JPS61150640A - Permanent magnet rotor - Google Patents

Abstract

PURPOSE:To improve efficiency enlarging the dimension in the direction of the laminated thickness of a permanent magnet, by a method wherein end rings are provided for the both ends of a rotor core, and wherein concave sections are formed on the end rings protruded from the outer diameter of the rotor core, and wherein the end sections of the permanent magnet are positioned at the concave sections. CONSTITUTION:A rotor core 18 having laminated thickness the same as that of a stator core 5 is provided, and the outer diameters of end rings 19, 20 fitting a permanent magnet 23 fitted on the outer periphery of the rotor core 18, at the both ends of the rotor core 18, are made larger than the outer diameter of the rotor core 18. Concave sections 21, 22 are formed on the end rings 19, 20 protruded from the outer diameter of the rotor core 18, and the end sections of the permanent magnet 23 are positioned at the concave sections 21, 22, and the dimension in the direction of the laminated thickness of the permanent magnet 23 is made larger than the dimension of the laminated thickness of the stator core 5.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Use This invention relates to a rotor in which permanent magnets are attached to the outer periphery of the rotor.

(b) Prior art A conventional permanent magnet rotor is, for example, disclosed in Japanese Patent Application Laid-Open No. 59-11747.
The structure is as shown in the publication. here,
To explain the conventional example with reference to this publication, in Fig. 4, (11 is a hermetic electric compressor, (2) is a rotary compression element,
(3) is a permanent magnet type synchronous motor, (4) is a sealed container, (
5) is the stator, (6) is the permanent magnet rotor, (7) is the rotor core, (8) is the permanent magnet, (9) is the aluminum die-casting, Ql is the upper balancer, (11) is the lower balancer, and Sho is the surface reinforcement. The rotor core (7) is made of laminated aluminum die-casting (9) K and has a side part QS (le) to which the permanent magnet (8) is attached in the axial direction. At the same time, the upper balancer (IG) is also integrally formed.Furthermore, the lower balancer (11) is attached as a separate member, and the permanent magnet (8) is aligned with the surface reinforcement member (13) to connect the permanent magnet (8) to the rotor. The permanent magnet rotor (6) is manufactured by fixing it on the outer peripheral surface of the iron core (7).
) is made higher than the lamination thickness of the stator (5), and the length of the permanent magnet (87) attached to the outer peripheral surface of the rotor core is made longer than the lamination thickness of the stator (5). , so that the efficiency of the motor is improved.

el Problems that the invention attempts to solveHowever,
The rotor core (7) is laminated to be longer than the lamination thickness of the stator (5) in order to increase the length of the permanent magnet (8). The expensive rotor core had to be extracted separately.

In order to solve the above problem, this invention forms a recess in the end ring that is provided at both ends of the rotor core and protrudes beyond the outer diameter of the rotor core, thereby changing the stacking thickness of the rotor core to the stacking thickness of the stator. The purpose of this is to enable permanent magnets that are longer than the stacking thickness of the stator to be attached to the outer periphery of the rotor core without causing any damage.

This invention provides a rotor core having the same thickness as the stator core, and a permanent magnet attached to the outer periphery of the rotor core is attached to the outside of the end ring sandwiched between both ends of the rotor core. The end ring has a diameter larger than the outer diameter of the rotor core, and a recess is formed in the end ring that protrudes beyond the outer diameter of the rotor core, and the end of the permanent magnet is positioned in this recess. The length in the stacking thickness direction is increased.

(e) Effect This invention has the above-described configuration, so that the length in the stacking thickness direction is longer than the stacking thickness of the stator due to the recess formed in the end ring with the permanent magnet attached on the outer peripheral surface of the rotor core. Even if the rotor core is compressed, the thickness of the rotor core does not become higher than the thickness of the stator.

(F) Embodiments - The present invention will be described below based on embodiments shown in FIGS. 1 to 3.

