Driven bearing

Abstract

A driven bearing (1) has: a shaft member (30) having a first raceway surface (11) in a circular ring shape on an outer peripheral surface; an outer ring (60) having a second raceway surface (41) in a circular ring shape on an inner peripheral surface opposite the first raceway surface (11); and a plurality of rollers (70) configured to contact the first raceway surface (11) and the second raceway surface (41) along the circular ring-shaped tracks of the first raceway surface (11) and the second raceway surface (41). The outer ring (60) includes: a first member (40) in a circular ring shape composed of steel; and a second member (50) in a circular ring shape composed of resin and covering an outer peripheral surface (44A, 44B) of the first member (40). The first member (40) includes: a cylindrical portion (42) having a hollow cylindrical shape and containing the second raceway surface; and a protruding portion (43) extending to a radially outer side from the cylindrical portion (42). Both sides of the protruding portion (43) in the axial direction are filled with the second member (50).

Description

Technical Field

[0001] This disclosure relates to driven bearings.

[0002] This application claims priority based on Japanese Application No. 2020-99452, filed on June 8, 2020, and invokes the entire contents of that Japanese application. Background Technology

[0003] A rolling bearing in which the outer ring is integrated with a resin pulley is known (see, for example, Patent Document 1). According to Patent Document 1, the outer ring has a flange at one end facing radially outward. In Patent Document 1, the end face of the flange on one axial side is exposed from the resin pulley, thereby improving the heat dissipation of the outer ring.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-191900 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In driven bearings, it is sometimes necessary to suppress operating noise, thereby suppressing corrosion of other components in contact with the outer ring. Using a structure where the outer circumferential surface of the outer ring is covered with resin can suppress both operating noise and corrosion of other components. However, if the outer circumferential surface of the outer ring is covered with the end face of the flange exposed on one side axially, as in Patent Document 1, the resin may peel off from the outer ring axially. This reduces reliability. Therefore, one objective is to provide a driven bearing that can suppress operating noise and corrosion of other components, and also improve reliability.

[0009] Technical means to solve the problem

[0010] The driven bearing disclosed herein comprises: an inner member having an annular first track surface on its outer circumferential surface; an outer ring having an annular second track surface on its inner circumferential surface facing the first track surface; and a plurality of rolling elements configured to contact the first and second track surfaces on an annular track along the first and second track surfaces. The outer ring includes: an annular first member made of steel; and an annular second member made of resin and covering the outer circumferential surface of the first member. The first member includes: a cylindrical portion having a hollow cylindrical shape and containing the second track surface; and a protrusion extending radially outward from the cylindrical portion. The second member fills both sides of the axially protruding portion.

[0011] Invention Effects

[0012] Based on the aforementioned driven bearing, it is possible to suppress operating noise and corrosiveness to other components, and to improve reliability. Attached Figure Description

[0013] Figure 1 This is a schematic three-dimensional diagram showing the structure of the driven bearing.

[0014] Figure 2 This is a schematic cross-sectional view showing the structure of the driven bearing.

[0015] Figure 3 It is a schematic three-dimensional diagram showing the structure of the first component of the outer ring.

[0016] Figure 4 It is an enlarged representation Figure 2 A schematic cross-sectional view of region IV.

[0017] Figure 5 It is an enlarged representation Figure 2 A rough cross-sectional view of region V.

[0018] Figure 6 This is a schematic cross-sectional view showing a modified example of the shape of the second component. Detailed Implementation

[0019] [Summary of Implementation Methods]

[0020] The driven bearing disclosed herein comprises: an inner member having an annular first track surface on its outer circumferential surface; an outer ring having an annular second track surface on its inner circumferential surface facing the first track surface; and a plurality of rolling elements configured to contact the first and second track surfaces on an annular track along the first and second track surfaces. The outer ring includes: an annular first member made of steel; and an annular second member made of resin and covering the outer circumferential surface of the first member. The first member includes: a cylindrical portion having a hollow cylindrical shape and containing the second track surface; and a protrusion extending radially outward from the cylindrical portion. The second member fills both sides of the axially protruding portion.

[0021] In the driven bearing disclosed herein, the outer ring includes a second member made of resin. This suppresses corrosiveness to other components in contact with the outer ring and reduces operating noise. Furthermore, in the aforementioned driven bearing, the first member includes a protrusion extending radially outward from the cylindrical portion. Moreover, the second member fills both sides of the protrusion axially. This reduces the likelihood of axial separation between the steel-made first member and the resin-made second member. As a result, improved reliability is achieved. Thus, according to the aforementioned driven bearing, operating noise and corrosiveness to other components can be suppressed, and improved reliability is achieved. Furthermore, in this disclosure, "resin" includes rubber. That is, the second member may also be made of rubber. Additionally, in this disclosure, "second member made of resin" includes a second member made of fiber-reinforced resin. That is, the resin constituting the second member may also contain reinforcing fibers. Examples of reinforcing fibers include glass fiber and carbon fiber.

