Oil-cooled motor rotor cooling structure and cooling method

Abstract

The invention discloses an oil-cooled motor rotor cooling structure, which is characterized in that a motor shaft comprises a hollow axial motor shaft inner cavity main oil way, a motor shaft excircle axial oil guide groove and a motor shaft radial oil guide hole arranged between the inner cavity main oil way and the motor shaft excircle axial oil guide groove; the rotor iron core is connected to the motor shaft; the two rotor end plates are respectively connected with the motor shaft and are respectively positioned at two ends of the rotor iron core; the rotor end plate is provided with a radial oil guide groove and a radial oil outlet groove; the radial oil guide grooves in the first rotor end plate are communicated with the axial oil guide grooves in the outer circle of the motor shaft and the rotor iron core magnetic isolation grooves, and the radial oil outlet grooves in the second rotor end plate are communicated with the rotor iron core magnetic isolation grooves. According to the invention, the flow distribution of the cooling oil paths at the two ends of the rotor can be more uniform at various rotating speeds without adding any additional parts, the influence on the dynamic balance of the rotor assembly is reduced, and the heat dissipation uniformity of the stator and the rotor of the motor can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of oil-cooled motors, and in particular to a cooling structure and a design method for an oil-cooled motor rotor. Background Art

[0002] At present, new energy vehicles have higher and higher requirements for the power density and maximum speed of permanent magnet synchronous drive motors (hereinafter referred to as motors). With the increase of power density and speed, the stator and rotor of the motor will generate a lot of heat, which will affect the efficiency and safety of the motor. The cooling method of traditional motors is mainly water cooling, which dissipates heat from the motor by taking away the heat through the cooling water in the water channel that fits the stator core. Although water cooling can have a good cooling effect on the motor stator, it cannot directly cool the motor rotor. With the increase of speed, the increase of rotor iron loss and wind friction loss will increase the temperature of the magnetic steel and reduce the residual magnetism, which will cause the motor to face the risk of reduced efficiency or even demagnetization. Therefore, it is very necessary to improve the heat dissipation capacity of the motor rotor. Summary of the invention

[0003] The purpose of the present invention is, on the one hand, to provide an oil-cooled motor rotor cooling structure; and on the other hand, to provide a cooling method based on the oil-cooled motor rotor cooling structure, which does not add any additional components, achieves more uniform rotor distribution without basically affecting the dynamic balance of the rotor assembly, and can improve the uniformity of heat dissipation of the motor stator and rotor.

[0004] The technical solution of the present invention includes designing an oil-cooled motor rotor cooling structure, including

[0005] Motor shaft: the motor shaft comprises a hollow axial motor shaft inner cavity main oil circuit, a motor shaft outer axial guide oil groove, and a motor shaft radial oil guide hole arranged between the inner cavity main oil circuit and the motor shaft outer axial guide oil groove;

[0006] The rotor core is connected to the motor shaft;

[0007] Two rotor end plates are respectively connected to the motor shaft and are respectively located at the two ends of the rotor core; the rotor end plates are provided with radial oil guide grooves and radial oil outlet grooves; the radial oil guide groove on the first rotor end plate is connected with the outer axial oil guide groove of the motor shaft and the magnetic isolation groove of the rotor core, and the radial oil outlet groove on the second rotor end plate is connected with the magnetic isolation groove of the rotor core.

[0008] The above design concept of the present invention is to connect the radial oil guide groove on the rotor end plate with the oil channel on the motor shaft (which can be understood as the oil inlet channel). At the same time, the radial oil guide groove and the outer axial oil guide groove of the motor shaft are respectively connected with the magnetic isolation groove of the rotor core, so that the cooling medium flows at the bottom and inside of the rotor core to achieve balanced cooling of the rotor core. Through the reasonable oil guide structure (cooling medium) opened on the rotor end plate, balanced cooling of the rotor core is achieved without adding other parts. The structure is simple and easy to manufacture and assemble.

[0009] An optimized design includes: the motor shaft is also provided with a motor shaft outer annular guide oil groove, which is connected with the motor shaft outer circular axial guide oil groove and the rotor end plate radial guide oil groove. On the one hand, the motor shaft outer annular guide oil groove provides structural support for setting a plurality of radial oil guide grooves along the circumference of the rotor end plate to guide oil, and on the other hand, it facilitates the processing of the motor shaft outer circular axial guide oil groove, such as processing the backing groove of the motor shaft outer circular axial guide oil groove.

