Bearing with sensor

Abstract

The purpose of the present invention is to prevent contraction of the inner diameter surface of an inner ring even when a magnetic ring of a magnetic rotation sensor is connected to the outer peripheral portion of the inner ring of a rolling bearing, to enable the outer peripheral portion of the inner ring to be connected to the magnetic ring even when the width of the inner ring is small, and to improve the reusability of the magnetic ring when the inner ring is replaced. In order to achieve the above, the present invention is provided with a hook member (20) formed in a ring shape from a resin. An outer peripheral groove (12a) extending in the circumferential direction is formed in the outer peripheral portion (12) of the inner ring (3). The hook member (20) has a protrusion (25) that engages with an outer peripheral groove (12a) of the inner ring (3). The core bar (18) is held by the hook member (20).

Description

Technical Field

[0001] The present invention relates to a bearing with a sensor, comprising a rolling bearing and a magnetic rotation sensor for detecting relative rotational motion between an inner ring and an outer ring of the rolling bearing. Background Art

[0002] As such a sensor-equipped bearing, there is a bearing in which a magnetic ring is connected to the outer periphery of the inner ring of a rolling bearing and a magnetic sensor unit is connected to the outer ring of the rolling bearing.

[0003] As the magnetic ring, a magnetic ring having magnetized magnetic rubber is used. The magnetic rubber has N poles and S poles alternately in the circumferential direction. In order to prevent deformation of the magnetic rubber, the magnetic rubber is fixed to the core metal. The magnetic ring is fixed to the inner ring by pressing the core metal into the outer periphery of the inner ring. As the inner ring and the outer ring rotate relative to each other, the magnetic ring and the magnetic sensor unit also rotate relative to each other, and thus the magnetic field detected by the magnetic sensor of the magnetic sensor unit changes. The magnetic sensor unit converts the change in the magnetic field into an electrical signal and outputs it (Patent Document 1).

[0004] Patent Document 1: Japanese Patent Application Publication No. 2005-256892

[0005] However, as in Patent Document 1, in the case of a connection structure in which the core of the magnetic ring is pressed into the outer periphery of the inner ring, the magnetic ring is fixed by friction at the pressed-in fitting portion, so the width and radial interference of the fitting portion must be ensured accordingly. Therefore, in the case where the thickness of the inner ring is small and the radial thickness between the inner diameter and the outer diameter of the rolling bearing (the height of the bearing section from the inner diameter surface of the inner ring to the outer diameter surface of the outer ring) is small, there is a concern that the inner diameter surface of the inner ring will shrink due to the pressing of the core relative to the outer periphery of the inner ring. In addition, in the case where the width of the inner ring is small, there is a concern that the width of the fitting portion for pressing in cannot be sufficiently ensured on the outer periphery of the inner ring. In the case of a rolling bearing with these concerns, the magnetic ring cannot be fixed to the outer periphery of the inner ring.

[0006] In addition, the core of the magnetic ring is pressed into the outer periphery of the inner ring, so it is difficult to remove the magnetic ring from the inner ring without damaging it. Therefore, when the rolling bearing or the inner ring needs to be replaced due to damage to the rolling bearing or the inner ring, it is impossible to remove the magnetic ring from the inner ring and replace it with a new inner ring for reuse. Summary of the invention

[0007] Therefore, the problem to be solved by the present invention is that even if the magnetic ring of the magnetic rotation sensor is connected to the outer periphery of the inner ring of the rolling bearing, the shrinkage of the inner diameter surface of the inner ring can be avoided, and even if the width of the inner ring is small, the outer periphery of the inner ring can be connected to the magnetic ring, and the reusability of the magnetic ring when the inner ring is replaced is improved.

[0008] In order to solve the above-mentioned problems, the present invention adopts structure 1, namely: a bearing with a sensor, comprising: a rolling bearing having an inner ring, an outer ring and a plurality of rolling elements; and a magnetic rotation sensor for detecting the relative rotational movement of the inner ring and the outer ring, the inner ring having: a raceway surface; a width located at one end of the width of the inner ring; and an outer periphery continuous from the width to the raceway surface, the magnetic rotation sensor having: a magnetic ring connected to the outer periphery of the inner ring; and a magnetic sensor unit connected to the outer ring, the magnetic ring having: a core bone formed in an annular shape; and magnetic rubber fixed to the core bone, the bearing with the sensor is characterized in that it also comprises a hook component, the hook component is formed in an annular shape by resin, an outer peripheral groove extending in the circumferential direction is formed on the outer periphery of the inner ring, the hook component has a protrusion that is locked in the outer peripheral groove of the inner ring, and the magnetic ring is held by the hook component.

[0009] According to the above-mentioned structure 1, the protrusion of the resin hook member can be pressed into the outer peripheral groove of the inner ring by utilizing the elastic deformation of the hook member side, and become a state of being locked in the outer peripheral groove. Therefore, between the hook member and the outer peripheral portion of the inner ring, it is not necessary to ensure a large radial interference and fitting width as in a connection structure that relies on press-fitting. Therefore, the hook member can be fixed to the outer peripheral portion of the inner ring while avoiding the shrinkage of the inner diameter surface of the inner ring, and the hook member can be fixed to the outer peripheral portion of the inner ring even when the width of the inner ring is small. The hook member holds the magnetic ring, so the position of the magnetic ring relative to the inner ring can be fixed by connecting the magnetic ring to the outer peripheral portion of the inner ring through the hook member. In addition, the protrusion can be easily removed from the outer peripheral groove of the inner ring by utilizing the elastic deformation of the hook member, so it is not easy to damage the hook member and the magnetic ring when removing them from the inner ring. Therefore, the reusability of the magnetic ring when replacing the inner ring can be improved.

[0010] In addition to the above-mentioned structure 1, a structure 2 may be adopted, in which the hook member has a groove extending in the circumferential direction, and the core metal is locked in the groove.

[0011] According to the above-mentioned structure 2, the core bone can be pressed into the groove portion of the resin hook component, and the core bone can be locked in the groove portion by utilizing the elastic deformation of the hook component. Therefore, there is no need to set a large interference fit between the groove portion of the hook component and the core bone. Therefore, it is also easy to remove the core bone from the groove portion by utilizing the elastic deformation of the hook component, so the magnetic ring is not easily damaged when the core bone is removed from the groove portion. As a result, the reusability of the magnetic ring removed from the hook component can be improved. Therefore, even in the case where the hook component removed from the inner ring is not suitable for reuse due to damage, deterioration, etc., the replacement of the magnetic ring can be avoided.

[0012] On the basis of the above-mentioned structure 2, structure 3 can be adopted, namely: the above-mentioned hook component has an inner circumference including the above-mentioned groove portion, the above-mentioned core bone has a first plate surface and a second plate surface axially opposite to each other, the above-mentioned groove portion is located radially outward than the width of the above-mentioned inner ring, the above-mentioned first plate surface is in axial contact with the width of the above-mentioned inner ring, and the above-mentioned groove portion is clamped on the above-mentioned second plate surface.

[0013] According to the above-mentioned structure 3, the groove portion is located radially outward from the width of the inner ring on the inner periphery of the hook member, so that in the first plate surface and the second plate surface of the core metal that are axially opposed, the first plate surface can be brought into contact with the width of the inner ring to receive the inner peripheral side of the core metal in the axial direction, and on the other hand, the groove portion is hooked to the second plate surface to receive the outer peripheral side of the core metal in the axial direction. Therefore, even if the hooking of the groove portion relative to the second plate surface is reduced, the position of the core metal relative to the hook member and the inner ring can be kept constant, and the core metal can be prevented from tilting relative to the radial direction. Therefore, the radial depth of the groove portion can be made shallow to reduce the hooking of the groove portion to the second plate surface, thereby suppressing the outer diameter of the hook member and making it easy for the core metal to enter and exit relative to the groove portion.

