TWI519041B - Interior-permanent-magnet motor structure - Google Patents

Description

Built-in permanent magnet motor improved structure

The present invention relates to electric motors, and more particularly to a built-in type of permanent magnet motor improved construction.

According to the built-in permanent magnet motor in which the permanent magnet is buried in the rotor core, since the buried permanent magnetic system is wrapped by the rotor core, it has better mechanical reliability and is suitable for high-speed operation, and the conventional technology is further To improve the performance of the permanent magnet motor or to improve the missing one, as shown in the first figure, a hollow groove (1b) is provided between the two-pole magnet (1a) in the rotor and the outer edges of the rotor to avoid magnetic short circuit. The effect is generated, and at the same time, the torque is increased and the vibration effect is reduced, thereby obtaining the effects of damping and sound reduction.

The above-mentioned prior art hollow groove (1b) is provided with a space which provides a magnetic resistance different from that of the rotor core, thereby adjusting the magnetic flux density distribution between the stator and the rotor, thereby making the operation of the permanent magnet motor better. The state, and the like, is a non-circular rotor (2a) structure disclosed by another conventional technique as shown in the second figure, which is formed by hollowing out corresponding portions of the rotor between the two poles to form a gap. Avoid the space of the magnetic short circuit.

Continuing to refer to the prior art shown in the third figure, which is further disclosed in the non-circular rotor (3a) provided, the hollowed-out gap (3b) space and buried in the non-circular rotor (3a) The relationship between the angle ratio between the inner magnet (3c) and the motor efficiency is as shown in the fourth figure. In the fourth figure, θ 2 is the angle of expansion between two adjacent magnets, and θ 4 is the angle of expansion between the notches (3b), where θ 2 / θ 4 when the rotor is circular without a notched structure. The ratio is 100%. At this time, the motor running performance is not good and unstable. After adjusting the magnetic flux by each of the gaps (3b), a relatively better motor performance and stable operating state can be obtained. It can also be seen from the curves of the four graphs that the degree of gain in motor performance is still limited. In the case of optimization, only the performance of the motor is increased from the per unit value (pu) to 1.02. The extent of the reduction effect is also limited.

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a built-in permanent magnet motor improved structure that approximates the air gap flux to an ideal sinusoidal state, effectively and significantly improving the ton effect of the permanent magnet motor. Make the permanent magnet motor run smoother.

Therefore, in order to achieve the above object, the present invention provides a built-in permanent magnet motor improved structure, and the main technical feature thereof is that the air gap width between the stator and the rotor is an annular band-shaped air gap. Within the range of the pole distance, there is a maximum value and a minimum value respectively, so that the air gap flux is close to the sine wave state.

Specifically, the built-in type permanent magnet motor improved structure of the present invention comprises a rotor member having a rotor seat, and a plurality of magnets are embedded in the rotor seat in pairs and have a v shape. The opening is opposite to the center of curvature of the rotor seat; a certain sub-piece has a hollow stator seat coaxially sleeved on the circumferential side of the rotor seat; a ring-shaped air gap is interposed between the inner circumferential surface of the stator seat and The outer circumference of the rotor seat; and the characteristic is that the air gap of the air gap is in each pole pitch, and has a maximum value and a minimum value respectively, and the maximum value and the minimum value are respectively The ratio between the two is in accordance with the following condition: g _min ÷g = cos(a ÷ b × θ), where g _min is the minimum value of the air gap annulus width, g is the maximum value of the air gap annulus width, a is Magnetic expansion angle, b is the pole distance, θ=-π÷2~+π÷2.

Furthermore, the change in the bandwidth size of the air gap can be achieved only by the shape change of the one-side end surface for forming the air gap, in other words, the outer circumferential surface of the rotor seat can be corresponding to each single Each of the arc faces in the range of the pole pitch has a respective center of curvature, and is different from the center of curvature of the rotor seat, corresponding to each of the pole pitches, and the outer circumferential surface of the rotor seat is formed opposite to the rotor The center of curvature of the seat is the arc surface of the rounded surface of the shaft, so that the bandwidth of the air gap changes.

Wherein, the center of curvature of each of the arc faces is between the center of curvature of the rotor seat and each of the arc faces.

Wherein, the center of curvature of the inner circumferential surface of the stator seat coaxially corresponds to the center of curvature of the rotor seat.

Wherein, the portion of the air gap having a minimum bandwidth within a single pole pitch is located at a central position of the associated pole pitch.

Further, in the above formula, the magnetic expansion angle refers to the side between the sides where the pair of magnets are farthest from each other, and the center of curvature of the rotor seat is an angle of the origin.

