Rolling bearing

Abstract

To provide a rolling bearing which can prevent electric corrosion and suppress influence on the quality of an outer ring at low costs.SOLUTION: In a rolling bearing, a plurality of rolling elements 4 held by a retainer 5 are interposed between an inner ring 2 and an outer ring 3. A first insulating member 6 made of resin has a first cylindrical part 8 fitted to an outer peripheral surface 3b of the outer ring 3 and a first inner flange part 9 covering one axial end surface of the outer ring 3. A second insulating member 7 made of resin has a second cylindrical part 10 fitted to the outer peripheral surface 3b of the outer ring 3 and a second inner flange part 11 covering the other axial end surface of the outer ring 3. The first cylindrical part 8 and the second cylindrical part 10 have engaging parts 20 that engage with each other at two positions in an axial direction, with an axial gap therebetween. The engaging parts 20 are each formed from a protruding part 12 extending in the axial direction and a receiving recessed part 13 engaging with the protruding part 12 with an axial engagement gap therebetween.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rolling bearing for supporting a rotating shaft of a vehicle drive motor or a transmission. [Background technology]

[0002] Generally, automobiles such as electric vehicles and electric hybrid vehicles, as well as industrial vehicles, are equipped with a drivetrain including a vehicle drive motor and a transmission. The rotating shaft of the vehicle drive motor or transmission is supported by a rolling bearing.

[0003] In rolling bearings that support the rotating shaft of a vehicle drive motor or a transmission connected to the motor, electric current may pass through the bearing during rotation, causing discharge between the raceway and the rolling elements, which may result in electrolytic corrosion of the raceway or the rolling elements.To prevent this electrolytic corrosion, some rolling bearings have been provided with a resin insulating coating that covers the outer peripheral surface and axial end faces of the outer ring (see, for example, Patent Document 1).

[0004] In the rolling bearing of Patent Document 1, a circumferential groove is formed on the outer peripheral surface of the outer ring, the outer ring is placed in a resin injection molding mold, molten resin is injected between the inner surface of the mold and the surface of the outer ring, and an insulating coating is formed on the outer peripheral surface and axial end faces of the outer ring by insert molding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3068311 Summary of the Invention [Problem to be solved by the invention]

[0006] With the rolling bearing of Patent Document 1, there are concerns that the raceway surface and inner peripheral surface of the outer ring may be damaged or that foreign matter may adhere to it when the insulating coating is formed by insert molding, making quality control difficult. In addition, the outer ring must be machined into a circumferential groove on its outer peripheral surface, which increases the cost of the outer ring.

[0007] Therefore, the problem to be solved by the present invention is to provide a rolling bearing that can prevent electrolytic corrosion and minimize the effect on the quality of the outer ring at low cost. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention comprises the following configurations 1 to 9. [Configuration 1] With inner circle, The outer ring and a plurality of rolling elements interposed between the inner ring and the outer ring; a cage that holds the plurality of rolling elements; a first insulating member made of resin, the first insulating member having a cylindrical portion fitted to the outer peripheral surface of the outer ring and an inner flange portion covering one axial end face of the outer ring; a second insulating member made of resin having a cylindrical portion fitted to the outer peripheral surface of the outer ring and an inner flange portion covering the other axial end face of the outer ring, a rolling bearing in which the cylindrical portion of the first insulating member and the cylindrical portion of the second insulating member are fitted to the outer peripheral surface of the outer ring in a line in the axial direction with an axial gap therebetween.

[0009] With this configuration, the first insulating member and second insulating member are separate from the outer ring and are manufactured independently of the outer ring, so there is no concern about damage to the raceway surface or inner peripheral surface of the outer ring or adhesion of foreign matter during manufacture of the outer ring, minimizing the impact on the quality of the outer ring. Furthermore, because there is no need to machine a circumferential groove into the outer peripheral surface of the outer ring, manufacturing costs can be reduced.

