Rotor assembly

Abstract

The utility model discloses a rotor assembly, rotor assembly includes rotor shaft, fixed frame, a plurality of magnetic steel and fixed ring. Fixed frame is sleeved in the outer periphery of rotor shaft. A plurality of magnetic steel are embedded in fixed frame, and along the circumferential direction radially arranged. The fixed ring is sleeved in the outer periphery side of fixed frame, and with fixed frame interference fit, to the hoop tight a plurality of magnetic steel. Wherein, fixed frame includes main frame body and two auxiliary frame bodies that are separately arranged on the both sides of main frame body in the axial direction, and the appearance of main frame body and auxiliary frame body adapts, and the material of main frame body is metal material, and the material of auxiliary frame body is non -metal material. Thus, not only can improve magnetic steel pre -tightening force, improve fixed frame overall support strength, satisfy high -speed condition demand. Moreover can reduce the eddy current influence, reduce energy loss, improve the efficiency of disc type motor.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a rotor assembly. Background Technology

[0002] Axial field motors, also known as disc motors, offer advantages such as small axial dimensions, high torque density, high power density, and high efficiency, making them widely used in electric vehicles, general industrial applications, and household appliances. In existing technologies, the rotor of an axial field motor typically includes a fixed frame, a retaining ring, and multiple magnets. Multiple slots are formed on the fixed frame, arranged radially along its circumference. Each slot houses one magnet. The retaining ring is fitted around the fixed frame to secure the magnets. During high-speed rotor rotation, insufficient constraint force from the fixed frame and retaining ring on the magnets can lead to rotor disintegration, thus failing to meet the demands of the ever-increasing speed of motors. Utility Model Content

[0003] The main purpose of this invention is to propose a rotor assembly that aims to solve the problem that existing motor rotors are prone to disintegration due to insufficient constraint force of the retaining ring on the magnets.

[0004] To achieve the above objectives, this utility model proposes a rotor assembly, comprising:

[0005] Rotor shaft;

[0006] A fixing frame is fitted around the outer circumference of the rotor shaft;

[0007] Multiple magnets are embedded in the fixing frame and arranged radially along the circumference; and,

[0008] A retaining ring is sleeved on the outer periphery of the fixing frame and is interference-fitted with the fixing frame to clamp the plurality of magnets;

[0009] The fixing frame includes a main frame and two auxiliary frames disposed on both sides of the main frame in the axial direction. The main frame and the auxiliary frames are adapted to each other in shape. The main frame is made of metal and the auxiliary frames are made of non-metallic materials.

[0010] Optionally, the main frame and the two auxiliary frames are integrally formed.

[0011] Optionally, the main frame and the two auxiliary frames are arranged separately;

[0012] The rotor assembly also includes two pressure plates and a connecting structure. The two pressure plates are respectively located on opposite sides of the two auxiliary frames. The two pressure plates are axially aligned and avoid the multiple magnets. The two pressure plates are connected by the connecting structure to axially fasten the main frame and the two auxiliary frames.

[0013] Optionally, the two pressure plates are sleeved on the outer periphery of the rotor shaft, one of the pressure plates and the fixing frame are respectively provided with through holes, and the other pressure plate is respectively provided with threaded holes;

[0014] The connection structure includes a locking bolt, the threaded section of which passes through the through hole and is threadedly connected to the threaded hole.

[0015] Optionally, the pressure plate with the threaded hole is integrally formed with the rotor shaft.

[0016] Optionally, a plurality of slots are formed on the fixing frame, the plurality of slots are arranged radially along the circumference, the slots are open on the radial side away from the rotor shaft, and each magnet is housed in one of the slots;

[0017] The magnet has two opposing end faces in the axial direction, and two first inclined surfaces are formed at the connection between at least one side of the magnet in the circumferential direction and the two end faces, respectively.

[0018] The fixing frame has two second inclined surfaces at the connection between its two axial surfaces and the groove wall of the groove body, and the second inclined surfaces fit into the first inclined surfaces on the corresponding sides.

[0019] Optionally, the magnet has two opposing sides in the circumferential direction, and two first inclined surfaces are formed at the connection between each side and the two end faces;

[0020] The groove has two opposing side walls in the circumferential direction, and each side wall of the groove and the fixing frame are provided with two second inclined surfaces in the axial direction.

[0021] Optionally, the second inclined surface is provided at the connection between the surface of the auxiliary frame away from the main frame and the groove wall of the groove.

[0022] Optionally, the angle between the first inclined surface and the side surface is set to 13° to 18°.