[0022] In the aforementioned driven bearing, the protrusion can also be connected to the axial end of the cylindrical portion. The first component with such a protrusion can be easily manufactured using stamping, drawing, or other processing methods.

[0023] In the aforementioned driven bearing, the protrusion may also have a continuous annular shape covering the entire circumferential region of the first member. This further reduces the possibility of axial separation between the first and second members.

[0024] In the aforementioned driven bearing, a through hole extending straight from the outside to the protrusion can also be formed in the second member. There are cases where an Acoustic Emission (AE) sensor is installed in the driven bearing to detect bearing malfunctions. As an AE sensor, it can detect sound (vibration) from the outer ring and detect malfunctions in the driven bearing. Here, if the AE sensor is installed on the second member, which is made of resin and covers the outer peripheral surface of the first member, sound from the rolling contact outer ring, inner member, and rolling elements can be detected via the resin-made second member. This makes it difficult to detect small sounds. According to the aforementioned driven bearing, when installing the AE sensor, the through hole allows the AE sensor to be installed in contact with the protrusion. Therefore, the possibility of sound attenuation before reaching the sensor can be reduced, and sound can be accurately detected by the AE sensor. As a result, when using an AE sensor to detect malfunctions in such a driven bearing, the through hole allows for accurate detection of malfunctions in the driven bearing. Furthermore, "extending straight" means that in a cross-section containing the axis of rotation, the two lines represented by the wall surrounding the through hole are both straight lines. The two straight lines can be parallel or tapered, widening towards the opening side.

[0025] In the aforementioned driven bearing, the through hole can also extend axially through the second component. This makes it easier to install the aforementioned AE sensor within the through hole.

[0026] In the aforementioned driven bearing, a radially inwardly recessed notch may be formed in the protrusion. This allows the second member to enter the interior of the notch. Therefore, the relative rotation of the first member with respect to the second member can be restricted.

[0027] In the aforementioned driven bearing, multiple slits may be formed at intervals in the circumferential direction. This further restricts the relative rotation of the first member with respect to the second member.

[0028] In the aforementioned driven bearing, when viewed from above along the direction of the through-hole's extension, at least a portion of the area defined by the wall surrounding the through-hole may also be located outside the cut. The through-hole can be formed using an ejector pin. Specifically, for example, by performing insert molding using the following method, an outer ring having a second member with a through-hole can be manufactured. First, a first member is placed in the cavity, positioned by the ejector pin, and then resin is injected. At this time, the ejector pin holds the position of the first member. Then, the ejector pin is removed. In this way, the through-hole, which functions as a hole for mounting an AE sensor, is opened. Here, by having at least a portion of the aforementioned area located outside the cut, a through-hole can be formed to mount the AE sensor in contact with the protrusion.

[0029] In the aforementioned driven bearing, the through hole can also extend axially through the second component. This makes it easier to install the aforementioned AE sensor within the through hole.

[0030] In the aforementioned driven bearing, the inner member may also include: a main body portion containing a first track surface; and a first protrusion having an annular shape with its central axis aligned with the first track surface, positioned axially on one side relative to the first track surface, and protruding radially outward from the outer periphery of the main body portion. The second member may also include a first portion having an annular shape with its central axis aligned with the first track surface, and extending between the first protrusion and the first member. This prevents the first protrusion from contacting the first member axially. It should be noted that for the first portion of such a structure, using the aforementioned ejector pin to position the first member within the cavity in a manner that creates a space axially outward of the protrusion can be achieved by allowing resin to flow into the space axially outward of the protrusion.

[0031] In the aforementioned driven bearing, the inner member may also include a second protrusion having an annular shape with its central axis aligned with the first track surface, positioned axially on the opposite side of the first track surface, and protruding radially outward from the outer periphery of the main body. The second member may also include a second portion having an annular shape with its central axis aligned with the first track surface, and extending between the second protrusion and the first member. This prevents the second protrusion from contacting the first member axially.

[0032] In the aforementioned driven bearing, the second component may also include a region opposite to the inner component. A sealing portion, having an annular shape with its central axis aligned with the first raceway surface and protruding towards the inner component, may also be formed in the region opposite the inner component. This prevents foreign matter from entering the bearing and prevents grease and other substances from leaking out of the bearing. Furthermore, compared to the case where a separate sealing component is arranged between the outer ring and the inner component, the number of components can be reduced. Moreover, the sealing portion may contact the inner component at its front end, or the front end of the sealing portion may face the inner component with a small gap. That is, the sealing portion may contact the inner component or be separated by a small gap, as long as the function of preventing foreign matter from entering the bearing from the outside and preventing grease and other substances from leaking out of the bearing is achieved.