[0010] [Configuration 2] the cylindrical portion of the first insulating member and the cylindrical portion of the second insulating member have engaging portions that engage with each other in the axial direction, and the engaging portions are formed at a plurality of locations spaced apart in the circumferential direction, one of the engaging portions that engage with each other in the axial direction is a protrusion that protrudes outward in the axial direction, and the other of the engaging portions that engage with each other in the axial direction is a receiving recess that opens at an axially inner position and is recessed outward in the axial direction, 2. The rolling bearing according to configuration 1, wherein the protrusion is engaged with the inner surface of the receiving recess with an axial engagement gap therebetween.

[0011] With this configuration, the first insulating member and the second insulating member are axially engaged with each other by the engagement of the protrusion and the receiving recess. Also, because the outer ring is sandwiched axially between the inner flanges of the first insulating member and the second insulating member, the first insulating member and the second insulating member can be prevented from falling off the outer ring when the outer ring is fitted into the housing.

[0012] [Configuration 3] A rolling bearing according to configuration 2, wherein the cylindrical portions and inner flanges of the first insulating member and the second insulating member have the same shape, the engaging portions are provided at an even number of locations, and the cylindrical portions of the first insulating member and the second insulating member have protrusions and receiving recesses of the engaging portions formed alternately at equal intervals along the circumferential direction.

[0013] This configuration allows the first insulating member and the second insulating member to be made of a common material, and the first insulating member and the second insulating member can be fitted to the outer ring from either axial direction without distinction. Furthermore, a common mold can be used when manufacturing the first insulating member and the second insulating member, reducing the costs of these members.

[0014] [Configuration 4] the protrusion has a base portion located axially inward and a tip portion located axially outward of the base portion and having a circumferential width dimension larger than that of the base portion, and the tip portion is elastically deformable so as to reduce its circumferential width dimension; 4. The rolling bearing according to configuration 2 or 3, wherein the receiving recess has a narrow portion that opens axially inward, and the circumferential opening width of the narrow portion is larger than the circumferential width dimension of the base portion.

[0015] According to this configuration, the tip of the protrusion is pressed axially against the inner surface of the narrow portion of the receiving recess, and the tip is elastically deformed so that its circumferential width dimension becomes smaller, allowing the tip to pass axially and engage with the receiving recess.

[0016] [Configuration 5] A rolling bearing according to configuration 4, wherein a guide edge portion is formed at the tip end of the protrusion portion on the axially outer side of the receiving recess portion, and the guide edge portion is inclined toward the axially inner side of the base portion as it extends circumferentially outward.

[0017] With this configuration, when the tip of the protrusion is pressed axially against the inner surface of the narrow portion of the receiving recess, the guide edge portion makes it easier for the tip of the protrusion to elastically deform so that its circumferential width dimension becomes smaller.

[0018] [Configuration 6] the outer ring has seal grooves provided on both axial sides of its inner peripheral surface, the first insulating member and the second insulating member each have an engaging cylindrical portion extending axially inward from the inner flange portion, 2. The rolling bearing according to configuration 1, wherein the engaging cylindrical portion is elastically deformable in the radial direction, and the engaging cylindrical portion has a protrusion that engages with a seal groove of the outer ring.

[0019] According to this configuration, the first insulating member and the second insulating member can be prevented from coming off in the axial direction relative to the outer ring by engaging the protruding portion of the engaging cylindrical portion with the seal groove of the outer ring.

[0020] [Configuration 7] 7. The rolling bearing according to any one of configurations 1 to 6, wherein the cylindrical portions of the first insulating member and the second insulating member have a thickness of 0.3 mm or more.

[0021] This ensures a sufficient radial distance between the outer peripheral surface of the outer ring and the inner surface of the housing into which the outer ring fits in the gap formed between the cylindrical portion of the first insulating member and the cylindrical portion of the second insulating member, thereby ensuring stable insulation performance.

[0022] [Configuration 8] 8. The rolling bearing of any one of Aspects 1 to 7, wherein the material of the first insulating member and the second insulating member is a resin composition containing a resin containing at least one of a polyphenylene sulfide resin, a polyamide resin, and an epoxy resin, and a fiber containing at least one of a glass fiber, a carbon fiber, and an aramid fiber.

