Bearing assembly and spindle assembly

Abstract

A bearing device and a spindle device including the bearing device are provided, each of which can accurately and quickly detect temperature changes in a bearing. The bearing device (1) includes a bearing (2), a preload unit (3), a housing (4), and a heat flux sensor (11). The bearing (2) supports a rotating body (5). The preload unit (3) includes an elastic body (9) that applies a preload to the bearing (2). The housing (4) fixes the bearing (2). The heat flux sensor (11) is fixed to one of the housing (4) and the preload unit (3), and detects heat flux.

Description

Technical Field

[0001] The invention relates to a bearing device and a main shaft device. Background Art

[0002] In the bearing device described in Japanese Patent Publication No. 2017-26078 (Patent Document 1), an attachment unit is provided on the end surface of the bearing to prevent problems such as bearing seizure. The attachment unit includes: a pump for supplying oil to the bearing portion; and a non-contact temperature sensor (infrared sensor) for measuring the temperature of the lubricating portion. When the time variation of the temperature obtained from the non-contact temperature sensor becomes greater than a threshold value, the temperature rise is prevented by supplying oil to the bearing portion using a pump.

[0003] Reference List

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Laid-Open No. 2017-26078

[0006] Patent Document 2: Japanese Patent Laid-Open No. 2016-166832 SUMMARY OF THE INVENTION

[0008] Technical issues

[0009] In the bearing device described in Japanese Patent Publication No. 2017-26078, signs of abnormality in the bearing are judged based on temperature. Here, for a non-contact temperature sensor (infrared sensor) provided in an attachment unit arranged adjacent to the bearing, it is difficult to measure the temperature of a metal surface having a low infrared emissivity. Therefore, the target measured by the non-contact temperature sensor is a retaining frame made of resin. However, when the retaining frame is not made of resin, it is difficult to measure its temperature using the structure described in Japanese Patent Publication No. 2017-26078.

[0010] In addition, the measurement accuracy of the non-contact temperature sensor is lower than that of the contact temperature sensor. Therefore, even if there is no abnormality, the non-contact temperature sensor may erroneously detect the temperature change, or when there is an abnormality, the non-contact temperature sensor may not detect the temperature change. In addition, it is considered that when the non-contact temperature sensor is used in an oil lubrication environment, the sensor is affected by the lubricating oil. For example, when the lubricating oil forms mist and the mist then enters between the measurement target and the non-contact temperature sensor, it is difficult to accurately measure the temperature.

[0011] The present invention is made to solve the above-mentioned problems, and its purpose is to provide a bearing device and a spindle device including the bearing device, through which the temperature change of the bearing can be accurately and quickly detected.

[0012] Technical solutions adopted to solve technical problems

[0013] The bearing device according to the present disclosure includes a bearing, a preload unit, a housing, and a heat flux sensor. The bearing supports a rotating body. The preload unit includes an elastic body that applies preload to the bearing. The housing fixes the bearing. The heat flux sensor is fixed to one of the housing and the preload unit, and detects the heat flux.

[0014] A spindle device according to the present disclosure includes a bearing device and a motor that rotates a rotating body.

[0015] Effects of the Invention

[0016] According to the above, a bearing device and a spindle device including the bearing device can be realized, each of which can accurately and quickly detect the temperature change of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 : is a schematic diagram showing the configuration of a bearing device according to a first embodiment of the present invention.

[0018] Figure 2 : is a schematic diagram showing the configuration of a bearing device according to a second embodiment of the present invention.

[0019] Figure 3 : is a schematic diagram showing the configuration of a bearing device according to a third embodiment of the present invention.

[0020] Figure 4 : is a schematic diagram showing the configuration of a bearing device according to a fourth embodiment of the present invention.

[0021] Figure 5 It is a block diagram for explaining the structure of a bearing device according to a fifth embodiment of the present invention.

[0022] Figure 6 1 is a flowchart for explaining a first example of abnormality determination processing executed by the abnormality diagnosis device.

[0023] Figure 7 1 is a flowchart for explaining a second example of abnormality determination processing executed by the abnormality diagnosis device.

[0024] Figure 8 : is a schematic diagram showing the configuration of a bearing device according to a sixth embodiment of the present invention.

[0025] Fig. 9 : is a schematic diagram showing the configuration of a bearing device according to a seventh embodiment of the present invention.

[0026] Fig.10: is a schematic diagram showing the configuration of a bearing device according to an eighth embodiment of the present invention.

[0027] Fig.11 is a diagram showing a configuration for wirelessly transmitting and receiving an output of a sensor.

[0028] Fig.12 : is a schematic diagram showing the configuration of a spindle device according to a ninth embodiment of the present invention.

[0029] Fig.13 It is shown Fig.12 A diagram of an exemplary controller for a spindle device is shown.

[0030] Fig.14 It is shown Fig.12 A diagram of another exemplary controller of a spindle device is shown.

[0031] Fig.15 It is shown Fig.12 A diagram of yet another exemplary controller of a spindle device is shown.

[0032] Fig.16 1 is a schematic diagram showing the configuration of a bearing device according to a tenth embodiment of the present invention.

[0033] Fig.17 : is a schematic diagram showing a configuration of a modification of the bearing device according to the tenth embodiment of the present invention. DETAILED DESCRIPTION

[0034] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be noted that in the drawings described below, the same or corresponding parts are given the same reference numerals and the description is not repeated.

[0035] (First Embodiment)

[0036] <Structure of bearing device>

[0037] Figure 1 : is a schematic diagram showing the configuration of a bearing device according to a first embodiment of the present invention. Figure 1 The bearing device 1 shown is a constant pressure preload type bearing device, comprising: a plurality of bearings 2, each of which supports a rotating body 5 used as a main shaft; a preload unit 3; a housing 4; and a heat flux sensor 11. Each of the bearings 2 rotatably supports the rotating body 5. A through hole is formed in the housing 4. The rotating body 5, the bearings 2, and the preload unit 3 are accommodated in the through hole. Two bearings 2 are fixed at respective ends of the through hole of the housing 4.

[0038] Each of the bearings 2 includes an inner ring 2i, an outer ring 2g, rolling elements 2t, and a cage 2r. The bearing 2 is a rolling bearing such as an angular contact ball bearing. That is, the rolling elements 2t are, for example, balls.

[0039] The rotating body 5 used as the main shaft is inserted and fixed to the inner ring 2i of the bearing 2. On the rotating body 5, a collar 6 is provided on the outer side relative to the inner ring 2i of the bearing 2 along the extending direction of the rotating body 5. A nut 7 is provided on the outer side relative to the collar 6 in the extending direction of the rotating body 5. By tightening with the nut 7, stress is applied to the inner ring 2i of the bearing 2 via the collar 6, so that the inner ring 2i is fixed to the rotating body 5. Figure 1 In the illustrated configuration, the outer ring 2g serves as a non-rotating ring, while the inner ring 2i serves as a rotating ring.

[0040] The preload unit 3 applies a constant preload to the bearing 2. The preload unit 3 includes: a spring holder 8; a spring 9, which is used as an elastic body for applying a preload to the bearing 2; and an intermediate member 10, which is used as an annular member. One end face 8a of the spring holder 8 abuts against the step portion 4a of the housing 4. The preload unit 3 presses the end face of the outer ring 2g through the intermediate member 10 by the elastic force of the spring 9. The outer ring 2g is a fixed ring of the bearing 2. As the spring 9, for example, a coil spring can be used. The preload unit 3 can be arranged at multiple positions in the circumferential direction along the outer ring 2g. It should be noted that as the spring 9, different types of springs, such as a disc spring, can be used, and the type and structure of the spring are not limited.

