WO2020166542A1

WO2020166542A1 - Bearing device and spindle device

Info

Publication number: WO2020166542A1
Application number: PCT/JP2020/005024
Authority: WO
Inventors: 小池　孝誌; 靖之福島; 勇介澁谷
Original assignee: Ntn株式会社
Priority date: 2019-02-12
Filing date: 2020-02-10
Publication date: 2020-08-20

Abstract

Provided are: a bearing device in which changes in bearing temperature can be precisely and rapidly detected; and a spindle device equipped with said bearing device. A bearing device (1) comprises a bearing (2), a preloading part (3), a housing (4), and a heat flux sensor (11). The purpose of the bearing (2) is to support a rotating element (5). The preloading part (3) includes an elastic body (9) for preloading the bearing (2). The housing (4) anchors the bearing (2). The heat flux sensor (11) is anchored to either the housing (4) or the preloading part (3), and detects heat flux.

Description

Bearing device and spindle device

The present invention relates to a bearing device and a spindle device.

In the bearing device described in Japanese Patent Application Laid-Open No. 2017-26078 (Patent Document 1), a non-contact temperature sensor that measures the temperature of a pump for lubricating the bearing and the temperature of the lubrication part in order to prevent problems such as seizure of the bearing. (Infrared sensor) is provided on the end surface of the bearing. When the time variation of the temperature obtained from the non-contact temperature sensor exceeds the threshold value, the bearing is lubricated by the pump to prevent the temperature rise.

JP, 2017-26078, A JP, 2016-166832, A

In the bearing device described in Japanese Unexamined Patent Publication No. 2017-26078, the sign of an abnormality occurring in the bearing is judged from the temperature. Here, it is difficult for the non-contact temperature sensor (infrared sensor) provided in the attached portion arranged next to the bearing to measure the temperature of the metal surface having a low infrared emissivity. Therefore, the non-contact temperature sensor uses a resin holder as a measurement target. However, if the cage is not made of resin, it is difficult to measure the temperature with the structure disclosed in JP-A-2017-26078.

Also, the non-contact temperature sensor has lower measurement accuracy than the contact type temperature sensor. Therefore, the non-contact temperature sensor may erroneously detect a temperature change even if no abnormality has occurred, or may not detect a temperature change even if an abnormality has occurred. Furthermore, when the non-contact temperature sensor is used in an oil lubrication environment, it is assumed that the sensor is affected by the lubricating oil. For example, when the lubricating oil becomes mist and enters between the measurement target and the non-contact temperature sensor, it is difficult to measure the temperature accurately.

The present invention is to solve the above problems, and an object thereof is to provide a bearing device capable of accurately and quickly detecting a temperature change of a bearing, and a spindle device including the bearing device. That is.

The bearing device according to the present disclosure includes a bearing, a preload portion, a housing, and a heat flux sensor. The bearing is for supporting the rotating body. The preload unit includes an elastic body that applies a preload to the bearing. The housing fixes the bearing. The heat flux sensor is fixed to either one of the housing and the preload portion and detects the heat flux.

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

Based on the above, it is possible to realize a bearing device capable of accurately and quickly detecting a temperature change of the bearing, and the bearing device.

It is a schematic diagram which shows the structure of the bearing device which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the structure of the bearing device which concerns on Embodiment 2 of this invention. It is a schematic diagram which shows the structure of the bearing device which concerns on Embodiment 3 of this invention. It is a schematic diagram which shows the structure of the bearing device which concerns on Embodiment 4 of this invention. It is a block diagram for demonstrating the structure of the bearing device which concerns on Embodiment 5 of this invention. It is a flow chart for explaining the 1st example of abnormality judgment processing which an abnormality diagnostic device performs. It is a flow chart for explaining the 2nd example of abnormality judgment processing which an abnormality diagnostic device performs. It is a schematic diagram which shows the structure of the bearing device which concerns on Embodiment 6 of this invention. It is a schematic diagram which shows the structure of the bearing device which concerns on Embodiment 7 of this invention. It is a schematic diagram which shows the structure of the bearing device which concerns on Embodiment 8 of this invention. It is a figure which shows the structure which transmits/receives the output of a sensor wirelessly. It is a schematic diagram which shows the structure of the spindle device which concerns on Embodiment 9 of this invention. It is a figure which shows an example of the control apparatus of the spindle device shown by FIG. It is a figure which shows another example of the control apparatus of the spindle device shown by FIG. FIG. 13 is a diagram showing still another example of the control device of the spindle device shown in FIG. 12. It is a schematic diagram which shows the structure of the bearing device which concerns on Embodiment 10 of this invention. It is a schematic diagram which shows the structure of the modification of the bearing device which concerns on Embodiment 10 of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and the description thereof will not be repeated.

(Embodiment 1)
<Structure of bearing device>
FIG. 1 is a schematic diagram showing a configuration of a bearing device according to the first embodiment of the present invention. A bearing device 1 shown in FIG. 1 is a constant pressure preload type bearing device and includes a plurality of bearings 2 that support a rotating body 5 that is a main shaft, a preload portion 3, a housing 4, and a heat flux sensor 11. .. The bearing 2 rotatably supports the rotating body 5. A through hole is formed in the housing 4. The rotating body 5, the bearing 2, and the preload portion 3 are housed inside the through hole. Two bearings 2 are fixed to both ends of the through hole of the housing 4.

The bearing 2 includes an inner ring 2i, an outer ring 2g, a rolling element 2t, and a cage 2r. The bearing 2 is a rolling bearing, for example, an angular ball bearing. That is, the rolling element 2t is, for example, a ball.

The rotating body 5 as the main shaft is inserted and fixed in the inner ring 2i of the bearing 2. In the rotating body 5, a collar 6 is arranged outside the inner ring 2i of the bearing 2 in the extending direction of the rotating body 5. A nut 7 is arranged outside 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. In the configuration shown in FIG. 1, the outer ring 2g is a non-rotating wheel and the inner ring 2i is a rotating wheel.

The preload unit 3 applies a constant pressure preload to the bearing 2. The preload unit 3 includes a spring holder 8, a spring 9 that is an elastic body that applies a preload to the bearing 2, and an intermediate member 10 that is a ring-shaped member. One end surface 8 a of the spring holder 8 contacts the step portion 4 a of the housing 4. The preload portion 3 presses the end surface of the outer ring 2g, which is the fixed ring of the bearing 2, via the intermediate member 10 by the elastic force of the spring 9. As the spring 9, for example, a coil spring can be used. A plurality of preload portions 3 may be arranged in the circumferential direction along the outer ring 2g. Note that other types of springs such as a disc spring may be used as the spring 9, and the type and structure of the spring are not limited.

