JP2021110385A - Rolling bearing and manufacturing method of the same - Google Patents

Abstract

To provide a manufacturing method which uses a simple masking method to perform coating process to multiple rolling bearings collectively and thereby improve productivity of the rolling bearings having insulation performance.SOLUTION: A rolling bearing 10 includes: an inner ring 12; an outer ring 11; rolling elements 13; and a retainer 14. The outer ring 11 includes: an outer ring body 11a having conductivity; and an insulation member 15 having insulation quality. The insulation member 15 is integrally formed with an outer peripheral surface 16 of the outer ring body 11a and one 17a of axial side surfaces.SELECTED DRAWING: Figure 1

Description

The present invention relates to a rolling bearing, particularly a rolling bearing used in an electric motor, and a method for manufacturing the rolling bearing.

The rotor of an electric motor is supported by rolling bearings at both ends in the axial direction. When the motor is driven by an inverter, a potential difference may occur between the inner and outer rings of the rolling bearing. In rolling bearings, the outer ring, inner ring, and ball are made of steel, so if this potential difference becomes large and exceeds the breakdown voltage of the oil film of the enclosed oil or grease, between the inner and outer rings and the ball. Discharges through the oil film and current flows. In this case, damage called electrolytic corrosion occurs on the raceway surface on which the ball rolls, causing abnormal noise during rotation of the rolling bearing, and further damage to the raceway surface may shorten the life of the rolling bearing. ..
In Patent Document 1, a film made of an insulating material such as ceramic is formed on the surface of a track member that comes into contact with a housing. In Patent Document 1, a cover is attached when the film is formed to prevent the material of the film from infiltrating the raceway surface during the film formation.

Japanese Unexamined Patent Publication No. 2008-280554

In order to form an insulating film such as ceramic as in Patent Document 1, it is necessary to use a method such as thermal spraying, which is costly and it is difficult to secure the accuracy of the raceway surface. Therefore, it has been studied to form a resin coating having an insulating property on the outer periphery of a track member such as an outer ring. When forming this coating, it is necessary to mask so that foreign matter such as paint does not enter the inside of the bearing.
However, if the cover coated with the paint is used repeatedly, the paint adhering to the cover may be peeled off and adhere to the raceway surface. Further, if the paint adhering to the cover is removed every time painting is performed, there is a problem that the cost for removing the paint increases and the price of the rolling bearing increases.

Therefore, an object of the present invention is to improve the productivity of rolling bearings having insulating performance by collectively coating a plurality of rolling bearings by using a simple masking method.

One embodiment of the present invention is a rolling bearing having an inner ring, an outer ring, a plurality of rolling elements rotatably arranged between the inner ring and the outer ring, and a cage for holding the rolling element. The outer ring includes a conductive outer ring main body and an insulating member having an insulating property integrally formed on the outer peripheral surface of the outer ring main body, and the outer ring main body includes a cylindrical outer peripheral surface and the said outer ring body. The insulating member has two side surfaces provided on both sides in the axial direction of the outer peripheral surface and extending in the radial direction, and the insulating member is formed on the outer peripheral surface and at least one side surface of the two side surfaces. It is a rolling bearing that is integrally formed.

Another embodiment of the present invention is the method for manufacturing a rolling bearing according to the above aspect, wherein a plurality of subassemblies of the rolling bearing including the outer ring main body, the inner ring, the rolling element, and the cage are provided. A plurality of rubber spacers and the sub-assemblies are arranged alternately in the axial direction, the plurality of sub-assemblies are arranged in the same orientation, and the plurality of spacers are arranged in the same orientation. With respect to one of the subassemblies arranged in one axially with respect to one of the spacers arranged in the axial direction and the other subassembly arranged in the other in the axial direction, the spacers are arranged in one of the axial directions. It has a first radial extending surface extending radially along one of the sub-assemblies, and on the other side of the axial direction, the outer peripheral surface of the inner ring of the other sub-assembly and the inner peripheral surface of the outer ring. An annular projecting portion that projects inward of the annular space while facing each other in the radial direction, a second radial extending surface that is connected to the projecting portion and extends outward in the radial direction, and is connected to the projecting portion. It has a third radial extending surface extending inward in the radial direction, and the second radial extending surface is located on one axial direction from the third radial extending surface. The protrusion is formed by the outer ring by bringing one sub-assembly and the other sub-assembly axially close to each other and axially compressing the spacer at the position of the third radial extending surface. This is a method for manufacturing a rolling bearing in which the insulating member is integrated with the outer ring main body from the radial outer side of the sub-assembly in a state of being in contact with the inner peripheral surface of the main body.

