WO2024013846A1

WO2024013846A1 - Rolling bearing device

Info

Publication number: WO2024013846A1
Application number: PCT/JP2022/027397
Authority: WO
Inventors: 隆文上本; 肇渡邉
Original assignee: 株式会社ジェイテクト
Priority date: 2022-07-12
Filing date: 2022-07-12
Publication date: 2024-01-18

Abstract

A rolling bearing device 1 comprises a tubular housing 2, a rolling bearing 3 having an outer ring 31 fitted to an inner peripheral surface 2a of the housing 2, a sensor 5 attached to an outer peripheral surface 31b of the outer ring 31, wiring 6 for receiving a detection signal from the sensor 5 outside of the rolling bearing 3, and a spacer 4 disposed on the first axial side of the outer ring 31 and fitted to the inner peripheral surface 2a of the housing 2. The spacer 4 has an annular spacer body 21, in an outer peripheral surface 21a of which is formed a first groove 21b that accommodates the wiring 6, and a cover 22 that is attached to the spacer body 21 and that covers, from the radially outer side, the wiring 6 accommodated in the first groove 21b.

Description

Rolling bearing device

The present invention relates to a rolling bearing device.

In recent years, the need to monitor the condition of mechanical equipment has increased. Rolling bearings are also required to have sensing functions. For example, if it is possible to detect the cutting load applied to the rolling bearing that supports the spindle of a machine tool, it will be possible to reduce tool wear by optimizing machining conditions, shorten machining time, and prevent failures by detecting abnormal machining. etc. The rolling bearing described in Patent Document 1 has a plurality of strain gauges attached to a groove formed on the outer peripheral surface of the outer ring, and each strain gauge detects strain in the outer ring when a load is applied to the rolling bearing. There is.

Utility Model Publication No. 06-032735

In the rolling bearing described in Patent Document 1, when the rolling bearing to which the strain gauge is attached is assembled into a housing, the wiring of the strain gauge may protrude from the groove of the outer ring. In that case, the strain gauge wiring may become caught between the outer ring and the housing and break.

The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a rolling bearing device that can suppress disconnection of wiring for extracting sensor detection signals when a rolling bearing is incorporated into a housing. purpose.

A rolling bearing device of the present disclosure includes a rolling bearing having a cylindrical housing, an outer ring fitted to an inner circumferential surface of the housing, a sensor attached to an outer circumferential surface of the outer ring, and a detection signal of the sensor. The rolling bearing includes a wiring taken out to the outside of the bearing, and a spacer disposed on a first axial side of the outer ring and fitted to the inner circumferential surface of the housing, the spacer accommodating the wiring. The spacer includes an annular spacer main body having a first groove formed on its outer peripheral surface, and a cover attached to the spacer main body and covering the wiring accommodated in the first groove from the outside in the radial direction.

According to the present disclosure, when a rolling bearing is incorporated into a housing, it is possible to suppress disconnection of the wiring for extracting the detection signal of the sensor.

FIG. 1 is a sectional view of a rolling bearing device according to a first embodiment. FIG. 2 is an enlarged cross-sectional view showing two rolling bearings arranged on the first axial side of FIG. 1; It is a perspective view which shows the said two rolling bearings and a spacer. FIG. 3 is an enlarged cross-sectional view of the spacer. FIG. 7 is a side view of the spacer seen from the second axial side. FIG. 7 is a side view of the spacer of the rolling bearing device according to the second embodiment, viewed from the second axial side.

First, the contents of the embodiment will be listed and explained.
<Overview of embodiment>
(1) A rolling bearing device according to an embodiment includes a rolling bearing having a cylindrical housing, an outer ring fitted to an inner circumferential surface of the housing, a sensor attached to an outer circumferential surface of the outer ring, and a detection of the sensor. Wiring for extracting a signal to the outside of the rolling bearing; and a spacer disposed on a first axial side of the outer ring and fitted to the inner circumferential surface of the housing, the spacer It has an annular spacer body in which a first groove for accommodating the wiring is formed on the outer peripheral surface, and a cover attached to the spacer body and covering the wiring accommodated in the first groove from the outside in the radial direction. .

According to the above-mentioned rolling bearing device, the wiring for extracting the detection signal of the sensor to the outside of the rolling bearing is covered from the outside in the radial direction by the cover while being accommodated in the first groove of the spacer body. As a result, the wiring is prevented from protruding from the first groove, so that it is possible to prevent the wiring from breaking when fitting the outer ring and spacer of the rolling bearing to the inner circumferential surface of the housing.