[0010] Another optimized design includes: multiple radial oil guide grooves of the rotor end plate are evenly spaced along the circumference; one end of the radial oil guide groove of the rotor end plate is connected to the shaft hole of the rotor end plate, and multiple radial oil guide grooves of the rotor end plate are opened radially. Evenly spaced multiple radial oil guide grooves of the rotor end plate increase the flow of cooling medium and improve the cooling effect on the one hand, and provide structural support for the dynamic balance of the rotor on the other hand.

[0011] Another optimized design includes: multiple radial oil outlet grooves of the rotor end plate are evenly spaced along the circumference; one end of the radial oil outlet groove of the rotor end plate is opened at the periphery of the rotor end plate, and multiple radial oil outlet grooves of the rotor end plate are opened radially and arranged in a staggered manner with the radial oil guide groove of the rotor end plate. Evenly spaced multiple radial oil outlet grooves of the rotor end plate increase the flow of cooling medium and improve the cooling effect on the one hand, and provide structural support for the dynamic balance of the rotor on the other hand. Third, they can be balanced with the radial oil guide groove of the rotor end plate to balance the rotor end plate structure.

[0012] The radial oil outlet groove of the rotor end plate can be further optimized in design: the radial oil outlet groove of the rotor end plate includes a first radial oil outlet groove and a second radial oil outlet groove, the bottoms of the first radial oil outlet groove and the second radial oil outlet groove are interconnected, forming a V-shape, and the opening ends of the first radial oil outlet groove and the second radial oil outlet groove are respectively arranged on the periphery of the rotor end plate, and the bottoms of the first radial oil outlet groove and the second radial oil outlet groove are used to respectively connect with the two adjacent rotor core magnetic isolation grooves with the openings facing away from the inner circle of the rotor end plate, and form a slot for leading out the cooling medium at the outer circle of the rotor end plate.

[0013] The above-mentioned optimized technical feature is that the radial oil outlet groove of the rotor end plate is composed of a group of two radial oil outlet grooves. On the one hand, it can be suitable for the setting of the magnetic steel and the corresponding setting of the magnetic isolation grooves of the adjacent rotor core. On the other hand, it can facilitate the processing of the radial oil outlet groove of the rotor end plate.

[0014] Another optimized design includes: the radial oil guide groove of the rotor end plate and the radial oil outlet groove of the rotor end plate are spaced apart from each other and are evenly distributed on the surface of the rotor end plate along the circumferential direction; the end of the radial oil guide groove of the rotor end plate close to the periphery of the rotor end plate is connected to the magnetic isolation groove of the rotor core; the end of the two radial oil outlet grooves of the rotor end plate that are connected at the bottom is connected to the magnetic isolation groove of the rotor core; the number and position of the radial oil guide groove of the rotor end plate and the radial oil outlet groove of the rotor end plate are corresponding to the magnetic isolation groove of the rotor core; the magnetic isolation groove of the rotor core is the part of the magnetic steel groove that is not filled with magnetic steel. On the one hand, the magnetic isolation groove of the rotor core is used as a cooling passage to achieve simultaneous cooling of the rotor core and the magnetic steel, thereby improving the cooling efficiency of the rotor core and the magnetic steel; on the other hand, the cooling efficiency of the rotor core and the magnetic steel is greatly improved by increasing the flow rate of the cooling medium flowing through the inside of the rotor core and the magnetic steel; the radial oil guide groove of the rotor end plate and the radial oil outlet groove of the rotor end plate are spaced apart from each other and evenly distributed on the surface of the rotor end plate along the circumferential direction to provide structural support for the dynamic balance of the rotor.

[0015] Another optimized design includes: the number of radial oil guide grooves on the rotor end plate is the same as the number of radial oil outlet grooves on the rotor end plate, that is, one radial oil guide groove on the rotor end plate corresponds to one radial oil outlet groove on the rotor end plate, and the number is half of the number of electromagnetic series on the rotor. On the one hand, the number of radial oil guide grooves on the rotor end plate and radial oil outlet grooves on the rotor end plate is the same as half of the number of electromagnetic series on the rotor, which provides structural support for the dynamic balance of the rotor, so that the cooling medium can evenly and comprehensively cool the rotor core and magnetic steel. On the other hand, the cooling medium in the magnetic isolation groove of the rotor core is fully and evenly discharged, avoiding untimely and insufficient discharge of the cooling medium in the magnetic isolation groove of the rotor core, which affects the dynamic balance of the motor rotor.

[0016] Another optimized design includes: the rotor end plate includes a first rotor end plate and a second rotor end plate, the first rotor end plate and the second rotor end plate are assembled at both ends of the rotor core, and the surfaces of the first rotor end plate and the second rotor end plate provided with the rotor end plate radial oil guide groove and the rotor end plate radial oil outlet groove are in contact with the rotor core end surface. The surfaces of the first rotor end plate and the second rotor end plate provided with the rotor end plate radial oil guide groove and the rotor end plate radial oil outlet groove are in contact with the rotor core end surface, so that the rotor end plate radial oil guide groove and the rotor end plate radial oil outlet groove, the oil guide groove provided on the motor shaft and the rotor core magnetic steel groove can form a cooling passage.

[0017] Another optimized design includes: the first rotor end plate and the second rotor end plate are assembled at an angle of 360° / rotor electromagnetic series. On the one hand, the first rotor end plate and the second rotor end plate are assembled at an angle of 360° / rotor electromagnetic series to ensure that the number of radial oil guide grooves and radial oil outlet grooves of the rotor end plate corresponds to the number of magnetic isolation grooves of the rotor core, and on the other hand, the radial oil guide grooves of the first rotor end plate and the radial oil outlet grooves of the second rotor end plate form a corresponding relationship, and at the same time, the radial oil outlet grooves of the first rotor end plate and the radial oil guide grooves of the second rotor end plate also form a corresponding relationship.

[0018] Another technical solution of the present invention is: a cooling method for an oil-cooled motor rotor based on the oil-cooled motor rotor cooling structure, comprising:

[0019] The cooling medium enters the main oil circuit of the motor shaft cavity from one end of the motor shaft;

[0020] The cooling medium flows into the outer axial oil guide groove of the motor shaft through the radial oil guide hole of the motor shaft;

[0021] The cooling medium flows into the guide oil groove of the outer ring of the motor shaft;

[0022] The cooling medium flows into the radial oil guide groove of the rotor end plate;

[0023] The cooling medium flows into the magnetic isolation groove of the rotor core;

[0024] The cooling medium flows into the radial oil outlet groove of the rotor end plate and is discharged through the radial oil outlet groove of the rotor end plate.

[0025] Beneficial effect: In the prior art, when designing the motor rotor cooling oil circuit, radial oil guide holes are usually directly set at different axial positions of the main oil circuit in the motor shaft cavity. When there is no oil guide pipe in the motor shaft cavity, the flow distribution of the oil circuits at both ends will change with the speed, which will cause uneven flow distribution at certain speeds, thereby causing uneven heat dissipation and poor rotor dynamic balance. If the oil guide pipe is fitted in the motor shaft cavity with interference fit, it will increase the cost and easily cause oil circuit blockage.

[0026] The present invention can make the cooling oil flow distribution at both ends of the rotor more uniform at various rotational speeds without adding any additional components, reduce the impact on the dynamic balance of the rotor assembly, and improve the heat dissipation uniformity of the motor stator and rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 : Schematic diagram of oil-cooled motor rotor assembly;

[0028] Figure 2 : Schematic diagram of motor shaft;

[0029] Figure 3 : Schematic diagram of cooling oil flow in the oil channel on the motor shaft;

[0030] Figure 4 : Schematic diagram of rotor end plate;

[0031] Figure 5 : Schematic diagram of rotor core;

[0032] Figure 6 : Schematic diagram of cooling oil flow in the rotor assembly;