[0023] According to this configuration, the material of the first insulating member and the second insulating member is suitable as an insulating material in terms of insulation resistance, breakdown voltage, mechanical strength, processability, and the like.

[0024] [Configuration 9] 9. The rolling bearing according to Aspect 8, wherein the first insulating member and the second insulating member are injection-molded articles, and the flow direction of the resin composition in the first insulating member and the second insulating member is aligned with the circumferential direction.

[0025] With this configuration, the first insulating member and the second insulating member have fibers oriented in the circumferential direction. In this state, the first insulating member and the second insulating member have a linear expansion coefficient in the circumferential direction that tends to be smaller than the linear expansion coefficient in the axial direction, which makes it possible to reduce the tensile stress generated in the circumferential direction in the above-mentioned low-temperature state. [Effects of the Invention]

[0026] As described above, by adopting the above configuration, the present invention can prevent electrolytic corrosion and suppress the impact on quality at low cost. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a partially cutaway front view showing a rolling bearing according to a first embodiment of the present invention; [Figure 2] Cross section along line AA in Figure 1 [Figure 3] FIG. 4 is a perspective view showing a first insulating member and a second insulating member of the rolling bearing; [Figure 4] FIG. 10 is an enlarged front view of the engagement portion of the rolling bearing; [Figure 5] Graph showing the relationship between effective power and minimum creepage distance [Figure 6] FIG. 10 is a partially cutaway front view showing a rolling bearing according to a second embodiment of the present invention; [Figure 7] Cross section along line BB in Figure 6 [Figure 8] FIG. 7 is a perspective view showing a first insulating member and a second insulating member of the rolling bearing of FIG. 6; DETAILED DESCRIPTION OF THE INVENTION

[0028] A rolling bearing 1 according to a first embodiment of the present invention will be described with reference to Figures 1 to 4. The rolling bearing 1 shown in Figures 1 to 4 supports the rotating shaft of a drive motor that constitutes the drive system of an automobile, such as an electric vehicle (EV) or an electric hybrid vehicle (HV), or an industrial vehicle, or of a transmission connected to that drive motor. The inner diameter of the rolling bearing of the present invention is used in a range of, for example, 30 mm to 45 mm.

[0029] 1 and 2, rolling bearing 1 has an inner ring 2, an outer ring 3 provided coaxially and radially outward of inner ring 2, a plurality of rolling elements 4 assembled at intervals in the circumferential direction between inner ring 2 and outer ring 3, a cage 5 that maintains the circumferential spacing of the plurality of rolling elements 4, and a first insulating member 6 and a second insulating member 7 that are fitted with an interference to the outer peripheral surface 3b of outer ring 3. Here, the direction along the axis of rolling bearing 1 is referred to as the "axial direction," the direction perpendicular to that axis is referred to as the "radial direction," and the direction going around the axis is referred to as the "circumferential direction."

[0030] The inner ring 2 is a cylindrical annular member. An inner ring raceway 2a, on which the rolling elements 4 roll, is formed on the outer peripheral surface of the inner ring 2. A rotating shaft of a vehicle drive motor or transmission is fitted onto the inner peripheral surface of the inner ring 2. The outer ring 3 is a cylindrical annular member. An outer ring raceway 3a, on which the rolling elements 4 roll, is formed on the inner peripheral surface of the outer ring 3. A first cylindrical portion 8 of a first insulating member 6 and a second cylindrical portion 10 of a second insulating member 7 are fitted onto the outer peripheral surface 3b of the outer ring 3, aligned in the axial direction. The rolling elements 4 are made of steel balls. The cage 5 is an annular bearing component that maintains a predetermined circumferential spacing between the multiple rolling elements 4 interposed between the inner ring raceway 2a of the inner ring 2 and the outer ring raceway 3a of the outer ring 3.

