Motor shaft current suppression device and installation method thereof

Abstract

The invention belongs to the field of variable frequency driving motors, and particularly relates to a motor shaft current suppression device and an installation method thereof.The motor shaft current suppression device is arranged on the side, close to a stator notch, of a stator end winding and comprises a plurality of shielding plates, the shielding plates are made of metal materials, and each shielding plate comprises at least two fixing holes, the through holes are formed in the shielding plate; the shielding body further comprises a fixing device, the fixing holes in the at least two shielding plates are opposite, the fixing device fixes the two shielding plates, and the two shielding plates are connected to form a shielding body. The other at least one fixing hole in the at least two shielding plates is opposite to the fixing hole of the shielding plate in the adjacent shielding body, the two adjacent shielding bodies are fixed by the fixer, and the two adjacent shielding bodies are sequentially connected to form an annular structure. The structure is high in mechanical strength, the shielding body is simple in structure, fixation is achieved through a fixator, and batch production can be achieved.

Description

Technical Field

[0001] The present invention belongs to the field of variable - frequency drive motors, and particularly relates to a device for suppressing motor shaft current, and also relates to an installation method of a device for suppressing motor shaft current as described above. Background Art

[0002] With the rapid development of power - electronics technology, high - performance semiconductor devices, as switching devices, are widely used in drive systems for controlling motor operation. Compared with the traditional three - phase alternating - current direct - drive technology, the variable - frequency drive technology has advantages such as high efficiency and excellent speed - regulation performance, and is widely used in motor drive systems in various fields such as wind power and urban rail transit. While people enjoy the economic benefits brought by the variable - frequency drive technology, they also bear the negative impacts brought by the variable - frequency drive technology, such as common - mode interference and shaft - current problems. Among them, the bearing electro - corrosion problem caused by shaft current has attracted wide attention. People adopt shaft - current suppression measures to reduce shaft current, thereby reducing bearing electro - corrosion and increasing the service life of bearings.

[0003] To solve the above problems, operators widely adopt carbon brushes, grounding rings, etc. as shaft - current suppression measures. Although such shaft - current suppression measures can suppress shaft current, they increase the maintenance cost of the device. Scholars strive to suppress shaft current by improving the motor structure during the motor design stage. Therefore, the measure of suppressing shaft current by electrostatic shielding has emerged. The shielding layer can effectively weaken the electromagnetic coupling between the stator winding and the rotating shaft, and then suppress the shaft current. Currently, according to the placement position of the shielding layer, it can be divided into: full shielding of the stator winding, shielding of the winding in the stator slot, and shielding of the winding at the stator end. Existing research shows that the shaft - current suppression effect of full shielding of the stator winding is the best, followed by that of shielding of the winding at the stator end, and then that of shielding of the winding in the stator slot. At the same time, considering economic cost issues such as the amount of metal shielding used, the shaft - current suppression measure based on shielding of the winding at the stator end is the optimal choice. Currently, the shielding of the winding at the stator end usually uses a complete metal shielding body to wrap the stator - end winding or metal wires to wrap the stator - end winding. Although both measures can suppress shaft current, the complete metal shielding body has problems such as a large amount of metal used and high cost, and the metal - wire wrapping of the stator - end winding has problems such as poor mechanical strength, easy bending, difficult fixing, and difficult mass production.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The present invention aims to design a motor shaft current suppression device that can achieve the characteristics of high mechanical strength, not easy to bend, and easy to fix, and can solve the problem of mass production. Specifically, a motor shaft current suppression device is provided, which includes multiple metal shielding plates with a length greater than the straight part of the end winding, and the shielding plate has at least two fixing holes. At least two shielding plates are fixed to the fixing holes through a fixer to form a shielding body, and two adjacent shielding bodies are connected in sequence to form an annular structure. The shielding body is made of metal material, which can ensure high mechanical strength. At the same time, the shielding body has a simple structure and can be fixed by a fixer, which can solve the problems of mass production and difficult fixing.

