JPS6091851A - Magnet rotary type motor - Google Patents

Abstract

PURPOSE:To reduce the bearing loss torque of a magnet rotary type motor by providing a pair of stators opposed to both sides of a magnet arranged fixedly to a rotor, thereby cancelling a thrust load. CONSTITUTION:A plurality of circular magnets 13 are axially arranged fixedly on a magnet retainer 12 engaged with a rotational shaft 11. A pair of stators 14, 15 are provided through air gaps to both sides of the magnets 13. Since the direction of a thrust load produced by the stator 14, coils 16 and the magnets 13 is opposed to that of a thrust load produced by the stator 15, a coil 17 and the magnets 13, the thrust load applied to the rotor can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a magnet rotating electric motor used in industry and in the general household.

Conventional Structure and Problems Conventionally, in this type of magnet rotating electric motor, as shown in FIG. A plurality of magnets 4 are arranged and fixed in an annular shape through an annular yoke 3 so as to form a plurality of poles in the axial direction. The rotating shaft 1, rotor housing 2, yoke 3, and magnet 4 are collectively referred to as a rotor.

A stator 5 has a toroidally wound core provided with slots in the axial direction and a coil 6 wound around the stator, and is disposed opposite the magnet 4. 7 is the stator 6 and bearing 8
It is a housing that holds the The bearing 8 receives the rotating shaft 1. A sensor 9 detects the magnetic pole of the magnet 4, and includes a control circuit (not shown) that generates a rotating magnetic field in the stator 6 in response to a signal from the sensor 9. ) 0 is a thrust stop.

However, in the above configuration, magnetic flux is generated in the axial direction because the magnets 4 fixedly fixed to the rotor and the stator 5 are arranged face-to-face, and as shown in FIG. , the horizontal axis shows the magnetic flux density B9) As the magnetic flux density Bq increases, the thrust load increases,
When this thrust load increases, the bearing loss torque T increases as shown in FIG. 3 (the vertical axis shows the bearing loss torque torque, the horizontal axis shows the thrust load W, and the parameter is the rotation speed n). As a result, the efficiency of the motor is significantly reduced, and furthermore, the bearing itself generates more heat, shortening its lifespan. However, in an inner rotor type electric motor or an outer rotor type electric motor, the magnetic flux is generated radially with respect to the shaft, so they cancel each other out, and basically no thrust load is generated. However, when used as a small-diameter motor, a face-to-face motor is better than an inner rotor motor.

Compared to outer rotor type electric motors, it can be said to be more suitable due to the following points. For example, when comparing a motor with an outermost diameter of about 60 mm as shown in Fig. 4 (the same parts as in Fig. 1 are given the same reference numerals and their explanations are omitted), an inner rotor type motor Figure 4a).

The outer rotor type electric motor (Fig. 4b) has a stator 5 and rotors 3 and 4 formed on plane concentric circles perpendicular to the axial direction of the rotating shaft 1, and slots of the stator 5 are provided radially with respect to the shaft. Therefore, the difference in the inner diameter of the stator rr'
It is impossible to increase the ir. Therefore, the number of coil turns is equivalent to the number of coil turns that can be wound in a surface-facing type electric motor as shown in Fig. 4C.It is extremely difficult to wind a coil in a Keinner rotor type or outer rotor type electric motor, and it is extremely difficult to obtain the desired characteristics. It becomes difficult.

OBJECTS OF THE INVENTION The present invention solves these conventional problems and provides a small-diameter electric motor in which the thrust load is offset by a surface-facing type, which is not possible with an inner rotor type or an outer rotor type.

Structure of the Invention The magnet-rotating electric motor of the present invention comprises a rotating shaft, a magnet fixed to the rotating shaft in an annular shape so as to have multiple poles in the axial direction, a pair of stators, and a magnet formed on the stator. Mello 1. The stator has a winding inserted into the stator and a sensor for detecting the magnetic pole of the magnet, and the pair of stators are provided opposite to each other on both sides of an annular magnet with a gap in the axial direction. .

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 6, 11 is a rotating shaft, and 12 is a magnet receiver into which the rotating shaft 11 is fitted, and magnets 13 are arranged and fixed in an annular shape so as to form a plurality of poles in the axial direction. 14.1
Reference numeral 5 denotes a stator in which a toroidally wound core is provided with slots in the axial direction, and a coil 16°17 is wound around the stator.
A gap is provided in the axial direction facing each other on both sides of 3.

18 is the stator 14.15 and the bearings 19, 2
0, the bearing 19°20
receives the rotating shaft 11. 21 is the magnet 13
It is a sensor that detects the magnetic pole of the sensor 21, and includes a control circuit (not shown) that generates a rotating magnetic field in the stator 14, 15 in response to a signal from the sensor 21. 22.2
3 is a thrust stopper. In the above configuration, a magnet 130 fixed to the rotor
A pair of stators 14 and 15 are arranged opposite to each other on both sides with a gap between them.
Since stator 14, coil 16 and magnet 1 are provided,
Since the directions of the thrust load generated by the rotor 3 and the thrust load generated by the stator 16, the coil 17, and the magnets are opposite to each other, they cancel each other out, and in total, the thrust load applied to the rotor can be eliminated. Therefore,
Bearing loss torque is independent of magnetic flux, and the efficiency of the motor can be increased by the amount of reduction in bearing loss torque, and the heat generation of the bearing itself can be suppressed, resulting in a longer service life.

Since a pair of stators 14 and 15 are provided opposite to each other on both sides of the magnet 13 arranged and fixed to the rotor, with a gap between them,
The conventional coil 9 has a small diameter, and the coils 16 and 17 can be easily inserted, providing excellent assemblability.

Effects of the Invention As is clear from the above embodiments, the magnet-rotating electric motor of the present invention has a pair of stators facing each other on both sides of the magnet arranged and fixed to the rotor, with an air gap between them. ,
It offsets the thrust load and, as a result, reduces the bearing loss torque.It increases the efficiency of the electric motor, suppresses the heat generation of the bearing, extends the life of the bearing, and can also be made smaller in diameter. It has excellent features.

[Brief explanation of drawings]

Figure 1 is a sectional view showing an example of a conventional magnet rotating electric motor.
Figure 2 is a curve diagram of thrust load vs. magnetic flux density, Figure 3 is a curve diagram of bearing loss thrust load, and Figure 4 is a curve diagram of thrust load vs. magnetic flux density.
... are sectional views schematically showing the inner rotor type and outer rotor type two-sided opposed type of the conventional magnet first rotating electric motor, respectively, and FIG. 5 is a sectional view of the magnet rotating electric motor showing an embodiment of the present invention. It is. 11... Rotating shaft, 13... Magnet, 14.
15... Stator, 16.17... Coil, 21... Sensor. Name of agent Patent attorney Toshio Nakao and one other person No. 4 Fig. 2 Fig. 3 Slide Kao W

Claims (1)

[Claims] A rotating shaft, a magnet arranged and fixed to the rotating shaft in an annular shape so as to have multiple poles in the axial direction, a pair of stators, a coil inserted into a slot formed in the stator, and magnetic poles of the magnet. 1. A magnet-rotating electric motor, comprising: a sensor for detecting annular magnets; and the pair of stators are provided opposite to each other on both sides of an annular magnet with a gap in the axial direction.