JP7657063B2 - Bearing device and spindle device - Google Patents

Description

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

Patent document 1 (JP 2012-37013 A) describes a bearing device. The bearing device described in Patent document 1 has a housing, a shaft, a first rolling bearing, a second rolling bearing, an inner ring spacer, an outer ring spacer, a temperature sensor, and wiring.

The housing has a first end and a second end opposite the first end along the extension direction of the shaft. The housing has an inner peripheral surface and an outer peripheral surface. A groove recessed toward the outer peripheral surface is formed in the inner peripheral surface. The groove extends from the first end toward the second end.

The shaft is housed in the housing. The first rolling bearing and the second rolling bearing rotatably support the shaft within the housing. The first rolling bearing has a first inner ring attached to the shaft and a first outer ring attached to the inner circumferential surface of the housing. The second rolling bearing has a second inner ring attached to the shaft and a second outer ring attached to the inner circumferential surface of the housing. The second rolling bearing is disposed at a position farther from the first end than the first rolling bearing in the extension direction of the shaft.

The inner ring spacer is attached to the shaft. The inner ring spacer is sandwiched between the first inner ring and the second inner ring in the extension direction of the shaft. The outer ring spacer is attached to the inner circumferential surface of the housing. The outer ring spacer is sandwiched between the first outer ring and the second outer ring in the extension direction of the shaft. The temperature sensor is an infrared sensor for non-contact detection of the temperatures of the first rolling bearing and the second rolling bearing. The temperature sensor is attached to the outer ring spacer.

One end of the wiring is connected to the temperature sensor, and the other end is connected to the outside of the bearing device. The wiring is passed through a groove formed on the inner surface of the housing.

JP 2012-37013 A

In the bearing device described in Patent Document 1, the temperature sensor is connected to the outside of the bearing device by wiring, so the wiring gets in the way during assembly, reducing workability when assembling the bearing device.

The present invention has been made in consideration of the problems of the conventional technology as described above. More specifically, the present invention provides a bearing device and a spindle device that can improve the workability during assembly.

The bearing device of the present invention includes a cylindrical housing having a first inner peripheral surface and a first outer peripheral surface, a shaft accommodated in the housing, a rolling bearing rotatably supporting the shaft within the housing, a non-rotating member attached to the first inner peripheral surface, a sensor attached to the non-rotating member for detecting the state of the rolling bearing, a substrate electrically connected to the sensor, and a cover member. The housing has a first end and a second end opposite the first end. The non-rotating member is located closer to the second end than the rolling bearing. A groove recessed toward the first outer peripheral surface is formed in the first inner peripheral surface. The groove extends from the first end toward the second end. The cover member is attached to the first end. A through hole communicating with the groove is formed in the cover member. The substrate is disposed in the groove and in the through hole.

In the above-mentioned bearing device, the substrate may be disposed radially outward from the non-rotating member and the outer ring of the rolling bearing.

The bearing device may further include a spacer. The non-rotating member may have a second inner peripheral surface facing the shaft and a second outer peripheral surface facing the first inner peripheral surface. The spacer may be disposed on the second outer peripheral surface. The substrate may be attached to the spacer. In the bearing device, the non-rotating member may have a second inner peripheral surface facing the shaft and a second outer peripheral surface facing the first inner peripheral surface. The second outer peripheral surface may include a protruding portion protruding on the side opposite to the second inner peripheral surface. The substrate may be attached to the protruding portion.

In the above-mentioned bearing device, the substrate may be divided into a first substrate on which the first connector is mounted and a second substrate on which the second connector is mounted and which is electrically connected to the sensor. The second connector may be detachably attached to the first connector.

The bearing device may further include a case that houses at least the first substrate. In the bearing device, the case may be attached to the cover member.

The bearing device may further include a first communication unit and a second communication unit. The first communication unit may be mounted on the substrate and configured to wirelessly transmit an output signal of the sensor to the second communication unit. The second communication unit may be configured to wirelessly supply power for driving the sensor to the first communication unit.

The bearing device may further include a third communication unit having an antenna and mounted on the substrate, and a generator that supplies power generated by the rotation of the shaft to the sensor and the third communication unit. The third communication unit may be configured to wirelessly transmit the output signal of the sensor from the antenna.

In the above bearing device, the non-rotating member may be an outer ring spacer.

The spindle device of the present invention is equipped with a bearing device and a motor that rotates the shaft.