According to the present invention, the portion in contact with the housing of the motor can be covered in a limited manner. Therefore, while reducing the amount of resin material used, the housing and shaft can be insulated to prevent electrolytic corrosion of the rolling bearing. In addition, since masking can be easily performed by simply sandwiching a spacer during painting, a plurality of rolling bearings can be collectively painted, and the productivity of rolling bearings having insulating performance is improved. As a result, rolling bearings having insulating performance can be manufactured at low cost.

It is sectional drawing in the axial direction of the rolling bearing which is one Embodiment of this invention. It is a schematic diagram which shows the axial cross section of the electric motor which incorporated the rolling bearing. It is explanatory drawing explaining the coating process which forms a coating film on the outer periphery of an outer ring. It is sectional drawing in the axial direction of a spacer. FIG. 5A is a schematic view showing a state of the spacer before it is compressed, and FIG. 5B is a schematic view showing a state when the spacer is compressed in the axial direction.

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an axial sectional view of a rolling bearing 10 according to an embodiment of the present invention (hereinafter referred to as the present embodiment). FIG. 2 is a schematic view showing an axial cross section of the electric motor 90 in which the rolling bearing 10 is incorporated.

The rolling bearing 10 will be described with reference to FIG. The rolling bearing 10 includes an outer ring 11, an inner ring 12, a plurality of balls 13 as rolling elements, and a cage 14.
The outer ring 11 and the inner ring 12 are annular, and are combined so that their central axes coincide with each other. The inner ring 12 is rotatable about the central axis m with respect to the outer ring 11. In the following description, the direction of the central axis m is referred to as an axial direction, the direction orthogonal to the central axis m is referred to as a radial direction, and the direction orbiting around the central axis m is referred to as a circumferential direction. The left side of the figure is referred to as one axial direction, and the right side of the figure is referred to as the other axial direction.

The outer ring 11 includes an outer ring main body 11a and a resin coating 15 (insulating member) that covers the outer circumference thereof.

The outer ring main body 11a is made of a steel material such as bearing steel and has conductivity. In addition, the hardness is increased by performing a heat treatment of quenching and tempering.
The outer ring main body 11a has a cylindrical main body outer peripheral surface 16 centered on the central axis m on the outer periphery. On both sides of the outer peripheral surface 16 of the main body in the axial direction, side surfaces extending in a direction orthogonal to the central axis m are provided. The side surface formed on one side in the axial direction is referred to as a first outer surface 17a, and the side surface formed on the other side in the axial direction is referred to as a second outer surface 17b. The outer peripheral side end of the first outer surface 17a and the axially one end of the main body outer peripheral surface 16 are connected via a chamfered portion 18 having a rounded shape in a cross section including the central axis, and the second outer surface is connected. The outer peripheral side end of 17b and the axially opposite end of the main body outer peripheral surface 16 are connected via a chamfered portion 18 having a rounded shape in a cross section including the central axis.
The outer ring main body 11a has a cylindrical inner peripheral surface 20 centered on the central axis m on the inner circumference. The outer raceway surface 21 is formed over the entire circumference at substantially the center of the inner peripheral surface 20 in the axial direction. The outer raceway surface 21 is recessed outward in the radial direction and has an arc shape in a cross section including the central axis. The inner peripheral side end of the first outer surface 17a and the axially one end of the inner peripheral surface 20 are connected to each other via a chamfered portion 27, and are connected to the inner peripheral side end of the second outer surface 17b. The ends of the inner peripheral surface 20 on the other side in the axial direction are connected to each other via a chamfered portion 27.

The coating film 15 is integrally formed from the outer peripheral surface 16 of the main body to the first outer surface 17a. In the present embodiment, the coating film 15 is also formed on the outer circumferences of the chamfered portions 18 and 18 connected to both axial sides of the outer peripheral surface 16 of the main body and the outer periphery of the chamfered portion 27 connected inward in the radial direction of the first outer surface 17a. However, as will be described later, the present invention aims to insulate the housing 91 of the electric motor 90, and may be formed on at least the outer peripheral surface 16 of the main body and the first outer surface 17a.

In the present embodiment, the thickness of the coating film 15 is approximately 5 μm to 60 μm. This is because when the thickness of the coating film 15 is small, the strength of the coating film 15 decreases and the rolling bearing 10 may be easily peeled off, and when the thickness of the coating film 15 is large, dripping occurs during painting. This is because not only it becomes difficult to form the film 15 having a uniform thickness, but also the amount of the resin material used increases and the cost increases. However, the thickness of the coating film 15 is not limited to the above.

