JPWO2019059010A1 - Mounting mechanism and electric motor using it - Google Patents

Abstract

The mounting mechanism is a direction in which the rotation shaft penetrates and extends along the axis of the rotation shaft and intersects the axis with the cylindrical portion having the first outer peripheral surface including the first screw thread. The rotation shaft penetrates the first nut including the flange portion having the first inner peripheral surface including the first thread groove and the convex portion in the direction opposite to the side where the rotation shaft is located. A second thread groove formed on a part of the second inner peripheral surface facing the rotation axis and screwed with the first thread, and a second thread groove on the second inner peripheral surface other than the second thread groove. A second nut including a small hole portion formed in the portion of the rotating shaft and fitting with the rotating shaft, and between the third inner peripheral surface of the cylindrical portion and the rotating shaft while the rotating shaft penetrates. When the first nut and the second nut are screwed in the direction of approaching each other, the force acting in the direction along the axis applied from each of the first nut and the second nut is the axis. A ring body having a first inclined surface that converts into a force acting in a direction intersecting the heart is provided.

Description

The present disclosure relates to a mounting mechanism for mounting a rotating body on a rotating shaft and an electric motor to which an encoder is mounted using the mounting mechanism. The electric motor has an encoder mounted using a mounting mechanism.

Conventionally, some electric motors are equipped with a rotary encoder. The rotary encoder includes a boss, a light emitting diode as a light source, a substrate on which a pattern for position detection is formed, and a rotating plate which is attached to the boss and has a transparent window through which the light of the light emitting diode is formed. ..

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

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

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

The boss is fixed to the rotating shaft by tightening with screws or the like from the outer peripheral side surface thereof. At this time, the tightening of the screw may cause a deviation between the rotation center of the boss and the rotation center of the rotation shaft. Due to the generated deviation, the rotary encoder causes center runout in the rotary plate with respect to the rotation center of the rotary encoder, that is, the rotation center of the rotation shaft. When runout occurs in the rotating plate, the detection accuracy of the position detection pattern provided on the rotating plate is lowered, and there arises a problem that desired control by the rotary encoder cannot be performed. In the following description, the center of rotation is also referred to as the axis of rotation.

Japanese Unexamined Patent Publication No. 08-168210 Japanese Unexamined Patent Publication No. 2008-228397

An object of the present disclosure is to suppress runout of a rotating body when a device having a rotating body such as a rotating plate is attached to a shaft body such as a rotating shaft.

The present disclosure is directed to a mounting mechanism for mounting a rotating body on a rotating shaft and an electric motor to which a rotary encoder is mounted using the mounting mechanism, and the following solutions are taken.

That is, one aspect of the present disclosure is a mounting mechanism for mounting a rotating body on a rotating shaft. The mounting mechanism includes a first nut, a second nut, and a ring body.

The first nut includes a cylindrical portion and a flange portion. The rotating shaft penetrates the cylindrical portion. The cylindrical portion extends along the axis of the rotation axis and has a first outer peripheral surface including a first thread. The flange portion has a first inner peripheral surface including a first screw groove as well as being convex in a direction intersecting the axis and in a direction opposite to the side on which the rotation axis is located.

The rotating shaft penetrates the second nut. The second nut includes a second thread groove and a small hole. The second thread groove is formed on a part of the second inner peripheral surface facing the rotation axis and is screwed with the first thread. The small hole portion is formed in a portion of the second inner peripheral surface other than the second thread groove, and is fitted with the rotating shaft.

The ring body is located between the third inner peripheral surface of the cylindrical portion and the rotation shaft while the rotation shaft penetrates the ring body. When the first nut and the second nut are screwed in the directions approaching each other, the ring body axes the force acting in the direction along the axial center applied from each of the first nut and the second nut. It has a first inclined surface that converts into a force acting in the direction intersecting the heart.

Another aspect of the present disclosure comprises a rotor with a rotor core attached to the rotating shaft, a bearing that rotatably supports the rotating shaft, and a stator located opposite the rotor, as described in the present disclosure. It is an electric motor with an encoder mounted on the rotating shaft using the mounting mechanism of.

According to the present disclosure, when a device having a rotating body such as a rotating plate is attached to a rotating shaft, it is possible to suppress runout of the rotating body.

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

(Background to this disclosure)
Conventionally, an electric motor capable of position control, speed control, and the like has been used as a power source for transporting various parts or products or moving an XY stage. An optical or magnetic rotary encoder (hereinafter, also simply referred to as an encoder) is generally attached to such an electric motor as a means for detecting the rotation speed and rotation angle of the rotation 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 shaft.

The rotating plate is attached and held to a boss which is a reinforcing component for reinforcing the tubular shaft body. The boss to which the rotating plate is attached has a shaft hole. The shaft hole is inserted into the rotating shaft to which the encoder is mounted. The boss is fixed to the rotating shaft. Specifically, the boss is fixed to the rotating shaft from the outer peripheral side surface thereof, for example, by tightening a screw.

Regarding the encoder configured in this way, first, the mounting accuracy of the rotating plate to the boss depends on the positioning accuracy of the rotation center of the rotating shaft and the rotation center of the boss. Therefore, if there is a gap between the shaft hole of the boss and the rotation shaft of the electric motor, a deviation occurs between the rotation center of the rotation shaft and the rotation center of the boss. Therefore, it is difficult to improve the mounting accuracy of the rotating plate to the boss. Therefore, it becomes difficult to suppress the runout of the rotating plate that rotates together with the rotating shaft.

The mounting accuracy of the boss with respect to the rotating shaft also depends on the positioning accuracy between the rotating center of the rotating shaft and the rotating center of the boss. Therefore, if there is a gap between the shaft hole of the boss and the rotation shaft, the tightening of the screw causes a deviation between the rotation center of the boss and the rotation center of the rotation shaft. Therefore, it becomes difficult to improve the mounting accuracy of the boss on the rotating shaft. Therefore, even in this case, it becomes difficult to suppress the runout of the rotating plate with respect to the rotating 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, more detailed explanation than necessary may be omitted. For example, detailed description of known matters or duplicate description of substantially the same configuration may be omitted. This is to facilitate the understanding of those skilled in the art by avoiding the following description from becoming unnecessarily redundant.

