WO2019059010A1

WO2019059010A1 - Mounting mechanism and electric motor using same

Info

Publication number: WO2019059010A1
Application number: PCT/JP2018/033337
Authority: WO
Inventors: 将克大久保
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2017-09-20
Filing date: 2018-09-10
Publication date: 2019-03-28
Also published as: CN111094902B; JPWO2019059010A1; CN111094902A; JP7113237B2

Abstract

This mounting mechanism is provided with: a first nut through which a rotating shaft extends, the first nut including a circular cylinder section which extends along the axis of the rotating shaft and which has a first outer peripheral surface including a first thread ridge, the first nut also including a flange section protruding in a direction which intersects the axis and which is away from the side on which the rotating shaft is located, the flange section having a first inner peripheral surface including a first thread trough; a second nut through which the rotating shaft extends, the second nut including a second thread trough which is formed in part of a second inner peripheral surface facing the rotating shaft and which engages with the first thread ridge, the second nut also including a small hole formed in the portion of the second inner peripheral surface other than the second thread trough and engaging with the rotating shaft; and a ring body through which the rotating shaft extends, the ring body being located between the rotating shaft and a third inner peripheral surface of the circular cylinder section and having a first sloped surface which, when the first nut and the second nut are engaged with each other in the direction in which the first nut and the second nut move toward each other, converts forces applied from the first nut and the second nut in the direction of the axis into forces acting in the direction intersecting the axis.

Description

Mounting mechanism and motor using the same

The present disclosure relates to an attachment mechanism for attaching a rotating body to a rotation shaft and a motor having an encoder attached thereto. The motor has an encoder mounted using a mounting mechanism.

2. Description of the Related Art Heretofore, there are some motors to which a rotary encoder is attached. The rotary encoder includes a boss, a light emitting diode as a light source, a substrate on which a position detection pattern is formed, and a rotary plate attached to the boss and having a light transmitting window through which light of the light emitting diode is formed. .

The boss is attached to the rotating shaft of the motor by being tightened with a screw or the like.

The rotating plate is located between the light emitting diode and the substrate. The rotating plate rotates with the rotation axis.

When the rotating plate rotates, light emitted from the light emitting diode passes through the light transmitting window formed on the rotating plate and reaches the position detection pattern (see, for example, Patent Documents 1 and 2).

The boss is fixed to the rotation shaft from its outer peripheral side surface by tightening it with a screw or the like. At this time, due to the tightening of the screw, a shift may occur between the rotation center of the boss and the rotation center of the rotation shaft. Due to the deviation that has occurred, in the rotary encoder, runout occurs in the rotary plate with respect to the rotation center of the rotary encoder, that is, the rotation center of the rotation shaft. If run-out occurs on the rotary plate, the detection accuracy of the position detection pattern provided on the rotary plate is lowered, which causes a problem that desired control by the rotary encoder can not be performed. In the following description, the rotation center is also referred to as an axial center.

Japanese Patent Application Publication No. 08-168210 JP 2008-228397 A

The present disclosure aims to suppress runout of a rotating body when attaching a device having a rotating body such as a rotating plate to a shaft body such as a rotating shaft.

The present disclosure is directed to an attachment mechanism for attaching a rotary body to a rotary shaft and a motor having a rotary encoder attached thereto using the same, and adopts the following solutions.

That is, one aspect of the present disclosure is an attachment mechanism for attaching a rotating body to a rotation shaft. The attachment mechanism includes a first nut, a second nut, and a ring body.

The first nut includes a cylindrical portion and a flange portion. The rotation axis passes through the cylindrical portion. The cylindrical portion extends along the axial center of the rotation axis and has a first outer peripheral surface including a first thread. The flange portion has a first inner circumferential surface including a first screw groove, which is convex in a direction intersecting with the axis and opposite to the side where the rotation axis is located.

The rotation axis passes through the second nut. The second nut includes a second thread groove and a small hole. The second thread groove is formed in a part of the second inner circumferential surface facing the rotation axis, and is screwed with the first thread. The small hole portion is formed in a portion other than the second screw groove in the second inner circumferential surface, and fitted with the rotation shaft.

The ring body is located between the rotation axis and the third inner circumferential surface of the cylindrical portion with the rotation axis passing through. When the first nut and the second nut are screwed in the direction in which they approach each other, the ring body exerts an axial force acting on the axial center applied from each of the first nut and the second nut. It has a first inclined surface that translates into a force acting in a direction intersecting the heart.

Another aspect of the present disclosure includes a rotor having a rotor core attached to a rotation shaft, a bearing that rotatably supports the rotation shaft, and a stator positioned opposite to the rotor. An encoder is attached to a rotating shaft using the mounting mechanism of

According to the present disclosure, when the apparatus having the rotating body such as the rotating plate is attached to the rotating shaft, the runout of the rotating body can be suppressed.

FIG. 1 is a cross-sectional view showing an outline of a motor in which a mounting mechanism according to a first embodiment of the present disclosure is used. FIG. 2 is an exploded perspective view showing a mounting mechanism according to Embodiment 1 of the present disclosure and an encoder mounted by the mounting mechanism. FIG. 3 is a cross-sectional view showing the attachment mechanism according to Embodiment 1 of the present disclosure and an encoder attached to the attachment mechanism. FIG. 4 is a schematic cross-sectional view showing the action on the rotation axis in the attachment mechanism according to the first embodiment of the present disclosure. FIG. 5 is a perspective view of one member of the attachment mechanism according to the first embodiment of the present disclosure. FIG. 6 is a front view of one member of the attachment mechanism according to the first embodiment of the present disclosure. FIG. 7 is a front view of another member of the mounting mechanism according to Embodiment 1 of the present disclosure. FIG. 8 is a perspective view of another member of the mounting mechanism according to Embodiment 1 of the present disclosure. FIG. 9 is a schematic cross-sectional view showing the action on the rotation axis in the attachment mechanism according to Embodiment 2 of the present disclosure. FIG. 10 is a perspective view of one member of the attachment mechanism according to the second embodiment of the present disclosure. FIG. 11 is a front view of one member of the attachment mechanism according to Embodiment 2 of the present disclosure. FIG. 12 is a front view of another member of the attachment mechanism according to Embodiment 2 of the present disclosure. FIG. 13 is a perspective view of another member of the attachment mechanism according to Embodiment 2 of the present disclosure. FIG. 14 is a schematic cross-sectional view showing the action on the rotation axis in the attachment mechanism according to Embodiment 3 of the present disclosure. FIG. 15 is a perspective view of one member of the attachment mechanism according to the third embodiment of the present disclosure. FIG. 16 is a front view of one member of the attachment mechanism according to Embodiment 3 of the present disclosure. FIG. 17 is a front view of another member of the attachment mechanism according to Embodiment 3 of the present disclosure. FIG. 18 is a perspective view of another member of the mounting mechanism according to Embodiment 3 of the present disclosure. FIG. 19 is a schematic cross-sectional view showing an operation on the rotation axis in the attachment mechanism according to Embodiment 4 of the present disclosure. FIG. 20 is a perspective view of one member of the attachment mechanism according to Embodiment 4 of the present disclosure. FIG. 21 is a front view of one member of the attachment mechanism according to Embodiment 4 of the present disclosure. FIG. 22 is a front view of another member of the attachment mechanism according to Embodiment 4 of the present disclosure. FIG. 23 is a perspective view of another member of the mounting mechanism according to Embodiment 4 of the present disclosure. FIG. 24 is a front view of one member of the attachment mechanism according to Embodiment 5 of the present disclosure. FIG. 25 is a front view of another member of the attachment mechanism according to Embodiment 5 of the present disclosure.

(Circumstances leading to the present disclosure)
Conventionally, for transportation of various parts or products, or movement of an XY stage, an electric motor capable of position control, speed control and the like is used as a power source. Generally, an optical or magnetic rotary encoder (hereinafter simply referred to as an encoder) is attached to such a motor as means for detecting the rotational speed and rotational angle of the rotational shaft.

A position detection pattern is formed on the rotating plate. An encoder is attached to the rotating shaft. Therefore, in order to improve the position detection accuracy of the encoder, it is important to accurately position the rotation center of the rotary plate with respect to the rotation center of the rotation axis.

