JP2001136692A - Inner rotor motor and manufacturing method of its rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inner rotor motor that allows a rotor protection sheet to be firmly adhered to a split rotor magnet without generating bias and unevenness, and a manufacturing method of its rotor. SOLUTION: A rotor body part 18 is stuck onto the outer-peripheral surface of a shaft 12, a number of split rotor magnets 19 are arranged on the entire outer-peripheral surface of the rotor body part 18 for bonding while being laid tightly, a rotor protection tape 21 where an impregnated epoxy resin is wound onto the outer surface of each split rotor magnet 19, and the rotor protection 21 is covered with a cylindrical heat-shrinkable film 22 for heating at a high temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a structure in which a divided rotor magnet is attached to the outer peripheral surface of a shaft and a rotor that rotates around the shaft is disposed inside the stator with a predetermined gap. The present invention relates to an inner rotor motor having a structure and a method for manufacturing a rotor in the inner rotor motor.

[0002]

2. Description of the Related Art A general inner rotor motor of this type has a structure in which a stator is provided inside a motor bracket, and a rotor that rotates around a shaft is disposed with a small predetermined gap from the stator. ing. Also,
As the rotor, a large number of divided rotor magnets were adhered in a circumferential arrangement over the entire outer periphery of the rotor main body portion fitted and fixed to the shaft, and a protection sheet such as a rotor protection tape was wound around the outer surfaces of these divided rotor magnets. Some have a structure. The rotor protection sheet prevents cracks and chips from being caused by a member such as a jig coming into contact with the divided rotor magnet during the motor manufacturing process, and also prevents the divided rotor magnet from rotating during rotation of the finished motor. Are prevented from scattering due to the centrifugal force acting by the high-speed rotation.

[0003]

For example, in the case of a tape-shaped protective sheet, a glass cloth impregnated with an epoxy resin is used as the rotor protective sheet. This rotor protection sheet is, for example, spirally wound around the outer peripheral surface of each divided rotor magnet in order to fix it in close contact with the outer surface of the plurality of divided rotor magnets, and then inserted into a constant temperature bath at a high temperature. Heated and thermoset. At this time, the rotor protection sheet is hardened with an epoxy resin, so that the strength is strengthened as compared with the case of a single glass cloth. Specifically, the tensile strength changes from 14.5 kgf / mm2 before curing to 30 kgf / mm2 after curing.

[0004] Incidentally, the epoxy resin impregnated in the rotor protection sheet is once softened in the process of being heated to a high temperature and thermally cured, and the softened epoxy resin tends to flow downward by its own weight. Conventionally, in order to prevent the softened resin from contacting and adhering to adjacent members, etc., conventionally, release paper is further applied to the outer surface of the rotor protection sheet spirally wound around the outer surface of the split rotor magnet. It was wound and inserted into a high-temperature bath.

However, in the conventional thermosetting process of the rotor protection sheet, it is possible to reliably prevent the softened epoxy resin from adhering to other members with the release paper, but the softened epoxy resin is hardened by the inside of the release paper. In this case, there is a problem that the epoxy resin is hardened in one direction or irregularities such as steps or wrinkles are generated on the surface of the cured epoxy resin. Such deviations, steps, or wrinkles that occur in the epoxy resin cause the rotation of the rotor to become unbalanced.In a conventional rotor manufacturing process, the surface of the heat-cured rotor protection sheet is cut by cutting. There is a problem that it is necessary to provide a step that requires a complicated operation of correcting surface irregularities. In addition, the heat-cured rotor protection sheet has the following disadvantages, such as unevenness and unevenness, occurring in the epoxy resin.
It cannot be firmly adhered to each split rotor magnet.

In view of the above, the present invention has been made in view of the above-mentioned conventional problems, and has an inner structure provided with a structure capable of firmly adhering a rotor protection sheet to a split rotor magnet without any deviation or unevenness. It is an object of the present invention to provide a rotor motor and a method for manufacturing the rotor thereof.