[0023] Optionally, the main frame includes a main disk and a plurality of main spokes. The main disk is sleeved on the rotor shaft, and the plurality of main spokes protrude from the outer periphery of the main disk and are arranged radially along the circumference.

[0024] Correspondingly, the auxiliary frame includes an auxiliary disc and a plurality of auxiliary spokes. The auxiliary disc and the main disc are stacked to form the disc body of the fixed frame, and the auxiliary spokes correspond to the main spokes and are stacked to form the spokes of the fixed frame.

[0025] On the fixing frame, two adjacent spokes are used for embedding the magnet.

[0026] The technical solution provided by this utility model has at least the following advantages:

[0027] The rotor assembly provided by this utility model includes a rotor shaft, a fixed frame, multiple magnets, and a fixing ring. The fixed frame is sleeved on the outer periphery of the rotor shaft, and the multiple magnets are embedded in the fixed frame and arranged radially along the circumference. The fixed frame includes a main frame body and two auxiliary frame bodies respectively disposed on both sides of the main frame body in the axial direction, and the main frame body and the auxiliary frame bodies are adapted in shape. A fixing ring is provided, which is sleeved on the outer periphery of the fixed frame and is interference-fitted with the fixed frame to clamp the multiple magnets. At the same time, the main frame body is made of metal. This can increase the preload of the magnets, improve the overall support strength of the fixed frame, and meet the requirements of high-speed operating conditions. Furthermore, the auxiliary frame bodies are made of non-metallic materials, so that the metal main frame body can be far away from the air gap surface, reducing the influence of eddy currents, reducing energy loss, and improving the efficiency of the disc motor. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0029] Figure 1 A schematic diagram of the structure of an embodiment of a rotor assembly provided by this utility model;

[0030] Figure 2 for Figure 1 An exploded view of the rotor assembly;

[0031] Figure 3 for Figure 1 A schematic diagram of the rotor assembly with respect to the mounting frame;

[0032] Figure 4 for Figure 3 An exploded view of the structure of the fixing frame;

[0033] Figure 5 for Figure 4 A magnified schematic diagram of part A;

[0034] Figure 6 for Figure 1 A schematic diagram of the rotor assembly with respect to the magnets;

[0035] Figure 7 for Figure 6 Another structural schematic diagram of the magnet.

[0036] Explanation of icon numbers:

[0037] 100 Rotor assembly; 1 Rotor shaft; 2 Fixing frame; 21 Main frame body; 211 Main disc; 212 Main spoke; 22 Auxiliary frame body; 221 Auxiliary disc; 222 Auxiliary spoke; 23 Groove; 24 Second inclined surface; 3 Magnet; 31 First inclined surface; 4 Fixing ring; 5 Pressure plate; 6 Connecting structure; 61 Locking bolt.

[0038] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0039] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0040] It should be noted that if the embodiments of this utility model involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0041] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0042] An axial field motor, also known as a disc motor, typically consists of a rotor comprising a fixed frame, a retaining ring, and multiple magnets. Multiple slots are formed on the fixed frame, arranged radially along its circumference. Each slot houses one magnet. The retaining ring is fitted around the fixed frame to secure the magnets to it.

[0043] To improve the constraint force on the magnets and thus meet the requirements of high-speed operation, this invention improves the rotor assembly 100 of the disc motor. The structure of the rotor assembly 100 is described in detail below with reference to the accompanying drawings.

[0044] Please see Figure 1 and Figure 2 The rotor assembly 100 includes a rotor shaft 1, a fixing frame 2, multiple magnets 3, and a fixing ring 4. The fixing frame 2 is sleeved on the outer periphery of the rotor shaft 1. The multiple magnets 3 are embedded in the fixing frame 2 and are arranged radially along the circumference.

[0045] In existing technologies, the mounting bracket is generally made of non-metallic insulating material, and a retaining ring is fitted around the outer periphery of the bracket to jointly constrain multiple magnets. However, under high-speed rotation conditions, the constraining force of the mounting bracket and retaining ring on the magnets is insufficient, which can cause the rotor assembly to disintegrate.

[0046] In this invention, the fixing frame 2 includes a main frame 21 and two auxiliary frame bodies 22 disposed on both sides of the main frame 21 in the axial direction. The main frame 21 and the auxiliary frame bodies 22 are adapted to each other in shape. That is, the fixing ring 4 is set as a multi-layer structure, and the material of the main frame 21 located in the middle is set as metal. At the same time, the fixing ring 4 is sleeved on the outer periphery of the fixing frame 2 and is interference-fitted with the fixing frame 2 to clamp multiple magnets 3. In this way, the preload of the magnets 3 can be increased, the overall support strength of the fixing frame 2 can be improved, and the requirements of high-speed working conditions can be met.

