Surface-mounted permanent magnet synchronous motor rotor structure with cooling flow channel and motor

Abstract

The invention discloses a surface-mounted permanent magnet synchronous motor rotor structure with a cooling flow channel and a motor, and belongs to the technical field of motor rotor cooling. The rotor iron core is sleeved on the rotating shaft and comprises two rotor iron core sections; the oil separation plate is sleeved on the rotating shaft and is positioned between the two rotor iron core sections; and a magnetic steel protection sleeve. In the rotor iron core subsections, the bottom of each magnetic steel groove is provided with an open groove, and N first cooling oil ways are formed by the open grooves and the inner circular surface of the rotor magnetic steel; the outer circle of the rotor magnetic steel is larger than that of the pole shoe, two corners of the rotor magnetic steel are chamfers, and N second cooling oil ways are formed by two adjacent rotor magnetic steel, the pole shoe between the two adjacent rotor magnetic steel and the magnetic steel protective sleeve; 2N oil guide grooves communicating with the rotating shaft oil cavity are formed in the inner circumference of the oil distribution plate and communicate with the 2N cooling oil ways correspondingly. According to the invention, the rotor heating problem of the surface-mounted permanent magnet synchronous motor with the high-temperature alloy protective sleeve during high-power and high-speed operation can be effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor rotor cooling, and more specifically, relates to a surface mounted permanent magnet synchronous motor rotor structure with a cooling channel and a motor. Background Art

[0002] In permanent magnet synchronous motors, there are various ways to install permanent magnets on the rotor, which are mainly divided into built-in permanent magnet synchronous motors and surface-mounted permanent magnet synchronous motors. The built-in type is to embed the permanent magnet inside the rotor core, and there is a pole shoe made of ferromagnetic material between the outer surface of the permanent magnet and the inner circle of the stator core to protect the permanent magnet. In surface-mounted permanent magnet synchronous motors, the permanent magnets are usually in the shape of tiles and are located on the outer surface of the rotor core. The rotors of high-power density permanent magnet synchronous motors are usually surface-mounted, while the built-in type is mostly used for high-speed motors. In the fields of aerospace, multi-electric / all-electric aircraft, and industrial robots, motors are required to have high speeds and high power density. Since there is no speed regulation requirement for motors in these fields, surface-mounted permanent magnet synchronous motors meet these requirements well.

[0003] During high-speed rotation of a surface-mounted permanent magnet motor, the permanent magnet will be subjected to great centrifugal force, so a protective cover must be added to the outside of the permanent magnet to protect the permanent magnet. In the prior art, a high-strength carbon fiber cover or a high-strength non-magnetic alloy cover is usually added to the outside of the rotor core. In high-temperature environments, the carbon fiber cover will soften and be damaged due to the poor heat resistance of the resin that serves as a connection. In this case, an alloy cover is a better choice. When the rotor of a surface-mounted permanent magnet synchronous motor with a high-temperature alloy cover is running at high power and high speed, large eddy current losses will be generated in the cover and the magnetic steel, which will in turn generate a lot of heat.

[0004] How to use efficient rotor cooling technology to remove this heat has become one of the key technologies that need to be urgently solved for high-power permanent magnet motors. Summary of the invention

[0005] In view of the defects of the prior art and the need for improvement, the present invention provides a surface-mounted permanent magnet synchronous motor rotor structure and a motor with a cooling channel, the purpose of which is to effectively solve the rotor heating problem of the surface-mounted permanent magnet synchronous motor with a high-temperature alloy protective sleeve when running at high power and high speed.

[0006] To achieve the above object, according to one aspect of the present invention, a surface mounted permanent magnet synchronous motor rotor structure with a cooling channel is provided, comprising: a rotating shaft, a rotor core, an oil separator plate and a magnetic steel protective sleeve; the rotor core is sleeved on the rotating shaft and comprises two rotor core segments; the oil separator plate is sleeved on the rotating shaft and is located between the two rotor core segments; the magnetic steel protective sleeve is sleeved on the outer sides of the two rotor core segments;

[0007] One end of the shaft is hollowed out to form a shaft oil chamber;