The inner ring 12 is made of a steel material such as bearing steel and has conductivity. In addition, the hardness is increased by performing a heat treatment of quenching and tempering.
The inner ring 12 has a cylindrical bearing inner diameter surface 22 centered on the central axis m on the inner circumference, and has side surfaces extending in a direction orthogonal to the central axis m on both sides in the axial direction. .. The side surface formed on one side in the axial direction is referred to as a first inner side surface 23a, and the side surface formed on the other side in the axial direction is referred to as a second inner side surface 23b. The inner peripheral side end of the first inner side surface 23a and the axially one end of the bearing inner diameter surface 22 are connected to each other via a chamfered portion 19, and the inner peripheral side end of the second inner side surface 23b, The ends of the bearing inner diameter surface 22 on the other side in the axial direction are connected to each other via a chamfered portion 19.
The inner ring 12 has an outer peripheral surface 24 which is a cylindrical surface centered on the central axis m on the outer circumference. An inner raceway surface 25 is formed over the entire circumference at substantially the center of the outer peripheral surface 24 in the axial direction. The inner raceway surface 25 is recessed inward in the radial direction and has an arc shape in a cross section including the central axis.
The axial dimensions of the first inner surface 23a and the second inner surface 23b are equivalent to the axial dimensions of the first outer surface 17a and the second outer surface 17b.

The ball 13 is made of a steel material such as bearing steel and has conductivity. A plurality of balls 13 are incorporated between the outer raceway surface 21 and the inner raceway surface 25.

The cage 14 is a resin crown type cage, and is incorporated in an annular space (annular space K) between the inner peripheral surface 20 of the outer ring 11 and the outer peripheral surface 24 of the inner ring 12 facing each other in the radial direction. It is combined with a plurality of balls 13. The cage 14 has an annular ring body 14a arranged along the ball 13 and a plurality of 14b protruding from one of the axial directions of the ring body 14a toward the ball 13 and the ball 13. .. The four 14b are arranged at equal intervals in the circumferential direction. The space between one 14b and one 14b adjacent to each other in the circumferential direction is called a pocket, and one ball 13 is incorporated in each pocket. In this way, the balls 13 are held at equal intervals in the circumferential direction.
As shown in FIG. 1, the position of the tip of each of the 14b protrudes in one axial direction beyond the center position of the ball 13 and does not exceed the position of the most extreme end of the axial direction of the ball 13. It protrudes in one axial direction. The tip of each of the 14b is curved toward the inside of the pocket, and the ball 13 is held so as not to come out of the pocket.

A state in which the rolling bearing 10 is incorporated into the electric motor 90 will be described with reference to FIG.
The electric motor 90 includes a rotor 94 and a stator 95 inside an aluminum housing 91. The rotor 94 rotates about the central axis p. Hereinafter, the direction of the central axis p is referred to as an axial direction.
The rotor 94 is an integral combination of the motor shaft 96 and the coil 97, and is rotatably supported by rolling bearings 10 and 10 at both ends of the motor shaft 96 in the axial direction with the coil 97 interposed therebetween. The stator 95 is fixed to the housing 91 and is arranged non-contactly on the outside of the coil 97.

The housing 91 has side walls 92 and 92 formed on both sides in the axial direction in a direction orthogonal to the central axis p. The rolling bearing 10 is fitted to bearing fitting portions 98 provided on the side walls 92 and 92 on both sides in the axial direction. The morphology of the bearing fitting portions 98 on both sides in the axial direction is the same as each other, and the bearing fitting portion 98 provided on the left side of the figure will be described, and the bearing fitting portion 98 provided on the other side (right side of the figure) will be described. Is omitted.
The bearing fitting surface 98a formed on the inner circumference of the bearing fitting portion 98 has a cylindrical shape centered on the central axis p. A brim 99 is formed on the axially outer side of the bearing fitting surface 98a (the side opposite to the coil 97 with respect to the bearing fitting surface 98a), and the axially inner side of the brim 99 (the side on which the coil 97 is installed). A contact surface 98b extending in the radial direction and connecting to the axially outer end of the bearing fitting surface 98a is formed on the bearing fitting surface 98a. The inner peripheral surface 93 of the brim 99 has a smaller diameter than the bearing fitting surface 98a, and is substantially the same as the diameter of the inner peripheral surface 20 of the outer ring 11.

In the rolling bearing 10, the outer circumference of the outer ring 11 is fitted to the bearing fitting surface 98a, and the rolling bearing 10 is pushed in the axial direction until the outer ring 11 comes into contact with the brim 99. In this way, the outer ring 11 and the brim 99 come into contact with each other in the axial direction, and the axial position of the rolling bearing 10 is regulated.

In the rolling bearing 10 of the present embodiment, a resin coating 15 is formed on the outer peripheral surface 16 of the main body and the first outer surface 17a (see FIG. 1). When the rolling bearing 10 is assembled to the bearing fitting portion 98, the outer peripheral surface 16 of the outer ring main body 11a and the housing 91 face each other in the radial direction via the coating film 15, and the first one in the axial direction of the outer ring 11 The outer side surface 17a and the housing 91 face each other in the axial direction via the coating film 15. In this way, the coating film 15 having an insulating property is arranged at the contact portion between the outer ring 11 and the housing 91, so that the outer ring 11 and the housing 91 can be reliably insulated.

