WO2019159838A1

WO2019159838A1 - Bearing device and spindle device

Info

Publication number: WO2019159838A1
Application number: PCT/JP2019/004617
Authority: WO
Inventors: 勇介澁谷; 小池　孝誌; 靖之福島
Original assignee: Ntn株式会社
Priority date: 2018-02-13
Filing date: 2019-02-08
Publication date: 2019-08-22

Abstract

Provided is a bearing (1) including an inner ring (4), an outer ring (2), a rolling body (3), and a cage (5). Also provided is a bearing device provided with the bearings (1) and heat flux sensors (7) each disposed at the outer ring (2) to detect a heat flux. The bearing device has a structure for holding spacers between the bearings (1) and supports a rotating body. The spacers include an outer ring spacer (13) and an inner ring spacer (14). The heat flux sensor (7) is disposed on a nonrotating spacer among the inner ring spacer (14) and the outer ring spacer (13).

Description

Bearing device and spindle device

This 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), in order to prevent problems such as seizure of the bearing, a non-contact sensor that measures the temperature of a pump for supplying oil to the bearing portion and the lubrication portion ( An attachment having an infrared sensor is provided on the bearing end surface. When the time change of the temperature obtained from the temperature sensor exceeds the threshold value, the bearing is lubricated by the pump to prevent the temperature from rising.

JP 2017-26078 A Japanese Unexamined Patent Publication No. 2016-166832

In the bearing device described in Japanese Patent Application Laid-Open No. 2017-26078, a sign of abnormality occurring in the bearing is determined from the temperature. The non-contact temperature sensor (infrared sensor) provided in the attachment portion arranged next to the bearing is difficult to measure the temperature of the metal surface having a low infrared emissivity, and therefore uses a resin cage as a measurement object. . However, when the cage is not made of resin, it is difficult to measure the temperature with the structure disclosed in Japanese Patent Application Laid-Open No. 2017-26078. Further, the non-contact temperature sensor has a lower measurement accuracy than the contact-type temperature sensor, and thus may be erroneously detected although no abnormality has occurred. Furthermore, when used in an oil-lubricated environment, it is assumed to be affected by the lubricating oil. Lubricating oil becomes mist and enters between the object to be measured and the non-contact temperature sensor, making accurate temperature measurement difficult.

The present invention is for solving the above-described problems, and an object of the present invention is to provide a bearing device capable of detecting a temperature change of a bearing with high accuracy and speed, and a spindle device including the bearing device. That is.

Summarizing, the present invention is a bearing device that supports a rotating body with a single bearing or a structure of a plurality of bearings and a spacer, and the bearing includes an inner ring and an outer ring. The bearing device includes a heat flux sensor that is disposed on an inner ring, an outer ring, or a spacer and detects a heat flux.

Preferably, the spacer includes an outer ring spacer and an inner ring spacer. The heat flux sensor is disposed in the non-rotating side spacer of the inner ring spacer and the outer ring spacer.

Preferably, the spacer includes an outer ring spacer and an inner ring spacer. The heat flux sensor is disposed in the rotation side spacer of the inner ring spacer and the outer ring spacer.

More preferably, the spacer includes an outer ring spacer and an inner ring spacer. The outer ring spacer includes a main body part and a protruding part that protrudes from the side surface of the main body part toward the outer diameter surface of the inner ring. The heat flux sensor is fixed to the protruding portion so as to face the outer diameter surface of the inner ring.

Preferably, the heat flux sensor is disposed on a non-rotating raceway ring of the inner ring and the outer ring.
Preferably, the heat flux sensor is disposed on the rotating raceway of the inner ring and the outer ring.

More preferably, the heat flux sensor is disposed inside the bearing in the width direction at a portion other than the raceway surface of the outer ring surface of the inner ring or a portion other than the raceway surface of the inner ring surface of the outer ring.

Preferably, the bearing device further includes a transmitter that wirelessly transmits output information of the heat flux sensor to the outside. The transmission unit is configured to transmit the output information of the heat flux sensor to a reception device that performs bearing abnormality determination.

Preferably, the bearing device further includes a temperature sensor arranged separately from the heat flux sensor, and an abnormality diagnosis unit that diagnoses an abnormality of the bearing based on the output of the heat flux sensor, the output of the temperature sensor, and the rotation speed signal.

According to the present invention, it is possible to detect the temperature change of the bearing accurately and quickly without limiting the material used for the bearing.

It is a figure which shows the structure of the bearing apparatus of Embodiment 1. FIG. It is a figure which shows the structure around the main axis | shaft of the machine tool by which the bearing apparatus of this Embodiment is arrange | positioned. FIG. 5 is a diagram for explaining the characteristics of the heat flux sensor used in the first embodiment. FIG. 3A is a graph in which the vertical axis indicates the output of the heat flux sensor, and the horizontal axis indicates the passage of time before and after the occurrence of the abnormality. In FIG. 3B, the vertical axis represents the output of the temperature sensor, and the horizontal axis represents the time elapsed before and after the occurrence of the abnormality. It is a figure which shows the example of arrangement | positioning of the heat flux sensor seen from the axial direction. It is a figure which shows the example which provided the temperature sensor 22 in the outer ring | wheel 2 of the bearing. It is a flowchart for demonstrating the 1st example of the abnormality determination process which an abnormality diagnosis apparatus performs. It is a flowchart for demonstrating the 2nd example of the abnormality determination process which an abnormality diagnosis apparatus performs. It is a figure which shows the structure of the bearing apparatus of Embodiment 2. FIG. It is a figure which shows the modification which has arrange | positioned the heat flux sensor 7 in the position close | similar to the inner ring | wheel 4. It is a figure which shows the modification which added the temperature sensor to the spacer. It is a figure which shows the modification which added the non-contact-type temperature sensor to the spacer. FIG. 6 is a diagram illustrating a configuration of a bearing device according to a third embodiment. It is a figure which shows the structure which transmits / receives the output of a sensor wirelessly. FIG. 6 is a diagram illustrating a configuration of a bearing device according to a fourth embodiment. FIG. 10 is a diagram illustrating a configuration of a bearing device according to a fifth embodiment. FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. 15. FIG. 16 is a cross-sectional view taken along line XVII-XVII in FIG. FIG. 10 is a diagram showing a configuration of a modified example of the bearing device according to the fifth embodiment. FIG. 10 is a diagram showing a configuration of another modification of the bearing device according to the fifth embodiment. FIG. 10 is a diagram illustrating a configuration of a spindle device including a bearing device according to a fifth embodiment. It is a figure which shows an example of the control apparatus of the spindle apparatus shown by FIG. It is a figure which shows another example of the control apparatus of the spindle apparatus shown by FIG. It is a figure which shows the structure of a spindle apparatus provided with the control apparatus shown by FIG. It is a figure which shows another example of the control apparatus of the spindle apparatus shown by FIG. FIG. 10 is a diagram illustrating a configuration of a modified example of a spindle device including the bearing device according to the fifth embodiment.