[0006] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is: A motor shaft current suppression device is arranged on the side of the stator end winding close to the stator slot, and includes a plurality of shielding plates, the shielding plates are made of metal. The shielding plate comprises: at least two fixing holes, which are through holes arranged on the shielding plate; It also includes a fixer, wherein at least one fixing hole of two shielding plates is opposite to each other, and the fixer fixes the two shielding plates to form a shielding body; At least one other fixing hole on at least two shielding plates is opposite to the fixing hole of the shielding plate in the adjacent shielding body. The fixer fixes the two adjacent shielding bodies and connects them in sequence to form an annular structure.

[0007] Furthermore, the fixer includes a fixing portion and a clamping portion, wherein the fixing portion is adapted to the fixing hole, and at least a portion of the fixing portion can pass through the fixing hole; the clamping portion is provided with a clamping groove, which is adapted to the fixing portion, and the clamping portion is clamped with a portion of the fixing portion passing through the fixing hole; the fixing portion includes a fixing portion body and a clamping edge arranged at one end of the body, wherein the diameter of the clamping edge is larger than the fixing hole, and the diameter of the body is smaller than the diameter of the fixing hole.

[0008] Furthermore, the fixing holes include: a first fixing hole arranged at the geometric center of the shielding plate, and second fixing holes arranged at two ends of the shielding plate.

[0009] Furthermore, the shielding body includes a first shielding plate and a second shielding plate, the first shielding plate and the second shielding plate are cross-arranged with the first fixing hole as the intersection point, and the fixing body passes through the first fixing hole and is clamped with the clamping part to form an X-shaped shielding body.

[0010] Furthermore, the first shielding plate in the X-shaped shielding body is arranged to intersect with the second shielding plates in any two adjacent shielding bodies with their second fixing holes as the intersection point, and the fixing body passes through the second fixing hole and is clamped with the clamping part to fix any two adjacent X-shaped shielding bodies.

[0011] Further, the second shielding plate in the X-shaped shielding body intersects and arranges with the first shielding plates in any two adjacent shielding bodies with another second fixing hole as the intersection point. The fixing body passes through the connecting hole and is clamped with the clamping part to fix any two adjacent X-shaped shielding bodies.

[0012] Further, the first shielding plates in any two adjacent X-shaped shielding bodies are parallel to each other.

[0013] Further, the second shielding plates in any two adjacent X-shaped shielding bodies are parallel to each other.

[0014] Further, it further includes an insulating medium, which is arranged between the shielding body and the stator end winding.

[0015] The present invention also provides an installation method based on the above-mentioned motor shaft current suppression device. Further, the installation method includes the following steps: S1. Take out the motor housing where the motor stator winding is placed; S2. Place the insulating medium closely on the side of the stator end winding close to the stator slot opening; S3. Place the assembled annular shielding body on the side where the insulating medium is not closely attached to the stator end winding; S4. Place the rotor core in the motor housing and assemble the motor to complete the installation of the motor shaft current suppression device. After adopting the above technical solutions, the present invention has the following beneficial effects compared with the prior art: 1. Using a metal plate as the shielding body, and the shielding body has a simple structure, which is convenient for mass production. Assembling the shielding body into an X-shaped shielding unit, by controlling the opening and closing angle of the shielding unit, the number of shielding units in the suppression device is controlled, which plays a role in controlling the economic cost and has a certain economy and flexibility.

[0016] 2. The shielding body adopts a punching design, which is convenient for assembly.

[0017] 3. Fully considering that the stator end winding has a more obvious coupling effect on the rotor core than the stator slot winding, using end winding shielding to hinder the electromagnetic coupling between the stator end winding and the rotor core and the housing. Description of the Drawings

[0018] The specification drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings: Figure 1 It is a schematic diagram of the overall structure of the suppression device; Figure 2 It is a schematic diagram of the X-shaped shielding body structure; Figure 3 It is a schematic diagram of the fixer structure; Figure 4 It is a schematic diagram of the V-shaped shielding structure; Figure 5 It is a schematic diagram of the stator core structure.

