Stable brake motor magnetic steel fixing structure

Abstract

The invention discloses a stable brake motor magnetic steel fixing structure, and relates to the technical field of motors. The structure comprises a shaft, an end plate assembly, magnetic steel and a sheath. The end plate assembly is fixed to the shaft in a transition fit mode and provided with a plurality of end plate grooves distributed in the circumferential direction. The magnetic steel is embedded in the end plate groove; and the sheath is sleeved outside the magnetic steel and the end plate assembly, and the end part of the sheath is fixedly connected with the riveting groove on the end plate assembly in a riveting manner. Accurate positioning of the magnetic steel is achieved through the integrated end plate assembly, a closed rigid structure is formed through riveting of the sheath, uniform distribution and high-reliability fixing of the magnetic steel are achieved on the premise that grooving of the rotating shaft is not needed, and the advantages of being low in machining cost and simple in process are achieved.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and more specifically, to a stable brake motor magnet fixing structure. Background Technology

[0002] Currently, there are two main types of structures for fixing rotor magnets in domestic brake motors: one is to directly machine slots for accommodating magnets onto the motor shaft; the other is to use a single-sided insulating end plate to axially limit the magnets.

[0003] While machining magnet slots on a shaft can achieve accurate positioning and fixation of the magnets, it has significant drawbacks. First, high-precision slot machining on a slender shaft requires extremely sophisticated equipment and involves a complex process, leading to a substantial increase in production costs. Second, slotting inevitably creates stress concentration points on the shaft surface, severely weakening its overall mechanical strength and fatigue resistance. Under high-speed operation or heavy loads, there is a potential risk of breakage from the root of the slot, directly impacting the motor's reliability and lifespan.

[0004] While the single-sided insulating end plate structure avoids the machining difficulties and strength reduction issues associated with slotting the shaft, the magnets are in an asymmetrical axial support state because the end plate is only placed at one end of the rotor for positioning. During high-speed motor rotation, centrifugal force can easily lead to uneven magnet distribution, disrupting the rotor's dynamic balance. This not only exacerbates motor vibration and noise but also causes distortion of the air gap magnetic field, generating additional torque pulsations and severely restricting the motor's control accuracy and operational stability. Furthermore, this structure is highly dependent on adhesives; under long-term thermal cycling and mechanical vibration, the adhesive interface is at risk of aging and failure, and the potential for magnet detachment remains unresolved.

[0005] In conclusion, there is an urgent need for an innovative magnetic steel fixing structure that can fundamentally overcome the above-mentioned defects and achieve a balance between cost, performance, and reliability. Summary of the Invention

[0006] The purpose of this invention is to provide a stable magnet fixing structure for a brake motor, so as to solve the problems of high processing cost, uneven distribution of magnets, easy detachment during high-speed operation, and complex assembly process of existing magnet fixing structures.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A stable brake motor magnet fixing structure includes a shaft, an end plate assembly, multiple magnets, and a sheath. The end plate assembly is fixed to the shaft via a transition fit and has multiple end plate grooves distributed circumferentially. The multiple magnets are arranged circumferentially along the shaft and are embedded in the corresponding end plate grooves. The sheath is sleeved over the magnets and the end plate assembly and is fixedly connected to the end plate assembly.

[0009] Furthermore, the end plate assembly is an integral structure, including a first end plate portion, a second end plate portion, and a plurality of connecting ribs; the first end plate portion and the second end plate portion are respectively fixed to both ends of the shaft; the plurality of connecting ribs are connected between the first end plate portion and the second end plate portion and are spaced apart along the circumferential direction; wherein, adjacent connecting ribs together with the first end plate portion and the second end plate portion define the end plate groove.

[0010] Furthermore, a limiting protrusion is provided on the inner circumference of the first end plate, and a limiting groove is provided on the shaft to cooperate with the limiting protrusion.

[0011] Furthermore, there are two limiting protrusions, symmetrically arranged on the first end plate; correspondingly, there are also two limiting grooves, each corresponding to one of the limiting protrusions.

