Bearing device and machine device

Abstract

To provide a bearing device and a machine device capable of efficiently consuming lubricant sealed in a tank while suppressing temperature rise of a bearing for high-speed rotation, without increasing the size of a facility.SOLUTION: A bearing device comprises a bearing and a lubricant supply unit that supplies lubricant to the bearing. The bearing includes an outer ring and an inner ring. The lubricant supply unit includes a holding part 30 that holds the lubricant to be supplied to the inside of the bearing, a Peltier element 24, and a power supply 26A that can supply power to the Peltier element 24. Driving the Peltier element 24 with the power supply 26 enables heat to be transferred from a first thermal conductor 23a to a second thermal conductor 23b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bearing device and a mechanical device. [Background technology]

[0002] Japanese Patent No. 6054095 (Patent Document 1) and Japanese Patent No. 6750296 (Patent Document 2) disclose bearing devices that combine rolling bearings with a lubricating oil supply unit (lubricating oil supply mechanism). In these documents, the lubricating oil is drawn from a tank attached to the lubricating oil supply unit. In these disclosed technologies, the tank is either a bag type, a casing type, or a type equipped with a porous body that retains the lubricating oil within the casing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6054095 [Patent Document 2] Patent No. 6750296 Summary of the Invention [Problem to be solved by the invention]

[0004] When a bearing rotates at high speeds, it generates a lot of heat. This can cause the lubricating oil film to break down or lead to an insufficient supply of lubricating oil to the desired locations within the bearing. Furthermore, if the bearing is operated for a long period of time while generating a large amount of heat, the bearing is more likely to be damaged. To solve the above problems, it is conceivable to use a high-output oil supply pump or a large lubricating oil tank. However, this would result in the bearing device becoming larger, which would make it unsuitable for use in small machines.

[0005] Bearing devices used in small machines have small oil pump discharge forces and small tank volumes. To use such devices for a long period of time, it is important to efficiently consume the lubricating oil sealed in the tank.

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a bearing device and a mechanical device that can efficiently consume lubricating oil sealed in a tank while suppressing temperature rise in a high-speed rotation bearing without increasing the size of the equipment. [Means for solving the problem]

[0007] A bearing device according to one embodiment of the present disclosure includes a bearing and a lubricant supply unit that supplies lubricant to the bearing. The bearing includes an outer ring and an inner ring. The outer ring has an outer ring rolling surface on its inner circumferential surface. The inner ring has an inner ring rolling surface on its outer circumferential surface and is disposed inside the outer ring so that the inner ring rolling surface faces the outer ring rolling surface. The lubricant supply unit includes a holding portion, a Peltier element, a first heat conductor, a second heat conductor, and a power source. The holding portion holds the lubricant to be supplied to the interior of the bearing. The first heat conductor and the second heat conductor sandwich the Peltier element. The power source is capable of supplying power to the Peltier element. Driving the Peltier element by the power source enables heat to be transferred from the first heat conductor to the second heat conductor.

[0008] A mechanical device according to one embodiment of the present disclosure includes a rotating shaft, a housing, and the bearing device. The housing is disposed on the outer periphery of the rotating shaft. The bearing device rotatably supports the rotating shaft relative to the housing. [Effects of the Invention]

[0009] According to the above, it is possible to provide a bearing device and a mechanical device that can efficiently consume the lubricating oil sealed in the tank while suppressing a rise in the temperature of the bearing even when rotating at high speeds, without increasing the size of the equipment. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic side view of a bearing device according to a first embodiment. [Figure 2] 2 is a schematic cross-sectional view of a portion taken along line II-II in FIG. 1 in the first embodiment. [Figure 3]FIG. 2 is a cross-sectional schematic diagram of the basic shape of a portion along line AA in FIG. 1. [Figure 4] 2 is a cross-sectional view of a first modified example taken along line AA in FIG. 1. FIG. [Figure 5] 1. FIG. 4 is a cross-sectional view of a second modified example taken along line AA in FIG. [Figure 6] FIG. 10 is a schematic side view of a bearing device according to a second embodiment. [Figure 7] 7 is a schematic perspective view showing an initial state of a first example of the lubricating oil tank shown in FIG. 6 in a simplified manner compared to FIG. 6. FIG. [Figure 8] FIG. 8 is a schematic cross-sectional view of a portion taken along line VIII-VIII in FIG. 7. [Figure 9] 8 is a schematic perspective view showing a state in which the bimetal is deformed compared to FIG. 7. FIG. [Figure 10] FIG. 10 is a schematic cross-sectional view of a portion taken along line XX in FIG. 9. [Figure 11] 7 is a schematic perspective view showing an initial state of a second example of the lubricating oil tank shown in FIG. 6 in a simplified manner compared to FIG. 6. FIG. [Figure 12] 12 is a schematic cross-sectional view of a portion taken along line XII-XII in FIG. 11. [Figure 13] 12 is a schematic perspective view showing a state in which the bimetal is deformed compared to FIG. 11. FIG. [Figure 14] 14 is a schematic cross-sectional view of a portion taken along line XIV-XIV in FIG. 13. [Figure 15] FIG. 10 is a schematic side view of a bearing device according to a third embodiment. [Figure 16] 8 is a schematic perspective view similar to FIG. 7 showing the initial state of the lubricating oil tank in the third embodiment. FIG. [Figure 17] 17 is a schematic perspective view showing a state in which the bimetal is deformed compared to FIG. 16. FIG. [Figure 18] FIG. 10 is a schematic side view of a bearing device according to a fourth embodiment. [Figure 19] FIG. 10 is a schematic side view of a bearing device according to a fifth embodiment. [Figure 20] 10 is a graph showing a first example of the voltage of another storage circuit over time. [Figure 21]10 is a graph showing a second example of the voltage of another power storage circuit over time. [Figure 22] 10 is a graph showing a third example of the voltage of another storage circuit over time. [Figure 23] 10 is a graph showing a fourth example of the voltage of another storage circuit over time. [Figure 24] FIG. 20 is a schematic side view of a bearing device according to a first example of the sixth embodiment. [Figure 25] FIG. 20 is a schematic side view of a bearing device according to a second example of the sixth embodiment. [Figure 26] 2 is a cross-sectional view of a mechanical device to which the bearing device shown in FIG. 1 is applied. [Figure 27] FIG. 27 is a cross-sectional schematic view of the mechanical device shown in FIG. 26. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described with reference to the drawings.

[0012] (Embodiment 1) <Bearing device configuration> FIG. 1 is a schematic side view of a bearing device according to this embodiment. FIG. 2 is a schematic cross-sectional view of a portion along line II-II in FIG. 1 in embodiment 1. Referring to FIGS. 1 and 2, bearing device 10 according to this embodiment is a rolling bearing device. Bearing device 10 includes bearing 11, which is a rolling bearing, and lubricant supply unit 20 (lubricant supply mechanism). Lubricant supply unit 20 supplies lubricant to bearing 11. A center line L0 passing through the center of bearing 11, which has an annular shape, extends in the left-right direction of FIG. 2, i.e., in the axial direction. Lubricant supply units 20 are arranged adjacent to each other in the axial direction of bearing 11, i.e., in the direction in which center line L0 extends.

[0013] An outer ring spacer 33 and an inner ring spacer 34 abut against one axial end of the bearing 11. The outer ring spacer 33 has an outer ring spacer outer ring 33A that is radially outer and an inner ring spacer inner ring 33B that is radially inner. The radial direction refers to the direction extending radially from the center of the annular bearing 11 toward the periphery, forming a diameter (radius). The lubricant supply unit 20 is incorporated inside the outer ring spacer 33, more specifically, between the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B. In this sense, the outer ring spacer 33 and the inner ring spacer 34 are not included in the lubricant supply unit 20. However, the lubricant supply unit 20 may also be considered to include the outer ring spacer 33 and the inner ring spacer 34. For example, the lubricant supply unit 20, the outer ring spacer 33, and the inner ring spacer 34 may be integrated into one unit.

[0014] The bearing device 10, which includes the bearing 11 and the lubricant supply unit 20, is used by being installed in a mechanical device, for example, between a rotating shaft and a spindle housing. When the bearing device 10 is installed in a mechanical device, for example, another spacer may be abutted against the other end of the bearing 11. In this case, the bearing 11 can be positioned in the axial direction by the outer ring spacer 33, inner ring spacer 34, and other spacers.

[0015] The bearing 11 mainly comprises an outer ring 13, an inner ring 14, multiple rolling elements 15, a cage 16, and a sealing member. The outer ring 13 is, for example, a fixed raceway. However, the outer ring 13 may also be a rotating raceway. The inner ring 14 is, for example, a rotating raceway. However, the inner ring 14 may also be a fixed raceway. The multiple rolling elements 15 are interposed between the inner ring 14 and the outer ring 13. The multiple rolling elements 15 are arranged on an annular track with spacing between them in the circumferential direction. The circumferential direction is the direction in which the circumference of the annular shape such as the inner ring 14 extends. The cage 16 holds the multiple rolling elements 15 at regular intervals. The sealing member is located on the outer periphery of the cage 16. The bearing 11 can be, for example, an angular contact ball bearing, a deep groove ball bearing, or a cylindrical roller bearing. The bearing 11 is pre-filled with the desired grease. The sealing member is disposed at the end opposite to the side where the outer ring spacer 33 and the like are disposed.

[0016] The outer ring 13 of the bearing 11 has an outer ring rolling surface formed on its inner peripheral surface with which the rolling elements 15 come into contact. The inner ring 14 of the bearing 11 has an inner ring rolling surface formed on its outer peripheral surface with which the rolling elements 15 come into contact. The inner ring rolling surface faces the outer ring rolling surface. Therefore, the inner ring 14 is positioned radially inside the outer ring 13. The outer peripheral surface also includes an inclined portion 14a that continues to the inner ring rolling surface. The inclined portion 14a is inclined with respect to the axial direction so as to approach the outer ring 13 from the axial end of the inner ring 14 toward the inner ring rolling surface.

[0017] The cage 16 of the bearing 11 has a cage inner diameter surface 16b. The cage inner diameter surface 16b is the surface of the cage 16 that faces radially inward. The cage inner diameter surface 16b has a cross-sectional shape that increases in diameter from the end portion of the bearing 11 in the axial direction toward the center. The cage inner diameter surface 16b may be linear extending along the axial direction. Thus, in the cross section of the bearing 11 taken along the axial direction shown in FIG. 2, the shape of the cage inner diameter surface 16b may be linear. However, the cage inner diameter surface 16b may also be curved and concave toward the outer periphery of the bearing 11.

