Rotor assembly, motor, compressor and refrigeration equipment

Abstract

The invention discloses a rotor assembly, a motor, a compressor and refrigeration equipment, the rotor assembly comprises a rotor iron core and magnetic steel, the rotor iron core is provided with a plurality of magnet grooves along the circumferential direction, each magnet groove comprises a middle section, and an inner side section and an outer side section which are respectively located at the inner side and the outer side of the middle section; the extension directions of the outer side section and the inner side section are the same as the radial direction of the rotor core; the magnetic steel comprises a main body, and a first extension part and a second extension part which are respectively connected to two ends of the main body in the length direction, the magnetic steel is mounted in the magnet groove, and the first extension part, the main body and the second extension part are respectively positioned in the outer side section, the middle section and the inner side section. According to the technical scheme, the usage amount of magnetic steel under the same size of the motor can be increased, and the power density of the motor is improved; the cost of the magnetic steel can be reduced, the demagnetization of the magnetic steel is improved, and the comprehensive cost of the motor is further reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to a rotor assembly, an electric machine, a compressor and a refrigeration device. BACKGROUND

[0002] At present, the structure of the plug-in rotor of the brushless permanent magnet motor mostly adopts rectangular magnetic steel, and the shape of the magnetic steel is relatively single. Due to the complex working environment of the motor and special use requirements, some performance requirements must be met, such as high torque density, high power density, adaptability to complex operating conditions and high temperature operating environment, etc. Therefore, the magnetic steel of the electronic rotor needs to have high magnetic performance. SUMMARY

[0003] The main purpose of the present application is to provide a rotor assembly, which aims to increase the amount of magnetic steel used in the same volume of the electric machine and improve the power density of the electric machine. The cost of the magnetic steel can be reduced, the demagnetization of the magnetic steel can be improved, and the overall cost of the electric machine can be reduced.

[0004] To achieve the above purpose, the present application provides a rotor assembly, which comprises:

[0005] A rotor core is provided with a plurality of magnet grooves in the circumferential direction, the magnet grooves comprise a middle section and an inner side section and an outer side section located on the inner side and the outer side of the middle section respectively, the extension direction of the outer side section and the inner side section is the same as the radial direction of the rotor core, the extension direction of the middle section intersects with the radial direction of the rotor core at a preset included angle, and

[0006] The magnetic steel comprises a main body and a first extension and a second extension connected to the two ends of the length direction of the main body respectively, the extension directions of the first extension and the second extension are parallel, and the preset included angle is formed between the extension direction of the main body.

[0007] The magnetic steel is installed in the magnet groove, and the first extension, the main body and the second extension are located in the outer side section, the middle section and the inner side section respectively.

[0008] Optionally, in the cross section of the magnetic steel perpendicular to the axial direction, the cross-sectional area of the first extension is A, the cross-sectional area of the main body is B, and the cross-sectional area of the second extension is C, B>C≥A.

[0009] Optionally, the lengths of the two sides of the cross section of the first extension are H1 and H3 respectively, and the lengths of the two sides of the cross section of the second extension are H2 and H4 respectively, wherein H3>H1, H2>H4, and H3 / H1≤H2 / H4.

[0010] Optionally, the width of the cross section of the first extension is W1, the width of the cross section of the second extension is W2, the distance between the midpoint of the width of the first extension and the midpoint of the width of the second extension is H6, and the length of the side of the cross section of the main body is H5;

[0011] The angle between the side of the length H2 of the second extension and the side of the main body is J4, and the angle between the side of the length H4 of the second extension and the side of the main body is J2.

[0012] The angle between the side of the length H1 of the first extension and the side of the main body is J3, and the angle between the side of the length H3 of the first extension and the side of the main body is J1.

[0013] The relationship abs(sin(J1))<(H1+H2+H5) / H6<H3 / H1<B / (A+C)<(H6 / W1) is satisfied.

[0014] Optionally, the material of the magnetic steel is ferrite material.

[0015] Optionally, the rotor core comprises a plurality of core punching sheets arranged in layers, a plurality of magnet grooves of the core punching sheets are communicated two by two to form a plurality of magnetic groove groups near the inner edge of the rotor core, and two magnet grooves of the magnetic groove group are communicated through a connecting groove.

[0016] Optionally, the core punching sheet has an inner ring part and a plurality of sector parts located on the outer peripheral side of the inner ring part, two sector parts spaced apart are connected with the inner ring part, the connecting groove is located between the two sector parts connected with the inner ring part, and a fixing spring is arranged on the inner ring part, the fixing spring is located in the connecting groove, and the fixing spring extends in the radial direction of the outer periphery of the inner ring part.