The end surface of the outer ring 2g, which is the fixed ring of the other bearing 2, contacts the step 4b of the housing 4. As a result, a constant pressure preload is applied to the bearing 2. In the bearing device 1 of FIG. 1, the bearings 2 are installed in a back surface combination (DB combination). The bearing 2 is a bearing that can apply a preload by a force in the axial direction. As the bearing 2, an angular ball bearing, a deep groove ball bearing, a tapered roller bearing or the like can be used.

The heat flux sensor 11 is a sensor that detects a heat flux, and is arranged near each of the plurality of bearings 2. One surface of the heat flux sensor 11 is fixed to a non-rotating member 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 gap. In the bearing device 1 of FIG. 1, the heat flux sensor 11 on the left side is fixed to the inner peripheral surface 4c of the housing 4. The heat flux sensor 11 on the right side is fixed to the surface portion 8b which is the inner diameter surface of the spring holder 8.

In the present embodiment, the heat flux sensor 11 is used to measure the temperature change inside the bearing device 1 during the operation of the bearing device 1. As the heat flux sensor 11, for example, the heat flux sensor described in Japanese Unexamined Patent Application Publication No. 2016-166832 (Patent Document 2) can be used. The output voltage of the heat flux sensor 11 is generated from a slight temperature difference between the front and back of the sensor. The heat flux sensor 11 uses the Seebeck effect to convert the heat flow into an electric signal.

<Operation of heat flux sensor and method for determining abnormality of bearing>
Hereinafter, an operation of the heat flux sensor 11 and a bearing abnormality determination method common to the respective embodiments disclosed in the present specification will be described using the bearing device 1 shown in FIG. In the bearing device 1 shown in FIG. 1, when a temperature difference occurs between the housing 4 and the rotating body 5, a heat flux passing through the heat flux sensor 11 is generated, and the output of the heat flux sensor 11 changes. The output change of the heat flux sensor 11 or the output change amount (change rate) per unit time is monitored. When there is a change (abnormal change) in the monitored data that deviates from the steady state, it is determined that an abnormality has occurred in the bearing 2 of the bearing device 1.

Consider, for example, a case where the preload of the bearing 2 increases and the contact surface pressure between the rolling element 2t and the raceway of the inner ring 2i or the outer ring 2g increases. In this case, the temperature of the bearing 2 rises as the contact surface pressure increases. Here, since the heat capacity of the rotating body 5 fixed to the housing 4 that houses the bearing 2 and the inner ring 2i is relatively large, the temperature of the housing 4 and the rotating body 5 rises from the timing when the temperature of the bearing 2 rises. Timing is delayed. Therefore, when the abnormality of the bearing 2 is determined based on the temperature change of the housing 4 or the rotating body 5 detected by using the temperature sensor or the like, the timing of detecting the abnormality of the bearing 2 is the timing of the actual abnormality occurrence. It is assumed that seizure has already occurred in the bearing 2 after the delay. On the other hand, if the heat flux sensor 11 is used, the heat flux changes prior to the temperature change of the housing 4 and the rotating body 5, so that the abnormality of the bearing 2 can be detected earlier. Further, usually, a cooling medium flow path is formed in the bearing device 1 mounted on the spindle device of the machine tool, and by flowing the cooling medium through the housing 4, the housing 4 and the outer ring 2g in contact with the housing 4 are cooled. Therefore, the temperature of the inner ring 2i is higher than the temperature of the outer ring 2g. When there is an abnormality, the temperature difference between the outer ring 2g and the inner ring 2i becomes larger.

Regarding the optimum arrangement of the heat flux sensor 11, the surface of the heat flux sensor 11 is arranged so as to face the most cooled portion (heat generation portion) (the surface of the heat flux sensor 11 should be located as close to the portion not cooled as possible). Is preferably arranged). Further, it is preferable to fix the heat flux sensor 11 to the most cooled portion (contact the back surface of the heat flux sensor 11 to the most cooled portion).

Here, consider a case where the heat flux sensor 11 is applied to, for example, the bearing device 1 that constitutes a spindle device. In the spindle device, the cooling medium flow path may be formed in the housing 4. In this case, the member fixing the heat flux sensor 11 may be the outer ring 2g of the bearing 2. The member for fixing the heat flux sensor 11 is preferably a member fixed to the housing 4, and more preferably the housing 4 itself. On the other hand, the part where the surfaces of the heat flux sensor 11 face each other may be the rotating body 5. Further, it is more preferable that the portion where the surfaces of the heat flux sensor 11 face each other is the inner ring 2i of the bearing 2.

It should be noted that the difference between the outputs of the two heat flux sensors 11 is calculated, or the difference between the output changes of the two heat flux sensors 11 per unit time is calculated, and the calculated value is compared with a preset threshold value. The presence or absence of an abnormality in the bearing 2 may be determined by. Further, a plurality of heat flux sensors 11 may be arranged along the outer ring 2g of one bearing 2 at intervals.

<Effects of bearing device>
The bearing device 1 according to the present disclosure includes a bearing 2, a preload portion 3, a housing 4, and a heat flux sensor 11. The bearing 2 is for supporting the 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 the heat flux.

With this configuration, when the temperature difference between the housing 4 and the rotating body 5 or the temperature difference between the preload portion 3 and the rotating body 5 changes due to the temperature change of the bearing 2 caused by the abnormality occurrence in the bearing 2, The heat flux passing through the heat flux sensor 11 changes, and the output of the heat flux sensor 11 changes. The change in the output of the heat flux sensor 11 occurs before the change in the temperatures of the rotating body 5 and the housing 4, as described above. Therefore, in the bearing device 1, when the temperature inside the bearing device 1 is measured by using the non-contact temperature sensor by detecting the change in the heat flux inside the bearing device 1 by using the heat flux sensor 11. An abnormality such as overload of the bearing 2 can be detected at an earlier stage.

Also, since the heat flux sensor 11 directly detects the heat flux in the heat flux sensor 11 by converting it into a voltage or the like, it is unlikely to erroneously detect a temperature change like a non-contact temperature sensor. Therefore, the abnormality of the bearing 2 can be accurately detected.

The heat flux sensor 11 is preferably arranged near the bearing 2. Arranging in the vicinity of the bearing 2 means that the heat flux sensor 11 is arranged in a region adjacent to the bearing 2, and for example, when the distance between the bearing 2 and the heat flux sensor 11 is 50 mm or less. Means The distance between the bearing 2 and the heat flux sensor 11 may be 30 mm or less, 20 mm or less, 10 mm or less, or 5 mm or less.

In the bearing device 1, the heat flux sensor 11 is arranged so as to face the rotating body 5. In this case, the heat flux sensor 11 can reliably detect a change in heat flux due to a temperature difference between the rotating body 5 and the housing 4 or the preload portion 3.

In the bearing device 1, the heat flux sensor 11 is fixed to the inner peripheral surface 4c of the housing 4 that faces the rotating body 5. In this case, the heat flux sensor 11 can reliably detect a change in heat flux due to a temperature difference between the rotating body 5 and the housing 4.