The bearing device and spindle device of the present invention can improve workability during assembly.

FIG. 2 is a cross-sectional view of the spindle device 100. FIG. 2 is an enlarged view of region II in FIG. 1 . 3 is a cross-sectional view taken along line III-III in FIG. 2. 2 is a plan view of a substrate 42 in the spindle device 100. FIG. 2 is a cross-sectional view of a bearing device 30 in a spindle device 200. FIG. 2 is a plan view of a substrate 42 in the spindle device 200. FIG. 3 is a cross-sectional view of a bearing device 30 in a spindle device 300. FIG. 4 is a plan view of a substrate 42 in a spindle device 300. FIG. 4 is a cross-sectional view of a bearing device 30 in a spindle device 400. FIG. 4 is a cross-sectional view of a bearing device 30 in a spindle device 500. FIG.

Details of the embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts will be given the same reference symbols, and redundant explanations will not be repeated.

First Embodiment
A spindle device according to a first embodiment (hereinafter, referred to as "spindle device 100") will be described below.

<Overall Configuration of Spindle Device 100>
Fig. 1 is a cross-sectional view of spindle device 100. Fig. 2 is an enlarged view of region II in Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. Note that in Fig. 3, illustrations of members not necessary for explanation are omitted. As shown in Figs. 1 to 3, spindle device 100 has a shaft 10, an outer cylinder 20, a bearing device 30, a motor 60, an end member 70, and a bearing device 80. Spindle device 100 is, for example, a built-in motor type spindle device for a machine tool.

<Configuration of shaft 10>
Shaft 10 has a central axis of rotation A. In the following, the direction along the central axis of rotation A will be referred to as the axial direction, the direction along the circumference passing through the central axis of rotation A will be referred to as the circumferential direction, and the direction passing through the central axis of rotation A and perpendicular to the axial direction will be referred to as the radial direction.

The shaft 10 has a first end 10a and a second end 10b. The first end 10a and the second end 10b are the ends of the shaft 10 in the axial direction. A cutting tool such as an end mill is attached to the first end 10a. The second end 10b is the end opposite the first end 10a.

The shaft 10 has a first shaft portion 11, a second shaft portion 12, and a tip portion 13. The first shaft portion 11 extends from the second end 10b toward the first end 10a. The tip portion 13 is located at the first end 10a. The second shaft portion 12 extends so as to connect the first shaft portion 11 and the tip portion 13.

The outer diameter of the shaft 10 at the first shaft portion 11 is smaller than the outer diameter of the shaft at the second shaft portion 12. The outer diameter at the second shaft portion 12 is smaller than the outer diameter at the end of the tip portion 13 on the second shaft portion 12 side. In other words, steps are formed on the outer peripheral surface of the shaft 10 at the boundary between the first shaft portion 11 and the second shaft portion 12 and at the boundary between the second shaft portion 12 and the tip portion 13.

<Configuration of outer cylinder 20>
The outer cylinder 20 has a cylindrical shape extending along the axial direction. The outer cylinder 20 has a first end 20a and a second end 20b in the axial direction. The first end 20a is the end of the outer cylinder 20 on the first end 10a side. The second end 20b is the end of the outer cylinder 20 on the second end 10b side. In other words, the second end 20b is the end opposite the first end 20a. The outer cylinder 20 has an inner circumferential surface 20c.

<Configuration of Bearing Device 30>
The bearing device 30 includes a housing 31, a rolling bearing 32, a rolling bearing 33, an inner ring spacer 34, an outer ring spacer 35, a cover member 36, a nut 37, a spacer 38, a sensor 39, wiring 40, wiring 41, and a substrate 42. The shaft 10 constitutes a part of the bearing device 30.

The housing 31 has a cylindrical shape extending along the axial direction. The housing 31 has a first end 31a and a second end 31b in the axial direction. The first end 31a is the end of the housing 31 on the first end 10a side. The second end 31b is the end of the housing 31 on the second end 10b side. In other words, the second end 31b is the end opposite the first end 31a. The shaft 10 is housed inside the housing 31.

The housing 31 is housed inside the outer cylinder 20. More specifically, the housing 31 has an inner peripheral surface 31c and an outer peripheral surface 31d, and is disposed so that the outer peripheral surface 31d is in contact with the inner peripheral surface 20c.