The rotary plate is attached to and held by a boss which is a reinforcing component for reinforcing the cylindrical shaft. The boss to which the rotating plate is attached has an axial hole. The axial hole is inserted into the rotary shaft on which the encoder is mounted. The boss is fixed to the rotation axis. Specifically, the boss is fixed to the rotation shaft from its outer peripheral side surface, for example, by tightening a screw.

In the encoder thus configured, first, the mounting accuracy of the rotary plate to the boss depends on the positioning accuracy between the rotation center of the rotation axis and the rotation center of the boss. For this reason, when a gap is generated between the shaft hole of the boss and the rotation shaft of the motor, a shift occurs between the rotation center of the rotation shaft and the rotation center of the boss. Therefore, it becomes difficult to improve the mounting accuracy of the rotary plate to the boss. Therefore, it becomes difficult to suppress run-out of the rotary plate rotating with the rotary shaft.

The mounting accuracy of the boss with respect to the rotation axis also depends on the positioning accuracy between the rotation center of the rotation axis and the rotation center of the boss. For this reason, if there is a gap between the shaft hole of the boss and the rotation axis, the screw tightening causes a shift between the rotation center of the boss and the rotation center of the rotation axis. Therefore, it is difficult to improve the mounting accuracy of the boss with respect to the rotation shaft. Therefore, even in this case, it is difficult to suppress run-out of the rotary plate with respect to the rotation shaft.

The present disclosure is made in view of the above problems. Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, the detailed description may be omitted if necessary. For example, detailed descriptions of well-known matters, or duplicate descriptions of substantially the same configurations may be omitted. This is to facilitate the understanding of those skilled in the art by avoiding unnecessary redundancy in the following description.

It is to be understood that the attached drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and they are not intended to limit the claimed subject matter.

Embodiment 1
Embodiments of the present disclosure will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing an outline of a motor 200 in which a mounting mechanism according to a first embodiment of the present disclosure is used.

(Overview of motor)
An embodiment of the present disclosure will be described by exemplifying an embodiment in which an encoder is attached to a motor using an attachment mechanism. In addition, the attachment mechanism in this indication can also be utilized except a motor, if a rotation body can be attached to a rotating shaft.

As shown in FIG. 1, a motor 200 according to an embodiment of the present disclosure includes a rotor 210, a bearing 220, and a stator 230.

In the rotor 210, a rotor core 212 is attached to the rotating shaft 110. In the present embodiment, the rotor core 212 is formed by laminating thin steel plates in the axial center C direction of the rotating shaft 110. The stacked rotor core 212 is formed with a plurality of magnet holes 214 along an axial center C of the rotation shaft 110. Permanent magnets 216 are respectively inserted into the magnet holes 214.

The bearing 220 rotatably supports the rotating shaft 110. In the present embodiment, the pair of bearings 220 is positioned to sandwich the rotor core 212. Each of the pair of bearings 220 is held by a case 222 forming an outer shell of the motor 200.

The stator 230 is located opposite to the rotor 210. In the present embodiment, stator 230 includes a stator core 232 and a winding 234. The stator core 232 is formed by laminating thin steel plates along the axial center C of the rotating shaft 110. The stacked stator core 232 has a plurality of teeth protruding toward the axial center C. Slots are respectively formed between the adjacent teeth among the plurality of teeth. The windings 234 are wound around the stator core 232 using slots. The winding 234 is wound around the stator core 232 via an insulator 236 which is an insulator.

The encoder 100 is attached to the rotation shaft 110 using the attachment mechanism 40.

The attachment mechanism 40 includes a boss fixing nut 10 which is a first nut, a lock nut 20 which is a second nut, and a taper ring 30 which is a ring body.

The encoder 100 includes an LED (Light Emitting Diode) element 151 that is a light emitting element, a phototransistor (Phototransistor) 152 that is a light receiving element, and a boss body 120 that fixes the rotating plate 130 to the rotating shaft 110. The rotary plate 130 is formed with a light transmission window through which light emitted from the LED element 151 passes.

Details of the attachment mechanism 40 and the encoder 100 will be described later.

In the present configuration, drive current is supplied to the winding 234 from the outside of the motor 200. The winding 234 supplied with the drive current generates a predetermined magnetic flux via the stator core 232. The permanent magnets 216 embedded in the rotor core 212 are affected by the magnetic flux generated by the stator core 232. The rotor 210 rotates about the rotation axis 110 as a rotation center under the influence of the magnetic flux received by the permanent magnet 216.

The rotary plate 130 mounted on the rotary shaft 110 using the mounting mechanism 40 rotates with the rotor 210.

The LED element 151 which comprises the encoder 100 emits light. The phototransistor 152 receives the light emitted from the LED element 151. Since the rotating plate 130 rotates, light emitted from the LED element 151 is received by the phototransistor 152 only when the light transmitting window formed on the rotating plate 130 passes between the LED element 151 and the phototransistor 152. . At other times, the light emitted from the LED element 151 is blocked by the rotary plate 130, so the phototransistor 152 can not receive the light emitted from the LED element 151.

When the phototransistor 152 receives the light emitted from the LED element 151, the encoder 100 can detect the rotating state of the rotor 210. In response to the detected rotational state of the rotor 210, the control unit of the motor 200 controls a drive current to be applied to the winding 234.

As described later, the encoder 100 in the present embodiment can be attached so that the axial center J of the boss body 120 is located on the axial center C of the rotation shaft 110. Therefore, it can suppress that a shift arises between the rotation center of rotation axis 110, and the rotation center of boss body 120. Therefore, the encoder 100 can detect the rotational state of the rotor 210 with high accuracy.

In the above description, a brushless motor provided with a magnet embedded rotor is exemplified as the motor 200. The motor according to the present disclosure can also be used as another form of brushless motor, commutator motor, induction motor or the like. In addition, the motor according to the present disclosure can be used as an inner rotor type motor or an outer rotor type motor.

(Configuration of encoder)
FIG. 2 is an exploded perspective view showing the attachment mechanism 40 and the encoder 100 attached by the attachment mechanism 40 according to the first embodiment of the present disclosure. FIG. 3 is a cross-sectional view showing the attachment mechanism 40 and the encoder 100 attached to the attachment mechanism 40 according to the first embodiment of the present disclosure.

As shown in FIGS. 2 and 3, the rotating body according to the present embodiment is an encoder 100 including a boss body 120 and a rotating plate 130.

The rotating shaft 110 passes through the boss body 120. The boss body 120 extends along the axial center C of the rotation axis 110. The boss body 120 has a second outer peripheral surface 124 including a second thread 122 screwed with the first thread groove 18 included in the flange portion 10B.

The rotating plate 130 is attached to intersect with the axis C. Specifically, the rotary plate 130 is formed so as to extend in the plane direction with the axis C as a normal.

This will be described in more detail using the drawings.

As shown in FIGS. 2 and 3, for example, the encoder 100 is attached to the end of the rotation shaft 110 by the attachment mechanism 40 according to the present embodiment. Here, the rotating shaft 110 is a shaft of a motor. In addition, the attachment mechanism 40 which concerns on this indication can be utilized also for the shaft which has the same function except the shaft of an electric motor.

The encoder 100 has a boss body 120 which is a rotating body fitted with the rotating shaft 110 and held by the mounting mechanism 40. A rotary plate 130 for detecting a rotational position or rotational speed is held by the projection 120 a of the boss body 120 so as to be orthogonal to the axial center J of the boss body 120. The rotary plate 130 is attached to the boss body 120 by screwing, fitting, or an adhesive. The rotary plate 130 is formed with a light transmission window 131 which is a transmission pattern for position detection which selectively transmits light. The light transmitting window 131 can be made of, for example, a transparent glass material or a resin material.

Further, as shown in FIG. 3, the encoder 100 is, for example, an optical detector in which an LED element 151 which is a light emitting element and a phototransistor 152 which is a light receiving element are disposed in a housing 100 a. The housing 100 a is made of, for example, a metal plate and attached so as to surround the encoder 100.

