A magnetic flux-adjusting and magnetic isolation plate structure for a permanent magnet motor rotor

Abstract

The present invention discloses a magnetic isolation plate structure for a permanent magnet motor rotor, wherein a plurality of magnetic steel slots are embedded on the rotor core, magnetic steel is embedded in the magnetic steel slots, magnetic isolation plates are respectively provided at both ends of the rotor core, a plurality of magnetic conductive slider holes corresponding to the magnetic steel slots are distributed on the magnetic isolation plates, a slidable slider is embedded in the slider hole, an elastic component for controlling the displacement of the slider is provided on one side of the slider hole, and the effective area of ​​the magnetic steel is controlled by the sliding of the slider. When in use, magnetic isolation plates are provided at both ends of the rotor core, and the magnetic leakage area of ​​the magnetic steel is controlled by the movement of the slider, so as to achieve the function of automatic adjustment of the rotor magnetic flux with the running speed of the motor, and overcome the problems of excessively high back electromotive force in the high-speed area under the wide speed regulation range of the motor in the prior art, difficulty in weak magnetic field, low operating efficiency, and large vibration noise.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of permanent magnet synchronous motors, and in particular to a magnetic isolation plate structure for a permanent magnet motor rotor, and more particularly to a magnetic isolation plate structure for a permanent magnet motor rotor that can automatically adjust leakage flux to reduce the back electromotive force of the motor during high-speed operation of the motor. Background Art

[0002] In the prior art, built-in permanent magnet synchronous motors have the advantages of high efficiency, high torque density, and wide speed regulation range, and are widely used in automotive drive motors. At present, the main speed regulation range of automotive drive motors is 2.5-3 times. For speed regulation ranges of 4 times and above, the built-in permanent magnet synchronous motor has relatively high no-load back electromotive force and poor motor performance in the high-speed area. The motor rotor flux improves the torque output capacity of the motor to a certain extent, and also improves the power factor of the motor and increases the power output of the motor. However, with the increase of the weak magnetic multiple, the control stability of the permanent magnet motor decreases. The increase of weak magnetic current not only deteriorates the air gap magnetic density waveform of the motor, but also increases the copper loss of the motor, and the motor efficiency decreases.

[0003] Under the requirement of wide speed regulation range, the traditional built-in permanent magnet synchronous motor can reduce the weak magnetic multiple by increasing the capacity of the controller module and moving the motor inflection point to the high-speed area. However, this method increases the cost of the controller, and the controller efficiency will be reduced when a large-capacity controller controls a relatively small-power motor. The second is to reduce the no-load back EMF value in the design, but this method weakens the low-speed torque output, and the motor power factor is greatly reduced at the inflection point due to the low no-load back EMF, the maximum output power of the motor decreases, and the decrease in the motor output capacity leads to an increase in the motor temperature rise. Summary of the invention

[0004] In view of the above problems, the present invention provides a magnetic isolation plate structure for a permanent magnet motor rotor. By arranging magnetic isolation plates at both ends of the rotor core and controlling the magnetic leakage area of ​​the magnetic steel by the movement of a slider, the rotor magnetic flux can be automatically adjusted according to the running speed of the motor, thereby overcoming the problems in the prior art of excessively high back electromotive force in the high-speed area under a wide speed regulation range of the motor, difficulty in weak magnetic field, low operating efficiency, and high vibration and noise.

[0005] The objective of the present invention can be achieved through the following technical scheme: a magnetic isolation plate structure for a permanent magnet motor rotor, comprising a rotor core, characterized in that a plurality of magnetic steel slots are embedded on the rotor core, magnetic steels are embedded in the magnetic steel slots, magnetic isolation plates are respectively provided at both ends of the rotor core, a plurality of slider holes corresponding to the magnetic steel slots are distributed on the magnetic isolation plates, the area of ​​the slider hole is larger than the area of ​​the magnetic steel slots, a slidable slider is embedded in the slider hole, an elastic component for controlling the displacement of the slider is provided on one side of the slider hole, and the effective area of ​​the magnetic steel is controlled by the sliding of the slider.

