Insulation rolling bearing unit

Abstract

To provide an insulation rolling bearing unit which can stably secure insulation properties between a housing in which an outer ring is incorporated and the outer ring.SOLUTION: In an insulation rolling bearing unit in which an outer ring 3 has an outer ring width surface 9, an outer peripheral cylindrical surface 10, and an outer ring chamfered part 11, and the entire outer peripheral cylindrical surface 10 and at least a part of the outer ring chamfered part 11 are coated with an insulation coating 12, the radius of curvature of an arc of the cross section of the outer ring chamfered part 11 is set to 10 mm or more.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an insulating rolling bearing unit. [Background technology]

[0002] Electric vehicles such as EVs (battery electric vehicles) and HEVs (hybrid electric vehicles) are known as vehicles that use electric motors as a driving force. In these electric vehicles, an inverter is used to convert the DC power of the battery into AC power in order to supply AC power to the electric motor, and the frequency of the AC power supplied to the electric motor is set high in order to increase the efficiency of the electric motor.

[0003] Here, when the frequency of the AC power supplied to the electric motor becomes high, the potential difference generated between the main shaft of the electric motor and the motor housing makes it easier for current to flow in the rolling bearing that supports the main shaft of the electric motor. When current flows in the rolling bearing, sparks are generated between the raceway surface and the rolling elements of the rolling bearing, and the sparks can cause a phenomenon (electrical corrosion) in which damage to the raceway surface gradually progresses.

[0004] Known insulated rolling bearing units capable of preventing this electrolytic corrosion are those described in Patent Documents 1 and 2. The insulated rolling bearing units of Patent Documents 1 and 2 have a rolling bearing and an annular insulating washer provided axially adjacent to the outer ring of the rolling bearing. The outer ring has an outer ring width surface perpendicular to the axial direction formed at the axial end on the insulating washer side, an outer peripheral cylindrical surface with a constant outer diameter along the axial direction, and an outer ring chamfered portion with an arc-shaped cross section connecting between the outer peripheral cylindrical surface and the outer ring width surface, and the outer peripheral cylindrical surface and the outer ring chamfered portion are coated with an insulating coating.

[0005] This insulating rolling bearing unit has an insulating washer provided axially adjacent to the outer ring, so that a large axial creepage distance can be secured between the outer ring width face and the axial end face of the inner circumference of the housing, which positions the outer ring axially, making it possible to stably ensure axial insulation. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Utility Model Application Publication No. 5-38420 [Patent Document 2] Patent Publication No. 2021-76227 Summary of the Invention [Problem to be solved by the invention]

[0007] In the insulated rolling bearing units of Patent Documents 1 and 2, in order to ensure radial insulation between the outer ring and the inner circumference of the housing, it is necessary to coat the entire outer cylindrical surface of the outer ring and the entire outer ring chamfer portion with an insulating coating.

[0008] However, it was found that, of the insulating coating applied to the outer cylindrical surface and outer ring chamfer of the outer ring, the portion coated on the outer ring chamfer is relatively more prone to peeling off than the portion coated on the outer cylindrical surface, and there is a risk of peeling off from the end of the outer ring chamfer on the outer ring width face side (i.e., the boundary between the outer ring chamfer and the outer ring width face).

[0009] If the insulating coating applied to the outer ring chamfer peels off from the edge on the outer ring width face side, it is no longer possible to ensure the radial creepage distance between the part of the outer ring chamfer where the insulating coating has peeled off and the inner circumference of the housing, which could result in electrolytic corrosion of the rolling bearing.

[0010] An object of the present invention is to provide an insulating rolling bearing unit that can stably ensure insulation performance between the outer ring and a housing in which the outer ring is assembled. [Means for solving the problem]

[0011] Incidentally, in a typical rolling bearing, the radius of curvature of the arc of the cross section of the outer ring chamfer having an arc-shaped cross section is set to about 2 mm to 3 mm.

[0012] The inventors of the present application came up with the idea that if the radius of curvature of the arc of the cross section of this outer ring chamfer is made larger than the radius of curvature of the arc of the cross section of a typical outer ring chamfer (approximately 2 mm to 3 mm), it is possible to increase the radial distance between the inner circumference of the housing to which the outer ring is assembled and the outer ring chamfer; as a result, even if part of the insulating coating coated on the outer ring chamfer peels off, it will be possible to ensure the radial surface distance between the part of the outer ring chamfer where the insulating coating has peeled off and the inner circumference of the housing.