[0033] In the aforementioned driven bearing, the resin constituting the second component may also be at least one resin selected from the group consisting of polyamide, polyacetal, polyphenylene sulfide, polyamide-imide, polyimide, polyetheretherketone, and polyurethane. Polyamide, polyacetal, polyphenylene sulfide, polyamide-imide, polyimide, polyetheretherketone, and polyurethane are suitable resins for constituting the second component.

[0034] In the aforementioned driven bearing, the rolling elements can also be rollers. This reduces the cross-sectional height of the driven bearing and facilitates achieving sufficient load-bearing capacity.

[0035] [Specific examples of implementation methods]

[0036] Next, an example of a specific embodiment of the driven bearing of this disclosure will be described with reference to the accompanying drawings. In the following drawings, the same or equivalent parts are labeled with the same reference numerals and repeated descriptions thereof are omitted.

[0037] Figure 1 This is a schematic perspective view showing the structure of the driven bearing in one embodiment of the present disclosure. Figure 2 This is a schematic cross-sectional view showing the structure of the driven bearing. Figure 2 It is a cross-sectional view cut by the plane containing the rotating shaft of the driven bearing. Figure 3 It is a schematic three-dimensional diagram showing the structure of the first component of the outer ring. Figure 4 It is an enlarged representation Figure 2 A schematic cross-sectional view of region IV. Figure 5 It is an enlarged representation Figure 2 A rough cross-sectional view of region V.

[0038] Reference Figures 1-5 In this embodiment, the driven bearing 1 includes a shaft member 30 as an inner member, an outer ring 60, a plurality of rollers 70 as rolling elements, and a cage 80 for retaining the rollers 70. Furthermore, in Figure 2 In the diagram, the rotation axis 31, which serves as the central axis of the shaft member 30, is illustrated by a dashed line.

[0039] The shaft member 30 includes: a rod-shaped (solid cylindrical) main body 10; a flange 12 formed at one end of the main body 10, with a diameter larger than that of the main body 10; and a side plate 20 as a ring, coaxially disposed on the main body 10 in such a way as to surround a portion of the outer peripheral surface of the main body 10 circumferentially. The main body 10 has a first end face 13 as one end in the axial direction, and a second end face 15 as the other end opposite to the first end face 13. Both the first end face 13 and the second end face 15 have a circular planar shape.

[0040] A hexagonal hole 13A with a regular hexagonal prism shape is formed in the region of the first end face 13 that intersects with the rotation axis 31, which is the central axis of the shaft member 30. A threaded portion 14 with a helical thread groove is disposed in the region of the main body 10 that includes the end face 15 (the other end). With this structure, when the driven bearing 1 is installed, for example, by screwing the threaded portion 14 into the threaded hole (not shown) formed in the retaining member that holds the driven bearing 1, and inserting and fixing a portion of a hexagonal wrench into the hexagonal hole 13A, or by passing the shaft member 30 through the housing hole and screwing the nut into the threaded portion 14, the driven bearing 1 can be fixed to the retaining member.

[0041] The main body 10 includes: a solid cylindrical shaft portion 17 containing a threaded portion 14; and a large-diameter portion 16, axially disposed between the region where the shaft portion 17 and the flange portion 12 are located, and having a diameter larger than that of the shaft portion 17. The diameter of the large-diameter portion 16 is smaller than that of the flange portion 12. A first track surface 11 with a cylindrical shape is formed on the outer peripheral surface of the large-diameter portion 16. That is, the shaft member 30 has an annular first track surface 11 on its outer peripheral surface. In this embodiment, the first protrusion is the flange portion 12, which has an annular shape with its central axis aligned with the first track surface 11, is disposed on one side axially relative to the first track surface 11, and protrudes radially outward from the outer periphery of the main body 10. The outer periphery of the main body 10 in the region where the flange portion 12 is located is formed by... Figure 2 , Figure 4 , Figure 5 The dashed line diagram in the image.