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

[Embodiment 1]
FIG. 1 is a diagram illustrating a configuration of a bearing device 400 according to the first embodiment. The bearing device shown in FIG. 1 is a bearing device that supports a rotating body with a structure in which a spacer is sandwiched between a single bearing or a plurality of bearings. The bearing 1 includes an inner ring 4, an outer ring 2, a rolling element 3, and a cage 5. The bearing 1 is a rolling bearing, for example, an angular ball bearing. That is, the rolling element 3 is a ball, for example. The bearing device includes a bearing 1 and a heat flux sensor 7 that is disposed on the outer ring 2 and detects a heat flux. The bearing 1 shown in FIG. 1 has an inner ring 4 as a rotating wheel and an outer ring 2 as a non-rotating wheel. The heat flux sensor 7 is attached to the outer ring 2 that is a non-rotating wheel, and a signal is output to an abnormality diagnosis unit (not shown) through the wiring 30. More preferably, as shown in FIG. 1, the heat flux sensor 7 is disposed inside the bearing 1 in the width direction of the inner diameter surface 6 of the outer ring 2 other than the raceway surface 6 </ b> A that contacts the rolling element 3. The

FIG. 2 is a view showing the structure around the spindle of the machine tool on which the bearing device of the present embodiment is arranged. The main shaft 17 is directly connected to the rotation shaft of the drive motor 80. A bearing 1 is disposed at a boundary portion between the housing 18 and the main shaft 17. The main shaft 17 is rotatably supported by the four bearings 1. A spacer 40 is disposed between the bearings 1.

The housing 18 is provided with an inlet / outlet for air-cooled air (air oil or oil mist), and the heat generated in the bearing 1 between the main shaft 17 and the housing 18 rotating at high speed is cooled by the air flow indicated by the arrow.

In this embodiment, the heat flux sensor 7 is used to measure a change in bearing temperature during operation. As the heat flux sensor 7, for example, a heat flux sensor described in JP-A-2016-166832 (Patent Document 2) can be used. The output voltage of the heat flux sensor is generated from a slight temperature difference between the front and back of the sensor. The heat flux sensor 7 converts the heat flow into an electrical signal using the Seebeck effect.

FIGS. 3A and 3B are diagrams for explaining the characteristics of the heat flux sensor used in the first embodiment. 3A and 3B schematically show the difference between the output F1 of the heat flux sensor and the output T1 of a thermocouple generally used for temperature measurement. In the steady state, there is no significant difference between the slopes of the output F1 and the output T1, but when an abnormality occurs at time t1, a large change occurs in the slope of the graph of the output F1 of the heat flux sensor at time t1. The output T1 of the thermocouple changes at the time t2 delayed from the time t1, but the gradient of the output T1 does not change as much as the output F1 of the heat flux sensor.

Therefore, the heat flux sensor 7 can quickly detect the unsteady state immediately after the occurrence of the abnormality.

FIG. 4 is a diagram illustrating an arrangement example of the heat flux sensor as viewed from the axial direction. Here, an example is shown in which the heat flux sensors 7 are provided at equal intervals in the circumferential direction on the inner diameter surface 6 of the outer ring 2 of the outer ring 2. As shown in FIG. 4, the heat flux sensor 7 may be attached to one place on the circumference of the inner ring 4 or the outer ring 2, but the temperature distribution may be monitored by attaching the heat flux sensor 7 to a plurality of places at equal intervals. Therefore, it is possible to detect an abnormality more accurately and quickly.

1 includes an inner ring 4, an outer ring 2, a rolling element 3, and a cage 5, and constitutes a rolling bearing. A heat flux sensor 7 is affixed to the outer ring 2. In FIG. 1, a heat flux sensor 7 is affixed to the inner diameter surface 6 of the outer ring. The heat flux sensor 7 generates an output voltage based on a temperature difference between the temperature of the attached outer ring 2 and the temperature of the rotating atmosphere 8 generated by the rotation of the inner ring 4, the rolling element 3, the cage 5, and the like.

Generally, when the main shaft bearing of a machine tool is seized, a slight temperature difference occurs between the inner ring and the outer ring. By quickly grasping this temperature difference by the heat flux sensor 7, it becomes possible to detect the bearing 1 at an early stage before seizure occurs.

As shown in FIG. 3, when an abnormality does not occur, the output F1 of the heat flux sensor 7 changes to a constant output or a gradual change depending on the change in the rotational speed and the operating state. A temperature change occurs in such a part, a change in the heat flow is large, and a large change appears in the output F1 of the heat flux sensor 7. By utilizing the large change in the output of the heat flux sensor 7, it is possible to detect that an abnormality has occurred in the bearing 1.

At this time, the heat flux sensor 7 is attached so as to be close to the rotation side member. The heat flux sensor 7 generates an output voltage due to a temperature difference between the surface temperature of the non-rotating member and the rotating member. The amount of change in the output voltage of the heat flux sensor is monitored, and when a change deviating from the steady state (abnormal change) is observed, it is determined that an abnormality has occurred in the bearing.

For example, when the temperature rises due to an increase in the surface pressure between the rolling elements of the bearing and the raceway surface, the heat capacity of the housing and rotating shaft that holds the bearing is large, so the heat generated between the rolling element of the bearing and the raceway surface causes the housing and rotation Transmission to the shaft causes a delay until the temperature of the inner ring, outer ring, or spacer rises. When detecting the seizure precursor of a bearing by measuring the temperature of the inner ring, outer ring, spacer, etc., it is assumed that the precursor cannot be detected because there is a delay in temperature rise. If the sensor is used, it changes slowly when viewed in terms of temperature, but changes rapidly in the heat flow, so that rapid heat generation can be detected quickly.

In addition to the heat flux sensor 7, the presence or absence of seizure may be determined from the result of directly or indirectly measuring the temperature of the inner and outer rings of the bearing and the rotational speed information. FIG. 5 shows an example in which a temperature sensor 22 is provided on the outer ring 2 of the bearing. In the configuration shown in FIG. 5, the bearing device includes, in addition to the bearing 1 and the heat flux sensor 7, a temperature sensor 22 arranged separately from the heat flux sensor 7, an output of the heat flux sensor 7, and an output of the temperature sensor 22. And an abnormality diagnosis unit 100 for diagnosing a bearing abnormality based on the rotation speed signal.

FIG. 6 is a flowchart for explaining a first example of abnormality determination processing executed by the abnormality diagnosis apparatus. In step S1, abnormality diagnosis unit 100 monitors the output of the sensor. Examples of the sensor include a heat flux sensor 7, a temperature sensor 22, and a rotation speed detection sensor (not shown). Subsequently, in step S2, the abnormality diagnosis unit 100 compares a threshold provided corresponding to the output of each sensor with a value detected by the sensor, and determines whether or not the threshold has been exceeded. The threshold determination may be performed for each sensor output individually or may be performed for a combination of sensors. As an example of the combination, it may be determined that an abnormality has occurred when the rotation speed exceeds a predetermined rotation speed, the temperature exceeds a predetermined temperature, and the output of the heat flux sensor exceeds a predetermined threshold.

If the detected value is smaller than the threshold value in step S2, the sensor monitoring process in step S1 is repeated. On the other hand, when the detected value is larger than the threshold value in step S2, abnormality diagnosis unit 100 outputs an instruction signal for avoiding the abnormal operation so that the abnormality avoiding operation in step S3 is executed.

An example of the abnormal avoidance operation control executed by the machine tool in response to this instruction signal is as follows. For example, control to lower the rotation speed than the current control, control to reduce the cutting depth of the blade smaller than the present, control to supply the lubricant or increase the supply amount, stop processing (cutting is stopped and the spindle rotation speed is reduced or rotated) Stop). In addition, when determining the presence / absence of abnormality in one threshold determination S2, it is also assumed that erroneous determination is made with noise or the like, and in order to avoid erroneous determination, it is determined as abnormal when an abnormality is detected multiple times in succession, You may make it transfer to abnormality avoidance operation | movement S3.

FIG. 7 is a flowchart for explaining a second example of the abnormality determination process executed by the abnormality diagnosis apparatus. In step S11, the abnormality diagnosis unit 100 monitors the output of the sensor. Examples of the sensor include a heat flux sensor 7, a temperature sensor 22, and a rotation speed detection sensor (not shown). Subsequently, in step S12, the abnormality diagnosis unit 100 calculates the rate of change per unit time of the output of each sensor, and then determines whether the rate of change calculated in step S13 exceeds the determination value (change rate). Judgment).