[0019] Wherein: 1. Shielding body; 11. First shielding plate; 12. Second shielding plate; 13. First fixing hole; 14. Second fixing hole; 2. Fixator; 21. Fixing part; 211. Main body; 212. Clamping edge; 22. Clamping part; 221. Card slot; 3. Stator end winding; 4. Insulating medium; 5. Stator slot opening; 100. Suppression device installation area.

[0020] Detailed description of specific embodiments The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0021] The following detailed descriptions are all exemplary descriptions, aiming to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the art to which this application belongs. The terms used in the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0022] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0023] In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more. In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Embodiment 1 As Figures 1-3 As shown in FIGS. 4 and 5, the present invention provides a device for suppressing motor shaft current. The device for suppressing motor shaft current is arranged on one side of the end winding 3 of the stator close to the stator slot opening 5. The device for suppressing motor shaft current includes a plurality of shielding plates. The shielding plates are made of metal and the length of the shielding plates is greater than the straight part of the end winding. The shielding plates include: at least two fixing holes, which are through holes arranged on the shielding plates; and a fixer 2 is also included; one fixing hole on at least two shielding plates is opposite, and the fixer 2 fixes the two shielding plates to be connected to form a shielding body 1; at least one other fixing hole on at least two shielding plates is opposite to the fixing hole of the shielding plate in the adjacent shielding body 1, and the fixer 2 fixes the two adjacent shielding bodies 1 to be connected in sequence to form an annular structure.

[0025] Preferably, copper can be selected as the material for the shielding plate. Copper has excellent electrical conductivity and can effectively absorb and reflect electromagnetic waves, achieving a good shielding effect. In addition, the metal plate can be selected according to the actual economic benefits to select a suitable metal material.

[0026] Specifically, the shielding body 1 is arranged on the side of the end winding 3 of the motor close to the stator slot opening 5, taking into account the following aspects: suppressing electromagnetic induction, when the motor operates with variable-frequency power supply, the high-order harmonic components in the supply voltage will cause electromagnetic induction among the entire stator winding coil, the stator housing, and the rotating shaft, thereby generating shaft voltage. Arranging the suppression device on the side of the end winding 3 of the stator close to the stator slot opening 5 can effectively shield and suppress the electromagnetic induction at the end of the stator, reduce the shaft voltage generated by high-order harmonics, and thus reduce the risk of generating shaft current; blocking the capacitive coupling path, there are distributed capacitances both between the turns of the stator winding of the asynchronous motor and between the stator winding and the motor housing. When the common-mode voltage of the inverter changes sharply, a common-mode voltage is induced between the stator winding and the housing of the motor. Through the voltage division of the distributed capacitance between the stator winding and the rotor core and between the rotor core and the housing, shaft voltage and shaft current are generated at both ends of the bearing. The suppression device located on the side of the end winding 3 of the stator close to the stator slot opening 5 can change the electric field distribution, block or weaken the coupling path formed by the distributed capacitance between the stator winding and the rotating shaft, and reduce the generation of shaft current; close to the source of shaft current generation, the end winding of the stator is an important source of shaft current generation. The magnetic field and electric field changes here are relatively complex, which is likely to cause shaft voltage and shaft current. Arranging the suppression device here can act more directly on the source of shaft current generation, timely suppress the generation and conduction of shaft current, and prevent it from further affecting the bearings and other components of the motor; facilitating installation and maintenance, the side of the end winding 3 of the stator close to the stator slot opening 5 is relatively an easily accessible and operable position inside the motor. Arranging the suppression device here facilitates operation and adjustment during the manufacturing, installation, and subsequent maintenance processes of the motor, and is also conducive to monitoring and optimizing the performance of the suppression device to ensure its long-term and effective suppression of shaft current; reducing the impact on the motor performance, arranging the suppression device on the side of the end winding 3 of the stator close to the stator slot opening 5 can, compared with other positions, effectively suppress the shaft current while minimizing the impact on the normal performance such as the internal magnetic field distribution and torque transmission of the motor, and ensure the operating efficiency and reliability of the motor.