(2) In the rolling bearing device of (1) above, it is preferable that the spacer main body and the cover are made of metal.
In this case, the wiring accommodated in the first groove is protected from external electric field noise by the metal spacer body and cover. Thereby, it is possible to suppress the influence of electric field noise from reaching the wiring.

(3) Preferably, the rolling bearing device of (2) further includes a motor provided within the housing.
In this case, the metal spacer main body and cover can suppress the influence of electric field noise from the motor on the wiring.

(4) In the rolling bearing device according to any one of (1) to (3), the wiring is connected to the outer peripheral surface of the spacer body from the first groove to the first axial direction of the spacer body. It is preferable that a second groove for drawing out to the side is formed, and the wiring is sandwiched between the cover and the second groove.
In this case, since the wiring is sandwiched between the cover and the second groove, even if a tensile load is applied to the wiring from the first axial side of the spacer body, the tensile load will be applied to the connecting end of the wiring on the sensor side. It is possible to suppress the effect on the parts. Thereby, it is possible to suppress the connection end portion of the wiring from separating from the connection point on the other side due to the tensile load.

<Details of embodiment>
Hereinafter, preferred embodiments will be described with reference to the drawings.
[First embodiment]
FIG. 1 is a sectional view of a rolling bearing device 1 according to a first embodiment. The rolling bearing device 1 is used, for example, to support a main shaft (spindle) 50 of a machine tool. The rolling bearing device 1 includes a housing 2, a plurality of rolling bearings 3, a spacer 4, a plurality of sensors 5, a plurality of wirings 6, and a motor 7 (see FIG. 3).

In the present disclosure, the direction along the central axis C of the rolling bearing 3 is the axial direction of the rolling bearing 3, and is simply referred to as the "axial direction." The axial direction also includes a direction parallel to the central axis C. For convenience, the axial right side of FIG. 1 will be referred to as the "axial first side," and the axial left side of FIG. 1 will be referred to as the "axial second side." The direction perpendicular to the central axis C is the radial direction of the rolling bearing 3, and is simply referred to as the "radial direction." The direction in which the inner ring 32 of the rolling bearing 3 rotates about the central axis C is the circumferential direction of the rolling bearing 3, and is simply referred to as the "circumferential direction."

The housing 2 is formed into a cylindrical shape and surrounds the main shaft 50. Inside the housing 2, a motor 7 is provided between the housing 2 and the main shaft 50. The motor 7 rotates the main shaft 50 with respect to the housing 2 . The motor 7 has a stator 7a and a rotor 7b. The stator 7a is fixed to the inner periphery of the housing 2. The rotor 7b is provided at a position facing the stator 7a so as to be rotatable concentrically and integrally with the main shaft 50. A plurality of rolling bearings 3 are arranged on both sides of the motor 7 in the axial direction. In this embodiment, a total of four rolling bearings 3 are arranged, two on each side of the motor 7 in the axial direction.

FIG. 2 is an enlarged sectional view showing two rolling bearings 3 arranged on the first axial side of FIG. 1. In FIG. 2, the two rolling bearings 3 include a first rolling bearing 3A arranged on the second axial side and a second rolling bearing 3B arranged on the first axial side. The first rolling bearing 3A and the second rolling bearing 3B are arranged adjacent to each other in the axial direction. Hereinafter, when explaining common matters between the first rolling bearing 3A and the second rolling bearing 3B, the first rolling bearing 3A and the second rolling bearing 3B will be collectively referred to as the rolling bearing 3.

The rolling bearing 3 of this embodiment is an angular contact ball bearing. The rolling bearing 3 includes an outer ring 31, an inner ring 32, a plurality of balls (rolling elements) 33, and a cage 34. A bearing outer diameter surface (outer peripheral surface) 31 a of the outer ring 31 is fitted into an inner peripheral surface 2 a of the housing 2 . An outer ring raceway 31b is provided on the inner peripheral surface of the outer ring 31. The plurality of balls 33 roll on the outer ring raceway 31b. The outer ring raceway 31b is a raceway groove whose axial cross section is arcuate. Inner ring 32 is arranged radially inward than outer ring 31 and concentrically with outer ring 31 . A bearing inner diameter surface (inner peripheral surface) 32 a of the inner ring 32 is fitted to an outer peripheral surface 50 a of the main shaft 50 . An inner ring raceway 32b is provided on the outer peripheral surface of the inner ring 32. The plurality of balls 33 roll on the inner raceway 32b. The inner ring raceway 32b is a raceway groove whose axial cross section is arcuate.

