JP2020048243A - Motor and manufacturing method of the same - Google Patents

Abstract

To provide a motor capable of suppressing interference of a rotor and an armature and improving production efficiency in a manufacturing process and to provide a manufacturing method of the motor.SOLUTION: The motor M comprises: a cylindrical armature E having a coil 1; a rotor R which is rotatably inserted into the armature E and has a magnet 3 facing the armature E; a cylindrical first housing H1 which has an insertion hole 7 for allowing insertion of the rotor R and a positioning section 8 for positioning the armature E in an axial direction, rotatably supports one end of the rotor R and to which an outer periphery of a side of one end e1 in the axial direction of the armature E is press-fitted inward; and a second housing H2 which is press-fitted to an outer periphery on a side of an other end e2 in the axial direction of the armature E and rotatably supports the other end of the rotor R.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor and a method for manufacturing the motor.

  The motor generally includes a cylindrical armature, a rotor rotatably inserted into the armature, and a housing that houses the armature and the rotor. The housing holds one bearing rotatably supporting both ends in the axial direction of the rotor, thereby ensuring smooth rotation of the rotor. The armature is housed and fixed in the housing by press fitting or shrink fitting.

  Here, there may be a case where it is desired to divide the housing in the axial direction for manufacturing reasons or the like. When the housing is divided into the first housing and the second housing in this way, it is necessary to hold the bearing on one end of the rotor in the first housing and hold the bearing on the other end of the rotor in the second housing. . In such a case, if the coaxiality of the first housing and the second housing is out of alignment, the rotor may be eccentric or inclined with respect to the armature, and the performance of the motor may be deteriorated.

  Accordingly, a motor has been developed in which one end of the armature in the axial direction is housed and fixed in the second housing by shrink fitting or press-fitting, and then the other end of the armature in the axial direction is pressed into the inside of the first housing ( For example, see Patent Document 1).

  In the motor configured as described above, the first housing and the second housing are positioned in the radial direction with reference to the armature, so that the coaxiality between the first housing and the second housing is improved, and the armature of the rotor is improved. Eccentricity and inclination can be suppressed.

JP 2008-17565 A

  However, in the conventional motor, the armature is housed and fixed in the second housing in advance by shrink fitting or press fitting, and after the rotor is mounted on the first housing, the armature is inserted into the opening of the first housing with the rotor mounted. It is manufactured through a step of press-fitting the armature housed in the two housings.

  When manufacturing the motor in this manner, in the step of press-fitting the armature into the first housing, it is necessary to insert an unstable rotor cantilevered in the second housing into the armature. The posture cannot be visually recognized from outside.

  The gap between the rotor and the armature in the motor is extremely narrow, and in the process of press-fitting the armature into the first housing, it cannot be confirmed even if the rotor is tilted, and the magnet mounted on the outer periphery of the rotor is damaged by the armature. The production efficiency is also deteriorated due to the need for careful work by the workers.

  Therefore, an object of the present invention is to provide a motor and a method for manufacturing a motor that can suppress interference between a rotor and an armature in a manufacturing process and can improve production efficiency.

  In order to achieve the above object, a motor includes a cylindrical armature having a coil, a rotor having a magnet rotatably inserted in the armature and facing the armature, and a cylindrical, armor-inserted rotor. A first housing having a through hole for allowing the pressure and a positioning portion for positioning the armature in the axial direction, rotatably supporting one end of the rotor, and press-fitting an outer periphery of one end in the axial direction of the armature inward. And a second housing press-fit into the outer periphery of the armature at the other axial end and rotatably supporting the other end of the rotor. In the motor configured as described above, the armature is press-fitted and the first housing having the positioning portion for positioning the armature in the axial direction is provided with the rotor insertion hole. After being assembled to one housing, the second housing can be pressed into the outer periphery of the armature. Since the motor can be manufactured in such a process, it is possible to assemble using a shim that prevents interference between the magnet of the rotor and the armature when the rotor is inserted into the armature.

  Also, the method for manufacturing a motor includes a cylindrical armature having a coil, a rotor having a magnet rotatably inserted in the armature and facing the armature, and a cylindrical and allowing insertion of the rotor. A first housing having an insertion hole and a positioning portion for positioning the armature in the axial direction, into which the outer periphery of one end in the axial direction of the armature is press-fitted, and A second housing into which the other end of the armature in the axial direction is press-fitted, wherein the rotor is inserted into the armature after press-fitting one axial end of the armature in the first housing. The two housings are pressed into the other end of the armature in the axial direction. According to the motor manufacturing method, it is possible to assemble using a shim that prevents interference between the magnet of the rotor and the armature when the rotor is inserted into the armature.

