JP2016153670A - Lubricant supply unit and bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubricant supply unit capable of detecting supply abnormality of lubricant.SOLUTION: A lubricant supply unit includes: a lubricant tank 30 holding lubricant; a pump 29 configured to supply lubricant from the lubricant tank 30 to the inside of a bearing; a power generation unit 25 configured to generate power for operating the pump 29; a power storage unit 86 charged by power generated by the power generation unit 25, and configured to supply power to the pump 29; a voltage detection unit (A/D converter 27d) configured to detect voltage of the power storage unit 86; and a data processing device 27a configured to determine that the power storage unit 86 is in an abnormal state when change of the detection value of the voltage detection unit does not show a preset charging characteristic.SELECTED DRAWING: Figure 4

Description

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

  The self-powered lubricating oil supply unit charges and stores the self-generated power inside the unit due to the temperature difference between the inner and outer rings of the bearing in the power storage device, and uses that power to supply the lubricating oil into the bearing at appropriate times from the lubricating oil tank. (Discharge). Such a self-powered lubricating oil supply unit does not need to supply electric power or lubricating oil from the outside, and therefore can use the bearing satisfactorily without maintenance for a long period of time.

  2. Description of the Related Art Conventionally, a rolling bearing device in which an oil supply unit is incorporated in a rolling bearing is known. The bearing device disclosed in Japanese Patent Application Laid-Open No. 2014-37879 (Patent Document 1) supplies lubricating oil to a bearing by operating a pump intermittently from a lubricating oil tank disposed in a spacer adjacent to the bearing. It can be supplied stably for a long time.

JP 2014-37879 A

  In the apparatus disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 2014-37879, a power supply unit for driving the lubricating oil pump is generated by a power generation unit that generates power based on a temperature difference between the inner and outer rings of the rolling bearing, and the power of the power generation unit. And a power storage unit for storing power. The pump is driven when the voltage of the power storage unit reaches the drive voltage of the pump. As the power storage unit, a secondary battery, a capacitor, or the like can be used.

  However, if the power storage unit deteriorates and the power storage capacity decreases or disappears, the lubricating oil pump cannot be driven and the lubricating oil cannot be supplied into the bearing. Such a malfunction of the lubricating oil supply device due to the deterioration of the power storage unit cannot be confirmed from the outside of the bearing device. For this reason, even if a lubricant supply failure or the like occurs due to factors such as deterioration of the power storage unit, it is difficult to grasp the problem of such lubricant supply failure until an abnormality occurs in the operation of the bearing. For this reason, in order to operate the bearing device stably for a long period of time, it has been difficult to take measures such as detecting an abnormality of the bearing device at an early stage and performing maintenance.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a lubricating oil supply unit capable of detecting an abnormal supply of lubricating oil.

  In summary, the present invention is a lubricating oil supply unit, which generates a holding part for holding lubricating oil, a supplying part for supplying lubricating oil from the holding part to the inside of the bearing, and electric power for operating the supplying part. A power generation unit to be charged, a power storage unit that is charged with power generated by the power generation unit and supplies power to the supply unit, a voltage detection unit that detects the voltage of the power storage unit, and a change in the detection value of the voltage detection unit is set in advance And a determination unit that determines that the power storage unit is abnormal when the charging characteristic is not exhibited.

  Preferably, the lubricating oil supply unit further includes a storage unit that stores the voltage detected by the voltage detection unit. The determination unit starts intermittently, monitors the change in the detection value by reading the voltage stored in the storage unit and comparing it with the detection value detected by the voltage detection unit.

  Preferably, the lubricating oil supply unit further includes a transmission unit that transmits a signal indicating that the power storage unit is abnormal from the determination unit to the external unit. The external unit is provided at a position distant from the bearing and visible from the outside of the device in which the bearing is built.

  More preferably, the transmission unit transmits a signal to the external unit using infrared rays or radio waves.

  Preferably, the lubricating oil supply unit is located away from the bearing and the transmitter that transmits a signal indicating that the power storage unit is abnormal from the determination unit, and is visible from the outside of the device in which the bearing is incorporated. And an external unit provided at a different position. The external unit includes a reception unit that receives a signal from the transmission unit, and a display unit that displays information based on the signal received by the reception unit.

  Preferably, the lubricating oil supply unit is located away from the bearing and the transmitter that transmits a signal indicating that the power storage unit is abnormal from the determination unit, and is visible from the outside of the device in which the bearing is incorporated. And an external unit provided at a different position. The external unit receives a signal from the transmission unit, and transmits information based on the received signal to at least one of the relay base and the management room using a radio wave.

  In another aspect, the present invention is a bearing device including any one of the above lubricating oil supply units.

  According to the present invention, it is possible to detect at an early stage that an abnormality has occurred in the power supply system of the self-powered lubricant supply unit, and it is possible to detect and maintain an abnormality of the bearing device at an early stage. Become.