The light emitting element may be, for example, the LED element 151. As the light emitting element, other elements can be used as long as they have the same function. The light receiving element may be, for example, a phototransistor 152. As the light receiving element, other elements can be used as long as they have the same function. The LED element 151 and the phototransistor 152 are disposed in the housing 100 a at positions facing each other across the rotary plate 130. Therefore, the transmitted light emitted from the LED element 151 and transmitted through the rotating plate 130 is received by the phototransistor 152 and is electrically detected. Furthermore, a circuit board mounted with a control circuit that controls the LED element 151 and the phototransistor 152 may be disposed inside the housing 100a.

Furthermore, the boss body 120 held by the rotation shaft 110 is rotatably supported with the housing 100 a via the bearing mechanism 140 and with the axis center J as the rotation center. The housing 100a may be held by an external member (not shown) or the like via, for example, a plate spring or the like.

(Configuration of mounting mechanism)
FIG. 4 is a schematic cross-sectional view showing an action on the rotation shaft 110 in the attachment mechanism 40 according to the first embodiment of the present disclosure. FIG. 5 is a perspective view of one member of the attachment mechanism 40 according to the first embodiment of the present disclosure. FIG. 6 is a front view of one member of the attachment mechanism 40 according to the first embodiment of the present disclosure. FIG. 7 is a front view of another member of the attachment mechanism 40 according to Embodiment 1 of the present disclosure. FIG. 8 is a perspective view of another member of the attachment mechanism 40 according to the first embodiment of the present disclosure.

As shown in FIG. 2 to FIG. 4, the attachment mechanism 40 according to the present embodiment is configured of three annular members penetrating the rotation shaft 110 respectively.

That is, in the attachment mechanism 40 according to the present embodiment, the boss body 120 which is a rotating body is attached to the rotation shaft 110.

The rotating shaft 110 passes through the boss fixing nut 10. The boss fixing nut 10 includes a cylindrical portion 10A and a flange portion 10B.

The cylindrical portion 10 A extends along the axial center C of the rotation shaft 110 and has a first outer circumferential surface 12 including a first screw thread 14. The flange portion 10B is convex in a direction intersecting with the axial center C and in a direction opposite to the side where the rotation shaft 110 is located, and the first inner circumferential surface 16 including the first screw groove 18 is Have. The first inner circumferential surface 16 of the flange portion 10B is positioned to face the rotation shaft 110.

The rotary shaft 110 passes through the lock nut 20. The lock nut 20 includes a second screw groove 22 and a small hole 24.

The second screw groove 22 is formed in a part of the second inner circumferential surface 26 facing the rotary shaft 110 and is screwed with the first screw thread 14 of the boss fixing nut 10 which is the first nut. Match. The small hole portion 24 is formed in a portion of the second inner circumferential surface 26 other than the second screw groove 22 and fitted with the rotation shaft 110.

The rotating shaft 110 passes through the taper ring 30 which is a ring body. The taper ring 30 is located between the third inner circumferential surface 17 of the cylindrical portion 10A and the rotation shaft 110. When the boss fixing nut 10, which is the first nut, and the lock nut 20, which is the second nut, are screwed together in a direction (D1, D2 in FIG. 4) where the taper fixing 30 is the first nut, Forces F01 and F02 acting in the direction along the axial center C applied from each of the certain boss fixing nut 10 and the second nut lock nut 20 force F1 and F2 acting in the direction intersecting the axial center C The inclined surface 32 is converted to

In particular, the form that exerts remarkable effects is as follows.

The ring bodies used in the mounting mechanism 40 are a pair of taper rings 30 having inclined

surfaces

32 a and 32 b which face each other and abut. The taper ring 30 is an example of a ring body such as a spanner ring, and includes an outer ring 30 a and an inner ring 30 b.

In the present embodiment, the inclined surface 32 is configured of a first inclined surface and a second inclined surface that is opposed to and in contact with the first inclined surface. In the following description, the inclined surface 32a of the outer ring 30a functions as a first inclined surface. On the other hand, the inclined surface 32b of the inner ring 30b functions as a second inclined surface.

This will be described in more detail using the drawings.

As shown in FIGS. 3 and 4, the boss fixing nut 10 includes a flange portion 10 B and a cylindrical portion 10 A. In the flange portion 10B, a first screw groove 18 is formed on a first inner circumferential surface 16 facing the boss body 120. The cylindrical portion 10A has a first outer peripheral surface 12 on the opposite side to the side on which the boss body 120 is located. A first thread 14 is formed on the first outer circumferential surface 12.

In the direction of the axis J, the second screw thread 122 is formed on the end portion 120 b of the boss 120 opposite to the protrusion 120 a formed on the boss 120. The second screw thread 122 is screwed into a first screw groove 18 formed in the boss fixing nut 10.

The lock nut 20 secures the boss fixing nut 10 to the boss body 120. In a part of the second inner circumferential surface 26 of the lock nut 20, a second screw groove 22 engaged with the first screw thread 14 formed on the boss fixing nut 10 is formed. The lock nut 20 has a small hole portion 24 fitted with the rotation shaft 110 in at least a part of the remaining portion of the second inner circumferential surface 26 of the lock nut 20.

Here, the cylindrical portion 10A of the boss fixing nut 10 is formed such that a gap 10C is generated between the cylindrical portion 10A and the rotation shaft 110. A pair of taper rings 30 is inserted into the gap 10C. The pair of taper rings 30 has an outer ring 30a and an inner ring 30b, each having an

inclined surface

32a, 32b facing and abutting each other. When the lock nut 20 is screwed in the direction D2 of the boss fixing nut 10, the inclined surface 32a of the outer ring 30a slides out of the inclined surface 32b of the inner ring 30b. In other words, in the pair of taper rings 30, the inclined surface 32b of the inner ring 30b is embedded inside the inclined surface 32a of the outer ring 30a. As a result, the thickness of the tapering 30 increases in the direction intersecting with the axial center C, so the outer diameter of the tapering 30 is enlarged. Therefore, as shown in FIG. 4, in the taper ring 30 whose outer diameter is enlarged, the boss fixing nut 10 and the lock nut 20 operate outward in the direction intersecting with the axial center C and outward. A force F1 is generated. Therefore, a force F2 which is a reaction to the boss body 120 is generated. As a result, in the direction intersecting with the axial center C, the boss body 120 is strongly pressed from the circumference of the boss fixing nut 10 and the lock nut 20 toward the axial center C in all directions. That is, the axial centers J (rotational centers) of the boss fixing nut 10, the locknut 20 and the taper ring 30 all coincide with the axial center C (rotational center) of the boss body 120. For this reason, it is possible to suppress center run-out of the boss body 120 which is a rotating body, and consequently the rotary plate 130.

The coefficient of friction of the

inclined surfaces

32a and 32b, which are the contact surfaces (sliding surfaces) of the outer ring 30a and the inner ring 30b constituting the taper ring 30, is preferably large.

As shown in FIG. 4, it is preferable that the end surface 34 on the boss fixing nut 10 side in the taper ring 30 is in contact with the end surface 120 c on the boss fixing nut 10 side in the boss body 120. Alternatively, the end surface 34 on the boss fixing nut 10 side of the taper ring 30 may be in contact with the inner surface 10 d of the flange portion 10B of the boss fixing nut 10.

Furthermore, it is preferable that the end face 34a of the taper ring 30 located on the small hole 24 side of the lock nut 20 be in contact with the inner surface 20a of the small hole 24.

With this configuration, it is possible to reliably generate the force F1 which is the action and the force F2 which is the reaction.

With the following configuration, it is possible to achieve further remarkable effects.

As shown in FIG. 5, of the pair of taper rings 30 used in the attachment mechanism 40, the extension ring of the inner ring 30b, which is a taper ring located on the rotary shaft 110 side, intersects the axis C. It suffices to have the formed slit 36. In other words, the inner ring 30 b has the slit 36. The extension of the slit 36 intersects with the axis C. Here, the extension line of the slit 36 refers to a line extended in the direction of cutting in the slit 36 which is a gap which is narrowly opened.

