JPS6155336B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small motor and a method for assembling the same.

In recent years, anisotropic ferrite magnets with a large amount of magnetic flux have been attracting attention as permanent magnets, and the yoke member to which this anisotropic ferrite magnet is attached needs to be thick to prevent magnetic saturation due to the large amount of magnetic flux. Because of this, the yoke member cannot be formed by deep drawing of a thin iron plate like a conventional motor case, and in order to attach the magnet, a cut-and-raised piece is provided in the thick yoke member, and the cut-and-raised piece is cannot be bent at right angles.

In view of the above, the present invention aims to provide a small motor with a simple structure and easy assembly, and an easy method for assembling the same. An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 shows an exploded perspective view, in which 1A and 1B are a pair of resin brackets, one of which is 1A, which also serves as a rotating head receiving case for an electric shaver, and has a pair of locking brackets connected to the razor case on its inner surface. Retaining claws 2, 2 are provided protrudingly. Bearings 4A, 4B are press-fitted into central recesses 3A, 3B on opposing inner surfaces of the pair of brackets 1A, 1B, respectively, and an annular projecting wall 5 is formed around the bearings.
A and 5B are provided. A pair of opposing walls 6A, 6A, 6B, and 6B are protruded from each of the annular projecting walls, and a pair of retaining grooves are provided on the circumferential surfaces of the annular projecting walls 5A, 5B in a direction perpendicular to the opposing directions. 7A, 7
A, 7B, 7B are formed. Each opposing wall 6
A, 6B have two fitting protrusions 8A, 8, respectively.
A, 8B, 8B are provided on the outer surface. A pair of insertion holes 9, 9 are provided on the inner surface of the other bracket 1B, and brushes 10, 1 are inserted into the insertion holes, respectively.
The leg pieces 11, 11 of No. 0 are inserted, and the tips of the leg pieces protrude from the lower surface of the bracket 1B. Further, a wedge piece 12 having a cut and raised retaining protrusion 12' is press-fitted into each insertion hole 9 to fix each brush 10.

Next, 13 is a rotor, and its shaft 14 has a rotor core 16 around which a rotor coil 15 is wound, and a commutator 1.
7 and a thrust receiving eyelet 18 are fixed. A pair of arcuate field magnets 19, 19 are made of anisotropic ferrite magnets with a large amount of magnetic flux, and are positioned and fixed between the side surfaces of the opposing walls 6A, 6A, 6B, 6B. 20, 20 are a pair of thick approximately C-shaped yoke plates, and a pair of field magnets 1.
It is located on the outer periphery of numbers 9 and 19. Each yoke plate 19 has protrusions 21C, 21C, 21 at both ends.
D, 21D and a pair of grooves 22C, 22 at both ends
C, 22D, and 22D, and are vertically and horizontally symmetrically formed.

The small motor according to the present invention has the above-mentioned structure, and a method for assembling the same will be explained next. First, the brushes 10, 10 are fixed in advance to the insertion holes 9, 9 of one bracket 1B by press-fitting the wedges 12, 12.
Using this bracket 1B as a base, set the bracket 1B so that the commutator 17 is located between the brushes 10, 10.
The shaft 14 of the rotor 13 is attached to the bearing 4B of the bracket 1B by inserting a jig into the pair of arcuate holes 23, 23 provided in the brushes 10 and 10 to widen the gap between the brushes 10, 10.
process). Next, one end side of the pair of field magnets 19, 19 is inserted and attached between the pair of opposing walls 6B, 6B of the bracket 1B (second step). In Fig. 2, the rotor 13 is attached to the bracket 1B, and one field magnet 1 is attached to the bracket 1B.
9 is shown attached. In this case, each field magnet 19, 19 is attracted to the core 16 of the rotor 13. Subsequently, as shown in FIGS. 3 and 4, the pair of concave grooves 22C, 22C on one end side of each yoke 20 are fitted into the fitting protrusions 8B, 8B on the outer surface of the opposing wall 6B, and the protrusions 21C, 21C on both sides, Bracket 1 for 21C
Insert into the locking grooves 7B, 7B of B (third step).
The attached state of the pair of yoke plates 20, 20 is shown in FIG. Next, in the state shown in FIG. 5, insert the bearing 4A of the other bracket 1A into the tip of the rotor shaft 14 (the fourth
process). Furthermore, the other bracket 1A is moved downward and the outer protrusions 8A, 8A of the pair of opposing walls 6A, 6A provided on the other bracket are inserted into the grooves 22D, 22D on the other end side of each yoke plate 20, respectively. A pair of locking grooves 7 on the other bracket 1A that fit together.
A, 7A are the protrusions 2 on both sides of the other end of each yoke plate 20.
A pair of opposing walls 6A, 6A are hung on 1D, 21D.
are positioned between the sides of the pair of field magnets 19, 19, respectively (fifth step). In this case, the opposing wall 6A,
In order to facilitate the insertion of the field magnets 19 and 6A, inclined surfaces 24, 24 are formed on the lower edges of both sides of each opposing wall 6A, and the inclined surfaces allow each opposing wall 6A to be inserted into the pair of field magnets 19, 24.
19, and thereby the pair of field magnets 19, 19 are inserted between the upper and lower four opposing walls 6A, 6A,
6B, 6B, it is positioned at the regular position,
A desired air gap 25 is formed between the magnetic pole surface of each field magnet 19 and the magnetic pole surface of the rotor core 13. Finally, as shown in FIG. 6, the side edge projecting pieces 26C, 26C, 26D, 26D of each groove 22C, 22D are bent so as to face each other, thereby completing the assembly.