[0027] Specifically, the length of the shielding plate is set to be greater than the straight part of the end winding. Since the shielding body 1 in the present invention is inclined compared to the straight part of the end winding, if the set length is less than or equal to the straight part of the end winding, there will be gaps at the upper and lower ends of the shielding body 1, affecting the shaft current suppression effect.

[0028] Specifically, this embodiment provides an X-shaped shield 1. The fixator 2 includes a fixing portion 21 and a clamping portion 22. The fixing portion 21 is adapted to the fixing hole, and at least a part of the fixing portion 21 can pass through the fixing hole. The clamping portion 22 is provided with a clamping groove 221, the clamping groove 221 is adapted to the fixing portion 21, and the clamping portion 22 is clamped with the part of the fixing portion 21 passing through the fixing hole. The fixing portion 21 includes a fixing portion main body 211 and a clamping edge 22 provided at one end of the main body 211. The diameter of the clamping edge 22 is larger than that of the fixing hole, and the diameter of the main body 211 is smaller than that of the fixing hole.

[0029] Among them, between the fixing portion main body 211 and the fixing hole, in the case of no clamping edge 22, a scheme of interference fit with the fixing hole can be selected to achieve fixation. Setting the clamping edge 22 can, on the one hand, make the fixation between the two shielding plates more firm, and on the other hand, can also achieve the effect of relative rotation between the two shielding plates, facilitating the adjustment of the intersection angle between the two shielding plates, and further changing the shape of the shield 1, which is applicable to various requirements.

[0030] Specifically, the fixing holes include: a first fixing hole 13 provided at the geometric center of the shielding plate, and a second fixing hole 14 provided at both ends of the shielding plate; the shield 1 includes a first shielding plate 11 and a second shielding plate 12. The first shielding plate 11 and the second shielding plate 12 are arranged crosswise with the first fixing hole 13 as the intersection point. The main body 211 of the fixator 2 passes through the first fixing hole 13 and is clamped with the clamping portion 22 to fixedly form the X-shaped shield 1.

[0031] Specifically, the first shielding plate 11 in the X-shaped shield 1 intersects and is arranged with the second shielding plates 12 in any two adjacent shields 1 with one of the second fixing holes 14 as the intersection point. The main body 211 of the fixator 2 passes through the second fixing hole 14 and is clamped with the clamping portion to fix any two adjacent X-shaped shields 1.

[0032] Specifically, the first shielding plates 11 in any two adjacent X-shaped shields 1 are parallel to each other; the second shielding plates 12 in any two adjacent X-shaped shields 1 are parallel to each other.

[0033] Specifically, by controlling the opening and closing angle of the shield 1 and controlling the number of shields 1 in the suppression device, the economic cost can be controlled, which has a certain economy and flexibility. When the opening and closing angle of the shield 1 is large, the number of shields 1 required to wind around the stator end winding for one week is less, thus reducing the cost; when the opening and closing angle of the shield 1 is small, the number of shields 1 required to wind around the stator end winding for one week is more, and the shaft current suppression effect is better. When using, the number of shields 1 should be selected through comprehensive consideration.

[0034] Specifically, in this embodiment, the equivalent height of the shielding body 1 can be made less than the height of the end winding by shortening the length of the shielding body 1 or increasing the opening angle of the shielding body 1, so as to adopt the form of arranging two or more suppression devices vertically one above the other, which can further improve the shaft current suppression effect of the shielding body 1.

[0035] Specifically, it further includes an insulating medium 4 arranged between the shielding body 1 and the stator winding. The insulating medium 4 is selected as a thin insulating medium 4 with a certain thickness, such as polyester film and polyester film, etc. It only needs to ensure good insulation performance and temperature resistance. One side of the insulating medium 4 is closely attached to the side of the stator end winding 3 close to the stator slot opening 5, and the shielding body 1 is assembled in sequence and attached to the other side of the insulating medium 4 to prevent the shielding body 1 from being punctured.