Furthermore, the rotor member further includes a plurality of slots, which are disposed in pairs in the rotor seat, and the respective pairs of magnets are embedded in the pair of slots.

Wherein, the volume of each of the embedded grooves is larger than the volume of the embedded magnet.

Wherein, the cross-section of each of the cavities is elongated, and the groove walls at both ends of the long axis are separated from the corresponding ends of the embedded magnets.

In addition, the stator component further includes a plurality of distributed windings respectively wound around the stator On the stator seat.

(1a)‧‧‧Two-pole magnet

(1b) ‧ ‧ empty slots

(2a) (3a) ‧ ‧ rotor

(3b) ‧ ‧ gap

(3c)‧‧‧ magnets

(10) ‧‧‧ Built-in permanent magnet motor improved structure

(20)‧‧‧Rotor parts

(21)‧‧‧ rotor seat

(211)‧‧‧Arc face

(22)‧‧‧Inlay

(23)‧‧‧ Magnets

(30)‧‧‧ stator parts

(31) ‧‧ ‧ Stator base

(311)‧‧‧

(312)‧‧‧ 极

(40) ‧ ‧ air gap

(a) (b) ‧ ‧ torque curve

(α)(β)‧‧‧Center of Curvature

The first figure is a cross-sectional view of the first prior art.

The second drawing is a cross-sectional view of a second prior art.

The third figure is a cross-sectional view of a third conventional technique.

The fourth figure is a graph showing the relationship between the notch and the motor efficiency in the third conventional technique.

Figure 5 is a plan view of a preferred embodiment of the present invention.

Figure 6 is a partial enlarged view of a preferred embodiment of the present invention.

Figure 7 is a graph of the torque-time curve of a preferred embodiment of the present invention.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings.

First, referring to the fifth and sixth figures, in the preferred embodiment of the present invention, the built-in type permanent magnet motor improved structure (10) is a conventional V-type built-in type. Based on the permanent magnet motor, it is further improved in terms of its air gap space, and its structure mainly comprises a rotor member (20), a certain sub-piece (30) and a ring-shaped air gap (40).

The rotor member (20) has a rotor seat (21), and a plurality of truncated grooves (22) having a plurality of sections are arranged in pairs with each other in the rotor seat (21) and arranged in a long axis direction. V-shaped, and the V-shaped opening is opposite to the center of curvature (α) of the rotor seat (21), and a plurality of magnets (23) having a plurality of sections are embedded in each of the slots (22). , the volume is smaller than the embedded groove volume, and the two ends of the long axis of each magnet (23) are separated from the groove walls at both ends of the long axis of the embedded groove (22). Further, a hollow space is formed at each of both ends of the long axis of each of the magnets (23), thereby adjusting the magnetic flux density of each of the magnets (23).

The stator member (30) has a hollow annular stator seat (31) coaxially sleeved on the circumferential side of the rotor seat (21), and a plurality of distributed windings (not shown) are respectively wound around the stator a majority of the poles (311) of the seat (31), and the respective palm faces of the plurality of poles (312) at the end of each of the poles (311) to form an inner circumferential surface of the stator seat (31), In other words, the inner circumferential surface of the stator seat (31) is formed by a discontinuous majority of the palm surface.

The air gap (40) is in the form of an endless belt, and between the outer circumferential surface of the rotor seat (21) and the inner circumferential surface of the stator seat (31), and the annular band of the air gap (40) The bandwidth is not a single value, and has a maximum value (g) and a minimum value (g _min ) in each pole distance range, and the ratio between the maximum value (g) and the minimum value (g _min ) is consistent. The following formula: g _min ÷g = cos(a ÷ b × θ).

In the above formula, g _min is the minimum width of the annulus of the air gap (40), g is the maximum width of the annulus of the air gap (40), and a is the magnetic expansion angle, which means that the pair of magnets (23) are between each other. The two points of the farthest distance of the straight line are at an angle formed by the center of curvature of the rotor seat, and b is the pole distance, θ=-π÷2~+π÷2.

Specifically, in this embodiment, the values of each parameter are: a=55.

b=60.

According to the above formula, when θ=-π÷2 and π÷2, the ratio of g _min ÷g is: 0.13053, and when θ=0, the ratio of g _min ÷g is 1.