  The motor may include an annular seal ring mounted on the first housing to seal the inside of the first housing. In the motor configured as described above, the rotor and the seal ring are coaxially aligned with respect to the first housing. Therefore, even when the motor is applied to a hydraulic device such as a pump, the inside of the motor can be sealed tightly. .

  Further, the motor may include a pump housed in the first housing and having an output shaft connected to the rotor. According to the motor configured as described above, the assembling process of the motor is easy even if the pump is provided.

  Further, the motor may include a sensor that is held by the second housing and detects a position of the rotor. According to the motor configured as described above, the sensor is provided in the second housing to which the driven device is not connected, not the first housing in which the insertion hole for connecting the rotor to the driven device is provided. Wiring can be easily arranged.

  ADVANTAGE OF THE INVENTION According to the motor and the manufacturing method of a motor of this invention, interference between a rotor and an armature can be suppressed in a manufacturing process, and production efficiency can be improved.

It is a longitudinal section of the motor in one embodiment. FIG. 5 is a diagram illustrating a manufacturing procedure of the motor according to the embodiment.

  Hereinafter, the present invention will be described based on the embodiment shown in the drawings. As shown in FIG. 1, a motor M according to an embodiment includes a cylindrical armature E having a coil 1 and a rotor having a magnet 3 rotatably inserted into the armature E and facing the armature E. R, a first housing H1 having a cylindrical shape and one end in the axial direction e1 of the armature E being press-fitted inward, and a second housing H2 being press-fitted in the outer circumference on the other end e2 side in the axial direction of the armature E. It is provided with.

  Hereinafter, each part of the motor M will be described in detail. First, the armature E includes a cylindrical core 2 having a slot (not shown) inside, and a coil 1 wound in the slot of the core 2. It is covered with resin.

  The rotor R includes an output shaft 4 and a plurality of magnets 3 mounted on the outer periphery of the output shaft 4 and is rotatably inserted into the armature E. 1 is rotatably supported by a first bearing 5 held by a first housing H1, and the other end of the output shaft 4 which is an upper end in FIG. It is rotatably supported by a second bearing 6 held by the housing H2. That is, the lower end in FIG. 1 that is one end of the rotor R is rotatably supported by the first housing H1, and the upper end in FIG. 1 that is the other end of the rotor R is rotatably supported by the second housing H2. . Therefore, the rotor R can rotate around the axis of the output shaft 4 with respect to the armature E. The output shaft 4 is provided with a hole 4a which opens from one end, which is the lower end in FIG. 1, and extends toward the other end, and a serration groove 4b is provided on the inner periphery of the hole 4a. . A small diameter portion 4c is provided at the other end, which is the upper end in FIG. 1, of the output shaft 4, and a resolver rotor 24 is mounted on the small diameter portion 4c.

  The first housing H1 has a cylindrical shape, an insertion hole 7 that allows the insertion of the rotor R, a positioning portion 8 that positions the armature E in the axial direction, and an inner end e1 side of the armature E inward. And a press-fit portion 9 at one end side into which the lower end in FIG. 1 is press-fitted. More specifically, the first housing H1 has an inner diameter smaller than that of the one-side press-fit portion 9 connected to the one-side press-fit portion 9 for accommodating the armature E from above in FIG. There is provided a small-diameter portion 10 forming the insertion hole 7 and a pump housing portion 11 having an inner diameter larger than the small-diameter portion 10 and connected to the lower end of the small-diameter portion 10 in FIG.

  In the first housing H1 of the present embodiment, a positioning portion 8 which is in contact with the lower end in FIG. 1 of the armature E is formed at a step between the one end side press-fit portion 9 and the small diameter portion 10. The axial length of the one end side press-fit portion 9 is shorter than the armature E. The insertion hole 7 is formed by a space inside the small-diameter portion 10, and an annular first bearing 5 that supports one end of the output shaft 4 of the rotor R is provided on the inner circumference of the small-diameter portion 10. An annular seal ring 12 and a pump bearing 19 which are arranged closer to the pump housing portion 11 than the first bearing 5 are mounted. Note that the first bearing 5 is a ball bearing, and smooth rotation of the output shaft 4 with respect to the armature E and the first housing H1 is guaranteed.

