JP6900166B2 - Lubricating oil supply unit and bearing device equipped with it - Google Patents

Description

The present invention relates to a lubricating oil supply unit, and more specifically to a lubricating oil supply unit that supplies lubricating oil to the inside of a bearing and a bearing device including the same.

The self-powered lubricating oil supply unit charges and stores the electric power self-generated inside the unit due to the temperature difference between the inner and outer rings of the bearing, and uses the electric power to supply the lubricating oil from the lubricating oil tank to the inside of the bearing in a timely manner. (Discharge). Since such a self-powered lubricating oil supply unit does not need to supply electric power or lubricating oil from the outside, the bearing can be used satisfactorily without maintenance for a long period of time.

A rolling bearing device in which a lubrication unit is incorporated inside a rolling bearing has been conventionally known. The bearing device disclosed in Japanese Patent Application Laid-Open No. 2014-37879 (Patent Document 1) applies lubricating oil to the bearing by intermittently operating a pump from a lubricating oil tank arranged in a spacer adjacent to the bearing. It is said that it can be stably supplied for a long period of time.

Japanese Unexamined Patent Publication No. 2014-37879

The self-powered lubrication unit is for long-term stable lubrication, and high reliability is required. The oil stored in the tank is pumped up and supplied to the bearings, but if the pump breaks down, oil cannot be supplied.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a lubricating oil supply unit with improved reliability.

In summary, the present invention is a lubricating oil supply unit, that is, a first holding portion that holds the lubricating oil, a first pump that supplies the lubricating oil from the first holding portion to the inside of the bearing, and lubrication from the first pump. It includes a second pump that supplies lubricating oil from the first holding portion to the inside of the bearing when oil is not supplied, and a power generation unit that generates electric power for operating the first pump and the second pump.

Preferably, the lubricating oil supply unit is provided in the first check valve provided in the first passage for supplying the lubricating oil from the first pump to the bearing and in the second passage for supplying the lubricating oil from the second pump to the bearing. It is further provided with a second check valve.

Preferably, the lubricating oil supply unit includes a second holding portion that holds the lubricating oil, a third pump that supplies the lubricating oil from the second holding portion to the inside of the bearing, and when the lubricating oil is not supplied from the third pump. A fourth pump for supplying lubricating oil from the second holding portion to the inside of the bearing, and a housing for accommodating the first holding portion, the second holding portion, the first to fourth pumps, and the power generating portion are further provided.

More preferably, the lubricating oil supply unit operates the second pump instead of the first pump when the first pump is abnormal, and replaces the second pump when the second pump is abnormal. A control unit for operating the 3rd pump and operating the 4th pump in place of the 3rd pump when the 3rd pump is abnormal is further provided.

Preferably, the lubricating oil supply unit further includes a control unit that operates the second pump in place of the first pump when the first pump is abnormal.

More preferably, the control unit receives a detection signal indicating the temperature of the bearing, and when the control signal for operating the first pump is transmitted to the first pump, the control unit of the first pump responds to the amount of change in temperature indicated by the detection signal. Determine if there is any abnormality.

More preferably, the lubricating oil supply unit further includes a first drive circuit for driving the first pump and a second drive circuit for driving the second pump. The control unit determines whether or not there is an abnormality in the first pump based on the detection signal indicating the operating status of the first drive circuit when the first control signal for operating the first pump is transmitted to the first drive circuit, and the first If it is determined that the pump is abnormal, a second control signal for operating the second pump is transmitted to the second drive circuit.

The present invention is, in other aspects, a bearing device comprising any of the above lubricating oil supply units.

According to the present invention, it is possible to realize a lubricating oil supply unit capable of continuing refueling even when a failure occurs in the pump.

It is a figure which shows the structure of the spindle for a machine tool which is an example of the mechanical apparatus to which the bearing apparatus which concerns on this embodiment is applied. It is a figure which shows the structure of the lubricating oil supply unit 20. It is sectional drawing in III-III of FIG. It is sectional drawing in IV-IV of FIG. It is a figure which shows an example of a pump. It is a block diagram for demonstrating the structure of the electric circuit of the main part of a lubricating oil supply unit. It is a basic waveform diagram for demonstrating the supply timing of lubricating oil. It is a waveform figure which showed the temperature change of a bearing at the time of a normal operation. It is a waveform figure which showed the temperature change of a bearing at the time of abnormal supply of lubricating oil. It is a flowchart for demonstrating control about charge / discharge of a power storage part and switching of a pump drive. It is a flowchart for demonstrating the pump switching process which a control device executes in Embodiment 2. It is a circuit block diagram which shows the structure of the lubricating oil supply unit 120 of Embodiment 3.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings below, the same or corresponding parts will be given the same reference number and the explanation will not be repeated.

[Embodiment 1]
FIG. 1 is a diagram showing a configuration of a spindle for a machine tool, which is an example of a mechanical device to which the bearing device according to the present embodiment is applied.

With reference to FIGS. 1 and 2, the machine spindle 50 according to the present embodiment has a rotating shaft 51, a spindle housing 52 arranged so as to surround the rotating shaft 51, and an outer periphery of the spindle housing 52. It includes an arranged outer peripheral housing 53 and a bearing device 10 that rotatably holds the rotating shaft 51 with respect to the spindle housing 52. The bearing device 10 includes a bearing 11, a lubricating oil supply unit 20, an outer ring spacer 33, and an inner ring spacer 34. The bearing 11 is an angular contact ball bearing, and includes an inner ring 14, an outer ring 13, and a rolling element 15 which is a ball arranged between the inner ring 14 and the outer ring 13.