Incidentally, the same parts or equivalent parts as in the conventional example shown in FIG. 4 are denoted by the same reference numerals, and the explanation thereof will be omitted.

The permanent magnet rotor (6) of the present invention has a rotor core α-thickness formed by laminating rotor cores αη so as to have the same stacking thickness as the stator (5), and an aluminum die-casting (9) on both ends of the rotor core. Iron core (end ring haze formed larger than the outside diameter of II), rotor core (annular recess r2 formed with end ring QI12GK that protrudes more than the outside diameter of one frame]) (c), and the rotor core located in this recess. A permanent magnet (to) is installed on the outer peripheral surface of the rotor core aυ, and a surface reinforcing member α protects the surface of this permanent magnet.
It is composed of Ri and K.

In the permanent magnet rotor configured as shown in FIG.
2N) @, the length l in the lamination thickness direction is longer than the lamination thickness l of the rotor core (Iυ), and is made to be longer than the lamination thickness of the stator (5). ) is known to improve motor efficiency by making it longer than the thickness of the stator (5).As shown in Figure 3, this motor efficiency is longer than the thickness of the stator (5). becomes almost constant when the length of the permanent magnet (c) becomes approximately 10 koms or more.This means that even if the permanent magnet (c) becomes longer than necessary, the magnetic field that contributes to the generation of torque in the electric motor will not reach the tip. In addition, the stacking thickness is made the same as that of the rotor core or stator (5), so that there is no need to separately punch out the rotor core fin.

The annular recess (21) formed in the end ring (Lic!I)
)■ can be easily formed by cutting the outer periphery after forming it by aluminum die casting (9). In addition, unlike an induction motor, the end ring α9 (a) does not require a secondary current to flow in order to generate torque, and by forming the annular recess 121) E, the end ring α9 (a) is a permanent magnet that does not reduce its strength. All you have to do is insert (c).

Incidentally, in the above description, it has been explained that the recess 01)E of the end ring cLI■ is formed by cutting, but it goes without saying that it may be formed at the same time during machining/drink molding using a die-casting mold.

(g) Effects of the Invention The permanent magnet rotor of the present invention has a rotor core having the same thickness as the stator core, and a permanent magnet attached to the outer periphery of the rotor core is sandwiched between end rings at both ends of the rotor core. The outer diameter is made larger than the outer diameter of the rotor core, and a recess is formed in the end ring that protrudes beyond the outer diameter of the rotor core, and the end of the permanent magnet is positioned in the recess. Since the length of the permanent magnet in the stacking thickness direction is increased, motor efficiency can be improved. Furthermore, unlike in the past, there is no need to increase the thickness of the rotor core in order to make the permanent magnets longer than the thickness of the stator, so the work of punching out the rotor core separately can be omitted.

[Brief explanation of drawings]

1 to 3 illustrate the present invention. FIG. 1 is a sectional view of a permanent magnet type synchronous motor, FIG. 2 is a sectional view of a permanent magnet rotor, FIG. 3 is a characteristic diagram showing motor efficiency, and FIG. 4 is a sectional view of a permanent magnet rotor. The figure is a sectional view showing a compressor incorporating a conventional permanent magnet type synchronous motor. (5)...Stator, (6)...Permanent magnet rotor, <lt...Rotor core, (11■...End ring, f21) (C)...Recess, (To)... permanent magnet.

Claims (1)

[Claims] (1) A rotor core is provided with the same thickness as the stator core, and the outer diameter of the end ring that sandwiches the permanent magnet attached to the outer periphery of the rotor core between both ends of the rotor core is larger than the outer diameter of the rotor core. , and a recess is formed in the end ring that protrudes beyond the outer diameter of the rotor core, and the end of the permanent magnet is located in this recess, so that the length of the permanent magnet in the stacking thickness direction is longer than the stator's stacking thickness. A permanent magnet rotor characterized by: