JP2010142055A - Electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor wherein, when fixing a frame and a stator core, the frame and the stator core can be firmly fixed together without requiring a special whirl-stop measure with respect to torque reaction of the motor and without having an adverse effect on electric characteristics. <P>SOLUTION: An electric motor includes a metallic frame having a load-side bracket, an electromagnetic section attached to the internal surface of the frame, and a resin integrally molding the electromagnetic section. The load-side bracket is provided an engagement section for a whirl-stop which is composed of a hole or recess wherein a resin is to be filled in and cured. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric motor having a metal frame and having an electromagnetic part molded with resin.

  In the structure of an electric motor, there is one in which a metal load side bracket and a metal frame are integrated to improve assembly man-hours and assembly accuracy (for example, Patent Document 1).

  FIG. 6 is a side sectional view showing a conventional electric motor of this type. FIG. 7 is an explanatory view showing assembly of a stator in a conventional electric motor.

As shown in FIG. 6 or FIG. 7, a conventional electric motor having a metal frame and having an electromagnetic part molded with resin is provided inside the stator core b for the purpose of fixing the winding a and improving thermal conductivity. The formed winding installation space, the overhang portion c of the winding, and the connection portion d are molded with a resin e to form a stator, and a metal frame f is shrink-fitted or press-fitted on the outside for the purpose of improving heat dissipation, or It is common to fix using adhesion or both.
JP 2008-167609 A

However, such conventional techniques have the following problems.
(1) The metal frame f and the stator core b need to be firmly fixed to withstand the torque reaction force of the electric motor. In addition to the main fixing method described above, a metal pin g is driven. Stop measures are necessary.
(2) When the stator core and the frame are fastened together by shrink fitting or press-fitting, the stress is generated in the stator core, and the cogging torque of the motor is increased.
(3) The contact surface between the metal frame f and the load-side bracket h cannot be made large, and an air layer j is formed between the resin mold i of the electromagnetic part and the load-side bracket h, resulting in poor thermal conductivity. .

  The present invention has been made to solve such a problem. The stator core and the frame can be firmly fixed without taking various kinds of anti-rotation measures, and the stator core is not stressed. An object of the present invention is to provide an electric motor capable of obtaining good electrical characteristics.

In order to solve the above problems, the present invention is configured as follows.
The invention according to claim 1 is a metal frame having a load side bracket portion, an electromagnetic portion attached to an inner surface of the frame, and a resin integrally molded with the electromagnetic portion,
The load-side bracket portion is provided with an anti-rotation engaging portion that fills and cures the resin.
The invention according to claim 2 is characterized in that the anti-rotation engaging portion is constituted by a hole or a groove.
The invention according to claim 3 is characterized in that the anti-rotation engaging portion passes through the load side bracket portion.
The invention according to claim 4 is characterized in that the electromagnetic part has a gap winding type structure.

  According to the first and second aspects of the present invention, the resin itself in which the electromagnetic part is molded becomes a non-rotating wedge after curing, and the frame and the stator core can be firmly fixed without taking special anti-rotation measures. it can. Further, since the resin is filled between the electromagnetic part and the frame and between the electromagnetic part and the load side bracket part, the thermal conductivity is improved.

  According to the third aspect of the present invention, while the effect of the first aspect is maintained as it is, the anti-rotation engaging portion penetrates the load side bracket portion, so that it can be used as a gas vent hole during resin filling. Is possible. In addition, when disassembling the electric motor, a service hole can be used to separate the frame and the stator.

According to the invention described in claim 4, since the excessive stress is not generated in the stator core while maintaining the effect of claim 1 or 2, it can be made extremely small without adversely affecting the cogging torque of the motor. A high-performance electric motor can be provided. further,
In a motor with a gap winding structure, torque reaction force is not generated in the stator core, so in the present invention in which the winding is firmly fixed, it is not necessary to fix the stator core, and it is possible to rely only on the adhesive force of the molded resin. It becomes possible. Therefore, the adhesion of the stator core and the like can be omitted from the assembly process, and man-hours can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a side sectional view showing an electric motor according to a first embodiment of the present invention.
As shown in FIG. 1, in the electric motor 1, the metal frame 2 has a load-side bracket portion 2 a and has a stator 3 inside a cylindrical portion corresponding to the frame body. Further, a rotor 4 is inserted through a gap at the axial center of the stator 3 and is rotatably supported by the load side bracket portion 2a and the anti-load side bracket 5 via a bearing. A detector 6 is attached to the rotor 4 to detect the rotational position.

  The stator 3 is formed by molding a stator core 7 and a winding 8 constituting an electromagnetic part with a resin 9. Here, the stator 3 is integrally molded with the resin 9 on the load side bracket portion 2 a of the frame 2. Thereby, the resin 9 is filled between the winding 8 and the load side bracket portion 2a without any gap.

  Further, the load side bracket portion 2 a is provided with a rotation-preventing engaging portion 10 at a portion in contact with the resin 9. The anti-rotation engaging portion 10 is configured by a hole or groove having a depth that does not penetrate the load side bracket portion 2a. When the stator core 7 and the winding 8 are molded with the resin 9, the resin 9 is filled into the anti-rotation engaging portion 10. When the resin 9 filled in the detent engagement portion 10 is cured, these resins 9 serve as detents for the stator 3.