[0031] 2 and 3, the first insulating member 6 and the second insulating member 7 are annular injection-molded products formed by injection molding a resin composition. The first insulating member 6 has a first cylindrical portion 8 and an annular first inner flange 9 formed integrally with the axial outer end of the first cylindrical portion 8 and extending radially inward. The second insulating member 7 has a second cylindrical portion 10 and an annular second inner flange 11 formed integrally with the axial outer end of the second cylindrical portion 10 and extending radially inward.

[0032] The first cylindrical portion 8 is fitted onto the outer peripheral surface 3b of the outer ring 3 with an interference, and the first inner rib portion 9 covers one axial end face 3c of the outer ring 3. The second cylindrical portion 10 is fitted onto the outer peripheral surface 3b of the outer ring 3 with an interference, and the second inner rib portion 11 covers the other axial end face 3d of the outer ring 3.

[0033] The first cylindrical portion 8 is provided with a protrusion 12 that protrudes in the axial direction toward the second cylindrical portion 10, and a receiving recess 13 that is recessed axially outward. The protrusion 12 extends in the axial direction from the axial inner end surface of the first cylindrical portion 8. The radial outer surface of the protrusion 12 and the outer peripheral surface of the first cylindrical portion 8 form a continuous curved surface with no steps in the radial direction. The radial inner surface of the protrusion 12 and the inner peripheral surface of the first cylindrical portion 8 form a continuous curved surface with no steps in the radial direction. In other words, the protrusion 12 has the same radial thickness as the first cylindrical portion 8. The protrusion 12 is elastically deformable circumferentially inward so that its circumferential width dimension decreases.

[0034] As shown in Figure 4, the protrusion 12 has a base 12a located on the first cylindrical portion 8 side (axially inner side) and a tip portion 12b located on the axially opposite side of the base 12a from the first cylindrical portion 8 (axially outer side). The tip portion 12b extends in both circumferential directions from the base 12a and is formed to be larger than the circumferential width dimension of the base 12a. A mountain-shaped guide edge portion 12c is formed on the tip portion 12b on the axially opposite side from the first cylindrical portion 8. The guide edge portion 12c is inclined axially toward the first cylindrical portion 8 as it extends from near the circumferential center of the tip portion 12b to both circumferential sides.

[0035] The receiving recesses 13 are provided at circumferential positions that are 180 degrees out of phase with the protrusions 12 of the first cylindrical portion 8 (see FIG. 3). That is, the protrusions 12 and the receiving recesses 13 are provided at equal intervals in the circumferential direction on the first cylindrical portion 8. The receiving recesses 13 have a similar shape to the protrusions 12 but are slightly larger. The receiving recesses 13 have a narrow portion 13a that opens axially inward of the first cylindrical portion 8 and a deep inner portion 13b that is continuous with the narrow portion 13a axially outward. The narrow portion 13a corresponds to the shape of the base portion 12a, and the deep inner portion 13b corresponds to the shape of the tip portion 12b.

[0036] The circumferential opening width of the narrow portion 13a is larger than the circumferential width of the base portion 12a and smaller than the circumferential width of the tip portion 12b. The narrow portion 13a restricts the tip portion 12b from passing axially into the innermost part 13b when the tip portion 12b is in its natural state, i.e., not elastically deformed to reduce its circumferential width. The narrow portion 13a also allows the tip portion 12b to pass axially into the innermost part 13b when the tip portion 12b is elastically deformed to reduce its circumferential width.

[0037] The radial thickness of the first cylindrical portion 8 of the first insulating member 6 is determined based on the graph shown in FIG. 5, which shows the relationship between effective power and minimum creepage distance. While the system voltage of recent electric vehicles (EVs), electric hybrid vehicles (HVs), and other automobiles is typically 400V, this is expected to increase to approximately 1,000V in the future. Furthermore, the voltage applied to the bearing is expected to be approximately 1 / 10 of the system voltage. According to FIG. 5, at an effective voltage of 100V, a creepage distance of 0.3mm or more is required to prevent damage due to surface current. Therefore, it is preferable that the radial thickness of the first cylindrical portion 8 of the first insulating member 6 be 0.3mm or more.