The change rate determination may be performed individually for each sensor output, or may be performed for a combination of sensors. As an example of the combination, when the rotation speed is a predetermined rotation speed, it may be determined that an abnormality has occurred when the temperature exceeds the predetermined temperature and the increase rate of the output of the heat flux sensor exceeds the determination value. .

If the rate of change is smaller than the determination value in step S13, the sensor monitoring process in step S11 is repeated. On the other hand, when the detected value is larger than the threshold value in step S13, abnormality diagnosis unit 100 outputs an instruction signal for avoiding the abnormal operation so that the abnormality avoiding operation in step S14 is executed. Also in this case, in order to suppress erroneous determination due to noise or the like, an abnormality may be determined when an abnormality is detected a plurality of times in succession.

The example of the abnormality avoidance operation control executed by the machine tool in response to this instruction signal is the same as in the case of FIG.

In the bearing device of the first embodiment, the temperature of the inner ring or outer ring of the non-rotating side bearing is used as a reference temperature, and the heat flux generated by the difference between the temperature of the surface of the heat flux sensor and the reference temperature is detected by the heat flux sensor. Thus, it is possible to detect an abnormality (a sign of seizure or the like) occurring in the bearing from the change in electromotive force at an early stage. For this reason, it is possible to prevent the bearing from being damaged by reducing the operating speed of the machine tool.

Also, since the heat flux sensor is provided on the non-rotating side, the wiring for transmitting the sensor output to the outside becomes easy.

Furthermore, for example, when measuring the inner ring temperature (or inner ring spacer temperature) with a non-contact temperature sensor, it is desirable to subject the inner ring surface (or inner ring spacer surface) to a surface treatment so as to increase the infrared emissivity. With the abnormality detection device according to the embodiment, the material used for the bearing is not limited, and by using the heat flux sensor, it is not necessary to consider the emissivity of the measurement unit like a radiation thermometer.

Also, by using a heat flux sensor, it is possible to detect a minute change in heat flux, so that heat generation can be detected more quickly than a thermometer.

¡By attaching the heat flux sensor 7 to the outer ring inner diameter side as shown in FIG. 1, it is possible to measure near the heat generating part and improve the detection sensitivity and detection speed.

[Embodiment 2]
In the first embodiment, an example in which the heat flux sensor 7 is attached to the inner diameter surface 6 of the outer ring of the bearing has been described. In the second embodiment, an example in which the heat flux sensor 7 is provided in the spacer will be described. By providing the heat flux sensor 7 in the spacer, the standard bearing can be used. For this reason, it is easy to cope with replacement of the bearing due to deterioration over time.

The bearing device 401 supports the rotating body with a structure in which a spacer is sandwiched between two bearings. In this bearing device, a heat flux sensor is attached to the non-rotating side of the spacer (for example, the outer ring spacer).

FIG. 8 shows a state in which the heat flux sensor 7 is attached to the outer ring spacer 13 in an example in which a bearing device is incorporated in the main spindle 17 of the machine tool. That is, the bearing device 401 according to the second embodiment includes the bearing 1, the outer ring spacer 13, and the heat flux sensor 7 that is disposed in the outer ring spacer 13 and detects the heat flux generated from the bearing 1.

8, an inner ring spacer 14 and an outer ring spacer 13 are inserted between two rolling bearings 1. The main shaft 17 is inserted into the inner diameter portion 9 and the inner ring spacer inner diameter portion 16 of the inner ring 4, and the outer diameter portion 10 and the outer ring spacer outer diameter portion 15 of the outer ring 2 are inserted into the housing 18 to support the rotation of the main shaft 17. Yes. When the main shaft 17 rotates, the bearing 1 generates heat due to contact between the inner ring rolling element raceway surface 12 and the rolling element 3 and contact between the outer ring rolling element raceway surface 11 and the rolling element 3. At this time, the temperature of the inner ring 4 in which the main shaft 17 is inserted tends to be higher than that of the outer ring 2 inserted in the housing 18.

In the temperature rise accompanying the increase in the surface pressure between the rolling element 3 of the bearing 1 and the raceway surface 11, the heat capacity of the housing 18 and the main shaft 17 that holds the bearing 1 is large, and thus occurs between the rolling element 3 of the bearing 1 and the raceway surface 11. The transmitted heat is transmitted to the housing 18 and the main shaft 17, and a delay occurs until the temperature of the inner ring 4, the outer ring 2, or the

spacers

13 and 14 rises. For this reason, if the temperature of each component is measured by the temperature sensor and an attempt is made to determine a bearing abnormality, the detection of the precursor is delayed.

Therefore, the difference between the temperature of the rotating atmosphere 8 generated by the rotation of the inner ring 4, the rolling element 3, and the cage 5 and the temperature of the outer ring 2 is detected by the heat flux sensor 7, and a voltage output different from the steady operation state is detected. If it is, it is judged as abnormal. In addition, although the example which inserted the bearing apparatus in the machine tool main axis | shaft was shown as an example, the bearing apparatus of the same structure is applicable also in an industrial field or a motor vehicle field | area other than a machine tool main axis | shaft.

8, the heat flux sensor 7 is disposed at the center of the outer ring spacer 13, but the heat flux sensor 7 may be disposed at a position close to the inner ring 4. By doing so, the inner ring 4, the outer ring 2, and the rolling element 3, which are the heat generating parts, can be arranged close to the contact part, the inner ring rolling element raceway surface 12 and the outer ring rolling element raceway surface 11, and the heat flow can be detected quickly. it can.

FIG. 9 is a view showing a modified example in which the heat flux sensor 7 is arranged at a position close to the inner ring 4. As shown in FIG. 9, a protrusion 19 may be provided so that the end of the outer ring spacer 13 is close to the inner ring outer diameter surface 20, and the heat flux sensor 7 may be fixed to the inner diameter surface 21 of the protrusion 19.

The spacer includes an outer ring spacer 13 (main body part) and a protruding part 19 that protrudes from the side surface of the outer ring spacer 13 (main body part) toward the outer diameter surface of the inner ring 4. The heat flux sensor 7 is fixed to the protruding portion 19 so as to face the outer diameter surface of the inner ring 4. The outer ring spacer 13 is adjacent to the outer ring 2 in the axial direction of the bearing 1 and is spaced from the inner ring spacer 14 in the radial direction of the bearing 1.

In this case, since the heat flux sensor 7 directly faces the inner ring outer diameter surface 20, the accuracy of abnormality detection can be improved. In the example shown in FIG. 9, the heat flux sensor 7 is provided on the left and right protrusions 19, but may be provided on only one of the left and right protrusions 19.

When the heat flux sensor 7 is provided in the protrusion 19 projecting from the inner ring provided in the spacer, the heat flux sensor can be disposed in the vicinity of the heat generating portion, and the detection speed of the abnormality can be increased.

Further, the heat flux sensor 7 may be arranged near the bearing side surface 24. By doing so, the heat flux sensor can be provided even if there is no space for providing the heat flux sensor in the bearing or the spacer.

FIG. 10 is a diagram showing a modification in which a temperature sensor is added to the spacer. As shown in FIG. 10, a temperature sensor 22 may be provided in the outer ring spacer 13, and the temperature sensor 22 may be disposed in the vicinity where the outer ring spacer 13 and the outer ring 2 are in contact with each other.

FIG. 11 is a diagram showing a modification in which a non-contact temperature sensor is added to the spacer. As shown in FIG. 11, a non-contact temperature sensor 23 is provided in the outer ring spacer 13 and the temperature of the inner ring 4 is measured using a non-contact temperature sensor 23 (for example, an infrared temperature sensor), and the output of the heat flux sensor 7. Therefore, the abnormality diagnosis unit 100 may determine a sign of a bearing abnormality (such as seizure).

