A high-reliability intelligent permanent magnet rotor and motor

Abstract

The present invention relates to a high-reliability intelligent permanent magnet rotor and motor, wherein the rotor comprises a rotor shaft and a rotor core, wherein the rotor core is provided with an oil passage A extending in the axial direction, and the two ends of the oil passage A are respectively connected to the oil passage B extending in the radial direction, wherein a hollow oil cavity is provided in the rotor shaft, and the two ends of the oil cavity are respectively connected to the oil passage B through the oil passage C extending in the radial direction, and the oil passage A, the oil passage B, the oil passage C and the oil cavity form a cooling oil circulation pipeline. The present invention adopts a rotor internal cooling design, and indirectly cools the rotor core, magnetic steel, etc. by arranging oil passages in the rotating shaft and the rotor core, thereby reducing the risk of magnetic steel demagnetization in the rotor high-speed state.

Description

Technical Field

[0001] The present invention relates to the technical field of electric motors for electric vehicles, and more specifically, to a high-reliability intelligent permanent magnet rotor and a motor. Background Art

[0002] New energy vehicles have extremely high requirements for the power density (torque density) of vehicle drive motors due to their requirements for vehicle mass and space. On the other hand, the high speed of vehicle motors has become an inevitable trend recognized by relevant manufacturers. Embedded permanent magnet synchronous motors have become the preferred type of vehicle drive motors due to their wide speed range and high power density.

[0003] Automotive drive motors have high requirements for motor speed, and the maximum speed can often reach tens of thousands of revolutions per minute. Due to the presence of various harmonic magnetic fields in the air gap magnetic field, when the motor is running, the rotor magnet and the air gap harmonic magnetic field will move relative to each other and cut the magnetic field, which will cause eddy current losses on the permanent magnet. High speed is currently one of the development trends of automotive motors. As the motor speed continues to increase, the eddy current of the magnetic steel is linearly related to the square of the speed, and the eddy current loss increases sharply. In severe cases, it may even cause irreversible demagnetization of the permanent magnet. In order to solve the problem of large eddy current loss of the magnetic steel when the motor is running at high speed, the existing technology often uses oil injection cooling for cooling. However, since most automotive motors use built-in magnetic steel design, it is difficult for the magnetic steel to contact the cooling oil, and the cooling effect is often average.

[0004] In addition, the eddy current loss of the magnet under different working conditions of the motor varies greatly. For example, at low speed and low load, the temperature rise of the permanent magnet is small, and the temperature has little effect on the motor performance, so there is no need to cool the magnet; at high speed and load, the temperature rise of the permanent magnet is large, and the temperature has a greater impact on the motor performance, so the magnet needs to be cooled in time. However, due to the rotation of the rotor, it is difficult to monitor the temperature of the magnet with a built-in temperature sensor, and the cooling oil flow cannot be controlled, resulting in energy loss. In the prior art, the rotor temperature is often estimated by establishing a rotor thermal model, but the accuracy is poor and it is easy to fail; or an infrared temperature sensor measurement method is used. Since the test accuracy of the infrared temperature sensor is related to many factors such as the type of material and surface roughness, the measurement accuracy is difficult to guarantee and the cost is too high.

[0005] Moreover, the inner rotor motor magnets are distributed on the outer circumference of the rotor, and when the motor runs at high speed, the eddy current loss of the magnets is the main component of the rotor loss; on the other hand, under the action of the skin effect, the eddy current of the magnets is mainly concentrated on the surface close to the air gap. In general, due to the effect of the eddy current loss of the magnets, the rotor temperature changes greatly from the outside to the inside along the radial direction, and the temperature distribution is uneven. The temperature of the rotor magnets and the outer circumference is high, while the temperature of the shaft is low. The heat of the magnets is transferred to the shaft through heat conduction, and then transferred to the outside. Summary of the invention

[0006] In order to solve the above technical problems, the first object of the present invention is to provide a high-reliability intelligent permanent magnet rotor, which can better achieve rotor cooling through a simple and reliable mechanical structure design. The second object of the present invention is to provide a motor using the above rotor.

