Ring-shaped member grinding device and grinding method, bearing manufacturing method, mechanical device manufacturing method, and vehicle manufacturing method

Abstract

The present invention comprises a rotation drive mechanism (2) that rotates a metal ring-shaped member (5) in the circumferential direction around a reference axis, a grinding mechanism (40) that has a grindstone (3) pressed against the outer peripheral surface of the ring-shaped member (5), and a support mechanism (4) that supports the ring-shaped member (5). The support mechanism (4) has a support part (42) that is in contact with the inner peripheral surface of the ring-shaped member (5) in at least one circumferential range around the reference axis.

Description

Ring-shaped member processing device and processing method, bearing manufacturing method, mechanical device manufacturing method, and vehicle manufacturing method

[0001] This disclosure relates to a processing device for processing the outer peripheral surface of a metal ring-shaped member. This application claims priority to Japanese Patent Application No. 2023-195436, filed November 16, 2023, the contents of which are incorporated herein by reference.

[0002] The outer peripheral surfaces of metal ring-shaped members such as the inner ring raceway of the inner ring and the outer peripheral surface of the outer ring that make up a radial rolling bearing are subjected to grinding to improve surface precision and surface roughness.

[0003] 13 shows a conventional grinding device 100 described in Patent Document 1 (JP 2004-195651 A). The grinding device 100 includes a backing plate 101 that can be rotated about its own central axis, a grinding wheel 102 that has a central axis that is arranged parallel to the central axis of the backing plate 101 and can be rotated about said central axis, and two shoes 104 for radially positioning a metal ring-shaped member 103, which is a workpiece (object to be processed).

[0004] When performing grinding processing on the outer peripheral surface of the ring-shaped member 103, the axial end face of the ring-shaped member 103 is magnetically attracted to the tip surface of the backing plate 101, and the tip ends (seat surfaces) of the two shoes 104 are brought into sliding contact with the outer peripheral surface of the ring-shaped member 103, thereby radially positioning the ring-shaped member 103.

[0005] In this state, by rotating the backing plate 101, the ring-shaped member 103 is rotated, and the grinding surface 105, which is the outer surface of the rotating grinding wheel 102, is pressed against a portion of the outer surface of the ring-shaped member 103 that is circumferentially away from the portion where the tip ends of the two shoes 104 are in sliding contact, thereby grinding the outer surface of the ring-shaped member 103.

[0006] In the conventional grinding apparatus 100 described in Patent Document 1, when grinding the outer peripheral surface of a ring-shaped member 103, the grinding surface 105 of the grinding wheel 102 is pressed against the outer peripheral surface of the ring-shaped member 103. Therefore, as shown in an exaggerated manner in Figure 14, the ring-shaped member 103 elastically deforms into an elliptical shape with the minor axis direction being the pressing direction of the grinding surface 105 of the grinding wheel 102. In particular, the raceways of rolling bearings designed in recent years to meet demands for weight reduction and miniaturization are thin-walled and have very low rigidity, so such elastic deformation is likely to occur when grinding the outer peripheral surface of a ring-shaped member using the raceway.

[0007] As described above, if the ring-shaped member 103 elastically deforms into an elliptical shape, that is, if the outer surface of the ring-shaped member 103 elastically deforms so as to move away from the grinding surface 105 of the grinding wheel 102, the amount of grinding of the outer surface of the ring-shaped member 103 and the amount of cutting of the grinding wheel 102 will not match, and it may become difficult to finish the outer surface of the ring-shaped member 103 to the desired diameter dimension.

[0008] Patent Document 2 (JP 2019-42864 A) describes a grinding device in which the portion of the outer surface of a ring-shaped member that is circumferentially away from the portion that is ground by a grinding wheel is supported by two shoes, and when the outer surface of the ring-shaped member is ground by a grinding wheel, a moment is applied to the ring-shaped member in a direction that presses the outer surface of the ring-shaped member toward the first shoe of the two shoes that is closer to the grinding wheel.

[0009] Specifically, the second shoe, which is the farthest from the grinding wheel, is supported so as to be able to swing about a swing axis located farther from the first shoe than the circumferential center of the second shoe. Therefore, as the grinding wheel is pressed against the outer circumferential surface of the ring-shaped member, the reaction force applied from the second shoe to the ring-shaped member is greater at the contact point between the ring-shaped member and the second shoe, on the side farther from the first shoe, than on the side closer to the first shoe. As a result, a moment is applied to the ring-shaped member in a direction pressing the outer circumferential surface against the first shoe.

[0010] According to the grinding device described in Patent Document 2, by pressing the grinding surface of the grinding wheel against the outer peripheral surface of the ring-shaped member, even if the ring-shaped member elastically deforms into an elliptical shape, the contact pressure between the first shoe and the outer peripheral surface of the ring-shaped member is effectively prevented from decreasing, and the posture of the ring-shaped member during grinding can be stabilized.

[0011] JP 2004-195651 A JP 2019-42864 A

[0012] In the grinding device described in Patent Document 2, the outer surface of the ring-shaped member is supported by two shoes, making it difficult to prevent the ring-shaped member from elastically deforming into an elliptical shape due to the pressing force of the grinding wheel.

[0013] As a result, the amount of grinding of the outer peripheral surface of the ring-shaped member and the amount of cutting in of the grinding wheel do not match, which may make it difficult to finish the outer peripheral surface of the ring-shaped member to the desired diameter dimension.

[0014] An object of an aspect of the present invention is to provide an apparatus and method for processing a ring-shaped member that are advantageous in improving quality.

[0015] In one aspect of the present invention, a processing device for a ring-shaped member includes a rotary drive mechanism that rotates a metal ring-shaped member in a circumferential direction around a reference axis, a grinding mechanism having a grinding wheel that is pressed against the outer peripheral surface of the ring-shaped member, and a support mechanism that has a support portion that contacts the inner peripheral surface of the ring-shaped member in at least one circumferential range around the reference axis and supports the ring-shaped member.

[0016] In one aspect of the present invention, a method for processing a ring-shaped member comprises the steps of rotating a metal ring-shaped member in a circumferential direction around a reference axis, and pressing a grinding wheel against the outer peripheral surface of the ring-shaped member, wherein the ring-shaped member is supported by contacting a support portion with the inner peripheral surface of the ring-shaped member in at least one circumferential range around the reference axis.

[0017] In one aspect of the present invention, a method for manufacturing a bearing including a ring-shaped member includes a step of processing an outer peripheral surface of the ring-shaped member using the method for processing a ring-shaped member of the above aspect.

[0018] In one aspect of the present invention, a method for manufacturing a mechanical device includes the steps of manufacturing a mechanical component using the bearing manufacturing method of the above aspect, and attaching the mechanical component to a device body.

[0019] In one aspect of the present invention, a method for manufacturing a vehicle includes the steps of manufacturing a bearing using the bearing manufacturing method of the above aspect, and attaching the bearing to a vehicle body.

[0020] According to an aspect of the present invention, an apparatus and a method for processing a ring-shaped member that are advantageous for improving quality are provided.

[0021] FIG. 1 is a side view schematically showing a ring-shaped member processing apparatus according to a first embodiment. FIG. 2 is a view schematically showing a support structure. FIG. 3 is a cross-sectional view of a mechanical device including a rolling bearing. FIG. 4 is a partially cutaway perspective view of a rolling bearing. FIG. 5 is a schematic cross-sectional view of a bearing having a coating film. FIG. 6 is a view schematically showing an example of a support portion (support member) set relative to an outer ring. FIG. 7 is a side view schematically showing a ring-shaped member processing apparatus according to a second embodiment. FIG. 8 is a side view schematically showing a ring-shaped member processing apparatus according to a third embodiment. FIG. 9 is a side view schematically showing a ring-shaped member processing apparatus according to a fourth embodiment. FIG. 10 is a side view schematically showing a ring-shaped member processing apparatus according to a fifth embodiment. FIG. 11 is a side view schematically showing a ring-shaped member processing apparatus according to a sixth embodiment. FIG. 12 is a side view schematically showing a ring-shaped member processing apparatus according to a seventh embodiment. Fig. 13 is a side view showing a typical example of a conventional structure of a processing device for a ring-shaped member, and Fig. 14 is an exaggerated view showing a state in which the ring-shaped member is elastically deformed into an elliptical shape.

[0022] First Embodiment A first embodiment will be described with reference to FIGS. 1 to 6. FIG.

[0023] In this embodiment, the processing device 1 for a ring-shaped member includes a rotation drive mechanism 2, a grinding mechanism 40, and a support mechanism 4. In one example, the processing device 1 is a grinding device for performing grinding. In another example, the processing device 1 can be a superfinishing device for performing superfinishing.

[0024] The rotary drive mechanism 2 is capable of rotating a metal ring-shaped member 5, which is a workpiece, in a predetermined direction α (clockwise in FIG. 1 ). The rotary drive mechanism 2 rotates the ring-shaped member 5 in the circumferential direction around a reference axis (Oa).

[0025] In one example, the rotation drive mechanism 2 has a holding member 6 that holds the ring-shaped member 5, and a drive unit 36. For example, the rotation drive mechanism 2 has a backing plate (holding member, plate member) 6 that rotates the ring-shaped member 5 while magnetically attracting the axial end face of the ring-shaped member 5. The backing plate 6 holds the ring-shaped member 5 by magnetic attraction. The drive unit 36 ​​rotates the ring-shaped member 5 via the backing plate (holding member) 6. In another example, the holding member 6 can have a structure different from that of the backing plate.