In the above bearing device 1, the preload part 3 includes a surface portion facing either one of the rotating body 5 and the bearing 2 (in FIG. 1, the surface portion 8b of the spring holder 8 facing the rotating body 5). The heat flux sensor 11 is fixed to the surface portion 8b. In this case, the change in heat flux due to the temperature difference between the rotating body 5 and the preload unit 3 can be reliably detected by the heat flux sensor 11.

In the bearing device 1, the preload part 3 includes a spring 9 and a spring holder 8. The spring 9 is used to generate preload. The spring holder 8 houses the spring 9. The surface portion 8b is a part 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 therein, a part of the surface of the spring holder 8 on which the heat flux sensor 11 is arranged, that is, the surface part 8b, of the housing 4. It is located in a region closer to the rotating body 5 than the inner peripheral surface 4c. Therefore, the heat flux sensor 11 can be arranged relatively close to the rotating body 5.

(Embodiment 2)
<Structure of bearing device>
FIG. 2 is a schematic diagram showing the configuration of the bearing device according to the second embodiment of the present invention. The bearing device 1 shown in FIG. 2 basically has the same configuration as the bearing device 1 shown in FIG. 1, but the configuration of the part to which the heat flux sensor 11 located on the left side of FIG. The bearing device 1 shown in FIG. That is, in the bearing device 1 shown in FIG. 2, the pedestal 12 is arranged at a position adjacent to the bearing 2 on the inner peripheral surface 4c of the housing 4. The pedestal 12 may be a dedicated member for installing the heat flux sensor 11 in the housing 4. The pedestal 12 is a member separate from the housing 4, but the pedestal 12 may be formed integrally with the housing 4. For example, when forming the housing 4, the inner peripheral surface 4c of the housing 4 may be processed so as to have the pedestal 12. The heat flux sensor 11 is fixed on the surface of the pedestal 12 facing the rotating body 5. The pedestal 12 includes a surface portion facing either one of the rotating body 5 and the bearing 2. In FIG. 2, the heat flux sensor 11 is fixed to the surface portion of the pedestal 12 facing the rotating body 5. The shape of the pedestal 12 may be a ring shape along the outer ring 2g of the bearing 2, or may be a columnar shape that faces only a part of the outer ring 2g. Further, a plurality of pedestals 12 may be arranged along the outer ring 2g, and the heat flux sensor 11 may be fixed to each pedestal 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 pedestal 12 on which the heat flux sensor 11 is fixed to the surface of the rotating body 5 is smaller than the distance from the inner peripheral surface 4c of the housing 4 to the surface of the rotating body 5. Alternatively, the pedestal 12 may be fixed to the housing 4 by forming a recess in the inner peripheral surface 4c of the housing 4 and arranging at least a part of the pedestal 12 inside the recess. In this case, the distance from the surface of the pedestal 12 on which the heat flux sensor 11 is fixed to the surface of the rotating body 5 and the area of the inner peripheral surface 4c of the housing 4 other than the area where the recess is formed to the surface of the rotating body 5. May be substantially the same in distance.

<Operation and effect of bearing device>
The bearing device 1 shown in FIG. 2 can basically obtain the same effect as the bearing device 1 shown in FIG. Further, in the bearing device 1 shown in FIG. 2, the housing 4 includes a pedestal 12 provided from the inner peripheral surface 4c facing the rotating body 5 toward the rotating body 5. That is, the housing 4 includes the pedestal 12 provided on the inner peripheral surface 4c. The heat flux sensor 11 is fixed to the pedestal 12. As described above, by disposing the heat flux sensor 11 on the pedestal 12, the distance between the heat flux sensor 11 and the rotating body 5 can be made smaller than the distance in the bearing device 1 shown in FIG. Therefore, the temperature change of the rotating body 5 caused by the abnormality in the bearing 2 can be detected more quickly and accurately.

(Embodiment 3)
<Structure of bearing device>
FIG. 3 is a schematic diagram showing the configuration of the bearing device according to the third embodiment of the present invention. The bearing device 1 shown in FIG. 3 basically has the same configuration as the bearing device 1 shown in FIG. 2, but the configuration of the portion to which the heat flux sensor 11 located on the right side of FIG. 3 is fixed is illustrated. 2 is different from the bearing device 1 shown in FIG. That is, in the bearing device 1 shown in FIG. 3, the preload part 3 includes the spring holder 8, the spring 9, and the intermediate member 10. The intermediate member 10 is a ring-shaped member that extends along the outer ring 2g of the bearing 2. A spring 9 is housed inside 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 10 a that 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.

<Effects of bearing device>
The bearing device 1 shown in FIG. 3 can basically obtain the same effect as the bearing device 1 shown in FIG. Furthermore, in the bearing device 1 shown in FIG. 3, the preload part 3 includes a spring 9 and an intermediate member 10. The intermediate member 10 is, for example, a ring-shaped member. The spring 9 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 10 a 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, the distance between the heat flux sensor 11 and the bearing 2 in the bearing apparatus 1 shown in FIG. 3 can be made smaller than the distance between the heat flux sensor 11 and the bearing 2 in the bearing apparatus 1 shown in FIG. Further, 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 brought as close as possible to the rotating body 5. Therefore, the heat flux sensor 11 can quickly and reliably detect the temperature change of the rotating body 5 and the bearing 2 due to the abnormality of the bearing 2.

(Embodiment 4)
<Structure of bearing device>
FIG. 4 is a schematic diagram showing the configuration of the bearing device according to the fourth embodiment of the present invention. The bearing device 1 shown in FIG. 4 basically has the same configuration as the bearing device 1 shown in FIG. 3, but the configuration of the portion to which the heat flux sensor 11 of FIG. 4 is fixed is shown in FIG. It differs from the bearing device 1. That is, in the bearing device 1 shown in FIG. 4, the ring-shaped spacer 20 is arranged so as to contact the outer ring 2g of the left bearing 2. One end of the spacer 20 contacts the inside of the outer ring 2g. The other end of the spacer 20 opposite to the one end is in contact with a step portion formed on the inner peripheral surface 4c of the housing 4. The heat flux sensor 11 is fixed on the surface portion 20 a of the spacer 20 that faces the rotating body 5. The spacer 20 and the intermediate member 10 are formed with a supply port 21 which is a nozzle for supplying a lubricating fluid such as lubricating oil to the bearing 2 for lubricating and cooling the bearing 2. The supply ports 21 formed in the spacer 20 and the intermediate member 10 are connected to the flow paths of the lubricating fluid formed in the housing 4, respectively. The flow path is connected to a lubricating fluid supply unit (not shown) via a pump, an on-off valve, and the like. Note that oil mist or air may be supplied to the bearing 2 from the supply port 21.