  The insertion hole 7 in the first housing H1 is an opening for connecting the output shaft 4 of the rotor R to a driven device driven by the power of the motor M, in this embodiment, a piston pump 13 described later.

  Then, the armature E configured as described above is inserted into the one-side press-fitting portion 9 of the first housing H1 until one axial end e1 at the lower end in FIG. When the armature E is housed in the one-end press-fitting portion 9 in the first housing H1, the armature E is tightened with a tightening force to the one-end press-fit portion 9, so that the armature E is fixed to the first housing H1. You. The armature E contacts the first housing H1 in a state where the lower end in FIG. 1 abuts on a positioning portion 8 formed of a step provided on the first housing H1 and is axially positioned with respect to the first housing H1. Housing and fixed.

  Further, a piston pump 13 as a pump is housed in the pump housing portion 11 of the first housing H1. The piston pump 13 includes a drive shaft 14 connected to the output shaft 4 of the rotor R, a cylinder block 15 connected to the outer periphery of the drive shaft 14 and having a plurality of cylinder holes 15a formed in the axial direction, A valve plate 16 having a port 16a and a port 16b in sliding contact with one end of the cylinder block 15, a plurality of pistons 17 inserted into the respective cylinder holes 15a from the other end of the cylinder block 15, and rotation of the cylinder block 15; And a swash plate 18 on which the base end of the piston 17 slides.

  It is inserted inside the small diameter portion 10 of the first housing H1 and connected to the output shaft 4. More specifically, a serration shaft 14a is provided at the tip of the drive shaft 14, which is inserted into the hole 4a of the output shaft 4 and meshes with and engages with the serration groove 4b. Can be transmitted to When the drive shaft 14 is inserted into the small diameter portion 10, the drive shaft 14 is also inserted into the seal ring 12 and the pump bearing 19 held on the small diameter portion 10 of the first housing H <b> 1, and Be linked. Therefore, the space between the drive shaft 14 and the first housing H1 is sealed by the seal ring 12, and the leakage of the hydraulic oil on the piston pump 13 side to the armature E side is prevented. This prevents the hydraulic oil from entering the motor M. Further, since the drive shaft 14 is rotatably supported by the pump bearing 19, smooth rotation with respect to the first housing H1 is guaranteed.

  When the drive shaft 14 is rotationally driven by the rotational drive of the rotor R of the motor M, the cylinder block 15 rotates and the piston 17 enters and exits the cylinder hole 15a. Thereby, the piston pump 13 sucks the hydraulic oil from one of the ports 16a and 16b and discharges it to the other according to the rotation direction of the drive shaft 14. In the present embodiment, the pump is the piston pump 13, but another pump such as a gear pump may be housed in the pump housing 11.

  The second housing H2 has a bottomed cylindrical shape, and has the other end side press-fitting portion 20 into which the outer periphery at the upper end side in FIG. In the present embodiment, when the second housing H2 is pressed into the outer periphery of the armature E on the side of the other end e2 in the axial direction, the second housing H2 comes into contact with the open end of the first housing H1 and closes the open end of the first housing H1. . The second housing H2 includes a bottomed cylindrical inner cylinder portion 21 that holds the outer periphery of the second bearing 6 that rotatably supports the other end of the output shaft 4 of the rotor R, and an outer cylinder provided on the outer periphery of the inner cylinder portion 21. 1, an annular flange portion 23 connecting the inner cylinder portion 21 and the outer cylinder portion 22, and an outer periphery protruding downward from the outer periphery of the outer cylinder portion 22 in FIG. And an annular other-side press-fitting portion 20 that is press-fitted into the housing. In addition, the lower end in FIG. 1, which is the armature side end of the inner cylindrical portion 21, protrudes more toward the armature than the lower end in FIG. 1, which is the armature side end of the other end side press-fitting portion 20.

