JPH01308159A - Opposed type motor - Google Patents

Abstract

PURPOSE:To eliminate the torque loss of apparatus by using a fixed yoke obtained through holding an insulating material between soft magnetic material foils, winding them spirally and insulating them radially. CONSTITUTION:A motor is composed of a rotor yoke fixing a permanent magnet, said permanent magnet, a coil, a fixed yoke 4, etc. To constitute said fixed yoke 4, soft magnetic material 4-1 such as Fe-Si-B amorphous material is insulated by an insulating material 4-2 such as Al2O3 and formed into a spiral shape. Thus, an eddy current loss generated in the fixed yoke 4 by rotation of the permanent magnet can be reduced to almost zero and the torque loss of apparatus also to zero.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stator yoke for a surface facing type motor.

[Conventional technology]

Conventionally, there are two types of surface-facing brushless DC motors: a fixed yoke type (Fig. 4) that does not take eddy current loss into account, and a rotating yoke type (Fig. 5) that takes eddy current loss into account. It was constructed from soft magnetic material plates such as silicon steel plates.

To explain the components of the motor, 1 is a fixed permanent magnet motor, 2 is a permanent magnet, 3 is a coil, and 4 is a yoke. Both the fixed yoke type (Figure 4) and the rotating yoke type (Figure 5) are made of silicon steel plates, etc. It is made up of soft magnetic material foils. 5 is a bearing unit, 6 is a spindle, 7 is an FG magnet, 8 is a speed detection element, 9 is a Hall element, 10 is a boss, 11, 12, and 13 are only rotating yoke types (Figure 5), and 11 is a print substrate,
12 is a thrust bearing, and 13 is a mantle.

[Problems to be solved by the invention] In the case of the conventional fixed yoke type (Fig. 4), when the rotation speed is high as can be seen from the equation of torque loss due to eddy current, -11 for boat fishing.
000 rpm or more, when the air gap magnetic flux density is set high, or when the permanent magnet diameter is large and the yoke diameter is large, the torque loss due to eddy current increases, so a rotating yoke type (Figure 5) has to be used. If a yoke type is used, as can be seen by comparing FIG. 2 and FIG. 3, in the case of a rotating yoke type, an air gap is required on both sides of the coil because the yoke is also rotated. As a result, the magnetic resistance increases (and the magnetic efficiency decreases, at the same time the motor thickness also increases.Also, since the permanent magnets and rotating yoke located on both sides of the coil rotate across the air gap, the coil has tonality. is required and of course becomes thicker, so the magnetic resistance also increases, the magnetic efficiency decreases, and at the same time the motor thickness also increases.Also, the number of component parts increases, and as mentioned above, the yoke also rotates. Therefore, it is necessary to improve the accuracy of parts, and at the same time it becomes difficult to assemble and adjust.
Connects to Up. Furthermore, in order to compensate for the decrease in magnetic efficiency, it is also necessary to increase the thickness of the permanent magnet. As a result, Co5t
This also increases the thickness of the motor.

In other words, the major problems with the rotating yoke type (Figure 5), which is a method to eliminate current loss, which is a major problem with the fixed yoke type (Figure 4), are as follows: 1. Magnetic efficiency Down (as a compensation method) Make the permanent magnet thicker → ■Co5t U
2. Motor thickness increases. 3. Co5t Up for assembly adjustment. 4. Co5t Up for increasing the number of parts.

t - Fixed yoke thickness P: Number of poles of permanent magnet N, motor rotation speed Bg: Magnetic flux density of gap between permanent magnet and yoke ρ: Electrical resistance γ of fixed yoke. , the radius of the yoke outer diameter γ1. Radius of the inner diameter of the yoke [Means (and effects) to solve the problem] In the case of the present invention, the problems of the rotating yoke type (Fig. 5) (1. Magnetic efficiency Down (as a way to compensate, the thickness of the permanent magnet is increased) →C
o5t Up, motor thickness becomes thicker) 2 Motor thickness becomes thicker. 30 assembly adjustment Co5t Up4, fixed yaw type without Co5t Upl to increase the number of parts (4th
This is a major problem with the fixed yoke type (Figure 4). In order to eliminate torque loss due to eddy current loss that occurs in the fixed yoke due to the rotation of the permanent magnet, the fixed yoke is made of a soft magnetic material and is wrapped in a spiral shape with an insulating material sandwiched between the ends, so that the fixed yoke is electrically insulated in the radial direction. By using a yoke, the eddy current generated in the fixed yoke due to the rotation of the permanent magnet cannot flow in the radial direction because the fixed yoke is insulated in the radial direction. Torque loss does not occur.

〔Example〕

1, 2, and 3 show embodiments of the present invention. FIG. 1 shows a fixed yoke, which is a main component of the present invention, and FIG. 2 shows an enlarged view of section A of the fixed yoke. FIG. 3 shows a motor using a fixed yoke according to the present invention.

First, the motor configuration will be explained using FIG. 3.

1 is a rotor yoke that fixes a permanent magnet, 2 is a permanent magnet, 3 is a coil, 4 is a fixed yoke which is a main component of the present invention, 5 is a bearing unit, 6 is a spindle, 7 is an FG
8 is a speed detection element, 9 is a position detection element, and 10 is a boss.

Next, the structure of the fixed yoke 4 will be explained using FIG. 1 and FIG. 2. The fixed yoke 4 is made of soft magnetic material 4-1 such as Fe-8i-E amorphous material. It is insulated with an insulating material 4-2 such as 203, and formed into a thinly wound shape to form a fixed yoke.

By using the fixed yoke as described above, the eddy current loss generated in the fixed yoke due to the rotation of the permanent magnet 2 can be reduced to almost zero. As a result, torque loss can be reduced to zero.

〔Effect of the invention〕

As explained above, by using a fixed yoke in which an insulating material is sandwiched between a soft magnetic material and an insulating material is wound in a spiral shape and insulated in the radial direction, torque loss due to eddy current can be eliminated. has an outer diameter of φ30 m
m, rotation speed 2000 rpm, magnetic flux density 4.000 G
Even in the case of a motor of the order of AUSS, it accounts for about 20% of the output torque.

Since torque loss does not occur, the original output torque of the motor may be reduced by about 20%, so a motor with the same torque can be obtained even if the permanent magnet thickness is made thinner or the drive current is reduced. Also, being able to make the permanent magnet thinner means that the motor thickness can be made thinner, and at the same time, rare earth magnets are very expensive among the motor components, so Co5t can be made thinner.
It also becomes Down.

In addition, since the drive current can be reduced, when driven by batteries, the battery life is extended and the product value is increased.
e also decreases.

On the other hand, if the fixed yoke of the present invention is used without reducing the permanent magnet thickness or drive current, torque loss will not occur, so the output l.
You can upload Ruku to a large size.

Also, as a method to prevent eddy current loss, there is a rotating yoke type motor, but compared to this rotating yoke type, the magnetic resistance is smaller and the magnetic efficiency is increased, so in order to obtain the same torque, it is natural to increase the permanent magnet thickness. Co5t Do
wn Motor thickness can be made thinner. Or it can be done without reducing the drive current. In addition, in the case of the rotary yoke type, as can be seen by comparing FIGS. 4 and 5, the motor thickness is essentially thicker.

That is, by using the fixed yoke of the present invention, it is possible to have both the advantages of a conventional fixed yoke type motor and the advantages of a rotating yoke type motor.

[Brief explanation of the drawing]

FIG. 1 shows a fixed yoke according to the present invention, FIG. 2 is a partially enlarged view of FIG. 1, FIG. 3 shows a motor using the fixed yoke according to the invention, FIG. 4 shows a conventional fixed yoke type motor, The figure also shows a conventional rotating yoke type motor. ■ is a rotor yoke, 2 is a permanent magnet, 3 is a coil, 4 is a fixed yoke which is the main component of the present invention, 4-] is a soft magnetic material, 4-2 is an insulating material, 5 is a bearing unit, 6 is a spindle , 7 is an FG magnet, 8 is a speed detection element, 9 is a position detection element, and 10 is a boss. 4th fixed yoke type magazine Figure 5 Rotating yoke type 2

Claims (2)

[Claims] (1) A surface-facing motor that uses a fixed yoke that faces a permanent magnet and is wound in a spiral shape with an insulating material sandwiched between soft magnetic foils. (2) The surface facing type motor according to claim 1, wherein the soft magnetic material foil has a thickness of 20μ to 200μ.