<Effects of bearing device>
The bearing device 1 shown in FIG. 4 includes a spacer 20 arranged adjacent to the bearing 2. The spacer 20 is formed with a supply port 21 which is a nozzle for supplying a lubricating fluid to the bearing 2. The spacer 20 includes a surface portion facing either one of the rotating body 5 and the bearing 2 (a surface portion 20a facing the rotating body 5 in FIG. 4). The heat flux sensor 11 is fixed to the surface portion 20a. In this case, since the heat flux sensor 11 can be arranged in the area adjacent to the bearing 2, the heat flux sensor 11 can reliably detect the temperature change of the rotating body 5 and the bearing 2 due to the abnormality of the bearing 2.

Further, in the bearing device 1, a supply port 21 which is a nozzle for supplying a lubricating fluid to the bearing 2 is formed in the intermediate member 10 which constitutes the preload portion 3, and the heat flux sensor 11 is fixed. .. Therefore, the heat flux sensor 11 can be arranged near the bearing 2 as in the bearing device 1 shown in FIG. Further, since it is not necessary to dispose a member having the supply port 21 for supplying the lubricating fluid separately from the intermediate member 10 in the vicinity of the preload portion 3, the device configuration of the bearing device 1 can be simplified.

When the supply port 21 for supplying the lubricating fluid is formed in the bearing device 1 as described above, the heat flux sensor 11 is placed at a position where it is less likely to be affected by the lubricating fluid supplied from the supply port 21. It is preferable to install. For example, it is preferable to arrange the heat flux sensor 11 in a region spaced apart from the position where the supply port 21 is arranged in the circumferential direction of the bearing 2. When a plurality of supply ports 21 are arranged in the circumferential direction of the bearing 2, it is preferable to arrange the heat flux sensor 11 at a position that is substantially equidistant from the plurality of supply ports 21 in the circumferential direction. Further, consider a case where the protruding direction of the lubricating fluid at the supply port 21 is inclined with respect to the rotation axis direction of the bearing 2 and the lubricating fluid is sprayed along the circumferential direction of the bearing 2. In this case, the lubricating fluid sprayed on the bearing 2 hits the transfer surface of the bearing 2 in the vicinity of the supply port 21, spreads over the entire circumference of the bearing 2 as the bearing 2 rotates, and the bearing 2 can be efficiently lubricated/cooled. .. In such a configuration, the position of the supply port 21 and the position of the heat flux sensor 11 are set in order to reduce the influence of the lubricating fluid not only in the circumferential direction of the bearing 2 but also in the rotational axis direction of the bearing 2. It is preferable to shift.

(Embodiment 5)
<Structure of bearing device>
FIG. 5 is a block diagram for explaining the configuration of the bearing device according to the fifth embodiment of the present invention. The bearing device according to the present embodiment basically has the same configuration as the bearing device 1 shown in FIG. 1, but is provided with an abnormality diagnosis unit 100 for diagnosing an abnormality of the bearing 2 (see FIG. 1). Further, the bearing device 1 is different from the bearing device 1 shown in FIG. 1 in that another sensor 22 is provided. The other sensor 22 can be installed at an arbitrary position such as the outer ring 2g of the bearing 2 or the vicinity of 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. Further, output information from other sensors 22 is also input to the abnormality diagnosis unit 100. Further, the abnormality diagnosis unit 100 also receives a shaft rotation speed signal 101, which is information on the rotation speed of the rotating body 5. The abnormality diagnosis unit 100 diagnoses an abnormality in the bearing 2 based on the output information of the heat flux sensor 11, the output information of the other sensors 22, and the shaft rotation speed signal 101. When the abnormality diagnosis unit 100 determines that an abnormality has occurred in the bearing 2, the abnormality diagnosis unit 100 outputs an instruction signal 102 for performing an abnormality avoidance operation in order to prevent the bearing from being damaged. In addition, as the other sensor 22, an arbitrary sensor such as a temperature sensor, an acceleration sensor, a weight sensor, and a rotation sensor may be added.

<Abnormality diagnosis processing>
Hereinafter, a specific example of the abnormality determination processing will be described. FIG. 6 is a flowchart for explaining the first example of the abnormality determination processing executed by the abnormality diagnosis device. Referring to FIGS. 5 and 6, the abnormality diagnosis unit 100 monitors the output of the sensor in step S1. Examples of the sensor include a heat flux sensor 11, a temperature sensor, a rotation speed detection sensor (not shown) that detects the rotation speed of the rotating body 5, an acceleration sensor, a weight sensor, and the like. Subsequently, in step S2, the abnormality diagnosis unit 100 compares the threshold value provided corresponding to the output of each sensor with the value (output information) detected by the sensor, and determines whether or not the threshold value is exceeded. To do. The threshold value determination may be performed individually for each output information of each sensor, or may be performed for a combination of output information of each sensor. As an example of the combination, the threshold value of the temperature inside the bearing device 1 which is the output information from the temperature sensor as an example of the other sensor 22 according to the rotation speed of the rotating body 5 which is the output information from the rotation speed detection sensor. And the threshold value of the output information of the heat flux sensor 11 is set, the output information from the temperature sensor (measured temperature inside the bearing device 1) exceeds the threshold value (predetermined temperature), and the output information of the heat flux sensor 11 is the threshold value. It is conceivable that the bearing 2 is determined to have an abnormality when the value exceeds.

If the output information (detection value) is smaller than the threshold value in step S2 (that is, the occurrence of abnormality is not detected), the sensor monitoring process of step S1 is repeatedly executed again. On the other hand, when the output information is larger than the threshold value in step S2 (that is, when the occurrence of an abnormality is detected), the abnormality diagnosis unit 100 executes the abnormality avoidance operation so that the abnormality avoidance operation of step S3 is executed. The instruction signal 102 of is output.

The following is an example of the abnormality avoidance operation control executed by the instruction signal 102 in the machine tool, which is an example of a mechanical device in which the bearing device 1 is incorporated. For example, the abnormality avoidance operation control may be control for lowering the rotation speed of the rotating body 5 from the present. The abnormality avoidance operation control may be control for reducing the cutting amount of the blade with respect to the object to be processed, compared to the present time, when cutting is performed in the machine tool, for example. The abnormality avoidance operation control may be control for supplying lubricating oil to the bearing 2 (see FIG. 1) of the bearing device 1 or for increasing the amount of lubricating oil supplied. The abnormality avoidance operation control may be control for stopping machining in the machine tool (for example, control for stopping cutting to reduce the rotation speed (spindle rotation speed) of the rotating body 5 or stopping rotation of the rotating body 5). .. When determining the presence/absence of abnormality by performing the threshold value determination once in step S2, it is also possible to make an erroneous determination due to noise or the like. Therefore, in order to avoid erroneous determination, when an abnormality is detected a plurality of times in succession in step S2, it is determined to be abnormal, and the process proceeds to step S3 in which an instruction signal for executing the abnormality avoidance operation is output. May be.

