JP4855069B2 - Manufacturing method of motor - Google Patents

Description

The present invention, while the positioning of the circumferential direction, are those concerning the manufacturing how a motor for shrink fitting the stator core in the cylindrical portion of the case.

Conventionally, a stator of a motor (brushless motor) has a stator core around which windings are wound and a case in which the stator core is accommodated and held. The stator core is press-fitted by shrink fitting on the inner peripheral surface of the cylindrical portion of the case. There is something that is held. In such a motor having a stator, a sensor for detecting the rotation angle of the rotor is fixed to an end housing for closing the opening of the case, and a drive current is applied to the windings based on the detection result of the sensor. (For example, refer to Patent Document 1).
JP 2003-32989 A

  By the way, in the motor as described above, if the rotation angle of the rotor with respect to the stator core cannot be accurately detected, for example, the motor efficiency is reduced and the cogging torque is increased. Therefore, for example, there is a method of appropriately adjusting the fixed position (circumferential position) of the sensor with respect to the stator core after assembling or the like. However, since this method is complicated to adjust, there is a demand to avoid as much as possible. There is a desire to prevent misalignment in the circumferential direction.

  Therefore, for example, a positioning hole is formed in the case, and the positioning of the stator in the circumferential direction with respect to the jig is performed while the circumferential positioning of the case with respect to the jig is performed by inserting a positioning pin of the jig. A method such as shrink fitting is considered. However, in the above method, a large radial force is applied to the positioning pin due to expansion or contraction of the case during the shrink fitting process, which may make it difficult to insert and remove the positioning pin. For example, when the positioning pin is made to correspond to the positioning hole of the expanded case, the case is heated to expand, the stator core is inserted into the cylindrical portion of the expanded case, and the positioning pin is inserted into the positioning hole. When the stator core is fixed to the cylindrical portion by cooling and contracting, the positioning hole moves radially inward with respect to the positioning pin. As a result, a large radial force is applied to the positioning pin, making it difficult to remove the positioning pin from the positioning hole. Conversely, when the positioning pin is made to correspond to the positioning hole of the case that is not expanded (in a normal state), it becomes difficult to insert the positioning pin into the positioning hole.

The present invention has been made in order to solve the above-described problems, and the object thereof is to satisfactorily position the stator core and the case in the circumferential direction, and a large force is applied to the positioning pin. it is to provide a manufacturing how the motor can be prevented.

The invention according to claim 1 is a method for manufacturing a motor in which a stator core is shrink-fitted into a cylindrical portion of a case while positioning in the circumferential direction, and a positioning hole penetrating in the axial direction is formed in the case. A positioning pin extending in the axial direction is formed on the jig, and the positioning hole and the positioning pin are restricted in relative movement in the circumferential direction in a state in which the positioning pin is inserted into the positioning hole. The stator core is formed with a positioning groove extending along the axial direction and recessed in the radial direction on the radially outer surface of the stator core. An engagement pin that extends along the axial direction and engages with the positioning groove is formed in the tool, and the positioning groove and the engagement pin are inserted into the positioning groove. The stator core is formed so as to be positioned in the circumferential direction with respect to the positioning pin of the jig in a state in which the engaging pin is fitted, and the engaging pin is fitted into the positioning groove to A holding step of positioning the stator core in the circumferential direction with respect to the positioning pin of the jig and holding the stator core on the jig, and a circumferential direction of the case with respect to the jig by inserting the positioning pin into the positioning hole And a shrink fitting step of shrink fitting the stator core, which has been circumferentially positioned with respect to the jig, to the case on the radially outer surface where the positioning groove is formed .