A groove 31ca is formed on the inner circumferential surface 31c. In the groove 31ca, the inner circumferential surface 31c is recessed toward the outer circumferential surface 31d. The groove 31ca extends from the first end 31a toward the second end 31b. A groove 31da is formed on the outer circumferential surface 31d. The groove 31da is formed in a spiral shape around the central axis of rotation A. The groove 31da and the inner circumferential surface 20c define a flow path through which a refrigerant for cooling the bearing device 30 flows.

The rolling bearing 32 is, for example, an angular ball bearing. The rolling bearing 32 rotatably supports the shaft 10 within the housing 31. The rolling bearing 32 supports the radial load and thrust load acting on the shaft 10.

The rolling bearing 32 has an inner ring 32a, an outer ring 32b, a rolling element 32c, and a retainer 32d. The inner ring 32a is attached to the shaft 10 (second shaft portion 12). The outer ring 32b is attached to the inner peripheral surface 31c. The inner ring 32a contacts a step formed on the outer peripheral surface of the shaft 10 at the boundary between the second shaft portion 12 and the tip portion 13 from the second end 10b side. The outer peripheral surface of the inner ring 32a and the inner peripheral surface of the outer ring 32b face each other. The rolling element 32c is disposed between the inner ring 32a and the outer ring 32b. The number of the rolling elements 32c is plural. The retainer 32d is disposed between the inner ring 32a and the outer ring 32b and holds the rolling element 32c. The cage 32d keeps the distance between two adjacent rolling elements 32c in the circumferential direction within a certain range.

The rolling bearing 33 is, for example, an angular ball bearing. The rolling bearing 33 rotatably supports the shaft 10 in the housing 31. The rolling bearing 33 supports the radial load and thrust load acting on the shaft 10. The rolling bearing 33 has an inner ring 33a, an outer ring 33b, a rolling element 33c, and a retainer 33d. The inner ring 33a is attached to the shaft 10 (the second shaft portion 12). The outer ring 33b is attached to the inner peripheral surface 31c. The outer peripheral surface of the inner ring 33a and the inner peripheral surface of the outer ring 33b face each other. The rolling element 33c is disposed between the inner ring 33a and the outer ring 33b. The number of the rolling elements 33c is plural. The retainer 33d is disposed between the inner ring 33a and the outer ring 33b and holds the rolling element 33c. The cage 33d keeps the distance between two adjacent rolling elements 33c in the circumferential direction within a certain range.

The rolling bearing 32 and the rolling bearing 33 are arranged spaced apart from each other in the axial direction. The rolling bearing 32 is closer to the first end 10a than the rolling bearing 33. The rolling bearing 32 and the rolling bearing 33 are in a back-to-back (DB) combination. The rolling bearing 32 and the rolling bearing 33 may also be in a face-to-face (DF) combination.

The inner ring spacer 34 is attached to the shaft 10 (second shaft portion 12). The inner ring spacer 34 contacts the inner ring 32a at the end on the first end 10a side, and contacts the inner ring 33a at the end on the second end 10b side. From another perspective, the inner ring spacer 34 is sandwiched between the inner rings 32a and 33a in the axial direction. The inner ring spacer 34 has a cylindrical shape that extends along the axial direction.

The outer ring spacer 35 is attached to the inner peripheral surface 31c. Therefore, the outer ring spacer 35 is a non-rotating member. Here, "non-rotating member" refers to a member that does not rotate with respect to the housing 31 (i.e., is attached to the housing 31). The outer ring spacer 35 contacts the outer ring 32b at the end on the first end 10a side, and contacts the outer ring 33b at the end on the second end 10b side. From another perspective, the outer ring spacer 35 is sandwiched between the outer rings 32b and 33b in the axial direction. The outer ring spacer 35 has a cylindrical shape that extends along the axial direction. The outer peripheral surface of the outer ring spacer 35 contacts the inner peripheral surface 31c.

A spacer 35a is attached to the outer peripheral surface of the outer ring spacer 35. At least a portion of the spacer 35a is located in the groove 31ca. A through hole 35b is formed in the outer ring spacer 35. The through hole 35b extends in the radial direction. One end of the through hole 35b reaches the inner peripheral surface of the outer ring spacer 35, and the other end of the through hole 35b reaches the outer peripheral surface of the outer ring spacer 35. A through hole 35c connected to the through hole 35b is formed in the spacer 35a. The spacer 35a may be formed integrally with the outer ring spacer 35. That is, a protrusion that protrudes toward the opposite side of the inner peripheral surface of the outer ring spacer 35 may be formed on the outer peripheral surface of the outer ring spacer 35.