Two bearings 11 are arranged on the outer circumference of the rotating shaft 51. The inner ring 14 and the inner ring spacer 34 of the bearing 11 are fitted and fixed to the side surface of the rotating shaft 51. Further, the outer ring 13 and the outer ring spacer 33 of the bearing 11 are fitted and fixed to the inner peripheral surface of the spindle housing 52.

A lubricating oil supply unit 20 is arranged between the inner ring spacer 34 and the outer ring spacer 33 arranged so as to be adjacent to the bearing 11. Further, between the two bearings 11 (the side opposite to the side where the lubricating oil supply unit is arranged), the other inner ring spacer 36 and the outer ring spacer 35 are fitted and fixed to the rotating shaft 51 and the spindle housing 52, respectively. At the same time, they are abutted against the inner ring 14 and the outer ring 13.

FIG. 2 is a diagram showing the configuration of the lubricating oil supply unit 20. FIG. 3 is a cross-sectional view taken along the line III-III of FIG. FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. As shown in FIG. 2, the lubricating oil supply unit 20 includes a power generation unit 25 arranged in an annular housing along the circumferential direction, a power supply circuit 26 including a power storage unit, a control device 27, and a drive circuit. It includes 28A, 28B, pumps 29A, 29B, and a lubricating oil tank 30 for holding lubricating oil.

With reference to FIGS. 3 and 4, the bearing device 10 includes a bearing 11 and a lubricating oil supply unit 20. As a bearing device, the bearing 11 and the lubricating oil supply unit 20 may be integrated.

The lubricating oil supply unit 20 is incorporated between the outer ring spacer 33 and the inner ring spacer 34, which are abutted against one end of the bearing 11 in the axial direction. The bearing device 10 is used by being incorporated between, for example, a rotating shaft and a housing of a mechanical device.

The bearing 11 includes, for example, an inner ring 14 which is a raceway ring on the rotating side, an outer ring 13 on the fixed side, a plurality of rolling elements 15 interposed between the inner ring 14 and the outer ring 13, and a plurality of rolling elements 15. Includes a cage 16 for holding the cage 16 at regular intervals, and a seal member 17 arranged on the outer peripheral side of the cage 16. An angular contact ball bearing is shown in the present embodiment, but as the bearing 11, for example, a deep groove ball bearing, a cylindrical roller bearing, or the like can also be used.

A predetermined amount of grease is previously sealed in the bearing 11. The seal member 17 is arranged at an end portion opposite to the side on which the outer ring spacer 33 or the like is arranged.

The inner ring spacer 34 and the outer ring spacer 33 form a spacer. The inner ring spacer 34 is abutted against one end surface of the inner ring 14. The outer ring spacer 33 is abutted against one end surface of the outer ring 13.

As shown in FIG. 2, the lubricating oil supply unit 20 includes a power generation unit 25, a power supply circuit 26, a control device 27, drive circuits 28A, 28B, and a pump 29A arranged in an annular housing body 21 in the circumferential direction. , 29B, including the lubricating oil tank 30. The lubricating oil tank 30 stores the same type of lubricating oil as the base oil of the grease sealed in the bearing 11. As will be shown later in FIG. 3, a lid 22 is attached to the housing body 21 by a screw 35. The power generation unit 25, the power supply circuit 26, the control device 27, the drive circuits 28A and 28B, the pumps 29A and 29B, and the lubricating oil tank 30 are arranged so as to be arranged in the circumferential direction inside the housing main body 21. The power generation unit 25 is connected to the power supply circuit 26, the power supply circuit 26 is connected to the control device 27, and the control device 27 is connected to the drive circuits 28A and 28B. The drive circuits 28A and 28B are circuits for operating pumps 29A and 29B such as a micropump. The pumps 29A and 29B are connected to suction tubes 31A and 31B connected to the bag body of the lubricating oil tank 30 and discharge tubes 32A and 32B for supplying lubricating oil from the pumps 29A and 29B to the inside of the bearing 11. Has been done. Check valves 80A and 80B are arranged in the middle of the discharge tubes 32A and 32B. As shown in FIG. 2, it is preferable to determine the positions of the pumps 29A and 29B so that the tips of the suction tubes 31A and 31B are located at the lowermost position. As a result, the oil accumulated in the lubricating oil tank 30 can be sucked to the end without waste.

A nozzle 37A is connected to the tip end portion of the discharge tube 32A (the end portion opposite to the root portion connected to the pump) as represented by FIG. 3 for the pump 29A. The tip of the nozzle 37A extends to the inside of the bearing 11 (a position adjacent to the rolling element 15, for example, between the raceway ring on the fixed side and the raceway ring on the rotation side of the bearing 11). The inner diameter of the nozzle hole of the nozzle 37A is appropriately set depending on the relationship between the surface tension caused by the viscosity of the base oil and the discharge amount. As for the pump 29B, the corresponding suction tube 31B, discharge tube 32B, check valve 80B, and nozzle 37B (not shown) are arranged in the same arrangement as in FIG.

As the power generation unit 25 of the lubricating oil supply unit 20, for example, one that generates power by the Seebeck effect can be used. Specifically, as shown in FIG. 2, the power generation unit 25 has a heat conductor 23a connected to the outer ring spacer 33, a heat conductor 23b arranged to face the inner ring spacer 34, and heat conduction. It has a thermoelectric element 24 (an element utilizing the Seebeck effect of the Pelche element) which is arranged so as to connect between the body 23a and the heat conductor 23b and is closely fixed to the heat conductors 23a and 23b.