[0008] N pole shoes are evenly distributed on the outer circumference of the rotor core segment, and the rotor magnets are inserted into the magnetic steel slots formed between adjacent pole shoes; the bottom of each magnetic steel slot is provided with a slot, and N first cooling oil paths are formed with the inner circumference of the rotor magnet; the outer circle of the rotor magnet is larger than the outer circle of the pole shoe, and the two corners of the rotor magnet that extend beyond the pole shoe are chamfered, and two adjacent rotor magnets and the pole shoe therebetween form an outer circle slot, and N second cooling oil paths are formed with the magnetic steel protective sleeve;

[0009] The outer circle of the oil separator is the same as the outer circle of the rotor magnetic steel; the inner circumference of the oil separator is provided with N first oil guide grooves and N second oil guide grooves which are alternately distributed, and the outer circumference of the oil separator is provided with N oil holes; the first oil guide grooves and the second oil guide grooves are both connected to the shaft oil cavity; the N first oil guide grooves are respectively connected to the N first cooling oil circuits; the N oil holes are respectively located directly above the N second oil guide grooves and are connected to the N second oil guide grooves one by one; the N oil holes are respectively connected to the N second cooling oil circuits;

[0010] Wherein, N is the number of magnetic poles.

[0011] In the rotor structure provided by the present invention, after the cooling medium is injected into the oil cavity of the rotating shaft, part of the cooling medium will be injected into the first cooling oil path in the rotor core segments on both sides through the first oil guide groove, and flow axially to the end through the first cooling oil path. The first cooling oil path is in direct contact with the rotor magnetic steel, and can effectively take away the heat caused by eddy current loss in the rotor magnetic steel; the other part of the cooling medium will be injected into the second cooling oil path in the rotor cores on both sides through the second oil guide groove, and flow to the end through the second cooling oil path. The second cooling oil path is in direct contact with the rotor magnetic steel and the magnetic steel protective cover, and can effectively take away the heat caused by eddy current loss in the rotor magnetic steel and the rotor cover.

[0012] Further, the depth of the second oil guiding groove is lower than the depth of the first oil guiding groove.

[0013] Furthermore, the slots arranged at the bottom of the magnetic steel slots are arc-shaped structures distributed along the bottom of the magnetic steel slots, and the arc length is greater than the slot depth.

[0014] Furthermore, magnetic steel baffles are provided at both axial ends of the rotor core;

[0015] The magnetic steel baffle is provided with oil holes of the same shape and corresponding position as the first cooling oil circuit and the second cooling oil circuit, and each oil hole is respectively connected to the corresponding first cooling oil circuit or the second cooling oil circuit.

[0016] According to another aspect of the present invention, another surface mounted permanent magnet synchronous motor rotor structure with a cooling channel is provided, comprising: a rotating shaft, a rotor core, an oil separator plate and a magnetic steel protective sleeve; the rotor core is sleeved on the rotating shaft and comprises two rotor core segments; the oil separator plate is sleeved on the rotating shaft and is located between the two rotor core segments; the magnetic steel protective sleeve is sleeved on the outer sides of the two rotor core segments;

[0017] One end of the shaft is hollowed out to form a shaft oil chamber;

[0018] N pole shoes are evenly distributed on the outer circumference of the rotor core segment, and the rotor magnets are inserted into the magnet grooves formed between adjacent pole shoes; the bottom of each magnet groove is provided with a slot, and N first cooling oil paths are formed with the inner circumference of the rotor magnet; the outer circumference of the rotor magnet is the same as the outer circumference of the pole shoe; each pole shoe is provided with a third cooling oil path, forming a total of N third cooling oil paths;

[0019] The outer circle of the oil separator is the same as the outer circle of the rotor magnetic steel; the inner circumference of the oil separator is provided with N first oil guide grooves and N second oil guide grooves which are alternately distributed; N oil holes are provided directly above the N second oil guide grooves, and the positions and shapes of the N oil holes correspond to the positions and shapes of the N third cooling oil circuits, and are connected to the N second oil guide grooves one by one; the first oil guide groove and the second oil guide groove are both connected to the shaft oil cavity; the N first oil guide grooves are respectively connected to the N first cooling oil circuits; the N oil holes are respectively connected to the N third cooling oil circuits;

[0020] Wherein, N is the number of magnetic poles.

