main body 4 is increased to, for example, Hv400 or more and 700 or less in the heat treatment step (S600), it cannot be said that the hardness is sufficient to suppress the wear of the outer diameter surface of the cage. That is, even if such a treatment is performed, if the cage is used in a harsh environment, its outer diameter surface may be worn.

When the roller bearing is formed by using the manufacturing method of the comparative example in this way, the finally obtained roller with a cage has cracks or chips in the roller stopper portion of the cage 10C after the heat treatment, or the roller 8 The surface may be scratched. There is such a problem to be solved when the cage is attached.

<Action effect>
This embodiment is designed to solve the problems of the above comparative example. Hereinafter, although partially overlapping with the above description, the configuration and action / effect of the present embodiment will be described.

In the method for manufacturing a roller bearing of the present embodiment, a cage (10A) is prepared. A plurality of rollers (8) to be incorporated in the cage (10A) are prepared. A plurality of rollers (8) are incorporated in the cage (10A). The step of preparing the cage (10A) includes a step of heat-treating the cage main body (4) constituting the cage (10A). The step of heat-treating the cage main body (4) is performed in a state where the plurality of rollers (8) are incorporated into the cage main body (4) after the step of incorporating the plurality of rollers (8).

In this way, the hardness of the pre-heat treatment cage 10A is lower than that of the post-heat treatment cage 10C when the rollers 8 are incorporated into the pre-heat treatment cage 10A. Therefore, it is possible to suppress the occurrence of the above-mentioned cracks, chips and scratches that may occur when the rollers 8 are incorporated into the cage 10C after a hard heat treatment.

Further, the pre-heat treatment cage 10A and the rollers 8 are heat-treated after the rollers 8 are incorporated, and there is no step in which the rollers 8 are incorporated after the heat treatment. Therefore, the cage 10B after the heat treatment can be hardened so as to have a higher hardness in the heat treatment step than in the case where the rollers 8 are incorporated after the heat treatment as in the comparative example. Thereby, the wear resistance of the cage 10B after the heat treatment can be further improved.

In the above manufacturing method, it is preferable that an oxide film is formed on the surfaces of the plurality of rollers (8) after the step of heat-treating the cage main body (4). That is, by heat-treating the cage main body 4 and the rollers 8 incorporated therein together, a very thin oxide film is formed not only on the surface of the cage main body 4 but also on the surface of the rollers 8. As a result, the surface of the roller 8 which is originally mirror-like is colored by the oxide film. That is, the difference in the surface color of the rollers 8 makes it possible to distinguish between the roller bearing 100C manufactured by the procedure of the present embodiment and the roller bearing 100D manufactured by the procedure of the comparative example. The surface of the roller 8 of the roller bearing 100C has a dull color due to the formation of an oxide film, whereas the surface of the roller 8 of the roller bearing 100D has no oxide film formed (removed by grinding or the like). ) This is because it has a mirror surface shape.

During the heat treatment of the cage main body 4, the surface of the incorporated roller 8 is colored. Therefore, it is not necessary to add a separate step for coloring the surface of the roller 8. Roller bearings 100C and 100D that can be easily identified between a plurality of lots having different process sequences can be formed by using the heat treatment step that is naturally performed when manufacturing the roller bearing as it is. Since no additional process is required, the roller bearing 100C can be manufactured at a lower cost.

That is, in the above manufacturing method, the step of preparing the plurality of rollers (8) may include a step of heat-treating the plurality of rollers (8) and a step of grinding the surface of the plurality of rollers (8) that have been heat-treated. Good. The step of incorporating the plurality of rollers (8) may be performed after the step of grinding the surface. In this way, the roller bearing 100C is formed by incorporating the roller 8 and then heat-treated as in the present embodiment, and the roller 8 is formed by incorporating the roller 8 after the heat treatment of the cage as in the comparative example. It is possible to distinguish it from the roller bearing 100D. The surface of the roller 8 of the roller bearing 100C has a dull color due to the formation of an oxide film, whereas the surface of the roller 8 of the roller bearing 100D has no oxide film formed (removed by grinding or the like). ) This is because it has a mirror surface shape.

In the above manufacturing method, the hardness of the surface of the cage main body (4) after the step of heat-treating the cage main body (4) is preferably Hv650 or more and 800 or less. This hardness is such that if a roller 8 is incorporated into the cage 10B after heat treatment to form a roller bearing (roller with a cage), cracks, chips, and scratches are likely to be formed. However, in the present embodiment in which the roller 8 is incorporated in the preheat treatment cage 10A and then heat-treated to form the roller bearing 100C (see FIG. 8), the surface hardness after the heat treatment is controlled as described above to perform the heat treatment. The wear resistance of the back cage 10B can be further improved.

In the above manufacturing method, the nitrogen concentration of the surface layer of the cage body (4) and the nitrogen concentration of the surface layer of the plurality of rollers after the step of heat-treating the cage body (4) are 0.3% by mass or more. It is preferable to have. By doing so, the wear resistance of the cage main body 4 can be improved. Further, in this way, it is possible to suppress a problem that peeling occurs on the surface of the roller 8 when the roller bearing is poorly lubricated. In addition, the life of the roller 8 can be extended when used in an environment containing foreign substances.