[0006] Preferably, the length of the slider hole is smaller than the length of the magnetic steel, so as to position the magnetic steel, and sliding grooves are provided on both sides of the slider hole, and convex strips cooperating with the sliding grooves are provided on both sides of the slider;

[0007] The thickness of the slider is D, D = k*l*n*s,

[0008] k=0.02—0.03, s=0.8-1.3, motor speed regulation range is n, n>4, rotor core length is l;

[0009] Slider length D_L, D_L = 2*D+L, L is the thickness of the magnetic steel;

[0010] Spring rate selection:

[0011]

[0012] Where: m is the weight of the slider, n is the maximum speed of the motor, r is the rotor radius, and b is the width of the slider;

[0013] The formula for the change of the effective area of ​​the magnetic steel with the current motor speed is:

[0014]

[0015] Where S is the magnet area, a is the magnet length, n is the maximum speed of the motor, and n1 is the current speed of the motor.

[0016] Furthermore, the slider is made of magnetic conductive material, specifically, electromagnetic pure iron or low carbon steel can be selected, the four sides of the slider are provided with arc chamfers, the outer side of the convex strip is arc-shaped, and the convex strip is set at 1 / 2-1 / 3 of the slider height. In order to achieve better results, cylindrical low carbon steel balls can be embedded in the electromagnetic pure iron.

[0017] Furthermore, the rotor core is made of stacked rotor sheets, and there are through holes and keyways on the core. The slots on the rotor sheets for placing magnetic steel are arranged in groups of two to form a V-shaped structure, and correspondingly, the slider holes are also arranged in groups of two to form a V-shaped structure.

[0018] Compared with the prior art, the technical solution of the present invention not only improves the overall technical solution, but also includes many improvements in details. Specifically, it has the following beneficial effects:

[0019] 1. The improved scheme of the present invention is that magnetic isolation plates are respectively provided at both ends of the rotor core, and a plurality of slider holes corresponding to the magnetic steel slots are distributed on the magnetic isolation plates, and a slidable slider is embedded in the slider hole. An elastic member for controlling the displacement of the slider is provided on one side of the slider hole, and the effective area of ​​the magnetic steel is controlled by sliding the slider. It is a permanent magnet motor rotor magnetic isolation plate structure that can automatically adjust the leakage magnetic field to reduce the back electromotive force of the motor during high-speed operation of the motor;

[0020] 2. In the technical solution of the present invention, the effective area of ​​the magnetic steel in operation is precisely controlled by selecting the slider size and the spring coefficient, so that the permanent magnetic electronic rotor of the present invention can be applied in a wider range of speed regulation;

[0021] 3. The layout of the present invention is reasonable, so that the operating efficiency of the built-in permanent magnet synchronous motor is improved, with high speed and high efficiency as the output characteristics;

[0022] 4. The present invention is easy to produce and process, has low cost, and is conducive to development and promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of an embodiment of the present invention.

[0024] Figure 2 It is a schematic structural diagram of the magnetic isolation plate of the present invention.

[0025] Figure 3 It is a structural schematic diagram of the slider of the present invention.

[0026] Figure 4 It is a schematic diagram of the structure of the intermediate magnetic plate under high speed movement in the implementation of the present invention.

[0027] Figure 5 It is a schematic structural diagram of the magnetic partition plate in the initial state in the implementation of the present invention.

[0028] Figure 6 It is a schematic structural diagram of the rotor core of the present invention.

[0029] Figure 7 It is a schematic structural diagram of the elastic component of the present invention.

[0030] Figure 8 It is another structural schematic diagram of the magnetic isolation plate of the present invention.

[0031] The following are marked in the figure:

[0032] 1. Rotor core 2. Magnetic isolation plate 3. Permanent magnet 4. Slider 41. Raised strip 5. Elastic component 6. Through hole 7. Keyway 8. Slider hole. DETAILED DESCRIPTION

[0033] The specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that those skilled in the art can more clearly understand how to practice the present invention. Although the present invention is described in conjunction with its preferred specific embodiments, these embodiments are only illustrative, rather than limiting the scope of the present invention.

[0034] like Figure 1As shown, a magnetic isolation plate structure for a permanent magnet motor rotor includes a rotor core 1. The difference between the structure and the prior art is that a plurality of magnetic steel slots are embedded in the rotor core, and magnetic steels 3 are embedded in the magnetic steel slots. Magnetic isolation plates 2 are respectively provided at both ends of the rotor core, and a plurality of slider holes corresponding to the magnetic steel slots are distributed on the magnetic isolation plates. The area of ​​the slider hole is larger than the area of ​​the magnetic steel slots. A slidable slider 4 is embedded in the slider hole 8. An elastic component 5 for controlling the displacement of the slider is provided on one side of the slider hole. The effective area of ​​the magnetic steel is controlled by sliding the slider.

