JP6001504B2 - Rotor body - Google Patents

Description

  The present invention belongs to the technical field of stepping motors mounted on various OA devices, home appliances, and the like, and particularly relates to a rotor body that is an essential component.

  Conventionally, as a rotor body which is an essential component of a PM type (permanent magnet type) stepping motor, a cylindrical permanent magnet having SN poles alternately and circumferentially magnetized is used as a disk-like support member. Some rotor collars (hereinafter referred to as “rotor collars”) are arranged around the outer periphery of the rotor collar, and the rotor collar is fixed to the rotating shaft.

  As such a rotor body, there is one that employs a light metal plate material for the rotor collar in order to reduce the weight and cost. Then, a pressure inlet is formed at the center of the disk-shaped rotor collar by burring of the press, and the rotary shaft is press-fitted and fixed to the pressure inlet, and the inner peripheral surface of the permanent magnet is bonded to the outer edge of the rotor collar. An integrated form is disclosed. For example, Patent Document 1 discloses a member corresponding to the rotor collar as a “cup”.

  In addition, as shown in Patent Document 2, a rotor collar (in the literature, “fixed” is formed by bending a fixed portion on the side surface of the rotary shaft and a fixed portion on the inner peripheral surface of the permanent magnet integrally with a connecting portion. A member ".) Discloses a rotor body that fixes a rotating shaft and a permanent magnet.

  Further, as shown in Patent Document 3, while fixing to the rotating shaft by press-fitting, the outer edge portion of the polygonal rotor collar (“bush member” in the document) is attached to the inner peripheral surface of the permanent magnet. A rotor body integrated so as to bite is disclosed.

JP 09-215234 A JP 2008-278647 A JP 2004-208353 A

  The rotor body disclosed in Patent Document 1 is relatively inexpensive because the rotor collar is formed by press working, and the rotary shaft can be fixed with sufficient press-fitting allowance to form the pressure inlet by burring. . However, fixing the rotor collar and the permanent magnet requires filling of an expensive adhesive over the entire circumference of the gap between them, and the bonding work is complicated and the management of the filling amount and curing time is also complicated. Met.

  The rotor body disclosed in Patent Document 2 is more advantageous than the rotor body disclosed in Patent Document 1 in that an adhesive is not required. On the other hand, since the outer peripheral surface of the permanent magnet of the rotor body faces the inner peripheral surface of the stator with a predetermined air gap (gap), high accuracy is required for the concentricity between the rotating shaft of the rotating shaft and the outer peripheral surface of the permanent magnet. It was. Therefore, in this rotor body, each part of the rotor collar that integrates the rotating shaft and the permanent magnet is required to have high accuracy in bending, and high processing accuracy is also required in the concentricity of the inner and outer diameters of the permanent magnet. As a result, the manufacturing cost is increased.

  In the rotor body disclosed in Patent Document 3, the outer edge portion of the rotor collar is formed in a polygonal shape, and the outer edge portion bites into the inner peripheral surface of the permanent magnet, so that no adhesive is required. In addition, it is considered easy to ensure dimensional accuracy. However, this rotor body has the outer edge bited into the permanent magnet side, so there is a risk of cracking or cracking in the permanent magnet after or after processing, and quality control is difficult. It was.

  Therefore, the present invention has been made paying attention to the above-mentioned problems, and while having a simple configuration, the concentricity accuracy of the outer peripheral surface of the rotating shaft and the permanent magnet and the dimensions of the axial center of the rotating shaft and the outer peripheral surface of the permanent magnet. Provided is a rotor body that ensures accuracy.

  In order to solve the above problems, the rotor body according to the present invention is configured as follows.

That is, a rotating shaft that is rotatably held in a motor case, one or a plurality of plate-like rotor collars that are vertically fixed to the rotating shaft with a central portion thereof, and coaxial with the rotating shaft via the rotor collar And a cylindrical permanent magnet in which different-polarized magnetized regions are alternately formed along the peripheral surface, and the rotor collar is inserted into the cylinder of the permanent magnet. a substrate of possible shapes, is projected on the outer diameter side than the cylindrical inner diameter of the permanent magnet from the substrate consists of two or more projecting pieces formed by a cylindrical inner periphery of the permanent magnet by deforming bending projecting pieces It is characterized by being fixed to the surface by friction.