[0041] The end face of the outer ring 2g serving as the fixed ring of the other bearing 2 abuts against the step portion 4b of the housing 4. As a result, a constant pressure preload is applied to the bearing 2. Figure 1 In the bearing device 1, the bearings 2 are installed in a back-to-back arrangement (DB arrangement). Each of the bearings 2 is a bearing that can be preloaded by a force in the axial direction. As the bearing 2, an angular contact ball bearing, a deep groove ball bearing, or a tapered roller bearing can be used.

[0042] Each of the heat flux sensors 11 is a sensor that detects heat flux. The heat flux sensors 11 are arranged near the plurality of bearings 2. One surface of each of the heat flux sensors 11 is fixed to a non-rotating member located near the bearing 2 by adhesion or the like. The other surface of the heat flux sensor 11 is arranged to face the rotating body 5 with a space interposed therebetween. Figure 1 In the bearing device 1 , the left heat flux sensor 11 is fixed to the inner peripheral surface 4 c of the housing 4 . The right heat flux sensor 11 is fixed to the surface portion 8 b which is the inner surface of the spring holder 8 .

[0043] In the present embodiment, each of the heat flux sensors 11 is used to measure the temperature change in the bearing device 1 during the operation of the bearing device 1. For the heat flux sensor 11, for example, the heat flux sensor described in Japanese Patent Publication No. 2016-166832 (Patent Document 2) can be used. The output voltage of the heat flux sensor 11 is generated according to the small temperature difference between the front and rear sides of the sensor. The heat flux sensor 11 converts the heat flow into an electrical signal using the Seebeck effect.

[0044] <Function of heat flux sensor and method of judging bearing abnormality>

[0045] In the following, we will use Figure 1 The bearing device 1 shown in the figure is used to describe the common functions of the heat flux sensor 11 in the embodiment disclosed in this specification and the method for judging the abnormality of the bearing. Figure 1 In the bearing device 1 shown, when a temperature difference occurs between the housing 4 and the rotating body 5, a heat flux is generated that passes through the heat flux sensor 11, thereby changing the output of the heat flux sensor 11. This change in the output of the heat flux sensor 11 or the amount of output change per unit time (rate of change) is monitored. When a change (abnormal change) that deviates from a stable state is observed in the monitoring data, it is determined that an abnormality has occurred in the bearing 2 of the bearing device 1.

[0046] For example, consider a case where the preload of the bearing 2 increases, resulting in an increase in the contact surface pressure between the rolling element 2t and the raceway surface of the inner ring 2i or the outer ring 2g. In this case, the temperature of the bearing 2 rises due to the increase in the contact surface pressure. Here, since the specific heat capacity of the housing 4 that accommodates the bearing 2 and the specific heat capacity of the rotating body 5 fixed to the inner ring 2i are relatively large, the timing of the temperature rise of each of the housing 4 and the rotating body 5 lags behind the timing of the temperature rise of the bearing 2. Therefore, considering that when the abnormality of the bearing 2 is judged based on the temperature change of the housing 4 or the rotating body 5 detected using a temperature sensor or the like, the timing of detecting the occurrence of the abnormality in the bearing 2 lags behind the timing of the actual occurrence of the abnormality, resulting in the occurrence of seizure in the bearing 2. On the other hand, since the heat flux changes before the temperature change of each of the housing 4 and the rotating body 5, the abnormality of the bearing 2 can be detected more quickly using the heat flux sensor 11. Generally, a coolant flow path is formed in the bearing device 1 provided in the spindle device of a machine tool. The housing 4 and the outer ring 2g in contact with the housing 4 are cooled by causing the coolant to flow through the housing 4. Therefore, the temperature of the inner ring 2i is higher than the temperature of the outer ring 2g. In an abnormal state, the temperature difference between the outer ring 2g and the inner ring 2i becomes large.

[0047] It should be noted that the optimal configuration of the heat flux sensor 11 is preferably as follows: the front surface of the heat flux sensor 11 is configured to face the area with the least cooling (heat generation area) (the front surface of the heat flux sensor 11 is configured at a position close to the area with the least cooling as possible). In addition, the heat flux sensor 11 is preferably fixed to the area with the most cooling (the rear surface of the heat flux sensor 11 is preferably in contact with the area with the most cooling).

[0048] Here, consider the case where the heat flux sensor 11 is applied to the bearing device 1 in, for example, a spindle device. In the spindle device, a coolant flow path may be formed in the housing 4. In this case, the member to which the heat flux sensor 11 is fixed may be the outer ring 2g of the bearing 2. It should be noted that the member to which the heat flux sensor 11 is fixed is preferably fixed to a member of the housing 4, and more preferably fixed to the housing 4 itself. On the other hand, the area to which the front surface of the heat flux sensor 11 faces may be the rotating body 5. Furthermore, the area to which the front surface of the heat flux sensor 11 faces is more preferably the inner ring 2i of the bearing 2.

[0049] It should be noted that whether an abnormality occurs in the bearing 2 can be determined by finding the difference between the outputs of the two heat flux sensors 11, or by calculating the difference between the amount of change per unit time in the outputs of the two heat flux sensors 11 and comparing the calculated value with a preset threshold value. In addition, a plurality of heat flux sensors 11 may be arranged at intervals along the outer ring 2g of one bearing 2.

[0050] <Function and role of bearing device>

[0051] The bearing device 1 according to the present disclosure includes a bearing 2, a preload unit 3, a housing 4, and a heat flux sensor 11. The bearing 2 supports a rotating body 5. The preload unit 3 applies a preload to the bearing 2. More specifically, the preload unit 3 includes an elastic body that applies a preload to the bearing 2. The housing 4 fixes the bearing 2. The heat flux sensor 11 is fixed to one of the housing 4 and the preload unit 3, and detects heat flux.

[0052] In this way, when the temperature difference between the housing 4 and the rotating body 5 or the temperature difference between the preload unit 3 and the rotating body 5 changes due to the temperature change of the bearing 2 caused by the abnormality occurring in the bearing 2, the heat flux passing through the heat flux sensor 11 changes to change the output of the heat flux sensor 11. The change in the output of the heat flux sensor 11 occurs before the temperature change of each of the rotating body 5 and the housing 4 as described above. Therefore, in the bearing device 1, by using the heat flux sensor 11 to detect the heat flux change inside the bearing device 1, an abnormality such as overload of the bearing 2 can be detected at an early stage compared to the case where the temperature inside the bearing device 1 is measured using a non-contact temperature sensor.

[0053] Furthermore, for detection, the heat flux sensor 11 directly converts the heat flux in the heat flux sensor 11 into a voltage or the like. Therefore, unlike a non-contact temperature sensor, temperature changes are less likely to be erroneously detected. Therefore, abnormalities of the bearing 2 can be accurately detected.

[0054] It should be noted that the heat flux sensor 11 is preferably arranged near the bearing 2. The expression "arranged near the bearing 2" means that the heat flux sensor 11 is arranged in an area near the bearing 2, for example, the distance between the bearing 2 and the heat flux sensor 11 is less than or equal to 50 mm. The distance between the bearing 2 and the heat flux sensor 11 may be less than or equal to 30 mm, less than or equal to 20 mm, less than or equal to 10 mm, or less than or equal to 5 mm.

[0055] In the bearing device 1, the heat flux sensor 11 is arranged to face the rotating body 5. In this case, the heat flux sensor 11 can reliably detect the heat flux change caused by the temperature difference between the rotating body 5 and the housing 4 or the preloading unit 3.