[0021] In the rotor structure provided by the present invention, after the cooling medium is injected into the oil cavity of the rotating shaft, part of the cooling medium will be injected into the first cooling oil path in the rotor core segments on both sides through the first oil guide groove, and flow axially to the end through the first cooling oil path. The first cooling oil path is in direct contact with the rotor magnetic steel, and can effectively take away the heat caused by eddy current loss in the rotor magnetic steel; another part of the cooling medium will be injected into the third cooling oil path in the rotor cores on both sides through the second oil guide groove, and flow to the end through the third cooling oil path. The third cooling oil path is close to the rotor magnetic steel and the magnetic steel protective cover, and can effectively take away the heat caused by eddy current loss in the magnetic steel and the magnetic steel protective cover.

[0022] Further, the depth of the second oil guiding groove is lower than the depth of the first oil guiding groove.

[0023] Furthermore, the slots arranged at the bottom of the magnetic steel slots are arc-shaped structures distributed along the bottom of the magnetic steel slots, and the arc length is greater than the slot depth.

[0024] Furthermore, magnetic steel baffles are provided at both axial ends of the rotor core;

[0025] The magnetic steel baffle is provided with oil holes of the same shape and corresponding position as the first cooling oil circuit and the second cooling oil circuit, and each oil hole is respectively connected to the corresponding first cooling oil circuit or the second cooling oil circuit.

[0026] According to another aspect of the present invention, there is provided a surface-mounted permanent magnet synchronous motor, comprising a rotor and a stator disposed outside the rotor;

[0027] The rotor is any one of the surface-mounted permanent magnet synchronous motor rotor structures with cooling channels provided by the present invention.

[0028] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0029] (1) In some embodiments of the present invention, one end of the rotating shaft is hollowed out to form a rotating shaft oil cavity, and the rotor core is divided into two sections by an oil separator plate. In each section of the rotor core, a slot is set at the bottom of the rotor magnetic steel slot to form a first cooling oil circuit directly in contact with the rotor magnetic steel with the inner circle of the rotor magnetic steel. At the same time, the outer circle of the rotor magnetic steel is set to be larger than the outer circle of the pole shoe, so that the end of the pole shoe, two adjacent rotor magnetic steels and the rotor protective sleeve form a second cooling oil circuit directly in contact with the rotor magnetic steel and the magnetic steel protective sleeve. An oil guide groove is set on the oil separator plate to make the first cooling oil circuit and the second cooling oil circuit communicate with the rotating shaft oil cavity respectively; based on the cooling structure design, after the cooling medium is injected into the rotating shaft oil cavity, part of the cooling medium will enter the first cooling oil circuit to take away the heat caused by eddy current loss of the rotor magnetic steel, and the other part will enter the second cooling oil circuit to take away the heat caused by eddy current loss of the rotor magnetic steel and the magnetic steel protective sleeve; the two cooling oil circuits cooperate with each other to effectively solve the rotor heating problem of the surface-mounted permanent magnet synchronous motor with a high-temperature alloy protective sleeve when running at high power and high speed.

[0030] (2) In some embodiments of the present invention, one end of the rotating shaft is hollowed out to form a rotating shaft oil cavity, and the rotor core is divided into two sections by an oil separator plate. In each section of the rotor core, a slot is set at the bottom of the rotor magnetic steel slot to form a first cooling oil circuit directly in contact with the rotor magnetic steel and the inner circle of the rotor magnetic steel. At the same time, a third cooling oil circuit is set on the pole shoe, which is close to the rotor magnetic steel and the magnetic steel protective sleeve. An oil guide groove is set on the oil separator plate, so that the first cooling oil circuit and the third cooling oil circuit are connected to the rotating shaft oil cavity respectively; based on the cooling structure design, after the cooling medium is injected into the rotating shaft oil cavity, part of the cooling medium will enter the first cooling oil circuit, effectively taking away the heat caused by eddy current loss of the rotor magnetic steel, and the other part will enter the third cooling oil circuit, effectively taking away the heat caused by eddy current loss of the rotor magnetic steel and the magnetic steel protective sleeve; the two cooling oil circuits cooperate with each other to effectively solve the rotor heating problem of the surface-mounted permanent magnet synchronous motor with a high-temperature alloy protective sleeve when running at high power and high speed.

[0031] (3) In the preferred embodiment of the present invention, the depth of the second oil guide groove is set to be lower than the depth of the first oil guide groove, thereby ensuring that the cooling medium in the shaft oil cavity enters each oil guide groove evenly and making the oil separator have a higher mechanical strength.

[0032] (4) In the preferred embodiment of the present invention, the slot at the bottom of the rotor magnetic steel slot is set to be a narrow arc, so that after the cooling medium enters the first cooling oil channel, it has a larger contact area with the rotor magnetic steel, which can further improve the cooling effect on the rotor magnetic steel.

[0033] (5) In the preferred embodiment of the present invention, magnetic steel baffles are provided at both axial ends of the rotor core, and the magnetic steel baffles can prevent the rotor magnet from axially moving; at the same time, oil holes with the same shape and corresponding positions as the first cooling oil circuit and the second cooling oil circuit are opened on the magnetic steel baffles, and each oil hole is connected to the corresponding first cooling oil circuit or the second cooling oil circuit, so that the cooling medium flowing to the axial end of the rotor through the first cooling oil circuit and the second cooling oil circuit is finally thrown to the end of the stator winding through the oil holes on the magnetic steel baffles, thereby further cooling the end winding. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The overall structural schematic diagram of the surface-mounted permanent magnet synchronous motor rotor structure with cooling channels provided in Example 1 of the present invention;

[0035] Figure 2 A schematic diagram of the installation of the rotor core and the oil separator plate in the rotor structure provided in Example 1 of the present invention;

[0036] Figure 3 A schematic diagram of the rotating shaft structure provided in Example 1 of the present invention;

[0037] Figure 4 A schematic diagram of the structure of the oil separator provided in Example 1 of the present invention;

[0038] Figure 5 A schematic diagram of the relative positions of the rotating shaft and the oil separation plate provided in Example 1 of the present invention;

[0039] Figure 6 A cross-sectional view of a rotor provided in Example 1 of the present invention;

[0040] Figure 7 A schematic diagram of a first cooling oil circuit provided in Example 1 of the present invention;

[0041] Figure 8 A schematic diagram of a second cooling oil circuit provided in Example 1 of the present invention;

[0042] Fig. 9 A schematic diagram of the overall structure of a surface-mounted permanent magnet synchronous motor rotor structure with cooling channels provided in Embodiment 2 of the present invention;

[0043] Fig.10 The installation intention of the rotor core and the oil separator plate in the rotor structure provided in Example 2 of the present invention;

[0044] Fig.11 A schematic diagram of the installation of rotor core segments and oil separators provided in Example 2 of the present invention; in all the drawings, the same reference numerals are used to represent the same elements or structures, wherein:

[0045] 1-shaft, 2-shaft oil outlet hole, 3-shaft oil chamber;

[0046] 4-oil distribution plate, 5-first oil guide groove, 6-second oil guide groove;

[0047] 7- rotor magnetic steel, 8- rotor iron core, 9- first cooling oil circuit, 10- second cooling oil circuit;

[0048] 11-Magnetic steel protective cover;

[0049] 12-Magnetic steel baffle. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0051] In the present invention, the terms "first", "second", etc. (if any) in the present invention and the accompanying drawings are used to distinguish similar objects but not necessarily to describe a specific order or sequence.

[0052] When the rotor of a surface-mounted permanent magnet synchronous motor with a high-temperature alloy protective sleeve runs at high power and high speed, large eddy current losses will be generated in the protective sleeve and the magnetic steel, and thus a large amount of heat will be generated. To address this problem, the present invention provides a surface-mounted permanent magnet synchronous motor rotor structure and a motor with a cooling flow channel. The overall concept is to design an oil circuit structure as close to the heat source (i.e., the magnetic steel and the magnetic steel protective sleeve) as possible in the motor rotor structure without affecting the performance of the motor, so as to effectively take away the heat generated by the magnetic steel and the magnetic steel protective sleeve due to eddy current losses.

[0053] The following are examples.

[0054] Embodiment 1:

[0055] A surface mounted permanent magnet synchronous motor rotor structure with a cooling channel, such as Figure 1 to Figure 6As shown, it includes: a rotating shaft 1, a rotor core 8, an oil separator 4 and a magnetic steel protective sleeve 11; the rotor core 8 is sleeved on the rotating shaft 1 and includes two rotor core segments; the oil separator 4 is sleeved on the rotating shaft and located between the two rotor core segments; the magnetic steel protective sleeve 11 is sleeved on the outer sides of the two rotor core segments;

[0056] like Figure 3 As shown, one end of the shaft 1 is hollowed out to form a shaft oil chamber 3;

[0057] In this embodiment, each rotor core segment is formed by laminating silicon steel sheets; Figure 6 As shown, N pole shoes are evenly distributed on the outer circumference of the rotor core segment, and the rotor magnetic steel 7 is inserted into the magnetic steel slot formed between adjacent pole shoes; N is the number of magnetic steel poles, and optionally, in this embodiment, N=6;

[0058] Each magnetic steel slot is provided with a slot at the bottom, and forms N first cooling oil paths 9 with the inner circumference of the rotor magnetic steel 7; the outer circumference of the rotor magnetic steel 7 is larger than the outer circumference of the pole shoe, and the two corners of the rotor magnetic steel 7 beyond the pole shoe are chamfered, and two adjacent rotor magnetic steels and the pole shoe therebetween form an outer circumferential slot, and form N second cooling oil paths 10 with the magnetic steel protective sleeve 11;

[0059] The outer circle of the oil separator 4 is the same as the outer circle of the rotor magnetic steel 7; Figure 4 and Figure 5 As shown, the inner circumference of the oil separator 4 is provided with N first oil guide grooves 5 and N second oil guide grooves 6 which are alternately distributed, and the outer circumference of the oil separator is provided with N oil holes; the first oil guide grooves 5 and the second oil guide grooves 6 are both connected to the shaft oil chamber 3, as shown in FIG. Figure 3 As shown, in order to facilitate the connection between the oil guide groove and the shaft oil chamber 3, in this embodiment, 2N shaft oil outlet holes 2 are opened along the circumference of the outer circle in the middle of the shaft, corresponding one-to-one to the oil guide grooves on the oil distribution plate; the N first oil guide grooves 5 are respectively connected to the N first cooling oil circuits 9; the N oil holes are respectively located directly above the N second oil guide grooves 6, and are connected one-to-one with the N second oil guide grooves 6; the N oil holes are respectively connected to the N second cooling oil circuits 10.

[0060] In order to form the above-mentioned second cooling oil circuit, in this embodiment, the outer circle of the rotor magnet is set to be larger than the outer circle of the pole shoe. At the same time, the two corners of the rotor magnet 7 extending beyond the pole shoe are set to be chamfered, which can reduce the stress concentration problem caused by the rotor when running at high speed and avoid adverse effects on the motor performance.

[0061] It is easy to understand that in this embodiment, in the two rotor core segments, the cooling oil circuits are in the same axial position and have no angle deviation.

[0062] In the rotor structure provided in this embodiment, after the cooling medium is injected into the oil cavity of the rotating shaft, part of the cooling medium will be injected into the first cooling oil path in the rotor core segments on both sides through the first oil guide groove, and flow axially to the end through the first cooling oil path. The first cooling oil path is in direct contact with the rotor magnetic steel, and can effectively take away the heat caused by eddy current loss in the rotor magnetic steel. Figure 7 As shown; another part of the cooling medium will be injected into the second cooling oil path in the rotor core on both sides through the second oil guide groove, and flow to the end through the second cooling oil path. The second cooling oil path is in direct contact with the rotor magnetic steel and the magnetic steel protective sleeve, which can effectively take away the heat caused by eddy current loss in the rotor magnetic steel and the rotor sleeve, such as Figure 8 shown.

[0063] like Figure 1 and Figure 2 As shown, the axial ends of the rotor core are respectively blocked by magnetic steel baffles 12, which can prevent the rotor core and the magnetic steel from axial movement; at the same time, the magnetic steel baffle 12 is provided with oil holes of the same shape as the first cooling oil circuit and the second cooling oil circuit, and these oil holes are respectively connected to the first cooling oil circuit and the second cooling oil circuit; the cooling oil in the first cooling oil circuit and the second cooling oil circuit is finally thrown to the end of the stator winding through the oil holes on the magnetic steel baffle, thereby further cooling the end of the winding.

[0064] It is easy to understand that in practical applications, the cooling medium may be cooling oil, or other gas or liquid cooling medium.

[0065] This embodiment uses an oil separator to divide the rotor core into two sections, and cools the two sections at the same time, which can alleviate the problem of uneven cooling of the motor rotor in the axial direction. In addition, this embodiment uses the oil guide groove on the oil separator to guide the cooling medium in the shaft oil cavity into each cooling oil circuit, which can ensure that the cooling medium is evenly introduced, thereby achieving uniform cooling of the entire rotor.

[0066] As a preferred implementation, in this embodiment, the depth of the second oil guide groove 6 is lower than that of the first oil guide groove, thereby ensuring that the cooling medium in the shaft oil cavity enters each oil guide groove evenly and making the oil separator have higher mechanical strength.

[0067] In practical applications, the slots set at the bottom of the magnetic steel slot should comprehensively consider the rotor cooling performance and the electromagnetic performance of the motor. On the one hand, it is necessary to ensure that the cooling medium discharged from the first oil guide groove can fill the first cooling oil circuit and ensure that the cooling medium can directly contact the rotor magnetic steel to ensure the cooling effect on the rotor magnetic steel. On the other hand, it is necessary to ensure that the impact on the equivalent air gap is not too large.

[0068] As a preferred implementation, in this embodiment, Figure 6As shown, the slots arranged at the bottom of the magnetic steel slots are arc-shaped structures distributed along the bottom of the magnetic steel slots, and the arc length is greater than the slot depth, and the first cooling oil path finally formed is a narrow and long arc; the first cooling oil path designed in this embodiment enables the cooling medium to have a larger contact area with the rotor magnetic steel after entering the first cooling oil path, and can further improve the cooling effect on the rotor magnetic steel while taking into account the cooling effect and the electromagnetic performance of the motor.

[0069] In general, this embodiment adopts the above cooling structure design, and the cooling oil circuit is in direct contact with the heat source, so that the rotor cooling efficiency is greatly improved, and can effectively solve the rotor heating problem of the high-temperature alloy protective sleeve surface-mounted permanent magnet synchronous motor when it runs at high power and high speed.

[0070] Embodiment 2:

[0071] A surface mounted permanent magnet synchronous motor rotor structure with a cooling channel, such as Figures 9 to 11 This embodiment is similar to the above-mentioned embodiment 1, and includes: a rotating shaft, a rotor core, an oil separator and a magnetic steel protective sleeve; the rotor core is sleeved on the rotating shaft and includes two rotor core segments; the oil separator is sleeved on the rotating shaft and is located between the two rotor core segments; the magnetic steel protective sleeve is sleeved on the outer sides of the two rotor core segments.

[0072] One end of the rotating shaft is hollowed out to form a rotating shaft oil chamber; in this embodiment, the specific implementation of the rotating shaft structure can refer to the description in the above embodiment 1;

[0073] N pole shoes are evenly distributed on the outer circumference of the rotor core segment, and the rotor magnets are inserted into the magnet grooves formed between adjacent pole shoes; each magnet groove is provided with a slot at the bottom, and forms N first cooling oil paths with the inner circumference of the rotor magnet; N is the number of magnet poles, and optionally, in this embodiment, N=6;

[0074] The difference between this embodiment and the above-mentioned embodiment 1 is that, in this embodiment, in order to realize cooling of the magnetic steel protective sleeve, the cooling oil circuit structure designed is different, such as Fig. 9 and Fig.10 As shown, in this embodiment, the outer circle of the rotor magnetic steel is the same as the outer circle of the pole shoe; a third cooling oil circuit is provided on each pole shoe, forming a total of N third cooling oil circuits.

[0075] Suitable for the designed cooling oil circuit, such as Fig.11As shown, in this embodiment, the outer circle of the oil separator is the same as the outer circle of the rotor magnetic steel; the inner circumference of the oil separator is provided with N first oil guide grooves and N second oil guide grooves which are alternately distributed; N oil holes are provided directly above the N second oil guide grooves, and the positions and shapes of the N oil holes correspond to the positions and shapes of the N third cooling oil circuits, and are connected with the N second oil guide grooves one by one; the first oil guide groove and the second oil guide groove are both connected with the shaft oil cavity; the N first oil guide grooves are respectively connected with the N first cooling oil circuits; the N oil holes are respectively connected with the N third cooling oil circuits.

