Low-vibration permanent magnet synchronous motor

Abstract

The invention discloses a low-vibration permanent magnet synchronous motor, and relates to the technical field of permanent magnet synchronous motors. The low-vibration permanent magnet synchronous motor comprises a motor stator which is fixed on the inner wall of a motor shell, and the motor stator comprises a stator iron core; the stator core comprises a stator yoke part and stator tooth parts, the outer wall of the stator yoke part is attached and fixed to the inner wall of the motor shell, and the stator tooth parts are distributed along the circumference of the inner wall of the stator yoke part; a plurality of damping holes are formed in the end face of the stator yoke part in a penetrating mode along the circumference of the stator yoke part, and the hole distances between every two adjacent damping holes are the same. According to the design of the invention, the vibration mode of the stator core is changed, and the change of the vibration mode can be divided into the change of the inherent frequency and the change of the modal vibration mode, so that the permanent magnet synchronous motor fundamentally reduces the vibration problem of the motor, prevents the vibration of the stator core from being transmitted to the motor shell, and achieves the purpose of reducing the vibration loss of the motor under the condition of not narrowing the application range of the motor. And equipment noise and structural fatigue are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of permanent magnet synchronous motor, in particular to a low-vibration permanent magnet synchronous motor. BACKGROUND

[0002] Permanent magnet synchronous motor has the advantages of simple structure, small size, high efficiency, high power factor, etc. Permanent magnet synchronous motor has achieved performance in medium and low voltage motors in industries such as metallurgy (iron mills and sintering plants, etc.), ceramics (ball mills), rubber (internal mixers), petroleum (oil pumps), and textiles (twist machines, spinning machines), and gradually accumulates design and operation experience.

[0003] At present, the common problem of permanent magnet synchronous motor is the noise and structural fatigue of the equipment caused by motor vibration (structural fatigue refers to the process that micro-damage accumulates in the material due to stress concentration under the repeated action of alternating load, and eventually forms a dominant crack and expands to fracture). 1. By adjusting the pole arc coefficient, permanent magnet thickness and stator slotting parameters, the low-order space harmonics (such as 3, 5 times) in the air gap magnetic flux density can be targeted to weaken, thereby reducing the radial electromagnetic force leading to vibration noise; 2. For interior permanent magnet synchronous motor (IPMSM), specific auxiliary slots are opened on the surface of the rotor, which can change the air gap permeance and reduce the specific harmonic content (such as 5, 7, 11, 13 times) of the air gap magnetic flux density, thereby significantly reducing the electromagnetic force density and noise of the key order (such as 0 order 48 times); 3. By wrapping a shock-absorbing pad outside the motor shell, the potential energy of vibration is absorbed to reduce noise; However, the above processing methods limit the parameters of the permanent magnet synchronous motor, narrow its application range, and the shock-absorbing pad cannot solve the problem of structural fatigue, and will affect the heat dissipation of the motor. SUMMARY

[0004] In view of the defects in the prior art, the technical problem solved by the present application is how to reduce the noise and structural fatigue of the equipment without narrowing the application range of the motor.

[0005] To achieve the above purpose, the low-vibration permanent magnet synchronous motor provided by the present application comprises: a motor shell; a motor stator fixed to the inner wall of the motor shell, the motor stator comprising a stator core; The stator core comprises a stator yoke and a stator tooth portion, the outer wall of the stator yoke is attached to and fixed to the inner wall of the motor shell, and a plurality of stator tooth portions are distributed along the inner wall circumference of the stator yoke; a plurality of damping holes are provided along the circumference of the end face of the stator yoke, and the hole spacing of two adjacent damping holes is the same.

[0006] By adopting the technical scheme, the plurality of damping holes are arranged at the end of the stator yoke of the stator core, and the damping holes are uniformly distributed along the circumference of the stator yoke, so that the vibration mode of the stator core is changed. The change of the vibration mode can be divided into the change of the natural frequency and the mode shape. The change of the natural frequency is according to the physical formula f = (1 / 2p) * sqrt(k / m). The natural frequency f is proportional to the square root of the stiffness k and inversely proportional to the square root of the mass m. The effect is that the natural frequency of a certain order that may occur resonance in the high-speed running interval is “pushed up” or “pulled down” after being punched, and is moved out of the main electromagnetic excitation force frequency range, thereby avoiding resonance. It is similar to adjusting the tightness of the string, so that it will not be strongly vibrated by the sound of a specific frequency. The change of the mode shape is that the “discontinuous point” is introduced in the continuous stator core, which destroys the overall stiffness of the structure. The effect is that the original overall vibration is decomposed into a plurality of local, smaller micro-vibrations, and the overall vibration amplitude is reduced. Therefore, the permanent magnet synchronous motor reduces the problem of motor vibration at the root, avoids the vibration of the stator core from being transmitted to the motor shell, and thus reduces the equipment noise and structural fatigue without reducing the application range of the motor.

[0007] In an embodiment, the inside of the damping hole is filled with an elastic damping material.

[0008] By adopting the technical scheme, the elastic damping material can absorb and dissipate vibration energy during vibration transmission, reducing the transmission effect of vibration to the motor shell, thereby further reducing equipment noise and structural fatigue.

[0009] In an embodiment, the cross section of the damping hole is a circular arc, and the radian of the circular arc is the same as the radian of the circumference of the stator yoke.

[0010] By adopting the technical scheme, the truncated circumference on the circumference of the stator yoke is increased without changing the opening area, the effect of cutting off vibration transmission is improved, thereby further reducing equipment noise and structural fatigue, and the strength of the stator core can also be ensured.

[0011] In an embodiment, the stator tooth is wound with a winding, and the winding includes a winding body inside the stator yoke and a winding end outside the stator yoke. The two ends of the winding body are provided with winding ends.

[0012] By adopting the technical scheme, it is ensured that the magnetic field is uniformly distributed on the surface of the stator core, and local magnetic field is avoided to be too strong or too weak. By reasonably designing the shape and extension length of the winding, the magnetic field harmonic component can be reduced, and the electromagnetic noise and vibration can be reduced.

[0013] In an embodiment, the peripheral of the winding end portion is sleeved with a heat-conducting material, and the heat-conducting material is located between the winding end portion and the motor shell.

[0014] By using the above technical scheme, when the motor is instantaneously overloaded, the winding instantaneously generates a large amount of heat, and the heat of the winding end portion can be transmitted to the motor shell through the heat-conducting material, so as to avoid that the winding end portion is glued and the insulation is burned.

[0015] In an embodiment, the inner wall of the motor shell, the end cover of the motor shell and the end surface of the stator core form a containing space, the winding end portion and the heat-conducting material are located in the interior of the containing space, and the interior of the containing space is filled with glue.

[0016] By using the above technical scheme, the filled glue not only has an insulating effect, but also can fix the winding end portion and the heat-conducting material, so as to ensure the heat transmission effect.

[0017] In an embodiment, the motor stator is internally provided with a motor rotor, and the motor shaft of the motor rotor is connected with the encoder through a connecting assembly.

[0018] By using the above technical scheme, the rotation data of the motor is collected to determine whether the motor works normally.

[0019] In an embodiment, the connecting assembly comprises an adapter shaft, an elastic coupling and an encoder shaft, one end of the motor shaft is fixedly connected with one end of the adapter shaft, the other end of the adapter shaft is connected with one end of the encoder shaft through the elastic coupling, and the other end of the encoder shaft is fixedly connected with the grating disc of the encoder, so as to realize the rotation of the grating disc.

[0020] By using the above technical scheme, when the motor vibrates or the motor rotor is impacted, the force is transmitted to the encoder, the deviation of the data collected by the encoder is avoided to be large, and the control precision of the motor is reduced.

[0021] In an embodiment, the shell of the encoder is fixed to the motor stator through a mounting frame.

[0022] By using the above technical scheme, the encoder and the motor stator are fixed, when the motor stator and the rotor relatively displace due to vibration, the elastic property of the coupling can play a compensation role to protect the encoder from rigid pulling.

[0023] In an embodiment, a terminal box is mounted on the outside of the motor shell.

[0024] By using the above technical scheme, when the current of one driver cannot meet the required current of the motor, multiple drivers can be connected to drive one motor at the same time, and the UVW of the driver are led to the terminal box.