  This rotor collar is formed from a light metal plate material, and the protrusion is plastically deformed by bending. After bending deformation, the rotor collar is exhibited by the contact area of the protrusion on the inner peripheral surface of the permanent magnet and its elastic force. The permanent magnet is fixed by the frictional force.

  Further, the rotor collar is characterized in that a stress concentration portion that is easily bent and deformed from the substrate is formed on the projecting piece. The stress concentration portion may be formed such that the protruding piece portion is formed thinner than the substrate portion, or a thin groove is formed between the protruding piece and the substrate. With this configuration, bending stress concentrates on the stress concentration portion of the projecting piece, and bending deformation of only the projecting piece becomes easy.

  Further, the formation position of the rotor collar protrusion is a position opposed to the center of the substrate, or a multipoint position equivalent to the circumference. For example, when two projecting pieces are formed, it is formed at a position opposed to the center part of the substrate. good. Thereby, the friction fixed position after the bending deformation of the protruding piece with respect to the permanent magnet becomes uniform, and the fixed state of both is stabilized. In addition, it is preferable that three or more projecting pieces are formed on the rotor collar at equal circumferential intervals.

  Furthermore, when the plurality of rotor collars are fixed to the rotating shaft, the formation position of the protruding pieces of each rotor collar is set so as not to overlap with the axial direction of the rotating shaft. For example, when two rotor collars are fixed to the rotating shaft, the rotor collar protrusions are shifted in the axial rotation direction of the rotating shaft between the rotor collars. More specifically, when there are two projecting pieces, the formation position between the rotor collars may be a position rotated 180 degrees in the axial rotation direction of the rotary shaft. Further, if there are three projecting pieces, the position is similarly rotated by 60 degrees, and if there are four projecting pieces, the position is similarly rotated by 45 degrees. The fixed number of rotor collars depends on the height of the permanent magnet, but it is preferable to arrange at least two or more.

  Since the rotor body configured as described above is characterized in that the permanent magnet is frictionally fixed by bending and deforming the protruding piece of the rotor collar, an assembly jig for assembling the rotor body will also be described below.

  Such an assembly jig allows a permanent magnet to be coaxially arranged with a gap around the rotary shaft, and centers a jig for at least concentricity between the axis of the rotary shaft and the outer peripheral surface of the permanent magnet, and the centering jig. An avoidance hole that avoids interference with the rotating shaft disposed in the tool is formed in the center portion, and a cylindrical shape that presses the rotor collar to a predetermined position of the rotating shaft by abutting other than the projecting piece of the rotor collar and the avoiding hole. A press-fitting jig

  Further, in addition to the centering jig and the press-fitting jig, it is fitted on the press-fitting jig arranged at the outer peripheral position of the rotation shaft of the motor, and the entire press-fitting jig is used as a guide means to end the permanent magnet. You may comprise from the pushing jig | tool which contacts a part and pushes a permanent magnet in the arrangement position of the said centering jig.

  The assembly jig having such a configuration is used as follows. As an example of fixing means for the rotary shaft and the rotor collar, an example in which a pressure inlet for press-fitting the rotary shaft into the center of the rotor collar is opened will be described.

First, a rotating shaft and a permanent magnet are arranged at predetermined positions of a centering jig.
Next, the rotor collar with the projecting pieces extending in the radial direction is arranged so that a part of the front end side of the rotary shaft is inserted into the pressure inlet.
Thereafter, a press-fitting jig is brought into contact with a portion other than the projecting piece and the pressure inlet of the rotor collar, and the rotor collar is press-fitted into the rotating shaft through the press-fitting jig. After the rotary shaft passes through the pressure inlet portion, the rotor collar is pressed into the permanent magnet side while avoiding interference with the rotary shaft by the avoidance hole. At this time, the projecting piece of the rotor collar bends (plastically deforms) in the direction opposite to the pushing-in direction while following the generatrix direction of the inner peripheral surface of the permanent magnet.
When the rotor collar reaches a predetermined height with respect to the rotating shaft, the press-fitting jig is stopped and the press-fitting jig is taken out from the centering jig. At this time, the rotor collar fixes a predetermined position of the rotating shaft by press-fitting, and the plastically deformed projecting piece is caused by the elastic force exerted by the abutting portion and the elastic force that pushes the inner peripheral surface of the permanent magnet outward in the radial direction. It is fixed.
Then, while the next rotor collar is press-fitted with a press-fitting jig in the same manner as described above, the protruding piece is bent and deformed, the rotor collar is fixed in a multistage shape in the axial extension direction of the rotating shaft, and a plurality of rotating shafts and permanent magnets are provided. Integrated through the rotor collar.
When the press-fitting of the predetermined number of rotor collars is completed, the press-fitting jig is taken out from the centering jig, and finally the rotor body is taken out from the centering jig.

