644results about "Asynchronous induction motors" patented technology

The invention relates to a high-temperature superconducting flywheel energy storage device and a control method of the high-temperature superconducting flywheel energy storage device. The problems that in the prior art, an electro-magnetic inductor motor has large standby loss, and the suspension force cannot be adjusted can be solved through the high-temperature superconducting flywheel energy storage device and the control method of the high-temperature superconducting flywheel energy storage device. The high-temperature superconducting flywheel energy storage device comprises a flywheel rotor. A stator core; a first high-temperature superconducting excitation coil; the stator iron core, the first high-temperature superconducting magnet exciting coil and the second high-temperature superconducting magnet exciting coil are arranged around a rotating shaft of the flywheel rotor in the circumferential direction of the flywheel rotor, and the first high-temperature superconducting magnet exciting coil and the second high-temperature superconducting magnet exciting coil are arranged on the two sides of the stator iron core in the extending direction of the rotating shaft respectively; the permanent magnet surrounds the rotating shaft and is arranged on one side of the flywheel rotor in the extending direction of the rotating shaft; and the control coil is arranged around the rotating shaft, and the control coil is arranged on the same side as the permanent magnet relative to the flywheel rotor.

The present invention relates to the technical field of electric motors, and specifically relates to a three-phase direct-current brushless electric motor, comprising: an electric motor housing, an inner shell, a rotating shaft, a rotor, a stator, a Hall sensor, and a circuit protection device, wherein the inner shell is fixedly mounted at the upper end of the electric motor housing; the rotating shaft is rotatably connected to the electric motor housing; the rotor and the stator are mounted inside the inner shell; and the Hall sensor is rotatably fitted with the rotating shaft. The circuit protection device is located above the rotor; during operation, when the rotating shaft is stuck due to a fault, or when there is an overload, the circuit protection device controls the disconnection of a circuit, thereby realizing the power-off self-locking of the electric motor by means of a load control module, thus avoiding the demagnetization of a rotor permanent magnet at a high temperature caused by heating of the electric motor, and avoiding affecting the rotation speed and normal use of the electric motor.

A coaxial asynchronous motor drive system, including a speed reducer, an electric motor and a main housing, and further including a motor controller, wherein the electric motor and the speed reducer are connected to form a motor reducer assembly and mounted inside the main housing, and the motor controller is fixed to the main housing and connected to the motor reducer assembly. The system reduces parasitic loss of an auxiliary motor drive system of a battery electric four-wheel-drive vehicle and increases the range per charge of the vehicle, and the compact and integrated coaxial motor drive system facilitates maximum utilization of available space of the vehicle.

Examples are disclosed that relate to an electric machine (102) that achieves independent speed, variable frequency power generation and has increased power density, efficiency, reliability, and reduced complexity relative to conventional electric machines. In one example, an electric machine (102) includes a stator (200), a first stationary winding (202) coupled to the stator (200), a second stationary winding (204) coupled to the stator (200), and a rotor (206). The second stationary winding (204) includes a plurality of winding segments (218) corresponding to a number of phases of power of the electric machine (102). The rotor (206) extends through the stator (200) and the second stationary winding (204). The rotor (206) includes a plurality of rotor segments (220.1, 220.2, 220.3). Each rotor segment (220) of the plurality of rotor segments (220.1, 220.2, 220.3) includes a plurality of pole lobes (222.1, 222.2, 222.3) that extend radially from the rotor segment (220). Two or more pole lobes (222) of each rotor segment (220) are located on opposing sides of a corresponding winding segment (218) of the second stationary winding (204).

The embodiment of the invention discloses a modular bearingless doubly salient electro-magnetic motor, relates to the technical field of bearingless doubly salient electro-magnetic motors, and can further improve the fault tolerance performance of the modular bearingless doubly salient electro-magnetic motor. The invention comprises a body structure of the modular bearingless electro-magnetic doubly salient motor and an annular direct current winding control method for suspension control of the modular bearingless electro-magnetic doubly salient motor. Structural optimization of a traditional bearingless electro-magnetic doubly salient motor is achieved, coupling between windings of the traditional bearingless electro-magnetic doubly salient motor is reduced, meanwhile, the modular topology is beneficial to physical isolation and electric, magnetic and thermal isolation of the motor windings, and the utilization rate of residual healthy windings is high when a fault occurs. The topological structure can be used for bearingless electro-magnetic doubly salient motors with other stator and rotor pole numbers.