  According to this invention, the positioning hole of the case and the positioning pin of the jig are regulated so that the relative movement in the circumferential direction is restricted and the relative movement in the radial direction is allowed with the positioning pin inserted in the positioning hole. It is formed. In the shrink-fitting process, the positioning pin is inserted into the positioning hole so that the circumferential positioning of the case with respect to the jig is performed, and the stator core that has been circumferentially positioned with respect to the jig is shrink-fitted into the case. Is done. In this way, for example, in each state before and after expansion and contraction of the case during the shrink-fitting process, the case can be well positioned in the circumferential direction with respect to the jig and thus the stator core, and a large force is applied to the positioning pin. It is prevented from being added, and the positioning pin can be easily inserted and removed.

  According to a second aspect of the present invention, in the method for manufacturing a motor according to the first aspect, the shrink fitting step includes a heating step of heating and expanding the case, and a step of expanding the case after the heating step. Inserting the stator core into the cylindrical portion and inserting the positioning pin into the positioning hole, and after the inserting step, the case is cooled and contracted while maintaining the state, and the cylindrical portion is moved into the cylindrical portion. And a cooling step for fixing the stator core.

  According to the invention, in the heating step, the case is heated and expanded, and in the subsequent insertion step, the stator core is inserted into the cylindrical portion of the expanded case, and the positioning pin is inserted into the positioning hole, and then the cooling is performed. In the process, the case is cooled and contracted while the positioning pin is inserted into the positioning hole, and the stator core is fixed to the cylindrical portion.

  According to a third aspect of the present invention, in the motor manufacturing method according to the first or second aspect, the positioning hole is a long hole formed in a flange portion of the case in a radial direction, and the positioning pin is , Formed in a circular shape.

  According to the present invention, the positioning hole is a long hole in the radial direction formed in the flange portion of the case, and the positioning pin is formed in a circular shape. Therefore, the positioning pin is inserted into the positioning hole. In the state, the relative movement in the circumferential direction is restricted, and the relative movement in the radial direction is allowed. Therefore, the effect of the invention according to claim 1 or 2 can be obtained. Further, the shape of the positioning hole and the positioning pin is simplified.

  According to a fourth aspect of the present invention, in the method for manufacturing a motor according to any one of the first to third aspects, the positioning hole is a contraction in which the width in the orthogonal direction of the radial direction decreases toward the inner side in the radial direction. It is a width hole.

  According to the present invention, the positioning hole is a reduced-width hole whose width in the orthogonal direction in the radial direction becomes smaller toward the inner side in the radial direction. It becomes large and can be made into the state where the positioning pin was inserted in the circumferential direction without backlash in each state before and after expansion and contraction of the case. That is, when the case is expanded during the shrink-fitting process, the positioning pin is inserted without any play in the circumferential direction inside the positioning hole whose width in the radial direction is increased, and when the case is contracted, the radial direction is orthogonal. The positioning pin is inserted without any play in the circumferential direction on the radially outer side of the positioning hole whose width in the direction is originally set large. Therefore, the positioning accuracy in the circumferential direction by the positioning hole and the positioning pin can be further increased.

  According to a fifth aspect of the present invention, in the motor manufacturing method according to the first or second aspect, the positioning hole is a circular round hole formed in a flange portion of the case, and the positioning pin is a circular shape. And having a slit inclined with respect to the radial direction of the case.

  According to the invention, the positioning hole is a circular round hole formed in the flange portion of the case. Since the positioning pins are circular and have slits that are inclined with respect to the radial direction of the case, the positioning pins are easily bent in the radial direction, and the relative movement in the circumferential direction thereof can be performed with the positioning pins inserted into the positioning holes. Regulated and relative movement in the radial direction is allowed. Therefore, the effect of the invention according to claim 1 or 2 can be obtained.

  According to a sixth aspect of the present invention, in the method for manufacturing a motor according to any one of the first to fifth aspects, a sensor for detecting a rotation angle of the rotor is fixed to the case. .

  According to the present invention, the sensor for detecting the rotation angle of the rotor is fixed to the case, but since the circumferential positioning of the case with respect to the stator core can be satisfactorily performed, the rotation angle of the rotor with respect to the stator core is It can be detected with high accuracy. Therefore, it is possible to prevent, for example, a decrease in motor efficiency and an increase in cogging torque.

