Asynchronous starting permanent magnet synchronous motor rotor magnetic isolation bridge, motor rotor and motor

Abstract

The present invention relates to the technical field of permanent magnet motors, and specifically discloses a rotor magnetic isolation bridge of an asynchronous starting permanent magnet synchronous motor, a motor rotor and a motor, comprising a rotor core, permanent magnet slots, magnetic isolation slots and magnetic isolation bridges arranged in sequence along the radial direction of the rotor core, the permanent magnet slots and magnetic isolation slots are all arranged through the rotor core, and also include a plurality of squirrel cage bar holes uniformly arranged along the outer circumference of the rotor core; the first arc segment, the second arc segment and the seventh arc segment and part of the eighth arc segment form a C-shaped magnetic isolation bridge; the radius R1 of the first arc segment is 6.1mm and the center angle is 180°, the end of the second arc segment and the seventh arc segment away from the first arc segment is equal to the distance from the outer circumference of the rotor core and L1 is 5.8mm-6.1mm, and the width L2 of the magnetic isolation bridge is 1mm-1.3mm. The present invention can reduce the rotor deformation caused by the centrifugal force generated when the motor runs at high speed while reducing the leakage flux, so that the permanent magnet motor has both good electromagnetic performance and strong mechanical strength.

Description

Technical Field

[0001] The invention relates to the technical field of permanent magnet motors, and in particular to an asynchronous starting permanent magnet synchronous motor rotor magnetic isolation bridge, a motor rotor and a motor. Background Art

[0002] High-efficiency permanent magnet synchronous motors are widely used in industry, agriculture, daily life and other fields due to their high power density, fast dynamic response and high reliability. In permanent magnet motors, in order to prevent the permanent magnet's leakage coefficient from being too large and causing the utilization rate of the permanent magnet to be too low, a magnetic isolation bridge is required. The principle of the magnetic isolation bridge is to limit the leakage flux by saturating the magnetic flux at the magnetic bridge. Therefore, the magnetic isolation bridge on the rotor lamination of the high-efficiency permanent magnet synchronous motor is an important factor affecting the motor's no-load leakage flux coefficient, and the magnetic isolation bridge also affects the motor's mechanical strength, the motor's manufacturing process and the motor's manufacturing cost. From the perspective of preventing magnetic leakage, the smaller the thickness of the magnetic isolation bridge, the better the magnetic isolation effect, because the smaller the size of the magnetic isolation bridge, the smaller the magnetic permeance at the magnetic isolation bridge, the more saturated the leakage flux at no-load, and the smaller the no-load leakage flux coefficient of the motor.

[0003] Different motor applications have different requirements for the size of the leakage coefficient. In motor design, appropriate magnetic isolation measures should be selected according to the requirements for the size of the leakage coefficient, so that the size of the magnetic isolation bridge can meet the requirements of the no-load leakage coefficient and have sufficient strength to improve the mechanical strength of the motor and reduce the manufacturing cost of the motor. However, the existing magnetic isolation bridge still cannot meet the requirements of the no-load leakage coefficient and strength at the same time, and the magnetic isolation bridge needs to be improved. Summary of the invention

[0004] The object of the present invention is to provide an asynchronous starting permanent magnet synchronous motor rotor magnetic isolation bridge, a motor rotor and a motor, so as to solve the problem that the magnetic isolation bridge cannot simultaneously meet the requirements of no-load leakage magnetic coefficient and strength.