[0012] Furthermore, the sheath is fixedly connected to the end plate assembly by riveting.

[0013] Furthermore, the first end plate is provided with a riveting groove.

[0014] Furthermore, the corresponding end of the sheath undergoes plastic deformation through a riveting process, and its material fills and locks into the riveting groove.

[0015] The beneficial effects of this invention compared to the prior art are:

[0016] 1. By adopting a combination of integrated end plate assembly and slotless optical shaft, the high-cost and high-difficulty machining of magnet slots on the shaft is completely avoided, which reduces manufacturing costs while ensuring the structural integrity and mechanical strength of the shaft.

[0017] 2. By utilizing the precisely constructed end plate slots on the integrated end plate assembly, symmetrical bidirectional positioning and precise constraint of the magnets are achieved, fundamentally solving the problem of uneven magnet distribution caused by the single-sided end plate structure. This effectively improves the air gap magnetic field, reduces torque pulsation, and thus enhances the electromagnetic performance and operational stability of the motor.

[0018] 3. A robust, enclosed, fully mechanical fixing structure is formed by the riveting interlocking of the sheath and the riveting grooves on the end plate assembly. This structure can effectively resist the huge centrifugal force and strong vibration generated by high-speed rotation, fundamentally eliminating the risk of magnet detachment. It does not rely on adhesives, avoiding the hidden dangers of glue aging and ensuring long-term operational reliability. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0021] Figure 2 This is a three-dimensional structural diagram of the endplate assembly of the present invention;

[0022] Figure 3 This is a schematic diagram of the assembly of the shaft, end plate assembly and magnet of the present invention.

[0023] In the figure: 1. Shaft; 11. Limiting groove; 2. End plate assembly; 21. First end plate part; 22. Second end plate part; 23. Connecting rib; 24. End plate groove; 25. Riveting groove; 26. Limiting protrusion; 3. Magnet; 4. Sheath. Detailed Implementation

[0024] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0025] Example 1

[0026] See Figures 1 to 3 This embodiment provides a stable brake motor magnet fixing structure. The structure includes a shaft 1, an end plate assembly 2, multiple magnets 3, and a sheath 4.

[0027] Shaft 1 is the basic component of the entire rotor, and its outer surface is a complete smooth cylindrical surface without any slots for fixing the magnets 3. This fundamentally solves the problems of high cost and weakened shaft strength caused by slotting. In addition, two symmetrically distributed limiting grooves 11 are machined in the mating area between shaft 1 and the first end plate 21.

[0028] End plate assembly 2 is a component integrally molded from high-strength insulating engineering plastic through precision injection molding, and its structure includes:

[0029] The first end plate portion 21 and the second end plate portion 22 serve as the two end support bases of the assembly. They are respectively fixedly fitted at predetermined positions at both ends of the shaft 1 using an transition fit, ensuring the concentricity of the assembly and the shaft 1. Specifically, two limiting protrusions 26 are integrally formed on the inner circumference of the first end plate portion 21, precisely engaging with the upper limit groove 11 of the shaft 1. The engagement of these limiting protrusions 26 with the limiting groove 11 constitutes a reliable mechanical interlock structure, effectively preventing relative rotation between the end plate assembly 2 and the shaft 1.

[0030] Connecting ribs 23: These connecting ribs 23 serve as structural connectors, axially connecting the first end plate portion 21 and the second end plate portion 22, and are evenly spaced circumferentially. These connecting ribs 23 axially connect the first end plate portion 21 and the second end plate portion 22, and circumferentially form the lateral boundaries of the end plate groove 24 for accommodating the magnet 3. This integrated design greatly enhances the structural rigidity, integrity, and circumferential positioning accuracy of the entire end plate assembly 2.

[0031] End plate groove 24: The end plate groove 24 is not obtained through subsequent machining, but is a structural cavity directly formed during injection molding. Specifically, two adjacent connecting ribs 23, together with the first end plate portion 21 and the second end plate portion 22, define an independent, window-like end plate groove 24. This design ensures that all grooves have extremely high circumferential division accuracy and consistency.