[0025] In summary, the present application comprises at least one of the following beneficial technical effects: 1. By penetrating a plurality of damping holes in the end of the stator yoke of the stator core, and uniformly distributing the damping holes along the circumference of the stator yoke, the vibration mode of the stator core is changed, which can be divided into changing the natural frequency and the mode shape; changing the natural frequency is according to the physical formula f=(1 / 2π)*√(k / m), the natural frequency f is proportional to the square root of the stiffness k and inversely proportional to the square root of the mass m, the effect is that the natural frequency of a certain order which may occur resonance in the high speed running interval is "pushed up" or "pulled down" after being punched, and is moved out of the main electromagnetic excitation force frequency range, thereby avoiding resonance, similar to adjusting the tightness of the string, so that it will not be strongly vibrated by the sound of a specific frequency; changing the mode shape is to introduce "discontinuous points" in the continuous stator core, which destroys the overall stiffness of the structure, and the effect is that the original overall vibration is decomposed into multiple local, smaller micro-vibrations, reducing the overall vibration amplitude. Therefore, the permanent magnet synchronous motor reduces the problem of motor vibration at the root, avoids the vibration of the stator core from being transmitted to the motor shell, so as to reduce the equipment noise and structural fatigue without reducing the application range of the motor. 2. Through the specific design of the heat-conducting material, when the motor is instantaneously overloaded, the winding instantaneously generates serious heat, and the heat of the winding end can be transmitted to the motor shell through the heat-conducting material to avoid the explosion of the winding end and the burning of the insulation; 3. Through the specific design of the connecting assembly and the mounting bracket, the motor vibration and the force transmitted to the encoder when the motor rotor is impacted can be reduced, the encoder data acquisition deviation is avoided to be large, thereby reducing the control accuracy of the motor, and when the motor stator and the rotor relatively displace due to vibration, the elastic property of the coupling can play a compensation role to protect the encoder from rigid pulling. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a structure diagram of the motor stator of the embodiment of the present application; Figure 2 It is a side view of Figure 1 ; Figure 3 It is a force analysis diagram of the motor stator of the embodiment of the present application; Figure 4 It is a structure diagram of the low-vibration permanent magnet synchronous motor of the embodiment of the present application; Figure 5 It is a structure diagram of the connecting assembly of the embodiment of the present application; Figure 6 It is a circuit diagram of the permanent magnet synchronous motor of the embodiment of the present application.

[0027] In the figure: 1-motor housing, 2-motor stator, 201-stator yoke, 202-stator tooth, 203-damping hole, 204-hole spacing, 3-winding end, 4-heat-conducting material, 5-glue, 6-motor rotor, 7-junction box, 8-motor shaft, 9-connection assembly, 901-adapter shaft, 902-elastic coupling, 903-encoder shaft, 10-encoder, 11-mounting frame. DETAILED DESCRIPTION

[0028] The embodiments of the present application are further described in detail below with reference to the accompanying drawings.

[0029] The low-vibration permanent magnet synchronous motor in the embodiments of the present application, as shown in the figure, Figure 1 , Figure 2 The low-vibration permanent magnet synchronous motor includes a motor housing 1; a motor stator 2 fixed to the inner wall of the motor housing 1, the motor stator 2 including a stator core; the stator core including a stator yoke 201 and a stator tooth 202, the outer wall of the stator yoke 201 being attached to and fixed with the inner wall of the motor housing 1, and a plurality of stator teeth 202 being distributed along the inner wall circumference of the stator yoke 201; a plurality of damping holes 203 being provided along the circumference of the end face of the stator yoke 201, and the hole spacing 204 of two adjacent damping holes 203 being the same.

[0030] Therefore, it can be seen that the present application provides a plurality of damping holes 203 in the end of the stator yoke 201 of the stator core, and the damping holes 203 are uniformly distributed along the circumference of the stator yoke 201, so as to change the vibration mode of the stator core (under the condition that the position of the hole spacing 204 is less stressed than the maximum stress that the punching sheet can withstand), and the change of the vibration mode can be divided into the change of the natural frequency and the modal shape; the change of the natural frequency is according to the physical formula f=(1 / 2π)*√(k / m), the natural frequency f is proportional to the square root of the stiffness k and inversely proportional to the square root of the mass m, and the effect is that the natural frequency of a certain order that may occur resonance in the original high-speed running interval is "pushed up" or "pulled down" after being punched, and is moved out of the main electromagnetic excitation force frequency range, thereby avoiding resonance, which is similar to adjusting the tightness of the string, so that it will not be strongly vibrated by the sound of a specific frequency; the change of the modal shape is that "discontinuous points" are introduced in the continuous stator core, which destroys the overall stiffness of the structure, and the effect is that the original overall vibration is decomposed into a plurality of local, smaller micro-vibrations, and the overall vibration amplitude is reduced. Therefore, the permanent magnet synchronous motor reduces the problem of motor vibration at the root, avoids the vibration of the stator core being transmitted to the motor housing 1, and thus reduces the equipment noise and structural fatigue without reducing the application range of the motor.

[0031] It should be noted that the hole diameter of the damping hole 203 can be designed according to the thickness of the stator yoke part 201, and the hole spacing 204 is evaluated according to the torque conducted by the motor. The evaluation method is through finite element analysis, as shown in Figure 3 The position force of the hole spacing 204 is 2.2853e-005, which satisfies the condition that the position force of the hole spacing 204 is less than the maximum stress that the punching sheet can withstand. The punching sheet refers to the structure of the motor except the motor shell.

[0032] Preferably, as shown in Figure 2 The inside of the damping hole 203 is filled with elastic damping material.

[0033] Specifically, the elastic damping material can be selected from silicone, rubber, etc., and the internal space of the damping hole 203 is filled as much as possible to improve the damping effect; at the same time, it also reduces the risk of falling of the elastic damping material. In order to avoid falling, the opening of the damping hole 203 can also be plugged.

[0034] Preferably, as shown in Figure 2 The cross section of the damping hole 203 is circular arc, and the radian of the circular arc is the same as the radian of the circumference of the stator yoke part 201.

[0035] Specifically, if the radian of the above two is not the same, then in the case of the same opening area, the hole spacing 204 will be expanded. In order to increase the truncated circumference on the circumference of the stator yoke part 201 and improve the effect of cutting off vibration conduction, thereby further reducing the equipment noise and structural fatigue, the above design is carried out. In the case of the same cutting effect, the smaller the opening area, the higher the strength of the stator core, so as to also ensure the strength of the stator core.

[0036] Preferably, as shown in Figure 2 , Figure 4 The stator tooth part 202 is provided with a winding, and the winding includes a winding main body located inside the stator yoke part 201 and a winding end part 3 located outside the stator yoke part 201. Both ends of the winding main body are provided with the winding end part 3.

[0037] Specifically, the coil is wound back and forth on the stator tooth part 202 to form a winding, and the above design ensures that the magnetic field is uniformly distributed on the surface of the stator core, avoiding local magnetic field being too strong or too weak. By reasonably designing the shape and extension length of the winding, the magnetic field harmonic component can be reduced, and the electromagnetic noise and vibration can be reduced.

[0038] Further, as shown in Figure 4 The periphery of the winding end part 3 is sleeved with a heat-conducting material 4, and the heat-conducting material 4 is located between the winding end part 3 and the motor shell 1.

[0039] Specifically, the heat-conducting material 4 can be selected from graphene heat dissipation film and aluminum-based silicon carbide composite material. When the motor is in transient high overload, the winding generates heat instantaneously. The heat of the winding end portion 3 can be transferred to the motor housing 1 through the heat-conducting material 4, so as to avoid the phenomenon of glue explosion and insulation burnout of the winding end portion 3.

[0040] It should be noted that the transient heating of the motor mainly occurs in the winding. The part of the winding in the core is fixed by the slot wedge and is close to the stator core, so it is not easy to occur the phenomenon of glue explosion; however, the end portion of the winding is the most likely to occur the phenomenon of glue explosion, so the heat-conducting coefficient material is added between the winding and the housing to absorb and balance the high temperature generated instantaneously as soon as possible, so as to prevent the glue explosion.

[0041] Further, referring to Figure 1 As shown, the inner wall of the motor housing 1, the end cover of the motor housing 1 and the end face of the stator core form a receiving space, the winding end portion 3 and the heat-conducting material 4 are located inside the receiving space, and the receiving space is filled with glue 5.

[0042] Specifically, the inner ring of the position where the heat-conducting material 4 is added is close to the outer circle of the winding end portion 3, the outer circle of the heat-conducting material 4 is smaller than the inner circle of the motor housing 1, and the end portion of the heat-conducting material 4 is greater than 5mm away from the inner wall of the motor housing 1, otherwise the glue 5 will be too thin to cause the strength to decrease, resulting in the strength of the winding end portion 3 to decrease; the filled glue 5 not only can play the role of insulation, but also can fix the winding end portion 3 and the heat-conducting material 4, so as to ensure the heat transfer effect.