  In this assembly jig, the concentricity between the rotating shaft and the outer peripheral surface of the permanent magnet is determined in advance, and the protruding piece of the rotor collar is bent and deformed in accordance with the inner peripheral surface of the permanent magnet. For this reason, the rotor body can ensure good concentricity accuracy with respect to the rotating shaft and the permanent magnet, particularly the outer peripheral surface thereof.

  When a plurality of rotor collars are arranged in two or more stages and it is desired to set the bending deformation direction of the projecting pieces of the rotor collar in different directions, the rotor body can be assembled by the following method. .

  That is, a rotor body in which a rotary shaft, an arbitrary rotor collar, and a permanent magnet are integrated after a rotary shaft and a permanent magnet are arranged in a centering jig and press-fitting of an arbitrary rotor collar and bending deformation of a protruding piece are completed. Once removed from the centering jig, the top and bottom are repeated, and the rotor body thus repeated is placed on the centering jig again, and the next rotor collar is press-fitted through the press-fitting jig in the same manner as described above. The projecting piece is bent and deformed.

  Moreover, in addition to said centering jig | tool and a press-fit jig | tool, when using the pushing jig | tool for permanent magnets, it uses for as follows.

First, place the rotating shaft only at a predetermined position on the centering jig, and then place the rotor collar with the protruding piece extending in the radial direction so that the tip of the rotating shaft is partially inserted into the pressure inlet. To do.
Thereafter, a press-fitting jig is brought into contact with a portion other than the projecting piece and the pressure inlet of the rotor collar, and the rotor collar is press-fitted into the rotating shaft through the press-fitting jig. After the rotary shaft passes through the pressure inlet portion, the rotor collar is press-fitted to a predetermined position with respect to the rotary shaft while avoiding interference with the rotary shaft by the avoidance hole.
Next, the permanent magnet is disposed at a predetermined position of the centering jig while the press-fitting jig is placed at the above position. At this time, since the press-fitted rotor-collar projecting piece expands in the radial direction, the permanent magnet stops halfway.
The pushing jig is brought into contact with the upper end portion of the permanent magnet while being externally fitted to the pressing jig, and the permanent magnet is pushed into the centering jig side by using the entire pressing jig as a guide means. At this time, the protruding piece of the rotor collar starts to bend and deform in the pushing direction side by the lower end portion of the permanent magnet, and when further pushed, the protruding piece is bent (plastically deformed) following the inner peripheral surface of the permanent magnet.
Next, remove the press-fitting jig and push-in jig from the centering jig, and place the next rotor collar with the protruding piece extending in the radial direction so that a part of the tip side of the rotating shaft is inserted into the pressure inlet. To do.
Thereafter, a press-fitting jig is brought into contact with a portion other than the projecting piece and the pressure inlet of the rotor collar, and the rotor collar is press-fitted into the rotating shaft through the press-fitting jig.
After the rotating shaft passes through the pressure inlet, avoiding interference with the rotating shaft with the avoidance hole, the rotor collar is further press-fitted into the permanent magnet side, and the rotor collar protrusion is copied to the inner peripheral surface of the permanent magnet. And bending deformation (plastic deformation) in the direction opposite to the pushing direction.
When the rotor collar reaches a predetermined height with respect to the rotating shaft, the press-fitting jig is stopped and the press-fitting jig is taken out.
Finally, the rotor body is taken out from the centering jig.

  The rotor body of the present invention configured as described above has the following technical effects.