FIG. 7 is a flowchart for explaining the second example of the abnormality determination processing executed by the abnormality diagnosis device. Referring to FIGS. 5 and 7, the abnormality diagnosis unit 100 monitors the output of the sensor in step S11. Examples of the sensor include a heat flux sensor 11, a temperature sensor, a rotation speed detection sensor (not shown) that detects the rotation speed of the rotating body 5, an acceleration sensor, a weight sensor, and the like, as in the abnormality determination process described in FIG. .. Subsequently, in step S12, the abnormality diagnosis unit 100 calculates the rate of change of the output of each sensor per unit time. After that, the abnormality diagnosis unit 100 determines whether or not the calculated change rate exceeds a threshold value (determination value) in step S13 (change rate determination).

The change rate determination may be performed individually for the output information of each sensor, or may be performed for a combination of the output information of each sensor. As an example of the combination, the rate of change in the rotation speed of the rotating body 5 per unit time, which is the output information from the rotation speed detection sensor, exceeds the threshold value, and the output information from the temperature sensor as an example of the other sensor 22 is used. When the rate of change of the temperature inside a certain bearing device 1 per unit time exceeds a threshold value and the rate of change of the output information of the heat flux sensor 11 per unit time exceeds a predetermined threshold value, an abnormality occurs in the bearing 2. It is conceivable to make a determination method such as “determine”.

If the rate of change detected is smaller than the threshold value (judgment value) in step S13, the sensor monitoring process of step S11 is repeatedly executed again. On the other hand, when the change rate detected in step S13 is larger than the threshold value, the abnormality diagnosis unit 100 outputs the instruction signal 102 for executing the abnormality avoidance operation so that the abnormality avoidance operation in step S14 is executed. In this case as well, in order to prevent erroneous determination due to noise or the like, it may be determined to be abnormal when the occurrence of abnormality is detected a plurality of times consecutively in step S13. Since the example of the abnormality avoidance operation control executed by the machine tool in response to the instruction signal 102 is the same as the case of the abnormality determination processing shown in FIG. 6, the description will not be repeated.

<Effects of bearing device>
The bearing device according to the present embodiment includes an abnormality diagnosis unit 100 that diagnoses an abnormality of the bearing 2 based on the output information of the heat flux sensor 11. In this case, since the bearing device itself includes the abnormality diagnosis unit 100, it is possible to diagnose whether or not an abnormality has occurred in the bearing 2 in the bearing device.

The above bearing device includes another sensor 22 arranged separately from the heat flux sensor 11. The output information of the heat flux sensor 11 and the output information of the other sensors 22 are transmitted to the abnormality diagnosis unit 100. The abnormality diagnosing unit 100 diagnoses an abnormality in 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 rotation speed signal 101 that is the rotation speed information of the rotating body. In this case, the abnormality of the bearing 2 can be diagnosed more accurately by using information other than the information from the heat flux sensor 11.

(Embodiment 6)
<Structure of bearing device>
FIG. 8 is a schematic diagram showing the configuration of the bearing device according to the sixth embodiment of the present invention. The bearing device 1 shown in FIG. 8 basically has the same configuration as the bearing device 1 shown in FIG. 1, but the configuration of the portion to which the heat flux sensor 11 of FIG. 8 is fixed is shown in FIG. It differs from the bearing device 1. That is, in the bearing device 1 shown in FIG. 8, the housing 4 has a portion located outside the bearing 2 in the extending direction of the rotating body 5. A 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 outside the bearing 2 and in the region 14 adjacent to the bearing 2 in the extending direction of the rotating body 5.

<Effects of bearing device>
The bearing device 1 basically has the same effects as the bearing device 1 shown in FIG. Further, in the bearing device 1 shown in FIG. 8, the heat flux sensor 11 is fixed to the inner peripheral surface 4Ad located on the outer peripheral side of the bearing 2 in the housing 4 and facing the rotating body. In this case, since the heat flux sensor 11 is arranged in a region outside the bearing 2 in the housing 4, maintenance of the heat flux sensor 11 is facilitated and wiring for outputting a signal from the heat flux sensor 11 to the outside is provided. Processing becomes easy.

(Embodiment 7)
<Structure of bearing device>
FIG. 9 is a schematic diagram showing the structure of the bearing device according to the seventh embodiment of the present invention. The bearing device 1 shown in FIG. 9 basically has the same configuration as the bearing device 1 shown in FIG. 8, but the configuration of the portion to which the heat flux sensor 11 of FIG. 9 is fixed is shown in FIG. It differs from the bearing device 1. That is, in the bearing device 1 shown in FIG. 9, the pedestal 13 provided from the inner peripheral surface 4Ad of the housing 4 toward the rotating body 5 is arranged outside the bearing 2 and adjacent to the bearing 2. That is, the housing 4 includes the pedestal 13 provided on the inner peripheral surface 4Ad. The pedestal 13 may be separate from the housing 4, like the pedestal 12 shown in FIG. The pedestal 13 includes a surface portion facing either one of the rotating body 5 (collar 6) and the bearing 2. In FIG. 9, the heat flux sensor 11 is fixed to the surface portion of the pedestal 13 that faces the rotating body 5. That is, the heat flux sensor 11 is fixed on the surface of the pedestal 13 facing the rotating body 5 (the collar 6). The pedestal 13 may be a ring-shaped member that extends along the outer ring 2g of the bearing 2, or may be a columnar member that faces only a part of the outer ring 2g. Alternatively, a plurality of pedestals 13 may be arranged along the outer ring 2g, and the heat flux sensor 11 may be fixed to each pedestal 13.

<Effects of bearing device>
The bearing device 1 shown in FIG. 9 can basically obtain the same effects as those of the bearing device 1 shown in FIG. Further, in the bearing device 1 shown in FIG. 9, the housing 4 includes a pedestal 13 provided from the inner peripheral surface 4Ad facing the rotating body 5 to the rotating body 5 outside the bearing 2. The heat flux sensor 11 is fixed to the pedestal 13. In this case, by disposing the heat flux sensor 11 on the pedestal 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) due to the abnormality in the bearing 2 can be detected more quickly and accurately.

(Embodiment 8)
<Structure of bearing device>
FIG. 10 is a schematic diagram showing the structure of the bearing device according to the eighth embodiment of the present invention. FIG. 11 is a diagram showing a configuration for wirelessly transmitting and receiving the output of the sensor. The bearing device 1 shown in FIG. 10 basically has the same configuration as the bearing device 1 shown in FIG. 8, but the point that the bearing device 1 shown in FIG. 8 includes a transmitter 200 and a receiver 300 that are wireless transmitters. It differs from the bearing device 1 shown. In the bearing device 1 shown in FIG. 10, the heat flux sensor 11 is connected to the transmitter 200. The wireless transmission device is also connected to another heat flux sensor 11, which is not shown in FIG. The outputs of the two heat flux sensors 11 may be transmitted by one wireless transmission device. The receiving device 300 receives the output information of the heat flux sensor 11 from the transmitting unit 200 and determines whether the bearing 2 is abnormal.

