Rolling bearing and bearing device

Abstract

To provide a rolling bearing whose operating condition can be monitored highly precisely and which is made at a low cost.SOLUTION: A sensor mounting member 11 is fixedly disposed on an axial end surface 10 of an outer race 2. The sensor mounting member 11 includes: a cylindrical part 24 whose axial one end is abuttingly disposed at a position deviated in an axial inward from an end on a radial outside of the axial end surface 10 so that an end part on an axial outside of the axial end surface 10 of the outer race 2 is exposed annularly without being covered; and a circular plate part 25 extending radially inward from the axial other end of the cylindrical part 24.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rolling bearing to which a bearing monitoring sensor can be attached, and to a bearing device using the rolling bearing. [Background technology]

[0002] In fields such as industrial equipment, rolling bearings are used to support rotating shafts and rotating bodies of mechanical devices. A rolling bearing generally has an outer ring, an inner ring disposed radially inside the outer ring, and a plurality of rolling elements incorporated into the annular bearing space between the outer ring and the inner ring.

[0003] In recent years, in order to avoid sudden shutdowns of equipment due to failures of rolling bearings, efforts have been made to install bearing monitoring sensors (vibration sensors, temperature sensors, etc.) that monitor the operating status of rolling bearings, and to carry out planned maintenance and replacement of rolling bearings based on the data obtained from these bearing monitoring sensors.

[0004] In relation to this bearing monitoring sensor, Patent Documents 1 and 2 propose a method in which a vibration sensor that detects vibrations of the rolling bearing is attached to a housing that accommodates the rolling bearing, and the operating state of the rolling bearing is monitored based on the vibration data obtained by the vibration sensor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-128477 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-149090 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, when a vibration sensor is attached to a housing that accommodates a rolling bearing, as in Patent Documents 1 and 2, the housing needs to be processed so that the vibration sensor (bearing monitoring sensor) can be attached.

[0007] The inventors of the present application therefore considered attaching a sensor that monitors the operating state of a rolling bearing (hereinafter referred to as a "bearing monitoring sensor") to the rolling bearing rather than to the housing. If the bearing monitoring sensor could be attached to the rolling bearing, it would be less costly because it would not require machining of the housing, and it would also be possible to monitor the rolling bearing more directly than if the bearing monitoring sensor were attached to the housing, making it possible to monitor the operating state of the rolling bearing with greater accuracy.

[0008] Furthermore, the inventors of the present application considered whether it would be possible to attach a bearing monitoring sensor by simply using the shapes of the outer and inner rings of existing rolling bearings, rather than machining the outer and inner rings of rolling bearings into shapes specifically for attaching a bearing monitoring sensor. If the shapes of the outer and inner rings of existing rolling bearings could be used as is, the cost required to attach a bearing monitoring sensor could be significantly reduced, accelerating the spread of bearing monitoring sensors. Furthermore, they believed that if the bearing monitoring sensor were detachable, it would be possible to reuse the bearing monitoring sensor attached to the previous rolling bearing when replacing the rolling bearing, thereby reducing costs.

[0009] The problem to be solved by the present invention is to provide a rolling bearing that can monitor the operating state of the rolling bearing with high accuracy and that is low in cost. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides a rolling bearing having the following configuration. [Configuration 1] The outer ring and an inner ring disposed radially inside the outer ring; a plurality of rolling elements incorporated in an annular bearing space formed between the outer ring and the inner ring, one of the outer ring and the inner ring is a fixed ring that is fixed so as not to rotate, and the other is a rotating ring that is rotatably supported by the fixed ring via the rolling elements, In a rolling bearing, the fixed ring has a cylindrical fitting surface located at the end opposite to the rotating ring side, and a flat axial end surface perpendicular to the fitting surface, a sensor mounting member having a sensor mounting surface on which a bearing monitoring sensor for monitoring the operating state of the rolling bearing is detachably mounted is fixedly provided on the axial end surface of the fixed ring; The sensor mounting member is characterized in that it has a cylindrical portion having one axial end abutted and fixed at a position radially shifted from the radial end of the axial end face on the fitting surface side so that the radial end portion of the axial end face on the fitting surface side is uncovered and exposed in an annular shape, and an annular plate portion extending radially from the other axial end of the cylindrical portion on the opposite side from the fitting surface side.

[0011] By adopting this configuration, the bearing monitoring sensor can be attached to the sensor mounting member provided on the fixed ring, so that the operating state of the rolling bearing can be monitored more directly than if the bearing monitoring sensor were attached to a housing that accommodates the rolling bearing, and the operating state of the rolling bearing can be monitored with high accuracy.

[0012] Furthermore, because the sensor mounting member is fixed to the axial end face of the fixed ring, the shapes of the fixed ring (one of the outer ring or inner ring) and rotating ring (the other of the outer ring or inner ring) of an existing rolling bearing can be used as is. This means that there is no need to process the outer ring and inner ring of the rolling bearing into a special shape for mounting the bearing monitoring sensor, which reduces costs.

[0013] Furthermore, since the bearing monitoring sensor is attached to the sensor mounting member in a detachable manner, when replacing a rolling bearing, it is possible to reuse the bearing monitoring sensor that was attached to the sensor mounting member of the rolling bearing before replacement, which is low cost.

[0014] Furthermore, since the radial end portion of the axial end face of the fixed ring on the side of the fitting surface is not covered by the sensor mounting member and is exposed in an annular shape, when assembling the rolling bearing, it is possible to fix the rolling bearing in the axial direction by butting the exposed portion in the axial direction.

[0015] [Configuration 2] 2. The rolling bearing according to claim 1, wherein the sensor mounting surface is configured so that the bearing monitoring sensor can be mounted in a radial range that overlaps with the bearing space when viewed from the axial direction.

[0016] By adopting this configuration, the bearing monitoring sensor can be installed in a radial range that overlaps with the bearing space when viewed from the axial direction (i.e., a radial range that is less likely to interfere with surrounding components when assembling the rolling bearing), making it easy to secure space to install the bearing monitoring sensor even when the bearing size is small.

[0017] [Configuration 3] a seal member that closes an end opening of the bearing space on the axial end face side, 3. The rolling bearing according to configuration 1 or 2, wherein the annular plate portion of the sensor mounting member is disposed opposite the sealing member in the axial direction.

[0018] By adopting this configuration, it is possible to attach a bearing monitoring sensor to the seal member of an existing sealed bearing, which is both reliable and economical, and to monitor the operating condition of the sealed bearing with the bearing monitoring sensor.

[0019] [Configuration 4] 4. The rolling bearing according to any one of configurations 1 to 3, wherein the sensor mounting surface is formed of a magnetic material, and the bearing monitoring sensor can be detachably mounted by attracting a permanent magnet provided on the bearing monitoring sensor to the sensor mounting surface.

[0020] [Configuration 5] 5. The rolling bearing according to any one of configurations 1 to 4, wherein a threaded hole is formed in the sensor mounting surface, and the bearing monitoring sensor can be detachably mounted by screwing a screw shaft provided in the bearing monitoring sensor into the threaded hole in the sensor mounting surface.

[0021] [Configuration 6] 6. The rolling bearing according to any one of configurations 1 to 5, wherein the sensor mounting surface is an annular flat surface formed on the annular plate portion and perpendicular to the axial direction.

[0022] With this configuration, the sensor mounting surface is an annular flat surface, which provides a large area for the sensor mounting surface, making it easy to ensure sufficient mounting space for multiple bearing monitoring sensors.

[0023] [Configuration 7] the sensor mounting member further includes a second cylindrical portion extending in the axial direction from an end of the annular plate portion opposite to the fitting surface side, 6. The rolling bearing according to any one of configurations 1 to 5, wherein the sensor mounting surface is a flat surface formed on the outer periphery of the second cylindrical portion and perpendicular to the radial direction.

[0024] With this configuration, the direction perpendicular to the sensor mounting surface is the same as the direction of vibrations that occur in the fixed ring during bearing rotation. Therefore, when a vibration sensor is attached to the sensor mounting surface as a bearing monitoring sensor, it is possible to accurately detect vibrations that occur in the fixed ring during bearing rotation.

[0025] [Configuration 8] 8. A rolling bearing according to any one of configurations 1 to 7, wherein one axial end of the cylindrical portion is fixed to the axial end face by a plurality of spot welds formed at intervals in the circumferential direction.

[0026] By adopting this configuration, the sensor mounting member is fixed to the fixed ring by spot welding, which reduces thermal distortion of the fixed ring caused by welding and makes it possible to prevent performance degradation of the rolling bearing due to thermal distortion of the fixed ring.

[0027] [Configuration 9] a chamfered surface inclined relative to the axial end surface is formed at one axial end of the cylindrical portion; 9. The rolling bearing according to configuration 8, wherein the spot welded portion is accommodated in an annular gap having a triangular cross section formed between the chamfered surface and the axial end surface.

[0028] By adopting this configuration, it is possible to prevent the spot weld from extending significantly onto the annular exposed portion of the axial end face of the fixed ring that is not covered by the sensor mounting member (i.e., the portion that becomes the axial abutment surface when assembling the rolling bearing).

[0029] The present invention also provides a bearing device using the rolling bearing of the above configuration, which has the following configuration. [Configuration 10] A rolling bearing according to any one of configurations 1 to 9; a housing that accommodates the rolling bearing; a rotating shaft rotatably supported by the rolling bearing; a bearing monitoring sensor attached to the sensor mounting member of the rolling bearing, The bearing device is configured so that the operating state of the rolling bearing can be monitored by the bearing monitoring sensor. [Effects of the Invention]

[0030] In the rolling bearing of this invention, a bearing monitoring sensor can be attached to a sensor mounting member provided on the fixed ring, so that the operating state of the rolling bearing can be monitored more directly than if a bearing monitoring sensor were attached to a housing that accommodates the rolling bearing, and the operating state of the rolling bearing can be monitored with greater accuracy.

[0031] Furthermore, because the sensor mounting member is fixed to the axial end face of the fixed ring, the shapes of the fixed ring (one of the outer ring or inner ring) and rotating ring (the other of the outer ring or inner ring) of an existing rolling bearing can be used as is. This means that there is no need to process the outer ring and inner ring of the rolling bearing into a special shape for mounting the bearing monitoring sensor, which reduces costs.

[0032] Furthermore, since the bearing monitoring sensor is attached to the sensor mounting member in a detachable manner, when replacing a rolling bearing, it is possible to reuse the bearing monitoring sensor that was attached to the sensor mounting member of the rolling bearing before replacement, which is low cost.

[0033] Furthermore, since the radial end portion of the axial end face of the fixed ring on the side of the fitting surface is not covered by the sensor mounting member and is exposed in an annular shape, when assembling the rolling bearing, it is possible to fix the rolling bearing in the axial direction by butting the exposed portion in the axial direction. [Brief explanation of the drawings]

[0034] [Figure 1] FIG. 1 is a perspective view showing a rolling bearing according to a first embodiment of the present invention; [Figure 2] Cross section of rolling bearing in Figure 1 [Figure 3] FIG. 3 is an enlarged view of the vicinity of the sensor mounting member in FIG. 2. [Figure 4] FIG. 4 is an enlarged view of the vicinity of the portion of the sensor mounting member in FIG. 3 that abuts against the axial end face of the outer ring. [Figure 5] FIG. 3 is a cross-sectional view showing a bearing device using the rolling bearing shown in FIG. 2. [Figure 6] FIG. 10 is a perspective view showing a rolling bearing according to a second embodiment of the present invention; [Figure 7] Cross-section of the rolling bearing in Figure 6 [Figure 8] FIG. 8 is a cross-sectional view showing a bearing device using the rolling bearing shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0035] 1 and 2 show a rolling bearing 1 according to a first embodiment of the present invention. As shown in Fig. 2, this rolling bearing 1 comprises an outer ring 2, an inner ring 3 arranged coaxially radially inward of the outer ring 2, a plurality of rolling elements 5 spaced circumferentially in an annular bearing space 4 formed between the outer ring 2 and the inner ring 3, an annular seal member 6 that closes an end opening on one axial side (the left side in the figure) of the bearing space 4, an annular seal member 7 that closes an end opening on the other axial side (the right side in the figure) of the bearing space 4, a cage 8 that maintains the circumferential spacing of the plurality of rolling elements 5, and a sensor mounting member 11 fixed to one axial end face 10 of both axial end faces 9, 10 of the outer ring 2. A lubricant (not shown) is sealed in the bearing space 4.

[0036] The axial direction is the direction parallel to the central axis of the outer ring 2 (the central axis of the bearing), the radial direction is the direction perpendicular to the central axis of the outer ring 2, and the circumferential direction is the direction along the circumference centered on the central axis of the outer ring 2.

[0037] The inner periphery of the outer ring 2 is formed with an outer ring raceway groove 12 with which the rolling elements 5 roll, a pair of outer ring shoulders 13 extending circumferentially on both sides of the outer ring raceway groove 12, and a pair of outer ring seal grooves 14 extending circumferentially on both sides of the pair of outer ring shoulders 13. The outer peripheries of seal members 6, 7 are fitted into and fixed to the pair of outer ring seal grooves 14, respectively.