Here, when a rolling bearing device is used as the bearing device 10 as shown in FIG. 2, the temperatures of the inner ring 14 and the outer ring 13 rise due to the frictional heat with the rolling element 15 (see FIG. 3). Normally, since the outer ring 13 is incorporated in the housing of the device, heat is dissipated by heat conduction. Therefore, a temperature difference occurs between the inner ring 14 and the outer ring 13 (the temperature of the inner ring 14 is higher than the temperature of the outer ring 13). The temperature is conducted to the heat conductors 23a and 23b.

The heat conductors 23a and 23b are arranged so as to penetrate the inner peripheral surface and the outer peripheral surface of the housing body 21, respectively. Therefore, a thermoelectric element arranged between the heat conductor 23a (heat sink) connected to the outer ring 13 via the outer ring spacer 33 and the heat conductor 23b located on the inner ring spacer 34 side (inner ring 14 side). A temperature difference occurs on both end faces of the 24. Therefore, the thermoelectric element 24 can generate electricity by the Seebeck effect.

By using such a power generation unit 25, it is not necessary to supply electric power to the lubricating oil supply unit from the outside, so that it is not necessary to attach an electric wire for supplying electric power to the machine tool spindle 50 from the outside.

The electric power generated by the power generation unit 25 is stored in the power supply circuit 26. Specifically, the electric power is stored in a storage battery, a capacitor, or the like included in the power supply circuit 26. As the capacitor, it is preferable to use an electric double layer capacitor (capacitor).

The pumps 29A and 29B are controlled by the control device 27 via the drive circuits 28A and 28B, respectively. The pumps 29A and 29B suck the lubricating oil in the lubricating oil tank 30 from the suction tubes 31A and 31B, and supply the sucked lubricating oil to the inside of the bearing 11 via the discharge tubes 32A and 32B and the nozzles 37A and 37B. When the pump 29A is normal, the pump 29A is used. If the pump 29A shows an abnormality, the pump 29B is used instead of the pump 29A. Therefore, for example, even if the pump 29A fails, the lubrication to the bearing 11 can be continued.

As shown in FIG. 3, the annular housing of the lubricating oil supply unit 20 closes the housing body 21 having a U-shaped cross section with the surface opposite to the bearing 11 open, and the opening of the housing body 21. It is composed of a lid 22 and a lid 22.

The lid 22 of the housing is fixed to the housing body 21 by screws 35. By fixing the lid body 22 to the housing body 21, the inside of the housing surrounded by the housing body 21 and the lid body 22 can be sealed. The lid 22 can be removed by removing the screw from the tap hole to which the screw 35 is fixed. In this way, the lubricating oil tank 30 housed in the housing main body 21 can be replenished with the lubricating oil without removing the entire lubricating oil supply unit 20 from the bearing device 10.

The outer peripheral surface of the housing body 21 is fixed to the inner peripheral surface of the outer ring spacer 33. The housing body 21 (that is, the lubricating oil supply unit 20) may be fixed to the stationary wheel of the bearing 11.

The bag body of the lubricating oil tank 30 is provided with suction tubes 31A and 31B connected to the pumps 29A and 29B. When the bag body of the lubricating oil tank 30 is formed by heat welding, the suction tubes 31A and 31B are sandwiched between resin sheets stacked to form the bag body and heat-welded. In this way, the suction tubes 31A and 31B can be integrated with the bag body.

The suction tubes 31A and 31B provided in the bag body of the lubricating oil tank 30 may be detachably connected to the pumps 29A and 29B, respectively. By making the suction tubes 31A and 31B removable with respect to the pumps 29A and 29B, when the remaining amount of lubricating oil in the lubricating oil tank 30 is exhausted, the suction tubes 31A and 31B are removed from the pumps 29A and 29B. Lubricating oil can be replenished in the bag from the suction tubes 31A and 31B.

Further, by making the bag body of the lubricating oil tank 30 removable with respect to the pumps 29A and 29B, a spare bag body filled with lubricating oil can be prepared and the bag body can be replaced. For example, when the lubricating oil in the lubricating oil tank 30 in use runs out, the bag body of the used lubricating oil tank 30 is removed and replaced with a spare bag body (a bag body filled with lubricating oil). By doing so, the lubricating oil in the lubricating oil supply unit 20 can be replenished in a short time.

The above bearing device is an inner ring rotation. Further, although the center of rotation is the horizontal axis, the vertical axis may be used.

FIG. 5 is a diagram showing an example of a pump. The pump is, for example, a rotary trochoidal pump. Each of the pumps 29A and 29B has an inner rotor 60 and an outer rotor 61 as rotating portions, and a case (not shown) as a fixing portion. A suction port 62 and a discharge port 63 are formed on the case. The suction port 62 and the discharge port 63 of the pump are connected to the suction tube 31A (31B) and the discharge tube 32A (32B), respectively. The inner rotor 60 and the outer rotor 61 can rotate in the direction R1.

The inner rotor 60 and the outer rotor 61 are in contact with each other at a plurality of points and are meshed with each other. Inside the pumps 29A and 29B, a plurality of spaces (for example, five spaces) are formed, which are divided by the contact portions of the inner rotor 60 and the outer rotor 61. When the inner rotor 60 rotates in the first direction R1, the outer rotor 61 rotates in the first direction R1 due to meshing with the inner rotor 60. When the inner rotor 60 and the outer rotor 61 rotate in the normal direction, the volumes of the plurality of spaces change.