It should be noted that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(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 an electric motor 200 in which the mounting mechanism according to the first embodiment of the present disclosure is used.

(Overview of electric motor)
As an embodiment of the present disclosure, a mode in which an encoder is attached to an electric motor by using an attachment mechanism will be illustrated and described. The mounting mechanism in the present disclosure can be used in addition to the electric motor as long as the rotating body can be mounted on the rotating shaft.

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

In the rotor 210, the 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 direction C direction of the rotating shaft 110. In the laminated rotor core 212, a plurality of magnet holes 214 are formed along the axis C of the rotating shaft 110. Permanent magnets 216 are inserted into the magnet holes 214, respectively.

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

The stator 230 is located opposite the rotor 210. In this embodiment, the stator 230 includes a stator core 232 and windings 234. The stator core 232 is formed by laminating thin steel plates along the axis C of the rotating shaft 110. The laminated stator core 232 has a plurality of teeth protruding toward the axis C. Of the plurality of teeth, slots are formed between adjacent teeth. The winding 234 is wound around the stator core 232 using the slot. 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 rotating shaft 110 by using the attachment mechanism 40.

The mounting 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 which is a light emitting element, a phototransistor 152 which is a light receiving element, and a boss body 120 which fixes a rotating plate 130 to a rotating shaft 110. The rotating plate 130 is formed with a translucent window through which the light emitted by the LED element 151 is transmitted.

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

In this configuration, the winding 234 is supplied with a drive current from the outside of the electric motor 200. The winding 234 to which the drive current is supplied generates a predetermined magnetic flux via the stator core 232. The permanent magnet 216 embedded in the rotor core 212 is affected by the magnetic flux generated by the stator core 232. The rotor 210 rotates about the rotation shaft 110 due to the influence of the magnetic flux received by the permanent magnet 216.

The rotating plate 130 attached to the rotating shaft 110 using the attaching mechanism 40 rotates together with the rotor 210.

The LED element 151 forming the encoder 100 emits light. The phototransistor 152 receives the light emitted by the LED element 151. Since the rotating plate 130 rotates, the light emitted by the LED element 151 is received by the phototransistor 152 only when the translucent window formed in the rotating plate 130 passes between the LED element 151 and the phototransistor 152. .. At other times, the light emitted by the LED element 151 is blocked by the rotating plate 130, so that the phototransistor 152 cannot receive the light emitted by the LED element 151.

When the phototransistor 152 receives the light emitted by the LED element 151, the encoder 100 can detect the state in which the rotor 210 is rotating. In response to the detected rotational state of the rotor 210, the control unit of the electric motor 200 controls the drive current that energizes the winding 234.

As will be 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 rotating shaft 110. Therefore, it is possible to prevent a deviation from occurring between the rotation center of the rotation shaft 110 and the rotation center of the boss body 120. Therefore, the encoder 100 can accurately detect the rotational state of the rotor 210.

In the above description, a brushless motor provided with a magnet-embedded rotor as the electric motor 200 has been exemplified. The electric motor according to the present disclosure can also be used in other forms of a brushless motor, a commutator motor, an induction motor, or the like. Further, the electric motor according to the present disclosure can be used for both an inner rotor type motor and an outer rotor type motor.

(Encoder configuration)
FIG. 2 is an exploded perspective view showing the mounting mechanism 40 according to the first embodiment of the present disclosure and the encoder 100 mounted by the mounting mechanism 40. FIG. 3 is a cross-sectional view showing a mounting mechanism 40 according to the first embodiment of the present disclosure and an encoder 100 mounted on the mounting mechanism 40.

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 penetrates the boss body 120. The boss body 120 extends along the axis C of the rotating shaft 110. The boss body 120 has a second outer peripheral surface 124 including a second thread 122 that is threaded with a first thread groove 18 included in the flange portion 10B.

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

It will be described in more detail with reference to the drawings.

As shown in FIGS. 2 and 3, for example, the encoder 100 is attached to the end of the rotating shaft 110 by the attachment mechanism 40 according to the present embodiment. Here, the rotating shaft 110 is a shaft of an electric motor. The mounting mechanism 40 according to the present disclosure can be used not only for the shaft of the electric motor but also for a shaft body having the same function.

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

Further, as shown in FIG. 3, the encoder 100 is, for example, an optical detector in which an LED element 151 as a light emitting element and a phototransistor 152 as a light receiving element are arranged in a housing 100a. The housing 100a is made of, for example, a metal plate and is 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, another element can be used as long as it has the same function. The light receiving element may be, for example, a phototransistor 152. As the light receiving element, another element can be used as long as it has the same function. The LED element 151 and the phototransistor 152 are arranged inside the housing 100a at positions facing each other with the rotating plate 130 interposed therebetween. 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. Further, a circuit board on which a control circuit for controlling the LED element 151 and the phototransistor 152 is mounted may be arranged inside the housing 100a.

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

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

As shown in FIGS. 2 to 4, the mounting mechanism 40 according to the present embodiment is composed of three annular members each penetrating the rotating shaft 110.

That is, the mounting mechanism 40 according to the present embodiment attaches the boss body 120, which is a rotating body, to the rotating shaft 110.

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

The cylindrical portion 10A extends along the axis C of the rotating shaft 110 and has a first outer peripheral surface 12 including a first thread 14. The flange portion 10B is in a direction intersecting the axis C and is convex toward the opposite direction to the side where the rotation shaft 110 is located, and the first inner peripheral surface 16 including the first screw groove 18 is formed. Have. The first inner peripheral surface 16 of the flange portion 10B is located so as to face the rotating shaft 110.

A rotating shaft 110 penetrates the lock nut 20. The lock nut 20 includes a second thread groove 22 and a small hole portion 24.

The second thread groove 22 is formed on a part of the second inner peripheral surface 26 facing the rotating shaft 110, and is screwed with the first thread 14 of the boss fixing nut 10 which is the first nut. It fits. The small hole portion 24 is formed in a portion of the second inner peripheral surface 26 other than the second thread groove 22, and is fitted with the rotating shaft 110.