[0042] The annular side plate 20 has a first end face 23 as one end face, a second end face 24 as the other end face, an outer peripheral surface 21, and an inner peripheral surface 22. The first end face 23 is parallel to the second end face 24. The outer peripheral surface 21 and the inner peripheral surface 22 are concentric cylindrical surfaces. The first end face 23 is parallel to the end face (stepped portion) on the axial side of the shaft portion 17 of the large diameter portion 16, i.e., the stepped surface 16A (see reference). Figure 2 and Figure 5 The side plate 20 is configured in a contact manner. The side plate 20 has an inner diameter (diameter of the inner circumferential surface 22) corresponding to the outer diameter of the shaft portion 17. The side plate 20 is pressed into the shaft portion 17 and fixed relative to the shaft portion 17. In this embodiment, the second protrusion is the side plate 20, which has an annular shape with its central axis aligned with the first track surface 11, and is disposed on the opposite side of the axial direction relative to the first track surface 11, protruding radially outward from the outer periphery of the main body portion 10. The shaft member 30 is made of steel such as carbon steel for mechanical structures, alloy steel for mechanical structures, or bearing steel. At least the area of ​​the main body portion 10 in the shaft member 30 that includes the first track surface 11 may also be hardened by quenching. In addition, a part or the entire side plate 20 may also be hardened by quenching.

[0043] The outer ring 60 has an annular second track surface 41 on its inner circumferential surface, which is opposite to the first track surface 11. The outer ring 60 includes a first member 40 and a second member 50. The first member 40 includes a cylindrical portion 42 having a hollow cylindrical shape and containing the second track surface 41; and a protrusion 43 extending radially outward from the cylindrical portion 42. The first member 40 is made of steel. For example, mild steel, carbon steel for mechanical structures, alloy steel for mechanical structures, etc., can be used as the steel constituting the first member 40. In addition, the first member 40 can also be hardened by quenching. The first member 40 can also be formed by stamping or drawing, for example, using a steel sheet made of mild steel.

[0044] The cylindrical portion 42 has: a second track surface 41 as an inner peripheral surface, an outer peripheral surface 44A, a first end surface 45A as one end surface in the axial direction, and another end surface 46 in the axial direction. The first member 40 includes the second track surface 41. The first end surface 45A of the first member 40 faces the flange portion 12. That is, the flange portion 12 and the first member 40 face each other in the axial direction.

[0045] The protrusion 43 is connected to the other end 46 of the cylindrical portion 42 in the axial direction. The protrusion 43 is plate-shaped. The protrusion 43 has a continuous annular shape covering the entire circumferential region of the first member 40. The protrusion 43 has: a second end face 45B as the other end face in the axial direction, an outer peripheral surface 44B, and a side surface 45C located on the opposite side of the second end face 45B in the axial direction. The boundary between the end 46 and the protrusion 43 is... Figure 2 and Figure 5 The diagram is shown in dashed lines. The second end face 45B faces the first end face 23 of the side plate 20. That is, the side plate 20 and the first member 40 face each other in the axial direction.

[0046] A radially inwardly recessed cut 47 is formed in the protrusion 43 (see in particular). Figure 3 Multiple cuts 47 are formed at intervals in the circumferential direction. The cuts 47 are formed in a manner that extends through the thickness direction of the plate-like protrusion 43.

[0047] The second component 50 has an annular shape. The second component 50 is made of resin. The resin constituting the second component 50 may be, for example, at least one resin selected from the group consisting of polyamide, polyacetal, polyphenylene sulfide, polyamide-imide, polyimide, polyetheretherketone, and polyurethane. The second component 50 is configured to be coaxial with the first component 40. The second component 50 covers the outer peripheral surfaces 44A and 44B of the first component 40 throughout its entire area. The second component 50 also covers the first end face 45A, the second end face 45B, and the side face 45C of the first component 40. That is, axially, both sides of the protrusion 43 are filled by the second component 50.

[0048] The second member 50 has an inner peripheral surface 51, an outer peripheral surface 52, a first end face 53A, and a second end face 53B. The second member 50 includes a first portion 54A, which has an annular shape with its central axis aligned with the first track surface 11, and enters between the flange portion 12 (which serves as a first protrusion) and the first member 40. The first portion 54A is formed over the entire circumference of the inner peripheral surface 51. Additionally, the second member 50 includes a second portion 54B, which has an annular shape with its central axis aligned with the first track surface 11, and enters between the side plate 20 (which serves as a second protrusion) and the first member 40. The second portion 54B is formed over the entire circumference of the inner peripheral surface 51. Furthermore, although not shown, the second member 50 enters the aforementioned cutout 47.

[0049] A through hole 56 is formed in the second member 50, extending straight from the outside to the protrusion 43. For the through hole 56, in a cross-section including the rotation shaft 31, the two lines represented by the wall 57 surrounding the through hole 56 are straight lines. In this embodiment, the two straight lines are parallel. The through hole 56 penetrates the second member 50 axially. Multiple through holes 56 are formed at circumferential intervals.