The pump 29A (29B) uses the discharge tube 32A (32B) and the check valve 80A to discharge the lubricating oil sucked from the lubricating oil tank 30 by rotating the inner rotor 60 and the outer rotor 61 toward the first direction R1. (80B) and nozzles 37A (37B) are provided inside the bearing 11 so that the bearing 11 can be discharged. When the inner rotor 60 and the outer rotor 61 rotate toward the first direction R1, the pumps 29A and 29B apply a discharge pressure equal to or higher than the reference value (valve opening pressure) of the check valves 80A and 80B to the lubricating oil. can do. The discharge pressure when the pumps 29A and 29B are driven is, for example, 1 kPa or more and 2 kPa or less.

As shown in FIG. 5, when the volume of one space is the smallest, the distance between the inner rotor 60 and the outer rotor 61 in the space (micro gap S) is, for example, a foreign substance (lubrication that can be mixed in the lubricating oil). It can be smaller than the outer diameter of something other than oil, or lubricating oil with a viscosity equal to or higher than a predetermined value. The pumps 29A and 29B are controlled by the control device 27 via the drive circuits 28A and 28B. If the pump 29A does not move due to foreign matter in the lubricating oil, the control device 27 uses the pump 29B to supply the lubricating oil to the bearings.

FIG. 6 is a block diagram for explaining the configuration of the electric circuit of the main part of the lubricating oil supply unit.

With reference to FIG. 6, the lubricating oil supply unit includes a power generation unit 25, a power supply circuit 26, a control device 27, a temperature sensor 9, switches 91A, 91B, 92, pump drive circuits 28A, 28B, and resistors. It includes 94, a lubricating oil tank 30, suction tubes 31A and 31B, pumps 29A and 29B, check valves 80A and 80B, and discharge tubes 32A and 32B.

The power generation unit 25 generates power by the temperature difference generated between the inner ring and the outer ring of the bearing. The power supply circuit 26 boosts the voltage of the boost converter 82 that boosts the voltage of the power generation unit 25, the power storage unit 86 that stores the electric energy generated by the power generation unit 25 via the boost converter 82, and the power storage unit 86. Includes a boost converter 85 that supplies the load.

The control device 27 is a control unit for controlling the operation of the pumps 29A and 29B via the drive circuits 28A and 28B, and is connected to the program storage unit in which the control program is held and the program storage unit to control the control program. Includes an arithmetic unit (microcomputer) to execute. The control device 27 presets the supply start timing of the lubricating oil to the bearing 11 (FIG. 3), the supply timing (interval), the driving time of the pumps 29A and 29B for supplying the lubricating oil, the supply amount of the lubricating oil, and the like. can do. Then, by maintaining an appropriate supply state of the lubricating oil in this way, the lubricating life of the bearing device can be extended.

More specifically, the control device 27 includes a data processing device 27a and a comparator 27b. The data processing device 27a includes an A / D converter 27d for capturing the output of the temperature sensor 9 and the value of the voltage VC as data, and a non-volatile memory 27c for non-volatilely storing data related to the temperature change monitored by the temperature sensor 9. including. The A / D converter 27d and the non-volatile memory 27c may be built in the data processing device 27a or may be provided outside the data processing device 27a.

When the comparator 27b detects that the voltage VC has reached a predetermined voltage, it outputs an interrupt signal. When the data processing device 27a receives an interrupt signal from the comparator 27b, it starts from the sleep state and discharges the electric energy of the power storage unit 86 by using the pump drive circuits 28A and 28B or the resistor 94. At this time, the data processing device 27a controls the pump drive circuits 28A and 28B to be driven to supply the lubricating oil to the inside of the bearing after performing the discharge using the resistor 94 a predetermined number of times. By doing so, the lubricating oil is supplied at appropriate time intervals.

Switches 91A, 91B, 92 are provided so that any one of the pump drive circuits 28A and 28B and the resistor 94 can be energized.

After the data processing device 27a is started, the data processing device 27a receives at least one of the inner ring temperature Ti1, the inner ring side heat conductor temperature Ti2, and the outer ring side heat conductor temperature To from the temperature sensor 9, and these temperature changes cause the pump drive circuits 28A and 28B. Analyze whether or not it is synchronized with the timing of the lubricating oil supply used.

The pumps 29A and 29B are connected to suction tubes 31A and 31B connected to the bag body of the lubricating oil tank 30 and discharge tubes 32A and 32B for supplying lubricating oil from the pumps 29A and 29B to the inside of the bearing 11. Has been done. Check valves 80A and 80B are arranged in the middle of the discharge tubes 32A and 32B.

Nozzles 37A and 37B are connected to the tips of the discharge tubes 32A and 32B as shown in FIG. 3 as a representative of the pump 29A. The tips of the nozzles 37A and 37B extend to the inside of the bearing 11 and supply the base oil to the bearing 11.

