JP2016192867A - Motor stator structure and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor stator structure capable of thinning an insulator and being manufactured with low manufacturing cost.SOLUTION: A core unit 45 of a motor 1 is used for the motor 1 using an air-core coil 35. The core unit 45 includes: a cylindrical back yoke part 41; and an insulator 43 arranged in the inner periphery of the back yoke part 41. The coil 35 is fixed to the inner peripheral surface of the insulator 43. The back yoke part 41 and the insulator 43 are integrally formed. The inner peripheral surface of the insulator 43 has a surface formed by performing processing for removing a part of the insulator 43 after the back yoke part 41 and the insulator 43 are integrally formed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor stator structure and a motor, and more particularly to an inner rotor type motor stator structure and a motor.

  In the motor, an insulator (insulator) is used to insulate the coil from the iron core. In order to improve the performance of the motor, it is important to secure a wider space for winding the coil. Therefore, the insulator is desirably formed as thin as possible as long as the withstand voltage is ensured.

  Patent Document 1 below describes a structure in which an insulator is provided by integral molding on a split iron core constituting a stator of a motor. By reducing the shape of the split iron core, the insulator is made thinner.

JP 2004-248471 A

  By the way, in the structure as described in Patent Document 1 above, a resin insulator is formed by injection molding. Therefore, there is a problem that it is difficult to make the insulator thin.

  That is, in order to allow the resin to flow properly through the gap between the mold and the iron core, it is necessary to ensure a certain thickness of the insulator. However, when it does so, there exists a problem that the space which winds a coil becomes narrow. Moreover, since there is a risk of short molding, it is difficult to reduce the thickness of the insulator beyond the allowable range of the molding machine and material.

  In addition, in order to form a thin wall, it is necessary to use an expensive resin with high fluidity, and there is a problem that the manufacturing cost of the motor increases. That is, in general, a resin having higher fluidity (that can be formed into a thinner wall) is more expensive. For example, compared to relatively inexpensive PBT (polybutylene terephthalate resin), PA (polyamide resin), etc., PPS (polyphenylene sulfide) heat-resistant resin has high fluidity but is expensive. Further, for example, LCP (liquid crystal polymer) has higher fluidity but is more expensive.

  In addition, there exists a method of insulating between a coil and an iron core by attaching an insulator on the upper and lower sides of an iron core with a length that does not cause a short mold and applying an insulating paint to an intermediate portion of the iron core. However, in this method, it is necessary to form the insulator separately from the upper and lower bodies and to combine the two after insulating coating is applied to the iron core. Therefore, there is a problem that the number of parts increases and the number of manufacturing steps increases.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a motor stator structure and a motor that can be thinned and can be easily manufactured at a low manufacturing cost.

  In order to achieve the above object, according to one aspect of the present invention, a stator structure of a motor used in a motor using an air-core coil is formed on a cylindrical back yoke portion and an inner periphery of the back yoke portion. The insulator includes an insulator and an air-core coil fixed to the inner peripheral surface of the insulator. The back yoke portion and the insulator are integrally formed. The inner peripheral surface of the insulator is integrated with the back yoke portion and the insulator. After the formation, the surface is formed by performing a process of removing a part of the insulator.

  Preferably, the back yoke portion is configured by laminating a plurality of ring-shaped members.

  Preferably, the surface roughness of the inner peripheral surface of the insulator is larger than the surface roughness of the surface of the insulator that has not been processed.

  According to another aspect of the present invention, a motor includes the above-described stator structure of the motor and a rotor disposed on the inner peripheral side of the coil, and the rotor is attached to the shaft and sandwiches the coil. And a permanent magnet arranged to face the back yoke portion.

  Preferably, the coil is bonded to the inner peripheral surface of the insulator.

  According to these inventions, the inner peripheral surface of the insulator has a surface formed by performing a process of removing a part of the insulator after the back yoke portion and the insulator are integrally formed. . Therefore, it is possible to provide a motor stator structure and a motor that can be thinned and can be easily manufactured at low manufacturing costs.