The rotating shaft 110 penetrates the taper ring 30 which is a ring body. The taper ring 30 is located between the third inner peripheral surface 17 of the cylindrical portion 10A and the rotation shaft 110. The taper ring 30 is a first nut when the boss fixing nut 10 which is the first nut and the lock nut 20 which is the second nut are screwed in the directions approaching each other (D1 and D2 in FIG. 4). Forces F01 and F02 applied in the direction along the axis C applied from each of the boss fixing nut 10 and the lock nut 20 which is the second nut, and the forces F1 and F2 acting in the direction intersecting the axis C. It has an inclined surface 32 that converts to.

In particular, the forms that exert a remarkable action effect are as follows.

The ring body used in the mounting mechanism 40 is a pair of tapered rings 30 having inclined surfaces 32a and 32b, each of which faces and abuts against each other. The taper ring 30 is an example of a ring body such as a span ring, and has an outer ring 30a and an inner ring 30b.

In the present embodiment, the inclined surface 32 is composed of a first inclined surface and a second inclined surface that faces and abuts the first inclined surface. In the following description, the inclined surface 32a included in 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.

It will be described in more detail with reference to the drawings.

As shown in FIGS. 3 and 4, the boss fixing nut 10 includes a flange portion 10B and a cylindrical portion 10A. In the flange portion 10B, a first thread groove 18 is formed on a first inner peripheral 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 where the boss body 120 is located. A first thread 14 is formed on the first outer peripheral surface 12.

In the axial J direction, a second thread 122 is formed on the boss body 120 at an end portion 120b located on the opposite side of the protrusion 120a formed on the boss body 120. The second thread 122 is screwed into the first thread groove 18 formed in the boss fixing nut 10.

The lock nut 20 holds the boss fixing nut 10 to the boss body 120. A second thread groove 22 that is screwed with the first thread 14 formed on the boss fixing nut 10 is formed on a part of the second inner peripheral surface 26 of the lock nut 20. The lock nut 20 has a small hole portion 24 that fits with the rotating shaft 110 in at least a part of the remaining portion of the second inner peripheral surface 26 of the lock nut 20.

Here, the cylindrical portion 10A of the boss fixing nut 10 is formed so that a gap portion 10C is formed between the boss fixing nut 10 and the rotating shaft 110. A pair of taper rings 30 are inserted into the gap portion 10C. The pair of tapered rings 30 have an outer ring 30a and an inner ring 30b, each of which has inclined surfaces 32a, 32b that face each other and abut. In the pair of taper rings 30, 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 tapered rings 30, the inclined surface 32b of the inner ring 30b slips inside the inclined surface 32a of the outer ring 30a. As a result, the thickness of the taper ring 30 increases in the direction intersecting the axis C, so that the outer diameter of the taper ring 30 increases. Therefore, as shown in FIG. 4, the taper ring 30 having an enlarged outer diameter has an action on the boss fixing nut 10 and the lock nut 20 in a direction intersecting the axis C and outward. The force F1 is generated. Therefore, the reaction force F2 is generated in the boss body 120. As a result, the boss body 120 is strongly pressed toward the axis C from the periphery of the boss fixing nut 10 and the lock nut 20 in the direction intersecting the axis C. That is, the axis J (rotation center) of the boss fixing nut 10, the lock nut 20, and the taper ring 30 all coincide with the axis C (rotation center) of the boss body 120. Therefore, it is possible to suppress the runout of the boss body 120, which is a rotating body, and eventually the rotating plate 130.

It is preferable that the outer ring 30a and the inner ring 30b constituting the taper ring 30 have a large friction coefficient on the inclined surfaces 32a and 32b, which are contact surfaces (sliding surfaces) with each other.

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

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

With this configuration, a force F1 which is an action and a force F2 which is a reaction can be surely generated.

With the following configuration, even more remarkable action and effect can be achieved.

As shown in FIG. 5, of the pair of taper rings 30 used for the mounting mechanism 40, the inner ring 30b, which is a taper ring located on the rotation shaft 110 side, has an extension line intersecting the axis C. It suffices to have the formed slit 36. In other words, the inner ring 30b has a slit 36. The extension line of the slit 36 intersects the axis C. Here, the extension line of the slit 36 means a line extended in the cutting direction of the slit 36, which is a narrowly cut open gap.

Alternatively, as shown in FIGS. 6 and 7, of the pair of taper rings 30 used in the mounting mechanism 40, the inner ring 30b, which is a taper ring located on the rotation shaft 110 side, has an extension line C as the axis C. It suffices to have a plurality of slits 36 formed so as to intersect with. In other words, the inner ring 30b has a plurality of slits 36. Each extension of the plurality of slits 36 intersects the axis C. On a plane orthogonal to the axis C, the plurality of slits 36 may be positioned at intervals in the circumferential direction centered on the axis C.

The slit 36 is 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 the plane orthogonal to the axis C, the plurality of slits 36 may be located on the circumference at appropriate angles in the radial direction centered on the axis C, respectively.

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

In the specific examples shown in FIGS. 6 and 7, the slits 36 are located at equal intervals. Equal intervals or appropriate angles are not intended to be mathematically even, as long as the holding force given to the rotating shaft 110 by each inclined surface 32b divided by each slit 36 is equal. Typically, the variability due to manufacturing tolerances is within the equidistant or appropriate angle range referred to in this embodiment.

According to this configuration, 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 axis C in all directions in the direction intersecting the axis C. Can be done. That is, the inner ring 30b can adjust the strength for tightening the boss body 120 within a range that can be adjusted by the width dimension of the slit 36. Therefore, the accuracy at which the axis J (rotation center) of the boss fixing nut 10, the lock nut 20, and the taper ring 30 coincides with the axis C (rotation center) of the boss body 120 is improved. Therefore, the runout of the boss body 120, which is a rotating body, and eventually the rotating plate 130 can be further suppressed.

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 surface 32b divided into each. The man-hours for forming the slit 36 on the inclined surface 32b can also be realized within an appropriate man-hour range.