[0005] In order to achieve the above-mentioned object, according to a first aspect of the present invention: an asynchronous starting permanent magnet synchronous motor rotor magnetic isolation bridge comprises a rotor core, permanent magnet slots, magnetic isolation slots and magnetic isolation bridges sequentially arranged along the radial direction of the rotor core, the permanent magnet slots and magnetic isolation slots are both arranged through the rotor core, and also comprises a plurality of squirrel cage bar holes uniformly arranged along the outer circumference of the rotor core;

[0006] With the side where the center of the rotor core is located as the inner side, and with the side where the outer circumference of the rotor core is located as the outer side, the magnetic isolation groove includes a first arc segment close to the outer side, a second arc segment and a seventh arc segment respectively forming an S-shape tangent to the two ends of the first arc segment, the squirrel cage bar hole includes an eighth arc segment close to the inner side and a second opening connected to the eighth arc segment, the first arc segment and the eighth arc segment are arranged cocentrically, and the first arc segment, the second arc segment and the seventh arc segment and part of the eighth arc segment form a C-shaped magnetic isolation bridge;

[0007] The permanent magnet slots include a first permanent magnet slot and a second permanent magnet slot, the first permanent magnet slot and the second permanent magnet slot form a V-shaped magnetic circuit structure with an opening direction facing outward, and the permanent magnet slots are arranged in 4n groups that are evenly distributed along the circumference of the rotor core and symmetrical along the radial direction of the rotor core, where n≥1 and n is an integer;

[0008] With the perpendicular bisector of the V-shaped magnetic circuit structure as the axis, the first permanent magnet slot, the magnetic isolation slot, the magnetic isolation bridge and the squirrel cage bar hole sequentially arranged with the first permanent magnet slot along the radial direction of the rotor core, and the second permanent magnet slot, the magnetic isolation slot, the magnetic isolation bridge and the squirrel cage bar hole sequentially arranged with the second permanent magnet slot along the radial direction of the rotor core are all arranged in mirror symmetry;

[0009] The radius R1 of the first arc segment is 6.1mm and the central angle is 180°. The ends of the second arc segment and the seventh arc segment away from the first arc segment are at the same distance from the outer circumference of the rotor core and L1 is 5.8mm-6.1mm. The width L2 of the magnetic isolation bridge is 1mm-1.3mm.

[0010] Preferably, the magnetic isolation groove further comprises a first straight line segment, a third arc segment, a fourth arc segment, a first opening, a fifth arc segment, a sixth arc segment and a fourth straight line segment connected in sequence, one end of the first straight line segment is connected to the second arc segment, and one end of the fourth straight line segment is connected to the seventh arc segment;

[0011] The fourth arc segment and the fifth arc segment are arranged cocircularly, the length of the fourth arc segment is less than the length of the fifth arc segment, and the fourth arc segment and the fifth arc segment are arranged cocenter with the first arc segment;

[0012] The first straight line segment is circumferentially connected to the second arc segment and the third arc segment, and the centers of the second arc segment and the third arc segment are both located on the same side of the first straight line segment;

[0013] The fourth straight line segment is circumferentially connected to the sixth arc segment and the seventh arc segment, and the centers of the sixth arc segment and the seventh arc segment are both located on the same side of the fourth straight line segment.

[0014] Preferably, the first opening includes a second straight line segment and a third straight line segment parallel to each other, one end of the second straight line segment is connected to the fourth arc segment, one end of the third straight line segment is connected to the fifth arc segment, and the distance between the second straight line segment and the third straight line segment is less than the width of the permanent magnet slot.

[0015] Preferably, the first arc segment is bisected by a straight line passing through the center of the circle where the first arc segment is located, and the second arc segment, the first straight line segment and the third arc segment are symmetrically arranged with the seventh arc segment, the fourth straight line segment and the sixth arc segment respectively with the straight line as the axis.

[0016] Preferably, the radii of the second arc segment, the third arc segment, the sixth arc segment and the seventh arc segment are equal and R3 is 0.3 mm, the arc lengths of the second arc segment and the seventh arc segment are equal and are both 1.42 mm, the arc lengths of the third arc segment and the sixth arc segment are equal and are both 0.48 mm, and the lengths of the first straight line segment and the fourth straight line segment are equal and L3 are both 0.9 mm.

[0017] Preferably, the radius R4 of the circle where the fourth arc segment and the fifth arc segment are located is 7.6 mm, the length of the fourth arc segment is 4.54 mm, and the length of the fifth arc segment is 14.12 mm.

