Reinforced built-in permanent magnet motor rotor structure and driving motor

Abstract

The utility model discloses a reinforced built-in permanent magnet motor rotor structure, which comprises a rotor core, a plurality of groups of first permanent magnets, second permanent magnets and reinforcing ribs, each group of the first permanent magnets and the second permanent magnets are mounted on the rotor core, a reinforcing rib is arranged between each group of the first permanent magnets and the second permanent magnets, and the polarities of the first permanent magnets and the second permanent magnets on the two sides of the reinforcing rib are the same. The method can solve the problems that the magnetic leakage becomes large, the utilization rate of the permanent magnets is reduced and the power density of the motor is not obviously improved due to a traditional method of increasing the thickness of the magnetic isolation bridge to improve the reliability of the rotor.

Description

Technical Field

[0001] This application belongs to the field of permanent magnet motor technology, and specifically relates to a reinforced built-in permanent magnet motor rotor structure and drive motor. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) are widely used in electric vehicles, aerospace, and other fields due to their high efficiency and high power density. PMSM rotor topologies are mainly divided into two types: surface-mounted and internal. Internal rotor topologies, due to the unequal inductances along the quadrature and direct axes, can generate reluctance torque, thus effectively increasing the motor's power density and torque density, and are therefore particularly widely used.

[0003] However, the design of built-in rotor topologies faces the dual challenges of strength and permanent magnet utilization. The rotor's strength design primarily depends on the size of the magnetic isolation bridge. While a larger bridge width reduces rotor stress, it also increases leakage flux, affecting permanent magnet utilization. Conversely, a smaller bridge reduces leakage flux but increases rotor stress and reduces safety. As permanent magnet motors evolve towards higher voltage and higher speeds, the increased rotor speed places higher demands on rotor reliability. Traditionally, increasing the thickness of the magnetic isolation bridge improves rotor reliability, but this exacerbates leakage flux, resulting in low magnet utilization and minimal improvement in motor power density.

[0004] In particular, finite element analysis revealed that the maximum stress in the rotor's magnetic isolation bridge occurs at the junction of two magnets on the same pole. A wider magnetic isolation bridge at this location tends to generate significant leakage flux on the same pole. To address this issue, a novel rotor structure is needed that can both ensure rotor strength and reduce leakage flux. Utility Model Content

[0005] The purpose of this application is to provide a reinforced built-in permanent magnet motor rotor structure and drive motor. This addresses the problems mentioned in the background art where the traditional method of increasing the thickness of the magnetic isolation bridge to improve rotor reliability leads to increased magnetic leakage, reduced utilization of permanent magnets, and insignificant improvement in motor power density.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] In one aspect, a reinforced built-in permanent magnet motor rotor structure is provided, including a rotor core, multiple sets of first permanent magnets, second permanent magnets, and reinforcing ribs;

[0008] Each set of the first permanent magnet and the second permanent magnet is mounted on the rotor core. A reinforcing rib is provided between each set of the first permanent magnet and the second permanent magnet, and the polarity of the first permanent magnet and the second permanent magnet on both sides of the reinforcing rib is the same.

[0009] In one possible implementation, the rotor laminations on the rotor core are provided with slots, and each set of the first permanent magnet and the second permanent magnet is embedded in the slot.

[0010] In one possible implementation, the arrangement of the first and second permanent magnets in each group can be any one of the following: a straight line, a V-shape, a U-shape, or a hybrid arrangement.

[0011] In one possible implementation, at least one third permanent magnet is further included, the third permanent magnet being disposed at:

[0012] Between the first permanent magnet and the second permanent magnet; or,

[0013] The side of the first permanent magnet away from the second permanent magnet; or,

[0014] The second permanent magnet is located on the side away from the first permanent magnet.

[0015] In one possible implementation, the reinforcing rib is shaped to be larger at both ends and smaller in the middle.

[0016] In one possible implementation, the reinforcing rib is made of a non-magnetic material, namely high-strength stainless steel.

[0017] In one possible implementation, the two ends of the reinforcing rib are engaged with the rotor core, and when the rotor rotates, the two ends of the reinforcing rib tighten the rotor core.

[0018] In one possible implementation, the engagement point between the reinforcing rib and the rotor core is provided with an anti-slip structure, which is an engagement protrusion or groove.

[0019] In one possible implementation, an adhesive layer is provided on the groove walls of the first permanent magnet and the second permanent magnet groove.

[0020] In one possible implementation, the rotor core is made of multiple stacked silicon steel sheets, with an insulating layer between adjacent silicon steel sheets.

[0021] Secondly, a drive motor is provided, including the enhanced built-in permanent magnet motor rotor structure of the first aspect.