[0043] Preferably, referring to Figure 4 As shown, the motor stator 2 is internally provided with a motor rotor 6, and the motor shaft 8 of the motor rotor 6 is connected with an encoder 10 through a connecting assembly 9.

[0044] Specifically, the encoder 10 is connected with the motor shaft 8 through the connecting assembly 9, so as to collect the rotation data of the motor to determine whether the motor works normally.

[0045] It should be noted that the permanent magnet synchronous motor will generate high frequency and high intensity vibration during frequent start-stop commutation. Such vibration environment poses a severe challenge to the performance of the encoder 10. Under strong vibration conditions, problems such as signal loss and counting error are likely to occur, which will directly affect the position and speed feedback accuracy of the motor, and further cause the control system to be unable to accurately track the command signal. Specifically, vibration can cause the relative position between the encoder 10 grating ruler and the reading head to change, thereby causing signal interference or loss; at the same time, vibration can also cause the internal electronic components of the encoder 10 to loosen or be damaged, further exacerbating the signal instability phenomenon.

[0046] Further, to solve the above problems, referring to Figure 5As shown, a specific structure of a connection assembly 9 is provided: The connection assembly 9 comprises an adapter shaft 901, an elastic coupling 902 and an encoder shaft 903. The motor shaft 8 is fixedly connected to one end of the adapter shaft 901. The other end of the adapter shaft 901 is connected to one end of the encoder shaft 903 through the elastic coupling 902. The other end of the encoder shaft 903 is fixedly connected to the grating disc of the encoder 10 to realize rotation of the grating disc.

[0047] Specifically, in the mechanical structure, the connection of the encoder 10 and the shaft is realized through multi-stage transmission components. The motor shaft 8 is the starting end of power and motion transmission. It is first matched with the connecting shaft to transmit motion and power outward. Then, the elastic coupling 902 is connected to the encoder shaft 903. Since the encoder shaft 903 is fixedly connected to the grating disc of the encoder 10, the grating disc can be driven to rotate inside the encoder 10. In this system, the elastic coupling 902 has the following functions. On the one hand, when the motor vibrates and the motor rotor 6 is impacted, the coupling absorbs and buffers the vibration energy of the shaft system by virtue of elastic deformation, blocks the rigid transmission path, and attenuates the vibration amplitude and frequency, thereby creating a stable working environment for the encoder 10 and ensuring high-precision signal output to meet the motor control requirements.

[0048] Further, the housing of the encoder 10 is fixed to the motor stator 2 through the mounting bracket 11.

[0049] Specifically, the encoder 10 is fixed to the motor stator 2. The above is another function of the elastic coupling 902. When the motor stator 2 and the rotor are relatively displaced due to vibration, the elastic properties of the coupling can play a compensation role. It allows a certain axial, radial or angular displacement deviation between the shaft system and the encoder 10, avoids the direct action of the forced force generated by the relative displacement of the motor stator 2 and the motor rotor 6 on the encoder 10, and protects the encoder 10 from rigid pulling and extrusion, thereby preventing damage to the internal structure of the encoder 10 (such as code disc misalignment and housing cracking), greatly improving the reliability and service life of the encoder 10 under complex vibration conditions, and ensuring long-term stable operation of the motor.

[0050] Preferably, as shown in Figure 4 , Figure 6 As shown, the motor housing 1 is externally provided with a junction box 7.

[0051] Specifically, a modular winding design is adopted. The winding is composed of multiple groups of switchable coil units. This paper takes two drives and a single drive motor as an example to illustrate that it can be extended to more drive ways. The number of drives is changed through internal wiring and terminal connection of the motor.

[0052] Principle of multi-frequency converter driven motor: When the current of a driver cannot meet the current required by the motor, multiple drivers can be connected to drive the motor simultaneously. This paper takes a single driver and two drivers to drive the same motor as an example to illustrate, which can be extended to multiple drivers to drive the same motor. The maximum number of paths that can be achieved is determined by the pole-slot matching inside the motor, each path is separately sealed, and then the UVW of each path or the number of drivers expected to be trial-produced is led out to the junction box, and then it is connected in series or parallel according to the number of drivers required by the motor.