[0056] In the bearing device 1, the heat flux sensor 11 is fixed to the inner peripheral surface 4c of the housing 4 facing the rotating body 5. In this case, the heat flux sensor 11 can reliably detect the heat flux change caused by the temperature difference between the rotating body 5 and the housing 4.

[0057] In the bearing device 1, the preload unit 3 includes a surface portion ( Figure 1 The heat flux sensor 11 is fixed to the surface portion 8b of the spring holder 8 facing the rotating body 5. In this case, the heat flux sensor 11 can more reliably detect the heat flux change caused by the temperature difference between the rotating body 5 and the pre-pressing unit 3.

[0058] In the bearing device 1, the preload unit 3 includes a spring 9 and a spring holder 8. The spring 9 is used to generate a preload. The spring holder 8 accommodates the spring 9. The surface portion 8b is a portion of the surface of the spring holder 8. In this case, since the spring holder 8 has a certain volume for accommodating the spring 9, the portion of the surface of the spring holder 8 where the heat flux sensor 11 is arranged, that is, the surface portion 8b is located in a region close to the rotating body 5 relative to the inner circumferential surface 4c of the housing 4. Therefore, the heat flux sensor 11 can be arranged relatively close to the rotating body 5.

[0059] (Second Embodiment)

[0060] <Structure of bearing device>

[0061] Figure 2: is a schematic diagram showing the configuration of a bearing device according to a second embodiment of the present invention. Figure 2 The bearing device 1 shown has Figure 1 The bearing device 1 shown is of substantially the same construction, but in Figure 2 The structure of the part of the left side that fixes the heat flux sensor 11 is compared Figure 1 The bearing arrangement 1 shown is different. Figure 2 In the bearing device 1 shown, a mounting member 12 is arranged at a position adjacent to the bearing 2 on the inner circumferential surface 4c of the housing 4. The mounting member 12 may be a dedicated component for mounting the heat flux sensor 11 in the housing 4. The mounting member 12 is a component independent of the housing 4, but may be formed as a single piece with the housing 4. For example, when forming the housing 4, the inner circumferential surface 4c of the housing 4 may be processed to have the mounting member 12. The heat flux sensor 11 is fixed to the surface of the mounting member 12 facing the rotating body 5. The mounting member 12 includes a surface portion facing one of the rotating body 5 and the bearing 2. Figure 2 , the heat flux sensor 11 is fixed to the surface portion of the mounting member 12 facing the rotating body 5. The mounting member 12 may be annular along the outer ring 2g of the bearing 2, or may be cylindrical only facing a portion of the outer ring 2g. In addition, a plurality of mounting members 12 may be arranged along the outer ring 2g, and the heat flux sensor 11 may be fixed to the corresponding mounting members 12. That is, a plurality of heat flux sensors 11 may be arranged along the outer ring 2g. The distance from the surface of the mounting member 12 to which the heat flux sensor 11 is fixed to the surface of the rotating body 5 is smaller than the distance from the inner circumferential surface 4c of the housing 4 to the surface of the rotating body 5. It should be noted that a recess may be formed in the inner circumferential surface 4c of the housing 4, and the mounting member 12 may be fixed to the housing 4 so that at least a portion of the mounting member 12 is arranged in the recess. In this case, the distance from the surface of the mounting member 12 to which the heat flux sensor 11 is fixed to the surface of the rotating body 5 is substantially the same as the distance from the area of ​​the inner circumferential surface 4c of the housing 4 other than the area where the recess is formed to the surface of the rotating body 5.

[0062] <Function and role of bearing device>

[0063] Figure 2 The bearing device 1 shown can be realized with Figure 1 The bearing device 1 shown in FIG. Figure 2 In the bearing device 1 shown, the housing 4 includes a mounting member 12 that is arranged to extend from the inner peripheral surface 4c facing the rotating body 5 toward the rotating body 5. That is, the housing 4 includes the mounting member 12 arranged on the inner peripheral surface 4c. The heat flux sensor 11 is fixed to the mounting member 12. By configuring the heat flux sensor 11 on the mounting member 12 in this way, the distance between the heat flux sensor 11 and the rotating body 5 can be less than Figure 1The distance between the heat flux sensor 11 and the rotating body 5 in the bearing device 1 is shown. Therefore, the temperature change of the rotating body 5 caused by the abnormality of the bearing 2 can be detected more quickly and accurately.

[0064] (Third Embodiment)

[0065] <Structure of bearing device>

[0066] Figure 3 : is a schematic diagram showing the configuration of a bearing device according to a third embodiment of the present invention.

[0067] Figure 3 The bearing device 1 shown has Figure 2 The bearing device 1 shown is essentially of the same construction, but in Figure 3 The right side of the fixed heat flux sensor 11 has the same structural aspects as Figure 2 The bearing device 1 shown is different. That is, Figure 3 In the bearing device 1 shown, the preload unit 3 includes a spring holder 8, a spring 9, and an intermediate member 10. The intermediate member 10 is an annular member extending along the outer ring 2g of the bearing 2. The spring 9 is accommodated in the spring holder 8. The intermediate member 10 is arranged between the spring 9 and the bearing 2. The intermediate member 10 is in contact with the outer ring 2g. The stress from the spring 9 is transmitted to the bearing 2 via the intermediate member 10. The surface portion 10a, which is a part of the surface of the intermediate member 10, faces the rotating body 5. The heat flux sensor 11 is fixed to the surface portion 10a.

[0068] <Function and role of bearing device>

[0069] Figure 3 The bearing device 1 shown can be realized with Figure 1 The bearing device 2 shown in FIG. Figure 3 In the bearing device 1 shown, the preload unit 3 includes a spring 9 and an intermediate member 10. The intermediate member 10 is, for example, an annular member. The spring 9, which serves as an elastic body, is used to generate a preload. The intermediate member 10 is arranged between the spring 9 and the bearing 2. The surface portion 10a to which the heat flux sensor 11 is fixed is a part of the surface of the intermediate member 10. In this case, the intermediate member 10 is arranged near the bearing 2. Therefore, Figure 3 The distance between the heat flux sensor 11 and the bearing 2 in the bearing device 1 shown can be less than Figure 2The distance between the heat flux sensor 11 and the bearing 2 in the bearing device 1 is shown. In addition, by adjusting the distance from the inner peripheral surface 4c of the housing 4 to the surface portion 10a of the intermediate member 10, the heat flux sensor 11 can be as close as possible to the rotating body 5. Therefore, the temperature change of each of the rotating body 5 and the bearing 2 caused by the abnormality of the bearing 2 can be detected quickly and reliably by the heat flux sensor 11.

[0070] (Fourth Embodiment)

[0071] <Structure of bearing device>

[0072] Figure 4 : is a schematic diagram showing the configuration of a bearing device according to a fourth embodiment of the present invention. Figure 4 The bearing device 1 shown has Figure 3 The bearing device 1 shown is basically of the same construction, but in the fixed Figure 4 The construction of a portion of the heat flux sensor 11 shown is similar to that of Figure 3 The bearing device 1 shown is different. That is, Figure 4 In the bearing device 1 shown, the annular intermediate spacer 20 is arranged to contact the outer ring 2g of the left bearing 2. One end of the spacer 20 contacts the inner side of the outer ring 2g. The other end of the spacer 20 opposite to the one end contacts the step formed at the inner peripheral surface 4c of the housing 4. The heat flux sensor 11 is fixed on the surface portion 20a of the spacer 20 facing the rotating body 5. Supply openings 21 are formed in the spacer 20 and the intermediate member 10. Each supply opening 21 is a nozzle for supplying a lubricating fluid such as lubricating oil to the bearing 2 to lubricate and cool the bearing 2. The supply openings 21 formed in the spacer 20 and the intermediate member 10 are connected to the corresponding lubricating fluid flow paths formed in the housing 4. Each flow path is connected to a supply portion (not shown) for lubricating fluid via a pump, an opening / closing valve, etc. It should be noted that oil mist or air can be supplied to the bearing 2 from the supply openings 21.