[0018] Preferably, the length L4 of the second straight line segment is 1.61 mm, the length L5 of the third straight line segment is 1.67 mm, and the distance L6 between the second straight line segment and the third straight line segment is 4.05 mm.

[0019] Preferably, a through hole is arranged between the first permanent magnet slot and the second permanent magnet slot, and the through hole includes a first side, a second side, a third side and a fourth side, the first side is parallel to the fourth side, the second side is parallel to the third side, the first side is connected to the second side and the angle ∠1 is 110°, the third side is connected to the fourth side and the angle ∠2 is 110°, the distance between the first side and the fourth side is equal to the distance between the second side and the third side and L7 is 4.05 mm, the length of the first side is equal to the length of the second side and L8 is 3.6 mm, the length of the third side is equal to the length of the fourth side and L9 is 1.77 mm.

[0020] According to a second aspect of the present invention, a motor rotor includes the above-mentioned asynchronous starting permanent magnet synchronous motor rotor magnetic isolation bridge, and also includes permanent magnets arranged in a first permanent magnet slot and a second permanent magnet slot, and the magnetic poles of the permanent magnets arranged in two adjacent groups of permanent magnet slots are opposite.

[0021] According to a third aspect of the present invention, a motor comprises the motor rotor described above and a stator, wherein the rotor is mounted in the stator, and an air gap is provided between the rotor and the stator.

[0022] Compared with the prior art, the asynchronous starting permanent magnet synchronous motor rotor magnetic isolation bridge, motor rotor and motor provided by the present invention have the following advantages:

[0023] By combining the C-shaped magnetic isolation bridge structure with the V-shaped magnetic circuit structure and related parameter settings, when the stator rotating magnetic field interacts with the rotor rotating magnetic field, the magnetic lines of force in the rotor magnetic field can interact with the stator rotating magnetic field more through the air gap, generating asynchronous torque to start the motor, reducing magnetic leakage while reducing the rotor deformation caused by the centrifugal force generated when the motor runs at high speed. Compared with the back electromotive force of the motor in the traditional magnetic isolation bridge design of 312V, the back electromotive force of the motor using the magnetic isolation bridge in the invention can reach 327V, which greatly improves the starting ability of the motor, so that the permanent magnet motor has both good electromagnetic performance and strong mechanical strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the structure of the magnetic bridge in the prior art;

[0025] Figure 2 It is a structural schematic diagram of a rotor magnetic isolation bridge of an asynchronous starting permanent magnet synchronous motor of the present invention;

[0026] Figure 3 for Figure 2 A partial enlarged view of the middle A;

[0027] Figure 4 for Figure 2 A partial enlarged view of point B in the middle;

[0028] Figure 5 The figure is a magnetic field line distribution diagram of a motor using a magnetic bridge in the prior art;

[0029] Figure 6 A magnetic field line distribution diagram of a motor using an asynchronous starting permanent magnet synchronous motor rotor magnetic isolation bridge of the present invention;

[0030] Figure 7 The waveform diagram of the motor using the intermediate magnetic bridge in the prior art;

[0031] Figure 8 The present invention is a waveform diagram of a motor using an asynchronous starting permanent magnet synchronous motor rotor magnetic isolation bridge of the present invention.

[0032] Description of reference numerals:

[0033] Rotor core 1; permanent magnet slot 2; first permanent magnet slot 21; through hole 22; first side 221; second side 222; third side 223; fourth side 224; second permanent magnet slot 23; magnetic isolation slot 3; first arc segment 30, second arc segment 31, first straight segment 32; third arc segment 33; fourth arc segment 34; first opening 35; second straight segment 351; third straight segment 352; fifth arc segment 36; sixth arc segment 37; fourth straight segment 38; seventh arc segment 39; magnetic isolation bridge 4; squirrel cage bar hole 5; second opening 51; eighth arc segment 52; stator 6. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with specific embodiments.