[0007] In order to achieve the above first invention objective, the present invention adopts the following technical solutions:

[0008] A high-reliability intelligent permanent magnet rotor comprises a rotor shaft and a rotor core, wherein the rotor core is provided with an oil passage A extending in the axial direction, and the two ends of the oil passage A are respectively connected to the oil passage B extending in the radial direction, and a hollow oil cavity is provided in the rotor shaft, and the two ends of the oil cavity are respectively connected to the oil passage B through the oil passage C extending in the radial direction, and the oil passage A, the oil passage B, the oil passage C and the oil cavity form a cooling oil circulation pipeline.

[0009] As a preferred solution: a plurality of step surfaces are further provided in the oil chamber, a two-way memory alloy spring is provided on one of the step surfaces, a hydraulic piston is fixed to one end of the two-way memory alloy spring, and the hydraulic piston is in close contact with the other step surface.

[0010] As a preferred solution: a retaining ring is further provided in the oil chamber, a spring seat is further provided on one side of the retaining ring, a return spring is further provided between the spring seat and the hydraulic piston, and the return spring and the two-way memory alloy spring are respectively located on both sides of the hydraulic piston.

[0011] As a preferred solution: a spiral supercharger is also rotatably provided in the oil chamber via an oil chamber sealing bearing, and the oil chamber sealing bearing is located outside the oil passage C.

[0012] As a preferred solution: a bearing end cover is fixed to one end of the rotor shaft by means of fixing bolts, and the bearing end cover abuts against the oil chamber sealing bearing.

[0013] As a preferred solution: the rotor shaft is further provided with an oil drain hole connected to the outside, and the oil drain hole is further provided with an oil outlet valve.

[0014] As a preferred solution: a plurality of magnets are evenly arranged on the rotor core, and the oil channel A is arranged on the inner side of the magnets.

[0015] In order to achieve the above second invention object, the present invention adopts the following technical solution:

[0016] A motor comprises a housing assembly, a stator assembly and a rotor assembly, wherein the rotor assembly is the permanent magnet rotor described in any one of the above items.

[0017] A motor comprises a housing component, a stator component and a rotor component, wherein the rotor component is a high-reliability intelligent permanent magnet rotor, comprising a rotor shaft and a rotor core, wherein the rotor core is provided with an oil passage A extending in the axial direction, and the two ends of the oil passage A are respectively connected to the oil passage B extending in the radial direction, wherein a hollow oil cavity is provided in the rotor shaft, and the two ends of the oil cavity are respectively connected to the oil passage B through the oil passage C extending in the radial direction, wherein the oil passage A, the oil passage B, the oil passage C and the oil cavity form a cooling oil circulation pipeline, wherein a spiral supercharger is also provided in the oil cavity through an oil cavity sealing bearing for rotation, wherein the oil cavity sealing bearing is located on the outside of the oil passage C, and wherein one end of the housing component is further provided with an adsorption component for fixing or releasing the spiral supercharger.

[0018] As a preferred solution: a bearing end cover is fixed to one end of the rotor shaft by means of fixing bolts, and the bearing end cover abuts against the oil chamber sealing bearing.

[0019] As a preferred solution: the adsorption component includes a control winding, an iron core and a spring, the iron core is fixed to the housing component through the spring, and the control winding is wound on the outside of the iron core.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention adopts a rotor internal cooling design, and indirectly cools the rotor core, magnetic steel, etc. by arranging oil channels in the rotating shaft and the rotor core, thereby reducing the risk of magnetic steel demagnetization when the rotor is in a high-speed state. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings in the specification, which constitute a part of the present application, are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute a limitation on the present application.

[0023] Figure 1 It is a schematic diagram of the motor decomposition of the present invention;

[0024] Figure 2 It is a schematic diagram of the cross-sectional structure of the motor of the present invention;

[0025] Figure 3 is an axial cross-sectional view of the rotor of the present invention;

[0026] Figure 4 is a radial cross-sectional view of the rotor of the present invention;

[0027] Figure 5 is a schematic cross-sectional view of a rotor shaft of the present invention;

[0028] Figure 6 It is a schematic cross-sectional view of the rotor core of the present invention.