[0050] The cage 80 has an annular shape. In this embodiment, the cage 80 is made of steel, but a resin cage can also be used. The cage 80 is concentrically disposed with the shaft member 30 and the outer ring 60 in the space sandwiched between the shaft member 30 and the outer ring 60. A plurality of pockets 81 are arranged at equal intervals along the circumference on the cage 80. Each of the plurality of pockets 81 contains a roller 70. Thus, held by the cage 80, the plurality of rollers 70 are configured to contact the first track surface 11 and the second track surface 41 on an annular track. The roller 70 has a solid cylindrical shape. The roller 70 has a cylindrical outer peripheral surface 71 and a pair of spherical end faces 72. The end faces 72 of the roller 70 can also be flat. The roller 70 contacts the first track surface 11 and the second track surface 41 on its outer peripheral surface 71. The roller 70 is made of steel, for example, bearing steel. Roller 70 can also be hardened by quenching.

[0051] The second member 50 includes a first region 58A that faces the flange portion 12, which is a first protrusion, in the axial direction. The first region 58A is contained within the first portion 54A. A first sealing portion 59A is formed in the first region 58A. The first sealing portion 59A has an annular shape with its central axis aligned with the first track surface 11 and protrudes axially toward the flange portion 12. The front end of the first sealing portion 59A contacts the flange portion 12. In this embodiment, a plurality of, more specifically, two (double-lipped) first sealing portions 59A are arranged radially spaced apart from each other.

[0052] The second member 50 includes a second region 58B that faces the side plate 20, which is a second protrusion, in the axial direction. The second region 58B is contained within the second portion 54B. A second sealing portion 59B is formed in the second region 58B. The second sealing portion 59B has an annular shape with its central axis aligned with the first track surface 11 and protrudes axially toward the side plate 20. The front end of the second sealing portion 59B contacts the side plate 20. In this embodiment, a plurality of, more specifically, two (double-lipped) second sealing portions 59B are arranged radially spaced apart from each other. That is, in this embodiment, the first sealing portion 59A and the second sealing portion 59B are arranged to close the axial ends of the space between the shaft member 30 and the outer ring 60. The first sealing portion 59A and the second sealing portion 59B are part of the second member 50 and are integrally formed with the second member 50.

[0053] The outer ring 60 with such a structure can be manufactured, for example, as follows: First component 40 of the aforementioned structure is prepared and pre-positioned within the cavity of the mold. Here, an ejector pin is used to press and support the end face of the ejector pin against the end face 45B of the protrusion 43. This positions the first component 40 on one axial side. Next, resin is injected into the cavity from the other axial side. At this time, on the other axial side, the pressure of the injected resin presses the end face 45B of the protrusion 43 against the end face of the ejector pin, fixing the first component 40 axially. Thus, the outer ring 60, where the first component 40 and the second component 50 are integrally formed, is thus created. After molding, if the ejector pin is removed, the resulting space becomes a through hole 56 extending straight from the outside to the protrusion 43.

[0054] In the driven bearing 1 of the above embodiment, by arranging the shaft member 30, outer ring 60, cage 80 and a plurality of rollers 70 as described above, the outer ring 60 can rotate relative to the shaft member 30 in the circumferential direction.

[0055] In the driven bearing 1 of the above embodiment, the outer ring 60 includes a second component 50 made of resin. Therefore, compared to a driven bearing where the outer peripheral surface of the outer ring is made of steel, it is possible to suppress corrosion of other components in contact with the outer peripheral surface 52 of the outer ring 60 and to suppress operating noise. Furthermore, the frequency of supplying lubricant between the outer peripheral surface 52 of the outer ring 60 and the aforementioned other components can be reduced, and the supply of lubricant can be eliminated altogether. This results in reduced or no maintenance. From this perspective, a self-lubricating resin, such as polyacetal, is preferably used as the resin constituting the second component 50. By eliminating the supply of lubricant, it is easily applicable to applications where oil splatter prevention is desired, such as in food manufacturing, processing equipment, medical devices, and semiconductor manufacturing equipment. Additionally, by including a second component 50 made of resin in the outer ring 60, rusting at the contact points with the aforementioned other components can be suppressed. As a result, since the second component 50 does not rust, rusting of the mating components in contact with the second component 50 can be prevented. Furthermore, dust generated by rust dispersion is suppressed, making it easily applicable to applications where dust suppression is desired, such as semiconductor manufacturing equipment and electronic component manufacturing equipment. Additionally, by including a second member 50 made of resin in the outer ring 60, the chemical resistance of the contact area with the aforementioned other members can also be improved.