[0073] <Function and role of bearing device>

[0074] Figure 4 The bearing device 1 shown includes a spacer 20 arranged adjacent to the bearing 2. A supply opening 21 is formed in the spacer 20. The supply opening 21 is a nozzle for supplying lubricating fluid to the bearing 2. The spacer 20 includes a surface portion ( Figure 4The heat flux sensor 11 is fixed to the surface portion 20a facing the rotating body 5. In this case, since the heat flux sensor 11 can be arranged in a region adjacent to the bearing 2, the heat flux sensor 11 can reliably detect the temperature change of each of the rotating body 5 and the bearing 2 caused by the abnormality of the bearing 2.

[0075] Furthermore, in the bearing device 1, the supply opening 21 is formed in the intermediate member 10 included in the pre-pressing unit 3, and the heat flux sensor 11 is fixed to the intermediate member 10. The supply opening 21 is a nozzle for supplying the lubricating fluid to the bearing 2. Figure 3 As with the bearing device 1 shown, the heat flux sensor 11 can be arranged near the bearing 2. Furthermore, a member having the supply opening 21 for supplying the lubricating fluid other than the intermediate member 10 does not need to be arranged near the pre-pressing unit 3. Therefore, the device configuration of the bearing device 1 can be simplified.

[0076] When the supply opening 21 for supplying the lubricating fluid is formed in the bearing device 1 as described above, the heat flux sensor 11 is preferably arranged at a position where the heat flux sensor 11 is less susceptible to the lubricating fluid supplied from the supply opening 21 and the like. For example, the heat flux sensor 11 is preferably arranged at a region separated from the position where the supply opening 21 is arranged in the circumferential direction of the bearing 2. When a plurality of supply openings 21 are arranged in the circumferential direction of the bearing 2, the heat flux sensor 11 is preferably arranged at a position substantially equidistant from the plurality of supply openings 21 in the circumferential direction. In addition, consider a case where the injection direction of the lubricating fluid in the supply opening 21 is inclined with respect to the rotation axis direction of the bearing 2, and the lubricating fluid is injected in the circumferential direction of the bearing 2. In this case, the lubricating fluid injected onto the bearing 2 collides with the transfer surface of the bearing 2 near the supply opening 21, and spreads over the entire circumference of the bearing 2 as the bearing 2 rotates, so that the bearing 2 can be effectively lubricated and cooled. In this configuration, the position of the supply opening 21 and the position of the heat flux sensor 11 are preferably offset from each other in order to reduce the influence of the lubrication fluid not only in the circumferential direction of the bearing 2 but also in the rotation axis direction of the bearing 2 .

[0077] (Fifth Embodiment)

[0078] <Structure of bearing device>

[0079] Figure 5 FIG. 1 is a block diagram for explaining the structure of a bearing device according to a fifth embodiment of the present invention. Figure 1 The bearing device 1 shown is essentially of the same construction, but with Figure 1 The difference of the bearing device 1 shown is that a pair of bearings 2 (see Figure 1); and another sensor 22 is provided. The other sensor 22 can be installed at any position such as the outer ring 2g of the bearing 2 or near the bearing 2. The abnormality diagnosis unit 100 diagnoses the abnormality of the bearing based on the output information of the heat flux sensor 11. The abnormality diagnosis unit 100 also receives output information from the other sensor 22. In addition, the abnormality diagnosis unit 100 also receives a shaft speed signal 101 representing information about the rotation speed of the rotating body 5. The abnormality diagnosis unit 100 diagnoses the abnormality of the bearing 2 based on the output information of the heat flux sensor 11, the output information of the other sensor 22, and the shaft speed signal 101. When it is determined that an abnormality has occurred in the bearing 2, the abnormality diagnosis unit 100 outputs an indication signal 102 for performing an abnormality avoidance operation to prevent damage to the bearing. It should be noted that any sensor such as a temperature sensor, an acceleration sensor, a load sensor, or a rotation sensor can be added as another sensor 22.

[0080] <Abnormal diagnosis and processing>

[0081] Hereinafter, an exemplary specific abnormality determination process will be described. Figure 6 FIG. 1 is a flowchart for explaining a first example of abnormality determination processing executed by the abnormality diagnosis device. Figure 5 and Figure 6 In step S1, the abnormality diagnosis unit 100 monitors the output of the sensor. Examples of the sensor include the heat flux sensor 11, the temperature sensor, the rotation speed detection sensor (not shown) for detecting the rotation speed of the rotating body 5, the acceleration sensor, and the load sensor. Next, in step S2, the abnormality diagnosis unit 100 compares the threshold value set to correspond to the output of each sensor with the value (output information) detected by the sensor to perform a threshold judgment on whether the threshold value is exceeded. The threshold judgment can be performed individually for the output information of each sensor, or can be performed for a combination of multiple output information of the sensor. As an example of such a combination, the following judgment method can be considered: the threshold value of the temperature inside the bearing device 1, which is the information output from the temperature sensor used as an example of another sensor 22, and the threshold value of the output information of the heat flux sensor 11 are set according to the output information from the rotation speed detection sensor, which is the rotation speed of the rotating body 5; and when the output information from the temperature sensor (the measured temperature inside the bearing device 1) is greater than the threshold value (prescribed temperature) and the output information of the heat flux sensor 11 is greater than the threshold value, it is judged that an abnormality has occurred in the bearing 2.

[0082] When the plurality of output information (detection values) is less than the threshold value in step S2 (i.e., the occurrence of abnormality is not detected), the sensor monitoring process in step S1 is repeated again. On the other hand, when the plurality of output information is greater than the threshold value in step S2 (i.e., the occurrence of abnormality is detected), the abnormality diagnosis unit 100 outputs the instruction signal 102 for performing the abnormality avoidance operation in step S3 so as to perform the abnormality avoidance operation.

[0083] The following describes an exemplary abnormality avoidance operation control performed in a machine tool according to the instruction signal 102. The machine tool is an exemplary mechanical device in which the bearing device 1 is assembled. For example, the abnormality avoidance operation control may be to control the rotation speed of the rotating body 5 to be lower than the current rotation speed. For example, when cutting is performed in the machine tool, the abnormality avoidance operation control may control the cutting edge to cut into the workpiece less than the current cutting amount. The abnormality avoidance operation control may be controlled to move the bearing 2 (see FIG. 1 ) of the bearing device 1 to the bearing 2 (see FIG. 1 ). Figure 1 ) supply lubricating oil or control to increase the supply amount of lubricating oil. The abnormality avoidance operation control can control to stop the processing in the machine tool (for example, control to end the cutting and reduce the rotation speed (spindle speed) of the rotating body 5 or control to stop the rotation of the rotating body 5). It should be noted that when judging whether there is an abnormality by performing a judgment with a threshold once in step S2, the judgment may be wrong due to noise and the like. Therefore, in order to avoid such an erroneous judgment, it can be judged that an abnormality has occurred when an abnormality is detected multiple times in succession in step S2, and it can be transferred to step S3 of outputting a command signal for performing an abnormality avoidance operation.