[0018] The spacer is made up of an outer ring spacer 33 and an inner ring spacer 34. In the axial direction, one end of the outer ring 13 contacts and is connected to the outer ring spacer 33. In the axial direction, one end of the inner ring 14 contacts and is connected to the inner ring spacer 34. Here, one end of the outer ring 13 (inner ring 14) means the end located on the left side of the bearing 11 in the axial direction. This brings the spacer into contact with the bearing 11. In addition, in the radial direction, a lubricating oil supply unit 20 is disposed between the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B. A discharge tube 32 extends from the lubricating oil supply unit 20 toward the bearing 11.

[0019] The outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B that constitute the outer ring spacer 33 may both be formed from a metal material (iron). In this case, the interior of the outer ring spacer 33 may be partially hollowed out to house the lubricant supply unit 20. In this case, the lubricant supply unit 20 is also sandwiched (encased) between the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B as shown in FIG. 2. However, the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B may be made of different materials. For example, the outer ring spacer outer ring 33A may be made from iron, and the outer ring spacer inner ring 33B may be made from resin. There is a radial gap between the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B at least within the range shown in FIG. 2, and the lubricant supply unit 20 is interposed in the gap. Regardless of whether the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B are made of the same material, the lubricant supply unit 20 may be disposed so as to be sandwiched radially between them as shown in Figure 2. Regardless of whether the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B are made of the same material, the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B are connected by an interposition portion 33C between them. This results in the outer ring spacer 33 being an integrated member consisting of the outer ring spacer outer ring 33A, the outer ring spacer inner ring 33B, and the interposition portion 33C.

[0020] The outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B may be formed by turning, or the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B may be formed by pressing.

[0021] The lubricant supply unit 20 mainly comprises a heat absorption / radiation section 25, a first power supply circuit 26A (power supply), a control circuit 27, a drive circuit 28, a pump 29, and a lubricant tank 30. These are arranged circumferentially on the radially inner side of the housing. Here, the housing refers to the outer diameter portion of the outer ring spacer 33, and more specifically, refers to the outer ring 33A of the outer ring spacer. The first power supply circuit 26A (power supply), the control circuit 27, and the drive circuit 28 may be protected by a casing or a resin mold.

[0022] The first power supply circuit 26A may include a charging section. The lubricating oil tank 30 (retention section) stores (holds) the same type of lubricating oil as the base oil of the grease already sealed in the bearing 11. Here, "pre-sealed in the bearing 11" means that the lubricating oil is stored (held) in the bearing 11 before being supplied by the lubricating oil tank 30. The heat absorption and radiation section 25, the first power supply circuit 26A, the control circuit 27, the drive circuit 28, the pump 29, and the lubricating oil tank 30 are arranged in a circumferential direction. The heat absorption and radiation section 25 is connected to the first power supply circuit 26A. The first power supply circuit 26A is connected to the control circuit 27. The control circuit 27 is connected to the drive circuit 28. The drive circuit 28 is a circuit for operating a pump 29, such as a micropump. The drive circuit 28 is connected to the pump 29. These are electrically connected by wiring 35. The pump 29 is connected to a suction tube 31 connected to, for example, a bag body of a lubricating oil tank 30, and a discharge tube 32 (see Figure 2) for supplying lubricating oil from the pump 29 to the inside of the bearing 11.

[0023] 2, a nozzle 32a is connected to the tip of the discharge tube 32. The tip of the discharge tube 32 is the end of the discharge tube 32 opposite to the base portion connected to the pump 29. A nozzle hole is formed inside the nozzle 32a.

[0024] The nozzle 32a is arranged to extend from the interior of the lubricant supply unit 20 inside the housing to the exterior of the lubricant supply unit 20. The tip of the nozzle 32a extends to the interior of the bearing 11. For example, the tip of the nozzle 32a may be arranged in the region between the cage inner diameter surface 16b and the inner ring rolling surface.

[0025] The heat absorption and radiation section 25 of the lubricant supply unit 20 may be, for example, a section that absorbs and releases heat by the Peltier effect. Specifically, the heat absorption and radiation section 25 has a first thermal conductor 23a, a second thermal conductor 23b, and a Peltier element 24. The first thermal conductor 23a is connected to the outer ring 33A of the outer ring spacer. The second thermal conductor 23b is connected to the inner ring 33B of the outer ring spacer. The Peltier element 24 is disposed so as to connect the first thermal conductor 23a and the second thermal conductor 23b. In other words, the Peltier element 24 is disposed so as to be sandwiched between the first thermal conductor 23a and the second thermal conductor 23b. The Peltier element 24 is tightly fixed to the first thermal conductor 23a and the second thermal conductor 23b. The Peltier element 24 is an element (thermoelectric element) that utilizes the Peltier effect.

[0026] The outer ring spacer inner ring 33B and the inner ring spacer 34 are not in contact with each other. A gap 36 may be formed between the outer ring spacer inner ring 33B and the inner ring spacer 34. Therefore, the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B are arranged to sandwich the entire heat absorption and radiation portion 25 in the radial direction.

[0027] The Peltier element 24 and the first power supply circuit 26A are electrically connected. Therefore, the first power supply circuit 26A (power supply) can supply power to the Peltier element 24. The first power supply circuit 26A may be an external power supply or a power storage circuit. In this case, power is stored in a power storage unit such as a storage battery or capacitor included in the first power supply circuit 26A. Alternatively, the first power supply circuit 26A may be composed of a generator and a power storage unit. In this case, the generator may be of an electromagnetic induction type, and the type is not important. The stored power can be supplied to the Peltier element 24. The first power supply circuit 26A may also be a battery. Furthermore, the first power supply circuit 26A may be a mechanism that supplies power to the Peltier element 24 via a wire or wirelessly from outside the rotating shaft of a machine tool spindle, which will be described later.

[0028] When the bearing device 10 is in use, power is supplied from the first power supply circuit 26A to the Peltier element 24. This drives the Peltier element 24. This allows heat to transfer from the first thermal conductor 23a, which is tightly secured to the Peltier element 24, to the second thermal conductor 23b. Specifically, when the Peltier element 24 is driven, heat is absorbed from the radially outer end face of the Peltier element 24 and dissipated to the radially inner end face of the Peltier element 24. As a result, the first thermal conductor 23a, which is tightly secured to the radially outer end face of the Peltier element 24, absorbs heat and cools. The second thermal conductor 23b, which is tightly secured to the radially inner end face of the Peltier element 24, dissipates heat and heats up.

[0029] Furthermore, by driving the Peltier element 24, the first thermal conductor 23a can absorb heat from the spacer (outer ring spacer 33), and the second thermal conductor 23b can radiate heat to the lubricating oil tank 30. To make this possible, a first thermal conductive member 23aa is connected to the first thermal conductor 23a, and a second thermal conductive member 23bb is connected to the second thermal conductor 23b.

[0030] First heat conducting member 23aa and second heat conducting member 23bb are made of a highly thermally conductive material, primarily composed of copper or aluminum, and are formed into a long, thin plate shape. First heat conducting member 23aa extends circumferentially from first heat conductor 23a along the inner circumferential surface of outer ring spacer outer ring 33A.

[0031] The first heat conducting member 23aa contacts the spacer. The first heat conducting member 23aa may be connected to the first heat conductor 23a and extend in an arc shape from there so as to contact the inner circumferential surface of the outer ring spacer outer ring 33A. This positions the first heat conducting member 23aa radially outward from the lubricating oil tank 30. It is preferable that the first heat conducting member 23aa does not contact the outer circumferential surface of the lubricating oil tank 30 in the radial direction.

[0032] 1 to 5, the second heat conducting member 23bb is in contact with the lubricant oil tank 30. This includes the case where the second heat conducting member 23bb is in contact with a partial area of ​​the lubricant oil tank 30. The second heat conducting member 23bb may be connected to the second heat conductor 23b and extend in an arc from there so as to contact the inner outer wall of the lubricant oil tank 30 in the radial direction. The second heat conducting member 23bb may extend in an arc from the connection portion with the second heat conductor 23b so as to contact the outer peripheral surface of the outer ring spacer inner ring 33B. As a result, the second heat conducting member 23bb is disposed radially inward of the lubricant oil tank 30 (inner than the first heat conducting member 23aa). The lubricant oil tank 30 is disposed radially inward relative to the first power supply circuit 26A, the control circuit 27, and the drive circuit 28. The first power supply circuit 26A, the control circuit 27, and the drive circuit 28 are disposed radially outward relative to the lubricant oil tank 30. Therefore, first power supply circuit 26A, control circuit 27, and drive circuit 28 may be in contact with first heat conduction member 23aa or the inner circumferential surface of outer ring spacer outer ring 33A.

[0033] As shown in FIG. 1, the first heat conducting member 23aa may extend so as to contact only a portion of the circumferential direction of the outer ring spacer outer ring 33A. For example, the first heat conducting member 23aa may not contact the region radially outward of the drive circuit 28. In other words, the first heat conducting member 23aa may contact only the region in the circumferential direction other than the portion where the drive circuit 28 is located. However, the first heat conducting member 23aa may extend so as to contact the entire circumferential direction of the outer ring spacer outer ring 33A. Also, as shown in FIG. 1, the second heat conducting member 23bb may be arranged only partially in the circumferential direction, i.e., only in the region where the lubricating oil tank 30 is located (including the region adjacent to that).

[0034] As described above, the Peltier element 24, the first heat conductor 23a, the second heat conductor 23b, and the first power supply circuit 26A are all installed in the outer ring spacer 33. Specifically, they are installed in the area sandwiched between the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B. Usually, they are installed in a spacer connected to the fixed ring.

[0035] For example, in the case of bearing device 10 for machine tools, the rotating shaft that performs machining is on the inner ring side, so the inner ring is the rotating ring and the outer ring is the fixed ring. However, in bearing device 10 used for other applications (for example, automobiles), the inner ring may be the fixed ring and the outer ring the rotating ring. In this case, Peltier element 24, first heat conductor 23a, second heat conductor 23b, and first power supply circuit 26A may all be installed in inner ring spacer 34. In this case, inner ring spacer 34 may include an inner ring spacer outer ring and an inner ring spacer inner ring, similar to outer ring spacer 33 described above.

[0036] By placing the Peltier element 24 and other components on a spacer connected to the fixed wheel, they can be installed stably. However, it is also possible to install the Peltier element 24, first thermal conductor 23a, second thermal conductor 23b, and first power supply circuit 26A on a spacer connected to the rotating wheel. Specific application examples include when the rotation speed is low or when the rotating member rotates on a pivot.

