JP2007143325A - Stator structure of electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To favorably ensure the circularity of a stator in a stator structure of an electric motor, improve the productivity of the stator, and ensure a sufficient assembling length to a motor housing. <P>SOLUTION: Each divided stator 10 of the electric motor is provided with a yoke 10a circumferentially divided, teeth radially extended from the yoke 10a, and a coil wound onto the teeth. A step 12b1 is formed at an axial end of the divided stator. A small diameter section 20b is formed, having a diameter smaller than an outside diameter of a cylinder 20a formed by an outer circumference of the yoke 10a while the step 12b1 is fitted. An annular member is fitted to the small diameter section 20b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a stator structure of an electric motor, and more particularly to a stator structure of an electric motor in which a stator is combined with a divided stator.

As one of the stator structures of this type of electric motor, a cylindrical stator is constituted by a plurality of divided stators divided in the circumferential direction, and each divided stator has a yoke portion divided in the circumferential direction, Some include a tooth portion extending in the radial direction from the yoke portion and a coil wound around the tooth portion.
Japanese Patent Laid-Open No. 8-265959

  By the way, in the stator structure of the electric motor described in the above-mentioned Patent Document 1, an uneven portion for positioning each yoke portion in the circumferential direction is formed at each circumferential end portion of each yoke portion. The divided stators are combined in a cylindrical shape by the engagement of the uneven portions. And after a division | segmentation stator is combined cylindrically, each coil is integrated with resin.

  In the stator structure of the electric motor, the step of integrating the coils with resin is performed after the step of combining the divided stators into a cylindrical shape. For this reason, it is necessary to load the divided stator combined in a cylindrical shape into the resin mold, and it is difficult to improve the productivity (handling property), and the roundness of the stator is improved. It is also difficult to secure.

  That is, when priority is given to ensuring the roundness of the stator and the fitting accuracy of the concave and convex portions is set high, the productivity may be reduced when the stator is combined into a cylindrical shape. On the other hand, if priority is given to improving the productivity when combining the stator into a cylindrical shape and the fitting accuracy of the concave and convex portions is set low, until the combined divided stator is loaded into the resin mold During this period, the combined stator may be separated, and the productivity may be reduced when the combined stator is handled. In this case, the roundness of the stator may not be ensured satisfactorily during resin molding.

  Further, in the above-described conventional stator structure of an electric motor, the cylindrical stator is assembled to the motor housing only at the outer peripheral portion of the yoke portion. For this reason, there is a possibility that the assembly length with the motor housing cannot be sufficiently secured.

  Therefore, the present invention can improve the productivity of the stator while sufficiently securing the roundness of the stator and can sufficiently secure the assembly length with the motor housing in order to cope with the above problem. The object is to provide a stator structure for an electric motor.

  In order to achieve the above object, in the present invention, a cylindrical stator is composed of a plurality of divided stators divided in the circumferential direction, and each divided stator includes a yoke portion divided in the circumferential direction, In a stator structure of an electric motor comprising a tooth portion extending in a radial direction from the yoke portion and a coil wound around the tooth portion, a step portion is formed at an axial end portion of each of the divided stators. A small diameter portion having a smaller diameter than the outer diameter of the cylindrical portion formed by the outer periphery of the yoke portion is formed in a state where the step portions are combined, and an annular member is fitted to the small diameter portion. is there.

  In the stator structure of this electric motor, an annular member is fitted to form a cylindrical stator in a state where the divided stators are combined. For this reason, it is possible to integrate the split stators while maintaining the roundness of the stator, and it is possible to easily ensure the roundness of the stator.

  Further, after the divided stators are combined in a cylindrical shape, the annular member is fitted to the small diameter portion of the cylindrical stator. For this reason, it is possible to prevent the stator combined in a cylindrical shape from being separated, and to improve the productivity of the stator.

  In carrying out the present invention, the outer diameter of the annular member may be the same as the outer diameter of the cylindrical portion formed by the outer periphery of the yoke portion.

  In this case, the total length obtained by adding the axial length of the annular member to the axial length of the cylindrical portion formed by the outer periphery of the yoke portion can be set as the assembly length with the motor housing. For this reason, it is possible to improve holding | maintenance force with a motor housing.

