High-speed permanent magnet motor

Abstract

The high-speed permanent magnet motor comprises a motor base, a motor stator and a motor rotor, the motor stator is arranged on the inner wall of the motor base, the motor rotor comprises a rotor iron core and a rotating shaft, a first air inlet hole and a first air outlet hole are formed in the two ends of the motor base respectively, the first air inlet hole is in butt joint with a cooling air generating device, and a cooling cavity is formed in the rotating shaft. A second air inlet hole is formed in one end of the cooling cavity and communicates with the first air inlet hole, a second air outlet hole is formed in the other end of the cooling cavity and communicates with the first air outlet hole, cooling air sequentially passes through the first air inlet hole, the second air inlet hole, the interior of the rotating shaft, the second air outlet hole and the first air outlet hole after being generated, and a heat dissipation structure assembly is arranged on the side wall of the cooling cavity. The heat dissipation structure assembly is used for increasing the heat exchange area of cooling air and the rotating shaft and increasing the flow speed of the cooling air in the rotating shaft. According to the high-speed permanent magnet motor, a large amount of cooling air is allowed to flow in, and the motor rotor cooling effect can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor cooling equipment, and in particular to a high-speed permanent magnet motor. Background Art

[0002] High-speed motors eliminate the need for speed-changing mechanical devices and are directly connected to high-speed loads. This can improve the transmission efficiency of the system while reducing noise, so high-speed motors have become an inevitable trend in motor development. As the motor speed increases, the high-frequency eddy current loss of the rotor will be much greater than that of ordinary motors, so the heat dissipation design of high-speed motors is particularly important.

[0003] In order to solve the heat dissipation problem of high-speed motors, the traditional heat dissipation method is to set a water cooling structure on the casing to suppress the temperature of the high-speed motor. Although the casing water cooling structure can effectively suppress the stator temperature, the heat generated by the rotor cannot be effectively dissipated due to the long distance between the rotor and the casing, and the cooling effect on the rotor is not ideal. To solve this problem, the prior art often uses a method of sending cooling gas into the air gap between the stator and the rotor to cool the rotor. For example, the Chinese patent document with the publication number of CN112886760A discloses an air cooling structure of an electric motor, including a rotor and a casing, a stator is fixedly installed inside the casing, both ends of the air cavity inside the stator are rotatably connected to the rotor, a bearing seat is fixedly installed inside the end cover, and the middle part of the bearing seat is rotatably connected to the bearing, the rotor passes through the two bearings and is located between the two bearings, an axial gap is formed between the rotor and the bearing seat, and a radial gap is formed between the rotor and the stator, one end of the rotor is fixedly connected to a heat dissipation impeller, and the heat dissipation impeller is located between the end covers on both sides, an air inlet is opened on one side of the casing, and an exhaust hole is opened on the other side of the casing. Due to the narrow radial gap between the rotor and the stator, the cooling air flow is limited, and the cooling air is easily heated to the same temperature as the rotor, resulting in poor cooling effect on the rotor core. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a high-speed permanent magnet motor that allows a large amount of cooling air to flow in and can improve the cooling effect on the motor rotor.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A high-speed permanent magnet motor comprises a base, a motor stator and a motor rotor, wherein the motor stator is arranged on the inner wall of the base, the motor rotor comprises a rotor core and a rotating shaft, the rotor core is sleeved on the rotating shaft, and the rotating shaft is rotatably arranged on the base, a first air inlet and a first air outlet are respectively arranged at two ends of the base, a cooling air generating device is connected to the first air inlet, a cooling chamber is arranged inside the rotating shaft, a second air inlet communicating with the first air inlet is arranged at one end of the cooling chamber, and a second air outlet communicating with the first air outlet is arranged at the other end of the cooling chamber, after the cooling air is generated, it passes through the first air inlet, the second air inlet, the inside of the rotating shaft, the second air outlet and the first air outlet in sequence to form a first cooling path, a heat dissipation structure component is arranged on the side wall of the cooling chamber, and the heat dissipation structure component is used to increase the heat exchange area between the cooling air and the rotating shaft, and to increase the flow rate of the cooling air in the rotating shaft.