[0029] The accompanying drawings are marked as follows: 1, motor rotor assembly; 2, motor end cover assembly; 3, motor housing; 4, motor stator assembly; 1-1, rotor shaft; 1-2, oil outlet valve; 1-3, rotor core; 1-4, two-way memory alloy spring; 1-5, hydraulic piston; 1-6, return spring; 1-7, spring seat; 1-8, snap ring; 1-9, spiral supercharger; 1-10, oil chamber sealing bearing; 1-11, bearing end cover; 1-12, fixing bolt; 1-13, rotor magnetic steel; 2-1, motor end cover; 2-2, front bearing end cover; 2-3, front bearing; 2-4, control winding; 2-5, iron core; 2-6, return spring; 3-1, motor housing; 3-2, rear bearing end cover; 3-3, rear bearing; 3-4, oil retaining ring; 4-1, stator core; 4-2, stator winding; 1-1-1, oil drain hole; 1-1-2, rear oil channel of rotor shaft; 1-1-3, rear oil chamber of rotor shaft; 1-1-4, front oil chamber of rotor shaft; 1-1-5, front oil channel of rotor shaft; 1-3-2, oil channel inside rotor core. DETAILED DESCRIPTION

[0030] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] In addition, in the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more, unless otherwise clearly specified.

[0034] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0036] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0037] like Figure 1 and Figure 2 A motor shown in the figure comprises a housing assembly 3, a stator assembly 4 and a rotor assembly 1, wherein the housing assembly 3 comprises an outer shell 3-1, and an end cover assembly 2 is further provided at one end of the outer shell 3-1, the stator assembly 4 comprises a stator core 4-1 and a stator winding 4-2 inserted in the stator core 4-1, the stator core 4-1 is fixed on the inner wall of the outer shell 3-1, and a rear bearing end cover 3-2 and a rear bearing 3-3 are further embedded in the other end of the outer shell 3-1; the end cover assembly 2 comprises a motor end cover 2-1, a front bearing end cover 2-2 and a front bearing 2-3; the motor end cover 2-1 and the outer shell 3-1 are fixed to each other, and the front bearing end cover 2-2 and the front bearing 2-3 are embedded in the motor end cover 2-1, and the two ends of the rotor assembly are rotatably connected to the motor end cover and the outer shell through the front bearing 2-3 and the rear bearing 3-3 respectively, and an oil retaining ring 3-4 is further provided between one end of the rotor assembly and the outer shell,

[0038] like Figure 5 and Figure 6 As shown, the rotor assembly 1 includes a rotor shaft 1-1 and a rotor core 1-3. The rotor core 1-3 is provided with an oil passage A extending in the axial direction, and the two ends of the oil passage A are respectively connected to the oil passage B extending in the radial direction. A hollow oil cavity is provided in the rotor shaft 1-1, and the two ends of the oil cavity are respectively connected to the oil passage B through the oil passage C extending in the radial direction. The oil passage A, the oil passage B, the oil passage C and the oil cavity form a cooling oil circulation pipeline. Figure 4 As shown, a plurality of magnetic steels 1-13 are evenly arranged on the rotor core 1-3, and the oil channel A is arranged inside the magnetic steel 1-13. Figure 5 and Figure 6 As shown, the oil passage A is the oil passage 1-3-2 in the rotor core, the oil passages C at both ends are the rotor shaft rear oil passage 1-1-2 and the rotor shaft front oil passage 1-1-5 respectively, and the oil cavity is divided into the rotor shaft rear oil cavity 1-1-3 and the rotor shaft front oil cavity 1-1-4 by the clamp ring 1-8. The cooling oil flowing in the circulation pipeline can directly cool the rotor core and indirectly cool the inner side of the stator core.