It is a cross-sectional schematic diagram which shows an example of the mechanical apparatus which concerns on this embodiment. It is a cross-sectional schematic diagram of the mechanical apparatus shown in FIG. It is a plane schematic diagram of the external unit 70 attached to the machine apparatus shown in FIG. It is a block diagram for demonstrating the structure of the electric circuit of the principal part of a lubricating oil supply unit. It is a block diagram for demonstrating the structure of the external unit in a lubricating oil supply unit. It is a schematic diagram which shows the whole lubricating oil supply unit 20 provided adjacent to the bearing apparatus. It is a cross-sectional schematic diagram in line segment VII-VII of FIG. It is a cross-sectional schematic diagram in line segment VIII-VIII of FIG. It is a cross-sectional schematic diagram in line segment IX-IX of FIG. It is an expansion schematic diagram of the area | region X of FIG. It is the figure which showed the electric current which flows into a pump from a pump drive circuit at the time of pump normal rotation. It is the figure which showed the electric current which flows into a pump from a pump drive circuit at the time of pump reverse rotation. It is the figure which showed the electric current which flows into a pump from a pump drive circuit at the time of the discharge by resistance. It is a basic wave form diagram for explaining change of voltage VC and supply timing of lubricating oil. It is a wave form diagram for demonstrating the change of the voltage VC when the rotational speed of a rotating shaft is low speed. It is a wave form chart for explaining change of voltage VC after rotation of a rotating shaft stops. It is a wave form diagram for demonstrating an example of the behavior of the voltage VC when abnormality has generate | occur | produced in the electrical storage part. It is a flowchart for demonstrating the basic control about charging / discharging of an electrical storage part, and a pump drive. It is a flowchart for demonstrating control about the detection of the charging / discharging abnormality of an electrical storage part.

  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.

<Configuration of mechanical device>
With reference to FIGS. 1-3, the structure of the spindle for machine tools which is an example of the mechanical apparatus to which the bearing apparatus which concerns on this embodiment is applied is demonstrated.

  FIG. 1 is a schematic cross-sectional view illustrating an example of a mechanical device according to the present embodiment. FIG. 2 is a schematic cross-sectional view of the mechanical device shown in FIG.

  With reference to FIGS. 1 and 2, a machine tool spindle 50 according to this embodiment includes a rotation shaft 51, a spindle housing 52 arranged to surround the rotation shaft 51, and an outer periphery of the spindle housing 52. It includes an outer peripheral housing 53 that is arranged, and a bearing device that rotatably holds the rotating shaft 51 with respect to the spindle housing 52.

  Two bearing devices are arranged on the outer periphery of the rotating shaft 51. The inner ring 14 and the inner ring spacer 34 of the bearing in the bearing device are fitted and fixed to the side surface of the rotating shaft 51. Further, the outer ring 13 of the bearing and the outer ring spacer 33 are fitted and fixed to the inner peripheral surface of the spindle housing 52. The bearing including the inner ring 14, the outer ring 13, and the rolling elements 15 that are balls disposed between the inner ring 14 and the outer ring 13 is an angular ball bearing.

  The lubricating oil supply unit 20 is disposed between the inner ring spacer 34 and the outer ring spacer 33 that are disposed adjacent to the bearing. In addition, between the two bearings (on the side opposite to the side where the lubricating oil supply unit is disposed), other spacers are fitted and fixed to the rotating shaft 51 and the spindle housing 52, and are connected to the inner ring 14 and the outer ring 13. It has been hit.

  As shown in FIG. 2, the lubricating oil supply unit 20 includes a power generation unit 25 arranged in a circumferential direction in an annular housing, a power supply circuit 26 including a power storage unit, a control circuit 27, and a drive circuit. 28, a pump 29, and a lubricating oil tank 30 that holds lubricating oil.

  A through hole that penetrates the housing main body 21 (see FIG. 7), the outer ring spacer 33, the spindle housing 52, and the outer peripheral housing 53 is formed in a region facing the control circuit 27 of the lubricating oil supply unit. A flat portion is provided on the surface of the outer peripheral housing 53 at the outer peripheral side end portion of the through hole, and a pedestal 57 is disposed on the flat portion. An output board 56 is disposed on the pedestal 57.

  The control circuit 27 of the lubricating oil supply unit 20 is connected to the light emitting element 54. The output substrate 56 is connected to the light receiving element 55. For example, the light emitting element 54 is mounted on the control board on which the control circuit 27 is formed, and the light receiving element 55 is mounted on the output board 56.

  The light emitting element 54 and the light receiving element 55 are disposed to face each other with the through hole interposed therebetween so that light emitted from the light emitting element 54 is received by the light receiving element 55 through the through hole. That is, the light emitting element 54 and the light receiving element 55 are arranged so that the optical axis of the light emitted from the light emitting element 54 passes through the through hole. The light transmitted and received between the light emitting element 54 and the light receiving element 55 may have an arbitrary wavelength, but is, for example, infrared light (infrared light). In other words, the light-emitting element 54 is provided so that, for example, infrared light is used as a carrier wave and light on which a signal wave including data related to the supply state of lubricating oil, which will be described later, is superimposed can be emitted toward the light-receiving element 55. As the light emitting element 54, for example, an infrared light emitting diode is used. As the light receiving element 55, for example, a photodiode is used.