[0022] Compared with the prior art, this application has the following beneficial effects:

[0023] This application provides a reinforced built-in permanent magnet motor rotor structure. By setting reinforcing ribs between each set of first and second permanent magnets, with both ribs having the same polarity, the structural strength of the rotor in this area can be effectively enhanced. Simultaneously, since the first and second permanent magnets on both sides of the reinforcing rib have the same polarity, it is beneficial to improve the utilization rate of the first and second permanent magnets, thereby improving the overall performance of the motor. This solves the problem that traditional methods of increasing the thickness of the magnetic isolation bridge to improve rotor reliability lead to increased magnetic leakage, reduced permanent magnet utilization, and insignificant improvement in motor power density.

[0024] In one possible implementation, this embedded mounting method allows the first and second permanent magnets to be tightly integrated with the rotor core, improving the overall integrity and stability of the rotor structure. Furthermore, compared to other mounting methods, it achieves a more secure installation of the first and second permanent magnets. Attached Figure Description

[0025] Figure 1 A schematic diagram of the overall structure of a reinforced built-in permanent magnet motor rotor provided in this application;

[0026] Figure 2 A schematic diagram of topological stress calculation for a reinforced built-in permanent magnet motor rotor structure provided in this application;

[0027] Figure 3 A schematic diagram of topological stress calculation for a reinforced built-in permanent magnet motor rotor structure provided in this application;

[0028] Figure 4 for Figure 2 Schematic diagram of the topological magnetic field lines of the rotor;

[0029] Figure 5 for Figure 3 Schematic diagram of the topological magnetic field lines of the rotor;

[0030] Figure 6 for Figure 2 Schematic diagram of the topological magnetic dense cloud of the central rotor;

[0031] Figure 7 for Figure 3 Schematic diagram of the topological magnetic dense cloud of the central rotor;

[0032] Figure 8 for Figure 2 The intention of indicating the back EMF of the rotor line;

[0033] Figure 9 for Figure 3 A schematic diagram of the back electromotive force of the rotor line;

[0034] Figure 10 for Figure 2A schematic diagram of the output torque of the intermediate rotor;

[0035] Figure 11 for Figure 3 A schematic diagram of the output torque of the rotor.

[0036] The attached diagram is labeled as follows: 1. Rotor core; 2. First permanent magnet; 3. Second permanent magnet; 4. Reinforcing rib. Detailed Implementation

[0037] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0038] like Figure 1 As shown, this application discloses a reinforced built-in permanent magnet motor rotor structure, which may include a rotor core 1, multiple sets of first permanent magnets 2, second permanent magnets 3, and reinforcing ribs 4.

[0039] The rotor core 1 can be made of silicon steel sheets.

[0040] Each set of first permanent magnets 2 and second permanent magnets 3 is mounted on the rotor core 1. A reinforcing rib 4 is provided between each set of first permanent magnets 2 and second permanent magnets 3, and the polarities of the first permanent magnets 2 and second permanent magnets 3 on both sides of the reinforcing rib 4 are the same.

[0041] In this embodiment of the application, the first permanent magnet 2 and the second permanent magnet 3 are provided in eight groups, and each group of the first permanent magnet 2 and the second permanent magnet 3 are uniformly arranged in a V-shape and installed on the periphery of the rotor core 1.

[0042] A reinforcing rib 4 is provided between the first permanent magnet 2 and the second permanent magnet 3 arranged in a V-shape in each group. The polarities of the first permanent magnet 2 and the second permanent magnet 3 on both sides of the reinforcing rib 4 are the same.

[0043] Specifically, the materials of the first permanent magnet 2 and the second permanent magnet 3 can both be one of AlNiCo, ferrite, Samarium Cobalt or Neodymium Iron Boron.

[0044] The reinforcing rib 4 is made of a non-magnetic material, such as high-strength stainless steel.

[0045] The reinforcing rib 4 is engaged with the rotor core 1 at both ends. When the rotor core 1 rotates, the two ends of the reinforcing rib 4 tighten the rotor core 1. This engaging connection method makes the reinforcing rib 4 and the rotor core 1 form a tight whole. When the rotor core 1 rotates at high speed, the reinforcing rib 4 can fully play its role in enhancing the structural strength, effectively preventing the rotor core 1 from structural deformation or damage caused by centrifugal force and other factors, and greatly improving the overall operational reliability and stability.

[0046] In this embodiment, by providing a reinforcing rib 4 between each group of first permanent magnets 2 and second permanent magnets 3, with both having the same polarity, the structural strength of the rotor at this location can be effectively enhanced. Simultaneously, since the first permanent magnets 2 and second permanent magnets 3 on both sides of the reinforcing rib 4 have the same polarity, same-pole magnetic leakage between the first permanent magnets 2 and second permanent magnets 3 is effectively avoided, improving the overall performance of the motor. This solves the problem that traditional methods of increasing the thickness of the magnetic isolation bridge to improve rotor reliability result in increased magnetic leakage, reduced permanent magnet utilization, and insignificant improvement in motor power density.