[0036] Specifically, for the insulating medium 4 between the shielding body 1 and the stator winding, on the one hand, the suppression device is usually made of metal, while the stator end winding is a charged conductor. If the two are in direct contact, it will cause current to form a short circuit through the suppression device, making the motor unable to work properly and even possibly causing electrical faults, such as burning out the motor winding and causing a fire. The presence of the insulating medium 4 can isolate the two to avoid the occurrence of a short circuit; on the other hand, the insulating medium 4 has high electrical strength and insulation resistance, which can increase the insulation distance between the suppression device and the stator end winding, improve the overall insulation performance, and prevent insulation breakdown during the operation of the motor; finally, the insulating medium 4 can reduce the energy loss during the operation of the motor. Since the insulating medium 4 has a high resistance, it can prevent current leakage between the suppression device and the stator end winding, thereby improving the efficiency and power factor of the motor.

[0037] Embodiment 2 As Figure 1 and 3 As shown in Fig. -5, the present invention provides a motor shaft current suppression device, which is arranged on the side of the stator end winding 3 close to the stator slot opening 5 and includes a plurality of shielding plates. The shielding plates are made of metal and the length of the shielding plates is greater than the straight part of the end winding. The shielding plates include: at least two fixing holes, which are through holes arranged on the shielding plates; and a fixer 2 is also included; one fixing hole on at least two shielding plates is opposite, and the fixer 2 fixes the two shielding plates to be connected to form a shielding body 1; at least one other fixing hole on at least two shielding plates is opposite to the fixing hole of the shielding plate in the adjacent shielding body 1, and the fixer 2 fixes the two adjacent shielding bodies 1 to be connected in sequence to form an annular structure.

[0038] Preferably, copper can be selected as the material for the shielding plate. Copper has excellent electrical conductivity and can effectively absorb and reflect electromagnetic waves, achieving a good shielding effect. In addition, the metal plate can be selected according to the actual economic benefits to select a suitable metal material.

[0039] Specifically, the shielding body 1 is arranged on the side of the electronic end winding 3 close to the stator slot opening 5. The following aspects are considered: To suppress electromagnetic induction, when the motor operates with inverter power supply, the high-order harmonic components in the supply voltage will cause electromagnetic induction between the end part of the stator winding coil, the wiring part, and the rotating shaft, thereby generating shaft voltage. Arranging the suppression device on the side of the stator end winding 3 close to the stator slot opening 5 can effectively shield and suppress the electromagnetic induction of the stator end winding, reduce the shaft voltage generated by high-order harmonics, and thus reduce the risk of generating shaft current; To block the capacitive coupling path, there are distributed capacitances both between the turns of the stator winding of the asynchronous motor and between the stator winding and the motor frame. When the common-mode voltage of the inverter changes sharply, a common-mode voltage is induced between the stator winding and the machine shell of the motor. Through the voltage division of the distributed capacitance between the stator winding and the rotor iron core and the distributed capacitance between the rotor iron core and the machine shell, shaft voltage and shaft current are generated at both ends of the bearing. The suppression device located on the side of the stator end winding 3 close to the stator slot opening 5 can change the electric field distribution, block or weaken the coupling path formed by the distributed capacitance between the stator winding and the rotating shaft, and reduce the generation of shaft current; Close to the source of shaft current generation, the stator end winding is an important source of shaft current generation. The magnetic field and electric field changes here are relatively complex, which is likely to trigger shaft voltage and shaft current. Arranging the suppression device here can act more directly on the source of shaft current generation, timely suppress the generation and conduction of shaft current, and prevent it from further affecting the bearings and other components of the motor; Facilitate installation and maintenance. The side of the stator end winding 3 close to the stator slot opening 5 is relatively an easily accessible and operable position inside the motor. Arranging the suppression device here facilitates operation and adjustment during motor manufacturing, installation, and subsequent maintenance, and is also conducive to monitoring and optimizing the performance of the suppression device to ensure its long-term and effective suppression of shaft current; Reduce the impact on the motor performance. Arranging the suppression device on the side of the stator end winding 3 close to the stator slot opening 5 can, compared with other positions, effectively suppress the shaft current while minimizing the impact on the normal performance such as the internal magnetic field distribution and torque transmission of the motor, and ensure the operation efficiency and reliability of the motor.