[0017] Optionally, the plurality of core punching sheets are outer open magnetic bridges, rivets are arranged on the inner and outer sides of the plurality of core punching sheets in the radial direction, and the plurality of core punching sheets are fixed through the rivets.

[0018] Optionally, in the rotor core formed by the plurality of core punching sheets, at least two core punching sheets of fully closed outer magnetic bridges are arranged in the middle part in the axial direction.

[0019] Optionally, the bottom of the fixing spring is higher than the groove opening of the magnet groove, and the height of the protrusion of the groove opening is 0.05mm-0.2mm.

[0020] Optionally, two magnetic steels are arranged in one magnet slot of the rotor core, and the two magnetic steels are inserted into the magnet slot from two ends of the rotor core respectively; and the deformation directions of the fixed elastic sheets at the two magnetic steels are opposite.

[0021] Optionally, the magnet slot and the magnetic steel are gap-fitted, and the gap range is 0.05mm≤D≤0.15mm.

[0022] Optionally, the rotor assembly further comprises a mounting end plate, the mounting end plate is fixed to the rotor core, the thickness of the mounting end plate is W3, the thickness of the rotor lamination is T, and the following relationship is met: (3*T)≤W3≤(H6 / W1).

[0023] Optionally, the preset included angle between the first extension and the second extension and the extension direction of the main body ranges from 5° to 60°.

[0024] The application further provides an electric machine comprising the rotor assembly.

[0025] The application further provides a compressor comprising the electric machine.

[0026] The application further provides a refrigeration device comprising the compressor.

[0027] The technical scheme of the application utilizes the outer side section close to the outer edge of the rotor and arranged perpendicularly to the outer edge of the rotor to improve the air gap magnetic field harmonic content of the electric machine under load, and reduce the vibration and noise of the electric machine; compared with the rectangular radiation type magnetic steel structure, the application utilizes the middle section inclined in the radial direction of the rotor assembly to arrange more magnetic steels, thereby improving the power density of the electric machine; because the magnetic flux area provided by the magnetic steels in the entire radiation direction of the rotor assembly is increased compared with the rectangular magnetic steel, the effective magnetic flux of the electric machine is increased, the torque of the electric machine is increased in the same core length range, the use amount of the magnetic steels under the same volume is increased, the output torque of the electric machine is improved, and the power density of the electric machine is improved under the same speed comparison. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only show some embodiments of the application, and for those skilled in the art, other drawings can also be obtained according to the structures shown in the drawings without any creative effort.

[0029] Figure 1 It is an exploded view of an embodiment of the rotor assembly of the application.

[0030] Figure 2 Fig. 1 is a structural schematic view of an embodiment of a rotor assembly; Figure 1

[0031] Figure 3 Fig. 2 is a structural schematic view of an embodiment of a magnetic steel; Figure 1

[0032] Figure 4 Fig. 3 is a structural schematic view of an embodiment of a cross-section structure at A-A; Figure 3

[0033] Figure 5 Fig. 4 is a structural schematic view of an embodiment of a core punching sheet; Figure 1

[0034] Figure 6 Fig. 5 is a structural schematic view of an embodiment of a core punching sheet; Figure 5

[0035] Figure 7 Fig. 6 is an enlarged view of A in Fig. 5; Figure 6

[0036] Figure 8 Fig. 7 is a structural schematic view of an embodiment of a magnetic steel and a magnetic groove;

[0037] Brief Description of the Drawings

[0038] Reference Name Reference Name 100 Rotor assembly 132 Inner side section 110 End plate 134 Outer side section 120 Rotor core 133 Connecting slot 121 Core lamination 140 Magnetic slot group 122 Outer open magnetic bridge 150 Magnetic steel 123 Fully closed outer magnetic bridge 151 Main body 124 Fixed elastic sheet 152 First extension 125 Riveted buckle 153 Second extension 126 Inner ring part 154 First side surface 127 Fan-shaped part 155 Second side surface 130 Magnet slot 131 Intermediate section

[0039] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without any creative work under the premise that the present application falls within the protection scope of the present application.

[0041] It should be noted that all the directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directionality indications also change accordingly.

[0042] ​​​​​​In addition, the description related to "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, also not within the protection scope required by the present application.