Therefore, a pair of substantially C-shaped yoke plates 20, 2
The movement in the axial direction with respect to the pair of brackets 1A and 1B is achieved by grooves 22 at both ends of each yoke plate 20, 20.
C, 22C, 22D, 22D and each bracket 1
External protrusions 8 provided on opposing walls 6A and 6B of A and 1B
A, 8A, 8B, blocked by fitting with 8B,
Further, the movement of each yoke plate 20 in the circumferential direction and the radial direction with respect to each bracket 1A, 1B is
0 both side protrusions 21C, 21C, 21D, 21
D and insertion grooves 7A and 7B of each bracket 1A and 1B
The structure is simple, and even when an anisotropic ferrite magnet with a large amount of magnetic flux is used as a field magnet, the thick yoke plate 2 is prevented.
Each yoke plate 2 is
0 and each bracket 1A, 1B. Further, a pair of arc-shaped field magnets 19, 19 are connected to opposing walls 6A, 6A, 6 of each bracket 1A, 1B.
Since it is positioned at B and 6B, the yoke plate 2
By combining 0, 20 and brackets 1A, 1B,
Assembling is facilitated by positioning and fixing the field magnets 19, 19 at predetermined positions. Further, each yoke plate 20 has protrusions 21C at both ends symmetrically in the vertical and horizontal directions.
21C, 21D, 21D and grooves at both ends 22C, 2
2C, 22D, and 22D, there is no mounting directionality of each yoke plate 20, and each yoke plate can be easily handled, which is advantageous for automatic assembly. In addition, the shaft 14 of the rotor 13 is mounted around one bracket 1B, and a pair of field magnets 19, 19 are placed between the pair of opposing walls 6B, 6B of one bracket 1B so that a portion of the field magnets 19 is attracted to the rotor core 16. Installed,
A pair of yoke plates 20, 20 are attached to one bracket 1.
B to attach the field magnets 19, 19 to the yoke plate 2.
0 and 20, and finally the other bracket 1A is attached to the yoke plates 20 and 20, making it easier to handle the field magnets 19 and 19 when assembling them.
Easier transition to automated assembly.

According to the present invention, by arranging a pair of arcuate field magnets between a pair of opposing walls formed on the inner surface of each bracket, the circumferential and axial positions of the field magnets are regulated, and A fitting protrusion is provided on the outer surface of each opposing wall, and a pair of retaining grooves are provided in the bracket in a direction orthogonal to the opposing direction of the pair of opposing walls, and these grooves are provided symmetrically in the vertical and horizontal directions of the pair of substantially C-shaped yoke plates. The protrusions on both ends are inserted into the locking grooves, and the grooves on both ends of each yoke plate are fitted into the fitting protrusions, so that the ends of each yoke relative to each bracket are positioned at three locations. This improves the mounting position accuracy and simplifies the mounting of each yoke to one bracket. Therefore, even when a field magnet with a large amount of magnetic flux is used and each yoke plate is made of a thick material, the yoke can be easily attached, and the protrusions on both ends and the protrusions on both ends for attaching to a pair of brackets are easy to install. Since the concave grooves at both ends are provided vertically and horizontally symmetrically, handling of the yoke plate becomes easy, and since the fitting protrusion is provided on the opposing wall, the motor can be downsized.

[Brief explanation of the drawing]

The drawings show an embodiment of a small motor according to the present invention, and FIG. 1 is an exploded perspective view. Figures 2 to 5
The figures show the assembly order, and FIGS. 2, 4, and 5 are perspective views of essential parts, and FIG. 3 is a side view. FIG. 6 is a half-sectional front view. 6A, 6A, 6B, 6B... Opposing wall, 7A, 7
A, 7B, 7B...Latching groove, 1A, 1B...Bracket, 4A, 4B...Bearing, 13...Rotor,
19, 19...Field magnet, 20, 20...Yoke plate, 21C, 21C, 21D, 21D...Protrusions on both ends, 22C, 22D...Concave groove, 8A, 8B...
...Fitting protrusion, 14...Rotor shaft.

Claims (1)

[Scope of Claims] 1. A pair of brackets each having a pair of opposing walls formed on their inner surfaces and a pair of latching grooves in a direction perpendicular to the opposing direction, and a bearing provided on the pair of brackets. A rotor that is supported by a shaft, a pair of arc-shaped field magnets that oppose the rotor through a gap and are positioned on each of the opposing walls, and a pair of approximately C-shaped field magnets located on the outer periphery of the pair of field magnets. a yoke plate, each of the yoke plates having both side protrusions at both ends and grooves at both ends symmetrically in the upper and lower directions, the protrusions being inserted into the latching grooves, and the grooves being provided on the outer surface of the opposing wall. A small motor characterized by fitting into a fitting protrusion. 2. A first step of mounting the shaft of the rotor on the bearing of one of the brackets, a second step of attaching a pair of arc-shaped field magnets between a pair of opposing walls provided on the one bracket, and The protrusions at each end of a pair of substantially C-shaped yoke plates each having protrusions on both ends and concave grooves on both ends are inserted symmetrically into a pair of locking grooves provided on one of the brackets, and the concave grooves are inserted into the opposing grooves. a third step of fitting into a fitting protrusion provided on the outer surface of the wall; a fourth step of inserting the bearing of the other bracket into the shaft; and an outer surface protrusion of the pair of opposing walls provided on the other bracket. are fitted into the grooves on the other end of each of the yoke plates, and a pair of latching grooves provided on the other bracket are engaged with protrusions on both sides of the other end of the yoke plate to secure the other bracket. a fifth step of positioning a pair of opposing walls between the pair of field magnets.