51results about How to "Reduce output torque ripple" patented technology

The invention provides a four-phase doubly salient motor, which belongs to doubly salient motors. The four-phase doubly salient motor consists of a stator and a rotor which are arranged around the same rotating shaft; 8n salient teeth are uniformly distributed on the stator; exciting windings are embedded or permanent magnet steel is arranged in slots at every four salient teeth on the stator; centralized armature windings are sleeved on the salient teeth of each stator respectively; the armature windings on the salient teeth at the same position in a magnetic field are connected in series with one another to form a one-phase winding; and 6n rotor poles are uniformly distributed on the rotor, wherein n is a positive integer and more than or equal to 1. A motor unit has an 8 / 6 structure. The polar distance of the stator is triple the arc length of a stator pole; and the rotor pole is as wide as the stator pole. When the rotor poles are widened until the polar arc coefficient is 1 / 3, the output power is maximum when the motor is used as a generator. Compared with a three-phase 6n / 4n polar doubly salient motor, the four-phase doubly salient motor has higher power density, lower winding copper loss, wider speed regulation range and smaller torque pulse.

The invention discloses a method for lowering torque pulsation of a permanent magnet synchronous motor. The method specifically comprising the steps of reasonably selecting a permanent magnet magnetic pole repetition unit method, selecting offset ways of primary offset and secondary offset and performing angle calculation. The offset units are applied to the permanent magnet magnetic pole repetition units singly or for multiple times, so that the motor performance is improved; the method can be applied to surface mounted, surface embedded type and internal embedded type permanent magnet motors, and torque pulsation caused by different torque components can be lowered; the permanent magnet synchronous motor can rapidly work out magnetic pole offset angles by reasonably selecting the offset units; after offset, the sine degree of counter electromotive force waveform can be effectively improved; each kind of sub-harmonic content of the torque pulsation can be reduced by peak valley cancellation between the torque pulsations generated by each repetition unit, so that the overall torque pulsation is lowered; and meanwhile, motor vibration noise can be introduced at the minimum level under the premise of ensuring that the output torque value of the motor is basically unchanged, so as to realize an optimal effect.

The invention discloses a control method of a self-balancing man-riding electric unicycle. The method includes: acquiring data from an accelerator and a gyroscope disposed on the unicycle, subjecting the acquired data to Kalman filtering to obtain current tilt angle and tilt angular velocity of the unicycle, acquiring a given motor speed value through a nonlinear PD (proportional plus derivative) controller, acquiring a given torque current value from a difference between the given motor speed value and a currently measured motor speed fed-back value through a PI (proportional plus integral) controller, acquiring a drive signal through vector control, and allowing a motor to output a proper torque to keep the unicycle balanced. The control method has the advantages that a control strategy features good dynamic and static properties, system vibration and noise are reduced, and the unicycle is allowed to self-balance the attitude and to carry a man riding.

The invention belongs to the field of drive of fracturing pump sets in shale gas extraction, and particularly relates to a multiphase fracturing machine set electric drive control system. The system comprises a ring main unit, a phase-shifting transformer, a frequency converter and a nine-phase motor, wherein high voltage electricity is introduced into the ring main unit from a power grid and converted into at least two nominal-voltage secondary three-phase commutating windings and an auxiliary secondary winding through the phase-shifting transformer, the commutating windings supply power to the frequency converter, and by outputting three sets of three-phase alternating current inversely, the frequency converter drives the nine-phase motor to drive a fracturing plunger pump to work; the auxiliary secondary winding is in charge of supplying power to a control cabinet, an MCC cabinet, a transformer fan and a cooling refrigerator system, and the MCC cabinet is in charge of supplying power to an external lubricating oil circulating pump and a lubricating oil heat-dissipation cooling fan; after state information detection is conducted, the ring main unit, the transformer fan and the nine-phase motor are used for logical judgment of the control cabinet. Compared with conventional diesel / natural gas engines, the multiphase fracturing machine set electric drive control system has theadvantage that the discharging amounts of nitrogen oxides and oxycarbides are almost zero, so that the multiphase fracturing machine set electric drive control system is environmentally friendly; moreover, the energy consumption cost is reduced, and the running cost is low.