[0047] In one possible embodiment, the rotor laminations on the rotor core 1 are provided with slots, and each set of first permanent magnets 2 and second permanent magnets 3 are embedded in the slots.

[0048] The rotor laminations on the rotor core 1 can be made of silicon steel sheets with a thickness of 0.35mm, and the laminations have grooves that match the shape of the permanent magnet.

[0049] The first permanent magnet 2 and the second permanent magnet 3 can be bonded neodymium iron boron permanent magnets, which are firmly embedded in the groove with a special adhesive to ensure that the permanent magnets will not be displaced when the motor rotates at high speed. The groove is shown in the embodiment of this application.

[0050] In this embodiment, the embedded installation method ensures that the first permanent magnet 2 and the second permanent magnet 3 are tightly integrated with the rotor core 1, improving the integrity and stability of the rotor structure. Furthermore, compared to other installation methods, this method achieves a secure installation of the first permanent magnet 2 and the second permanent magnet 3, ensuring the stability of the magnetic field generated by the first permanent magnet 2 and the second permanent magnet 3 during overall operation, which is beneficial for improving electromagnetic performance and operational reliability.

[0051] In one possible embodiment, the arrangement of each group of first permanent magnets 2 and second permanent magnets 3 can be set to any one of the following: a straight line, a V-shape, a U-shape, or a hybrid arrangement. The number of layers of the first permanent magnets 2 and second permanent magnets 3 can be one, two, or multiple layers. Through this design, the magnetic field generated by the permanent magnets is fully utilized within a limited space, thereby improving the output torque.

[0052] In the embodiments of this application, the various arrangement methods and multi-layer settings increase the design flexibility and can be optimized according to different application scenarios and performance requirements. For example, for applications requiring high starting torque, the V-shaped arrangement can enhance reluctance torque; the multi-layer setting can increase the magnetic flux of the motor without significantly increasing the volume, thereby improving the overall power density and torque density.

[0053] In one possible embodiment, at least one third permanent magnet may be included, which may be disposed between the first permanent magnet 2 and the second permanent magnet 3. Alternatively,

[0054] The third permanent magnet 2 is positioned on the side of the first permanent magnet 2 that is away from the second permanent magnet 3. Alternatively,

[0055] The third permanent magnet is located on the side of the second permanent magnet 3 away from the first permanent magnet 2.

[0056] The reinforcing ribs are respectively arranged between the adjacent first permanent magnet 2, second permanent magnet 3 and third permanent magnet.

[0057] The third permanent magnet has the same polarity as the first permanent magnet 2 and the second permanent magnet 3, and the third permanent magnet is not shown in this embodiment.

[0058] In the embodiments of this application, by setting at least one third permanent magnet, there are a variety of different combinations that can achieve rotor safety, reduce rotor leakage flux, and thus improve motor power density.

[0059] In one possible embodiment, the shape of the reinforcing rib 4 can be set to be large at both ends and small in the middle.

[0060] The reinforcing rib 4 is designed as an I-shaped structure, larger at both ends and smaller in the middle. The larger ends have a larger contact area with the rotor core 1 and employ a special surface treatment process to increase surface roughness, thereby improving friction and connection stability with the rotor core 1. The smaller middle part, while ensuring strength, minimizes its impact on the internal magnetic field.

[0061] In this embodiment, the shape design, which is large at both ends and small in the middle, increases the connection area between the reinforcing rib 4 and the rotor core 1, thereby improving the connection strength when the rotor rotates at high speed and generates a large centrifugal force.

[0062] In one possible embodiment, the engagement point between the reinforcing rib 4 and the rotor core 1 is provided with an anti-slip structure, which can be configured as an engagement protrusion or a groove.

[0063] At the engagement point between the reinforcing rib 4 and the rotor core 1, multiple triangular engagement protrusions are provided at the end of the reinforcing rib 4, and corresponding triangular grooves are machined into the inner wall of the groove in the rotor core 1. During installation, the reinforcing rib 4 is cooled and quickly installed into the groove in the rotor core 1 using thermal expansion and contraction. Once the reinforcing rib 4 returns to room temperature, it engages tightly with the rotor core 1, with the engagement protrusions and grooves interlocking.

[0064] In this embodiment, the anti-slip structure such as the locking protrusion or groove further increases the friction and interlocking force between the reinforcing rib 4 and the rotor core 1, effectively preventing relative displacement between the reinforcing rib 4 and the rotor core 1 during operation under complex working conditions, thereby ensuring that the reinforcing rib 4 can always stably play the role of enhancing the structural strength of the rotor core 1.