Also, it is possible to estimate the inner ring temperature from the temperature of the outer ring 2, the number of rotations of a rotating body such as a bearing, and the output of the heat flux sensor 7. The bearing load applied to the bearing portion can be estimated from the estimated inner ring temperature, outer ring temperature, and rotation speed.

The bearing load estimation method will be described below. In the case where the outer ring is inserted into the housing and the shaft is supported by the inner ring, for example, the temperature rises and expands when the inner ring rotates while receiving the preload. Therefore, the preload of the bearing rises from the initial set value. If this relationship is prepared by an arithmetic expression or the like, the preload can be estimated. Parameters used in the arithmetic expression are, for example, the rotational speed of the bearing, the outer ring temperature, the inner ring temperature, the heat flux sensor output, and the like.

Although the output of the heat flux sensor is not the temperature of the measurement object itself, it is possible to detect the change in the heat flow that occurs when the measurement object changes in temperature. It can be used as an alternative to detecting temperature with a thermocouple. For example, the preload load estimation method described in JP 2009-68533 A (paragraph 0008) can be used.

As described above, in the second embodiment, the heat flux sensor 7 is arranged in the spacer. As a result, it is possible to quickly detect a sign of occurrence of an abnormality in the bearing without performing special processing on the bearing itself. In addition, by installing a temperature sensor in the bearing, the temperature of the inner and outer rings of the bearing is estimated from the output of the heat flux sensor, the bearing rotation speed (support section rotation speed), and the temperature at the location where the heat flux sensor is attached. Not only the generation but also the load applied to the bearing device can be estimated.

[Embodiment 3]
In the first and second embodiments, when the outer ring or outer ring spacer is on the fixed side and the inner ring or inner ring spacer is on the rotation side, a heat flux sensor is arranged on the outer ring or outer ring spacer and the sensor is connected to the outside by wiring. The case of extracting the output of was explained. However, conversely, the outer ring or the outer ring spacer may be the rotating side, and the inner ring or the inner ring spacer may be the fixed side. In Embodiment 3, an example in which the inner ring is on the fixed side will be described.

FIG. 12 is a diagram illustrating a configuration of the bearing device 402 according to the third embodiment. The example shown in FIG. 12 shows a state where the rotating wheel is the outer ring 2 and the non-rotating wheel is the inner ring 4 and the heat flux sensor 7 is attached to the inner ring 4 that is a non-rotating wheel.

The heat flux sensor 7 is disposed inside the bearing 1 in the width direction on the outer diameter surface 106 of the inner ring 4 other than the raceway surface 106 </ b> A that contacts the rolling element 3.

As shown in FIG. 12, the heat flux sensor 7 is attached to the inner ring 4. In the bearing device having this configuration, the outer ring 2 is a rotating ring and the inner ring 4 is a non-rotating ring.

¡By attaching the heat flux sensor 7 on the inner ring outer diameter side as shown in FIG. 12, it is possible to measure near the heat generating part, and to improve detection sensitivity and detection speed.

Even if the relationship between the rotating wheel and the non-rotating wheel is opposite to that shown in FIG. 1, if the structure shown in FIG. 12 is applied, an abnormality occurring in the bearing is detected using the output from the heat flux sensor 7. It is possible. If the output information generated by the heat flux sensor 7 is transmitted to the outside by the wireless transmission device 200, the same diagnosis can be performed by the external abnormality diagnosis device. In addition, Preferably, you may further provide the electric power feeder which supplies electric power to this. As the power supply device, in addition to the battery, a power generation device that generates power by a temperature difference or vibration, an electromagnetic induction generator, or the like can be used.

FIG. 13 is a diagram illustrating a configuration in which sensor outputs are transmitted and received wirelessly. As illustrated in FIG. 13, the wireless transmission device 200 (FIG. 12) includes a signal processing unit 201 and a data transmission unit 202. The signal processing unit 201 receives the output of the heat flux sensor 7, removes noise components, performs analog-digital conversion processing, modulation processing, and the like, and outputs data for transmission to the data transmission unit 202. The data transmission unit 202 transmits data to the reception device 300 wirelessly.

The receiving device 300 is installed outside the machine tool. The receiving apparatus 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 after the signal processing unit 201, the amount of transmission data can be reduced and the power consumption can be reduced. Note that the determination process of abnormality determination unit 303 is the same as the process described with reference to FIGS. 6 and 7, and therefore description thereof will not be repeated.

The bearing device according to the third embodiment receives the output information of the heat flux sensor 7 wirelessly from the wireless transmitter 200 and receives the output information of the heat flux sensor 7 from the wireless transmitter 200 to determine the abnormality of the bearing. A receiving apparatus 300. Thereby, even when the inner ring is a fixed ring and the outer ring is a rotating ring, the detection result of the heat flux sensor can be output to the outside. For this reason, as in the first and second embodiments, a sign of a bearing abnormality can be quickly detected.

[Embodiment 4]
In the fourth embodiment, a case where the inner ring is a fixed ring as in the third embodiment will be described. However, in the fourth embodiment, a configuration in which the heat flux sensor is arranged in the inner ring spacer instead of the inner ring will be described.

FIG. 14 is a diagram illustrating a configuration of the bearing device 403 according to the fourth embodiment. The bearing device supports the rotating body with a structure in which a spacer is sandwiched between two bearings, and the inner ring is on the non-rotating side. In the example shown in FIG. 14, the heat flux sensor 7 is attached to the non-rotating side of the spacer (for example, the inner ring spacer 14).

That is, the bearing device according to the fourth embodiment is arranged in the inner ring spacer 14 and wirelessly transmits the output information of the heat flux sensor 7 to the outside, and the output of the heat flux sensor 7 from the wireless transmitter 200. It further includes a receiving device 300 (FIG. 13) that receives information and determines abnormality of the bearing 1.

In this bearing device, the outer ring 2 is a rotating ring and the inner ring 4 is a non-rotating ring. Even if the relationship between the rotating wheel and the non-rotating wheel is opposite to that shown in FIG. 8, if the structure shown in FIG. 14 is applied, an abnormality occurring in the bearing 1 can be detected using the output from the heat flux sensor 7. Is possible. If the output information generated by the heat flux sensor 7 is transmitted to the outside by the wireless transmission device 200, the same diagnosis can be performed by the external abnormality diagnosis device. In addition, Preferably, you may further provide the electric power feeder which supplies electric power to this. As the power supply device, in addition to the battery, a power generation device that generates power by a temperature difference or vibration, an electromagnetic induction generator, or the like can be used. Since wireless transmitting apparatus 200 has been described with reference to FIG. 13, description thereof will not be repeated.

In addition to the heat flux sensor 7, a temperature sensor 22 may be attached to the inner ring spacer 14 in order to measure the temperature in the vicinity of the inner ring.

According to the bearing device of the fourth embodiment, even when the inner ring is a fixed ring and the outer ring is a rotating ring, the detection result of the heat flux sensor can be output to the outside. Therefore, as in the first to third embodiments, it is possible to quickly detect a sign of a bearing abnormality. Further, since the bearing itself does not require special processing, the spacer and the heat flux sensor can be used as they are even if the bearing is replaced due to deterioration over time, as in the second embodiment.

