JP5487450B2 - Processing method of encoder in bearing device - Google Patents

Description

  The present invention relates to a method for processing an encoder in a bearing device, and more particularly to a method for processing an encoder in a bearing device with a load sensor capable of measuring an axial load acting on a rotating shaft such as a main shaft of a machine tool.

  In a machine tool, measuring an axial load acting on a spindle shaft has a great merit. That is, the axial load acting on the spindle axis of the machine tool is an important parameter having a great influence on machining accuracy, machining efficiency, tool life, and the like. Therefore, it is possible to select an appropriate machining condition by knowing the axial load. For example, machining conditions are generally determined by the rotation speed and feed rate of the tool, but are also affected by factors that are difficult to control, such as friction and heat generated by machining. Even if set to a constant value, the same machining accuracy is not always obtained. By considering the cutting load (that is, the axial load of the spindle shaft) corresponding to the change of the machining surface as a new parameter, it becomes possible to select a more strict machining condition and to improve the machining accuracy.

  Specifically, if the chip discharge amount is the same, the machining condition with a small cutting load is an efficient machining condition, which is advantageous for saving energy and extending the tool life. Further, from the increase in the cutting load, it is possible to estimate the deterioration of the cutting property (sharpness) of the tool and the occurrence of cutting edge wear and the like, and it becomes possible to know the tool life and the tool replacement time. Furthermore, by managing the history of changes in cutting load, it is possible to estimate bearing damage factors such as unreasonable cutting conditions and collisions (impact load) between the tool and workpiece, and from the grasped tool life characteristics The tool can be improved and improved.

  As a conventional apparatus capable of measuring an axial load, a load measuring apparatus for measuring an axial load incorporated in a rolling bearing unit for supporting a vehicle is known (for example, see Patent Document 1). In the load measuring device described in Patent Document 1, an encoder 284 shown in FIG. 12 is externally fitted and fixed to a portion between a plurality of inner ring raceways at an intermediate portion in the axial direction of the hub. In the encoder 284, convex portions 293 that are first detection portions and concave portions 294 that are second detection portions are formed on the outer peripheral surface alternately and at equal intervals in the circumferential direction.

JP 2006-317420 A

  By the way, as shown in FIG. 13, in the encoder 284 described in Patent Document 1, a tool 201 such as a milling machine is placed perpendicularly to the central axis O (X-axis direction in the figure) of the encoder (Z-axis direction in the figure). The concave portion 294 is formed on the outer peripheral surface of the encoder 284 by moving in the biaxial directions of the XY axes.

However, as shown in FIG. 14, when the recess 294 is machined by the XY-axis biaxial feed of the tool 201, the depth of the recess 294 increases as the Y-axis direction is cut from the Y-axis intermediate portion (virtual line p). Is gradually shallower with Δl ₁ at the imaginary line p, Δl ₂ at the imaginary lines q and q ′, Δl ₃ at the imaginary lines r and r ′, and Δl ₁ > Δl ₂ > Δl ₃ . As described above, since the groove depth of the concave portion 294 is different, there is a problem that an error occurs in detection of displacement by the sensor and resolution is deteriorated.
In particular, when the distance in the Y-axis direction of the concave portion 294 is long, the difference in groove depth becomes large, and this problem tends to become apparent.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a method for processing an encoder in a bearing device that forms a groove that constitutes a detected surface of the encoder so that load measurement can be performed with high accuracy. It is to provide.

