JPH01170354A - Rotor for magnet generator - Google Patents

Abstract

PURPOSE:To smoothly rotate a rotor by providing a plurality of partition walls protruding axially from the annular base of the inner bottom of a cup-shaped yoke, and securing a magnet disposed between the walls by elastic protrusion pieces attached to the walls. CONSTITUTION:An annular positioning member 8 of synthetic resin is loosely press-fitted to the inner bottom of a cup-shaped yoke 6, and its base 8b is secured by a pin 8a to a predetermined position. The member 8 has two axial partition walls 8c, 8d, a magnet 7 is inserted to a zone A therebetween, pressed by a cuplike suppressing cylinder 9 clamped by screws to the bottom, and secured by an adhesive coating in advance the outer periphery. The wall 8d has elastic members 8e elastically protruding circumferentially at both sides. Thus, the magnet 7 is effectively held, and even if magnet pieces has irregular dimensions, a rotor can be smoothly rotated.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a rotor suitable for a magnetic generator used in a small engine. This invention relates to a positioning structure for fixing permanent magnet pieces.

[Conventional technology]

Conventionally, it is known that permanent magnet pieces are positioned on the inner circumferential surface of a cup-shaped yoke using a holder, and the inner surface thereof is fixed with a cup-shaped metal inner cover. (For example, JP-A-56-56158).

[Problem that the invention seeks to solve]

However, when adopting such a fixing method, if the dimensional accuracy of the magnet piece is poor, the size of the gap between the holder and the magnet will fluctuate, which will inevitably reduce the positioning accuracy of the magnet and cause the output power to change. Since the rotational balance of the yoke deteriorates due to waveform distortion, a balancing process is required to prevent this, which hinders productivity improvement.

[Means for solving problems]

In order to solve the above-mentioned problems, this invention aims to reduce the unbalance of the position of the magnet piece as much as possible even if the dimensional accuracy of the magnet piece is reduced. A positioning member comprising a current base and a plurality of partitions protruding from the base in the axial direction is provided at the bottom, and a magnet piece is held between the plurality of partitions,
The present invention is characterized in that the partition wall portion is provided with a protruding piece that elastically protrudes toward the magnet piece.

[Effect]

Since the magnet pieces are pressed against the other partition wall by the protruding pieces provided on one partition wall, they are positioned at a constant position even if the dimensions of the magnet pieces vary.

〔Example〕

Hereinafter, the present invention will be explained with reference to the illustrated embodiment. In the figure, 1 is a small generator used for a motorcycle, a rotating magnet 3 attached to a crankshaft 2, and a generating coil 5 supported by a case 4. It is made up of.

The rotating magnet 3 is constituted by a permanent magnet piece T adhered to the inner surface of a cup-shaped soft iron yoke 6. That is, after the current positioning member 8 made of synthetic resin is loosely press-fitted into the inner bottom of the yoke 6 and fixed in a predetermined position by the pin 8a, an arc shape is formed within the nine predetermined spaces A defined by the positioning member 8. A substantially square magnet piece T is inserted, pressed by a cup-shaped holding tube 9, and fixed with an adhesive applied to the outer peripheral surface in advance.

Here, the positioning member 8 is currently a positioning protrusion 8a.
The inner periphery of the yoke 6 is rotated by 90° by the base 8b having
The magnet piece 7 is pushed in at an angle of ! Set 4 spaces A. Note that the partition wall 8c merely projects vertically from the base 8b, but the other partition wall 8d is formed into a bifurcated shape as shown in FIG. A protruding piece 8e is formed to elastically protrude in the direction. In addition, in this embodiment, the partition wall portion is 8e+
It consists of two types of structures as shown in 8d, but all of them may have protruding pieces 8, or as shown in Fig. 6, the - partitions are bifurcated and only the - sides are provided with protruding pieces 8. Of course, a protruding piece 8 may also be provided. Furthermore, as shown by the two-dot chain line in FIG.
Alternatively, an elastic auxiliary protruding piece 8f may be protruded toward the opening of the yoke to serve for positioning.

According to this embodiment, when the positioning member 8 is fixed in the yoke 6 and the magnet piece 7 is inserted into the space A divided by the partition walls 8c' and 8d, the magnet piece T is moved by the elastic protruding piece 8e. Since it is pressed against the other partition wall portion 8c+8d, the position of the magnet piece T in the circumferential direction is determined and it does not become in a floating state.

〔Effect of the invention〕

As described above, in this invention, a positioning member having a plurality of partition walls is provided at the bottom of the inner surface of the yoke 6, and a magnet piece held between the partition walls is elastically held by a protruding piece provided on the partition wall. Therefore, even if the gap between the partition wall of the holder and the magnet piece differs for each magnet piece due to variations in the dimensions of the magnet pieces, the position of the magnet piece will be fixed and the magnet piece will not move between the partition parts. Since there is no distortion in the output waveform of the generator, the yoke 60 rotation balance will not deteriorate.
This has the effect of eliminating the need for balance adjustment, allowing the initial objective to be achieved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a front view of the generator, FIG. Figure 4 shows the mV-I
5 is a sectional view taken along line v--2, and FIG. 6 is a sectional view corresponding to FIG. 5 showing another embodiment. 4... Rotating magnet, 6... Fist... Yoke, 7... Magnet piece, 8... Positioning member, 9... Holding tube, 8
b...11 current base, 8e+8d...partition part,
8...Protruding piece.

Claims (4)

[Claims] (1) A positioning member consisting of an existing base and a plurality of partition walls protruding from the current base in the axial direction is provided at the bottom of the inner surface of a cup-shaped yoke, and a magnet piece is held between the plurality of partition walls. A rotor for a magnet generator according to the invention, wherein the partition wall is provided with a protruding piece that elastically protrudes toward the magnet piece. (2) A rotor for a magnet generator according to claim 1, wherein the protruding piece is molded integrally with the partition wall part from synthetic resin. (3) A rotor for a magnet generator according to claim 1, wherein the partition wall portion is an even number, and a protruding piece is provided at every other partition wall. (4) The rotor of the magnet generator according to claim 1, wherein the base of the positioning member is provided with an auxiliary protruding piece that elastically protrudes toward the opening direction of the yoke between the partition walls. .