Heat dissipating permanent magnet magneto

Abstract

The application relates to the technical field of energy-saving motors, in particular to a heat-dissipation type permanent magnet motor which comprises a machine shell, a stator arranged in the machine shell, a rotor rotatably supported in the machine shell through a rotating shaft, and a heat-dissipation unit arranged on the machine shell and used for accelerating heat dissipation of the motor. The cooling medium is directly led to pass through the surface of the permanent magnet on the rotor by the rotation of the spiral outer circulation cavity, the permanent magnet is directly cooled, the copper consumption is reduced, energy saving is realized, the cooling medium is driven into the spiral inner circulation cavity by the rotation of the spiral outer circulation cavity, the secondary heat exchange is completed with the stator core and the winding end part, the average temperature of the stator core is reduced, the iron loss is reduced, the local hot spot temperature of the winding end part is reduced, the resistance is reduced, the copper consumption is further reduced, the cooling medium after absorbing heat is discharged into the spiral cooling ribs through the exhaust port by the centrifugal fan and the spiral outer circulation cavity, and the third heat exchange is carried out with the inner wall of the machine shell and the outer wall of the core of the stator.

Description

A heat-dissipating permanent magnet motor Technical Field

[0001] This invention relates to the field of energy-saving motors, and in particular to a heat-dissipating permanent magnet motor. Background Technology

[0002] Permanent magnet motors (PMMs) replace excitation windings with the combination of permanent magnets and rotating magnetic fields, offering advantages such as high efficiency, high power density, and compact structure. They have become core components in high-performance drive applications such as electric vehicles, servo systems, and wind turbine pitch control. However, heat loss is an unavoidable problem in the use of PMMs. The copper loss of the stator windings, the iron loss of the stator core, and the eddy current loss of the rotor continuously generate heat. Studies have shown that when the temperature of the permanent magnet exceeds 50°C, its remanence density decreases linearly with increasing temperature. To maintain output torque, the motor will spontaneously consume more electrical energy, increasing energy consumption. Existing PMMs typically improve heat dissipation by adding a fan at the tail end. However, the cooling airflow generated by the fan only passes over the outer surface of the casing and cannot directly remove heat from the winding ends and the inside of the rotor, causing heat accumulation inside the motor and increasing energy consumption. Summary of the Invention

[0003] In view of the problems in the above or existing technologies, existing permanent magnet motors usually improve the heat dissipation effect by adding a fan at the tail end. However, the cooling airflow generated by the fan only passes over the outer surface of the housing and cannot directly remove the heat from the winding ends and the inside of the rotor, causing heat accumulation inside the motor and increasing the energy consumption of the motor. Therefore, the present invention is proposed.

[0004] Therefore, the object of the present invention is to provide a heat-dissipating permanent magnet motor.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: including a housing, a stator disposed inside the housing, a rotor rotatably supported inside the housing by a rotating shaft, and a heat dissipation unit disposed on the housing for accelerating motor heat dissipation; a centrifugal fan is disposed at one end of the rotating shaft, and a partition plate is disposed inside the housing to divide the interior of the housing into two parts, the side closer to the stator is disposed as an intake chamber, and the side closer to the centrifugal fan is disposed as an exhaust chamber, and an air inlet is disposed on the partition plate to connect the intake chamber and the exhaust chamber.

[0006] As a preferred embodiment of the heat-dissipating permanent magnet motor of the present invention, a spiral cooling rib is provided on the inner wall of the air intake chamber, and the outer wall of the stator core is in contact with the spiral cooling rib.

[0007] As a preferred embodiment of the heat-dissipating permanent magnet motor of the present invention, an exhaust port is provided on the inner wall of the exhaust chamber, and the exhaust port is connected to one end of the spiral cooling rib.

[0008] As a preferred embodiment of the heat-dissipating permanent magnet motor of the present invention, a spiral inner circulation cavity is provided on the inner wall of the stator core.

[0009] As a preferred embodiment of the heat-dissipating permanent magnet motor of the present invention, a spiral external circulation cavity is provided on the outer wall of the rotor core.

[0010] In a preferred embodiment of the heat-dissipating permanent magnet motor of the present invention, the number of turns of the spiral external circulation cavity is set to 4-6 turns.

