Insulation rolling bearing unit

Abstract

To provide an insulation rolling bearing unit which can stably secure insulation performance between a housing into which an outer ring is assembled and an outer ring chamfer part.SOLUTION: An insulation rolling bearing unit has a rolling bearing 1 and an insulation washer 2. An outer ring 3 has an outer ring width surface 9, an outer peripheral cylindrical surface 10, and an outer ring chamber part 11. The outer peripheral cylindrical surface 10 is coated with an insulation coating 12. The insulation washer 2 has an annular projection 14.SELECTED DRAWING: Figure 1

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] Incidentally, when rolling bearings whose outer rings are coated with an insulating coating are mass-produced, the thickness of the insulating coating applied to the outer ring is measured to control whether the coating is of the designed thickness.

[0008] Here, the thickness of the insulating coating on the outer peripheral cylindrical surface of the outer ring can be easily measured using an electromagnetic thickness gauge or the like, but because the insulating coating on the outer ring chamfer is coated on a surface with a large radius of curvature, it is difficult to measure the thickness with an electromagnetic thickness gauge or the like.

[0009] For this reason, in order to guarantee the insulating performance of the insulating coating on the outer ring chamfer, it was necessary to conduct an insulating performance test (current test) on the insulating coating on the outer ring chamfer.

[0010] The problem to be solved by the present invention is to provide an insulating rolling bearing unit capable of stably ensuring insulation performance between a housing in which the outer ring is assembled and a chamfered portion of the outer ring. [Means for solving the problem]

[0011] 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, an insulating rolling bearing unit, wherein 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, an outer ring chamfer formed between the outer peripheral cylindrical surface and the outer ring width surface, and an insulating coating coating the outer peripheral cylindrical surface, an insulating rolling bearing unit characterized in that the insulating washer has an annular plate portion axially facing the outer ring width surface, and an annular protrusion formed to protrude axially from the radial outer end of the annular plate portion so as to surround the outer ring chamfer portion from the radial outside.

[0012] With this configuration, the insulating washer has an annular protrusion that surrounds the outer race chamfered portion from the radially outside, so insulation between the inner periphery of the housing to which the outer race is assembled and the outer race chamfered portion can be achieved by the annular protrusion of the insulating washer without relying on an insulating coating, thereby ensuring stable insulation performance between the housing to which the outer race is assembled and the outer race chamfered portion.

[0013] [Configuration 2] 2. The electrically insulating rolling bearing unit according to claim 1, wherein the annular projection has a tapered cross-sectional shape in which the radial width gradually decreases toward the tip.

[0014] By adopting this configuration, the annular protrusion of the insulating washer can easily enter the radial gap between the housing to which the outer ring is assembled and the outer ring chamfered portion, making it possible for the annular protrusion of the insulating washer to reliably surround the outer ring chamfered portion.

[0015] [Configuration 3] the outer ring has a slightly inclined surface, which has a linear cross section and is inclined at an angle of 10° or less with respect to the outer peripheral cylindrical surface, between the outer peripheral cylindrical surface and the outer ring chamfered portion, the slightly inclined surface is coated with the insulating coating, 3. The insulating rolling bearing unit according to claim 1, wherein the annular protrusion has an insertion portion at a tip thereof that is inserted into an annular gap on the radial outside of the slight inclination surface.

[0016] When this configuration is adopted, the tip of the annular protrusion of the insulating washer and the insulating coating coated on the slightly inclined surface of the outer periphery of the outer ring overlap radially, thereby ensuring radial insulation between the outer ring and the housing in which the outer ring is assembled.

[0017] [Configuration 4] 4. The insulated rolling bearing unit according to any one of configurations 1 to 3, wherein the outer ring chamfer portion is not coated with the insulating coating.

[0018] By adopting this configuration, the area to be coated with the insulating film can be reduced, thereby reducing costs.

[0019] [Configuration 5] The insulating washer further includes a second annular protrusion formed to protrude in the axial direction from a radial inner end of the annular plate portion, 5. The insulating rolling bearing unit according to claim 1, wherein the second annular projection is fitted onto the inner periphery of the outer ring.

[0020] When this configuration is employed, the insulating washer and the outer ring can be positioned in the radial direction by fitting the second annular projection into the inner periphery of the outer ring.