The above object of the present invention can be achieved by the following constitution.
(1) A stationary side race ring fitted and fixed to a stationary member, a rotation side race ring fitted and fixed to a rotating member, a stationary side race of the stationary side race ring, and a rotational side race of the rotary side race ring A bearing provided with a plurality of rolling elements which are arranged so as to be freely rollable between,
An encoder configured by alternately changing characteristics of a detected surface provided on an outer peripheral surface of the rotation-side spacer rotating with the rotation-side raceway or the rotation-side raceway in a circumferential direction, and the encoder A sensor unit comprising a sensor that is disposed opposite to the detected surface and detects a change in the characteristic of the detected surface, and a processing method for an encoder in a bearing device comprising:
Attaching the rotating side raceway or the rotating side spacer to a rotating body;
While rotating the rotary side raceway or the rotary side spacer together with the rotary body, a tool arranged orthogonal to the rotary axis direction of the rotary body is moved in the rotary axis direction, and the rotary side raceway ring Or a step of machining a groove on the outer peripheral surface of the rotary spacer.
A bearing in which the pitch of the characteristic that changes in the circumferential direction continuously changes in the axial direction due to the processed groove is formed in the detected surface of the encoder in a single row in the axial direction. Processing method of encoder in apparatus.
(2) A stationary side race ring fitted and fixed to a stationary member, a rotation side race ring fitted and fixed to a rotary member, a stationary side race of the stationary side race ring, and a rotational side race of the rotary side race ring A bearing provided with a plurality of rolling elements which are arranged so as to be freely rollable between,
An encoder configured by alternately changing characteristics of a detected surface provided on an outer peripheral surface of the rotation-side spacer rotating with the rotation-side raceway or the rotation-side raceway in a circumferential direction, and the encoder An encoder in a bearing device comprising: a sensor unit that is disposed opposite to the detected surface and that includes a sensor that detects a change in the characteristic of the detected surface;
The encoder is manufactured by the encoder processing method according to (1),
The detected surface of the encoder is configured by a single row in the axial direction in which the pitch of the characteristic that changes in the circumferential direction continuously changes in the axial direction by a groove having a uniform depth. An encoder in a bearing device.

  According to the processing method of the encoder in the bearing device of the present invention, the tool arranged orthogonal to the rotational axis direction of the rotating body is rotated in the rotational axis direction while rotating the rotating side race ring or the rotating side spacer together with the rotating body. Since the groove is formed on the outer peripheral surface of the rotating raceway or the rotating spacer, the groove constituting the detection surface of the encoder can be provided with a uniform depth, and accurate displacement measurement can be performed. It becomes possible.

  Further, the surface to be detected of the encoder is constituted by a single row in the axial direction because the processed groove has a portion in which the pitch of the characteristic that changes in the circumferential direction continuously changes in the axial direction. It can be constituted by only one magnetic sensor. Thereby, the cost of the sensor unit can be reduced, and the axial width of the rotation side raceway or the rotation side spacer constituting the sensor and encoder can be reduced.

It is sectional drawing of the spindle apparatus of the machine tool by which the encoder processed using the processing method of the encoder which concerns on 1st Embodiment was employ | adopted. It is principal part sectional drawing of the main axis | shaft apparatus of FIG. It is a figure explaining the processing method of the encoder which concerns on 1st Embodiment, (a) is the figure seen from the front side of the encoder, (b) is the figure seen from the side surface side. It is a perspective view of the encoder processed using the encoder processing method according to the first embodiment. (A) is the figure which expand | deployed the encoder of FIG. 4 and was seen from the outer peripheral side, (b) is the principal part side view of the encoder, (c) is a front view. It is a perspective view of the encoder of other forms processed using the processing method of the encoder concerning a 1st embodiment. It is a perspective view of the encoder of other forms processed using the processing method of the encoder concerning a 1st embodiment. It is principal part sectional drawing of the bearing apparatus with a load sensor by which the encoder processed using the processing method of the encoder which concerns on 2nd Embodiment was employ | adopted. (A) is a front view of the encoder processed using the encoder processing method according to the second embodiment, and (b) is a perspective view thereof. It is a perspective view of the encoder of other forms processed using the processing method of the encoder concerning a 2nd embodiment. It is a perspective view of the encoder of another form processed using the processing method of the encoder concerning a 2nd embodiment. FIG. 10 is a perspective view of an encoder described in Patent Document 1. It is a figure explaining the processing method of the conventional encoder, (a) is the figure seen from the front side of the encoder, (b) is the figure seen from the side surface side. (A) is the figure which unfolded the encoder of FIG. 12, and was seen from the outer peripheral side, (b) is the principal part side view of the encoder, (c) is a front view.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First embodiment)
As shown in FIGS. 1 and 2, an encoder 84 machined using the encoder machining method according to the first embodiment is employed in, for example, a spindle device 10 of a machine tool.