  A resolver stator 25 is mounted on the inner periphery of the inner cylindrical portion 21 of the second housing H2, which is disposed closer to the armature side than the second bearing 6 is. 1 until the lower end in FIG. 1 of the other end side press-fitting portion 20 and the upper end in FIG. 1 of the one end side press-fitting portion 9 of the first housing H1 come into contact with each other. Is inserted into the other end side press-fitting portion 20 and press-fitted, the other end side press-fitting portion 20 tightens the armature E, and the armature E is fixed to the second housing H2. Therefore, the first housing H1 and the second housing H2 are fixed to the armature E and integrated with each other to house the armature E inside. Further, when the second housing H2 is connected to the first housing H1 via the armature E, the second housing H2 closes the open end at the upper end in FIG. 1 of the first housing H1. As described above, the second housing H2 is connected to the first housing H1 via the armature E in a state of contacting the first housing H1, so that the second housing H2 is axially positioned with respect to the first housing H1. When the first housing H1 and the second housing H2 are integrated via the armature E, the positioning portion 8 of the first housing H1 facing the armature E and the flange portion of the second housing H2. Since the length up to 23 is longer than the axial length of the armature E, the flange portion 23 of the second housing H2 does not interfere with the armature E.

  The other end of the output shaft 4 is inserted into the second bearing 6 and inserted into the inner cylindrical portion 21 of the second housing H2. The resolver rotor 24 provided at the other end of the output shaft 4 faces a resolver stator 25 mounted on the inner periphery of the inner cylindrical portion 21 of the second housing H2 via an annular gap. A resolver Rs for detecting the position in the rotational direction of the resolver Rs. Therefore, in the motor M of the present embodiment, the sensor for detecting the position of the rotor R is the resolver Rs, but a sensor other than the resolver Rs may be used as the sensor.

  The motor M is configured as described above. When the coil 1 of the armature E is energized and the output shaft 4 is driven to rotate in a desired direction, power in the rotation direction is transmitted to the drive shaft 14 of the piston pump 13. Then, the drive shaft 14 is rotationally driven. Therefore, when the motor M is driven, the piston pump 13 is driven.

  In order to assemble the motor M configured as described above, the following is performed. First, the first bearing 5, the second bearing 6, and the resolver rotor 24 are previously assembled to the output shaft 4 of the rotor R and assembled to obtain a rotor assembly.

  Further, the armature E is attached to the first housing H1. More specifically, the armature E is press-fitted into the press-fit portion 9 on one end side of the first housing H1 until the first housing H1 comes into contact with the positioning portion 8 from the one end e1 side at the lower end in the axial direction. Into a first housing H1 to obtain a housing assembly.

  The rotor assembly is incorporated into the housing assembly assembled in this manner. At this time, as shown in FIG. 2, a cylindrical shim S is inserted into the inner periphery of the armature E in the housing assembly. The shim S is formed of a non-magnetic material, has an outer diameter that can be fitted to the inner periphery of the armature E, and has an inner diameter larger than the maximum outer diameter of the rotor R. With the shim S inserted into the armature E, the rotor assembly is inserted into the housing assembly, and the first bearing 5 of the rotor assembly is fitted to the inner periphery of the small diameter portion 10 of the first housing H1. Thereafter, the shim S is removed from the gap between the rotor R and the armature E.

  As described above, when the rotor assembly is assembled to the housing assembly, the rotor assembly is inserted into the shim S, so that the magnet 3 provided on the rotor R does not interfere with the armature E. Therefore, the magnet 3 can be protected from the armature E when the motor M is assembled, so that the magnet 3 can be prevented from being damaged, the assembling work is facilitated, and the manufacturing efficiency is improved.

  Then, after assembling the rotor housing to the housing assembly, the other end side press-fitting portion 20 of the second housing H2 is press-fitted to the outer periphery of the armature E on the other end side in the axial direction e2. In the press-fitting step of the second housing H2, the other end side press-fitting portion 20 is press-fitted to the outer periphery of the armature E while the other end of the rotor R is inserted into the inner cylinder portion 21 of the second housing H2. Since the rotor R projects from the armature E toward the second housing H2 due to the structure inserted into the second bearing 6 held by the second housing H2, the rotor R is inserted into the inner cylindrical portion 21. This operation can be performed easily while visually recognizing the position of the rotor R. Further, in the present embodiment, since the armature side end of the inner cylindrical portion 21 protrudes toward the armature side from the armature side end of the other end side press-fitting portion 20, the other end side press-fitting portion 20 is fitted to the armature E. The rotor R can be inserted into the inner cylinder portion 21 before the engagement. Therefore, in the operation of inserting the rotor R into the inner cylinder portion 21, the position of the rotor R can be visually recognized from the outside, so that the operation of assembling the second housing H2 to the housing assembly and the rotor assembly is further facilitated.

