JP7346106B2 - Bearing device and spindle device - Google Patents

Description

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

Patent Document 1 (Japanese Unexamined Patent Publication No. 2012-37013) describes a bearing device. The bearing device described in Patent Document 1 includes 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 to the first end along the direction in which the shaft extends. The housing has an inner peripheral surface and an outer peripheral surface. A groove is formed in the inner circumferential surface and is recessed toward the outer circumferential surface. The groove extends from the first end toward the second end.

The shaft is housed within 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 peripheral surface of the housing. The second rolling bearing has a first inner ring attached to the shaft and a first outer ring attached to the inner peripheral surface of the housing. The second rolling bearing is located further away from the first end than the first rolling bearing in the extending 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 extending direction of the shaft. The outer ring spacer is attached to the inner peripheral surface of the housing. The outer ring spacer is sandwiched between the first outer ring and the second outer ring in the extending direction of the shaft. The temperature sensor is an infrared sensor for detecting the temperature of the first rolling bearing and the second rolling bearing in a non-contact manner. The temperature sensor is attached to the outer ring spacer.

The wiring is connected to the temperature sensor at one end and to the outside of the bearing device at the other end. The wiring is arranged in a groove formed in the inner peripheral surface of the housing.

Japanese Patent Application Publication No. 2012-37013

In the bearing device described in Patent Document 1, the temperature sensor and the outside of the bearing device are connected by wiring, so the wiring gets in the way during assembly, reducing work efficiency when assembling the bearing device.

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

A rolling bearing according to one aspect of the present invention includes a housing having an inner circumferential surface and an outer circumferential surface, a shaft housed in the housing, a rolling bearing rotatably supporting the shaft in the housing, and an inner circumferential surface. A non-rotating member attached to the peripheral surface, a sensor attached to the non-rotating member and detecting the state of the rolling bearing, a first wiring electrically connected to the sensor, and a first wiring electrically connected to the first wiring. and a first connector having a first terminal electrically connected to the first terminal. The housing has a first end and a second end opposite to the first end in the axial direction. The non-rotating member is located closer to the second end than the rolling bearing. A groove that is depressed toward the outer circumferential surface is formed on the inner circumferential surface. The groove extends from the first end toward the second end. The first wiring is drawn out from the non-rotating member into the groove. The first connector is inserted into the groove.

The bearing device described above may further include a lid member attached to the first end and a second wiring electrically connected to the second terminal. The second wiring may be passed between the lid member and the first end.

In the above bearing device, the first connector may have a first portion, a second portion, and a third portion that are detachable from each other. The first portion may include a first terminal. The second portion may include a second terminal. The third portion may include a first contact and a second contact electrically connected to each other. The third portion may be disposed between the first portion and the second portion such that the first contact contacts the first terminal and the second contact contacts the second terminal.

In the above bearing device, the first connector may have a first portion and a second portion that are detachable from each other. The first portion may include a first terminal and a first contact electrically connected to the first terminal. The second portion may include a second terminal. The second portion may be arranged such that the first contact contacts the second terminal.

In the above bearing device, the first portion may be attached to a non-rotating member. The second portion may be attached to the lid member.

The above bearing device further includes a third wiring that is electrically connected to the sensor and drawn out from the non-rotating member into the groove, and a fourth wiring that is passed between the lid member and the first end. It's okay. The first connector may further include a third terminal electrically connected to the third wiring and a fourth terminal electrically connected to the fourth wiring. The third terminal and the fourth terminal may be electrically connected to each other.

The above bearing device includes a third wiring electrically connected to the sensor and drawn out from the non-rotating member into the groove, a fourth wiring passed between the lid member and the first end, and a third wiring. The device may further include a second connector having a third terminal electrically connected to and a fourth terminal electrically connected to the fourth wiring. The third terminal and the fourth terminal may be electrically connected to each other.

The bearing device described above may further include an insulating member that insulates between the first connector and the second connector.

In the above bearing device, the output signal from the sensor may be output via the first wiring. Power for driving the sensor may be supplied via the third wiring.

In the above bearing device, the first connector may further include a processing circuit that performs signal processing on the output signal from the sensor.

The above bearing device may further include a connector attached to the lid member and a cable having a socket connected to the connector. The cable may be electrically connected to the second wiring and the fourth wiring via a connector and a socket.

The bearing device described above may further include a first communication section attached to the lid member, and a second communication section disposed apart from the first communication section. The first communication unit may be electrically connected to the second wiring and the fourth wiring. The first communication unit may be configured to wirelessly transmit an output signal from 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.

In the above bearing device, the non-rotating member may be an outer ring spacer. In the above bearing device, the non-rotating member may be a holding member that holds a spring for applying constant pressure preload to the rolling bearing. In the above bearing device, the sensor may be a heat flux sensor that detects heat flux from the shaft side to the housing side. The bearing device described above may further include a generator that generates power by rotating the shaft.

A spindle device according to one aspect of the present invention includes a motor that rotates a shaft and the above bearing device.