[0043] At present, the structure of the plug-in rotor of the brushless permanent magnet motor mostly adopts rectangular magnetic steel, and the shape of the magnetic steel is relatively single. Due to the complex working environment of the motor and special use requirements, some performance requirements must be met, such as high torque density, high power density, adaptability to complex operating conditions and higher temperature operating environment, etc. These require the magnetic steel of the electronic rotor to have very high magnetic properties.

[0044] Therefore, with reference to Figure 1 and Figure 2 The present application provides a rotor assembly 100, comprising: a plurality of magnetic steels 150 and a rotor core 120, the rotor core 120 comprising a plurality of magnet grooves 130 arranged circumferentially, and a magnetic steel 150 placed in a magnet groove 130.

[0045] With reference to Figure 3 , Figure 4 In an embodiment of the present application, the magnetic steel 150 comprises a main body 151 and a first extension 152 and a second extension 153. When installed, the magnetic steel 150 is placed in the magnet groove 130 of the rotor core 120 of the rotor assembly 100, the main body 151 is located in the middle section 131 of the magnet groove 130, the first extension 152 is located in the outer section 134, and the second extension 153 is located in the inner section 132, and the end of the main body 151 close to the outer edge of the rotor deviates from the radial direction of the rotor assembly 100, that is, intersects with the radial direction of the rotor assembly 100; in this way, compared with arranging in parallel with the radial direction, the main body 151 can be placed in a larger number. The first extension 152 is connected with the main body 151, close to the outer edge of the rotor assembly 100, and perpendicular to the radial direction of the rotor assembly 100, which helps to reduce the distortion of the magnetic field caused by the inclined placement of the main body 151.

[0046] Specifically, the main body 151 is defined to have a first side 154 and a second side 155 in the extension direction thereof, the end of the first extension 152 is inclinedly arranged towards the first side 154 of the main body 151, and the end of the second extension 153 is inclinedly arranged towards the second side 155.

[0047] With the counterclockwise rotation of the rotor assembly 100 as an example, the radial inclination of the main body 151 compared to the rotor assembly 100, compared with the rectangular radiation type magnetic steel 150 structure, the application uses more magnetic steel 150 structure placed in the middle position of the magnetic steel 150 to improve the power density of the motor, because compared with the rectangular structure of the magnetic steel 150, the magnetic steel 150 provides more magnetic flux area in the entire rotor radiation direction compared with the rectangular structure of the magnetic steel 150, the effective magnetic flux of the motor increases, the torque of the motor increases in the same core length range of the motor, so that the use amount of the magnetic steel 150 under the same volume can be improved.

[0048] In addition, in order to reduce the distortion of the magnetic field, improve the operating performance of the motor, reduce the energy loss, and reduce the noise and vibration level, the first extension 152 close to the outer diameter is used to improve the air gap magnetic field harmonic content of the motor under load, reduce the tooth slot harmonic generated in the motor, thereby reducing the motor vibration and noise; and the radial inclination of the main body 151 and the vertical first extension 152 of the rotor assembly 100 can reduce the hysteresis loss and eddy current loss of the rotor core 120, improve the efficiency of the motor, and improve the dynamic response characteristics of the motor, so that the motor has better performance when starting, accelerating and decelerating.

[0049] The technical scheme of the application uses the first extension 152 close to the outer edge of the rotor and perpendicular to the outer edge of the rotor to improve the air gap magnetic field harmonic content of the motor under load, reduce the motor vibration and noise; compared with the rectangular radiation type magnetic steel 150 structure, the application uses the main body 151 inclined in the radial direction of the rotor assembly 100, which can place more magnetic steel 150, thereby improving the power density of the motor, because compared with the rectangular structure of the magnetic steel 150, the magnetic steel 150 provides more magnetic flux area in the entire rotor assembly 100 radiation direction compared with the rectangular magnetic steel 150, the effective magnetic flux of the motor increases, the torque of the motor increases in the same core length range of the motor, so that the use amount of the magnetic steel 150 under the same volume can be improved, thereby improving the output torque of the motor, and the power density of the motor is improved under the same speed comparison.

[0050] Further, in order to reduce the distortion of the magnetic field, improve the operating performance of the motor, reduce the energy loss, the size of the first extension 152 is half of the size of the main body 151, such as the longest side of the first extension 152 is half of the side of the main body 151.

[0051] In order to further improve the air gap magnetic field harmonic content when the motor is loaded, and reduce the tooth slot harmonic generated in the motor, the magnetic steel 150 further comprises a second extension 153 connected with the main body 151, and close to the inner edge of the rotor assembly 100 relative to the first extension 152, and perpendicular to the radial direction of the rotor assembly 100. The presence of the second extension 153 can increase the strength of the magnetic field, because the magnetic field lines will be more concentrated through the rotor assembly 100, thereby improving the magnetic performance.