[0026] The backing plate 6 can be rotated about a central axis (reference axis, rotation axis) Oa. In one example, the central axis Oa of the backing plate 6 is arranged along the horizontal direction (the direction from the front to the back of the paper in FIG. 1 ). In another example, the central axis of the backing plate can be arranged in a direction other than the horizontal direction.

[0027] For example, the backing plate 6 has a tip end surface (an end surface facing the front side of the paper in FIG. 1 , a holding surface) that includes a flat surface perpendicular to the central axis Oa. The backing plate 6 can support the ring-shaped member 5 coaxially with itself by magnetically attracting the axial end surface (an end surface facing the back side of the paper in FIG. 1 , an axial end surface) of the ring-shaped member 5 to the tip end surface.

[0028] The grinding mechanism 40 has a grindstone 3 and a drive unit 37. The grindstone 3 can be pressed against the outer peripheral surface 5 a of the ring-shaped member 5 in order to perform grinding on the outer peripheral surface 5 a of the ring-shaped member 5.

[0029] In one example, the grinding wheel 3 is rotated by the drive unit 37. The grinding wheel 3 has a grinding surface 7 on its outer circumferential surface and is configured as a rotary grinding wheel that can be rotated about a central axis (rotation axis) Ob that is parallel to the central axis Oa of the backing plate 6. The grinding surface 7 has a generatrix shape that matches the generatrix shape of the outer circumferential surface 5a of the ring-shaped member 5, which is the surface to be ground. For example, the grinding wheel 3 can be rotated about the central axis Ob in a direction β (counterclockwise in FIG. 1 ) opposite to the predetermined direction α, so that the peripheral speed of its outer circumferential surface (grinding surface 7) is faster than the peripheral speed of the outer circumferential surface 5a of the ring-shaped member 5. In another example, the rotation direction and rotation speed of the grinding wheel 3 and the ring-shaped member 5 can be set arbitrarily.

[0030] The grinding wheel 3 can move its central axis Ob toward or away from the central axis Oa of the backing plate 6, i.e., can move left and right in Fig. 1. In other words, the grinding surface 7 of the grinding wheel 3 can be pressed against the outer peripheral surface 5a of the ring-shaped member 5 supported by the backing plate 6.

[0031] Alternatively, the grinding mechanism 40 can be configured so that the grinding wheel 3 does not substantially rotate. That is, when performing processing such as grinding on the outer peripheral surface 5 a of the ring-shaped member 5, it is possible to rotate only the ring-shaped member 5 without rotating the grinding wheel. If the processing device is a superfinishing device, when performing superfinishing on the outer peripheral surface 5 a of the ring-shaped member 5, it is possible to rotate only the ring-shaped member 5 and oscillate the grinding wheel without rotating it.

[0032] The support mechanism 4 has a support portion 42 that contacts the inner circumferential surface 5b of the ring-shaped member 5 in at least one circumferential range (W11, W21) around the reference axis (Oa). The support portion 42 has inner diameter side support members 8a, 8b that contact the inner circumferential surface 5b of the ring-shaped member 5 and support the ring-shaped member 5 in the radial direction. Additionally, the support portion 42 may have an outer diameter side support member that contacts the outer circumferential surface 5a of the ring-shaped member 5 and supports the ring-shaped member 5 in the radial direction. In the example of FIG. 1 , the support portion 42 has inner diameter side support members 8a, 8b and does not have an outer diameter side support member.

[0033] 1, the support portion 42 has two inner diameter side support members 8a and 8b. In other examples, the support portion 42 may have one inner diameter side support member or three or more inner diameter side support members.

[0034] In the example shown in FIG. 1 , the support members 8a, 8b are spaced apart from each other in the circumferential direction. The support members 8a, 8b contact the inner circumferential surface 5b of the ring-shaped member 5 and have bearing surfaces (tip surfaces, support surfaces, contact surfaces) 9a, 9b that support the ring-shaped member 5. At least a portion of the bearing surfaces 9a, 9b has a curved shape corresponding to the curved shape of the inner circumferential surface 5b of the ring-shaped member 5. During grinding, when the ring-shaped member 5 rotates, the support portions 42 (support members 8a, 8b) do not substantially move in the circumferential direction, and the circumferential positions of the support members 8a, 8b (circumferential positions around the reference axis Oa) remain constant. The inner circumferential surface 5b of the ring-shaped member 5 moves in the circumferential direction relative to the support portions 42 (bearing surfaces 9a, 9b of the support members 8a, 8b). The bearing surfaces 9a, 9b slide against the inner circumferential surface 5b of the ring-shaped member 5.

[0035] For example, the two inner diameter side support members 8a, 8b each have a shoe that slides against the inner peripheral surface 5b of the ring-shaped member 5. The shoe can be made of a hard material with excellent wear resistance, such as cemented carbide, ceramics, or diamond.

[0036] In the example of FIG. 1, the two inner diameter side support members 8 a and 8 b are supported and fixed to a support base (frame, housing) (not shown) that constitutes the support mechanism 4 .

[0037] In the example shown in FIG. 2 , a holding member (backing plate) 6 for holding the ring-shaped member 5 is attached to a frame 50. Support members 8a and 8b, which contact the inner peripheral surface 5b of the ring-shaped member 5, are also attached to the frame 50. That is, the holding member 6 and the support member 8a (8b) are attached to the common frame 50. The holding member 6 is supported by the frame 50 so as to be rotatable about a reference axis Oa. The support member 8a (8b) is supported by the frame 50 via an adjustment mechanism 51. The adjustment mechanism 51 can adjust the position and / or attitude of the support member 8a (8b) relative to the reference axis Oa (the position of the seating surface 9a (9b) in a plane intersecting the reference axis Oa). For example, the adjustment mechanism 51 includes a linear motion mechanism and / or an eccentric mechanism. The holding member 6 and the support member 8a (8b) are positioned relative to the common reference axis Oa. This configuration is advantageous for simplifying the adjustment process and improving positional accuracy.

[0038] In the example of FIG. 2 , both axial ends (a first axial end and a second axial end opposite the first axial end) of the support member 8 a (8 b) are supported by the frame body 50 (see FIG. 2 (a)). A double-sided support structure is advantageous for ensuring high rigidity. The support member 8 a (8 b) is detachable from the frame body 50. In another example, one axial end of the support member 8 a (8 b) is supported by the frame body 50 (see FIG. 2 (b) and FIG. 2 (c)). A single-sided support structure is advantageous for facilitating the attachment and detachment of the ring-shaped member 5. For example, in a single-sided support structure, the support member 8 a (8 b) is supported on the same side as the holding member 6 (see FIG. 2 (b)). This structure is advantageous for saving space. Alternatively, for example, the support member 8 a (8 b) is supported on the side opposite the side on which the holding member 6 is supported. This structure is advantageous in that it makes it easier to adjust the support member 8a (8b).

[0039] In one example, a single housing 53 provided with an adjustment mechanism 51 holds multiple support members 8a, 8b. The housing 53 holding the multiple support members 8a, 8b is attached to a frame 50. The multiple support members 8a, 8b are simultaneously set on or removed from the frame 50 via the housing 53. Additionally, the housing 53 can be configured to be separable in the axial direction. For example, the housing 53 has a first portion and a second portion, and the first portion and the second portion can be combined with each other in the axial direction. The first portion of the housing 53 supports the first axial end of the support member 8a (8b), and the second portion of the housing 53 supports the second axial end of the support member 8a (8b). A separable structure is advantageous for ensuring high rigidity and facilitating attachment and detachment.

[0040] Returning to FIG. 1 , each of the inner diameter side support members 8a, 8b has a tip surface (seat surface, support surface, contact surface) 9a, 9b that comes into sliding contact with the inner circumferential surface 5b of the ring-shaped member 5. In one example, each of the tip surfaces 9a, 9b is configured as a partially cylindrical surface that curves along the inner circumferential surface 5b of the ring-shaped member 5. The radius of curvature of each of the tip surfaces 9a, 9b is substantially the same as the radius of curvature of the inner circumferential surface 5b of the ring-shaped member 5. That is, each of the tip surfaces 9a, 9b comes into surface contact with the inner circumferential surface 5b of the ring-shaped member 5. In another example, the tip portion (seat surface) of the inner diameter side support member 8a (8b), which is a shoe, can come into line contact or point contact with the inner circumferential surface 5b of the ring-shaped member 5.

[0041] The circumferential positions of the bearing surfaces 9a, 9b of the support members 8a, 8b are set according to the grinding position, etc. In the example of Fig. 1, the circumferential range (W11) which is the support range of the first support member 8a includes the circumferential position corresponding to the contact position (rear side position) between the grinding wheel 3 and the ring-shaped member 5.

[0042] The support position (P1) of the first support member 8a on the inner peripheral surface 5b and the contact position (P10) on the outer peripheral surface 5a between the grinding wheel 3 and the ring-shaped member 5 are located on or near a straight line (L1) extending radially of the ring-shaped member 5. The support position (P1) and the contact position (P10) are essentially on opposite sides of the wall of the ring-shaped member 5. The first support member 8a receives, on its inner peripheral surface 5b, a radially inward force from the grinding wheel 3 acting on the outer peripheral surface 5a of the ring-shaped member 5. The ring-shaped member 5 is supported by the support portion 42 at or near the circumferential position substantially the same as the circumferential position where the pressing force of the grinding wheel 3 acts. Changes in the shape of the ring-shaped member 5 during the grinding process are suppressed.

