JPS63154050A - Manufacture of rotor with permanent magnet - Google Patents

Abstract

PURPOSE:To sufficiently enhance the attracting strength of a permanent magnet and to improve the productivity by engaging a nonmagnetic reinforcing cylinder with the magnet disposed on the outer periphery of a shaft, pressing the cylinder, and then spot-welding it to the shaft between the magnets. CONSTITUTION:A reinforcing cylinder 4 formed in a cylindrical shaft of predetermined inner diameter in advance is engaged with the outer periphery of a permanent magnet 2. Then, it is set in a press, the magnets 2 are pressed by the die 6 of the press therebetween. Thus, the cylinder 4 is deformed, and closely contacted with a shaft 1 exposed at the inner periphery between the outer surface of the magnet 2 and the magnet 2. Thereafter, when it is set in a spot- welder to spot-weld the contacting parts of the cylinder 4 and the shaft 1, the cylinder 4 is completely secured to the shaft 1. Then, when the magnet 2 is magnetized, a rotor with a permanent magnet is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method of manufacturing a rotor with permanent magnets, in which permanent magnets are arranged around the outer periphery of a shaft.

(Prior Art) Conventionally, this type of rotor has generally had a configuration in which permanent magnets are attached to the outer periphery of a shaft using an adhesive so as to be positioned intermittently in the circumferential direction. However, especially in recent years, rotating electric machines have become faster and more powerful, and rotors manufactured using the conventional method described above have a high risk of permanent magnets being separated and scattered due to centrifugal force acting on the permanent magnets. . Therefore, a structure as shown in, for example, Japanese Utility Model Application Publication No. 55-120285 has also been considered. This involves fixing a permanent magnet to the outer circumferential surface of the shaft with adhesive, then fitting a non-magnetic reinforcing tube into it, pressing the reinforcing tube between the permanent magnets so that it contacts the shaft, and then attaching the reinforcing tube to the shaft. It is screwed to the shaft at the contact area.

(Problems to be Solved by the Invention) However, in the above manufacturing method, the reinforcing tube is not press-processed, and many steps such as drilling and thread cutting of the shaft, drilling of the reinforcing tube, and screwing of screws are required. This has the disadvantage that it becomes necessary and leads to a decrease in productivity. Moreover, since it is fastened with screws, there is a risk that the screws may come loose due to vibrations during rotation after long-term operation, which is a problem in that reliability is still lacking.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for manufacturing a rotor with permanent magnets, which can sufficiently increase the reliability of the fixing strength of the permanent magnets and also improve productivity. be.

[Structure of the Invention] (Means for Solving the Problems) A method for manufacturing a rotor with permanent magnets according to the present invention is to arrange permanent magnets intermittently in the circumferential direction on the outer periphery of a shaft, and to After fitting the non-magnetic reinforcing tube, the reinforcing tube is pressed between the permanent magnets so as to be deformed toward the shaft, and then the reinforcing tube is spot welded to the shaft between the permanent magnets. It is something that is unique in its own way.

(Function) Since the reinforcing tube is spot welded to the shaft between the permanent magnets, the fixing strength of the reinforcing tube is sufficiently high, and unlike screw fixing, there is no risk of the fixing strength being reduced due to vibration. Moreover, the reinforcing tube is deformed by press working,
After that, only spot welding is required, so the number of steps is small and automation is extremely easy.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

First, in FIG. 1 showing the completed form, 1 is a shaft having a large-diameter portion 1a approximately in its center, and 2 is a permanent magnet arranged intermittently in the circumferential direction at equal angular intervals around the outer periphery of this large-diameter portion 1a. ,
Each permanent magnet 2 is, for example, formed by molding and sintering magnetic powder into an arcuate cross-section, and is fixed to the large-diameter portion 1a by an adhesive layer 3. Reference numeral 4 denotes a reinforcing cylinder made of, for example, non-magnetic steel, which, as will become clear from the explanation below, is in a form in which it is in close contact with the surface of the permanent magnet 2 and the portion of the shaft 1 exposed between the permanent magnets 2. and shaft 1
Spot welded at the contact area. The welded portion is indicated by reference numeral 5 in FIG.

Next, we will describe a method for manufacturing a two-legged permanent magnet rotor. First, the outer surface of the large diameter portion 1a of the shaft 1 and the inner peripheral surface of the permanent magnet 2 are degreased and cleaned. Thereafter, an epoxy or acrylic adhesive, for example, is applied to the inner circumferential surface of the permanent magnet 2, and the permanent magnet 2 is placed in a predetermined position and held down with a jig (not shown). As a result, each permanent magnet 2 is fixed to the shaft 1 by the adhesive layer 3. Next, the reinforcement n4, which has been previously formed into a cylindrical shape with an inner diameter of t, is fitted onto the outer periphery of the permanent magnet 2, as shown in FIG. Thereafter, this is set in a press, and as shown in FIG. 3, pressure is applied between the permanent magnets 2 by the press die 6 of the press. As a result, the reinforcing tube 4 is deformed so that its inner circumferential surface closely contacts the outer surface of the permanent magnet 2 and the shaft 1 exposed between the permanent magnets 2. Thereafter, the reinforcing tube 4 is completely fixed to the shaft 1 by setting it in a spot welding machine (not shown) and spot welding the contact portion between the reinforcing tube 4 and the shaft 1. Thereafter, by magnetizing the permanent magnets 2, a rotor with permanent magnets is completed.

According to this embodiment, the permanent magnet 2 is attached to the shaft 1.
After gluing, the permanent magnet 2 can be completely fixed to the shaft 1 simply by fitting the reinforcing T7i4, press working, and spot welding, so it is easy to make holes in the shaft, thread cutting, and drilling holes in the reinforcing cylinder. Productivity is significantly improved compared to conventional methods that require multiple steps such as screw fixing.

In addition, the bonding strength of the welded portion 4 is extremely high compared to conventional screw fastening, so there is no risk of the solid strength of the permanent magnet 2 decreasing due to vibration, etc., and reliability is maintained even at high speed rotation. can be significantly improved.

In the above embodiment, press working and spot welding are each performed using dedicated machines, but the present invention is not limited to this, and both can be performed using the same machine, which improves productivity. Needless to say, this will further improve.

[Effects of the Invention] As described above, in the present invention, a non-magnetic reinforcing cylinder is fitted to a permanent magnet arranged on the outer periphery of a shaft, and after this reinforcing cylinder is press-worked, the shaft is fitted between each permanent magnet. It is characterized by spot welding, which has the excellent effect of greatly increasing productivity as well as greatly increasing the reliability of the permanent magnet's orbit. be.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is a perspective view of a rotor with permanent magnets, FIG. 2 is a sectional view showing a state in which a reinforcing cylinder is fitted, and FIG. 3 shows a press working process. FIG. In the drawing, 1 is a shaft, 2 is a permanent magnet, 4 is a reinforcing cylinder, 5
6 is a welding part, and 6 is a press mold. Applicant: Toshiba Corporation Page 1, Figure 2, Figure 5

Claims (1)

[Claims] 1. Permanent magnets are arranged intermittently in the circumferential direction on the outer periphery of the shaft, and after fitting a non-magnetic reinforcing cylinder to the outer periphery of the permanent magnet, the reinforcing cylinder is deformed toward the shaft between the permanent magnets. 1. A method of manufacturing a rotor with permanent magnets, characterized in that the reinforcing tube is spot-welded to the shaft between the permanent magnets.