[0033] Among them, 1 is the motor shaft; 101 is the radial oil guide hole of the motor shaft; 102 is the outer axial guide oil groove of the motor shaft; 103 is the outer annular guide oil groove of the motor shaft; 104 is the main oil circuit of the inner cavity of the motor shaft; 105 is the assembly surface of the motor shaft and the rotor end plate, rotor core and pressure ring; 2 is the rotor end plate; 201 is the rotor end plate oil guide groove; 202 is the rotor end plate oil outlet groove; 203 is the inner circle of the rotor end plate; 3 is the rotor core; 301 is the rotor core magnetic steel groove; 302 is the inner circle of the rotor core; 4 is the magnetic steel; 5 is the pressure ring; 31 to 36 are the rotor core. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0035] The invention with application number CN202210207036.1 sets axial and radial oil circuits on the motor shaft, and sets an oil circuit on the end face of the rotor end plate facing the rotor core, and is also provided with parts such as oil guide punching sheets. After the motor shaft, rotor end plate, rotor core, oil guide punching sheets and other parts are assembled as required, a complete cooling oil circuit is formed. After the cooling oil enters from one end of the motor shaft, it can enter the rotor end plate oil circuit at both ends and the oil guide plate oil circuit in the middle through the axially distributed radial oil holes, and finally the cooling oil is thrown out through the outer circle outlets of the rotor end plate and the oil guide plate, respectively cooling the windings at both ends of the stator and the middle section of the stator core.

[0036] The disadvantages of this invention are as follows: (1) adding an oil-guiding punch in the middle of the rotor core will simultaneously increase the stack length of the stator core, resulting in increased costs; (2) the flow distribution of the three branch oil circuits in the first main oil circuit in the motor shaft will change with the rotational speed, resulting in uneven flow distribution at certain rotational speeds; (3) the design of the interference fit oil circuit assembly in the internal cavity of the motor shaft is prone to wire cutting during assembly, and the fine chips produced are difficult to discharge, which can easily cause oil circuit blockage.

[0037] The patent with application number CN202123453813.0 has an interference fit oil pipe inside the motor shaft. After the cooling oil enters through one end of the oil pipe, it flows into the motor shaft cavity through the hole in the middle of the oil pipe. There are radial oil holes in the motor shaft cavity leading to the rotor end plates at both ends. The cooling oil can flow to the rotor end plates at both ends through the radial oil holes, and then flow to the outlet on the opposite rotor end plate through the weight-reducing holes of the rotor core. After the cooling oil is thrown out through the outlet, it can cool the windings at both ends of the stator.

[0038] The disadvantages of this invention are: (1) The interference fit of the oil circuit assembly in the internal cavity of the motor shaft will increase the cost, and it is easy to generate fine chips when the interference fit occurs, causing the oil circuit to be blocked; (2) The small hole radial outlet oil circuit on the rotor end plate will increase the processing time, resulting in cost increase.

[0039] The present invention can form a complete motor rotor cooling oil circuit by designing oil guide holes and oil guide grooves on the motor shaft and rotor end plates based on the inherent parts of the permanent magnet synchronous motor rotor assembly, such as the motor shaft, rotor end plate, and rotor core, and assembling them with the rotor core as required, and then using the weight reduction holes or magnetic steel grooves on the rotor core. Without adding any additional parts, the cooling oil circuit flow distribution at both ends of the rotor can be more uniform at various speeds, reducing the impact on the dynamic balance of the rotor assembly, and improving the uniformity of heat dissipation of the motor stator and rotor.

[0040] like Figure 1 As shown, an oil-cooled motor rotor cooling structure comprises:

[0041] Motor shaft 1: The motor shaft comprises a hollow axial motor shaft inner cavity main oil circuit 104, a motor shaft outer axial guide oil groove 102, and a motor shaft radial oil guide hole 101 arranged between the inner cavity main oil circuit 104 and the motor shaft outer axial guide oil groove 102. Figure 2 As shown; the outer axial guide oil groove 102 of the motor shaft can be a straight groove parallel to the motor axis, or a spiral groove along the axial direction, extending to the connection position with the rotor end plate. In the embodiment, the outer axial guide oil groove of the motor shaft is a straight groove parallel to the motor axis. Under the premise of ensuring the strength requirement of the motor shaft, it can be a plurality of mutually parallel ones. The preferred number of the outer axial guide oil grooves of the motor shaft is one-half of the number of electromagnetic series of the rotor. The rotor core 3 is connected to the motor shaft 1; the rotor core 3 is composed of a plurality of rotor core units 31 to 36 stacked obliquely. The rotor core units 31 to 36 are formed by stacking a plurality of core punching sheets. When assembled into a rotor assembly, a plurality of stacked rotor core units are stacked in a certain oblique manner. After stacking, the magnetic steel slots on the core have symmetrical through holes (magnetic isolation holes), and the cooling oil can flow from the through holes at one end to the core end face at the other end.

[0042] Two rotor end plates 2 are respectively connected to the motor shaft 1 and are respectively located at the two ends of the rotor core 3; the rotor end plates 2 are provided with radial oil guide grooves 201 and radial oil outlet grooves 202; the radial oil guide grooves 201 on the first rotor end plate 2 are connected with the motor shaft outer axial oil guide grooves 102 and the rotor core magnetic isolation grooves 301, and the radial oil outlet grooves 202 on the second rotor end plate 2 are connected with the rotor core magnetic isolation grooves 301.

[0043] The inner circle 203 of the rotor end plate, the inner circle 302 of the rotor core and the inner circle of the pressing ring are all in an interference fit relationship with the motor shaft and the assembly surface 105 of the rotor end plate, the rotor core and the pressing ring.

[0044] The pressure ring 5 fixes the axial position of the rotor end plate 2 and the rotor core 3. The inner circles of the rotor end plate 2 and the rotor core 3 are interference-fitted onto the outer circle of the motor shaft in a positional relationship that can form a closed oil path.

[0045] Several stacked rotor core units are stacked in an oblique pole manner. After stacking, the magnetic steel slots on the core have symmetrical through holes, and cooling oil can flow from one through hole to the other end of the core. The heat generated by the rotor assembly mainly comes from the iron loss, wind wear loss and electromagnetic loss of the rotor core. After the coolant flows through the rotor core magnetic isolation slot 301, it can directly cool down the magnetic steel and the rotor core, thereby achieving a better cooling effect.

[0046] like Figure 3 As shown, the motor shaft radial oil guide holes 101 are located at the axial middle position of the rotor core 3 , the number of the oil guide holes is ≥ 2, and the motor shaft radial oil guide holes 101 are evenly distributed along the circumference of the motor shaft 1 .

[0047] In some embodiments, the number of oil guide holes is half of the number of electromagnetic stages of the rotor. This design allows the motor rotor to have better flow distribution on both sides at any speed, so that the rotor assembly has a better dynamic balance state during operation and a more uniform temperature distribution.

[0048] It should be noted that after the rotor assembly is assembled, the inner circle 302 of the rotor core and the outer circle axial guide oil groove 102 of the motor shaft form a closed oil circuit, and the fitting surface of the rotor core 3 and the rotor end plate 2 and the rotor end plate oil guide groove 201 and the rotor end plate oil outlet groove 202 of the rotor end plate 2 form the inlet and outlet oil circuit of the core. The inner circle 203 of the rotor end plate and the rotor end plate oil guide groove 201 form a closed oil circuit with the outer annular guide oil groove 103 of the motor shaft, which is used to realize that the cooling oil can flow from the outer annular guide oil groove 103 of the motor shaft into the rotor end plate oil guide groove 201 on one side, and then pass through the rotor core magnetic isolation groove 301 to the rotor end plate oil outlet groove 202 on the other side; the rotor end plate oil guide groove 201 can guide the cooling oil from the outer annular guide oil groove 103 of the motor shaft into the rotor core 3.

[0049] In one embodiment, the motor shaft 1 is further provided with a motor shaft outer annular guide oil groove 103, which is communicated with the motor shaft outer annular guide oil groove 102 and the rotor end plate radial oil guide groove 201. In the embodiment, two motor shaft outer annular guide oil grooves 103 are provided, which are respectively located on both sides of the motor shaft, relative to the positions where the two rotor end plates are installed.

[0050] A plurality of rotor end plate oil guide grooves 201 are provided along the circumference of the rotor end plate, and an outer annular oil guide groove 103 of the motor shaft is provided to enable the cooling medium to flow faster and evenly flow into each rotor end plate oil guide groove 201 .

[0051] In one embodiment, a plurality of radial oil guide grooves 201 of the rotor end plate are evenly spaced along the circumference; one end of the radial oil guide groove 201 of the rotor end plate is connected to the shaft hole of the rotor end plate, and the plurality of radial oil guide grooves 201 of the rotor end plate are opened radially.