[0043] 1, the circumferential range (W21) of the second support member 8b includes a circumferential position above the reference axis (Oa) on a vertical line passing through the reference axis (Oa). In other examples, the multiple support members 8a, 8b can be arranged in other ways. Furthermore, the support portion 42 can have only one support member in contact with the inner circumferential surface 5b of the ring-shaped member 5.

[0044] Circumferential center positions P1, P2 of the portions of two circumferentially adjacent inner diameter side support members 8a, 8b that contact the inner circumferential surface 5b of the ring-shaped member 5 can be positioned apart from each other by δ1 when expressed in terms of a central angle centered on the central axis Oa of the ring-shaped member 5. In other words, the angle formed by one imaginary straight line La that connects the central axis Oa of the ring-shaped member 5 and the circumferential center position P1 of the tip end face 9a, which is the portion of one inner diameter side support member 8a that contacts the inner circumferential surface 5b of the ring-shaped member 5, and the other imaginary straight line Lb that connects the central axis Oa of the ring-shaped member 5 and the circumferential center position P2 of the tip end face 9b, which is the portion of the other inner diameter side support member 8b that contacts the inner circumferential surface 5b of the ring-shaped member 5, can be set to δ1. The inner diameter side support member 8a has a first support range (first contact range) W11, and the inner diameter side support member 8a has a second support range (second contact range) W21. The angle δ1 (central angle around the reference axis) between the circumferential center position of the first support range W11 and the circumferential center position of the second support range W21 is appropriately set. For example, δ1 can be 20° or more and 160° or less, 75° or more and 105° or less, or 75° or more and 90° or less. In the example of FIG. 1, δ1 is 90°. The above values ​​are merely examples and are not limiting.

[0045] In one example, the circumferential position and shape of one of the inner diameter side support members 8a are restricted so that at least a portion of the tip surface 9a, which is the portion of one of the inner diameter side support members 8a that contacts the inner circumferential surface 5b of the ring-shaped member 5, is within a first circumferential range W1 in which the central angle about the central axis Oa of the ring-shaped member 5 is within a range of ±θ1, based on a first imaginary line L1 connecting the central axis Oa of the ring-shaped member 5 and the central axis Ob of the grinding wheel 3, when viewed in the axial direction of the ring-shaped member 5. The support member 8a has an area (seat surface (support surface, contact surface) 9a) that can contact the inner circumferential surface 5b of the ring-shaped member 5, and the circumferential range (central angle) W1 corresponding to that area (the circumferential length of the seat surface 9a) is appropriately set. For example, θ1 is 45°, 22.5°, or 15°. For example, θ1 can be approximately 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5°. The above values ​​are merely examples and are not limiting.

[0046] In one example, the circumferential position of one of the inner diameter side support members 8a and the shape of the tip surface 9a are regulated so that the entire portion where the tip surface 9a of one of the inner diameter side support members 8a contacts the inner surface 5b of the ring-shaped member 5 is within the first circumferential range W1.

[0047] For example, the angle between the first imaginary line L1 and the one imaginary line La can be set to -22.5° to +22.5° or -15° to +15° when the rotation direction α of the ring-shaped member 5 is taken as positive. In the example of Figure 1, the angle between the first imaginary line L1 and the one imaginary line La is 0°, and the circumferential center position P1 of the tip end surface 9a of one inner diameter side support member 8a is located on the first imaginary line L1.

[0048] In another example, only a portion of the contact area of ​​the inner diameter side support member 8a with the inner circumferential surface 5b of the ring-shaped member 5 can be present in the first circumferential range W1. And / or, the circumferential center position P1 can be located at a circumferential position different from the first imaginary straight line L1.

[0049] In one example, the circumferential position and shape of the other inner diameter side support member 8b are restricted so that at least a portion of a tip end surface 9b, which is a portion of the other inner diameter side support member 8b that contacts the inner circumferential surface 5b of the ring-shaped member 5, is within a second circumferential range W2 having a central angle of ±θ2 about the central axis Oa of the ring-shaped member 5, based on a second imaginary line L2 that extends from the central axis Oa of the ring-shaped member 5 in a direction offset by 90° from the first imaginary line L1 in the direction β opposite the rotational direction α of the ring-shaped member 5. The support member 8b has an area (seat surface (support surface, contact surface) 9b) that can contact the inner circumferential surface 5b of the ring-shaped member 5, and the circumferential range (central angle) W2 corresponding to that area (the circumferential length of the seat surface 9b) is appropriately set. For example, θ2 is 45° or 22.5°. For example, θ2 can be approximately 60, 55, 50, 45, 40, 35, 30, 25, 20, 15, 10, or 5°. The above values ​​are merely examples and are not limiting.

[0050] In another example, when grinding the outer peripheral surface of the ring-shaped member 5, if the grinding wheel 3 rotates in the same direction as the rotation direction of the ring-shaped member, the second virtual straight line L2 can be a straight line extending from the central axis of the ring-shaped member in a direction shifted by 90 degrees from the first virtual straight line L1 in the rotation direction of the ring-shaped member 5.

[0051] In one example, the circumferential position and the shape of the tip surface 9b of the other inner diameter side support member 8b are regulated so that the entire portion where the tip surface 9b of the other inner diameter side support member 8b contacts the inner surface 5b of the ring-shaped member 5 is located within the second circumferential range W2.

[0052] For example, the angle between the second imaginary line L2 and the other imaginary line Lb can be set to -45° to +45°, 0° to +45°, or 0° to +15°, assuming that the rotational direction α of the ring-shaped member 5 is positive. In the example of Figure 1, the angle between the second imaginary line L2 and the other imaginary line Lb is 0°, and the circumferential center position P2 of the tip end surface 9a of the other inner diameter side support member 8a is located on the second imaginary line L2.

[0053] In another example, only a portion of the contact area of ​​the inner diameter side support member 8b with the inner circumferential surface 5b of the ring-shaped member 5 can be present in the second circumferential range W2. And / or, the circumferential center position P2 can be located at a circumferential position different from the second imaginary straight line L2.

[0054] In the first embodiment, when grinding is performed on the outer peripheral surface 5a of the ring-shaped member 5 using the processing device 1, the axial end face of the ring-shaped member 5 is held by magnetic attraction on the backing plate 6. The backing plate 6 rotates in a predetermined direction α. ​​The ring-shaped member 5 rotates in the predetermined direction α around the central axis Oa. As shown in FIG. 1 , the tip surfaces 9a, 9b of the two inner diameter side support members 8a, 8b are in sliding contact with the inner peripheral surface 5b of the ring-shaped member 5. The ring-shaped member 5 is supported in the radial direction by the two inner diameter side support members 8a, 8b.

[0055] The grinding wheel 3 rotates around the central axis Ob in the direction β opposite to the predetermined direction α. ​​For example, the peripheral speed of the grinding surface 7 is faster than the peripheral speed of the outer peripheral surface 5 a of the ring-shaped member 5. The grinding surface 7 is pressed against the outer peripheral surface 5 a of the ring-shaped member 5, and the outer peripheral surface 5 a is ground.

[0056] If necessary, a predetermined fluid such as coolant is supplied during grinding. For example, the inner diameter side support members (two inner diameter side support members 8 a, 8 b) constituting the support mechanism 4 may be provided with coolant supply holes having openings. The coolant discharged from the openings of the coolant supply holes is supplied to the contact portion between the outer peripheral surface 5 a of the ring-shaped member 5 and the grinding surface 7 of the grinding wheel 3.

[0057] In this embodiment, when the outer peripheral surface 5a of the ring-shaped member 5 is ground, the inner peripheral surface 5b of the ring-shaped member 5 is supported by the inner diameter side support members (two inner diameter side support members 8a, 8b) of the support mechanism 4. This suppresses deformation of the ring-shaped member 5 during the grinding process. The rigidity of the ring-shaped member 5 against the processing force applied from the grinding surface 7 of the grinding wheel 3 to the outer peripheral surface 5a is improved compared to conventional methods.

[0058] In this embodiment, when grinding the outer peripheral surface 5a of the ring-shaped member 5, elastic deformation of the outer peripheral surface 5a into an elliptical shape so as to escape from the grinding surface 7 of the grinding wheel 3 is suppressed, compared to the conventional technology in which the outer peripheral surface 5a is ground while being supported by a shoe. For example, by roughly matching the grinding amount of the outer peripheral surface 5a of the ring-shaped member 5 with the cutting amount of the grinding wheel 3, it becomes easy to finish the outer peripheral surface 5a of the ring-shaped member 5 to a desired diameter dimension. It also becomes easy to make the radial thickness of the ring-shaped member 5 nearly uniform in the circumferential direction.

[0059] In one example, circumferential center positions P1, P2 of the portions of two circumferentially adjacent inner diameter side support members 8a, 8b that contact the inner peripheral surface 5b of the ring-shaped member 5 are spaced apart by δ1 when expressed as a central angle centered on the central axis Oa of the ring-shaped member 5. This makes it possible to efficiently improve the rigidity of the ring-shaped member 5 against elastic deformation in the radial direction due to the processing force applied from the grinding surface 7 of the grinding wheel 3 to the outer peripheral surface 5a of the ring-shaped member 5.

[0060] In one example, at least a portion of the inner diameter side support members (two inner diameter side support members 8a, 8b) constituting the support mechanism 4 that contact the inner circumferential surface 5b of the ring-shaped member 5 is located within the first circumferential range W1. Specifically, at least a portion (in this example, the entirety) of the tip end surface 9a of one of the inner diameter side support members 8a is located within the first circumferential range W1. Therefore, at the contact portion between the outer circumferential surface 5a of the ring-shaped member 5 and the grinding surface 7 of the grinding wheel 3, the normal processing force Fn (the pressing force of the grinding wheel 3 acting leftward in FIG. 1 ) applied to the outer circumferential surface 5a of the ring-shaped member 5 can be efficiently supported by the tip end surface 9a of one of the inner diameter side support members 8a located within the first circumferential range W1. Therefore, from this perspective as well, elastic deformation of the ring-shaped member 5 into an elliptical shape can be effectively prevented.