[0011] In a preferred embodiment of the heat-dissipating permanent magnet motor of the present invention, the spiral inner circulation cavity and the spiral outer circulation cavity are connected to the exhaust port through the air inlet.

[0012] As a preferred embodiment of the heat dissipation type permanent magnet motor of the present invention, the heat dissipation unit includes a cooling chamber disposed on the housing, and a connecting ring one and a connecting ring two disposed on the cooling chamber; one end of the spiral cooling rib is connected to the connecting ring two; one end of the spiral inner circulation cavity and the spiral outer circulation cavity are connected to the connecting ring one.

[0013] As a preferred embodiment of the heat-dissipating permanent magnet motor of the present invention, wherein: a first connecting ring is provided with a first connecting port to connect the cooling chamber with the inner spiral circulation cavity and the outer spiral circulation cavity; a second connecting ring is provided with a second connecting port to connect the cooling chamber with the spiral cooling ribs.

[0014] As a preferred embodiment of the heat dissipation type permanent magnet motor of the present invention, a guide plate is provided inside the cooling chamber, the guide plate is located between the first connecting port and the second connecting port, and heat exchange fins are also provided on the outer wall of the cooling chamber.

[0015] The beneficial effects of the heat-dissipating permanent magnet motor of the present invention are as follows: The rotation of the spiral outer circulation cavity drives the cooling medium to directly pass over the surface of the permanent magnet on the rotor, directly cooling the permanent magnet, reducing copper loss, and achieving energy saving. Then, the rotation of the spiral outer circulation cavity drives the cooling medium into the spiral inner circulation cavity, where it completes secondary heat exchange with the stator core and winding ends, reducing the average temperature of the stator core and iron loss; it also reduces the temperature of local hot spots at the winding ends, reducing resistance and further reducing copper loss. Then, driven by the centrifugal fan and the spiral outer circulation cavity, the cooling medium, after absorbing heat, is discharged into the spiral cooling fins through the exhaust port, where it undergoes a third heat exchange with the inner wall of the casing and the outer wall of the stator core, further cooling the medium. Finally, it enters the cooling chamber, where it completes heat exchange with the outside through the heat exchange fins, achieving circulating heat dissipation, continuously reducing energy consumption, and extending service life. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 is a schematic diagram of the overall structure of a heat-dissipating permanent magnet motor.

[0018] Figure 2 is a schematic diagram of the exploded structure of a heat-dissipating permanent magnet motor.

[0019] Figure 3 is a cross-sectional structural diagram of the housing of a heat-dissipating permanent magnet motor.

[0020] Figure 4 is a schematic diagram of the partition plate of a heat-dissipating permanent magnet motor.

[0021] Figure 5 is a schematic diagram of the spiral cooling fins of a heat-dissipating permanent magnet motor.

[0022] Figure 6 is a schematic diagram of the stator structure of a heat-dissipating permanent magnet motor.

[0023] Figure 7 is a schematic diagram of the rotor structure of a heat-dissipating permanent magnet motor.

[0024] Figure 8 is a schematic diagram of the heat dissipation unit of a heat-dissipating permanent magnet motor.

[0025] In the diagram: 1. Housing; 11. Partition plate; 111. Air inlet; 112. Spiral cooling fins; 113. Exhaust port; 12. Intake chamber; 13. Exhaust chamber; 2. Stator; 21. Spiral inner circulation chamber; 3. Rotor; 31. Spiral outer circulation chamber; 4. Shaft; 41. Centrifugal fan; 5. Heat dissipation unit; 51. Cooling chamber; 511. Guide plate; 512. Heat exchange fins; 52. Connecting ring one; 521. Connecting port one; 53. Connecting ring two; 531. Connecting port two. Detailed Implementation

[0026] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0027] Example 1, referring to Figures 1-3, is the first embodiment of the present invention. This embodiment provides a heat-dissipating permanent magnet motor, which includes a housing 1, which serves as the outer shell of the motor and provides support and protection for the motor as a whole; a stator 2 disposed inside the housing 1; a rotor 3 rotatably supported inside the housing 1 via a rotating shaft 4, the rotor 3 being used to cooperate with the stator 2 to output torque via the rotating shaft 4; and a heat dissipation unit 5 disposed on the housing 1 to accelerate the heat dissipation of the motor. The interior of the housing 1 is connected to the heat dissipation unit 5 for storing and circulating a cooling medium. The cooling medium is set as air, which reduces the temperature of the components inside the housing 1, maintains torque output, and reduces energy consumption.