According to the bearing device and spindle device according to one aspect of the present invention, workability during assembly can be improved.

1 is a cross-sectional view of a spindle device 100. FIG. FIG. 2 is an enlarged view of region II in FIG. 1; FIG. 3 is a sectional view taken along line III-III in FIG. 2; 4 is a sectional view taken along IV-IV in FIG. 3. FIG. 4 is a sectional view taken along line VV in FIG. 3. FIG. 3 is a sectional view taken along VI-VI in FIG. 2. FIG. 7 is a sectional view taken along VII-VII in FIG. 6. FIG. 7 is a cross-sectional view taken along line VIII-VIII in FIG. 6. FIG. 3 is a sectional view taken along line IX-IX in FIG. 2. FIG. 9 is a sectional view taken along line XX in FIG. 9. FIG. 9 is a sectional view taken along line XI-XI in FIG. 9. FIG. 3 is a sectional view of a bearing device 30 in a spindle device 200. FIG. 13 is a sectional view taken along line XIII-XIII in FIG. 12. FIG. 14 is a sectional view taken along line XIV-XIV in FIG. 13. FIG. 14 is a sectional view taken along line XV-XV in FIG. 13. FIG. 3 is a sectional view of a bearing device 30 in a spindle device 300. FIG. 17 is a sectional view taken along line XVII-XVII in FIG. 16. FIG. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. 17. FIG. 18 is a sectional view taken along line XIX-XIX in FIG. 17. FIG. 3 is a sectional view of a bearing device 30 in a spindle device 400. FIG. 3 is a cross-sectional view of a bearing device 30 in a spindle device 500. FIG. 6 is a cross-sectional view of the bearing device 30 in the spindle device 600. FIG.

Details of the embodiments will be described with reference to the drawings. In the following drawings, the same or corresponding parts are given the same reference numerals, and overlapping descriptions will not be repeated.

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

<Overall configuration of spindle device 100>
FIG. 1 is a cross-sectional view of a spindle device 100. FIG. 2 is an enlarged view of region II in FIG. As shown in FIGS. 1 and 2, the spindle device 100 includes a shaft 10, an outer cylinder 20, a bearing device 30, a motor 60, an end member 70, and a bearing device 80. The spindle device 100 is, for example, a built-in motor spindle device for a machine tool.

<Configuration of shaft 10>
The shaft 10 has a rotation center axis A. In the following, the direction along the rotation center axis A is called the axial direction, the direction along the circumference passing through the rotation center axis A is called the circumferential direction, and the direction passing through the rotation center axis A and orthogonal to the axial direction is called the circumferential direction. This is called 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 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 to 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 to connect the first shaft portion 11 and the tip portion 13.

The outer diameter of the shaft 10 in the first shaft portion 11 is smaller than the outer diameter of the shaft in the second shaft portion 12. The outer diameter of the second shaft portion 12 is smaller than the outer diameter of the end of the tip portion 13 on the second shaft portion 12 side. That is, steps are formed on the outer circumferential 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 located on the first end 10a side. The second end 20b is the end of the outer tube 20 located on the second end 10b side. That is, the second end 20b is the end opposite to the first end 20a. The outer cylinder 20 has an inner peripheral 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, and wiring. 40 (see FIG. 4), wiring 41 (see FIG. 4), connector 42, wiring 43, wiring 44, connector 45, and cable 46. Note that 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. That is, the second end 31b is the end opposite to 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 circumferential surface 31c and an outer circumferential surface 31d, and is arranged such that the outer circumferential surface 31d is in contact with the inner circumferential surface 20c.

A groove 31ca is formed in the inner peripheral surface 31c. In the groove 31ca, the inner peripheral surface 31c is depressed toward the outer peripheral surface 31d. The groove 31ca extends from the first end 31a toward the second end 31b. A groove 31da is formed in the outer peripheral surface 31d. The groove 31da is formed in a spiral shape around the rotation center axis A. A flow path through which a coolant for cooling the bearing device 30 flows is defined by the groove 31da and the inner circumferential surface 20c.

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 supports the load in the radial direction (radial direction) and the load in the thrust direction (axial direction) acting on the shaft 10.

The rolling bearing 32 has an inner ring 32a, an outer ring 32b, rolling elements 32c, and a cage 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 is in contact with 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 are opposed to each other. The rolling elements 32c are arranged between the inner ring 32a and the outer ring 32b. The number of rolling elements 32c is plural. The cage 32d is disposed between the inner ring 32a and the outer ring 32b, and holds the rolling elements 32c. The cage 32d maintains the distance between the two rolling elements 32c adjacent to each other 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 within the housing 31. The rolling bearing supports the load in the radial direction and the load in the thrust direction acting on the shaft 10. The rolling bearing 33 has an inner ring 33a, an outer ring 33b, rolling elements 33c, and a cage 33d. The inner ring 33a is attached to the shaft 10 (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 are opposed to each other. The rolling elements 33c are arranged between the inner ring 33a and the outer ring 33b. The number of rolling elements 33c is plural. The cage 33d is disposed between the inner ring 33a and the outer ring 33b, and holds the rolling elements 33c. The cage 33d maintains the distance between two rolling elements 33c adjacent to each other in the circumferential direction within a certain range.