[0061] In one example, at least a portion of the contact area between the inner diameter support members (two inner diameter support members 8a, 8b) constituting the support mechanism 4 and the inner peripheral surface 5b of the ring-shaped member 5 is located in the second circumferential range W2. Specifically, at least a portion (in this example, the entirety) of the tip end surface 9b of the other inner diameter support member 8b is located in the second circumferential range W2. Therefore, at the contact area between the outer peripheral surface 5a of the ring-shaped member 5 and the grinding surface 7 of the grinding wheel 3, the tangential processing force Ft (a grinding force acting downward in FIG. 1 ) applied to the outer peripheral surface 5a of the ring-shaped member 5 can be efficiently supported by the tip end surface 9b of the other inner diameter support member 8b located in the second circumferential range W2. This effectively prevents the ring-shaped member 5 from being displaced in the tangential direction (downward in FIG. 1 ), allowing stable grinding of the outer peripheral surface 5a of the ring-shaped member 5.

[0062] In this embodiment, the inner peripheral surface 5b of the ring-shaped member 5 is supported by inner diameter side support members (two inner diameter side support members 8a, 8b) that make up the support mechanism 4, and the outer peripheral surface 5a of the ring-shaped member 5 is ground. This prevents scratches (shoe marks) from occurring on the outer peripheral surface of the ring-shaped member 5. This maintains a good appearance of the ring-shaped member 5 and prevents damage to the coating applied to the outer peripheral surface 5a of the ring-shaped member 5.

[0063] FIG. 3 shows an electric motor 10 equipped with a bearing including a ring-shaped member that has been machined by the above-described grinding method.

[0064] The electric motor 10 includes a housing 11 , an output shaft 12 , two bearings 13 a and 13 b , a motor stator 14 , and a motor rotor 15 .

[0065] It should be noted that one axial side of the electric motor 10 is the right side in FIG. 3, and the other axial side is the left side in FIG.

[0066] The housing 11 has a cylindrical housing body 16 with a bottom that is open only at one axial end, and a hollow circular plate-shaped cover body 17 attached to the open end at one axial end of the housing body 16.

[0067] The output shaft 12 is disposed inside the housing 11 and coaxial with the housing 11. One axial end of the output shaft 12 protrudes outside the housing 11 through the radially inner side of the cover 17.

[0068] The two bearings 13a, 13b rotatably support the output shaft 12 relative to the housing 11. Specifically, one bearing 13a rotatably supports a portion of the output shaft 12 near one axial end relative to the cover 17. The other bearing 13b rotatably supports the other axial end of the output shaft 12 relative to a retaining recess 19 provided in the center of one axial side surface of a bottom 18 constituting the housing main body 16.

[0069] Each of the two bearings 13a, 13b is a radial deep groove ball bearing as shown in Fig. 4. The radial deep groove ball bearing includes an inner ring 20, an outer ring 21, a plurality of balls 22, each of which is a rolling element, and a cage 23.

[0070] The inner ring 20 has an inner ring raceway 24 with an arc-shaped cross section on its outer peripheral surface. The outer ring 21 has an outer ring raceway 25 with an arc-shaped cross section on its inner peripheral surface. A plurality of balls 22 are held by a cage 23 and are arranged to roll freely between the inner ring raceway 24 and the outer ring raceway 25.

[0071] The inner peripheral surface of the inner ring 20 constituting one bearing 13a is fitted by an interference fit onto the outer peripheral surface of a portion of the output shaft 12 near one axial end. The outer peripheral surface of the outer ring 21 constituting one bearing 13a is fitted by an interference fit onto the inner peripheral surface of the cover body 17. The inner peripheral surface of the inner ring 20 constituting the other bearing 13b is fitted by an interference fit onto the outer peripheral surface of the other axial end of the output shaft 12. The outer peripheral surface of the outer ring 21 constituting the other bearing 13b is fitted by an interference fit onto the inner peripheral surface of the retaining recess 19.

[0072] The motor stator 14 is configured to be cylindrical as a whole, and is fitted and fixed to the inner circumferential surface of the housing main body 16 .

[0073] The motor rotor 15 is configured to be cylindrical as a whole, and is fitted and fixed to the outside of the output shaft 12 radially inside the motor stator 14 .

[0074] In the electric motor 10 , when the motor stator 14 is energized, an electromagnetic force is generated relative to the motor stator 14 to rotate the motor rotor 15 , and the output shaft 12 rotates together with the motor rotor 15 .

[0075] When manufacturing the inner ring 20 and the outer ring 21, a hard metal material such as medium carbon steel or bearing steel is forged to obtain an intermediate body having the general shape of the respective target part (inner ring 20 or outer ring 21), and each intermediate body is then sequentially subjected to cutting to adjust the shape, heat treatment to impart the required hardness and other mechanical properties, and finishing to achieve the final shape and surface roughness.

[0076] In one example, the grinding method using the processing device 1 can be applied to perform the finishing grinding process on the outer peripheral surface of a ring-shaped material, such as the inner ring 20 or the outer ring 21. In this application, when grinding the outer peripheral surface of the inner ring 20, at least the inner ring raceway 24 can be ground.

[0077] In another example, the method for grinding a ring-shaped member using the processing device 1 can be applied not only to the outer peripheral surfaces of the inner ring 20 and outer ring 21 of the bearings 13a, 13b that make up the electric motor 10, but also to grinding the outer peripheral surfaces of various ring-shaped members, for example, the outer peripheral surfaces of ring-shaped members such as raceways that make up bearings incorporated in various mechanical devices and automobiles.

[0078] In one example, the bearings 13a, 13b shown in FIGS. 3 and 4 can have a coating film provided on the surface of the inner ring 20 or the outer ring 21. For example, the coating film imparts functions such as wear resistance, corrosion resistance, adhesion resistance, anti-magnetic properties, mold releasability, and / or insulation to the bearings 13a, 13b. For example, the coating film is made of a material that is substantially the same as or different from the material of the main body of the inner ring 20 or the outer ring 21. Various materials can be used for the coating film, such as resin materials, metal materials, and ceramics. Bearings with coating films are not limited to the configuration of the bearings shown in FIGS. 3 and 4. Furthermore, bearings with coating films can be used in various devices, not just electric motors.

[0079] In one example, as shown in FIG. 5 , at least the outer peripheral surface of the outer ring (ring-shaped member) 21 is covered with a coating film 121. For example, the outer peripheral surface covered with the coating film 121 (coating surface (coating film 121 on the outer peripheral surface)) is processed by a grinding device. In the grinding device 100 shown in FIG. 13 , the outer peripheral surface of the ring-shaped member (e.g., outer ring) 103 is supported by a shoe 104. In this case, when the coating surface is ground, marks or scratches (e.g., marks from the shoe 104, scratches caused by sand particles that have entered between the shoe 140 and the ring-shaped member 103) may occur in the coating film on the outer peripheral surface. On the other hand, in the grinding device 1 shown in FIG. 1 , the inner peripheral surface 5 b of the ring-shaped member 5 is supported by a support portion 42, and when the coating surface is ground, the support portion 42 is prevented from contacting the outer peripheral surface 5 a of the ring-shaped member 5. As a result, the occurrence of marks or scratches and deterioration of the functionality of the coating film are suppressed.

[0080] For example, a method for processing the ring-shaped member 5 includes a metal surface grinding step of grinding the outer peripheral surface and / or inner peripheral surface of the ring-shaped member 5, a coating film forming step of forming a coating film on the outer peripheral surface of the ring-shaped member 5 after the metal surface grinding step, and a coating surface grinding step of grinding the outer peripheral surface (coating surface) on which the coating film has been formed. The metal surface grinding step makes the radial thickness (wall thickness) of the ring-shaped member 5 uniform. Even if the coating film formed in the coating film forming step is uneven, the coating surface grinding step makes the thickness of the coating film uniform. Furthermore, by supporting the inner peripheral surface of the ring-shaped member 5 during grinding of the coating surface, the occurrence of marks and scratches associated with supporting the coating surface is avoided.

[0081] In one example, prior to the step of coating the ring-shaped member 5 with a film, both the outer peripheral surface and the inner peripheral surface of the ring-shaped member 5 are processed by a grinding device. For example, the outer peripheral surface is ground first, and then the inner peripheral surface is ground. Furthermore, a coating film is formed on the outer peripheral surface of the ring-shaped member 5, and then the outer peripheral surface covered with the coating film (the coating film on the outer peripheral surface, the coating surface) is processed by a grinding device.

[0082] For example, in grinding the outer peripheral surface before the coating process, the outer peripheral surface or inner peripheral surface of the ring-shaped member is supported by a shoe. Also, in grinding the inner peripheral surface before the coating process, the outer peripheral surface of the ring-shaped member is supported by a shoe (outer shoe, outer diameter shoe, outer support part).