[Embodiment 5]
The bearing device 404 according to the fifth embodiment has basically the same configuration as the bearing device 401 according to the second embodiment, and the outer ring 2 is configured as a fixed ring. However, the bearing device according to the fifth embodiment further includes a supply path for supplying the lubricating fluid to the bearing 1, and the arrangement of the heat flux sensor 7 in the circumferential direction of the bearing apparatus is limited based on the arrangement of the supply path. This is different from the bearing device according to the second embodiment. The lubricating fluid includes lubricating oil, and includes, for example, lubricating oil and air.

FIGS. 15 to 17 show a configuration example of the bearing device according to the fifth embodiment, in which the first bearing 1a and the second bearing 1b sandwich the outer ring spacer 13 and the inner ring spacer 14 in the axial direction. A first heat flux sensor 7a for detecting a heat flux generated from the first bearing 1a and a second heat flux sensor 7b for detecting a heat flux generated from the second bearing 1b. The bearing apparatus by which is arrange | positioned is shown. In FIG. 15, the inner ring spacer 14, the main shaft 17, the housing 18, and the outer cylinder 41 are not illustrated. 16 and 17, the main shaft 17 is not viewed in cross section. The first bearing 1a and the second bearing 1b are, for example, angular ball bearings. Although the combination of the 1st bearing 1a and the 2nd bearing 1b may be selected arbitrarily, it is a back surface combination, for example. The 1st bearing 1a and the 2nd bearing 1b have the mutually equivalent structure, for example.

As shown in FIGS. 15 to 17, in the bearing device according to the fifth embodiment, as a supply path, a first supply path 31a for supplying lubricating fluid to the internal space of the first bearing 1a, And a second supply path 31b for supplying a lubricating fluid to the internal space of the second bearing 1b. The first supply path 31a and the second supply path 31b are connected to a lubricating fluid supply apparatus (not shown) arranged outside the bearing device via an external supply path 34 arranged outside the bearing apparatus.

The first supply path 31 a has a first supply port 32 a disposed facing the internal space of the first bearing 1 a and a first inflow port 33 a connected to the external supply path 34. The first supply path 31a and the second supply path 31b are disposed, for example, inside the outer ring spacer 13. The first supply port 32a is disposed, for example, on the axial end surface 13a of the outer ring spacer 13. The first inflow port 33a is disposed, for example, on the outer diameter surface of the outer ring spacer 13. The second supply path 31 b has a second supply port 32 b disposed facing the internal space of the second bearing 1 b and a second inflow port 33 b connected to the external supply path 34. The 2nd supply port 32b is arrange | positioned at the end surface 13b of the said axial direction of the outer ring spacer 13, for example. The second inflow port 33b is disposed on the outer diameter surface of the outer ring spacer 13, for example. The end surface 13a and the end surface 13b in the axial direction of the outer ring spacer 13 have, for example, the same configuration.

The external supply path 34 is disposed, for example, inside the housing 18. The external supply path 34 includes a branch portion, a third outlet port 34a and a fourth outlet port 34b that are located downstream of the branch portion in the flow direction of the lubricating fluid, and an upstream side of the branch portion in the flow direction. It has the 3rd inflow port 34c located. The third outlet 34a is connected to the first inlet 33a. The fourth outlet 34b is connected to the second inlet 33b. The 3rd outflow port 34a and the 4th outflow port 34b are arrange | positioned at the internal-diameter surface of the housing 18 connected to the outer-diameter surface of the outer ring | wheel spacer 13, for example. The third inflow port 34c is connected to a lubricating fluid supply device via a pipe or the like (not shown). The third inflow port 34c is provided in the front lid 60 connected to, for example, the axial end surface of the housing 18.

As shown in FIGS. 15 to 17, the bearing device according to the fifth embodiment is provided with a discharge path for discharging the lubricating fluid in the internal space of each bearing 1. Specifically, in the bearing device according to the fifth embodiment, as the discharge path, the first discharge path 35a for discharging the lubricating fluid from the internal space of the first bearing 1a and the inside of the second bearing 1b are used. And a second discharge path 35b for supplying a lubricating fluid to the space. The first discharge passage 35a and the second discharge passage 35b are connected to a lubricating fluid discharge device (not shown) disposed outside the bearing device via an external discharge passage 38 disposed outside the bearing device.

The first discharge path 35a has a first discharge port 36a disposed facing the internal space of the first bearing 1a, and a fifth outlet 37a connected to the external discharge path 38. The first discharge path 35a is disposed, for example, between the outer ring 2a of the first bearing 1a and the outer ring spacer 13. In the outer ring spacer 13, a groove portion that is continuous with the end surface 13 a is formed on the connection surface that is in contact with the end surface of the outer ring 2 a in the axial direction. The first discharge path 35a is defined by, for example, the end surface of the outer ring 2a and the inner peripheral surface of the groove formed in the outer ring spacer 13.

The second discharge path 35b has a second discharge port 36b disposed facing the internal space of the second bearing 1b, and a sixth outlet 37b connected to the external discharge path 38. The second discharge path 35b is disposed, for example, between the outer ring 2b of the second bearing 1b and the outer ring spacer 13. In the outer ring spacer 13, a groove portion that is continuous with the end surface 13 b is formed on the connection surface that is in contact with the axial end surface of the outer ring 2 b. The second discharge path 35b is partitioned by, for example, the end surface of the outer ring 2b and the inner peripheral surface of the groove portion formed in the outer ring spacer 13.

As shown in FIG. 15, the first discharge port 36 a is disposed at a distance from the first supply port 32 a in the circumferential direction when the bearing device is viewed from the axial direction. When the bearing device is viewed from the axial direction, the center angle formed by the centers of the first supply port 32a and the first discharge port 36a with respect to the center axis of the bearing device is, for example, 180 degrees. The second discharge port 36b is disposed at a distance from the second supply port 32b in the circumferential direction when the bearing device is viewed from the axial direction. When the bearing device is viewed from the axial direction, the center angle formed by the centers of the second supply port 32b and the second discharge port 36b with respect to the central axis of the bearing device is, for example, 180 degrees.

A first supply path 31a, a first supply port 32a, an internal space of the first bearing 1a, a first discharge port 36a, and a first discharge path 35a are sequentially connected to the inside of the bearing device according to the fifth embodiment. A second flow path formed by sequentially connecting the first flow path, the second supply path 31b, the second supply port 32b, the internal space of the second bearing 1b, the second discharge port 36b, and the second discharge path 35b. A road is formed. The first channel and the second channel have, for example, the same configuration.

Since the internal space of the first bearing 1a is provided in an annular shape, a first branch path and a second branch path that connect between the first supply port 32a and the first discharge port 36a are provided in the internal space. Is formed. That is, the first flow path is branched and merged between the first supply port 32a and the first discharge port 36a.

Since the internal space of the second bearing 1b is provided in an annular shape, a third branch path and a fourth branch path that connect between the second supply port 32b and the second discharge port 36b are provided in the internal space. Is formed. That is, the second flow path is branched and merged between the second supply port 32b and the second discharge port 36b.

1st heat flux sensor 7a and 2nd heat flux sensor 7b are being fixed to the surface facing inner ring spacer 14 as a rotation side spacer in outer ring spacer 13 as a fixed side spacer, for example. The first heat flux sensor 7a and the second heat flux sensor 7b are arranged so as to detect the heat flux extending along the radial direction between the outer ring spacer 13 and the inner ring spacer 14. The first heat flux sensor 7a and the second heat flux sensor 7b may be fixed to the fixed side spacer by any method, but are fixed by, for example, adhesion or screw tightening. The relative positional relationship between the first heat flux sensor 7a and the first flow path is, for example, the same as the relative positional relationship between the second heat flux sensor 7b and the second flow path.

