JPS6188749A - Preparation of permanent magnet type rotor - Google Patents

Abstract

PURPOSE:To exactly position mutual permanent magnets between them and prevent resin from leaking, by a method wherein the jointed sections of the permanent magnets are impregnated with thermosetting resin, and wherein the sections are covered with thermoshrinkable tube and heated. CONSTITUTION:A plurality of permanent magnets 2 are arranged at equal intervals in the direction of the periphery on a rotary shaft 1, and are covered with thermoshrinkable tube 3. The tube 3 is protruded from the end face of the permanent magnets 2, and the central sections 3a jointed to the permanent magnets 2 are impregnated with thermosetting resin. The thermoshrinkable tube 3 is thermally shrunk by heating the jointed sections in a furnace, and the unhardened resin of said thermosetting resin is made to flow into the spaces between mutual permanent magnets 2 in the direction of the periphery, and the spaces are filled up with resin to be thermally hardened 4. Then, the both salient end sections 3b protruded from the end face of the permanent magnets 2 are also shrunk by heating, and said resin is put in contact with each end face and is prevented from leaking out of the spaces. And each permanent magnet 2 is exactly fixed on the rotary shaft 1.

Description

[Detailed description of the invention] (Technical field to which the invention pertains) The present invention provides a method of disposing a plurality of permanent magnets at equal intervals in the circumferential direction on the outer peripheral surface of a rotating shaft or a ring-shaped yoke fitted thereto. The present invention relates to a method of manufacturing a permanent magnet type rotor.

[Conventional technology]

When manufacturing this type of permanent magnet rotor, the permanent magnet is fixed on the rotating shaft by covering the permanent magnet with a heat-shrinkable tube, heating it to shrink the heat-shrinkable tube, and permanently dissipating the shrinking force. There is a method that works on a magnet.

Fixed h'' of such a permanent magnet: Structure is 1. Permanent 141i
The fixing of J is based solely on the radial contraction force of the heat shrinkable tube, and it does not have a positioning function in the circumferential direction relative to the permanent magnet. Therefore, in order to prevent the permanent magnets from shifting in the circumferential direction, we have a structure that does not create circumferential gaps between the permanent magnets when they are arranged on the rotating shaft. It is necessary to have a structure in which the surfaces are in close contact with each other, so there is no tolerance in the dimensions of the permanent magnet, and dimension management in (a) is troublesome.

[Purpose of the invention]

Therefore, an object of the present invention is to provide a rotating permanent magnet type that facilitates dimensional control by providing dimensional tolerance to permanent magnets in manufacturing, and that also provides a circumferential positioning function between the permanent magnets. The objective is to provide a method for producing children.

[Wx essentials for invention]

In order to achieve this object, the present invention arranges a plurality of permanent magnets at equal intervals in the circumferential direction on the outer peripheral surface of a rotating shaft or a ring-shaped yoke fitted thereto, and A heat-shrink tube having a length that projects in the axial direction and is impregnated with a thermosetting resin is placed only on the central permanent magnet contacting part, and by heating, the thermosetting resin is attached to the permanent magnet. The permanent magnet is fixed by causing the permanent magnet to flow between the permanent magnets and hardening the heat-shrinkable tube and heat-shrinking the heat-shrinkable tube.

[Example of invention in action]

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings.

According to the present invention, as shown in FIG. permanent magnet 2
, and then cover it with the heat shrink tube 3. The heat shrinkable tube 3 has an axial length longer than that of the permanent magnet 2, and has projecting ends 3b, 3b projecting from the end face of the permanent magnet 2 on both sides in the axial direction. A contact center portion 3a of the heat-shrinkable tube 3 that contacts the permanent magnet 2 is impregnated with a thermosetting resin. Both protruding ends 3b are not impregnated with thermosetting resin.

After the heat-shrinkable tube 3 is placed on the permanent magnet 2 as shown in FIG. 1, the heat-shrinkable tube 3 is heated in a furnace. As a result, the heat-shrinkable tube 3 begins to wear out due to heat, and the uncured impregnated resin in the abutment center portion 3a is squeezed out, creating a gap between the permanent magnets 2 in the circumferential direction as shown in FIG. It flows into the interior and heat-cures while filling these voids. Reference numeral 4 indicates a thermosetting resin that flows into the gap between the permanent magnets 2, is filled therein, and is thermosetted. At this time, both protruding ends 3b, 3b protruding from the end face of the permanent magnet 2 are also contracted by heating, and as shown in FIG. Prevent leakage to the outside.

As the heat-shrinkable tube 3 is heat-shrinked and the resin is cured, the permanent magnets 2 are securely fixed on the rotating shaft 1, including their circumferential positioning.

〔Effect of the invention〕

As described above, according to the present invention, when a permanent magnet is fixed on a rotating shaft using a heat-shrinkable tube, the contact portion with the permanent magnet is impregnated with a thermosetting resin, and both axial ends are permanently fixed. By using the hot acid bath 11 tube that protrudes from the end face of the magnet, the impregnated resin that flows out due to heating is filled into the gap between the permanent magnets and hardened, so that the permanent magnets can be reliably positioned with respect to each other. Therefore, the gap between the C1 permanent 14i stones will no longer have a negative effect on the positioning of the permanent magnet, and dimensional control in the production of permanent magnets will become easier. By covering with magnets, fixation of the permanent 611 stones is additionally strengthened over and above that achieved by heat shrink tubing alone. Even if thermosetting resin is used, both protruding ends of the heat-shrinkable tube adhere tightly to both end faces of the permanent magnet due to thermal acid 4III, preventing resin from leaking to the outside, so problems caused by resin leakage can be avoided. It will never occur.

[Brief explanation of drawings]

FIG. 1 shows hot acid on a permanent magnet according to the present invention. 111 is a vertical cross-sectional view showing the state before heating with the tube covered, FIG. 2 is a vertical cross-sectional view showing the state of the same device after heating, and FIG. 3 is a cross-sectional view along the line ■-■ in FIG. . 1...Rotating shaft, 2...Permanent magnet, 3...Heat-shrinkable tube, 4...Thermosetting glue (grease).

Claims (1)

[Claims] A plurality of permanent magnets are arranged at equal intervals in the circumferential direction on the outer peripheral surface of the rotating shaft or a ring-shaped yoke fitted thereto, and the permanent magnets have a length such that they protrude in the axial direction from both end surfaces of the permanent magnets. , and a heat-shrinkable tube impregnated with a thermosetting resin is placed only on the central permanent magnet contacting part, and heated to cause the thermosetting resin to flow between the permanent magnets and harden. A method of manufacturing a permanent magnet rotor, comprising fixing the permanent magnets by heat-shrinking a heat-shrinkable tube.