[0083] In grinding the inner peripheral surface of the ring-shaped member 5, a grinding stone is placed inside (the inner diameter side) of the ring-shaped member 5, and a shoe (outer shoe) is placed on the outside. For example, the support position by the outer shoe and the contact position between the grinding stone and the ring-shaped member 5 on the inner peripheral surface are located on or near a straight line extending radially of the ring-shaped member 5. In other words, the support position by the outer shoe and the contact position between the grinding stone and the ring-shaped member on the inner peripheral surface are essentially on opposite sides of the wall of the ring-shaped member 5. The outer shoe is placed opposite (outside of) the grinding position by the grinding stone placed on the inner diameter side of the ring-shaped member 5. The outer shoe receives a radially outward force from the grinding stone acting on the inner peripheral surface of the ring-shaped member 5 on its outer (back) peripheral surface. The ring-shaped member 5 is supported by the shoe (support portion) at or near the circumferential position where the pressing force of the grinding stone acts. Therefore, deformation of the ring-shaped member 5 during the grinding process is suppressed. Furthermore, the inner peripheral surface of the ring-shaped member 5 is ground using the outer peripheral surface that has been ground to a uniform circularity as a reference. This is advantageous for improving the circularity of the outer diameter and the circularity of the inner diameter of the ring-shaped member 5.

[0084] Furthermore, the radial thickness of the ring-shaped member 5 is controlled during grinding of the inner peripheral surface of the ring-shaped member 5. For example, the position of the grinding stone is controlled based on a position corresponding to the surface (seat surface) of the outer shoe (support portion) that abuts against the outer peripheral surface of the ring-shaped member 5, and a ring-shaped member 5 having a predetermined uniform radial thickness around the entire circumference is formed.

[0085] Thereafter, a coating film is formed on the outer peripheral surface of the ring-shaped member 5, and the coating surface on which the coating film is formed is subjected to a grinding process. For example, in the grinding apparatus 1 shown in FIG. 1 , the coating surface (outer peripheral surface 5 a) of the ring-shaped member 5 is ground while the inner peripheral surface 5 b of the ring-shaped member 5 is supported by a support portion 42. The coating surface grinding process includes a step of rotating the ring-shaped member 5 in a circumferential direction around a reference axis and a step of pressing a grinding wheel 3 against the coating surface (outer peripheral surface 5 a on which the coating film is formed) of the ring-shaped member 5, thereby supporting the ring-shaped member 5 by contacting the support portion 42 with the inner peripheral surface of the ring-shaped member 5 in at least one circumferential range around the reference axis. When grinding the coating surface, the support portion 42 is positioned on the inner diameter side of the ring-shaped member 5. When grinding the coating surface, the support portion 42 is prevented from contacting the outer peripheral surface 5 a of the ring-shaped member 5. This prevents marks and scratches and deterioration of the coating film's functionality. Furthermore, grinding the coating surface achieves uniform thickness of the coating film over the entire circumference. A uniform coating film is advantageous for obtaining high film function and high film effect.

[0086] In another example, in grinding the ring-shaped member 5 before the coating step, the inner peripheral surface may be ground first, and then the outer peripheral surface may be ground. Alternatively, in grinding the ring-shaped member 5 before the coating step, only one of the inner peripheral surface and the outer peripheral surface of the ring-shaped member 5 may be ground.

[0087] For example, prior to the process of coating the ring-shaped member with a film, the outer peripheral surface of the ring-shaped member is machined using a grinding device. In the grinding device 1 shown in FIG. 1 , the inner peripheral surface 5 b of the ring-shaped member 5 is supported by a support 42. In machining the outer peripheral surface 5 a of the ring-shaped member 5, the radial thickness of the ring-shaped member 5 is controlled. For example, the position of the grinding wheel 3 is controlled based on a position corresponding to the surface (seat surface) of the support 42 that abuts against the inner peripheral surface 5 b of the ring-shaped member 5, thereby forming a ring-shaped member 5 having a predetermined uniform radial thickness over the entire circumference. Thereafter, a coating film is formed on the outer peripheral surface 5 a of the ring-shaped member 5. Further, the coating film is ground to achieve a uniform thickness over the entire circumference. A uniform coating film is advantageous for achieving high film function and high film effectiveness.

[0088] In one example, the bearing surfaces of the support portions 42 (bearing surfaces 9a, 9b of the support members 8a, 8b) that abut against the inner circumferential surface 5b of the ring-shaped member 5 have a uniform planar shape with substantially no irregularities. In another example, the bearing surfaces of the support portions 42 have irregularities, curves, corners, and / or steps. For example, the bearing surfaces of the support portions 42 have a shape that corresponds to at least a portion of the irregularities, curves, corners, and / or steps on the inner circumferential surface 5b of the ring-shaped member 5. Having the bearing surfaces of the support portions 42 have a shape that at least partially matches the shape of the inner circumferential surface 5b is advantageous for improving support stability, polishing accuracy, and / or product quality.

[0089] 6 shows an example of the bearing surface 9a (9b) of the support member 8a (8b) set on the outer ring 21. In the example shown in part (a) of Fig. 6, the bearing surface 9a (9b) of the support member 8a (8b) has a surface shape (for example, a flat shape) that corresponds to an inner circumferential surface that is different from the raceway surface 25 of the outer ring 21. The bearing surface 9a (9b) is in contact with an inner circumferential surface of the outer ring 21 that is located radially inward from the raceway surface 25, and is not in contact with the raceway surface 25.

[0090] 6(b), the bearing surface 9a (9b) (or the contour of the bearing surface) has a curved shape (curvature, curved surface) 45 that corresponds to the curvature of the raceway surface 25 (or the contour of the raceway surface) of the outer ring 21. For example, the bearing surface 9a (9b) has a curvature 45 that at least partially matches the curvature of the raceway surface 25. At least a portion of the bearing surface 9a (9b) of the support member 8a (8b) can be in contact with the raceway surface 25 of the outer ring 21.

[0091] In the example shown in part (c) of Figure 6, the bearing surface 9a (9b) (or the contour of the bearing surface) has a curved shape (curve, curved surface) 45 that corresponds to the curvature of the raceway surface 25 (or the contour of the raceway surface) of the outer ring 21, and surface shapes (e.g., flat shapes) 46a, 46b that correspond to an inner circumferential surface different from the raceway surface 25. For example, the bearing surface 9a (9b) has a curvature 45 that at least partially matches the curvature of the raceway surface 25. Furthermore, the bearing surface 9a (9b) has surface shapes (e.g., flat shapes) 46a, 46b that correspond to an inner circumferential surface different from the raceway surface 25 of the outer ring 21. At least a portion of the bearing surface 9a (9b) of the support member 8a (8b) can be in contact with the raceway surface 25 of the outer ring 21 and / or a surface different from the raceway surface 25.

[0092] In the example shown in part (d) of FIG. 6 , the bearing surface 9 a (9 b) (or the contour of the bearing surface) has curved shapes (curvatures, curved surfaces) 45 a, 45 b corresponding to the curvature of the raceway surface 25 (or the contour of the raceway surface) of the outer ring 21, and surface shapes (e.g., planar shapes) 46 a, 46 b corresponding to an inner circumferential surface different from the raceway surface 25. The curved surface 45 a and the surface 46 a form a corner (inner corner) 47 a. The curved surface 45 b and the surface 46 b form a corner (inner corner) 47 b. The corner 47 a and the corner 47 b are spaced apart from each other in the axial direction. The corner 47 a has a shape corresponding to the corner (outer corner) 61 a on the inner circumferential surface side of the outer ring 21. The corner 47 a at least partially matches the corner 61 b. The corner 47 b has a shape corresponding to the corner (outer corner) 61 b ​​on the inner circumferential surface side of the outer ring 21. The corner 47b at least partially matches the corner 61b. At least a portion of the bearing surface 9a (9b) of the support member 8a (8b) can be in contact with the raceway surface 25 of the outer ring 21 and / or a surface different from the raceway surface 25.

[0093] In one example, the support portion 42 has a surface at least partially in contact with the raceway surface 25 of the outer ring 21. The raceway surface 25 of the outer ring 21 is supported by the seating surface 45 of the support portion 42 (the seating surfaces 9a, 9b of the support members 8a, 8b). The radial thickness (groove bottom thickness) of the outer ring 21 can be controlled in machining the outer peripheral surface of the outer ring 21 or the outer peripheral surface including the coating film. For example, in a grinding device, the position of a grinding stone is controlled based on a position corresponding to the seating surface of the support portion 42 that abuts against the raceway surface 25 of the outer ring 21, and the outer ring 21 is formed to have a predetermined radial thickness that is uniform throughout its circumference. If necessary, the outer ring 21 may additionally be heat treated, followed by turning or grinding the inner peripheral surface of the outer ring 21.

[0094] The coating film treatment and / or bearing surface shape described above can be applied to various configurations, including the embodiments described below. In one example, the support portion 42 contacting the inner peripheral surface of the ring-shaped member has a rotatable roller, and the outer peripheral surface (bearing surface) of the roller has a shape corresponding to at least a portion of the irregularities, curves, corners, and / or steps on the inner peripheral surface of the ring-shaped member. The ring-shaped member has a first inner peripheral surface and a second inner peripheral surface that is at least partially deeper than the first inner peripheral surface, and the support portion 42 is disposed so as to contact the second inner peripheral surface. For example, in a grinding device, the roller of the support portion 42 abuts against the raceway surface 25 of the outer ring 21, and the roller makes rolling contact with the raceway surface 25. This is advantageous for preventing marks and scratches on the raceway surface 25.

[0095] Second Embodiment A second embodiment will be described with reference to FIG.