In the bearing device 1 shown in FIG. 10, the output information generated by the heat flux sensor 11 can be transmitted to the outside by the transmitter 200. In this case, the abnormality of the bearing 2 can be diagnosed by an external abnormality diagnosis device. In addition, preferably, the bearing device 1 may further include a power supply device that supplies power to the transmission unit 200. As the power supply device, a battery, a power generation device that generates power by a temperature difference, vibration, or the like, an electromagnetic induction power generator, or the like can be used.

As shown in FIG. 11, the transmission unit 200 includes a signal processing unit 201 and a data transmission unit 202. The signal processing unit 201 receives a signal that is output information from the heat flux sensor 11 and amplifies the signal or removes a noise component from the signal. Further, the signal processing unit 201 performs analog-digital conversion processing, modulation processing, etc. on the signal. The signal processing unit 201 outputs the signal subjected to the above-described processing to the data transmitting unit 202 as transmission data. The data transmitting unit 202 wirelessly transmits the data to the receiving device 300.

The receiving device 300 is installed, for example, outside the mechanical device in which the bearing device 1 is incorporated. The receiving device 300 includes a data receiving unit 301 that wirelessly receives data, a signal processing unit 302 that demodulates data from a received signal, and an abnormality determination unit 303 that receives data from the signal processing unit 302 and determines a bearing abnormality. including. If the abnormality determination unit 303 is inserted in the subsequent stage of the signal processing unit 201, it is possible to reduce the amount of transmission data and power consumption. The process of abnormality determination unit 303 is similar to the process described with reference to FIGS. 6 and 7, and thus description will not be repeated.

<Effects of bearing device>
The bearing device includes a transmitter 200 that wirelessly transmits the 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 the receiving device 300 that diagnoses the abnormality of the bearing 2. In this case, the output information of the heat flux sensor 11 can be transmitted to the receiving device 300 without arranging wiring so as to extend from the heat flux sensor 11 to the receiving device 300. Therefore, the abnormality diagnosis of the bearing 2 can be performed in the receiving device 300 without complicating the configuration of the bearing device.

The bearing device 1 includes a transmitter 200 that wirelessly transmits the output information of the heat flux sensor 11, and a receiver 300 that receives the output information of the heat flux sensor 11 from the transmitter 200 and determines whether the bearing 2 is abnormal. .. As a result, even when the heat flux sensor 11 is connected to a member that rotates inside the bearing device 1, the detection result of the heat flux sensor 11 can be output to the outside. Therefore, the abnormality of the bearing 2 can be promptly detected.

(Embodiment 9)
<Structure of bearing device>
FIG. 12 is a schematic diagram showing the configuration of the spindle device according to the ninth embodiment of the present invention. As shown in FIG. 12, the spindle device 30 mainly includes, for example, the bearing device 1 according to the second embodiment, the rotating body 5 as the main shaft, the outer cylinder 32, the motor 31, and the bearing 33. The spindle device 30 is used, for example, as a built-in motor type spindle device of a machine tool. The spindle device 30 is connected to the control device 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 outer cylinder 32 by the bearing device 1 and the bearing 33. The motor 31 is arranged between the bearing device 1 and the bearing 33.

The spindle device 30 shown in FIG. 12 is, for example, a spindle device for a machine tool spindle. In the spindle device 30, a motor 31 is incorporated on one end side of the rotating body 5, and a cutting tool such as an end mill (not shown) is connected to the other end side. The bearing device 1 is an improved version of the bearing device 1 shown in FIG. Bearing device 1 has substantially the same structure as bearing device 1 shown in FIG. 2 except that cooling medium flow path G is formed on the outer peripheral surface of housing 4, and therefore description thereof will not be repeated. The bearing device 1 is fixed to the inner peripheral surface of the outer cylinder 32. In the housing 4 of the bearing device 1, the cooling medium passage G described above is formed on the surface of the outer cylinder 32 facing the inner peripheral surface.

The single-row bearing 33 mainly includes an inner ring 33a, an outer ring 33b, and rolling elements. The inner ring 33 a is axially positioned with respect to the rotating body 5 by a tubular member 34 fitted to the outer periphery of the rotating body 5 and an inner ring retainer 35. The inner ring retainer 35 is fixed to the rotating body 5 by a nut 36 screwed to the rotating body 5. The outer ring 33b of the bearing 33 is sandwiched between a positioning member 37 fixed to the tubular member 34 and a positioning member 38 fixed to the inner ring retainer 35. The outer ring 33b is slidable with respect to the end member 39 integrally with the inner ring 33a according to expansion and contraction of the rotating body 5 caused by heat generation of the bearing 33 during operation of the spindle device 30.

In the space 40 formed between the rotating body 5 and the outer cylinder 32, the rotating body 5 is located at an intermediate position in the axial direction between the double row bearing 2 and the single row bearing 33 of the bearing device 1. A motor 31 for driving the motor is arranged. The rotor 41 of the motor 31 is fixed to a tubular member 34 fitted on the outer circumference of the rotating body 5. The stator 42 of the motor 31 is fixed to the inner peripheral surface of the outer cylinder 32. The spindle device 30 includes a cooling medium passage (not shown). The cooling medium flow path cools the motor 31. Although the motor 31 is arranged next to the bearing device 1 in FIG. 12, the motor 31 may be arranged in the space between the two bearings 2 included in the bearing device 1. Further, the bearing device 1 according to the first to third embodiments described above may be applied to the spindle device 30 shown in FIG.

The heat flux sensor 11 that measures the heat flux is mounted on the spindle device 30 as a sensor unit. Specifically, two heat flux sensors 11 are arranged inside the bearing device 1 that constitutes the spindle device 30.

Here, as the contact surface pressure between the rolling elements 2t (see FIG. 2) of the bearing 2 and the raceways of the inner ring 2i (see FIG. 2) and the outer ring 2g (see FIG. 2) increases, the inner ring 2i and the outer ring 2g The temperature rises. At this time, the heat initially generated between the rolling elements 2t and the raceways of the inner ring 2i and the outer ring 2g is transferred to the rotating body 5 and the housing 4. The temperature of the housing 4 having a large heat capacity is delayed until it rises. Further, since the housing 4 is cooled by the cooling medium flowing through the cooling medium flow passage G, the temperature rise is further delayed.

Therefore, if an attempt is made to detect a sign of an abnormality such as seizure of the bearing 2 by measuring the temperature of the housing 4 or the rotating body 5, there is a delay in the temperature rise, so that the sign of the abnormality may not be detected early. is assumed. If the heat flux sensor 11 is used in such a case, a change in heat flux occurs earlier than a temperature change, so that an abnormality such as a sudden heat generation of the bearing 2 can be quickly detected.