  As described above, the motor M of the present invention includes the cylindrical armature E having the coil 1, the rotor R having the magnet 3 rotatably inserted into the armature E and facing the armature E, It has an insertion hole 7 that allows the insertion of the rotor R and a positioning portion 8 that positions the armature E in the axial direction, rotatably supports one end of the rotor R, and has the armature E inward. A first housing H1 into which one end e1 in the axial direction is press-fitted, and a second housing H2 press-fit into the outer periphery on the other end e2 in the axial direction of the armature E and rotatably support the other end of the rotor R are provided. It is configured.

  In the motor M configured as described above, the insertion hole 7 of the rotor R is provided in the first housing H1 having the positioning portion 8 for press-fitting the armature E and positioning the armature E in the axial direction. After assembling the armature E and the rotor R to the first housing H1, the second housing H2 can be pressed into the outer periphery of the armature E. In the motor M of the present invention, since the motor M can be manufactured in such a process, the shim S for preventing interference between the magnet 3 of the rotor R and the armature E when the rotor R is inserted into the armature E is used. Assembly becomes possible. Further, in the motor M of the present invention, when inserting the rotor R into the armature E, the shim S can be used, and when the second housing H2 is pressed into the armature E, the position of the rotor R is changed. Since it is visible, the assembling process is very simple and the production efficiency of the motor M is improved. Therefore, according to the motor M of the present invention, it is possible to suppress the interference between the armature E and the rotor R in the manufacturing process and improve the production efficiency.

  Further, the method for manufacturing the motor M according to the present invention includes a cylindrical armature E having the coil 1, a rotor R having a magnet 3 rotatably inserted into the armature E and facing the armature E; A first housing having an insertion hole 7 for allowing insertion of the rotor R and a positioning portion 8 for positioning the armature E in the axial direction, and into which the one end e1 of the armature E in the axial direction is press-fitted inward. A method for manufacturing a motor M, comprising: a first housing H1; and a second housing H2 having a bottomed cylindrical shape and into which the other end e2 of the armature E in the axial direction is press-fitted. After press-fitting E, the rotor R is inserted into the armature E, and the second housing H2 is press-fitted to the outer periphery of the armature E.

  According to the method of manufacturing the motor M of the present invention, it is possible to assemble using the shim S for preventing interference between the magnet 3 of the rotor R and the armature E when the rotor R is inserted into the armature E. Further, in the method of manufacturing the motor M of the present invention, the shim S can be used when the rotor R is inserted into the armature E, and the rotor R is pressed when the second housing H2 is pressed into the armature E. Since the position is visible, the assembling process is very simple, and the production efficiency of the motor M is improved. Therefore, according to the method of manufacturing the motor M according to the present invention, it is possible to suppress the interference between the armature E and the rotor R in the manufacturing process and improve the production efficiency.

  On the other hand, in the conventional motor, the armature is housed and fixed in advance in the second housing having no insertion hole through which the rotor is inserted, and after the rotor is mounted on the first housing, the second housing in the state where the rotor is mounted is mounted. The armature accommodated in the second housing is pressed into the opening of one housing. In the conventional motor, since the first housing does not have a positioning function for positioning the armature in the axial direction, the armature cannot be assembled in the first housing in advance. Therefore, in the conventional motor manufacturing process, the insertion of the rotor into the armature must be performed in the process of integrating the first housing and the second housing, and when a shim is inserted between the armature and the rotor. You will not be able to remove the shim. That is, in the structure of the conventional motor, no measures can be taken to avoid interference between the armature and the rotor during assembly.

  Note that, in the motor M of the present embodiment, the armature side end of the inner cylindrical portion 21 that holds the second bearing 6 in the second housing H2 projects more toward the armature side than the armature side end of the other end side press-fit portion 20. Therefore, the rotor R can be inserted into the inner cylindrical portion 21 before the other end side press-fit portion 20 is fitted to the armature E. Therefore, in the operation of inserting the rotor R into the inner cylinder portion 21, the position of the rotor R can be visually recognized from the outside, so that the operation of assembling the second housing H2 to the housing assembly and the rotor assembly is further facilitated.

