JP2008154369A - Outer rotor type motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an outer rotor type motor which secures specified thrust force without using a thrust magnet and also is inexpensive and is stable in property since it suppresses the temperature rise within a rotor frame. <P>SOLUTION: The roof of a rotor frame 2 includes a through hole 12, and the vicinity of the through hole 12 includes a vane 3 for exhaust or air intake, and also the periphery of the rotor frame 2 is extended in the radial direction of the motor, at a specified air-gap 4 from a board 1 thereby generating thrust force. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an outer rotor type motor having a stator inside and a rotor outside.

The structure of a conventional outer rotor type rotor is shown in FIG. Conventionally, in order to obtain the axial force (thrust force) for the purpose of preventing the rotor from slipping off or suppressing excessive levitation during rotation, it has been generally practiced to use a thrust magnet separately from the field magnet. Yes. That is, a thrust magnet 11 is provided, and an axial force (thrust force) is obtained by using a magnetic attractive force between the thrust magnet 11 and the rotor frame 2. (For example, refer to Patent Document 1.)
JP 2001-25208 A

  A problem to be solved is that a thrust magnet is provided for the purpose of preventing the rotor from coming off or suppressing over-levitation during rotation, which has been a factor in increasing the cost of the motor. Further, since the rotor frame is on the cup, it is difficult to suppress the temperature rise of the windings, and an increase in loss due to an increase in resistance or the like causes a decrease in drive efficiency.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and ensures a predetermined thrust force without using a thrust magnet and suppresses a temperature increase in the rotor frame. An object is to provide a motor.

  In order to solve the above-described problems, the present invention provides a base, a sleeve disposed on the base, a stator on which a coil is wound and disposed on the sleeve, a shaft, and a shaft that rotatably supports the shaft. In an outer rotor type motor consisting of a disposed bearing, a cup-shaped rotor frame attached to the shaft, and a magnet disposed inside the rotor frame so as to face the stator, it penetrates the top surface of the rotor frame. An outer rotor type motor characterized in that a hole is provided, an exhaust or intake vane is provided in the vicinity of the through hole, and the outer periphery of the rotor frame is extended in the radial direction of the motor with a predetermined gap from the base. is there.

  Motor According to the outer rotor type motor of the present invention, an outer rotor type motor that is inexpensive and has stable motor characteristics is provided to ensure a predetermined thrust force without using a thrust magnet and to suppress a temperature rise in the rotor frame. Can be provided.

  A base, a sleeve disposed on the base, a stator wound with a coil and disposed on the sleeve, a shaft, a bearing rotatably supporting the shaft and disposed in the sleeve, and attached to the shaft In an outer rotor type motor comprising a cup-shaped rotor frame and a magnet disposed inside the rotor frame so as to face the stator, a through hole is provided in the top surface of the rotor frame, and exhaust or In addition to providing intake blades, the outer periphery of the rotor frame is extended in the radial direction of the motor with a predetermined gap from the base.

  FIG. 1 is a structural sectional view of an outer rotor type motor according to the present embodiment, and FIG. 2 is a bird's eye view of a rotor frame. In FIG. 1, a bearing 8 that rotatably supports a shaft 10 is disposed on a sleeve 9 disposed on the base 1, and a stator 6 around which a coil 7 is wound is disposed. A cup-shaped rotor frame 2 is attached to the shaft 10, and a magnet 5 is disposed on the inner periphery thereof so as to face the stator 6. Here, as shown in FIG. 2, a through hole 12 is provided in the top surface of the rotor frame 2, exhaust or intake blades 3 are provided in the vicinity of the through hole 12, and the outer periphery of the rotor frame 2 is connected to the base 1. A predetermined gap 4 is extended in the radial direction of the motor. When the rotor rotates, due to the effect of the blades 3 of the rotor frame 2, air in the rotor frame 2 is exhausted and air enters through the gap 4 as shown in FIG. 3. At this time, since the air gap 4 is a predetermined air gap, the speed of the air flow increases in this air gap 4, and the pressure in the air gap 4 decreases due to Bernoulli's law, and the thrust that sucks the rotor frame 2 to the base 1 is obtained. Force is generated. That is, a thrust magnet is not necessary. Furthermore, since the air in the rotor frame 2 flows, the temperature rise of the heating element such as the coil 7 is suppressed, so that an increase in loss can be suppressed.

  In addition, although it is exhausting with the blade | wing 3 in the above, it is good also as intake. Further, the blade 3 is integrated with the rotor frame 2 in FIG. 2, but may be a separate member.

  The outer rotor type motor of the present invention is inexpensive and optimal for stabilization of motor characteristics, and is useful for applications that dislike temperature rise, applications that require low-cost motors, and the like.

Cross-sectional view of an outer rotor type motor according to the present invention Bird's-eye view of rotor frame in the present invention Explanatory drawing of air flow and thrust force in the present invention Cross-sectional view of a conventional outer rotor type motor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Rotor frame 3 Blade | blade 4 Air gap 5 Magnet 6 Stator 7 Coil 8 Bearing 9 Sleeve 10 Shaft 11 Thrust magnet 12 Through-hole

Claims (2)

A base, a sleeve disposed on the base, a stator wound with a coil and disposed on the sleeve, a shaft, a bearing rotatably supporting the shaft and disposed in the sleeve, and attached to the shaft In an outer rotor type motor composed of a cup-shaped rotor frame and a magnet disposed inside the rotor frame so as to face the stator, a through hole is provided in the top surface of the rotor frame, and exhaust or An outer rotor type motor characterized in that intake blades are provided and the outer periphery of the rotor frame extends in the radial direction of the motor with a predetermined gap from the base. A disk drive device on which the outer rotor type motor according to claim 1 is mounted.