[0052] With reference to Figure 4 Specifically, the cross section of the magnetic steel 150 is a plane perpendicular to the axial direction of the magnetic steel 150, i.e. parallel to the surface of the core punching sheet 121, the cross-sectional area A of the first extension 152, i.e. the area of the region surrounded by the first extension, is A, the cross-sectional area B of the main body 151 is B, and the cross-sectional area C of the second extension 153 is C, B > C ≥ A. The limitation of the cross-sectional area of the first extension 152 (A), the main body 151 (B) and the second extension 153 (C) can ensure that the magnetic field distribution is more uniform and stable when the magnetic steel 150 is placed in the rotor magnet slot 130, which is conducive to improving the efficiency of the motor. By controlling the size relationship of the areas of each section, the magnetic resistance of the magnetic circuit can be reduced, the energy consumption of the motor can be reduced, and the performance of the motor can be improved. The main body 151 (B) plays an important role in bearing the main magnetic field, and its area is greater than that of the second extension 153 (C), which helps to ensure the strength and stability of the magnetic field when the motor is working; and the area of the second extension 153 (C) is greater than that of the first extension 152 (A), which can effectively control the degree of concentration of the magnetic field, and is conducive to improving the uniformity and stability of the magnetic field.

[0053] Specifically, in order to ensure that the magnetic steel 150 can produce ideal magnetic field distribution and stable working performance during placement and movement in the rotor magnet slot 130, the lengths of the two sides of the first extension 152 along the rotation direction are H1 and H3 respectively, and the lengths of the two sides of the second extension 153 along the rotation direction are H2 and H4 respectively, wherein H3 > H1, H2 > H4, and H3 / H1 ≤ H2 / H4. By limiting the relationship between H1, H2, H3 and H4, the magnetic steel 150 can better adapt to the magnet slot 130 of the rotor after installation, thereby optimizing the distribution of the magnetic field and improving the efficiency and performance of the motor. Reasonable design of the magnetic steel 150 can reduce the magnetic resistance of the magnetic circuit, reduce the energy consumption of the motor, and improve the energy utilization rate. By controlling the size ratio of the magnetic steel 150, the noise and vibration of the motor during operation can be reduced, and the running stability and comfort of the motor can be improved.

[0054] With reference to Figure 4, specifically, in order to improve the power density of the motor, it is beneficial to improve the uniformity and stability of the magnetic field, the width of the first extension part 152 is W1, the width of the second extension part 153 is W2, the distance between the midpoint of the width of the first extension part 152 and the midpoint of the width of the second extension part 153 is H6, the length of the main body 151 is H5; The included angle between the side of length H2 of the second extension part 153 and the side of the main body 151 is J4, the included angle between the side of length H4 of the second extension part 153 and the side of the main body 151 is J2; The included angle between the side of length H1 of the first extension part 152 and the side of the main body 151 is J3, the included angle between the side of length H3 of the first extension part 152 and the side of the main body 151 is J1; And satisfy the relationship: abs(sin(J1))<(H1+H2+H5) / H6<H3 / H1<B / (A+C)<(H3+H2) / H1<(H6 / W1).

[0055] In order to ensure that the magnetic steel 150 is installed and operated in the rotor magnet slot 130 with good stability and performance. By limiting the relationship between the size and the included angle of each part of the magnetic steel 150, the performance of the magnetic steel 150 during operation can be ensured, the magnetic leakage and energy loss can be prevented, the magnetic field leakage and energy loss can be reduced, and the energy efficiency of the whole system can be improved. By satisfying the above relationship, the magnetic field distribution and the magnetic flux closed path can be better controlled, and unnecessary energy loss can be reduced. The size design of limiting each part of the magnetic steel 150 can reduce the electromagnetic interference generated by the motor or generator during operation, improve the electromagnetic compatibility of the equipment, improve the working efficiency of the magnetic steel 150, and reduce the noise and vibration of the motor during operation. Improve the smoothness and comfort of the motor operation.

[0056] The following table is the output torque data of the rectangular magnetic steel motor of the same size specification and the motor of the application at the same speed:

[0057]

[0058] Through the analysis of the above table, under the same speed comparison, the output torque of the motor using the rotor assembly 100 of the present scheme is greater than that of the traditional rectangular magnetic steel motor. By increasing the use amount of magnetic steel 150 under the same volume, the output torque of the motor is improved, and the power density of the motor is improved under the same speed comparison.

[0059] Referring to Figure 1 , in combination with Figure 5 to Figure 8Specifically, the rotor core 120 includes a plurality of core punching sheets 121, a plurality of magnet grooves 130 of one of the core punching sheets 121 are connected in pairs to form a magnet groove group 140 near the inner diameter of the rotor core 120, and the core punching sheet 121 is provided with a fixed spring 124 in the magnet groove 130 of the magnet groove group 140, a plurality of core punching sheets 121 are sequentially provided in a preset angle, and the fixed springs 124 of the core punching sheets 121 adjacent to each other are staggered; when one of the magnet steels 150 is inserted into one of the magnet grooves 130, the fixed spring 124 is deformed by being extruded, thereby providing support for the magnet steel 150.

[0060] Specifically, the magnet groove 130 includes an intermediate section 131 and an inner side section 132 connected in communication, and an outer side section 134, two inner side sections 132 of the magnet groove group 140 are connected in communication through a connecting groove 133, and both ends of the connecting groove 133 extend beyond the magnet groove 130, thereby forming a "π" shape.

[0061] The core punching sheet 121 has an inner ring portion 126 and a plurality of sector portions 127 located on the outer peripheral side of the inner ring portion 126, two sector portions 127 spaced apart from each other are connected to the inner ring portion 126, the connecting groove 133 is located between the two sector portions 127 connected to the inner ring portion 126, the fixed spring 124 is provided on the inner ring portion 126, the fixed spring 124 is located in the connecting groove 133, and the fixed spring 124 extends in the radial direction of the outer periphery of the inner ring portion 126.

[0062] Since the magnet steel 150 and the magnet groove 130 are gap-fitted, in order to ensure the performance of the motor, the magnet steel 150 needs to be fixed in the magnet groove 130. The mainstream fixing method is: overall injection / molding of the rotor; applying adhesive between the magnet steel 150 and the magnet groove 130; adding end plates 110 to both ends of the rotor in the axial direction; adding expansion material in the magnet groove 130; in the above methods, the rotor punching sheet and the magnet steel 150 need to be fixed using multiple materials such as glue, plastic, end plates 110, etc., which requires additional processes during production, resulting in low production efficiency and high production cost. At the same time, in the long-term environment of refrigerant and lubricant, glue, plastic, etc. are prone to compatibility problems, affecting product performance, and even leading to the failure of the fixation of the permanent magnet steel 150 and the rotor core 120, resulting in failure.

[0063] In the present scheme, the fixed spring 124 at the inner diameter of the rotor fixes the inserted magnet steel 150, which can not only ensure the gap fitting of the magnet steel 150 and the magnet groove 130, but also provide sufficient fixing strength for the magnet steel 150, and can realize simple assembly.

[0064] In one embodiment, the fixed spring 124 is a single spring structure.

[0065] In one embodiment, the fixed spring 124 is a double spring structure, which is a double tongue type (snake tongue type).

[0066] The magnetic slot group 140 is in the shape of a "π" character, and the inner diameter of the rotor lamination is provided with a fixed spring 124, which is located in one of the magnet slots 130 of the magnetic slot group 140. In the rotation direction, the fixed spring 124 is arranged in the other magnetic slot group 140 in sequence. When assembling, a plurality of said core laminations 121 are sequentially pre-set angle stacked, and the fixed springs 124 of the upper and lower adjacent said core laminations 121 are offset from each other; so that when the fixed spring 124 is extruded and deformed by the magnetic steel 150, it can be placed in the magnet slot 130, avoiding interference between the fixed springs 124 of the upper and lower adjacent core laminations 121, and affecting the assembly quality of the rotor core 120.

[0067] Referring to Figure 5 and Figure 6 , the magnetic slot group 140 actually corresponds to an inner open magnetic bridge. The inner open magnetic bridge refers to the existence of a certain gap or opening in the middle of the magnetic circuit, so that the magnetic field can flow in this gap or opening.

[0068] Compared with the independent arrangement of the magnet slot 130, the arrangement of the magnetic slot group 140 in the present scheme can provide a more flexible magnetic field adjustment mode. By controlling the size or shape of the gap, the distribution and strength of the magnetic field can be effectively adjusted. The effective length of the magnetic circuit can be reduced, thereby reducing the magnetic resistance, improving the conduction efficiency of the magnetic circuit, and reducing energy loss. It is beneficial to heat dissipation, so that the heat in the magnetic circuit is more easily dissipated, which helps to improve the stability and reliability of the equipment. The structure design can be simplified, the number of parts can be reduced, the manufacturing cost can be reduced, and the production efficiency can be improved.

