KR20020048700A - Compress motor - Google Patents

Abstract

PURPOSE: A compressor motor is provided to increase a reluctance torque and a magnet torque by forming a magnet embedded on a rotator with protruding poles. CONSTITUTION: A motor for a compressor is comprised of a stator and a rotor(20) arranged therein. The rotor(20) is comprised of a magnet(22) having protruding poles and a core(21). The core(21) is layered by a sheet iron core having an inserting groove for inserting the magnet(22). The core(21) has a coupling groove(21a) for coupling the sheet iron core on the front and the rear of the inserting groove. The protruding poles are formed on both side of the magnet(22) in an outer direction of the core(21). An angle between the protruding poles is larger than an angle between a tangent line contacting the internal sides of the protruding poles and one internal side thereof.

Description

Compressor Motor {COMPRESS MOTOR}

The present invention relates to a compressor motor, and more particularly, to a compressor motor having an improved shape of a magnet embedded in a rotor.

In general, compressors that form an element of a refrigeration cycle are equipped with a compressor motor, and such compressor motors are classified into various types according to a driving method. For example, a brushless motor is used for a variable capacity compressor, and a method of driving a compressor motor by applying a voltage generated according to a switching operation of a switching element of an inverter controlled by a controller to a motor winding is commonly used.

The compressor motor is composed of a stator and a rotor. The SPM (surface permanent magnet type) magnet is enclosed around the rotor according to the coupling structure and the IPM type (interior permanent magnet type) in which the magnet is embedded in the rotor and fixed. ).

1A and 1B are a plan view and a cross-sectional view of a conventional SPM-type rotor, in which a magnet 2 surrounds a core 1 formed by stacking sheet iron cores and a motor shaft (not shown) inside the core 1. The coupling groove (1b) for coupling the fixed groove (1a) and the sheet iron core is inserted is fixed. Then, the magnet 2 is bonded to the outside of the core 1 by using an adhesive, and a thin film cover of a nonmagnetic material such as aluminum (Al) is put thereon.

Since the SPM-type rotor is surrounded by a magnet 1 having a uniform reluctance, the magnetoresistance does not change and is purely dependent on the torque generated by the magnet 1, resulting in less torque generated per unit current. There is a disadvantage that the efficiency is lowered.

In addition, assembling work becomes complicated, such as a magnet bonding process, and there is a fear that a gap is formed due to the detachment of the magnet 2 from the core 1 during high-speed rotation, and an eddy current flows through the nonmagnetic material, resulting in power loss. This will occur.

Accordingly, an IPM type rotor in which a magnet is embedded and fixed to the rotor has been proposed.

2A and 2B are a plan view and a cross-sectional view of a conventional IPM-type rotor, in which a rod-shaped magnet 12 having a straight shape is embedded in a core 11 formed by filling a sheet iron core to fix the core 11. The coupling groove 11b for coupling the fixed groove 11a and the sheet iron core into which the motor shaft is inserted and formed is formed therein.

However, the motor torque, which determines the efficiency of the compressor motor, is obtained by adding the magnet torque to the magnetoresistance torque. In the conventional IPM rotor, the magnet 12 is magnetized in a straight bar shape. Reluctance torque is reduced, resulting in lower efficiency.

In other words, when magnetizing a magnet by applying a magnetic field press to a ferromagnetic material, anisotropy so that the direction of the magnetic domain of the magnet is collected can reduce the magnetoresistance and increase the magnetoresistance torque. Since (11) is a straight bar, anisotropy is very difficult. For this reason, the concentration of the magnet 11 in the magnetic domain direction is remarkably low, so that the effective magnetic flux drops and eventually the efficiency of the motor decreases.

An object of the present invention to improve the shape of the magnet embedded in the rotor to increase the concentration in the magnetic domain direction and to provide a compressor motor that can increase the motor torque by widening the cross-sectional area of the magnet.

1A is a plan view of a conventional SPM type rotor,

Figure 1b is a cross-sectional view of a conventional SPM type rotor,

Figure 2a is a plan view of the IPM rotor of the longitudinal cooling,

Figure 2b is a cross-sectional view of a conventional IPM type rotor,

3 is a view for explaining the coupling structure of the rotor applied to the compressor motor of the present invention,

4 is a plan view of a rotor according to an embodiment of the present invention;

Figure 5a is a view for explaining the magnetic domain direction of the magnet according to the present invention,

5B is a view for explaining an effective magnetic flux generated by the magnet according to the present invention;

5c is a view for explaining the shape of a magnet according to the present invention;

6A and 6B are views for explaining a plan view and a shape of a magnet of a rotor according to another embodiment of the present invention;