[0096] In the second embodiment, the support portion 42 of the support mechanism 4a has one support member 8c. The support mechanism 4 has the support portion 42 that contacts the inner circumferential surface 5b of the ring-shaped member 5 in one circumferential range (W31) around the reference axis (Oa). In the second embodiment, the number of parts that make up the support mechanism 4a is kept small. In one example, the inner diameter side support member 8c that makes up the support mechanism 4a has a shoe.

[0097] The circumferential width of the portion of one inner diameter side support member 8c that contacts the inner peripheral surface 5b of the ring-shaped member 5 (seat surface (support surface, contact surface) 9c) is set to δ2 when expressed as a central angle centered on the central axis Oa of the ring-shaped member 5. For example, δ2 can be 20° or more and 90° or less, 30° or more and 90° or less, 45° or more and 180° or less, or 75° or more and 90° or less. For example, δ2 is approximately 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, or 180°. In the example of Fig. 7, δ2 is 90°. The above values ​​are merely examples and are not limiting.

[0098] In one example, the inner diameter side support member 8c has a sectorial end face shape with a central angle of δ2 (90°) when viewed from the axial direction. That is, the tip end surface (seat surface) 9c of the inner diameter side support member 8c is configured as a partial cylindrical surface with a central angle of δ2 (90°), and the radius of curvature thereof is substantially the same as the radius of curvature of the inner circumferential surface 5b of the ring-shaped member 5. That is, the entire tip end surface 9c of the inner diameter side support member 8c is in sliding contact with the inner circumferential surface 5b of the ring-shaped member 5.

[0099] 7, the circumferential width (central angle δ2) of the portion of the inner diameter side support member 8c that contacts the inner circumferential surface 5b of the ring-shaped member 5 is set to be sufficiently wide, so that the inner circumferential surface 5b of the ring-shaped member 5 can be stably supported. In other examples, the contact width of the inner diameter side support member 8c can be set to be relatively narrow, as in the support member 8a of the first embodiment.

[0100] In the second embodiment, although there is only one support member 8c, the support position (Pf) and the contact position (P10) are essentially on opposite sides of the wall of the ring-shaped member 5. The support member 8c receives, on its inner peripheral surface 5b, the radially inward force from the grinding wheel 3 acting on the outer peripheral surface 5a of the ring-shaped member 5. The ring-shaped member 5 is supported by the support portion 42 at or near the circumferential position that is essentially the same as the circumferential position where the pressing force of the grinding wheel 3 acts. Changes in the shape of the ring-shaped member 5 during the grinding process are suppressed.

[0101] In the example of FIG. 7, the front end of the tip end surface 9c of the inner diameter side support member 8c in the rotation direction α of the ring-shaped member 5 exists in the first circumferential range W1.

[0102] In one example, of the tip end surface 9c of the inner diameter side support member 8c, a front edge Pf in the rotation direction α of the ring-shaped member 5 is located at the same circumferential position as the first imaginary straight line L1. Alternatively, the edge Pf is located forward of the first imaginary straight line L1 in the rotation direction α of the ring-shaped member 5. In the example of Fig. 7, the edge Pf is located at substantially the same circumferential position as the first imaginary straight line L1.

[0103] In FIG. 7, the rear end of the tip end surface 9c of the inner diameter side support member 8c in the rotation direction α of the ring-shaped member 5 exists in the second circumferential range W2.

[0104] In one example, the rear edge Pr of the tip surface 9c of the inner diameter side support member 8c in the rotation direction α of the ring-shaped member 5 is positioned at substantially the same circumferential position as the second imaginary straight line L2.

[0105] The other configurations and effects are the same as those of the first embodiment.

[0106] Third Embodiment A third embodiment will be described with reference to FIG.

[0107] In the processing apparatus 1b of the third embodiment, the support mechanism 4b has elastic members (biasing members) 26a, 26b that elastically bias the respective inner diameter side support members 8a, 8b toward the inner surface 5b of the ring-shaped member 5.

[0108] In one example, each of the inner diameter side support members 8a, 8b is supported by a support base (not shown) that constitutes the support mechanism 4b so as to be displaceable in the radial direction of the ring-shaped member 5. Furthermore, each of the inner diameter side support members 8a, 8b is elastically biased toward the inner circumferential surface 5b of the ring-shaped member 5 by elastic members 26a, 26b assembled between the inner diameter side support members 8a, 8b and the support base.

[0109] For example, each of the elastic members 26a, 26b may be made of a coil spring. Alternatively, the elastic members 26a, 26b may be made of various elastic members such as leaf springs, disc springs, etc. Furthermore, the shoes (shoe tips) of the inner diameter side support members 8a, 8b may be made of an elastic body such as rubber or resin.

[0110] In the third embodiment, the elastic biasing force of each elastic member 26a, 26b is adjusted. The pressing force of the grinding surface 7 of the grinding wheel 3 against the outer peripheral surface 5a of the ring-shaped member 5 is prevented from becoming excessively large. Elastic deformation of the ring-shaped member 5 into an elliptical shape is more effectively prevented. Alternatively, the contact pressure of the tip surfaces 9a, 9b of each inner diameter side support member 8a, 8b against the inner peripheral surface 5b of the ring-shaped member 5 is prevented from becoming excessively large. Circumferential scratches (shoe marks) on the inner peripheral surface 5b are effectively prevented.

[0111] The other configurations and effects are the same as those of the first embodiment.

[0112] Fourth Embodiment A fourth embodiment will be described with reference to FIG.

[0113] In the processing device 1 c of the fourth embodiment, the two inner diameter side support members 8 d and 8 e in the support mechanism 4 c each have a support roller that rolls and comes into contact with the inner peripheral surface 5 b of the ring-shaped member 5 .

[0114] In one example, each of the inner diameter side support members 8d, 8e has a cylindrical outer peripheral surface 27a, 27b, and is supported so as to be able to rotate freely around its own central axis on a support base (not shown) that constitutes the support mechanism 4c, with its central axis positioned parallel to the central axis Oa of the ring-shaped member 5.

[0115] In one example, the portion of the outer circumferential surface 27a of one of the inner diameter side support members 8d that contacts the inner circumferential surface 5b of the ring-shaped member 5 exists in a first circumferential range W1.

[0116] In one example, the circumferential center position P1 of the portion of the outer surface 27a of one of the inner diameter side support members 8d that contacts the inner circumferential surface 5b of the ring-shaped member 5 is located at the same circumferential position as the first virtual straight line L1.

[0117] In one example, the portion of the outer circumferential surface 27b of the other inner diameter side support member 8e that contacts the inner circumferential surface 5b of the ring-shaped member 5 exists in the second circumferential range W2.

[0118] In one example, the circumferential center position P2 of the portion of the outer surface 27b of the other inner diameter side support member 8e that contacts the inner surface 5b of the ring-shaped member 5 is located at the same circumferential position as the second virtual straight line L2.

[0119] In the third embodiment, the outer surfaces 27a, 27b of the respective inner diameter side support members 8d, 8e are in rolling contact with the inner surface 5b of the ring-shaped member 5, thereby preventing circumferential scratches from occurring on the inner surface 5b.

[0120] The other configurations and effects are the same as those of the first embodiment.

[0121] Fifth Embodiment A fifth embodiment will be described with reference to FIG.

[0122] In the processing apparatus 1d of the fifth embodiment, the rotary drive mechanism 2a has a drive roller 28 having an outer circumferential surface 29 that frictionally engages with the inner circumferential surface 5b of the ring-shaped member 5, instead of a backing plate.

[0123] In one example, the drive roller 28 has a cylindrical outer peripheral surface 29. For example, the central axis of the drive roller 28 is arranged parallel to the central axis Oa of the ring-shaped member 5. The drive roller 28 is driven to rotate around its own central axis.

[0124] In one example, when grinding the outer peripheral surface 5a of the ring-shaped member 5, the drive roller 28 is disposed radially inside the ring-shaped member 5 at a circumferential position where it does not interfere with the two inner diameter side support members 8a, 8b. In addition, the outer peripheral surface 29 of the drive roller 28 is frictionally engaged with the inner peripheral surface 5b of the ring-shaped member 5. In this state, the drive roller 28 is rotationally driven, thereby rotating the ring-shaped member 5.

[0125] In the fifth embodiment, when grinding is performed on the outer peripheral surface 5a of the ring-shaped member 5, the ring-shaped member 5 is rotated by the driving roller 28 frictionally engaged with the inner peripheral surface 5b of the ring-shaped member 5. Therefore, even if the radial thickness of the ring-shaped member 5 is small and it is difficult to magnetically attract the axial end face of the ring-shaped member 5 to the backing plate, the ring-shaped member 5 rotates stably.

[0126] The other configurations and effects are the same as those of the first embodiment.

[0127] Sixth Embodiment A sixth embodiment will be described with reference to FIG.

[0128] In the processing device 1e of the sixth embodiment, when grinding the outer peripheral surface 5a of the ring-shaped member 5, the drive roller 28 is disposed radially outside the ring-shaped member 5 at a circumferential position where it does not interfere with the grinding wheel 3. Furthermore, the outer peripheral surface 29 of the drive roller 28 is frictionally engaged with the outer peripheral surface 5a of the ring-shaped member 5. In this state, the drive roller 28 is rotationally driven, thereby rotating the ring-shaped member 5.

[0129] Therefore, in the sixth embodiment, even if the radial thickness of the ring-shaped member 5 is small and it is difficult to magnetically attract the backing plate to the axial end face of the ring-shaped member 5, the ring-shaped member 5 rotates stably.

[0130] The other configurations and effects are the same as those of the fifth embodiment.

[0131] Seventh Embodiment A seventh embodiment will be described with reference to FIG.