The rolling bearing 32 and the rolling bearing 33 are spaced apart from each other in the axial direction. The rolling bearing 32 is located 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 be a face-to-face (DF) combination.

Inner ring spacer 34 is attached to shaft 10 (second shaft portion 12). The inner ring spacer 34 is in contact with the inner ring 32a at the end on the first end 10a side, and is in contact with the inner ring 33a at the end on the second end 10b side. To put this in another perspective, the inner ring spacer 34 is sandwiched between the inner ring 32a and the inner ring 33a in the axial direction. The inner ring spacer 34 has a cylindrical shape extending 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, the term "non-rotating member" refers to a member that does not rotate with respect to the housing 31 (that is, is attached to the housing 31). The outer ring spacer 35 is in contact with the outer ring 32b at the end on the first end 10a side, and is in contact with the outer ring 33b at the end on the second end 10b side. To put this in another perspective, the outer ring spacer 35 is sandwiched between the outer ring 32b and the outer ring 33b in the axial direction. The outer ring spacer 35 has a cylindrical shape extending along the axial direction. The outer peripheral surface of the outer ring spacer 35 is in contact with the inner peripheral surface 31c. A part of the outer peripheral surface of the outer ring spacer 35 is exposed from the groove 31ca.

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 circumferential surface of the cylindrical portion 36a is in contact with the inner circumferential surface 31c. The cylindrical portion 36a holds the outer ring 32b between the outer ring spacer 35 and the outer ring spacer 35 in the axial direction. The flange portion 36b protrudes from the end of the cylindrical portion 36a opposite to the outer ring 32b in a plane perpendicular to the axial direction. The flange portion 36b is fixed to the first end 31a. Thereby, the lid member 36 is attached to the first end 31a.

The nut 37 is attached (threaded) to the shaft 10. The nut 37 is located closer to the second end 10b than the rolling bearing 33 (inner ring 33a) in the axial direction. Spacer 38 is attached to shaft 10. The spacer 38 is in contact with the inner ring 33a at the end on the first end 10a side, and is in contact with the nut 37 at the end on the second end 10b side. To put this in 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, 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 a rotating member (inner ring 32a, inner ring 33a, or inner ring spacer 34) attached to the shaft 10. Thereby, the heat flux from the shaft 10 side to the housing 31 side can be detected. 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). Prior to this temperature difference, the heat flux from the shaft 10 side to the housing 31 side changes, so by detecting the above heat flux with the sensor 39, abnormalities in the rolling bearing 32 (rolling bearing 33) can be quickly detected. Can be detected (early). The sensor 39 may be a sensor other than a heat flux sensor (for example, a temperature sensor).

The wiring 40 is electrically connected to the sensor 39 at one end. The wiring 40 is drawn out from the outer ring spacer 35 into the groove 31ca at the other end. The output signal from sensor 39 is output via wiring 40. The wiring 41 is electrically connected to the sensor 39 at one end. The wiring 41 is drawn out from the outer ring spacer 35 into the groove 31ca at the other end. Electric power for driving the sensor 39 is supplied from the wiring 41 .

The connector 42 is inserted into the groove 31ca. The connector 42 has a first portion 42a, a second portion 42b, and a third portion 42c. The first portion 42a, the second portion 42b, and the third portion 42c are removable from each other.

FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 4 is a cross-sectional view taken along IV-IV in FIG. FIG. 5 is a sectional view taken along line VV in FIG. 3. Note that in FIGS. 3 to 5, illustrations of members unnecessary for explanation are omitted. As shown in FIGS. 3 to 5, the first portion 42a includes a case 42aa, a terminal 42ab, and a terminal 42ac.

Case 42aa is made of an insulating material. A terminal 42ab and a terminal 42ac are arranged inside the case 42aa. Terminals 42ab and 42ac are exposed from case 42aa. Terminal 42ab is electrically connected to wiring 40, and terminal 42ac is electrically connected to wiring 41. Terminal 42ab and terminal 42ac are formed on printed wiring board 42ad, and by soldering wiring 40 and wiring 41 to the back surface of printed wiring board 42ad, wiring 40 and wiring 41 are connected to terminal 42ab and terminal 42ac. They are electrically connected to each other. The first portion 42a is preferably attached to the outer ring spacer 35 (more specifically, the outer peripheral surface of the outer ring spacer 35 exposed from the groove 31ca).

FIG. 6 is a cross-sectional view taken along VI-VI in FIG. FIG. 7 is a sectional view taken along VII-VII in FIG. 6. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. Note that in FIGS. 6 to 8, illustrations of members unnecessary for explanation are omitted. As shown in FIGS. 6 to 8, the second portion 42b includes a case 42ba, a terminal 42bb, and a terminal 42bc.