[0038] The outer ring raceway groove 12 is a groove extending circumferentially through the axial center of the inner circumference of the outer ring 2. The outer ring shoulder 13 is a bank-shaped portion extending circumferentially along the edge of the outer ring raceway groove 12, and is formed into a cylindrical shape with a constant inner diameter along the axial direction. A pair of outer ring seal grooves 14 are formed at one axial end and the other axial end of the inner circumference of the outer ring 2, and are shaped symmetrically to each other. The outer ring 2 is shaped symmetrically with respect to an imaginary axis-perpendicular plane that passes through the axial center of the outer ring 2.

[0039] The outer periphery of the inner ring 3 is formed with an inner ring raceway groove 15 with which the rolling elements 5 roll and make contact, a pair of inner ring shoulders 16 located on either side of the inner ring raceway groove 15, and a pair of inner ring seal grooves 17 located on either side of the pair of inner ring shoulders 16. The pair of inner ring seal grooves 17 accommodate the radially inner ends of the seal members 6, 7, respectively.

[0040] The inner ring raceway groove 15 is a groove extending circumferentially through the axial center of the outer periphery of the inner ring 3. The inner ring shoulder 16 is a bank-shaped portion extending circumferentially along the edge of the inner ring raceway groove 15, and is formed into a cylindrical shape with a constant outer diameter along the axial direction. A pair of inner ring seal grooves 17 are formed at one axial end and the other axial end of the outer periphery of the inner ring 3, and are shaped symmetrically to each other. The inner ring 3 is shaped symmetrically with respect to an imaginary axis-perpendicular plane that passes through the axial center of the inner ring 3.

[0041] The rolling elements 5 are sandwiched radially between the outer ring raceway groove 12 and the inner ring raceway groove 15. In this embodiment, the rolling elements 5 are balls, the outer ring raceway groove 12 is an arc groove having a concave arc cross section symmetrical about the axial center of the outer ring 2, and the inner ring raceway groove 15 is also an arc groove having a concave arc cross section symmetrical about the axial center of the inner ring 3. In other words, the rolling bearing 1 in this embodiment is a deep groove ball bearing.

[0042] As shown in FIG. 3, the seal member 7 is formed by vulcanization bonding rubber 19 to a circular plate-shaped core metal 18. A rubber seal lip 20 is formed at the radially inner end of the seal member 7, and a minute labyrinth gap is formed between the seal lip 20 and the inner surface of the inner ring seal groove 17. The seal lip 20 may be in sliding contact with the inner surface of the inner ring seal groove 17. It is also possible to use a shield plate formed by press-molding a metal plate as the seal member 7. The seal member 6 shown in FIG. 2 is configured in the same manner as the seal member 7.

[0043] As shown in FIG. 3 , the outer ring 2 has a mating surface 21 located at the end opposite the inner ring 3 side (i.e., on the radially outer side), and an axial end face 10 perpendicular to the mating surface 21. The mating surface 21 is a cylindrical surface with a constant outer diameter that does not change along the axial direction, and the axial end face 10 is an annular flat surface perpendicular to the axial direction. The axial end face 10 intersects with the mating surface 21 via a chamfered portion 22 that has an arc-shaped cross section. The radially outer end of the axial end face 10 connects to the chamfered portion 22, and the radially inner end of the axial end face 10 connects to a groove shoulder 23 of the outer ring seal groove 14. The groove shoulder 23 has an inner circumference that is smaller than the groove bottom diameter of the outer ring seal groove 14 and larger than the outer ring shoulder 13.

[0044] The sensor mounting member 11 has a cylindrical portion 24 and an annular plate portion 25. One axial end (left end in the drawing) of the cylindrical portion 24 is abutted against and fixed to a position shifted radially (here, radially inward) from the radial end (here, the radially outer end) on the fitting surface 21 side of the axial end face 10 of the outer ring 2 on the opposite side. The annular plate portion 25 is formed to extend radially (here, radially inward) from the other axial end (right end in the drawing) of the cylindrical portion 24 on the opposite side from the fitting surface 21 side. The cylindrical portion 24 and the annular plate portion 25 form an annular body with an L-shaped cross section.

[0045] As shown in FIG. 4 , one axial end (the left end in the figure) of the cylindrical portion 24 is formed with a chamfered surface 26 that is inclined relative to the axial end face 10 of the outer ring 2. One axial end (the left end in the figure) of the cylindrical portion 24 is fixed to the axial end face 10 of the outer ring 2 by a plurality of spot welds 27 formed at intervals in the circumferential direction. The spot welds 27 are formed by laser welding at intervals in the circumferential direction at the butted portions of the outer ring 2 and the cylindrical portion 24. The spot welds 27 are accommodated in an annular gap with a triangular cross section formed between the chamfered surface 26 and the axial end face 10. Note that the spot welds 27 may be welded in a continuous line rather than in a spot-like manner. Here, the cylindrical portion 24 is fixed to the axial end face 10 by welding, but it is also possible to fix it with an adhesive.

[0046] As shown in Figure 3, the annular plate portion 25 is formed to extend straight radially inward from the cylindrical portion 24 to a position beyond the radial position of the pitch circle. The pitch circle is an imaginary circle connecting the centers of multiple rolling elements 5. The annular plate portion 25 faces the seal member 7 in the axial direction. The axial distance from the axial end face 10 of the outer ring 2 to the end face on one axial side (the left side in the figure) of the annular plate portion 25 is set to 10 mm or less (preferably 5 mm or less).

[0047] When viewed from the axial direction, the radial end of the axial end face 10 of the outer ring 2 on the side where the fitting surface 21 is located (here, the radially outer side) is not covered by the sensor mounting member 11 and is exposed in an annular shape, while the remaining portion is covered by the sensor mounting member 11. The radial width of the exposed portion of the axial end face 10 of the outer ring 2 (specifically, the radial distance from the boundary between the axial end face 10 and the chamfered portion 22 to the outer periphery of the cylindrical portion 24) is set to a size equal to or greater than the dimension corresponding to the shoulder height of the housing defined in "5.2 Shoulder height and diameter of shaft and housing" of radial bearings defined in Japanese Industrial Standard JIS B1566:2015 "Rolling bearings - Mounting dimensions and fits," and is set to, for example, 2.25 mm or more, preferably 2.75 mm or more.

[0048] The sensor mounting member 11 is made of a magnetic material (a ferromagnetic metal such as iron). The sensor mounting member 11 can be formed by cutting, but it is less expensive to form it by pressing a metal plate (such as a magnetic steel plate).

[0049] The axial end face of the annular plate portion 25 serves as a sensor mounting surface 31 to which a bearing monitoring sensor 30 (see FIG. 5) is detachably attached. The sensor mounting surface 31 is an annular flat surface perpendicular to the axial direction. A plurality of screw holes 32 (see FIGS. 1 and 2) for sensor mounting are formed on the sensor mounting surface 31. The bearing monitoring sensor 30 (see FIG. 5) can be attached to the sensor mounting surface 31 in a radial range that overlaps with the bearing space 4 when viewed from the axial direction.

[0050] 5 shows a bearing device incorporating the rolling bearing 1 of this embodiment. This bearing device comprises the above-mentioned rolling bearing 1, a housing 33 that houses the rolling bearing 1, a rotating shaft 34 that is rotatably supported by the rolling bearing 1, a cover member 35 that presses and fixes the rolling bearing 1 in the axial direction, and a bearing monitoring sensor 30.

[0051] The housing 33 has a housing bore 36 that is open at one end and a lid mounting surface 37 formed around the edge of the opening of the housing bore 36. The lid mounting surface 37 is an annular flat surface perpendicular to the axial direction. The inner periphery of the housing bore 36 is formed with a cylindrical inner peripheral fitting surface 38 that fits with the outer peripheral fitting surface 21 of the outer ring 2, and an annular step portion 39 that rises radially inward from one axial end of the inner peripheral fitting surface 38. The step portion 39 axially receives the axial end face 9 of the outer ring 2, thereby positioning the outer ring 2 in the axial direction. The rotating shaft 34 is fitted onto the inner periphery of the inner ring 3.

[0052] Here, the outer ring 2 is a fixed ring that is fixed so as not to rotate, and the inner ring 3 is a rotating ring that is rotatably supported on the outer ring 2 via rolling elements 5. In other words, this rolling bearing 1 is an inner ring rotating type rolling bearing.

[0053] The lid member 35 has a circular plate-shaped flange portion 41 fixed to a lid mounting surface 37 of the housing 33 with bolts 40, an annular protrusion portion 42 protruding in the axial direction from the radial inner end of the flange portion 41 along the inner peripheral fitting surface 38 of the housing 33, and a lid main body portion 43 extending radially inward from the flange portion 41. The tip of the annular protrusion portion 42 abuts against the radially outer end of the axial end face 10 of the outer ring 2 (the annular portion exposed and not covered by the sensor mounting member 11).