[0132] In the machining apparatus 1f of the seventh embodiment, the support mechanism 4d further includes an outer diameter side support member 30 that contacts the outer peripheral surface 5a of the ring-shaped member 5 to radially support the ring-shaped member 5. The support mechanism 4d includes a support portion 42 that contacts the inner peripheral surface 5b of the ring-shaped member 5 in at least one circumferential range (W11) around the reference axis (Oa) and that contacts the outer peripheral surface 5a of the ring-shaped member 5 in at least another circumferential range (W71).

[0133] In one example, the support mechanism 4d has one outer diameter side support member 30. In another example, the support mechanism 4d can have a plurality of outer diameter side support members.

[0134] In the example of FIG. 12, in comparison with the example of FIG. 1, a support mechanism 4d has an inner diameter side support member 8a, and also has an outer diameter side support member 30 instead of the inner diameter side support member 8b.

[0135] In one example, the outer diameter support member 30 includes a shoe. In another example, the outer diameter support member 30 can include a support roller, as shown in FIG.

[0136] In the example of FIG. 12 , the support member 30 has a bearing surface (tip surface, support surface, contact surface) 31 that contacts the outer peripheral surface 5 a of the ring-shaped member 5 and supports the ring-shaped member 5. At least a portion of the bearing surface 31 has a curved shape that corresponds to the curved shape of the outer peripheral surface 5 a of the ring-shaped member 5. In the grinding process, when the ring-shaped member 5 rotates, the support portions 42 (support member 8 a, support member 30) do not substantially move in the circumferential direction, and the circumferential positions of the support members 8 a, 30 remain constant. The inner peripheral surface 5 b or the outer peripheral surface 5 a of the ring-shaped member 5 moves in the circumferential direction relative to the support portions 42 (seat surface 9 a of the support member 8 a, seat surface 31 of the support member 30). The seat surface 9 a slides against the inner peripheral surface 5 b of the ring-shaped member 5, and the seat surface 31 slides against the outer peripheral surface 5 a.

[0137] In one example, the outer diameter side support member 30 is supported and fixed to a support base (not shown) that constitutes the support mechanism 4d. The outer diameter side support member 30 has a tip surface (seat surface, support surface, contact surface) 31 that comes into sliding contact with the outer peripheral surface 5a of the ring-shaped member 5. The tip surface 31 is configured as a partially cylindrical surface that curves along the outer peripheral surface 5a of the ring-shaped member 5. The radius of curvature of the tip surface 31 is substantially the same as the radius of curvature of the outer peripheral surface 5a of the ring-shaped member 5. In other examples, the tip portion (seat surface) of the outer diameter side support member 30, which is a shoe, can also be in line contact or point contact with the outer peripheral surface 5a of the ring-shaped member 5.

[0138] A circumferential center position P1 of a portion of the inner diameter side support member 8a that contacts the inner circumferential surface 5b of the ring-shaped member 5 and a circumferential center position Q of a portion of the outer diameter side support member 30 that contacts the outer circumferential surface 5a of the ring-shaped member 5 can be positioned apart from each other by δ3 when expressed as a central angle centered around the central axis Oa of the ring-shaped member 5. In other words, the angle formed by one imaginary line La connecting the circumferential center position P1 and the central axis Oa of the ring-shaped member 5 and the other imaginary line Lc connecting the circumferential center position Q and the central axis Oa of the ring-shaped member 5 can be defined as δ3. δ3 can be, for example, 20° to 160°, 75° to 105°, or 90° to 105°. For example, δ3 is approximately 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, or 180°. In the example of Fig. 12, δ3 is 90°. The above numerical values ​​are merely examples and are not limiting.

[0139] In one example, the circumferential position and shape of the outer diameter side support member 30 are restricted so that at least a portion of the tip surface 31, which is the portion of the outer diameter side support member 30 that contacts the outer peripheral surface 5a of the ring-shaped member 5, is within a third circumferential range W3, which has a central angle of ±θ3 about the central axis Oa of the ring-shaped member 5, based on a third imaginary line L3 that extends from the central axis Oa of the ring-shaped member 5 in a direction offset by 90° in the rotational direction α of the ring-shaped member 5 with respect to the first imaginary line L1. For example, θ3 can be 45° or 22.5°. For example, θ3 can be approximately 60°, 55°, 50°, 45°, 40°, 35°, 30°, 25°, 20°, 15°, 10°, or 5°. The above values ​​are merely examples and are not limiting.

[0140] In another example, when grinding the outer surface 5a of the ring-shaped member 5, if the grinding wheel 3 rotates in the same direction as the rotation direction of the ring-shaped member 5, the third virtual line L3 can be a line extending from the central axis of the ring-shaped member 5 in a direction 90 degrees shifted from the first virtual line L1 in the opposite direction to the rotation direction of the ring-shaped member 5.

[0141] In one example, the circumferential position of the outer diameter side support member 30 and the shape of the tip surface 31 are regulated so that the entire portion where the tip surface 31 of the outer diameter side support member 30 contacts the outer peripheral surface 5a of the ring-shaped member 5 is located within the third circumferential range W3.

[0142] For example, the angle between the third imaginary line L3 and the other imaginary line Lc can be set to −45° to +45°, 0° to +45°, or 0° to +15° when the rotation direction α of the ring-shaped member 5 is taken as positive. In the example of Fig. 12, the angle between the third imaginary line L3 and the other imaginary line Lc is set to 0°, and the circumferential center position Q of the tip end surface 31 of the outer diameter side support member 30 is positioned on the third imaginary line L3.

[0143] When grinding the outer peripheral surface 5a of the ring-shaped member 5, a tangential processing force (a grinding force acting downward in FIG. 12 ) Ft is applied to the outer peripheral surface 5a of the ring-shaped member 5 at the contact point between the outer peripheral surface 5a of the ring-shaped member 5 and the grinding surface 7 of the grinding wheel 3. Therefore, as the outer diameter of the outer peripheral surface 5a of the ring-shaped member 5 decreases as grinding progresses, the ring-shaped member 5 moves in a direction approaching the outer diameter side support member 30 relative to the tip surface of the backing plate 6 (downward in FIG. 12 ) in response to the decrease in the outer diameter. This maintains an appropriate sliding state of the tip surface 31 of the outer diameter side support member 30 against the outer peripheral surface 5a of the ring-shaped member 5.

[0144] Additionally, the processing device may be provided with a mechanism for moving the outer diameter side support member 30 closer to the outer peripheral surface of the ring-shaped member in response to the decrease in the outer diameter of the outer peripheral surface 5a as processing of the outer peripheral surface 5a of the ring-shaped member 5 progresses. For example, a configuration may be adopted in which the support mechanism 4d has an elastic member (biasing member) that elastically biases the outer diameter side support member 30 toward the outer peripheral surface 5a of the ring-shaped member 5.

[0145] The other configurations and effects are the same as those of the first embodiment.

[0146] The present disclosure can be implemented by appropriately combining the above-described embodiments to the extent that no contradiction occurs.

[0147] In one embodiment, the processing device for a ring-shaped member includes a rotational drive mechanism for rotating a metal ring-shaped member in a predetermined direction, a grinding wheel that is pressed against the outer peripheral surface of the ring-shaped member to process the outer peripheral surface of the ring-shaped member, and a support mechanism having an inner diameter side support member that contacts the inner peripheral surface of the ring-shaped member and supports the ring-shaped member radially.

[0148] In the above processing apparatus, for example, the support mechanism has a plurality of the inner diameter side support members, and in this case, for example, the support mechanism has two of the inner diameter side support members.

[0149] In the above-described processing apparatus, for example, the circumferential center positions of the portions of two of the inner diameter side support members that are adjacent to each other in the circumferential direction of the ring-shaped member that contact the inner surface of the ring-shaped member are arranged at a distance of 20° to 160° from each other when expressed in terms of a central angle centered on the central axis of the ring-shaped member.

[0150] In the above processing device, for example, the inner diameter side support member is configured by a shoe that slides against the inner peripheral surface of the ring-shaped member.

[0151] In the above-mentioned processing device, for example, the circumferential width of the portion of the inner diameter side support member that contacts the inner surface of the ring-shaped member is 45° or more and 180° or less when expressed as a central angle centered on the central axis of the ring-shaped member.

[0152] In the above processing apparatus, for example, the support mechanism has an elastic member that elastically biases the inner diameter side support member toward the inner circumferential surface of the ring-shaped member.

[0153] In the above processing device, for example, the inner diameter side support member is configured by a support roller that rolls and contacts the inner peripheral surface of the ring-shaped member.

[0154] In the above processing apparatus, for example, the rotation drive mechanism has a backing plate that rotates the ring-shaped member while magnetically attracting the axial end face of the ring-shaped member.

[0155] In the above processing device, for example, the rotation drive mechanism includes a drive roller having an outer circumferential surface that frictionally engages with the inner circumferential surface or the outer circumferential surface of the ring-shaped member.

[0156] In the above processing device, for example, the grindstone is configured as a rotary grindstone that rotates about its own central axis and presses its outer circumferential surface against the outer circumferential surface of the ring-shaped member.

[0157] In the above-described processing apparatus, for example, at least a portion of the portion of the inner diameter side support member that contacts the inner peripheral surface of the ring-shaped member is present in a first circumferential range in which the central angle around the central axis of the ring-shaped member is within a range of ±45°, when viewed from the axial direction of the ring-shaped member, based on a first imaginary line connecting the central axis of the ring-shaped member and the central axis of the grinding wheel.