  Thus, the structure provided with the anti-rotation engaging part 10 used as the anti-rotation structure of an electromagnetic part when the resin 9 which molded the stator core 7 and the coil | winding 8 entered and hardened | cured in the load side bracket part 2a of the flame | frame 2 in this way. Therefore, the electromagnetic part can be firmly fixed. This eliminates the need for special anti-rotation measures between the frame 2 and the stator core 7 and eliminates the need for a fastening method that stresses the stator core 7 such as shrink fitting or press-fitting. The conventional problems that adversely affect the system are solved. In addition, since the resin 9 is filled between the electromagnetic part and the frame 2 and between the electromagnetic part and the load side bracket part 2a, the thermal conductivity is improved and a high-performance electric motor can be provided.

FIG. 2 is a side sectional view showing an electric motor according to a second embodiment of the present invention.
The second embodiment is characterized in that the anti-rotation engaging portion 10 penetrates the load side bracket portion 2a. Other configurations are almost the same as those of the first embodiment.
In the second embodiment, the anti-rotation engaging portion 10 is provided through the load side bracket portion 2a. Thereby, the said detent | locking engagement part 10 can be utilized as a degassing hole at the time of filling of the said resin 9, and a high quality mold of the resin 9 is possible.
Further, as shown in FIG. 3, when the electric motor 1 is disassembled, the electric motor 1 can be easily disassembled by using a disassembly jig 11 that passes through the detent engagement portion 10 that penetrates the load side bracket portion 2a. Can do.

FIG. 4 is a side sectional view showing an electric motor according to a third embodiment of the present invention.
This third embodiment has a so-called gap winding type stator structure in which the electromagnetic part is attached to the inner surface of the stator core 7 having no teeth part. Other configurations are substantially the same as those in the first or second embodiment.
In the configuration of the third embodiment, since the electromagnetic part has a cap winding structure, the winding 8 is disposed between the cylindrical stator core 7 and the rotor 4. The torque reaction force of the electric motor 1 is generated in the winding 8 and is supported only by the cured resin 9. Also here, the electromagnetic portion can be firmly fixed by the resin 9 that has entered and hardened the anti-rotation engaging portion 10 of the load side bracket portion 2a becoming a non-rotating wedge. Due to the structural characteristics of the gap winding method, it is possible to make a structure that does not transmit the torque reaction force to the stator core 7, and the strength for fixing the stator core 7 is not required more than in the first or second embodiment. Therefore, by making the structure completely dependent only on the adhesive force of the resin 9, the stress applied to the stator core 7 can be reduced as compared with the first embodiment or the second embodiment. For this reason, it becomes possible to make the cogging torque of the electric motor 1 very small.

5A to 5F show an example of the anti-rotation engaging portion 10 of the load side bracket portion 2a in the first to third embodiments as a shape viewed from the anti-load side. ing.
FIG. 5A shows an example in which the anti-rotation engaging portion 10 is configured by a round hole 10a. The round hole 10a may or may not penetrate. (B) is an example in which the anti-rotation engaging portion 10 is configured by a long hole 10b that is long in the radial direction. The long hole 10b may or may not penetrate. (C) is an example in which the anti-rotation engaging portion 10 is configured by a fan-shaped long groove 10c. The long groove 10c may or may not penetrate, but since it is large in size, it is preferable that it does not penetrate in terms of strength. (D) is an example in which the anti-rotation engaging portion 10 is configured by a long hole 10d that is long in the circumferential direction. The long hole 10d may or may not penetrate. (E) is an example in which the anti-rotation engaging portion 10 is configured by combining the long hole 10b long in the radial direction of (b) and the fan-shaped long groove 10c of (c). It is preferable to penetrate only the long hole 10b that is long in the radial direction. (F) is an example in which the anti-rotation engaging portion 10 is configured by combining the round hole 10a of (a) and the fan-shaped long groove 10c of (c). It is preferable to penetrate only the round hole 10a.
It should be noted that the shape and number of the anti-rotation engaging portions 10 in the present invention are not limited to those shown in FIG. 5, and various other forms and combinations are conceivable.

It is a sectional side view which shows the electric motor in the 1st Example of this invention. It is a sectional side view which shows the electric motor in the 2nd Example of this invention. It is a decomposition process explanatory drawing of the electric motor in FIG. It is a sectional side view which shows the electric motor in the 3rd Example of this invention. (A)-(f) is explanatory drawing which shows the example of the rotation prevention engaging part of the load side bracket in the 1st-3rd Example. It is a sectional side view which shows the conventional electric motor. It is explanatory drawing which shows the assembly of the stator of the conventional electric motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric motor 2 Load side bracket 3 integrated with frame 3 Stator 4 Rotor 5 Anti-load side bracket 6 Detector 7 Stator core 8 Winding 9 Resin 10 Hole or groove 11 Disassembly jig a Winding b Stator core c Winding overhang Part d Connection part e Resin f Metal frame g Metal pin h Load side bracket i Resin mold j Air layer

Claims (4)

A metal frame having a load side bracket portion;
An electromagnetic part attached to the inner surface of the frame;
A resin integrally molded with the electromagnetic part;
In an electric motor having
An electric motor characterized in that the load side bracket portion is provided with an anti-rotation engaging portion for filling and curing the resin.   The electric motor according to claim 1, wherein the anti-rotation engaging portion is configured by a hole or a groove.   The electric motor according to claim 1, wherein the anti-rotation engaging portion passes through the load side bracket portion. 2. The electric motor according to claim 1, wherein the electromagnetic part has a gap winding type structure.

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