The plurality of balls 33 are arranged in an annular space between the outer ring 31 and the inner ring 32. The retainer 34 holds a plurality of balls 33 at equal intervals along the circumferential direction. When the inner ring 32 rotates, the plurality of balls 33 are held by the retainer 34 and roll on the outer ring raceway 31b and the inner ring raceway 32b. A spacer 4 is arranged adjacent to the first axial side of the second rolling bearing 3B.

FIG. 3 is a perspective view showing the first rolling bearing 3A, the second rolling bearing 3B, and the spacer 4. FIG. 4 is an enlarged cross-sectional view of the spacer 4. As shown in FIG. In FIGS. 3 and 4, the spacer 4 includes a spacer main body 21 and a cover 22. Note that in FIG. 3, illustration of the cover 22 is omitted. The spacer main body 21 is an annular member made of metal. The inner diameter of the spacer body 21 is larger than the outer diameter of the main shaft 50 (see FIG. 2).

The first groove 21b is provided in the axially intermediate portion of the outer circumferential surface 21a of the spacer body 21. The first groove 21b is provided in an annular shape over the entire circumferential direction of the spacer main body 21. The first groove 21b has a size that accommodates a plurality of wiring lines 6 and a plurality of terminal blocks 11 (described later). The outer peripheral surface 21a of the spacer body 21 has a first fitting surface 21a1 formed on the second axial side of the first groove 21b and a second fitting surface 21a1 formed on the first axial side of the first groove 21b. It has a fitting surface 21a2.

The first fitting surface 21a1 is fitted to the inner peripheral surface 2a of the housing 2 (see FIG. 2). A plurality of notch grooves 21c are provided on the first fitting surface 21a1 at equal intervals in the circumferential direction. The number of the plurality of notch grooves 21c is the same as the number of sensors 5. The cutout groove 21c is a groove for drawing the wiring 6 into the first groove 21b. The cutout groove 21c is provided at the end of the first fitting surface 21a1 on the first groove 21b side. Since the wiring 6 passes through the notch groove 21c and is drawn into the first groove 21b, the wiring 6 does not interfere with the cover 22. Note that the notch groove 21c may be provided in the cover 22.

The diameter of the second fitting surface 21a2 is smaller than the diameter of the first fitting surface 21a1. A second groove 21d is provided in the second fitting surface 21a2. The second groove 21d is a groove for pulling out the plurality of wiring lines 6 from the first groove 21b toward the first axial side of the spacer body 21. The second groove 21d is provided at one location in the circumferential direction of the second fitting surface 21a2 over the entire axial direction. The second groove 21d is shallower in the radial direction than the first groove 21b. The second groove 21d extends from the side surface of the spacer body 21 on the first axial side to one end of the first groove 21b in the axial direction. Thereby, the second groove 21d communicates with the first groove 21b.

In FIGS. 2 and 3, a plurality of sensors 5 are attached to the bearing outer diameter surface 31a of the outer ring 31 of the first rolling bearing 3A at equal intervals in the circumferential direction. The sensor 5 of this embodiment is a strain gauge. The strain gauge is a sensor 5 that detects strain in the outer ring 31 of the first rolling bearing 3A. The sensor 5 is bonded to the bearing outer diameter surface 31a of the outer ring 31 of the first rolling bearing 3A. The same number of terminal blocks 11 as the sensors 5 are fixed to the bottom surface of the first groove 21b of the spacer body 21 at equal intervals in the circumferential direction.

The plurality of wirings 6 are used to take out the detection signals of each sensor 5 to the outside of the first rolling bearing 3A. Each wiring 6 has a pair of lead wires 6a and a pair of signal wires 6b. The pair of lead wires 6a extend in the axial direction from the sensor 5 to the terminal block 11 across the bearing outer diameter surface 31a of the outer ring 31 of the second rolling bearing 3B. The pair of signal wires 6b are electrically connected to the pair of lead wires 6a at the terminal block 11 by soldering or the like.

A pair of signal lines 6b connected to each terminal block 11 are arranged along the circumferential direction within the first groove 21b of the spacer body 21. The plurality of signal lines 6b extending from all the terminal blocks 11 are bundled at one location in the circumferential direction within the first groove 21b. The plurality of bundled signal lines 6b pass through the second groove 21d of the spacer body 21 and are drawn out to the outside of the spacer body 21. Note that FIG. 3 shows only some of the signal lines 6b among the plurality of signal lines 6b (the same applies to FIGS. 4 and 5). A plurality of signal lines 6b drawn out from the spacer body 21 are covered with a shield 12. The shield 12 is a cylindrical member made of synthetic resin such as polyvinyl chloride.