According to the present invention, together with the circumferential direction of the positioning of the stator core and the case can be satisfactorily performed, it is to provide a manufacturing how the motor can be prevented that a large force to the positioning pins will be applied it can.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1A and 1B, the motor (brushless motor) includes a stator 1 and a rotor 2. The stator 1 is fixed to a stator core 4 around which a winding 3 (see FIG. 1B, omitted in FIG. 1A) is wound, a case 5 in which the stator core 4 is accommodated and held, and an opening of the case 5. An end housing 6 and a resolver stator 7 as a sensor fixed to the end housing 6.

  The case 5 is made of a magnetic material and has a substantially bottomed cylindrical shape. Specifically, the cylindrical portion 5a and one end of the cylindrical portion 5a (upward in FIG. 1A) are closed. And a flange portion 5c that extends radially outward from the other end (downward in FIG. 1A) of the cylindrical portion 5a. The stator core 4 has an annular ring portion 4a and twelve teeth portions 4b that extend radially inward from the ring portion 4a and on which the winding 3 is wound. Further, in the annular portion 4a of the stator core 4 of the present embodiment, a positioning groove 4c that is recessed radially inward is formed on the radially outer side at a position corresponding to each tooth portion 4b. The stator core 4 is held in pressure contact with the inner peripheral surface of the cylindrical portion 5a of the case 5 by shrink fitting. The end housing 6 is formed in a shape corresponding to the opening of the case 5 and is substantially closed by being fixed to the opening. The resolver stator 7 is for detecting the rotation angle of the rotor 2 and is fixed to the end housing 6 so as to be arranged inside the case 5.

  The rotor 2 has a permanent magnet (not shown), and is provided so as to be rotatable inside the stator core 4. In the present embodiment, a resolver rotor 2b is fixed at a position corresponding to the radially inner side of the resolver stator 7 on the rotation shaft 2a of the rotor 2.

  Here, in the flange portion 5c of the case 5, an elongated hole 5d is formed as a positioning hole that penetrates in the axial direction and is long in the radial direction. The long hole 5d of the present embodiment has a shape that is closed by the radially outer end of the flange portion 5c (not open at the radially outer end), and has a semicircular shape that is semicircular at both radial ends. These are the portions 5e and 5f, and the middle (the middle in the radial direction) is a parallel portion 5g having a parallel shape.

Next, a method for manufacturing the above-described motor (stator 2) will be described.
First, in the “holding step”, the stator core 4 is held by the jig 11 as shown in FIG. Specifically, the jig 11 is erected on the base part 11a at a position apart from the base part 11a, the placing part 11b that is erected in a cylindrical shape on the base part 11a, and the placing part 11b. And positioning pins 11c. At the tip of the mounting portion 11b, there are three engagement pins 11d having a shape corresponding to the positioning groove 4c of the stator core 4 and extending in the standing direction at equal angular intervals (120 ° in this example) (three in this example). ) Is formed. Then, as shown in FIG. 2, the stator core 4 is placed on the placement portion 11b so that the engagement pin 11d is fitted in the positioning groove 4c. As a result, the stator core 4 is positioned in the circumferential direction with respect to the jig 11 (positioning pin 11c) and held. The stator core 4 at this stage has already been wound with the winding 3 (see FIG. 1B), but the winding 3 is not shown in FIG.

  Further, the positioning pin 11c is formed in a circular shape when viewed from the standing direction. The long hole 5d and the positioning pin 11c of the case 5 are restricted in relative movement in the circumferential direction with the positioning pin 11c inserted in the long hole 5d and allowed to move in the radial direction. The positioning pin 11c has a distance from the axial center of the mounting portion 11b (stator core 4) in the radial direction of the elongated hole 5d from the axial center of the case 5 in the case 5 that is not expanded by heating (in a normal state). It is formed to be the same as the distance to the outer side (semicircle portion 5f).