Case 42ba is made of an insulating material. A terminal 42bb and a terminal 42bc are arranged inside the case 42ba. Terminals 42bb and 42bc are exposed from case 42ba. Terminal 42bb is electrically connected to wiring 43, and terminal 42bc is electrically connected to wiring 44. The terminals 42bb and 42bc are formed on the printed wiring board 42bd, and by soldering the wiring 43 and the wiring 44 to the back surface of the printed wiring board 42bd, the wiring 43 and the wiring 44 are connected to the terminal 42bb and the terminal 42bc. They are electrically connected to each other. It is preferable that the second portion 42b of the terminal 42bb and the terminal 42bc be attached to the lid member 36.

FIG. 9 is a sectional view taken along line IX-IX in FIG. FIG. 10 is a cross-sectional view taken along line XX in FIG. FIG. 11 is a sectional view taken along line XI-XI in FIG. Note that in FIGS. 9 to 11, illustrations of members unnecessary for explanation are omitted. As shown in FIGS. 9 to 11, the third portion 42c includes a case 42ca, and an electrode 42cb and an electrode 42cc arranged inside the case 42ca.

Case 42ca is made of an insulating material. The electrode 42cb has a contact 42cba at one end and a contact 42cbb at the other end. The electrode 42cc has a contact point 42cca at one end and a contact point 42cca at the other end. That is, the contact 42cba and the contact 42cbb are electrically connected to each other, and the contact 42cca and the contact 42ccb are electrically connected to each other.

A contact 42cba and a contact 42cca are exposed from one end of the case 42ca, and a contact 42cbb and a contact 42ccb are exposed from the other end of the case 42ca. The third portion 42c is arranged such that the first portion 42a and the second portion 42b are arranged such that the contact 42cba is in contact with the terminal 42ab, the contact 42cbb is in contact with the terminal 42bb, the contact 42cca is in contact with the terminal 42ac, and the contact 42ccb is in contact with the terminal 42bc. is placed between. Thereby, the terminal 42ab and the terminal 42bb are electrically connected, and the terminal 42ac and the terminal 42bc are electrically connected.

In the above example, the electrode 42cb and the electrode 42cc are arranged inside the case 42ca, but an insulating film is formed on the outer peripheral surface of the outer ring 32b, and the electrode 42cb and the electrode 42cc are arranged on the insulating film. Good too. In this case, the structure of the connector 42 can be made compact.

Although not shown, the connector 42 may include a processing circuit that performs signal processing on the output signal from the sensor 39. This processing circuit includes, for example, an amplifier circuit that amplifies the output signal from the sensor 39, a circuit that determines an abnormality of the rolling bearing 32 (rolling bearing 33) based on the output signal from the sensor, and a serial circuit for the output signal from the sensor 39. It is a circuit etc. for communication. This processing circuit is mounted, for example, on a printed wiring board 42ad disposed inside the first portion 42a (case 42aa).

As shown in FIGS. 1 and 2, the wiring 43 and the wiring 44 are passed between the lid member 36 and the first end 31a. More specifically, the wiring 43 and the wiring 44 are arranged in a groove formed in the lid member 36 that is in contact with the first end 31a. Note that, as described above, the wiring 43 and the wiring 44 are electrically connected to the terminal 42bb and the terminal 42bc, respectively.

Connector 45 is electrically connected to wiring 43 and wiring 44 . Cable 46 has a socket 46a. The cable 46 is electrically connected to the wiring 43 and the wiring 44 by fitting the socket 46a into the connector 45.

<Configuration of motor 60>
As shown in FIG. 1, the motor 60 includes 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 peripheral surface 10c at the boundary between the first shaft section 11 and the second shaft section 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. By sequentially switching the direction of the current flowing through the stator 63 by an inverter circuit, a rotational force is generated on the rotor 62, and the shaft 10 rotates around the rotation center axis A due to the rotational force.

<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 penetrates 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 ring 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 as to be rotatable around the rotation center axis A. The rolling bearing 81 supports the load acting on the shaft 10 in the radial direction. 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 ring pressing member 82 is attached to the shaft 10. The inner ring pressing member 82 is in contact with the inner ring of the rolling bearing 81 from the second end 10b side. That is, the inner ring of the rolling bearing 81 is sandwiched between the cylindrical member 61 and the inner ring 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 is in contact with the outer ring of the rolling bearing 81 from the first end 10a side. That is, the outer ring of the rolling bearing 81 is sandwiched between the positioning member 83 and the positioning member 84 in the axial direction. Thereby, when the shaft 10 expands or contracts, the inner ring of the rolling bearing 81 slides in the axial direction along the through hole 71 of the end member 70 integrally with the shaft 10.

The nut 85 is attached (threaded) to the shaft 10. The nut 85 is arranged to sandwich the inner ring pressing member 82 between the inner ring of the rolling bearing 81 in the axial direction. That is, the inner ring holding member 82 is prevented from coming off the shaft 10 by the nut 85.