As shown in FIG. 15, the first heat flux sensor 7 a is disposed at a distance from the first supply port 32 a and the first discharge port 36 a in the circumferential direction when the bearing device is viewed from the axial direction. ing. The first heat flux sensor 7a is disposed between the first supply port 32a and the first discharge port 36a when the bearing device is viewed from the axial direction. That is, the first heat flux sensor 7a is disposed adjacent to the first branch path or the second branch path. Preferably, the first heat flux sensor 7a is disposed at the approximate center between the first supply port 32a and the first discharge port 36a in the circumferential direction when the bearing device is viewed from the axial direction. If it says from a different viewpoint, the 1st heat flux sensor 7a will be arrange | positioned adjacent to the area | region furthest from the 1st supply port 32a and the 1st discharge port 36a in the said 1st branch path or the said 2nd branch path. Is preferred. Preferably, the center angle formed by each center of the first heat flux sensor 7a and the first supply port 32a with respect to the center axis, and the center of each of the first heat flux sensor 7a and the first discharge port 36a are defined by the center axis. The central angle formed with respect to it is 80 degrees or more and 100 degrees or less.

The second heat flux sensor 7b is disposed at a distance from the second supply port 32b and the second discharge port 36b in the circumferential direction when the bearing device is viewed from the axial direction. The second heat flux sensor 7b is disposed between the second supply port 32b and the second discharge port 36b when the bearing device is viewed from the axial direction. That is, the second heat flux sensor 7b is disposed adjacent to the third branch path or the fourth branch path. Preferably, the second heat flux sensor 7b is disposed substantially at the center between the second supply port 32b and the second discharge port 36b in the circumferential direction when the bearing device is viewed from the axial direction. If it says from a different viewpoint, the 2nd heat flux sensor 7b will be arrange | positioned adjacent to the area | region furthest from the 2nd supply port 32b and the 2nd discharge port 36b in the said 3rd branch path or the said 4th branch path. Is preferred. Preferably, the center angle formed by the centers of the second heat flux sensor 7b and the second supply port 32b with respect to the center axis, and the centers of the second heat flux sensor 7b and the second discharge port 36b are set on the center axis. The central angle formed with respect to it is 80 degrees or more and 100 degrees or less.

As shown in FIG. 17, the first heat flux sensor 7a is disposed in an area adjacent to the inner ring 4a of the first bearing 1a on the inner diameter surface of the outer ring spacer 13. The second heat flux sensor 7 b is disposed in a region adjacent to the inner ring 4 b of the second bearing 1 b on the inner diameter surface of the outer ring spacer 13.

The first supply port 32a is disposed so as to overlap the second supply port 32b in the axial direction, for example. For example, the first discharge port 36a is disposed so as to overlap the second discharge port 36b in the axial direction. In this case, the first heat flux sensor 7a is disposed at a distance from the second supply port 32b and the second discharge port 36b in the circumferential direction when the bearing device is viewed from the axial direction. The second heat flux sensor 7b is disposed at a distance from the first supply port 32a and the first discharge port 36a in the circumferential direction when the bearing device is viewed from the axial direction. The first heat flux sensor 7a and the second heat flux sensor 7b are arranged, for example, so as to overlap in the axial direction. The first heat flux sensor 7a and the second heat flux sensor 7b are arranged between the first supply port 32a and the first discharge port 36a and the second supply port in the circumferential direction when the bearing device is viewed from the axial direction. It is disposed on the region R1 or the region R2 of the outer ring spacer 13 positioned between 32b and the second discharge port 36b.

In the bearing device according to the fifth embodiment, the first heat flux sensor 7a is spaced apart from the first supply port 32a and the first discharge port 36a in the circumferential direction when the bearing device is viewed from the axial direction. Has been placed. Although such a first heat flux sensor 7a is disposed in a region adjacent to the first bearing 1a in the axial direction, the flow rate of the lubricating fluid is relatively large in the first flow path and the second flow path. The first branch path and the second branch path may be arranged apart from the junction part, that is, the first supply port 32a and the first discharge port 36a and the region adjacent to the axial direction. Specifically, the first heat flux sensor 7a can be disposed adjacent to the first branch path in which the flow rate of the lubricating fluid is relatively small in the first flow path. Therefore, the first heat flux sensor 7a can detect a change in the heat flux generated from the first bearing 1a with high accuracy and high speed. This is due to the following reason.

The change in the heat flux generated in the bearing device is caused by a change in the balance of the heat generation and cooling operations in the bearing device and the heat dissipation action to the outside of the bearing device. In order for the first heat flux sensor 7a to detect the change of the heat flux accompanying the change of the heat generating action in the first bearing 1a with high accuracy and high speed, the first heat flux sensor 7a is used for the first bearing 1a. It is preferable to arrange it close. On the other hand, the closer to the first bearing 1a, the stronger the cooling action by the lubricating fluid flowing in the internal space of the first bearing 1a. Further, the region closer to the first supply port 32a or the first discharge port 36a where the flow rate of the lubricating fluid is relatively increased is more strongly subjected to the cooling action by the lubricating fluid. Therefore, for example, when the first heat flux sensor 7a is disposed near the first supply port 32a or the first discharge port 36a, the first heat flux sensor 7a changes the heat generation action in the first bearing 1a. There is concern that the accompanying change in heat flux cannot be detected with high accuracy and high speed.

On the other hand, the first heat flux sensor 7a, which is disposed at a distance in the circumferential direction from the first supply port 32a and the first discharge port 36a, is disposed away from the merging portion. Even if it is arranged near the bearing 1a, it is hardly affected by the cooling action by the lubricating fluid, and the change in the heat flux accompanying the change in the heat generation action can be detected with high accuracy and at high speed.

The second heat flux sensor 7b can also achieve the same effect as the first heat flux sensor 7a for the same reason as the first heat flux sensor 7a described above.

In addition, the 1st supply port 32a may be arrange | positioned so that it may not overlap with the 2nd supply port 32b in the said axial direction, for example. In this case, as long as the first heat flux sensor 7a is disposed at a distance in the circumferential direction from the first supply port 32a and the first discharge port 36a when the bearing device is viewed from the axial direction, You may arrange | position so that the 2nd supply port 32b may overlap with the said axial direction. For example, the first discharge port 36a may be arranged so as not to overlap the second discharge port 36b in the axial direction. In this case, as long as the first heat flux sensor 7a is disposed at a distance in the circumferential direction from the first supply port 32a and the first discharge port 36a when the bearing device is viewed from the axial direction, You may arrange | position so that the 2nd supply port 32b or the 2nd discharge port 36b may overlap with the said axial direction. As long as the second heat flux sensor 7b is arranged at a distance from the second supply port 32b and the second discharge port 36b in the circumferential direction when the bearing device is viewed from the axial direction, the first supply is performed. You may arrange | position so that the opening | mouth 32a or the 1st discharge port 36a may overlap with the said axial direction.

Further, the lubricating fluid discharge device may be configured integrally with the lubricating fluid supply device. The supply path and the discharge path may be configured as a part of a circulation path for circulating the lubricating fluid.

A preload is applied to the first bearing 1a and the second bearing 1b in the axial direction. The housing 18 protrudes inward with respect to the inner diameter surface that contacts the outer diameter surface of the outer ring 2a of the first bearing 1a, and has an end surface 18a that contacts the end surface in the axial direction of the outer ring 2a. The main shaft 17 protrudes outward with respect to the outer diameter surface in contact with the inner diameter surface of the inner ring 4b of the second bearing 1b, and has an end surface 17a in contact with the end surface in the axial direction of the inner ring 4b. The end surface 17a of the main shaft 17 and the end surface 18a of the housing 18 are provided so as to face each other. The outer ring 2a of the first bearing 1a, the outer ring spacer 13 and the outer ring 2b of the second bearing 1b are sandwiched between the end face 18a of the housing 18 and the front lid 60. The inner ring 4 a of the first bearing 1 a, the inner ring spacer 14, and the inner ring 4 b of the second bearing 1 b are sandwiched between the nut 61 and the end surface 17 a of the main shaft 17. The preload applied to the first bearing 1 a and the second bearing 1 b includes the axial width between the end surface 18 a and the front lid 60 and the axial width between the end surface 17 a and the nut 61. It is determined by the difference. The difference between the end face 17 a and the nut 61 in the axial direction varies depending on the tightening amount of the nut 61.

