JPH0753415Y2 - Outer rotor motor - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an outer rotor type motor.

[0002]

2. Description of the Related Art Outer rotor type motors have been known for a long time, but recently, for the purpose of simplifying the structure and reducing the number of manufacturing processes, the outer rotor cup is made of synthetic resin and has a metal frame inside. The applicant (hereinafter referred to as a back yoke) and a magnet integrally molded have been proposed.

FIG. 2 shows an example of such a resin-integrated outer rotor type motor. That is, the shaft 1 is rotatably provided via the bearing 2 to the stator 3 in which the stator coil 3a is arranged. Around the stator 3, rotor cups 4 each having a cup shape with an end surface and a circumferential surface are provided at regular intervals so as to cover the stator 3. The rotor cup 4 has a back yoke 5 and a magnet 6 which are made by pouring resin into a mold.
It is molded together with. The central portion of the shaft 1 is fixed to the protruding portion of the shaft 1 from the stator 3 and is rotatable with the shaft 1.

By the way, a printed circuit board 7 is attached integrally with the stator 3 at the end of the stator 3 in the opening direction of the rotor cup 4. A sensor such as a photo interrupter 8 is attached to a part of the side edge of the printed board 7.

Such an outer rotor motor includes a stator coil 3a arranged on the stator 3 and a magnet 6 mounted on the inner peripheral surface of the rotor cup 4 through the back yoke 5 at a position corresponding to the stator coil 3a. ,
The rotor cup 4 is rotating. The rotation of the rotor cup 4 is controlled by a sensor such as the photo interrupter 8.

[0006]

However, the conventional outer rotor motor is not provided with any cooling means for heat generation of the stator 3 during its operation. Since the cooling is not sufficient only by providing a fixed gap between the stator 3 and the rotor cup 4, there is a problem that the stator 3 and the rotor cup 4 around the stator 3 are overheated, and eventually burnout occurs. There are drawbacks. In order to cool this heat generation, it has been proposed to provide a means for forced cooling with a separate member, but the manufacturing process is complicated and the cost becomes high. Moreover, the motor is increased in size because it is a separate member.

The present invention is provided to solve the above-mentioned problems of the prior art. The object of the present invention is to provide an outer rotor type motor with cooling means for heat generation of the stator, and to cool the stator and its surroundings. An object of the present invention is to provide an outer rotor motor with high safety by suppressing overheating of the rotor cup.

[0008]

According to a first aspect of the present invention, there is provided an outer rotor motor including a stator and a rotor cup which is formed into a cup shape by an end surface and a circumferential surface and is provided so as to cover the stator. An end surface side fin formed so as to project outward is provided on the end surface of the rotor cup, and an opening portion is provided in the end surface side fin in either one of the forward and reverse rotation directions of the rotor cup, so that the rotor cup can be ventilated. The formed ventilation hole, the circumferential surface side fin formed on the circumferential surface of the rotor cup so as to project outward, and the circumferential surface fin in the other rotation direction of either the forward or reverse direction of the rotor cup. And a vent hole formed in the rotor cup so as to be ventilated.

[0009]

In the outer rotor motor having the above-mentioned structure, the rotor cup is provided with a cooling means in order to cool the heat of the stator when the motor is driven. That is, during rotation of the rotor cup, air in contact with either one of the fins on the end surface side or the fins on the circumferential surface side, which have ventilation holes that open in the rotational direction, is constantly taken into the inner surface of the rotor cup through the ventilation holes. Be done. Further, this air flows between the rotor cup and the stator and is discharged from the ventilation hole of the other fin. Therefore, even when the rotor cup rotates only in one of the forward and reverse directions, or when it rotates in both directions, air is constantly supplied from the vent holes of one of the end surface side fins or the circumferential surface side fins to the inner surface of the rotor cup. And is discharged from the other vent hole to constantly cool the periphery of the stator.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the outer rotor motor of the present invention will be described below with reference to FIG.

In this embodiment, the same members as those in the prior art are designated by the same reference numerals and the description thereof will be omitted. That is, the rotor cup 4 provided in the outer rotor motor of this embodiment is provided so as to be ventilated with respect to the stator 3. Around the shaft 1 fixing portion on the end surface of the rotor cup 4, a plurality of end surface side fins 9 are formed so as to project at regular intervals. These end surface side fins 9 have a vent hole 9a which has an opening in the forward rotation direction of the rotor cup (clockwise when viewed from the end surface of the rotor cup in the drawing) and which is ventilated with the inner surface of the rotor cup 4. Has been formed. Further, a plurality of circumferential surface side fins 10 are formed so as to project at regular intervals in the vicinity of the end portion of the circumferential surface of the rotor cup 4. The circumferential surface fin 10 has an opening in the reverse rotation direction of the rotor cup (counterclockwise rotation when viewed from the end surface side of the rotor cup in the drawing), and has ventilation holes that can communicate with the inner surface of the rotor cup 4. Pores 10a are formed.

When forming such a rotor cup 4,
Inside the mold including an upper mold and a lower mold in which the end surface side fins 9, the ventilation holes 9a, the circumferential surface side fins 10 and the ventilation holes 10a, and the portion corresponding to the photo interrupter 8 of the rotor cup 4 are integrally formed. Then, the shaft 1, the back yoke 5 and the magnet 6 are set, and resin is poured to form the rotor cup 4. As a result, the shaft 1, the back yoke 5, and the magnet 6 are formed integrally with the rotor cup 4.

The operation of the present embodiment configured as described above is as follows.

That is, when the rotor cup 4 rotates in the normal direction, fresh outside air contacting the end surface side fins 9 is always taken in from the vent hole 9a as the rotor cup 4 rotates. The amount of air taken in at this time is proportional to the rotation speed of the rotor cup 4. Then, the taken air is used for the rotor cup 4 and the stator 3.
Air flowing between the end surface side fins 9 side to the printed circuit board 7 side and contacting the circumferential surface side fins 10 is ventilated.
It is discharged from a.

When the rotor cup is rotated in the reverse direction, the air coming in contact with the fins 10 on the circumferential surface is rotated with the rotation of the ventilation holes 10.
It is always taken in from a, flows between the stator 3 and the rotor cup 4, and is discharged from the ventilation hole 9a of the end face side fin 9.

In this embodiment as described above, the rotor cup 4 is provided with the end surface side fins 9 and the circumferential surface side fins 10 each having a ventilation hole that is freely ventilated with the inner surface of the rotor cup 4, and each ventilation hole is further provided. Are open in mutually opposite directions, so that when the rotor cup 4 rotates, fresh outside air can always be taken in between the stator 3 and the rotor cup 4 and around the stator from the rotation direction. The exothermic heat of can be directly and sufficiently cooled. Further, the air taken in during the rotation of the rotor cup 4 is constantly discharged from the ventilation hole that opens in the reverse rotation direction, so that the rotation of the rotor cup 4 is affected by the stagnant exhausted air in the rotor cup 4. Without this, the cooling air can be discharged smoothly. Therefore, a rotor cup that rotates in either one of the forward and reverse directions, and a rotor cup that rotates in both directions can be used without modification, and can be used as it is, which is practical. .

Furthermore, since the amount of air taken into the rotor cup 4 during rotation is proportional to the rotational speed of the rotor cup 4, even if the amount of heat generated by the stator 3 increases at high speeds, the amount of air taken in is proportional to it. Therefore, the stator 3 can be sufficiently cooled. Therefore, the cooling efficiency is increased as compared with the case where the forced cooling means is provided as a separate member, and the number of members is reduced, so that the manufacturing process is simplified and the outer rotor motor can be downsized. Therefore, it is possible to inexpensively provide the outer rotor motor with high safety without fear of burning.

The present invention is not limited to the above-mentioned embodiment, and the concrete shape of each member, the mounting position and method of each member, etc. can be changed as appropriate.

For example, the shapes of the fins 9 and 10 and the opening directions of the ventilation holes 9a and 10a are not limited. That is,
Even when the opening portion of the ventilation hole 9a formed in the end surface side fin 9 is formed in the reverse rotation direction and the opening portion of the ventilation hole 10a formed in the circumferential surface side fin 10 is formed in the normal rotation direction, the same is true. The effect of can be obtained. In that case, when the rotor cup rotates in the forward direction (clockwise when viewed from the end face side), it changes from the ventilation hole 10a of the circumferential surface side fin to the ventilation hole 9a of the end face side fin, and when it rotates in the reverse direction, the ventilation hole of the end face side fin. Fresh outside air flows from 9a to the ventilation holes 10a of the fins on the circumferential surface side, and it is possible to sufficiently prevent the stator 3 from overheating.

Further, in order to allow the air sucked from the vent holes 9a of the end face side fins to smoothly diffuse and pass between the stator 3 and the rotor cup 4, a groove serving as a flow path of air is formed on the inner surface of the rotor cup 4. It is also effective to provide. As a result, the flow velocity of the air taken in can be increased, so that a higher cooling effect can be obtained.

[0021]

According to the present invention, the cooling means for heat generation of the stator when the motor is operating is formed integrally with the rotor, so that it is possible to provide an inexpensive, highly safe and miniaturized outer rotor motor.

[Brief description of drawings]

FIG. 1 is a side sectional view of a main part showing an outer rotor motor according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a main part showing a conventional outer rotor motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Shaft 2 ... Bearing 3 ... Stator 4 ... Rotor cup 5 ... Back yoke 6 ... Magnet 7 ... Printed circuit board 8 ... Photointerrupter 9 ... End surface side fin 10 ... Circumferential surface side fin

Claims (1)

[Scope of utility model registration request] 1. An outer rotor motor comprising a stator and a rotor cup which is formed into a cup shape with an end surface and a circumferential surface and is provided so as to cover the stator. An outer rotor motor is formed on the end surface of the rotor cup so as to project outward. An end face side fin, a vent hole formed in the rotor cup so as to be ventilated, having an opening in either the normal or reverse rotation direction of the rotor cup in the end face side fin, and the circumferential surface of the rotor cup. A circumferential surface side fin formed so as to project outward, and an opening portion in the rotation direction of either the forward or reverse direction of the rotor cup in the circumferential surface side fin, which allows ventilation in the rotor cup. An outer rotor motor, comprising: a formed vent hole.