  The spindle device 10 is a motor built-in system, and a hollow rotating shaft (spindle shaft) 11 that is a rotating member is provided at the center thereof. A tool (not shown) is held at the axial end of the rotating shaft 11 (left side in FIG. 1).

  The rotary shaft 11 is rotatably supported by a housing 50 that is a stationary member by a pair of front bearings 20 and 30 that support the tool side and a rear bearing 40 that supports the opposite tool side. A rotor 51 is fitted on the outer peripheral surface of the rotary shaft 11 between the front bearings 20 and 30 and the rear bearing 40. In addition, the stator 52 disposed around the rotor 51 is fixed to the housing 50, and by supplying electric power to the stator 52, a rotational force is generated in the rotor 51 to rotate the rotating shaft 11. The housing 50 includes a housing 50 a and a housing 50 b that are divided in the axial direction between the front bearing 30 and the stator 52.

  The front bearings 20 and 30 are a pair of angular ball bearings having substantially the same dimensions arranged so as to form a rear combination, outer rings 21 and 31 that are stationary bearing rings, and inner rings 22 and 32 that are rotating bearing rings. And a plurality of balls 23 and 33 as rolling elements arranged with a contact angle between the outer ring raceway groove which is a stationary side raceway and the inner ring raceway groove which is a rotation side raceway.

  The outer rings 21 and 31 of the front bearings 20 and 30 are fitted in the housing 50 and fixed to the housing 50 via an outer ring spacer 54 which is a stationary side spacer by a front bearing outer ring presser 53 which is bolted to the housing 50. ing.

  Further, the inner rings 22 and 32 of the front bearings 20 and 30 are externally fitted to the rotating shaft 11 and are fixed to the rotating shaft 11 via an inner ring spacer 81 which is a rotating side spacer by a nut 55 fastened to the rotating shaft 11. Has been. The front bearings 20 and 30 are loaded with a fixed position preload by a nut 55, and the axial position of the rotary shaft 11 is positioned by the front bearings 20 and 30.

  The rear bearing 40 is a cylindrical roller bearing and includes an outer ring 41, an inner ring 42, and a plurality of cylindrical rollers 43 as rolling elements. The outer ring 41 of the rear bearing 40 is fitted in the housing 50 and fixed to the housing 50 via the outer ring spacer 44 by a rear bearing outer ring retainer 56 that is bolted to the housing 50. The inner ring 42 of the rear bearing 40 is fixed to the rotating shaft 11 via an inner ring spacer 45 by another nut 57 fastened to the rotating shaft 11.

  On the outer peripheral surface of the housing 50 corresponding to the front bearings 20 and 30 and the stator 52 in the axial direction, annular cooling oil grooves 58 and 59 are formed. The cooling oil grooves 58, 59 are covered with ring-shaped cooling jackets 60, 61 fitted with O-rings 62, 63 and fitted to the housing 50. The front bearings 20 and 30 and the stator 52 are cooled by the cooling oil supplied to the cooling oil grooves 58 and 59.

  A sensor mounting hole 68 and a through hole 54a are formed in the housing 50 and the outer ring spacer 54 continuously in the radial direction, respectively. A sensor 82 constituting the sensor unit 80 is disposed in the sensor mounting hole 68.