The control device 600 controls the motor 31. Further, the control device 600 determines the occurrence of abnormality of the bearing 2 from the output signal of the heat flux sensor 11.

FIG. 13 is a diagram showing an example of a control device of the spindle device shown in FIG. As shown in FIG. 13, in the spindle device 30, even if the control device 600 that controls the operation of the spindle device 30 diagnoses the abnormality of the bearing 2 (see FIG. 12) based on the output of the heat flux sensor 11. Good. The control device 600 includes a determination unit 601. The determination unit 601 is a predetermined determination for determining the output of the heat flux sensor 11, the rotation speed of the motor 31 of the spindle device 30, machine information D1 such as lubrication conditions and cooling conditions, and the presence or absence of abnormality of the bearing 2. The presence or absence of abnormality of the bearing 2 is determined based on the standard D2. The abnormality of the bearing 2 is, for example, occurrence or risk of seizure of the bearing 2. The output information of the heat flux sensor 11 is transmitted to the determination unit 601 of the control device 600 by any method. For example, the transmitting unit 200 shown in FIG. 10 may be installed in the bearing device 1. The control device 600 may include the receiving device 300 shown in FIG. 11. The control device 600 is provided so as to change at least one of the rotation speed, the lubrication condition, and the cooling condition of the motor 31, based on the determination result by the determination unit 601. Note that the determination unit 601 may determine whether or not there is an abnormality in the bearing 2 based on at least the output of the heat flux sensor 11 and a determination criterion D2 that is predetermined to determine whether or not there is an abnormality in the bearing 2. ..

The determination unit 601 can also diagnose the abnormality of the bearing 2 based on the outputs of the heat flux sensor 11 and the other sensors, as in the abnormality diagnosis unit 100 shown in FIG. FIG. 14 is a diagram showing another example of the control device for the spindle device shown in FIG.

As shown in FIG. 14, the determination unit 601 diagnoses an abnormality in the bearing 2 based on the outputs of the temperature sensor 602, the acceleration sensor 603, and the load sensor 604 in addition to the heat flux sensor 11, for example. The temperature sensor 602 is provided so as to detect a temperature rise of the housing 4 due to poor lubrication of the bearing 2, for example. The temperature sensor 602 may be arranged at a position adjacent to the bearing 2 in the housing 4, for example. The acceleration sensor 603 detects vibrations of at least one of the rotating body 5 in the axial direction, which is the extending direction of the rotating body 5 and the radial direction intersecting the axial direction, due to the separation of the raceway surfaces of the bearing 2, for example. It is provided in. The acceleration sensor 603 may be arranged on the end surface of the housing 4 in the axial direction, for example. The load sensor 604 is provided so as to detect, for example, a change in the load applied from the outside or the impact load applied to the bearing 2. The load sensor 604 is arranged so as to connect the outer ring 2g of the bearing 2 and the intermediate member 10 (see FIG. 2) in the axial direction, for example. The load sensor 604 is, for example, a thin film sensor, and its electric resistance changes with pressure.

FIG. 15 is a diagram showing still another example of the control device of the spindle device shown in FIG. As shown in FIG. 15, in addition to the outputs of the heat flux sensor 11, the temperature sensor 602, the acceleration sensor 603, and the load sensor 604, the determination unit 601 further rotates the motor 31 that is output information of the rotation sensor 605. It may be provided so as to diagnose the abnormality of the bearing 2 based on the speed.

In the spindle device 30, an abnormality diagnosis unit as shown in FIG. 5 may be installed inside the spindle device 30. For example, the above-described abnormality diagnosis unit may be mounted on the board arranged in the housing 4 of the bearing device 1. In this case, the distance between the abnormality diagnosing unit and the heat flux sensor 11 is the distance between the abnormality diagnosing unit and the heat flux sensor 11 when the abnormality diagnosing unit is arranged outside the bearing device 1, particularly outside the spindle device 30. Short compared to the distance between. Therefore, the influence of noise is reduced in the abnormality diagnosis unit installed inside the spindle device 30 compared with the output signal of the heat flux sensor 11 acquired by the abnormality diagnosis unit arranged outside the bearing device 1. The presence or absence of the abnormality can be determined based on the output signal.

<Effects of bearing device>
A spindle device 30 according to the present disclosure includes the bearing device 1 and a motor 31 that rotates the rotating body 5. By doing so, it is possible to realize the spindle device 30 that can detect abnormality of the bearing 2 quickly and accurately.

In each of the above-described embodiments, the constant pressure preload structure in which the bearing 2 is installed in the back combination (DB combination) has been described, but the present disclosure also relates to the constant pressure preload structure in which the bearing 2 is in the front combination (DF combination). The configuration is applicable.

(Embodiment 10)
<Structure of bearing device>
FIG. 16 is a schematic diagram showing the structure of the bearing device according to the tenth embodiment of the present invention. The bearing device 1 shown in FIG. 16 basically has the same configuration as the bearing device 1 shown in FIG. 3, but the shapes of the pedestal 12 and the intermediate member 10 and the arrangement of the heat flux sensor 11 are different from those in FIG. The bearing device 1 shown in FIG. That is, in the bearing device 1 shown in FIG. 16, the pedestal 12 includes a surface portion 12a facing the rotating body 5, a surface portion 12c facing the rolling element 2t of the bearing 2 and extending in the radial direction of the bearing 2, and a surface portion. 12a and a surface portion 12b connecting 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 arranged so as to face the inner ring 2i of the bearing 2 adjacent to the pedestal 12. The heat flux sensor 11 may be fixed to the surface portion 12c of the pedestal 12 that faces the bearing 2.

Further, in the bearing device 1 shown in FIG. 16, the intermediate member 10 of the preload portion has a surface portion 10a facing the rolling element 5 and a surface portion 10c facing the rolling element 2t of the bearing 2 and extending in the radial direction of the bearing 2. And a surface portion 10b connecting the surface portion 10a and 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 arranged so as to face the inner ring 2i of the bearing 2 adjacent to the intermediate member 10. The heat flux sensor 11 may be fixed to the surface portion 12c of the intermediate member 10 that faces the bearing 2.

FIG. 17 is a schematic diagram showing a configuration of a modified example of the bearing device according to the tenth embodiment of the present invention. The bearing device 1 shown in FIG. 17 basically has the same configuration as the bearing device 1 shown in FIG. 4, but the shapes of the spacer 20 and the intermediate member 10 and the arrangement of the heat flux sensor 11 are different. The bearing device 1 shown in FIG. That is, in the bearing device 1 shown in FIG. 17, the spacer 20 includes a surface portion 20 a facing the rotating body 5, a surface portion 20 c facing the rolling element 2 t of the bearing 2 and extending in the radial direction of the bearing 2, and a surface. It includes a surface portion 20b connecting the portion 20a and 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 arranged so as to face the inner ring 2i of the bearing 2 adjacent to the pedestal 12. In the bearing device 1 shown in FIG. 17, the heat flux sensor 11 is arranged in a region of the spacer 20 opposite to the supply port 21 when viewed from the rotating body 5. The heat flux sensor 11 may be fixed to the surface portion 20b of the spacer 20 adjacent to the supply port 21. The heat flux sensor 11 may be fixed to the surface portion 20c of the spacer 20 facing the bearing 2.