  In carrying out the present invention, the step portion provided at the axial end of each of the divided stators may be formed of a resin that integrates the coils. In this case, for example, a resin molding step of integrating the coil wound around the teeth portion with a resin, a combination step of combining the divided stators produced through the resin molding step into a cylindrical shape, and this combination A cylindrical stator may be manufactured by including a fitting step of fitting an annular member to the small-diameter portion formed by the step portion through a step.

  In this case, the step part which forms a small diameter part is formed with resin. For this reason, it is possible to easily form a small-diameter portion having a predetermined shape and a predetermined size.

  In carrying out the present invention, the resin is formed with uneven portions for positioning the divided stators in the circumferential direction by engaging the divided stators in a combined state. Is also possible.

  In this case, the divided stators are combined in a cylindrical shape by the engagement of the concavo-convex portions formed of resin. For this reason, the jig | tool for combining a division | segmentation stator into a cylindrical shape becomes unnecessary, and it is possible to position a division | segmentation stator in the circumferential direction easily by engagement of an uneven part.

  In carrying out the present invention, the annular member is assembled to one axial end of the cylindrical stator, and may have a connection portion for connecting the coils. Is possible. In this case, it is possible to make the annular member function as a bus bar without providing a bus bar for connection.

  In carrying out the present invention, a second annular member is assembled to the other axial end of the cylindrical stator, and the second annular member is nonmagnetic and conductive. It is also possible to provide a rotation angle sensor for detecting the rotation angle of the rotor assembled in the cylindrical stator on the outer side of the second annular member.

  In this case, the second annular member is made of a nonmagnetic and conductive material. For this reason, since the magnetism generated in the cylindrical stator is shielded by the second annular member, it is possible to suppress the magnetic interference to the rotation angle sensor, thereby reducing the detection accuracy of the rotation angle sensor. It is possible to prevent.

  Hereinafter, each embodiment of the present invention will be described with reference to the drawings. FIG. 1 and FIG. 2 show a divided stator 10 that is commonly used in the respective embodiments employing the stator structure according to the present invention, and a plurality (12) of this divided stator 10 are combined into an annular shape (cylindrical shape). Thus, one cylindrical stator 20 (three-phase motor stator) is configured (see FIG. 3).

  The split stator 10 is formed by laminating electromagnetic steel plates in the longitudinal direction (axial direction of the stator) to form a block, and has a sectoral fan-shaped yoke portion 10a and radially inward from the yoke portion 10a. A tooth portion 10b extending integrally and a coil 11 wound around the tooth portion 10b are provided.

  The teeth portion 10b has a predetermined air gap and a permanent magnet (not shown) arranged on the outer peripheral surface of the rotor R (see FIG. 4) assembled in the cylindrical stator 20 in a state where the divided stators 10 are combined. Are arranged opposite to each other. The coil 11 is a copper wire having an outer periphery coated with an insulating coating, and is integrally held by a resin 12 in a concave coil housing portion 10c formed by a yoke portion 10a and a tooth portion 10b.

  The resin 12 is formed in a cross-sectional fan shape having an outer periphery near the inner peripheral position of the yoke portion 10a, and the circumferential end surface 12a and the circumferential end surface 10a1 of the yoke portion 10a are located on substantially the same plane. Is set to The resin 12 is set such that each axial end 12b (longitudinal end) protrudes outward in the axial direction by a predetermined amount from the axial end surfaces 10a2 and 10b1 of the yoke portion 10a and the teeth portion 10b. A step portion 12b1 is formed by each axial end surface 10a2 of the yoke portion 10a.

  Further, in the circumferential direction corner of one axial end portion 12b of the resin 12, that is, the portion where the coil 11 is not wound, the divided stators 10 are engaged with each other in a state where the divided stators 10 are combined. A concave portion 12b2 and a convex portion 12b3 are formed for positioning in the direction. In this case, the fitting accuracy between the concave portion 12b2 and the convex portion 12b3 is set low so as to facilitate the engagement between the concave portion 12b2 and the convex portion 12b3. Note that one end 11 a and the other end 11 b of the coil 11 extend from one axial end 12 b of the resin 12.

  By the way, in each divided stator 10 described above, the coil 11 is wound around the tooth portion 10b by a predetermined amount over the coil accommodating portion 10c (outside the circumferential end surface 10a1 of the yoke portion 10a). The resin 12 is integrated by a molding process. Thereafter, the divided stators 10 are combined in a cylindrical shape by the combining process, and the stator 20 combined in a cylindrical shape by the fitting process is integrated.