In the above manufacturing method, it is preferable that the carburizing nitriding treatment is performed in the step of heat-treating the cage main body (4). In this way, the nitrided layer can be formed not only in the cage main body 4 but also in the region adjacent to the surface of the roller 8 incorporated therein.

The roller bearing (100C) of the present embodiment includes a cage (10B) and a plurality of rollers (8) incorporated in the cage (10B). The cage (10B) has an annular portion (5A) of a pair of annular portions (5: 5A, 5B) and a pair of annular portions (5A, 5B) arranged at intervals in the extending direction. ) And a plurality of pillars (6) extending in the extending direction so as to connect the other annular portion (5B). An oxide film is formed on the surface of the plurality of rollers (8).

The roller bearing 100C is formed by performing heat treatment after the rollers 8 are incorporated in the pre-heat treatment cage 10A as in the present embodiment. This can be easily determined by visually recognizing the oxide film formed on the surface of the roller 8. As in the comparative example, the roller bearing 100D in which the roller 8 is incorporated in the cage 10B after the heat treatment has a mirror-like surface with the surface of the roller 8 incorporated, so that it can be visually recognized as the roller bearing 100C of the present embodiment. This is because it can be easily discriminated by comparison.

<Measurement method>
In the present embodiment, the nitrogen concentration in the steel material such as the cage body 4 described above, particularly in the region (surface layer) adjacent to the surface, is determined by line analysis of EPMA (Electron Probe Micro Analyzer) or emission spectroscopic analysis. Be measured. Further, the hardness of the surface of the cage main body 4 is preferably measured by a micro Vickers hardness tester.

<Example of use of this embodiment>
The roller bearing manufacturing method of the present embodiment and the roller bearing formed by the manufacturing method are used for a planetary gear mechanism and a bearing for a large end of an engine connecting rod. Hereinafter, an example of application of the bearing for the large end of the connecting rod of the engine will be described with reference to FIG.

FIG. 12 is a vertical sectional view of a two-cycle engine using the roller bearing of the present embodiment. With reference to FIG. 12, the two-stroke engine has a piston 20, a connecting rod 21, and a crankshaft 22. The piston 20 makes a linear motion by combustion. The connecting rod 21 is an abbreviation for a connecting rod, and converts a linear reciprocating motion into a rotary motion. The crankshaft 22 outputs a rotary motion. The crankshaft 22 rotates about the rotation center shaft 23, and the balance of rotation is maintained by the balance weight 24.

The connecting rod 21 is provided with a large end portion 25 and a small end portion 26. The large end portion 25 is provided below the linear rod body. The small end portion 26 is provided above the linear rod body. The crankshaft 22 is rotatably supported via the roller bearing 100C according to the present embodiment, which is attached to the engaging hole of the large end portion 25 of the connecting rod 21.

The above-mentioned features may be applied so as to be appropriately combined within a technically consistent range.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Connecting rod, 1E One end, 1F Other end, 2, 3 pockets, 4 Cage body, 5 Ring, 5A One ring, 5B The other ring, 6 Pillar, 7 Body Surface, 7A outer diameter surface, 7B inner diameter surface, 7C, 7D annular end surface, 10A pre-heat treatment cage, 10B, 10C post-heat treatment cage, 17 intake pipe, 17a intake valve, 18a exhaust valve, 19 combustion chamber, 20 pistons, 21 connecting rod, 22 crankshaft, 23 rotation center shaft, 24 balance weight, 100C roller bearing.

Claims (5)

The process of preparing the cage and
The process of preparing a plurality of rollers to be incorporated in the cage and
The cage is provided with a step of incorporating the plurality of rollers into the cage.
The step of preparing the cage includes a step of heat-treating the cage main body constituting the cage.
A method for manufacturing a roller bearing, wherein the step of heat-treating the cage main body is performed in a state where the plurality of rollers are incorporated in the cage main body after the step of incorporating the plurality of rollers. The method for manufacturing a roller bearing according to claim 1, wherein an oxide film is formed on the surfaces of the plurality of rollers after the step of heat-treating the cage main body. The method for manufacturing a roller bearing according to claim 1 or 2, wherein the hardness of the surface of the cage main body after the step of heat-treating the cage main body is Hv650 or more and 800 or less. The nitrogen concentration of the surface layer of the cage body and the nitrogen concentration of the surface layer of the plurality of rollers after the step of heat-treating the cage body is 0.3% by mass or more, claim 1 to 3. The method for manufacturing a roller bearing according to any one item. Cage and
With multiple rollers built into the cage,
The cage is arranged in the extending direction so as to connect a pair of annular portions arranged at intervals in the extending direction and one annular portion and the other annular portion of the pair of annular portions. Including multiple pillars extending to
A roller bearing in which an oxide film is formed on the surfaces of the plurality of rollers.