As shown in FIG. 18, the first supply path 31a of the bearing device according to the fifth embodiment has a plurality of (for example, three) first supply ports 32a for supplying lubricating oil to the internal space of one bearing. You may have. The plurality of first supply ports 32a are arranged at intervals in the circumferential direction, and are arranged at intervals from the first discharge ports 36a in the circumferential direction. For example, the plurality of first supply ports 32a are arranged at equal intervals in the circumferential direction, and the first discharge port 36a is arranged at the center between the two first supply ports 32a adjacent in the circumferential direction. ing. The 1st heat flux sensor 7a is arrange | positioned in the said circumferential direction between the 1st discharge ports 36a of another set different from the 1st set of 1st discharge ports 36a on both sides of the 1st discharge port 36a. Even in this case, the first heat flux sensor 7a is disposed at a distance from the plurality of first supply ports 32a and the first discharge ports 36a in the circumferential direction, so that the first heat flux sensor 7a is close to the first bearing 1a. Even if it is disposed, it is difficult to be influenced by the cooling action by the lubricating fluid, and the change in the heat flux accompanying the change in the heat generation action can be detected with high accuracy and at high speed. Note that the second supply path 31b may have the same configuration as the first supply path 31a.

As shown in FIG. 19, the heat flux sensor 7 of the bearing device according to the fifth embodiment is the same as the heat flux sensor 7 of the bearing device shown in FIG. 3 may be disposed in a portion other than the raceway surface 6A (see FIG. 1) that abuts the track 3. Such a heat flux sensor 7 is also disposed at a distance from the supply port 32 and the discharge port 36 in the circumferential direction when the bearing device is viewed from the axial direction. As a result, even when the heat flux sensor 7 is disposed near the bearing 1, the heat flux sensor 7 is not easily affected by the cooling action by the lubricating fluid, and can detect the change in the heat flux accompanying the change in the heat generation action with high accuracy and high speed. Can do.

In the first to fifth embodiments described above, the heat flux sensor is provided on the non-rotating side of the bearing or spacer, but the heat flux sensor may be provided on the rotating side.

Further, in Embodiments 1 to 5 described above, the surface for measuring the temperature of the rotating atmosphere facing the heat flux sensor 7 so that the lubricating oil adheres to the surface of the heat flux sensor 7 and the heat flow detection accuracy does not deteriorate. The oil repellent treatment may be applied.

A device to which the bearing device according to the first to fifth embodiments is applied is not particularly limited, but is, for example, a built-in motor type spindle device of a machine tool. FIG. 20 shows a spindle device 500 including a bearing device 404 according to the fifth embodiment. As shown in FIG. 20, the spindle device 500 mainly includes, for example, the bearing device according to the fifth embodiment, the main shaft 17, the housing 18, the motor 80, the bearing 84, and the outer cylinder 41. The main shaft 17 and the housing 18 have basically the same configuration as those shown in FIG. The main shaft 17 is rotatably supported by the bearing 1 and the bearing 84 of the bearing device. The axial direction of the bearing 84 is along the axial direction. The first bearing 1a, the second bearing 1b, and the bearing 84 are arranged so as to sandwich the motor 80 in the axial direction. The first bearing 1a and the second bearing 1b are, for example, angular ball bearings. The bearing 84 is, for example, a cylindrical roller bearing. The first bearing 1 a and the second bearing 1 b support a radial load and an axial load that act on the main shaft 17. The bearing 84 supports a radial load acting on the main shaft 17.

The housing 18 is fixed to the outer cylinder 41. The outer diameter surface of the housing 18 is in contact with the inner diameter surface of the outer cylinder 41. A stator 81 of the motor 80 is fixed to the outer cylinder 41. The outer diameter surface of the stator 81 is in contact with the inner diameter surface of the outer cylinder 41. The rotor 82 of the motor 80 is fixed to the main shaft 17. The rotor 82 is fixed to the main shaft 17 via a cylindrical member 83, for example. The cylindrical member 83 is provided in an annular shape, and the main shaft 17 is inserted inside the cylindrical member 83.

The outer ring of the bearing 84 is sandwiched between the positioning member 85 fixed to the cylindrical member 83 and the outer ring retainer 86 in the axial direction. The outer ring retainer 86 is fixed to the end member 87. The outer ring of the bearing 84 is disposed inside the end member 87 in the radial direction, and is provided so as to slide with respect to the outer ring retainer 86 and the end member 87 in accordance with the expansion and contraction of the main shaft 17 in the axial direction. Yes. The end member 87 is fixed to the outer cylinder 41.

The inner ring of the bearing 84 is sandwiched between the cylindrical member 83 and the inner ring retainer 88 in the axial direction. The cylindrical member 83, the inner ring of the bearing 84, and the inner ring retainer 88 are positioned in the axial direction by the main shaft 17 and the nut 89. The positioning member 85, the outer ring retainer 86, the end member 87, the inner ring retainer 88, and the nut 89 are provided in an annular shape, and the main shaft 17 is inserted through the inside thereof.

The spindle device is provided with a cooling unit for cooling the bearing device. The cooling unit is disposed outside the bearing device. The cooling unit includes a flow path through which a cooling medium flows, for example. For example, the flow passage is provided as a space defined by a spiral groove 18 b formed on the outer diameter surface of the housing 18 and an inner diameter surface of the outer cylinder 41. The cooling unit cools the bearing device by circulating a cooling medium in the groove 18b when the spindle device is in use. The first heat flux sensor 7a and the second heat flux sensor 7b are disposed closer to the first bearing 1a and the second bearing 1b than the cooling unit. The spindle device is provided with a motor cooling unit for cooling the motor 80, but is not shown here.

Since such a spindle device includes the bearing device, the first heat flux sensor 7a and the second heat flux sensor 7b are used for the first heat flux sensor 7b as compared with the spindle device in which the heat flux sensor is disposed outside the housing. It is possible to detect a change in heat flux generated from the bearing 1a and the second bearing 1b with high accuracy and high speed.

21, in the above spindle device, the control device 600 that controls the operation of the spindle device may diagnose an abnormality of the bearing 1 based on the output of the heat flux sensor 7. The control device 600 includes a determination unit 601. The determination unit 601 determines the output of the heat flux sensor 7, the rotational speed of the motor 80 of the spindle device, the machine information D1 such as the lubrication condition and the cooling condition, and the predetermined determination criteria for determining whether there is an abnormality in the bearing 1. Based on D2, the presence or absence of abnormality of the bearing 1 is determined. The abnormality of the bearing 1 is, for example, the occurrence of seizure of the bearing 1 or the fear thereof. In this case, the transmission unit of the bearing device is provided to transmit the output of the heat flux sensor 7 to the determination unit 601 of the control device 600. The control device 600 is provided so as to change at least one of the rotational speed of the motor 80, the lubrication condition, and the cooling condition based on the determination result by the determination unit 601. The determination unit 601 may determine whether there is an abnormality in the bearing 1 based on at least the output of the heat flux sensor 7 and a determination criterion D2 that is predetermined in order to determine whether there is an abnormality in the bearing 1. .