The lid member 36 has a cylindrical portion 36a and a flange portion 36b. The cylindrical portion 36a has a cylindrical shape extending along the axial direction. The outer peripheral surface of the cylindrical portion 36a is in contact with the inner peripheral surface 31c. The cylindrical portion 36a sandwiches the outer ring 32b between itself and the outer ring spacer 35 in the axial direction. The flange portion 36b protrudes from the end of the cylindrical portion 36a opposite the outer ring 32b in a plane perpendicular to the axial direction. The flange portion 36b is fixed to the first end 31a. In this way, the lid member 36 is attached to the first end 31a.

A through hole 36c is formed in the cover member 36. The through hole 36c penetrates the cover member 36. More specifically, the through hole 36c penetrates the flange portion 36b along the axial direction. The through hole 36c is connected to the groove 31ca.

The nut 37 is attached (screwed) to the shaft 10. The nut 37 is located axially closer to the second end 10b than the rolling bearing 33 (inner ring 33a). The spacer 38 is attached to the shaft 10. The spacer 38 is in contact with the inner ring 33a at its end on the first end 10a side, and in contact with the nut 37 at its end on the second end 10b side. From another perspective, the spacer 38 is sandwiched between the inner ring 33a and the nut 37 in the axial direction. By moving the nut 37 toward the first end 10a side, a preload is applied to the rolling bearing 32 and the rolling bearing 33. This preload is a fixed-position preload.

The sensor 39 is attached to the outer ring spacer 35. More specifically, the sensor 39 is attached to the inner peripheral surface of the outer ring spacer 35. The sensor 39 is, for example, a heat flux sensor. The sensor 39 is arranged to face the rotating member (the inner ring 32a, the inner ring 33a, or the inner ring spacer 34) attached to the shaft 10. This makes it possible to detect the heat flux from the shaft 10 side to the housing 31 side. When an abnormality occurs in the rolling bearing 32 (rolling bearing 33), a difference occurs between the temperature of the inner ring 32a (inner ring 33a) and the temperature of the outer ring 32b (outer ring 33b). Since the heat flux from the shaft 10 side to the housing 31 side changes prior to this temperature difference, the above heat flux is detected by the sensor 39, and thus an abnormality in the rolling bearing 32 (rolling bearing 33) can be detected quickly (early). The sensor 39 may be a sensor other than a heat flux sensor (for example, a temperature sensor).

The number of sensors 39 is, for example, multiple. In the example shown in FIG. 1 and FIG. 2, the number of sensors 39 is two. Of the two sensors 39, the sensor 39 arranged on the rolling bearing 32 side is sensor 39a, and the sensor 39 arranged on the rolling bearing 33 side is sensor 39b.

Wiring 40 is electrically connected to sensor 39a. Wiring 41 is electrically connected to sensor 39b. Wiring 40 and wiring 41 are pulled out through through-holes 35b and 35c. An output signal from sensor 39a (sensor 39b) is output via wiring 40 (wiring 41). Furthermore, power is supplied from wiring 40 (wiring 41) to sensor 39a (sensor 39b) that requires a power source. That is, wiring 40 (wiring 41) may include a signal wiring and a power wiring.

The substrate 42 is disposed in the groove 31ca and in the through hole 36c. The substrate 42 is electrically connected to the sensor 39a and the sensor 39b by the wiring 40 and the wiring 41. The substrate 42 is attached to the spacer 35a.

Figure 4 is a plan view of the substrate 42 in the spindle device 100. As shown in Figure 4, wiring 42a is formed on the surface of the substrate 42. At the end of wiring 42a, a through hole 42b is formed which penetrates the substrate 42 in the thickness direction. Wiring 40 and wiring 41 are connected to through hole 42b, for example, by soldering. This electrically connects substrate 42 to sensor 39 (sensor 39a and sensor 39b).

The substrate 42 is equipped with a processing circuit 43 and a connector 44. The processing circuit 43 and the connector 44 are connected to the wiring 42a. The processing circuit 43 includes, for example, an amplifier (instrumentation amplifier) and a microcontroller.

The output signal from the sensor 39 is amplified by the amplifier to become an analog signal. This amplified analog signal is converted to a digital signal in the ADC (Analog to Digital Converter) circuit of the microcontroller, and is also converted to a serial communication signal conforming to, for example, RS422 or CAN (Controller Area Network) in the communication circuit of the microcontroller. This makes it possible to suppress an increase in the number of wires connected to the connector 44, even if the number of sensors 39 increases.