[0037] Control circuit 27 is a control unit for controlling the operation of pump 29 via drive circuit 28. Control circuit 27 includes a program storage unit that stores a control program and a calculation unit (microcomputer) that is connected to the program storage unit and executes the control program. Control circuit 27 can be used to preset the start time of lubricating oil supply to bearing 11, the supply timing (interval), the operating time of pump 29 for supplying lubricating oil, the amount of lubricating oil to be supplied, and other settings. By maintaining an appropriate lubricating oil supply state in this way, the lubrication life of the bearing device can be extended.

[0038] In addition, the control circuit 27 acquires data relating to the supply status of lubricant in the lubricant supply unit 20. The control circuit 27 is also capable of outputting the data to the outside of the control circuit 27 (for example, to an output board 56 (see FIG. 27) serving as a receiving unit). The control circuit 27 also controls the operation of the Peltier element 24.

[0039] Drive circuit 28 may include, for example, any sensors (bearing temperature sensor, bearing rotation sensor, lubricant remaining amount sensor, lubricant temperature sensor, etc.) Signals from these sensors may be input to a calculation unit (microcomputer) of drive circuit 28, which may automatically control pump 29 according to the temperature of bearing 11 and its rotation status to adjust the amount of lubricant supplied.

[0040] Pump 29 is controlled by control circuit 27 via drive circuit 28. Pump 29 draws lubricating oil from lubricating oil tank 30 through suction tube 31 and supplies the drawn lubricating oil to the inside of bearing 11 via discharge tube 32 and nozzle 32a.

[0041] Next, FIG. 3 is a cross-sectional schematic diagram of the basic form of a portion taken along line AA in FIG. 1. FIG. 4 is a cross-sectional schematic diagram of a first modified example of a portion taken along line AA in FIG. 1. Referring to FIG. 3, the lubricant oil tank 30 may be entirely made of an outer frame 30a. In this case, the outer frame 30a may be made of a metal material or a resin material. The lubricant oil tank 30 may be arranged in an arc shape along an annular housing (outer ring spacer outer ring 33A). The lubricant oil 38 may be stored in the outer frame 30a. However, referring to FIG. 4, the lubricant oil tank 30 may include the outer frame 30a and a bag body 30b. In this case, the lubricant oil 38 is stored in the bag body 30b.

[0042] The bag body 30b may be formed by stacking resin sheets and heat-sealing the outer periphery of the lubricating oil tank 30. The bag body 30b may be the portion to which the outer periphery of the lubricating oil tank 30 is heat-sealed.

[0043] The bag body 30b is provided with a suction tube 31 that connects to the pump 29. When the bag body 30b of the lubricating oil tank 30 is formed by heat welding, the suction tube 31 is sandwiched between the resin sheets that are stacked to form the bag body 30b and heat-welded. In this way, the suction tube 31 can be integrated with the bag body 30b.

[0044] The bag 30b may be made of a resin material. Specifically, the bag 30b may be made of nylon, polyethylene, polyester, polypropylene, or the like. The bag 30b may be made of any material that is flexible and can be deformed by a small external force, and is durable against the lubricating oil 38. The presence of the bag 30b can prevent the lubricating oil 38 from leaking from the outer frame 30a of the lubricating oil tank 30.

[0045] As shown in FIG. 3, the second heat conducting member 23bb may be provided so as to contact the outer surface of the lubricating oil tank 30 on the radially inner side. Alternatively, as shown in FIG. 4, the outer frame 30a of the lubricating oil tank 30 may be missing a portion (a radially inner region), and the second heat conducting member 23bb may be disposed in the missing portion. That is, in FIG. 4, the second heat conducting member 23bb forms a portion of the outer frame 30a of the lubricating oil tank 30. In FIG. 4, as in FIG. 1, the second heat conducting member 23bb is in contact with the outer frame 30a of the lubricating oil tank 30 (the portion of the outer frame 30a other than the second heat conducting member 23bb). The second heat conducting member 23bb in FIG. 4 is integrated (integrated) with the outer frame 30a (the portion other than the second heat conducting member 23bb).

[0046] 5 is a cross-sectional schematic diagram of a second modified example taken along line AA in FIG. 1. Referring to FIG. 5, second heat conducting member 23bb may be formed to constitute the entire outer frame 30a of lubricating oil tank 30. In other words, the entire portion of outer frame 30a of lubricating oil tank 30 that surrounds and houses lubricating oil 38 as shown in FIG. 3 is formed by second heat conducting member 23bb. Second heat conducting member 23bb in FIG. 5 is integrated (integrated) with second heat conducting member 23bb in FIG. 1. Second heat conducting member 23bb is arranged as the outer frame 30a of the entire lubricating oil tank 30. As shown in FIG. 5, a bag body 30b may be housed within outer frame 30a of lubricating oil tank 30.

[0047] Although the cross section of the outer frame 30a of the lubricating oil tank 30 shown in FIGS. 3 to 5 is rectangular, the cross-sectional shape of the lubricating oil tank 30 is not limited to this.

[0048] <Bearing device operation> In the bearing device 10 including the bearing 11 and the lubricating oil supply unit 20, the operation of the pump 29 is controlled by the control circuit 27. This allows lubricating oil to be supplied from the lubricating oil tank 30 to the bearing 11.

[0049] The lubricating oil supplied to the interior of bearing 11 through nozzle 32a is temporarily stored in the region between cage inner diameter surface 16b and the inner ring rolling surface. Then, due to centrifugal force caused by the rotation of inner ring 14 and capillary action, the lubricating oil flows from this region toward rolling elements 15. In this way, the lubricating oil supplied to the interior of bearing 11 is supplied to the contact areas between rolling elements 15 and inner ring 14 and outer ring 13. As a result, the lubricating performance of bearing 11 can be maintained for a long period of time.

[0050] Pump 29 may be driven when the power generated by heat absorption and radiation unit 25 is stored in a power storage unit (e.g., a capacitor) in first power supply circuit 26A and the voltage of the power storage unit reaches a certain voltage. In this case, pump 29 is driven by the power stored in first power supply circuit 26A. Strictly speaking, pump 29 is driven by the power stored in first power supply circuit 26A being supplied to control circuit 27. This is because first power supply circuit 26A, control circuit 27, drive circuit 28, and pump 29 are all connected in series. However, pump 29 may also be driven by a power source other than the above, not shown.

[0051] <Action and effect> Next, the effects of the present embodiment will be described, while referring to the background art, etc. Note that the description in this section may partially overlap with the description in the section on the configuration of the bearing device described above.

[0052] The bearing device of this embodiment includes a bearing 11 and a lubricant supply unit 20 that supplies lubricant to the bearing 11. The bearing 11 includes an outer ring 13 and an inner ring 14. The outer ring 13 has an outer ring rolling surface on its inner circumferential surface. The inner ring 14 has an inner ring rolling surface on its outer circumferential surface and is disposed inside the outer ring 13 so that the inner ring rolling surface faces the outer ring rolling surface. The lubricant supply unit 20 includes a holding portion (lubricant tank 30), a Peltier element 24, a first thermal conductor 23a and a second thermal conductor 23b, and a power source (first power supply circuit 26A). The lubricant tank 30 holds the lubricant to be supplied to the inside of the bearing 11. The first thermal conductor 23a and the second thermal conductor 23b sandwich the Peltier element 24. The first power supply circuit 26A is capable of supplying power to the Peltier element 24. Driving the Peltier element 24 by the first power supply circuit 26A enables heat to be transferred from the first thermal conductor 23a to the second thermal conductor 23b.

[0053] The first power supply circuit 26A supplies power to the Peltier element 24 to drive it. The Peltier effect of the Peltier element 24 allows the first thermal conductor 23a, which is radially sandwiching the Peltier element 24, to function as a cool heat-absorbing member, and the second thermal conductor 23b to function as a hot heat-dissipating member. This can be used to cool desired members within the bearing device 10 and raise the temperature of other desired members. Therefore, the desired cooling and heating can be achieved simply by the heat absorption and radiation of the heat-absorbing and heat-dissipating section 25 by the first power supply circuit 26A, without unnecessary driving of the device for cooling or heating.

[0054] An example of a component within the bearing device 10 that needs to be cooled is the bearing 11. An example of a component within the bearing device 10 that needs to be heated is the lubricating oil tank 30. According to this embodiment, the lubricating oil 38 sealed in the lubricating oil tank 30 can be efficiently consumed while suppressing the temperature rise of the high-speed rotation bearing 11. The lubricating oil 38 can be efficiently consumed because the viscosity of the lubricating oil 38 sealed in the lubricating oil tank 30 decreases as the temperature rises, increasing its fluidity and making it easier to supply to the pump 29. Efficient consumption of the lubricating oil 38 means that a sufficient amount of lubricating oil 38 can be supplied to the desired position. This improves the lubrication durability of the bearing 11.

[0055] When the bearing device 10 rotates at high speeds, heat generated by the bearing 11 accelerates the deterioration of the lubricating oil. This can lead to a problem in which the lubrication durability of the bearing 11 cannot be ensured even at rotational speeds lower than the maximum usable rotational speed of the bearing 11. On the other hand, the market demands even higher rotational speeds, that is, demands for improving the lubrication durability of the bearing 11 by supplying sufficient lubricating oil to the bearing 11 under high-speed rotation. According to this embodiment, heat transfer from the first thermal conductor 23a to the second thermal conductor 23b can prevent temperature rise in areas where heat generation is not desired. As a result, the lubrication durability of the bearing 11 can be improved even when the bearing 11 rotates at high speeds.

[0056] Air-oil lubrication is suitable for high-speed rotation. However, air-oil lubrication equipment is large and consumes a lot of air-oil. For this reason, there are situations where using air-oil is not desirable, such as when miniaturizing equipment. In such situations, the bearing device 10 of this embodiment is suitable. The bearing device 10 is compact and can easily supply a small amount of lubricating oil to the bearing 11 even under high-speed rotation, without using air-oil. Therefore, by consuming a small amount of lubricating oil highly efficiently, the lubrication durability of the bearing 11 can be maintained at a high level.

[0057] The bearing device 10 includes spacers (outer ring spacer 33, inner ring spacer 34) arranged to sandwich the lubricating oil supply unit 20. The outer ring spacer 33 (or inner ring spacer 34) contacts the bearing 11. When the Peltier element 24 is driven, the first heat conductor 23a can absorb heat from the outer ring spacer 33 (or inner ring spacer 34). When the Peltier element 24 is driven, the second heat conductor 23b can radiate heat to the lubricating oil tank 30.

[0058] The first thermal conductor 23a absorbs heat from the spacer, and thus can absorb heat from the bearing 11. This is because the spacer is in contact with the bearing 11. This makes it possible to suppress heat generation in the bearing 11 and the associated early depletion of lubricating oil in the bearing 11. As a result, damage to the bearing 11 can be suppressed. The control circuit 27 may also be installed adjacent to the cool first thermal conductor 23a. In this way, it is possible to suppress the heat generated by the bearing 11 due to driving from being transmitted to the control circuit 27. This prevents the board that constitutes the control circuit 27 from being affected by heat.

[0059] The second heat conductor 23b heats the lubricating oil tank 30. That is, as shown in FIGS. 3 and 4, heat H is supplied from the second heat conductor 23bb to the lubricating oil 38 inside the lubricating oil tank 30. This heats the lubricating oil 38, improving the fluidity of the lubricating oil 38 and making it easier to discharge the lubricating oil from the nozzle. This allows the lubricating oil to be supplied sufficiently into the bearing 11. In other words, malfunctions of the bearing 11 caused by an insufficient supply of lubricating oil to the bearing 11 can be suppressed.

[0060] In the above-described bearing device 10, a first heat conducting member 23aa is connected to the first heat conductor 23a, and a second heat conducting member 23bb is connected to the second heat conductor 23b. It is more preferable that the first heat conducting member 23aa contacts the outer ring spacer 33 (inner ring spacer 34), and the second heat conducting member 23bb contacts the lubricating oil tank 30.

[0061] The first heat conductor 23a can absorb heat from the spacer through the first heat conduction member 23aa connected thereto. For example, if the first heat conduction member 23aa contacts the inner circumferential surface of the outer ring spacer 33A, the outer ring spacer 33A is actively cooled. This can suppress temperature rise due to heat generated in the bearing 11 that contacts the spacer. If the control circuit 27 or the first heat conduction member 23aa comes into contact with the outer ring spacer 33A or the first heat conduction member 23aa, the control circuit 27 and the like can be protected from heat. The second heat conductor 23b can dissipate heat to the lubricant oil tank 30 through the second heat conduction member 23bb connected thereto (see heat H in Figures 3 and 4). For example, if the second heat conduction member 23bb extends in an arc shape so as to contact the lubricant oil tank 30, the lubricant oil tank 30 and the lubricant oil therein can be warmed. The second heat conducting member 23bb may come into contact with the outer peripheral surface of the outer ring spacer inner ring 33B, thereby actively heating the outer ring spacer inner ring 33B.

[0062] The first heat conducting member 23aa actively cools the outer ring spacer outer ring 33A, and the second heat conducting member 23bb actively heats the outer ring spacer inner ring 33B. This effect is achieved by using either copper or aluminum as the main component of the first heat conducting member 23aa and the second heat conducting member 23bb. This is because copper and aluminum have high thermal conductivity.

[0063] The outer ring spacer outer ring 33A, which is actively cooled, and the outer ring spacer inner ring 33B, which is actively heated, are the same component (outer ring spacer 33). In other words, the outer ring 33A and inner ring 33B of the outer ring spacer are integral. The outer ring 33A and inner ring 33B may be made of the same material. For this reason, by cooling and heating as described above, the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B may become approximately the same temperature. However, even if this occurs, there is no particular problem as long as the bearing 11 is not excessively heated and the lubricating oil 38 has a viscosity that allows it to flow sufficiently, and the object of this embodiment can be achieved.

[0064] In the above-described bearing device 10, the bearing 11 is pre-filled with lubricating oil. The lubricating oil is grease. This allows for applications where air-oil lubrication is undesirable. For example, grease lubrication is increasingly being used instead of air-oil lubrication for machine tool spindle bearings. This is intended to reduce environmental impact and costs. Grease lubrication eliminates the need for the lubricating oil tank and lubricating oil supply system used in air-oil lubrication. The lubricating oil tank used in air-oil lubrication is large, and the lubricating oil supply system is a complex one with a pump that has a forced discharge function. Therefore, grease lubrication allows for a more compact facility compared to air-oil lubrication. Furthermore, grease lubrication uses less lubricating oil than air-oil lubrication. Therefore, grease lubrication is environmentally friendly and reduces initial and running costs.

[0065] In the case of a grease-lubricated bearing, application of this embodiment facilitates the separation of grease adhering to the cage bore surface 16b. In other words, capillary action actively acts on the liquid lubricating oil adhering to the cage bore surface 16b. This allows the liquid lubricating oil to sufficiently reach the rolling surfaces inside the bearing 11 when the grease is depleted, i.e., when there is little grease.

[0066] (Embodiment 2) In each of the following embodiments, the same configurations, features, materials, etc. as those of the first embodiment will not be described repeatedly unless it is preferable to do so again.

[0067] <Bearing device configuration> Fig. 6 is a schematic side view of a bearing device according to embodiment 2. Referring to Fig. 6, in bearing device 10 according to this embodiment, movable piece 23cc is connected to either second heat conductor 23b or second heat conduction member 23bb. Movable piece 23cc is formed in the shape of an elongated plate, similar to first heat conduction member 23aa and second heat conduction member 23bb. In this respect, embodiment 2 differs from embodiment 1.

[0068] In FIG. 6, similarly to FIG. 4, the second heat conducting member 23bb forms part of the outer frame 30a of the lubricating oil tank 30 and is integrated with the lubricating oil tank 30. In other words, the second heat conducting member 23bb contacts the lubricating oil tank 30 (portions other than the second heat conducting member 23bb). However, also in this embodiment, the entire outer frame 30a may be made of a single member as shown in FIG. 3, with the second heat conducting member 23bb provided on its outer side. The movable piece 23cc is connected to either the second heat conductor 23b or the second heat conducting member 23bb. When the movable piece 23cc is included, the lubricating oil tank 30 has a bag body 30b as shown in FIG. 4.

[0069] Movable piece 23cc is formed of a bimetal. In particular, movable piece 23cc is preferably formed by bonding two types of metal materials, a low-expansion material and a high-expansion material. The low-expansion material is, for example, a Ni-Fe alloy. The high-expansion material is, for example, any one selected from the group consisting of copper, nickel, a Ni-Cu alloy, a Cu-Zn alloy, a Ni-Mn-Fe alloy, a Ni-Cr-Fe alloy, a Ni-Cu-Mn alloy, and a Ni-Mo-Fe alloy.

[0070] Movable piece 23cc is in contact with a partial area of ​​lubricant oil tank 30. In FIG. 6, one end of movable piece 23cc (the end opposite to the side connected to second thermal conductor 23b) is in contact with a wall surface inside lubricant oil tank 30. Movable piece 23cc preferably contacts a radially outer wall surface of bag body 30b of lubricant oil tank 30. Movable piece 23cc is connected to at least one (one or both) of a portion where second heat conductive member 23bb is in contact with heat absorption and radiation unit 25 and heat absorption and radiation unit 25.

[0071] Fig. 7 is a schematic perspective view showing the initial state of a first example of the lubricating oil tank shown in Fig. 6, which is simplified from Fig. 6. Fig. 8 is a schematic cross-sectional view of a portion taken along line VIII-VIII in Fig. 7. Fig. 9 is a schematic perspective view showing a state in which the bimetal has deformed compared to Fig. 7. Fig. 10 is a schematic cross-sectional view of a portion taken along line XX in Fig. 9. Figs. 8 and 10 not only show the portion cut along line VIII-VIII, etc., but also show the cross-sectional view of the portion behind that portion that is not actually visible because the lubricating oil tank 30 is curved.

[0072] 7, the movable piece 23cc is usually installed inside the outer frame 30a of the lubricant tank 30. When the lubricant tank 30 has a bag body 30b, the movable piece 23cc is arranged outside the bag body 30b. However, the movable piece 23cc may also be arranged inside the bag body 30b. Whether the movable piece 23cc is arranged outside or inside the bag body 30b, the movable piece 23cc can come into contact with (is in contact with) the wall surface of the bag body 30b.

[0073] In the first example, in the initial state, movable piece 23cc is connected to a region of second heat conducting member 23bb adjacent to the portion connected to second heat conductor 23b. There is a gap between movable piece 23cc and second heat conducting member 23bb in the radial direction. Bag 30b is disposed in this gap. Referring to FIG. 8, in this state, the liquid level of lubricating oil 38 stored inside bag 30b is relatively low.

[0074] Referring to FIG. 9, consider a state in which the movable piece 23cc has deformed and contracted relative to the initial state shown in FIG. 7. The deformation of the movable piece 23cc is caused by the temperature rise of the lubricant tank 30 due to the second thermal conductor 23b and the second thermal conductive member 23bb, as shown in the first embodiment. Because the movable piece 23cc is in contact with the lubricant tank 30, the temperature rise of the lubricant tank 30 also causes the movable piece 23cc to rise and deform. Referring to FIG. 10, the movable piece 23cc moves in the direction indicated by arrow M. That is, the movable piece 23cc deforms so that the diameter of the arc-shaped portion of the movable piece 23cc decreases. In this way, in accordance with the displacement of the movable piece 23cc indicated by arrow M, the movable piece 23cc presses against the bag body 30b, thereby reducing the volume of the bag body 30b. As a result, the liquid level of the lubricant 38 is higher in FIG. 10 than in FIG. 8.

[0075] Fig. 11 is a perspective view showing the initial state of a second example of the lubricating oil tank shown in Fig. 6, which is simplified from Fig. 6. Fig. 12 is a cross-sectional view taken along line XII-XII in Fig. 11. Fig. 13 is a perspective view showing a state in which the bimetal has deformed relative to Fig. 11. Fig. 14 is a cross-sectional view taken along line XIV-XIV in Fig. 13. As with Figs. 8 and 10, Figs. 12 and 14 not only show the portion cut along line XII-XII, etc., but also show the cross-sectional view of the portion behind that portion that is not actually visible because the lubricating oil tank 30 is curved.