The invention discloses a method for reducing the torque ripple of a five-phase embedded permanent magnet motor. According to the invention, a stator magnetomotive force model is established. An equivalent magnetic circuit diagram of the motor is extracted, and an odd harmonic part in the rotor magnetomotive force is converted into an even harmonic part according to the interaction principle between the stator magnetomotive force and the rotor magnetomotive force of the motor. In this way, the permanent magnet torque ripple is reduced. Meanwhile, an optimal extreme arc coefficient ratio underthe condition of an asymmetric magnetic pole structure is solved. On the basis of the asymmetric magnetic pole structure, the repeated units of a permanent magnet magnetic pole are determined. The angle of one-time offset is calculated, and a proper offset method is selected for carrying out the magnetic pole deviation. The performances of the reluctance torque and the cogging torque are reduced.According to the invention, the equivalent magnetic circuit method is used for analyzing and calculating an optimal extreme arc coefficient. Not only the optimal permanent magnet torque performance isobtained, but also the design period is shortened. By adopting the magnetic pole offset method, the pulsation of the output torque of the embedded motor is further reduced.

The invention discloses a stator / rotor permanent magnetic type magnetic-flux-variable axial magnetic flux switching permanent magnetic generator. The generator comprises a first rotor, a first stator,a second rotor, a second stator and a third rotor which are installed coaxially in order, the first rotor and the third rotor are symmetric by taking the second rotor as the center, the first statorand the second stator are symmetric by taking the second rotor as the center, and each of the rotors and stators is of a salient pole structure. An aluminum-nickel-cobalt permanent magnet is low in acoercive force, so that different pulse currents are applied to change the magnetization magnitude and direction of the aluminum-nickel-cobalt permanent magnet, the magnetization level of the permanent magnet can be changed and memorized, and an air gap magnetic field of a motor can be controlled flexibly by adjusting the directions and magnitudes of the pulse currents. In addition, a pulse winding only applies a magnetizing / demagnetizing current in a very short time, there is nearly no exciting copper loss, and the problem that the power or torque density of an existing axial variable magnetic flux switching permanent magnetic generator is not high enough is solved.

The invention discloses a low-torque ripple sensorless control method for a synchronous reluctance motor, and belongs to the technical field of motor control. The invention aims to solve the problemsof high-frequency torque pulsation and noise pollution of a direct-axis high-frequency signal injection method used at a zero low speed in the position sensorless control of a conventional synchronousreluctance motor. The method comprises the following steps: simultaneously injecting predetermined high-frequency pulse voltages with the same phase and fixed amplitude proportion into a dq shaft system of the synchronous reluctance motor; obtaining a rotor position estimation error based on the extracted three-phase pulse current in the abc three-phase shaft system of the synchronous reluctancemotor; further obtaining a rotor estimation position and a rotor estimation rotating speed which are used for closed-loop control of the motor; and performing calculating to obtain q-axis compensationcurrent, and compensating for the q-axis current of the motor, so the actual rotating speed of the rotor better tracks the given rotating speed of the rotor, and the output torque ripple of the synchronous reluctance motor is reduced. According to the invention, the output torque ripple of the synchronous reluctance motor can be reduced on the basis of realizing sensorless control.

The invention belongs to the field of mining hydraulic motors, and especially discloses a same-distribution-angle hydraulic cylinder motor. A technical problem to be solved is providing a same-distribution-angle hydraulic cylinder motor with the advantages of simple structure, operation convenience, high safety coefficient, long service life and effective reduction of the coal mine underground accident rate. The motor comprises a case body, three hydraulic cylinders, a crankshaft, a case body front end assembly and a control system, the whole case body is a shell structure, the three hydraulic cylinders are arranged in the case body side by side, the front end of the case body is provided with a case body semicircle seat for installing the crankshaft, the case body front end assembly is fixedly connected with the case body to fix the crankshaft, the piston terminals of the hydraulic cylinders are connected with the crankshaft through piston terminal covers, the hydraulic cylinders move back and forth to drive the crankshaft to rotate, the crankshaft drives the control system to move, and the control system controls the reciprocating motion of the three hydraulic cylinders in order to drive the crankshaft to continuously revolve. The motor adopting the hydraulic cylinders to drive the crankshaft to rotate has the advantages of low rotating speed, large torque, and suitableness for the use requirements of coal mine underground equipment.