[0056] In the driven bearing 1 of the above embodiment, the first member 40 includes: a cylindrical portion 42 having a hollow cylindrical shape and including a second track surface 41; and a protrusion 43 extending radially outward from the cylindrical portion 42. Axially, the two sides of the protrusion 43 are filled by the second member 50. Therefore, the possibility of axial separation between the first member 40 and the second member 50 can be reduced. Thus, such a driven bearing 1 becomes a driven bearing capable of achieving improved reliability.

[0057] In the driven bearing 1 of the above embodiment, the protrusion 43 is connected to the axial end 46 of the cylindrical portion 42. Therefore, the first member 40 having such a structure of protrusion 43 can be easily manufactured using stamping, drawing, or other methods. Furthermore, the shape of the protrusion 43 is not limited to the above embodiment; for example, the shape after bending radially outward and then folding back towards the outer peripheral surface 44A of the cylindrical portion 42 can be appropriately selected. In addition, the protrusion 43 may also be formed at both axial ends of the cylindrical portion 42.

[0058] In the driven bearing 1 of the above embodiment, the protrusion 43 has a continuous annular shape covering the entire circumferential region of the first member 40. The driven bearing 1, which includes the first member 40 with such a structure, becomes a driven bearing that can further reduce the possibility of axial separation between the first member 40 and the second member 50.

[0059] In the driven bearing 1 of the above embodiment, a through hole 56 is formed in the second member 50, extending straight from the outside to the protrusion 43. Therefore, when an AE (Acoustic Emission) sensor is provided in the driven bearing 1 for detecting bearing abnormalities, the through hole 56 allows the AE sensor to be positioned in contact with the protrusion 43. This reduces the possibility of sound attenuation before reaching the AE sensor, enabling accurate sound detection by the AE sensor. As a result, such a driven bearing 1 becomes a driven bearing capable of accurately detecting abnormalities using an AE sensor.

[0060] In the driven bearing 1 of the above embodiment, the through hole 56 passes through the second member 50 in the axial direction. Therefore, such a driven bearing 1 is a driven bearing that facilitates the placement of the AE sensor in the through hole 56.

[0061] In the driven bearing 1 of the above embodiment, a radially inward recessed cut 47 is formed in the protrusion 43. Therefore, the second member 50 can enter the interior of the cut 47. Thus, such a driven bearing 1 becomes a driven bearing capable of limiting the relative rotation of the first member 40 with respect to the second member 50.

[0062] In the driven bearing 1 of the above embodiment, multiple cutouts 47 are formed at intervals in the circumferential direction. Therefore, such a driven bearing 1 becomes a driven bearing capable of further limiting the relative rotation of the first member 40 with respect to the second member 50.

[0063] In the driven bearing 1 of the above embodiment, the first sealing portion 59A and the second sealing portion 59B protrude axially. Therefore, when the driven bearing 1 of the above embodiment is subjected to a radial load, compared with the case where the first sealing portion 59A and the second sealing portion 59B protrude radially, the increase in rotational torque caused by the first sealing portion 59A and the second sealing portion 59B each contacting the shaft member 30, which is an inner member, is suppressed, making it a driven bearing capable of stabilizing the rotational torque. Furthermore, it is possible to suppress the leakage of lubricant such as grease from inside the bearing (the space between the shaft member 30 and the outer ring 60) and the intrusion of foreign matter into the bearing from the outside.

[0064] In the driven bearing 1 of the above embodiment, multiple first sealing portions 59A and second sealing portions 59B are formed at radial intervals. Therefore, by having multiple first sealing portions 59A and multiple second sealing portions 59B, it is possible to further suppress the intrusion of foreign matter into the bearing interior and the leakage of lubricating grease to the outside of the bearing. Thus, such a driven bearing 1 becomes a driven bearing capable of improving the function of the first sealing portions 59A and second sealing portions 59B as sealing elements.

[0065] In the driven bearing 1 of the above embodiment, when viewed from above in the extending direction of the through hole 56, at least a portion of the area defined by the wall surface 57 surrounding the through hole 56 is located outside the cutout 47. Therefore, when installing the AE sensor, the AE sensor installed in the through hole 56 can be installed in contact with the protrusion 43.

[0066] In the driven bearing 1 of the above embodiment, the shaft member 30 includes: a main body portion 10 including a first track surface 11; and a flange portion 12 as a first protrusion, the flange portion 12 having an annular shape with its central axis aligned with the first track surface 11, and being disposed on one side axially relative to the first track surface 11 and protruding radially outward from the outer periphery of the main body portion 10. Furthermore, the second member 50 includes a first portion 54A, the first portion 54A having an annular shape with its central axis aligned with the first track surface 11, and entering between the flange portion 12 and the first member 40. Therefore, such a driven bearing 1 is a driven bearing capable of preventing the flange portion 12 from contacting the first member 40 axially.