[0065] In one possible embodiment, an adhesive layer is provided on the groove wall of the first permanent magnet 2 and the second permanent magnet 3.

[0066] Specifically, an adhesive layer is provided on the groove wall of the first permanent magnet 2 and the second permanent magnet 3 to fix the first permanent magnet 2 and the second permanent magnet 3 on the rotor core 1, thereby improving the installation stability.

[0067] In one possible embodiment, the rotor core 1 is made of multiple silicon steel sheets stacked together, with an insulating layer between adjacent silicon steel sheets.

[0068] In one possible embodiment, a drive motor is provided, including any of the enhanced built-in permanent magnet motor rotor structures provided above.

[0069] The characteristics of the rotor topology proposed in this application are further illustrated below through finite element analysis.

[0070] like Figure 2 and Figure 3 As shown, a comparative calculation is performed between the existing technology and the two rotor topologies of this application:

[0071] In the prior art, the stress at the connection of the IPM rotor topological magnet is 236.04 MPa, the safety factor is 1.9, and optionally, the yield strength of the silicon steel sheet is 450 MPa.

[0072] The stress at the rotor topology magnet connection in this application is 230 MPa, and the safety factor is 4.35. Optionally, the reinforcing rib material is precipitation-hardening stainless steel with a yield strength of 1000 MPa.

[0073] like Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, the rotor topology magnetic field lines and rotor topology magnetic cloud of the prior art and this application were compared, and it was found that the rotor topology proposed in this application can effectively avoid the generation of same-pole leakage magnetic field.

[0074] like Figure 8 , Figure 9 , Figure 10 and Figure 11As shown, by comparing the rotor topology back EMF and rotor topology torque of the prior art and this application, it is found that the rotor topology back EMF proposed in this application is higher than that of the rotor topology. Since the rotor topology of this patent has less leakage flux, under the same current, the rotor output torque of this application (average value of 544.6 Nm) is greater than the average value of the rotor output torque of the prior art (average value of 525.2 Nm).

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions for some or all of the technical features, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A reinforced built-in permanent magnet motor rotor structure, characterized in that, It includes a rotor core (1), multiple sets of first permanent magnets (2), second permanent magnets (3), and reinforcing ribs (4); Each set of the first permanent magnet (2) and the second permanent magnet (3) is mounted on the rotor core (1). A reinforcing rib (4) is provided between each set of the first permanent magnet (2) and the second permanent magnet (3), and the polarity of the first permanent magnet (2) and the second permanent magnet (3) on both sides of the reinforcing rib (4) is the same.

2. The reinforced built-in permanent magnet motor rotor structure according to claim 1, characterized in that, The rotor laminations on the rotor core (1) are provided with slots, and each set of the first permanent magnet (2) and the second permanent magnet (3) are embedded in the slots.

3. The reinforced built-in permanent magnet motor rotor structure according to claim 1, characterized in that, The arrangement of the first permanent magnet (2) and the second permanent magnet (3) in each group can be any one of the following: line, V, U, or a combination thereof.

4. The reinforced built-in permanent magnet motor rotor structure according to claim 1, characterized in that, It also includes at least one third permanent magnet, said third permanent magnet being disposed at: Between the first permanent magnet (2) and the second permanent magnet (3); or, The first permanent magnet (2) is located on the side away from the second permanent magnet (3); or, The second permanent magnet (3) is located on the side away from the first permanent magnet (2); The reinforcing ribs are respectively arranged between the adjacent first permanent magnet (2), second permanent magnet (3) and third permanent magnet.

5. The reinforced built-in permanent magnet motor rotor structure according to claim 1, characterized in that, The reinforcing rib (4) is shaped with large ends and small middle.

6. The reinforced built-in permanent magnet motor rotor structure according to claim 1, characterized in that, The reinforcing rib (4) is made of a non-magnetic material, which is high-strength stainless steel.

7. The reinforced built-in permanent magnet motor rotor structure according to claim 1, characterized in that, The engagement point between the reinforcing rib (4) and the rotor core (1) is provided with an anti-slip structure, which is an engagement protrusion or a groove.

8. The reinforced built-in permanent magnet motor rotor structure according to claim 1, characterized in that, A coating layer is provided on the groove wall of the first permanent magnet (2) and the second permanent magnet (3).

9. The reinforced built-in permanent magnet motor rotor structure according to claim 1, characterized in that, The rotor core (1) is made of multiple silicon steel sheets stacked together, with an insulating layer between adjacent silicon steel sheets.

10. A drive motor, characterized in that, Includes the reinforced built-in permanent magnet motor rotor structure as described in any one of claims 1-9.

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