[0035] Furthermore, the length of the slider hole here is smaller than the length of the magnetic steel slot, ensuring that the magnetic steel will not be thrown out of the magnetic steel slot during the movement of the rotor. At the same time, the magnetic steel slot here can be V-shaped, U-shaped or semicircular, and the slider hole is placed at the front end of the magnetic steel slot. The position of the slidable slider in the slider hole corresponds to the magnetic steel. By changing the sliding position of the slider, the magnetic steel is shielded in a variable manner to further control the effective area of ​​the magnetic steel. In this process, the setting method of the magnetic steel, the setting position and size of the slider, and the elastic component used to control the sliding motion are particularly important, and they will be analyzed one by one through the following embodiments.

[0036] Example 1

[0037] See also Figure 1 In the figure, 8 groups of V-shaped magnetic steel slots are embedded in the rotor core, and a group of magnets are embedded in each V-shaped magnetic steel slot. Magnetic isolation plates are provided at both ends of the rotor core, and 16 slider holes corresponding to the magnets are distributed on the magnetic isolation plates. Among them, an angle is set between every two slider holes, and this angle corresponds to the V-shaped angle of the V-shaped magnetic steel slot. The area of ​​the slider hole is larger than the area of ​​the magnetic steel slot, and the length direction of the slider hole is smaller than the length of the magnet, ensuring that the magnet will be blocked and will not be thrown out when the rotor moves. The width direction of the slider hole is 2-2.5 times the width of the magnet, ensuring that the slider can effectively block the area of ​​the magnet when moving.

[0038] Specifically, a slidable slider is embedded in the slider hole, and an elastic member for controlling the displacement of the slider is provided on one side of the slider hole. The effective area of ​​the magnetic steel is controlled by sliding the slider. The initial position of the slider here is that the slider is set close to the elastic member, and the magnetic steel is fully exposed to achieve the maximum effective area. Figure 5 middle.

[0039] For further information, see Figure 2 , Figure 3The slider is made of magnetic conductive material, and the four sides of the slider are provided with arc chamfers. The outer side of the convex strip is arc-shaped, and the convex strip is set at 1 / 2-1 / 3 of the slider height, and the preferred height is 2 / 5. At the same time, in order to ensure the shielding effect, the arc chamfers of the four sides of the slider correspond to the inner arc chamfers at the corners of the inner wall around the slider hole, ensuring that the slider is completely fitted with the slider hole when sliding to the upper and lower bottom edges of the slider hole.

[0040] Furthermore, the main body of the slider hole is a square groove for placing the slider, and an elastic member placement hole is provided on the inner side of the square groove, the width of the elastic member placement hole is 1 / 3-1 / 4 of the width of the slider hole, and the length is 1 / 2-2 / 3 of the length of the slider hole; the elastic member is a tension spring or a compression spring, and both ends of the tension spring are respectively provided with fixing hooks, one end of the tension spring is connected to the slider, and the other end is connected to the inner wall of the slider hole, in order to achieve a better elastic control effect,

[0041] The thickness of the slider here is D, D = k*l*n*s,

[0042] k=0.025,s=0.1.1, the motor speed regulation range is n, n>4, n can be 6, 8, 10 and 12, and the rotor core length is l;

[0043] Slider length D_L, D_L = 2*D+L, L is the thickness of the magnetic steel;

[0044] Spring rate selection:

[0045]

[0046] Where: m is the weight of the slider, n is the maximum speed of the motor, r is the rotor radius, and b is the width of the slider.

[0047] Example 2

[0048] The rotor core is made of stacked rotor punchings. There are through holes and keyways on the core. The slots on the rotor punchings for placing magnetic steel are grouped in pairs to form a V-shaped structure. Correspondingly, the slider holes are also arranged in pairs in a V-shape.

[0049] Furthermore, a mounting hole is provided at the center of the rotor core, a group of corresponding key slots 7 are provided on the inner wall of the mounting hole, a group of through holes are distributed around the mounting hole, the positions of the through holes match the slider holes, and a through hole 6 is provided corresponding to the gap position between the two slider holes.