The invention discloses a shaded pole motor, and relates to the technical field of motors, and the shaded pole motor comprises a stator assembly, a rotor assembly disposed in the stator assembly, and a support assembly covering the rotor assembly. The support assembly comprises a support body, a pressing claw and a pressing disc. The pressing claw and the pressing disc form an elastic piece based on overlapping riveting. An installation part is arranged in the middle of the support body, a wool felt and an installation step structure are arranged in the installation part, the elastic piece is correspondingly embedded between the installation step structure and the wool felt, and the elastic piece and the wool felt are matched to form a limiting space for containing a bearing. The mounting step structure is arranged in the bracket main body and matched with the wool felt to realize the limiting mounting of the elastic piece, so that the bearing mounting area is formed under the matching of the elastic piece and the wool felt, the assembly accuracy of the elastic piece and the bearing is improved, and the connection stability of the internal structure of the shaded pole motor is effectively improved.

The invention provides a high-speed induction motor solid rotor structure and a motor, the rotor structure comprises an integrated conductive and magnetic conductive rotor and a rotating shaft, the surface of the rotor is provided with two groups of grooves, any groove in any group and all grooves in the other group are arranged in a staggered manner along the circumferential direction of the rotor, and the two groups of grooves are arranged at intervals along the axial direction of the rotor. Distances are reserved between the far ends of the two groups of grooves and the close end faces of the rotor. The motor comprises the solid rotor structure. The two sections of non-penetrating rectangular straight grooves are axially formed in the surface of the rotor, so that the equivalent impedance of the rotor part is increased, the penetration depth of an air-gap magnetic field in the rotor is increased, the torque output capacity of the motor is improved, and meanwhile, the eddy current strength of the surface of the rotor is weakened.

The invention discloses an explosion-proof three-phase asynchronous motor which comprises a shell, a front end cover, a rear end cover, a stator, a rotor and a rotating shaft, wherein the stator, the rotor and the rotating shaft are arranged inside the shell. The radiating fins are arranged on the outer wall of the machine shell, the reciprocating lead screw transmission mechanism is connected through the supporting frame, the cleaning plate is driven to do reciprocating motion along the guide rod, dust on the radiating fins is automatically removed through the arc-shaped brush plate, and efficient radiating is ensured. The cooling box is arranged below the machine shell, the cooling box and the machine shell are designed to share the wall, an internal cooling pipe conveys cooled gas into the machine shell through a gas circulation system, the temperature is forcibly reduced, combustible gas is dispersed, and the anti-explosion safety is improved. The eccentric wheel on the rotating shaft drives the piston pipe to reciprocate, one-way flow of gas is achieved in combination with the non-return cover plate structure, and active gas circulation is formed in cooperation with the annular gas inlet channel and the gas outlet hole. The motor integrates self-cleaning heat dissipation and gas circulation cooling functions, adapts to high-temperature, high-humidity and closed environments, effectively reduces energy consumption, prolongs the service life of the motor, and is suitable for flammable and explosive places.

The utility model discloses an induction motor, compressor and refrigeration equipment, relates to the motor technical field, the induction motor comprises a stator part, a stator iron core comprises a plurality of stator punching sheets laminated along the axial direction of the stator iron core, each stator punching sheet comprises a stator yoke and a plurality of stator teeth arranged on the inner side of the stator yoke and arranged along the circumferential direction of the stator yoke at intervals, a stator slot is formed between every two adjacent stator teeth; wherein any two intersection points exist between a line segment of the stator punching sheet passing through the circle center and the outer contour of the stator punching sheet, the maximum value of the line segment between any two intersection points is L1, the minimum value of the line segment between any two intersection points is L2, and L1 / L2 is greater than or equal to 1.02 and less than or equal to 1.2, the tooth width of the stator teeth is W1, the maximum slot width of the stator slots is W2, W2 / W1 is greater than or equal to 2.6 and less than or equal to 3.6, the minimum stator yoke width of the stator punching sheet is Y1, the inner diameter of the stator punching sheet is L3, and Y1 / ((L1-L3) / 2) is greater than or equal to 0.3 and less than or equal to 0.45. According to the induction motor, the efficiency of the induction motor can be improved, and the calorific value is reduced.