As shown in FIG. 8, the slit 36a used in the mounting 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, the slit 36a of the inner ring 30b of the taper ring located on the rotation shaft 110 side has a slit width W2 on the taper ring opening 36c side wider than the slit width W1 on the taper ring tip 36b side. There is.

With this configuration, even if there is a gap between the inner peripheral surface of the inner ring 30b and the outer peripheral surface of the rotating shaft 110 due to some factor, the difference between the slit width W2 and the slit width W1 will make this gap. Absorb. That is, since there is a difference between the slit width W2 and the slit width W1, the inner ring 30b and the rotating shaft 110 can always secure an appropriate holding force.

As described above, the mounting mechanism 40 of the present embodiment is a mounting mechanism 40 that mounts a rotating body corresponding to the boss body 120 on the rotating shaft 110, and includes the first nut 10 and the second nut 20. A ring body 30 is provided.

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 10A extends along the axis C of the rotating shaft 110 and has a first outer peripheral surface 12 including a first thread 14. The flange portion 10B is in a direction intersecting the axis C and is convex toward the opposite direction to the side where the rotation shaft 110 is located, and the first inner peripheral surface 16 including the first screw groove 18 is formed. Have.

The rotating shaft 110 penetrates the second nut 20. The second nut 20 includes a second thread groove 22 and a small hole portion 24. The second thread groove 22 is formed on a part of the second inner peripheral surface 26 facing the rotating shaft 110, and is screwed with the first thread 14. The small hole portion 24 is formed in a portion of the second inner peripheral surface 26 other than the second thread groove 22, and is fitted with the rotating shaft 110.

The ring body 30 penetrates the rotating shaft 110 and is located between the third inner peripheral surface 17 of the cylindrical portion 10A and the rotating shaft 110. When the first nut 10 and the second nut 20 are screwed in a direction approaching each other, the ring body 30 has a direction along the axis C applied from each of the first nut 10 and the second nut 20. It has a first inclined surface corresponding to an inclined surface 32a that converts a force acting on the force into a force acting in a direction intersecting the axis C.

As a result, it is possible to suppress the runout of the rotating body corresponding to the boss body 120.

Further, the ring body 30 may be a pair of tapered rings 30 further having a second inclined surface corresponding to the inclined surface 32b that faces and contacts 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 30b located on the rotation shaft 110 side has a slit 36. The extension line of the slit 36 may intersect the axis C.

Further, among the pair of taper rings 30, the taper ring corresponding to the inner ring 30b located on the rotation shaft 110 side has a plurality of slits 36. Each extension line of the plurality of slits 36 intersects the axis C. On a plane orthogonal to the axis C, the plurality of slits 36 may be positioned at intervals in the circumferential direction centered on the axis C.

Further, the slit 36a of the taper ring corresponding to the inner ring 30b located on the rotation shaft 110 side is a taper ring corresponding to the inner ring 30b with respect to 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.

Further, in the mounting mechanism 40, the rotating body may be an encoder 100 including a boss body 120 and a rotating plate 130. The rotating shaft 110 penetrates the boss body 120. The boss body 120 extends along the axis C of the rotating shaft 110 and 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. do it. The rotating plate 130 may be attached so as to intersect the axis C.

Further, in the electric motor 200 of the present embodiment, the rotor 210 in which the rotor core 212 is attached to the rotating shaft 110, the bearing 220 that rotatably supports the rotating shaft 110, and the stator located facing the rotor 210 230 and. The encoder 100 is attached to the rotating shaft 110 by using the attachment mechanism 40 described above.

(Embodiment 2)
The configuration of the mounting mechanism 440 according to the second embodiment will be described.

FIG. 9 is a schematic cross-sectional view showing the action of the mounting mechanism 440 according to the second embodiment of the present disclosure on the rotating shaft 110. FIG. 10 is a perspective view of one member constituting the mounting mechanism 440 according to the second embodiment of the present disclosure. FIG. 11 is a front view of one member constituting the mounting mechanism 440 according to the second embodiment of the present disclosure. FIG. 12 is a front view of another member constituting the mounting mechanism 440 according to the second embodiment of the present disclosure. FIG. 13 is a perspective view of another member constituting the mounting mechanism 440 according to the second embodiment of the present disclosure.

In describing the mounting mechanism 440, the same components as those of the above-described first embodiment are designated by the same reference numerals, and the description thereof will be incorporated.

As shown in FIG. 9, the boss body 460, which is a rotating body in which the mounting mechanism 440 is used, has a taper extending between the third inner peripheral surface 17 and the rotating shaft 110 in the direction along the axis C. It has a part 462. The tapered portion 462 includes an inclined surface 432b facing the inclined surface 432a included in the tapered ring 430 which is a ring body.

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

It will be described in more detail with reference to 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 thread groove 18 is formed on a first inner peripheral surface 16 facing the boss body 460. The cylindrical portion 10A has a first outer peripheral surface 12 on the opposite side to the side where the boss body 460 is located. A first thread 14 is formed on the first outer peripheral surface 12.

In the axial J direction, a second thread 122 is formed on the boss body 460 at an end portion 460b located on the opposite side of the protrusion formed on the boss body 460. The second thread 122 is screwed into the first thread groove 18 formed in the boss fixing nut 10.

The lock nut 20 holds the boss fixing nut 10 to the boss body 460. A second thread groove 22 that is screwed with the first thread 14 formed on the boss fixing nut 10 is formed on a part of the second inner peripheral surface 26 of the lock nut 20. The lock nut 20 has a small hole portion 24 that fits with the rotating shaft 110 in at least a part of the remaining portion of the second inner peripheral surface 26 of the lock nut 20.