  Further, in the motor M of the present embodiment, the second housing H2 abuts on the open end of the first housing H1 to close the open end of the first housing H1, and the other end of the second housing H2 The contact between the axial end surface of the side press-fitting portion 20 and the axial end surface of the one-side press-fitting portion 9 of the first housing H1 positions each other in the axial direction. Since the length from the positioning portion 8 of the first housing H1 facing the armature E to the flange portion 23 of the second housing H2 is longer than the axial length of the armature E, the armature E of the second housing H2 is Unnecessary axial force of the armature E is not applied at the time of press-fitting to the armature, and the armature E can be protected. Note that a structure in which the first housing H1 and the second housing H2 do not come into contact with each other can also be adopted.

  Further, the motor M of the present embodiment includes the annular seal ring 12 mounted on the first housing H1 to seal the inside of the first housing H1. In the motor M configured as described above, the rotor R and the seal ring 12 are coaxially aligned with respect to the first housing H1. Therefore, even when the motor M is applied to a hydraulic device such as a pump, the motor M is densely packed. The inside of the motor M can be sealed.

  Further, the motor M of the present embodiment includes a piston pump (pump) 13 housed in the first housing H1 and having the output shaft 4 connected to the rotor R. In the motor M configured as described above, the piston pump (pump) 13 is housed in the first housing H1. Therefore, the piston pump (pump) 13 can be integrated with the motor M, and the piston pump (pump) 13 The drive shaft 14 and the rotor R can be coaxially aligned with the first housing H1. Therefore, in the motor M configured as described above, even if the piston M is provided, the assembling process of the motor M becomes easy.

  Further, the motor M of the present embodiment includes a resolver (sensor) Rs that is held by the second housing H2 and detects the position of the rotor R. According to the motor M configured as described above, the driven device is not connected, not the first housing H1 in which the insertion hole 7 for connecting the rotor R to the driven device (in this case, the piston pump 13) is provided. Since the resolver (sensor) Rs is provided in the second housing H2, the wiring of the resolver (sensor) Rs is facilitated.

  Note that the shape and structure of the first housing H1 are the same as those described above, as long as the first housing H1 includes the insertion hole 7 that enables the connection of the rotor R to the driven device and the positioning portion 8 that positions the armature E in the axial direction. It is not limited to shape and structure. The second housing H2 also needs to be press-fitted to the outer periphery of the armature E on the side of the other end e2 in the axial direction, and the shape and structure described above are merely examples, and the shape and structure can be appropriately changed in design.

  The present invention can be applied to a generator, and can be used for manufacturing a generator.

  As described above, the preferred embodiments of the present invention have been described in detail, but modifications, variations, and changes can be made without departing from the scope of the claims.

DESCRIPTION OF SYMBOLS 1 ... coil, 3 ... magnet, 7 ... insertion hole, 8 ... positioning part, 12 ... seal ring, 13 ... piston pump (pump), 14 ... drive shaft,
E: armature, e1: one end in the axial direction of the armature, e2: the other end in the axial direction of the armature, H1: first housing, H2: second housing, M ... Motor, R: rotor, Rs: resolver (sensor)

Claims (5)

A cylindrical armature having a coil,
A rotor having a magnet rotatably inserted into the armature and facing the armature,
It has a through hole that is cylindrical and allows the rotor to pass therethrough, and a positioning portion that positions the armature in the axial direction, and rotatably supports one end of the rotor and moves the electric motor inward. A first housing into which the outer periphery of one end in the axial direction of the child is press-fitted,
A second housing that is press-fitted into the outer periphery of the armature at the other end in the axial direction and rotatably supports the other end of the rotor. The motor according to claim 1, further comprising an annular seal ring mounted on the first housing to seal the inside of the first housing. The motor according to claim 2, further comprising a pump housed in the first housing and having a drive shaft connected to the rotor. 4. The motor according to claim 1, further comprising a sensor that is held by the second housing and detects a position of the rotor. 5. A cylindrical armature having a coil, a rotor having a magnet rotatably inserted into the armature and facing the armature, an insertion hole which is cylindrical and allows insertion of the rotor, and A first housing having a positioning portion for positioning the armature in the axial direction and having an outer circumference at one axial end of the armature press-fitted inward, and A second housing press-fitted at the other end in the axial direction, the method comprising:
After press-fitting one end of the armature in the axial direction to the first housing, the rotor is inserted into the armature, and the second housing is press-fitted to the other end of the armature in the axial direction. Motor manufacturing method.

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