  That is, since the plurality of projecting pieces of the rotor collar abut against the inner peripheral surface of the permanent magnet with a resilient force due to the bending deformation, a frictional force is generated on each projecting piece and the inner peripheral surface. The collar and the permanent magnet can be fixed. As a result, it is possible to provide a rotor body in which the rotating shaft, the rotor collar, and the permanent magnet ensure sufficient integrity. In addition, an expensive and complicated fixing operation that has been necessary in the past is unnecessary, and the manufacturing cost of the entire stepping motor can be reduced.

  In addition, since the rotor body can be assembled by preliminarily setting the concentricity accuracy of the axis of the rotating shaft and the outer peripheral surface of the permanent magnet, and bending and deforming the rotor collar protrusion so as to conform to this, It is also easy to ensure accuracy and dimensional accuracy from the axial center of the rotating shaft on the outer peripheral surface of the permanent magnet.

It is a partially cutaway longitudinal cross-sectional view of the stepping motor provided with the rotor body of a present Example. It is a partially cutaway perspective view showing a rotor body of this example. It is a partially cutaway perspective view (A), (B) showing the rotor collar of the rotor body of the present embodiment. It is a partially cut away assembly perspective view showing the assembly jig for the rotor body of the present embodiment. It is explanatory drawing (A) which shows the usage method of the assembly jig for rotor bodies of a present Example (B). It is explanatory drawing (C), (D) which shows the usage method of the assembly jig for rotor bodies of a present Example.

  Hereinafter, the best embodiment of the rotor body of the present invention will be described with reference to the drawings.

  First, the reference symbol M is a stepping motor (hereinafter abbreviated as “motor”) having the rotor body 1 as an essential component.

  As shown in FIG. 1, the motor M of the present embodiment has a cylindrical stator S mainly arranged in a two-stage shape inside a motor case O of the motor M, and a rotor body 1 in a central internal space of the stator S. Is configured to be rotatably arranged with two bearings B.

  A part of the rotating shaft 2 protrudes from the motor case O to form an output portion 21 of the entire motor. The stator S has a two-layer structure in which a substantially cylindrical body around which the coil C is wound is stacked in two layers in the thickness direction, and has a cylindrical shape that forms a central internal space as a whole.

  Since the basic configuration of the motor M and the stator S is the same as that of the prior art, further detailed description is omitted.

Next, the rotor body 1 which is the main focus of the present invention will be described.
The rotor body 1 fixes two disk-like rotor collars 3 at a predetermined interval in the axial extension direction of the rotating shaft 2 that outputs the rotational force of the motor M, and further has a cylindrical shape on the outer edge portion of the rotor collar 3. The permanent magnet 4 is fixed coaxially to the rotary shaft 2, and the rotary shaft 2, the two rotor collars 3, and the permanent magnet 4 are integrated together.

  The rotor body 1 is disposed in the central internal space of the stator S so as to be rotatable with respect to the stator S by axially supporting both ends of the rotary shaft 2 by two upper and lower bearings B disposed in the motor case O. The

  The rotor collar 3 has a substrate 31 formed from a plated steel plate in a substantially disc shape that can be inserted into the permanent magnet 4, and a pressure inlet 32 that fixes the rotary shaft 2 in a press-fit state at the center of the substrate 31. Yes. Further, a thick boss portion 32 a is formed around the pressure inlet 32 of the substrate 31 on one side in order to improve the rigidity of the rotor collar 3 and ensure the press-fitting dimension with the rotary shaft 2.

  Further, on the outer edge portion of the substrate 31 of the rotor collar 3, three protrusions 33 which are thin on the boss formation side and protrude outward from the inner diameter dimension of the permanent magnet 4 are formed in three equal parts on the circumference. . The projecting piece 33 has a trapezoidal shape (or claw shape) whose outer side is short when viewed from above, and is plastically deformed by bending so as to follow the generatrix direction of the inner peripheral surface 42 of the permanent magnet 4 at the connection portion with the substrate 31. (Arrow a). Further, the three projecting pieces 33 have a resilient force (arrow b) that expands outward after the bending deformation and a frictional force that is exerted by a contact state with the inner peripheral surface 42 of the permanent magnet 4. 4 is fixed. Further, the protrusion 33 forms a stress concentration portion by making it thin, and the bending deformation of the protrusion 33 from the substrate 31 is facilitated by increasing the concentration of bending stress.

  In the rotor body 1 of this embodiment, two rotor collars 3 are arranged in two stages in the axial extension direction of the rotary shaft 2, but the position of the projecting piece 33 is the rotary shaft for each rotor collar. The entire rotor collar is rotated and fixed so as to be at a position that does not overlap in the axial direction of 2, specifically, at a position shifted by 60 degrees with respect to the axial rotation direction of the rotary shaft 1.

  The permanent magnet 4 fixed to the outer edge portion of the rotor collar 3 is made of ferrite, alnico, samarium cobalt having an appropriate rigidity capable of withstanding the elastic force at the time of bending deformation of the protruding piece 33 of the rotor collar 3 and the frictional force after deformation. It is composed of a sintered material appropriately selected from neodymium.

  The permanent magnet 4 has a cylindrical shape from an inner peripheral surface 42 that is frictionally fixed to the rotor collar 3 and an outer peripheral surface 41 in which a magnetization area of SN poles is alternately formed in the circumferential direction and continuously at a predetermined pitch. It is formed as follows.

  When the outer peripheral surface 41 of the permanent magnet 4 forms the rotor body 1 and is disposed in the central internal space of the stator S, it faces each magnetic pole (not shown) of the yoke of the stator S with a predetermined gap (gap).

  The rotor body 1 of the present embodiment has the above configuration, but the configuration may be changed as follows.

  That is, the rotor collar 3 for fixing the permanent magnet 4 is not limited to the two-stage arrangement with respect to the rotating shaft 2, and may be one, three, or more depending on the specifications of the motor M (for example, required torque). The arrangement may be changed as appropriate.

  In addition, the protrusion 33 of the rotor collar 3 of the above-described embodiment is used to secure an area for exerting a frictional force on the inner peripheral surface 42 of the permanent magnet 4 after plastic deformation by bending and a so-called meat escape space during bending deformation. Although the above trapezoidal shape is formed and the number is three, it is not limited to this shape. That is, as long as the area that exerts the frictional force capable of fixing the permanent magnet 4 and the deformation clearance space after the deformation can be secured, the shape can be appropriately changed to a rectangle, a triangle, and a semicircle, and the number thereof can be changed as appropriate. It may be increased or decreased. Further, as the stress concentration portion of the protruding piece 33, not only the entire protruding piece is made thin, but a groove may be formed between the protruding piece 33 and the substrate 31.

  As for the material of the rotor collar 3, since the protruding piece 33 and the boss portion 32 a can be easily formed by pressing or burring, a plated steel plate that can be easily processed is adopted. However, the material is not limited to this material. Absent. That is, the material of the rotor collar 3 may be another metal material such as aluminum as long as it has predetermined rigidity and has predetermined properties of plastic deformation, elastic deformation, and friction coefficient.

  Further, in order to prevent the rotor collar 3 and the permanent magnet 4 from being displaced during rotation, in addition to the protruding piece 33 of the rotor collar 3, for example, both the outer edge portion of the rotor collar 3 and the inner peripheral surface 42 of the permanent magnet 4 are provided. It is good also as a structure which forms the uneven | corrugated | grooved part which mutually fits previously and engages this (illustration omitted).

  Since the rotor body 1 of the present embodiment is characterized in that the protrusion 33 of the rotor collar 3 is bent and deformed and the permanent magnet 4 is frictionally fixed, an embodiment of a specific assembly jig 5 for assembling the rotor body 1 Will also be described below.

  The assembly jig 5 of the present embodiment is mainly composed of three elements: a centering jig 51, a press-fit jig 52 that can be partially inserted into the centering jig 51, and a pressing jig 53. .

  First, the centering jig 51 has a substantially low cylindrical shape into which the entire permanent magnet 4 can be inserted. The centering jig 51 has a shaft hole 51a in which the rotary shaft 2 is erected and disposed at the center, and a part of the shaft hole 51a is formed around the shaft hole 51a. Is formed by forming a flat contact surface 51c that protrudes from the bottom surface portion 51b.