[0035] In the present invention, unless otherwise clearly specified and limited, when terms such as "set on", "connected", and "connected" appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or connected through one or more intermediate media. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The directional words that appear in the present invention are to better illustrate the characteristics of the features and the relationship between the features. It should be understood that when the placement direction of the present invention changes, the characteristics of the features and the direction of the relationship between the features also change accordingly. Therefore, the directional words do not constitute an absolute limitation on the characteristics of the features and the relationship between the features in space, but only play a relative limitation role.

[0036] See also Figure 2-4 , Figure 6 and Figure 8 According to a first aspect of the present invention: an asynchronous starting permanent magnet synchronous motor rotor magnetic isolation bridge is provided, comprising a rotor core 1, permanent magnet slots 2, magnetic isolation slots 3 and magnetic isolation bridges 4 sequentially arranged along the radial direction of the rotor core 1, the permanent magnet slots 2 and the magnetic isolation slots 3 are all arranged through the rotor core 1, and also comprising a plurality of squirrel cage bar holes 5 uniformly arranged along the circumferential direction of the outer periphery of the rotor core 1;

[0037] With the side where the center of the rotor core 1 is located as the inner side, and the side where the outer circumference of the rotor core 1 is located as the outer side, the magnetic isolation slot 3 includes a first arc segment 30 close to the outer side, a second arc segment 31 and a seventh arc segment 39 respectively forming an S-shaped tangent (S-shaped tangent means that the opening directions of the two arcs are opposite, and the centers of the two arc segments are respectively located on both sides of the arc segments) with the two ends of the first arc segment 30, the squirrel cage bar hole 5 includes an eighth arc segment 52 close to the inner side and a second opening 51 connected to the eighth arc segment 52, the second opening 51 extends to the outer circumference of the rotor core 1, the first arc segment 30 and the eighth arc segment 52 are cocentrically arranged, and the first arc segment 30, the second arc segment 31 and the seventh arc segment 39 and part of the eighth arc segment 52 form a C-shaped magnetic isolation bridge 4;

[0038] The permanent magnet slots 2 include a first permanent magnet slot 21 and a second permanent magnet slot 23, the first permanent magnet slots 21 and the second permanent magnet slots 23 form a V-shaped magnetic circuit structure with the opening direction facing outward, and the permanent magnet slots 2 are arranged to be 4n groups uniformly distributed along the circumference of the rotor core 1 and symmetrical along the radial direction of the rotor core 1, where n≥1 and n is an integer; preferably, the permanent magnet slots 2 are arranged to be 8 groups, and the squirrel cage bar holes 5 are arranged to be 40;

[0039] With the perpendicular bisector of the V-shaped magnetic circuit structure as the axis, the first permanent magnet slot 21, the magnetic isolation slot 3, the magnetic isolation bridge 4 and the squirrel cage bar hole 5 sequentially arranged with the first permanent magnet slot 21 along the radial direction of the rotor core 1, and the second permanent magnet slot 23, the magnetic isolation slot 3, the magnetic isolation bridge 4 and the squirrel cage bar hole 5 sequentially arranged with the second permanent magnet slot 23 along the radial direction of the rotor core 1 are all arranged in mirror symmetry;

[0040] The radius R1 of the first arc segment 30 is 6.1 mm and the central angle is 180°. The ends of the second arc segment 31 and the seventh arc segment 39 away from the first arc segment 30 are equidistant from the outer circumference of the rotor core 1 and L1 is 5.8 mm-6.1 mm. The width L2 of the magnetic isolation bridge 4 is 1 mm-1.3 mm.