The invention discloses a sinusoidal doubly-salient motor with a trapezoid rotor tooth structure and a design method of the sinusoidal doubly-salient motor. The sinusoidal doubly-salient motor is composed of stators and rotors. The stators and the rotors are both of a salient pole tooth groove structure. The number of stator teeth and the number of rotor teeth meet the relation of 6 / 4N, wherein N=1, 2, 3...; stator tooth grooves are identical in width, armature windings and exciting windings (or magnetic steel) are embedded in the stator tooth grooves, and the rotors are of the trapezoid tooth structure and are distributed in a lateral symmetric mode. The design method is used for optimizing the widths of the rotor teeth and the widths of rotor tooth grooves, the widths of the narrow sides of the rotor teeth are equal to those of the stator teeth, the widths of the wide sides of the rotor teeth are twice those of the stator teeth, and the optimal trapezoid wave rotor tooth structure is formed. Under the exciting of the exciting windings or the magnetic steel, in the rotating process of the rotor teeth, sinusoidal counter potential waveforms are sensed in three-phase armature windings of the stators of the doubly-salient motor.

The invention discloses a virtual polarity fractional-slot concentrated winding spoke type permanent magnet motor and a torque ripple inhibition method thereof. A novel spoke type permanent magnet synchronous motor which is provided with a virtual polarity and is in hybrid connection with a star triangular winding is provided. The torque ripple of the motor is reduced by reducing stator and rotorharmonic orders respectively on the basis of determining the stator and rotor magnetomotive force harmonic orders influencing the torque ripple. The specific process comprises the step of determiningthe harmonic orders of rotor gap flux density influencing the torque ripple according to the relation that the rotor gap flux density is in direct proportion to rotor magnetomotive force. 11-th and 13-th harmonics in rotor magnetomotive force are eliminated by using unequal pole-arc coefficients, so that 12-th harmonics of torque ripple are eliminated. And then, 5-th, 7-th, 17-th and 19-th harmonics in stator magnetomotive force are eliminated by using the hybrid connection of the star triangular winding, so that 6-th and 18-th harmonics of torque ripple are eliminated, and the purpose of reducing the torque ripple integrally is reached.

The invention provides a motor rotor, a motor and a compressor. The motor rotor includes a rotor body, wherein a plurality of poles are disposed on the rotor body in a circumferential direction; eachof the poles includes two magnetic steel slots spaced apart in the radial direction of the rotor body and permanent magnets embedded in the magnetic steel slots; and at least one magnetic barrier structure is arranged between the two magnetic steel slots of each pole. The reactance of the quadrature-axis magnetic circuit of the motor rotor can be controlled within a reasonable range so as to ensure that the motor rotor has a certain output torque, reduce the output torque ripple and the radial electromagnetic force, improve a cogging effect, and reduce the electromagnetic excitation force andelectromagnetic noise caused thereby.

The invention provides a double-stator circumferential direction misalignment angle electro-magnetic direct current motor and a control method thereof, relating to the technical field of direct current motors. The motor comprises a motor shell, a rotational shaft, a stator and a coil of the stator, a rotor and a central exciting coil; a layer of magnetizers are fixedly covered on the surface of the rotational shaft inside the motor shell; the stator comprises a first group of salient pole stators and a second group of salient pole stators; and the rotor comprises a first group of salient pole rotors and a second group of salient pole rotors. The first group of salient pole stators and the first group of salient pole rotors have the same centers, and are in teeth alignment placement; the centers of the second group of salient pole stators and the centers of the second group of salient pole rotors are coaxial, and are placed by staggering a 15-degree mechanical angle in the circumferential direction between teeth. By adopting neural network-based angle optimizing position control, when the voltage on the coil is constant, the torque of the motor is adjusted through changing an angle of flow theta on and a turn-off angle theta off of a main switching tube, which are connected in series with the coil. According to the direct current motor provided by the invention, a magnet exciting coil is added between two groups of stators while the stators are misaligned in the circumferential direction; the torque pulsation is reduced fundamentally; and the demagnetizing risk of a permanent magnet can be avoided.