[0052] The rotor end plate radial oil outlet grooves 202 are evenly arranged along the circumference; one end of the rotor end plate radial oil outlet groove 202 is opened at the periphery of the rotor end plate, and multiple rotor end plate radial oil outlet grooves 202 are opened in the radial direction and staggered with the rotor end plate radial oil guide groove 201. The length of the rotor end plate radial oil guide groove 201 extends to a group of magnetic isolation grooves at the lower part of the magnet, and the rotor end plate radial oil guide groove 201 covers two adjacent magnetic isolation grooves.

[0053] Regarding the structure of the radial oil outlet groove 202 of the rotor end plate, in some embodiments, the radial oil outlet groove 202 of the rotor end plate is set in a "V" shape. The "V" shape makes the design of the oil outlet groove 202 more in line with the liquid flow characteristics, improves the cooling medium discharge efficiency of the oil outlet groove 202, and accelerates the flow speed when the cooling medium is discharged. After the cooling medium is discharged from the rotor core, it will cool the motor stator winding. The faster the flow speed of the cooling medium when it is discharged, the higher the efficiency, and the better the cooling effect on the motor stator winding. The oil outlet groove 202 includes a first radial oil outlet groove 2021 and a second radial oil outlet groove 2022. The bottoms of the first radial oil outlet groove 2021 and the second radial oil outlet groove 2022 are interconnected and V-shaped. The opening ends of the first radial oil outlet groove 2021 and the second radial oil outlet groove 2022 are respectively arranged on the periphery of the rotor end plate, and the bottoms of the first radial oil outlet groove 2021 and the second radial oil outlet groove 2022 are used to be respectively connected to the two adjacent rotor core magnetic isolation grooves 301. The core magnetic isolation groove 301 is a group of the lower part of the magnet. The lower part of the first radial oil outlet groove 2021 covers one magnetic isolation groove, and the lower part of the second radial oil outlet groove 2022 covers another adjacent magnetic isolation groove. The radial oil outlet groove 202 and the radial oil guide groove 201 of the same rotor end plate are separated and do not communicate with each other.

[0054] The radial oil guide groove 201 of the rotor end plate and the radial oil outlet groove 202 of the rotor end plate are spaced from each other and evenly distributed on the surface of the rotor end plate along the circumferential direction, and are in a corresponding relationship with the rotor core magnetic isolation groove 301. In this way, when the two rotor end plates are connected to the motor shaft, the two rotor end plates are staggered at an angle to achieve the connection between the radial oil guide groove 201 on the first rotor end plate 2 and the motor shaft outer axial oil guide groove 102 and the rotor core magnetic isolation groove 301, and the radial oil outlet groove 202 on the second rotor end plate 2 is connected to the rotor core magnetic isolation groove 301.

[0055] In some embodiments, the number of the radial oil guide grooves 201 of the rotor end plate is the same as the number of the radial oil outlet grooves 202 of the rotor end plate, which is half of the number of electromagnetic stages of the rotor.

[0056] In one embodiment, if the number of electromagnetic stages of the rotor is 6, the number of oil guide grooves 201 and oil outlet grooves 202 of each rotor end plate is 3, which are evenly distributed along the circumference of the rotor end plate 2. The number of oil guide grooves 201 and oil outlet grooves 202 of the rotor end plate is designed to be half of the number of electromagnetic stages of the rotor in order to make a circumferentially symmetrical cooling design, which has little effect on the dynamic balance of the motor and can evenly and comprehensively cool the magnetic steel.

[0057] The rotor end plate 2 includes a first rotor end plate and a second rotor end plate, which are assembled at both ends of the rotor core 3. The first rotor end plate and the second rotor end plate are provided with a rotor end plate radial oil guide groove 201 and a rotor end plate radial oil outlet groove 202, and the surface of the first rotor end plate and the second rotor end plate is in contact with the end surface of the rotor core 3.

[0058] The first rotor end plate and the second rotor end plate are assembled at an angle of 360° / rotor electromagnetic series.

[0059] The rotor end plate radial oil guide groove 201 of the first rotor end plate and the rotor end plate radial oil outlet groove 202 of the second rotor end plate are communicated through the rotor core magnetic isolation groove 301 .