[0014] On the basis of the above-mentioned structure 3, structure 4 can be adopted, that is, the above-mentioned magnetic rubber is bonded to the above-mentioned second plate surface.

[0015] According to the above configuration 4, the magnetic rubber can be arranged with the axial thickness corresponding to the second plate surface where the groove of the hook member is hooked to the core metal, so the axial protrusion amount of the magnetic ring relative to the width of the inner ring can be suppressed.

[0016] In addition to the above-mentioned structure 3 or 4, a structure 5 can be adopted, that is, the core bar is composed of a metal plate along the radial direction.

[0017] According to the above configuration 5, since the core bar is made of a metal plate along the radial direction, the core bar can be processed at a low cost, and the width and the total length in the radial direction of the core bar can be suppressed.

[0018] In addition to any one of the above-mentioned structures 3 to 5, a structure 6 may be adopted in which the magnetic sensor unit includes a magnetic sensor at a position facing the magnetic rubber in the axial direction.

[0019] According to the above configuration 6, the magnetic sensor and the circuit board can be arranged avoiding the space located radially outside the magnetic rubber. Such an arrangement is suitable for arranging the magnetic rotation sensor so as not to protrude radially from the rolling bearing even when the radial thickness between the inner diameter and the outer diameter of the rolling bearing is small.

[0020] As described above, for the present invention, by adopting the above-mentioned structure 1, even if the magnetic ring of the magnetic rotation sensor is connected to the outer periphery of the inner ring of the rolling bearing, the shrinkage of the inner diameter surface of the inner ring can be avoided, and even if the width of the inner ring is small, the outer periphery of the inner ring can be connected to the magnetic ring, and the reusability of the magnetic ring when the inner ring is replaced can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is used Figure 2 A cross-section taken along line II of FIG. 1 is a longitudinal front view of the sensor bearing according to the first embodiment of the present invention.

[0022] Figure 2 It is a right side view of the sensor bearing according to the first embodiment.

[0023] Figure 3 Yes means Figure 2 A partially enlarged cross-sectional view of the cut surface along line III-III.

[0024] Figure 4 It is a diagram showing a jig set used in the step of attaching the magnetic ring to the inner ring according to the first embodiment.

[0025] Figure 5 Yes Figure 1 A diagram showing an example of a structure in which a preload is applied to a bearing with a sensor.

[0026] Figure 6 Yes Figure 1 FIG. 2 is a diagram showing another example of a structure for applying preload to a bearing with a sensor.

[0027] Figure 7 It is used with Figure 1 The same cross section shows a longitudinal sectional front view of a sensor bearing according to a second embodiment of the present invention.

[0028] Figure 8 It is used with Figure 3 The same cut surface shows Figure 7 A partial enlarged cross-sectional view of a bearing with a sensor.

[0029] Fig. 9 It is a partial plan view showing a modified example of the outer protrusion of the sensor holder according to the second embodiment.

[0030] Fig.10 This is a right side view showing an extract of an outer ring of a sensor bearing and a magnetic sensor unit according to a second embodiment.

[0031] Fig.11 It is used with Figure 1The same cut plane shows a longitudinal sectional front view of a sensor bearing according to a third embodiment of the present invention.

[0032] Fig.12 It is used with Figure 3 The same cut surface shows Fig.11 A partial enlarged cross-sectional view of a bearing with a sensor.

[0033] Fig.13 This is a right side view showing an extract of an outer ring of a sensor bearing and a magnetic sensor unit according to a third embodiment. DETAILED DESCRIPTION

[0034] based on Figure 1 to Figure 6 A sensor-equipped bearing according to a first embodiment will be described as an example of the present invention.

[0035] Figure 1 , Figure 2 The sensor bearing shown includes a rolling bearing 1 and a magnetic rotation sensor 2 .

[0036] The rolling bearing 1 includes an inner ring 3 , an outer ring 4 , a plurality of rolling elements 5 , a cage 6 for holding the rolling elements 5 , and a seal 7 attached to the outer ring 4 .

[0037] The inner ring 3 is composed of a single seamless raceway ring having an outer circumference including a raceway surface 8 on the outer circumference and an inner diameter surface 9 that defines the inner diameter of the rolling bearing 1. The outer ring 4 is composed of a single raceway ring having a shape corresponding to the inner ring 3 and having an outer diameter surface 10 that defines the outer diameter of the rolling bearing 1. The inner ring 3 and the outer ring 4 are each formed of a metal such as bearing steel.

[0038] Hereinafter, the direction along the rotation center axis of the rolling bearing 1 is referred to as the "axial direction", the radial direction is the direction at right angles to the rotation center axis is referred to as the "radial direction", and the circumferential direction around the rotation center axis is referred to as the "circumferential direction". Figure 1 In the figure, the axial direction corresponds to the left-right direction, the radial direction corresponds to the up-down direction, and the center axes of the inner ring 3 and the outer ring 4 coincide with the rotation center axis of the rolling bearing 1.

[0039] The rolling elements 5 are interposed between the inner ring 3 and the outer ring 4. The cage 6 maintains the circumferential spacing between the rolling elements 5. The inner ring 3 is used as a rotating ring. The outer ring 4 is used as a stationary ring. The rolling elements 5 roll on the raceway surface 8 as the inner ring 3 rotates relative to each other.

[0040] Although a ball bearing is exemplified as the rolling bearing 1, the rolling bearing 1 may be replaced by a roller bearing. Furthermore, although a non-separable bearing such as a deep groove ball bearing is exemplified as the rolling bearing 1, the rolling bearing 1 may be replaced by a separable bearing such as a tapered roller bearing.

[0041] The example of the retainer 6 being formed of a metal sheet formed by stamping is shown, but the material and manufacturing method of the retainer 6 are not limited thereto, and the retainer 6 may be an iron plate retainer or a resin retainer formed by injection molding of a resin. As the resin, for example, a thermoplastic resin such as polyamide (PA) reinforced with glass fiber or the like can be used. In addition, when the retainer 6 is a resin retainer, it may be a so-called crown retainer or a cage retainer.

[0042] The inner ring 3 has an outer periphery including a raceway surface 8 and an inner diameter surface 9 that defines the inner diameter of the rolling bearing 1 .

[0043] The inner ring 3 has: a width 11, located at one end of the width of the inner ring 3 ( Figure 1 on the right side); and an outer peripheral portion 12, which is continuous from the raceway surface 8 to the width 11. The width of the inner ring 3 refers to the total axial length of the inner ring 3. The width 11 is a circular annular surface along the radial direction. An outer peripheral groove 12a extending in the circumferential direction is formed on the outer peripheral portion 12 of the inner ring 3. The outer peripheral groove 12a is continuous over the entire circumference with a groove width smaller than the width of the outer peripheral portion 12. The shoulder 12b in the outer peripheral portion 12 of the inner ring 3 that is continuous between the outer peripheral groove 12a and the width 11 is composed of a cylindrical surface-shaped portion that is continuous with the outer peripheral groove 12a and defines the outer diameter of the shoulder 12b, and a chamfer that is continuous from the portion to the width 11. On the other end side of the inner ring 3 ( Figure 1 A sealing groove 13 is formed on the outer periphery of the left side of the casing so as to be continuous over the entire periphery.

[0044] At one end of the inner circumference of the outer ring 4 ( Figure 1 The inner peripheral groove 14 is formed at the right end portion of Figure 1 A sealing groove 15 is formed at the left end portion of the inner circumferential groove 14. The inner circumferential groove 14 and the sealing groove 15 are respectively continuous over the entire circumference.

[0045] The inner ring 3 and the outer ring 4 are standard sealed bearing components having shapes that are plane-symmetrical with respect to an imaginary plane along the radial direction at positions that bisect the widths of the inner ring 3 and the outer ring 4 .