[0038] The first insulating member 6 is an injection-molded body. The material of the first insulating member 6 can be a resin composition containing a resin containing at least one of polyphenylene sulfide resin, polyamide resin, and epoxy resin, and a fiber containing at least one of glass fiber, carbon fiber, and aramid fiber. The first insulating member 6 is formed by injection molding so that the flow direction of the molten resin composition is parallel to the circumferential direction.

[0039] In the first insulating member 6 formed by injection molding in this manner, the glass fibers are oriented in the circumferential direction of the first cylindrical portion 8 and the first inner flange 9. The first cylindrical portion 8 and the first inner flange 9 tend to have a smaller linear expansion coefficient in the circumferential direction than the linear expansion coefficient in the axial direction. This makes it possible to reduce the tensile stress generated in the circumferential direction of the first cylindrical portion 8 and the first inner flange 9 in low-temperature conditions, such as when starting a vehicle in winter.

[0040] 3, the second insulating member 7 has the same shape as the first insulating member 6, but is formed so that the axial direction faces in the opposite direction. The second cylindrical portion 10 of the second insulating member 7 is formed with the protrusions 12 and receiving recesses 13 formed on the first cylindrical portion 8 of the first insulating member 6, facing in the axial direction in the opposite direction. Therefore, the shape and function of the protrusions 12 and receiving recesses 13 formed on the second cylindrical portion 10 are the same as those of the protrusions 12 and receiving recesses 13 formed on the first cylindrical portion 8 of the first insulating member 6, and therefore a description thereof will be omitted.

[0041] The material of the second insulating member 7 is the same resin composition as that of the first insulating member 6. The second insulating member 7 is formed so that the circumferential direction is parallel to the flow direction of the resin composition. As with the first insulating member 6, the second insulating member 7 also makes it possible to reduce the tensile stress generated in the circumferential direction of the second cylindrical portion 10 and the second inner flange portion 11 in the above-mentioned low temperature state.

[0042] 2, the first cylindrical portion 8 of the first insulating member 6 is fitted onto the outer peripheral surface 3b of the outer ring 3 from one axial side with an interference in the axial direction, and the first inner rib 9 covers one axial end face 3c of the outer ring 3 with an axial clearance. Similarly, the second cylindrical portion 10 of the second insulating member 7 is fitted onto the outer peripheral surface 3b of the outer ring 3 from the other axial side with an interference in the axial direction, and the second inner rib 11 covers the other axial end face 3d of the outer ring 3 with an axial clearance.

[0043] In this state, as shown in Fig. 1, the protrusions 12 of the first cylindrical portion 8 engage with the receiving recesses 13 of the second cylindrical portion 10, and the protrusions 12 of the second cylindrical portion engage with the receiving recesses 13 of the first cylindrical portion 8. The protrusions 12 and the receiving recesses 13 form engagement portions 20 at two equally spaced locations in the circumferential direction on the first cylindrical portion 8 and the second cylindrical portion 10, which engage with each other in the axial direction. A gap in the axial direction is provided between the first cylindrical portion 8 of the first insulating member 6 and the second cylindrical portion 10 of the second insulating member 7 via the engagement portions 20. Furthermore, as shown in Fig. 4, an engagement gap w is provided between the protrusions 12 and the inner surface of the receiving recesses 13 at the engagement portions 20.

[0044] The rolling bearing 1 of the first embodiment according to the present invention is as described above, and the first insulating member 6 and second insulating member 7 are separate from the outer ring 3 and are manufactured independently of the outer ring 3. Therefore, when manufacturing the outer ring 3, there is no concern about damage to the outer ring raceway surface 3a of the outer ring 3 or the inner circumferential surface of the outer ring 3 or the adhesion of foreign matter, minimizing the impact on quality. Furthermore, because there is no need to machine a circumferential groove into the outer circumferential surface 3b of the outer ring 3, the outer ring 3 can be manufactured at low cost.