A cable with a socket (not shown) is connected to the connector 44. The output signal from the sensor 39 is output to a control device (not shown) through the cable with a socket. The connector 44 is located outside the bearing device 30. It is preferable that the surface of the substrate 42 is covered with a coating material or an insulating material such as a resin material.

<Configuration of Motor 60>
1 , the motor 60 has a cylindrical member 61, a rotor 62, and a stator 63. The cylindrical member 61 is attached to the shaft 10. The end of the cylindrical member 61 on the first end 10a side is in contact with a step formed on the outer circumferential surface 10c at the boundary between the first shaft portion 11 and the second shaft portion 12.

The rotor 62 is attached to the cylindrical member 61. The stator 63 is attached to the inner peripheral surface 20c so as to face the rotor 62. The direction of the current flowing through the stator 63 is sequentially switched by the inverter circuit, generating a rotational force on the rotor 62, which rotates the shaft 10 around the central axis of rotation A.

<Configuration of end member 70>
The end member 70 is attached to the second end 20b. A through hole 71 is formed in the end member 70. The through hole 71 passes through the end member 70 along the axial direction. The shaft 10 is inserted through the through hole 71.

<Configuration of Bearing Device 80>
The bearing device 80 includes a rolling bearing 81 , an inner race pressing member 82 , a positioning member 83 , a positioning member 84 , and a nut 85 .

The rolling bearing 81 is, for example, a cylindrical roller bearing. The rolling bearing 81 supports the shaft 10 so that it can rotate around the central axis of rotation A. The rolling bearing 81 supports a radial load acting on the shaft 10. The inner ring of the rolling bearing 81 is attached to the shaft 10, and the outer ring of the rolling bearing 81 is attached to the end member 70 (more specifically, the inner wall surface of the through hole 71). The inner ring of the rolling bearing 81 is in contact with the end of the cylindrical member 61 on the second end 10b side.

The inner race pressing member 82 is attached to the shaft 10. The inner race pressing member 82 contacts the inner race of the rolling bearing 81 from the second end 10b side. In other words, the inner race of the rolling bearing 81 is sandwiched between the cylindrical member 61 and the inner race pressing member 82 in the axial direction.

The positioning member 83 is attached to the end member 70 and contacts the outer ring of the rolling bearing 81 from the second end 10b side. The positioning member 84 is attached to the end member 70 and contacts the outer ring of the rolling bearing 81 from the first end 10a side. In other words, the outer ring of the rolling bearing 81 is sandwiched between the positioning members 83 and 84 in the axial direction. As a result, when the shaft 10 expands or contracts, the inner ring of the rolling bearing 81 slides axially along the through hole 71 of the end member 70 integrally with the shaft 10.

The nut 85 is attached (screwed) to the shaft 10. The nut 85 is arranged to sandwich the inner ring holding member 82 between the nut 85 and the inner ring of the rolling bearing 81 in the axial direction. In other words, the nut 85 prevents the inner ring holding member 82 from coming off the shaft 10.

<Effects of the bearing device 30>
In assembling the bearing device 30, first, the rolling bearing 32, the inner ring spacer 34, the outer ring spacer 35, the rolling bearing 33, and the spacer 38 are attached to the shaft 10 in that order. At this stage, the spacer 35a is attached to the outer ring spacer 35, and the board 42 is attached to the spacer 35a. Also, at this stage, the wires 40 and 41 are soldered to the board 42. In assembling the bearing device 30, second, the nut 37 is screwed onto the shaft 10. As a result, a preload is applied to the rolling bearings 32 and 33.

In assembling the bearing device 30, thirdly, the shaft 10 to which the rolling bearing 32, inner ring spacer 34, outer ring spacer 35, rolling bearing 33, nut 37 and spacer 38 are attached is inserted into the housing 31. At this time, the base plate 42 is inserted into the groove 31ca. In assembling the bearing device 30, fourthly, the cover member 36 is attached to the first end 31a. At this time, the base plate 42 is inserted into the through hole 36c.

In this way, the assembly of the bearing device 30 is performed while the wiring 40 and wiring 41 remain connected to the substrate 42, so there is no need to route long wiring during assembly, improving ease of assembly.