[0069] In addition, compared with the full-open inner magnetic bridge scheme, the design of the magnetic slot group 140 provides better connection and support between the magnet slots 130, which can reduce vibration and noise during rotor operation, improve the running stability and comfort of the motor. The design of the magnetic slot group 140 can effectively reduce the deformation and damage of the magnet slots 130, improve the reliability and service life of the rotor.

[0070] Specifically, the rotor core 120 is provided with a magnet slot 130, and a magnetic steel 150 is arranged inside the magnet slot 130; the rotor core 120 is provided with one or more pairs of protruding elastic sheets at part of the magnet slots 130, for clamping the movement of the magnetic steel 150. During the stacking of the core punching sheets 121, each layer of core punching sheets 121 is rotated by a certain angle, and end plates 110 are arranged at both ends of the axial direction of the rotor, for increasing the rotational inertia of the rotor. The magnet slot 130 and the magnetic steel 150 are gap-fitted, when the magnetic steel 150 is inserted into the magnet slot 130, the magnetic steel 150 is fixed with the rotor core 120 through the protruding fixing elastic sheet 124 inside the magnet slot 130. Through the design of the pair of grooves, the fixing elastic sheet 124 has sufficient bending space, in a larger range of gap fitting, it can not only generate sufficient elastic force to fix the magnetic steel 150 on the core, but also avoid plastic deformation and lose the elastic force. The punching sheet and the magnetic steel 150 structure described in the application reduce the cost of the magnetic steel 150, improve the demagnetization of the magnetic steel 150, and further reduce the comprehensive cost of the motor.

[0071] In order to avoid interference of the fixing elastic sheet 124, the fixing elastic sheet 124 is higher than the slot opening position of the magnet slot 130, and the height of the slot opening is 0.05mm-0.2mm, when the magnetic steel 150 is inserted, the fixing elastic sheet 124 is extruded and deformed, providing fixing support force; it is helpful to increase the pre-tightening force of the magnetic steel 150. Understandably, the range is too small, the deformation is limited, and the effect is not obvious; too large leads to high cost; therefore, in order to ensure the effective cooperation of the magnet slot 130 and the magnetic steel 150, the height of the fixing elastic sheet 124 above the slot opening of the magnet slot 130 can be 0.05mm, 0.08mm, 0.10mm, 0.18mm, etc.

[0072] In addition, in order to facilitate the insertion of the magnetic steel 150 into the magnet slot 130 of the rotor core 120, the end face edge of the magnetic steel 150 is chamfered, which can guide the deformation direction of the elastic sheet during the insertion of the magnetic steel 150, and reduce the difficulty of the insertion of the magnetic steel 150.

[0073] Further, the plurality of core punching sheets 121 are outer open magnetic bridges 122, and the plurality of core punching sheets 121 are provided with rivet buckles 125 on the inner and outer sides in the radial direction, and the plurality of core punching sheets 121 are clamped and fixed through the rivet buckles 125.

[0074] Specifically, the plurality of core punching sheets 121 constitute the outer open magnetic bridge 122 in the rotor core 120, and at least two fully closed outer magnetic bridges 123 of core punching sheets 121 are arranged in the middle of the axial direction.

[0075] Therefore, compared with the rotor core 120 formed by the core punching pieces 121 with the outer open magnetic bridge 122, arranging two, three or more core punching pieces 121 with the fully enclosed outer magnetic bridge 123 helps to improve the structural stability of the rotor core 120. The arrangement of the at least two core punching pieces 121 with the fully enclosed outer magnetic bridge 123 is not limited, for example, the two core punching pieces 121 with the fully enclosed outer magnetic bridge 123 can be arranged at intervals, or arranged together.

[0076] With reference to Figure 5 Specifically, the preset angle is 360° / p, and p is the number of rotor magnet slots 130. Taking the number of ten magnet slots 130 as an example, the angle of rotation of the adjacent core punching pieces 121 is 36° when stacked.

[0077] With reference to Figure 2 Further, two magnetic steels 150 are arranged in one magnet slot 130 of the rotor core 120, and the two magnetic steels 150 are inserted into the magnet slot 130 from two ends of the rotor core 120 respectively; the deformation directions of the fixed elastic pieces 124 located at the two magnetic steels 150 in the magnet slot 130 are opposite.