[0067] In the driven bearing 1 of the above embodiment, the shaft member 30 includes a side plate 20 as a second protrusion. The side plate 20 has an annular shape with its central axis aligned with the first track surface 11, and is disposed on the opposite side axially relative to the first track surface 11, protruding radially outward from the outer periphery of the main body 10. The second member 50 includes a second portion 54B, which has an annular shape with its central axis aligned with the first track surface 11, and enters between the side plate 20 and the first member 40. Therefore, such a driven bearing 1 is a driven bearing that can prevent the side plate 20 and the first member 40 from contacting each other axially.

[0068] Furthermore, in the above embodiment, the driven bearing 1 includes a first sealing portion 59A and a second sealing portion 59B that protrude axially, but is not limited thereto. In the driven bearing 1, the second member 50 may also include a region opposite to the shaft member 30. A sealing portion having an annular shape with its central axis aligned with the first track surface 11 and protruding toward the shaft member 30 may also be formed in the region opposite to the shaft member 30. In this way, it is possible to suppress the intrusion of foreign matter into the bearing interior and the leakage of grease and the like to the outside of the bearing. In addition, compared with the case where a separate sealing member is arranged between the outer ring and the inner member, the number of components can be reduced. For example, the driven bearing 1 may also include a first sealing portion and a second sealing portion that protrude radially. Specifically, the driven bearing 1 may also have a first sealing portion 59A and a second sealing portion 59B formed at the front end of the inner circumferential surface 51 of the second member 50, which contact the outer circumferential surface 12A of the flange portion 12, which is the outer circumferential surface of the shaft member 30, and the outer circumferential surface 21 of the side plate 20. Therefore, compared to the case where a separate sealing member is arranged between the outer ring 60 and the shaft member 30, the number of components can be reduced. Furthermore, by integrating the first sealing part 59A and the second sealing part 59B with the second member 50, compared to the case where separate sealing members are arranged, it is possible to prevent the sealing member from falling off due to excessive grease supply. Thus, the driven bearing 1 of the above embodiment becomes a driven bearing that can reduce the number of components and suppress corrosion of other components in contact with the outer ring 60, as well as suppress operating noise.

[0069] In the aforementioned driven bearing, the resin constituting the second component 50 is not particularly limited, and a resin with appropriate wear resistance, hardness, etc., can be used depending on the application. Specifically, it can be at least one resin selected from the group consisting of polyamide, polyacetal, polyphenylene sulfide, polyamide-imide, polyimide, polyetheretherketone, and polyurethane. Polyamide, polyacetal, polyphenylene sulfide, polyamide-imide, polyimide, polyetheretherketone, and polyurethane are suitable as resins constituting the second component 50. Alternatively, rubber (natural rubber and synthetic rubber) can also be used as the resin constituting the second component 50. Furthermore, the resin constituting the second component 50 may also include reinforcing fibers. As reinforcing fibers, for example, glass fiber, carbon fiber, etc., can be used.

[0070] Furthermore, while the above embodiment describes the use of rollers 70 as the rolling elements of the driven bearing 1, balls can also be used as rolling elements. Additionally, while the above embodiment describes the rolling elements as arranged in a single row, multiple rows are also possible. Furthermore, while the above embodiment describes the use of a solid shaft member 30 as the inner member, a raceway ring (inner ring) can also be used as the inner member. Moreover, the second member 50 can be appropriately selected to be a hollow cylindrical member, a member with a spherical outer surface, or the like.

[0071] In the above embodiments, such as Figure 4 and Figure 5 As shown, the first sealing portion 59A and the second sealing portion 59B are described as having a shape that tapers towards the front end (a triangular shape in the cross-section of the central shaft containing the driven bearing). However, the shape of the sealing portion is not limited to this, and any suitable shape can be adopted depending on the application. Alternatively, the first and second sealing portions may have an arc-shaped surface in the cross-section of the rotating shaft containing the driven bearing. Furthermore, the first and second sealing portions may be lip-shaped, protruding radially outward from the inner circumferential surface 51 of the second member 50 in the cross-section of the rotating shaft containing the driven bearing. In the above embodiment, the first sealing portion 59A and the second sealing portion 59B are described as contacting the shaft member 30, which is an inner member. They may also be provided with a small gap between them. Furthermore, two of each of the first sealing portion 59A and the second sealing portion 59B are provided, but this is not a limitation; one or more of each of the first sealing portion 59A and the second sealing portion 59B may be used.

[0072] In the above embodiment, the case where a through hole 56 extending straight from the outside to the protrusion 43 is formed in the second member 50 has been described, but it is not limited to this, such as Figure 6As shown, the driven bearing 1 may not have a through hole 56.