[0045] Here, because the linear expansion coefficient of resin is much greater than that of metal, when the bearing reaches a high temperature during operation, the first cylindrical portion 8 of the first insulating member 6 and the second cylindrical portion 10 of the second insulating member 7 undergo thermal expansion in the axial direction. At this time, the first cylindrical portion 8 and the second cylindrical portion 10 can tolerate dimensional changes in the axial direction due to thermal expansion by the size of the axial gap between them.

[0046] In addition, in this rolling bearing 1, the first insulating member 6 and the second insulating member 7 are axially engaged with each other through engagement between the protrusions 12 and the receiving recesses 13. Furthermore, the outer ring 3 is sandwiched axially between the first inner rib portion 9 of the first insulating member 6 and the second inner rib portion 11 of the second insulating member 7. This makes it possible to prevent the first insulating member 6 and the second insulating member 7 from falling off the outer ring when, for example, fitting the outer ring into a housing.

[0047] Furthermore, by releasing the engagement between the protrusion 12 and the receiving recess 13, the outer ring 3, the first insulating member 6, and the second insulating member 7 of this rolling bearing 1 can be easily disassembled, making it easy to separate and highly recyclable.

[0048] This rolling bearing 1 reaches a low temperature, for example, when the vehicle is started in winter. In this low temperature state, the first insulating member 6 and the second insulating member 7 shrink more than the outer ring 3. The first insulating member 6 and the second insulating member 7 are able to displace axially outward by the size of the axial engagement gap w while maintaining an engaged state at the engaging portion 20. This prevents the first inner rib portion 9 of the first insulating member 6 and the second inner rib portion 11 of the second insulating member 7, which shrink in low temperatures, from being pushed axially outward by the axial end faces 3c, 3d on both sides of the outer ring 3.

[0049] Furthermore, in this rolling bearing 1, the first insulating member 6 and the second insulating member 7 have the same shape, and the engaging portions 20 are provided in two even-numbered locations. Furthermore, the protrusions 12 and receiving recesses 13 of the first cylindrical portion 8 of the first insulating member 6 and the second cylindrical portion 10 of the second insulating member 7 are arranged alternately and at equal intervals along the circumferential direction. This allows the first insulating member 6 and the second insulating member to be made common, and the first insulating member 6 and the second insulating member 7 can be fitted to the outer peripheral surface 3b of the outer ring 3 from either axial direction without distinction. Furthermore, the first insulating member 6 and the second insulating member 7 can be injection molded using the same mold, reducing molding costs.

[0050] In this rolling bearing 1, first, the guide edge 12c of the tip 12b of the protrusion 12 is pressed axially against the inner surface of the narrow portion 13a of the receiving recess 13. Then, the tip 12b is elastically deformed so that its circumferential width decreases, and the tip 12b passes into the innermost part 13b of the receiving recess 13. Thereafter, the tip 12b in its natural, non-elastically deformed state is inserted into the innermost part 13b of the receiving recess 13, and the protrusion 12 engages with the receiving recess 13. In this way, the first cylindrical portion 8 of the first insulating member 6 and the second cylindrical portion 10 of the second insulating member 7 can be easily engaged with each other.

[0051] In the engaging portion 20 of this rolling bearing 1, for example, the protrusion 12 can be formed on either the first cylindrical portion 8 or the second cylindrical portion 10, and the receiving recess 13 can be formed on the other.

[0052] Furthermore, in this rolling bearing 1, the material for the first insulating member 6 and the second insulating member 7 can be made solely of a resin containing at least one of polyphenylene sulfide resin, polyamide resin, and epoxy resin, without containing fibers such as glass fiber. In this case, the first insulating member 6 and the second insulating member 7 can be made at even lower cost and more recyclable than those formed from the resin compositions containing the above-mentioned fibers.

[0053] Next, a rolling bearing 21 according to a second embodiment of the present invention will be described with reference to Figures 6 to 8. This rolling bearing 21 differs from the rolling bearing 1 according to the first embodiment described above in that seal grooves 3f are provided on both axial sides of the inner circumferential surface 3e of the outer ring 3, that protrusions 12 and receiving recesses 13 are not formed on the first cylindrical portion 8 of the first insulating member 6 and the second cylindrical portion 10 of the second insulating member 7, and that engaging cylindrical portions 14 that engage with the seal grooves 3f are formed on the first inner rib portion 9 of the first insulating member 6 and the second inner rib portion 11 of the second insulating member 7. As the other configurations are the same as those of the first embodiment, the same reference numerals as in the first embodiment are used and description thereof will be omitted.