[0021] [Configuration 6] an outer ring raceway groove with which the rolling elements roll and contact, and an annular groove extending in a circumferential direction between the outer ring raceway groove and the outer ring width surface are formed on an inner circumference of the outer ring; 5. The insulating rolling bearing unit according to any one of configurations 1 to 4, wherein the insulating washer has an engaging claw portion that engages with the annular groove.

[0022] When this configuration is adopted, the insulating washer is held on the outer ring by engagement between the engaging claw portion and the annular groove so that it does not come off the outer ring width face, making it possible to handle the rolling bearing and insulating washer as a single assembly.

[0023] [Configuration 7] 7. The insulating rolling bearing unit according to configuration 6, wherein the engaging claw portion is provided in a plurality of portions spaced apart from each other in the circumferential direction.

[0024] When this configuration is adopted, the insulating washer and the outer ring can be positioned in the radial direction by the engagement between the multiple engaging claws and the annular groove.

[0025] [Configuration 8] 8. The insulating rolling bearing unit according to any one of configurations 1 to 7, wherein the insulating washer is made of insulating resin or insulating rubber.

[0026] By adopting this configuration, the annular projection of the insulating washer can be easily formed using a mold, resulting in low cost.

[0027] [Configuration 9] 9. The insulated rolling bearing unit according to any one of configurations 1 to 8, wherein the thickness of the insulating coating is set to 10 to 50 μm. Effect of the Invention

[0028] In the insulating rolling bearing unit of the present invention, the insulating washer has an annular protrusion that radially surrounds the outer ring chamfer, so insulation between the inner periphery of the housing to which the outer ring is assembled and the outer ring chamfer can be achieved by the annular protrusion of the insulating washer without relying on an insulating coating, thereby ensuring stable insulation performance between the housing to which the outer ring is assembled and the outer ring chamfer. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a cross-sectional view showing an insulating rolling bearing unit according to a first embodiment of the present invention; [Diagram 2] A partially enlarged cross-sectional view showing the insulated rolling bearing unit of FIG. 1 mounted in a housing. [Diagram 3] FIG. 4 is a cross-sectional view showing an insulating rolling bearing unit according to a second embodiment of the present invention. [Figure 4]FIG. 4 is a partially enlarged cross-sectional view showing the insulated rolling bearing unit of FIG. 3 mounted in a housing. [Diagram 5] FIG. 11 is a cross-sectional view showing an insulating rolling bearing unit according to a third embodiment of the present invention. [Figure 6] FIG. 6 is a partially enlarged cross-sectional view showing the insulated rolling bearing unit of FIG. 5 mounted in a housing. [Figure 7] FIG. 11 is a cross-sectional view showing an insulating rolling bearing unit according to a fourth embodiment of the present invention. [Figure 8] FIG. 13 is a cross-sectional view showing an insulating rolling bearing unit according to a fifth embodiment of the present invention. [Figure 9] Axial view of the insulating washer in Figure 8 [Figure 10] FIG. 13 is a cross-sectional view showing an insulating rolling bearing unit according to a sixth embodiment of the present invention. [Figure 11] FIG. 11 is a partially enlarged cross-sectional view showing the insulated rolling bearing unit of FIG. 10 assembled into a housing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] 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.

[0031] 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.

[0032] The outer ring 3, the inner ring 4, and the rolling elements 5 are each formed of steel. In this example, 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. It is possible to use elements other than balls as the rolling elements 5.

[0033] 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 (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 formed between the outer peripheral cylindrical surface 10 and the outer ring width surface 9. The outer ring width surface 9 and the outer peripheral cylindrical surface 10 are connected via the outer ring chamfered portion 11.

[0034] As shown in Fig. 2, the outer peripheral cylindrical surface 10 and the 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.

[0035] 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 a withstand voltage of 0.01 kV / μm or more.

[0036] The insulating washer 2 is provided axially adjacent to the outer ring 3. The insulating washer 2 has an annular plate portion 13 that faces the outer ring width surface 9 in the axial direction, and an annular protrusion 14 that is formed to protrude in the axial direction from the radial outer end of the annular plate portion 13 so as to surround the outer ring chamfered portion 11 from the radial outside.

[0037] The annular plate portion 13 is formed in a flat plate shape with a constant axial thickness along the radial direction. The annular plate portion 13 has a circular ring shape covering the outer ring width surface 9 when viewed from the axial direction. The inner diameter of the annular plate portion 13 is smaller than the diameter of the radial inner end of the outer ring width surface 9.