Second Embodiment
A spindle device according to the second embodiment (hereinafter, referred to as "spindle device 200") will be described below. Here, differences from spindle device 100 will be mainly described, and overlapping descriptions will not be repeated.

The spindle device 200 has a shaft 10, an outer cylinder 20, a bearing device 30, a motor 60, an end member 70, and a bearing device 80. In this respect, the spindle device 200 is common to the spindle device 100.

Figure 5 is a cross-sectional view of the bearing device 30 in the spindle device 200. Figure 6 is a plan view of the substrate 42 in the spindle device 200. As shown in Figures 5 and 6, the spindle device 200 differs from the spindle device 100 in that the substrate 42 is divided into a first substrate 42c and a second substrate 42d.

The first board 42c is equipped with a connector 42e. The second board 42d is equipped with a connector 42f. The connector 42f is detachably attached to the connector 42e.

The through-hole 42b is formed in the second board 42d. That is, the second board 42d is connected to the sensor 39 (sensor 39a and sensor 39b) by the wiring 40 and wiring 41. The second board 42d is attached to the spacer 35a. The processing circuit 43 and the connector 44 are mounted on the first board 42c.

In the spindle device 200, the bearing device 30 can be assembled with the first board 42c removed, further improving ease of assembly. It is preferable that the width of the first board 42c is approximately equal to the width of the groove 31ca. In this case, when fitting the connector 42f into the connector 42e, the first board 42c is guided by the groove 31ca, so that the connector 42f does not shift relative to the connector 42e, making it easier to fit the connector 42f into the connector 42e.

Third Embodiment
A spindle device according to a third embodiment (hereinafter, referred to as "spindle device 300") will be described below. Here, differences from spindle device 200 will be mainly described, and overlapping descriptions will not be repeated.

The spindle device 300 has a shaft 10, an outer cylinder 20, a bearing device 30, a motor 60, an end member 70, and a bearing device 80. In this respect, the spindle device 300 is common to the spindle device 200.

Figure 7 is a cross-sectional view of the bearing device 30 in the spindle device 300. Figure 8 is a plan view of the substrate 42 in the spindle device 300. As shown in Figures 7 and 8, the spindle device 300 differs from the spindle device 200 in that it further includes a case 45.

The first substrate 42c is housed in the case 45. The case 45 may be attached to the cover member 36 by, for example, a fixing member 46. The fixing member 46 is, for example, a bolt. Although not shown, the first substrate 42c may be sealed by a resin molding material inside the case 45. Although not shown, the case 45 may also have a cover that covers the first substrate 42c. Furthermore, although not shown, the surface of the second substrate 42d may be protected by a resin molding material or the like.

In the spindle device 300, the first board 42c is housed in the case 45, so the first board 42c is reinforced by the case 45, making it easier to attach and detach the first board 42c from the second board 42d. Also, in the spindle device 300, the case 45 is attached to the cover member 36 by the fixing member 46, so vibration of the first board 42c is suppressed when the spindle device 300 is in operation. As a result, poor contact between the connector 42e and the connector 42f is suppressed.

Fourth Embodiment
A spindle device according to a fourth embodiment (hereinafter, referred to as a "spindle device 400") will be described below. Here, differences from the spindle device 100 will be mainly described, and overlapping descriptions will not be repeated.

The spindle device 400 has a shaft 10, an outer cylinder 20, a bearing device 30, a motor 60, an end member 70, and a bearing device 80. In this respect, the spindle device 400 is common to the spindle device 100.

Figure 9 is a cross-sectional view of the bearing device 30 in the spindle device 400. As shown in Figure 9, the spindle device 400 differs from the spindle device 100 in that the bearing device 30 further includes a communication unit 47 and a communication unit 48.

The communication unit 47 is mounted on the substrate 42. The communication unit 48 is disposed at a distance from the communication unit 47. The communication unit 48 is electrically connected to a cable 49, and is electrically connected to a control device (not shown) and a power source (not shown) via the cable 49. The communication unit 47 has a built-in power receiving coil, and the communication unit 48 has a built-in power transmitting coil.

The communication unit 47 is supplied with an output signal from the sensor 39 (sensor 39a and sensor 39b) via the wiring 40 and wiring 41. The communication unit 47 wirelessly transmits the output signal from the sensor 39 to the communication unit 48. The communication unit 48 wirelessly supplies power to the communication unit 47 via the receiving coil of the communication unit 47 using a transmitting coil. The power supplied to the communication unit 47 is converted to direct current by a smoothing process and then supplied to the sensor 39 via the wiring 40 and wiring 41. This power may also be supplied to the processing circuit 43 mounted on the substrate 42. The communication unit 47 and communication unit 48 may be separated into a part used for transmitting and receiving the output signal from the sensor 39 and a part used for wireless power supply.