[0053] Specifically, the determination method of the number of drivers used by the motor is as follows: 1. Generally, since the maximum output current of the driver is 1900A, when the current is greater than this, two or more drivers are needed to drive a motor; 2. When the customer has limited space for installing the driver or has other considerations, the number of drivers required by the customer is determined.

[0054] The determination method of the number of paths of the motor is as follows: 2.1, On the one hand, the actual needs of the customer are considered, and the number of drivers required by the customer is determined; on the other hand, whether the motor can meet the demand is verified through the pole-slot matching of the motor.

[0055] 2.2, The calculation method of the maximum number of paths of the motor is as follows: Calculate the number of slots per pole per phase of the motor, Wherein, q is the number of slots per pole per phase, Z is the number of stator slots, m is the number of phases, and p is the number of pole pairs. The number of slots per pole per phase q is an integer, which is called an integer slot winding; when q is a fraction, it is called a fractional slot winding.

[0056] For single-layer winding, only integer slot winding is allowed, and the maximum number of paths of the motor is the number of pole pairs, i.e. Lu=p For double-layer winding, when the slot is an integer, the number of paths is the number of poles, i.e. Lu=2p For double-layer winding, when the slot is a fraction, the number of paths is Lu=p / d 3. The selection of the actual number of paths of the motor is determined according to the number of drivers used, and the number of drivers used must be the number of paths that can be achieved by the motor.

[0057] The above is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A low-vibration permanent magnet synchronous motor, characterized by, It includes: The motor housing (1); The motor stator (2) is fixed to the inner wall of the motor housing (1), and the motor stator (2) includes a stator core; The stator core includes a stator yoke (201) and a stator tooth (202), the outer wall of the stator yoke (201) is attached to and fixed to the inner wall of the motor housing (1), and a plurality of stator teeth (202) are distributed along the inner wall circumference of the stator yoke (201); The end face of the stator yoke (201) is provided with a plurality of damping holes (203) along its circumference, and the hole spacing (204) of two adjacent damping holes (203) is the same.

2. The low-vibration permanent magnet synchronous motor according to claim 1, characterized by: The inside of the damping hole (203) is filled with elastic damping material.

3. The low-vibration permanent magnet synchronous motor according to claim 1, characterized by: The cross section of the damping hole (203) is circular arc, and the radian of the circular arc is the same as the radian of the circumference of the stator yoke (201).

4. The low-vibration permanent magnet synchronous motor according to claim 1, characterized by: The stator tooth (202) is provided with a winding, and the winding includes a winding main body inside the stator yoke (201) and a winding end portion (3) outside the stator yoke (201), both ends of the winding main body are provided with winding end portions (3).

5. The low-vibration permanent magnet synchronous motor as claimed in claim 4, characterized by: The outer periphery of the winding end portion (3) is sleeved with a heat conducting material (4), and the heat conducting material (4) is located between the winding end portion (3) and the motor housing (1).

6. The low-vibration permanent magnet synchronous motor according to claim 5, characterized by: The inner wall of the motor housing (1), the end cover of the motor housing (1) and the end face of the stator core form a receiving space, the winding end portion (3) and the heat conducting material (4) are located inside the receiving space, and the receiving space is filled with glue (5).

7. The low-vibration permanent magnet synchronous motor according to claim 1, characterized by: The inside of the motor stator (2) is provided with a motor rotor (6), and the motor shaft (8) of the motor rotor (6) is connected with the encoder (10) through the connecting assembly (9).

8. The low-vibration permanent magnet synchronous motor as claimed in claim 7, characterized by: The connecting assembly (9) includes an adapter shaft (901), an elastic coupling (902) and an encoder shaft (903), the motor shaft (8) is fixedly connected with one end of the adapter shaft (901), the other end of the adapter shaft (901) is connected with one end of the encoder shaft (903) through the elastic coupling (902), and the other end of the encoder shaft (903) is fixedly connected with the grating disc of the encoder (10) to realize the rotation of the grating disc.

9. The low-vibration permanent magnet synchronous motor as claimed in claim 8, characterized by: The shell of the encoder (10) is fixed on the motor stator (2) through the mounting bracket (11).

10. The low-vibration permanent magnet synchronous motor as claimed in claim 1, characterized by: The outside of the motor housing (1) is provided with a junction box (7).

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