  In the resin molding process, the resin 11 is injected into the coil housing portion 10c in a state where the coil 11 is pushed into the coil housing portion 10c by the press die P which also serves as a resin mold, and the coil 11 is integrated with the resin 12 (See FIG. 2). As a result, when the split stators 10 are combined, interference between the coils 11 can be avoided, and the split stators 10 can be combined in a state in which the split stators 10 are in contact with each other at the circumferential end surface 10a1 of the yoke portion 10a. The space factor of the coil 11 can be improved while ensuring a good degree. In addition, the step 12b1 and the concavo-convex portions 12b2 and 12b3 are formed of the resin 12 by this resin molding process.

  In the combination step, the divided stators 10 produced through the resin molding step are combined into a cylindrical shape by engagement of the concavo-convex portions 12b2 and 12b3 as shown in FIG. By this combination, the stepped portion 12b1 is connected in a circumferential shape, and a small diameter portion 20b having a smaller diameter than the outer diameter of the cylindrical portion 20a formed by the outer periphery of the yoke portion 10a is formed at each shaft end of the stator 20.

  In the fitting step, as shown in FIG. 4, the annular member 21 is press-fitted and fitted into each small diameter portion 20b. The annular member 21 is made of a material having sufficient strength, such as iron or aluminum alloy, and the outer diameter thereof is the same as the outer diameter of the cylindrical portion 20a formed by the outer periphery of the yoke portion 10a. Is formed. Then, after the fitting step, one end 11a and the other end 11b of each coil 11 are fixedly inserted in predetermined connection portions 22a of the bus bar 22 as shown in FIG. 20 assembly is completed.

  In the first embodiment configured as described above, the annular stator 21 is fitted into the cylindrical stator 20 in a state where the divided stators 10 are combined. Thereby, the split stator 10 can be integrated while maintaining the roundness of the stator 20, and the roundness of the stator 20 can be easily secured.

  Moreover, in the said 1st Embodiment, a fitting process is performed immediately after a combination process. Thereby, it is avoided that the stator 20 combined in the cylindrical shape is separated, and the productivity of the stator 20 can be improved.

  Moreover, in the said 1st Embodiment, the outer diameter of the annular member 21 is formed in the same diameter as the outer diameter of the cylindrical part 20a formed by the outer periphery of the yoke part 10a. As a result, the total length obtained by adding the axial length of the annular member 21 to the axial length of the cylindrical portion 20a formed by the outer periphery of the yoke portion 10a can be set as an assembly length with the motor housing (not shown). As a result, the holding force with the motor housing can be improved.

  Moreover, in the said 1st Embodiment, the annular member 21 is formed with the member which has sufficient intensity | strength. Thereby, the deformation | transformation of the cylindrical stator 20 resulting from a magnetic force is prevented, and generation | occurrence | production of the vibration of the electric motor incorporating the said stator 20 and noise can be suppressed.

  Moreover, in the said 1st Embodiment, the step part 12b1 which forms the small diameter part 20b is formed of the resin 12. FIG. Thereby, the small diameter part 20b of a predetermined shape and a predetermined magnitude | size can be formed easily.

  Moreover, in the said 1st Embodiment, each division | segmentation stator 10 is combined cylindrically by engagement of the uneven | corrugated | grooved part 12b2, 12b3 formed with the resin 12. FIG. Thereby, the jig | tool for combining the division | segmentation stator 10 in a cylindrical shape becomes unnecessary, and the division | segmentation stator 10 can be easily positioned in the circumferential direction by engagement of the uneven | corrugated | grooved part 12b2, 12b3.

  In the first embodiment, the annular member 21 and the bus bar 22 that are fitted at one axial end of the cylindrical stator 20 (on one end 11a and the other end 11b side of each coil 11). Consists of separate members. However, the annular member 21 may be set and implemented so as to have a connection portion for connecting the coils 11. According to the second embodiment, the annular member 21 can function as a bus bar without providing the bus bar 22. In addition, since the other structure of this 2nd Embodiment is the same as the said 1st Embodiment, description about another member is abbreviate | omitted.