Here, the cylindrical portion 10A of the boss fixing nut 10 is formed so that a gap portion 410C is formed between the cylindrical portion 10A and the tapered portion 462. A taper ring 430 is inserted into the gap 410C. The taper ring 430 has an inclined surface 432a that faces and contacts the inclined surface 432b of the tapered portion 462. When the lock nut 20 is screwed in the direction D2 of the boss fixing nut 10, the tapered surface 432a of the tapered ring 430 slides out of the inclined surface 432b of the tapered portion 462. In other words, in the tapered portion 462, the inclined surface 432b of the tapered portion 462 slips inside the inclined surface 432a of the taper 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 the axis C, so that the outer diameter of the taper ring 430 is expanded. Therefore, as shown in FIG. 9, the taper ring 430 having an enlarged outer diameter acts with respect to the boss fixing nut 10 and the lock nut 20 in a direction intersecting the axis C and outward. A certain force F1 is generated. Therefore, the reaction force F2 is generated in the boss body 460. As a result, the boss body 460 is strongly pressed toward the axis C from around the boss fixing nut 10 and the lock nut 20 in the direction intersecting the axis C. That is, the axis J (center of rotation) of the boss fixing nut 10, the lock nut 20, and the taper ring 430 all coincide with the axis C (center of rotation) of the boss body 460. Therefore, it is possible to suppress the runout of the boss body 460, which is a rotating body, and eventually the rotating plate 130.

The friction coefficient on 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.

With the following configuration, even more remarkable action and effect can be achieved.

As shown in FIG. 10, the tapered portion 462 of the boss body 460 may have a slit 436 formed so that its extension line intersects the axis C. In other words, the tapered portion 462 has a slit 436. Here, the extension line of the slit 436 means a line extended in the cutting direction of the slit 436, which is a narrowly cut open gap.

Alternatively, as shown in FIGS. 11 and 12, the tapered portion 462 of the boss body 460 may have a plurality of slits 436 formed so that its extension line intersects the axis C. In other words, the tapered portion 462 has a plurality of slits 436. Each extension of the plurality of slits 436 intersects the axis C. The plurality of slits 436 may be positioned at intervals in the circumferential direction about the axis C on a plane orthogonal to the axis C.

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, on the plane orthogonal to the axis C, the plurality of slits 436 may be located on the circumference at appropriate angles in the radial direction centered on the axis C, respectively.

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

In the specific examples shown in FIGS. 11 and 12, the slits 436 are located at equal intervals. Equal intervals or appropriate angles are not intended to be mathematically even, as long as the holding forces given to the rotation shaft 110 by each inclined surface 432b divided by each slit 436 are equal. Typically, the variability due to manufacturing tolerances is within the equidistant or appropriate angle range referred to in this embodiment.

According to this configuration, 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 axis C in all directions in the direction intersecting the axis C. Can be done. That is, the taper portion 462 can adjust the strength for tightening the boss body 460 within a range that can be adjusted by the width dimension of the slit 436. Therefore, the accuracy at which the boss fixing nut 10, the lock nut 20, and the axis J (rotation center) of the taper ring 430 coincide with the axis C (rotation center) of the boss body 460 is improved. Therefore, the runout of the boss body 460, which is a rotating body, and eventually the rotating plate 130 can be further suppressed.

In particular, when 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 rotating shaft 110 from the inclined surface 432b divided into each. The man-hours for forming the slit 436 on the inclined surface 432b can also be realized within an appropriate man-hour range.

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 included in the tapered portion 462 has a wider slit width W2 on the opening 36c side of the tapered portion 462 than a slit width W1 on the tip 436b side of the tapered portion 462.

With this configuration, even if a gap occurs between the inner peripheral surface of the tapered portion 462 and the outer peripheral surface of the rotating shaft 110 due to some factor, the difference between the slit width W2 and the slit width W1 will make this gap. Absorb. That is, since there is a difference between the slit width W2 and the slit width W1, the tapered portion 462 and the rotating shaft 110 can always secure an appropriate holding force.

As is clear from the above description, in the second embodiment described above, the boss body 460 has a tapered portion 462 that reaches between the third inner peripheral surface 17 of the boss fixing nut 10 and the outer peripheral surface of the rotating shaft 110. Has. The tapered portion 462 has an action corresponding to the inner ring 30b described in the first embodiment. In this configuration, the taper ring 430 has an action corresponding to the outer ring 30a described in the first embodiment. That is, in the second embodiment, the taper ring 430 can be composed of one member as compared with the first embodiment. Therefore, the second embodiment improves the workability of assembly as compared with the mounting mechanism 40 shown in the first embodiment.

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

As a result, it is possible to suppress the runout of the rotating body corresponding to the boss body 460.

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

Further, the tapered portion 462 has a plurality of slits 436. Each extension of the plurality of slits 436 intersects the axis C. On a plane orthogonal to the axis C, the plurality of slits 436 may be positioned at intervals in the circumferential direction centered on the axis C.

Further, the slit 436a included in the tapered portion 462 may be wider in the slit width W2 on the opening 436c side of the tapered portion 462 than in the slit width W1 on the tip 436b side of the tapered portion 462.

(Embodiment 3)
The configuration of the mounting mechanism 540 according to the third embodiment will be described.

FIG. 14 is a schematic cross-sectional view showing the action of the mounting mechanism 540 according to the third embodiment of the present disclosure on the rotating shaft 110. FIG. 15 is a perspective view of one member constituting the mounting mechanism 540 according to the third embodiment of the present disclosure. FIG. 16 is a front view of one member constituting the mounting mechanism 540 according to the third embodiment of the present disclosure. FIG. 17 is a front view of another member constituting the mounting mechanism 540 according to the third embodiment of the present disclosure. FIG. 18 is a perspective view of another member constituting the mounting mechanism 540 according to the third embodiment of the present disclosure.

In describing the mounting mechanism 540, the same components as those of the above-described first and second embodiments are designated by the same reference numerals, and the description thereof will be incorporated.

As shown in FIG. 14, the third inner peripheral surface 517 of the boss fixing nut 510, which is the first nut used in the mounting mechanism 540, is inclined so as to face the inclined surface 532a of the tapered ring 530, which is a ring body. Includes surface 532b. In other words, the third inner peripheral surface 517 also serves as an inclined surface 532b.

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

It will be described in more detail with reference to 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 510B, a first thread groove 18 is formed on a first inner peripheral surface 16 facing the boss body 120. The cylindrical portion 510A has a first outer peripheral 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 peripheral surface 12.