[0007]

In order to achieve the above-mentioned object, an inner rotor motor according to the present invention comprises a stator comprising a stator core and a stator coil wound on the stator core, and a stator disposed inside the stator. A rotor that rotates around a shaft, the rotor includes a rotor main body provided on the outer periphery of the shaft, and a plurality of split rotor magnets bonded to an outer peripheral surface of the rotor main body. A rotor protection sheet wound around the outer surface of each divided rotor manet and closely adhered to the divided rotor manet by thermosetting, and a rotor protection sheet covered on the outer surface of the rotor protection sheet and thermally adhered to the rotor protection sheet by heat shrinkage. And a heat-shrinkable film.

[0008] In this inner rotor motor, since the heat-shrinkable film is covered on the outside of the rotor protection sheet, when the rotor protection sheet is heat-cured by high-temperature heating, it is thermally shrunk from the outside to the whole. Since the heat-shrinkable film that is evenly adhered keeps its shape and cures so that deformation such as unevenness or unevenness does not occur, unevenness or unevenness can hardly occur on the surface of the cured rotor protection sheet. Instead, the rotor magnets are uniformly and firmly adhered to each of the divided rotor magnets over the entire rotor magnet. Therefore, the conventional repairing step after the thermosetting of the rotor protection sheet becomes unnecessary.

Further, according to the method of manufacturing a rotor of an inner rotor motor of the present invention, a step of bonding a large number of divided rotor magnets in a circumferential arrangement to the entire outer periphery of a rotor body at an outer periphery of a shaft; The method includes a step of winding a rotor protection sheet impregnated with an epoxy resin around an outer surface of the magnet, and a step of covering the rotor protection sheet with a tubular heat-shrinkable film and then heating it at a high temperature. Thus, the rotor protection sheet is temporarily softened before being hardened by high-temperature heating, but is prevented from being deformed such as bias or unevenness by the heat-shrinkable film which is uniformly adhered from the outside while being thermally contracted. It keeps its shape and cures. Therefore, the surface of the cured rotor protection sheet hardly has irregularities or deviations, and is uniformly and firmly adhered to the entire divided rotor magnet.

[0010]

Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an inner rotor motor according to one embodiment of the present invention. A motor housing 1 as an outer body of the inner rotor motor is configured such that a bottom opening of a cylindrical motor case 2 is covered with a cover 3 and a bracket 7 is attached to an upper opening with bolts 4 or the like. ing. A stator 8 is fitted and fixed inside the motor case 2. The stator 8 includes a stator core 9 formed by laminating a plurality of magnetic thin plates, an insulator 10 externally fixed to the stator core 9, and an insulator 10. And a stator coil 11 wound around the coil.

A shaft 12 is housed inside the motor housing 1 with its upper part protruding outside. This shaft 12 has an upper bearing 13 at a substantially central portion thereof.
Is rotatably supported in the insertion hole of the bracket 7 through
The lower end of the motor case 2 is connected via the lower bearing 14.
Are rotatably supported by the support recess. Shaft 12
The rotor 17 is fixed to a portion from the substantially central portion to the lower portion of the inside of the motor case 2 at a predetermined gap from the inner peripheral surface of the stator 8. The rotor 17 is adhered to the rotor main body portion 18 fixed to the outer peripheral surface of the shaft 12 with an adhesive in an arrangement in which the entire outer peripheral surface of the rotor main body portion 18 is laid in multiple stages and multiple rows (circumferential arrangement in each stage). And a plurality of divided rotor magnets 19 are provided.
Is held in close contact with the rotor body 18 by a magnet protection unit 20 described later. The stator coil 11 is connected to an external power supply (not shown) via a terminal (not shown).

Next, the magnet protection unit 20 will be described with reference to FIG. As shown in FIG. 2 (a), the rotor 17 has a cylindrical rotor body 18 externally fitted and fixed to a predetermined outer peripheral surface of the shaft 12, and a large number of divided rotor magnets are fitted over the entire outer periphery of the rotor body 18. 19 are adhered by an adhesive in an arrangement arranged in the axial direction and the circumferential direction. At this time, an adhesive is applied to each of the divided rotor magnets 19, and the divided rotor magnets 19 are adhered to the rotor body 18 so as to spread the adhesive.

Next, as shown in FIG. 2B, a rotor protection tape 21 as a rotor protection sheet made of glass cloth impregnated with epoxy resin is spirally formed on the outer surface of each of the divided rotor magnets 19. It is wound.
At this time, the rotor protection tape 21 is wound twice or three times while applying a tensile force of, for example, 5 kgf or more while overlapping adjacent ends so that the surface of the divided rotor magnet 19 is not exposed.

When the winding of the rotor protection tape 21 is completed, a special P used for a PET bottle or the like is used.
A cylindrical heat-shrinkable film 22 containing ET resin as a main component,
As shown by a virtual line, the rotor protection tape 21 wound spirally is covered. In this state, insert the
High-temperature heating is carried out at a temperature of 0 ° C. for 15 hours or at 150 ° C. for 8 hours. The heat-shrinkable film 22 heated to a high temperature under these curing conditions is different from, for example, a hot air blown by a heat gun. 21.

Therefore, the rotor protection tape 21 once softens before being hardened by heating at a high temperature, but is deformed by unevenness and unevenness due to the heat shrinkable film 22 which is uniformly adhered from the outside while thermally contracting. The shape is maintained so as not to cause the hardening, and the hardening is performed, and the rotor 17 as shown in FIG. 2C is completed. As a result, the hardened rotor protection tape 21 hardly has unevenness or deviation on its surface, and uniformly and firmly adheres to the divided rotor magnets 19 over the entirety. Therefore, the conventional repairing process after the thermosetting of the rotor protection tape 21 becomes unnecessary. Finally, as shown in FIG. 2C, after the balance is corrected using the balance weight 23, the split rotor magnet 19 is magnetized.

In the above-described embodiment, the case where the plurality of rotor magnets 19 are arranged in the axial direction and the circumferential direction has been described. However, the present invention is not limited to this. The present invention can be implemented in the same manner when the rotor body is adhered in the directional arrangement. Needless to say, the rotor protection sheet is not limited to the above-described tape shape.

[0017]

As described above, according to the inner rotor motor of the present invention, since the heat shrinkable film is covered on the outside of the rotor protection sheet, when the rotor protection sheet is thermally cured by high temperature heating, The heat-shrinkable film, which is evenly adhered to the entire surface from the outside, cures while maintaining its shape so that it does not deform such as bias or unevenness. No longer occurs, and the rotor magnets uniformly and firmly adhere to the entire divided rotor magnets. This eliminates the need for a conventional repairing step after heat curing of the rotor protection film.

Further, according to the method of manufacturing the rotor of the inner rotor motor of the present invention, the rotor protection sheet wound around each of the divided rotor magnets is covered with a tubular heat-shrinkable film and heated at a high temperature. Almost no irregularities or deviations occur on the surface of the later rotor protection sheet,
The rotor protection sheet is evenly and firmly adhered to each divided rotor magnet over the whole.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an inner rotor motor according to an embodiment of the present invention.

FIGS. 2A and 2B sequentially show a rotor manufacturing process in the inner rotor motor according to the embodiment, in which FIG. 2A is a perspective view showing a state where a divided rotor magnet is attached to a shaft, and FIG. 2B is an outer surface of the divided rotor magnet; (C) is a partially broken front view showing the rotor in a completed state.

[Explanation of symbols]

 8 Stator 9 Stator Core 11 Stator Coil 12 Shaft 17 Rotor 18 Rotor Body 19 Split Rotor Magnet 21 Rotor Protection Tape 22 Heat Shrink Film

Claims (2)

[Claims] 1. A stator comprising a stator core and a stator coil wound on the stator core, and a rotor arranged on the inner side of the stator and rotating around a shaft, wherein the rotor is A rotor main body portion provided on the outer periphery, a plurality of divided rotor magnets bonded to the outer peripheral surface of the rotor main body portion, and the respective divided rotor magnets wound around the outer surfaces of the respective divided rotor magnets and thermally cured. An inner rotor motor comprising: a rotor protection sheet adhered to the rotor protection sheet; and a heat shrinkable film covered on an outer surface of the rotor protection sheet and closely adhered to the rotor protection sheet by heat shrinkage. 2. A step of adhering a large number of divided rotor magnets in the circumferential direction to the entire outer periphery of the rotor body at the outer periphery of the shaft, and a rotor protection sheet in which an outer surface of each divided rotor magnet is impregnated with epoxy resin. And a step of covering the rotor protection sheet with a tubular heat-shrinkable film and then heating the rotor protection sheet to a high temperature.