[0054] The rolling bearing 1 is inserted into the housing bore 36 so that the sensor mounting member 11 faces the opening side of the housing bore 36 (the right side in the figure). A bearing monitoring sensor 30 that monitors the operating state of the rolling bearing 1 is attached to a sensor mounting surface 31 of the sensor mounting member 11. A vibration sensor, a temperature sensor, or the like can be used as the bearing monitoring sensor 30. When a vibration sensor is attached to the sensor mounting surface 31 as the bearing monitoring sensor 30, using a sensor that detects acceleration along three mutually perpendicular axes makes it possible to accurately detect vibrations that occur in the outer ring 2 while the bearing is rotating.

[0055] The bearing monitoring sensor 30 is detachably attached to the sensor mounting surface 31 by attracting a permanent magnet (not shown) fixed to the bearing monitoring sensor 30 to the sensor mounting surface 31. As shown by the chain line in the figure, the bearing monitoring sensor 30 can also be attached by screwing a screw shaft provided on the bearing monitoring sensor 30 into a threaded hole 32 in the sensor mounting surface 31. In this way, the sensor mounting surface 31 can accommodate multiple bearing monitoring sensors 30.

[0056] As shown in Figure 3, the annular plate portion 25 is positioned so as to face an imaginary axis-perpendicular plane passing through the axial end face 10 of the outer ring 2 with a gap therebetween. Therefore, as shown in Figure 5, even if the screw shaft of the bearing monitoring sensor 30 (see Figure 5) protrudes to the back side of the annular plate portion 25, it is possible to prevent the protruding portion from interfering with the sealing member 7, etc.

[0057] 5, a sensor cable 44 is connected to the bearing monitoring sensor 30, which supplies power to the bearing monitoring sensor 30 and outputs a sensor signal. The sensor cable 44 is drawn out to the outside through a through-hole 45 formed in the lid main body 43. The sensor cable 44 may be connected to the bearing monitoring sensor 30 in a detachable manner using a connector.

[0058] This rolling bearing 1 allows a bearing monitoring sensor 30 to be attached to a sensor mounting member 11 provided on the outer ring 2, which serves as a fixed ring. This makes it possible to monitor the operating state of the rolling bearing 1 more directly than if the bearing monitoring sensor 30 were attached to the housing 33, and makes it possible to monitor the operating state of the rolling bearing 1 with high accuracy.

[0059] Furthermore, as shown in Figure 2, this rolling bearing 1 employs a configuration in which the sensor mounting member 11 is fixed to the axial end face 10 of the outer ring 2, which serves as the fixed ring, so the shapes of the outer ring 2 and inner ring 3 of an existing rolling bearing 1 can be used as is. In particular, it is possible to use standard rolling bearings 1, that is, outer rings 2 and inner rings 3 having shapes and dimensions specified in Japanese Industrial Standards JIS B1512-1 "Rolling bearings - Boundary dimensions - Part 1: Radial bearings" and JIS B1521 "Rolling bearings - Deep groove ball bearings", etc. As a result, there is no need to machine the outer ring 2 and inner ring 3 into a special shape for mounting the bearing monitoring sensor 30, which reduces costs.

[0060] Furthermore, in this rolling bearing 1, the bearing monitoring sensor 30 is detachably attached to the sensor mounting member 11, so when replacing the rolling bearing 1, it is possible to reuse the bearing monitoring sensor 30 that was attached to the sensor mounting member 11 of the previous rolling bearing 1, which is low cost. It is also possible to use a commercially available sensor as the bearing monitoring sensor 30, which is economical.

[0061] Furthermore, as shown in Figure 3, in this rolling bearing 1, the end portion of the axial end face 10 of the outer ring 2 on the side of the fitting surface 21 (radially outward) is not covered by the sensor mounting member 11 and is exposed in an annular shape. Therefore, as shown in Figure 5, when assembling the rolling bearing 1, the exposed portion of the axial end face 10 can be abutted axially against the cover member 35 to fix the rolling bearing 1 in the axial direction.

[0062] 3, in this rolling bearing 1, the sensor mounting member 11 has a cylindrical portion 24 and an annular plate portion 25, and these cylindrical portion 24 and annular plate portion 25 form a ring-shaped body with an L-shaped cross section, so that the rigidity of the sensor mounting member 11 is higher than that of a sensor mounting member 11 that has a linear cross section and is composed only of the annular plate portion 25 without the cylindrical portion 24. Therefore, when a vibration sensor (for example, an acceleration sensor) is attached to the sensor mounting surface 31 as the bearing monitoring sensor 30, noise due to vibration of the sensor mounting member 11 can be prevented, enabling stable monitoring.

[0063] Furthermore, as shown in Figure 5, this rolling bearing 1 allows the bearing monitoring sensor 30 to be mounted in a radial range that overlaps with the bearing space 4 when viewed from the axial direction (i.e., a radial range that is less likely to interfere with surrounding components when assembling the rolling bearing 1), making it easy to secure space for mounting the bearing monitoring sensor 30 even when the bearing size is small.

[0064] 2, in this rolling bearing 1, the annular plate portion 25 of the sensor mounting member 11 is arranged axially opposite the seal member 7, so it is possible to use the seal member 7 of an existing sealed bearing as is to mount the bearing monitoring sensor 30. In other words, it is possible to use an existing sealed bearing that is both reliable and economical, and to monitor the operating state of that sealed bearing with the bearing monitoring sensor 30.

[0065] 2, the sensor mounting surface 31 of this rolling bearing 1 is an annular flat surface that is formed on the annular plate portion 25 and is perpendicular to the axial direction, so the area of ​​the sensor mounting surface 31 is large. Therefore, even when multiple bearing monitoring sensors 30 are attached, as shown by the solid and chain lines in FIG. 5, it is easy to ensure enough space to attach these bearing monitoring sensors 30.

[0066] Furthermore, as shown in Figure 4, this rolling bearing 1 is secured to the axial end face 10 of one axial end of the cylindrical portion 24 by a plurality of spot welds 27 formed at intervals around the circumferential direction, thereby minimizing thermal distortion of the outer ring 2 due to welding and preventing a decrease in the performance of the rolling bearing 1 due to thermal distortion of the outer ring 2.

[0067] Furthermore, as shown in Figure 4, this rolling bearing 1 accommodates the spot weld 27 in an annular gap with a triangular cross section formed between the chamfered surface 26 formed at one axial end of the cylindrical portion 24 and the axial end face 10 of the outer ring 2, thereby making it possible to prevent the spot weld 27 from protruding significantly into the annularly exposed portion of the axial end face 10 of the outer ring 2 that is not covered by the sensor mounting member 11 (i.e., the portion that becomes the axial abutment surface when the rolling bearing 1 is assembled, as shown in Figure 5).

[0068] 6 to 8 show a second embodiment of the present invention. The second embodiment is different from the first embodiment only in the configuration of a portion of the sensor mounting member 11, and the other configurations are the same. Therefore, parts corresponding to those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0069] 7, the sensor mounting member 11 has a cylindrical portion 24, an annular plate portion 25, and a second cylindrical portion 46. The second cylindrical portion 46 is formed in a cylindrical shape extending in the axial direction from the end (here, the radially inner end) of the annular plate portion 25 opposite the fitting surface 21. The cylindrical portion 24 and the annular plate portion 25 form an annular body with an L-shaped cross section, and the annular plate portion 25 and the second cylindrical portion 46 also form an annular body with an L-shaped cross section.

[0070] A sensor mounting surface 31 is formed on the outer periphery of the second cylindrical portion 46, to which a bearing monitoring sensor 30 (see FIG. 8) is detachably attached. The sensor mounting surface 31 is a flat surface perpendicular to the radial direction. A plurality of sensor mounting surfaces 31 (four in this case) are provided on the outer periphery of the second cylindrical portion 46 at equal intervals (90° intervals in this case) in the circumferential direction. A screw hole 32 (see FIGS. 6 and 7) for sensor attachment is formed in the sensor mounting surface 31. The bearing monitoring sensor 30 (see FIG. 8) can be attached to the sensor mounting surface 31 in a radial range that overlaps with the bearing space 4 when viewed in the axial direction.

[0071] As shown in Fig. 7, in this rolling bearing 1, the direction perpendicular to the sensor mounting surface 31 (radial direction) and the direction of vibrations occurring in the outer ring 2 during bearing rotation (radial direction) are the same. Therefore, when an acceleration sensor that detects uniaxial acceleration in a direction perpendicular to the sensor mounting surface 31 is mounted on the sensor mounting surface 31 as the bearing monitoring sensor 30, it is possible to accurately detect vibrations occurring in the outer ring 2 during bearing rotation. In addition, the same effects as those of the first embodiment can be obtained.

[0072] In the above embodiments, the rolling bearing 1 is described as having the outer ring 2 as a fixed ring and the inner ring 3 as a rotating ring (i.e., an inner-ring rotating type rolling bearing), but the present invention can also be applied to a rolling bearing 1 in which the inner ring 3 is a fixed ring and the outer ring 2 is a rotating ring (i.e., an outer-ring rotating type rolling bearing). In this case, the relationship between the radially inner and radially outer sides of the sensor mounting member 11 in the above embodiments can be reversed, and the sensor mounting member 11 can be fixed to the axial end face of the inner ring 3 by spot welding or the like.

[0073] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0074] 1. Rolling bearings 2 Outer ring (fixed ring) 3 Inner wheel (rotating wheel) 4 Bearing space 5 rolling elements 7 Sealing material 10 Axial end face 11 Sensor mounting member 21 Fitting surface 24 Cylindrical part 25 Annular plate 26 Chamfered surface 27 Spot welds 30 Bearing monitoring sensor 31 Sensor mounting surface 32 screw holes 33 Housing 34 Rotation axis 46 Second cylindrical section

Claims

1. outer ring (2), an inner ring (3) disposed radially inside the outer ring (2); a plurality of rolling elements (5) incorporated in an annular bearing space (4) formed between the outer ring (2) and the inner ring (3); One of the outer ring (2) and the inner ring (3) is a fixed ring that is fixed so as not to rotate, and the other is a rotating ring that is rotatably supported on the fixed ring via the rolling elements (5), In a rolling bearing, the fixed ring has a cylindrical fitting surface (21) located at the end opposite to the rotating ring side, and a flat axial end surface (10) perpendicular to the fitting surface (21), a sensor mounting member (11) having a sensor mounting surface (31) on which a bearing monitoring sensor (30) for monitoring the operating state of the rolling bearing (1) is detachably mounted is fixed to the axial end surface (10) of the fixed ring; The sensor mounting member (11) has a cylindrical portion (24) whose one axial end is abutted and fixed at a position radially shifted from the radial end of the axial end face (10) on the side of the fitting surface (21) so that the radial end of the axial end face (10) on the side of the fitting surface (21) is exposed in an annular shape without being covered, and an annular plate portion (25) extending radially from the other axial end of the cylindrical portion (24) on the side opposite to the side of the fitting surface (21).

2. 2. The rolling bearing according to claim 1, wherein the sensor mounting surface (31) is adapted to mount the bearing monitoring sensor (30) in a radial range that overlaps with the bearing space (4) when viewed in the axial direction.

3. a seal member (7) for closing an end opening of the bearing space (4) on the axial end face (10) side; 3. The rolling bearing according to claim 1, wherein the annular plate portion (25) of the sensor mounting member (11) is arranged axially opposite the seal member (7).

4. 3. A rolling bearing according to claim 1 or 2, wherein the sensor mounting surface (31) is formed of a magnetic material, and the bearing monitoring sensor (30) can be detachably mounted by attracting a permanent magnet provided on the bearing monitoring sensor (30) to the sensor mounting surface (31).

5. 3. A rolling bearing according to claim 1 or 2, wherein a threaded hole (32) is formed in the sensor mounting surface (31), and the bearing monitoring sensor (30) can be detachably mounted by screwing a screw shaft provided in the bearing monitoring sensor (30) into the threaded hole (32) in the sensor mounting surface (31).

6. 3. The rolling bearing according to claim 1, wherein the sensor mounting surface (31) is an annular flat surface formed on the annular plate portion (25) and perpendicular to the axial direction.

7. The sensor mounting member (11) further includes a second cylindrical portion (46) extending in the axial direction from an end of the annular plate portion (25) opposite to the fitting surface (21), 3. The rolling bearing according to claim 1, wherein the sensor mounting surface (31) is a flat surface that is formed on the outer periphery of the second cylindrical portion (46) and is perpendicular to the radial direction.

8. 3. A rolling bearing according to claim 1, wherein the axial end of the cylindrical portion (24) is fixed to the axial end face (10) by a plurality of spot welds (27) formed at intervals in the circumferential direction.

9. A chamfered surface (26) inclined relative to the axial end surface (10) is formed at one axial end of the cylindrical portion (24), 9. The rolling bearing according to claim 8, wherein the spot weld (27) is accommodated in an annular gap having a triangular cross section formed between the chamfered surface (26) and the axial end surface (10).

10. A rolling bearing (1) according to claim 1 or 2; a housing (33) for accommodating the rolling bearing (1); a rotating shaft (34) rotatably supported by the rolling bearing (1); a bearing monitoring sensor (30) attached to the sensor mounting member (11) of the rolling bearing (1); The bearing device is capable of monitoring the operating state of the rolling bearing (1) with the bearing monitoring sensor (30).

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