In the axial J direction, the boss body 120 is formed with a second thread 122 at an end portion 120b located on the opposite side of the protrusion formed on the boss body 120. The second thread 122 is screwed into the first thread groove 18 formed in the boss fixing nut 510.

The lock nut 20 holds the boss fixing nut 510 to the boss body 120. A second thread groove 22 screwed with the first thread 14 formed on the boss fixing nut 510 is formed on a part of the second inner peripheral surface 26 of the lock nut 20. The lock nut 20 has a small hole portion 24 that fits with the rotating shaft 110 in at least a part of the remaining portion of the second inner peripheral surface 26 of the lock nut 20.

Here, the cylindrical portion 510A of the boss fixing nut 510 is formed so that a gap portion 510C is formed between the boss fixing nut 510 and the rotating shaft 110. A taper ring 530 is inserted into the gap 510C. The taper ring 530 has an inclined surface 532a that faces and abuts the inclined surface 532b 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 tapered ring 530 slips inside the inclined surface 532b 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. As a result, the cylindrical portion 510A moves in the direction away from the axial center C of the rotating shaft 110 in the direction intersecting the axial center C, so that the outer diameter of the cylindrical portion 510A is expanded. Therefore, as shown in FIG. 14, the cylindrical portion 510A whose outer diameter is expanded by the taper ring 530 is in the direction intersecting the axis C with respect to the boss fixing nut 510 and the lock nut 20, and is outside A force F1 that is an action toward the direction is generated. Therefore, the reaction force F2 is generated in the boss body 120. As a result, the boss body 120 is strongly pressed toward the axis C from the periphery of the boss fixing nut 510 and the lock nut 20 in the direction intersecting the axis C. That is, the axis J (center of rotation) of the boss fixing nut 510, the lock nut 20, and the taper ring 530 all coincide with the axis C (center of rotation) of the boss body 120. Therefore, it is possible to suppress the runout of the boss body 120, which is a rotating body, and eventually the rotating plate 130.

The friction coefficient on the contact surface (sliding 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.

With the following configuration, even more remarkable action and effect can be achieved.

As shown in FIG. 15, the taper ring 530, which is a ring body, may have a slit 536 formed so that its extension line intersects the axis C. In other words, the taper ring 530, which is a ring body, has a slit 536. Here, the extension line of the slit 536 means a line extended in the cutting direction of the slit 536, which is a narrowly cut open gap.

Alternatively, as shown in FIGS. 16 and 17, the taper ring 530, which is a ring body, may have a plurality of slits 536 formed so that its extension line intersects the axis C. In other words, the taper ring 530 has a plurality of slits 536. Each extension of each of the plurality of slits 536 intersects the axis C. The plurality of slits 536 may be positioned at intervals in the circumferential direction about the axis C on a plane orthogonal to the axis C.

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 axis C, the plurality of slits 536 may be located on the circumference at appropriate angles in the radial direction centered on the axis C, respectively.

As a particularly preferable example, as shown in FIG. 16, each slit 536 may be positioned at every θ1 = 120 °. Alternatively, as shown in FIG. 17, each slit 536 may be located at intervals of θ2 = 90 °.

In the specific example shown in FIGS. 16 and 17, the slits 536 are located at equal intervals. Equal intervals or appropriate angles are not intended to be mathematically even, as long as the holding forces given to the rotating shaft 110 by each inclined surface 532a divided by each slit 536 are equal. Typically, the variability due to manufacturing tolerances is within the equidistant or appropriate angle range referred to in this embodiment.

According to this configuration, 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 axis C in all directions in the direction intersecting the axis C. Can be done. That is, the taper ring 530 can adjust the strength of tightening the boss body 120 within the range that can be adjusted by the width dimension of the slit 536. Therefore, the accuracy at which the axis J (rotation center) of the boss fixing nut 510, the lock nut 20, and the taper ring 530 coincides with the axis C (rotation center) of the boss body 120 is improved. Therefore, the runout of the boss body 120, which is a rotating body, and eventually the rotating plate 130 can be further suppressed.

In particular, when 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 rotating shaft 110 from the inclined surface 532a divided into each. The man-hours for forming the slit 536 on the inclined surface 532a can also be realized within an appropriate man-hour range.

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

With this configuration, even if there is a gap between the inner peripheral surface of the taper ring 530 and the outer peripheral surface of the rotating shaft 110 due to some factor, the difference between the slit width W2 and the slit width W1 will make this gap. Absorb. That is, since there is a difference between the slit width W2 and the slit width W1, the taper ring 530 and the rotating shaft 110 can always secure an appropriate holding force.

As is clear 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. Therefore, in this configuration, the taper ring 530 has an action corresponding to the inner ring 30b described in the first embodiment. That is, in the third embodiment, the taper ring 530 can be composed of one member as compared with the first embodiment. Therefore, the third embodiment improves the workability of assembly as compared with the mounting mechanism 40 shown in the first embodiment.

As described above, the third inner peripheral surface 517 of the first nut 510 used in the mounting mechanism 540 of the present embodiment is formed on the inclined surface 532b facing the first inclined surface corresponding to the inclined surface 532a. Includes a corresponding second slope.

As a result, the workability of assembly in the mounting mechanism 540 is improved.

Further, the taper ring 530, which is a ring body, may have a slit 536 in the direction along the axis C.

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

Further, the slit 536a of the taper ring 530, which is a ring body, has a slit width W2 on the opening 536c side of the taper ring 530, which is a ring body, wider than the slit width W1 on the tip 536b side of the taper ring 530, which is a ring body. Just do it.

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

FIG. 19 is a schematic cross-sectional view showing the action of the mounting mechanism 640 according to the fourth embodiment of the present disclosure on the rotating shaft 110. FIG. 20 is a perspective view of one member constituting the mounting mechanism 640 according to the fourth embodiment of the present disclosure. FIG. 21 is a front view of one member constituting the mounting mechanism 640 according to the fourth embodiment of the present disclosure. FIG. 22 is a front view of another member constituting the mounting mechanism 640 according to the fourth embodiment of the present disclosure. FIG. 23 is a perspective view of another member constituting the mounting mechanism 640 according to the fourth embodiment of the present disclosure.