[0050] The main body of the slider hole is a square groove for placing the slider. The inner side of the square groove is provided with an elastic member placement hole. The width of the elastic member placement hole is 1 / 4 of the width of the slider hole, and the length is 1 / 2 of the length of the slider hole, but it needs to be set 1-2.5mm eccentric to the left; the elastic member is a tension spring or a compression spring, and both ends of the tension spring are provided with fixing hooks, one end of the tension spring is connected to the slider, and the other end is connected to the inner wall of the slider hole, in order to achieve a better elastic control effect. Slide grooves are provided on both sides of the slider hole, and convex strips 41 cooperating with the slide grooves are provided on both sides of the slider. The slide groove here is not parallel to the bottom surface of the slider hole, but there is a very small angle between them. The angle is 3-5 degrees, which is convenient for the sliding of the slider and the pulling back of the spring. The entire sliding movement process can be seen in Figure 4 , Figure 5 changes.

[0051] The thickness of the slider is D, D = k*l*n*s,

[0052] k=0.283,s=0.95,motor speed regulation range is n,n>4,rotor core length is l;

[0053] Slider length D_L, D_L = 2*D+L, L is the thickness of the magnetic steel;

[0054] Spring rate selection:

[0055]

[0056] Where: m is the weight of the slider, n is the maximum speed of the motor, r is the rotor radius, and b is the width of the slider;

[0057] The formula for the change of the effective area of ​​the magnetic steel with the current motor speed is:

[0058]

[0059] Where S is the magnet area, a is the magnet length, n is the maximum speed of the motor, and n1 is the current speed of the motor.

[0060] Example 3

[0061] The rotor core is made of stacked rotor sheets, the core is provided with through holes and keyways, and the rotor sheet structure is V-shaped.

[0062] The magnetic isolation plate is provided with a slider hole, the hole is parallel to the magnetic steel groove, and grooves are provided on both sides of the slider hole to enable the slider to slide; the length of the slider hole is slightly smaller than the length of the magnetic steel to prevent the magnetic steel from being thrown out.

[0063] The slider is made of magnetic conductive material, and has convex strips 41 on both sides of the slider, which are arc-shaped and fit with the grooves on both sides of the slider hole. The width of the slider is the same as the width of the permanent magnet.

[0064] The spring connects the slider to the inner wall of the slider hole. In a natural state, the slider is pulled below the slider hole. When the motor runs at high speed, the slider slides outward under the action of centrifugal force, stretching the spring, and returns to its original state when the motor stops.

[0065] Slider thickness selection, motor speed range n, n>4, rotor core length l, slider thickness is

[0066] D = k*l*n*s;

[0067] k=0.02-0.03, which is related to the magnetic leakage coefficient of the motor itself; s is the magnetic leakage severity coefficient of the slider, and the normal value is 1. If the weak magnetic effect needs to be improved, the value can be appropriately increased, and vice versa.

[0068] Furthermore, the slider length D_L is selected, where L is the thickness of the magnetic steel.

[0069] D_L=2*D+L(magnetic steel thickness)

[0070] Further, the spring elastic coefficient is selected:

[0071]

[0072] Where: m is the weight of the slider, n is the maximum speed of the motor, r is the rotor radius, and b is the width of the slider

[0073] The formula of the change of the effective area of ​​the magnetic steel with the current motor speed

[0074]

[0075] Where S is the magnetic steel area, a is the magnetic steel length, n is the maximum speed of the motor, and n1 is the current speed of the motor. The magnetic isolation plate is axially fixed to the rotor core through the through hole and circumferentially fixed through the keyway. The magnetic isolation plate is a new motor structural component sandwiched between the rotor core and the balance end plate. The balance end plate is as follows Figure 8 As shown, the balancing action is started.

[0076] Furthermore, the spring is a tension spring or a compression spring, such as Figure 7 The tension spring is shown. It is selected according to the rotor size and rotor structure. The tension spring is fixed inside the slider hole and the other end is connected to the slider. If a compression spring is used, it is fixed outside the slider hole. If the elastic member selected is a compression spring, see Figure 8 As shown, the compression spring is arranged inside the slider hole, one end of the compression spring is fixed to the inner wall of the slider hole, and the other end directly contacts the slider.

[0077] Example 4

[0078] A 48-slot 8-pole motor is set up, and the slider is made of magnetic conductive material, specifically, electromagnetic pure iron can be selected, and the four sides of the slider are provided with arc chamfers, and the outer side of the convex strip is arc-shaped, and the convex strip is set at 1 / 2-1 / 3 of the slider height. A groove is provided at the bottom of the slider, and a guide strip matching the slider groove is provided on the bottom surface of the slider hole to help the slider slide quickly and not deviate from the position.