Further, in the bearing device 1 shown in FIG. 17, the intermediate member 10 of the preload portion is provided on the surface portion 10a facing the rotating body 5 and the rolling element 2t of the bearing 2 as in the bearing device 1 shown in FIG. It includes a facing surface portion 10c and a surface portion 10b connecting the surface portion 10a and the surface portion 10c. The heat flux sensor 11 is fixed to the surface portion 10b. The heat flux sensor 11 is arranged so as to face the inner ring 2i of the bearing 2 adjacent to the intermediate member 10. In the bearing device 1 shown in FIG. 17, the heat flux sensor 11 is arranged in the region of the intermediate member 10 opposite to the supply port 21 when viewed from the rotating body 5. The heat flux sensor 11 may be fixed to the surface portion 10b of the intermediate member 10 adjacent to the supply port 21. The heat flux sensor 11 may be fixed to the surface portion 12c of the intermediate member 10 that faces the bearing 2.

<Effect>
In the bearing device 1 shown in FIGS. 16 and 17, the heat flux sensor 11 is arranged so as 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 pedestal 12 and the spacer 20 which face the bearing 2. Therefore, the same effect as that of the bearing device 1 shown in FIG. 3 or FIG. 4 is obtained, and the temperature change due to the heat generation between the rolling element 2t and the inner ring 2i due to the abnormality of the bearing 2 or the like causes the heat flux sensor 11 to detect the temperature change. Can be detected quickly and surely. When the heat flux sensor 11 faces the bearing 2, it is preferable that the heat flux sensor 11 be close to the inner ring 2i.

The heat flux sensor 11 may be fixed to the

surface portions

10c, 12c, 20c of the intermediate member 10, the pedestal 12, and the spacer 20 that face the rolling elements 2t of the bearing 2. In this case, the heat flux sensor 11 can detect the temperature change due to the heat generation of the rolling element 2t due to the abnormality of the bearing 2 quickly and reliably. Further, the heat flux sensor 11 may be arranged so as to face a member such as the inner ring 2i of the bearing 2 that is fixed to the rotating body 5. In this way, by disposing the heat flux sensor 11 as close to and as close to the heat-generating portion as possible, it is possible to quickly detect a temperature change in the heat-generating portion.

In order to dispose the heat flux sensor 11 as close as possible to the heat generating portion and face it, the heat flux sensor 11 is arranged at a position facing the concave portion or the convex portion provided on the rotating body 5 and the end surface of the rotating body 5 close to the heat generating portion. The heat flux sensor 11 may be fixed to the recesses (grooves) not shown in the

surface portions

10c, 12c, 20c. Further, the heat flux sensor 11 may be formed in a ring shape, and the shape of the heat flux sensor 11 does not matter.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the scope of the claims, and is intended to include meanings equivalent to the scope of the claims and all modifications within the scope.

1 bearing device, 2, 33 bearing, 2g, 33b outer ring, 2i, 33a inner ring, 2r cage, 2t rolling element, 3 preload section, 4 housing, 4Ad, 4c inner peripheral surface, 4a, 4b step section, 5 rotating body , 6 collars, 7, 36 nuts, 8 spring holders, 8a one end surface, 8b, 10a, 10b, 10c, 12a, 12b, 12c, 20a, 20b, 20c surface part, 9 springs, 10 intermediate member, 11 heat flux sensor , 12, 13 pedestal, 14 area, 20 spacer, 21 supply port, 22,602 temperature sensor, 30 spindle device, 31 motor, 32 outer cylinder, 34 cylindrical member, 35 inner ring retainer, 37, 38 positioning member, 39 End member, 40 space section, 41 rotor, 42 stator, 100 abnormality diagnosis section, 101 axis rotation speed signal, 102 abnormality avoidance operation instruction signal, 200 transmission section, 201, 302 signal processing section, 202 data transmission section, 300 reception device , 301 data receiving unit, 303 abnormality determination unit, 600 control device, 601, determination unit, 603 acceleration sensor, 604 load sensor, 605 rotation sensor, D1 machine information, D2 determination standard, G cooling medium flow path.

Claims

A bearing for supporting the rotating body,
A preload portion including an elastic body for applying a preload to the bearing,
A housing for fixing the bearing,
A bearing device, comprising: a heat flux sensor that is fixed to one of the housing and the preload portion and that detects a heat flux.
The bearing device according to claim 1, wherein the heat flux sensor is arranged so as to face the rotating body.
The bearing device according to claim 1, wherein the heat flux sensor is arranged so as to face the bearing.
The bearing device according to any one of claims 1 to 3, wherein the heat flux sensor is fixed to an inner peripheral surface of the housing facing the rotating body.
The housing includes a pedestal provided from an inner peripheral surface facing the rotating body toward the rotating body,
The bearing device according to claim 1, wherein the heat flux sensor is fixed to the pedestal.
The preload portion includes a surface portion facing one of the rotating body and the bearing,
The bearing device according to any one of claims 1 to 3, wherein the heat flux sensor is fixed to the surface portion.
The preload section is
A spring as the elastic body,
A spring holder for accommodating the spring,
The bearing device according to claim 6, wherein the surface portion is a part of a surface of the spring holder.
The preload section is
A spring as the elastic body,
An intermediate member disposed between the spring and the bearing,
The bearing device according to claim 6, wherein the surface portion is a part of a surface of the intermediate member.
A spacer disposed adjacent to the bearing,
In the spacer, a supply port for supplying a lubricating fluid to the bearing is formed,
The spacer includes a surface portion facing one of the rotating body and the bearing,
The bearing device according to any one of claims 1 to 3, wherein the heat flux sensor is fixed to the surface portion.
A transmitter for wirelessly transmitting output information of the heat flux sensor,
The bearing device according to any one of claims 1 to 9, wherein the transmission unit is configured to transmit the output information of the heat flux sensor to a reception device that diagnoses an abnormality of the bearing.
The bearing device according to any one of claims 1 to 10, further comprising an abnormality diagnosis unit that diagnoses an abnormality of the bearing based on output information of the heat flux sensor.
It comprises another sensor arranged separately from the heat flux sensor,
Output information of the heat flux sensor and output information of the other sensor are transmitted to the abnormality diagnosis unit,
The bearing device according to claim 11, wherein the abnormality diagnosis unit diagnoses an abnormality of the bearing based on output information of the heat flux sensor, output information of the other sensor, and information of a rotation speed of the rotating body. ..
A bearing device according to any one of claims 1 to 12,
A spindle device, comprising: a motor that rotates the rotating body.