  Since the light emitting element 54 functions as a transmission unit that transmits a signal from the control circuit 27 to the external unit 70, the light emitting element 54 is described as the transmission unit 54 in the block diagrams of FIGS. Since the light receiving element 55 functions as a receiving unit that receives a signal from the transmitting unit, it is described as the receiving unit 55 in the block diagrams of FIGS. The transmission unit 54 and the reception unit 55 are not limited to infrared light, and may use other light, or may use radio waves.

  FIG. 3 is a schematic plan view of the external unit 70 attached to the machine apparatus shown in FIG. With reference to FIGS. 2 and 3, the cover member 58 is fixed to the pedestal 57 so as to cover the output board 56 disposed on the pedestal 57. On the output board 56, a battery 60 as a power source for driving the circuit of the output board 56 and a storage unit 59 are arranged. As the battery 60, for example, a coin battery or a button battery can be used. Although it is desirable to use a lithium ion battery as the battery 60, other batteries such as a nickel metal hydride battery may be used. A holder for fixing the battery 60 is disposed on the surface of the output substrate 56. As the storage unit 59, for example, a holding unit (slot) for connecting and fixing a card-type external storage medium and an external storage medium fixed to the holding unit in a removable manner can be used. As the external storage medium, any conventionally known storage medium such as a memory card can be used.

  The cover member 58 is formed with a U-shaped elongated hole (a hole in which the fixing bolt is disposed) so that the cover member 58 can be removed from the pedestal 57 simply by loosening the fixing bolt as a connecting member with the pedestal 57. Replacement of the battery 60 and the external storage medium can be performed with the cover member 58 removed from the pedestal 57.

  The output board 56 sealed by the pedestal 57 and the cover member 58 constitutes a main part of the external unit. The pedestal 57 and the cover member 58 can be added with an arbitrary waterproof structure in order to prevent intrusion of coolant or the like used during processing using the processing machine spindle. As the waterproof structure, for example, packing, O-ring, caulking, resin mold or the like can be used.

  In addition, it is preferable to use a transparent material for the cover member 58 so that the display content of the display part 71 mentioned later can be visually recognized.

  The configuration of the electric circuit of the lubricating oil supply unit installed on the above-described machine tool spindle 50 will be described below mainly with reference to FIGS.

  FIG. 4 is a block diagram for explaining the configuration of the electric circuit of the main part of the lubricating oil supply unit. FIG. 5 is a block diagram for explaining the configuration of the external unit in the lubricating oil supply unit.

  4 and 5, the lubricating oil supply unit includes a power generation unit 25, a power supply circuit 26, a control circuit 27, a pump drive circuit 28, a resistor 94, and a pump 29.

  The power generation unit 25 includes a heat transfer conversion element (Peltier element) that generates power by a temperature difference generated between the inner ring and the outer ring of the bearing. The power supply circuit 26 boosts the voltage of the power storage 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 voltage of the power storage unit 86. And a boost converter 85 that supplies the load to the load.

  Boost converter 82 boosts the voltage of power generation unit 25 to power supply voltage Vdd (eg, 2.2 V) of the data processing device, and outputs a charging voltage to power storage unit 86 separately from this. The charging voltage is, for example, 2.5V at the maximum. Boost converter 85 is ON / OFF controlled by an ON / OFF signal from data processing device 27a. Boost converter 85 boosts voltage VC and outputs drive voltage Vdrv of drive circuit 28 when ON. The drive voltage Vdrv is, for example, 3.0V.

  The control circuit 27 is a control unit for controlling the operation of the pump 29 via the drive circuit 28, and includes a program storage unit that stores a control program and an arithmetic unit that is connected to the program storage unit and executes the control program (Microcomputer). The control circuit 27 sets in advance the supply start timing of lubricant oil to the bearing 11 (FIG. 7), the supply timing (interval), the driving time of the pump 29 for supplying the lubricant, the supply amount of the lubricant, and the like. Can do. And the lubrication life of a bearing apparatus can be extended by maintaining the supply state of lubricating oil appropriately in this way.

  More specifically, the control circuit 27 includes a data processing device 27a and a comparator 27b. Data processing device 27a includes an A / D converter 27d for taking in voltage VC of power storage unit 86 as a digital value, and a memory 27c for storing various digital data such as voltage VC, a control program, and the like in a nonvolatile manner. The A / D converter 27d and the 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 (for example, 2.5V), it outputs an interrupt signal. When the data processing device 27a receives an interrupt signal from the comparator 27b, the data processing device 27a starts from the sleep state and discharges the electrical energy of the power storage unit 86 using the pump drive circuit 28 or the resistor 94. At this time, the data processing device 27a performs control so that the pump drive circuit 28 is driven after the discharge using the resistor 94 is performed a predetermined number of times to supply the lubricating oil into the bearing. By doing so, the lubricating oil is supplied at an appropriate time interval.