[0007] As a further improvement of the above technical solution: the heat dissipation structure assembly includes a plurality of heat dissipation fins arranged on the side wall of the cooling chamber, the plurality of heat dissipation fins are arranged at intervals along the rotation direction of the shaft, the height of the heat dissipation fins gradually decreases from one end to the other end, the end of the heat dissipation fin with a higher height is close to the second air inlet, and the other end of the heat dissipation fin is close to the second air outlet.

[0008] As a further improvement of the above technical solution: the second air inlet and the second air outlet are both arranged on the side wall of the rotating shaft.

[0009] As a further improvement of the above technical solution: the air intake direction of the second air intake hole deviates from the axis of the rotating shaft, and forms an obtuse angle with the speed direction of the second air intake hole when rotating.

[0010] As a further improvement of the above technical solution: the air outlet direction of the second air outlet deviates from the axis of the rotating shaft, and forms an acute angle with the speed direction of the second air outlet when rotating.

[0011] As a further improvement of the above technical solution: the second air inlet and the second air outlet are elliptical.

[0012] As a further improvement of the above technical solution: a plurality of the second air inlet holes and the second air outlet holes are arranged at intervals along the rotation direction of the shaft.

[0013] As a further improvement of the above technical solution: the second air inlet is located directly below the first air inlet, and the second air outlet is located directly below the first air outlet.

[0014] As a further improvement of the above technical solution: an air gap is formed between the motor stator and the rotor core, and after the cooling wind is generated, it passes through the first air inlet, the air gap and the first air outlet in sequence to form a second cooling path.

[0015] As a further improvement of the above technical solution: the base includes a casing and a first end cover and a second end cover respectively arranged at both ends of the casing, the first air inlet is arranged at one end of the casing, the first air outlet is arranged at the other end of the casing, the motor stator is arranged on the inner wall of the casing, the first end cover and the second end cover are both provided with bearing seats, and the rotating shaft is supported on the two bearing seats.

[0016] Compared with the prior art, the advantages of the high-speed permanent magnet motor disclosed in the present invention are: the heat generated by the rotor core will be transferred to the rotating shaft, the cooling air can enter the cooling chamber inside the rotating shaft from the second air inlet hole to exchange heat with the rotating shaft, and flow out from the second air outlet hole to complete the cooling of the motor rotor, the space of the cooling chamber inside the rotating shaft is large, allowing a large amount of cooling air to enter to complete the heat exchange, and the cooling air is not easily heated to the same temperature as the rotor core. A heat dissipation structure component is provided on the side wall of the cooling chamber, which can increase the heat exchange area between the cooling air and the rotating shaft and increase the flow rate of the cooling air inside the rotating shaft, thereby improving the heat exchange efficiency between the cooling air and the motor rotor and achieving a good cooling effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the internal structure of the high-speed permanent magnet motor of the present invention.

[0018] Figure 2 yes Figure 1 Schematic diagram of the enlarged structure of part A.

[0019] Figure 3 It is a structural schematic diagram of the rotating shaft of the high-speed permanent magnet motor of the present invention.

[0020] Figure 4 It is a schematic diagram of the arrangement structure of the heat dissipation structural components of the high-speed permanent magnet motor of the present invention.

[0021] Figure 5 It is a structural schematic diagram of the heat dissipation fins of the high-speed permanent magnet motor of the present invention.

[0022] Figure 6 It is a cross-sectional schematic diagram of the second air inlet of the high-speed permanent magnet motor of the present invention.

[0023] Figure 7 It is a cross-sectional schematic diagram of the second air outlet of the high-speed permanent magnet motor of the present invention.

[0024] The numbers in the figure represent: 1. base; 11. casing; 111. first air inlet; 112. first air outlet; 12. first end cover; 13. second end cover; 2. motor stator; 3. motor rotor; 31. rotor core; 32. rotating shaft; 33. cooling chamber; 331. second air inlet; 332. second air outlet; 4. cooling air generating device; 5. heat dissipation structure assembly; 50. mounting sleeve; 51. heat dissipation fin; 6. air gap; 7. bearing seat. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0027] In the present invention, unless otherwise clearly specified and limited, the terms "assemble", "connect", "connect", "fix" and the like 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 a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Figures 1 to 7An embodiment of the high-speed permanent magnet motor of the present invention is shown. The high-speed permanent magnet motor of this embodiment includes a base 1, a motor stator 2 and a motor rotor 3. The motor stator 2 is arranged on the inner wall of the base 1. The motor rotor 3 includes a rotor core 31 and a rotating shaft 32. The rotor core 31 is sleeved on the rotating shaft 32. The rotating shaft 32 is rotatably arranged on the base 1. The two ends of the base 1 are respectively provided with a first air inlet 111 and a first air outlet 112. The first air inlet 111 is connected to a cooling air generating device 4. A cooling chamber 33 is provided inside the rotating shaft 32. The cooling chamber 33 A second air inlet 331 communicating with the first air inlet 111 is provided at one end of the cooling chamber 33, and a second air outlet 332 communicating with the first air outlet 112 is provided at the other end of the cooling chamber 33. After the cooling wind is generated, it passes through the first air inlet 111, the second air inlet 331, the inside of the rotating shaft 32, the second air outlet 332 and the first air outlet 112 in sequence to form a first cooling path. A heat dissipation structure component 5 is provided on the side wall of the cooling chamber 33. The heat dissipation structure component 5 is used to increase the heat exchange area between the cooling wind and the rotating shaft 32, and to increase the flow rate of the cooling wind in the rotating shaft 32.

[0029] In the high-speed permanent magnet motor of this embodiment, the heat generated by the rotor core 31 will be transferred to the rotating shaft 32, and the cooling air can enter the cooling chamber 33 inside the rotating shaft 32 from the second air inlet 331 to exchange heat with the rotating shaft 32, and flow out from the second air outlet 332 to complete the cooling of the motor rotor 3. The space of the cooling chamber 33 inside the rotating shaft 32 is large, allowing a large amount of cooling air to enter to complete the heat exchange, and the cooling air is not easily heated to the same temperature as the rotor core 31. A heat dissipation structure component 5 is provided on the side wall of the cooling chamber 33, which can increase the heat exchange area between the cooling air and the rotating shaft 32 and increase the flow rate of the cooling air in the rotating shaft 32, thereby improving the heat exchange efficiency between the cooling air and the motor rotor 3 and achieving a good cooling effect.

[0030] See Figure 1 , Figure 3 , Figure 4 and Figure 5Further, in this embodiment, the heat dissipation structure assembly 5 includes a plurality of heat dissipation fins 51 disposed on the side wall of the cooling chamber 33, and the plurality of heat dissipation fins 51 are arranged at intervals along the rotation direction of the rotating shaft 32. The height of the heat dissipation fins 51 gradually decreases from one end to the other end. The end of the heat dissipation fin 51 with a higher height is close to the second air inlet 331, and the other end of the heat dissipation fin 51 is close to the second air outlet 332. The cooling air will flow through the heat dissipation fins 51 when entering the interior of the rotating shaft 32, and the cooling air will flow along the surface of the heat dissipation fins 51. As the height of the heat dissipation fins 51 gradually decreases, the linear velocity of the cooling air gradually increases. According to the Bernoulli principle, the greater the flow velocity, the smaller the pressure, so that the pressure at one end of the cooling chamber 33 close to the second air inlet 331 is greater than the pressure at one end close to the second air outlet 332. This pressure difference will accelerate the flow of the cooling air in the rotating shaft 32, thereby improving the heat exchange efficiency and cooling effect between the cooling air and the motor rotor 3. Preferably, the length direction of each heat dissipation fin 51 is parallel to the length direction of the rotating shaft 32 , and the plurality of heat dissipation fins 51 are evenly spaced along the rotation direction of the rotating shaft 32 , which helps to ensure the stability of the rotating shaft 32 during rotation.

[0031] See Figure 4 Furthermore, in this embodiment, the heat dissipation structure assembly 5 also includes a mounting sleeve 50 disposed on the side wall of the cooling chamber 33. The mounting sleeve 50 is sleeved inside the rotating shaft 32 and has an interference fit with the rotating shaft 32. Each heat dissipation fin 51 is installed on the inner side of the mounting sleeve 50, which is convenient for maintenance and replacement of the heat dissipation structure assembly 5.

[0032] See Figure 1 , Figure 2 , Figure 3 , Figure 6 and Figure 7 Furthermore, in this embodiment, the second air inlet 331 and the second air outlet 332 are both provided on the side wall of the rotating shaft 32. When the rotating shaft 32 rotates at a high speed, a negative pressure area will be formed at the second air inlet 331 and the second air outlet 332, forcing the cooling air entering the inside of the base 1 from the first air inlet 111 to be attracted to the second air inlet 331 and enter the cooling chamber 33 inside the rotating shaft 32. When the cooling air moves to the vicinity of the second air outlet 332 in the cooling chamber 33, the cooling air will be attracted by the second air outlet 332 and discharged from the rotating shaft 32, which is conducive to ensuring that the cooling air spontaneously flows along the first cooling path to cool the motor rotor 3.

[0033] See Figure 6 Furthermore, in this embodiment, the air intake direction of the second air inlet 331 deviates from the axis of the rotating shaft 32, and forms an obtuse angle with the speed direction of the second air inlet 331 when rotating. When the rotating shaft 32 rotates, the cooling air can enter the cooling chamber 33 along the side wall of the second air inlet 331, which is conducive to the cooling air entering the interior of the rotating shaft 32.

[0034] See Figure 7 Furthermore, in this embodiment, the outlet direction of the second air outlet 332 deviates from the axis of the rotating shaft 32, and forms an acute angle with the speed direction of the second air outlet 332 when rotating. The cooling air moves to the second air outlet 332 in the cooling chamber 33, and will be "thrown out" of the rotating shaft 32 along the rotating direction of the rotating shaft 32, which is conducive to the cooling air being discharged from the cooling chamber 33.

[0035] See Figures 1 to 3 Furthermore, in this embodiment, the second air inlet 331 and the second air outlet 332 are elliptical, which is beneficial to increase the air inlet and outlet volume of the cooling air inside the rotating shaft 32 .

[0036] See Figure 1 , Figure 2 , Figure 3 , Figure 6 and Figure 7 As a preferred embodiment, a plurality of second air inlet holes 331 and second air outlet holes 332 are evenly spaced along the rotation direction of the shaft 32, thereby improving the efficiency of cooling air entering the shaft 32 and further improving the cooling effect.

[0037] See Figure 1 Furthermore, in this embodiment, the cooling air generating device 4 is a blower, and the cooling air blown out by the blower has a large air volume, a fast flow rate, and a good cooling effect.

[0038] See Figure 1 Further, in this embodiment, the second air inlet 331 is located directly below the first air inlet 111, and the second air outlet 332 is located directly below the first air outlet 112. When the cooling wind just occurs, the temperature is low and it is easy to sink. The second air inlet 331 is located directly below the first air inlet 111, and the cooling wind easily enters the inside of the shaft 32; after the cooling wind completes the heat exchange with the shaft 32, the temperature is high and there is a tendency to move upward. The second air outlet 332 is located directly below the first air outlet 112, and the cooling wind is easily discharged from the inside of the shaft 32.

[0039] See Figure 1 and Figure 2 Further, in this embodiment, an air gap 6 is formed between the motor stator 2 and the rotor core 31, and the cooling wind passes through the first air inlet 111, the air gap 6 and the first air outlet 112 in sequence to form a second cooling path. The cooling wind flows through the second cooling path and the first cooling path, and can cool the inner and outer sides of the motor rotor 3 at the same time, further improving the cooling effect.

[0040] See Figure 1Further, in this embodiment, the base 1 includes a housing 11 and a first end cover 12 and a second end cover 13 respectively disposed at both ends of the housing 11, a first air inlet 111 disposed at one end of the housing 11, a first air outlet 112 disposed at the other end of the housing 11, a motor stator 2 disposed on the inner wall of the housing 11, a bearing seat 7 disposed on each of the first end cover 12 and the second end cover 13, and a rotating shaft 32 supported on the two bearing seats 7. It should be noted that the second air inlet 331 and the second air outlet 332 are not disposed at the position where the rotating shaft 32 cooperates with the two bearing seats 7, which is conducive to ensuring the stability of the rotating shaft 32 when in use.

[0041] See Figure 1 Furthermore, in this embodiment, both ends of the rotating shaft 32 are sealed, which is beneficial to prevent the cooling air from leaking axially from the inside of the rotating shaft 32 and to ensure the cooling effect of the cooling air on the motor rotor 3.