7a and 7b is a view for explaining the top view and the shape of the magnet of the rotor according to another embodiment of the present invention,

8a and 8b are views for explaining the top view and the shape of the magnet of the rotor according to another embodiment of the present invention,

9A and 9B are views for explaining a plan view and a shape of a magnet of a rotor according to still another embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

20: rotor 21: core

21a: coupling groove 21b: fixing groove

21c: fitting groove 22, 22a, 22b, 22c, 22d: magnet

23: stator

The present invention for achieving the above object is a compressor motor having a stator and a rotor disposed inside the stator, the rotor is a pole-shaped magnet bent so that the magnetic domain direction is concentrated, Characterized by consisting of a core made by laminating a sheet iron core formed with a fitting groove for fitting the magnet.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a view for explaining the coupling structure of the rotor applied to the compressor motor of the present invention. As shown in the drawing, the rotor 20 according to the present invention includes a bent pole-shaped magnet 22 and a core 21 made by stacking a plurality of sheet iron cores having a predetermined thickness T.

The core 21 has a fixing groove 21a for fixing the motor shaft and a coupling groove 21b for coupling the sheet iron cores therein, and a fitting groove 21c for fitting the magnet 22 therein. It is.

The torque of the motor is determined by the sum of the magnet torque and the magnetoresistance torque, and the larger the torque, the greater the motor torque and the higher the motor efficiency. The motor torque changes according to the shape of the magnet.

The magnet torque is proportional to the volume of the magnet so that the size of the magnet can be made larger.At the same time, when the concentration of the magnet in the magnetic domain direction is low, the magnetoresistance decreases and the magnetoresistance torque drops, so that the magnet is collected. It is necessary.

Therefore, in the present invention, an embodiment of the magnet for increasing the cross-sectional area of the magnet so as to increase the magnet torque and concentrating the magnetic domain direction so as to increase the magnetoresistive torque will be described in order.

4 is a plan view of the rotor according to an embodiment of the present invention, showing a state in which the magnet 22 of the protrusion shape is fitted into the fitting groove 21c of the core 21. This magnet 22 has a V shape.

As shown in FIG. 4, a stator 23 in which a coil is wound is disposed outside the rotor 21, and a driving voltage is input to the coil by an inverter control method to drive the motor.

The magnets 22 are arranged in plural in the core 21 in a symmetrical structure, and protrusions are formed in a shape protruding to both sides toward the outside of the core 21. The thickness D1 of the magnet 22 is equal to or greater than the distance D2 from the outside of the core 21, that is, the distance D2 from the outside of the core 21 to the contact point between the inner surfaces of the two poles 22 of the magnet 22. Set to.

In addition, both ends of the magnet 22 is disposed close to the outside of the core 21, the shortest distance (D3) between the magnets adjacent to each other the shortest distance (D4) between the front end and the outside of the core (21). Shorter. In this way, the distance between the tip of the magnet 22 and the outside of the core 21 should be narrowed to suppress leakage magnetic flux flowing to other magnets adjacent to each other. this is. This is because the longer the distance D4 is, the larger the area becomes, so that the magnetic resistance decreases and the magnetic flux leaking to another magnet increases.

If the distance D4 is too short, it is difficult to form the fitting groove 21c made in the same shape as the magnet 22, so that the length D4 is longer than the thickness T of the sheet iron core.

Preferably, the distance D4 is appropriately selected within the setting range [T <D4 <D3 / 2].

As such, when the magnet 22 is formed in a curved pole shape, anisotropy for concentrating the magnetic domain direction by applying a magnetic field press on the ferromagnetic material is easy, and as shown in FIG. Direction and the magnetic domain direction generated at both ends are collected so that the concentration of magnetic domain direction is increased and the magnetic resistance is reduced. As a result, the magnetic flux passing through the predetermined area A near the center of the magnet 22 increases. That is, as shown in FIG. 5B, the magnetic flux density induced between the magnet 22 and the stator 23 increases, and as a result, the magnetoresistive torque increases, thereby improving motor efficiency.

As shown in FIG. 5C, the shape of the magnet is set so that the angle θ1 of both inner pole surfaces of the magnet 22 is larger than the angle θ2 between the tangent of the contact point where the inner pole surface of the magnet meets and the inner surface of one of the poles. do. In addition, the cross-sectional area S1 of the magnet 22 is larger than the cross-sectional area S2 of the core belonging to the region where the magnetic domain direction of the magnet 22 is concentrated.

6A and 6B illustrate a plan view of a rotor and a shape of a magnet according to another exemplary embodiment of the present invention.

As shown, one end of the magnet 22a extends convexly toward the inner center of the core 21, and the distance D5 therebetween is set to be greater than or equal to the thickness T of the sheet iron core. This makes it longer than the thickness T of the sheet iron core, because if the distance D5 is too short, it is difficult to form the fixing groove 21a made to fix the motor shaft.

In addition, the magnet 22a is formed in a shape in which the angles of the inner surfaces of both salient poles are narrowed. It is set larger than the angle θ12. Here, the angle θ11 is smaller than the angle θ1 of FIG. 5C.

In addition, the cross-sectional area S11 of the magnet 22a is wider than the cross-sectional area S12 of the core, and the cross-sectional area S11 is wider than the cross-sectional area S1 of FIG. 5C. Therefore, the magnet torque which the magnet 22a has increases more.

7A and 7B illustrate a plan view of a rotor and a shape of a magnet according to still another exemplary embodiment of the present invention.

As shown, the magnet 22b has a shape in which one end is convexly extended toward the inner center of the core 21. The cross-sectional area S21 of the magnet 22b is smaller than the cross-sectional area S11 of the magnet 22a of FIG. 6B and is wider than the cross-sectional area S1 of the magnet 22. The distance D5 is set to be equal to or greater than the thickness T of the sheet iron core. Therefore, the magnet torque which the magnet 22b has becomes larger than the magnet torque which the magnet 22 has.

8A and 8B illustrate a plan view of a rotor and a shape of a magnet according to still another exemplary embodiment of the present invention.

As shown, the magnet 22c has a narrow angle between the inner surfaces of both of the salient poles, and the angle θ31 of the inner sides of the salient poles of the magnet 22c is the angle between the tangent of the contact point where the inner faces of the salient poles meet and the inner surface of one of the salient poles. It is set larger than (θ32). Here, the angle θ31 is smaller than the angle θ1 of FIG. 5C.

Since the cross-sectional area S31 of the magnet 22c is larger than the cross-sectional area S1 of the magnet 22, the magnet torque of the magnet 22c increases by that amount.

9A and 9B illustrate a plan view of a rotor and a shape of a magnet according to still another exemplary embodiment of the present invention.

As shown, the magnet 22d is formed in a straight line on a part of both inner poles, and the cross-sectional area S41 is wider than the cross-sectional area S1 of the magnet 22, and the magnet 22d is as much as that. ) Magnet torque increases.

As described above, in the present invention, since the magnet embedded in the rotor is made in a curved pole shape, the magnetic domain direction of the magnet is gathered so that the concentration is increased, so that the magnetoresistance is reduced and the effective magnetic flux is increased, thereby increasing the magnetoresistive torque. Since the cross-sectional area is increased, the magnet torque can be increased, and thus the motor efficiency can be increased by improving the motor torque. In addition, since the distal end of the magnet is disposed closer to the outer side of the core than the distance from other adjacent magnets, the leakage magnetic flux can be suppressed.

Claims (11)

In a compressor motor having a stator and a rotor disposed inside the stator, The rotor, Compressor motor, characterized in that the core is made by stacking a magnetic pole of the curved pole shape so that the magnetic domain direction is concentrated, and a sheet iron core formed with a fitting groove for fitting the magnet. According to claim 1, wherein the magnet is a protrusion formed on both sides toward the outer side of the core, the angle formed by the inner surface of both of the protrusions is formed to be larger than the angle formed by the tangential contact between the inner surface of the protrusion and any one inner surface. Compressor motor, characterized in that. 3. The compressor motor of claim 2, wherein the magnet has a thickness greater than or equal to the longest distance from the outside of the core to the inner surface of both protrusions of the magnet. The compressor motor according to claim 1, wherein the magnet has a larger cross-sectional area than a cross-sectional area of the core belonging to a region in which magnetic domain directions are concentrated. The compressor motor of claim 1, wherein one end of the magnet is convex toward the inner center of the core. 6. The compressor motor according to claim 5, wherein the magnet has a shortest distance between one end thereof and an inner side of the core equal to or more than a thickness of the sheet iron core. The compressor motor according to claim 1, wherein the magnet has a shortest distance from the front end to the outside of the core than a shortest distance from other magnets adjacent to each other. The compressor motor according to claim 1, wherein the magnet has a shortest distance from the front end to the outside of the core than the thickness of the sheet iron core. The compressor motor of claim 1, wherein the fitting groove is formed in the same shape as the magnet. The compressor motor of claim 1, wherein the magnet is made into a V shape. The compressor motor according to claim 1, wherein the core has coupling grooves for coupling the sheet iron cores to the front and the rear of the fitting groove.