[0078] On the one hand, being divided into two parts can better utilize raw materials and avoid waste, and the production process is also easier to process and handle, which can reduce production costs. Dividing the magnetic steel 150 into two parts and inserting it into the magnet slot 130 can make the assembly more convenient and fast, reduce the complexity and difficulty in the assembly process, and improve the production efficiency. Higher flexibility: dividing the magnetic steel 150 into two parts can also increase the design flexibility, which can better adjust the magnetic field distribution and performance to meet different needs. If the magnetic steel 150 needs to be replaced or repaired, dividing it into two parts can make maintenance more convenient, and more accurate operation can be performed on individual components, reducing maintenance time and cost.

[0079] On the other hand, compared with inserting two magnetic steels 150 from the same direction, i.e. generating fixed elastic pieces 124 with the same deformation direction, by arranging two magnetic steels 150 with opposite insertion directions, the magnetic steel 150 is fixed more firmly, which can make the magnetic field in the magnet slot 130 more uniform, reduce the fluctuation and unevenness of the magnetic field, and improve the stability and performance of the motor. The deformation directions of the fixed elastic pieces 124 are opposite, which can reduce the vibration and noise caused by the change of the magnetic field, and improve the smoothness and comfort of the motor during operation.

[0080] Specifically, the preset included angle between the first extension and the second extension and the extension direction of the main body ranges from 5° to 60°, for example, 5°, 15°, 20°, 25°, etc.

[0081] Specifically, the magnet slot 130 and the magnetic steel 150 are gap-fitted, with a gap range of 0.05mm≤D≤0.15mm. Too large or too small a gap can cause an increase in instability of the magnetic steel 150 during operation, increasing vibration and noise, and reducing the operational stability and reliability of the motor. If the gap is less than 0.05mm, the friction between the magnetic steel 150 and the magnet slot 130 will increase; a suitable gap can reduce the friction between the magnetic steel 150 and the magnet slot 130, reducing energy loss. Therefore, in order to ensure effective fitting of the magnet slot 130 and the magnetic steel 150, it is necessary to strictly control the gap to be between 0.05mm and 0.15mm, such as 0.05mm, 0.06mm, 0.08mm, 0.10mm, 0.12mm, etc., in order to fully exploit the advantages brought by the design gap fitting.

[0082] Specifically, in order to ensure the accuracy of assembly, the tolerance of the magnet slot 130 is ±0.05mm, and the tolerance of the magnetic steel 150 is ±0.05mm.

[0083] Further, in order to improve the rotational inertia of the rotor, the rotor assembly 100 further comprises a mounting end plate 110 that fixes the rotor core 120, the thickness of the mounting end plate 110 being W3, and the thickness of the rotor lamination being T, satisfying the relationship: (3*T)≤W3≤(H6 / W1).

[0084] Increasing the thickness of the end plate 110 increases the rotational inertia of the rotor, making the rotor more stable when rotating at high speed, reducing vibration and noise caused by imbalance. The increase in rotational inertia can reduce the impact force on the rotor during start-up and shutdown, thereby reducing the impact on bearings and other mechanical components, prolonging the service life of the equipment. The increase in rotational inertia of the rotor can reduce the acceleration and deceleration of the rotor, reducing the inertial loss generated by the rotor during start-stop, thereby improving the electrical energy utilization efficiency of the equipment.

[0085] Specifically, the thickness of the end plate 110 is 5mm-10mm.

[0086] By limiting the thickness range of the end plate 110, the problem of structural instability or material waste caused by the end plate 110 being too thick or too thin is avoided, ensuring the rationality of the rotor structure. The thickness of the end plate 110 directly affects the moment of inertia of the rotor, and by limiting the thickness range of the end plate 110, the performance of the rotor can be effectively controlled. Adjusting the thickness of the end plate 110 within a certain range can make the performance of the rotor reach the best state, meeting the requirements of equipment operation. Under the premise of meeting the performance requirements, the material consumption is reduced as much as possible, which is conducive to reducing the cost. Moreover, by regulating the thickness range of the end plate 110, the safety of the rotor structure can be ensured. The end plate 110 being too thin may result in insufficient strength, while the end plate 110 being too thick may result in unnecessary material waste, and regulating a reasonable range helps to ensure the safe operation of the rotor.