[0073] In this disclosure, a driven bearing refers to a bearing in which the outer ring contacts other components while rotating circumferentially relative to the shaft component in a fixed state. The other components are not particularly limited and may be, for example, a cam, a guide rail, or a belt.

[0074] The embodiments disclosed herein are illustrative in all respects and should be understood as not being limited in any way. The scope of the invention is not limited by the foregoing description, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0075] Explanation of reference numerals in the attached figures

[0076] 1 Driven bearing; 10 Main body; 11 First track surface; 12 Flange; 12A Outer peripheral surface; 13, 45A First end face; 13A Hexagonal hole; 14 Threaded part; 15 Second end face; 16 Large diameter part; 16A Stepped surface; 17 Shaft part; 20 Side plate; 21 Outer peripheral surface; 22 Inner peripheral surface; 23 First end face; 24 Second end face; 30 Shaft member (inner member); 31 Rotating shaft; 40 First member; 41 First track surface; 42 Cylindrical part; 43 Protrusion; 44A, 44B Outer peripheral surface; 45A First end face; 45B Second end face; 45C Side surface; 46 End end; 50 Second component; 51 Inner peripheral surface; 52 Outer peripheral surface; 53A First end face; 53B Second end face; 54A First part; 54B Second part; 56 Through hole; 57 Wall surface; 58A First region; 58B Second region; 59A First sealing part; 59B Second sealing part; 60 Outer ring; 70 Roller; 71 Outer peripheral surface; 72 End face; 80 Retainer; 81 Pocket.

Claims

1. A driven bearing, wherein there are: an inner member having a first raceway surface of a circular ring shape on an outer peripheral surface; an outer ring having a second raceway surface of a circular ring shape on an inner peripheral surface opposite to the first raceway surface; and a plurality of rolling elements configured to be in contact with the first raceway surface and the second raceway surface on a raceway of a circular ring shape along the first raceway surface and the second raceway surface; the outer ring includes: a first member of a circular ring shape composed of steel; and a second member of a circular ring shape composed of resin and covering an outer peripheral surface of the first member, the first member includes: a cylindrical portion having a hollow cylindrical shape and containing the second raceway surface; and a protruding portion extending to a radially outer side from the cylindrical portion, both sides of the protruding portion in an axial direction are filled with the second member, the inner member includes: a main body portion containing the first raceway surface; and a first protruding portion having a circular ring shape with a center axis coinciding with the first raceway surface, and being configured on one side in an axial direction with respect to the first raceway surface, and protruding to a radially outer side from an outer periphery of the main body portion, the second member includes a first portion having a circular ring shape with a center axis coinciding with the first raceway surface, and entering between the first protruding portion and the first member.

2. The driven bearing according to claim 1, wherein the protruding portion is connected to an end portion of the cylindrical portion in the axial direction.

3. The driven bearing according to claim 1 or 2, wherein the protruding portion has a circular ring shape that is continuous over an entire region in a peripheral direction of the first member.

4. The driven bearing according to claim 1 or 2, wherein a through-hole extending straight from the outside to the protruding portion is formed in the second member.

5. The driven bearing according to claim 4, wherein the through-hole penetrates the second member in the axial direction.

6. The driven bearing according to claim 4, wherein a cutout recessed to a radially inner side is formed in the protruding portion.

7. The driven bearing according to claim 6, wherein a plurality of the cutouts are formed at intervals in a peripheral direction of the first member.

8. The driven bearing according to claim 6 or 7, wherein when viewed in a direction along an extension direction of the through-hole, at least a portion of a region defined by a wall surface surrounding the through-hole is located outside the cutout.

9. The driven bearing according to claim 8, wherein the through-hole penetrates the second member in the axial direction.

10. The driven bearing according to claim 1, wherein the inner member includes a second protruding portion having a circular ring shape with a center axis coinciding with the first raceway surface, and being configured on the other side in the axial direction with respect to the first raceway surface, and protruding to a radially outer side from an outer periphery of the main body portion, the second member includes a second portion having a circular ring shape with a center axis coinciding with the first raceway surface, and entering between the second protruding portion and the first member.

11. The driven bearing according to claim 1 or 2, wherein the second member includes a region opposite to the inner member, ​ A seal portion having a circular ring shape in which a central axis coincides with the first track surface and protruding toward the inner member is formed in a region opposite to the inner member.

12. The driven bearing of claim 1 or 2, wherein, The resin constituting the second member is at least one resin selected from the group consisting of polyamide, polyacetal, polyphenylene sulfide, polyamide-imide, polyimide, polyether ether ketone, and polyurethane.

13. The driven bearing of claim 1 or 2, wherein, The rolling element is a roller.

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