If it is assumed that the outer ring 11 and the housing 91 are not insulated, the following inconveniences occur. This will be described with reference to FIG.
When the motor 90 is driven by an inverter, a potential difference is generated between the housing 91 to which the stator 95 is fixed and the motor shaft 96 to which the coil 97 is assembled. When the outer ring 11 of the rolling bearing 10 and the housing 91 are not insulated, electricity is applied between the outer ring 11 and the housing 91, so that the outer ring 11 fixed to the housing 91 and the inner ring fixed to the motor shaft 96 are energized. A potential difference is generated with 12. As a result, dielectric breakdown of the grease oil film occurs between the raceway surfaces 21 and 25 of the inner and outer rings 11 and 12 and the ball 13, and the stator 95 → housing 91 → rolling bearing 10 → rotor 94 → stator 95. A current circulates along the route. This current causes damage (electrolytic corrosion) to the raceway surfaces 21 and 25 of the rolling bearing 10, and noise of the electric motor 90 is generated.

On the other hand, in the rolling bearing 10 of the present embodiment, since the housing 91 and the outer ring 11 are insulated from each other, the current circulating inside the motor 90 is not generated as described above. Therefore, it is possible to prevent electrolytic corrosion and prevent the noise of the motor 90 for a long period of time.
Further, in the rolling bearing 10 of the present embodiment, the coating film 15 is formed only on one side surface (first outer surface 17a) and the outer circumference of the outer ring 11. Then, when the motor 90 is incorporated into the housing 91, the portion where the outer ring 11 and the housing 91 come into contact with each other is effectively insulated by incorporating the first outer surface 17a on which the coating film 15 is formed in a direction in which the first outer surface 17a is in contact with the brim 99. be able to. Therefore, the amount of resin material used can be reduced, and the rolling bearing 10 can be manufactured at low cost. The resin coating 15 is colored, and the coated first outer surface 17a and the uncoated second outer surface 17b can be easily distinguished. Therefore, when the rolling bearing 10 is assembled into the housing 91, its orientation can be easily confirmed.

(Manufacturing method of rolling bearing)
A method of manufacturing the rolling bearing 10 will be described with reference to FIGS. 3 and 4. FIG. 3 is an explanatory diagram illustrating a step of forming a coating film 15 on the outer periphery of the outer ring 11 (hereinafter, referred to as a coating step). FIG. 4 is an axial cross-sectional view of the spacer 30.

See FIG. When manufacturing the rolling bearing 10, a plurality of sub-assemblies 40 (hereinafter, simply referred to as "sub-assemblies 40") of the rolling bearing 10 are prepared.
First, the outer ring main body 11a and the inner ring 12 on which the coating film 15 has not yet been formed are coaxially combined. Next, a plurality of balls 13 are incorporated between the outer raceway surface 21 and the inner raceway surface 25. After that, the cage 14 is incorporated from one of the axial directions, and the plurality of balls 13 are held at equal intervals in the circumferential direction. In this way, the sub-assembly 40 is assembled. An annular space K (see FIG. 1) is formed between the inner circumference of the outer ring main body 11a and the outer circumference of the inner ring 12.

After that, in the painting process, a coating film 15 is formed on the outer periphery of the outer ring main body 11a. In the painting process, as shown in FIG. 3, a plurality of subassemblies 40 and a plurality of spacers 30 (details will be described later) are fitted in a row on the outer circumference of the alignment shaft 41, and are radially outward. The resin material is ejected together with the compressed air from the nozzle 44 installed in the above. In FIG. 3, the sub-assembly 40 is assembled so that the annular body 14a of the cage 14 is located on the right side of each sub-assembly 40, as in FIG. 1. Therefore, also in FIG. 3, the left side of the figure is referred to as one axial direction, and the right side of the figure is referred to as the other axial direction.

The spacer 30 will be described with reference to FIG. The spacer 30 in FIG. 4 is shown in the same orientation as the spacer 30 shown in FIG. Therefore, also in FIG. 4, the left side of the figure is referred to as one axial direction, and the right side of the figure is referred to as the other axial direction. Further, the direction of the central axis n is referred to as an axial direction.
The spacer 30 is manufactured by molding a rubber material in a mold. In this embodiment, acrylic rubber (ACM) is used as the rubber material. This is because acrylic rubber has heat resistance against heat when the resin material is baked, and also has oil resistance against oil and the like adhering to the subassembly 40 of the rolling bearing 10. The material of the rubber material is an example and is not limited to this.

The spacer 30 is an annular body having a predetermined thickness in the axial direction, and the outer peripheral surface 31 of the spacer and the inner peripheral surface 32 of the spacer are cylindrical surfaces coaxial with the central axis n, respectively. The diameter dimension of the spacer outer peripheral surface 31 is substantially the same as the diameter dimension of the main body outer peripheral surface 16 of the outer ring main body 11a, and the diameter dimension of the spacer inner peripheral surface 32 is substantially the same as the diameter dimension of the bearing inner diameter surface 22 of the inner ring 12. be.

A first radial extending surface 33 extending in the radial direction is formed on one axial direction of the spacer 30, and one end in the axial direction of the outer peripheral surface 31 of the spacer and one end in the axial direction of the inner peripheral surface 32 of the spacer 32 are formed. The parts are connected in the radial direction. In the present embodiment, the first radial extending surface 33 is a flat surface.

On the other side of the spacer 30 in the axial direction, an annular portion 37 coaxial with the central axis n and projecting toward the other in the axial direction is formed over the entire circumference. The protruding portion 37 has a convex portion outer peripheral surface 37a, a convex portion inner peripheral surface 37b, and a convex portion side surface 37c. The outer peripheral surface of the convex portion 37a and the inner peripheral surface of the convex portion 37b are cylindrical surfaces having a central axis n as a central axis, respectively. The convex portion side surface 37c is a surface extending in a direction orthogonal to the central axis n, and includes an end portion of the convex portion outer peripheral surface 37a on the other side in the axial direction and an end portion of the convex portion inner peripheral surface 37b on the other side in the axial direction. Are connected in the radial direction. The outer diameter of the outer peripheral surface 37a of the convex portion is slightly smaller than the inner diameter of the inner peripheral surface 20 of the outer ring 11. In the present embodiment, the value is about 1 mm smaller than the inner diameter of the inner peripheral surface 20 of the outer ring 11. The inner diameter of the convex inner peripheral surface 37b is slightly larger than the outer diameter of the outer peripheral surface 24 of the inner ring 12. In the present embodiment, the value is about 1 mm larger than the outer diameter dimension of the outer peripheral surface 24 of the inner ring 12.
As will be described later, the convex outer peripheral surface 37a may come into contact with the inner peripheral surface 20 of the outer ring 11 when the spacer 30 is compressed in the axial direction. Therefore, the dimensions of the outer peripheral surface 37a of the convex portion are not limited to the above, and can be appropriately changed within a target range.

A second radial extending surface 34 extending outward in the radial direction is formed on the radial outer side of the protruding portion 37 so as to be connected to one end in the axial direction of the outer peripheral surface 37a of the convex portion. The radial outer end of the second radial extending surface 34 is connected to the spacer outer peripheral surface 31 via a chamfered portion 36. In the present embodiment, the second radial extending surface 34 is a flat surface. The chamfered portion 36 has an inclined surface that is inclined in one axial direction as it advances outward in the radial direction.
A third radial extending surface 35 extending inward in the radial direction is formed on the radial inward side of the protruding portion 37 so as to be connected to one end in the axial direction of the inner peripheral surface 37b of the convex portion. In the present embodiment, the third radial extending surface 35 is a flat surface.
The radial inward end of the first radial extending surface 33 and the radial inward end of the third radial extending surface 35 are connected by a spacer inner peripheral surface 32.
In the following description, the portion formed on the radial outer side of the protruding portion 37 and defined by the first radial extending surface 33, the spacer outer peripheral surface 31, and the second radial extending surface 34 is referred to as the cover portion 38. The portion formed inward in the radial direction of the protruding portion 37 and defined by the first radial extending surface 33, the spacer inner peripheral surface 32, and the third radial extending surface 35 is referred to as a base portion 39.
The second radial extending surface 34 is formed so as to be displaced in one axial direction from the third radial extending surface 35, and the thickness of the cover portion 38 in the axial direction is the axial thickness of the base portion 39. It is smaller than the thickness.

See FIG. 3 again. In the painting process, the subassembly 40 and the spacer 30 are alternately fitted to the alignment shaft 41 and arranged in a row along the alignment shaft 41. The spacers 30 are incorporated between adjacent sub-assemblies 40 and on both outer sides in the axial direction of a plurality of sub-assemblies 40 (hereinafter, referred to as "bearing rows") arranged in a row. Therefore, the number of spacers 30 incorporated in the bearing row is one more than the number of subassemblies 40.

The subassembly 40 is assembled on the outer circumference of the alignment shaft 41 in the same orientation as each other. In the present embodiment, the orientation of each subassembly 40 is such that the annular body 14a of the cage 14 is located on the other side in the axial direction, and the 14b is assembled so as to project in one direction in the axial direction. Further, each spacer 30 is assembled in a direction in which the protruding portion 37 protrudes toward the other in the axial direction.
As a result, the protruding portion 37 of the spacer 30 is placed inside the annular space K on the side opposite to the side where the annular body 14a is located in the annular space K between the outer ring main body 11a and the inner ring 12 of the subassembly 40. It is protruding. Since the outer diameter of the convex outer peripheral surface 37a is smaller than the inner diameter of the inner peripheral surface 20 of the outer ring 11, and the inner diameter of the convex inner peripheral surface 37b is larger than the outer diameter of the outer peripheral surface 24 of the inner ring 12, the protruding portion 37 has an outer ring. It is easily inserted inside the annular space K between the main body 11a and the inner ring 12.

As shown in FIG. 3, a fixing ring 42 is fixedly attached to the alignment shaft 41 on one side of the bearing row in the axial direction. The outer circumference of the fixing ring 42 has a cylindrical shape coaxial with the central axis q of the alignment shaft 41, and its outer diameter is equivalent to the outer diameter of the outer peripheral surface 24 of the inner ring 12. A movable ring 43 is fitted on the other side of the bearing row in the axial direction with a gap on the outer circumference of the alignment shaft 41. The movable ring 43 can easily move in the axial direction along the outer circumference of the alignment shaft 41. The outer circumference of the movable ring 43 has a cylindrical shape coaxial with the central axis q, and its outer diameter is equivalent to the outer diameter of the outer peripheral surface 24 of the inner ring 12.

Next, the movable ring 43 assembled on the other side in the axial direction of the bearing row is axially urged toward the fixing ring 42. As a result, the base portion 39 of each spacer 30 is compressed in the axial direction, and the dimension in the axial direction is reduced. At this time, the fixed ring 42 and the movable ring 43 approach each other in the axial direction so that the axial dimension of the base portion 39 of each spacer 30 is smaller than the axial dimension of the base portion 39 in the free state by about 1 mm. It is pressed to do.
The outer diameter of the alignment shaft 41 is set to be slightly smaller than the inner diameter of the bearing inner diameter surface 22 and the inner diameter of the spacer inner peripheral surface 32, and the subassembly 40 and the spacer 30 are along the outer circumference of the alignment shaft 41. Can be freely displaced in the axial direction.

The deformed state of the spacer 30 when the base portion 39 is compressed in the axial direction will be described with reference to FIG. FIG. 5A is a schematic view showing a state of any one spacer 30 in FIG. 3 before being compressed. FIG. 5B is a schematic view showing a state when the subassembly 40 on the other side in the axial direction moves in one axial direction and the spacer 30 is compressed in the axial direction.

The state of the spacer 30 before being compressed will be described with reference to FIG. 5 (a).
The first radial extending surface 33 of the spacer 30 is a second outer surface on the other side in the axial direction of the outer ring main body 11a of the sub-assembly 40 (hereinafter referred to as “one sub-assembly 40a”) located on one side in the axial direction. It is in contact with the second inner side surface 23b on the other side in the axial direction of the 17b and the inner ring 12.
The third radial extending surface 35 of the spacer 30 is the first inner side surface 23a on one side in the axial direction of the inner ring 12 of the sub-assembly 40 (hereinafter referred to as “another sub-assembly 40b”) located on the other side in the axial direction. Are in contact with. The second radial extending surface 34 of the spacer 30 faces the first outer surface 17a on one side in the axial direction of the outer ring main body 11a of the other subassembly 40b in the axial direction with a gap.
The protrusion 37 is inserted inside the annular space K of the other subassembly 40b. A radial clearance s is formed between the outer peripheral surface 37a of the convex portion 37 of the protruding portion 37 and the inner peripheral surface 20 of the outer ring main body 11a.

Further, since the axial dimension of the convex inner peripheral surface 37b is set to be smaller than the axial distance between the first inner side surface 23a on one side of the inner ring 12 in the axial direction and the surface of the ball 13, the convex portion side surface 37c Does not come into contact with the outer peripheral surface of the ball 13. As a result, it is possible to prevent foreign matter from adhering to the ball 13 and prevent foreign matter from entering the raceway surfaces 21 and 25 of the rolling bearing 10.

A state when the spacer 30 is compressed in the axial direction will be described with reference to FIG. 5 (b).
In FIG. 5B, the radial position of the protruding portion 37 before the spacer 30 is deformed is shown by a broken line. Since the figure becomes complicated, the display of the axial misalignment before and after the compression deformation is omitted.

As shown in FIG. 3, when the movable ring 43 is displaced in one axial direction, the base portion 39 of each spacer 30 is axially compressed by the inner rings 12 adjacent to each other in the axial direction. Since each of the spacers 30 has the same shape and the spring constant of the base portion 39 in the axial direction is the same, the base portion 39 of each spacer 30 is reduced by substantially the same size. FIG. 5B shows a state in which the base portion 39 is compressed by δ.