[0041] Through the above technical solution, through the C-shaped magnetic isolation bridge structure combined with the V-shaped magnetic circuit structure and related parameter settings, when the stator rotating magnetic field interacts with the rotor rotating magnetic field, the magnetic lines of force in the rotor magnetic field can interact with the stator rotating magnetic field more through the air gap, generating asynchronous torque to start the motor, reducing magnetic leakage while reducing the rotor deformation caused by the centrifugal force generated when the motor runs at high speed. The starting ability of the motor is greatly improved, so that the permanent magnet motor has both good electromagnetic performance and strong mechanical strength.

[0042] In this embodiment, the magnetic isolation groove 3 further includes a first straight segment 32, a third arc segment 33, a fourth arc segment 34, a first opening 35, a fifth arc segment 36, a sixth arc segment 37 and a fourth straight segment 38 connected in sequence, one end of the first straight segment 32 is connected to the second arc segment 31, and one end of the fourth straight segment 38 is connected to the seventh arc segment 39;

[0043] The fourth arc segment 34 and the fifth arc segment 36 are arranged cocircularly, the length of the fourth arc segment 34 is less than the length of the fifth arc segment 36, and the fourth arc segment 34 and the fifth arc segment 36 are arranged cocentrically with the first arc segment 30;

[0044] The first straight line segment 32 is circumferentially connected to the second arc segment 31 and the third arc segment 33. The centers of the second arc segment 31 and the third arc segment 33 are both located on the same side of the first straight line segment 32. The second arc segment 31 and the third arc segment 33 have the same opening direction and are both arranged inside the magnetic isolation groove.

[0045] The fourth straight line segment 38 is externally connected to the sixth arc segment 37 and the seventh arc segment 39. The centers of the sixth arc segment 37 and the seventh arc segment 39 are located on the same side of the fourth straight line segment 37. The opening directions of the sixth arc segment 37 and the seventh arc segment 39 are the same and are both arranged inside the magnetic isolation groove.

[0046] In this embodiment, the first opening 35 includes a second straight line segment 351 and a third straight line segment 352 which are parallel to each other, one end of the second straight line segment 351 is connected to the fourth arc segment 34, one end of the third straight line segment 352 is connected to the fifth arc segment 36, and the distance between the second straight line segment 351 and the third straight line segment 352 is less than the width of the permanent magnet slot 2.

[0047] In this embodiment, the first arc segment 30 is bisected by a straight line passing through the center of the circle where the first arc segment 30 is located, and the second arc segment 31, the first straight line segment 32 and the third arc segment 33 are symmetrically arranged with the seventh arc segment 39, the fourth straight line segment 38 and the sixth arc segment 37 respectively with the straight line as the axis.

[0048] In this embodiment, the radii of the second arc segment 31, the third arc segment 33, the sixth arc segment 37 and the seventh arc segment 39 are equal and R3 is 0.3 mm, the arc lengths of the second arc segment 31 and the seventh arc segment 39 are equal and are both 1.42 mm, the arc lengths of the third arc segment 33 and the sixth arc segment 37 are equal and are both 0.48 mm, and the lengths of the first straight line segment 32 and the fourth straight line segment 38 are equal and L3 are both 0.9 mm.

[0049] In this embodiment, the radius R4 of the circle where the fourth arc segment 34 and the fifth arc segment 36 are located is 7.6 mm, the length of the fourth arc segment 34 is 4.54 mm, and the length of the fifth arc segment 36 is 14.12 mm.

[0050] In this embodiment, the length L4 of the second straight line segment 351 is 1.61 mm, the length L5 of the third straight line segment 352 is 1.67 mm, and the distance L6 between the second straight line segment 351 and the third straight line segment 352 is 4.05 mm.

[0051] Through the above technical scheme, by setting the magnetic isolation groove 3 that passes through the rotor core 1, and the magnetic isolation groove 3 and the permanent magnet groove 2 are also set through, it can not only achieve the magnetic isolation effect, but also appropriately reduce the stress of the magnetic isolation bridge 4 under the action of high-speed rotation centrifugal force, thereby improving the mechanical strength.