[0040] Specifically, the length of the shielding plate is set to be greater than the straight part of the end winding. Since the shielding body 1 in the present invention is inclined compared with the straight part of the end winding, if the set length is less than or equal to the straight part of the end winding, there will be gaps at the upper and lower ends of the shielding body 1, affecting the shaft current suppression effect.

[0041] Specifically, this embodiment provides a V-shaped shielding body 1. The fixture 2 includes a fixing portion 21 and a clamping portion 22. The fixing portion 21 is adapted to the fixing hole, and at least a part of the fixing portion 21 can pass through the fixing hole. The clamping portion 22 is provided with a clamping groove 221, the clamping groove 221 is adapted to the fixing portion 21, and the clamping portion 22 is clamped with the part of the fixing portion passing through the fixing hole. The fixing portion 21 includes a fixing portion main body 211 and a clamping edge 22 provided at one end of the main body 211. The diameter of the clamping edge 22 is larger than that of the fixing hole, and the diameter of the main body 211 is smaller than that of the fixing hole.

[0042] Among them, between the fixing portion main body 211 and the fixing hole, in the case of no clamping edge 22, a scheme of interference fit with the fixing hole can be selected to achieve fixation. Setting the clamping edge 22 can, on the one hand, make the fixation between the two shielding plates more firm, and on the other hand, can also achieve the effect of relative rotation between the two shielding plates, facilitating the adjustment of the intersection angle between the two shielding plates, thereby changing the shape of the shielding body 1 and being applicable to various requirements.

[0043] Specifically, the fixing holes include: a first fixing hole 13 provided at one end of the shielding plate, and a second fixing hole 14 provided at the other end of the shielding plate; the shielding body 1 includes a first shielding plate 11 and a second shielding plate 12. The first shielding plate 11 and the second shielding plate 12 are arranged intersecting with the first fixing hole 13 as the intersection point. The main body 211 of the fixture 2 passes through the first fixing hole 13 and is clamped with the clamping portion 22 to form a V-shaped shielding body 1.

[0044] Specifically, the first shielding plate 11 in the V-shaped shielding body 1 intersects and is arranged with the second shielding plates 12 in any two adjacent shielding bodies 1 with the second fixing hole 14 as the intersection point. The main body 211 of the fixture 2 passes through the second fixing hole 14 and is clamped with the clamping portion 22 to fix any two adjacent V-shaped shielding bodies 1.

[0045] Specifically, the first shielding plates 11 in any two adjacent V-shaped shielding bodies 1 are parallel to each other; the second shielding plates 12 in any two adjacent V-shaped shielding bodies 1 are parallel to each other.

[0046] Specifically, by controlling the opening and closing angle of the shielding body 1 and controlling the number of shielding bodies 1 in the suppression device, it plays a role in controlling the economic cost, having a certain economy and flexibility. When the opening and closing angle of the shielding body 1 is large, the number of shielding bodies 1 required to wind around the stator end winding for one week is less, thereby reducing the cost; when the opening and closing angle of the shielding body 1 is small, the number of shielding bodies 1 required to wind around the stator end winding for one week is more, and the shaft current suppression effect is better. When using, the number of shielding bodies 1 should be selected through comprehensive consideration.

[0047] Specifically, in this embodiment, the equivalent height of the shielding body 1 can be made less than the height of the end winding by shortening the length of the shielding body 1 or increasing the opening angle of the shielding body 1, so that two or more suppression devices can be arranged vertically one above the other, which can further improve the shaft current suppression effect of the shielding body 1.

[0048] Specifically, it further includes an insulating medium 4 provided between the shielding body 1 and the stator winding. The insulating medium 4 is selected as a thin insulating medium 4 with a certain thickness, such as polyester film and polyester film, etc. It is only necessary to ensure good insulation performance and temperature resistance. One side of the insulating medium 4 is closely attached to one side of the stator end winding 3 close to the stator slot opening 5. The shielding bodies 1 are assembled in sequence and attached to the other side of the insulating medium 4 to prevent the shielding body 1 from being punctured.