[0013] Based on this idea, in order to solve the above problems, the present invention provides an insulating rolling bearing unit having the following configuration. [Configuration 1] a rolling bearing including an outer ring, an inner ring disposed radially inside the outer ring, and a plurality of rolling elements disposed between the outer ring and the inner ring; an annular insulating washer provided adjacent to the outer ring in the axial direction, the outer ring has an outer ring width surface perpendicular to the axial direction formed at an axial end on the insulating washer side, an outer peripheral cylindrical surface having a constant outer diameter along the axial direction, and an outer ring chamfered portion having an arc-shaped cross section connecting the outer peripheral cylindrical surface and the outer ring width surface, an insulating rolling bearing unit in which the entire outer peripheral cylindrical surface and at least a part of the outer ring chamfered portion are coated with an insulating coating, An insulating rolling bearing unit, characterized in that the radius of curvature of the arc of the cross section of the outer ring chamfer is set to 10 mm or more.

[0014] When this configuration is adopted, the radius of curvature of the arc of the cross section of the outer ring chamfer is larger than the radius of curvature of the arc of the cross section of a typical outer ring chamfer (approximately 2 mm to 3 mm), so the radial distance between the inner circumference of the housing in which the outer ring is assembled and the outer ring chamfer is increased, making it possible to stably ensure insulation performance between the outer ring and the housing in which the outer ring is assembled.

[0015] [Configuration 2] 2. The insulated rolling bearing unit according to configuration 1, wherein the insulating coating is coated only on a portion of the outer ring chamfered portion from an end of the outer ring chamfered portion on the side of the outer peripheral cylindrical surface to a portion midway in the axial direction of the outer ring chamfered portion, and an axial range of the outer ring chamfered portion from a portion midway in the axial direction of the outer ring chamfered portion to an end of the outer ring chamfered portion on the side of the outer ring width surface is not coated with the insulating coating, forming an exposed surface of the steel material constituting the outer ring.

[0016] By adopting this configuration, the insulating coating on the outer ring chamfer is not coated on the end of the outer ring chamfer on the outer ring width face side (i.e., the boundary between the outer ring chamfer and the outer ring width face), which is the part that is likely to cause the insulating coating to peel off, making it possible to suppress peeling of the insulating coating on the outer ring chamfer.

[0017] [Configuration 3] 3. The insulated rolling bearing unit according to claim 1, wherein the insulating coating is coated over an area of ​​the outer ring chamfered portion from the end of the outer ring chamfered portion on the outer cylindrical surface side to 50% or more and 70% or less of the axial width dimension of the outer ring chamfered portion.

[0018] By adopting this configuration, it is possible to ensure the radial surface distance between the portion of the outer ring chamfer that is not coated with the insulating coating and the inner circumference of the housing, while reducing the area to be coated with the insulating coating, thereby reducing costs.

[0019] [Configuration 4] 4. An insulating rolling bearing unit according to any one of configurations 1 to 3, wherein the insulating washer has an annular plate portion axially facing the outer ring width surface, and an annular protrusion formed to protrude in the axial direction from the radial outer end of the annular plate portion so as to surround the outer ring chamfer portion from the radial outside.

[0020] When this configuration is adopted, the insulating washer has an annular protrusion that surrounds the outer ring chamfered portion from the radially outside, making it possible to more stably ensure insulation performance between the inner circumference of the housing to which the outer ring is assembled and the outer ring chamfered portion.

[0021] [Configuration 5] 5. The insulating rolling bearing unit according to any one of configurations 1 to 4, wherein the insulating washer is formed by coating the entire surface of a metal washer with a resin film.

[0022] [Configuration 6] 5. The insulating rolling bearing unit according to any one of configurations 1 to 4, wherein the insulating washer is made of insulating resin.

[0023] [Configuration 7] 7. The insulated rolling bearing unit according to any one of configurations 1 to 6, wherein the thickness of the insulating coating is set to 10 to 50 μm.

[0024] In this way, since the thickness of the insulating film is 50 μm or less, peeling of the insulating film can be effectively suppressed.

[0025] [Configuration 8] 8. The insulating rolling bearing unit according to any one of configurations 1 to 7, wherein the axial width dimension and radial width dimension of the outer ring chamfered portion are each set to 3.5 mm or less.