The spindle device 400 eliminates the need to pull out a long cable to connect the bearing device 30 to the outside, further improving ease of assembly.

Fifth Embodiment
A spindle device according to a fifth embodiment (hereinafter, referred to as a "spindle device 500") will be described below. Here, differences from the spindle device 100 will be mainly described, and overlapping descriptions will not be repeated.

The spindle device 500 has a shaft 10, an outer cylinder 20, a bearing device 30, a motor 60, an end member 70, and a bearing device 80. In this respect, the spindle device 500 is common to the spindle device 100.

Figure 10 is a cross-sectional view of the bearing device 30 in the spindle device 500. As shown in Figure 10, the spindle device 500 differs from the spindle device 100 in that the bearing device 30 further includes a generator 50 and a communication unit 51.

The generator 50 is, for example, a claw-pole type generator. The generator 50 has a magnetic ring 50a and a magnetic yoke 50b. The magnetic ring 50a is magnetized with alternating north and south poles along the circumferential direction. The magnetic ring 50a is attached to the outer peripheral surface of the inner ring spacer 34. The magnetic yoke 50b has a built-in coil. The magnetic yoke 50b is attached to the inner peripheral surface of the outer ring spacer 35 so as to face the magnetic ring 50a.

A notch 35d may be formed on the inner peripheral surface of the outer ring spacer 35. The inner diameter of the notch 35d is smaller than the inner diameter of the rest of the notch 35d. The magnetic yoke 50b may be attached to the notch 35d. A ring member 35e may be attached to the portion of the notch 35d where the magnetic yoke 50b is not attached.

The generator 50 generates electricity by rotating the shaft 10. More specifically, as the shaft 10 rotates, the magnetic ring 50a rotates relative to the magnetic yoke 50b. As the magnetic ring 50a rotates, a current flows through a coil built into the magnetic yoke 50b, generating electricity.

However, the generator 50 is not limited to a claw-pole type generator, and may be any generator that generates electricity by rotating the shaft 10. For example, the generator 50 may be a Peltier element. This Peltier element is attached to the inner peripheral surface of the outer ring spacer 35 so as to face the outer peripheral surface of the inner ring spacer 34. As the shaft 10 rotates, a temperature difference occurs between the inner ring spacer 34 and the outer ring spacer 35. The Peltier element generates an electromotive force due to this temperature difference, so that electricity is generated as the shaft 10 rotates.

The communication unit 51 has an antenna 52. An output signal from the sensor 39 is wirelessly transmitted from the communication unit 51 via the antenna 52. The communication unit 51 and the sensor 39 may be driven by power generated by the generator 50. In the spindle device 500, since there is no cable drawn out from the bearing device 30, the ease of assembly can be further improved.

Although the embodiment of the present invention has been described above, the above-mentioned embodiment can be modified in various ways. Furthermore, the scope of the present invention is not limited to the above-mentioned embodiment. The scope of the present invention is indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

The above embodiment is particularly advantageously applicable to bearing devices and spindle devices used in machine tools.

100 spindle device, 10 shaft, 10a first end, 10b second end, 10c outer peripheral surface, 11 first shaft portion, 12 second shaft portion, 13 tip portion, 20 outer cylinder, 20a first end, 20b second end, 20c inner peripheral surface, 30 bearing device, 31 housing, 31a first end, 31b second end, 31c inner peripheral surface, 31ca groove, 31d outer peripheral surface, 31da groove, 32 rolling bearing, 32a inner ring, 32b outer ring, 32c rolling element, 32d retainer, 33 rolling bearing, 33a inner ring, 33b outer ring, 33c rolling element, 33d retainer, 34 inner ring spacer, 35 outer ring spacer, 35a spacer, 35b, 35c Through hole, 35d notch portion, 35e ring member, 36 cover member, 36a cylindrical portion, 36b flange portion, 36c through hole, 37 nut, 38 spacer, 39, 39a, 39b sensor, 40, 41 wiring, 42 board, 42a wiring, 42b through hole, 42c first board, 42d second board, 42e, 42f connector, 43 processing circuit, 44 connector, 45 case, 46 fixing member, 47, 48 communication unit, 49 cable, 50 generator, 50a magnetic ring, 50b magnetic yoke, 51 communication unit, 52 antenna, 60 motor, 61 cylindrical member, 62 rotor, 63 stator, 70 end member, 71 through hole, 80 bearing device, 81 rolling bearing, 82 Inner ring holding member, 83, 84 positioning member, 85 nut, 200, 300, 400, 500 spindle device, A central rotating shaft.