[0047] Understandably, while the metal main frame 21 can improve the supporting strength of the magnet 3, during motor operation, the metal main frame 21 is in a changing magnetic field, and the resulting eddy currents will cause the main frame 21 to heat up. On the one hand, this will cause energy loss and reduce the efficiency of the disc motor. On the other hand, it will cause the remanence of the magnet 3 to decrease or even demagnetize, affecting the normal operation and service life of the motor.

[0048] In this invention, two auxiliary frames 22 are respectively provided on both sides of the main frame 21 in the axial direction. The auxiliary frames 22 are made of non-metallic material. The arrangement of the auxiliary frames 22 keeps the main frame 21 away from the air gap between the rotor assembly 100 and the stator. With the main frame 21 away from the air gap, the magnetic flux passing through it is reduced, and the induced electromotive force generated within it is lowered, thereby significantly reducing the eddy current and ultimately reducing eddy current losses, thus improving the efficiency of the disc motor.

[0049] This utility model does not impose specific restrictions on the formation method of the fixing frame 2.

[0050] In one embodiment, the main frame 21 and the two auxiliary frames 22 are integrally formed. Preferably, the two auxiliary frames 22 can be integrally molded onto the main frame 21 by injection molding, thereby making the fixing frame 2 a single plastic-coated part.

[0051] In another embodiment, please refer to Figures 2 to 4 The main frame 21 and the two auxiliary frames 22 are set separately. That is to say, the fixing frame 2 is assembled from the main frame 21 and the two auxiliary frames 22.

[0052] To ensure the assembly stability of the fixing frame 2, in some cases, the auxiliary frame 22 is bonded and fixed to the main frame 21.

[0053] In other cases, the rotor assembly 100 also includes two pressure plates 5 and a connecting structure 6. The two pressure plates 5 are respectively located on opposite sides of the two auxiliary frames 22. The two pressure plates 5 are axially aligned and avoid multiple magnets 3. The two pressure plates 5 are connected by the connecting structure 6 to axially fasten the main frame 21 and the two auxiliary frames 22.

[0054] Specifically, two pressure plates 5 are fitted around the outer periphery of the rotor shaft 1. One pressure plate 5 and the fixing bracket 2 are respectively provided with through holes, and the other pressure plate 5 is respectively provided with threaded holes. The connecting structure 6 includes a locking bolt 61, the threaded section of which passes through the through hole and is threadedly connected to the threaded hole.

[0055] In this embodiment, please refer to Figure 2 In the axial direction, two auxiliary frames 22 and a main frame 21 are fitted onto the rotor shaft 1, with the main frame 21 sandwiched between the two auxiliary frames 22. Two pressure plates 5 are then fitted onto the rotor shaft 1, positioned on opposite sides of the two auxiliary frames 22. Finally, locking bolts 61 are used to secure the two pressure plates 5, the two auxiliary frames 22, and the main frame 21.

[0056] More specifically, the pressure plate 5 with threaded holes is integrally set with the rotor shaft 1. Compared to setting both pressure plates 5 separately from the rotor shaft 1, in this embodiment, the pressure plate 5 with threaded holes is integrally set with the rotor shaft 1. After the two pressure plates 5 are locked with locking bolts 61, the fixing frame 2 has better stability.

[0057] As described above, multiple magnets 3 are embedded in the fixing frame 2 and arranged radially along the circumference. In one embodiment, please refer to... Figures 4 to 7 Multiple slots 23 are formed on the fixed frame 2, and the slots 23 are arranged radially along the circumference. The slots 23 are open on the radial side away from the rotor shaft 1, and each magnet 3 is housed in one slot 23. At the same time, a fixing ring 4 is sleeved on the outer circumference of the fixed frame 2 and is interference-fitted with the fixed frame 2 to clamp the multiple magnets 3.

[0058] During the operation of the disc motor, the magnet 3 is subjected to axial magnetic pull. To further constrain the magnet 3 axially and prevent it from falling off, it is necessary to limit the magnet 3 axially. In one embodiment, please refer to... Figures 4 to 7 The magnet 3 has two opposing end faces in the axial direction, and two first inclined surfaces 31 are formed at the connection between at least one side of the magnet 3 and the two end faces in the circumferential direction. Two second inclined surfaces 24 are correspondingly provided at the connection between the two side surfaces of the fixing frame 2 in the axial direction and the groove wall of the groove body 23, and the second inclined surfaces 24 are in contact with the first inclined surfaces 31 on the corresponding side.

[0059] A first inclined surface 31 and a second inclined surface 24 are provided on the magnet 3 and the fixing frame 2 to fit together. When the magnet 3 tends to move axially due to the axial magnetic pull, the first inclined surface 31 and the second inclined surface 24, which are fitted together on the corresponding sides, will press against each other. The pressing force generated between them is converted into an axial component force opposite to the direction of movement, directly canceling out the movement force. At the same time, the physical edge of the second inclined surface 24 on the fixing frame 2 forms a barrier to prevent the magnet 3 from breaking through the constraint, thus reliably limiting the axial displacement of the magnet 3.

[0060] Specifically, the magnet 3 has two opposing sides in the circumferential direction, and two first inclined surfaces 31 are formed at the connection between each side and the two end faces. The groove 23 has two opposing side walls in the circumferential direction, and two second inclined surfaces 24 are correspondingly provided on the two axial side surfaces of each groove wall and the fixing frame 2.

[0061] The magnet 3 has a first inclined surface 31 on each of its two opposite sides (e.g., left and right sides) and a second inclined surface 24 on each side of the groove 23, so that the magnet 3 is constrained by the inclined surfaces in both circumferential directions. At this time, the magnet 3 no longer relies on a single contact surface (e.g., a single inclined surface) to bear the axial force, but instead contacts the fixing frame 2 through four inclined surfaces on both sides of the circumference (two on each side, corresponding to the two ends in the axial direction), dispersing the axial force (such as magnetic pull, vibration impact) to the contact points of the four inclined surfaces. The force on each inclined surface is smaller, avoiding excessive local stress that could lead to wear or deformation of the inclined surface.

[0062] Meanwhile, during the operation of the disc motor, the magnet 3 may experience eccentric stress due to uneven magnetic field or assembly errors (e.g., one side experiences greater stress than the other). The magnet 3 has two circumferentially opposite sides with first inclined surfaces 31, which contact and are subjected to stress simultaneously. If one side experiences a greater axial force, the inclined surface on the other side will generate a balancing reaction force through synchronous compression, preventing the magnet 3 from tilting to one side. This balanced stress not only prevents localized cracking of the magnet 3 due to excessive stress but also avoids excessive wear on one side of the slot wall of the fixing frame 2, extending the service life of the overall structure.

[0063] Continuing from the above, the fixing frame 2 is assembled from a main frame 21 and two auxiliary frame bodies 22. In one embodiment, the main frame 21 includes a main disk 211 and a plurality of main spokes 212. The main disk 211 is sleeved on the rotor shaft 1, and the plurality of main spokes 212 protrude from the outer periphery of the main disk 211 and are arranged radially along the circumference. An open first groove is formed between two adjacent main spokes 212 and the main disk 211.

[0064] The auxiliary frame 22 is externally compatible with the main frame 21. Specifically, the auxiliary frame 22 includes an auxiliary disk 221 and multiple auxiliary spokes 222. The auxiliary disk 221 is fitted onto the rotor shaft 1, and the multiple auxiliary spokes 222 protrude from the outer periphery of the auxiliary disk 221 and are arranged radially along the circumference. Adjacent auxiliary spokes 222 and the auxiliary disk 221 together form an open second groove. After the auxiliary frame 22 and the main frame 21 are assembled, the second groove and the first groove together form an open groove 23.

[0065] Since the two auxiliary frames 22 are respectively located on both sides of the main frame 21 in the axial direction, the two auxiliary frames 22 are set close to the outside of the fixed frame 2. The second inclined surface 24 is set at the connection between the surface of the auxiliary frame 22 away from the main frame 21 and the groove wall of the groove 23, which facilitates the processing of the second inclined surface 24.

[0066] This invention does not impose specific limitations on the included angle between the first inclined surface 31 and the side surface. When the included angle between the first inclined surface 31 and the side surface is too small, the axial component of the force generated by the inclined surface extrusion is very small, which may not be able to counteract the axial movement force, causing the magnet 3 to still move axially and lose its limiting function. However, at this time, the radial component of the force generated by the inclined surface extrusion is very large, which may cause deformation of the groove wall of the fixing frame 2, or damage to the side surface of the magnet 3 due to excessive extrusion.

[0067] When the angle between the first inclined surface 31 and the side is too large, although the axial component of the pressure generated by the inclined surface is large enough, the large angle results in a large cutting amount for the magnet 3, making it very easy for the magnet 3 to crack due to the large processing stress. At the same time, the angle of the second inclined surface 24 on the fixing frame 2 is also set to be large. Continuing from the above, the second inclined surface 24 is set on the auxiliary frame 22, which is made of non-metallic material. When processing the auxiliary frame 22, the large inclined surface angle will make the mold design of the auxiliary frame 22 complex, and the flatness and angle of the second inclined surface 24 after forming are prone to large errors, and the first inclined surface 31 and the second inclined surface 24 cannot fit tightly together.