[0026] [Configuration 9] 9. An insulating rolling bearing unit according to any one of configurations 1 to 8, wherein the axial width dimension of the outer ring chamfered portion is set to 2.0 mm or more, and the radial width dimension of the outer ring chamfered portion is set to 0.5 mm or more. Effect of the Invention

[0027] In the insulating rolling bearing unit of the present invention, the radius of curvature of the arc of the cross section of the outer ring chamfer is larger than the radius of curvature of the arc of the cross section of a typical outer ring chamfer (approximately 2 mm to 3 mm), and therefore the radial distance between the inner circumference of the housing in which the outer ring is assembled and the outer ring chamfer is large, making it possible to stably ensure insulation performance between the outer ring and the housing in which the outer ring is assembled. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a cross-sectional view showing a state in which an insulating rolling bearing unit according to a first embodiment of the present invention is mounted in a housing; [Diagram 2] An enlarged cross-sectional view of the insulating washer in FIG. 1 [Diagram 3] FIG. 3 is an enlarged cross-sectional view showing a second embodiment of the present invention, corresponding to FIG. 2. [Figure 4] FIG. 2 is a cross-sectional view showing a third embodiment of the present invention, corresponding to FIG. 1. [Diagram 5] An enlarged cross-sectional view of the insulating washer in FIG. [Figure 6] FIG. 4 is a cross-sectional view showing a fourth embodiment of the present invention, corresponding to FIG. 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] 1 shows an insulating rolling bearing unit according to a first embodiment of the present invention. The insulating rolling bearing unit has a rolling bearing 1 and an annular insulating washer 2.

[0030] The rolling bearing 1 has an outer ring 3, an inner ring 4 arranged coaxially radially inside the outer ring 3, a plurality of rolling elements 5 assembled between the outer ring 3 and the inner ring 4 at intervals circumferentially, and a retainer 6 which maintains the circumferential spacing of the plurality of rolling elements 5.

[0031] The outer ring 3, the inner ring 4, and the rolling elements 5 are each formed of steel. Here, the rolling elements 5 are balls. The rolling elements 5 are radially sandwiched between an outer ring raceway groove 7 formed on the inner circumference of the outer ring 3 and an inner ring raceway groove 8 formed on the outer circumference of the inner ring 4. The outer ring raceway groove 7 and the inner ring raceway groove 8 are grooves whose cross sections perpendicular to the circumferential direction are arc-shaped.

[0032] As shown in FIG. 2, the outer ring 3 has an outer ring width surface 9 perpendicular to the axial direction formed at the axial end on the insulating washer 2 side (the left side in the figure), an outer peripheral cylindrical surface 10 whose outer diameter does not change along the axial direction, and an outer ring chamfered portion 11 having an arc-shaped cross section connecting the outer peripheral cylindrical surface 10 and the outer ring width surface 9.

[0033] The entire outer peripheral cylindrical surface 10 and the entire outer ring chamfered portion 11 are coated with an insulating coating 12. On the other hand, the outer ring width surface 9 is not coated with the insulating coating 12, and the steel material constituting the outer ring 3 is exposed.

[0034] The insulating coating 12 is made of a resin. Examples of resins that can be used to form the insulating coating 12 include polyamideimide resin, polyamide resin, polyimide resin, fluororesin, isocyanate resin, silicone resin, furan resin, butyral resin, elastomer resin, epoxy resin, phenol resin, urea resin, amino resin, and acrylic resin. The insulating coating 12 can be formed by subjecting the outer peripheral cylindrical surface 10 and the outer ring chamfered portion 11 of the outer ring 3 to a surface treatment, applying a resin dissolved in a solvent, and baking the dried coating. The insulating coating 12 has a thickness of 10 to 50 μm and has a withstand voltage of 0.01 kV / μm or more. Note that the thickness of the insulating coating 12 is exaggerated in the figure for ease of understanding, but the actual thickness of the insulating coating 12 is much thinner than that shown in the figure.

