JPH03143238A - Rotor - Google Patents

Abstract

PURPOSE:To protect a permanent magnet by winding a wire rod made of a metal on the outer circumferential section of the permanent magnet and conducting brazing and resin mold extending over a plurality of positions in the direction of a shaft including a winding end or overall length in the direction of the shaft. CONSTITUTION:A yoke 2 is formed in a thick cylindrical shape by laminating a plurality of doughnut-shaped sheet metals having shaft holes 3 and a plurality of resin through-holes 8, and a plurality of tile-shaped permanent magnets 4 are arranged at regular intervals and mounted. Wire rods 6 wound on the outer circumferential sections of the permanent magnets 4 are wound in single layers, and sections among winding ends and the wire rods are fixed through brazing. A work under a state in which the permanent magnets 4 are set up to the yoke 2 and the wire rods 6 are wound on the outer circumferential sections of the permanent magnets 4 is set to a molding die, and a resin 7 molding the whole rotor is molded through an arbitrary molding means. Accordingly, overall strength reduction is prevented, and quality corresponding to centrifugal force and shearing stress can be improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotor equipped with permanent magnets used in an inner rotor type electric motor, and in particular to a rotor equipped with a permanent magnet for use in an inner rotor type electric motor. Regarding the rotor.

[Prior art]

In the rotor of an inner rotor type electric motor equipped with permanent magnets such as ferrite magnets having poor mechanical strength, the protection structure of the permanent magnets has been a problem for some time. In addition, with the trend toward higher speeds of electric motors, countermeasures for centrifugal force resistance of not only ferrite magnets but also permanent magnets located on the outer periphery of the rotor have become an important issue.

Conventionally, as disclosed in JP-A-58-151855, for example, in a structure in which the outer circumference of a permanent magnet is covered with a cylindrical cover, a thin metal tube such as stainless steel is generally used as the material of the cylindrical cover. We have achieved some results in terms of mechanical strength and workability when the rotor is started up in the morning.

However, the biggest drawback in this case is that a large amount of eddy current is generated in the metal tube when the motor is operated, which results in an increase in so-called stray load loss, which causes a significant reduction in motor efficiency.

For example, in the protective structure of the outer periphery of the permanent magnet,
The device disclosed in Japanese Patent No. 9-148555 is constructed by winding a metal wire instead of a metal tube, which increases the electrical resistance of the protective member by 2, thereby reducing stray load loss. It is possible.

[Problem to be solved by the invention]

The above-mentioned protective structure in which a metal wire is wound around the outer periphery of a permanent magnet has the problem of fixing the ends of the wound wire, and in the past, it was attached to both axial ends of the rotor to secure the ends of the permanent magnet. A structure has been proposed in which the terminal is bent into a protective end plate to be clamped.

However, since the above-mentioned clamping structure is a clamp made of soft metal, it is still insufficient in terms of quality assurance against centrifugal force during high-speed rotation and shear stress during acceleration and deceleration. Furthermore, if the clamp part breaks, or if there is a weak point in the wire being wound, the breakage of that part will cause all the wires to come loose, damaging the entire protective structure. There was a risk of

The quality concerns regarding the protective structure of these permanent magnets are as follows:
This problem has become more serious as rotors rotate at higher speeds, and rotors are now required to have higher quality reliability than ever before.

[Means to solve the problem]

The present invention protects a permanent magnet using a wound wire and a resin molded therein.

In the rotor of the present invention, a metal wire is wound around the outer periphery of a permanent magnet, and the wire is brazed at a plurality of locations in the direction of the rotation axis including at least the winding end, or over the entire length in the direction of the rotation axis,
It is constructed by roughly covering the wound layer of the wire and molding it with a resin.

[Effect]

By brazing, the wound end of the wire rod is fixed and protected against loosening in a quality-stable configuration, and the above-mentioned fixation and protection are further strengthened by the resin covering the outer periphery of the wound layer of the wire rod and between the wire rods.

〔Example〕

Embodiments of the present invention will be described based on the drawings.

1 and 2 show respectively a top sectional view and a front sectional view of a rotor 1 according to the invention.

In the figure, reference numeral 2 denotes a yoke, which is formed into a thick cylindrical shape by laminating a plurality of doughnut-shaped thin iron plates having a shaft hole 3 and a plurality of resin through holes 8. 4 is a tile-shaped permanent magnet;
A plurality of them are mounted on the outer periphery of the yoke 2 in an evenly distributed manner. As the permanent magnet 4, a ring-shaped one integrally formed may be used. A wire rod 6 is wound around the outer circumference of the permanent magnet 4, and is wound in a single layer, and the winding end and the wire rod are fixed by brazing, which will be described later. As the wire, a metal wire with excellent tensile shear strength such as a stainless steel wire is suitable, and in particular, if a round wire is used, it is inexpensive and dimensionally stable, making it easy to control accuracy.

Further, 7 is a resin for molding the entire rotor, and a permanent magnet 4 is attached to the yoke 2, and a workpiece with a wire rod 6 wound around the outer periphery is set in a mold, and molded by any molding method. It is something that will be done. If productivity is important, injection molding is preferable for boat fishing, and in this case resin 7
A thermoplastic material is used. In addition, PPS resin is particularly suitable for applications that require refrigerant resistance, such as the rotor of a hermetic electric compressor, and has heat resistance, resistance to
5=-4= Inorganic material such as glass fiber is added within a range of about 40% by weight as required for strength etc.

By the above molding, the resin 7 fills the resin through hole 8 and passes through the inside of the yoke 2, and the outer periphery of the wound wire 6 is covered with the resin 7, and end rings 9, 9 are attached to both axial ends. is formed. Furthermore, the gaps 5 between the permanent magnets 4 are also filled with the resin 7, and as a result, the permanent magnets 4 are fixed.