As shown in FIG. 2, a housing groove 2b is provided on the inner circumferential surface 2a of the housing 2 so as to extend in the axial direction. The number of accommodation grooves 2b is the same as the number of sensors 5. The accommodation groove 2b is a groove that accommodates the sensor 5 attached to the outer ring 31 of the first rolling bearing 3A and the pair of lead wires 6a. The housing grooves 2b are provided at equal intervals in the circumferential direction on the inner circumferential surface 2a. As described above, when the two rolling bearings 3 and the spacer 4 are fitted and assembled into the inner circumferential surface 2a of the housing 2, the sensor 5 and the pair of lead wires 6a are accommodated in each accommodation groove 2b.

As shown in FIGS. 1 and 2, the shield 12 covering the plurality of signal lines 6b is inserted into a hole 2c formed in the housing 2 and pulled out of the rolling bearing device 1. The hole 2c opens near the spacer 4 on the inner peripheral surface 2a of the housing 2. The hole 2c communicates from the vicinity of the spacer 4 to the radially outer side of the stator 7a of the motor 7 to the side surface of the housing 2 on the first axial side. A plurality of signal lines 6b within the shield 12 are drawn out to the outside of the rolling bearing device 1 and connected to an amplifier (not shown). The amplifier amplifies the detection signal of the sensor 5 input from each signal line 6b.

As described above, the signal line 6b connected to the amplifier is protected by the shield 12 when passing through the hole 2c of the housing 2. Thereby, the influence of magnetic field noise from the motor 7 can be suppressed from reaching each signal line 6b. As a result, the detection signal of the sensor 5 is appropriately amplified by the amplifier.

FIG. 5 is a side view of the spacer 4 viewed from the second axial side. 4 and 5, the cover 22 of the spacer 4 is a member that covers the plurality of wirings 6 (lead wires 6a, signal wires 6b) and the plurality of terminal blocks 11 accommodated in the first groove 21b from the outside in the radial direction. be. The cover 22 of this embodiment is a cylindrical member made of metal. The cover 22 has a first annular portion 22a on a first axial side and a second annular portion 22b on a second axial side. The first annular portion 22a of the cover 22 is fitted and attached to the second fitting surface 21a2 of the outer peripheral surface 21a of the spacer body 21. The second annular portion 22b of the cover 22 is provided to cover the entire opening of the first groove 21b of the spacer body 21. Thereby, the second annular portion 22b of the cover 22 covers the plurality of signal lines 6b accommodated in the first groove 21b from the outside in the radial direction.

The outer diameter of the cover 22 is slightly smaller than the outer diameter of the first fitting surface 21a1 of the spacer body 21. As a result, when the first fitting surface 21a1 of the spacer body 21 is fitted to the inner circumferential surface 2a of the housing 2 (see FIG. 2), the outer circumferential surface of the cover 22 is aligned with the inner circumferential surface 2a of the housing 2. It is contactless.

When the first annular portion 22a of the cover 22 is fitted to the second fitting surface 21a2 of the spacer main body 21, the first annular portion 22a of the cover 22 covers the entire opening of the second groove 21d. The second groove 21d has a groove width w that allows the pair of signal lines 6b extending from each terminal block 11 to be arranged side by side in the circumferential direction. The second groove 21d has a groove depth h that allows the pair of signal lines 6b extending from each terminal block 11 to be sandwiched between the bottom surface of the second groove 21d and the inner peripheral surface of the first annular portion 22a. As described above, the pair of signal lines 6b extending from each terminal block 11 is sandwiched between the first annular portion 22a of the cover 22 and the second groove 21d.

According to the rolling bearing device 1 of this embodiment, the plurality of wirings 6 (a part of the lead wire 6a and the signal wire 6b) for taking out the detection signal of the sensor 5 to the outside of the rolling bearing 3 are connected to the first wire of the spacer body 21. It is accommodated in the groove 21b. The wiring 6 accommodated in the first groove 21b is covered from the outside in the radial direction by the cover 22. This can prevent the wiring 6 from protruding from the first groove 21b, thereby preventing the wiring 6 from breaking when fitting the outer ring 31 and spacer 4 of the rolling bearing 3 to the inner circumferential surface 2a of the housing 2. Can be suppressed.

Furthermore, the plurality of wires 6 accommodated in the first groove 21b are protected from electric field noise from the outside by the metal spacer main body 21 and cover 22. Thereby, the influence of electric field noise from the motor 7 can be suppressed from reaching the wiring 6 that is not protected by the shield 12.