[0049] Specifically, for the insulating medium 4 between the shielding body 1 and the stator winding, on the one hand, the suppression device is usually made of metal, while the stator end winding is a live conductor. If the two are in direct contact, it will cause current to form a short circuit through the suppression device, making the motor unable to operate normally and even possibly causing electrical faults, such as burning out the motor winding and causing a fire. The presence of the insulating medium 4 can isolate the two to avoid the occurrence of a short circuit. On the other hand, the insulating medium 4 has a high electrical strength and insulation resistance, which can increase the insulation distance between the suppression device and the stator end winding, improve the overall insulation performance, and prevent insulation breakdown during the operation of the motor. Finally, the insulating medium 4 can reduce the energy loss during the operation of the motor. Since the insulating medium 4 has a high resistance, it can prevent current leakage between the suppression device and the stator end winding, thereby improving the efficiency and power factor of the motor.

[0050] Embodiment Three As Figures 1-5 shown, in this embodiment, a method for installing a suppression device for suppressing the shaft current of a motor is provided. It is applicable to a motor shaft current suppression device in the above embodiment, but not limited to the motor shaft current suppression device in the above embodiment. Specifically, it includes the following steps: S1. Take out the motor housing where the motor stator winding is placed In this step, the motor housing and the stator core are integrated, and the winding is placed in the stator slots. At this time, the rotor core has not been installed inside the motor to facilitate the subsequent installation work of the suppression device.

[0051] S2. Place the insulating medium 4 closely against one side of the stator end winding 3 close to the stator slot opening 5 According to the motor specifications and shielding requirements, select a thin insulating medium 4 with an appropriate thickness and material, such as polyester film and polyester film, etc. It is only necessary to ensure good insulation performance and temperature resistance.

[0052] Specifically, as Figure 5As shown, the part of the motor winding extending from both ends of the iron core is the motor end winding 3, and the effective sides of the motor winding embedded in the iron core slots are the straight parts of the motor winding. The thin insulating medium 4 is arranged between the motor end windings 3 at both ends. One part is placed closely on the inner side of the straight part of the stator winding, that is, on the side close to the axis of the iron core, and the other part is placed closely on the side of the stator end winding 3 close to the stator slot opening 4 direction, ensuring that the insulating medium 4 completely covers the end winding and fits tightly to prevent electromagnetic leakage and short circuit. The part covered by the insulating medium 4 is the installation area 100 of the suppression device.

[0053] S3. Place the assembled annular shield 1 on the side where the insulating medium 4 does not closely adhere to the stator end winding 3 Take out the previously assembled suppression device. The design of this device is to protect the stator end winding 3 from external interference and ensure the stable operation of the motor. Before installation, check whether the suppression device is damaged, deformed, and whether the connections of all components are firm, etc.

[0054] Place the suppression device on the inner surface of the thin insulating medium 4. Here, the inner surface refers to the side of the insulating medium 4 that does not closely adhere to the stator end winding 3. When placing, ensure that the position between the suppression device, the insulating medium 4, and the stator winding is accurate. The suppression device should completely cover the area to be protected and fit tightly with the insulating medium 4 without looseness or deviation. Some small clamps can be used for temporary fixation, and then fix it after confirming the position is correct.

[0055] S4. Place the rotor core in the motor housing and assemble the motor to complete the installation of the motor shaft current suppression device The rotor core is usually assembled with the rotor winding to form a complete rotor component. Before installation, also check the rotor core and winding to ensure that there is no damage and the winding is not short - circuited, etc.

[0056] Place the rotor core (including the rotor winding) in the motor housing. During the placement process, pay attention to aligning with the center position of the housing to avoid collision with the stator winding or other components. A positioning pin or a guiding sleeve can be used to assist the installation to ensure that the rotor can accurately fall into the predetermined position in the housing.

[0057] When the rotor core is placed in place, start the assembly work of the motor. This includes installing components such as the front and rear end covers, bearings, and fans of the motor. After ensuring that all components are installed correctly, the assembly work of the motor is completed.