  The pump drive circuit 28 controls the forward drive terminals D +, D− and the reverse drive terminals R +, R− based on the positive / negative forward rotation ON / OFF signal and the positive / negative reverse rotation ON / OFF signal from the data processing device 27a. Details of the control of these terminals will be described later with reference to FIGS.

  In addition, the pump drive circuit 28 may be provided with arbitrary sensors (a bearing temperature sensor, a bearing rotation sensor, a lubricant remaining amount sensor, a lubricant temperature sensor, etc.), for example. Signals from these sensors may be input to a calculation unit (microcomputer) of the drive circuit 28, and the pump 29 may be automatically controlled in accordance with the temperature of the bearing 11 and its rotation state to adjust the supply amount of the lubricating oil.

  Referring to FIG. 5, the external unit 70 includes a calculation unit 56 a that receives a signal Sout regarding the voltage of the power storage unit 86 and the supply state of the lubricating oil from the transmission unit 54 on the control circuit 27 via the reception unit 55, and the calculation unit. A storage unit 59 that exchanges data with 56a, a display unit 71 that is visible from the outside, and a battery 60 that supplies a power supply voltage to the calculation unit 56a, the storage unit 59, and the display unit 71 are included.

  The storage unit 59 stores data relating to the voltage of the power storage unit 86 and the supply state of the lubricating oil transmitted from the control circuit 27. Examples of the data include lubricating oil supply timing, lubricating oil supply interval, voltage (power storage voltage) data in the power storage unit 86, temperature around the inner ring or the outer ring, and the like.

  Any timing can be adopted as the timing at which this data is transmitted from the control circuit 27 to the external unit 70. For example, the storage unit of the control circuit 27 (independent of the memory 27c or the memory 27c included in the data processing device 27a) can be used. The data may be transferred from the control circuit 27 to the external unit 70 when the storage element provided in the control circuit 27 becomes full of data.

  The calculation unit 56a causes the display unit 71 to display information related to the voltage abnormality of the power storage unit 86 and the supply of lubricant indicated by the signal Sout. For example, as will be described later, when the voltage of the power storage unit 86 does not exhibit normal behavior, the calculation unit 56a displays a display indicating that an abnormality has occurred in the power generation unit 25 or the power supply circuit 26 on the display unit 71. Let

  In addition, the data stored in the storage unit 59 may be transmitted to a relay base or a computer in a management room using the wireless transmission unit 72. In this way, it is possible to check the state of the lubricating oil supply unit (power generation state, operation state of the pump 29, etc.) on the external computer.

<Details of configuration of bearing device and lubricating oil supply unit>
With reference to FIGS. 6-10, the detail of the bearing apparatus and lubricating oil supply unit which are used for the machine apparatus shown in the said FIG. 1 is demonstrated.

  FIG. 6 is a schematic view showing the entire lubricating oil supply unit 20 provided adjacent to the bearing device. FIG. 7 is a schematic cross-sectional view taken along line VII-VII in FIG. FIG. 8 is a schematic cross-sectional view taken along line VIII-VIII in FIG. FIG. 9 is a schematic sectional view taken along line IX-IX in FIG.

  With reference to FIGS. 7 and 8, the bearing device 10 includes a bearing 11 and a lubricating oil supply unit 20. Note that the bearing 11 and the lubricating oil supply unit 20 may be integrated as a bearing device.

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

  The bearing 11 includes, for example, an inner ring 14 which is a rotating raceway ring, a fixed outer ring 13, a plurality of rolling elements 15 interposed between the inner ring 14 and the outer ring 13, and a plurality of rolling elements 15. Is held at a constant interval, and a seal member disposed on the outer peripheral side of the retainer 16 is included. An angular ball bearing is illustrated in the present embodiment, but as the bearing 11, for example, a deep groove ball bearing or a cylindrical roller bearing can be used.

  The bearing 11 is filled with desired grease in advance. The seal member is disposed at the end opposite to the side where the outer ring spacer 33 or the like is disposed.

  The inner ring spacer 34 and the outer ring spacer 33 constitute a spacer, and the inner ring spacer 34 abuts against one end face of the inner ring 14. The outer ring spacer 33 is abutted against one end face of the outer ring 13.

  As shown in FIG. 6, the lubricating oil supply unit 20 includes a power generation unit 25, a power supply circuit 26, a control circuit 27, a drive circuit 28, a pump 29, a lubricating oil tank arranged in an annular housing in the circumferential direction. 30 is included. The lubricating oil tank 30 stores the same type of lubricating oil as the base oil of the grease sealed in the bearing 11. The power generation unit 25, the power supply circuit 26, the control circuit 27, the drive circuit 28, the pump 29, and the lubricating oil tank 30 are arranged in the circumferential direction in the housing body 21. The power generation unit 25 is connected to a power circuit 26, the power circuit 26 is connected to a control circuit 27, and the control circuit 27 is connected to a drive circuit 28. The drive circuit 28 is a circuit for operating a pump 29 such as a micropump. A suction tube 31 connected to the bag body of the lubricating oil tank 30 and a discharge tube 32 for supplying lubricating oil from the pump 29 to the inside of the bearing 11 are connected to the pump 29. A nozzle 37 is connected to the distal end of the discharge tube 32 (the end opposite to the base connected to the pump 29), as shown in FIG. The tip of the nozzle 37 extends to the inside of the bearing 11 (position adjacent to the rolling element 15, for example, between the bearing ring on the fixed side and the bearing ring on the rotating side of the bearing 11). Note that the inner diameter of the nozzle hole of the nozzle 37 is appropriately set according to the relationship between the surface tension resulting from the viscosity of the base oil and the discharge amount.

  As the power generation unit 25 of the lubricating oil supply unit 20, for example, a unit that generates power by the Seebeck effect can be used. Specifically, as illustrated in FIG. 6, the power generation unit 25 includes a heat conductor 23 a connected to the outer ring spacer 33, a heat conductor 23 b disposed to face the inner ring spacer 34, and heat conduction. The thermoelectric element 24 (element utilizing the Seebeck effect of the Peltier element) is disposed 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. 6, the temperature of the inner ring 14 and the outer ring 13 rises due to frictional heat with the rolling elements 15 (see FIG. 7). Normally, the outer ring 13 is dissipated by heat conduction because it is incorporated in the housing of the device. 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 each heat conductor 23a, 23b.

  The heat conductors 23a and 23b are disposed so as to penetrate the inner peripheral surface and the outer peripheral surface of the housing body 21, respectively. Therefore, a thermoelectric element disposed 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 between both end faces of 24. For this reason, the thermoelectric element 24 can generate electric power by the Seebeck effect.

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

  The electric charge generated (generated) by the power generation unit 25 is stored in the power supply circuit 26. Specifically, the electric charge is stored in a power storage unit 86 such as a storage battery or a capacitor included in the power supply circuit 26 shown in FIG. As a capacitor, it is preferable to use an electric double layer capacitor (capacitor).

  The pump 29 is controlled by the control circuit 27 via the drive circuit 28. The pump 29 sucks the lubricating oil in the lubricating oil tank 30 from the suction tube 31 and supplies the sucked lubricating oil to the inside of the bearing 11 through the discharge tube 32 and the nozzle 37.

  As shown in FIG. 7, the annular housing of the lubricating oil supply unit 20 has a U-shaped housing body 21 whose surface opposite to the bearing 11 is open, and the opening of the housing body 21 is closed. The lid body 22 is detachably attached to the housing body 21.

  The housing lid 22 may be fixed to the housing body 21 with screws 39 (see FIG. 9). 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 39 from the tap hole 35 to which the screw 39 is fixed. In this way, the lubricating oil can be replenished to the lubricating oil tank 30 housed in the housing body 21 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 ring of the bearing 11. A gap 36 is formed between the housing body 21 and the inner ring spacer 34.

  FIG. 10 is an enlarged schematic view of region X in FIG. The bag body of the lubricating oil tank 30 is provided with a suction tube 31 connected to the pump 29. When the bag body of the lubricating oil tank 30 is formed by heat welding, the suction tube 31 is sandwiched between the stacked resin sheets to form the bag body and heat-welded. In this way, the suction tube 31 can be integrated with the bag.

  The suction tube 31 provided in the bag body of the lubricating oil tank 30 may be detachably connected to the pump 29. By making the suction tube 31 detachable from the pump 29, when the remaining amount of lubricating oil in the lubricating oil tank 30 runs out, the suction tube 31 is removed from the pump 29 and lubricated from the suction tube 31 into the bag body. Oil can be replenished.

  Moreover, by making the bag body of the lubricating oil tank 30 removable with respect to the pump 29, 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 used lubricating oil tank 30 runs out, remove the used lubricating oil tank 30 bag and replace it with a spare bag (a bag filled with lubricating oil). By doing so, the lubricating oil supply unit 20 can be replenished in a short time.

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

<Operation of pump drive circuit>
FIG. 11 is a diagram showing the current flowing from the pump drive circuit to the pump during normal pump rotation. Referring to FIG. 11, when data processor 27a activates the + forward ON / OFF signal and the −forward ON / OFF signal, and deactivates the + reverse ON / OFF signal and the −reverse ON / OFF signal, A current flows through the drive terminals D + and D−, and a current does not flow through the drive terminals R + and R−. Therefore, a current I (D) indicated by an arrow in FIG. 11 flows.

  FIG. 12 is a diagram showing a current flowing from the pump drive circuit to the pump during reverse rotation of the pump. Referring to FIG. 12, when data processor 27a deactivates the + forward ON / OFF signal and the −forward ON / OFF signal, and activates the + reverse ON / OFF signal and the −reverse ON / OFF signal, The drive terminals D + and D− are in a state where no current flows, and the drive terminals R + and R− are in a state where current flows. For this reason, a current I (R) indicated by an arrow in FIG. 12 flows.