  The first wiring hole 70 is machined from the side opposite to the tool of the housing 50 a, and is inclined in parallel to the inclined hole 71 provided in the radial direction and inclined from the outer peripheral surface of the housing 50. It communicates with a second wiring hole 72 extending to the tool side. In this way, the first wiring hole 70, the inclined hole 71, and the second wiring hole 72 are bent, so that the wiring 83 of the sensor 82 can be routed without interfering with the stator 52. A plug 74 is inserted and closed at the end of the first wiring hole 70 on the side opposite to the tool, and foreign matter intrusion from the motor side is prevented.

  In addition, the insertion work of the wiring 83 with respect to the 1st routing hole 70, the inclination hole 71, and the 2nd routing hole 72 is the 1st routing hole 70, when it is difficult to insert at once as mentioned above. In addition, the wiring 83 inserted through the inclined hole 71 may once be taken out of the inclined hole 71 and then inserted through the inclined hole 71 into the second routing hole 72 again. In addition, after the wiring 83 is inserted, a plug (not shown) is inserted into the opening of the inclined hole 71 and closed, thereby preventing foreign matter from entering. One end of the wiring 83 wired in this way is connected to the arithmetic unit 150 and an output signal detected by the sensor 82 is input.

  The sensor 82 is mounted with O-rings 91a and 91b, and the wiring 83 of the sensor 82 is inserted through the first wiring hole 70, the inclined hole 71, and the second wiring hole 72, and the sensor mounting hole 68 of the housing 50, and The outer ring spacer 54 is assembled by being inserted into the through hole 54a.

  Then, the fixing jig 88 is fitted into the housing 50, and the male screw 89 is screwed into the housing 50 and fixed. As a result, the magnetic sensor 90 provided at the tip of the sensor 82 is positioned at a predetermined position and is disposed so as to face the detected surface of the encoder 84 formed on the outer peripheral surface of the inner ring spacer 81.

FIG. 3 shows a processing method of the encoder 84 of the present embodiment, and FIGS. 4 and 5 show an encoder processed using the processing method. Hereinafter, the processing method of the encoder 84 will be described in detail with reference to these drawings.
In the drawing, the X, Y, and Z axes are respectively an axis parallel to the rotation axis C of the rotating body 2 described later, an axis perpendicular to the rotating axis C and perpendicular to the radial direction of the rotating body 2, and the rotation body 2 An axis parallel to the radial direction.

  First, the inner ring spacer 81 made of a magnetic metal material is attached to the outer peripheral surface of the rotating body 2 of the machine tool. At this time, the central axis of the inner ring spacer 81 substantially coincides with the rotational axis C of the rotating body 2. Then, the inner ring spacer 81 is rotated around the rotation axis C together with the rotating body 2.

Next, a tool 1 such as an end mill is orthogonal to the rotation axis C (parallel to the Z axis), and is brought into contact with the X axis direction one portion 81a on the outer peripheral surface of the inner ring spacer 81 to be predetermined in the Z axis direction. After being moved to the depth of, the individualized portion 86 is recessed by moving to the other portion 81b in the X-axis direction over a predetermined length in the rotation axis C direction (X-axis direction).
Thereafter, the tool 1 is once separated from the outer peripheral surface of the inner ring spacer 81, and again brought into contact with the other portion 81b 'in the X-axis direction on the outer peripheral surface and moved to a predetermined depth in the Z-axis direction. The individualized portion 86 having a characteristic different from that of the above-described individualized portion 86 is recessed by moving to the one portion 81a ′ in the X-axis direction over a predetermined length in the −X-axis direction.
In this way, a pair of personalized portions 86 and 86 having different characteristics are formed, and a combination part 85 for detection is configured.

  Then, by repeating the above steps on the outer peripheral surface of the inner ring spacer 81 at equal intervals in the circumferential direction, a plurality of combination parts for detection 85 are provided, and an encoder 84 is formed.