<Effects of 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 sequentially attached to the shaft 10. At this stage, the sensor 39 and the first portion 42a are attached to the outer ring spacer 35, and the wiring 40 and the wiring 41 are arranged inside the outer ring spacer 35. In assembling the bearing device 30, secondly, the nut 37 is screwed onto the shaft 10. As a result, preload is applied to the rolling bearing 32 and the rolling bearing 33.

In assembling the bearing device 30, thirdly, the shaft 10 to which the rolling bearing 32, the inner ring spacer 34, the outer ring spacer 35, the rolling bearing 33, the nut 37, and the spacer 38 are attached is inserted into the housing 31. . At this time, the first portion 42a is inserted into the groove 31ca. In assembling the bearing device 30, fourthly, the third portion 42c is inserted into the groove 31ca. In assembling the bearing device 30, fifthly, the lid member 36 to which the second portion 42b is attached is attached to the first end 31a. At this time, by inserting the second portion 42b into the groove 31ca, the terminal 42ab (terminal 42ac) is electrically connected to the terminal 42bb (terminal 42bc) via the third portion 42c.

In this way, when assembling the bearing device 30, the electrical connection between the sensor 39 and the outside of the bearing device 30 can be made using the connector 42 without drawing out the wiring 40 and the wiring 41 to the outside of the bearing device 30. This eliminates the need to route long wiring during assembly, which improves assembly efficiency.

(Second embodiment)
A spindle device (hereinafter referred to as "spindle device 200") according to a second embodiment will be described below. Here, the points that are different from the spindle device 100 will be mainly explained, and redundant explanations will not be repeated.

The spindle device 100 includes 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, spindle device 200 has in common with spindle device 100. However, the spindle device 200 differs from the spindle device 100 with respect to the bearing device 30. More specifically, spindle device 200 differs from spindle device 100 with respect to the details of connector 42.

FIG. 12 is a sectional view of the bearing device 30 in the spindle device 200. As shown in FIG. 12, in the bearing device 30 of the spindle device 200, the connector 42 has a first portion 42d and a second portion 42b. The first portion 42d and the second portion 42b are removable from each other.

FIG. 13 is a sectional view taken along line XIII-XIII in FIG. 12. FIG. 14 is a sectional view taken along line XIV-XIV in FIG. 13. FIG. 15 is a sectional view taken along line XV-XV in FIG. 13. Note that in FIGS. 13 to 15, illustrations of members unnecessary for explanation are omitted. As shown in FIGS. 13 to 15, the first portion 42d includes a case 42da, a terminal 42db, a terminal 42dc, an electrode 42dd, and an electrode 42de. Case 42da is made of an insulating material. The terminal 42db and the terminal 42dc are arranged inside the case 42da. Terminal 42db and terminal 42dc are formed on printed wiring board 42df, and wiring 40 and wiring 41 are soldered to them. Thereby, the wiring 40 and the wiring 41 are electrically connected to the terminal 42db and the terminal 42dc, respectively. Note that an electric circuit such as an instrumentation amplifier for amplifying the output of the sensor 39 may be mounted on the printed wiring board 42df.

The electrode 42dd is electrically connected to the terminal 42db via the printed wiring board 42df at one end, and has a contact 42dda at the other end. The electrode 42de is electrically connected to the terminal 42dc via the printed wiring board 42df at one end, and has a contact 42dea at the other end. That is, the terminal 42db is electrically connected to the contact 42dda, and the terminal 42dc is electrically connected to the contact 42dea. The contact 42dda and the contact 42dea are exposed to the outside of the case 42da. The first portion 42d is preferably attached to the outer ring spacer 35. To describe the above from another perspective, the first portion 42d has a structure in which the first portion 42a and the third portion 42c are integrated.

The contact 42dda and the contact 42dea are in contact with the terminal 42bb and the terminal 42bc, respectively. Thereby, the terminal 42db and the terminal 42dc are electrically connected to the terminal 42bb and the terminal 42bc, respectively.

The method for assembling the bearing device 30 in the spindle device 200 is the same as the method for assembling the bearing device 30 in the spindle device 100, except that the third portion 42c does not need to be inserted. Therefore, the bearing device in the spindle device 200 can also improve ease of assembly, similar to the bearing device 30 in the spindle device 100.

(Third embodiment)
Below, a spindle device (hereinafter referred to as "spindle device 300") according to a third embodiment will be described. Here, the points that are different from the spindle device 100 will be mainly explained, and redundant explanations will not be repeated.

The spindle device 100 includes 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, spindle device 300 has in common with spindle device 100. However, the spindle device 300 differs from the spindle device 100 with respect to the bearing device 30. More specifically, spindle device 300 differs from spindle device 100 with respect to the details of connector 42 .