[0042] See Figure 1 Furthermore, in this embodiment, the shaft 32 is composed of multiple shaft sections, which can be connected by shrink fitting or friction welding. The shaft section located inside the base 1 has a cooling chamber 33, and the shaft section located outside the base 1 can be solid or hollow. In this embodiment, the shaft section of the shaft 32 located outside the base 1 is solid.

[0043] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the technical content disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention should fall within the scope of protection of the technical solution of the present invention.

Claims

1. A high-speed permanent magnet motor, comprising a base (1), a motor stator (2) and a motor rotor (3), wherein the motor stator (2) is arranged on the inner wall of the base (1), the motor rotor (3) comprises a rotor core (31) and a rotating shaft (32), the rotor core (31) is sleeved on the rotating shaft (32), the rotating shaft (32) is rotatably arranged on the base (1), and a first air inlet (111) and a first air outlet (112) are respectively arranged at two ends of the base (1), characterized in that: The first air inlet (111) is connected to a cooling air generating device (4); a cooling chamber (33) is provided inside the rotating shaft (32); one end of the cooling chamber (33) is provided with a second air inlet (331) connected to the first air inlet (111); the other end of the cooling chamber (33) is provided with a second air outlet (332) connected to the first air outlet (112); after the cooling air is generated, it passes through the first air inlet (111), the second air inlet (331), the inside of the rotating shaft (32), the second air outlet (332) and the first air outlet (112) in sequence to form a first cooling path; a heat dissipation structure component (5) is provided on the side wall of the cooling chamber (33); the heat dissipation structure component (5) is used to increase the heat exchange area between the cooling air and the rotating shaft (32) and to increase the flow rate of the cooling air in the rotating shaft (32).

2. The high-speed permanent magnet motor according to claim 1, characterized in that: The heat dissipation structure component (5) comprises a plurality of heat dissipation fins (51) arranged on the side wall of the cooling chamber (33); the plurality of heat dissipation fins (51) are arranged at intervals along the rotation direction of the rotating shaft (32); the height of the heat dissipation fins (51) gradually decreases from one end to the other end; the end of the heat dissipation fin (51) with a higher height is close to the second air inlet (331), and the other end of the heat dissipation fin (51) is close to the second air outlet (332).

3. The high-speed permanent magnet motor according to claim 1, characterized in that: The second air inlet (331) and the second air outlet (332) are both arranged on the side wall of the rotating shaft (32).

4. The high-speed permanent magnet motor according to claim 3, characterized in that: The air intake direction of the second air intake hole (331) deviates from the axis of the rotating shaft (32), and forms an obtuse angle with the speed direction of the second air intake hole (331) when rotating.

5. The high-speed permanent magnet motor according to claim 3, characterized in that: The air outlet direction of the second air outlet (332) deviates from the axis of the rotating shaft (32), and forms an acute angle with the speed direction of the second air outlet (332) when rotating.

6. The high-speed permanent magnet motor according to claim 3, characterized in that: The second air inlet (331) and the second air outlet (332) are elliptical in shape.

7. The high-speed permanent magnet motor according to claim 3, characterized in that: A plurality of the second air inlet holes (331) and the second air outlet holes (332) are arranged at intervals along the rotation direction of the rotating shaft (32).

8. The high-speed permanent magnet motor according to claim 3, characterized in that: The second air inlet (331) is located directly below the first air inlet (111), and the second air outlet (332) is located directly below the first air outlet (112).

9. The high-speed permanent magnet motor according to any one of claims 1 to 8, characterized in that: An air gap (6) is formed between the motor stator (2) and the rotor core (31), and cooling air is generated and passes through the first air inlet (111), the air gap (6) and the first air outlet (112) in sequence to form a second cooling path.

10. The high-speed permanent magnet motor according to any one of claims 1 to 8, characterized in that: The base (1) comprises a casing (11) and a first end cover (12) and a second end cover (13) respectively arranged at two ends of the casing (11); the first air inlet (111) is arranged at one end of the casing (11); the first air outlet (112) is arranged at the other end of the casing (11); the motor stator (2) is arranged on the inner wall of the casing (11); the first end cover (12) and the second end cover (13) are both provided with bearing seats (7); and the rotating shaft (32) is supported on the two bearing seats (7).

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