  In the “shrink fitting process”, the circumferential positioning of the jig 11 was performed while positioning the circumferential direction of the case 5 with respect to the jig 11 by inserting the positioning pins 11c into the long holes 5d. The stator core 4 is shrink-fitted into the case 5.

Specifically, the “shrink fitting process” of the present embodiment includes a “heating process”, an “insertion process”, and a “cooling process”.
First, in the “heating step”, the case 5 is heated and expanded. At this time, the cylindrical portion 5a is mainly heated and expanded so that the inner diameter of the cylindrical portion 5a is increased.

  Next, in the “insertion step”, the stator core 4 is inserted into the cylindrical portion 5a of the expanded case 5, and the positioning pins 11c are inserted into the long holes 5d. That is, as shown in FIG. 2, the stator core 4 held by the jig 11 by the “holding step” is moved together with the jig 11 and inserted into the cylindrical portion 5a, and the positioning pin 11c is inserted into the elongated hole 5d. To do. At this time, since the case 5 is expanded, the distance of the flange portion 5c (the long hole 5d) from the axial center of the case 5 is increased. Therefore, the positioning pin 11c is indicated by a two-dot chain line in FIG. Thus, it inserts in the radial direction inner side (semicircle part 5e side) of the long hole 5d.

  Next, in the “cooling step”, the case 5 is cooled and contracted while maintaining the state of the “insertion step”, that is, the state where the stator core 4 is inserted into the cylindrical portion 5a and the positioning pin 11c is inserted into the elongated hole 5d. Then, the stator core 4 is fixed to the cylindrical portion 5a.

  Then, in the “extraction step”, the jig 11 is moved with respect to the stator core 4 and the case 5 to extract the positioning pin 11c from the long hole 5d and the engaging pin 11d from the positioning groove 4c. The jig 11 is separated. At this time, since the case 5 is not expanded (in a normal state), the positioning pin 11c is arranged on the radially outer side (on the semicircular portion 5f side) of the long hole 5d as shown by a solid line (hatched) in FIG. )It is in.

  Then, the resolver stator 7 is fixed so that the rotor 2 excluding a part of the rotating shaft 2a is accommodated in the case 5 while positioning the case 5 and the end housing 6 in the circumferential direction. The end housing 6 is fixed to the opening of the case 5 (see FIG. 1). In this way, the manufacture of the motor is completed.

Next, characteristic effects of the above embodiment will be described below.
(1) Since the positioning hole is a long hole 5d in the radial direction formed in the flange portion 5c of the case 5, and the positioning pin 11c is formed in a circular shape, the positioning pin 11c is formed in the long hole 5d. In the inserted state, relative movement in the circumferential direction is restricted and relative movement in the radial direction is allowed. Therefore, in each state before and after expansion and contraction of the case 5 during the “shrink fit process”, the circumferential positioning of the case 5 with respect to the jig 11 and eventually the stator core 4 can be performed well, and the positioning pin 11c A large force is prevented from being applied, and as a result, the positioning pin 11c can be easily inserted and removed. That is, as in the present embodiment, the case 5 is heated and expanded, the stator core 4 is inserted into the cylindrical portion 5a of the case 5, and the positioning pins 11c are inserted into the long holes 5d, and the case 5 is cooled and contracted. Even if the stator core 4 is fixed to the cylindrical portion 5a, the positioning pin 11c only moves in the radial direction relative to the long hole 5d, and a large radial force is not applied. Therefore, the positioning pin 11c can be easily removed from the long hole 5d.

  Further, since the positioning of the stator core 4 in the circumferential direction with respect to the case 5 is excellent in this way, the positional deviation between the stator 7 of the resolver fixed to the case 5 and the stator core 4 (via the end housing 6). The rotation angle of the rotor 2 with respect to the stator core 4 can be detected with high accuracy. Therefore, it is possible to prevent, for example, a decrease in motor efficiency and an increase in cogging torque.