The invention relates to a single-phase asynchronous capacitor motor, which comprises a stator part, a rotor part and a motor rotating shaft, the capacitor motor further comprises a casing, the casing comprises a front casing wall, a rear casing wall and a ventilation rear cover, the front end part of the motor rotating shaft is coupled in the front casing wall through a front bearing, and the rear end part of the motor rotating shaft is coupled in the rear casing wall through a rear bearing. The rear end part of the motor rotating shaft is coupled in the rear shell wall through a rear bearing, the rear bearing comprises an outer bearing sleeve, an inner bearing sleeve and a bearing roller, the inner bearing sleeve is fixedly sleeved on the rear end part of the motor rotating shaft, the inner bearing sleeve comprises an inner bearing ring pipe and a connecting disc body, and the inner bearing ring pipe is sleeved on the inner bearing ring pipe. The connecting disc body is fixedly connected to the outer end of the inner bearing ring pipe, the coaxial cooling fan is connected to the connecting disc body, when the inner bearing sleeve rotates, the connecting disc body and the motor rotating shaft coaxially and synchronously rotate, and the connecting disc body drives the coaxial cooling fan and the motor rotating shaft to coaxially and synchronously rotate.

An electric motor comprises: a stator; a rotor shaft having a hollow interior and a rotor axis with at least one inlet into the hollow interior and at least one outlet from the hollow interior to an outer diameter of the rotor shaft; a rotor comprising: a rotor body having a first end structure and a second end structure opposite each other along the rotor shaft, wherein the second end structure has an outlet to an outside of the rotor; and an axial cooling channel extending through the rotor body; and wherein the electric motor is configured so that a fluid is centrifugally driven by rotation of the rotor to enter through the inlet of the rotor shaft, exit through the outlet of the rotor shaft, enter the axial cooling channel, and flow to the outside of the rotor through the outlet of the second end structure.

A vehicle drive system includes a motor that has a cylindrical stator and a cylindrical rotor provided in the stator to be coaxially rotatable with a center axis of the stator and drives a front wheel of a vehicle by rotation of the rotor. The rotor has a cage section and a permanent magnet section provided on an inner circumferential side of the cage section and formed of a rare earth magnet. The vehicle drive system further includes a controller that executes a synchronous operation mode when a temperature of the permanent magnet section is lower than a predetermined temperature, and executes an asynchronous operation mode when the temperature of the permanent magnet section is equal to or higher than the predetermined temperature. In the synchronous operation mode, the rotor is rotated by using a magnetic force of the permanent magnet section.

To increase an efficiency of conversion into a thermal energy while downsizing a device.SOLUTION: An electrothermal conversion device (10) includes: a rotary heat generator (20); and an electric motor (11) that rotates a rotor (22) via a shaft (12). The rotary heat generator includes: a stator (21) configured by holding a stator winding (26) in a cylindrical stator core (25) along a rotation direction; the rotor (22) provided with a heating conductor (32) disposed inside the stator (21); and a flow path (36) formed between the stator and the rotor. A heat medium (M) flows through a flow path. The heating conductor is formed of a massive soft magnetic conductor.SELECTED DRAWING: Figure 2

The invention discloses a pole-changing multi-speed three-phase asynchronous motor with a dust-free temperature control function, and relates to the field of pole-changing multi-speed three-phase asynchronous motors. The pole-changing multi-speed three-phase asynchronous motor comprises a motor body, a plurality of heat dissipation copper plates are arranged on the outer surface of the motor body at equal intervals in the circumferential direction, a sealing cylinder is arranged on the motor body, and a conical partition plate is arranged in the sealing cylinder; and the interior of the sealing cylinder is divided into two independent cavities by the partition plate. Through driving of the output shaft of the motor main body, the functions of efficient dust removal, heat dissipation and automatic reset are achieved, the scraping frame collects dust on the filter plate into the discharging groove, and secondary diffusion is prevented; the turbine rotates to generate negative pressure, air flow is promoted, heat is taken away, and effective cooling is achieved; the vibration design enhances the dust removal effect; when operation is stopped, all the parts automatically reset under the action of the springs, structural stability is guaranteed, equipment operation efficiency is improved, the service life is prolonged, operation is convenient, and environment friendliness and reliability are achieved.