[0076] In the rotor structure provided by the present invention, after the cooling medium is injected into the oil cavity of the rotating shaft, part of the cooling medium will be injected into the first cooling oil path in the rotor core segments on both sides through the first oil guide groove, and flow axially to the end through the first cooling oil path. The first cooling oil path is in direct contact with the rotor magnetic steel, and can effectively take away the heat caused by eddy current loss in the rotor magnetic steel; another part of the cooling medium will be injected into the third cooling oil path in the rotor cores on both sides through the second oil guide groove, and flow to the end through the third cooling oil path. The third cooling oil path is close to the rotor magnetic steel and the magnetic steel protective cover, and has a small thermal resistance, so it can effectively take away the heat caused by eddy current loss in the magnetic steel and the magnetic steel protective cover.

[0077] Similar to Example 1, in this embodiment, the depth of the second oil guide groove is lower than the depth of the first oil guide groove, so that the oil separator has a higher mechanical strength while ensuring that the cooling medium in the shaft oil cavity enters each oil guide groove evenly.

[0078] Similar to Example 1, in this embodiment, the slot arranged at the bottom of the magnetic steel slot is an arc-shaped structure distributed along the bottom of the magnetic steel slot, and the arc length is greater than the slot depth, so that after the cooling medium enters the first cooling oil channel, it has a larger contact area with the rotor magnetic steel, which can further improve the cooling effect on the rotor magnetic steel.

[0079] Similar to Example 1, in this embodiment, the axial ends of the rotor core are respectively blocked by magnetic steel baffles to prevent the rotor core and the magnetic steel from axial movement; at the same time, oil holes with the same shape as the first cooling oil circuit and the second cooling oil circuit are opened on the magnetic steel baffle, and these oil holes are respectively connected to the first cooling oil circuit and the second cooling oil circuit; the cooling oil in the first cooling oil circuit and the second cooling oil circuit is finally thrown to the end of the stator winding through the oil holes on the magnetic steel baffle, thereby further cooling the end of the winding.

[0080] It is easy to understand that in practical applications, the cooling medium may be cooling oil, or other gas or liquid cooling medium.

[0081] This embodiment uses an oil separator to divide the rotor core into two sections, and cools the two sections at the same time, which can alleviate the problem of uneven cooling of the motor rotor in the axial direction. In addition, this embodiment uses the oil guide groove on the oil separator to guide the cooling medium in the shaft oil cavity into each cooling oil circuit, which can ensure that the cooling medium is evenly introduced, thereby achieving uniform cooling of the entire rotor.

[0082] Compared with the above-mentioned embodiment 1, since the third cooling oil channel does not directly contact the heat source magnetic steel and the magnetic steel protective sleeve, the cooling effect of this embodiment is slightly worse, but since the outer circle of the magnetic steel is the same as the outer circle of the pole shoe, it can be applied to scenes with higher speeds. It should be noted that in this embodiment, the third cooling oil channel set on the pole shoe has a very small thermal resistance with the magnetic steel and the magnetic steel protective sleeve. Although the cooling effect is not as good as that of embodiment 1, it can still effectively take away the heat generated by the magnetic steel and the magnetic steel protective sleeve due to eddy current loss.

[0083] Embodiment 3: A surface-mounted permanent magnet synchronous motor comprises a rotor and a stator arranged outside the rotor;

[0084] The rotor is a surface-mounted permanent magnet synchronous motor rotor structure with cooling channels provided in the above-mentioned embodiment 1 or 2.

[0085] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A surface mounted permanent magnet synchronous motor rotor structure with a cooling channel, characterized in that: include: A rotating shaft, a rotor core, an oil separator and a magnetic steel protective sleeve; the rotor core is sleeved on the rotating shaft and includes two rotor core segments; the oil separator is sleeved on the rotating shaft and located between the two rotor core segments; the magnetic steel protective sleeve is sleeved on the outer sides of the two rotor core segments; One end of the rotating shaft is hollowed out to form a rotating shaft oil chamber; The outer circumference of the rotor core segment is provided with N pole shoes evenly distributed, and the rotor magnet is inserted into the magnetic steel slot formed between adjacent pole shoes; the bottom of each magnetic steel slot is provided with a slot, and N first cooling oil paths are formed with the inner circumference of the rotor magnet; the outer circle of the rotor magnet is larger than the outer circle of the pole shoe, and the two corners of the rotor magnet that extend beyond the pole shoe are chamfered, and two adjacent rotor magnets and the pole shoe therebetween form an outer circle slot, and N second cooling oil paths are formed with the magnetic steel protective sleeve; The outer circle of the oil separator is the same as the outer circle of the rotor magnetic steel; the inner circumference of the oil separator is provided with N first oil guide grooves and N second oil guide grooves which are alternately distributed, and the outer circumference of the oil separator is provided with N oil holes; the first oil guide groove and the second oil guide groove are both connected with the shaft oil cavity; the N first oil guide grooves are respectively connected with the N first cooling oil circuits; the N oil holes are respectively located directly above the N second oil guide grooves, and are connected with the N second oil guide grooves one by one; the N oil holes are respectively connected with the N second cooling oil circuits; Wherein, N is the number of magnetic poles.