[0084] Figure 7 2 is a flowchart for explaining a second example of abnormality determination processing executed by the abnormality diagnosis device. Figure 5 and Figure 7 In step S11, the abnormality diagnosis unit 100 monitors the output of the sensor. Figure 6 As in the abnormality judgment process described above, examples of the sensor include the heat flux sensor 11, the temperature sensor, the rotation speed detection sensor (not shown) for detecting the rotation speed of the rotating body 5, the acceleration sensor, and the load sensor. Then, in step S12, the abnormality diagnosis unit 100 calculates the output change rate per unit time of each sensor. Thereafter, in step S13, the abnormality diagnosis unit 100 judges whether the calculated change rate is greater than a threshold value (standard value) (change rate judgment).

[0085] The change rate judgment may be performed for each sensor output information individually, or may be performed for a combination of multiple sensor output information. As an example of such a combination, the following judgment method may be considered: when the output information from the rotation speed detection sensor, i.e., the rotation speed change rate per unit time of the rotating body 5, becomes greater than a threshold value, the output information from the temperature sensor used as an exemplary other sensor 22, i.e., the change rate per unit time of the internal temperature of the bearing device 1, becomes greater than a threshold value, and the change rate per unit time of the output information of the heat flux sensor 11 becomes greater than a prescribed threshold value, it is judged that an abnormality has occurred in the bearing 2.

[0086] When the rate of change detected in step S13 is less than the threshold value (standard value), the sensor monitoring process of step S11 is repeatedly performed again. On the other hand, when the rate of change detected in step S13 is greater than the threshold value, the abnormality diagnosis unit 100 outputs an indication signal 102 for performing an abnormality avoidance operation so as to perform an abnormality avoidance operation in step S14. Similarly, in this case, in order to suppress erroneous judgments due to noise, etc., it is possible to judge that an abnormality has occurred when an abnormality is detected multiple times in succession in step S13. It should be noted that the exemplary abnormality avoidance operation control performed in the machine tool according to the indication signal 102 is the same as that in Figure 6 The case of the abnormality determination processing shown is the same, so the description will not be repeated.

[0087] <Function and role of bearing device>

[0088] The bearing device according to the present embodiment includes abnormality diagnosis unit 100 for diagnosing abnormality of bearing 2 based on output information of heat flux sensor 11. In this case, since the bearing device itself includes abnormality diagnosis unit 100, it is possible to diagnose whether abnormality occurs in bearing 2 in the bearing device.

[0089] The bearing device includes another sensor 22 configured in addition to the heat flux sensor 11. The output information of the heat flux sensor 11 and the output information of the another sensor 22 are sent to the abnormality diagnosis unit 100. The abnormality diagnosis unit 100 diagnoses the abnormality of the bearing 2 based on the output information of the heat flux sensor 11, the output information of the another sensor 22, and the shaft speed signal 101 indicating information on the rotation speed of the rotating body. In this case, the abnormality of the bearing 2 can also be diagnosed more accurately using information other than the information from the heat flux sensor 11.

[0090] (Sixth Embodiment)

[0091] <Structure of bearing device>

[0092] Figure 8: is a schematic diagram showing the configuration of a bearing device according to a sixth embodiment of the present invention. Figure 8 The bearing device 1 shown has Figure 1 The bearing device 1 shown is essentially of the same construction, but in Figure 8 The construction of the portion of the heat flux sensor 11 shown is compared to Figure 1 The bearing device 1 shown is different. Figure 8 In the bearing device 1 shown, a portion of the housing 4 is located outside the bearing 2 in the extending direction of the rotating body 5. The portion of the housing 4 located outside the bearing 2 has an inner peripheral surface 4Ad facing the rotating body 5. The heat flux sensor 11 is fixed to the inner peripheral surface 4Ad. That is, the heat flux sensor 11 is arranged at a region 14 that is located outside the bearing 2 in the extending direction of the rotating body 5 and is located close to the bearing 2.

[0093] <Function and role of bearing device>

[0094] In the bearing device 1 as described above, basically, Figure 1 The same effect as the bearing device 1 shown. Figure 8 In the bearing device 1 shown, the heat flux sensor 11 is fixed to the inner peripheral surface 4Ad of the housing 4, which is located on the outer peripheral side relative to the bearing 2 and faces the rotating body. In this case, the heat flux sensor 11 is arranged in the outer area relative to the bearing 2 in the housing 4, thereby facilitating the maintenance of the heat flux sensor 11 and the processing of wiring for outputting a signal from the heat flux sensor 11 to the outside.

[0095] (Seventh Embodiment)

[0096] <Structure of bearing device>

[0097] Fig. 9 : is a schematic diagram showing the configuration of a bearing device according to a seventh embodiment of the present invention. Fig. 9 The bearing device 1 shown has Figure 8 The bearing device 1 shown is essentially of the same construction, but in Fig. 9 The construction of the portion of the heat flux sensor 11 shown is different from that of Figure 8 The bearing arrangement 1 shown is different. Fig. 9 In the bearing device 1 shown in FIG. 1 , a mounting member 13 extending from the inner peripheral surface 4Ad of the housing 4 toward the rotating body 5 is arranged at a position outside the bearing 2 and close to the bearing 2. That is, the housing 4 includes the mounting member 13 provided on the inner peripheral surface 4Ad. Figure 2Like the mounting member 12 shown, the mounting member 13 can be separated from the housing 4. The mounting member 13 includes a surface portion facing one of the rotating body 5 (the collar 6) and the bearing 2. Fig. 9 , the heat flux sensor 11 is fixed to the surface portion of the mounting member 13 facing the rotating body 5. That is, the heat flux sensor 11 is fixed to the surface of the mounting member 13 facing the rotating body 5 (the collar 6). The mounting member 13 may be an annular member extending along the outer ring 2g of the bearing 2, or may be a columnar member facing only a portion of the outer ring 2g. In addition, a plurality of mounting members 13 may be arranged along the outer ring 2g, and the heat flux sensor 11 may be fixed to the corresponding mounting members 13.

[0098] <Function and role of bearing device>

[0099] exist Fig. 9 In the bearing device 1 shown, basically the same Figure 8 The same effect as the bearing device 1 shown. Fig. 9 In the bearing device 1 shown, the housing 4 includes a mounting member 13 provided on the outside of the bearing 2 and extending from the inner peripheral surface 4Ad facing the rotating body 5 toward the rotating body 5. The heat flux sensor 11 is fixed to the mounting member 13. In this case, by arranging the heat flux sensor 11 on the mounting member 13, the distance between the heat flux sensor 11 and the rotating body 5 can be reduced. Therefore, the temperature change of the rotating body 5 (and the collar 6) caused by the abnormality of the bearing 2 can be detected more quickly and accurately.

[0100] (Eighth Embodiment)

[0101] <Structure of bearing device>

[0102] Fig.10 : is a schematic diagram showing the configuration of a bearing device according to an eighth embodiment of the present invention. Fig.11 is a diagram showing a configuration for wirelessly transmitting and receiving an output of a sensor. Fig.10 The bearing device 1 shown has Figure 8 The bearing device 1 shown is essentially of the same construction, but with Figure 8 The bearing arrangement 1 shown differs in that Fig.10 The bearing device 1 shown includes a transmitting unit 200 used as a wireless transmitting device, and a receiving device 300. Fig.10 In the bearing device 1 shown, the transmitting unit 200 is connected to the heat flux sensor 11. It should be noted that the wireless transmitting device is also connected to Fig.10Another heat flux sensor 11 not shown in the figure. It should be noted that the outputs of the two heat flux sensors 11 can be transmitted by one wireless transmitting device. The receiving device 300 receives the output information of the heat flux sensor 11 from the transmitting unit 200 and performs abnormality judgment on the bearing 2.