Claims (10)

a cylindrical housing having a first inner circumferential surface and a first outer circumferential surface;
A shaft housed within the housing;
a rolling bearing that rotatably supports the shaft within the housing;
A non-rotating member attached to the first inner circumferential surface;
A sensor attached to the non-rotating member for detecting a state of the rolling bearing;
a substrate electrically connected to the sensor;
A cover member.
The housing has a first end and a second end opposite the first end,
The non-rotating member is located closer to the second end than the rolling bearing,
A groove recessed toward the first outer circumferential surface is formed on the first inner circumferential surface,
The groove extends from the first end toward the second end,
The cover member is attached to the first end,
The cover member has a through hole communicating with the groove,
the substrate is disposed within the groove and the through hole;
Further comprising a spacer;
the non-rotating member has a second inner circumferential surface facing the shaft and a second outer circumferential surface facing the first inner circumferential surface,
The spacer is disposed on the second outer circumferential surface,
The substrate is attached to the spacer . The bearing device according to claim 1, wherein the substrate is disposed radially outward of the non-rotating member and the outer ring of the rolling bearing. a cylindrical housing having a first inner circumferential surface and a first outer circumferential surface;
A shaft housed within the housing;
a rolling bearing that rotatably supports the shaft within the housing;
A non-rotating member attached to the first inner circumferential surface;
A sensor attached to the non-rotating member for detecting a state of the rolling bearing;
a substrate electrically connected to the sensor;
A cover member.
The housing has a first end and a second end opposite the first end,
The non-rotating member is located closer to the second end than the rolling bearing,
A groove recessed toward the first outer circumferential surface is formed on the first inner circumferential surface,
The groove extends from the first end toward the second end,
The cover member is attached to the first end,
The cover member has a through hole communicating with the groove,
the substrate is disposed within the groove and the through hole;
the non-rotating member has a second inner circumferential surface facing the shaft and a second outer circumferential surface facing the first inner circumferential surface,
The second outer circumferential surface includes a protruding portion protruding toward a side opposite to the second inner circumferential surface,
The substrate is attached to the protrusion . a cylindrical housing having a first inner circumferential surface and a first outer circumferential surface;
A shaft housed within the housing;
a rolling bearing that rotatably supports the shaft within the housing;
A non-rotating member attached to the first inner circumferential surface;
A sensor attached to the non-rotating member for detecting a state of the rolling bearing;
a substrate electrically connected to the sensor;
A cover member.
The housing has a first end and a second end opposite the first end,
The non-rotating member is located closer to the second end than the rolling bearing,
A groove recessed toward the first outer circumferential surface is formed on the first inner circumferential surface,
The groove extends from the first end toward the second end,
The cover member is attached to the first end,
The cover member has a through hole communicating with the groove,
the substrate is disposed within the groove and the through hole;
the substrate is divided into a first substrate on which a first connector is mounted and a second substrate on which a second connector is mounted and which is electrically connected to the sensor;
The second connector is detachably attached to the first connector. The bearing device according to claim 4 , further comprising a case that houses at least the first substrate. The bearing device according to claim 5 , wherein the case is attached to the cover member. Further comprising a first communication unit and a second communication unit,
the first communication unit is mounted on the substrate and configured to wirelessly transmit an output signal of the sensor to the second communication unit;
The bearing device according to any one of claims 1 to 6 , wherein the second communication unit is configured to wirelessly supply power for driving the sensor to the first communication unit. a third communication unit having an antenna and mounted on the substrate;
a generator that supplies electric power generated by rotation of the shaft to the sensor and the third communication unit,
The bearing device according to any one of claims 1 to 6 , wherein the third communication section is configured to wirelessly transmit an output signal of the sensor from the antenna. The bearing device according to any one of claims 1 to 8 , wherein the non-rotating member is an outer ring spacer. The bearing device according to any one of claims 1 to 9 ,
and a motor for rotating the shaft.

Images