Further, a pair of signal lines 6b extending from each terminal block 11 are sandwiched between the cover 22 and the second groove 21d. This ensures that even if a tensile load acts on each signal line 6b from the first axial side of the spacer body 21, the tensile load will not act on the connection end of the signal line 6b on the terminal block 11 side. It can be suppressed. As a result, the connection end of the signal line 6b can be prevented from peeling off and separating from the terminal block 11 due to the tensile load.

[Second embodiment]
FIG. 6 is a side view of the spacer 4 of the rolling bearing device 1 according to the second embodiment, viewed from the second axial side. The second embodiment illustrated in FIG. 6 differs from the first embodiment in the configurations of the spacer main body 21 and cover 22 of the spacer 4.

According to this embodiment, the recessed portion 21e is provided on the second fitting surface 21a2 of the spacer main body 21. The recessed portion 21e is provided at one location in the circumferential direction of the second fitting surface 21a2 over the entire axial direction. The second groove 21d is provided in the circumferential center of the bottom surface of the recess 21e. Two screw holes 21f are provided on both circumferential sides of the second groove 21d in the bottom surface of the recessed portion 21e. The radial depth of the recessed portion 21e is such that the head 23a of the screw 23, which will be described later, does not protrude further radially outward than the second fitting surface 21a2.

The cover 22 of this embodiment is a thin metal plate member. The cover 22 has a first annular portion 22a wrapped around the spacer main body 21 in the circumferential direction along the second fitting surface 21a2. Both ends of the first annular portion 22a in the longitudinal direction overlap in the radial direction at the bottom surface of the recessed portion 21e. A pair of first through holes 22c are provided at one end of the first annular portion 22a in an overlapping portion (hereinafter referred to as an overlapping portion) of the first annular portion 22a, and a pair of first through holes 22c are provided at the other end of the first annular portion 22a. A second through hole 22d is provided. Each first through hole 22c is located radially outward of each screw hole 21f. Further, each second through hole 22d is located radially outward of each first through hole 22c.

The overlapping portion of the first annular portion 22a is fixed to the bottom surface of the recessed portion 21e by a pair of screws 23. Specifically, the male thread of the shaft portion 23b of each screw 23 passes through the second through hole 22d and the first through hole 22c from the radially outer side of the overlapping portion of the first annular portion 22a, It is tightened into the female thread of the screw hole 21f. As a result, the pair of signal lines 6b extending from each terminal block 11 are sandwiched between the first annular portion 22a of the cover 22 and the second groove 21d.

The other configurations of the second embodiment are the same as those of the first embodiment, so the same reference numerals are given and the description thereof will be omitted. The rolling bearing device 1 of the second embodiment also provides the same effects as the first embodiment.

[others]
The embodiments disclosed above are illustrative in all respects and are not restrictive. For example, the rolling bearing device 1 can be applied to other than machine tools. The rolling bearing 3 can be applied not only to angular contact ball bearings but also to deep groove ball bearings and the like. In the above embodiment, the housing groove 2b that accommodates each sensor 5 and the pair of lead wires 6a is formed in the housing 2, but the bearing outer diameter of both outer rings 31 of the first rolling bearing 3A and the second rolling bearing 3B is It may be formed on the surface 31a.

1 Rolling bearing device 2 Housing 2a Inner peripheral surface 3 Rolling bearing 4 Spacer 5 Sensor 6 Wiring 7 Motor 21 Spacer body 21a Outer peripheral surface 21b First groove 21d Second groove 22 Cover 31 Outer ring 31a Bearing outer diameter surface (outer peripheral surface)

Claims

a cylindrical housing;
a rolling bearing having an outer ring fitted to the inner peripheral surface of the housing;
a sensor attached to the outer peripheral surface of the outer ring;
Wiring for extracting the detection signal of the sensor to the outside of the rolling bearing;
a spacer disposed on a first axial side of the outer ring and fitted to the inner circumferential surface of the housing;
The spacer is
an annular spacer body having a first groove formed on the outer peripheral surface to accommodate the wiring;
A rolling bearing device comprising: a cover attached to the spacer main body and covering the wiring housed in the first groove from the outside in the radial direction.
The rolling bearing device according to claim 1, wherein the spacer main body and the cover are made of metal.
The rolling bearing device according to claim 2, further comprising a motor provided within the housing.
A second groove is formed in the outer circumferential surface of the spacer body for pulling out the wiring from the first groove to the first axial side of the spacer body,
The rolling bearing device according to any one of claims 1 to 3, wherein the wiring is sandwiched between the cover and the second groove.