FIG. 16 is a sectional view of the bearing device 30 in the spindle device 300. FIG. 17 is a sectional view taken along line XVII-XVII in FIG. 16. Further, FIG. 18 is a cross-sectional view taken along line XVIII-XVIII in FIG. 17. FIG. 19 is a sectional view taken along line XIX-XIX in FIG. 17. Note that in FIGS. 16 to 19, illustrations of members unnecessary for explanation are omitted. As shown in FIGS. 16 to 19, the bearing device 30 in the spindle device 300 includes a connector 421 and a connector 422 instead of the connector 42.

The connector 421 has a first portion 421a, a second portion 421b, and a third portion 421c. The connector 422 has a first portion 422a, a second portion 422b, and a third portion 422c.

The first portion 421a includes a case 421aa made of an insulating material and a terminal 42ab. The second portion 421b includes a case 421ba made of an insulating material and a terminal 42bb. The third portion 421c includes a case 421ca made of an insulating material and an electrode 42cb.

The first portion 422a includes a case 422aa made of an insulating material and a terminal 42ac. The second portion 422b includes a case 422ba made of an insulating material and a terminal 42bc. The third portion 422c includes a case 422ca made of an insulating material and an electrode 42cc.

That is, the connector 421 and the connector 422 are formed by dividing each case of the connector 42 so that a conductive path for transmitting an output signal from the sensor 39 and a conductive path for supplying power to the sensor 39 are separated. has been done. As shown in FIG. 17, the connectors 421 and 422 are preferably spaced apart from each other in the circumferential direction. An insulating member 423 may be arranged between the connector 421 and the connector 422.

In the bearing device 30 of the spindle device 300, the conductive path that transmits the output signal from the sensor 39 and the conductive path that supplies power to the sensor 39 are separated. can be prevented from being superimposed on the conductive path that transmits the output signal. When the bearing device 30 in the spindle device 300 further includes the insulating member 423, noise caused by power supply to the sensor 39 can be further suppressed from being superimposed on the conductive path that transmits the output signal from the sensor 39.

(Fourth embodiment)
A spindle device (hereinafter referred to as "spindle device 400") according to a fourth embodiment will be described below. Here, the points that are different from the spindle device 100 will be mainly explained, and redundant explanations will not be repeated.

The spindle device 400 includes 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, spindle device 400 has in common with spindle device 100. However, the spindle device 400 differs from the spindle device 100 with respect to the bearing device 30. More specifically, the spindle device 400 differs from the spindle device 100 in that the bearing device 30 does not have the connector 45, but has a communication section 47a and a communication section 47b.

FIG. 20 is a sectional view of the bearing device 30 in the spindle device 400. As shown in FIG. 20, the communication section 47a is attached to the lid member 36. The communication section 47a is electrically connected to the wiring 43 and the wiring 44. The communication section 47b is arranged apart from the communication section 47a. Cable 46 is electrically connected to communication section 47b.

The communication unit 47a is configured to wirelessly transmit the output signal from the sensor 39 to the communication unit 47b. The communication section 47a has a receiving coil, and the communication section 47b has a transmitting coil. The communication unit 47b is configured to use a transmission coil to wirelessly supply power for driving the sensor 39 to the communication unit 47a via a reception coil. The power supplied to the communication section 47b is supplied to the sensor 39 via the wiring 44, the connector 42, and the wiring 41. In the spindle device 400, since there is no cable pulled out from the bearing device 30, replacement is easy.

(Fifth embodiment)
A spindle device (hereinafter referred to as "spindle device 500") according to a fifth embodiment will be described below. Here, the points that are different from the spindle device 100 will be mainly explained, and redundant explanations will not be repeated.

The spindle device 500 includes 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, spindle device 500 has in common with spindle device 100.

However, the bearing device 30 in the spindle device 500 further includes a generator 48 . Further, the bearing device 30 in the spindle device 500 does not have the connector 45 and the cable 46, but does have a communication section 49a and an antenna 49b. Spindle device 500 differs from spindle device 100 in these respects.

FIG. 21 is a sectional view of the bearing device 30 in the spindle device 500. As shown in FIG. 21, the generator 48 is, for example, a claw pole type generator. The generator 48 has a magnetic ring 48a and a magnetic yoke 48b.

The magnetic ring 48a is magnetized with north poles and south poles alternately along the circumferential direction. The magnetic ring 48a is attached to the outer peripheral surface of the inner ring spacer 34. The magnetic yoke 48b has a built-in coil. The magnetic yoke 48b is attached to the inner peripheral surface of the outer ring spacer 35 so as to face the magnetic ring 48a.

A notch 35a may be formed in the inner peripheral surface of the outer ring spacer 35. The inner diameter at the cutout portion 35a is smaller than the inner diameter at other portions other than the cutout portion 35a. The magnetic yoke 48b may be attached to the notch 35a. A ring member 35b may be attached to a portion of the notch 35a where the magnetic yoke 48b is not attached.

The generator 48 generates electricity by rotating the shaft 10. More specifically, as the shaft 10 rotates, the magnetic ring 48a rotates relative to the magnetic yoke 48b. As the magnetic ring 48a rotates, current flows through a coil built into the magnetic yoke 48b, thereby generating electricity.