[0076] Referring to FIG. 11 , the initial state of the second example is generally similar to that of the first example. However, FIG. 11 differs from FIG. 7 in the following respects. In FIG. 11 , the lubricant tank 30 is positioned such that the radially outer side is positioned vertically higher than the inner side. That is, in FIG. 11 , if the two are positioned at the same horizontal coordinate, the movable piece 23cc is positioned vertically higher than the second heat conduction member 23bb. Therefore, the lubricant tank 30 is tilted overall so that the movable piece 23cc is positioned higher than the second heat conduction member 23bb. This is shown in FIG. 11 as the movable piece 23cc extending radially outward from the portion connecting with the second heat conduction member 23bb, and then bending in an arc shape along the inner circumferential surface of the lubricant tank 30 when it reaches the inner circumferential surface. The movable piece 23cc is positioned inside the outer frame 30a (not clearly shown in FIG. 11 ) of the lubricant tank 30. Movable piece 23cc is in contact with bag body 30b. In this respect, the configuration of Figure 11 differs from that of Figure 7, in which movable piece 23cc is not inclined vertically upward relative to second heat conduction member 23bb.

[0077] However, Figures 12 to 14 are similar to Figures 8 to 10. In the second example, too, the movable piece 23cc deforms as the temperature rises, reducing the diameter of the arc-shaped portion indicated by arrow M. In response to this displacement of the movable piece 23cc, the bag body 30b is pressed and deformed, raising the liquid level of the lubricating oil 38. In the second example, the cross-sectional shape of the bag body 30b in the cross-sectional views of Figures 12 and 14 is tilted compared to Figures 8 and 10. Specifically, the lower right side of the figure, where the suction tube 31 is located, is tilted further downward. This tilt allows for a higher liquid level relative to the suction tube 31, as shown in Figure 14, even with an even smaller amount of lubricating oil 38 than in the first example.

[0078] <Action and effect> In the bearing device 10 of this embodiment, the retaining portion (lubricant tank 30) includes a resin bag body 30b. A movable piece 23cc is connected to either the second heat conductor 23b or the second heat conductive member 23bb. The movable piece 23cc is formed of a bimetal. The movable piece 23cc is in contact with the lubricant tank 30, and presses against the bag body 30b in accordance with the displacement of the movable piece 23cc, thereby changing the volume of the bag body 30b.

[0079] As shown in Figures 10 and 14, the volumetric contraction of the bag body 30b causes the liquid level of the lubricating oil 38 inside it to rise and become higher than the suction tube 31. This allows the lubricating oil in the lubricating oil tank 30 to be sucked through the suction tube 31 and supplied to the inside of the bearing 11, even if the amount of lubricating oil 38 is small. Even when the amount of lubricating oil 38 is so small that it does not reach the suction tube 31, as shown in Figures 8 and 12, the liquid level reaches the height of the suction tube 31, as shown in Figures 10 and 14. This improves the fluidity of the lubricating oil 38 even with a small amount of lubricating oil 38. As a result, the lubricating oil 38 can be efficiently supplied from the suction tube 31 to the inside of the bearing 11 through the nozzle 32a (see Figure 2). This ensures the lubrication durability of the bearing 11 and allows the lubricating oil 38 to be consumed efficiently. Furthermore, the movable piece 23cc applies pressure to the bag body 30b from the outside, thereby increasing the discharge pressure of the lubricating oil 38 from the pump 29 (see Figure 6).

[0080] The same effect can be achieved whether the embodiment shown in FIG. 10 or the embodiment shown in FIG. 14 is used. In other words, the same effect can be achieved regardless of the shape of the component that stores the lubricating oil 38, such as the bag 30b. For this reason, as a third example (not shown), an example in which the bag 30b is not provided, as shown in FIG. 3, and the main body of the lubricating oil tank 30 (corresponding to the outer frame 30a) is formed of a flexible resin material is also conceivable. In this case, the movable piece 23cc may be installed on the outside of the main body of the lubricating oil tank 30 (corresponding to the outer frame 30a). In the third example, as in the first and second examples, the movable piece 23cc formed of a bimetal is connected to either the second heat conductor 23b or the second heat conduction member 23bb. This movable piece 23cc contacts the outside of the resin lubricating oil tank 30 and can change the volume of the resin lubricating oil tank 30 by displacing it. This also achieves the same effect as described above. However, the third example is different from the second example in that the lubricating oil tank 30 does not have two layers of a bag body and an outer frame thereof, but has only one layer of a bag body made of a resin material.

[0081] (Embodiment 3) <Bearing device configuration> FIG. 15 is a schematic side view of a bearing device according to a third embodiment. Referring to FIG. 15, in this embodiment, the first thermal conductor 23a is connected to the outer ring spacer inner ring 33B. In this embodiment, the second thermal conductor 23b is connected to the outer ring spacer outer ring 33A. In other words, in this embodiment, the positions of the first thermal conductor 23a and the second thermal conductor 23b are reversed compared to FIG. 1. Also in this embodiment, the first thermal conductor 23a is connected to the first thermal conductor 23a, and the second thermal conductor 23bb is connected to the second thermal conductor 23b. Therefore, in this embodiment, the positions of the first thermal conductor 23aa and the second thermal conductor 23bb are reversed compared to FIG. 1. In this embodiment, the second thermal conductor 23bb extends in an arc shape so as to contact the inner circumferential surface of the outer ring spacer outer ring 33A. The first thermal conductor 23aa extends in an arc shape so as to contact the outer circumferential surface of the outer ring spacer inner ring 33B. As a result, second heat conducting member 23bb is disposed radially outward of lubricant tank 30 (outward of first heat conducting member 23aa).

[0082] The lubricating oil tank 30 is disposed radially outward of the first power supply circuit 26A, the control circuit 27, and the drive circuit 28. The first power supply circuit 26A, the control circuit 27, and the drive circuit 28 are disposed radially inward of the lubricating oil tank 30. Therefore, the first power supply circuit 26A, the control circuit 27, and the drive circuit 28 may be in contact with the first heat conduction member 23aa, or may be in contact with the outer peripheral surface of the outer ring spacer inner ring 33B.

[0083] In Fig. 15, movable piece 23cc is provided as shown in the following Figs. 16 and 17, but movable piece 23cc is omitted in Fig. 15. Fig. 16 is a perspective schematic view showing the initial state of the lubricant tank in embodiment 3, similar to Fig. 7. Fig. 17 is a perspective schematic view showing a state in which the bimetal has deformed compared to Fig. 16. Referring to Figs. 16 and 17, in this embodiment as well, second heat conducting member 23bb is part of outer frame 30a of lubricant tank 30 and is integrated with lubricant tank 30. Second heat conducting member 23bb contacts lubricant tank 30 (portions other than second heat conducting member 23bb).

[0084] In the present embodiment, the movable piece 23cc is connected to either the second thermal conductor 23b or the second thermal conduction member 23bb. Therefore, in Figures 16 and 17, the movable piece 23cc is in contact with the part of the second thermal conduction member 23bb at the bottom of the figure, and extends from there toward the top of the figure.

[0085] It is preferable that the movable piece 23cc contacts the radially outer wall surface of the bag 30b of the lubricant tank 30. In this embodiment, the second heat conductor 23b and the second heat conduction member 23bb, which are heated, are arranged radially outward of the first heat conductor 23a and the first heat conduction member 23aa, which absorb heat. This allows the bag 30b to be smoothly pressed by the displacement of the movable piece 23cc. This is because the movable piece 23cc is arranged on the same radial side of the lubricant tank 30 as the second heat conduction member 23bb.

[0086] Although not shown, as another example, the movable piece 23cc connected to the second heat conduction member 23bb that contacts the outer ring spacer inner ring 33B, as in embodiment 1, may contact the radially inner wall surface of the bag body 30b of the lubricating oil tank 30.

[0087] As yet another example (not shown), the bearing device 10 of Fig. 15 may be configured without the heat absorption and dissipation section 25, but with a movable piece 23cc that contacts the radially outer or inner wall surface of the bag body 30b of the lubricating oil tank 30. In this case as well, if the volume of the bag body 30b changes due to the displacement of the movable piece 23cc, an effect such as raising the liquid level of the lubricating oil 38 stored therein can be obtained.

[0088] (Fourth embodiment) <Bearing device configuration> Fig. 18 is a schematic side view of a bearing device according to embodiment 4. Referring to Fig. 18, in the bearing device 10 according to this embodiment, the lubricating oil supply unit 20 includes a power storage circuit capable of storing electricity. Specifically, the first power supply circuit 26A has a first power storage circuit 17A. The first power storage circuit 17A has the following features. For this reason, the first power storage circuit 17A of this embodiment is separate from the power storage circuit and power storage unit of the first power supply circuit 26A described in embodiment 1.

[0089] In the bearing device 10 of this embodiment, the operation of the Peltier element 24 changes depending on the state. That is, while the bearing device 10 is operating, the Peltier element 24 can be in two states: a first state and a second state. Specifically, in the first state, the Peltier element 24 operates as a generator, and the power generated by the Peltier element 24 is stored in the first power storage circuit 17A.

[0090] During use, the temperatures of the inner ring 14 and the outer ring 13 rise due to frictional heat with the rolling elements 15. The outer ring 13 is usually incorporated into a spindle housing of a device, etc. Therefore, the outer ring 13 dissipates heat through thermal conduction. This causes a temperature difference between the inner ring 14 and the outer ring 13. The temperature of the inner ring 14 is higher than that of the outer ring 13. The temperature of the outer ring 13 is conducted to the first thermal conductor 23a, and the temperature of the inner ring 14 is conducted to the second thermal conductor 23b. Therefore, a temperature difference occurs between the first thermal conductor 23a and the second thermal conductor 23b in the first state. As a result, a temperature difference occurs between the two end faces of the Peltier element 24, which is arranged between the first thermal conductor 23a and the second thermal conductor 23b. This allows the Peltier element 24 to generate electricity through the Seebeck effect. In this embodiment, similarly to the first embodiment, the first heat conductor 23a is connected to the outer ring spacer outer ring 33A, and the second heat conductor 23b is connected to the outer ring spacer inner ring 33B. The outer ring spacer outer ring 33A absorbs heat, and the outer ring spacer inner ring 33B dissipates heat.

[0091] In this embodiment, the second thermal conductor 23b is also installed on the outer ring spacer 33, just like the first thermal conductor 23a. However, the second thermal conductor 23b is located radially inward of the first thermal conductor, i.e., closer to the inner ring 14. For this reason, the temperature of the second thermal conductor 23b is higher than that of the first thermal conductor 23a.

[0092] In the first state, the bearing device 10 rotates at a medium or low speed. In the first state, the electric power stored in the first power storage circuit 17A is used, for example, to drive the pump 29. The electric power may also be used to drive the control circuit 27 and the drive circuit 28.