A system includes an induction motor configured to drive an electric submersible pump (ESP). The induction motor includes a one or more rotors disposed about a rotational axis, and a plurality of bearings disposed about the rotational axis. Each bearing of the plurality of bearings is disposed axially between a pair of rotors of the one or more rotors. The induction motor further includes one or more stators disposed about the one or more rotors.

A rotor for an electric machine of a motor vehicle is provided, which can be used as a rotor of the electric machine, which is rotatably mounted with respect to a stator of the electric machine, wherein the rotor has a plurality of recesses distributed along a circumferential direction and extending along a longitudinal direction, wherein the geometric shapes of the cross sections of the recesses differ from one another along the circumferential direction, wherein, with respect to the assembled state of the electric machine, the recesses are each closed with respect to a radial direction towards a side of the rotor which faces the stator.

A dynamoelectric machine includes a shaft, a rotor arranged fixedly on the shaft for conjoint rotation, and a slip ring system enabling a rotor winding system to be contacted electrically and including a slip ring body having slip rings arranged spaced-apart axially behind one another and assigned to an electrical phase. The slip ring body is connected fixedly to the shaft for conjoint rotation and has between an inner side thereof and the shaft a section which forms an axially open cavity on both skies. In a region of the slip ring system, the shaft is hollow with a hollow shaft portion assigned to the slip ring system for routing feed lines to the rotor winding system. Recesses are provided on the cavity axially on an inside and axially on an outside for introducing a cooling medium flow axially into the cavity and discharge thereof into an outlet region.

The invention relates to the technical field of electromagnetic coils, and discloses a laminated tooth-shaped coil winding based on interlayer phases and a design method of the laminated tooth-shaped coil winding. According to the tooth-shaped coil, the number of effective edges of the winding is remarkably increased through a multi-branch parallel connection mode, and the end portions are reduced; meanwhile, gaps of the concave tooth portion and the convex tooth portion of the tooth-shaped coil provide enough space for winding assemblies such as an iron core, a heat dissipation pipe, an insulating material, a structural material and a sensor, forming of an integrated winding with magnetism gathering, heat dissipation, insulation, structural strength and sensing control is facilitated, and application and popularization of the type of winding are greatly facilitated through the design method.

The present invention relates to the field of magnetic levitation motors, and particularly to a high-speed magnetic levitation asynchronous motor. The motor includes a housing, a stator, a motor shaft, a radial bearing, and an axial bearing; the motor shaft includes a first shaft section, two second shaft sections respectively located outside both ends of the first shaft section, and two third shaft sections respectively located outside both ends of the second shaft sections; a permanent magnet is arranged inside the first shaft section, a copper-clad layer is arranged on the surface of the first shaft section, and the first shaft section is connected to the driving end of the stator; the second shaft section and the third shaft section are respectively connected to the supporting end of the axial bearing and the supporting end of the radial bearing. By arranging a copper-clad layer on the surface of the rotor, the motor does not need to be provided with a sheath, thereby improving the rotational speed and power of the high-speed motor and the heat dissipation performance of the motor.

The utility model relates to the technical field of new energy high-altitude operation parts, and discloses a series excitation three-phase asynchronous drive motor stator assembly, which comprises a flat wire coil formed by winding a bare flat wire, interlayer insulation paper is arranged between layers of the bare flat wire, the bare flat wire comprises a flat wire end, and the flat wire end is provided with an insulation layer. And wrapping cloth is arranged on the surfaces of the four groups of flat wire coils. According to the series excitation three-phase asynchronous drive motor stator assembly, through the flat wire coil formed by the bare flat wire in the winding mode shown in the attached drawing, when a winding machine carries out winding processing on the stator assembly, winding equipment can complete winding at a time, secondary processing is not needed, time and labor are saved, the production efficiency is improved, and the production cost is reduced. Meanwhile, wrapping equipment can conduct wrapping processing on the flat wire coil conveniently, stranded wires are welded conveniently, and finally, the first soft red copper stranded wires and the second soft red copper stranded wires are connected with the designated flat wire ends respectively in a flexible connection welding mode, so that assembly in the subsequent procedure is facilitated, and the production efficiency is improved.