However, the generator 48 is not limited to a claw-pole type generator, and may be any generator that generates power by rotating the shaft 10. For example, the generator 48 may be a Peltier device. 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. Since an electromotive force is generated in the Peltier element due to this temperature difference, power is generated as the shaft 10 rotates.

The output signal from the sensor 39 is wirelessly transmitted from the communication unit 49a via the antenna 49b. The communication unit 49a and the sensor 39 may be driven by electric power generated by the generator 48. In the spindle device 500, since there is no cable pulled out from the bearing device 30, replacement is easy.

(Sixth embodiment)
A spindle device (hereinafter referred to as "spindle device 600") according to a sixth embodiment will be described below. Here, the points that are different from the spindle device 100 will be mainly explained, and redundant explanations will not be repeated.

The spindle device 600 includes 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, spindle device 600 has in common with spindle device 100.

However, the bearing device 30 in the spindle device 600 does not have the inner ring spacer 34 and the outer ring spacer 35. Further, the bearing device 30 in the spindle device 600 includes a nut 50, a spacer 51, and a preload portion 52. Spindle device 600 differs from spindle device 100 in these respects.

FIG. 22 is a sectional view of the bearing device 30 in the spindle device 600. As shown in FIG. 22, the shaft 10 in the spindle device 600 has a stepped portion 14 on its outer peripheral surface. The outer diameter of the shaft 10 at the stepped portion 14 is larger than the outer diameter of the shaft 10 at the portion other than the stepped portion 14. The stepped portion 14 is in contact with the inner ring 32a at the end on the first end 10a side, and is in contact with the inner ring 33a at the end on the second end 10b side. That is, the stepped portion 14 is sandwiched between the inner ring 32a and the inner ring 33a in the axial direction.

The housing 31 of the bearing device 30 in the spindle device 600 has a stepped portion 31e on the inner peripheral surface 31c. The inner diameter of the housing 31 at the stepped portion 31e is smaller than the inner diameter of the housing 31 at other portions than the stepped portion 31e. The stepped portion 31e is in contact with the outer ring 32b at the end on the first end 31a side, and is in contact with the spring holder 52b at the end on the second end 31b side.

The nut 50 is attached (threaded) to the shaft 10. The nut 50 is located closer to the first end 10a than the rolling bearing 32 (inner ring 32a). The spacer 51 is attached to the shaft 10. The spacer 51 is in contact with the nut 50 at the end on the first end 10a side, and is in contact with the inner ring 32a at the end on the second end 10b side. That is, the spacer 51 is sandwiched between the nut 50 and the inner ring 32a in the axial direction.

The preload portion 52 includes a ring 52a, a spring holder 52b, and a spring 52c. The ring 52a is attached to the inner peripheral surface 31c. The ring 52a is in contact with the outer ring 33b from the first end 10a side. The spring holder 52b is attached to the inner peripheral surface 31c. Therefore, the spring holder 52b is a non-rotating member. The spring holder 52b is arranged closer to the first end 10a than the ring 52a. A sensor 39 is attached to the inner peripheral surface of the spring holder 52b. Wiring 40 and wiring 41 (not shown in FIG. 22) are arranged inside the spring holder 52b. The first portion 42a may be attached to the spring holder 52b. The spring 52c biases the ring 52a along the direction from the first end 10a to the second end 10b by being held by the spring holder 52b. As a result, a constant preload is applied to the rolling bearing 32 and the rolling bearing 33.

Similarly to the bearing device 30 in the spindle device 100, in the bearing device 30 in the spindle device 600, the connector 42 is used instead of the wire being drawn out from the non-rotating member (spring holder 52b) to which the sensor 39 is attached. Therefore, ease of assembly can be improved.

Although the embodiments of the present invention have been described above, the embodiments described above can be modified in various ways. Moreover, the scope of the present invention is not limited to the above-described embodiments. The scope of the present invention is indicated by the claims, and is intended to include all changes within the meaning and scope equivalent to the claims.

The embodiments described above are particularly advantageously applied to bearing devices and spindle devices used in machine tools.

