KR20170075595A - A rotor for interior permanent magnet motors - Google Patents

Abstract

The present invention relates to a rotor for a permanent magnet type permanent magnet motor, which has an effect of reducing weight and cost and has a high efficiency of cooling a motor.
According to the present invention, there is provided a rotor comprising: a circular rotor having a shaft hole formed at its center for insertion and coupling of a shaft; at least one or more permanent magnets formed along the outer circumferential direction of the rotor and each having two permanent magnets A permanent magnet insertion hole into which a magnet is inserted; a plurality of rivet holes formed in a circumferential direction between the permanent magnet insertion hole and the shaft hole; and a plurality of circumferential through holes formed between the permanent magnet insertion hole and the shaft hole Of the permanent magnet motor of the present invention.

Description

[0001] The present invention relates to a rotor for permanent magnet motors,

The present invention relates to a rotor for an electric motor, and more particularly, to a rotor for an interior permanent magnet (IPM) motor in which a permanent magnet is embedded in a rotor body.

In recent years, a so-called brushless DC motor (BLDC motor) using an electronic switching system using semiconductor elements has been widely used in consideration of the problem of mechanical contact between a commutator and a brush, and a brushless motor has a stator and a rotor According to the arrangement structure, it can be distinguished as an interior rotor type and an exterior rotor type.

In the internal combustion type motor, a so-called IPM type in which a shaft is inserted into the center of a cylindrical permanent magnet or a shaft is inserted into the center of a rotor core in which an electric steel plate is laminated and a plurality of permanent magnets are inserted into the rotor core A permanent magnet insertion type rotor is used.

Recently, permanent magnet embedded type motors (hereinafter referred to as IPM motors) using reluctance torque in addition to magnet torque have been used as high efficiency motors. Reluctance torque is a force generated by using the saliency of the d-axis inductance (Ld) and the q-axis inductance (Lq). For this purpose, permanent magnets are often arranged in a V-shape.

1 is a sectional view for explaining a conventional rotor, and a conventional rotor will be described with reference to the same.

The driving unit of the motor-driven compressor includes a stator (not shown) fixed to the motor-driven compressor and having a coil wound around the teeth and the teeth protruding inwardly, and a rotor 10 having a permanent magnet disposed inside the stator, The rotor 10 is coupled with a driving shaft that rotates integrally with the rotor.

A drive shaft hole 20 is formed at the center of the rotor 10 so that the drive shaft is inserted therethrough. In the outer circumferential direction, a permanent magnet insertion hole 30 in which a permanent magnet is disposed is formed in a V As shown in FIG. The rotor core portion 12 between the drive shaft hole 20 and the permanent magnet insertion hole 30 serves as a passage through which the magnetic flux can pass and supports the rotational force of the drive shaft.

A plurality of permanent magnets are installed in the drive shaft hole 20 so that the drive shaft is in close contact with the permanent magnet insertion hole 30 and the permanent magnet closes all the insertion holes. As a result, there is a problem in that the rotor 10 may be overheated due to the absence of a passage for releasing heat.

In addition, in recent years, there has been a need to reduce the weight of the rotor 10 in order to reduce the cost and improve the rotating force.

However, if the through hole is formed anywhere in the rotor core portion 12, the supporting force for supporting the driving shaft is reduced, the rotation becomes unstable, and the magnetic flux is weakened by interfering with the passage of the magnetic flux .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a buried permanent magnet motor rotor having a weight and cost reduction effect and a high motor cooling efficiency.

A hole is formed in a rotor core portion between a shaft hole formed at the center of the rotor and a permanent magnet insertion hole formed in the outer circumferential direction of the rotor.

The holes may be rivet holes for penetrating the rivets connecting the rotors to be laminated. Or it may be a slit hole to eliminate the flesh of the unwanted rotor core.

The rivet hole and the slit hole may be formed at the same time.