[0054] 6, the outer ring 3 of the rolling bearing 21 has seal grooves 3f provided on both axial sides of the inner circumferential surface 3e, and shoulders 3g formed axially outward of each seal groove 3f. The shoulders 3g have an inner diameter larger than that of the inner circumferential surface 3e.

[0055] As shown in Figures 7 and 8, an engaging cylindrical portion 14 is formed integrally with the first inner flange portion 9 of the first insulating member 6. The engaging cylindrical portion 14 protrudes axially inward from the radially inner end portion of the first inner flange portion 9. The radially inner peripheral surface of the engaging cylindrical portion 14 is a cylindrical surface having the same inner diameter as the inner peripheral surface 3e of the outer ring 3. The radially outer peripheral surface of the engaging cylindrical portion 14 is a cylindrical surface that fits along the shoulder portion 3g of the outer ring 3. A radially outward protruding portion 14a is formed around the entire periphery of the axially inner end portion of the engaging cylindrical portion 14. The protruding portion 14a engages with a seal groove 3f on one axial side of the outer ring 3. The engaging cylindrical portion 14 is elastically deformable so that the inner diameter dimension of the protruding portion 14a increases.

[0056] The first insulating member 6 can be fitted to the outer peripheral surface 3b of the outer ring 3 by fitting the first cylindrical portion 8 to the outer peripheral surface 3b of the outer ring 3, elastically deforming the engaging cylindrical portion 14 so that the inner diameter dimension of the protruding portion 14a increases, and engaging the protruding portion 14a with the seal groove 3f on one axial side of the outer ring 3. Furthermore, the engagement between the protruding portion 14a of the engaging cylindrical portion 14 and the seal groove 3f of the outer ring 3 prevents the first insulating member 6 from slipping outward in the axial direction relative to the outer ring 3.

[0057] An engaging cylindrical portion 14 is also formed integrally with the second inner flange portion 11 of the second insulating member 7. The second insulating member 7 has the same shape as the first insulating member 6, and differs only in that the axial direction faces in the opposite direction. Therefore, the second insulating member 7 is given the same reference numeral as the engaging cylindrical portion 14 of the first insulating member 6, and a description of its structure will be omitted.

[0058] The second insulating member 7 can be fitted to the outer peripheral surface 3b of the outer ring 3 by fitting the second cylindrical portion 10 to the outer peripheral surface 3b of the outer ring 3, elastically deforming the engaging cylindrical portion 14 so that the inner diameter dimension of the protruding portion 14a increases, and engaging the protruding portion 14a with the seal groove 3f on the other axial side of the outer ring 3. Furthermore, the engagement between the protruding portion 14a of the engaging cylindrical portion 14 and the seal groove 3f of the outer ring 3 prevents the second insulating member 7 from slipping outward in the axial direction relative to the outer ring 3.

[0059] As shown in Figure 6, in the rolling bearing 21 of this second embodiment, the first cylindrical portion 8 of the first insulating member 6 and the second cylindrical portion 10 of the second insulating member 7 are fitted side by side in the axial direction to the outer peripheral surface 3b of the outer ring 3 with an axial gap between them.