Reference Signs List 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, 14 step portion, 20 outer cylinder, 20a first end, 20b second end, 20c inner circumferential surface, 30 bearing device, 31 housing, 31a first end, 31b second end, 31c inner circumferential surface, 31ca groove, 31d outer circumferential surface, 31da groove, 31e step portion, 32 rolling bearing, 32a Inner ring, 32b Outer ring, 32c Rolling element, 32d Cage, 33 Rolling bearing, 33a Inner ring, 33b Outer ring, 33c Rolling element, 33d Cage, 34 Inner ring spacer, 35 Outer ring spacer, 35a Notch, 35b Ring member , 36 lid member, 36a cylinder part, 36b flange part, 37 nut, 38 spacer, 39 sensor, 40, 41 wiring, 42 connector, 42a first part, 42aa case, 42ab, 42ac terminal, 42ad printed wiring board, 42b second part, 42ba case, 42bb, 42bc terminal, 42bd printed wiring board, 42c third part, 42ca case, 42cb electrode, 42cba, 42cbb contact, 42cc electrode, 42cca, 42ccb contact, 42d first part, 42da case, 42db terminal, 42dc terminal, 42dd electrode, 42dda contact, 42de electrode, 42dea contact, 42df printed wiring board, 421 connector, 421a first part, 421aa case, 421b second part, 421ba case, 421c third part, 421ca case , 422 connector, 422a first part, 422aa case, 422b second part, 422ba case, 422c third part, 422ca case, 423 insulating member, 43 wiring, 44 wiring, 45 connector, 46 cable, 46a socket, 47a communication part, 47b communication part, 48 generator, 48a magnetic ring, 48b magnetic yoke, 49a communication part, 49b antenna, 50 nut, 51 spacer, 52 preload part, 52a ring, 52b spring holder, 52c spring, 60 motor, 61 cylinder shaped 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, 600 spindle device ,A rotation center axis.

Claims (17)

a housing having an inner circumferential surface and an outer circumferential surface;
a shaft housed in the housing;
a rolling bearing rotatably supporting the shaft within the housing;
a non-rotating member attached to the inner peripheral surface;
a sensor attached to the non-rotating member and detecting the state of the rolling bearing;
a first wiring electrically connected to the sensor;
comprising a first connector having a first terminal electrically connected to the first wiring and a second terminal electrically connected to the first terminal,
The housing has a first end and a second end opposite to the first end in the axial direction,
The non-rotating member is located closer to the second end than the rolling bearing,
A groove that is depressed toward the outer circumferential surface is formed in the inner circumferential surface,
The groove extends from the first end toward the second end,
The first wiring is drawn out from the non-rotating member into the groove,
The bearing device, wherein the first connector is inserted into the groove. a lid member attached to the first end;
The bearing device according to claim 1, further comprising a second wiring that is passed between the lid member and the first end and electrically connected to the second terminal. The first connector has a first part, a second part, and a third part that are detachable from each other,
the first portion includes the first terminal;
the second portion includes the second terminal;
The third portion includes a first contact and a second contact that are electrically connected to each other,
The third portion is arranged between the first portion and the second portion such that the first contact contacts the first terminal and the second contact contacts the second terminal. , The bearing device according to claim 2. The first connector has a first part and a second part that are detachable from each other,
The first portion includes the first terminal and a first contact electrically connected to the first terminal,
the second portion includes the second terminal;
The bearing device according to claim 2, wherein the second portion is arranged such that the first contact contacts the second terminal. the first portion is attached to the non-rotating member;
The bearing device according to claim 3 or 4, wherein the second portion is attached to the lid member. a third wire electrically connected to the sensor and drawn out from the non-rotating member into the groove;
further comprising a fourth wiring passed between the lid member and the first end,
The first connector further includes a third terminal electrically connected to the third wiring, and a fourth terminal electrically connected to the fourth wiring,
The bearing device according to claim 2, wherein the third terminal and the fourth terminal are electrically connected to each other. a third wire electrically connected to the sensor and drawn out from the non-rotating member into the groove;
a fourth wiring passed between the lid member and the first end;
further comprising a second connector having a third terminal electrically connected to the third wiring and a fourth terminal electrically connected to the fourth wiring,
The bearing device according to claim 2, wherein the third terminal and the fourth terminal are electrically connected to each other. The bearing device according to claim 7, further comprising an insulating member that insulates between the first connector and the second connector. The output signal from the sensor is output via the first wiring,
The bearing device according to any one of claims 6 to 8, wherein power for driving the sensor is supplied via the third wiring. The bearing device according to claim 9, wherein the first connector further includes a processing circuit that performs signal processing on the output signal from the sensor. a connector attached to the lid member;
and a cable having a socket connected to the connector,
The bearing device according to any one of claims 6 to 10, wherein the cable is electrically connected to the second wiring and the fourth wiring via the connector and the socket. a first communication unit attached to the lid member;
further comprising a second communication unit located apart from the first communication unit,
The first communication unit is electrically connected to the second wiring and the fourth wiring,
The first communication unit is configured to wirelessly transmit an output signal from the sensor to the second communication unit,
The bearing according to any one of claims 6 to 10, wherein the second communication unit is configured to wirelessly supply power for driving the sensor to the first communication unit. Device. The bearing device according to any one of claims 1 to 12, wherein the non-rotating member is an outer ring spacer. The bearing device according to any one of claims 1 to 12, wherein the non-rotating member is a holding member that holds a spring for applying constant pressure preload to the rolling bearing. The bearing device according to claim 1, wherein the sensor is a heat flux sensor that detects heat flux from the shaft side to the housing side. The bearing device according to any one of claims 1 to 15, further comprising a generator that generates power by rotating the shaft. a motor that rotates the shaft;
A spindle device comprising the bearing device according to any one of claims 1 to 16.

Images