The check valves 80A and 80B are provided in the middle of the discharge tubes 32A and 32B, respectively. In the check valves 80A and 80B, lubricating oil to which a discharge pressure equal to or higher than a reference value (valve opening pressure) is applied is circulated in the discharge tubes 32A and 32B toward the bearing 11 side. On the other hand, the check valves 80A and 80B block the circulation of the lubricating oil to which the discharge pressure less than the reference value is applied in the discharge tubes 32A and 32B. The check valves 80A and 80B may have any configuration. The reference values of the check valves 80A and 80B are equal to or less than the discharge pressure when the pumps 29A and 29B are driven. Further, the reference values of the check valves 80A and 80B are values that exceed the discharge pressure (for example, less than 1 kPa) of the lubricating oil of the pumps 29A and 29B when the pumps 29A and 29B are stopped. The reference values of the check valves 80A and 80B are, for example, 2 kPa or less, preferably 1 kPa or more.

<Supply operation of lubricating oil supply unit and abnormality detection>
The lubricating oil supply unit described above periodically supplies lubricating oil to the bearing 11 (see FIG. 3) to improve the reliability and durability of the machine tool spindle 50.

The timing of driving the pumps 29A and 29B may be performed when the electric power generated by the power generation unit 25 is stored in the power storage unit 86 (for example, a capacitor) in the power supply circuit 26 and the voltage of the power storage unit reaches a constant voltage. It is possible. Further, in order to prolong the lubrication life of the bearing 11 filled with grease and prolong the time until maintenance, it is desirable to set the following intervals.

FIG. 7 is a basic waveform diagram for explaining the supply timing of the lubricating oil. In FIG. 7, the vertical axis represents the voltage of the power storage unit, the horizontal axis represents time, and the time change (charging and discharging status) of the voltage VC of the power storage unit is shown as a waveform.

When the voltage of the power storage unit reaches (or becomes fully charged) the voltage V2 required to drive the pumps 29A and 29B, the pump 29A or the pump 29B is driven by the electric power stored in the power storage unit at time t1.

Further, as shown in FIG. 7, when the pump 29A or the pump 29B is once driven to perform a partial discharge and then further discharge is performed by a resistor and the voltage of the power storage unit 86 drops to the voltage V1, the battery is charged again. The operation is performed. As a result, the voltage VC of the power storage unit 86 reaches the voltage V2. However, if the pump 29A or the pump 29B is driven to supply the lubricating oil to the inside of the bearing each time the voltage reaches V2, the supply amount may be too large. Therefore, once the pump 29A or the pump 29B is driven, the electric charge of the power storage unit 86 is discharged a predetermined number of times by the resistor 94 of FIG.

Specifically, as shown in FIG. 7, after driving the pump 29A or the pump 29B once (time t1), charging and discharging are repeated 8 times, and when the 9th full charge is reached (voltage V2 is reached). The drive interval of the pump 29A or the pump 29B may be managed so as to repeat the cycle of driving the pump 29A or the pump 29B at the time t2). In order to control in this way, if the number of discharges N is stored in the control device 27, N is increased each time one discharge is performed, and control is performed so as to drive the pump 29A or the pump 29B when N = 9. Good.

In FIG. 7, the post-discharge voltage V1 when the pump is driven is lower than the post-discharge voltage V3 due to the resistor. Although it is set as such to make it easier to observe the timing of pump drive, the voltage V3 and the voltage V1 may be equal to each other. Since the data processing device 27a of FIG. 6 drives the pump by itself, the timing of the pump drive can be known without referring to the voltage VC.

The discharge time (amount) and interval (interval) of the lubricating oil can be determined in advance by programming in the data processing device 27a inside the lubricating oil supply unit.

When such basic control is executed, the temperature of the bearing is also monitored in this embodiment. When the temperature changes in synchronization with the drive timing of the pump, it is judged that the lubricating oil is actually discharged to the inside of the bearing, but if the temperature does not change, the lubricating oil is not supplied. to decide.

For example, for a spindle for a machine tool, a method of detecting abnormal heat generation of a bearing may be adopted by monitoring the temperature on the outer ring side of the bearing. When the lubrication performance inside the bearing deteriorates, heat generation due to rolling friction of the rolling element increases, and the temperature of the inner and outer rings becomes higher than in the normal state. Therefore, the temperature sensor 9 shown in FIG. 6 is often provided on the bearing.

The supply of lubricating oil can be detected by using the temperature sensor 9. If the amount of lubricating oil inside the bearing is greater than the amount that contributes to lubrication, the temperature of the inner and outer rings will be higher than when the amount of lubricating oil is appropriate due to the influence of stirring resistance due to the rotation of the rolling elements and cages. .. Immediately after the lubricating oil is discharged into the bearing, such a temperature rise is observed.

Therefore, in the present embodiment, the temperature rise on the outer ring (or inner ring) side immediately after the lubricating oil is discharged into the bearing is recorded together with the time information, and the temperature rise is compared with the pre-programmed discharge interval to compare the outer ring (or inner ring). The supply history of the lubricating oil can be confirmed based on the temperature rise on the side and the time information.

FIG. 8 is a waveform diagram showing a temperature change of the bearing in a normal state. FIG. 9 is a waveform diagram showing a temperature change of the bearing when the lubricating oil supply is abnormal. 8 and 9 show the inner ring temperature Ti1, the inner ring side heat conductor temperature Ti2, the outer ring side heat conductor temperature To, and the voltage VC of the power storage unit 86.

In FIG. 8, the temperatures Ti1, Ti2, and To rise in synchronization with the pump drive times t1A and t2A. Therefore, when such a waveform is observed, it can be seen that the lubricating oil is actually supplied to the inside of the bearing.

On the other hand, in FIG. 9, the temperature Ti1, Ti2, and To do not increase in synchronization with the pump drive times t1B and t2B. Therefore, when such a waveform is observed, it can be seen that the lubricating oil is not supplied to the inside of the bearing.