[0058] In the description of this specification, the descriptions referring to the terms "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0059] As is known by those skilled in the art, the present invention can be implemented by other embodiments that do not depart from its spiritual essence or essential features. Therefore, the above-disclosed embodiments are illustrative in all respects and not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are encompassed by the present invention.

Claims

1. A motor shaft current suppression device, arranged on a side of a stator end winding (3) close to a stator slot (5), characterized in that: including a plurality of shielding plates; The shielding plate comprises: at least two fixing holes, which are through holes arranged on the shielding plate; It also includes a fixer (2), wherein at least two fixing holes on the two shielding plates are opposite to each other, and the fixer (2) fixes the two shielding plates to form a shielding body (1); At least one other fixing hole on at least two shielding plates is opposite to a fixing hole of a shielding plate in an adjacent shielding body (1), and the fixer (2) fixes the two adjacent shielding bodies (1), which are sequentially connected to form an annular structure.

2. A motor shaft current suppression device according to claim 1, characterized in that: The fixer (2) comprises a fixing portion (21) and a clamping portion (22), wherein the fixing portion (21) is adapted to the fixing hole, and at least a portion of the fixing portion (21) can pass through the fixing hole; the clamping portion (22) is provided with a clamping groove (221), the clamping groove (221) is adapted to the fixing portion (21), and the clamping portion (22) is clamped with the portion of the fixing portion (21) passing through the fixing hole; The fixing portion (21) comprises a fixing portion (21) body (211) and a clamping edge (212) arranged at one end of the body (211); the diameter of the clamping edge (212) is larger than the fixing hole, and the diameter of the body (211) is smaller than the diameter of the fixing hole.

3. A motor shaft current suppression device according to claim 2, characterized in that: The fixing holes include: A first fixing hole (13) is arranged at the geometric center of the shielding plate, and second fixing holes (14) are arranged at two ends of the shielding plate.

4. A motor shaft current suppression device according to claim 3, characterized in that: The shielding body (1) comprises a first shielding plate (11) and a second shielding plate (12); the first shielding plate (11) and the second shielding plate (12) are arranged crosswise with the first fixing hole (13) as an intersection; the main body (211) of the fixer (2) passes through the first fixing hole (13) and is clamped with the clamping portion (22) to form an X-shaped shielding body (1).

5. A motor shaft current suppression device according to claim 4, characterized in that: The first shielding plate (11) in the X-shaped shielding body (1) and the second shielding plates (12) in any two adjacent shielding bodies (1) are arranged to intersect with each other with their second fixing holes (14) as the intersection point, and the main body (211) of the fixer (2) passes through the second fixing hole (14) and is clamped with the clamping portion (22) to fix any two adjacent X-shaped shielding bodies (1).

6. A motor shaft current suppression device according to claim 5, characterized in that: The second shielding plate (12) in the X-shaped shielding body (1) is arranged to intersect with the first shielding plates (11) in any two adjacent shielding bodies (1) with another second fixing hole (14) as an intersection point, and the main body (211) of the fixer (2) passes through the connection hole to be clamped with the clamping portion (22) to fix any two adjacent X-shaped shielding bodies (1).

7. A motor shaft current suppression device according to claim 6, characterized in that: The first shielding plates (11) in any two adjacent X-shaped shielding bodies (1) are parallel to each other.

8. The motor shaft current suppression device according to claim 7, characterized in that: The second shielding plates (12) in any two adjacent X-shaped shielding bodies (1) are parallel to each other.

9. The motor shaft current suppression device according to claim 8, characterized in that: It also includes an insulating medium (4) which is arranged between the shielding body (1) and the stator end winding (3).

10. A method for installing a motor shaft current suppression device, characterized in that: The motor shaft current suppression device according to any one of claims 1 to 9 is implemented, and the installation method comprises the following steps: S1, take out the motor casing where the motor stator winding is placed; S2, placing an insulating medium (4) close to the stator end winding (3) and close to the stator slot (5); S3, placing the assembled annular shield (1) on the side of the insulating medium (4) that is not in close contact with the stator end winding (3); S4. Place the rotor core in the motor housing and assemble the motor to complete the installation of the motor shaft current suppression device.

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