It is a sectional side view showing the motor in one of the embodiments of the invention. It is a disassembled perspective view of a stator. It is a cross-sectional perspective view at the time of cut | disconnecting a stator by the plane which passes along the rotating shaft of a motor. It is a 1st figure explaining the manufacturing process of a core unit. It is a 2nd figure explaining the manufacturing process of a core unit. It is a table | surface which shows the measurement result of surface roughness. It is a graph which shows the measurement result of the surface roughness about the insulator before post-processing. It is a graph which shows the measurement result of the surface roughness about the insulator after post-processing. It is a 1st figure which shows the simulation result about shaping | molding of an insulator. It is a 2nd figure which shows the simulation result about shaping | molding of an insulator.

  Hereinafter, a motor having a stator structure according to one embodiment of the present invention will be described.

  [Embodiment]

  FIG. 1 is a side sectional view showing a motor 1 according to one embodiment of the present invention.

  As shown in FIG. 1, the motor 1 includes a rotor 10, a stator 40, and a housing 30. The rotor 10 is disposed on the inner diameter side of a stator 40 that is roughly formed in a cylindrical shape. That is, the motor 1 is a so-called inner rotor type.

  In the present embodiment, the motor 1 is a small-diameter cylindrical coreless motor having a diameter of about 5 millimeters or less. The size and shape of the motor 1 are not limited to this.

  The rotor 10 has a shaft 11 and a cylindrical permanent magnet 12. The permanent magnet 12 is fixed to the shaft 11 so as to be coaxial with the shaft 11. The shaft 11 passes through the permanent magnet 12.

  The housing 30 includes, for example, a case 31 formed using a nonmagnetic metal plate and an end piece 32. One end of the case 31 is open to the extent that the shaft 11 can pass therethrough. A bearing 33 for supporting the rotor 10 is fitted at this end. The other end of the case 31 is open on the entire surface. An end piece 32 is disposed at this end. The end piece 32 holds a bearing 34 for supporting the rotor 10.

  The rotor 10 is rotatably attached to the housing 30 with the shaft 11 being pivotally supported by the bearings 33 and 34. The shaft 11 protrudes from the end on the bearing 33 side to the outside of the housing 30. The permanent magnet 12 is accommodated in the housing 30.

  The stator 40 has a core unit 45 and a coil 35 fixed inside the core unit 45. The stator 40 is accommodated in the housing 30. The stator 40 is fixed with respect to the case 31. Accordingly, the permanent magnet 12 of the rotor 10 is disposed so as to face the back yoke portion 41 with the coil 35 interposed therebetween.

  FIG. 2 is an exploded perspective view of the stator 40.

  As shown in FIG. 2, the coil 35 is of an air core having a cylindrical shape. The outer diameter of the coil 35 is substantially the same as the inner diameter of the core unit 45. A lead-out end line 35 a is located at one end of the coil 35.

  The core unit 45 has a cylindrical back yoke portion 41 and an insulator 43 disposed on the inner periphery thereof. The core unit 45 has an insulator structure in which the back yoke portion 41 and the insulator 43 are integrally formed. The core unit 45 has a substantially cylindrical shape. The outer diameter of the core unit 45 is substantially the same as the inner diameter of the case 31. The inner peripheral surface 43a (inner diameter side surface) of the core unit 45 is a cylindrical surface.

  The coil 35 is inserted into the core unit 45 and bonded to the core unit 45. At this time, the coil 35 is fixed to the inner peripheral surface 43a of the core unit 45 by adhesion.

  FIG. 3 is a cross-sectional perspective view of the stator 40 cut along a plane that passes through the rotation axis of the motor 1.

  As shown in FIG. 3, in the present embodiment, the back yoke portion 41 is formed by laminating a large number of core sheets (an example of a ring-shaped member) 41a. The core sheet 41a is a ring-shaped member formed by processing a steel plate, for example. Note that the back yoke portion 41 may have other structures.

  In the stator 40, the insulator 43 is located between the back yoke portion 41 and the coil 35. That is, the coil 35 is bonded to the inner peripheral surface 43 a of the insulator 43. The insulator 43 is made of resin and insulates the coil 35 from the back yoke portion 41.

