JPS5925570A - Field pole of motor - Google Patents

Abstract

PURPOSE:To remove the cogging operation by a method wherein the pole pieces of stators to be arranged alternately facing mutually are set as to make a gap surrounding the pole pieces to be equalized in the axial direction. CONSTITUTION:The pole pieces 20a, 21a of stators 20, 21 are formed in the pedestal type, the stators are engaged alternately interposing an interval between them, and the gap surrounding totally the pole pieces is set as to equalize the interval (d) in the axial direction at all points. When the gap surrounding totally the adjoining pole pieces is formed equally in the axial direction like this, because the area of the field system in relation to the magnetic poles of a rotor is fixed always regardless of the rotating position of the rotor, the cogging operation is not occurred.

Description

[Detailed Description of the Invention] The present invention aims to improve the startability of a stepping motor, etc. by reducing inertial vibrations and bearing noise caused by the twitching action occurring between the rotor and field poles. This relates to field poles for motors.

BACKGROUND ART Conventionally, stepping motors shown in an exploded perspective view in FIG. 1 and an assembled view in FIG. 2 have been used.

In the figure, (1) is a rotor consisting of a cylindrical multi-pole permanent magnet (2+) and a rotating shaft (3), C, (4) and (5).
) is a pair of left and right coil bobbins with one coil wound in a balanced manner.

The coil bobbin (4) (5) has a stator (3) which also serves as a casing and has a large number of identically shaped magnetic pole pieces (6a), and an equal number of identically shaped magnetic pole pieces (7).
a) A stator (held from both sides of the sword and the sword,
and the other coil bobbin (5) each has a magnetic pole piece (8
a)+(9a), which is held from both sides by the stators (8) and (91);
The rotating shaft (3) of the rotor (1) passing through the center of (force + (8), (9)) is the bearing 00 of the stator (6) which also serves as the casing and the bearing (11'a) of the lid body aυ.
It is rotatably supported.

In the configuration of the stepping motor, each stator has identical magnetic pole pieces (6a) (!: (7a) , and (
8a) and (9a) are positioned alternately facing each other without contacting each other, and the left and right coil bobbins (4) and (
5), each magnetic pole is positioned out of phase.

However, in the conventional stepping motor mentioned above, the multi-pole field poles, which are comb-shaped magnetic pole pieces forming the stator, generally have square teeth or rectangular teeth, as shown in Figure 6. The magnetic pole pieces face each other with a gap left, but no particular consideration is given to the size of that gap. That is, the difference between the distance (a) between the tooth profile base ends and the distance (b) between the tooth tips in the axial direction of the stator increases, and this difference in gap size appears as a change in magnetic force. This is the cause of the Kotsuking phenomenon.

As a result, residual torque increases, torque loss increases, efficiency decreases, vibrations and noise are caused, and the life of the bearing is shortened due to bearing loss caused by the above. There is.

This invention was made to solve the above-mentioned conventional drawbacks, and in order to eliminate the knitting phenomenon that occurs between the rotor and field poles in stepping morphs, etc., the shape and arrangement of the comb-shaped magnetic pole pieces of the stator are taken into consideration. The present invention provides field poles for a motor, characterized in that gaps around magnetic pole pieces of stators arranged alternately facing each other are set to be equal in the axial direction.

First, the basic principle of this invention will be explained based on FIG. 4 and FIG. M5. As shown in Fig. 4, a state in which there is no Kotsuking phenomenon means that a cylindrical field pole magnetic iron plate (S) is placed coaxially with the row 20 of the cylindrical magnet, and the rotor (to) In this case, there is no change in magnetic resistance, so no tipping occurs.

Furthermore, even if the cylindrical magnetic iron plate (8) is cut into rings at the center, or even if the cut pieces are slightly moved in the axial direction while remaining coaxial, there is no change in magnetic resistance.
Kotsuking does not occur.

Therefore, by changing the above-mentioned round cutting method, cutting is performed in an arbitrary shape on the circumference with the round cutting part as the center line, for example, in the shape of a triangular wave, a sine wave, or a trapezoidal wave as shown in FIG. Even if the cylindrical magnetic iron plates (S), (S) are moved a certain distance in the axial direction, no twitching occurs as in the above case.

In this case, the constant distance in the axial direction of the cylindrical magnetic iron plates (S) (E) means that they are set at equal intervals at any point in the axial direction, are interlocked alternately, and have the same shape. It is necessary.

What is shown in FIG. 6 is an embodiment of the present invention constructed based on the above-mentioned basic principle, and the comb-shaped stator (2) (2) is shown in a developed view. The magnetic pole pieces (20a) and (21a) of Q0υ are formed into a trapezoidal shape and are interlocked alternately with gaps between them. It is set to be.

As mentioned above, if the gaps around the entire circumference of adjacent magnetic pole pieces are formed equally in the axial direction, the field area with respect to the rotor's magnetic poles will always be constant regardless of the rotor's rotational position. , the trickling phenomenon does not occur.

In addition, the magnetic pole piece (20a) of the stator (2 (Jol))
The shape of (21a) is not limited to a trapezoid, but may be any shape as long as the spacing in the axial direction can be made equal at all points; for example, a shape such as a triangular wave and one sine wave can be arbitrarily selected. be.

As described above, according to the present invention, in a field pole for a motor in which a large number of Fi & pole pieces of the same shape oriented in the axial direction are arranged alternately N and S at the same pitch in the circumferential direction, Since the gaps around the entire circumference of the nine adjacent magnetic poles are equal in the axial direction, the field area with respect to the rotor's magnetic poles is always constant regardless of the rotational position of the rotor, and changes in reluctance are virtually constant. It can be considered that there is no minimum reluctance position like in conventional motors, but because the rotor is attracted to the minimum reluctance position, it is a phenomenon that requires torque to escape from the starting position, i.e. Since no twitching phenomenon occurs, stable rotation can be obtained during motor operation.

Moreover, by eliminating the above-mentioned twitching phenomenon, inertial vibrations and bearing noise are also reduced, and there are other effects such as improvement in starting and stopping.

[Brief explanation of the drawing]

Figure 1 is an exploded perspective view of the stepping motor, Figure 2 is a partially sectional side view showing the assembled state, Figure 3 is an enlarged side view showing the arrangement of the magnetic pole pieces in Figure 2, and Figures 4 and 5. The figure is a perspective view of the main part of the morph to explain the basic principle of this invention, and FIG. 6 is a developed view of the stator showing an embodiment of this J. (1)...Rotor, (2)...Cylindrical magnet, (3)...
... Rotating shaft, (4) (5) ... Coil bobbin, (
61(7) +8) (9)...Stator, (6a)
(7a) (8a) (9a)...Magnetic pole piece, tl11+
... bearing, (11) ... lid, (11a) ... bearing, (to) ... rotor, (S) (S) ... cylindrical iron plate for field, t2U) (2υ・...Stator, (20a)
(21a)...Magnetic pole piece. Patent applicant Asumo Co., Ltd. Reisha

Claims (1)

[Claims] Regarding a field pole for a motor in which a large number of magnetic pole pieces of the same shape oriented in the axial direction are arranged alternately N and S at the same pitch in the circumferential direction, the gap between adjacent magnetic pole pieces around the entire circumference is as follows: A field pole for a motor, characterized in that the field poles are formed to be equal in the axial direction.