According to an aspect of the present invention, there is provided a rotor comprising: a circular rotor having a shaft hole formed at a center thereof to be inserted and coupled with a shaft; at least one or more rotor blades formed along the outer circumferential direction of the rotor, A plurality of rivet holes formed in a circumferential direction between the permanent magnet insertion hole and the shaft hole and a plurality of rivet holes formed between the permanent magnet insertion hole and the shaft hole, And a plurality of depressed holes formed in a direction perpendicular to the longitudinal direction of the permanent magnet motor.

The plurality of depressed holes may be formed to intersect a circle that passes through centers of the plurality of rivet holes.

The plurality of rivet holes and the plurality of the slit holes may be formed radially outwardly of each inner end portion at a distance of 15.9 mm from the center of the shaft hole.

The plurality of rivet holes and the plurality of fattening holes may be formed radially inwardly at a distance of 20.1 mm from the center of the shaft hole.

The plurality of rivet holes may have a circular shape and an extension of a symmetry axis of each of the permanent magnet insertion holes may be positioned to pass through the center of each of the rivet holes.

The plurality of slit holes may be symmetrical with respect to a straight line connecting the center of the gap between the pair of adjacent permanent magnet insertion holes and the center of the shaft hole.

Wherein each of the weight-loss holes is formed as a part of a circle whose inner end and outer end are referenced to the center of the shaft hole, and both ends of the inner end portion and the outer end portion are connected to each other with respect to the center of the opposing rivet hole May be formed as part of a circle.

The outer end portion is formed to be longer than the inner end portion, and the both side end portions have the same length.

Both side ends of the slit hole may be formed so that each side end portion is spaced apart from the center of the opposing rivet hole by 8 mm or more.

And the number of the permanent magnet insertion holes is eight.

According to the buried permanent magnet motor rotor of the present invention as described above, the rotor includes a plurality of rivet holes and a plurality of fattening holes formed in a circumferential direction between the permanent magnet insertion holes and the shaft holes, It is possible to reduce the weight and reduce the cost.

In addition, the plurality of rivets for engaging the rotors laminated along the plurality of rivet holes penetrate to easily assemble the laminated rotor members.

In addition, the plurality of rivet holes and the plurality of slit holes serve as a passage through which the refrigerant can pass, and the efficiency of cooling the motor can be increased.

The plurality of rivet holes and the plurality of slit holes are formed radially outward from the center of the shaft hole at a distance of 15.9 mm from the center of the shaft hole and each of the outer ends is spaced from the center of the shaft hole by 20.1 mm The support force of the shaft can be maintained without interfering with the passage of the magnetic flux while forming the holes.

The plurality of rivet holes are formed in a circular shape, and each of the slit holes is formed as a part of a circle having an inner end and an outer end relative to the center of the shaft hole, The end portion is formed as a part of a circle with each side end portion being the center of the opposing rivet hole so that the interval between the rivet hole and the slit hole and the gap between the shaft hole and the slit hole are fixed and the stiffness of the rotor is kept constant .

1 is a cross-sectional view illustrating a conventional rotor.
2 is a front view showing a schematic configuration of an electric motor equipped with a rotor according to an embodiment of the present invention.
3 is a cross-sectional view of a rotor according to an embodiment of the present invention.
4 is an enlarged view of a portion A in Fig.
5 is a view showing the magnetic flux density according to the position of the rotor of FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a rotor for a permanent magnet type permanent magnet motor according to the present invention will be described with reference to FIGS.

It is to be understood that both the foregoing description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention, and are not intended to limit the scope of the invention. But are merely illustrative of the elements recited in the claims.

FIG. 2 is a front view showing a schematic configuration of an electric motor equipped with a rotor according to an embodiment of the present invention, FIG. 3 is a sectional view of the rotor according to an embodiment of the present invention, FIG. And FIG. 5 is a view showing the magnetic flux density according to the position of the rotor of FIG. Hereinafter, a rotor for a buried permanent magnet motor according to an embodiment of the present invention will be described.

BACKGROUND ART [0002] An electric motor compressor for a vehicle generally comprises a compression unit in which a refrigerant is compressed by reciprocating motion of a machine, an electric motor for transferring mechanical energy to the compression unit, and an inverter for supplying electric energy to the electric motor. However, the main part of the present invention is in the structure of the rotor, and the rest of the structure is not so different from that of a general motor-driven compressor, so that the rotor according to the present invention will be described below.

First, as shown in FIG. 2, the motor of the motor-driven compressor is mainly composed of the stator 50 and the rotor 100. The stator 50 is fixed to the motor-driven compressor in the form of a ring through which the inside of the stator 50 penetrates. The stator 50 has a tooth 52 protruding inward in the ring and a coil 54 wound around the tooth. The stator 50 may form a 12-slot stator having twelve teeth each wound with a coil. A rotor 100 is installed inside the stator 50. The rotor 100 includes a plurality of permanent magnets 320 so as to be rotated by receiving an electromagnetic force generated as current flows through a coil wound on the stator . As the rotor 100 rotates, the shaft 220 coupled to the center of the rotor rotates integrally and transmits rotational force to the compression section of the motor-driven compressor.

As shown in FIG. 3, a shaft hole 200 is formed at the center of the rotor, and the shaft 220 is press-fitted into the shaft hole 200. The rotor 100 and the shaft hole 200 preferably have a substantially circular shape. The shaft rotates integrally with the rotor.

At least one permanent magnet insertion hole 300 is formed along the outer circumferential direction of the rotor 100. Each permanent magnet insertion hole 300 is formed on the side opposite to the stator 50, It is a form of V that is opened toward. In the V-shaped permanent magnet insertion hole 300, two permanent magnets 320 are inserted.

Preferably, the permanent magnet insertion holes 300 are arranged at regular intervals along the outer circumferential direction of the rotor 100.

A plurality of rivet holes 400 are formed in the circumferential direction between the permanent magnet insertion holes 300 and the shaft holes 200. Eight of the rivet holes 400 are preferably arranged at equal intervals as the number of the permanent magnet insertion holes Do.

The rotor is formed by stacking a plurality of thin disk-shaped rotor members, and a plurality of rivets (420) penetratingly coupled to the plurality of rivet holes (400) are formed so that the stacked rotor members can form one rotor It is a function of combining.

The plurality of rivet holes 400 may have a circular shape, and may have a rectangular shape or a ladder shape in addition to the circular shape. Each of the rivet holes 400 is located such that the extension line a of the symmetry axis of each of the permanent magnet insertion holes 300 passes through the center of each of the rivet holes.

The rotor core portion between the V-shaped permanent magnets serves as a passage through which the magnetic flux flows, so that when the rivet hole is formed, the magnetic flux is resisted. Therefore, a rivet hole must be formed in a portion of the rotor core space portion between the shaft hole and the permanent magnet insertion hole where the magnetic path is not formed.

Accordingly, the plurality of rivet holes 400 are formed at radially outward portions at a distance of 15.9 mm from the center of the shaft hole 200, and have outer ends of 20.1 mm from the center of the shaft hole 200 Is formed on the inner side in the radial direction from the distance.

This is because the magnetic flux density corresponds to the low magnetic flux density region, referring to FIG. 5, which shows the magnetic flux density according to the position of the rotor. 5, the section with the lowest magnetic flux density appears purple around the shaft hole 200, and the section with the lower magnetic flux density has a lower magnetic flux density than the rotor core portion between the shaft hole 200 and the permanent magnet insertion hole 300 And the magnetic flux density is high in the vicinity of the permanent magnet insertion hole 300.

However, when a plurality of rivet holes 400 are formed in the vicinity of the shaft hole 200 where the magnetic flux density is the lowest, the supporting force for supporting the shaft becomes weak and the rotation of the rotor becomes unstable. Therefore, it is preferable that the rivet hole is formed at a position where the inner and outer ends of the plurality of rivet holes 400 are limited so that the magnetic flux density is low and the shaft can be sufficiently supported without interfering with the passage of the magnetic flux. Therefore, loss of performance and efficiency of the rotor is not caused by the formation of the rivet holes.

4, a plurality of rivet holes 400 of a rotor for a buried permanent magnet motor according to an embodiment of the present invention are located at a distance of 18 mm in the radial direction from the center of the shaft hole 200, And has a circular shape with a diameter of 4.15 mm.

The plurality of depressed holes 500 are formed in a circumferential direction between the permanent magnet insertion hole 300 and the shaft hole 200 and intersect the circle passing through the centers of the plurality of rivet holes 400 . The plurality of depressed holes 500 are formed between the respective rivet holes 400 and are formed in the same number as the plurality of rivet holes 400. Therefore, it is preferable that eight slit holes are formed at regular intervals.

The plurality of slit holes 500 are disposed symmetrically with respect to a straight line b connecting the center of the gap between the pair of adjacent permanent magnet insertion holes 300 and the center of the shaft hole 200 desirable.

Since the rotor core portion between the V-shaped permanent magnets serves as a passage through which the magnetic flux flows, a resistance to the magnetic flux is generated when the slit hole is formed. Therefore, it is necessary to form a depression hole in a portion of the space between the plurality of rivet holes where a magnetic path is not formed.

Therefore, the plurality of the slit holes 500 are formed radially outward from the center of the shaft hole 200 at a distance of 15.9 mm from the center of the shaft hole 200, and the outer ends thereof are spaced apart from the center of the shaft hole 200 by 20.1 mm Is formed on the inner side in the radial direction from the distance.

This is because the magnetic flux density corresponds to the low magnetic flux density region, referring to FIG. 5, which shows the magnetic flux density according to the position of the rotor. 5, the section with the lowest magnetic flux density appears purple around the shaft hole 200, and the section with the lower magnetic flux density has a lower magnetic flux density than the rotor core portion between the shaft hole 200 and the permanent magnet insertion hole 300 And the magnetic flux density is high in the vicinity of the permanent magnet insertion hole 300.

However, when a plurality of slit holes 500 are formed in the vicinity of the shaft hole 200 where the magnetic flux density is the lowest, the supporting force for supporting the shaft is weakened and the rotation of the rotor becomes unstable. Therefore, it is preferable to form the slit hole at a position where the shaft can be sufficiently supported without interfering with the passage of the magnetic flux because the magnetic flux density is low and the range of the inner end and the outer end of the plurality of slit holes 500 is limited. Thus, loss of performance and efficiency of the rotor is not caused by the formation of the slit hole.

In addition, the weight of the rotor can be reduced due to the formation of the plurality of worn-out holes 500, and each of the worn-out holes serves as a passage through which the refrigerant can pass, thereby improving the efficiency of cooling the motor.

Referring to FIG. 4, a plurality of depressed holes 500 of the rotor for a buried permanent magnet motor according to an exemplary embodiment of the present invention are formed at centers 18 mm away from the center of the shaft hole 200, And the detailed shape is described below.

Each of the slender holes 500 preferably has a trapezoidal shape composed of a part of all the mutual circles. According to this configuration, the section that is not disturbed by the magnetic path in a state in which the rigidity of the rotor is maintained can be maximized and lightened. However, the present invention is not limited thereto, and it can be changed into any shape such as a circle, a square, and a triangle depending on the shape and size of the rotor.

The inner and outer ends 502 and 501 are formed as part of a circle with respect to the center of the shaft hole 200 and the inner end 502 and the outer end 501 are formed as a circle, Side end portions 503 and 504 are formed as part of a circle with each side end portion being the center of the opposing rivet hole.