[0052] In this embodiment, a through hole 22 is arranged between the first permanent magnet slot 21 and the second permanent magnet slot 23, and the through hole 22 includes a first side 221, a second side 222, a third side 223 and a fourth side 224, the first side 221 is parallel to the fourth side 224, the second side 222 is parallel to the third side 223, the first side 221 is connected to the second side 222 and the angle ∠1 is 110°, the third side 223 is connected to the fourth side 224 and the angle ∠2 is 110°, the distance between the first side 221 and the fourth side 224 is equal to the distance between the second side 222 and the third side 223 and L7 is 4.05 mm, the length of the first side is equal to the length of the second side and L8 is 3.6 mm, the length of the third side is equal to the length of the fourth side and L9 is 1.77 mm.

[0053] It should be noted that the through hole 22 refers to the through hole 22 formed after the permanent magnet is installed in the first permanent magnet slot 21 and the second permanent magnet slot 23. The third side 223 of the through hole 22 refers to the line segment formed by the intersection of the first permanent magnet slot 21 and the second permanent magnet slot 23 near the outer frame after the permanent magnet is installed in the second permanent magnet slot 23, and the one end of the permanent magnet near the through hole 22 contacts the one end of the second permanent magnet slot 23 near the through hole 22 and near the outer frame, and the second permanent magnet slot 23 near the outer frame; similarly, the fourth side 224 of the through hole 22 refers to the line segment formed by the intersection of the first permanent magnet slot 21 and the second permanent magnet slot 23 near the outer frame after the permanent magnet is installed in the first permanent magnet slot 21. That is, after the permanent magnet is installed, the first side 221, the second side 222, the end of the permanent magnet in the second permanent magnet slot 23 close to the through hole 22, the third side 223, the fourth side 224 and the end of the permanent magnet in the first permanent magnet slot 21 close to the through hole 22 are arranged in sequence to form a through hole 22.

[0054] Through the above technical solution, by providing the through hole 22, the magnetic isolation effect can be achieved.

[0055] According to the second aspect of the present invention, a motor rotor includes the above-mentioned asynchronous starting permanent magnet synchronous motor rotor magnetic isolation bridge, and also includes permanent magnets arranged in the first permanent magnet slots 21 and the second permanent magnet slots 23, and the magnetic poles of the permanent magnets arranged in two adjacent groups of permanent magnet slots 2 are opposite.

[0056] Through the above technical solution, such as Figure 6 As shown, the magnetic lines of force of the rotor magnetic field can interact more with the stator magnetic field through the air gap to generate asynchronous torque to start the motor. Figure 5 As shown, part of the magnetic lines of force generated by the rotor magnetic field directly form a loop on the rotor and do not interact with the stator magnetic field through the air gap, which will cause energy loss and deteriorate the starting ability of the motor.

[0057] According to a third aspect of the present invention, a motor comprises the motor rotor described above and a stator 6 , wherein the rotor is installed in the stator 6 , and an air gap is provided between the rotor and the stator 6 .

[0058] Through the above technical solution, compared with the back EMF of the motor of 312V in the traditional magnetic isolation bridge design, the back EMF of the motor using the magnetic isolation bridge in the invention can reach 327V, which greatly improves the starting ability of the motor and enables the permanent magnet motor to have both good electromagnetic properties and strong mechanical strength.

[0059] In order to further illustrate the performance effect of the present invention, the performance test data of the following embodiments and comparative examples are provided.

[0060] Embodiment: The rotor magnetic isolation bridge of the asynchronous start permanent magnet synchronous motor with the preferred parameters of the present invention is applied to the motor to obtain test case data, and the magnetic isolation bridge of the prior art (set as Figure 1 The structure shown in the figure is applied to the motor for testing to obtain comparative data. Figure 5 The comparison ratio and Figure 6 Magnetic field line distribution diagram of the test case, Figure 7 The comparison ratio and Figure 8 Waveform diagram of the motor of the test example.