  In addition, the space | interval regarding the circumferential direction of each pair of individualization parts 86 and 86 which comprise each to-be-detected combination part 85 and 85 is the same direction regarding an axial direction in all the to-be-detected combination parts 85 and 85. It is changing continuously. That is, the interval in the circumferential direction between the pair of individualized portions 86, 86 constituting each detected combination portion 85, 85 becomes smaller in the axial direction one end (upper right end in FIG. 4) of the encoder 84, The interval in the circumferential direction between the individualized portions 86 and 86 constituting each of the detected combination portions 85 and 85 adjacent to each other in the circumferential direction becomes smaller as the other axial end of the encoder 84 (the lower left end in FIG. 4). Inclined in the direction. The encoder 84 constitutes a sensor unit 80 together with the sensor 82.

  Here, the encoder 84 processed by the encoder processing method of the present embodiment will be described more specifically with reference to FIG. In FIG. 5, the imaginary lines S, T, T ′ are all parallel to the X axis, the imaginary line S passes through the middle part of the individualized portion 86 in the Y axis direction, and the imaginary lines T, T ′ are Each of the individualized portions 86 is in contact with one end portion in the Y-axis direction and the other end portion in the Y-axis direction.

According to the processing method of the encoder of the present embodiment, the outer ring spacer 81 has an outer periphery by moving the tool 1 in the direction of the rotation axis C while rotating the inner ring spacer 81 around the rotation axis C together with the rotating body 2. Since the surface is processed, the depths ΔL ₁ , ΔL ₂ , ΔL ₂ in the Z-axis direction to the outer peripheral surface of the individualized portion 86 at the virtual lines S, T, T ′ are equal. That is, the individualized portion 86 constituting the detection surface of the encoder 84 can be provided with a uniform depth, and the displacement can be measured with high accuracy by the sensor.

  In particular, even when the distance in the Y-axis direction of the individualized portion 86 is long, it is possible to prevent the variation in the depth in the Z-axis direction as in the conventional processing method, and the depth can be provided uniformly. Therefore, the resolution of displacement detection is not adversely affected.

  In the present embodiment, the detected surface of the encoder 84 is configured by a single row in the axial direction where the pitch of the characteristic that changes in the circumferential direction continuously changes in the axial direction. Only one magnetic sensor 90 can be used. As a result, the cost of the sensor unit can be reduced, and the axial width of the inner ring spacer 81 constituting the sensor 82 and the encoder 84 can also be reduced. Thereby, the axial direction length of the spindle device 10 can also be shortened. In particular, in the case of a spindle shaft turning (for example, turning around ± 120 °) with a 5-axis machine, etc., if the spindle shaft length is shortened, the turning radius can be reduced, saving space for the entire machine tool. Therefore, there is an advantage that the operation of the spindle device 10 is facilitated, such as when performing three-dimensional machining, and the ease of machining program creation and machinability can be improved.

The individualized portion 86 has a shape that opens in these annular grooves by providing annular grooves having a depth greater in the Z-axis direction than the individualized portion 86 on both ends of the outer peripheral surface of the inner ring spacer 81 in the X-axis direction. There may be. In that case, the individualized portion 86 can be formed by cutting the tool 1 through these annular grooves in the X-axis direction, and it is not necessary to move the tool 1 in the Z-axis direction.
Further, when the tool 1 cuts through the individualized portion 86, even if a burr is generated in the vicinity of the axial end surface, the burr affects the axial end surface of the inner ring spacer 81 contacting the inner rings 22 and 32. Therefore, the parallelism of the end surface of the inner ring spacer 81 is improved. As a result, the inner rings 22, 32 and the inner ring spacer 81 can be assembled with high accuracy.

  It should be noted that the encoder processing method of the present embodiment can be applied to encoders of other forms.