[0103] exist Fig.10 In the bearing device 1 shown, the output information generated by the heat flux sensor 11 can be transmitted to the outside by the transmission unit 200. In this case, the external abnormality diagnosis device can perform abnormality diagnosis on the bearing 2. It should be noted that, preferably, the bearing device 1 can also include a power supply device that supplies power to the transmission unit 200. Examples of the power supply device that can be used hereinafter include: a battery; a power generation device that generates power using temperature difference, vibration, etc.; and an electromagnetic induction generator, etc.

[0104] like Fig.11 As shown, the transmission unit 200 includes a signal processing unit 201 and a data transmission unit 202. The signal processing unit 201 receives a signal serving as output information of the heat flux sensor 11, and amplifies the signal or removes a noise component from the signal. In addition, the signal processing unit 201 performs analog-to-digital conversion processing, modulation processing, etc. on the signal. The signal processing unit 201 outputs the signal processed as described above to the data transmission unit 202 as data for transmission. The data transmission unit 202 wirelessly transmits the data to the receiving device 300.

[0105] For example, the receiving device 300 is installed on the outside of a mechanical device in which the bearing device 1 is assembled. The receiving device 300 includes: a data receiving unit 301, which receives data wirelessly; a signal processing unit 302, which demodulates data from a received signal; and an abnormality judgment unit 303, which judges an abnormality in the bearing in response to the data received from the signal processing unit 302. When the abnormality judgment unit 303 is provided in a stage after the signal processing unit 201, the amount of data sent can be reduced, thereby reducing power consumption. It should be noted that the processing of the abnormality judgment unit 303 is similar to that of the signal processing unit 201. Figure 6 and Figure 7 The processing shown in each is the same, so it will not be repeated.

[0106] <Function and role of bearing device>

[0107] The bearing device includes a transmitting unit 200 that wirelessly transmits output information of the heat flux sensor 11. The transmitting unit 200 is configured to transmit the output information of the heat flux sensor 11 to a receiving device 300 that performs abnormality diagnosis on the bearing 2. In this case, the output information of the heat flux sensor 11 can be transmitted to the receiving device 300 without configuring a wiring extending from the heat flux sensor 11 to the receiving device 300. Therefore, the abnormality diagnosis of the bearing 2 can be performed by the receiving device 300 without complicating the configuration of the bearing device.

[0108] The bearing device 1 includes: a transmitting unit 200, which wirelessly transmits output information of the heat flux sensor 11; and a receiving device 300, which receives the output information of the heat flux sensor 11 from the transmitting unit 200 and makes an abnormality judgment on the bearing 2. Therefore, when the heat flux sensor 11 is connected to a rotatable member in the bearing device 1, the detection result of the heat flux sensor 11 can also be output to the outside. Therefore, the abnormality of the bearing 2 can be quickly detected.

[0109] (Ninth Embodiment)

[0110] <Structure of bearing device>

[0111] Fig.12 Schematic diagram showing the structure of a spindle device according to a ninth embodiment of the present invention. Fig.12 As shown, for example, the spindle device 30 mainly includes: a bearing device 1 according to the second embodiment; a rotating body 5 used as a spindle; an outer cylinder 32; a motor 31; and a bearing 33. For example, the spindle device 30 is used as a built-in motor type spindle device of a machine tool. The spindle device 30 is connected to the controller 600. In the spindle device 30, the bearing device 1, the rotating body 5, the motor 31 and the bearing 33 are arranged inside the outer cylinder 32. The rotating body 5 is rotatably supported by the bearing device 1 and the bearing 33 in the outer cylinder 32. The motor 31 is arranged between the bearing device 1 and the bearing 33.

[0112] Fig.12 The spindle device 30 shown is, for example, a spindle device for a spindle portion of a machine tool. In the spindle device 30, a motor 31 is assembled on one end side of a rotating body 5, and a cutting tool (not shown) such as an end mill is connected to the other end of the rotating body 5. The bearing device 1 is Figure 2 The bearing device 1 shown in FIG. 1 has a modified version of the bearing device 1. In addition to the coolant flow path G being formed on the outer peripheral surface of the housing 4, the bearing device 1 has a Figure 2The bearing device 1 shown has substantially the same structure, so description will not be repeated. The bearing device 1 is fixed to the inner peripheral surface of the outer cylinder 32. A coolant flow path G is formed on the surface of the housing 4 of the bearing device 1 facing the inner peripheral surface of the outer cylinder 32.

[0113] The single-row bearing 33 mainly includes an inner ring 33a, an outer ring 33b and rolling elements. The inner ring 33a is positioned relative to the rotating body 5 in the axial direction by a cylindrical member 34 and an inner ring press 35 assembled on the outer periphery of the rotating body 5. The inner ring press 35 is fixed to the rotating body 5 by a nut 36 fastened to the rotating body 5. The outer ring 33b of the bearing 33 is interposed between a positioning member 37 fixed to the cylindrical member 34 and a positioning member 38 fixed to the inner ring press 35. In response to the expansion and contraction of the rotating body 5 caused by the heat of the bearing 33 during the operation of the spindle device 30, the outer ring 33b and the inner ring 33a can slide together relative to the end member 39.

[0114] In the space portion 40 formed between the rotating body 5 and the outer cylinder 32, the motor 31 that drives the rotating body 5 is arranged at an intermediate position between the double-row bearing 2 and the single-row bearing 33 of the bearing device 1 in the axial direction. The rotor 41 of the motor 31 is fixed to the cylindrical member 34 assembled on the outer periphery of the rotating body 5. The stator 42 of the motor 31 is fixed to the inner peripheral surface of the outer cylinder 32. It should be noted that the spindle device 30 includes a coolant flow path (not shown). The coolant flow path cools the motor 31. It should be noted that in Fig.12 The motor 31 is arranged at a position close to the bearing device 1; however, the motor 31 may be arranged in a space between two bearings 2 included in the bearing device 1. Fig.12 In the illustrated spindle device 30 , each of the bearing devices 1 according to the first embodiment and the third to eighth embodiments can be applied.

[0115] The heat flux sensors 11 that each measure heat flux are provided as a sensor unit in the spindle device 30. Specifically, two heat flux sensors 11 are arranged inside the bearing device 1 included in the spindle device 30.

[0116] Here, in response to the rolling element 2t of the bearing 2 (see Figure 2 ) and inner ring 2i (see Figure 2 ) and outer ring 2g (see Figure 2) increases, the temperature of the inner ring 2i and the outer ring 2g rises. In this case, the heat generated between the rolling element 2t and the track surface of each of the inner ring 2i and the outer ring 2g is first transferred to the rotating body 5 and the housing 4. There is a lag before the temperature of the housing 4 with a large heat capacity rises. In addition, since the housing 4 is cooled by the coolant flowing through the coolant flow path G, there is a further lag in its temperature rise.

[0117] Since there is a hysteresis phenomenon in the temperature rise, it is considered that the sign of abnormality such as burning of the bearing 2 cannot be detected at an early stage by measuring the temperature of the housing 4 or the rotating body 5. In this case, abnormality such as sudden heating of the bearing 2 can be quickly detected by using the heat flux sensor 11 because the change in heat flux occurs before the temperature changes.

[0118] The controller 600 controls the motor 31 . In addition, the controller 600 determines whether an abnormality of the bearing 2 has occurred based on an output signal of the heat flux sensor 11 .