[0038] The annular protrusion 14 has a tapered cross-sectional shape with its radial width gradually decreasing towards its tip. The outer periphery of the annular protrusion 14 is a cylindrical surface with an outer diameter equal to or smaller than the outer diameter of the insulating coating 12 coating the outer peripheral cylindrical surface 10 of the outer ring 3, and the inner periphery of the annular protrusion 14 is a curved surface with a concave arc-shaped cross section that fits into the outer ring chamfered portion 11. The annular plate portion 13 and the annular protrusion 14 of the insulating washer 2 are integrally formed from insulating resin made of a resin material to which fiber reinforcing materials such as glass fibers have been added.

[0039] This insulating rolling bearing unit can be used by being assembled into a housing 15, as shown in Fig. 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.

[0040] 2, this insulated rolling bearing unit has an insulating washer 2 with an annular protrusion 14 that surrounds the outer ring chamfered portion 11 from the radial outside, so that insulation between the inner fitting surface 16 of the housing 15 and the outer ring chamfered portion 11 can be achieved by the annular protrusion 14 of the insulating washer 2 without relying on the insulating coating 12. This makes it possible to stably ensure the insulating performance between the housing 15 and the outer ring chamfered portion 11. Therefore, when mass-producing the rolling bearing 1, it is possible to eliminate the need for an insulation performance test (current test) to guarantee the insulating performance of the insulating coating 12 of the outer ring chamfered portion 11.

[0041] Furthermore, as shown in FIG. 1, the annular protrusion 14 of the insulating washer 2 has a tapered cross-sectional shape in which the radial width gradually decreases toward the tip, so that the annular protrusion 14 of the insulating washer 2 can easily enter the radial gap between the inner mating surface 16 of the housing 15 and the outer chamfered portion 11, enabling the annular protrusion 14 of the insulating washer 2 to reliably surround the outer chamfered portion 11.

[0042] Furthermore, since the insulating washer 2 is formed from insulating resin, the annular projection 14 of the insulating washer 2 can be easily formed using a mold, which is low cost. Here, an example has been described in which the insulating washer 2 is formed from insulating resin, but the insulating washer 2 having the shape shown in FIG. 1 may also be formed from insulating rubber. Even in this case, the annular projection 14 of the insulating washer 2 can be easily formed using a mold, which is low cost. When the insulating washer 2 is formed from insulating rubber, the rigidity of the insulating washer 2 can be ensured by adopting a configuration in which a core metal is embedded inside the insulating rubber.

[0043] A second embodiment of the present invention is shown in Figures 3 and 4. The second embodiment differs from the first embodiment only in that the outer ring chamfer 11 is not coated with the insulating coating 12, and the rest of the configuration is the same as the first embodiment. In this way, the area coated with the insulating coating 12 can be reduced, resulting in lower costs.

[0044] In this embodiment, when the insulating washer 2 is formed from insulating rubber, the insulating washer 2 is first assembled into the housing 15 (see Figure 4), and then when the rolling bearing 1 is assembled into the housing 15, the tip of the annular protrusion 14 formed from insulating rubber is pulled between the inner mating surface 16 of the housing 15 and the outer cylindrical surface 10 of the outer ring 3, thereby ensuring insulation between the inner mating surface 16 of the housing 15 and the outer ring chamfered portion 11.

[0045] A third embodiment of the present invention is shown in Figures 5 and 6. The parts corresponding to those in the first embodiment are given the same reference numerals and the description thereof will be omitted.

[0046] 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 (left side in the figure), an outer peripheral cylindrical surface 10 whose outer diameter is constant along the axial direction and does not change, an outer ring chamfered portion 11 with an arc-shaped cross section formed between the outer peripheral cylindrical surface 10 and the outer ring width surface 9, and a slightly inclined surface 19 with a linear cross section formed between the outer peripheral cylindrical surface 10 and the outer ring chamfered portion 11. The outer ring width surface 9 and the outer peripheral cylindrical surface 10 are connected to the outer ring chamfered portion 11 via the slightly inclined surface 19.

[0047] The slightly inclined surface 19 is formed in a cross-sectional linear shape inclined at an angle of 10° or less with respect to the outer peripheral cylindrical surface 10. The slightly inclined surface 19 is formed in a range of the outer circumference of the outer ring 3 that does not have a portion overlapping with the outer ring raceway groove 7 when viewed from the radial direction, or even if there is an overlapping portion, at least in a range that does not have a portion overlapping with the osculating ellipse of the rolling element 5 and the outer ring raceway groove 7.