[0035] In a typical rolling bearing, the radius of curvature of the arc of the cross section of the outer ring chamfered portion 11 is set to about 2 mm to 3 mm, but in this embodiment, the radius of curvature of the arc of the cross section of the outer ring chamfered portion 11 is set to 10 mm or more. The axial width dimension of the outer ring chamfered portion 11 (i.e., the axial distance from the boundary between the outer ring chamfered portion 11 and the outer peripheral cylindrical surface 10 to the boundary between the outer ring chamfered portion 11 and the outer ring width surface 9) is set to 2.0 mm or more and 3.5 mm or less. The radial width dimension of the outer ring chamfered portion 11 (i.e., the radial distance from the boundary between the outer ring chamfered portion 11 and the outer peripheral cylindrical surface 10 to the boundary between the outer ring chamfered portion 11 and the outer ring width surface 9) is set to 0.5 mm or more (preferably 1.0 mm or more, more preferably 1.5 mm or more) and 3.5 mm or less.

[0036] The insulating washer 2 is provided adjacent to the outer ring 3 in the axial direction. The insulating washer 2 is formed in a flat plate shape with a constant axial thickness along the radial direction. The insulating washer 2 is annular in shape covering the outer ring width surface 9 when viewed from the axial direction. The inner diameter of the insulating washer 2 is smaller than the diameter of the radially inner end of the outer ring width surface 9.

[0037] 2, the insulating washer 2 is formed by coating the entire surface of a washer 13 made of metal (stainless steel, etc.) with a resin film 14. Examples of the resin that can be used to form the resin film 14 include polyamideimide resin, polyamide resin, polyimide resin, fluororesin, isocyanate resin, silicone resin, furan resin, butyral resin, elastomer resin, epoxy resin, phenol resin, urea resin, amino resin, and acrylic resin. The resin film 14 has a thickness of 10 to 50 μm and a withstand voltage of 0.01 kV / μm or more.

[0038] This insulating rolling bearing unit can be used by being assembled to a housing 15, as shown in Figures 1 and 2. As shown in Figure 2, the housing 15 has a cylindrical inner peripheral fitting surface 16 that fits into the outer peripheral cylindrical surface 10 of the outer ring 3, an axial end face 17 that extends radially inward from the axial end of the inner peripheral fitting surface 16, and an inner peripheral cylindrical surface 18 that extends from the radial inner end of the axial end face 17 to the side opposite the inner peripheral fitting surface 16 (the left side in the figure). The insulating washer 2 is assembled by abutting against the axial end face 17 of the housing 15. The inner diameter of the insulating washer 2 is set to be smaller than the inner diameter of the inner peripheral cylindrical surface 18 of the housing 15.

[0039] 2 is set to 10 mm or more, which is larger than the radius of curvature of the arc of a cross section of a typical outer ring chamfered portion 11 (approximately 2 mm to 3 mm), so that the radial distance between the inner fitting surface 16 of the housing 15 and the outer ring chamfered portion 11 is large. Therefore, even if part of the insulating coating 12 coated on the outer ring chamfered portion 11 peels off from the end of the outer ring chamfered portion 11 on the outer ring width surface 9 side (i.e., the boundary between the outer ring chamfered portion 11 and the outer ring width surface 9), it is possible to ensure the radial creepage distance between the part of the outer ring chamfered portion 11 where the insulating coating 12 has peeled off and the inner fitting surface 16 of the housing 15, and it is possible to stably ensure the insulation performance between the housing 15 and the outer ring 3.

[0040] Moreover, since the thickness of the insulating coating 12 is 50 μm or less, peeling of the insulating coating 12 can be effectively prevented.

[0041] 3 shows a second embodiment of the present invention. The second embodiment is different from the first embodiment in the shape of the insulating washer 2, but the other configurations are the same. The parts corresponding to the first embodiment are given the same reference numerals and the description will be omitted.

[0042] The insulating washer 2 has an annular plate portion 19 axially opposed to the outer ring width surface 9, and an annular protrusion 20 formed to protrude axially from the radial outer end of the annular plate portion 19 so as to surround the outer ring chamfer portion 11 from the radial outside.

[0043] The annular plate portion 19 is formed in a flat plate shape with a constant axial thickness along the radial direction. The annular plate portion 19 is annular and covers the outer ring width surface 9 when viewed from the axial direction. The inner diameter of the annular plate portion 19 is smaller than the diameter of the radial inner end of the outer ring width surface 9. The annular protrusion 20 has a tapered cross-sectional shape whose radial width gradually decreases toward the tip. The inner circumference of the annular protrusion 20 is curved to have a concave arc-shaped cross section that fits into the outer ring chamfered portion 11.