In explaining the mounting mechanism 640, the same reference numerals will be given to the same configurations as those of the above-mentioned components 1 to 3, and the description will be incorporated.

As shown in FIG. 19, the lock nut 620, which is the second nut used in the mounting mechanism 640, has a convex portion 622 reaching between the second inner peripheral surface 626 and the rotating shaft 110. The convex portion 622 includes an inclined surface 632a facing the inclined surface 632b included in the tapered ring 630 which is a ring body.

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

It will be described in more detail with reference to 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 thread groove 18 is formed on a first inner peripheral 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 where the boss body 120 is located. A first thread 14 is formed on the first outer peripheral surface 12.

In the axial J direction, the boss body 120 is formed with a second thread 122 at an end portion 120b located on the opposite side of the protrusion formed on the boss body 120. The second thread 122 is screwed into the first thread groove 18 formed in the boss fixing nut 10.

The lock nut 620 holds the boss fixing nut 10 to the boss body 120. A second thread groove 22 screwed with the first thread 14 formed on the boss fixing nut 10 is formed on a part of the second inner peripheral surface 626 of the lock nut 620. The lock nut 620 has a small hole portion 24 that fits with the rotating shaft 110 in at least a part of the remaining portion of the second inner peripheral surface 626 of the lock nut 620.

Here, the cylindrical portion 10A of the boss fixing nut 10 is formed so that a gap portion 610C is formed between the boss fixing nut 10 and the rotating shaft 110. A taper ring 630 is inserted into the gap portion 610C. The taper ring 630 has an inclined surface 632b that faces and contacts the inclined surface 632a of the convex portion 622. In the taper ring 630, when the lock nut 620 is screwed in the direction D2 of the boss fixing nut 10, the inclined surface 632b of the taper ring 630 slips inside the inclined surface 632a 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 the direction away from the axial center C of the rotating shaft 110 in the direction intersecting the axial center C, so that the outer diameter of the convex portion 622 is expanded. Therefore, as shown in FIG. 19, the convex portion 622 whose outer diameter is expanded by the taper ring 630 is in the direction intersecting the axis C with respect to the boss fixing nut 10 and acts outward. A certain force F1 is generated. Therefore, the reaction force F2 is generated in the boss body 120. As a result, the boss body 120 is strongly pressed toward the axis C from the periphery of the boss fixing nut 10 and the lock nut 620 in the direction intersecting the axis C. That is, the axis J (center of rotation) of the boss fixing nut 10, the lock nut 620, and the taper ring 630 all coincide with the axis C (center of rotation) of the boss body 120. Therefore, it is possible to suppress the runout of the boss body 120, which is a rotating body, and eventually the rotating plate 130.

The friction coefficient on the contact surface (sliding 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.

With the following configuration, even more remarkable action and effect can be achieved.

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 the axis 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 means a line extended in the cutting direction of the slit 636, which is a narrowly cut open gap.

Alternatively, as shown in FIGS. 21 and 22, the taper ring 630, which is a ring body, may have a plurality of slits 636 formed so that its extension line intersects the axis C. In other words, the taper ring 630 has a plurality of slits 636. Each extension of the plurality of slits 636 intersects the axis C. On a plane orthogonal to the axis C, the plurality of slits 636 may be positioned at intervals in the circumferential direction centered on the axis C.

The slit 636 may be formed along the inclined surface 632b. 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 axis C, the plurality of slits 636 may be located on the circumference at appropriate angles in the radial direction centered on the axis C, respectively.

As a particularly preferable example, as shown in FIG. 21, each slit 636 may be positioned at every θ1 = 120 °. Alternatively, as shown in FIG. 22, each slit 636 may be positioned at every θ2 = 90 °.

In the specific example shown in FIGS. 21 and 22, the slits 636 are located at equal intervals. Equal intervals or appropriate angles are not intended to be mathematically even, as long as the holding forces given to the rotating shaft 110 by each inclined surface 632b divided by each slit 636 are equal. Typically, the variability due to manufacturing tolerances is within the equidistant or appropriate angle range referred to in this embodiment.

According to this configuration, 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 axis C in all directions in the direction intersecting the axis C. Can be done. That is, the taper ring 630 can adjust the strength of tightening the boss body 120 within the range that can be adjusted by the width dimension of the slit 636. Therefore, the accuracy at which the axis J (rotation center) of the boss fixing nut 10, the lock nut 620, and the taper ring 630 coincides with the axis C (rotation center) of the boss body 120 is improved. Therefore, the runout of the boss body 120, which is a rotating body, and eventually the rotating plate 130 can be further suppressed.

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 rotating shaft 110 from the inclined surface 632b divided separately. The man-hours for forming the slit 636 on the inclined surface 632b can also be realized within an appropriate man-hour range.

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 has a wider slit width W2 on the opening 636c side of the taper ring 630 than a slit width W1 on the tip 636b side of the taper ring 630.

With this configuration, even if there is a gap between the inner peripheral surface of the taper ring 630 and the outer peripheral surface of the rotating shaft 110 due to some factor, the difference between the slit width W2 and the slit width W1 will make this gap. Absorb. That is, since there is a difference between the slit width W2 and the slit width W1, the taper ring 630 and the rotating shaft 110 can always secure an appropriate holding force.

As is clear from the above description, in the above-described fourth embodiment, the lock nut 620 has a shape in which the lock nut 20 and the outer ring 30a described in the first embodiment are combined. Therefore, in this configuration, the taper ring 630 has an action corresponding to the inner ring 30b described in the first embodiment. That is, in the fourth embodiment, the taper ring 630 can be composed of one member as compared with the first embodiment. Therefore, the fourth embodiment improves the workability of assembly as compared with the mounting mechanism 40 shown in the first embodiment.

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

As a result, it is possible to suppress the runout of the rotating body corresponding to the boss body 120.

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

Further, the taper ring 630, which is a ring body, may have a plurality of slits 636 formed in a direction along the axis C. On a plane orthogonal to the axis C, the plurality of slits 636 may be located at equal intervals in the circumferential direction centered on the axis C, respectively.

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

(Embodiment 5)
The configuration of the mounting mechanism according to the fifth embodiment will be described.