[0048] The contact ellipse is the elliptical surface contact portion formed between the rolling element 5 and the outer ring 3 when a load is applied between them, and its dimensions are determined from a formula based on Hertz's theory, based on the magnitude of the load acting between the rolling element 5 and the outer ring 3. When determining the dimensions of the contact ellipse, the basic static radial load rating can be used for the magnitude of the load acting between the rolling element 5 and the outer ring 3.

[0049] The outer peripheral cylindrical surface 10 and the slightly inclined surface 19 are coated with an insulating coating 12. Meanwhile, the outer ring chamfer 11 and the outer ring width surface 9 are not coated with the insulating coating 12, leaving surfaces where the steel material constituting the outer ring 3 is exposed. Here, the portion of the insulating coating 12 that coats the slightly inclined surface 19, like the portion of the insulating coating 12 that coats the outer peripheral cylindrical surface 10, is coated on a surface with a small curvature, and therefore the coating thickness can be easily measured with an electromagnetic coating thickness gauge or the like.

[0050] 6, the annular protrusion 14 of the insulating washer 2 has at its tip an annular insertion portion 20 that is inserted into an annular gap on the radial outside of the slightly inclined surface 19. In the figure, the insertion portion 20 is shown as being inserted to the deepest position of the annular gap between the inner fitting surface 16 of the housing 15 and the slightly inclined surface 19 on the outer periphery of the outer ring 3, but the insertion portion 20 may be inserted to a position halfway in the axial direction of the annular gap between the inner fitting surface 16 of the housing 15 and the slightly inclined surface 19 on the outer periphery of the outer ring 3.

[0051] As shown in Figure 6, in the insulating rolling bearing unit of this embodiment, the tip of the annular protrusion 14 of the insulating washer 2 and the insulating coating 12 coated on the slightly inclined surface 19 on the outer periphery of the outer ring 3 overlap radially, ensuring radial insulation between the inner fitting surface 16 of the housing 15 and the outer ring chamfered portion 11.

[0052] Also, as in the second embodiment, outer ring chamfer 11 is not coated with insulating coating 12, so the area coated with insulating coating 12 can be reduced, resulting in low costs. Other effects are the same as in the first embodiment.

[0053] 7 shows a fourth embodiment of the present invention. In the fourth embodiment, a second annular protrusion 21 is added to the insulating washer 2 of the third embodiment, and the other configurations are the same as those of the third embodiment. Therefore, the parts corresponding to the third embodiment are given the same reference numerals and the description thereof will be omitted.

[0054] The insulating washer 2 has a second annular projection 21 formed to protrude in the axial direction from the radial inner end of the annular plate portion 13. The second annular projection 21 is fitted onto the inner periphery of the outer ring 3.

[0055] When this configuration is adopted, the insulating washer 2 and the outer ring 3 can be positioned in the radial direction by fitting the second annular projection 21 into the inner periphery of the outer ring 3.

[0056] 8 and 9 show a fifth embodiment of the present invention. In the fifth embodiment, an engaging claw portion 22 is added to the insulating washer 2 of the third embodiment, and the other configurations are the same as those of the third embodiment. Therefore, the parts corresponding to the third embodiment are given the same reference numerals and the description thereof will be omitted.

[0057] An outer ring raceway groove 7 with which the rolling elements 5 roll and make contact, and an annular groove 23 extending circumferentially between the outer ring raceway groove 7 and the outer ring width face 9 are formed on the inner periphery of the outer ring 3. The insulating washer 2 has an engaging claw portion 22 formed to protrude in the axial direction from the radial inner end of the annular plate portion 13. A hook portion 24 protruding radially inward is formed at the tip of the engaging claw portion 22, and the hook portion 24 fits into the annular groove 23 on the inner periphery of the outer ring 3, thereby restricting axial movement of the insulating washer 2 in a direction away from the outer ring 3.

[0058] As shown in FIG. 9, the engaging claw portions 22 are provided at a plurality of locations (three locations in the figure) at regular intervals (120° intervals in the figure) in the circumferential direction.

[0059] As shown in Figure 8, in this embodiment of the insulating rolling bearing unit, the insulating washer 2 is held on the outer ring 3 by the engagement between the engaging claw portion 22 and the annular groove 23, preventing it from moving away from the outer ring width surface 9, and the rolling bearing 1 and the insulating washer 2 can be handled as a single assembly.