[0093] In the second state, the bearing device 10 rotates at a higher speed than in the first state. In the second state, the power stored in the first power storage circuit 17A is supplied to the Peltier element 24. This causes heat to be transferred from the first thermal conductor 23a to the second thermal conductor 23b. In the second state, the Peltier element 24 and the heat absorption and dissipation unit 25 including it operate by the Peltier effect in the same manner as in the first embodiment, and therefore the description thereof will not be repeated.

[0094] The control circuit 27 switches the operation of the Peltier element 24 between a first state in which the rotating wheel is at a low or medium speed and a second state in which the rotating wheel is at a high speed when the detected value of the temperature sensor or bearing rotation sensor of the drive circuit 28 exceeds or falls below an arbitrarily set threshold value.

[0095] <Action and effect> In the bearing device 10 of this embodiment, the lubricating oil supply unit 20 further includes a power storage circuit (first power storage circuit 17A) that can store power. The Peltier element 24 is switchable between a first state and a second state. In the first state, the Peltier element 24 operates as a generator, and power is stored in the first power storage circuit 17A. In the second state, the power stored in the first power storage circuit 17A is supplied to the Peltier element 24A, and heat is transferred from the first thermal conductor 23a to the second thermal conductor 23b.

[0096] Damage to bearing 11 due to heat generation is a concern mainly when bearing device 10 rotates at high speeds. This is because the amount of heat generated is large during high-speed rotation. For this reason, when a rotating shaft for a machine tool, for example, attached to bearing device 10 rotates at medium or slower speeds, Peltier element 24 operates as a generator in the first state, storing electricity in first power storage circuit 17A. Then, in the second state when the rotating shaft switches to high-speed rotation, the power stored in first power storage circuit 17A in the first state is used by heat absorption and radiation unit 25, including Peltier element 24, to absorb and release heat. In this way, the same effects as those of embodiment 1 and the like can be achieved, while further improving the power consumption efficiency of bearing device 10.

[0097] (Embodiment 5) <Bearing device configuration> Fig. 19 is a schematic side view of a bearing device according to embodiment 5. Referring to Fig. 19, in bearing device 10 according to this embodiment, lubricating oil supply unit 20 has two Peltier elements. The two Peltier elements are Peltier element 24a and another Peltier element 24b.

[0098] The lubricant supply unit 20 includes a heat absorption / radiation section 25A and a power generation section 25B. The heat absorption / radiation section 25A has a first thermal conductor 23a1, a second thermal conductor 23b1, and a Peltier element 24a. The power generation section 25B has a first thermal conductor 23a2, a second thermal conductor 23b2, and another Peltier element 24b. The first thermal conductor 23a1 and the first thermal conductor 23a2 are connected to the outer ring of the outer ring spacer 33A. The second thermal conductor 23b1 and the second thermal conductor 23b2 are connected to the inner ring of the outer ring spacer 33B. The Peltier element 24a is sandwiched between the first thermal conductor 23a1 and the second thermal conductor 23b1 and is fixed in close contact therewith. The other Peltier element 24b is sandwiched between the first thermal conductor 23a2 and the second thermal conductor 23b2 and is fixed in close contact therewith.

[0099] The lubricant oil supply unit 20 includes a first power supply circuit 26A. The first power supply circuit 26A has a first power storage circuit 17A. The control circuit 27 has a first control circuit 27A and a second control circuit 27B. The first control circuit 27A and the second control circuit 27B may be integrated, but they do not have to be integrated. The second power storage circuit 17B (another power storage circuit) may be included in the second power supply circuit 26B.

[0100] As shown in FIG. 19 , the heat absorption and radiation unit 25A, the first power supply circuit 26A (first power storage circuit 17A), the first control circuit 27A, the second control circuit 27B, the drive circuit 28, the power generation unit 25B, the second power storage circuit 17B (second power supply circuit 26B), the pump 29, and the lubricating oil tank 30 are arranged in this order in the circumferential direction on the radially inner side of the housing. The heat absorption and radiation unit 25A is connected to the first power supply circuit 26A. The first power supply circuit 26A is connected to the first control circuit 27A. The first control circuit 27A is connected to the drive circuit 28. These are connected to each other by a first wiring 35A. Meanwhile, the second control circuit 27B is connected to the power generation unit 25B. The power generation unit 25B is connected to the second power storage circuit 17B. The second power storage circuit 17B is connected to the pump 29. These are connected to each other by a second wiring 35B. The arrangement of the suction tube 31 and the discharge tube 32 from the pump 29 is the same as in the other embodiments.

[0101] The operation of heat absorption and dissipation unit 25A and first power supply circuit 26A is the same as in embodiment 1. That is, first power supply circuit 26A (first power storage circuit 17A) supplies power to Peltier element 24a, thereby driving Peltier element 24a. This allows heat to be transferred from first thermal conductor 23a1, which is tightly fixed to Peltier element 24a, to second thermal conductor 23b1. Peltier element 24a absorbs and dissipates heat due to the Peltier effect. As a result, first thermal conduction member 23aa absorbs heat, and second thermal conduction member 23bb dissipates heat.

[0102] Meanwhile, the operation of the power generation unit 25B and the second power storage circuit 17B is as follows. During operation, a temperature difference occurs between the first thermal conductor 23a2 on the outer ring side of the adjacent lubricant supply unit 20 and the second thermal conductor 23b2 on the inner ring side due to the temperature difference between the inner ring 14 and the outer ring 13. This causes a temperature difference between the two end faces of the other Peltier element 24b disposed between them. The other Peltier element 24b can utilize this temperature difference to generate electricity through the Seebeck effect. The power obtained by the power generation by the other Peltier element 24b is supplied to the second power supply circuit 26B connected thereto. As a result, power is supplied to the second power storage circuit 17B and stored therein. The power stored in the second power storage circuit 17B is used to drive the pump 29.

[0103] Pump 29 is driven after a preset time has elapsed from the point in time when the voltage of second power storage circuit 17B reaches the drive voltage of pump 29. Next, drive control of pump 29 will be described with reference to Figs. 20 to 23.

[0104] FIG. 20 is a graph showing a first example of the voltage of another storage circuit over time. In this graph, the horizontal axis represents elapsed time, and the vertical axis represents the voltage of the second storage circuit 17B. This also applies to the subsequent FIGS. 21 to 23. Referring to FIG. 20, the initial voltage of the second storage circuit 17B before charging (time T=0) is set to V0. The voltage when the second storage circuit 17B is fully charged is set to V1. The voltage V1 is a voltage for driving the pump 29. The voltage increases from V0 to V1 over time t1 due to charging. As shown in FIG. 20, even after the fully charged voltage V1 is reached, a predetermined time is set as the charging time (delay time). That is, from time t1 to time t2, the voltage of the second storage circuit 17B is maintained at the pump driving voltage V1. After the charging time has elapsed, the second storage circuit 17B is discharged at time t2, and the voltage drops to V0. Thereafter, the cycle of increasing the voltage (i.e., charging), maintaining the voltage, and decreasing the voltage (i.e., discharging) is repeated at a constant cycle t2. At each timing when the voltage decreases from V1 to V0, such as times t2 and t2, the pump 29 is driven to supply lubricating oil to the bearing 11. The drive of the pump may be controlled in this manner.

[0105] Fig. 21 is a graph showing a second example of the voltage of another storage circuit over time. Referring to Fig. 21, second storage circuit 17B is charged from time T=0, and at time t3 when the voltage first rises to drive voltage V1 of pump 29, only discharging is performed, causing the drive voltage to fall to V0. At this point, pump 29 is not driven, and lubricating oil is not supplied to bearing 11. However, the rise in voltage, i.e., charging, and the fall in voltage, i.e., discharging, are repeated. For example, at time 4t3 when the fourth discharge occurs, pump 29 is driven for the first time, and lubricating oil is supplied to bearing 11. The drive of the pump may be controlled in this manner.

[0106] Fig. 22 is a graph showing a third example of the voltage of another storage circuit over time. Referring to Fig. 22, in the third example, second storage circuit 17B is charged from time T=0, as in the second example, and then charging and discharging are repeated. However, in the third example, second storage circuit 17B is charged for a period of time t4, which is longer than t3 in the second example. For example, at time t4, when the third discharge is performed, pump 29 is driven for the first time, and lubricating oil is supplied to bearing 11. Control may be performed in this manner.

[0107] FIG. 23 is a graph showing a fourth example of the voltage of another storage circuit over time. Referring to FIG. 23, in the fourth example, similar to the first example, second storage circuit 17B is charged, the voltage is maintained, and then discharged. Charging is performed over a period of time t5 from time T=0, and the first discharge occurs at time t6. However, the time (t6-t5) during which the voltage is maintained, which is the storage time (delay time) after the first charge, is longer than the corresponding time (t2-t1) in the first example. At time t6, which is the first discharge, pump 29 is driven, and lubricating oil is supplied to bearing 11. The period from charge to discharge thereafter may be shorter than the first time. For example, the third discharge occurs at t7 (t7<3t6).

[0108] <Action and effect> In the bearing device 10 of this embodiment, the lubricating oil supply unit 20 further includes another Peltier element 24b, another electricity storage circuit (second electricity storage circuit 17B) capable of storing electricity, and a pump 29. The pump 29 supplies lubricating oil 38 from a holding section (lubricating oil tank 30) to the inside of the bearing 11. The other Peltier element 24b generates electricity in accordance with the temperature difference between the outer ring 13 side (first thermal conductor 23a2 side) and the inner ring 14 side (second thermal conductor 23b2 side) of the lubricating oil supply unit 20 in the radial direction, and supplies the electricity to the second electricity storage circuit 17B. After a preset time has elapsed since the voltage of the second electricity storage circuit 17B reaches the drive voltage of the pump 29, the pump 29 is driven, and the second electricity storage circuit 17B repeatedly charges and discharges, thereby enabling drive control of the pump 29.

[0109] For example, as in the first embodiment, if there is only one Peltier element 24, the single Peltier element 24 may have two functions: power generation by the Seebeck effect and heat generation by the thermal gradient by the Peltier effect. In this case, however, in order to increase the heat absorption and dissipation effect using the Peltier effect, the temperature difference around the Peltier element 24 becomes excessively large. The thermal stress caused by this temperature difference increases the pressure on the surfaces of the rolling elements 15 of the bearing 11. If this high pressure is applied to the lubricating oil, the film of lubricating oil supplied to the bearing 11 may be broken, and the lubricating effect of the lubricating oil on the bearing 11 may be reduced.