FIG. 24 is a front view of one member constituting the mounting mechanism according to the fifth embodiment of the present disclosure. FIG. 25 is a front view of another member constituting the mounting mechanism according to the fifth embodiment of the present disclosure.

In explaining the mounting mechanism, the same components as those of the above-described components 1 to 4 are designated by the same reference numerals, and the description thereof will be incorporated.

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

The shape of the notch forming the slit can be realized by the linear slit 736 as shown in FIG. 24. Alternatively, the shape of the notch forming the slit can also be realized by the spiral slit 736a as shown in FIG.

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

Even if the slits 736 and 736a having this shape are used, the same effects as those of the above-described embodiments 1 to 4 can be obtained.

(A modified example of the embodiment)
As a modification of the embodiment according to the present disclosure, a known anti-loosening means such as a metal washer is provided between the facing surfaces of the flange portion 10B of the boss fixing nut 10 and the lock nut 20. You may. In this way, rotational stability in the boss body 120 including the rotating plate 130 can be obtained for a long period of time.

The attachment mechanism according to the present disclosure can attach a rotating body in a device including a rotating body to a rotatable shaft body. The mounting mechanism according to the present disclosure is used, for example, to detect a rotational position in a servo system. The mounting mechanism according to the present disclosure is useful for an encoder or the like that detects the 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 part 10B, 510B Flange part 10C, 410C, 510C, 610C Void part 10d, 20a Inner surface 12 First outer peripheral surface 14 First thread 16 First inner peripheral surface 17, 517 Third inner circumference Surface 18 First thread groove 20, 620 Lock nut (second nut)
22 Second thread groove 24 Small hole 26, 626 Second inner peripheral surface 30, 430, 530, 630, 730 Tapering (ring body)
30a Outer ring 30b Inner ring 32, 32a, 32b, 432a, 432b, 532a, 532b, 632a, 632b, 732b Inclined surfaces 34, 34a, 120c End surfaces 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, 640 Mounting mechanism 100 Encoder 100a Housing 110 Rotating shaft 120, 460 Boss body (rotating body)
120a Projection 120b, 460b End 122 Second thread 124 Second outer peripheral surface 130 Rotating plate (rotating 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 Tapered part 622 Convex part

Claims (16)

It is a mounting mechanism that attaches a rotating body to the rotating shaft.
A cylindrical portion through which the rotating shaft penetrates, extends along the axis of the rotating shaft, and has a first outer peripheral surface including a first thread.
A flange portion having a first inner peripheral surface including a first screw groove, which is in a direction intersecting the axis and is convex toward the opposite direction to the side where the rotation axis is located.
With the first nut, including
The axis of rotation penetrates
A second thread groove formed on a part of the second inner peripheral surface facing the rotation axis and screwed with the first thread.
A small hole portion formed in a portion of the second inner peripheral surface other than the second thread groove and fitted with the rotating shaft, and a small hole portion.
With a second nut, including
The rotating shaft penetrates and is located between the third inner peripheral surface of the cylindrical portion and the rotating shaft, and the first nut and the second nut are screwed in a direction approaching each other. When, a first inclined surface that converts a force applied from each of the first nut and the second nut in a direction along the axis into a force acting in a direction intersecting the axis is provided. With a ring body
A mounting mechanism. The mounting mechanism according to claim 1, wherein the ring body is a pair of tapered rings further having a second inclined surface that faces the first inclined surface and is in contact with the first inclined surface. The mounting mechanism according to claim 2, wherein of the pair of taper rings, the taper ring located on the rotation axis side has a slit, and the extension line of the slit intersects the axis. Of the pair of taper rings, the taper ring located on the rotation axis side has a plurality of slits, and each extension line of the plurality of slits intersects the axis.
The mounting mechanism according to claim 2, wherein the plurality of slits are located at intervals in the circumferential direction about the center of the axis on a plane orthogonal to the center of the axis. The mounting mechanism according to claim 3 or 4, wherein the slit of the taper ring located on the rotation axis side has a slit width on the opening side of the taper ring wider than a slit width on the tip side of the taper ring. .. The rotating body has a tapered portion extending between the third inner peripheral surface and the rotating shaft in a direction along the axial center.
The mounting mechanism according to claim 1, wherein the tapered portion includes a second inclined surface facing the first inclined surface. The mounting mechanism according to claim 6, wherein the tapered portion has a slit, and an extension line of the slit intersects the axial center. The tapered portion has a plurality of slits, and each extension line of the slits intersects the axial center.
The mounting mechanism according to claim 6, wherein the plurality of slits are located at intervals in the circumferential direction about the center of the axis on a plane orthogonal to the center of the axis. The mounting mechanism according to claim 7 or 8, wherein the slit included in the tapered portion has a slit width on the opening side of the tapered portion wider than a slit width on the tip end side of the tapered portion. The mounting mechanism according to claim 1, wherein the third inner peripheral surface of the first nut includes a second inclined surface facing the first inclined surface. The second nut further has a convex portion reaching between the second inner peripheral surface and the rotation shaft, and the convex portion has a second inclined surface facing the first inclined surface. The mounting mechanism according to claim 1, which includes. The mounting mechanism according to claim 10 or 11, 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 mounting mechanism according to claim 10 or 11, wherein the plurality of slits are located at equal intervals in the circumferential direction about the axis, respectively, on a plane orthogonal to the axis. The mounting mechanism according to claim 12 or 13, wherein the slit included in the ring body has a slit width on the opening side of the ring body wider than a slit width on the tip end side of the ring body. The rotating body
A boss through which the rotating shaft penetrates, extends along the axis of the rotating shaft, and has a second outer peripheral surface including a second thread that is screwed with the first thread groove included in the flange portion. With the body
A rotating plate mounted so as to intersect the axis,
The mounting mechanism according to any one of claims 1, 2, 6, 10 and 11, which is an encoder including the above. A rotor with a rotor core attached to the rotating shaft, and
Bearings that rotatably support the rotating shaft,
A stator located opposite to the rotor and
With
An electric motor that mounts the encoder on the rotating shaft using the mounting mechanism according to claim 15.