This gap 5 plays the role of improving the resin rotation in the axial direction, and since the resin 7 also circulates around the inner circumference of the wire 6 in the gap δ, the wire 6 can be sandwiched from both the inner and outer circumferences. This will strengthen the fixation. When a round wire is used as the wire as shown in the figure, gaps are likely to occur between the wound wires, so the resin surroundings are also good.

In particular, by roughly winding the wire rods 6 at intervals, the resin 7 is also filled between adjacent wire rods 6, as shown in FIG. can do. In this case, the shear strength of the resin layer itself is also strengthened, and for example, strength deterioration occurs at the confluence of resin flows during molding, resulting in cracks.
5, the adhesive force of the resin 7 existing between the wire rods 6 prevents the resin layer from being destroyed.

FIG. 4 shows an example of the winding structure of a wire around the outer periphery of a permanent magnet and its fixing structure. In the figure, 10 shows a wave-wound body with a permanent magnet attached to the outer periphery of a yoke, and 11 shows a wave-wound body with a permanent magnet attached to the outer periphery of a yoke. The brazing of the wire rod 6 wound around the outer periphery of the permanent magnet is shown in the figure. The winding configuration of the wire rod 6 is determined according to the mechanical strength such as centrifugal force resistance, the mounting form of the permanent magnet, etc., as shown in (a) and () in Fig. 4.
As shown in b), the structure is densely wound over the entire length in the direction of the rotation axis, or as shown in (C) and (d), the winding is unevenly wound, or as shown in (e), there is a specific winding. A configuration is adopted in which the wire is wound around only a portion of the wire. Also wire rod 6
As shown in (b) to (e), the brazing portions 11 are provided at multiple locations in the direction of the rotating shaft including at least the winding ends at the beginning and end of the winding, or as shown in (a), the brazing portions 11 are It is effective to provide it over the entire length in the axial direction, and to provide it in a dense portion of 60 turns of the wire as shown in the figure. In this case, if the wire rod itself, which is the base material, is melted and bonded by manual welding, the wire rod is likely to melt and break, making quality control extremely difficult. Therefore, each of the brazing parts 11 is made by brazing and joining several wire rods 6 together using silver solder, solder, etc. without melting the base material.

The rotor 1a in FIGS. 5 and 6 shows another embodiment of the present invention, in which the end ring 9 formed of the resin 7 in the embodiment in FIG. 2 is replaced with a non-magnetic metal material such as zinc. An example is shown in which a separately formed end plate 9a is used.
The same reference numerals are given to the same or equivalent parts as those in the figures and FIG. When equipping the rotor with a balance weight, the end plates 9a, 9a can be used to attach a balance weight to the end plate, to provide an unbalanced weight to the end plate, or to make a balance by drilling holes in the end plate. Considering this advantage, it is provided as a separate part because it makes it easy to make adjustments.

R- In FIGS. 5 and 6, the yoke 2a is provided with a plurality of crimping pin through holes 8a, and the end plates 9a, 9a are fixed to both ends of the yoke 2a by crimping pins 12 passing through the crimping pin through holes 8a. ing. In addition, 14.14
is a protrusion for positioning the permanent magnet 4. The resin 7 for molding the rotor is placed on the end plate 9a toward the gap 5 between the permanent magnets.

It is injected through injection holes 13, 13 provided in 9a, which also function as gas vents, to fill the gaps 5 between the permanent magnets, and at the same time cover the outer periphery of the wound wire 6 and fix them. still,
If the wire rod 6 is wound tightly and the resin 70 does not flow around the wire outer periphery, the resin can be filled without problems by locally cutting out the outer diameter portion of the end plate 9a and adding a resin injection hole.

〔Effect of the invention〕

According to the present invention, the wire rod wound around the outer periphery of the permanent magnet is fixed by brazing, so that quality-stable fixing can be achieved without melting the wire rod, and the outer periphery of the wound layer of the wire rod or By molding the wire rods together with resin, the wire rods can be fixed even more firmly. In addition, even if a wound wire is partially damaged, the adhesive force of the resin or brazing between the wires can be applied at multiple locations in the direction of the rotation axis or over the entire length. This prevents strength deterioration, and as a result, the quality against centrifugal force and shear stress is improved, and a rotor with excellent reliability against high-speed rotation can be constructed.

In addition, since the outer periphery of the wire is protected by the resin, the wire does not come into contact with a jig or the like and be damaged when the motor is started up in the morning.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a plan sectional view of the rotor taken along the line Q--Q in FIG. 2, and FIG.
A front cross-sectional view of the rotor cut along the P line, Fig. 3 is an enlarged view of the main part of the cross section corresponding to Fig. 2 showing another embodiment, and Fig. 4 shows different winding and fixing structures of the wire rods. FIGS. 5 and 6 are perspective views showing an embodiment, and FIGS. 5 and 6 show still another embodiment. FIG. 5 is a plan view of the rotor taken along the line S-3 in FIG. The figure is a front sectional view of the rotor taken along line R-0-R in FIG. 1.1a...rotor, 2,2a...yoke, 4...
・Permanent magnet, 6... Wire rod, 7... Resin, 11...
Brazing is the department.

Claims (2)

[Claims] (1) A metal wire is wound around the outer periphery of a permanent magnet, and the wire is brazed at multiple locations in the direction of the rotation axis, including at least the winding end, or over the entire length of the wire in the direction of the rotation axis, so as to cover the wound layer of the wire. A rotor characterized in that it is constructed by resin molding. (2) The rotor according to claim 1, characterized in that the winding of the wire rod is unevenly arranged in the outer circumference of the permanent magnet.