The spacer 30 is made of a rubber material. The base portion 39 is elastically deformed in the direction in which the length in the radial direction is extended by being compressed in the axial direction. Therefore, the protruding portion 37 is displaced outward in the radial direction, and the outer peripheral surface 37a of the convex portion abuts in the radial direction with the inner peripheral surface 20 of the outer ring main body 11a. At the same time, the cover portion 38 is displaced outward in the radial direction along the second outer surface 17b of the outer ring main body 11a of one subassembly 40a.

The spacers 30 arranged on both outer sides of the bearing row are also deformed in the same manner as described above. Although not shown, one of the spacers 30 in the axial direction is sandwiched between the inner ring 12 and the fixing ring 42 of the subassembly 40 on the one side in the axial direction, and the spacer 30 in the other axial direction is the spacer 30 on the other side in the axial direction. It is sandwiched between the inner ring 12 of the subassembly 40 and the movable ring 43 (see FIG. 3). Since the outer diameter of the fixed ring 42 and the outer diameter of the movable ring 43 are the same as the outer diameter of the outer peripheral surface 24 of the inner ring 12, the spacers 30 and 30 arranged on both outer sides of the bearing row are also used. , It is deformed in the same manner as the spacer 30 sandwiched between the subassembly 40.

Next, as shown in FIG. 3, in a state where the subassembly 40 and the spacer 30 are integrally combined, the solvent containing the resin material is compressed air from the nozzle 44 while rotating around the central axis m. Is being sprayed with. At the same time, the nozzle 44 moves in the axial direction, and the resin material is evenly sprayed on the entire bearing row.
In the bearing row, the outer peripheral surface 16 of the outer ring main body 11a and the first outer surface 17a on one side in the axial direction are exposed to the outside. Therefore, the resin material is applied to the outer peripheral surface 16 of the outer ring main body 11a of the subassembly 40 and the first outer surface 17a on one side in the axial direction.
In the manufacturing method of the present embodiment, the inner peripheral surface 20 of the outer ring main body 11a and the outer peripheral surface 37a of the convex portion of the spacer 30 are in contact with each other, so that the outer space and the annular space K of the subassembly 40 are surely separated. There is. Therefore, it is possible to reliably prevent the resin material injected toward the first outer surface 17a on one side in the axial direction from entering the inside of the rolling bearing 10.
Further, on the other side of each subassembly 40 in the axial direction, the cover portion 38 extends along the second outer surface 17b of the outer ring main body 11a, so that the resin material injected toward the outer ring main body 11a can be obtained. It is possible to reliably prevent the rolling bearing 10 from entering the inside.

When the resin material is sprayed toward the outer ring main body 11a, the resin material is simultaneously applied to the outer peripheral surface 31 of the spacer, the extending surface 34 in the second radial direction, and the outer peripheral surface 37a of the convex portion of the protruding portion 37. Therefore, the spacer 30 is not used repeatedly.

With the resin material applied to the outer circumference of the bearing row in this way, the subassembly 40 and the spacer 30 are held in a high temperature atmosphere. As a result, the resin material is solidified, and a resin film 15 integrated with the outer ring main body 11a is formed. The temperature of the high temperature atmosphere is lower than the tempering temperature of the rolling bearing 10, and is set to, for example, about 150 ° C. Therefore, since the metal structure of the outer ring 11 and the inner ring 12 is not affected, the rolling bearing 10 can maintain a good rolling life.
After that, by removing the force urging the movable ring 43 in the axial direction, the axial dimension of the base portion 39 is elastically restored to the original dimension, and at the same time, the radial dimension is reduced and the protruding portion 37 is formed. It separates inward in the radial direction from the inner circumference of the outer ring 11.

In this way, in the rolling bearing 10, an insulating resin coating 15 is formed on the bearing outer diameter surface of the outer ring 11 and the first outer surface 17a on one side in the axial direction. The thickness of the coating film 15 formed on the outer circumference of the outer ring 11 is approximately 5 μm to 60 μm.

As described above, in the present embodiment, when forming the resin film, it is possible to mask the foreign matter such as paint so as not to enter the inside of the bearing. By using an inexpensive and recyclable rubber material for the spacer, it is possible to form an insulating resin film on the outer periphery of the rolling bearing without reusing it. Therefore, it is possible to reliably prevent foreign matter such as peeled paint from adhering to the raceway surface. In this way, in the method for manufacturing a rolling bearing of the present embodiment, it is possible to limit the portion of the rolling bearing that comes into contact with the housing of the electric motor. Therefore, while reducing the amount of resin material used, the housing and shaft can be insulated to prevent electrolytic corrosion of the rolling bearing. In addition, since masking can be easily performed by simply sandwiching a spacer during painting, a plurality of rolling bearings can be collectively painted, and the productivity of rolling bearings having insulating performance is improved. As a result, rolling bearings having insulating performance can be manufactured at low cost.