[0046] The seal 7 is installed on the other axial end side ( Figure 1The left side of the seal 7 is clamped in the seal groove 15 of the outer ring 4 (stationary ring). The seal 7 cooperates with the seal groove 13 of the inner ring 3 to prevent grease leakage from the internal space of the bearing and prevent foreign matter from intruding into the internal space of the bearing. In addition, the seal 7 is a core made of a thin plate formed by stamping by vulcanization bonding of oil-resistant rubber, and the lip portion sliding relative to the seal groove 13 and the outer peripheral portion clamped in the seal groove 15 are formed by the oil-resistant rubber. As the oil-resistant rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluororubber (FKM), acrylic rubber (ACM), etc. can be cited. The material and manufacturing method of the seal 7 are not particularly limited. For example, a seal formed by applying a rust-proof coating such as tin plating or zinc plating to a metal thin plate formed by stamping, or a seal formed by stamping a plated steel plate that has been pre-surface treated can also be used. In addition, a contact seal is exemplified as the seal 7, but a non-contact seal can also be used.

[0047] The magnetic rotation sensor 2 detects the relative rotational motion between the inner ring 3 and the outer ring 4. The magnetic rotation sensor 2 includes a magnetic ring 16 connected to the outer peripheral portion 12 of the inner ring 3 and a magnetic sensor unit 17 connected to the outer ring 4.

[0048] The magnetic ring 16 is composed of a core metal 18 formed in an annular shape and a magnetic rubber 19 fixed to the core metal 18. The magnetic ring 16 is connected to the outer peripheral portion 12 of the inner ring 3 via a hook member 20.

[0049] The core bar 18 is made of a seamless metal plate. The core bar 18 is formed by stamping a thin plate. Examples of the metal plate include a mild steel plate, a stainless steel plate, and the like. Examples of the mild steel plate include SPCC, SPCCT, SPCD, SPCE, SPCEN, and the like specified in Japanese Industrial Standards. In addition, examples of the stainless steel plate include SUS430, SUS201, SUS304, SUS316, SUS321, SUS403, SUS410, and the like specified in Japanese Industrial Standards. In addition, when cutting the core bar 18, carbon steel for mechanical structures such as S45C specified in Japanese Industrial Standards may also be used. In addition, the use of a magnetic body in the core bar 18 is beneficial to the improvement of magnetic properties.

[0050] The core metal 18 is in the shape of a ring having concentric inner and outer circumferences and extending along the radial direction. Figure 3As shown, the core bone 18 has a first plate surface 21 and a second plate surface 22 which are axially opposed to each other. The first plate surface 21 and the second plate surface 22 are respectively composed of flat surfaces which are continuous along the radial direction and over the entire circumference. The core bone 18 has an outer diameter surface 23 which is formed into a cylindrical surface. The peripheral edge of one end side (right side of the figure) of the outer diameter surface 23 of the core bone 18 forms a corner with the second plate surface 22. The outer diameter of the first plate surface 21 is set to be smaller than the outer diameter surface 23. The portion between the peripheral edge of the other end side (left side of the figure) of the outer diameter surface 23 and the first plate surface 21 in the outer periphery of the core bone 18 becomes a tapered surface 24, and the tapered surface 24 has an inclination in a direction which becomes smaller in diameter from the outer diameter surface 23 toward the other end side (left side of the figure). The inner periphery of the core bone 18 becomes a cylindrical surface.

[0051] In order to suppress the entire axial length of the core bone 18, a radial metal plate is used as the core bone 18, but it is not limited to this. For example, the flange extending axially from the second plate surface 22 toward one end side can also be subjected to stamping such as drawing for the purpose of positioning the magnetic rubber 19 and strengthening the core bone.

[0052] The magnetic rubber 19 is formed into a ring shape by a rubber magnet material. The rubber magnet material is a material obtained by mixing magnetic powder in rubber. Examples of the rubber include NBR, HNBR, FKM, ACM, etc. Examples of the magnetic powder include ferrite-based powder, neodymium (Nd)-based powder, samarium (Sm)-based powder, etc.

[0053] The magnetic rubber 19 is fixed to the second plate surface 22 of the core metal 18 by bonding. The magnetic rubber 19 has an inner periphery and an outer periphery concentric with the core metal 18 and is annular along the radial direction. In order to avoid interference between the magnetic rubber 19 and the hook member 20, the outer diameter of the magnetic rubber 19 is set to be smaller than the outer diameter of the core metal 18 with a margin.

[0054] The magnetic rubber 19 may be bonded to the core metal 18 at the same time as vulcanization. When performing the vulcanization bonding, an adhesive may be applied to the second plate surface 22 of the core metal 18 in advance.

[0055] The magnetic rubber 19 is multipolarly magnetized so as to have N poles and S poles alternately in the circumferential direction. The number of magnetized columns (tracks) of the multipolar magnetization is not particularly limited as long as there is at least one magnetized column.

[0056] Although not shown in the figure, the magnetization process of the magnetic rubber 19 is, for example, to constitute a magnetized ring that fixes the magnetic rubber to the second plate surface of the core bone, and to install the magnetized ring on a rotating chuck (including a mounting fixture) of a magnetizing device, and to rotate it in the circumferential direction at a constant rotation speed, and to alternately magnetize the N pole and the S pole in the circumferential direction in multiple stages. In addition, the magnetizing device has a magnetizing coil wound on a magnetizing yoke, and is configured to set a desired gap on the outer peripheral surface or width (flat surface) of the magnetized ring. And, by alternately switching the direction of the current flowing through the magnetizing coil in synchronization with the rotation of the magnetized ring, it is magnetized in multiple poles. The number of magnetized poles can be appropriately determined.

[0057] As another magnetization method, a device in which a magnetizing coil is wound around a magnetizing yoke having a convex shape corresponding to the number of magnetic poles and a desired gap is provided on the outer peripheral surface or width (flat surface) of a magnetized ring fixed in a non-rotating state as a magnetization device can be cited. In this case, the direction of the current flowing through the magnetizing coil can be limited to one direction, and magnetization can be completed in a short time. This magnetization method can be used for magnetization of Nd series, Sm series, etc.

[0058] The hook member 20 is formed into a ring shape by resin. The hook member 20 is composed of a single seamless resin member having an inner periphery and an outer periphery concentric with the inner ring 3 .

[0059] The inner periphery of the hook member 20 includes a protrusion 25 that is engaged with the outer peripheral groove 12 a of the inner ring 3 and a groove 26 that extends in the circumferential direction.

[0060] The protrusion 25 is formed by a portion of the hook member 20 whose outer diameter is smaller than the shoulder 12b provided on the inner ring 3. The protrusion 25 is continuous over the entire circumference of the hook member 20. The other end side (left side in the figure) of the protrusion 25 has a first slope 25a which is inclined in a direction from the inner diameter of the protrusion 25 (the inner peripheral portion defining the inner diameter of the protrusion 25) toward the other end side (left side in the figure) to a larger diameter. The one end side (right side in the figure) of the protrusion 25 has a second slope 25b which is inclined in a direction from the inner diameter of the protrusion 25 toward the one end side (right side in the figure) to a larger diameter. The second slope 25b of the protrusion 25 is engaged with the outer peripheral groove 12a in the axial direction. A space is formed between the portion of the hook member 20 located on the inner diameter of the protrusion 25 and the other end side (left side in the figure) of the inner diameter and the inner ring 3. The space and the first and second inclined surfaces 25a and 25b are used to facilitate elastic deformation of the hook member 20 when the protrusion 25 moves in and out of the outer peripheral groove 12a from one end side (right side in the figure) relative to the inner ring 3 over the shoulder 12b.