The control device 27 of FIG. 6 determines whether or not the pump has operated normally by observing the changes in the bearing temperature shown in FIGS. 8 and 9. The pump switching control based on this determination will be described below with reference to a flowchart.

FIG. 10 is a flowchart for explaining control regarding charging / discharging of the power storage unit and switching of pump drive. The processing of this flowchart is called and executed from a predetermined main routine. With reference to FIGS. 6 and 10, when the processing of this flowchart is started, it is determined in step S1 whether or not there is an interrupt signal from the comparator 27b that is generated when the voltage VC becomes 2.5 V or more. If there is no interrupt signal in step S1, the data processing device 27a remains in sleep state and control is returned to the main routine in step S26.

On the other hand, when the interrupt signal is input in step S1, the process proceeds to step S2, and the data processing device 27a wakes up.

Then, in step S3, the data processing device 27a reads out the number of discharges N of the power storage unit 86 stored in the non-volatile memory 27c. Subsequently, the data processing device 27a determines in step S4 whether or not the number of discharges N is less than the specified value.

If the number of discharges N is less than the specified value in step S4 (YES in S4), the process proceeds to step S5. In step S5, the data processing device 27a discharges the electric charge of the power storage unit 86 by the resistor 94. Then, in step S6, the data processing device 27a measures the bearing temperature (temperature T1) by the temperature sensor 9 and stores it in the non-volatile memory 27c. Then, 1 is added to the number of discharges N in step S7, and the number of discharges N is written to the non-volatile memory 27c in step S24.

On the other hand, if the number of discharges N is equal to or greater than the specified value in step S4 (NO in S4), the process proceeds to step S8.

The data processing device 27a drives the pump drive circuit 28A in step S8, and discharges the lubricating oil to the pump 29A in step S9. Then, in step S10, the data processing device 27a measures the bearing temperature (temperature T2) by the temperature sensor 9. Then, in step S11, the temperature T1 stored in the non-volatile memory 27c at the time of the previous process of step S6 is read out, and it is determined whether or not T2> T1. In addition, this judgment may be judged by the fact that T2-T1> a. Here, a may be a predetermined value in consideration of measurement error and the like.

As described in FIGS. 8 and 9, if T2 is higher than T1, the lubricating oil is normally supplied to the bearing, and if there is no difference between T2 and T1, the lubricating oil is not supplied to the bearing. It can be judged that it was.

If T2-T1> a is satisfied in step S11 (YES in S11), the process proceeds to step S12. In step S12, the number of times the lubricating oil is discharged is added once, and in step S13, discharge pump information such as the number of times of discharge is written to the non-volatile memory 27c. Subsequently, after the discharge to the voltage V1 is completed using the resistor 94 in step S14, the number of discharges is reset in step S15, and the reset number of discharges is written to the non-volatile memory 27c in step S24.

On the other hand, if T2-T1> a is not satisfied in step S11 (NO in S11), the process proceeds to step S16, and the data processing device 27a determines that an abnormality has occurred in the supply of lubricating oil from the pump 29A. Operate the pump 29B.

The data processing device 27a drives the pump drive circuit 28B in step S16, and discharges lubricating oil to the pump 29B in step S17. Then, in step S18, the data processing device 27a measures the bearing temperature (temperature T3) by the temperature sensor 9. Then, in step S19, the temperature T1 stored in the non-volatile memory 27c at the time of the previous process of step S6 is read out, and it is determined whether or not T3> T1. In addition, this judgment may be judged by the fact that T3-T1> a. Here, a may be a predetermined value in consideration of measurement error and the like.

As described in FIGS. 8 and 9, if T3 is higher than T1, the lubricating oil is normally supplied to the bearing, and if there is no difference between T3 and T1, the lubricating oil is not supplied to the bearing. It can be judged that it was.

If T3-T1> a is established in step S19 (YES in S19), the process proceeds to step S20. In step S20, the number of times the lubricating oil is discharged is added once, and in step S21, the discharge pump information such as the number of times of discharge is written in the non-volatile memory 27c. Subsequently, after the discharge to the voltage V1 is completed using the resistor 94 in step S22, the number of discharges is reset in step S23, and the reset number of discharges is written to the non-volatile memory 27c in step S24.

After the writing in step S24 is completed, the process proceeds to step S25. In step S25, the data processing device 27a goes to sleep, and in step S26, control is returned to the main routine.

If T3-T1> a is not satisfied in step S19, it is determined that an abnormality has occurred in the pump 29B, and the control ends in step S27. At this time, a signal for notifying the abnormality may be output to the outside.

Although the temperature change of the outer ring of the bearing is not shown in FIGS. 8 and 9, the temperature change of the outer ring of the bearing can be confirmed immediately after the lubricating oil is discharged as in the case of the inner ring and the heat conductor on the inner and outer ring sides. Therefore, the temperature of the outer ring may be observed to determine whether or not the lubricating oil is discharged.

In the processing of the flowchart of FIG. 10, the bearing temperature T1 immediately after discharging to the resistor 94 is recorded, and compared with the bearing temperatures T2 and T3 immediately after operating the pumps 29A and 29B, immediately after the pumps 29A and 29B are operated. When the bearing temperatures T2 and T3 are higher than T1, the function of the unit is normal, and when there is no difference between T1 and T2 and T3, it is judged to be abnormal. Although the example in which the temperature rises when the lubricating oil is discharged has been described, it is conceivable that the temperature will drop when the temperature of the supplied lubricating oil is low, such as when the lubricating oil is supplied from the outside. Therefore, even if the temperature change is not a temperature rise but a temperature drop, the same judgment can be made by observing whether or not the change is synchronized with the timing of pump operation. Further, if the temperature is constantly monitored and the timing of the temperature change and the timing of the pump operation do not have a predetermined relationship (not synchronized), it may be determined as an abnormality.