The above-described embodiment is merely an example for carrying out the present invention. The present invention is not limited to the above-described embodiment, and the above-described embodiment can be appropriately modified and implemented within a range that does not deviate from the gist thereof.
For example, in the above-described embodiment, the first radial extending surface 33 is a flat surface, the second radial extending surface 34 is a flat surface, and the third radial extending surface 35 is a flat surface. However, the spacer 30 can be compressed in the axial direction, the first radial extending surface 33 seals the second outer surface 17b in an annular shape over the entire circumference, and the convex outer peripheral surface 37a is the inner peripheral surface of the outer ring body 11a. If it is possible to abut the 20 in the radial direction over the entire circumference and seal it in an annular shape, the first radial extending surface 33 has a contour line in which the central axis n other than the plane is coaxial and extends in the radial direction. The surface to be formed, for example, a conical surface or a cross section including the central axis n may be a curved surface. Further, the second radial extending surface 34 may extend in the radial direction and may not come into contact with the first outer surface 17a when the spacer 30 is compressed in the axial direction, and the third radial extending surface 35 may be a surface. Any surface that extends in the radial direction and comes into contact with the first inner side surface 23a may be used.

11: outer ring, 11a: outer ring body, 13: inner ring, 13: ball, 14: cage, 14a: annular body, 14b: one, 15: coating, 16: main body outer peripheral surface, 17a: first outer surface, 20: Inner peripheral surface, 21: outer raceway surface, 22: bearing inner diameter surface, 23a: first inner surface, 24: outer peripheral surface, 25: inner raceway surface, 26: bearing outer diameter surface, 30: spacer, 31: spacer outer peripheral surface , 32: Spacer inner peripheral surface, 33: 1st radial extending surface, 34: 2nd radial extending surface, 35: 3rd radial extending surface, 37: protruding portion, 37a: convex outer peripheral surface, 37b: Inner peripheral surface of convex part, 37c: Side surface of convex part, 38: Cover part, 39: Base part, 40: Subassembly, 41: Alignment shaft, 42: Fixed ring, 43: Movable ring, 44: Nozzle, 90: Motor, 91: housing, 92: side wall, 94: rotor, 95: stator, 96: motor shaft, 97: coil, 98: bearing fitting part, 98a: bearing fitting surface, 98b: contact surface, 99 :spit

Claims (3)

A rolling bearing having an inner ring, an outer ring, a plurality of rolling elements rotatably arranged between the inner ring and the outer ring, and a cage for holding the rolling element.
The outer ring includes a conductive outer ring main body and an insulating insulating member integrally formed on the outer periphery of the outer ring main body.
The outer ring body has a cylindrical outer peripheral surface and two side surfaces provided on both sides of the outer peripheral surface in the axial direction and extending in the radial direction.
The insulating member is a rolling bearing integrally formed on the outer peripheral surface and at least one of the two side surfaces. The cage is a crown-shaped cage having an annular ring body arranged along the rolling element and a plurality of annular bodies projecting from the annular body toward the rolling element in the axial direction. ,
The insulating member is
It is integrally formed with the outer peripheral surface and the first outer surface of the two side surfaces on the side away from the annular body.
The rolling bearing according to claim 1, wherein the outer ring main body is exposed on the second outer surface of the two side surfaces on the side closer to the annular body. The method for manufacturing a rolling bearing according to claim 1.
A plurality of subassemblies of rolling bearings including the outer ring main body, the inner ring, the rolling element, and the cage are prepared.
A plurality of rubber spacers and the subassembly are arranged alternately in the axial direction.
The plurality of subassemblies are arranged in the same orientation, and the plurality of spacers are arranged in the same orientation.
For one said subassembly arranged axially on one side across any one said spacer and the other subassembled arranged on the other side of the axial direction.
The spacer is
One axially extending surface has a first radial extending surface extending radially along one of the subassemblies, and the other axially extending the outer peripheral surface of the inner ring and the outer ring of the other subassemblies. An annular protrusion that projects inward of the annular space while the inner peripheral surfaces of the above project in the radial direction, a second radial extension surface that is connected to the protrusion and extends outward in the radial direction, and the above. It has a third radial extending surface that is connected to the projecting portion and extends inward in the radial direction.
The second radial extending surface is located on one axial direction with respect to the third radial extending surface.
The protrusion is formed by the outer ring by bringing one sub-assembly and the other sub-assembly axially close to each other and axially compressing the spacer at the position of the third radial extension surface. A method for manufacturing a rolling bearing, in which the insulating member is integrated with the outer ring main body from the radial outside of the sub-assembly in a state of being in contact with the inner peripheral surface of the main body.

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