[0039] like Figure 3 As shown, a spiral supercharger 1-9 is also provided in the oil chamber for rotation through an oil chamber sealing bearing 1-10, and the oil chamber sealing bearing 1-10 is located on the outside of the oil passage C. A bearing end cover 1-11 is also fixed to one end of the rotor shaft 1-1 through a fixing bolt 1-12, and the bearing end cover 1-11 is against the oil chamber sealing bearing 1-10, and the spiral supercharger 1-9 passes through the bearing end cover 1-11; an adsorption component for fixing or releasing the spiral supercharger 1-9 is also provided at one end of the housing assembly 3. Specifically, the adsorption component is arranged on the motor end cover 2-1 at one end of the housing assembly 3, and the adsorption component includes a control winding 2-4, an iron core 2-5 and a spring 2-6, the iron core 2-5 is fixed to the housing assembly 3 through the spring 2-6, and the control winding 2-4 is wound on the outside of the iron core 2-5.

[0040] By controlling the on and off of the control winding 2-4, the iron core and the spiral supercharger 1-9 can be attracted or disconnected, thereby controlling the rotation or stop of the spiral supercharger 1-9. When energized for adsorption, the spiral supercharger 1-9 is fixed to the motor end cover and rotates relative to the hydraulic oil inside the rotor, thereby generating pressure. When not energized, the spiral supercharger 1-9 rotates with the rotor and does not generate oil pressure.

[0041] The oil chamber is also provided with a plurality of step surfaces, one of which is provided with a two-way memory alloy spring 1-4, one end of which is fixed with a hydraulic piston 1-5, and the hydraulic piston 1-5 is in close contact with the other step surface.

[0042] A retaining ring 1-8 is also provided in the oil chamber, a spring seat 1-7 is also provided on one side of the retaining ring 1-8, a return spring 1-6 is also provided between the spring seat 1-7 and the hydraulic piston 1-5, and the return spring 1-6 and the two-way memory alloy spring 1-4 are respectively located on both sides of the hydraulic piston 1-5.

[0043] The above structure combines a two-way memory alloy spring, a hydraulic piston and a return spring (forming a temperature control valve), and is built into a hollow shaft after processing. When the temperature is low and the speed is low, the two-way memory alloy spring contracts, pulling the hydraulic piston close to the shaft end, blocking the flow of hydraulic oil; when the temperature increases or the oil pressure increases due to an increase in speed, the memory alloy spring extends, pushing the hydraulic piston to move, thereby opening the valve and allowing the hydraulic oil to circulate, thereby reducing the temperature rise of the magnetic steel and improving the temperature distribution of the rotor.

[0044] The above structure overcomes the current situation of difficulty in monitoring the rotor temperature. At present, the motor stator often uses a built-in temperature sensor to monitor the temperature, and then accurately control the cooling flow. However, due to the continuous rotation of the rotor, its temperature is difficult to monitor through the built-in temperature sensor. The magnetic steel is a component with large losses and easy demagnetization at high speed. After adopting the above structure, the cooling flow changes in real time with the temperature, which can not only effectively cool the magnetic steel, but also reduce other unnecessary losses caused by cooling.

[0045] The rotor shaft 1-1 is also provided with an oil drain hole 1-1-1 communicating with the outside, and an oil outlet valve 1-2 is also provided in the oil drain hole 1-1-1. The setting of the oil outlet valve can conveniently replace the cooling oil in the rotor.

[0046] In summary, the present invention opens an oil channel at a position of the rotor core close to the magnetic steel but not in the magnetic circuit, and communicates with the oil cavity of the rotor shaft, and the oil channel and the inner cavity are filled with hydraulic oil; the spiral blade end of the boost component is built into the hollow shaft of the rotor, and the other end is selectively fixed by electromagnetic adsorption according to actual needs. When the motor speed is high or the load is large, the added component is fixed to the motor end cover by electromagnetic adsorption, causing the oil in the hollow shaft to rotate relative to the spiral blade, thereby generating oil pressure to accelerate the circulation of the cooling oil; when the motor speed is low or the load is small, the rotor does not need to be cooled, and the boost component is disconnected from the end cover and rotated with the rotor to reduce the energy loss caused by stirring the oil.