[0061] The groove 26 is continuous over the entire circumference at a position radially outward from the width of the inner ring. The core metal 18 is stopped by the groove 26. The groove 26 receives the outer diameter surface 23 of the core metal 18 in the radial direction, and is engaged with the second plate surface 22 in the axial direction. The groove bottom surface of the groove 26 that receives the outer diameter surface 23 in the radial direction is cylindrical. The portion of the groove 26 that is engaged with the second plate surface 22 in the axial direction is along the radial direction. The width of the groove 26 is wider than the width of the core metal 18.

[0062] The inner peripheral portion of the connecting groove 26 and the protrusion 25 of the hook member 20 is in radial contact with the outer diameter of the shoulder 12b of the inner ring 3. The inner shoulder 27 constituting one end (the right end in the figure) of the inner periphery of the hook member 20 is in a convex curved surface shape that protrudes most radially inward in the middle of the width of the inner shoulder 27.

[0063] The first plate surface 21 of the core metal 18 is in contact with the width surface 11 of the inner ring 3 in the axial direction, but is not in contact with the hook member 20 in the axial direction. A space is formed between the first plate surface 21 and the hook member 20. This space, the curved surface shape of the inner shoulder 27, and the tapered surface 24 of the core metal 18 are used to facilitate elastic deformation of the hook member 20 and the core metal 18 when the core metal 18 moves in and out of the groove 26 relative to the hook member 20 from one end side (the right side in the figure) over the inner shoulder 27.

[0064] The hook member 20 is axially engaged with the outer peripheral groove 12a of the inner ring 3 and the second plate surface 22 of the core metal 18, so that the three components of the inner ring 3, the hook member 20 and the core metal 18 are restricted so as not to be separated from each other in the axial direction. The inner periphery of the hook member 20 is fitted with the outer peripheral groove 12a and the shoulder 12b of the inner ring 3, so that the inner ring 3 and the hook member 20 are arranged concentrically. The groove 26 of the hook member 20 is fitted with the outer diameter surface 23 of the core metal 18, so that the hook member 20 and the core metal 18 are arranged concentrically. The friction acting on the contact portion between the outer periphery of the inner ring 3 and the inner periphery of the hook member 20, the contact portion between the width surface 11 of the inner ring 3 and the first plate surface 21 of the core metal 18, and the contact portion between the second plate surface 22 and the outer diameter surface 23 of the core metal 18 and the hook member 20 prevents the above three components (20, 3, 19) from rotating relative to each other. By limiting the axial displacement, concentric arrangement and anti-rotation of the three components (20, 3, 19), Figure 1 , Figure 2 As shown, the hook member 20 is fixed to the outer peripheral portion 12 of the inner ring 3, and the position of the magnetic ring 16 relative to the inner ring 3 is also fixed, so that the magnetic ring 16 is connected to the outer peripheral portion 12 of the inner ring 3. Therefore, the radial interference of the contact portion between the inner periphery of the hook member 20 and the outer peripheral portion 12 of the inner ring 3 is not set to a magnitude that generates a force that causes the inner diameter surface 9 of the inner ring 3 to shrink.

[0065] As the resin forming the hook member 20, for example, an injection-moldable thermoplastic resin can be used. The portion of the groove 26 that is hooked on the second plate surface 22 of the core metal 18 takes into consideration the detachability of the core metal 18 relative to the groove 26, and for example, an elastically deformable resin such as a polyacetal resin without a filler can be appropriately used.

[0066] In the assembly process of connecting the magnetic ring 16 to the inner ring 3, for example, Figure 4 By using the jigs Z1 to Z3 as shown, the magnetic ring 16 and the inner ring 3 can be easily connected.

[0067] As a first step, the large diameter shaft portion of the stepped shaft-shaped jig Z2 is fitted into the inner diameter surface of the jig Z1 installed on the workbench. In addition, it is preferred that the gap between the fitting portions of the two jigs Z1 and Z2 be small.

[0068] Next, as a second step, the inner diameter surface 9 of the inner ring 3 of the rolling bearing 1 is inserted into the large diameter shaft portion of the jig Z2 from the seal 7 side, so that the inner ring 3 abuts against the upper surface of the jig Z1. In addition, it is preferred that the gap between the large diameter shaft portion of the jig Z2 and the inner diameter surface 9 of the inner ring 3 is small.

[0069] Next, as a third step, the hook member 20 is passed through the small-diameter shaft portion of the jig Z2 with the protrusion 25 facing downward, and the first inclined surface 25a (see Figure 3 ) is arranged to be aligned with the shoulder 12b of the inner ring 3 in the vertical direction (see Figure 3 ) The hook member 20 is guided to a positional relationship substantially concentric with the inner ring 3 by the contact between the first inclined surface 25a of the protrusion 25 and the shoulder 12b of the inner ring 3.

[0070] Next, as a fourth step, the protrusion 25 of the hook member 20 is pressed into the outer peripheral groove 12a from above the inner ring 3, and is locked in the outer peripheral groove 12a. Figure 4 The jig Z3 shown in the figure has an inner diameter surface corresponding to the small diameter shaft portion of the jig Z2. When the jig Z3 is inserted into the small diameter shaft portion of the jig Z2, the lower end of the jig Z3 is used to press downward the upper part of the protrusion 25 of the hook member 20 (the upper end portion opposite to the protrusion 25 in the vertical direction), so that a component force in the direction of expanding the diameter of the hook member 20 is generated at the contact portion between the first inclined surface 25a of the hook member 20 and the shoulder 12b of the inner ring 3. As a result, the elastic deformation of the hook member 20 required for the hook member 20 to pass over the shoulder 12b downward can be easily generated. In addition, it is preferred that the gap between the small diameter shaft portion of the jig Z2 and the fitting portion of the jig Z3 is small.

[0071] Next, as a fifth step, the core metal 18 is passed through the small-diameter shaft portion of the jig Z2 with the magnetic rubber 19 of the magnetic ring 16 facing upward, and is arranged so that the tapered surface 24 (see Figure 3 ) and the inner shoulder 27 of the hook member 20 (refer to Figure 3 ) are in contact in the vertical direction. The two components (18, 20) are guided to a substantially concentric positional relationship by the contact between the tapered surface 24 of the core metal 18 and the inner shoulder 27 of the hook component 20.

[0072] Next, as a sixth step, the upper surface of the magnetic rubber 19 is pressed downward from above to press the outer periphery of the core metal 18 into the groove 26 of the hook member 20, as shown in FIG. Figure 4 As shown, the core metal 18 is brought into a state of being locked in the groove 26. By this locking, the core metal 18 is held by the groove 26 of the hook member 20. In the sixth step, while the clamp Z3 is inserted into the small-diameter shaft portion of the clamp Z2, the upper surface of the magnetic rubber 19 is pressed downward by the lower end of the clamp Z3, thereby generating a component force in the direction of expanding the diameter of the hook member 20 at the contact portion between the tapered surface 24 of the core metal 18 and the inner shoulder 27 of the hook member 20. As a result, the elastic deformation of the hook member 20 required for the outer circumference of the core metal 18 to pass over the inner diameter of the inner shoulder 27 downward can be easily generated.

[0073] In the case of the rolling bearing 1 in which grease is sealed in the bearing internal space between the inner ring 3 and the outer ring 4 , the grease sealing step may be performed before the hook member 20 is fixed to the inner ring 3 .

[0074] Figure 1 The magnetic sensor unit 17 shown includes a sensor holder 28 connected to the outer ring 4 and a circuit board 29 mounted on the sensor holder 28. The circuit board 29 is mounted with a magnetic sensor 30, a connector 31, and the like.

[0075] The sensor holder 28 is connected to the inner circumference of the outer ring 4 by being locked in the inner circumferential groove 14 of the outer ring 4. Therefore, the radial interference between the sensor holder 28 and the inner circumferential groove 14 is not set to a magnitude that generates a force that expands the outer diameter surface 10 of the outer ring 4.