[Embodiment 2]
In the first embodiment, the temperature change of the bearing at the time of refueling was monitored to determine whether or not the pump operates normally. In the second embodiment, the pump drive signals output by the pump drive circuits 28A and 28B are detected by the voltage sensor, and it is determined whether or not the pump operates normally. Since the configurations of FIGS. 1 to 6 are common to the second embodiment, the description will not be repeated.

FIG. 11 is a flowchart for explaining the pump switching process executed by the control device in the second embodiment.

The processing of the flowchart of FIG. 11 differs from the processing executed in the first embodiment described with reference to FIG. 10 in the following points.

First, step S6 is deleted, and step S7 is executed after step S5. Further, instead of steps S10 and S11, the processes of steps S101 and S102 are executed. Further, instead of S18 and S19, the processes of steps S103 and S104 are executed. Since the processing of other parts is the same as the processing described with reference to FIG. 10, the description is not repeated here.

With reference to FIGS. 6 and 11, when the pump 29A was operated in step S8 and the lubricating oil was discharged in step S9, the control device 27 used the voltage sensor 40A in step S101. Then, the drive voltage V1 output by the pump drive circuit 28A to the pump 29A is measured. Subsequently, in step S102, the control device 27 determines whether or not the drive voltage V1 is larger than the threshold value Va. In step S102, if V1> Va, the process proceeds to step S12, while if V1> Va, the process proceeds to step S16.

When the pump 29B is operated instead of the pump 29A in steps S16 and S17, in step S103, the control device 27 uses the voltage sensor 40B to output the drive voltage V2 that the pump drive circuit 28B outputs to the pump 29B. To measure. Subsequently, in step S104, the control device 27 determines whether or not the drive voltage V2 is larger than the threshold value Va. In step S104, if V2> Va, the process proceeds to step S20, while if V2> Va, the process proceeds to step S27, and the process of this flowchart ends.

In this way, the pump may be switched by determining the operation / non-operation of the pump based on the observation result other than the temperature rise.

[Embodiment 3]
In the first and second embodiments, an example in which two pumps are provided in one lubricating oil tank has been described. However, it is conceivable that foreign matter is mixed into the oil inside the lubricating oil tank, and as a result, both pumps may not operate due to foreign matter being caught.

Therefore, in the third embodiment, an example in which one lubricating oil tank and two pumps are additionally provided will be described.

FIG. 12 is a circuit block diagram showing the configuration of the lubricating oil supply unit 120 according to the third embodiment. In addition to the configuration of the lubricating oil supply unit 20 shown in FIG. 6, the lubricating oil supply unit 120 has switches 91C and 91D, pump drive circuits 28C and 28D, a lubricating oil tank 130, pumps 29C and 29D, and a check valve. Includes valves 80C, 80D.

In such a configuration, the control device 27 energizes the pump drive circuit 28B when the pump 29A does not operate even when the pump drive circuit 28A is energized, and pumps when the pump 29B does not operate even when the pump drive circuit 28B is energized. When the drive circuit 28C is energized and the pump 29C does not operate even if the pump drive circuit 28C is energized, the pump drive circuit 28D is energized to operate the pump 29D.

By doing so, even if dirt or the like flows back into the lubricating oil tank 30 and the pumps 29A and 29B malfunction, the operation can be continued.

The operation of the pump may be determined by the change in the bearing temperature as shown in FIG. 10 or by the drive voltage of the pump drive circuit as shown in FIG.

Although an example of two tanks and four pumps has been described in the third embodiment, the control of FIGS. 10 and 11 can be easily extended for these switching controls.

[Summary of Embodiment]
Finally, the first to third embodiments will be summarized again with reference to the drawings.

With reference to FIG. 6, the lubricating oil supply unit 20 includes a lubricating oil tank 30 for holding the lubricating oil, a first pump 29A for supplying the lubricating oil from the lubricating oil tank 30 to the inside of the bearing 11, and a first pump 29A. A second pump 29B that supplies lubricating oil from the lubricating oil tank 30 to the inside of the bearing 11 when the lubricating oil is not supplied from, and a power generation unit 25 that generates electric power for operating the first pump 29A and the second pump 29B. And.

Preferably, the lubricating oil supply unit 20 further includes a control device 27 that operates the second pump 29B instead of the first pump 29A when the first pump 29A is abnormal.

With such a configuration, when one pump becomes inoperable, a substitute pump can be operated to continue the supply of lubricating oil.

Preferably, the lubricating oil supply unit 20 has a first check valve 80A provided in the first passage for supplying the lubricating oil from the first pump 29A to the bearing, and a second pump 29B for supplying the lubricating oil to the bearing. A second check valve 80B provided in the two passages is further provided.

With such a configuration, it is possible to prevent backflow of dirty lubricating oil from the bearing side to the pump or the lubricating oil tank, and after the first pump 29A fails, the second pump 29B also fails. You can prevent that.

As shown in FIGS. 8 to 10, more preferably, the control device 27 receives the detection signals Ti1, Ti2, To indicating the temperature of the bearing 11 and transmits the control signal for operating the first pump 29A to the first pump 29A. The presence or absence of an abnormality in the first pump 29A is determined according to the amount of change in temperature indicated by the detection signals Ti1, Ti2, and To when transmitted.