  For example, the encoder 84 shown in FIG. 6 includes a convex portion 93 as a first detected portion and a concave portion 94 as a second detected portion having different characteristics on the outer peripheral surface of the inner ring spacer 81 made of a magnetic metal material. Are formed alternately and at equal intervals in the circumferential direction. The convex portion 93 and the concave portion 94 are formed in a trapezoidal shape or an inverted trapezoidal shape, and the width of the convex portion 93 is wider toward one end in the axial direction (lower end in FIG. 6), and the width of the concave portion 94 is the other end in the axial direction (see FIG. The upper end of 6 is wider.

  The encoder 84 is formed by forming a concave portion 94 on the outer peripheral surface of the inner ring spacer 81 using the tool 1. At that time, by applying the machining method of the encoder of the present embodiment and performing cutting with the tool 1 while rotating the inner ring spacer 81 together with the rotating body 2 around the rotation axis C, the concave portion having a uniform depth is obtained. 94 can be provided.

In addition, the processing method of the encoder of the present embodiment can be similarly applied to the encoder 84 of another form as shown in FIG. 7, for example.
The encoder 84 stabilizes the output signal of the magnetic sensor 90 by devising the shapes of the convex portions 93 and 93 and the concave portions 94 and 94 formed on the outer peripheral surface thereof. That is, in the case of this embodiment, the axial dimensions of the convex portions 93 and 93 and the concave portions 94 and 94 are parallel to each other so that the width dimension in the circumferential direction of the encoder 84 does not change in the axial direction of the encoder 84. The parts 93a, 93b, 94a, 94b are used. Therefore, the pitch at which the characteristic of the outer peripheral surface that is the detection surface of the encoder 84 changes in the circumferential direction varies depending on the axial position at the axial intermediate portion of the outer peripheral surface, but at the axial position at both axial end portions. Regardless of

In the case of this encoder 84, the reason why the output signal of the sensor 82 can be stabilized by providing the parallel portions 93a, 93b, 94a, 94b is as follows.
If the distance between the concave and convex portions is shortened in order to shorten the pitch of the characteristic change of the detected surface of the encoder 84, the detection portion of the sensor will be close to both ends in the width direction (both axial ends) of the detected surface of the encoder. In a state of being opposed to each other, the flow of magnetic flux flowing between the detection unit and the surface to be detected becomes unstable, and the output of the sensor tends to become unstable. For example, when the pitch of the convex portions 93 and 93 and the concave portions 94 and 94 is shortened with the encoder 84 shown in FIG. 6, the bases of the trapezoidal convex portions 93 and 93 adjacent in the circumferential direction are close to each other. In particular, in order to enable detection of the rotational speed of the rotary shaft 11 even when the encoder 84 and the sensor 82 are greatly displaced in the axial direction, the relative displacement amount in the axial direction allowed between the encoder 84 and the sensor 82 is set. In order to ensure, when the height of the trapezoidal shape is increased, the tendency of the bases of the trapezoidal convex portions 93 and 93 adjacent in the circumferential direction to approach each other becomes remarkable as described above.

  On the other hand, in the case of the encoder 84 in FIG. 7, the bases of the trapezoidal convex portions 93 and 93 adjacent in the circumferential direction are excessively provided with the provision of the parallel portions 93a, 93b, 94a, and 94b. Proximity can be prevented. Even when the detection portion of the sensor 82 faces the portion corresponding to the bottom sides of the convex portions 93 and 93 at the axial end portion of the outer peripheral surface of the encoder 84, the detection portion of the sensor 82 and the detected surface of the encoder 84 The output of the sensor 82 can be stabilized by stabilizing the flow of magnetic flux flowing between them. Further, even if the axial displacement amount between the encoder 84 and the sensor 82 is slightly increased, the rotational speed of the rotating shaft 11 can be detected by the sensor 82.

  In addition, although the shape of the both sides of the circumferential direction of each parallel part 93a, 93b, 94a, 94b is made into the straight line, the shape of this part does not necessarily need to be a straight line. For example, depending on the sensitivity of the sensor 82 and the sensitive range (spot diameter), the sensor 82 may be slightly inclined with respect to the axial direction or may be formed in an arc shape having a large curvature radius.