[0061] After the optimization and improvement of the magnetic isolation bridge by the present invention, the back electromotive force and the stability of the motor are significantly improved, the rotor leakage coefficient is significantly reduced, the loss of the motor is reduced, and the efficiency of the motor is improved; Figure 5 and Figure 6 It can be seen from the magnetic field line distribution diagram that the rotor magnetic isolation bridge of the asynchronous starting permanent magnet synchronous motor of the present invention can better isolate magnetic flux and prevent magnetic leakage, thereby greatly improving the starting ability of the motor; Figure 7 and Figure 8 It can be seen from the waveform diagram of the motor that the motor back EMF under the two magnetic isolation bridges is different. The back EMF of the original magnetic isolation bridge design is only 312.6V. After optimization and improvement, the magnetic isolation bridge design can increase the back EMF to 327.6V, and the EMF is increased by 4.79%. The magnetic isolation bridge designed by the present invention can effectively avoid magnetic leakage, so that the sine wave of the motor of the present invention can more easily reach the highest effective value of the motor, reduce the loss, and effectively improve the efficiency and back EMF of the motor.

[0062] In summary, through the asynchronous starting permanent magnet synchronous motor rotor magnetic isolation bridge, motor rotor and motor of the present invention, the leakage flux is reduced and the rotor deformation caused by the centrifugal force generated when the motor runs at high speed is reduced, so that the permanent magnet motor has both good electromagnetic performance and strong mechanical strength.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An asynchronous start permanent magnet synchronous motor rotor magnetic isolation bridge, comprising a rotor core, permanent magnet slots, magnetic isolation slots and magnetic isolation bridges arranged in sequence along the radial direction of the rotor core, wherein the permanent magnet slots and magnetic isolation slots are both arranged through the rotor core, and characterized in that: It also includes a plurality of squirrel cage bar holes uniformly arranged circumferentially along the outer periphery of the rotor core; With the side where the center of the rotor core is located as the inner side, and with the side where the outer circumference of the rotor core is located as the outer side, the magnetic isolation groove includes a first arc segment close to the outer side, a second arc segment and a seventh arc segment respectively forming an S-shape tangent to the two ends of the first arc segment, the squirrel cage bar hole includes an eighth arc segment close to the inner side and a second opening connected to the eighth arc segment, the first arc segment and the eighth arc segment are arranged cocentrically, and the first arc segment, the second arc segment and the seventh arc segment and part of the eighth arc segment form a C-shaped magnetic isolation bridge; The permanent magnet slots include a first permanent magnet slot and a second permanent magnet slot, the first permanent magnet slot and the second permanent magnet slot form a V-shaped magnetic circuit structure with an opening direction facing outward, and the permanent magnet slots are arranged in 4n groups that are evenly distributed along the circumference of the rotor core and symmetrical along the radial direction of the rotor core, where n≥1 and n is an integer; With the perpendicular bisector of the V-shaped magnetic circuit structure as the axis, the first permanent magnet slot, the magnetic isolation slot, the magnetic isolation bridge and the squirrel cage bar hole sequentially arranged with the first permanent magnet slot along the radial direction of the rotor core, and the second permanent magnet slot, the magnetic isolation slot, the magnetic isolation bridge and the squirrel cage bar hole sequentially arranged with the second permanent magnet slot along the radial direction of the rotor core are all arranged in mirror symmetry; The radius R1 of the first arc segment is 6.1mm and the central angle is 180°. The ends of the second arc segment and the seventh arc segment away from the first arc segment are at the same distance from the outer circumference of the rotor core and L1 is 5.8mm-6.1mm. The width L2 of the magnetic isolation bridge is 1mm-1.3mm.