  FIG. 13 is a diagram showing a current flowing from the pump drive circuit to the pump during discharging by the resistor. When executing the discharge by the resistor 94, the data processing device 27a activates only the + forward ON / OFF signal, the −forward ON / OFF signal, the + reverse ON / OFF signal, and the −reverse ON / OFF signal. Is deactivated. Then, a current flows through the drive terminal D +, but no current flows through the drive terminals D−, R +, and R−. Then, the discharge current Ic of FIG.

  As described above with reference to FIGS. 11 to 13, normal rotation and reverse rotation of the pump 29 and discharge by the resistor 94 are executed.

<Lubricating oil supply unit supply operation and abnormality detection>
The lubricating oil supply unit described above improves the reliability and durability of the machine tool spindle 50 by periodically supplying lubricating oil to the bearing 11 (see FIG. 7).

  The driving timing of the pump 29 can be performed when the electric power generated in 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 certain voltage. is there. Furthermore, in order to extend the lubrication life of the bearing 11 filled with grease and to increase the time to maintenance, it is desirable to set the following intervals.

  FIG. 14 is a basic waveform diagram for explaining the change in voltage VC and the supply timing of the lubricating oil. In FIG. 14, the vertical axis indicates the voltage of the power storage unit, the horizontal axis indicates 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 rotation of the rotating shaft is started, the power generation unit 25 in FIG. 4 starts power generation due to the temperature difference between the inner ring 14 and the outer ring 13 of the bearing 11, and the boost converter 82 supplies the power voltage Vdd to the data processing device 27a. Is output, and the power storage unit 86 is also charged. Voltage VC of power storage unit 86 increases as charging proceeds.

  When voltage VC of the power storage unit reaches voltage Vcmp (for example, 2.5 V) necessary for driving pump 29, pump 29 is driven by the electric power stored in the power storage unit at time t1.

  In addition, once the pump 29 is driven and a part of the discharge is performed, the discharge by the resistance is further performed and the voltage of the power storage unit 86 is lowered to a predetermined value, and then the charging operation is performed again. As a result, the voltage VC of the power storage unit 86 reaches the voltage Vcmp again. However, if the pump 29 is driven each time the voltage reaches the voltage Vcmp to supply the lubricating oil into the bearing, the supply amount may be too large. Therefore, after driving the pump 29 once, 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. 14, after the pump 29 is driven once (time t1), charging / discharging is repeated 6 times, and the pump 29 is driven at time t2 when the voltage Vcmp is reached the seventh time. You may manage the drive interval of the pump 29 so that a cycle may be repeated. In order to control in this way, the number N of discharges is stored in the control circuit 27, and N is increased every time discharge is performed, and control is performed so that the pump 29 is driven when N = 7. N = 7 is an example, and the time interval for driving the pump can be changed by appropriately changing the number of times.

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

  FIG. 15 is a waveform diagram for explaining a change in the voltage VC when the rotation speed of the rotation shaft is low. When the rotational speed is low, the frictional heat generated in the bearing is small. For this reason, the temperature difference which generate | occur | produces between the inner ring | wheel and outer ring | wheel of a bearing becomes small, and the electric power generation amount in the electric power generation part 25 is also small. For this reason, the voltage VC shown in FIG. 15 rises slowly compared with FIG.

  FIG. 16 is a waveform diagram for explaining a change in the voltage VC after the rotation of the rotating shaft is stopped. When the rotation of the rotating shaft stops, the temperature difference between the inner ring and the outer ring of the bearing gradually decreases. For this reason, the power generation unit 25 of FIG. 4 stops power generation, and the boost converter 82 also stops operating. For this reason, the voltage VC gradually decreases, and the power supply voltage Vdd also decreases from 2.2 V to 0 V in the middle.

  FIG. 17 is a waveform diagram for explaining an example of the behavior of the voltage VC when an abnormality has occurred in the power storage unit. Referring to FIGS. 4 and 17, voltage VC stored in power storage unit 86 temporarily decreases due to driving of lubricating oil supply pump 29 or discharging to resistor 94, but the power generated by power generation unit 25. Increases as a result of being charged and charged again. The power storage unit 86 is repeatedly charged and discharged while the rotation shaft is rotating, but the voltage VC does not increase when the power storage unit 86 is deteriorated or damaged over time. FIG. 17 shows an example in which the voltage VC is saturated at a voltage lower than Vcmp. In such a case, the output signal of the storage voltage monitoring comparator 27b of the power storage unit 86 is not output, and the lubricating oil supply pump 29 does not operate. If such a state is left undetected, the operation of the machine is continued in a state where the lubricating oil is not supplied into the bearing, leading to damage to the bearing.

  Therefore, in the present embodiment, the data processing device 27a is activated at a constant time interval by the timer interrupt separately from the interrupt signal output from the comparator 27b and measures the voltage VC. Then, the time TP1 at which the voltage VC is saturated and constant at less than Vcmp is measured, and if this time exceeds the specified time, it is determined that the power generation unit 25 or the power supply circuit 26 is abnormal, and the abnormality is displayed outside. Notify the management room of the abnormality.