  Moreover, in the said 1st Embodiment, it implemented so that the annular member 21 which has the same shape and material at each axial direction edge part of the cylindrical stator 20 might each be fitted. However, the present invention is not limited to the case where the similar annular member 21 is used at each axial end portion of the cylindrical stator 20, but, for example, the other axial end portion of the cylindrical stator 20 is shown in FIG. In addition, it is also possible to use a cap 121 as a second annular member having a wide part covering the bottom surface. In addition, since the other structure of this 3rd Embodiment is the same as the said 1st Embodiment, description about another member is abbreviate | omitted.

  The cap 121 is made of a nonmagnetic and conductive material, such as copper. A rotation angle sensor (for example, a resolver) that detects the rotation angle of the rotor R (see FIG. 4) is provided outside the cap 121.

  According to the third embodiment, since the magnetism generated in the cylindrical stator 20 is shielded by the cap 121, magnetic interference with the rotation angle sensor is suppressed, and a decrease in detection accuracy of the rotation angle sensor is prevented. The

  In the first embodiment and the like, the step portion 12b1 provided at the axial end portion 12b of each divided stator 10 is formed by the resin 12 that integrates the coils 11, but the electromagnetic steel plate is formed in the longitudinal direction. It is also possible to implement so that the stepped portion is formed according to the shape of the yoke portion itself when it is stacked on the substrate.

It is a perspective view which shows the division | segmentation stator used in common with the 1st-3rd embodiment which employ | adopted the stator structure by this invention. It is 2-2 sectional drawing of FIG. It is a perspective view which shows the state by which the division | segmentation stator of FIG. 1 was combined by the combination process. FIG. 4 is a perspective view showing a state where the stator of FIG. 3 is integrated by a fitting process. It is a top view which shows the bus bar for connecting the coil in the stator of FIG. It is a perspective view which shows the other of the annular member used for 3rd Embodiment which employ | adopted the stator structure by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Split stator, 10a ... Yoke part, 10a1 ... Circumferential end face, 10a2 ... Axial end face, 10b ... Teeth part, 10c ... Coil accommodating part, 11 ... Coil, 12 ... Resin, 12a ... Circumferential end face, 12b ... Shaft Direction end part, 12b1 ... Step part, 12b2 ... Concavity part, 12b3 ... Convex part, 20 ... Stator, 20a ... Cylinder part, 20b ... Small diameter part, 21 ... Ring member, 22 ... Bus bar, 22a ... Connection part, 121 ... Cap (Second annular member), P ... press die, R ... rotor

Claims (7)

The cylindrical stator is constituted by a plurality of divided stators divided in the circumferential direction, and each divided stator has a yoke portion divided in the circumferential direction, and a teeth portion extending in the radial direction from the yoke portion. In the stator structure of the electric motor comprising the coil wound around the teeth portion,
A step portion is formed at an axial end of each of the divided stators, and a small diameter portion smaller than the outer diameter of the cylindrical portion formed by the outer periphery of the yoke portion in a state where the step portions are combined, A stator structure of an electric motor, wherein an annular member is fitted to a small diameter portion. In the stator structure of the electric motor according to claim 1,
The stator structure of an electric motor, wherein an outer diameter of the annular member is formed to be the same as an outer diameter of a cylindrical portion formed by an outer periphery of the yoke portion. In the stator structure of the electric motor according to claim 1 or 2,
A stator structure for an electric motor, wherein a step provided at an axial end of each of the divided stators is formed of a resin that integrates the coils. In the stator structure of the electric motor according to claim 3,
The resin has a concavo-convex portion for engaging with each other in a state where the divided stators are combined to position the divided stators in the circumferential direction. Construction. In the stator structure of the electric motor according to claim 1,
The annular member is assembled to one axial end portion of the cylindrical stator, and has a connection portion for connecting the coils. . In the stator structure of the electric motor according to claim 5,
A second annular member is assembled to the other axial end of the cylindrical stator, and the second annular member is made of a nonmagnetic and conductive material. A stator structure for an electric motor, wherein a rotation angle sensor for detecting a rotation angle of a rotor assembled in the cylindrical stator is provided on an outer side of the second annular member. A method of manufacturing a stator for an electric motor according to claim 2,
A resin molding step of integrating the coil wound around the teeth portion with resin;
A combination step of combining the divided stators made through the resin molding step in an annular shape;
A method of manufacturing a stator for an electric motor, comprising: a fitting step of fitting an annular member to the small diameter portion formed by the step portion through the combination step.

Images