[0044] In the insulating rolling bearing unit of this embodiment, the insulating washer 2 has the annular protrusion 20 that surrounds the outer ring chamfered portion 11 from the radial outside, making it possible to more stably ensure insulation performance between the inner periphery of the housing 15 to which the outer ring 3 is assembled and the outer ring chamfered portion 11. Other effects and advantages are similar to those of the first embodiment.

[0045] 4 and 5 show a third embodiment of the present invention. The third embodiment is different from the first embodiment in the coating range of the insulating coating 12 and the material of the insulating washer 2, but the other configurations are the same. Parts corresponding to those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0046] As shown in FIG. 5, of the outer ring chamfered portion 11, the insulating coating 12 is applied only to the range from the end of the outer ring chamfered portion 11 on the side of the outer peripheral cylindrical surface 10 (the right side in the figure) to halfway along the axial direction of the outer ring chamfered portion 11, and the axial range of the outer ring chamfered portion 11 from halfway along the axial direction of the outer ring chamfered portion 11 to the end of the outer ring chamfered portion 11 on the side of the outer ring width surface 9 (the left side in the figure) is not coated with the insulating coating 12, leaving an exposed surface of the steel material that constitutes the outer ring 3.

[0047] Here, the insulating coating 12 is coated over an area of ​​the outer ring chamfer 11, from the end position of the outer ring chamfer 11 on the side of the outer peripheral cylindrical surface 10 (the right side in the figure), which is 50% to 70% of the axial width dimension of the outer ring chamfer 11 (i.e., the axial distance from the boundary between the outer ring chamfer 11 and the outer peripheral cylindrical surface 10 to the boundary between the outer ring chamfer 11 and the outer ring width surface 9).

[0048] The insulating washer 2 is integrally formed from insulating resin in which fiber reinforcement such as glass fiber is added to the resin material. Examples of the insulating resin that can be used include polyamide-imide resin, polyamide resin, polyimide resin, fluororesin, isocyanate resin, silicone resin, furan resin, butyral resin, elastomer resin, epoxy resin, phenol resin, urea resin, amino resin, and acrylic resin.

[0049] In the insulated rolling bearing unit of this embodiment, the insulating coating 12 on the outer ring chamfered portion 11 is not coated on the end of the outer ring chamfered portion 11 on the outer ring width face 9 side (i.e., the boundary between the outer ring chamfered portion 11 and the outer ring width face 9), which is the portion that is likely to cause the insulating coating 12 to peel off, and therefore it is possible to suppress peeling of the insulating coating 12 on the outer ring chamfered portion 11.

[0050] Furthermore, in the insulating rolling bearing unit of this embodiment, the outer ring chamfered portion 11 is coated over a range of 50% to 70% of the axial width dimension of the outer ring chamfered portion 11 from the end of the outer ring chamfered portion 11 on the side of the outer cylindrical surface 10 (the right side in the figure), so that it is possible to reduce the area coated with the insulating coating 12 and reduce costs while maintaining the radial surface distance between the part of the outer ring chamfered portion 11 that is not coated with the insulating coating 12 and the inner mating surface 16 of the housing 15.

[0051] 6 shows a fourth embodiment of the present invention. The fourth embodiment is different from the third embodiment in the shape of the insulating washer 2, but the other configurations are the same. The parts corresponding to the third embodiment are given the same reference numerals and the description will be omitted.

[0052] The insulating washer 2 has an annular plate portion 19 axially opposed to the outer ring width surface 9, and an annular protrusion 20 formed to protrude axially from the radial outer end of the annular plate portion 19 so as to surround the outer ring chamfer portion 11 from the radial outside.

[0053] The annular plate portion 19 is formed in a flat plate shape with a constant thickness in the axial direction along the radial direction. The annular plate portion 19 is annular and covers the outer ring width surface 9 when viewed from the axial direction. The inner diameter of the annular plate portion 19 is smaller than the diameter of the radial inner end of the outer ring width surface 9. The annular protrusion 20 has a tapered cross-sectional shape whose radial width gradually decreases toward the tip. The inner circumference of the annular protrusion 20 is curved to have a concave arc-shaped cross section that fits into the outer ring chamfered portion 11. The tip of the annular protrusion 20 is arranged to overlap the insulating coating 12 coated on the outer ring chamfered portion 11 in the radial direction.