Further, as shown in FIG. 11, more preferably, the lubricating oil supply unit 20 further includes a first drive circuit 28A for driving the first pump 29A and a second drive circuit 28B for driving the second pump 29B. .. The control device 27 of the first pump 29A is based on a detection signal (voltage V1) indicating the operating status of the first drive circuit 28A when the first control signal for operating the first pump 29A is transmitted to the first drive circuit 28A. When it is determined whether or not there is an abnormality and it is determined that the first pump 29A is abnormal, a second control signal for operating the second pump 29B is transmitted to the second drive circuit 28B.

With reference to FIG. 12, preferably, the lubricating oil supply unit 120 includes a lubricating oil tank 130 for holding the lubricating oil, and a third pump 29C for supplying the lubricating oil from the lubricating oil tank 130 to the inside of the bearing 11. 3 The fourth pump that supplies the lubricating oil from the lubricating oil tank 130 to the inside of the bearing 11 when the lubricating oil is not supplied from the pump 29C, the lubricating oil tank 30, the lubricating oil tank 130, the first to fourth pumps, and power generation. A housing (housing body 21 and lid 22) for accommodating the portion 25 is further provided.

More preferably, the lubricating oil supply unit 120 operates the second pump 29B instead of the first pump 29A when the first pump 29A is abnormal, and when the second pump 29B is abnormal, the second pump 29B is operated. A control device 27 for operating the third pump 29C instead of the pump 29B and operating the fourth pump 29D instead of the third pump 29C when the third pump 29C is abnormal is further provided.

With such a configuration, it is possible to continue the supply of lubricating oil not only in the case of a simple pump failure but also in the case of a pump failure due to oil contamination of the lubricating oil tank. It becomes.

Although the embodiment of the present invention has been described above, it is possible to modify the above-described embodiment in various ways. Moreover, the scope of the present invention is not limited to the above-described embodiment. The scope of the present invention is indicated by the scope of claims and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

30,130 Lubricating oil tank, 29A, 29B, 29C, 29D pump, 9 Temperature sensor, 10 Bearing device, 11 Bearing, 13 Outer ring, 14 Inner ring, 15 Rolling element, 16 Cage, 20,120 Lubricating oil supply unit, 21 Housing body, 22 lids, 23a, 23b thermal conductors, 24 thermoelectric elements, 25 power generators, 26 power supply circuits, 27 controllers, 27a data processing equipment, 27b comparators, 27c non-volatile memory, 27d converters, 28A, 28B, 28C , 28D pump drive circuit, 31A, 31B suction tube, 32A, 32B discharge tube, 33,35 outer ring bearing, 34,36 inner ring bearing, 37A, 37B nozzle, 40A, 40B voltage sensor, 50 machine spindle, 51 Rotating shaft, 52 Spindle housing, 53 Outer housing, 60 Inner rotor, 61 Outer rotor, 62 Suction port, 63 Discharge port, 80, 80A, 80B, 80C, 80D Check valve, 82,85 Boost converter, 86 Power storage unit, 91A, 91B, 91C, 91D, 92 switches, 94 resistors.

Claims (6)

The first holding part that holds the lubricating oil and
A first pump that supplies lubricating oil to the inside of the bearing from the first holding portion,
A second pump that supplies lubricating oil to the inside of the bearing from the first holding portion when lubricating oil is not supplied from the first pump.
A power supply unit for supplying electric power to the first pump and the second pump is provided.
The power supply unit, seen including a thermoelectric element for generating the electric power by the temperature difference between the inner and outer rings of the bearing,
Presence or absence of abnormality in the first pump according to the amount of change in temperature indicated by the detection signal when a detection signal indicating the temperature of the bearing is received and a control signal for operating the first pump is transmitted to the first pump. A lubricating oil supply unit further comprising a control unit that operates the second pump in place of the first pump when the first pump is abnormal. The first holding portion, the first pump, the second pump, and the power supply portion are placed in a space between an inner ring spacer that abuts on the inner ring of the bearing and an outer ring spacer that abuts on the outer ring of the bearing. The lubricating oil supply unit according to claim 1, which is arranged. A second holding portion for holding the lubricating oil and
A third pump that supplies lubricating oil to the inside of the bearing from the second holding portion,
A fourth pump that supplies lubricating oil to the inside of the bearing from the second holding portion when lubricating oil is not supplied from the third pump.
The lubricating oil supply unit according to claim 1, further comprising the first holding portion, the second holding portion, the first to fourth pumps, and a housing for accommodating the power supply portion. When the first pump is abnormal, the control unit operates the second pump in place of the first pump, and when the second pump is abnormal, the control unit operates in place of the second pump. It activates the third pump, wherein when the third pump is abnormal, the third Ru in place of the pump is operated the fourth pump, the lubricating oil supply unit according to claim 3. The first drive circuit that drives the first pump and
A second drive circuit for driving the second pump is further provided.
When the control unit transmits the first control signal for operating the first pump to the first drive circuit, the control unit determines the presence or absence of an abnormality in the first pump based on the detection signal indicating the operating status of the first drive circuit. determination and, when said first pump is abnormal transmits a second control signal for operating the second pump to said second driving circuit, the lubricating oil supply unit of claim 1. A bearing device including the lubricating oil supply unit according to any one of claims 1 to 5.

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