Thus, the outer end 501, the inner end 502, and the shaft hole 200 of the rotor 100 and the slender holes are all concentrically positioned. The spacing between the inner end 502 of each wedge hole and the shaft hole 200 can be kept constant at any portion, thereby maintaining the stiffness of the rotor constant.

Further, since the interval between the opposite side end portions 503 and 504 of the respective slit holes and the opposing rivet holes at the side end portions are kept constant at any portion, the stiffness of the rotor can be kept constant.

The outer end portion 501 is longer than the inner end portion 502 and the both end portions 503 and 504 may have the same length. It is preferable that the side ends 503 and 504 of the slit hole are spaced apart by 8 mm or more from the center of the opposite rivet hole in the radial direction. This is because when the side ends 503 and 504 are located within 8 mm in the radial direction from the center of the opposite rivet hole, the thickness of the rotor core portion between each rivet hole and the slit hole becomes thin, And the overall bearing capacity and durability are weakened.

Referring to FIG. 4, each of the plurality of depressed holes 500 of the rotor for a buried permanent magnet motor according to an embodiment of the present invention has an inner end portion 502 having a diameter of 31.85 mm, and the outer end portion 501 is formed as a part of a circle having a diameter of 40.15 mm with respect to the center of the shaft hole 200. Each of the side ends 503 and 504 is formed as a part of a circle having a diameter of 8 mm with respect to the center of the opposing rivet hole and is spaced apart by 8 mm.

50: stator 52: teeth
54: coil 100: rotor
200: shaft hole 220: shaft
300: permanent magnet insertion hole 320: permanent magnet
400: Rivet hole 420: Rivet
500: Draining hole 501: Outer end
502: Inner end 503, 504: Both ends

Claims (10)

A circular rotor in which a shaft hole for inserting and coupling the shaft is formed at the center;
At least one permanent magnet insertion hole formed in at least one direction along the outer circumferential direction of the rotor, each permanent magnet insertion hole having two permanent magnets inserted in a V-shape facing the stator;
A plurality of rivet holes formed in a circumferential direction between the permanent magnet insertion hole and the shaft hole; And
A plurality of recesses formed in the circumferential direction between the permanent magnet insertion hole and the shaft hole;
Wherein the permanent magnet motor is a permanent magnet. The method according to claim 1,
Wherein the plurality of recesses are formed so as to intersect a circle passing through centers of the plurality of rivet holes. 3. The method of claim 2,
Wherein the plurality of rivet holes and the plurality of fattening holes are formed radially outward from the center of the shaft hole at a distance of 15.9 mm from the center of the shaft hole. The method of claim 3,
Wherein the plurality of rivet holes and the plurality of recesses are formed radially inwardly at a distance of 20.1 mm from the center of the shaft hole. 5. The method of claim 4,
Wherein the plurality of rivet holes are in a circular shape and the extension line of the symmetry axis of each of the permanent magnet insertion holes is positioned so as to pass the center of each of the rivet holes. 5. The method of claim 4,
Wherein the plurality of slit holes are symmetrical with respect to a straight line connecting a center of a gap between a pair of adjacent permanent magnet insertion holes and a center of the shaft hole. The method according to claim 6,
Wherein each of the weight-loss holes is formed as a part of a circle whose inner end and outer end are referenced to the center of the shaft hole, and both ends of the inner end portion and the outer end portion are connected to each other with respect to the center of the opposing rivet hole A rotor for a buried permanent magnet motor formed as part of a circle. 8. The method of claim 7,
Wherein the outer end portion is formed to be longer than the inner end portion, and the both side end portions have the same length. 9. The method of claim 8,
And both side ends of the slit hole are formed so that each side end portion is spaced apart by 8 mm or more from the center of the opposing rivet hole. The method according to claim 1,
Wherein the number of the permanent magnet insertion holes is eight.

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