[0047] On the other hand, through special processing inside the hollow shaft, the two-way memory alloy spring, hydraulic piston and return spring are built into the hollow shaft to form a structure similar to a hydraulic pump. When the temperature is low and the oil pressure is low, the two-way memory alloy spring contracts, pulling the hydraulic piston close to the inner end face of the hollow shaft, blocking the flow of hydraulic oil; when the temperature rises or the rotor speed increases, the oil pressure caused by the relative rotation of the spiral blades increases, the memory alloy spring extends, pushing the hydraulic piston to move, and then opening the valve to promote the circulation of hydraulic cooling oil, absorbing the heat of the magnet and the core quickly.

[0048] In the present invention, as the speed increases, due to the action of the spiral supercharging component, the oil pressure at one end of the hydraulic piston memory spring also continues to increase, pushing the piston to move. The larger the valve opening, the faster the hydraulic oil circulates, and the temperature rise of the rotor magnet due to the increase in speed is controlled in real time. At the same time, due to the temperature characteristics of the memory alloy spring, the increase in rotor temperature caused by the increase in speed or load will cause the memory spring to elongate, thereby causing the valve opening to increase, the hydraulic oil circulates faster, and the rotor temperature rise can also be effectively reduced in real time.

[0049] The present invention arranges spiral superchargers 1-9 (supercharged propeller blades with shafts) and mechanical structures such as temperature control valves in the rotor shaft, and the cooling oil flow rate changes in real time with the motor rotor temperature and rotation speed, thereby achieving intelligent control of the cooling oil circulation flow speed, thereby realizing the cooling of the permanent magnet temperature and reducing the uneven temperature distribution inside and outside the rotor.

[0050] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0051] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A motor, comprising a housing assembly (3), a stator assembly (4) and a rotor assembly (1), characterized in that: The rotor assembly (1) comprises a rotor shaft (1-1) and a rotor core (1-3); an oil passage A extending in the axial direction is provided on the rotor core (1-3); and both ends of the oil passage A are respectively connected to oil passages B extending in the radial direction; a hollow oil cavity is provided in the rotor shaft (1-1); and both ends of the oil cavity are respectively connected to oil passages B via oil passages C extending in the radial direction; and the oil passages A, B, C and the oil cavity form a cooling oil circulation pipeline; A plurality of step surfaces are also provided in the oil cavity, a two-way memory alloy spring (1-4) is provided on one of the step surfaces, a hydraulic piston (1-5) is fixed to one end of the two-way memory alloy spring (1-4), and the hydraulic piston (1-5) is in close contact with another step surface; A clamping ring (1-8) is also provided in the oil chamber, a spring seat (1-7) is also provided on one side of the clamping ring (1-8), a return spring (1-6) is also provided between the spring seat (1-7) and the hydraulic piston (1-5), and the return spring (1-6) and the two-way memory alloy spring (1-4) are respectively located on both sides of the hydraulic piston (1-5); A spiral supercharging component (1-9) is also rotatably provided in the oil cavity via an oil cavity sealing bearing (1-10), and the oil cavity sealing bearing (1-10) is located outside the oil passage C; One end of the housing component (3) is also provided with an adsorption component for fixing or releasing the spiral supercharging component (1-9); the adsorption component comprises a control winding (2-4), an iron core (2-5) and a spring (2-6); the iron core (2-5) is fixed to the housing component (3) by means of the spring (2-6); and the control winding (2-4) is wound on the outside of the iron core (2-5).

2. A motor according to claim 1, characterized in that: A bearing end cover (1-11) is also fixed to one end of the rotor shaft (1-1) via a fixing bolt (1-12), and the bearing end cover (1-11) abuts against the oil chamber sealing bearing (1-10).

3. A motor according to claim 1, characterized in that: An oil drain hole (1-1-1) communicating with the outside is also provided on the rotor shaft (1-1), and an oil outlet valve (1-2) is also provided in the oil drain hole (1-1-1).

4. The motor according to claim 1, characterized in that: A plurality of magnetic steels (1-13) are evenly arranged on the rotor core (1-3), and the oil channel A is arranged on the inner side of the magnetic steels (1-13).

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