  (2) Since the positioning hole is a long hole 5d in the radial direction formed in the flange portion 5c of the case 5 and the positioning pin 11c is formed in a circular shape, the shape of the positioning hole and the positioning pin 11c Becomes simple.

  (3) Since the elongated hole 5d has a shape closed by the radially outer end of the flange portion 5c (not opened at the radially outer end), it extends to the radially outer end of the flange 5c. Compared to the shape (opened at the radially outer end), the surrounding rigidity is higher. Therefore, the positioning accuracy in the circumferential direction by the long hole 5d and the positioning pin 11c can be further increased.

The above embodiment may be modified as follows.
-The positioning hole (long hole 5d) of the said embodiment is a shape long in radial direction, and is the shape closed by the radial direction outer end part of the flange part 5c (it is not open | released by the radial direction outer end part). Then, both radial ends are semicircular semicircular portions 5e, 5f, and the middle (diameter intermediate) is a parallel parallel portion 5g, but is not limited thereto, The shape may be changed.

  For example, as shown in FIG. 4, the positioning hole may be changed to a reduced-width hole 21 having a shape in which the width in the orthogonal direction in the radial direction decreases toward the inner side in the radial direction. Specifically, the reduced-width hole 21 has a shape that is long in the radial direction, and is closed by the radially outer end of the flange portion 5c (not open at the radially outer end). The radially inner side is a semicircular portion 21a having a smaller diameter, the radially outer side is a semicircular portion 21b having a larger diameter, and the middle (diameter direction middle) between them is orthogonal to the radial direction as it goes radially inward. The reduced width portion 21c has a smaller width in the direction. In FIG. 4, the ratio of the reduced width hole 21 to be reduced is exaggerated and schematically illustrated.

  Thus, when the case 5 is expanded, the width in the radial direction inside the radial direction is slightly increased, and the positioning pin 11c is inserted into the positioning hole (reduced width hole 21) before and after the case 5 is expanded and contracted. Can be inserted without play in the circumferential direction. That is, when the case 5 is expanded during the “shrink fitting process”, the positioning pin is inserted without any play in the circumferential direction on the radially inner side of the positioning hole (reduced width hole 21) whose width in the radial direction is increased, When the case 5 is contracted, the positioning pin is inserted in the circumferential direction without play in the radial direction outside the positioning hole (reduced width hole 21) whose width in the orthogonal direction of the radial direction is originally set large. Therefore, the positioning accuracy in the circumferential direction by the positioning hole (reduced width hole 21) and the positioning pin 11c can be further increased.

  Further, for example, as shown in FIG. 5, the positioning hole may be changed to a long hole 22 having a shape extending to the radially outer end of the flange portion 5c (opened at the radially outer end). In this case, as shown in the two-dot chain line in FIG. 5, for example, as compared to the shape closed by the radially outer end of the flange portion 5c as in the above embodiment (see FIG. 1B). Thus, the protrusion amount to the radial direction outer side of the flange part 5c can be made small.