In addition, the recessed part 94 may be a shape which opens to these annular grooves by providing annular grooves having a greater depth in the Z-axis direction than the recessed part 94 on both ends of the outer peripheral surface of the inner ring spacer 81 in the X-axis direction. . In that case, the recess 94 can be formed by cutting the tool 1 between these annular grooves in the X-axis direction, and it is not necessary to move the tool 1 in the Z-axis direction.
Further, when the tool 1 cuts through the recess 94, even if a burr is generated in the vicinity of the axial end surface, the burr affects the axial end surface of the inner ring spacer 81 that contacts the inner rings 22, 32. Therefore, the parallelism of the end surface of the inner ring spacer 81 is improved. As a result, the inner rings 22, 32 and the inner ring spacer 81 can be assembled with high accuracy.

(Second Embodiment)
As shown in FIG. 8, the encoder machined using the encoder machining method according to the second embodiment is employed in a bearing device 110 with a load sensor, for example.
The bearing device 110 with a load sensor is in contact between an outer ring 111 that is a stationary side raceway, an inner ring 112 that is a rotation side raceway, an outer ring raceway groove 111a that is a stationary side raceway, and an inner ring raceway groove 112a that is a rotation side raceway. An angular ball bearing 120 including a plurality of balls 113 as rolling elements that are arranged with corners and are rotatably held by a cage 114. The outer ring 111 of the angular ball bearing 120 is fitted and fixed to a housing (not shown) that is a stationary member, and the inner ring 112 is fitted and fixed to a rotating shaft (not shown) that is a rotating member.

  A sensor unit 130 including an encoder 131 and a sensor 132 is disposed on one end side (right side in FIG. 8) of the angular ball bearing 120 in the axial direction. That is, the encoder 131 is formed in a ring shape on the outer peripheral surface on one end side of the inner ring 112, and the sensor 132 is mounted in a sensor mounting hole 115 formed in the outer ring 111 so as to face the encoder 131.

  The sensor 132 has a built-in magnetic sensor 136 as a detection unit, and a signal line 137 for outputting the detection signal to an arithmetic device (not shown) is led out from the side surface of the sensor 132.

  Thereby, the magnetic sensor 136 provided at the tip of the sensor 132 is positioned at a predetermined position so as to face the detection surface of the encoder 131 provided in the inner ring 112. That is, the encoder 131 and the sensor 132 are such that the magnetic sensor 136 is positioned at the axially intermediate portion P (see FIG. 9) of the detected surface.

The encoder 131 of this embodiment is processed by the same method as the encoder processing method of the first embodiment.
That is, the inner ring 112, which is a magnetic metal member, is attached to the outer peripheral surface of the rotating body 2 and is rotated around the rotation axis C together with the rotating body 2. Then, the tool 1 is brought into contact with the outer peripheral surface of the inner ring 112 so as to be orthogonal to the rotation axis C and moved in the direction of the rotation axis C, so that each of the tools 1 is arranged at equal intervals in the circumferential direction on the outer ring surface. A pair of individualized portions 134 and 134 constituting the detected combination portions 133 and 133 are recessed, and an encoder 131 is formed.

According to this encoder processing method, the individualized portion 134 constituting the detection surface of the encoder 131 can be provided with a uniform depth, and the displacement can be accurately measured by the sensor.
In particular, even when the distance in the circumferential direction of the individualized portion 134 is long, the variation in depth can be prevented as in the conventional processing method, and the depth can be uniformly provided. Does not adversely affect detection resolution.