[0060] In some embodiments, magnetic steel slots are distributed on the rotor core 3, such as Figure 5 As shown, the magnetic steel slot of the rotor core 3 includes a portion filled with magnetic steel and a portion not filled with magnetic steel, and the portion of the magnetic steel slot not filled with magnetic steel is the rotor core magnetic isolation slot 301. The magnetic isolation slot 301 not filled with magnetic steel can pass cooling medium. The rotor core magnetic isolation slot 301 on the rotor core 3 can form a through axial oil passage in the axial direction, and the cooling medium can flow from one end of the rotor core magnetic isolation slot 301 to the other end.

[0061] In some embodiments, if the number of rotor electromagnetic stages is 6, the first rotor end plate is assembled by rotating the second rotor end plate by 60°.

[0062] It should be noted that if Figure 1As shown, set Figure 1 The rotor end plate 2 on the left is the first rotor end plate 2, set Figure 1 The rotor end plate 2 on the right is the second rotor end plate 2. The first rotor end plate 2 is assembled at a certain angle relative to the second rotor end plate. The cooling medium flows from the radial oil guide groove 201 of the first rotor end plate 2 into the rotor core magnetic isolation groove 301, and then is discharged from the radial oil outlet groove 202 of the second rotor end plate. At the same time, the cooling medium flows from the radial oil guide groove 201 of the second rotor end plate 2 into the rotor core magnetic isolation groove 301, and then is discharged from the radial oil outlet groove 202 of the first rotor end plate.

[0063] A cooling method for an oil-cooled motor rotor based on the oil-cooled motor rotor cooling structure comprises:

[0064] The cooling medium enters the main oil passage 104 in the inner cavity of the motor shaft from one end of the motor shaft;

[0065] The cooling medium flows into the outer axial oil guide groove 102 of the motor shaft through the radial oil guide hole 101 of the motor shaft;

[0066] The cooling medium flows into the outer ring guide oil groove 103 of the motor shaft;

[0067] The cooling medium flows into the radial oil guide groove 201 of the rotor end plate;

[0068] The cooling medium flows into the rotor core magnetic isolation slot 301;

[0069] The cooling medium flows into the radial oil outlet groove 202 of the rotor end plate and is discharged through the radial oil outlet groove 202 of the rotor end plate.

[0070] In one embodiment, Figure 6 As shown, the cooling medium flows from one end of the motor shaft into the main oil path 104 of the motor shaft inner cavity, and flows from the main oil path 104 of the motor shaft inner cavity into the motor shaft outer circular axial guide oil groove 102 arranged along the axial direction of the motor shaft through a plurality of motor shaft radial oil guide holes 101 evenly distributed along the circumference of the motor shaft 1, and flows into the two motor shaft outer circular annular guide oil grooves 103 on both sides of the motor shaft 1 at both ends of the motor shaft 1, and then flows from the motor shaft outer circular annular guide oil grooves 103 on both sides of the motor shaft 1 into the oil guide grooves 103 as shown in FIG. Figure 4 The radial oil guide grooves 201 of the two rotor end plates are shown, and the oil flows into the radial oil guide grooves 201 of the two rotor end plates. Figure 5 The rotor core magnetic isolation slots 301 shown in the figure directly cool the rotor core 3 and the magnetic steel 4 at the same time, and finally the cooling medium is led out to the motor stator winding through the radial oil outlet slots 202 of the two rotor end plates and cools the motor stator winding. Figure 1 As shown, set Figure 1 The rotor end plate 2 on the left is the first rotor end plate 2, set Figure 1The rotor end plate 2 on the right is the second rotor end plate 2. The first rotor end plate 2 is assembled at a set angle relative to the second rotor end plate 2. The cooling medium flows from the radial oil guide groove 201 of the first rotor end plate 2 into the rotor core magnetic isolation groove 301, and then is discharged from the radial oil outlet groove 202 of the second rotor end plate 2. At the same time, the cooling medium flows from the radial oil guide groove 201 of the second rotor end plate 2 into the rotor core magnetic isolation groove 301, and then is discharged from the radial oil outlet groove 202 of the first rotor end plate.