[0028] A centrifugal fan 41 is provided at one end of the rotating shaft 4 to rotate in conjunction with the shaft 4, generating centrifugal force and driving airflow. A partition plate 11 is provided inside the housing 1 to separate and seal the interior of the housing 1 into two parts. The side closer to the stator 2 is set as the intake chamber 12 for air intake, and the side closer to the centrifugal fan 41 is set as the exhaust chamber 13 for air exhaust. An air inlet 111 is provided on the partition plate 11 to connect the intake chamber 12 and the exhaust chamber 13, so that air can only enter the exhaust chamber 13 from the intake chamber 12 through the air inlet 111. The air inlet 111 is opposite to the centrifugal fan 41. This arrangement allows the centrifugal fan 41 to fully draw air from the intake chamber 12 through the air inlet 111 when it rotates.

[0029] In summary, when the motor starts, three-phase alternating current is applied to the windings on stator 2, generating a rotating magnetic field. The permanent magnet on rotor 3 generates a constant magnetic field. The two magnetic fields interact to generate electromagnetic torque, driving rotor 3 to rotate and causing shaft 4 to rotate, thus outputting torque. At this time, centrifugal fan 41 rotates with shaft 4, drawing air from intake chamber 12 into exhaust chamber 13. During this process, the air comes into contact with various parts of the casing 1, stator 2, and rotor 3, cooling them down. Then, centrifugal fan 41 throws the air into heat dissipation unit 5 for heat exchange with the outside air. The cooled air is then drawn back into casing 1 through the cooperation of heat dissipation unit 5 and centrifugal fan 41, achieving circulating heat dissipation. Simultaneously, circulating heat dissipation through internal air also prevents impurities from clogging the motor, preventing heat buildup and further extending the motor's service life.

[0030] Example 2, referring to Figures 1-7, is the second embodiment of the present invention. Unlike the previous embodiment, it provides the specific structures of the spiral inner circulation cavity 21 and the spiral outer circulation cavity 31 in the heat-dissipating permanent magnet motor. Compared to Example 1, furthermore, spiral cooling ribs 112 are provided on the inner wall of the intake cavity 12. The outer wall of the stator 2's iron core contacts the spiral cooling ribs 112, allowing airflow to cool the inner wall of the housing 1 and the outer wall of the stator 2's iron core.

[0031] The inner wall of the exhaust chamber 13 is provided with an exhaust port 113, which is connected to one end of the spiral cooling fin 112. It is used to cooperate with the rotation of the centrifugal fan 41 to drive the air flowing from the air inlet 111 through the exhaust port 113 into the spiral cooling fin 112 for three heat exchanges, so as to fully reduce the internal temperature of the motor and suppress the state of increased power consumption and reduced output torque caused by heat accumulation in the motor.

[0032] The stator 2 has a spiral internal circulation cavity 21 on the inner wall of the iron core for air flow to cool the inner wall of the iron core on the stator 2 and the iron core and permanent magnet on the rotor 3.

[0033] The rotor 3 has a spiral external circulation cavity 31 on the outer wall of the iron core. This cavity is used to rotate the rotor 3 and use the air in the spiral external circulation cavity 31 as a miniature nut to be turned. The air is squeezed and pushed by the groove surface of the spiral external circulation cavity 31 and continuously moves forward along the spiral angle. This draws the air from one end of the stator 2 to the other end, forming an internal and external circulation with the heat dissipation unit 5. This accelerates the flow of air between the rotor 3 and the stator 2 and improves the cooling effect.