[0079] Furthermore, the rotor core is made of rotor laminations, with through holes and keyways on the core, and slots for placing magnetic steel on the rotor laminations are arranged in pairs to form a V-shaped structure, and correspondingly, the slider holes are arranged in pairs to form a V-shaped layout. The stator outer diameter is less than 200mm, the maximum speed is greater than 10000rpm, the motor speed range is greater than 4 times, and the slider length is less than 18mm, which can achieve the best effect.

[0080] It should be noted that the fully described invention may also have a variety of variations and modifications, and is not limited to the specific embodiments of the above embodiments. The above embodiments are merely illustrative of the invention, not limiting thereof. In short, the scope of protection of the invention should include those variations or substitutions and modifications that are obvious to a person of ordinary skill in the art, and shall be subject to the appended claims.

Claims

1. A magnetic isolation plate structure for a permanent magnet motor rotor, comprising a rotor core, characterized in that: A plurality of magnetic steel slots are embedded in the rotor core, and magnetic steel is embedded in the magnetic steel slots. Magnetic isolation plates are respectively provided at both ends of the rotor core, and a plurality of magnetic conductive slider holes corresponding to the magnetic steel slots are distributed on the magnetic isolation plates. The area of ​​the slider hole is larger than the area of ​​the magnetic steel slot. A slidable slider is embedded in the slider hole. An elastic component for controlling the displacement of the slider is provided on one side of the slider hole, and the magnetic leakage area of ​​the magnetic steel is controlled by sliding the slider. The length of the slider hole is smaller than the length of the magnetic steel, and is used to position the magnetic steel. Slide grooves are provided on both sides of the slider hole, and convex strips matching the slide grooves are provided on both sides of the slider. The thickness of the slider is D, D = k*l*n*s, k=0.02-0.03,s=0.8-1.3,motor speed regulation range is n,n>4,rotor core length is l; Slider length D_L, D_L = 2*D+L, L is the thickness of the magnetic steel; Spring rate selection: Where: m is the weight of the slider, n is the maximum speed of the motor, r is the rotor radius, and b is the width of the slider; The formula for the change of the effective area of ​​the magnetic steel with the current motor speed is: Where S is the magnet area, a is the magnet length, n is the maximum speed of the motor, and n1 is the current speed of the motor.

2. A magnetic isolation plate structure for a permanent magnet motor rotor according to claim 1, characterized in that: The slider is made of magnetic conductive material, the four sides of the slider are provided with arc chamfers, the outer side of the convex strip is in an arc shape, and the convex strip is arranged at 1 / 2-1 / 3 of the slider height.

3. The magnetic isolation plate structure for a permanent magnet motor rotor according to claim 1, characterized in that: The main body of the slider hole is a square groove for placing the slider. An elastic member placement hole is provided on the inner side of the square groove. The width of the elastic member placement hole is 1 / 3-1 / 4 of the width of the slider hole, and the length is 1 / 2-2 / 3 of the length of the slider hole. The elastic component is a tension spring or a compression spring. Both ends of the tension spring are respectively provided with fixing hooks. One end of the tension spring is connected to the slider, and the other end is connected to the inner wall of the slider hole.

4. The magnetic isolation plate structure for a permanent magnet motor rotor according to claim 1, characterized in that: The elastic component is a compression spring, which is arranged inside the slider hole, one end of the compression spring is fixed to the inner wall of the slider hole, and the other end directly contacts the slider.

5. The magnetic isolation plate structure for a permanent magnet motor rotor according to claim 1, characterized in that: The rotor core is made of stacked rotor punchings. There are through holes and keyways on the core. The slots on the rotor punchings for placing magnetic steel are grouped in pairs to form a V-shaped structure. Correspondingly, the slider holes are also arranged in pairs in a V-shape.

6. A magnetic isolation plate structure for a permanent magnet motor rotor according to claim 5, characterized in that: A mounting hole is provided at the center of the rotor core, a group of corresponding key slots are provided on the inner wall of the mounting hole, a group of through holes are distributed around the mounting hole, the positions of the through holes match the slider holes, and a through hole is provided corresponding to the gap position between the two slider holes.

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