[0071] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. An oil-cooled motor rotor cooling structure, characterized in that: include: The motor shaft (1) comprises a hollow axial motor shaft inner cavity main oil circuit (104), a motor shaft outer axial guide oil groove (102), and a motor shaft radial oil guide hole (101) arranged between the inner cavity main oil circuit (104) and the motor shaft outer axial guide oil groove (102); A rotor core (3) connected to the motor shaft (1); Two rotor end plates (2) are respectively connected to the motor shaft (1) and are respectively located at two ends of the rotor core (3); the rotor end plates (2) are provided with radial oil guide grooves (201) and radial oil outlet grooves (202); the radial oil guide grooves (201) on the first rotor end plate (2) are connected to the motor shaft outer axial oil guide groove (102) and the rotor core magnetic isolation groove (301), and the radial oil outlet grooves (202) on the second rotor end plate (2) are connected to the rotor core magnetic isolation groove (301).

2. The oil-cooled motor rotor cooling structure according to claim 1, characterized in that: The motor shaft (1) is also provided with a motor shaft outer annular guide oil groove (103), and the motor shaft outer annular guide oil groove (103) is communicated with the motor shaft outer axial guide oil groove (102) and the rotor end plate radial oil guide groove (201).

3. The oil-cooled motor rotor cooling structure according to claim 1, characterized in that: A plurality of radial oil guide grooves (201) of the rotor end plate are evenly arranged along the circumference; one end of the radial oil guide groove (201) of the rotor end plate is connected to the shaft hole of the rotor end plate, and the plurality of radial oil guide grooves (201) of the rotor end plate are opened in the radial direction.

4. The oil-cooled motor rotor cooling structure according to claim 1, characterized in that: A plurality of radial oil outlet grooves (202) of the rotor end plate are evenly arranged along the circumference; one end opening of the radial oil outlet groove (202) of the rotor end plate is arranged at the periphery of the rotor end plate; and the plurality of radial oil outlet grooves (202) of the rotor end plate are opened radially and arranged in a staggered manner with the radial oil guide groove (201) of the rotor end plate.

5. The oil-cooled motor rotor cooling structure according to claim 4, characterized in that: The radial oil outlet groove (202) of the rotor end plate comprises a first radial oil outlet groove (2021) and a second radial oil outlet groove (2022); the bottoms of the first radial oil outlet groove (2021) and the second radial oil outlet groove (2022) are interconnected and V-shaped; the opening ends of the first radial oil outlet groove (2021) and the second radial oil outlet groove (2022) are respectively arranged on the periphery of the rotor end plate; the bottoms of the first radial oil outlet groove (2021) and the second radial oil outlet groove (2022) are respectively used to be connected to two adjacent rotor core magnetic isolation grooves (301).

6. The oil-cooled motor rotor cooling structure according to claim 1, characterized in that: The radial oil guide groove (201) of the rotor end plate and the radial oil outlet groove (202) of the rotor end plate are spaced apart from each other and evenly distributed on the surface of the rotor end plate along the circumferential direction, and are in a corresponding relationship with the magnetic isolation groove (301) of the rotor core.

7. The oil-cooled motor rotor cooling structure according to claim 1, characterized in that: The number of the radial oil guide grooves (201) of the rotor end plate is the same as the number of the radial oil outlet grooves (202) of the rotor end plate, which is half of the number of electromagnetic stages of the rotor.

8. The oil-cooled motor rotor cooling structure according to claim 1, characterized in that: The rotor end plate (2) comprises a first rotor end plate and a second rotor end plate, the first rotor end plate and the second rotor end plate are mounted at both ends of the rotor core (3), and the surfaces of the first rotor end plate and the second rotor end plate provided with the rotor end plate radial oil guide groove (201) and the rotor end plate radial oil outlet groove (202) are in contact with the end surface of the rotor core (3).

9. The oil-cooled motor rotor cooling structure according to claim 1 or 8, characterized in that: The first rotor end plate and the second rotor end plate are assembled at an angle of 360° / rotor electromagnetic series.

10. A method for cooling an oil-cooled motor rotor according to any one of claims 1 to 9, characterized in that: The cooling medium enters the main oil passage (104) of the inner cavity of the motor shaft from one end of the motor shaft; The cooling medium flows into the outer axial oil guide groove (102) of the motor shaft through the radial oil guide hole (101) of the motor shaft; The cooling medium flows into the guide oil groove (103) on the outer ring of the motor shaft; The cooling medium flows into the radial oil guide groove (201) of the rotor end plate; The cooling medium flows into the rotor core magnetic isolation groove (301); The cooling medium flows into the radial oil outlet groove (202) of the rotor end plate and is discharged through the radial oil outlet groove (202) of the rotor end plate.

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