  The contact surface 51c is formed in a circular shape having substantially the same area as the substrate 31 excluding the protrusions 33 of the rotor collar 3. On the other hand, the bottom surface portion 51b of the centering jig 51 presents a ring-shaped groove that can be erected by inserting one end surface side of the permanent magnet 4 by forming the contact surface 51c.

  The centering jig 51 can center the concentricity between the axis of the rotating shaft 2 and the outer peripheral surface 41 of the permanent magnet when the rotating shaft 2 and the permanent magnet 4 are arranged, and the axis of the rotating shaft 2 and the permanent magnet. The dimensional accuracy in the radial direction with respect to the outer peripheral surface 41 of 4 is ensured. In addition to the above dimensions, the position of the permanent magnet 4 in the axial direction with respect to the rotary shaft 2 is also set.

  The press-fitting jig 52 is formed in a substantially cylindrical shape that can be inserted with a predetermined gap on the inner side of the permanent magnet 4 arranged in the centering jig 51. The press-fitting jig 52 has an avoidance hole 52a that avoids interference with the rotating shaft 2 disposed in the centering jig 51 at the center thereof, and is formed on one end side (lower side of the drawing) of the rotor collar 3. A press-fit surface 52b that can be brought into contact with the substrate 31 excluding the press-in port 32 is formed, and a relief hole 52c is formed by further expanding the periphery of the avoidance hole on the press-fit surface side. The press-fitting surface 52 b has substantially the same area as the contact surface 51 c of the centering jig 51.

  The pushing jig 53 is formed in a substantially cylindrical shape having a flange portion 53c having one end side having substantially the same diameter as the permanent magnet 4 and the other end side having a diameter larger than that. Further, the pushing jig 53 is formed with a guide hole 53a through which the entire press-fitting jig 52 is fitted as a guide means at the center thereof, and the end on the opposite side of the flange (the lower side in the drawing) of the permanent magnet 4 is formed. A pushing surface 53b that can contact the upper end portion is formed.

  The assembly jig 5 having such a configuration can be used in the following manner to assemble the rotor body 1 of this embodiment.

  First, the centering jig 51 is placed on the flat plate surface, and the rotary shaft 2 is arranged upright in the shaft hole 51a.

  Next, the rotor collar 3 in a state in which the protruding piece 33 is expanded in the radial direction is arranged so that a part of the upper end portion of the rotary shaft 2 is inserted into the pressure inlet 32 on the opposite side of the boss portion 32a.

  After the arrangement of the rotor collar 3, the press-fitting surface 52 b of the press-fitting jig 52 is brought into contact with the substrate 31 excluding the press-in inlet 32, and the rotor collar 3 is press-fitted into the rotary shaft 2 through the press-fitting jig 52. At this time, since the relief hole 52c is formed in the press-fitting jig 52, interference between the boss portion 32a and the press-fitting surface 52b is avoided.

  After the rotary shaft 2 has passed through the pressure inlet portion, interference with the rotary shaft 2 is avoided by the avoidance hole 52a, and the rotor collar 3 is pressed into the centering jig side (arrow c). Is pressed against the contact surface 51c of the centering jig 51 and stopped. At this time, the protruding piece 33 of the rotor collar 3 protrudes outward from the contact surface 51 c of the centering jig 51.

  Next, the permanent magnet 4 is disposed on the centering jig 51 while maintaining the pressing force at the time of press-fitting at the position of the press-fitting jig 52. At this time, since the protruding piece 33 of the rotor collar 3 is expanded in the radial direction, the lower end portion of the permanent magnet 4 is caught by the protruding piece 33 and stops in the middle.

  Thereafter, the pushing jig 53 is used as a guide means by fitting the guide hole 53a to the press fitting jig 52, and is pushed into the centering jig side while pressing the pushing surface 53b against the upper end side of the permanent magnet 4. (Arrow d). At this time, the projecting piece 33 of the rotor collar 3 starts to bend and deform in the pushing direction by the lower end portion of the permanent magnet 4, and is further bent and plastically deformed while following the inner peripheral surface 42 by further pushing. On the other hand, since the substrate 31 of the rotor collar 3 maintains the pressing force of the press-fitting jig 52, the lifting from the contact surface 51c of the centering jig 51 is suppressed.