[0119] Fig.13 Shows Fig.12 An exemplary controller of the spindle device is shown. Fig.13 As shown, in the spindle device 30, the controller 600 that controls the operation of the spindle device 30 can control the bearing 2 (see FIG. 1 ) based on the output of the heat flux sensor 11. Fig.12 ) is diagnosed. The controller 600 includes a judgment unit 601. The judgment unit 601 judges the abnormality of the bearing 1 based on the output of the heat flux sensor 11, the rotation speed of the motor 31 of the spindle device, the machine information D1 such as the lubrication condition and the cooling condition, and the standard D2 predetermined to judge whether the bearing 2 has an abnormality. It should be noted that the abnormality of the bearing 2 refers to, for example, the occurrence or possibility of sintering of the bearing 2. The output information of the heat flux sensor 11 is sent to the judgment unit 601 of the controller 600 in any way. For example, Fig.10 The transmission unit 200 shown can be installed in the bearing device 1. The controller 600 may include Fig.11 The receiving device 300 shown. The controller 600 is configured to change at least one of the rotation speed, lubrication condition and cooling condition of the motor 31 based on the judgment result of the judgment unit 601. It should be noted that the judgment unit 601 judges whether the bearing 2 has an abnormality based on at least the output of the heat flux sensor 11 and the standard D2 predetermined for judging whether the bearing 2 has an abnormality.

[0120] In addition, Figure 5Like the abnormality diagnosis unit 100 shown, the determination unit 601 can also diagnose abnormality of the bearing 2 based on the output of each of the heat flux sensor 11 and another sensor. Fig.14 Shows Fig.12 Another exemplary controller of a spindle device is shown.

[0121] like Fig.14 As shown, the judgment unit 601 diagnoses the abnormality of the bearing 2 based on the outputs of the heat flux sensor 11, the temperature sensor 602, the acceleration sensor 603 and the load sensor 604. The temperature sensor 602 is configured to detect the temperature rise of the housing 4 caused by, for example, insufficient lubrication of the bearing 2. For example, the temperature sensor 602 can be configured at a position adjacent to the bearing 2 in the housing 4. The acceleration sensor 603 is configured to detect vibrations in at least one of the axial direction extending from the rotating body 5 and the radial direction intersecting the axial direction. For example, the vibration is caused by peeling of each track surface of the bearing 2. For example, the acceleration sensor 603 can be configured on the end face of the housing 4 along the axial direction. For example, the load sensor 604 is configured to detect the load applied to the bearing 2 from the outside, or to detect changes in the impact load. The load sensor 604 is configured to, for example, axially align the outer ring 2g of the bearing 2 with the intermediate member 10 (see Figure 2 The load sensor 604 is, for example, a thin film sensor and has a resistance that changes according to pressure.

[0122] Fig.15 Shows Fig.12 Another exemplary controller of the spindle device shown in FIG. Fig.15 As shown, the judgment unit 601 may be configured to diagnose the abnormality of the bearing 2 based on the rotation speed of the motor 31 in addition to the output of each of the heat flux sensor 11, the temperature sensor 602, the acceleration sensor 603, and the load sensor 604. The rotation speed of the motor 31 is output information of the rotation speed sensor 605.

[0123] In the spindle device 30, a Figure 5The abnormality diagnosis unit shown. For example, the abnormality diagnosis unit as described above may be mounted on a substrate disposed in the housing 4 of the bearing device 1. In this case, the distance between the abnormality diagnosis unit and the heat flux sensor 11 is shorter than the distance between the abnormality diagnosis unit and the heat flux sensor 11 when the abnormality diagnosis unit is disposed outside the bearing device, especially outside the spindle device 30. Thus, compared with the output signal of the heat flux sensor 11 obtained by the abnormality diagnosis unit disposed outside the bearing device 1, the abnormality diagnosis unit installed in the spindle device 30 can judge whether there is an abnormality based on the output signal that is less affected by noise.

[0124] <Function and role of bearing device>

[0125] The spindle device 30 according to the present invention includes the bearing device 1 and the motor 31 that rotates the rotating body 5. In this way, the spindle device 30 that can detect abnormality of the bearing 2 quickly and accurately can be realized.

[0126] In each of the embodiments described above, a constant pressure preload structure in which the bearing 2 is installed in a back-to-back arrangement (DB arrangement) has been described; however, the construction according to the present disclosure can also be applied to a constant pressure preload structure in which the bearing 2 is installed in a face-to-face arrangement (DF arrangement).

[0127] (Tenth Embodiment)

[0128] <Structure of bearing device>

[0129] Fig.16 1 is a schematic diagram showing the configuration of a bearing device according to a tenth embodiment of the present invention. Fig.16 The bearing device 1 shown has Figure 3 The bearing device 1 shown is basically of the same construction, but has differences in the shapes of the mounting member 12 and the intermediate member 10 and the construction of the heat flux sensor 11. Figure 3 The bearing arrangement 1 shown is different. Fig.16 In the bearing device 1 shown, the mounting member 12 includes: a surface portion 12a, the surface portion 12a faces the rotating body 5; a surface portion 12c, the surface portion 12c faces the rolling element 2t of the bearing 2 and extends in the radial direction of the bearing 2; and a surface portion 12b, the surface portion 12b connects the surface portion 12a with the surface portion 12c. The surface portion 12b is a tapered surface facing the inner ring 2i of the bearing 2. The heat flux sensor 11 is fixed to the surface portion 12b. The heat flux sensor 11 is configured to face the inner ring 2i of the bearing 2 adjacent to the mounting member 12. It should be noted that the heat flux sensor 11 can be fixed to the surface portion 12c of the mounting member 12 facing the bearing 2.

[0130] In addition, Fig.16 In the bearing device 1 shown, the intermediate member 10 of the preload unit includes: a surface portion 10a, the surface portion 10a faces the rolling element 5; a surface portion 10c, the surface portion 10c faces the rolling element 2t of the bearing 2 and extends in the radial direction of the bearing 2; and a surface portion 10b, the surface portion 10b connects the surface portion 10a with the surface portion 10c. The surface portion 10b is a tapered surface facing the inner ring 2i of the bearing 2. The heat flux sensor 11 is fixed to the surface portion 10b. The heat flux sensor 11 is configured to face the inner ring 2i of the bearing 2 adjacent to the intermediate member 10. It should be noted that the heat flux sensor 11 can be fixed to the surface portion 12c of the intermediate member 10 facing the bearing 2.

[0131] Fig.17 : is a schematic diagram showing a configuration of a modification of the bearing device according to the tenth embodiment of the present invention. Fig.17 The bearing device 1 shown has Figure 4 The bearing device 1 shown is basically of the same construction as that of the first embodiment, but differs from the first embodiment in the shapes of the spacer 20 and the intermediate member 10 and the construction of the heat flux sensor 11. Figure 4 The bearing device 1 shown is different. That is, Fig.17 In the bearing device 1 shown, the spacer 20 includes: a surface portion 20a, which faces the rotating body 5; a surface portion 20c, which faces the rolling element 2t of the bearing 2 and extends in the radial direction of the bearing 2; and a surface portion 20b, which connects the surface portion 20a with the surface portion 20c. The surface portion 20b is a tapered surface facing the inner ring 2i of the bearing 2. The heat flux sensor 11 is fixed to the surface portion 12b. The heat flux sensor 11 is configured to face the inner ring 2i of the bearing 2 adjacent to the mounting member 12. Fig.17 In the bearing device 1 shown, the heat flux sensor 11 is arranged in the area of ​​the spacer 20 opposite to the supply opening 21 when viewed from the rotating body 5. It should be noted that the heat flux sensor 11 can be fixed to the surface portion 20b of the spacer 20 adjacent to the supply opening 21. The heat flux sensor 11 can be fixed to the surface portion 20c of the spacer 20 facing the bearing 2.