The invention relates to the technical field of squirrel-cage rotors, and discloses a high-torque double-squirrel-cage rotor structure which comprises a rotating shaft and a rotor core installed on the rotating shaft, a lower cage assembly is installed on the rotor core, and an upper cage assembly is arranged on the outer side of the upper cage assembly; the lower cage assembly comprises two lower end rings and a plurality of lower cage conducting bars mounted on the rotor core, the plurality of lower cage conducting bars are located between the two lower end rings, and the end parts of the lower cage conducting bars are connected with the surfaces of the lower end rings; the upper cage assembly comprises two upper end rings and a plurality of upper cage conducting bars installed on the rotor core, the plurality of upper cage conducting bars are located between the two upper end rings, and the end portions of the upper cage conducting bars are connected with the surfaces of the upper end rings. According to the high-torque double-squirrel-cage rotor structure, the lower cage assembly and the upper cage assembly are arranged, and the conductivity of the lower cage assembly and the conductivity of the upper cage assembly are combined, so that the loss and heating of the motor are reduced, and meanwhile, a torque curve is stable and accords with actual working conditions.

The present invention relates to a method for manufacturing an armature and / or rotor for an electric machine, in particular a short-circuit or cage-type rotor, comprising the method steps of inserting a slotted bar, in particular manufactured by an additive manufacturing process, machining, extrusion or die-casting, into an axially extending slot of a laminate stack so that the slotted bar has, on at least one of its end faces, a protrusion above or flush with the laminate stack, in particular at the height of at least one insertion, and of layerwise applying, in particular printing, at least one ring, preferably a short-circuit ring, to at least one of the end faces of the slotted bar, in particular by an additive printing process.

Rotating electric machine (1) with a central longitudinal axis (1C), comprising: a stator (100) comprising armature coils (104) wound around the stator (100) with concentrated winding, the armature coils (104) being configured to generate magnetic flux when excited; and a rotor (300) which is rotatable about the central longitudinal axis (1C) in response to the flow of the magnetic flux, wherein the rotor (300) comprises a plurality of salient poles (302) which are wound by rotor windings (330) which are capable of inducing at least one induced current when the magnetic flux couples with the rotor (300), wherein the rotor (300) comprises at least one rectifier circuit (C1 to C6), wherein the rotor windings (330) are wound such that the salient poles (302) can operate as electromagnets whose magnetization directions are alternately reversed along an arc length of a circle around the central longitudinal axis (1C), wherein each rectifier circuit forms a closed circuit consisting of a group of rotor windings (330), wherein in each group some of the rotor windings (330), whose current phases of the induced current are the same, are connected in series with a rectifier element (D1 to D8), wherein the rotor windings (330) are either divided into four groups such that in each group all rotor windings (330) are connected in series with a rectifier element to form a rectifier circuit or the rotor windings (330) are divided into two groups such that each group comprises several series circuits, of which a first and a second series circuit are connected in parallel and each of these first and second series circuits is connected in series with a rectifying element.

Electric motor comprising a squirrel-cage rotor in the form of a cage, which electrically conductively carries a plurality of rotor end rings formed as cast parts made of a casting material, wherein at least one reinforcing element made of a different material is cast into each of the cast parts, and wherein the casting material substantially forms the outermost free surface of the rotor end ring.

Disclosed herein is an electric vehicle comprising: an electric motor switchable between a first mode having a first number of poles and a second mode having a second number of poles smaller than the first number of poles; a plurality of inverters coupled to the electric motor; and a control module coupled to the plurality of inverters. The control module receives current vehicle information, determines based on the current vehicle information that a mode switch is required between a first mode and a second mode of the electric motor, wherein the first mode achieves higher torque than the second mode; and performs the mode switch by controlling the inverter.

The invention provides a straight-bar stator punching sheet and a forming method thereof, a stator core, a stator structure and a motor. The straight-bar stator punching sheet comprises punching sheet split bodies (1), each punching sheet split body (1) comprises yoke parts (2), stator tooth parts (3) and shoe parts (4), the yoke parts (2) of the adjacent punching sheet split bodies (1) are connected into a whole through a connecting bridge (5), the punching sheet split bodies (1) are divided into at least two groups, the lengths of the shoe parts (4) of the at least two groups of punching sheet split bodies (1) are different along the arrangement direction, and the punching sheet split bodies (1) of different groups are alternately arranged along the arrangement direction. According to the straight-strip stator punching sheet, stator and rotor tooth groove harmonic waves can be effectively weakened, the influence of electromagnetic force is reduced, and motor noise is reduced.