[0054] In the insulating rolling bearing unit of this embodiment, the insulating washer 2 has an annular protrusion 20 that surrounds the outer ring chamfered portion 11 from the radial outside, making it possible to more stably ensure insulation performance between the inner circumference of the housing 15 to which the outer ring 3 is assembled and the outer ring chamfered portion 11.

[0055] Furthermore, in the insulating rolling bearing unit of this embodiment, the tip of the annular protrusion 20 of the insulating washer 2 and the insulating coating 12 coated on the outer ring chamfered portion 11 are positioned so as to overlap radially, ensuring radial insulation between the inner mating surface 16 of the housing 15 and the outer ring chamfered portion 11.

[0056] In addition, in the insulating rolling bearing unit of this embodiment, since the insulating washer 2 is made of insulating resin, the annular projection 20 of the insulating washer 2 can be easily formed by a mold, resulting in low cost. Other functions and effects are similar to those of the third embodiment.

[0057] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0058] 1. Rolling bearings 2 Insulating washers 3 Outer ring 4. Inner Circle 5 Rolling elements 9 Outer ring width 10 Outer cylindrical surface 11 Outer ring chamfer 12 Insulation film 13 Washer 14 Resin film 19 Annular plate 20 Ring-shaped protrusion

Claims

1. A rolling bearing (1) having an outer ring (3), an inner ring (4) disposed radially inside the outer ring (3), and a plurality of rolling elements (5) assembled between the outer ring (3) and the inner ring (4); and an annular insulating washer (2) provided adjacent to the outer ring (3) in the axial direction, the outer ring (3) has an outer ring width surface (9) perpendicular to the axial direction formed at an axial end on the insulating washer (2) side, an outer peripheral cylindrical surface (10) having a constant outer diameter along the axial direction, and an outer ring chamfered portion (11) having an arc-shaped cross section connecting between the outer peripheral cylindrical surface (10) and the outer ring width surface (9); The entire outer peripheral cylindrical surface (10) and at least a part of the outer ring chamfered portion (11) are coated with an insulating coating (12), The insulated rolling bearing unit is characterized in that the radius of curvature of the arc of the cross section of the outer ring chamfered portion (11) is set to 10 mm or more.

2. 2. The insulated rolling bearing unit according to claim 1, wherein the insulating coating (12) is coated only on a portion of the outer ring chamfered portion (11) from an end of the outer ring chamfered portion (11) on the side of the outer peripheral cylindrical surface (10) to a portion of the outer ring chamfered portion (11) in the axial direction, and an axial range of the outer ring chamfered portion (11) from a portion of the outer ring chamfered portion (11) in the axial direction to an end of the outer ring chamfered portion (11) on the side of the outer ring width surface (9) is not coated with the insulating coating (12), forming an exposed surface of the steel material constituting the outer ring (3).

3. 3. The insulated rolling bearing unit according to claim 2, wherein the insulating coating (12) is coated over an area of ​​the outer ring chamfered portion (11) from an end of the outer ring chamfered portion (11) on the outer peripheral cylindrical surface (10) side to 50% or more and 70% or less of an axial width dimension of the outer ring chamfered portion (11).

4. 4. An insulating rolling bearing unit as described in any one of claims 1 to 3, wherein the insulating washer (2) has an annular plate portion (19) axially opposed to the outer ring width surface (9), and an annular protrusion (20) formed protruding in the axial direction from the radial outer end of the annular plate portion (19) so as to surround the outer ring chamfer portion (11) from the radial outside.

5. 4. The insulating rolling bearing unit according to claim 1, wherein the insulating washer (2) is formed by coating the entire surface of a metal washer (13) with a resin film (14).

6. 4. The insulating rolling bearing unit according to claim 1, wherein the insulating washer (2) is made of insulating resin.

7. 4. The insulated rolling bearing unit according to claim 1, wherein the thickness of the insulating film (12) is set to 10 to 50 μm.

8. 4. The insulating rolling bearing unit according to claim 1, wherein the axial width and radial width of the outer ring chamfered portion (11) are set to 3.5 mm or less.

9. 4. An insulating rolling bearing unit according to claim 1, wherein the axial width dimension of the outer ring chamfered portion (11) is set to 2.0 mm or more, and the radial width dimension of the outer ring chamfered portion (11) is set to 0.5 mm or more.

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