Alternatively, as shown in FIG. 6 and FIG. 7, of the pair of taper rings 30 used in the attachment mechanism 40, the extension line of the inner ring 30 b located on the rotary shaft 110 side is the axial center C It is sufficient to have a plurality of slits 36 formed so as to intersect with. In other words, the inner ring 30 b has a plurality of slits 36. Each extension line of the plurality of slits 36 intersects the axial center C, respectively. In the plane orthogonal to the axial center C, the plurality of slits 36 may be spaced apart in the circumferential direction around the axial center C, respectively.

The slits 36 are formed along the inclined surface 32. When the center line of the slit 36 is extended, the extension line may intersect the axis C.

In other words, on a plane orthogonal to the axial center C, the plurality of slits 36 may be radially positioned around the axial center C, and may be circumferentially positioned at appropriate angles.

As a particularly preferred example, as shown in FIG. 6, each slit 36 may be positioned every θ1 = 120 °. Alternatively, as shown in FIG. 7, each slit 36 may be positioned every θ2 = 90 °.

In the example shown in FIGS. 6 and 7, the slits 36 are positioned at equal intervals. The equal intervals or appropriate angles are not intended to be mathematically equivalent, as long as the holding forces given to the rotation axis 110 by the respective inclined surfaces 32b divided by the respective slits 36 are equal. Typically, variations due to manufacturing tolerances are within the equal intervals or an appropriate range of angles as described in the present embodiment.

According to this configuration, in the direction intersecting with the axial center C, the inner ring 30b presses the boss body 120 more strongly from the periphery of the boss fixing nut 10 and the lock nut 20 toward the axial center C in all directions. Can. That is, the inner ring 30 b can adjust the tightening strength of the boss body 120 in the range which can be adjusted by the width dimension of the slit 36. Therefore, the accuracy with which the axial center J (rotation center) of the boss fixing nut 10, the lock nut 20 and the taper ring 30 coincides with the axial center C (rotation center) of the boss body 120 is improved. For this reason, it is possible to further suppress center run-out of the boss body 120 which is a rotating body, and consequently the rotary plate 130.

In particular, when the three slits 36 shown in FIG. 6 and the four slits 36 shown in FIG. 7 are formed, an appropriate holding force is applied to the rotating shaft 110 from the inclined surfaces 32 b divided respectively. The number of steps for forming the slits 36 in the inclined surface 32b can also be realized within the range of appropriate number of steps.

As shown in FIG. 8, the slit 36a used in the attachment mechanism 40 may have a slit width W2 on the opening 36c side wider than the slit width W1 on the tip 36b side. In other words, among the taper rings located on the rotary shaft 110 side, the slit 36a of the inner ring 30b has a slit width W2 on the opening 36c side of the tapering wider than a slit width W1 on the tip 36b side of the tapering. There is.

With this configuration, even if a gap is generated between the inner circumferential surface of the inner ring 30b and the outer circumferential surface of the rotating shaft 110, the difference between the slit width W2 and the slit width W1 is equal to this gap. Absorb. That is, due to the difference between the slit width W2 and the slit width W1, the inner ring 30b and the rotary shaft 110 can always ensure appropriate holding power.

As described above, the mounting mechanism 40 of the present embodiment is the mounting mechanism 40 for mounting the rotating body corresponding to the boss body 120 to the rotating shaft 110, and includes the first nut 10 and the second nut 20; And a ring body 30.

The first nut 10 includes a cylindrical portion 10A and a flange portion 10B. The rotating shaft 110 penetrates the cylindrical portion 10A. The cylindrical portion 10 A extends along the axial center C of the rotation shaft 110 and has a first outer circumferential surface 12 including a first screw thread 14. The flange portion 10B is convex in a direction intersecting with the axial center C and in a direction opposite to the side where the rotation shaft 110 is located, and the first inner circumferential surface 16 including the first screw groove 18 is Have.

The rotating shaft 110 passes through the second nut 20. The second nut 20 includes a second screw groove 22 and a small hole 24. The second screw groove 22 is formed in a part of the second inner circumferential surface 26 facing the rotation shaft 110 and screwed with the first screw thread 14. The small hole portion 24 is formed in a portion of the second inner circumferential surface 26 other than the second screw groove 22 and fitted with the rotation shaft 110.

The ring body 30 is located between the third inner circumferential surface 17 of the cylindrical portion 10A and the rotary shaft 110, with the rotary shaft 110 penetrating therethrough. When the first nut 10 and the second nut 20 are screwed in the direction in which they approach each other, the ring body 30 is a direction along the axial center C applied from each of the first nut 10 and the second nut 20 Has a first inclined surface corresponding to the inclined surface 32a that converts the force acting on the shaft into a force acting in the direction intersecting the axial center C.

Thereby, the runout of the rotating body corresponding to the boss body 120 can be suppressed.

Further, the ring body 30 may be a pair of taper rings 30 further having a second inclined surface corresponding to the inclined surface 32b opposed to and in contact with the first inclined surface corresponding to the inclined surface 32a.

Further, of the pair of taper rings 30, the taper ring corresponding to the inner ring 30 b located on the rotation shaft 110 side has a slit 36. The extension line of the slit 36 may intersect the axis C.

Further, of the pair of taper rings 30, the taper ring corresponding to the inner ring 30 b located on the rotation shaft 110 side has a plurality of slits 36. Each extension line of the plurality of slits 36 intersects the axial center C, respectively. In the plane orthogonal to the axis C, the plurality of slits 36 may be spaced apart in the circumferential direction around the axis C, respectively.

The slit 36a of the taper ring corresponding to the inner ring 30b located on the rotary shaft 110 side is a taper ring corresponding to the inner ring 30b than the slit width W1 on the tip 36b side of the taper ring corresponding to the inner ring 30b. The slit width W2 on the opening 36c side may be wider.

In addition, in the attachment mechanism 40, the rotary body may be the encoder 100 including the boss body 120 and the rotary plate 130. The rotating shaft 110 passes through the boss body 120. The boss body 120 extends along the axial center C of the rotary shaft 110 and has a second outer circumferential surface 124 including a second thread 122 which is screwed with the first thread groove 18 included in the flange portion 10B. do it. The rotating plate 130 may be attached so as to intersect the axis C.

In the motor 200 according to the present embodiment, a rotor 210 having a rotor core 212 attached to the rotation shaft 110, a bearing 220 rotatably supporting the rotation shaft 110, and a stator positioned opposite to the rotor 210 And 230. The encoder 100 is attached to the rotating shaft 110 using the attachment mechanism 40 described above.

Second Embodiment
The configuration of the attachment mechanism 440 according to the second embodiment will be described.

FIG. 9 is a schematic cross-sectional view showing an operation on the rotation shaft 110 in the attachment mechanism 440 according to the second embodiment of the present disclosure. FIG. 10 is a perspective view of one member of the attachment mechanism 440 according to the second embodiment of the present disclosure. FIG. 11 is a front view of one member of an attachment mechanism 440 according to Embodiment 2 of the present disclosure. FIG. 12 is a front view of another member of the attachment mechanism 440 according to Embodiment 2 of the present disclosure. FIG. 13 is a perspective view of another member of the attachment mechanism 440 according to Embodiment 2 of the present disclosure.

In the description of the attachment mechanism 440, the same components as those in the first embodiment described above are denoted by the same reference numerals, and the description is used.

As shown in FIG. 9, the boss body 460 which is a rotating body in which the attachment mechanism 440 is used has a taper which extends between the third inner circumferential surface 17 and the rotation axis 110 in the direction along the axis C. It has a portion 462. The tapered portion 462 includes an inclined surface 432 b opposite to the inclined surface 432 a of the taper ring 430 which is a ring body.

In the following description, the inclined surface 432a of the taper ring 430 functions as a first inclined surface. On the other hand, the inclined surface 432b of the tapered portion 462 functions as a second inclined surface.

This will be described in more detail using the drawings.

As shown in FIG. 9, the boss fixing nut 10 includes a flange portion 10B and a cylindrical portion 10A. In the flange portion 10B, a first screw groove 18 is formed on a first inner circumferential surface 16 facing the boss body 460. The cylindrical portion 10A has a first outer circumferential surface 12 on the opposite side to the side on which the boss 460 is located. A first thread 14 is formed on the first outer circumferential surface 12.