The invention discloses a high-inertia multi-port composite motor for new energy grid connection. The high-inertia multi-port composite motor comprises a brushless doubly-fed motor, an axial permanent magnet motor and a magnetic gear structure. The brushless doubly-fed motor comprises a radial stator and a squirrel cage rotor, a power winding and a control winding are arranged in the stator and serve as a first electric port and a second electric port respectively, the axial permanent magnet motor comprises an axial stator and an axial permanent magnet rotor, and an armature winding is arranged in the stator and serves as a third electric port. The magnetic gear structure is arranged on the inner side of the squirrel cage rotor and the outer side of the rotating shaft, a brushless doubly-fed motor rotor magnetic field is used as a modulation magnetic source, the phase and amplitude of the magnetic field are adjustable, dynamic adjustment of the transmission ratio of the magnetic gear is achieved through a control winding, and electromagnetic and mechanical dual coupling is achieved. The equivalent rotational inertia of the composite motor is obviously higher than that of a single machine, stronger inertia support and frequency stability can be provided for a power grid in a new energy grid connection process, and the composite motor is provided with three independent electric ports, realizes multi-mode operation, and is compact in structure and high in power density.

The invention relates to a rotor (10) of an asynchronous machine (100), comprising: a rotor shaft (11) which extends along an axis of rotation (DA); a rotor lamination stack (12) which is directly or indirectly connected to the rotor shaft (11); a plurality of rotor bars (13, 13a, 13b, 13c) which extend in the direction of the rotational axis (DA) and are arranged in a distributed manner in the circumferential direction about the rotational axis (DA); and at least one shorting ring connecting all the rotor bars (13, 13a, 13b, 13c) to one another in an electrically conductive manner. The plurality of rotor bars (13, 13a, 13b, 13c) comprise at least three different rotor bars (13a, 13b, 13c), which are different from each other in width. The invention further relates to an asynchronous machine (100) having a rotor (10) and to a method for determining a rotational position (DP) of a rotor (10).

The utility model relates to the technical field of squirrel-cage synchronous motors, in particular to a rotor punching sheet and a stator punching sheet on a squirrel-cage synchronous motor of a refrigerator compressor, which comprise 24 stator grooves including two special-shaped grooves A and two special-shaped grooves B, two punching sheet yoke parts 1 form a tip structure of the stator punching sheet, and the included angle of the tip end of the rotor groove is set to be 150-165 degrees. According to the technical scheme of the utility model, one side of the stator punching sheet structure adopts the traditional long-edge design, the other side adopts the pointed-end structure, and four of the 24 slots adopt the special-shaped slot design, so that the size rationality of the yoke part of the motor is ensured, the rationality of the magnetic circuit of the motor in design is ensured, the utilization rate of silicon steel of the motor is improved, and the consumption of silicon steel is reduced; the groove-shaped tooth tip parts of the rotor punching sheet are distributed at 150-165 degrees, and on the premise that the tooth width and the groove-shaped length of the rotor are not changed, the cast aluminum volume of the rotor is improved, so that the impedance of the rotor is improved, the magnetic flux density of the rotor is increased, the maximum torque of the motor is improved, and the starting performance of the compressor is improved.

The utility model discloses a direct-drive electro-magnetic annular synchronous motor, and belongs to the technical field of large-scale synchronous motors. The motor comprises a split stator which is formed by splicing and fixing a plurality of stator petals along the circumferential direction; the block magnetic poles form a motor rotor, a plurality of independently-formed magnetic pole units are arranged at intervals in the circumferential direction, and each magnetic pole unit is directly and fixedly installed on the outer wall of the load rotating cylinder; the supporting and sealing structure is arranged at the axial end part between the split stator and the block magnetic pole and is used for sealing a gap between the split stator and the block magnetic pole; and the collector ring and brush carrier system is arranged at one axial end of the motor, and the output end of the collector ring and brush carrier system is electrically connected with the excitation windings of the block magnetic poles. According to the utility model, the split stator and the block magnetic pole structure are adopted, so that the transportation and field installation of the ultra-large motor are facilitated; the rotor is directly mounted on the outer wall of the milling cylinder to realize direct drive, a gear transmission link is omitted, the transmission efficiency is high, and operation is stable; a multi-layer sealing structure adapts to a high-dust environment, and the reliability is high; the speed regulation performance is good and the maintenance is convenient.