  The back yoke portion 41 and the insulator 43 are integrally formed by insert molding. That is, the core unit 45 in which the insulator 43 and the back yoke part 41 are integrally formed is obtained by installing the back yoke part 41 in the mold and pouring resin into the mold.

  Here, in the present embodiment, the insulator 43 is formed thick (thick) so that when the back yoke portion 41 and the insulator 43 are integrally formed, the resin easily spreads in the mold. And the insulator 43 is thinned by post-processing with respect to the insulator 43 formed in thickness.

  FIG. 4 is a first diagram illustrating the manufacturing process of the core unit 45.

  FIG. 4 shows a state after the back yoke portion 41 and the insulator 43 are integrally formed in the manufacturing process of the core unit 45 and before the post-processing is performed. As shown in FIG. 4, integral molding is performed so that the thickness of the insulator 43 on the inner diameter side is increased. The thickness of the insulator 43 before post-processing is, for example, about 0.3 mm to 0.4 mm.

  FIG. 5 is a second diagram for explaining the manufacturing process of the core unit 45.

  FIG. 5 shows a state after post-processing is performed on the insulator 43 in the manufacturing process of the core unit 45. That is, the state where the manufacture of the core unit 45 is completed is shown.

  As shown in FIG. 5, in the post-processing, a portion on the inner diameter side of the insulator 43 formed thick as described above is removed. The insulator 43 is thinned by post-processing. The thickness of the insulator 43 after post-processing is, for example, about 0.1 millimeter. The inner peripheral surface 43a of the insulator 43 after post-processing is a surface to which the coil 35 is bonded. That is, in the present embodiment, the inner peripheral surface 43a of the insulator 43 to which the coil 35 is bonded is processed to remove a part of the insulator 43 after the back yoke portion 41 and the insulator 43 are integrally formed. It has a surface formed by being bent.

  Since the entire outer diameter of the motor 1 is about 5 mm, it is impossible to perform post-processing of the insulator 43 by cutting with a lathe (processing with a cutting tool blade). Therefore, the post-processing may be performed by drilling, for example. The post-processing may be performed by removing a portion on the inner diameter side of the insulator 43 by applying a drill blade to the insulator 43 while the outer diameter of the core unit 45 after being integrally formed is chucked. In addition, when a motor is a comparatively large size, you may post-process by a normal cutting process and may process by another method.

  Here, in the present embodiment, the surface roughness of the inner peripheral surface 43 a of the insulator 43 is larger than the surface roughness of the surface of the insulator 43 that is not post-processed. That is, the surface of the surface of the insulator 43 that has not been post-processed is a surface at the time of integral molding, and its surface roughness is relatively small. On the other hand, the inner peripheral surface 43a formed by post-processing is a drilling processed surface, and the surface roughness thereof is relatively large.

  Before and after post-processing of the insulator 43 by drilling, the surface roughness of the inner peripheral surface changes, for example, as follows.

  That is, “Surfcom 1400G” manufactured by Tokyo Seimitsu Co., Ltd. was used as the surface roughness measuring instrument. The measuring needle is applied to the inner wall surface of the insulator 43 of the sample to be measured, and the measuring needle is scanned at a measuring speed of 0.06 millimeters per second within the measuring range of 2 millimeters in the axial direction. The height roughness (Rz) was calculated. The measurement was performed on three samples before and after the post-processing.

  FIG. 6 is a table showing the measurement results of the surface roughness. FIG. 7 is a graph showing the measurement results of the surface roughness of the insulator 43 before post-processing. FIG. 8 is a graph showing the measurement results of the surface roughness of the insulator 43 after post-processing.

  As shown in FIGS. 6, 7, and 8, in this measurement example, it is understood that the arithmetic average roughness (Ra) is increased by about 5 times that after the post-processing by performing the post-processing. .

  Thus, the effect that the adhesiveness of the coil 35 and the insulator 43 becomes favorable is acquired by the surface roughness of the internal peripheral surface 43a being larger than the surface roughness of the surface which is not post-processed. Note that when post-processing is performed, processing for increasing the surface roughness may be further performed on the processed surface.

  [Effects of the embodiment]

  As described above, in the present embodiment, the insulator 43 is formed into a thick wall by integral molding and then processed into a thin wall.