[0110] However, according to this embodiment, as described above, two Peltier elements are provided: the Peltier element 24a for the Peltier effect (for generating heat) and the other Peltier element 24b for the Seebeck effect (for generating electromotive force). In other words, by dividing the roles of each element into the Peltier element 24a for generating heat and the other Peltier element 24b for generating electromotive force, the other Peltier element 24b can generate electromotive force without absorbing or dissipating heat. This allows the second power storage circuit 17B to repeatedly charge and discharge regardless of the operation of the first power storage circuit 17A. This allows the pump 29 to be driven after a preset time has elapsed since the drive voltage of the pump 29 is reached, thereby appropriately controlling the timing of supplying lubricating oil to the bearing 11. For example, consider a case where the temperature difference between the first thermal conductor 23a2 and the second thermal conductor 23b2 is large, resulting in insufficient lubrication of the bearing 11. In this case, the charge / discharge cycle (time interval) can be shortened to increase the number of times lubricating oil is discharged to the bearing 11 per unit time. This makes it possible to suppress a decrease in lubricating effect caused by a break in the oil film.

[0111] The power generating unit 25B generates electricity from the temperature difference between the outer ring 13 and inner ring 14 of the bearing 11. However, in this case, the power generating unit 25B particularly uses the temperature difference between the outer ring spacer outer ring 33A and the outer ring spacer inner ring 33B. Therefore, when the temperature difference is large, the amount of electricity generated increases. In this case, it is preferable to shorten the charging time and shorten the interval between lubricating oil supplies, as shown in Figure 21, for example. Conversely, when the temperature difference is small, it is preferable to lengthen the charging time and lengthen the interval between lubricating oil supplies, as shown in Figure 22, for example.

[0112] Additionally, it is also possible to control second storage circuit 17B as shown in these figures, depending on the amount of power generated by power generation unit 25B. For example, if the time at which the voltage required to drive pump 29 is reached through charging is earlier than the timing at which the required lubricating oil is supplied, control is performed as shown in Figure 20. In other words, a predetermined amount of storage time (delay time) is added even after the fully charged voltage is reached, and management is performed so that the time at which lubricating oil is supplied is delayed.

[0113] Furthermore, in the case of a grease-sealed rolling bearing 11, sufficient lubrication can be ensured by the grease sealed in the bearing 11 at the beginning of operation. For this reason, as shown in Fig. 23, the initial supply of lubricant oil may be started after the lubrication life of the grease sealed in the bearing 11 has expired. In this way, delaying the initial supply of lubricant oil extends the life of the bearing 11, and the time until maintenance can be extended.

[0114] The control circuit 27 changes the drive of the second storage circuit 17B in accordance with the amount of power generated by the power generation unit 25B, for example, when the detection value of the temperature sensor or bearing rotation sensor of the drive circuit 28 exceeds or falls below an arbitrarily set threshold value.

[0115] (Embodiment 6) <Bearing device configuration> FIG. 24 is a schematic side view of a bearing device according to a first example of the sixth embodiment. Referring to FIG. 24, in the bearing device 10 according to this embodiment, the first heat conducting member 23aa extends in an arc shape so as to contact the outer peripheral surface of the outer ring spacer outer ring 33A connected to the first heat conductor 23a. In this respect, this embodiment differs in configuration from the first embodiment (FIG. 1), in which the first heat conducting member 23aa is connected to the first heat conductor 23a and extends in an arc shape from there so as to contact the inner peripheral surface of the outer ring spacer outer ring 33A. As shown in FIG. 24, the first heat conducting member 23aa may extend so as to contact the entire circumferential surface of the outer ring spacer outer ring 33A.

[0116] Although not shown in FIG. 24, a first thermal conductive member 23aa may also be connected to first thermal conductor 23a in this embodiment.

[0117] Fig. 25 is a schematic side view of a bearing device according to a second example of the sixth embodiment. Referring to Fig. 25, the first heat conducting member 23aa may extend so as to contact only a portion of the circumferential direction of the outer ring spacer outer ring 33A. For example, the first heat conducting member 23aa may not contact the area radially outward of the drive circuit 28. In other words, the first heat conducting member 23aa may contact only the area in the circumferential direction other than the area where the drive circuit 28 is disposed.

[0118] <Action and effect> The examples of Figures 24 and 25 can also achieve substantially the same effects as the example of Figure 1. First heat conductor 23a absorbs heat, and then outer ring spacer outer ring 33A in contact with first heat conductor 23a absorbs heat. Furthermore, first heat conducting member 23aa absorbs heat. Because copper or aluminum forming first heat conducting member 23aa has high thermal conductivity, the entire first heat conducting member 23aa absorbs heat in a short time. This further cools outer ring spacer outer ring 33A in contact with first heat conducting member 23aa. As long as the first heat conducting member 23aa can be cooled quickly, first heat conducting member 23aa may be disposed radially outward of outer ring spacer outer ring 33A.

[0119] (Embodiment 7) <Machinery Configuration> The configuration of a spindle for a machine tool, which is an example of a mechanical device to which the bearing devices according to the first to sixth embodiments are applied, will be described with reference to FIGS.

[0120] FIG. 26 is a cross-sectional view of a machine device to which the bearing device shown in FIG. 1 is applied. FIG. 27 is a cross-sectional view of the machine device shown in FIG. 26. FIG. 26 includes a cross-sectional view of a portion taken along line XXVI-XXVI in FIG. 27. Referring to FIGS. 26 and 27, a machine tool spindle 50 serving as a machine device according to this embodiment mainly includes a rotating shaft 51, a spindle housing 52, an outer peripheral housing 53, and a bearing device 10 (see FIG. 1). The spindle housing 52 (housing) is disposed on the outer peripheral side of the rotating shaft 51 so as to surround the periphery of the rotating shaft 51. The outer peripheral housing 53 is disposed on the outer periphery of the spindle housing 52. The bearing device 10 supports the rotating shaft 51 rotatably relative to the spindle housing 52.

[0121] Two bearing devices are arranged on the outer periphery of the rotating shaft 51. The inner ring 14 and inner ring spacer 34 of the bearing in the bearing device are fitted and fixed to the side surface of the rotating shaft 51. The outer ring 13 and outer ring spacer outer ring 33A of the bearing are fitted and fixed to the inner circumferential surface of the spindle housing 52. The bearing including the inner ring 14, outer ring 13, and rolling elements 15, which are balls, arranged between the inner ring 14 and outer ring 13 is an angular contact ball bearing. A lubricant supply unit 20 is arranged between the outer ring spacer outer ring 33A and outer ring spacer inner ring 33B, which are arranged adjacent to the bearings. Another spacer is fitted and fixed to the rotating shaft 51 and spindle housing 52 between the two bearings (on the side opposite to the side where the lubricant supply unit is arranged), and abuts against the inner ring 14 and outer ring 13.

[0122] A through-hole is formed in an area facing the control circuit 27 of the lubricant supply unit, penetrating the outer ring spacer outer ring 33A, the spindle housing 52, and the outer housing 53. A flat portion is provided on the surface of the outer housing 53 at the outer peripheral end 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 output board 56 and the control circuit 27 of the lubricant supply unit 20 are electrically connected, for example, by a contact probe 54. The contact probe 54 is disposed inside the through-hole. One end of the contact probe 54 contacts an electrode pad (not shown) of the control circuit 27, and the other end of the contact probe 54 is connected to the output board 56 by a conductive wire 55. The contact probe 54 may be connected and fixed to the output board 56 side. The output board 56 and the control circuit 27 may be connected by wire as described above, or may be connected by other connection means (for example, optical communication means using a light-emitting element and a light-receiving element).

[0123] A cover member 58 is fixed to the base 57 so as to cover the output board 56 arranged on the base 57. A battery, which is a power source for driving the circuit of the output board 56, and a storage unit are arranged on the output board 56. The battery may be, for example, a coin battery or a button battery. A lithium battery is preferably used as the battery. A holder for securing such a battery is arranged on the surface of the output board 56. The storage unit may be, for example, a holding unit (slot) for connecting and securing a card-type external storage medium, and the external storage medium removably secured to the holding unit. Any conventionally known storage medium, such as a memory card, may be used as the external storage medium.

[0124] Cover member 58 has a U-shaped elongated hole (a hole for arranging a fixing bolt) formed therein so that cover member 58 can be removed from base 57 simply by loosening fixing bolt 59, which is a connecting member to base 57. The battery and external storage medium can be replaced with cover member 58 removed from base 57.

[0125] The output board 56, sealed by the base 57 and cover member 58, constitutes the main part of the voltage monitoring unit. The base 57 and cover member 58 can be provided with any waterproof structure to prevent the intrusion of coolant used during processing using the processing machine spindle. Examples of waterproof structures that can be used include packing, O-rings, caulking, and resin molding.

[0126] The machine tool spindle 50 described above also includes a unit main body and a lubricant supply unit. The unit main body is connected to the bearing 11 (see FIG. 2) including the inner ring 14, outer ring 13, and rolling elements 15 as described above, and includes a control unit having a control circuit 27 (see FIG. 1). The lubricant supply unit includes an external output unit 70, which is a voltage monitoring unit connected to the control unit by a connection line (contact probe 54).

[0127] The unit main body includes a control unit, a power supply unit, a lubricant supply unit, and a lubricant storage unit (lubricant tank 30). The control unit includes a control circuit 27. The power supply unit includes a heat absorption / radiation unit 25 (see FIG. 1) and a power supply circuit 26 (see FIG. 1). The lubricant supply unit includes a power supply circuit 26, a drive circuit 28, and a pump 29. The control unit is connected to the power supply unit and the lubricant supply unit. The control unit controls the lubricant supply state in the lubricant supply unit and acquires data related to the lubricant supply state. Examples of such data include the timing of lubricant supply, the interval between lubricant supply, and data on the voltage (storage voltage) in the power supply circuit (specifically, the power storage unit) when pump 29 is operated.

[0128] Any configuration can be adopted for the connection between the control circuit 27 of the control unit and the output board 56 of the external output unit 70. However, for example, the calculation unit (microcomputer) installed in the control circuit 27 and the calculation unit of the output board 56 may be connected by a connection wire. The calculation unit of the control circuit 27 is connected to a power source and a ground by wiring or the like. Furthermore, in the output board 56, the calculation unit is connected to a battery and a memory unit. A signal (a signal transmitted from the control circuit 27) indicating data such as voltage can be transmitted from the calculation unit to the memory unit.