[0087] The above description is only the preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made under the concept of the present application, using the content of the present application specification and drawings, or directly / indirectly applied in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A rotor assembly, characterized in that, The rotor assembly includes: The rotor core has multiple magnet slots along its circumference. Each magnet slot includes a central section and inner and outer sections located on either side of the central section. The outer and inner sections extend in the same direction as the radial direction of the rotor core. The central section extends at a predetermined angle to the radial direction of the rotor core. The magnet includes a main body and a first extension and a second extension respectively connected to both ends of the main body along its length. The extension directions of the first extension and the second extension are parallel and form the preset angle with the extension direction of the main body. The magnet is installed in the magnet slot, and the first extension, the main body, and the second extension are respectively located in the outer section, the middle section, and the inner section.

2. The rotor assembly as claimed in claim 1, characterized in that, In the cross-section of the magnet perpendicular to the axial direction, the cross-sectional area of ​​the first extension is A, the cross-sectional area of ​​the main body is B, and the cross-sectional area of ​​the second extension is C, where B > C ≥ A.

3. The rotor assembly as claimed in claim 2, characterized in that, The lengths of the two sides of the cross-section of the first extension are H1 and H3, respectively, and the lengths of the two sides of the cross-section of the second extension are H2 and H4, respectively, wherein H3 > H1, H2 > H4, and H3 / H1 ≤ H2 / H4.

4. The rotor assembly as claimed in claim 3, characterized in that, The width of the cross-section of the first extension is W1, the width of the cross-section of the second extension is W2, the distance between the midpoint of the width of the first extension and the midpoint of the width of the second extension is H6, and the side length of the cross-section of the main body is H5. The angle between the side of the second extension with a length of H2 and the side of the main body is J4, and the angle between the side of the second extension with a length of H4 and the side of the main body is J2. The angle between the side of the first extension with a length of H1 and the side of the main body is J3, and the angle between the side of the first extension with a length of H3 and the side of the main body is J1. The following relationship is satisfied: abs(sin(J1))<(H1+H2+H5) / H6<H3 / H1<B / (A+C)<(H6 / W1).

5. The rotor assembly as described in any one of claims 1 to 4, characterized in that, The magnet is made of ferrite material.

6. The rotor assembly as claimed in claim 1, characterized in that, The rotor core includes multiple core laminations stacked in phase. Multiple magnet slots of the core laminations are connected in pairs near the inner edge of the rotor core to form multiple magnetic slot groups. Two magnet slots in the magnetic slot group are connected by a connecting slot.

7. The rotor assembly as claimed in claim 6, characterized in that, The core lamination has an inner ring portion and a plurality of sector portions located on the outer periphery of the inner ring portion. Two spaced sector portions are connected to the inner ring portion. A connecting groove is located between two sector portions connected to the inner ring portion. A fixing spring is provided on the inner ring portion. The fixing spring is located in the connecting groove and extends radially along the outer periphery of the inner ring portion.

8. The rotor assembly as claimed in claim 7, characterized in that, The plurality of iron core laminations are open magnetic bridges, and the plurality of iron core laminations are provided with rivets on the inner and outer sides in the radial direction. The plurality of iron core laminations are fixed by the rivets. And / or, in the rotor core of the plurality of core laminations forming an open magnetic bridge, at least two fully enclosed external magnetic bridge core laminations are provided in the middle part of the axial direction.

9. The rotor assembly as claimed in claim 7, characterized in that, The bottom of the fixing spring is higher than the opening of the magnet slot, and the height of the spring above the opening is 0.05mm-0.2mm.

10. The rotor assembly as claimed in claim 7, characterized in that, Two magnets are provided in one of the magnet slots of the rotor core, and the two magnets are inserted into the magnet slot from both ends of the rotor core respectively; the fixed springs located at the two magnets in the magnet slot deform in opposite directions.

11. The rotor assembly as claimed in claim 1, characterized in that, The preset angle between the first extension and the second extension and the extension direction of the main body ranges from 5° to 60°.

12. The rotor assembly as claimed in claim 1, characterized in that, The magnet slot and the magnet are in clearance fit, with a clearance range of 0.05mm≤D≤0.15mm.

13. The rotor assembly as claimed in claim 1, characterized in that, The rotor assembly also includes a mounting end plate, which fixes the rotor core. The thickness of the mounting end plate is W3, and the thickness of the rotor lamination is T, satisfying the relationship: (3*T)≤W3≤(H6 / W1).

14. An electric motor, comprising: Stator assembly; and The rotor assembly as described in any one of claims 1 to 13.

15. A compressor comprising the motor as claimed in claim 14.

16. A refrigeration device comprising the compressor as claimed in claim 15.

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