[0034] The number of turns in the spiral external circulation chamber 31 is set to 4-6. The number of turns in the spiral external circulation chamber 31 is equal to the thread length of the pump. Too few turns result in a short airflow stroke, causing pressure to be released before the pressure head is fully built up, resulting in low airflow. Too many turns lead to increased friction area and friction resistance, which in turn reduces airflow and increases noise. Therefore, there is an optimal number of turns to maintain a balance between airflow velocity and static pressure. Tests show that when the casing thickness 1 is 90mm, the thread helix angle of the spiral external circulation chamber 31 is 20°, the groove depth of the spiral external circulation chamber 31 is 2mm, the rotation speed is 3000r / min, and the cooling medium is air, the airflow and heat transfer coefficient generated by different numbers of turns in the spiral external circulation chamber 31 are shown in the following figure:

[0035]

[0036] As shown in the table above, the appropriate number of rotations for the spiral external circulation chamber 31 is 5. Beyond that, although the static pressure will increase slightly, the friction resistance will dominate, the airflow will turn downwards, and the heat dissipation benefit will saturate or even decrease.

[0037] The spiral inner circulation chamber 21 and the spiral outer circulation chamber 31 are connected to the exhaust port 113 through the air inlet 111. The spiral inner circulation chamber 21 and the spiral outer circulation chamber 31 send hot air into the exhaust port 113 through the air inlet 111 to achieve circulating heat exchange.

[0038] The rest of the structure is the same as in Example 1.

[0039] In summary, when the motor starts, the rotor 3 drives the shaft 4 to rotate in the stator 2. At this time, the centrifugal fan 41 rotates with the shaft 4, generating centrifugal force, which causes the air in the intake chamber 12 to flow in the spiral inner circulation chamber 21 and the spiral outer circulation chamber 31. The air then enters the exhaust chamber 13 through the air inlet 111 and then enters the heat dissipation unit 5 through the exhaust port 113. At this time, the spiral outer circulation chamber 31 rotates in coordination with the rotor 3. The rotation of the spiral outer circulation chamber 31 twists the air, accelerating the air flow in the spiral outer circulation chamber 31, realizing simultaneous pumping and stirring, doubling the heat dissipation efficiency, and achieving the expected energy saving and noise reduction effect.

[0040] Example 3, referring to Figures 1-8, is the second embodiment of the present invention. Unlike the previous embodiment, it provides a specific structure for the heat dissipation unit 5 in a heat-dissipating permanent magnet motor. Compared to Example 2, the heat dissipation unit 5 further includes a cooling chamber 51 disposed on the housing 1 for storing air, and a first connecting ring 52 and a second connecting ring 53 disposed on the cooling chamber 51. The first connecting ring 52 is used for drawing air out of the cooling chamber 51, and the second connecting ring 53 is used for pumping air into the cooling chamber 51.

[0041] One end of the spiral cooling fin 112 is connected to the second connecting ring 53. Air enters the spiral cooling fin 112 through the exhaust port 113 to exchange heat and cool the inner wall of the casing 1 and the outer wall of the iron core on the stator 2. The air after heat exchange is then pumped into the cooling chamber 51 through the second connecting ring 53.

[0042] One end of the spiral inner circulation chamber 21 and the spiral outer circulation chamber 31 is connected to the connecting ring 52. The suction force generated by the rotation of the spiral outer circulation chamber 31 and the centrifugal fan 41 draws the air out of the cooling chamber 51 through the connecting ring 52, so that the air flows in the spiral inner circulation chamber 21 and the spiral outer circulation chamber 31 to exchange heat and cool the inside of the motor.

[0043] Among them, the connecting ring 52 is provided with a connecting port 521, which connects the cooling chamber 51 with the spiral inner circulation chamber 21 and the spiral outer circulation chamber 31, so as to draw air out of the cooling chamber 51;

[0044] The connecting ring 2 53 is provided with a connecting port 2 531, which connects the cooling chamber 51 with the spiral cooling rib 112, so that the air in the spiral cooling rib 112 can enter the cooling chamber 51 through the connecting port 2 531.

[0045] The cooling chamber 51 is equipped with a baffle plate 511, which is located between the first connecting port 521 and the second connecting port 531. The baffle plate 511 is used to separate the pumped hot air from the cold air that is about to be drawn out, so as to prevent the hot air and cold air from mixing and reducing the cooling effect. The outer wall of the cooling chamber 51 is also equipped with heat exchange fins 512, which are used to accelerate the heat exchange between the hot air in the cooling chamber 51 and the outside air.

[0046] The rest of the structure is the same as in Example 2.

[0047] In summary, when the motor starts, the spiral outer circulation chamber 31 and the centrifugal fan 41 work together with the rotor 3 and the shaft 4 to rotate. The centrifugal fan 41 generates suction, drawing the cold air from the cooling chamber 51 through the connecting port 521 into the spiral inner circulation chamber 21 and the spiral outer circulation chamber 31 for heat exchange. The rotation of the spiral outer circulation chamber 31 accelerates the airflow between the spiral outer circulation chamber 31 and the spiral inner circulation chamber 21, improving the heat exchange effect. The hot air passing through the spiral outer circulation chamber 31 and the spiral inner circulation chamber 21 is then drawn in by the centrifugal fan 41. The hot air is drawn into the exhaust chamber 13 and then thrown into the exhaust port 113 by the centrifugal force generated by the rotation of the centrifugal fan 41. At this time, the hot air enters the spiral cooling fins 112 through the exhaust port 113, and exchanges heat with the contact parts of the outer shell of the casing 1 and the stator 2 again. Then, the hot air enters the connecting ring 2 53 through the spiral cooling fins 112 and is pumped into the cooling chamber 51 through the connecting port 2 531. The hot air exchanges heat with the outside air through the heat exchange fins 512 and then enters the intake chamber 12 through the connecting port 1 521 to achieve circulating heat dissipation.

[0048] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A heat-dissipating permanent magnet motor, characterized in that: The device includes a housing (1), a stator (2) disposed inside the housing (1), a rotor (3) rotatably supported inside the housing (1) via a shaft (4), and a heat dissipation unit (5) disposed on the housing (1) for accelerating motor heat dissipation; a centrifugal fan (41) is provided at one end of the shaft (4), and a partition plate (11) is provided inside the housing (1) to divide the interior of the housing (1) into two parts, with the side near the stator (2) being the intake chamber (12) and the side near the centrifugal fan (41) being the exhaust chamber (13), and an air inlet (111) provided on the partition plate (11) to connect the intake chamber (12) and the exhaust chamber (13); the heat dissipation unit (5) includes a cooling chamber (51) disposed on the housing (1), and a connecting plate (51) disposed on the cooling chamber (51). One connecting ring (52) and another connecting ring (53); one end of the spiral cooling rib (112) is connected to the second connecting ring (53); one end of the spiral inner circulation cavity (21) and the spiral outer circulation cavity (31) is connected to the first connecting ring (52); the first connecting ring (52) is provided with a first connecting port (521) to connect the cooling chamber (51) with the spiral inner circulation cavity (21) and the spiral outer circulation cavity (31); the second connecting ring (53) is provided with a second connecting port (531) to connect the cooling chamber (51) with the spiral cooling rib (112); a guide plate (511) is provided inside the cooling chamber (51), the guide plate (511) is located between the first connecting port (521) and the second connecting port (531), and heat exchange fins (512) are also provided on the outer wall of the cooling chamber (51).

2. The heat-dissipating permanent magnet motor as described in claim 1, characterized in that: Spiral cooling ribs (112) are provided on the inner wall of the air intake chamber (12), and the outer wall of the stator (2) core contacts the spiral cooling ribs (112).

3. The heat-dissipating permanent magnet motor as described in claim 2, characterized in that: An exhaust port (113) is provided on the inner wall of the exhaust chamber (13), and the exhaust port (113) is connected to one end of the spiral cooling rib (112).

4. The heat-dissipating permanent magnet motor as described in claim 3, characterized in that: A spiral internal circulation cavity (21) is provided on the inner wall of the stator (2) core.

5. The heat-dissipating permanent magnet motor as described in claim 4, characterized in that: The rotor (3) has a spiral external circulation cavity (31) on the outer wall of the iron core.

6. The heat-dissipating permanent magnet motor as described in claim 5, characterized in that: The number of turns of the spiral external circulation cavity (31) is set to 4-6 turns.

7. The heat-dissipating permanent magnet motor as described in claim 6, characterized in that: The spiral inner circulation chamber (21) and the spiral outer circulation chamber (31) are connected to the exhaust port (113) through the air inlet (111).

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