[0158] In the above-described processing apparatus, for example, at least a portion of the portion of the inner diameter side support member that contacts the inner peripheral surface of the ring-shaped member, when viewed from the axial direction of the ring-shaped member, is present in a second circumferential range in which the central angle around the central axis of the ring-shaped member is within a range of ±45°, based on a second imaginary line that extends from the central axis of the ring-shaped member in a direction that forms an angle of 90° with the first imaginary line.

[0159] In the above-described processing device, for example, the grinding wheel is composed of a rotating grinding wheel that rotates around its own central axis in a direction opposite to the predetermined direction and such that the peripheral speed of its outer peripheral surface is faster than the peripheral speed of the outer peripheral surface of the ring-shaped member, while pressing its outer peripheral surface against the outer peripheral surface of the ring-shaped member, and the second imaginary line extends from the central axis of the ring-shaped member in a direction that is 90° offset from the first imaginary line in the opposite direction to the rotation direction of the ring-shaped member.

[0160] In the above processing device, for example, at least a portion of a portion of one of the plurality of support members that contacts the inner circumferential surface of the ring-shaped member is present in the first circumferential range, and at least a portion of a portion of another of the plurality of support members that contacts the inner circumferential surface of the ring-shaped member is present in the second circumferential range.

[0161] In the above processing apparatus, for example, when the support mechanism has one support member, a portion of the portion of the one support member that contacts the inner circumferential surface of the ring-shaped member is configured to be present in the first circumferential range, and another portion of the portion of the one support member that contacts the inner circumferential surface of the ring-shaped member is configured to be present in the second circumferential range.

[0162] In the above processing apparatus, for example, the support mechanism further includes an outer diameter side support member that contacts the outer peripheral surface of the ring-shaped member and supports the ring-shaped member in the radial direction.

[0163] In the above-mentioned processing apparatus, for example, the support mechanism has only the inner diameter side support member out of the inner diameter side support member and the outer diameter side support member that contacts the outer peripheral surface of the ring-shaped member and supports the ring-shaped member radially.

[0164] In one embodiment, a method for processing a ring-shaped member uses the above-mentioned ring-shaped member processing device, in which a metal ring-shaped member is supported radially by the support mechanism, while the ring-shaped member is rotated in the specified direction around the central axis of the ring-shaped member by the rotation drive mechanism, and the grinding stone is pressed against the outer peripheral surface of the ring-shaped member, thereby processing the outer peripheral surface of the ring-shaped member.

[0165] In one embodiment, a method for manufacturing a bearing including a ring-shaped member includes a step of processing an outer peripheral surface of the ring-shaped member by the above-described method for processing a ring-shaped member.

[0166] In the above manufacturing method, for example, the bearing includes an inner ring as the ring-shaped member.

[0167] In the above manufacturing method, for example, the bearing includes an outer ring as the ring-shaped member.

[0168] In one embodiment, a method for manufacturing a mechanical device is a method for manufacturing a mechanical device configured to include a bearing, and includes a step of manufacturing the bearing by the above-described method for manufacturing a bearing.

[0169] In one embodiment, a method for manufacturing a vehicle is a method for manufacturing a vehicle including a bearing, and includes a step of manufacturing the bearing by the above-described method for manufacturing a bearing.

[0170] 1, 1a, 1b, 1c, 1d, 1e, 1f Processing device 2, 2a Rotation drive mechanism 3 Grinding stone 4, 4a, 4b, 4c, 4d Support mechanism 5 Ring-shaped member 5a Outer peripheral surface 5b Inner peripheral surface 6 Backing plate 7 Grinding surface 8a, 8b, 8c, 8d, 8e Inner diameter side support member 9a, 9b, 9c Tip surface 10 Electric motor 11 Housing 12 Output shaft 13a, 13b Bearing 14 Motor stator 15 Motor rotor 16 Housing body 17 Cover 18 Bottom 19 Retaining recess 20 Inner ring 21 Outer ring 22 Ball 23 Cage 24 Inner ring raceway 25 Outer ring raceway 26a, 26b Elastic member 27a, 27b Outer peripheral surface 28 Drive roller 29 Outer peripheral surface 30 Outer diameter side support member 31 Tip surface 40 Grinding mechanism 100 Grinding device 101 Backing plate 102 Grinding stone 103 Ring-shaped member 104 Shoe 105 Grinding surface

Claims

1. A first mechanism that supports a metal ring-shaped member and rotates the ring-shaped member in a circumferential direction around a reference axis; a second mechanism having a grindstone that is pressed radially inward against the outer peripheral surface of the ring-shaped member to grind the outer peripheral surface; a third mechanism that supports the ring-shaped member and has a support portion that contacts the inner peripheral surface of the ring-shaped member in at least one circumferential range around the reference axis, and the inner peripheral surface of the ring-shaped member moves circumferentially relative to the support portion.

2. The grinding device for a ring-shaped member according to claim 1 , wherein the at least one circumferential range includes a circumferential position corresponding to a contact position between the grindstone and the ring-shaped member.

3. 2. The grinding device for a ring-shaped member according to claim 1, wherein the support portion has a plurality of inner diameter side support members each of which is brought into contact with the inner peripheral surface of the ring-shaped member.

4. 4. The grinding device for a ring-shaped member according to claim 3, wherein the plurality of inner diameter side support members include a first member having a first support range and a second member having a second support range, and an angle between a circumferential center position of the first support range and a circumferential center position of the second support range is equal to or greater than 20° and equal to or less than 160°.

5. 5. The grinding device for a ring-shaped member according to claim 1, wherein the support portion has a shoe that slides against the inner peripheral surface of the ring-shaped member.

6. 6. The grinding device for a ring-shaped member according to claim 5, wherein the support portion has an area capable of contacting the inner peripheral surface of the ring-shaped member, and a central angle corresponding to the area is 20 degrees or more and 180 degrees or less.

7. The grinding device for a ring-shaped member according to claim 5 , wherein the third mechanism has a biasing member that biases the support portion toward the inner circumferential surface of the ring-shaped member.

8. The grinding device for a ring-shaped member according to claim 1 , wherein the support portion is in rolling contact with the inner circumferential surface of the ring-shaped member.

9. 5. The grinding device for a ring-shaped member according to claim 1, wherein the first mechanism has a holding member that holds the ring-shaped member by magnetic attraction and drives the ring-shaped member to rotate.

10. 5. The grinding device for a ring-shaped member according to claim 1, wherein the first mechanism comprises a drive roller having an outer circumferential surface that is frictionally engaged with the inner circumferential surface or the outer circumferential surface of the ring-shaped member.

11. 5. The grinding device for a ring-shaped member according to claim 1, wherein the grindstone is pressed against the outer peripheral surface of the ring-shaped member while rotating.

12. 5. A grinding device for a ring-shaped member as described in any one of claims 1 to 4, wherein at least a portion of the support portion that contacts the inner peripheral surface of the ring-shaped member is located in a first circumferential range having a central angle of ±45° about the central axis of the ring-shaped member, with a first imaginary line connecting the central axis of the ring-shaped member and the central axis of the grinding wheel as a reference, when viewed in the axial direction of the central axis of the ring-shaped member.

13. 13. The grinding device for a ring-shaped member as described in claim 12, wherein at least a portion of the support portion that contacts the inner peripheral surface of the ring-shaped member is located in a second circumferential range in which the central angle about the central axis of the ring-shaped member is within a range of ±45°, based on a second imaginary line that extends from the central axis of the ring-shaped member in a direction that makes an angle of 90° with the first imaginary line, when viewed in the axial direction of the ring-shaped member.

14. the grindstone is a rotating grindstone that rotates around its central axis in a direction opposite to the rotation direction of the ring-shaped member and such that the peripheral speed of its outer circumferential surface is faster than the peripheral speed of the outer circumferential surface of the ring-shaped member, while pressing its outer circumferential surface against the outer circumferential surface of the ring-shaped member; 14. The grinding device for a ring-shaped member according to claim 13, wherein the second imaginary line extends from the central axis of the ring-shaped member in a direction offset by 90 degrees from the first imaginary line in a direction opposite to the rotation direction of the ring-shaped member.

15. 5. The grinding device for a ring-shaped member according to claim 1, wherein the third mechanism further includes an outer diameter side support member that contacts the outer peripheral surface of the ring-shaped member and supports the ring-shaped member in the radial direction.

16. 4. The grinding device for a ring-shaped member according to claim 3, wherein the third mechanism has only the inner diameter side support member out of the inner diameter side support member and an outer diameter side support member that contacts the outer peripheral surface of the ring-shaped member and supports the ring-shaped member in the radial direction.

17. A step of supporting a metal ring-shaped member by a first mechanism and rotating the ring-shaped member in a circumferential direction around a reference axis; a step of pressing a grindstone against an outer peripheral surface of the ring-shaped member by a second mechanism, the step including a step of supporting a support portion that is in contact with an inner peripheral surface of the ring-shaped member in at least one circumferential range around the reference axis by a third mechanism; A method for grinding a ring-shaped member, comprising:

18. A method for manufacturing a bearing including an inner ring or an outer ring as a ring-shaped member, comprising a step of machining an outer peripheral surface of the ring-shaped member using the grinding method for a ring-shaped member according to claim 17.

19. manufacturing a bearing using the manufacturing method of claim 18; a step of attaching the shaft rotatably supported by the bearing to an apparatus body; A method for manufacturing a mechanical device, comprising:

20. manufacturing a bearing using the manufacturing method of claim 18; a step of attaching the shaft rotatably supported by the bearing to a vehicle body; A method for manufacturing a vehicle, comprising: