A high-speed permanent magnet synchronous motor

Abstract

This utility model discloses a high-speed permanent magnet synchronous motor, including: a motor housing, a cover plate at the tail of the motor housing, a rotor, and a stator. A cavity is formed at one end of the rotor near the cover plate, and a cooling pipe is provided at one end of the rotor cavity. The cooling pipe has an inlet hole and a return hole, both of which communicate with the cavity inside the rotor. An inlet connector is provided on the cover plate, and one end of the inlet connector communicates with the inlet hole of the cooling pipe, allowing coolant to enter the cavity inside the rotor through the inlet connector and the inlet hole, and then flow out through the return hole. A return fluid chamber is provided on the motor, and a return fluid connector is connected to the return fluid chamber, which is connected to a self-priming pump. Through the above method, this utility model can improve rotor cooling efficiency and significantly reduce rotor temperature by circulating a cooling medium to the center of the rotor without altering the electromagnetic design of the stator and rotor.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a high-speed permanent magnet synchronous motor. Background Technology

[0002] In the field of high-speed permanent magnet synchronous motors, surface-mounted rotor structures are widely used due to their advantages. However, the permanent magnets are subjected to enormous centrifugal forces during high-speed rotation, requiring high-strength carbon fiber sheaths or non-magnetic alloy protective sleeves for constraint. However, carbon fiber sheaths are at risk of resin softening and damage under high-temperature environments, while alloy protective sleeves generate significant eddy current losses and heat in themselves and the magnets during high-power, high-speed operation. More critically, the presence of the protective sleeve severely restricts the rotor's heat dissipation capacity. If the temperature of the permanent magnets on the rotor exceeds their maximum tolerance limit, irreversible overheating and demagnetization will occur. Therefore, employing efficient rotor cooling technology to remove this heat has become a key technological bottleneck in the development of high-power, high-speed permanent magnet motors. Currently, mainstream rotor cooling technologies such as air cooling are limited by the low specific heat capacity of air and the limited heat exchange area under the compact structure of high-speed motors, making it difficult to meet the heat exchange requirements of high power. While oil cooling is more effective, it requires the addition of complex oil channels in the stator and rotor, significantly increasing system complexity and design difficulty. Therefore, there is an urgent need for a new cooling solution that can effectively improve rotor cooling efficiency and simplify the system structure while maintaining the original stator and rotor electromagnetic design. Utility Model Content

[0003] The main technical problem solved by this utility model is to provide a high-speed permanent magnet synchronous motor that can improve rotor cooling efficiency and significantly reduce rotor temperature by circulating a cooling medium to the center of the rotor without altering the electromagnetic design of the stator and rotor.

[0004] To solve the above-mentioned technical problems, the present invention provides a high-speed permanent magnet synchronous motor, comprising: a motor housing, a cover plate at the tail of the motor housing, a rotor, and a stator. A cavity is formed at one end of the rotor near the cover plate, and a cooling pipe is provided at one end of the rotor cavity. The cooling pipe has an inlet hole and a return hole, both of which are connected to the cavity inside the rotor. An inlet connector is provided on the cover plate, and one end of the inlet connector is connected to the inlet hole of the cooling pipe, so that the coolant can enter the cavity inside the rotor through the inlet connector and the inlet hole and flow out through the return hole. A return liquid chamber is provided on the motor, and the return liquid chamber is connected to a return liquid connector, which is connected to a self-priming pump.

[0005] Preferably, the reflux holes are arranged on the upper and lower sides of the inflow hole.

[0006] Preferably, the reflux holes are arranged circumferentially along the inflow holes.

[0007] Preferably, the cooling pipe includes an inflow section and a return section, with an inflow hole in the inflow section and a return hole in the return section, and the length of the end of the inflow section extending into the cavity is greater than the length of the end of the return section extending into the cavity.

[0008] Preferably, the cooling pipe has a mating groove at one end near the cover plate, the inlet connector has a small gap mating with the mating groove at one end near the mating groove, and the inflow hole communicates with the mating groove.

[0009] Preferably, a labyrinth seal is provided on the end of the rotor near the inlet connector to ensure that coolant does not flow from the return chamber into the stator.

[0010] Preferably, the end of the inlet connector furthest from the rotor is bolted to the cover plate.

[0011] The beneficial effects of this invention are as follows: By setting a cavity structure with an internal cooling pipe on the rotor near-end cover side, and combining it with the connection design between the inlet connector and the cooling pipe inflow hole, the coolant is directly injected into the high-temperature area of ​​the rotor for targeted heat exchange. Utilizing the fluid passage between the return hole and the return chamber, combined with the forced suction of the self-priming pump, a closed-loop circulation is formed, significantly improving the rotor's heat dissipation efficiency while completely preserving the original electromagnetic design of the stator and rotor. The cooling pipe adopts a deep-extending inflow structure to guide the coolant to impact the far end of the cavity, avoiding short-path backflow of insufficiently heat-exchanged media, ensuring a uniform temperature drop across the entire rotor. The precise clearance fit between the inlet connector and the cooling pipe groove, supplemented by a labyrinth seal, isolates and protects the stator windings, achieving dynamic sealing during high-speed rotor rotation while maximizing coolant pressure, effectively blocking the risk of coolant leakage to the stator side, and fundamentally solving the problem of permanent magnet overheating and demagnetization. This structure only requires integrating the cooling pipe and sealing components at the rotor end, without modifying the motor stator oil passages or adding complex external pipelines, significantly reducing system complexity and manufacturing costs. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view of the present invention.

[0013] The components in the attached diagram are labeled as follows:

[0014] 1. Motor housing;

[0015] 2. Cover plate;

[0016] 3. Rotor; 31. Cavity;

[0017] 4. Stator;

[0018] 5. Cooling pipe; 51. Inlet section; 511. Inlet hole; 52. Return section; 521. Return hole;

[0019] 6. Inlet connector; 7. Return chamber; 71. Return connector; 8. Labyrinth seal. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0021] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0022] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0023] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0024] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0025] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0026] Unless otherwise specified, physical quantities in formulas should be understood as basic quantities of SI base units, or derived quantities derived from basic quantities through mathematical operations such as multiplication, division, differentiation, or integration.

[0027] Example:

[0028] refer to Figure 1 A high-speed permanent magnet synchronous motor includes: a motor housing 1, a cover plate 2 at the tail of the motor housing 1, a rotor 3, and a stator 4. A cavity 31 is formed at one end of the rotor 3 near the cover plate 2. A cooling pipe 5 is provided at one end of the cavity 31 near the cover plate 2. The cooling pipe 5 can be screwed onto the rotor 3, thereby ensuring the secure position of the cooling pipe 5 and the rotor 3. The cooling pipe 5 has an inflow hole 511 and a return hole 521, both of which communicate with the cavity 31 inside the rotor 3. An inlet connector 6 is provided on the cover plate 2. One end of the inlet connector 6 is connected to the inflow hole 511 of the cooling pipe 5, so that the coolant can enter the cavity 31 inside the rotor 3 through the inlet connector 6 and the inflow hole 511 and flow out through the return hole 521. A return chamber 7 is arranged on the motor, and the return chamber 7 is connected to a return connector 71. The return connector 71 is connected to a self-priming pump, so that the coolant is quickly drawn out from the return chamber 7 and the cooled coolant is circulated back into the cavity 31 of the rotor 3 through the inflow hole 511. The end of the inlet connector 6 away from the rotor 3 is bolted to the cover plate 2, so the position of the inlet connector 6 is fixed.

[0029] refer to Figure 1The return hole 521 can be arranged on the upper and lower sides of the inlet hole 511, or the return hole 521 can be arranged along the circumference of the inlet hole 511.

[0030] refer to Figure 1 The cooling pipe 5 includes an inflow section 51 and a return section 52. An inflow hole 511 is opened in the inflow section 51, and a return hole 521 is opened on the return section 52. The length of the end of the inflow section 51 that extends into the cavity 31 is greater than the length of the end of the return section 52 that extends into the cavity 31. This helps the coolant to impact the bottom of the cavity 31 and return under pressure. At the same time, it can also prevent the coolant that has just flowed into the cavity 31 and has not circulated sufficiently in the cavity 31 from being directly drawn away by the return hole 521, thereby further ensuring the heat dissipation effect on the rotor 3.

[0031] refer to Figure 1 The cooling pipe 5 has a mating groove at one end near the cover plate 2. The inlet connector 6 has a small gap fitting with the mating groove at one end. This gap is small, so as not to affect the rotation of the rotor 3 and to reduce the attenuation of the cooling hydraulic pressure. The inlet hole 511 is connected to the mating groove, so that the coolant is directly injected into the cavity 31 of the rotor 3 through the inlet connector 6.

[0032] refer to Figure 1 A labyrinth seal 8 is provided on the end of rotor 3 near the inlet connector 6 to ensure that coolant does not flow from the return chamber 7 into stator 4.

[0033] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A high-speed permanent magnet synchronous motor, comprising: The motor housing (1), the cover plate (2) at the tail of the motor housing, the rotor (3), and the stator (4) are characterized in that a cavity (31) is provided at one end of the rotor (3) near the cover plate (2), and a cooling pipe (5) is provided at one end of the cavity (31) of the rotor (3). The cooling pipe (5) has an inflow hole (511) and a return hole (521), and both the inflow hole (511) and the return hole (521) are connected to the cavity (31) inside the rotor (3). An inlet connector (6) is provided on the cover plate (2). One end of the inlet connector (6) is connected to the inflow hole (511) of the cooling pipe (5), so that the coolant can enter the cavity (31) inside the rotor (3) through the inlet connector (6) and the inflow hole (511) and flow out through the return hole (521). The motor is provided with a return chamber (7), which is connected to a return connector (71). The return connector (71) is connected to a self-priming pump.

2. The high-speed permanent magnet synchronous motor according to claim 1, characterized in that: The reflux hole (521) is arranged on the upper and lower sides of the inflow hole (511).

3. A high-speed permanent magnet synchronous motor according to claim 1, characterized in that: The return hole (521) is arranged circumferentially along the inlet hole (511).

4. A high-speed permanent magnet synchronous motor according to claim 2 or 3, characterized in that: The cooling pipe (5) includes an inflow section (51) and a return section (52). The inflow hole (511) is opened in the inflow section (51), and the return hole (521) is opened on the return section (52). The length of the end of the inflow section (51) that extends into the cavity (31) is greater than the length of the end of the return section (52) that extends into the cavity (31).

5. A high-speed permanent magnet synchronous motor according to claim 1, characterized in that: The cooling pipe (5) has a mating groove at one end near the cover plate (2), the inlet connector (6) is mated with the mating groove at one end with a small gap, and the inflow hole (511) is connected to the mating groove.

6. A high-speed permanent magnet synchronous motor according to claim 1, characterized in that: The rotor (3) is provided with a labyrinth seal (8) at one end near the inlet connector (6) to ensure that coolant does not flow from the return chamber (7) into the stator (4).

7. A high-speed permanent magnet synchronous motor according to claim 1, characterized in that: The end of the inlet connector (6) away from the rotor (3) is bolted to the cover plate (2).

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