  FIG. 18 is a flowchart for illustrating basic control for charging / discharging the power storage unit and driving the pump. The process of this flowchart is called from a predetermined main routine and executed. Referring to FIGS. 4 and 18, when the processing of this flowchart is started, in step S1, it is determined whether or not there is an interrupt signal from comparator 27b that is generated when voltage VC is 2.5 V or higher. If there is no interrupt signal in step S1, the data processing device 27a maintains the sleep state, and control is returned to the main routine in step S20.

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

  In step S3, the data processing device 27a reads the number N of discharges of the power storage unit 86 stored in the nonvolatile memory 27c. Subsequently, in step S4, the data processing device 27a determines whether or not the number of discharges N is less than a 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 number of ejections is read from the nonvolatile memory 27c. In step S <b> 6, the data processing device 27 a transmits the number of ejections and the remaining number of ejections to the external unit 70. In step S <b> 7, the data processing device 27 a discharges the electric charge of the power storage unit 86 by the resistor 94.

  Subsequently, in step S8, the data processing device 27a adds 1 to the number N of discharges, and writes the number N of discharges in the nonvolatile memory 27c in step S14.

  On the other hand, if the number of discharges N is greater than or equal to the specified value in step S4 (NO in S4), the process proceeds to step S9.

  In step S9, the data processing device 27a drives the pump drive circuit 28 to cause the pump 29 to discharge the lubricating oil. Subsequently, in step S10, the number of discharges of the lubricating oil is added once, and in step S11, the number of discharges is written in the nonvolatile memory 27c. Subsequently, after the discharge is completed to a predetermined voltage by the resistor 94 in step S12, the number of discharges is reset in step S13, and the reset number of discharges is written in the nonvolatile memory 27c in step S14.

  After the writing in step S14 is completed, the process proceeds to step S15. In step S15, the data processing device 27a shifts to the sleep state, and in step S16, the control is returned to the main routine.

  FIG. 19 is a flowchart for explaining the control for detecting the charging / discharging abnormality of the power storage unit. The processing of this flowchart is performed by a timer built in the data processing device 27a, in addition to the interrupt signal from the comparator 27b. It is activated by a timer interrupt that occurs at regular time intervals. Preferably, the timer interruption interval is set shorter than the charging / discharging interval of power storage unit 86 so that the change in voltage VC can be monitored in detail. This timer circuit operates even when the data processing device 27a is in the sleep state.

  Referring to FIGS. 4 and 19, when the process is started by a timer interruption in step S51, data processing device 27a wakes up in step S52. Subsequently, in step S53, the value of voltage VC of power storage unit 86 is read into data processing device 27a via A / D converter 27d.

  In step S54, the data processing device 27a reads the value of the voltage VC recorded in the past from the nonvolatile memory 27c and writes the value of the voltage VC measured this time. In step S55, the data processing device 27a determines whether or not the saturation state in which the voltage VC is less than the voltage Vcmp (for example, 2.5 V) has continued for a predetermined time.

  In step S55, it is determined whether or not the voltage VC is saturated by comparing the previous measurement value and the current measurement value. If the saturation state of the voltage VC has continued for a predetermined time (YES in S55). While the process proceeds to step S56, if the saturation state has not continued for a predetermined time (NO in S55), the process proceeds to step S57 without executing step S56.

  In step S56, the data processing device 27a outputs a signal Sout indicating an abnormality of the lubricating oil supply unit. In step S57, the data processing device 27a returns to the sleep state again.

  The signal Sout transmitted in step S56 can be transmitted from the unit to the outside of the spindle using infrared communication, radio wave communication, or the like. An external unit 70 that receives the above information is provided on the outer peripheral surface of the spindle, and is displayed on the liquid crystal screen of the display unit 71 or recorded on an external recording medium of the storage unit 59. Can be confirmed.

  In addition, information may be transmitted from the external unit 70 outside the spindle to the relay base or the management room by radio waves by the radio transmission unit 72. The type of radio wave is not specified.

The present invention can also be applied to various rotating machines other than the machine tool spindle.
Since the lubricating oil supply unit shown in the present embodiment can monitor the stored voltage VC of the power storage unit 86 and transmit deterioration and damage to the outside of the unit, the reliability of the lubricating oil supply unit is improved.

Finally, referring to FIG. 4 again, the present embodiment will be generally described.
The lubricating oil supply unit according to the present embodiment includes a lubricating oil tank 30 that holds lubricating oil, a pump 29 that supplies lubricating oil from the lubricating oil tank 30 to the inside of the bearing, and electric power for operating the pump 29. A power generation unit 25 to be generated, a power storage unit 86 that is charged with power generated by the power generation unit 25 and supplies power to the pump 29, and a voltage detection unit (A / D converter 27d) that detects the voltage of the power storage unit 86 And a data processing device 27a that determines that the power storage unit 86 is abnormal when the change in the detection value of the voltage detection unit does not indicate a preset charging characteristic.