A second screw thread 122 is formed on the end 460 b of the boss 460 opposite to the projection formed on the boss 460 in the axial center J direction. The second screw thread 122 is screwed into a first screw groove 18 formed in the boss fixing nut 10.

The lock nut 20 secures the boss fixing nut 10 to the boss body 460. In a part of the second inner circumferential surface 26 of the lock nut 20, a second screw groove 22 engaged with the first screw thread 14 formed on the boss fixing nut 10 is formed. The lock nut 20 has a small hole portion 24 fitted with the rotation shaft 110 in at least a part of the remaining portion of the second inner circumferential surface 26 of the lock nut 20.

Here, the cylindrical portion 10A of the boss fixing nut 10 is formed such that a gap 410C is generated between the cylindrical portion 10A and the tapered portion 462. A taper ring 430 is inserted into the air gap portion 410C. The taper ring 430 has an inclined surface 432 a that faces and abuts on the inclined surface 432 b of the tapered portion 462. In the taper ring 430, when the lock nut 20 is screwed in the direction D 2 of the boss fixing nut 10, the inclined surface 432 a of the taper ring 430 slides out of the inclined surface 432 b of the tapered portion 462. In other words, in the tapered portion 462, the inclined surface 432 b of the tapered portion 462 is embedded inside the inclined surface 432 a of the tapered ring 430. As a result, the taper ring 430 moves in the direction away from the axis C of the rotating shaft 110 in the direction intersecting with the axis C, so the outer diameter of the taper ring 430 is enlarged. Therefore, as shown in FIG. 9, the tapered ring 430 whose outer diameter is expanded is a direction intersecting the axial center C with respect to the boss fixing nut 10 and the lock nut 20, and has an outward action. A force F1 is generated. Therefore, a force F2 which is the reaction is generated in the boss body 460. As a result, in the direction intersecting with the axial center C, the boss body 460 is strongly pressed from the circumference of the boss fixing nut 10 and the lock nut 20 toward the axial center C in all directions. That is, the axial center J (rotation center) of the boss fixing nut 10, the lock nut 20, and the taper ring 430 coincides with the axial center C (rotation center) of the boss 460. For this reason, it is possible to suppress center run-out of the boss body 460 which is a rotating body, and consequently the rotary plate 130.

The coefficient of friction of the contact surface (sliding surface) where the inclined surface 432a of the taper ring 430 and the inclined surface 432b of the tapered portion 462 are in contact with each other is preferably large.

As shown in FIG. 10, the tapered portion 462 of the boss 460 may have a slit 436 formed so that the extension line thereof intersects with the axial center C. In other words, the tapered portion 462 has a slit 436. Here, the extension line of the slit 436 refers to a line extended in the direction to cut in the slit 436 which is a gap which is narrow and cut open.

Alternatively, as shown in FIG. 11 and FIG. 12, the tapered portion 462 of the boss 460 may have a plurality of slits 436 formed such that the extension line thereof intersects with the axial center C. In other words, the tapered portion 462 has a plurality of slits 436. Each extension line of the plurality of slits 436 intersects the axial center C, respectively. In the plane orthogonal to the axial center C, the plurality of slits 436 may be spaced apart in the circumferential direction around the axial center C, respectively.

The slit 436 is formed along the inclined surface 432b. When the center line of the slit 436 is extended, the extension line may intersect the axis C.

In other words, in the plane orthogonal to the axial center C, the plurality of slits 436 may be radially positioned around the axial center C, and may be circumferentially positioned at appropriate angles.

As a particularly preferable example, as shown in FIG. 11, each slit 436 may be positioned every θ1 = 120 °. Alternatively, as shown in FIG. 12, each slit 436 may be positioned every θ2 = 90 °.

In the example shown in FIGS. 11 and 12, the slits 436 are located at equal intervals. The equal intervals or appropriate angles are not intended to be mathematically equivalent as long as the holding forces given to the rotation axis 110 by the respective inclined surfaces 432b divided by the respective slits 436 are equal. Typically, variations due to manufacturing tolerances are within the equal intervals or an appropriate range of angles as described in the present embodiment.

According to this configuration, in the direction intersecting with the axial center C, the tapered portion 462 presses the boss body 460 more strongly from the periphery of the boss fixing nut 10 and the lock nut 20 toward the axial center C in all directions. Can. That is, the tapered portion 462 can adjust the tightening strength of the boss 460 in a range that can be adjusted by the width dimension of the slit 436. Therefore, the accuracy with which the axial center J (rotation center) of the boss fixing nut 10, the lock nut 20 and the taper ring 430 coincides with the axial center C (rotation center) of the boss 460 is improved. For this reason, it is possible to further suppress center run-out of the boss body 460 which is a rotating body, and consequently the rotary plate 130.

In particular, in the case where the three slits 436 shown in FIG. 11 and the four slits 436 shown in FIG. 12 are formed, an appropriate holding force is applied to the rotation shaft 110 from the inclined surfaces 432 b divided respectively. The number of steps for forming the slit 436 on the inclined surface 432b can also be realized within the range of an appropriate number of steps.

As shown in FIG. 13, the slit 436a may have a slit width W2 on the opening 436c side wider than the slit width W1 on the tip 436b side. In other words, the slit 436a of the tapered portion 462 has a slit width W2 on the opening 36c side of the tapered portion 462 larger than the slit width W1 on the tip 436b side of the tapered portion 462.

With this configuration, even if a gap is generated between the inner circumferential surface of the tapered portion 462 and the outer circumferential surface of the rotating shaft 110, the difference between the slit width W2 and the slit width W1 corresponds to this gap. Absorb. That is, due to the difference between the slit width W2 and the slit width W1, the tapered portion 462 and the rotating shaft 110 can always ensure appropriate holding power.

As is apparent from the above description, in the above-described second embodiment, the boss 460 has a tapered portion 462 that reaches between the third inner circumferential surface 17 of the boss fixing nut 10 and the outer circumferential surface of the rotary shaft 110. Have. The tapered portion 462 exerts an action corresponding to the inner ring 30 b described in the first embodiment. In the present configuration, the taper ring 430 has an effect corresponding to the outer ring 30a described in the first embodiment. That is, in the second embodiment, as compared with the first embodiment, the taper ring 430 can be configured by one member. Therefore, in the second embodiment, assembling workability is improved as compared with the attachment mechanism 40 shown in the first embodiment.

As described above, the rotating body corresponding to the boss body 460 of the present embodiment has the tapered portion 462 extending between the third inner circumferential surface 17 and the rotating shaft 110 in the direction along the axial center C. Have. The tapered portion 462 includes a second inclined surface corresponding to the inclined surface 432 b opposed to the first inclined surface corresponding to the inclined surface 432 a.

Thereby, the runout of the rotating body corresponding to the boss body 460 can be suppressed.

The tapered portion 462 also has a slit 436. The extension line of the slit 436 may intersect the axis C.

The tapered portion 462 also has a plurality of slits 436. The extension line of each of the plurality of slits 436 intersects with the axial center C, respectively. In the plane orthogonal to the axis C, the plurality of slits 436 may be spaced apart in the circumferential direction around the axis C, respectively.

The slit 436a of the tapered portion 462 may be wider at the slit width W2 at the opening 436c side of the tapered portion 462 than at the slit width W1 at the tip 436b side of the tapered portion 462.

Third Embodiment
The configuration of the attachment mechanism 540 according to the third embodiment will be described.

FIG. 14 is a schematic cross-sectional view showing an operation on the rotation shaft 110 in the attachment mechanism 540 according to the third embodiment of the present disclosure. FIG. 15 is a perspective view of one member of the attachment mechanism 540 according to the third embodiment of the present disclosure. FIG. 16 is a front view of one member of the attachment mechanism 540 according to the third embodiment of the present disclosure. FIG. 17 is a front view of another member of the attachment mechanism 540 according to Embodiment 3 of the present disclosure. FIG. 18 is a perspective view of another member of the attachment mechanism 540 according to the third embodiment of the present disclosure.