[0129] With the above configuration, data related to the lubricant supply status transmitted from the control circuit 27 is stored in the memory unit of the output board 56. The timing for transmitting the data from the control circuit 27 to the output board 56 can be any timing. However, for example, the data may be transferred from the control circuit 27 to the output board 56 when the memory unit of the control circuit 27 (such as a memory element included in the calculation unit or a memory element provided in the control circuit 27 independently of the calculation unit) is full of the data. If the data includes data on the time change in the stored voltage of the power supply unit, the data can be saved in an external storage medium via the memory unit of the output board 56 and then imported into an external computer or the like using the external storage medium. In this way, the status of the lubricant supply unit (such as the power generation status and the operating status of the pump 29) can be checked on the external computer.

[0130] <Operation of mechanical device> 26 and 27 show a machine tool spindle 50, which is an example of a mechanical device, in which a rotating shaft 51 is connected to a predetermined drive shaft and is rotatable relative to a spindle housing 52. In a bearing device that supports the rotating shaft 51, a lubricating oil supply unit periodically supplies lubricating oil to bearings 11 (see FIG. 2). This improves the reliability and durability of the machine tool spindle 50.

[0131] The timing of oil supply to the bearing 11 by the lubricating oil supply unit 20 in the bearing device 10 is arbitrary. However, when the rotating shaft 51 rotates at high speed, a swirling air flow occurs around the rolling elements 15 as the bearing 11 rotates. This can cause the lubricating oil to spread, which can hinder smooth delivery of the lubricating oil. Therefore, from the perspective of avoiding such problems, it is preferable to oil the bearing 11 while the bearing 11 is stopped or when the bearing 11 is rotating at a rotational speed with a dn value of 200,000 or less.

[0132] <Action and effect> The mechanical device (machine tool spindle 50) according to this embodiment includes a rotating shaft 51, a housing (spindle housing 52) arranged on the outer periphery of the rotating shaft 51, and the above-described bearing device 10 that rotatably supports the rotating shaft 51 relative to the housing. This allows the bearing device 10 to operate stably for a long period of time, which in turn allows the mechanical device to operate stably for a long period of time.

[0133] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. Unless there is a contradiction, at least two of the embodiments disclosed herein may be combined. The basic scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0134] Various aspects of the present disclosure are summarized below as appendices.

[0135] (Appendix 1) A bearing, a lubricating oil supply unit for supplying lubricating oil to the bearing, The bearing is an outer ring having an outer ring rolling surface on its inner circumferential surface; an inner ring having an inner ring rolling surface on its outer peripheral surface and disposed inside the outer ring so that the inner ring rolling surface faces the outer ring rolling surface, The lubricating oil supply unit includes: a retaining portion for retaining lubricating oil to be supplied to the inside of the bearing; A Peltier element, a first thermal conductor and a second thermal conductor sandwiching the Peltier element; a power source capable of supplying power to the Peltier element; The bearing device is configured such that heat can be transferred from the first thermal conductor to the second thermal conductor by driving the Peltier element with the power supply.

[0136] (Appendix 2) a spacer disposed so as to sandwich the lubricant oil supply unit; the spacer contacts the bearing, When the Peltier element is driven, the first thermal conductor can absorb heat from the spacer; 2. The bearing device according to claim 1, wherein the second thermal conductor is capable of dissipating heat to the holding portion by driving the Peltier element.

[0137] (Appendix 3) 3. The bearing device according to claim 2, wherein the Peltier element, the first thermal conductor, the second thermal conductor, and the power source are installed in the spacer connected to a fixed ring that is either the outer ring or the inner ring.

[0138] (Appendix 4) a first thermal conductive member connected to the first thermal conductor; 4. The bearing device according to claim 2, wherein a second heat conducting member is connected to the second heat conductor.

[0139] (Appendix 5) 5. The bearing device according to claim 4, wherein the first heat conducting member and the second heat conducting member are primarily composed of either copper or aluminum.

[0140] (Appendix 6) 6. The bearing device according to claim 4, wherein the first heat conducting member is in contact with the spacer, and the second heat conducting member is in contact with the retaining portion.

[0141] (Appendix 7) The holding portion includes a resin bag, a movable piece is connected to either the second thermal conductor or the second thermal conduction member; the movable piece is formed of a bimetal, The bearing device according to any one of appendix 4 to 6, wherein the movable piece is in contact with the holding portion and is capable of pressing the bag body and changing the volume of the bag body in accordance with the displacement of the movable piece.

[0142] (Appendix 8) The lubricant oil supply unit further includes a storage circuit capable of storing electricity, The bearing device according to any one of appendixes 1 to 7, wherein the Peltier element operates as a generator and is switchable between a first state in which power is stored in the power storage circuit and a second state in which power stored in the power storage circuit is supplied to the Peltier element and heat is transferred from the first thermal conductor to the second thermal conductor.

[0143] (Appendix 9) The lubricating oil supply unit includes: Other Peltier elements, Another storage circuit capable of storing electricity; a pump for supplying the lubricating oil from the holding portion to the inside of the bearing, the other Peltier element generates electricity in response to a temperature difference between the outer ring side and the inner ring side of the lubricating oil supply unit in a radial direction, and supplies power to the other power storage circuit; The bearing device according to any one of appendix 1 to 8, wherein the pump is driven after a preset time has elapsed from the point in time when the voltage of the other power storage circuit reaches the drive voltage of the pump, and the other power storage circuit is capable of repeatedly charging and discharging, thereby controlling the drive of the pump.

[0144] (Appendix 10) The lubricating oil is sealed in the bearing in advance, 10. The bearing device according to any one of claims 1 to 9, wherein the enclosed lubricating oil is grease.

[0145] (Appendix 11) A rotation axis; a housing disposed on an outer circumferential side of the rotary shaft; A mechanical device comprising: the bearing device according to any one of appendices 1 to 10, which rotatably supports the rotating shaft relative to the housing. [Explanation of symbols]

[0146] 10 bearing device, 11 bearing, 13 outer ring, 14 inner ring, 14a inclined portion, 15 rolling element, 16 retainer, 16b retainer inner diameter surface, 17A first power storage circuit, 17B second power storage circuit, 20 lubricating oil supply unit, 23a, 23a1, 23a2 first heat conductor, 23aa first heat conduction member, 23b, 23b1, 23b2 second heat conductor, 23bb second heat conduction member, 23cc moving piece, 24, 24a Peltier element, 24b other Peltier element, 25, 25A heat absorption and dissipation portion, 25B power generation portion, 26A first power supply circuit, 26B second power supply circuit, 27 control circuit, 27A first control circuit, 27B second control circuit, 28 drive circuit, 29 pump, 30 lubricating oil tank, 30a outer frame, 30b Bag body, 31 suction tube, 32 discharge tube, 32a nozzle, 33 outer ring spacer, 33A outer ring spacer outer ring, 33B outer ring spacer inner ring, 33C interposition portion, 34 inner ring spacer, 35 wiring, 35A first wiring, 35B second wiring, 36 gap, 38 lubricating oil, 50 machine tool spindle, 51 rotating shaft, 52 spindle housing, 53 outer peripheral housing, 54 contact probe, 55 conductive wire, 56 output board, 57 base, 58 cover member, 59 fixing bolt, 70 external output portion, L0 center line.

Claims

1. A bearing, a lubricating oil supply unit for supplying lubricating oil to the bearing, The bearing is an outer ring having an outer ring rolling surface on its inner circumferential surface; an inner ring having an inner ring rolling surface on its outer peripheral surface and disposed inside the outer ring so that the inner ring rolling surface faces the outer ring rolling surface, The lubricating oil supply unit includes: a retaining portion for retaining lubricating oil to be supplied to the inside of the bearing; A Peltier element, a first thermal conductor and a second thermal conductor sandwiching the Peltier element; a power source capable of supplying power to the Peltier element; The bearing device is configured such that heat can be transferred from the first thermal conductor to the second thermal conductor by driving the Peltier element with the power supply.

2. a spacer disposed so as to sandwich the lubricant oil supply unit; the spacer contacts the bearing, When the Peltier element is driven, the first thermal conductor can absorb heat from the spacer; The bearing device according to claim 1 , wherein the second heat conductor is capable of dissipating heat to the holding portion by driving the Peltier element.

3. 3. The bearing device according to claim 2, wherein the Peltier element, the first thermal conductor, the second thermal conductor, and the power source are installed in the spacer connected to a fixed ring that is one of the outer ring and the inner ring.

4. a first thermal conductive member connected to the first thermal conductor; The bearing device according to claim 2 , wherein a second heat conducting member is connected to the second heat conductor.

5. The bearing device according to claim 4 , wherein the first heat conducting member and the second heat conducting member are primarily made of either copper or aluminum.

6. 5. The bearing device according to claim 4, wherein the first heat conducting member is in contact with the spacer, and the second heat conducting member is in contact with the retaining portion.

7. The holding portion includes a resin bag, a movable piece is connected to either the second thermal conductor or the second thermal conduction member; the movable piece is formed of a bimetal, 5. The bearing device according to claim 4, wherein the movable piece is in contact with the holding portion and is capable of pressing the bag body and changing the volume of the bag body in accordance with the displacement of the movable piece.

8. The lubricant oil supply unit further includes a storage circuit capable of storing electricity, 3. The bearing device according to claim 1, wherein the Peltier element operates as a generator and is switchable between a first state in which electric power is stored in the power storage circuit and a second state in which electric power stored in the power storage circuit is supplied to the Peltier element and heat is transferred from the first thermal conductor to the second thermal conductor.

9. The lubricating oil supply unit includes: Other Peltier elements, Another storage circuit capable of storing electricity; a pump for supplying the lubricating oil from the holding portion to the inside of the bearing, the other Peltier element generates electricity in response to a temperature difference between the outer ring side and the inner ring side of the lubricating oil supply unit in a radial direction, and supplies power to the other power storage circuit; 3. The bearing device according to claim 1, wherein the pump is driven after a preset time has elapsed since the voltage of the other power storage circuit reaches a drive voltage of the pump, and the other power storage circuit is repeatedly charged and discharged, thereby controlling the drive of the pump.

10. The lubricating oil is sealed in the bearing in advance, 3. The bearing device according to claim 1, wherein the enclosed lubricating oil is grease.

11. A rotation axis; a housing disposed on an outer circumferential side of the rotary shaft; A mechanical device comprising: the bearing device according to claim 1 or 2, which rotatably supports the rotating shaft relative to the housing.

Images