  Next, both the press-fitting jig 52 and the pushing jig 53 are extracted from the centering jig 51 (arrow e), and the next rotor collar 3 with the protruding pieces 33 extending in the radial direction is used as the pressure inlet 32 on the boss portion side. It arrange | positions so that the upper end part of the rotating shaft 2 may insert partially. At this time, the position of the projecting piece 33 of the rotor collar 3 is shifted from the projecting piece 33 of the previous rotor collar 3 by a predetermined angle (60 degrees in this embodiment) in the rotation direction of the rotary shaft 2 so as not to overlap vertically. To do.

  After the arrangement of the rotor collar 3, the press-fitting surface 52 b of the press-fitting jig 52 is brought into contact with the substrate 31 other than the pressure inlet 32 and the projecting piece 33, and the rotor collar 3 is press-fitted into the rotary shaft 2 through the press-fitting jig 52. .

  After the rotary shaft 2 passes through the pressure inlet portion of the rotor collar 3, the rotor collar 3 is further press-fitted into the permanent magnet side while avoiding interference with the rotary shaft 2 through the avoidance hole 52a (arrow f). By this press-fitting, the protruding piece 33 of the rotor collar 3 starts to bend and deform by the upper end surface of the permanent magnet 4, and further bends (plastically deforms) in the direction opposite to the pushing direction while following the inner peripheral surface 42 thereof.

  When the press-fitting distance of the press-fitting jig 52 reaches a predetermined height with respect to the rotary shaft 2, the press-fitting of the press-fitting jig 52 is stopped and the press-fitting jig 52 is taken out from the rotary shaft 2.

  Finally, the rotor body 1 in which the rotating shaft 2, the two rotor collars 3 and the permanent magnet 4 are integrated is taken out from the centering jig 51. The rotor body 1 assembled by the assembly jig 5 is concentric with the outer peripheral surface 41 of the rotary shaft 2 and the permanent magnet 4 in advance, and the protrusion 33 of the rotor collar 3 is bent and deformed accordingly. Therefore, not only good concentricity accuracy can be ensured for the outer peripheral surface 41 of the rotating shaft 2 and the permanent magnet 4, but also the dimensional accuracy of the outer peripheral surface 41 of the permanent magnet 4 from the axial center of the rotating shaft 2 can be ensured. Yes.

DESCRIPTION OF SYMBOLS 1 Rotor body 2 Rotating shaft 21 Output part 3 Rotor collar 31 Substrate 32 Pressure inlet 32a Boss part 33 Projection piece 4 Permanent magnet 41 Outer peripheral surface 42 Inner peripheral surface 5 Assembly jig 51 Centering jig 51a Shaft hole 51b Bottom surface part 51c Contact surface 52 Press-fitting jig 52a Avoidance hole 52b Press-fitting surface 52c Relief hole 53 Push-in jig 53a Guide hole 53b Push-in surface 53c Flange part M Motor S Stator C Coil B Bearing O Motor case

Claims (4)

A rotating shaft that is rotatably held in the motor case;
One or a plurality of plate-like rotor collars fixed vertically to the rotating shaft with its center portion;
Cylindrical permanent magnets that are circularly held and held coaxially with the rotary shaft via the rotor collar and are alternately formed with different polarity magnetized regions along the circumferential surface;
In the rotor body composed of
The rotor collar is composed of a substrate insertable shape into a cylinder of the permanent magnet, and two or more projecting pieces formed by projecting the outer diameter side than the cylindrical inner diameter of the permanent magnet from the substrate, projecting A rotor body, wherein a piece is bent and deformed and fixed to a cylindrical inner peripheral surface of a permanent magnet by friction.   The rotor body according to claim 1, wherein the rotor collar is formed with a stress concentration portion that is easily bent and deformed from the substrate on the projecting piece.   The rotor body according to claim 1 or 2, wherein the formation position of the protruding piece of the rotor collar is a position opposed to the center of the substrate or a multipoint position equivalent to the circumference.   4. When fixing a plurality of rotor collars to a rotary shaft, the formation positions of the projecting pieces of each rotor collar are set so as not to overlap with the axial direction of the rotary shaft. The rotor body described.

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