2. The rotor magnetic isolation bridge of an asynchronous start permanent magnet synchronous motor according to claim 1, characterized in that: The magnetic isolation groove also includes a first straight line segment, a third arc segment, a fourth arc segment, a first opening, a fifth arc segment, a sixth arc segment and a fourth straight line segment connected in sequence, one end of the first straight line segment is connected to the second arc segment, and one end of the fourth straight line segment is connected to the seventh arc segment; The fourth arc segment and the fifth arc segment are arranged cocircularly, the length of the fourth arc segment is less than the length of the fifth arc segment, and the fourth arc segment and the fifth arc segment are arranged cocenter with the first arc segment; The first straight line segment is circumferentially connected to the second arc segment and the third arc segment, and the centers of the second arc segment and the third arc segment are both located on the same side of the first straight line segment; The fourth straight line segment is circumferentially connected to the sixth arc segment and the seventh arc segment, and the centers of the sixth arc segment and the seventh arc segment are both located on the same side of the fourth straight line segment.

3. The rotor magnetic isolation bridge of an asynchronous start permanent magnet synchronous motor according to claim 2, characterized in that: The first opening includes a second straight line segment and a third straight line segment which are parallel to each other, one end of the second straight line segment is connected to the fourth arc segment, one end of the third straight line segment is connected to the fifth arc segment, and the distance between the second straight line segment and the third straight line segment is less than the width of the permanent magnet slot.

4. The rotor magnetic isolation bridge of an asynchronous start permanent magnet synchronous motor according to claim 3, characterized in that: The first arc segment is bisected by a straight line passing through the center of the circle where the first arc segment is located, and the second arc segment, the first straight line segment and the third arc segment are symmetrically arranged with the seventh arc segment, the fourth straight line segment and the sixth arc segment respectively with the straight line as the axis.

5. The rotor magnetic isolation bridge of an asynchronous start permanent magnet synchronous motor according to claim 4, characterized in that: The radii of the second arc segment, the third arc segment, the sixth arc segment and the seventh arc segment are equal and R3 is 0.3mm, the arc lengths of the second arc segment and the seventh arc segment are equal and are both 1.42mm, the arc lengths of the third arc segment and the sixth arc segment are equal and are both 0.48mm, the lengths of the first straight line segment and the fourth straight line segment are equal and L3 is both 0.9mm.

6. The rotor magnetic isolation bridge of an asynchronous start permanent magnet synchronous motor according to claim 5, characterized in that: The radius R4 of the circle where the fourth arc segment and the fifth arc segment are located is 7.6 mm, the length of the fourth arc segment is 4.54 mm, and the length of the fifth arc segment is 14.12 mm.

7. The rotor magnetic isolation bridge of an asynchronous start permanent magnet synchronous motor according to claim 6, characterized in that: The length L4 of the second straight line segment is 1.61 mm, the length L5 of the third straight line segment is 1.67 mm, and the distance L6 between the second straight line segment and the third straight line segment is 4.05 mm.

8. The rotor magnetic isolation bridge of an asynchronous start permanent magnet synchronous motor according to claim 7, characterized in that: A through hole is arranged between the first permanent magnet slot and the second permanent magnet slot, and the through hole includes a first side, a second side, a third side and a fourth side, the first side is parallel to the fourth side, the second side is parallel to the third side, the first side is connected to the second side and the angle ∠1 is 110°, the third side is connected to the fourth side and the angle ∠2 is 110°, the distance between the first side and the fourth side is equal to the distance between the second side and the third side and L7 is 4.05mm, the length of the first side is equal to the length of the second side and L8 is 3.6mm, the length of the third side is equal to the length of the fourth side and L9 is 1.77mm.

9. A motor rotor, characterized in that: It includes the rotor magnetic isolation bridge of the asynchronous starting permanent magnet synchronous motor as described in any one of claims 1 to 8, and also includes permanent magnets arranged in the first permanent magnet slots and the second permanent magnet slots, and the magnetic poles of the permanent magnets arranged in two adjacent groups of permanent magnet slots are opposite.

10. A motor, characterized in that: The invention comprises the motor rotor as claimed in claim 9, and also comprises a stator, wherein the rotor is installed in the stator, and an air gap is arranged between the rotor and the stator.

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