[0076] The magnetic sensor 30 is composed of an element that converts the magnetic field of the magnetic rubber 19 into an electrical signal. The magnetic sensing portion of the magnetic sensor 30 that converts the magnetic field into an analog electrical signal is arranged at a position axially opposite to the magnetic rubber 19. The surface of the magnetic sensor 30 is mounted on the board surface of the other end side (left side of the figure) of the circuit substrate 29. The sensor-side circuit required for input and output between the magnetic sensor 30 and the outside is constructed on the circuit substrate 29. The connector 31 is the input and output end of the circuit on the sensor side, and is connected to the circuit on the external side. The connector 31 is in a shape that allows the cable (not shown) to be plugged in and out in the radial direction.

[0077] In addition, various electronic components (not shown) such as nonvolatile memory and protection circuit are mounted on the surface of the circuit substrate 29. The purpose of mounting various electronic components is to attenuate or block harmful electrical noise from the outside. Examples of various electronic components include common mode filters, single mode filters, resistors, ceramic capacitors (capacitors), coils, varistors, inductors, ceramic filters, EMI filters, ferrite beads, and the like.

[0078] The number of magnetic sensors 30 configured using the sensor bracket 28 may be one or more. In the case of using multiple magnetic sensors, they may be installed on one circuit substrate 29 or separately installed on two or more circuit substrates. In addition, the sensor bracket 28 may also be used to configure sensors other than the magnetic sensor 30, such as temperature sensors, vibration sensors, etc. The temperature sensor, etc. may be installed on the circuit substrate 29 or on a circuit substrate separate from the circuit substrate 29 to be installed on the sensor bracket.

[0079] It is preferred that lead-free solder be used for soldering of the magnetic sensor 30 and the like. It is preferred that the magnetic sensor 30, the ceramic capacitor, and the nonvolatile memory be surface mounted on the same surface of the circuit substrate 29, and other electronic components, such as protection circuit components and the connector 31, be surface mounted on the opposite surface. In particular, the ceramic capacitor is mounted at a position close to the power supply terminal and the GND terminal of the magnetic sensor 30, so that the external electrical noise (voltage change) component superimposed on the power supply can be effectively reduced to the GND.

[0080] In addition, it is preferable to use glass-added epoxy resin as the circuit substrate 29, and if a material with a compression strength of 340 to 500 MPa and a bending strength of 390 to 550 MPa is selected, the rigidity becomes high, thereby improving the rotation detection accuracy. In addition, by making the circuit substrate 29 a multilayer substrate, the size of the circuit substrate 29 can be further reduced.

[0081] In order to prevent migration, the circuit board 29, the magnetic sensor 30, and various electronic components may be covered with a sheet of thermosetting resin, or may be coated with a resin-based moisture-proof film.

[0082] When using a magnetic sensor 30 that can write data, it is only necessary to provide a through hole (not shown) that passes through the circuit substrate 29 in a portion of the mounting surface of the connector 31 of the circuit substrate 29, insert a connecting terminal such as a pin header (not shown) to write data during the writing operation, and then pull out the connecting terminal.

[0083] like Figure 1As shown, the sensor holder 28 has a sensor window 32 formed at a position axially opposed to the magnetic rubber 19 of the magnetic ring 16. The sensor window 32 is a space for arranging the magnetic sensor 30 at a position axially opposed to the magnetic pole surface of the magnetic rubber 19.

[0084] like Figure 2 , Figure 3 As shown, the sleeve integrated nut 33 is inserted from the other end side (at Figure 3 The left side in the figure) is inserted into the through-hole of the sensor bracket 28, and at one end side of the sensor bracket 28 (at Figure 3 The through-hole of the circuit board 29 and the circular hole of the washer 35 are arranged, and the screw member 34 is relative to the washer 35 from one end side (at Figure 3 The circuit board 29 and the sensor bracket 28 are fastened by screwing the nut 33 into the sleeve integral nut 33. Such fastening parts are provided at two locations on both sides of the circuit board 29 in the circumferential direction.

[0085] The sensor bracket 28 is composed of an outer ring member 36 formed into a cylindrical shape by a metal plate and a rubber portion 38 fixed to an outer flange portion 37 of the outer ring member 36. The outer ring member 36 has an inner flange portion 36a, which is formed at one end of the outer ring member 36 (at the Figure 3 The inner flange portion 36a is formed over the entire circumference. The sensor window 32 passes through the inner flange portion 36a in the axial direction. The circumferential angle θ of the inner flange portion 36a including the sensor window 32 protrudes radially inwards more than the circumferential portion other than the angle θ. The circuit board 29 is fastened within the range of the angle θ. The angle θ is, for example, 65°. In addition, the outer flange portion 37 is formed over the entire circumference of the outer ring member 36. Figure 3 The outer ring component 36 protrudes radially outward. Such an outer ring component 36 can be manufactured by stamping a thin plate such as a mild steel plate or a stainless steel plate. For example, a disc-shaped blank can be drawn into a roughly cup shape to form a cup body with an outer flange portion 37, and the bottom of the cup can be punched to form an inner flange portion. In addition, the outer flange portion 37 does not need to be continuous around the entire circumference. Although the illustration is omitted, the outer flange portion can also be provided intermittently in the circumferential direction so that the outer flange portions adjacent to each other in the circumferential direction form a slit (space).

[0086] The rubber portion 38 is bonded to the sensor holder 28 so as to cover the outer periphery and both ends of the outer flange portion 37. The rubber portion 38 may be bonded to the outer ring member 36 by vulcanization of oil-resistant rubber such as NBR, HNBR, FKM, or ACM.

[0087] The assembly process of connecting the sensor holder 28 to the outer ring 4 is performed after the magnetic ring 16 is mounted on the inner ring 3. In addition, this assembly process is performed in a state where the circuit board 29 is mounted on the inner flange portion 36a of the sensor holder 28. In this assembly process, the outer ring 4 is connected to the outer ring 4 at one end (at the inner ring 3). Figure 3 The sensor holder 28 is arranged on the right side of the outer ring 4, and the elasticity of the rubber portion 38 is used to press the rubber portion 38 into the inner peripheral groove 14 in a contracted and deformed state. After the pressing, the rubber portion 38 is fitted into the inner peripheral groove 14 by the restoring force of the rubber portion 38, and the sensor holder 28 is thus locked in the inner peripheral groove 14. By this locking, the displacement of the sensor holder 28 in the axial, radial and circumferential directions relative to the outer ring 4 is restricted, so that the sensor holder 28 is fixed to the inner periphery of the outer ring 4.

[0088] It may happen though Figure 1 The magnetic rotation sensor 2 of the sensor bearing shown in the figure has no problem, but the inner ring 3 must be replaced with a new one. Figure 1 In the case of the bearing with sensor shown, the rolling bearing 1 is a non-separable bearing, so when at least one of the inner ring 3, the outer ring 4, the rolling element 5 and the retainer 6 is damaged and cannot be used further, the entire rolling bearing 1 including the inner ring 3 is replaced with a new one. At this time, in order to achieve the reuse of the magnetic rotation sensor 2, the following measures can be taken.

[0089] In order to reuse the magnetic sensor unit 17, first, the magnetic sensor unit 17 is removed from the outer ring 4. For example, if an appropriate bearing puller (not shown) is hooked on the inner flange portion 36a of the sensor bracket 28 (see Figure 1 , Figure 3 ), and by using a bearing remover to pull the sensor holder 28 uniformly in the circumferential direction toward one end (the right side of the figure), the rubber portion 38 of the sensor holder 28 can be elastically compressed and easily removed from the inner circumferential groove 14 of the outer ring 4. If the removed sensor holder 28 is not damaged, the removed magnetic sensor unit 17 can be connected to the outer ring 4 of a new rolling bearing 1 and reused.

[0090] Assuming that when the sensor bracket 28 is removed from the outer ring 4, even if the sensor bracket 28 is damaged to the extent that it is not suitable for reuse, the circuit unit including the circuit substrate 29 and the magnetic sensor 30 can be removed from the damaged sensor bracket 28 by simply pulling out all the threaded parts 34 that fasten the damaged sensor bracket 28 to the circuit substrate 29, and the removed circuit unit can be replaced with a new sensor bracket 28 and connected to the outer ring 4 of the new rolling bearing 1, thereby reusing the circuit unit.

[0091] In addition, when the magnetic sensor unit 17 is reused, first, the hook member 20 holding the magnetic ring 16 is removed from the inner ring 3. For this removal, for example, if an appropriate bearing remover (not shown) is hooked to the other end of the hook member 20 ( Figure 1 , Figure 3 The left end of the inner ring 3 is removed by pulling the hook member 20 uniformly toward one end side (the right side of the figure) along the circumferential direction by the bearing remover, and a component force in the direction of expanding the diameter of the hook member 20 is generated at the contact portion between the second inclined surface 25b of the protrusion 25 of the hook member 20 and the outer peripheral groove 12a of the inner ring 3. As a result, the resin hook member 20 can be easily elastically deformed to easily remove the protrusion 25 from the outer peripheral groove 12a. If the removed hook member 20 is not damaged, the removed hook member 20 and the magnetic ring 16 held by the hook member 20 can be connected to the inner ring 3 of a new rolling bearing 1 and reused.

[0092] Assuming that when the hook member 20 is removed from the inner ring 3, even if the hook member 20 is damaged to the extent that it is not suitable for reuse, as long as the core metal 18 is removed from the groove portion 26 of the damaged hook member 20, the magnetic ring 16 can be removed from the damaged hook member 20, and the removed magnetic ring 16 can be replaced with a new hook member 20 and connected to the inner ring 3 of the new rolling bearing 1, thereby reusing the magnetic ring 16. Here, if the hook member 20 is removed from the inner ring 3, the contact between the width 11 of the inner ring 3 and the first plate surface 21 of the core metal 18 disappears, so that the core metal 18 held by the groove portion 26 of the removed hook member 20 can be close to the other end side of the groove portion 26 (the left side of the figure), and a gap can be generated between the second plate surface 22 of the core metal 18 and the groove portion 26. Moreover, the radial depth of the groove 26 of the resin hook component 20 is shallow, and there is little engagement with the second plate surface 22 of the core metal 18 (the diameter difference between the inner diameter of the inner shoulder 27 and the outer diameter surface 23 of the core metal 18 is small). Therefore, if a removal tool such as a flat-blade screwdriver is inserted into the gap between the inner shoulder 27 and the outer periphery of the magnetic rubber 19, and the inner shoulder 27 is pressed radially outward by the removal tool, the hook component 20 can be elastically deformed in such a way that the inner shoulder 27 passes over the outer diameter surface 23 of the core metal 18 toward the other end side (the left side of the figure), thereby easily removing the core metal 18 from the groove 26.

[0093] Figure 5 The following shows an example of using the sensor-equipped bearing. Figure 5 A partial cross section shows a general structure of, for example, an electric motor (induction motor / synchronous motor, DC motor, etc.).

[0094] The inner diameter surface 9 of the inner ring 3 is fitted into the small diameter shaft portion of the stepped shaft-shaped rotating shaft 100. The width of the other end side (left side of the figure) of the inner ring 3 abuts against the shaft shoulder 101. The outer diameter surface 10 of the outer ring 4 is fitted into the housing 102. The nut 103 is screwed into one end side (right end side of the figure) of the rotating shaft 100. The annular spacer 104 is sandwiched between the nut 103 and the inner ring 3 in the axial direction. By screwing the nut 103, the inner ring 3 is mounted on the rotating shaft 100. The width of the other end side (left side of the figure) of the outer ring 4 abuts against the gasket 105. The cover 106 is axially fastened to one end side (right end side of the figure) of the housing 102. The outer ring 4 is fixed in the axial direction by being pressed toward the other end side (left side of the figure) by the cover 106. At this time, the force is transmitted from the width of one end side (right side of the figure) of the outer ring 4 to the width of the other end side (left side of the figure) of the inner ring 3 via the rolling element 5, and a preload is applied to the rolling bearing 1. As a result, the clearances between the inner ring 3, the rolling element 5, and the outer ring 4 of the rolling bearing 1 are appropriately maintained. In this case, the width dimension of the liner 105 is appropriately managed. As a result, the rigidity of the rolling bearing 1 is increased, and high-speed rotation, rotation accuracy, positioning accuracy, etc. are improved.

[0095] When the rotating shaft 100 rotates relative to the housing 102, the inner ring 3 that rotates integrally with the rotating shaft 100 rotates relative to the outer ring 4. Figure 1 , Figure 5 ), the magnetic rubber 19 of the magnetic ring 16 rotates relative to the magnetic sensor 30 in correspondence with the relative rotation of the inner ring 3 and the outer ring 4, so that the magnetic field of the magnetic rubber 19 detected by the magnetic sensor 30 changes. The magnetic sensor 30 converts the change in the magnetic field into an electrical signal and outputs it from the connector 31 as a signal indicating the rotation angle of the inner ring 3 (rotating shaft 100) or the like.

[0096] In addition, Figure 5 The fixed position preloading method is shown in the example, but Figure 6 As shown, a constant pressure preload method may also be used, that is, a spring 110 such as a wave washer is clamped between the cover 106 and the inner ring 3, and the spring 110 is compressed by tightening the cover 106 relative to the housing 102 to apply preload to the rolling bearing 1.

[0097] Figures 1 to 3The sensor-equipped bearing shown is as described above, comprising: a rolling bearing 1 having an inner ring 3, an outer ring 4 and a plurality of rolling elements 5; and a magnetic rotation sensor 2 for detecting the relative rotational motion between the inner ring 3 and the outer ring 4, the inner ring 3 having: a raceway surface 8; a width 11 located at one end of the width of the inner ring 3; and an outer peripheral portion 12 continuous from the width 11 to the raceway surface 8, the magnetic rotation sensor 2 having: a magnetic ring 16 connected to the outer peripheral portion 12 of the inner ring 3; and a magnetic sensor unit 17 connected to the outer ring 4, the magnetic ring 16 having: a core bar 18 formed in a ring shape; and a magnetic rubber 19 fixed to the core bar 18.

[0098] In particular, the sensor-equipped bearing further includes a hook member 20, which is formed of resin in an annular shape, and has an outer peripheral groove 12a extending in the circumferential direction formed on the outer peripheral portion 12 of the inner ring 3. The hook member 20 has a protrusion 25 that is locked in the outer peripheral groove 12a of the inner ring 3. The magnetic ring 16 is held by the hook member 20, and the protrusion 25 of the resin hook member 20 can be pressed into the outer peripheral groove 12a of the inner ring 3 by elastic deformation of the hook member 20 side, and is locked in the outer peripheral groove 12a. Therefore, between the hook member 20 and the outer peripheral portion 12 of the inner ring 3, it is not necessary to ensure a large radial interference and fitting width as in a connection structure that relies on press-fitting. Therefore, the hook member 20 can be fixed to the outer peripheral portion 12 of the inner ring 3 while avoiding the shrinkage of the inner diameter surface 9 of the inner ring 3, and the hook member 20 can be fixed to the outer peripheral portion 12 of the inner ring 3 even when the width of the inner ring 3 is small. The hook member 20 holds the magnetic ring 16, so the hook member 20 can also connect the magnetic ring 16 to the outer peripheral portion 12 of the inner ring 3 to fix the position of the magnetic ring 16 relative to the inner ring 3. In addition, the protrusion 25 can be easily removed from the outer peripheral groove 12a of the inner ring 3 by utilizing the elastic deformation of the hook member 20, so it is not easy to damage the hook member 20 and the magnetic ring 16 when removing them from the inner ring 3. Therefore, the reusability of the magnetic ring 16 when the inner ring 3 (rolling bearing 1) is replaced can be improved.

[0099] In this way, the bearing with sensor can avoid the shrinkage of the inner diameter surface 9 of the inner ring 3 even if the magnetic ring 16 of the magnetic rotation sensor 2 is connected to the outer peripheral portion 12 of the inner ring 3 of the rolling bearing 1, and can connect the outer peripheral portion 12 of the inner ring 3 and the magnetic ring 16 even when the width of the inner ring 3 is small, and the reusability of the magnetic ring 16 when the inner ring 3 is replaced is improved.

[0100] Furthermore, the hook member 20 of the sensor-equipped bearing has a groove 26 extending in the circumferential direction, and the core metal 18 is locked in the groove 26, so that the core metal 18 can be pressed into the groove 26 of the resin hook member 20, and the core metal 18 is locked in the groove 26 by utilizing the elastic deformation of the hook member 20. Therefore, it is not necessary to set a large interference between the groove 26 of the hook member 20 and the core metal 18. Therefore, it is also easy to remove the core metal 18 from the groove 26 by utilizing the elastic deformation of the hook member 20, so the magnetic ring 16 is not easily damaged when the core metal 18 is removed from the groove 26. Therefore, the sensor-equipped bearing can improve the reusability of the magnetic ring 16 removed from the hook member 20. Therefore, even if the hook member 20 removed from the inner ring 3 is not suitable for reuse due to damage, deterioration, etc., it is possible to avoid replacement of the magnetic ring 16.

[0101] Furthermore, the hook member 20 of the bearing with a sensor has an inner periphery including a groove 26, the core metal 18 has a first plate surface 21 and a second plate surface 22 which are mutually opposed in the axial direction, the groove 26 is located radially outward of the width 11 of the inner ring 3, the first plate surface 21 is in contact with the width 11 of the inner ring 3 in the axial direction, and the groove 26 is hooked on the second plate surface 22, thereby making it possible to make the first plate surface 21 contact with the width 11 of the inner ring 3 to receive the inner periphery of the core metal 18 in the axial direction, and on the other hand, making the groove 26 hooked on the second plate surface 22 to receive the outer periphery of the core metal 18 in the axial direction. Therefore, even if the hooking of the groove 26 with respect to the second plate surface 22 is reduced, the position of the core metal 18 with respect to the hook member 20 and the inner ring 3 can be kept constant, and the core metal 18 can be prevented from tilting with respect to the radial direction. Therefore, the sensor bearing can reduce the radial depth of the groove 26 to reduce the hooking of the groove 26 on the second plate surface 22 , thereby suppressing the outer diameter of the hook member 20 and making it easier for the core metal 18 to enter and exit the groove 26 .

[0102] Furthermore, for the belt sensor, the magnetic rubber 19 of the bearing is bonded to the second plate surface 22, so that the magnetic rubber 19 can be configured by utilizing the axial thickness (the width of the inner shoulder 27) corresponding to the second plate surface 22 in which the groove 26 of the hook part 20 is hooked on the core bone 18, thereby suppressing the axial protrusion of the magnetic ring 16 relative to the width 11 of the inner ring 3.

[0103] Furthermore, the core bone 18 of the bearing with the sensor is composed of a metal plate along the radial direction. Since the core bone 18 is made of a metal plate along the radial direction, no flange forming or deep drawing is performed when manufacturing the core bone 18. Therefore, the core bone 18 can be processed at a low cost, and the width and the total radial length of the core bone 18 can be suppressed.

[0104] In addition, in the sensor-equipped bearing, the magnetic sensor unit 17 has the magnetic sensor 30 at a position axially opposed to the magnetic rubber 19, thereby being able to arrange the magnetic sensor 30 and the circuit board 29 avoiding the space located radially outside the magnetic rubber 19. Such an arrangement is suitable for arranging the magnetic rotation sensor 2 so as not to protrude radially from the rolling bearing 1 even when the radial thickness between the inner diameter (the inner diameter surface 9 of the inner ring 3) and the outer diameter (the outer diameter surface 10 of the outer ring 4) of the rolling bearing 1 is small.

[0105] Furthermore, the outer ring 4 of the bearing with the sensor has an inner circumferential groove 14, and the magnetic sensor unit 17 is clamped in the inner circumferential groove 14. Therefore, when the outer ring 4 is replaced, the reusability of the magnetic sensor unit 17 can be improved, and even if the magnetic sensor unit 17 is connected to the inner circumference of the outer ring 4, the expansion of the outer diameter surface 10 of the outer ring 4 can be avoided, and the magnetic sensor unit 17 can be connected to the inner circumference of the outer ring 4 even if the dimension of the outer ring 4 in the width direction is small.

[0106] As described above, when the rolling bearing 1 is replaced, the sensor bearing can remove the magnetic ring 16 , the hook member 20 , and the magnetic sensor unit 17 from the rolling bearing 1 and reuse them, which is economical.

[0107] In addition, the bearing with a sensor has a structure in which the hook component 20 is clamped in the outer circumferential groove 12a of the inner ring 3 and the sensor bracket 28 is clamped in the inner circumferential groove 14 of the outer ring 4. Therefore, a standard bearing with a seal can be used as the rolling bearing 1. There is no need to increase the width of the inner ring 3 and the outer ring 4, and no additional cost is incurred in the bearing manufacturing process, which is conducive to suppressing the overall cost.

[0108] In addition, the bearing with a sensor has a structure in which the hook part 20 that holds the magnetic ring 16 is latched in the outer circumferential groove 12a of the inner ring 3, and the sensor bracket 28 is latched in the inner circumferential groove 14 of the outer ring 4. Therefore, even when the radial thickness between the inner diameter (inner diameter surface 9 of the inner ring 3) and the outer diameter (outer diameter surface 10 of the outer ring 4) of the rolling bearing 1 is small, the inner diameter surface 9 of the inner ring 3 does not shrink, and even if the sensor bracket 28 is connected to the inner periphery of the outer ring 4, the outer diameter surface 10 of the outer ring 4 does not expand.

[0109] In addition, for the bearing with a sensor, even if the magnetic ring 16 is connected to the outer periphery 12 of the inner ring 3 through the hook part 20, the inner diameter surface 9 of the inner ring 3 does not shrink, and even if the sensor bracket 28 is connected to the inner periphery of the outer ring 4, the outer diameter surface 10 of the outer ring 4 does not expand. Therefore, the size of the rolling bearing 1 can be treated as a standard size rolling bearing.

[0110] Furthermore, the present invention is not limited to a rolling bearing having a small thickness in the radial direction between the inner diameter and the outer diameter, and can be applied to all rolling bearings.

[0111] In addition, the locking structure of the sensor bracket relative to the inner peripheral groove of the outer ring is not limited to the structure using the elastic deformation of the rubber part, and can also be changed to other locking structures. Figure 7 to Figure 10 In addition, only the differences from the first embodiment will be described below.

[0112] The magnetic sensor unit 40 according to the second embodiment includes a sensor holder 41 formed of resin. The sensor holder 41 is composed of a seamless single cylindrical member. Figure 8 , Fig. 9 As shown, the outer periphery of the sensor bracket 41 includes: a first protrusion 42, located at the other end of the sensor bracket 41 ( Figure 8 and a second protrusion 43, located at one end side of the protrusion 42 ( Figure 8 on the right side of the screen).

[0113] The first protrusion 42 is locked to the inner circumferential groove 14 of the outer ring 4. The first protrusion 42 is provided intermittently in the circumferential direction in order to be easily pressed into the inner circumferential groove 14. A slit (space) is formed between each of the adjacent first protrusions 42 in the circumferential direction. In addition, the first protrusion 42 can also be continuous over the entire circumference.

[0114] The second protrusion 43 is used to axially contact with one end side ( Figure 8 The sensor bracket 41 is abutted against the right side of the width to limit the axial direction of the sensor bracket 41 ( Figure 8 The second protrusion 43 is continuous over the entire circumference.

[0115] like Figure 8 , Fig.10 As shown, the sensor bracket 41 has an inner flange portion 44 of the same shape as that of the first embodiment, and as shown in FIG. Figure 8 As shown in FIG. 1 , the thickness of the required parts such as the inner flange 44 is increased compared to the first embodiment, so although it is made of resin, it has sufficient strength and rigidity for fastening and supporting the circuit board 29. The periphery of the nut 33 is formed into a countersunk hole. In addition, Fig.10 The inner ring, hook member and magnetic ring are omitted in the figure.

[0116] The sensor bracket 41 can be seamlessly formed as a whole by, for example, injection molding a thermoplastic resin material. In addition, the resin forming the sensor bracket 41 can be appropriately selected according to the use environment of the sensor bracket 41. For example, in the case of using a thermoplastic resin in which glass fiber, calcium carbonate, etc. are filled in polyphenylene sulfide (PPS), the stability of the size of the sensor bracket 41 relative to the ambient temperature is improved. In addition, in the case of using in an environment with a small temperature change such as room temperature, for example, polybutylene terephthalate (PBT), polyacetal (POM), etc. can be used.

[0117] In the first and second embodiments, the sensor holder is exemplified as being continuous over the entire circumference, but the sensor holder may be in a headed ring shape that is completely disconnected in a partial region in the circumferential direction. Figures 11 to 13 The third embodiment is shown as an example. The third embodiment also changes the sensor bracket relative to the second embodiment, so only the changes relative to the second embodiment are described here. Fig.13 The inner ring, hook member and magnetic ring are omitted in the figure.

[0118] The sensor bracket involved in the third embodiment is composed of a bracket body 50 and a spring component 53. The bracket body 50 is completely discontinuous in a part of the circumferential direction and has a first circumferential end 51 and a second circumferential end 52 that are opposite to each other in the circumferential direction. The spring component 53 is configured to apply force to the bracket body 50 in the diameter expansion direction.

[0119] The stent body 50 is formed of a seamless single resin portion, and includes the first protrusion 42 and the second protrusion 43. A space is formed between the first circumferential end portion 51 and the second circumferential end portion 52.

[0120] The spring component 53 is formed into a headed ring shape with a portion of the circumference being completely discontinuous. The spring component 53 is formed of a thin-walled metal plate formed into a C shape with a portion of the circumference being completely discontinuous. The spring component 53 is installed from the other end side ( Fig.11 , Fig.12 The end face of the left side of the Fig.11 , Fig.12 The spring member 53 extends over substantially the entire length of the bracket body 50 in the circumferential direction.

[0121] The first protrusion 42 is inserted into the inner peripheral groove 14 of the outer ring 4 while elastically deforming the bracket body 50 (including the spring member 53) in a direction in which the first circumferential end 51 and the second circumferential end 52 of the bracket body 50 on which the spring member 53 is mounted are brought close to each other. After the insertion, if the bracket body 50 and the spring member 53 are elastically restored, the first protrusion 42 is locked in the inner peripheral groove 14, and this state is subsequently maintained by the elastic restoring force of the spring member 53. Thus, the bracket body 50 is fixed to the outer ring 4.

[0122] In addition, the spring member 53 is not limited to a C-shaped leaf spring, and a C-shaped wire spring may be used. In addition, a structure may be formed in which the spring member is interposed between the first circumferential end and the second circumferential end of the stent body, and the elastic restoring force of the spring member is used to press the two circumferential ends of the stent body in a direction away from each other in the circumferential direction to apply force in a direction to expand the diameter of the stent body.

[0123] The sensor bearing according to each of the above-described embodiments can be applied to, for example, the following functions a to c, uses a to f, and the like.

[0124] Function a: Detects the absolute angle of rotation based on the absolute output of the magnetic rotation sensor.

[0125] Function b: Detects the speed and direction of rotation based on the incremental output of the magnetic rotation sensor.

[0126] Function c: Detect the rotational position of a rotating body such as a motor rotor.

[0127] Application a: Rotation angle detection of joints of various robots such as household robots, industrial robots, and AI robots

[0128] Application b: Detection of the rotation angle of the turning part of various robots

[0129] Application c: Rotation detection of various motors such as AC servo motors, DC servo motors, hydraulic motors, etc.

[0130] Application d: Rotation detection of various transmissions such as reducers and speed increasers

[0131] Application e: Position detection of various polygon mirrors that reflect lasers in laser printers, image diagnostic devices, etc.

[0132] Application f: Rotation detection and position detection of various machines such as industrial machinery, construction machinery, spindles, etc.

[0133] Furthermore, sensor-equipped bearings having thin-walled, narrow-width rolling bearings are used in, for example, various robots, small motors, and the like.

[0134] The embodiments disclosed herein are to be considered in all respects as illustrative and non-restrictive. The scope of the present invention is indicated by the scope of the present application rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of the present application.

[0135] Description of Reference Numerals

[0136] 1…rolling bearing; 2…magnetic rotation sensor; 3…inner ring; 4…outer ring; 5…rolling element; 8…raceway surface; 9…inner diameter surface; 10…outer diameter surface; 11…width; 12…peripheral portion; 12a…peripheral groove; 16…magnetic ring; 17, 40…magnetic sensor unit; 18…core metal; 19…magnetic rubber; 20…hook component; 21…first plate surface; 22…second plate surface; 25…protrusion; 26…groove; 30…magnetic sensor.

Claims

1. A bearing with a sensor, comprising: a rolling bearing having an inner ring, an outer ring, and a plurality of rolling elements; and a magnetic rotation sensor for detecting relative rotational motion between the inner ring and the outer ring, The inner ring has: a raceway surface; a width surface located at one end of the width of the inner ring; and an outer peripheral portion, which is continuous from the width surface to the raceway surface. The magnetic rotation sensor comprises: a magnetic ring connected to the outer peripheral portion of the inner ring; and a magnetic sensor unit connected to the outer ring. The magnetic ring comprises: a core bone formed into a ring shape; and a magnetic rubber fixed to the core bone. The sensor-equipped bearing is characterized in that it further comprises: The hook member is formed of resin into a ring shape. An outer peripheral groove extending in the circumferential direction is formed on the outer peripheral portion of the inner ring. The hook member has a protrusion that is locked in the outer peripheral groove of the inner ring. The core metal is held by the hook member.

2. The bearing with a sensor according to claim 1, characterized in that: The hook member has a groove extending in the circumferential direction, The core bar is locked in the groove.

3. The bearing with a sensor according to claim 2, characterized in that: The hook member has an inner periphery including the groove portion, The core bone has a first plate surface and a second plate surface which are axially opposed to each other. The groove portion is located radially outward of the width of the inner ring. The first plate surface is in contact with the width of the inner ring, The groove portion is hooked on the second plate surface.

4. The bearing with a sensor according to claim 3, characterized in that: The magnetic rubber is fixed to the second plate surface.

5. The bearing with a sensor according to claim 3 or 4, characterized in that: The core bar is composed of a metal plate along a radial direction.

6. The bearing with a sensor according to claim 3 or 4, characterized in that: The magnetic sensor unit includes a magnetic sensor at a position facing the magnetic rubber in the axial direction.

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