[0032] Riveting Groove 25: A riveting groove 25 is pre-formed on the outer end face of the first end plate portion 21. This groove can be a continuous annular groove or multiple independent recesses distributed circumferentially, and its function is to provide mechanical interlocking space for the riveting and fixing of the sheath. In this embodiment, the riveting groove is composed of four independent recesses evenly distributed circumferentially.

[0033] The magnet 3 is a high-performance tile-shaped permanent magnet. In this embodiment, the end plate assembly 2 is provided with ten end plate slots 24 and ten corresponding connecting ribs 23, and ten magnets 3 are assembled accordingly. During assembly, the two ends and sides of each magnet 3 are precisely embedded in the corresponding end plate slots 24 formed by the end plate assembly.

[0034] The sheath 4 is a cylindrical component made of non-magnetic stainless steel. Its inner diameter is adapted to the outer diameter of the end plate assembly 2 in which the magnet is embedded. The sheath 4 is fitted over the entire magnet 3 and end plate assembly 2 as the final constraint component.

[0035] During assembly in this embodiment, the limiting protrusion 26 of the end plate assembly 2 is first aligned with the limiting groove 11 on the shaft 1, and then the end plate assembly 2 is press-fitted to the predetermined position on the shaft 1. Subsequently, ten magnets 3 are sequentially embedded radially into the corresponding end plate grooves 24. Next, the sheath 4 is fitted onto one end of the shaft 1 to cover all the magnets 3. Finally, a special riveting device is used to partially rivet the sheath 4 in the riveting groove 25 area corresponding to the first end plate portion 21, so that the material at the end of the sheath 4 undergoes plastic deformation and is embedded in the riveting groove 25, thereby forming a firm mechanical interlock that prevents the sheath 4 from axially moving.

[0036] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A stable brake motor magnet fixing structure, characterized in that, include: Shaft (1), the shaft (1) is used to connect to the main shaft; End plate assembly (2), the end plate assembly (2) is fixed to the shaft (1) in a transition fit manner, and the end plate assembly (2) is provided with a plurality of end plate grooves (24) distributed along the circumferential direction. Multiple magnets (3) are arranged circumferentially along the shaft (1) and are embedded in the corresponding end plate grooves (24); Sheath (4) is fitted over the magnet (3) and the end plate assembly (2) and is fixedly connected to the end plate assembly (2).

2. The stable brake motor magnet fixing structure according to claim 1, characterized in that, The end plate assembly (2) is an integral structure, including: The first end plate (21) and the second end plate (22) are respectively fixed to both ends of the shaft (1); Multiple connecting ribs (23) are connected between the first end plate portion (21) and the second end plate portion (22) and are spaced apart in the circumferential direction; The adjacent connecting ribs (23), together with the first end plate portion (21) and the second end plate portion (22), define the end plate groove (24).

3. The stable brake motor magnet fixing structure according to claim 2, characterized in that: The first end plate (21) has a limiting protrusion (26) on its inner circumference, and the shaft (1) has a limiting groove (11) that cooperates with the limiting protrusion (26).

4. The stable brake motor magnet fixing structure according to claim 3, characterized in that: The limiting protrusion (26) is provided in two places and is symmetrically arranged on the first end plate (21); correspondingly, the limiting groove (11) is also provided in two places and corresponds one-to-one with the limiting protrusion (26).

5. The stable brake motor magnet fixing structure according to claim 2, characterized in that, The sheath (4) is fixedly connected to the end plate assembly (2) by riveting.

6. The stable brake motor magnet fixing structure according to claim 5, characterized in that: The first end plate (21) is provided with a riveting groove (25).

7. The stable brake motor magnet fixing structure according to claim 6, characterized in that: The corresponding end of the sheath (4) undergoes plastic deformation through a riveting process, and its material fills and locks into the riveting groove (25), thereby achieving a fixed connection between the sheath (4) and the first end plate (21).

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