In the description of the attachment mechanism 540, the same components as those in the first and second embodiments described above are denoted by the same reference numerals, and the description is used.

As shown in FIG. 14, the third inner circumferential surface 517 of the boss fixing nut 510 which is the first nut used for the attachment mechanism 540 is inclined to face the inclined surface 532 a of the taper ring 530 which is the ring body. The surface 532 b is included. In other words, the third inner circumferential surface 517 doubles as the inclined surface 532 b.

That is, in the following description, the inclined surface 532a of the taper ring 530 which is a ring body functions as a first inclined surface. On the other hand, the inclined surface 532b of the cylindrical portion 510A functions as a second inclined surface.

This will be described in more detail using the drawings.

As shown in FIG. 14, the boss fixing nut 510 includes a flange portion 510B and a cylindrical portion 510A. In the flange portion 510 B, a first screw groove 18 is formed on the first inner circumferential surface 16 facing the boss body 120. The cylindrical portion 510A has the first outer circumferential surface 12 on the opposite side to the side where the boss body 120 is located. A first thread 14 is formed on the first outer circumferential surface 12.

In the direction of the axis J, the second screw thread 122 is formed at the end 120 b of the boss 120 opposite to the protrusion formed on the boss 120. The second screw thread 122 is screwed into a first screw groove 18 formed in the boss fixing nut 510.

The lock nut 20 secures the boss fixing nut 510 to the boss body 120. In a part of the second inner circumferential surface 26 of the lock nut 20, a second screw groove 22 to be screwed with the first screw thread 14 formed on the boss fixing nut 510 is formed. The lock nut 20 has a small hole portion 24 fitted with the rotation shaft 110 in at least a part of the remaining portion of the second inner circumferential surface 26 of the lock nut 20.

Here, the cylindrical portion 510A of the boss fixing nut 510 is formed such that a space 510C is generated between the cylindrical portion 510A and the rotation shaft 110. A taper ring 530 is inserted into the air gap portion 510C. The taper ring 530 has an inclined surface 532 a that faces and abuts the inclined surface 532 b of the cylindrical portion 510A. In the taper ring 530, when the lock nut 20 is screwed in the direction D2 of the boss fixing nut 510, the inclined surface 532a of the taper ring 530 sinks inside the inclined surface 532 b of the cylindrical portion 510A. In other words, in the cylindrical portion 510A, the inclined surface 532b of the cylindrical portion 510A slides out of the inclined surface 532a of the taper ring 530. Thus, the cylindrical portion 510A moves in a direction away from the axial center C of the rotation shaft 110 in the direction intersecting the axial center C, so that the outer diameter of the cylindrical portion 510A is enlarged. Therefore, as shown in FIG. 14, in the cylindrical portion 510A whose outer diameter is enlarged by the taper ring 530, the boss fixing nut 510 and the lock nut 20 are in the direction intersecting with the axial center C and outside. A force F1 is generated which is an action directed to the side. Therefore, a force F2 which is a reaction to the boss body 120 is generated. As a result, in the direction intersecting with the axial center C, the boss body 120 is strongly pressed from the circumference of the boss fixing nut 510 and the lock nut 20 toward the axial center C in all directions. That is, the axial centers J (rotational centers) of the boss fixing nut 510, the locknut 20 and the taper ring 530 all coincide with the axial center C (rotational center) of the boss body 120. For this reason, it is possible to suppress center run-out of the boss body 120 which is a rotating body, and consequently the rotary plate 130.

The coefficient of friction at the contact surface (slip surface) where the inclined surface 532a of the taper ring 530 and the inclined surface 532b of the cylindrical portion 510A are in contact with each other is preferably large.

As shown in FIG. 15, the taper ring 530 which is a ring body may have a slit 536 formed so that the extension line thereof intersects with the axial center C. In other words, taper ring 530 which is a ring body has slit 536. Here, the extension line of the slit 536 refers to a line extended in the direction of cutting in the slit 536 which is a gap which is narrow and cut open.

Alternatively, as shown in FIG. 16 and FIG. 17, the taper ring 530 which is a ring body may have a plurality of slits 536 formed such that the extension line intersects with the axial center C. In other words, the taper ring 530 has a plurality of slits 536. Each extension line of the plurality of slits 536 intersects the axial center C, respectively. In the plane orthogonal to the axial center C, the plurality of slits 536 may be spaced apart in the circumferential direction around the axial center C, respectively.

The slit 536 may be formed along the inclined surface 532a. When the center line of the slit 536 is extended, the extension line may intersect the axis C.

In other words, on the plane orthogonal to the axial center C, the plurality of slits 536 may be radially positioned around the axial center C, respectively, and may be circumferentially positioned at appropriate angles.

As a particularly preferable example, as shown in FIG. 16, each slit 536 may be positioned every θ 1 = 120 °. Alternatively, as shown in FIG. 17, the slits 536 may be positioned every θ2 = 90 °.

In the specific example shown in FIGS. 16 and 17, the slits 536 are positioned at equal intervals. The equal intervals or appropriate angles are not intended to be mathematically equivalent, as long as the holding forces given to the rotation axis 110 by the respective inclined surfaces 532a divided by the respective slits 536 are equal. Typically, variations due to manufacturing tolerances are within the equal intervals or an appropriate range of angles as described in the present embodiment.

According to this configuration, in the direction intersecting with the axial center C, the taper ring 530 presses the boss body 120 more strongly from the periphery of the boss fixing nut 510 and the lock nut 20 toward the axial center C in all directions. Can. That is, the taper ring 530 can adjust the tightening strength of the boss body 120 in the range which can be adjusted by the width dimension of the slit 536. Therefore, the accuracy with which the axial center J (rotation center) of the boss fixing nut 510, the lock nut 20 and the taper ring 530 matches the axial center C (rotation center) of the boss body 120 is improved. For this reason, it is possible to further suppress center run-out of the boss body 120 which is a rotating body, and consequently the rotary plate 130.

In particular, in the case where the three slits 536 shown in FIG. 16 and the four slits 536 shown in FIG. 17 are formed, an appropriate holding force is applied to the rotary shaft 110 from the inclined surfaces 532 a divided respectively. The number of steps for forming the slits 536 in the inclined surface 532a can also be realized within the range of an appropriate number of steps.

As shown in FIG. 18, in the slit 536a, the slit width W2 on the opening 536c side may be wider than the slit width W1 on the tip 536b side. In other words, the slit 536a of the taper ring 530 is wider at the slit width W2 at the opening 536c side of the taper ring 530 than at the slit width W1 at the tip 536 b side of the taper ring 530.

With this configuration, even if a gap is generated between the inner circumferential surface of the taper ring 530 and the outer circumferential surface of the rotating shaft 110, the difference between the slit width W2 and the slit width W1 is equal to this gap. Absorb. That is, due to the difference between the slit width W2 and the slit width W1, the tapering 530 and the rotating shaft 110 can always ensure appropriate holding power.

As apparent from the above description, in the third embodiment described above, the boss fixing nut 510 has a shape in which the boss fixing nut 10 described in the first embodiment and the outer ring 30a are combined. Thus, in the present configuration, the taper ring 530 exerts an action equivalent to that of the inner ring 30b described in the first embodiment. That is, in the third embodiment, the taper ring 530 can be configured by one member as compared with the first embodiment. Therefore, in the third embodiment, assembling workability is improved as compared with the attachment mechanism 40 shown in the first embodiment.

As described above, the third inner circumferential surface 517 of the first nut 510 used in the attachment mechanism 540 of the present embodiment is the inclined surface 532 b opposite to the first inclined surface corresponding to the inclined surface 532 a. It includes the corresponding second inclined surface.

Thereby, in the attachment mechanism 540, the workability of assembly is improved.

In addition, the taper ring 530 which is a ring body may have a slit 536 in a direction along the axial center C.

Further, the taper ring 530 which is a ring body may have a plurality of slits 536 formed in a direction along the axial center C. The plurality of slits 536 may be positioned at equal intervals in the circumferential direction around the axis C on a plane orthogonal to the axis C.