  For example, as shown in FIG. 6, the positioning hole is a circular round hole 23 formed in the flange portion 5 c, and the positioning pin 11 c of the above embodiment is circular and is in a radial direction of the case 5. The positioning pin 24 may have a slit 24a inclined (including 90 °). Specifically, the positioning pin 24 of this example has a slit 24 a that is inclined with respect to the radial direction of the case 5 and the direction orthogonal thereto. As a result, the positioning pins 24 are easily bent in the radial direction, and in the state where the positioning pins 24 are inserted into the positioning holes (round holes 23), the relative movement in the circumferential direction is restricted and the relative movement in the radial direction is allowed. Will be. Moreover, in this example, since the positioning hole is the circular round hole 23, the formation becomes easy. Further, as in this example, the slit 24a is also inclined with respect to the direction orthogonal to the radial direction of the case 5 (because the end of the slit 24a is not disposed in the direction orthogonal to the radial direction of the case 5), The positioning pin 24 is inserted in the positioning hole (round hole 23) without play in the circumferential direction. Therefore, the positioning accuracy in the circumferential direction by the positioning hole (round hole 23) and the positioning pin 24 can be increased. Of course, the slit 24 a may be inclined by 90 ° with respect to the radial direction of the case 5, that is, extend along the direction orthogonal to the radial direction of the case 5. This makes it difficult for the positioning pin to bend in the direction perpendicular to the radial direction, so that the positioning accuracy in the circumferential direction by the positioning hole (round hole 23) and the positioning pin 24 can be increased even when a strong force is applied. The round hole 23 in this example may be changed to another shape, for example, a long hole that is long in the radial direction.

  In the above embodiment, the “shrink fitting process” includes the “heating process”, the “insertion process”, and the “cooling process”. However, the present invention is not limited to this. For example, the “heating process” and the “insertion process” You may change the method of at least one of any of a "process" and a "cooling process."

  For example, in the “insertion step” of the above embodiment, when the stator core 4 held by the jig 11 is moved together with the jig 11 and inserted into the cylindrical portion 5a, the positioning pin 11c is inserted into the elongated hole 5d. However, this “insertion step” may be changed. For example, the positioning pin 11c is configured to be embedded in the base portion 11a, the stator core 4 is moved together with the jig 11 and inserted into the cylindrical portion 5a, and then the jig 11 and the stator core 4 are rotated with respect to the case 5. The positioning pin 11c may be inserted into the long hole 5d while being moved.

  The resolver stator 7 as the sensor of the above embodiment may be changed to another sensor such as a Hall IC as long as it detects the rotation angle of the rotor 2. Of course, in the case of a Hall IC, it is necessary to change the resolver rotor 2b fixed to the rotating shaft 2a to a sensor magnet.

  In the above embodiment, the stator core 4 is positioned in the circumferential direction with respect to the jig 11 (positioning pin 11c) by the positioning groove 4c and the engaging pin 11d. If the direction is determined, another configuration may be used. Moreover, in the said embodiment, although the number of the engaging pins 11d was set to three, of course, you may change the number of the engaging pins 11d.

In the above embodiment, the number of the tooth portions 4b is twelve. However, the number is not limited to this, and may be changed to other numbers.
In the above embodiment, the long hole 5d as the positioning hole is formed in the case 5 and the positioning pin 11c is formed in the jig 11. On the contrary, the positioning pin is formed in the case 5 and the jig A positioning hole may be formed in the plate 11. Of course, the positioning holes formed in the jig 11 may be the same as the elongated holes 5d, 22 and the reduced-width holes 21, and the positioning pins formed in the case 5 are the positioning pins 11c, 24. It is good also as the same thing.

The technical idea that can be grasped from the above embodiments will be described below together with the effects thereof.
(A) The motor manufacturing method according to claim 3, wherein the elongated hole has a shape closed by a radially outer end portion of the flange portion.

  According to the present invention, the elongated hole has a shape closed by the radially outer end portion of the flange portion, and therefore the rigidity around the elongated hole is larger than that of the shape extending to the radially outer end portion of the flange portion. Get higher. Therefore, the positioning accuracy by the positioning hole and the positioning pin can be further increased.

(B) The method for manufacturing a motor according to claim 3, wherein the elongated hole has a shape extending to a radially outer end of the flange portion.
According to the invention, since the elongated hole has a shape extending to the radially outer end of the flange portion (opened at the radially outer end), the elongated hole is closed by the radially outer end of the flange portion. The amount of protrusion of the flange portion toward the outside in the radial direction can be reduced compared to the above.