[0060] In addition, as shown in Figure 9, multiple engagement claws 22 are provided at intervals in the circumferential direction, so that the insulating washer 2 and the outer ring 3 can be positioned radially by engagement between the engagement claws 22 and the annular groove 23.

[0061] 10 and 11 show a sixth embodiment of the present invention. The sixth embodiment has the same basic configuration as the third embodiment, but is different in the material of the insulating washer 2. The parts corresponding to the third embodiment are given the same reference numerals and the description thereof will be omitted.

[0062] 11, insulating washer 2 has an annular plate portion 13 axially facing outer ring width surface 9, and an annular protrusion 14 formed to protrude in the axial direction from the radial outer end of annular plate portion 13 so as to surround outer ring chamfered portion 11 from the radial outside. Annular protrusion 14 has a rectangular cross-sectional shape with a constant radial width along the axial direction. Insulating washer 2 is formed by coating the entire surface of a metal washer with insulating film 12.

[0063] The annular protrusion 14 of the insulating washer 2 has at its tip an annular insertion portion 20 that is inserted into an annular gap on the radial outside of the slightly inclined surface 19. The insertion portion 20 is inserted into the annular gap between the inner peripheral fitting surface 16 of the housing 15 and the slightly inclined surface 19 on the outer periphery of the outer ring 3 up to a position halfway in the axial direction.

[0064] As shown in Figure 11, in the insulating rolling bearing unit of this embodiment, the tip of the annular protrusion 14 of the insulating washer 2 and the insulating coating 12 coated on the slightly inclined surface 19 on the outer periphery of the outer ring 3 overlap radially, ensuring radial insulation between the inner fitting surface 16 of the housing 15 and the outer ring chamfered portion 11.

[0065] 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]

[0066] 1. Rolling bearings 2 Insulating washers 3 Outer ring 4. Inner Circle 5 Rolling elements 7 Outer ring raceway 9 Outer ring width 10 Outer cylindrical surface 11 Outer ring chamfer 12 Insulation film 13 Annular plate 14 Annular protrusion 19 Slightly inclined surface 20 Insertion section 21 Second annular protrusion 22 Engagement claw portion 23 Annular groove

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 the 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) formed between the outer peripheral cylindrical surface (10) and the outer ring width surface (9), and the outer peripheral cylindrical surface (10) is coated with an insulating coating (12), an insulating rolling bearing unit characterized in that the insulating washer (2) has an annular plate portion (13) axially opposed to the outer ring width surface (9), and an annular protrusion (14) formed protruding axially from the radial outer end of the annular plate portion (13) so as to surround the outer ring chamfer portion (11) from the radial outside.

2. 2. The insulating rolling bearing unit according to claim 1, wherein the annular projection (14) has a tapered cross-sectional shape in which the radial width gradually decreases toward the tip.

3. the outer ring (3) has a slightly inclined surface (19) having a linear cross section that is inclined at an angle of 10° or less with respect to the outer peripheral cylindrical surface (10) between the outer peripheral cylindrical surface (10) and the outer ring chamfered portion (11); The slightly inclined surface (19) is coated with the insulating coating (12), 3. The insulating rolling bearing unit according to claim 1, wherein the annular projection (14) has at its tip an insertion portion (20) that is inserted into an annular gap on the radially outer side of the slight inclination surface (19).

4. 3. The insulated rolling bearing unit according to claim 1, wherein the outer ring chamfer (11) is not coated with the insulating coating (12).

5. The insulating washer (2) further has a second annular projection (21) formed to protrude in the axial direction from a radial inner end of the annular plate portion (13), 3. The insulating rolling bearing unit according to claim 1, wherein the second annular projection (21) is fitted onto the inner periphery of the outer ring (3).

6. An outer ring raceway groove (7) with which the rolling elements (5) roll and contact, and an annular groove (23) extending in the circumferential direction between the outer ring raceway groove (7) and the outer ring width surface (9) are formed on the inner circumference of the outer ring (3); 3. The insulating rolling bearing unit according to claim 1, wherein the insulating washer (2) has an engaging claw portion (22) that engages with the annular groove (23).

7. 7. The insulating rolling bearing unit according to claim 6, wherein the engaging claw portion (22) is provided in a plurality of portions spaced apart from each other in the circumferential direction.

8. 3. The insulating rolling bearing unit according to claim 1, wherein the insulating washer (2) is made of insulating resin or insulating rubber.

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

Images