  Preferably, the lubricating oil supply unit further includes a nonvolatile memory 27c that stores the voltage detected by the voltage detection unit. The data processing device 27a starts intermittently and monitors the change in the detected value by reading the voltage stored in the nonvolatile memory 27c and comparing it with the detected value detected by the voltage detecting unit.

  Preferably, the data processing device 27a determines that the preset charging characteristic is not exhibited when the detection value detected by the voltage detection unit is lower than the determination threshold value for a predetermined time or longer.

  Preferably, the lubricating oil supply unit further includes a transmission unit 54 that transmits a signal indicating that the power storage unit 86 is abnormal from the data processing device 27a to the external unit 70. The external unit 70 is provided at a position distant from the bearing and visible from the outside of the device in which the bearing is built.

  More preferably, the transmission unit 54 transmits a signal to the external unit 70 using infrared rays or radio waves.

  Preferably, the lubricating oil supply unit is a position separated from the bearing and the transmission unit 54 that transmits a signal indicating that the power storage unit 86 is abnormal from the data processing device 27a, and is a device that includes the bearing. And an external unit 70 provided at a position visible from the outside. The external unit 70 includes a receiving unit 55 that receives a signal from the transmitting unit 54 and a display unit 71 that displays information based on the signal received by the receiving unit 55.

  Preferably, the lubricating oil supply unit is a position separated from the bearing and the transmission unit 54 that transmits a signal indicating that the power storage unit 86 is abnormal from the data processing device 27a, and is a device that includes the bearing. And an external unit 70 provided at a position visible from the outside. The external unit 70 receives a signal from the transmission unit 54 and transmits information based on the received signal to at least one of the relay base and the management room using radio waves.

  Although the embodiment of the present invention has been described above, the above-described embodiment can be variously modified. The scope of the present invention is not limited to the above-described embodiment. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 11 Bearing, 13 Outer ring, 14 Inner ring, 15 Rolling element, 16 Cage, 20 Lubricating oil supply unit, 21 Housing body, 22 Lid body, 23a, 23b Thermal conductor, 24 Thermoelectric element, 25 Power generation part, 26 Power supply circuit, 27 Control circuit, 27a Data processing device, 27b Comparator, 27c Non-volatile memory, 27d Converter, 28 Pump drive circuit, 29 Lubricating oil supply pump, 30 Lubricating oil tank, 31 Tube, 32 Discharge tube, 33 Outer ring spacer, 34 Between inner ring Seat, 35 Tap hole, 36 Clearance, 37 Nozzle, 39 Screw, 50 Machine tool spindle, 51 Rotating shaft, 52 Spindle housing, 53 Outer housing, 54 Transmitter (light emitting element), 55 Receiver (light receiving element), 56 Output board, 56a calculation unit, 57 base, 58 cover member, 59 storage unit, 60 battery, 70 external unit, 71 display unit, 72 wireless transmission unit, 82, 85 boost converter, 86 power storage unit, 94 resistance.

Claims (8)

A holding part for holding lubricating oil;
A supply unit for supplying the lubricating oil from the holding unit to the inside of the bearing;
A power generation unit for generating electric power for operating the supply unit;
A power storage unit that is charged with power generated by the power generation unit and supplies power to the supply unit;
A voltage detection unit for detecting a voltage of the power storage unit;
A lubricating oil supply unit comprising: a determination unit that determines that the power storage unit is abnormal when a change in the detection value of the voltage detection unit does not indicate a preset charging characteristic. A storage unit for storing the voltage detected by the voltage detection unit;
The determination unit is activated intermittently, and monitors a change in the detection value by reading a voltage stored in the storage unit and comparing it with a detection value detected by the voltage detection unit. The lubricating oil supply unit described.   The lubricating oil supply unit according to claim 1, wherein the determination unit determines that the charging characteristic is not exhibited when a state where the detection value is lower than a determination threshold value continues for a predetermined time or longer. A transmission unit that transmits a signal indicating that the power storage unit is abnormal from the determination unit to an external unit;
The lubricating oil supply unit according to claim 1, wherein the external unit is provided at a position distant from the bearing and visible from the outside of a device in which the bearing is built.   The lubricating oil supply unit according to claim 4, wherein the transmission unit transmits the signal to the external unit using infrared rays or radio waves. A transmission unit that transmits a signal indicating that the power storage unit is abnormal from the determination unit;
An external unit provided at a position distant from the bearing and visible from the outside of the device in which the bearing is incorporated;
The external unit is
A receiver that receives the signal from the transmitter;
The lubricating oil supply unit according to claim 1, further comprising a display unit that displays information based on the signal received by the receiving unit. A transmission unit that transmits a signal indicating that the power storage unit is abnormal from the determination unit;
An external unit provided at a position distant from the bearing and visible from the outside of the device in which the bearing is incorporated;
The lubricating oil supply unit according to claim 1, wherein the external unit receives the signal from the transmission unit, and transmits information based on the received signal to at least one of a relay base and a management room using a radio wave. .   A bearing device comprising the lubricating oil supply unit according to claim 1.

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