  FIG. 9 is a first diagram showing a simulation result for molding the insulator 43. FIG. 10 is a second diagram showing a simulation result for molding the insulator 43.

  9 and 10, the colored portion indicates the portion where the resin flows, and the numerical value indicates the number of seconds that have elapsed since the start of resin filling. FIG. 9 shows a simulation result when the thickness of the insulator 43 at the time of molding is 0.3 mm. FIG. 10 shows a simulation result when it is assumed that the thickness of the insulator 43 during molding is 0.1 millimeter. As shown in the figure, the thicker one spreads out the resin all over about 0.11 seconds, while the thinner one takes twice as much time, but the resin is not in the whole. I don't have it. That is, if the thickness is small, the possibility of occurrence of a short mold increases.

  In the present embodiment, since the insulator 43 is formed with a large thickness at the time of molding, the integral molding can be easily and easily performed using a relatively inexpensive resin without using an expensive resin with high fluidity. It can be done reliably. Moreover, since post-processing is performed after molding, the insulator 43 can be formed thin. Therefore, the manufacturing cost of the motor 1 can be kept low, and a large space for providing the coil 35 can be secured to improve the performance of the motor 1.

  Further, since the back yoke portion 41 is configured by laminating the ring-shaped core sheet 41a, the dimensional accuracy of the shape of the back yoke portion 41 can be easily increased. If the coaxiality between the outer peripheral surface of the back yoke portion 41 and the inner peripheral surface of the insulator 43 at the time of integral molding deviates even by 0.05 mm, one-side uneven thickness occurs, and short molding is likely to occur during injection molding. However, in the present embodiment, by using the ring-shaped core sheet 41a, the back yoke portion 41 can be molded with high accuracy so as not to become uneven in the injection molding. Further, when post-processing of the insulator 43, the processing can be performed based on the outer diameter of the back yoke portion 41. Therefore, the core unit 45 can be easily formed with high accuracy so as not to be uneven even after post-processing.

  Furthermore, the inner peripheral surface 43a of the insulator 43 has a larger surface roughness than the other surfaces. The adhesiveness between the coil 35 and the insulator 43 is improved, and the coil 35 is firmly fixed. Therefore, the reliability of the motor 1 is increased. An inner peripheral surface 43a of the insulator 43 is a processed surface generated by post-processing the insulator 43 by drilling. Therefore, it is possible to easily improve the adhesion between the coil 35 and the insulator 43 without performing special processing to increase the surface roughness.

  [Others]

  The motor is not limited to the inner rotor motor. Another type of motor using the same insulator structure as described above may be used.

  The outer peripheral shape of the motor and the outer peripheral shape of the core unit are not limited to the cylindrical shape. For example, it may have a prismatic shape.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Motor 10 Rotor 11 Shaft 12 Permanent magnet 35 Coil 40 Stator 41 Back yoke part 41a Core sheet (an example of a ring-shaped member)
43 Insulator 43a Inner peripheral surface 45 Core unit

Claims (5)

A stator structure of a motor used for a motor using an air-core coil,
A cylindrical back yoke portion;
An insulator formed on the inner periphery of the back yoke portion;
An air-core coil fixed to the inner peripheral surface of the insulator,
The back yoke portion and the insulator are integrally formed,
The stator of the motor, wherein the inner peripheral surface of the insulator has a surface formed by performing a process of removing a part of the insulator after the back yoke portion and the insulator are integrally formed. Construction.   The stator structure of the motor according to claim 1, wherein the back yoke portion is configured by laminating a plurality of ring-shaped members.   The stator structure of the motor according to claim 1 or 2, wherein a surface roughness of an inner peripheral surface of the insulator is larger than a surface roughness of a surface of the insulator not subjected to the processing. The stator structure of the motor according to any one of claims 1 to 3,
A rotor disposed on the inner peripheral side of the coil,
The rotor includes a shaft and a permanent magnet attached to the shaft and disposed so as to face the back yoke portion with the coil interposed therebetween.   The motor according to claim 4, wherein the coil is bonded to an inner peripheral surface of the insulator.

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