The slit 536a of the taper ring 530 is wider than the slit width W1 of the end 536b of the taper ring 530, which is the slit width W2 of the opening 536c of the taper ring 530. Just do it.

Embodiment 4
The configuration of the attachment mechanism 640 according to the fourth embodiment will be described.

FIG. 19 is a schematic cross-sectional view showing an operation on the rotation shaft 110 in the attachment mechanism 640 according to the fourth embodiment of the present disclosure. FIG. 20 is a perspective view of one member of a mounting mechanism 640 according to Embodiment 4 of the present disclosure. FIG. 21 is a front view of one member of an attachment mechanism 640 according to Embodiment 4 of the present disclosure. FIG. 22 is a front view of another member of the attachment mechanism 640 according to Embodiment 4 of the present disclosure. FIG. 23 is a perspective view of another member of the attachment mechanism 640 according to Embodiment 4 of the present disclosure.

In the description of the mounting mechanism 640, the same components as those of the components 1 to 3 described above are denoted by the same reference numerals, and the description is used.

As shown in FIG. 19, a lock nut 620 which is a second nut used for the attachment mechanism 640 has a convex portion 622 which reaches between the second inner circumferential surface 626 and the rotation shaft 110. The convex portion 622 includes an inclined surface 632 a opposed to the inclined surface 632 b of the taper ring 630 which is a ring body.

That is, in the following description, the inclined surface 632b of the taper ring 630 which is a ring body functions as a first inclined surface. On the other hand, the inclined surface 632a of the convex portion 622 functions as a second inclined surface.

This will be described in more detail using the drawings.

As shown in FIG. 19, the boss fixing nut 10 includes a flange portion 10B and a cylindrical portion 10A. In the flange portion 10B, a first screw groove 18 is formed on a first inner circumferential surface 16 facing the boss body 120. The cylindrical portion 10A has a first outer peripheral surface 12 on the opposite side to the side on which the boss body 120 is located. A first thread 14 is formed on the first outer circumferential surface 12.

In the direction of the axis J, the second screw thread 122 is formed at the end 120 b of the boss 120 opposite to the protrusion formed on the boss 120. The second screw thread 122 is screwed into a first screw groove 18 formed in the boss fixing nut 10.

The lock nut 620 secures the boss fixing nut 10 to the boss body 120. In a part of the second inner circumferential surface 626 of the lock nut 620, a second screw groove 22 engaged with the first screw thread 14 formed on the boss fixing nut 10 is formed. The lock nut 620 has a small hole 24 fitted with the rotating shaft 110 in at least a part of the remaining portion of the second inner circumferential surface 626 of the lock nut 620.

Here, the cylindrical portion 10A of the boss fixing nut 10 is formed such that a gap 610C is generated between the cylindrical portion 10A and the rotation shaft 110. A taper ring 630 is inserted into the air gap 610C. The taper ring 630 has an inclined surface 632 b opposed to and in contact with the inclined surface 632 a of the convex portion 622. When the lock nut 620 is screwed in the direction D 2 of the boss fixing nut 10, the inclined surface 632 b of the taper ring 630 sinks inside the inclined surface 632 a of the convex portion 622. In other words, in the convex portion 622, the inclined surface 632a of the convex portion 622 slides out of the inclined surface 632b of the taper ring 630. As a result, the convex portion 622 moves in a direction away from the axial center C of the rotating shaft 110 in the direction intersecting with the axial center C, so that the outer diameter of the convex portion 622 is enlarged. Therefore, as shown in FIG. 19, the convex portion 622 whose outer diameter is enlarged by the taper ring 630 is a direction that intersects with the axial center C with respect to the boss fixing nut 10 and acts outward. A force F1 is generated. Therefore, a force F2 which is a reaction to the boss body 120 is generated. As a result, in the direction intersecting with the axial center C, the boss body 120 is strongly pressed from the periphery of the boss fixing nut 10 and the lock nut 620 toward the axial center C in all directions. That is, the axial center J (rotation center) of the boss fixing nut 10, the lock nut 620, and the taper ring 630 coincides with the axial center C (rotation center) of the boss body 120. For this reason, it is possible to suppress center run-out of the boss body 120 which is a rotating body, and consequently the rotary plate 130.

The coefficient of friction at the contact surface (slip surface) where the inclined surface 632b of the taper ring 630 and the inclined surface 632a of the convex portion 622 are in contact with each other is preferably large.

As shown in FIG. 20, the taper ring 630, which is a ring body, may have a slit 636 formed so that its extension line intersects with the axial center C. In other words, the taper ring 630 which is a ring body has a slit 636. Here, the extension line of the slit 636 refers to a line extended in the direction to cut in the slit 636 which is a gap which is narrow and cut open.

Alternatively, as shown in FIG. 21 and FIG. 22, the taper ring 630 which is a ring body may have a plurality of slits 636 formed so that the extension line thereof intersects with the axial center C. In other words, taper ring 630 has a plurality of slits 636. Each extension line of the plurality of slits 636 intersects the axial center C, respectively. In the plane orthogonal to the axial center C, the plurality of slits 636 may be spaced apart in the circumferential direction around the axial center C, respectively.

The slit 636 may be formed along the inclined surface 632 b. When the center line of the slit 636 is extended, the extension line may intersect the axis C.

In other words, on the plane orthogonal to the axial center C, the plurality of slits 636 may be radially positioned around the axial center C, and may be circumferentially positioned at appropriate angles.

As a particularly preferable example, as shown in FIG. 21, each slit 636 may be positioned every θ 1 = 120 °. Alternatively, as shown in FIG. 22, each slit 636 may be positioned every θ2 = 90 °.

In the example shown in FIGS. 21 and 22, the slits 636 are positioned at equal intervals. The equal intervals or appropriate angles are not intended to be mathematically equivalent as long as the holding forces given to the rotation axis 110 by the respective inclined surfaces 632 b divided by the respective slits 636 are equal. Typically, variations due to manufacturing tolerances are within the equal intervals or an appropriate range of angles as described in the present embodiment.

According to this configuration, in the direction intersecting with the axial center C, the taper ring 630 presses the boss body 120 more strongly from the periphery of the boss fixing nut 10 and the lock nut 620 toward the axial center C in all directions. Can. That is, the taper ring 630 can adjust the tightening strength of the boss body 120 within the range that can be adjusted by the width dimension of the slit 636. Therefore, the accuracy with which the axial center J (rotation center) of the boss fixing nut 10, the lock nut 620, and the taper ring 630 coincides with the axial center C (rotation center) of the boss body 120 is improved. For this reason, it is possible to further suppress center run-out of the boss body 120 which is a rotating body, and consequently the rotary plate 130.

In particular, when the three slits 636 shown in FIG. 21 and the four slits 636 shown in FIG. 22 are formed, an appropriate holding force is applied to the rotation shaft 110 from the inclined surfaces 632 b divided respectively. The number of steps for forming the slits 636 in the inclined surface 632 b can also be realized within the range of an appropriate number of steps.

As shown in FIG. 23, the slit 636a may have a slit width W2 on the opening 636c side wider than the slit width W1 on the tip 636b side. In other words, the slit 636a of the taper ring 630 is wider at the slit width W2 at the opening 636c side of the taper ring 630 than at the slit width W1 at the tip 636b side of the taper ring 630.

With this configuration, even if a gap is generated between the inner circumferential surface of the taper ring 630 and the outer circumferential surface of the rotating shaft 110, the difference between the slit width W2 and the slit width W1 is equal to this gap. Absorb. That is, due to the difference between the slit width W2 and the slit width W1, the tapering 630 and the rotary shaft 110 can always ensure appropriate holding power.

As apparent from the above description, in the fourth embodiment described above, the lock nut 620 has a shape in which the lock nut 20 described in the first embodiment and the outer ring 30 a are combined. Thus, in the present configuration, the taper ring 630 exerts an action equivalent to that of the inner ring 30b described in the first embodiment. That is, in the fourth embodiment, the taper ring 630 can be configured by one member as compared with the first embodiment. Therefore, in the fourth embodiment, assembling workability is improved as compared with the attachment mechanism 40 shown in the first embodiment.