[0060] Furthermore, in this rolling bearing 21, as with the rolling bearing 1 of the first embodiment, the first insulating member 6 and second insulating member 7 are separate from the outer ring 3 and are manufactured independently of the outer ring 3. Therefore, there is no concern about damage to or adhesion of foreign matter to the outer ring raceway surface 3a of the outer ring 3 or the inner circumferential surface of the outer ring 3 during manufacturing of the outer ring 3, minimizing the impact on quality. Furthermore, because there is no need to machine a circumferential groove into the outer circumferential surface 3b of the outer ring 3, the outer ring 3 can be manufactured at low cost. [Explanation of symbols]

[0061] 1. Rolling bearings 2. Inner circle 2a Inner ring raceway surface 3 outer ring 3a Outer ring raceway 3b Outer surface 3c, 3d end face 3e Inner surface 3f seal groove 4 rolling elements 5 Cage 6. First insulating member 7 Second insulating member 8 First cylindrical part 9 First inner flange 10 Second cylindrical part 11 Second inner flange 12 Protrusion 12a base 12b Tip 12c Guide edge 13 Receiving recess 13a Narrow part 13b Inside 14 Engagement tube portion 14a Protrusion 20 Engagement portion 21 Rolling bearings w Engagement gap

Claims

1. With inner circle, The outer ring and a plurality of rolling elements interposed between the inner ring and the outer ring; a cage that holds the plurality of rolling elements; a first insulating member made of resin, the first insulating member having a cylindrical portion fitted to the outer peripheral surface of the outer ring and an inner flange portion covering one axial end face of the outer ring; a second insulating member made of resin having a cylindrical portion fitted to the outer peripheral surface of the outer ring and an inner flange portion covering the other axial end face of the outer ring, a rolling bearing in which the cylindrical portion of the first insulating member and the cylindrical portion of the second insulating member are fitted to the outer peripheral surface of the outer ring in a line in the axial direction with an axial gap therebetween.

2. the cylindrical portion of the first insulating member and the cylindrical portion of the second insulating member have engaging portions that engage with each other in the axial direction, and the engaging portions are formed at a plurality of locations spaced apart in the circumferential direction, one of the engaging portions that engage with each other in the axial direction is a protrusion that protrudes outward in the axial direction, and the other of the engaging portions that engage with each other in the axial direction is a receiving recess that opens on the inner side in the axial direction and is recessed on the outer side in the axial direction, 2. A rolling bearing according to claim 1, wherein said projection is engaged with an inner surface of said receiving recess with an axial engagement gap therebetween.

3. 3. A rolling bearing according to claim 2, wherein the first insulating member and the second insulating member have cylindrical portions and inner flanges having the same shape, the engaging portions are provided at an even number of locations, and the cylindrical portions of the first insulating member and the second insulating member have protrusions and receiving recesses of the engaging portions formed alternately at equal intervals along the circumferential direction.

4. the protrusion has a base portion located axially inside and a tip portion having a circumferential width dimension larger than that of the base portion, and the tip portion is elastically deformable so as to reduce the circumferential width dimension; 4. The rolling bearing according to claim 2, wherein the receiving recess has a narrow portion that opens axially inward, and the circumferential width of the narrow portion is larger than the circumferential width of the base portion.

5. 5. A rolling bearing as described in claim 4, wherein a guide edge portion is formed at the tip portion of the protrusion portion on the axial side of the receiving recess portion, and the guide edge portion is inclined axially toward the base portion side as it extends circumferentially outward.

6. the outer ring has seal grooves provided on both axial sides of its inner peripheral surface, the first insulating member and the second insulating member each have an engaging cylindrical portion extending axially inward from the inner flange portion, 2. The rolling bearing according to claim 1, wherein the cylindrical engaging portion is elastically deformable in the radial direction, and the cylindrical engaging portion has a protrusion that engages with a seal groove of the outer ring.

7. 2. The rolling bearing according to claim 1, wherein the cylindrical portions of the first insulating member and the second insulating member have a thickness of 0.3 mm or more.

8. 2. The rolling bearing according to claim 1, wherein the material of the first insulating member and the second insulating member is a resin composition containing a resin containing at least one of a polyphenylene sulfide resin, a polyamide resin, and an epoxy resin, and a fiber containing at least one of a glass fiber, a carbon fiber, and an aramid fiber.

9. 9. The rolling bearing according to claim 8, wherein the first insulating member and the second insulating member are injection-molded products, and the flow direction of the resin composition in the first insulating member and the second insulating member is aligned along the circumferential direction.

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