Further, the composition of the air gap (40) bandwidth size can be as For example, the inner circumferential surface of the stator seat (31) is annular, and the center of curvature is coaxial with the center of curvature of the rotor seat (21), so that the outer circumferential surface of the rotor seat (21) corresponds to each single pole. The curvature of the arc surface (211) in the range is different from the circular curvature centered on the center of curvature (α) of the rotor seat (21), and the center of curvature of the arc surface in each pole range (β) Different from the curvature center (α) of the rotor seat, and between the curvature center (α) of the rotor seat and the associated arc surface (211), so that each of the arc surfaces (211) is opposite to the rotor seat The center of curvature (α) is a rounded surface of the shaft, and each has a bulge shape, and the highest point of the keel is located at a central position of the associated pole pitch, and the minimum bandwidth portion is formed at the position. .

With the composition of the above-mentioned members, the built-in type permanent magnet motor improved structure (10) changes the size of the air gap bandwidth, so that the air gap space through which the magnetic circuit passes changes with the operation of the rotor, thereby The air gap flux is changed from a square wave to a sine wave, so that the torque of the turn can be greatly reduced, and a smooth transition torque curve (a) can be achieved as shown in the seventh figure. Compared with the conventional technology torque curve (b), the built-in permanent magnet motor improved structure (10) can reduce the torque of about 50%, and can greatly improve the operation time. Stationarity.

Furthermore, the built-in permanent magnet motor improved structure (10) is only required to be arc-trimmed on the outer circumferential surface of the rotor seat (21) compared to the prior art, and the manufacturing process is very smooth. For the sake of simplicity and ease of high precision, the commercialization of the built-in permanent magnet motor improved structure (10) is more advantageous in terms of low cost, high precision, and low processing difficulty. Know the technical income to compare.

(10) ‧‧‧ Built-in permanent magnet motor improved structure

(20)‧‧‧Rotor parts

(21)‧‧‧ rotor seat

(22)‧‧‧Inlay

(23)‧‧‧ Magnets

(30)‧‧‧ stator parts

(31) ‧‧ ‧ Stator base

(311)‧‧‧

(312)‧‧‧ 极

(40) ‧ ‧ air gap

Claims (10)

A built-in permanent magnet motor improved structure comprises: a rotor member having a rotor seat, a plurality of magnets embedded in the rotor seat in pairs, and having a v-shaped opening facing away from a center of curvature of the rotor seat a fixed component having a hollow stator seat coaxially sleeved on a circumferential side of the rotor seat; a ring-shaped air gap between the inner circumferential surface of the stator seat and the outer circumferential surface of the rotor seat; The utility model is characterized in that: the annular band bandwidth of the air gap is in each pole pitch, and has a maximum value and a minimum value respectively, and the ratio between the maximum value and the minimum value meets the following condition: g _min ÷g =cos(a÷b×θ), where g _min is the minimum value of the air gap annulus width, g is the maximum value of the air gap annulus width, a is the magnetic expansion angle, b is the pole distance, θ=-π ÷2~+π÷2. The improved structure of the permanent magnet motor of the built-in type according to claim 1, wherein the outer circumferential surface of the rotor seat corresponds to each curved surface within each single pole distance range, and each has its own center of curvature, and is different At the center of curvature of the rotor seat. The improved permanent magnet motor structure of the built-in type according to claim 2, wherein a center of curvature of each of the curved surfaces is between a center of curvature of the rotor seat and each of the curved surfaces. The improved permanent magnet motor structure of the built-in type according to claim 3, wherein the center of curvature of the inner circumferential surface of the stator seat coaxially corresponds to the center of curvature of the rotor seat. The improved permanent magnet motor structure of the built-in type according to claim 1, wherein the portion of the air gap having a minimum bandwidth within a single pole pitch is located at a central position of the associated pole pitch. A built-in type permanent magnet motor improved structure according to claim 1 of the patent application scope, wherein The magnetic expansion angle refers to the side between the sides where the pair of magnets are farthest from each other, and the center of curvature of the rotor seat is the angle between the origins. The improved permanent magnet motor structure of the built-in type according to claim 1, wherein the rotor component further comprises a plurality of slots, which are disposed in pairs in the rotor seat, and each pair is paired The magnet is embedded in the pair of slots. According to the improved structure of the permanent magnet motor of the built-in type described in claim 7, wherein the volume of each of the cavities is larger than the volume of the embedded magnet. According to the improved structure of the permanent magnet motor built in the eighth aspect of the patent application, wherein the cross section of each of the cavities is elongated, and the groove walls at both ends of the long axis and the embedded magnet are The corresponding ends are spaced apart from each other. The built-in type permanent magnet motor improved structure according to claim 1, wherein the stator member further comprises a plurality of distributed windings respectively wound around the stator base.