As described above, the second nut 620 used in the attachment mechanism 640 of the present embodiment has the convex portion 622 that reaches between the second inner circumferential surface 626 and the rotation shaft 110. The convex portion 622 includes a second inclined surface corresponding to the inclined surface 632 a facing the first inclined surface corresponding to the inclined surface 632 b.

Further, the taper ring 630 which is a ring body may have a slit 636 in a direction along the axial center C.

Further, the taper ring 630 which is a ring body may have a plurality of slits 636 formed in a direction along the axial center C. In the plane orthogonal to the axial center C, the plurality of slits 636 may be equally spaced in the circumferential direction around the axial center C.

Further, the slit 636a of the taper ring 630 which is a ring body has a wider slit width W2 on the opening 636c side of the taper ring 630 than the slit width W1 of the tip 636b of the taper ring 630 which is a ring body. Just do it.

Fifth Embodiment
The configuration of the mounting mechanism according to the fifth embodiment will be described.

FIG. 24 is a front view of one member of the attachment mechanism according to Embodiment 5 of the present disclosure. FIG. 25 is a front view of another member of the attachment mechanism according to Embodiment 5 of the present disclosure.

In the description of the mounting mechanism, the same components as those in the first to fourth embodiments described above are designated by the same reference numerals, and the description will be incorporated.

As shown in FIG. 24, the taper ring 730 which is a ring body has a plurality of slits 736 in the inclined surface 732 b. When viewed in the axial center C direction, the plurality of slits 736 have adjacent openings 736c at equal intervals in the circumferential direction centering on the axial center C, respectively. Each of the plurality of slits 736 is formed with a notch in the direction of the axis C and the position of twist. Thus, the adjacent tips 736b are equally spaced in the circumferential direction.

The shape of the notch forming the slit can be realized by a linear slit 736 as shown in FIG. Alternatively, the shape of the notch forming the slit can be realized by a spiral slit 736a as shown in FIG.

The

slits

736 and 736a of this shape can be provided on the inclined surfaces shown in the first to fourth embodiments described above.

Even when the

slits

736 and 736a of this shape are used, the same function and effect as those of the first to fourth embodiments can be obtained.

(Modified Example of Embodiment)
As a modification of the embodiment according to the present disclosure, a known locking means such as a metal washer is disposed between the facing surfaces of the flange portion 10B of the boss fixing nut 10 and the lock nut 20. May be In this way, the rotational stability of the boss body 120 including the rotary plate 130 can be obtained over a long period of time.

The attachment mechanism according to the present disclosure can attach a rotating body in a device including the rotating body to a rotatable shaft. The attachment mechanism according to the present disclosure is used, for example, to detect a rotational position in a servo system. The attachment mechanism according to the present disclosure is useful for an encoder or the like that detects an absolute position of a tool or the like of a machine tool with high accuracy and high resolution.

10, 510 Boss fixing nut (first nut)
10A, 510A

cylindrical portion

10B,

510B flange portion

10C, 410C, 510C,

610C gap portion

10d, 20a inner surface 12 first outer circumferential surface 14 first thread 16 first inner

circumferential surface

17, 517 third inner circumferential surface Face 18

first thread groove

20, 620 lock nut (second nut)
22 second thread groove 24

small hole

26, 626 second inner

circumferential surface

30, 430, 530, 630, 730 taper ring (ring body)
30a outer ring 30b

inner ring

32, 32a, 32b, 432a, 432b, 532a, 532b, 632a, 632b, 732b inclined

surface

34, 34a, 120c

end surface

36, 36a, 436, 436a, 536, 536a, 636, 636a, 736 , 736a slit

36b

436b 536b

636b

736b tip

36c

436c 536c 636c 736c opening 40 440 540 540 attachment mechanism 100 encoder 100a housing 110 rotation shaft 120 boss body (rotary body)

120a protrusion

120b, 460b end 122 second screw thread 124 second outer circumferential surface 130 rotary plate (rotary body)
131 translucent window 140 bearing mechanism 151 LED element (light emitting element)
152 phototransistor (light receiving element)
200 motor 210 rotor 212 rotor core 214 magnet hole 216 permanent magnet 220 bearing 222 case 230 stator 232 stator core 234 winding 236 insulator 462 taper portion 622 convex portion

Claims

An attachment mechanism for attaching a rotating body to a rotating shaft,
A cylindrical portion having the first outer peripheral surface through which the rotary shaft passes and extends along the axial center of the rotary shaft;
A flange portion having a first inner circumferential surface including a first screw groove and being convex in a direction that intersects the axis and is opposite to the side on which the rotation axis is located;
A first nut including
The rotating shaft penetrates,
A second thread groove formed on a part of the second inner circumferential surface facing the rotation axis and screwed with the first thread;
A small hole formed in a portion of the second inner peripheral surface other than the second screw groove and fitted with the rotation shaft;
And a second nut including
The rotary shaft penetrates, is positioned between the third inner circumferential surface of the cylindrical portion and the rotary shaft, and the first nut and the second nut are screwed in a direction approaching each other When the force applied in the direction along the axis, which is applied from each of the first nut and the second nut, is converted into a force acting in the direction intersecting with the axis, With a ring body,
, Mounting mechanism.
The attachment mechanism according to claim 1, wherein the ring body is a pair of taper rings further having a second inclined surface opposed to and in contact with the first inclined surface.
The attachment mechanism according to claim 2, wherein the taper ring located on the rotation shaft side among the pair of taper rings has a slit, and an extension line of the slit intersects the axis.
Among the pair of taper rings, the taper ring located on the rotation shaft side has a plurality of slits, and extension lines of the plurality of slits respectively intersect the axis,
The attachment mechanism according to claim 2, wherein the plurality of slits are spaced apart in a circumferential direction about the axis on a plane orthogonal to the axis.
The attachment mechanism according to claim 3 or 4, wherein the slit of the taper ring located on the rotation shaft side has a slit width on the opening side of the taper ring wider than a slit width on the tip end of the taper ring. .
The rotating body has a tapered portion extending between the third inner circumferential surface and the rotation axis in a direction along the axis.
The attachment mechanism according to claim 1, wherein the tapered portion includes a second inclined surface opposite to the first inclined surface.
The attachment mechanism according to claim 6, wherein the tapered portion has a slit, and an extension of the slit intersects the axis.
The tapered portion has a plurality of slits, and extension lines of the slits respectively intersect the axis.
The attachment mechanism according to claim 6, wherein the plurality of slits are spaced apart in a circumferential direction about the axis on a plane orthogonal to the axis.
The attachment mechanism according to claim 7 or 8, wherein the slit of the tapered portion has a slit width on the opening side of the tapered portion that is wider than a slit width on the tip end side of the tapered portion.
The attachment mechanism according to claim 1, wherein the third inner circumferential surface of the first nut includes a second inclined surface opposite to the first inclined surface.
The second nut further includes a convex portion reaching between the second inner peripheral surface and the rotation axis, and the convex portion has a second inclined surface facing the first inclined surface. The attachment mechanism according to claim 1, comprising:
The attachment mechanism according to claim 10, wherein the ring body has a slit in a direction along the axis.
The ring body has a plurality of slits formed in a direction along the axis,
The attachment mechanism according to claim 10, wherein the plurality of slits are equally spaced in a circumferential direction about the axis on a plane orthogonal to the axis.
The attachment mechanism according to claim 12 or 13, wherein the slit of the ring body has a slit width on the opening side of the ring body wider than a slit width on the tip side of the ring body.
The rotating body is
A boss having a second outer peripheral surface including a second screw thread through which the rotation shaft penetrates and extends along the axial center of the rotation shaft and which is screwed with the first screw groove included in the flange portion Body,
A rotary plate attached to intersect with the axis;
The attachment mechanism according to any one of claims 1, 2, 6, 10 and 11, wherein the attachment mechanism comprises an encoder.
A rotor having a rotor core attached to the rotating shaft;
A bearing rotatably supporting the rotating shaft;
A stator located opposite to the rotor;
Equipped with
The motor according to claim 15, wherein the encoder is attached to the rotation shaft using the attachment mechanism according to claim 15.