[0132] In addition, Fig.17 In the bearing device 1 shown, Fig.16Like the bearing device 1 shown in the figure, the intermediate member 10 of the preloading unit includes: a surface portion 10a, the surface portion 10a faces the rotating body 5; a surface portion 10c, the surface portion 10c faces the rolling element 2t of the bearing 2; and a surface portion 10b, the surface portion 10b connects the surface portion 10a with the surface portion 10c. The heat flux sensor 11 is fixed to the surface portion 10b. The heat flux sensor 11 is configured to face the inner ring 2i of the bearing 2 adjacent to the intermediate member 10. Fig.17 In the bearing device 1 shown, the heat flux sensor 11 is arranged in the region of the intermediate member 10 opposite to the supply opening 21 when viewed from the rotating body 5. It should be noted that the heat flux sensor 11 may be fixed to a surface portion 10b of the intermediate member 10 adjacent to the supply opening 21. The heat flux sensor 11 may be fixed to a surface portion 12c of the intermediate member 10 facing the bearing 2.

[0133] <Functions and Effects>

[0134] exist Fig.16 and Fig.17 In the bearing device 1 shown, the heat flux sensor 11 is arranged to face the bearing 2. Specifically, the heat flux sensor 11 is fixed to the surface portions 10b, 12b, 20b of the intermediate member 10, the mounting member 12, and the spacer 20 that face the bearing 2. Therefore, it is possible to obtain the same Figure 3 or Figure 4 The same effect as the bearing device 1 shown in the figure can be achieved, and the temperature change caused by the heat generation between the rolling element 2t and the inner ring 2i caused by the abnormality of the bearing 2, etc. can be quickly and reliably detected by the heat flux sensor 11. It should be noted that when each heat flux sensor 11 faces the bearing 2, the heat flux sensor 11 is preferably located close to the inner ring 2i.

[0135] Furthermore, the heat flux sensor 11 may be fixed to the surface portions 10c, 12c, 20c of the intermediate member 10, the mounting member 12, and the spacer 20 that face the rolling element 2t of the bearing 2. In this case, the temperature change caused by the heating of the rolling element 2t due to the abnormality of the bearing 2 may be detected quickly and reliably by the heat flux sensor 11. Furthermore, the heat flux sensor 11 may be configured to face a member that abuts against the rotating body 5, such as the inner ring 2i of the bearing 2. In this way, by configuring each heat flux sensor 11 as close as possible to the heating area to face the heating area, the temperature change at the heating area may be detected quickly.

[0136] In order to arrange the heat flux sensor 11 as close as possible to the heat generating area to face the heat generating area, the following structure may be adopted: the heat flux sensor 11 is arranged at a recess or protrusion provided in the rotating body 5 so as to be close to the heat generating area, or at a position facing the end surface of the rotating body 5. In addition, a recess (groove) (not shown) may be provided in the surface portions 10c, 12c, 20c, and the heat flux sensor 11 may be fixed to the recess. In addition, each heat flux sensor 11 may be formed in the form of a ring, and the shape of the heat flux sensor 11 is not limited.

[0137] The embodiments disclosed herein are exemplary and non-restrictive in any aspect. The scope of the present invention is defined by the terms of the claims rather than the embodiments described above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0138] Reference numerals list

[0139] 1: bearing device; 2, 33: bearing; 2g, 33b: outer ring; 2i, 33a: inner ring; 2r: cage; 2t: rolling element; 3: preload unit; 4: housing; 4Ad, 4c: inner circumference; 4a, 4b: step portion; 5: rotating body; 6: collar; 7, 36: nut; 8: spring retainer; 8a: one end surface; 8b, 10a, 10b, 10c, 12a, 12b, 12c, 20a, 20b, 20c: surface portion; 9: spring; 10: intermediate member; 11: heat flux sensor; 12, 13: mounting member; 14: area; 20: spacer; 21: supply opening; 22, 602: temperature sensor; 30: spindle device; 31: Motor; 32: outer cylinder; 34: cylindrical member; 35: inner ring press; 37, 38: positioning member; 39: end member; 40: space portion; 41: rotor; 42: stator; 100: abnormality diagnosis unit; 101: shaft speed signal; 102: abnormality avoidance operation indication signal; 200: sending unit; 201, 302: signal processing unit; 202: data sending unit; 300: receiving device; 301: data receiving unit; 303: abnormality judgment unit; 600: controller; 601: judgment unit; 603: acceleration sensor; 604: load sensor; 605: rotation sensor; D1: machine information; D2: standard; G: coolant flow path.

Claims

1. A bearing device, comprising: A bearing, wherein the bearing supports the rotating body; A preloading unit, the preloading unit comprising an elastic body for applying a preload to the bearing; A housing, wherein the housing fixes the bearing device; a heat flux sensor fixed to one of the housing and the pre-pressing unit and detecting heat flux; as well as an abnormality diagnosis unit, the abnormality diagnosis unit diagnoses an abnormality of the bearing based on output information of the heat flux sensor, The output information of the heat flux sensor includes a change in the output of the heat flux sensor or an amount of change in the output of the heat flux sensor per unit time, that is, a rate of change. One surface of the heat flux sensor is fixed to a non-rotating member located near the bearing by adhesion, and the other surface of the heat flux sensor is configured to face the rotating body with a space interposed therebetween, The heat flux sensor includes two, Whether an abnormality has occurred in the bearing is determined by calculating a difference between the output changes of the two heat flux sensors per unit time and comparing the calculated value with a preset threshold value.

2. The bearing device according to claim 1, characterized in that: The heat flux sensor is arranged to face the rotating body.

3. The bearing device according to claim 1, characterized in that: The heat flux sensor is configured to face the bearing.

4. The bearing device according to any one of claims 1 to 3, characterized in that: The heat flux sensor is fixed to an inner peripheral surface of the housing that faces the rotating body.

5. The bearing device according to any one of claims 1 to 3, characterized in that: The housing includes a mounting member, and the mounting member is arranged to extend from an inner peripheral surface of the housing facing the rotating body toward the rotating body, The heat flux sensor is secured to the mount.

6. The bearing device according to any one of claims 1 to 3, characterized in that: The preloading unit includes a surface portion facing one of the rotating body and the bearing, The heat flux sensor is fixed to the surface portion.

7. The bearing device according to claim 6, characterized in that The pre-pressing unit comprises: a spring serving as the elastic body; and a spring holder, the spring holder accommodating the spring, The surface portion is a portion of a surface of the spring retainer.

8. The bearing device according to claim 6, characterized in that: The pre-pressing unit comprises: a spring serving as the elastic body; and an intermediate member disposed between the spring and the bearing, The surface portion is a portion of a surface of the intermediate member.

9. The bearing device according to any one of claims 1 to 3, characterized in that: comprising a spacer disposed adjacent to the bearing, wherein The spacer is provided with a supply opening for supplying lubricating fluid to the bearing, The spacer includes a surface portion facing one of the rotating body and the bearing, and The heat flux sensor is fixed to the surface portion.

10. The bearing device according to any one of claims 1 to 3, characterized in that: A transmitting unit is included, wherein the transmitting unit wirelessly transmits the output information of the heat flux sensor, wherein The transmitting unit is configured to transmit output information of the heat flux sensor to a receiving device that performs abnormality diagnosis on the bearing.

11. The bearing device according to claim 1, characterized in that: In addition to the heat flux sensor, another sensor is also configured, wherein The output information of the heat flux sensor and the output information of the other sensor are sent to the abnormality diagnosis unit, and The abnormality diagnosis unit diagnoses abnormality of the bearing based on output information of the heat flux sensor, output information of the another sensor, and information on a rotation speed of the rotating body.

12. A spindle device, comprising: The bearing device according to any one of claims 1 to 3; as well as A motor is provided to rotate the rotating body.

Images