2. The surface mounted permanent magnet synchronous motor rotor structure with cooling channels according to claim 1, characterized in that: The depth of the second oil guiding groove is lower than the depth of the first oil guiding groove.

3. The surface mounted permanent magnet synchronous motor rotor structure with cooling channel according to claim 1 or 2, characterized in that: The slots arranged at the bottom of the magnetic steel slots are arc-shaped structures distributed along the bottom of the magnetic steel slots, and the arc length is greater than the slot depth.

4. The surface mounted permanent magnet synchronous motor rotor structure with cooling channel according to claim 1 or 2, characterized in that: Magnetic steel baffles are provided at both axial ends of the rotor core; The magnetic steel baffle is provided with oil holes of the same shape and corresponding position as the first cooling oil circuit and the second cooling oil circuit, and each oil hole is connected to the corresponding first cooling oil circuit or the second cooling oil circuit.

5. A surface mounted permanent magnet synchronous motor rotor structure with a cooling channel, characterized in that: include: A rotating shaft, a rotor core, an oil separator and a magnetic steel protective sleeve; the rotor core is sleeved on the rotating shaft and includes two rotor core segments; the oil separator is sleeved on the rotating shaft and located between the two rotor core segments; the magnetic steel protective sleeve is sleeved on the outer sides of the two rotor core segments; One end of the rotating shaft is hollowed out to form a rotating shaft oil chamber; The outer circumference of the rotor core segment is provided with N pole shoes evenly distributed, and the rotor magnets are inserted into the magnet grooves formed between adjacent pole shoes; the bottom of each magnet groove is provided with a slot, and N first cooling oil paths are formed with the inner circumference of the rotor magnet; the outer circumference of the rotor magnet is the same as the outer circumference of the pole shoe; each pole shoe is provided with a third cooling oil path, and a total of N third cooling oil paths are formed; The outer circle of the oil separator is the same as the outer circle of the rotor magnetic steel; the inner circumference of the oil separator is provided with N first oil guide grooves and N second oil guide grooves which are alternately distributed; N oil holes are provided directly above the N second oil guide grooves, and the positions and shapes of the N oil holes correspond to the positions and shapes of the N third cooling oil circuits, and are connected with the N second oil guide grooves one by one; the first oil guide groove and the second oil guide groove are both connected with the shaft oil cavity; the N first oil guide grooves are respectively connected with the N first cooling oil circuits; the N oil holes are respectively connected with the N third cooling oil circuits; Wherein, N is the number of magnetic poles.

6. The surface mounted permanent magnet synchronous motor rotor structure with cooling channels as claimed in claim 5, characterized in that: The depth of the second oil guiding groove is lower than the depth of the first oil guiding groove.

7. The surface mounted permanent magnet synchronous motor rotor structure with cooling channels according to claim 5 or 6, characterized in that: The slots arranged at the bottom of the magnetic steel slots are arc-shaped structures distributed along the bottom of the magnetic steel slots, and the arc length is greater than the slot depth.

8. The surface mounted permanent magnet synchronous motor rotor structure with cooling channels as claimed in claim 5 or 6, characterized in that: Magnetic steel baffles are provided at both axial ends of the rotor core; The magnetic steel baffle is provided with oil holes of the same shape and corresponding position as the first cooling oil circuit and the second cooling oil circuit, and each oil hole is connected to the corresponding first cooling oil circuit or the second cooling oil circuit.

9. A surface mounted permanent magnet synchronous motor, characterized in that: It includes a rotor and a stator arranged outside the rotor; The rotor is a surface-mounted permanent magnet synchronous motor rotor structure with cooling channels as described in any one of claims 1 to 8.

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