  (C) A stator having a stator core on which windings are wound and a case in which the stator core is accommodated and held, and the stator core is held in pressure contact with the inner peripheral surface of the cylindrical portion of the case by shrink fitting. And a rotor that is rotatably provided inside the stator core, and a sensor that is fixed to the case and that detects a rotation angle of the rotor, wherein the case includes a jig A positioning pin that can be inserted into the positioning hole is formed, and in the state where the positioning pin is inserted into the positioning hole, movement in the circumferential direction with respect to the positioning hole is restricted and movement in the radial direction is allowed. A motor characterized by being formed as described above.

(A) The partial cross section figure of the motor in this Embodiment. (B) AA sectional drawing of (a). Explanatory drawing for demonstrating the manufacturing method of the jig | tool and motor in this Embodiment. Explanatory drawing for demonstrating the manufacturing method of the motor in this Embodiment. The elements on larger scale of the positioning hole in another example. The elements on larger scale of the positioning hole in another example. The elements on larger scale of the positioning hole and positioning pin in another example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Stator, 2 ... Rotor, 3 ... Winding, 4 ... Stator core, 5 ... Case, 5a ... Cylindrical part, 5c ... Flange part, 5d, 22 ... Long hole (positioning hole), 7 ... Resolver stator (sensor ), 11... Jig, 11 c, 24... Locating pin, 21... Reduced width hole (positioning hole), 23.

Claims (6)

A method of manufacturing a motor in which a stator core is shrink-fitted into a cylindrical portion of a case while performing circumferential positioning,
A positioning hole penetrating in the axial direction is formed in the case, and a positioning pin extending in the axial direction is formed in the jig.
The positioning hole and the positioning pin are formed so that relative movement in the circumferential direction is restricted and relative movement in the radial direction is allowed in a state where the positioning pin is inserted into the positioning hole. ,
The stator core is formed with a positioning groove extending in the axial direction on the radially outer surface thereof and recessed inward in the radial direction, and the jig extends in the axial direction and is fitted into the positioning groove. An engaging pin is formed to be engaged,
The positioning groove and the engaging pin are formed so that the stator core is positioned in the circumferential direction with respect to the positioning pin of the jig in a state where the engaging pin is fitted in the positioning groove. Because
A holding step of positioning the stator core in the circumferential direction with respect to the positioning pin of the jig by holding the engaging pin in the positioning groove and holding the stator core on the jig;
The positioning groove is formed in the stator core that has been positioned in the circumferential direction with respect to the jig while the positioning pin is inserted into the positioning hole to position the case in the circumferential direction with respect to the jig. A shrink-fitting step of shrink-fitting the case on the radially outer surface. In the manufacturing method of the motor according to claim 1,
The shrink fitting process includes
A heating step of expanding the case by heating;
After the heating step, an insertion step of inserting the stator core into the cylindrical portion of the expanded case and inserting the positioning pin into the positioning hole;
A method for manufacturing a motor, comprising: a cooling step of cooling the case while being kept in the state after the inserting step and contracting the case to fix the stator core to the cylindrical portion. In the manufacturing method of the motor according to claim 1 or 2,
The positioning hole is a long hole in the radial direction formed in the flange portion of the case,
The method of manufacturing a motor, wherein the positioning pin is formed in a circular shape. In the manufacturing method of the motor according to any one of claims 1 to 3,
The method for manufacturing a motor according to claim 1, wherein the positioning hole is a reduced-width hole whose width in the orthogonal direction in the radial direction decreases toward the inner side in the radial direction. In the manufacturing method of the motor according to claim 1 or 2,
The positioning hole is a circular round hole formed in the flange portion of the case,
The method of manufacturing a motor, wherein the positioning pin is circular and has a slit inclined with respect to a radial direction of the case. In the manufacturing method of the motor according to any one of claims 1 to 5,
A method for manufacturing a motor, wherein a sensor for detecting a rotation angle of a rotor is fixed to the case.

Images