Also, the determination unit 601 can diagnose the abnormality of the bearing 1 based on the outputs of the heat flux sensor 7 and other sensors, similarly to the abnormality diagnosis unit. As shown in FIG. 22, the determination unit 601 diagnoses an abnormality of the bearing 1 based on outputs of the temperature sensor 602, the acceleration sensor 603, and the load sensor 604 in addition to the heat flux sensor 7, for example. The temperature sensor 602 is provided so as to detect an increase in the temperature of the outer ring spacer 13 due to, for example, poor lubrication of the first bearing 1a and the second bearing 1b. As shown in FIG. 23, for example, the temperature sensor 602 is disposed on each end face of the outer ring spacer 13 that faces each of the first bearing 1a and the second bearing 1b in the axial direction. The acceleration sensor 603 is provided so as to detect, for example, vibration of the main shaft 17 in at least one of the axial direction and the radial direction accompanying the separation of the raceway surfaces of the first bearing 1a and the second bearing 1b. . As shown in FIG. 23, the acceleration sensor 603 is arranged side by side with the temperature sensor 602, for example, on each end face of the outer ring spacer 13 facing each of the first bearing 1a and the second bearing 1b in the axial direction. Has been. The load sensor 604 is provided to detect a change in the axial preload applied to the first bearing 1a and the second bearing 1b, for example. As shown in FIG. 23, the load sensor 604 is disposed so as to connect, for example, the outer ring 2b of the second bearing 1b and the outer ring spacer 13 in the axial direction. The load sensor 604 is, for example, a thin film sensor, and the electric resistance changes with pressure.

Further, the determination unit 601 diagnoses the abnormality of the bearing 1 based on the rotation speed of the motor 80 in addition to the outputs of the heat flux sensor 7, the temperature sensor 602, the acceleration sensor 603, and the load sensor 604. It may be provided. The determination unit 601 may be provided so as to acquire the rotation speed of the motor 80 as a rotation sensor signal output from the motor 80. Further, as shown in FIG. 24, the determination unit 601 performs rotation measured by a magnetic ring (not shown) fixed to the inner ring spacer 14 and a rotation sensor (magnetic sensor) 605 fixed to the outer ring spacer 13. It may be provided so as to be acquired as a speed.

Also in the spindle device, the abnormality diagnosis unit can diagnose the abnormality of the bearing 1. The abnormality diagnosis unit may be disposed in the outer ring spacer 13, for example. Specifically, as shown in FIG. 25, the abnormality diagnosis unit may be mounted on a substrate 610 disposed on the outer diameter surface of the outer ring spacer 13. The distance between the abnormality diagnosing unit and the heat flux sensor 7 is such that the abnormality diagnosing unit is located outside the bearing device, in particular, between the abnormality diagnosing unit and the heat flux sensor 7 arranged outside the spindle device. Short compared to distance. Therefore, the abnormality diagnosis unit arranged in the outer ring spacer 13 has an output in which the influence of noise is reduced compared to the output signal of the heat flux sensor 7 acquired by the abnormality diagnosis unit arranged outside the bearing device. Based on the signal, the presence or absence of the abnormality can be determined.

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

1 bearing, 2 outer ring, 3 rolling element, 4 inner ring, 5 cage, 6,21 inner diameter surface, 6A, 11, 12, 106A raceway surface, 7 heat flux sensor, 8 rotating atmosphere, 9 inner diameter portion, 10 outer diameter portion , 13 Outer ring spacer, 14 Inner ring spacer, 15 Outer ring spacer outer diameter part, 16 Inner ring spacer inner diameter part, 17 Main shaft, 18 Housing, 19 Protruding part, 20 Inner ring outer diameter surface, 22 Temperature sensor, 23 Non-contact temperature Sensor, 30 wiring, 80 drive motor, 100 abnormality diagnosis unit, 106 outer diameter surface, 200 wireless transmission device, 201, 302 signal processing unit, 202 data transmission unit, 300 reception device, 301 data reception unit, 303 abnormality determination unit.

Claims

A bearing device that supports a rotating body with a structure of a single bearing or a plurality of bearings and a spacer,
The bearing includes an inner ring and an outer ring,
A bearing device provided with a heat flux sensor which is arranged in the inner ring, the outer ring, or the spacer and detects a heat flux.
The spacer includes an outer ring spacer and an inner ring spacer,
The bearing device according to claim 1, wherein the heat flux sensor is disposed in a non-rotating side spacer of the inner ring spacer and the outer ring spacer.
The outer ring spacer is the non-rotating side spacer;
The outer ring spacer is
A main body portion that is adjacent to the outer ring in the axial direction of the bearing and spaced from the inner ring spacer in the radial direction of the bearing;
A projecting portion projecting from the side surface of the main body portion toward the outer diameter surface of the inner ring,
The bearing device according to claim 2, wherein the heat flux sensor is fixed to the protrusion so as to face an outer diameter surface of the inner ring.
The outer ring spacer is the non-rotating side spacer;
The bearing device according to claim 2, wherein the heat flux sensor is fixed on an inner diameter surface of the outer ring spacer.
The spacer includes an outer ring spacer and an inner ring spacer,
The bearing device according to claim 1, wherein the heat flux sensor is disposed on a rotating side spacer of the inner ring spacer and the outer ring spacer.
The bearing device according to claim 1, wherein the heat flux sensor is disposed on a non-rotating raceway ring of the inner ring and the outer ring.
The bearing device according to claim 1, wherein the heat flux sensor is disposed on a rotating raceway of the inner ring and the outer ring.
The heat flux sensor according to claim 6 or 7, wherein the heat flux sensor is disposed in a portion other than the raceway surface of the outer diameter surface of the inner ring or a portion other than the raceway surface of the inner diameter surface of the outer ring, in the width direction of the bearing. The bearing device described.
A transmitter that wirelessly transmits output information of the heat flux sensor;
The bearing device according to claim 1, wherein the transmission unit is configured to transmit output information of the heat flux sensor to a receiving device that performs abnormality determination of the bearing.
The bearing device according to any one of claims 1 to 9, further comprising an abnormality diagnosis unit that diagnoses an abnormality of the bearing based on an output of the heat flux sensor.
A temperature sensor arranged separately from the heat flux sensor;
The output of the heat flux sensor and the output of the temperature sensor are transmitted to the abnormality diagnosis unit, and the abnormality diagnosis unit is configured to output the bearing of the bearing based on the output of the heat flux sensor, the output of the temperature sensor, and the rotation speed signal. The bearing device according to claim 10, which diagnoses an abnormality.
A supply path for supplying a lubricating fluid to an internal space of the bearing located between the inner ring and the outer ring;
The supply path has at least one supply port arranged facing the internal space,
The heat flux sensor is disposed at a distance from the at least one supply port in the circumferential direction of the bearing when the bearing device is viewed from the axial direction of the bearing. The bearing device according to claim 1.
The supply path has a plurality of supply ports arranged facing the internal space,
The plurality of supply ports are arranged at intervals in the circumferential direction,
The bearing according to claim 12, wherein the heat flux sensor is disposed at a center between two of the plurality of supply ports adjacent in the circumferential direction when the bearing device is viewed from the axial direction. apparatus.
A discharge passage for discharging a lubricating fluid from an internal space of the bearing located between the inner ring and the outer ring;
The discharge path has at least one discharge port arranged facing the internal space,
The at least one discharge port is disposed at a distance from the at least one supply port in the circumferential direction when the bearing device is viewed from the axial direction.
The bearing device according to claim 12 or 13, wherein the heat flux sensor is disposed at a distance from the at least one discharge port in the circumferential direction when the bearing device is viewed from the axial direction.
A bearing device according to any one of claims 1 to 14,
A spindle device comprising a housing for supporting the bearing device.