[0068] In one embodiment, the angle θ between the first inclined surface 31 and the side surface is set to 13° to 18°. Preferably, the angle θ between the first inclined surface 31 and the side surface is set to 15°. Setting the angle θ between the first inclined surface 31 and the side surface to 13° to 18° can, on the one hand, convert most of the inclined surface extrusion force into an axial component force, which is sufficient to resist the axial magnetic pull common in disc motors, while preventing the radial component force from being too large and avoiding deformation of the fixing frame 2. On the other hand, for the magnet 3, the small angle of the inclined surface of 13° to 18° results in a small cutting amount, making it less likely for the magnet 3 to crack due to processing stress; for the auxiliary frame 22, the mold design of the small angle inclined surface is simpler, and the flatness and angle error of the inclined surface after molding are easier to control, ensuring a tight fit with the inclined surface of the magnet 3.

[0069] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the concept of the present utility model and using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present utility model.

Claims

1. A rotor assembly, characterized in that, include: Rotor shaft; A fixing frame is fitted around the outer circumference of the rotor shaft; Multiple magnets are embedded in the fixing frame and arranged radially along the circumference; as well as, A retaining ring is sleeved on the outer periphery of the fixing frame and is interference-fitted with the fixing frame to clamp the plurality of magnets; The fixing frame includes a main frame and two auxiliary frames disposed on both sides of the main frame in the axial direction. The main frame and the auxiliary frames are adapted to each other in shape. The main frame is made of metal and the auxiliary frames are made of non-metallic materials.

2. The rotor assembly according to claim 1, characterized in that, The main frame and the two auxiliary frames are integrated into one unit.

3. The rotor assembly according to claim 1, characterized in that, The main frame and the two auxiliary frames are arranged separately; The rotor assembly also includes two pressure plates and a connecting structure. The two pressure plates are respectively located on opposite sides of the two auxiliary frames. The two pressure plates are axially aligned and avoid the multiple magnets. The two pressure plates are connected by the connecting structure to axially fasten the main frame and the two auxiliary frames.

4. The rotor assembly according to claim 3, characterized in that, Two pressure plates are sleeved on the outer periphery of the rotor shaft, one of the pressure plates and the fixing frame are respectively provided with through holes, and the other pressure plate is respectively provided with threaded holes; The connection structure includes a locking bolt, the threaded section of which passes through the through hole and is threadedly connected to the threaded hole.

5. The rotor assembly according to claim 4, characterized in that, The pressure plate with the threaded hole is integrally formed with the rotor shaft.

6. The rotor assembly according to claim 1, characterized in that, Multiple slots are formed on the fixed frame, and the multiple slots are arranged radially along the circumference. The slots are open on the radial side away from the rotor shaft, and each magnet is housed in one of the slots. The magnet has two opposing end faces in the axial direction, and two first inclined surfaces are formed at the connection between at least one side of the magnet in the circumferential direction and the two end faces, respectively. The fixing frame has two second inclined surfaces at the connection between its two axial surfaces and the groove wall of the groove body, and the second inclined surfaces fit into the first inclined surfaces on the corresponding sides.

7. The rotor assembly according to claim 6, characterized in that, The magnet has two opposing sides in the circumferential direction, and two first inclined surfaces are formed at the connection between each side and the two end faces. The groove has two opposing side walls in the circumferential direction, and each side wall of the groove and the fixing frame are provided with two second inclined surfaces in the axial direction.

8. The rotor assembly according to claim 6 or 7, characterized in that, The second inclined surface is provided at the connection between the surface of the auxiliary frame away from the main frame and the groove wall of the groove.

9. The rotor assembly according to claim 6 or 7, characterized in that, The angle between the first inclined plane and the side plane is set to 13° to 18°.

10. The rotor assembly according to claim 1, characterized in that, The main frame includes a main disk and multiple main spokes. The main disk is sleeved on the rotor shaft, and the multiple main spokes protrude from the outer periphery of the main disk and are arranged radially along the circumference. Correspondingly, the auxiliary frame includes an auxiliary disc and a plurality of auxiliary spokes. The auxiliary disc and the main disc are stacked to form the disc body of the fixed frame, and the auxiliary spokes correspond to the main spokes and are stacked to form the spokes of the fixed frame. On the fixing frame, two adjacent spokes are used for embedding the magnet.

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