  In the present embodiment, the detected surface of the encoder 131 is configured by a single row in the axial direction where the pitch of the characteristic that changes in the circumferential direction continuously changes in the axial direction. Only one magnetic sensor 136 can be used. Thereby, the cost of the sensor unit can be reduced and the axial width of the inner ring 112 constituting the sensor 132 and the encoder 131 can also be reduced. Thereby, the axial direction length of the bearing apparatus 110 can also be shortened, and the axial length of the main spindle apparatus when the bearing apparatus 110 is applied to the main spindle apparatus for machine tools can be shortened. In particular, in the case of a spindle shaft turning (for example, turning around ± 120 °) with a 5-axis machine, etc., if the spindle shaft length is shortened, the turning radius can be reduced, saving space for the entire machine tool. Therefore, there is an advantage that the operation of the bearing device 110 is facilitated, such as when three-dimensional machining is performed, and the ease of creating a machining program and workability can be improved.

  In addition, as shown in FIG. 10, the encoder processing method of the present embodiment includes a case where the encoder 131 is configured by providing the inner ring 112 with a convex portion 193 and a concave portion 194 having a uniform depth, as shown in FIG. As shown, the inner ring 112 has a convex portion 193 having parallel portions 193a and 193b, and a parallel portion 194a and 194b, and a concave portion 194 having a uniform depth. Applicable.

In addition, this invention is not limited to each embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
Although an end mill is illustrated as the tool 1, any tool that can be machined may be used. For example, an electric discharge machine may be used.

Further, in the present embodiment, the inner ring spacer 81 or the inner ring 112 is rotated around the rotation axis C together with the rotating body 2 while the tool 1 is moved in the rotation axis C direction (X-axis one axis direction), whereby the inner ring The outer peripheral surface of the spacer 81 or the inner ring 112 is processed.
However, as another encoder processing method, the inner ring spacer 81 or the inner ring 112 is not rotated, and the detected surface of the encoder is configured by matching the tool 1 with the curvature of the outer peripheral surface of the inner ring spacer 81 or the inner ring 112. You may employ | adopt the processing method moved to a XYZ axis | shaft 3 axial direction, controlling so that the Z-axis direction depth of a groove | channel may become uniform.

1 Tool 2 Rotating body C Rotating shaft 21 Outer ring (stationary raceway)
22 Inner ring (Rotating raceway)
23 balls (rolling elements)
30 Angular contact ball bearing (front bearing)
31 Outer ring (stationary track theory)
32 Inner ring (rotation side trajectory)
33 balls (rolling elements)
50 Housing (stationary member)
80 Sensor unit 81 Inner ring spacer (rotating side spacer)
82 Sensor 84 Encoder 86 Individualized part (groove)
94 Recess (groove)
111 Outer ring (stationary raceway)
112 Inner ring (Rotating raceway)
113 balls (rolling elements)
120 Angular contact ball bearing
130 Sensor unit 131 Encoder 132 Sensor 134 Individualized part (groove)
194 Recess (groove)

Claims (1)

The stationary side race ring fitted and fixed to the stationary member, the rotational side race ring fitted and fixed to the rotary member, and the stationary side raceway of the stationary side raceway and the rotational side raceway of the rotary side raceway A bearing provided with a plurality of rolling elements movably arranged;
An encoder configured by alternately changing characteristics of a detected surface provided on an outer peripheral surface of the rotation-side spacer rotating with the rotation-side raceway or the rotation-side raceway in a circumferential direction, and the encoder A sensor unit comprising a sensor that is disposed opposite to the detected surface and detects a change in the characteristic of the detected surface, and a processing method for an encoder in a bearing device comprising:
Attaching the rotating side raceway or the rotating side spacer to a rotating body;
While rotating the rotary side raceway or the rotary side spacer together with the rotary body, a tool arranged orthogonal to the rotary axis direction of the rotary body is moved in the rotary axis direction, and the rotary side raceway ring Or a step of machining a groove on the outer peripheral surface of the rotary spacer.
The detected surface of the encoder has a single row in the axial direction in which the pitch of the characteristic that changes in the circumferential direction continuously changes in the axial direction due to the processed grooves. A method for processing an encoder in a bearing device.

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