The invention discloses a hybrid rotor continuous pole permanent magnet synchronous motor and a method for reducing torque ripple thereof. The hybrid rotor continuous pole permanent magnet synchronousmotor comprises an outer stator and an inner rotor. The outer stator is provided with five phases of distributed armature windings; and the inner rotor is provided with surface-embedded permanent magnets and spoke type permanent magnets. The method for reducing torque ripple of the hybrid rotor continuous pole permanent magnet synchronous motor comprises the following specific steps: to begin with, increasing phase number of the permanent magnet motors to reduce the torque ripples; then, optimizing pole arc coefficient and thickness of the surface-embedded permanent magnets and the length andwidth of the spoke type permanent magnets to reduce the torque ripples again; and carrying out angular deflection on the spoke type permanent magnets to further reduce the torque ripples. The motor overcomes the disadvantages of large torque ripple, large eddy-current loss of the permanent magnets and easy demagnetization of the permanent magnets when overloaded of a conventional continuous polepermanent magnet synchronous motor, and meanwhile, maintains the characteristics of high torque density and high utilization rate of the permanent magnets of an original motor.

The invention discloses a harmonic wave reducing method of a permanent-magnetic fault tolerance motor. The method comprises reduction of sine harmonic waves, reduction of sine and third harmonic waves, reduction of arc cosine harmonic waves and reduction of arc cosine and third harmonic waves, harmonic wave reduction is applied to a stator or rotor independently, or harmonic wave reduction is applied to both the stator and rotor at the same time by combining different methods, and the performance of the motor is improved. The method can be applied to an iron core portion of the rotor or stator as well as to a permanent magnet portion of the rotor or stator. When the harmonic wave reducing method is applied to the permanent-magnetic fault tolerance motor, the air-gap flux density and the sine degree of counter-electromotive force waves can be effectively improved, the content of different sub-harmonic waves is reduced, and the whole torque ripples are reduced; and the operation stability of the motor is enhanced, and noises and vibration are reduced.

The invention discloses a method for reducing torque ripples of a continuous pole permanent magnet synchronous motor, which specifically comprises the steps of firstly, determining the harmonic orderof the rotor magnetomotive force affecting the torque ripples starting from the principle of the generation of the torque ripples; then determining the harmonic order of the rotor air gap flux densityaffecting the torque ripples according to a relation that the rotor air gap flux density is in direct proportion to the rotor magnetomotive force; deducing a formula of the angle difference of unequal continuous pole permanent magnet pole-arc coefficients for weakening the main harmonic order of the specific torque ripple through deducing the Fourier expression of the rotor air gap flux density in the cases of equal continuous pole permanent magnet pole-arc coefficients and unequal continuous pole permanent magnet pole-arc coefficients; and furthermore, reducing the primary main harmonic waves of the torque ripples through the peak-valley cancellation generated by the unequal pole-arc coefficients between the torque ripples so as to achieve the purpose of reducing the overall torque ripples. Therefore, the method has high permanent magnet utilization rate and low torque ripples under the condition of ensuring that the average output torque of the motor is almost unchanged.

The invention relates to an electric wheel mining dump truck, in particular to a power control system of a new energy electric wheel mining dump truck. The defects and problems existing in an electricwheel mining dump truck which adopts a diesel generator set to provide power are solved. The power control system of the new energy electric wheel mining dump truck comprises a lithium battery, a hydrogen fuel cell engine, a direct-current bus, a first DC / DC triple chopper, a second DC / DC triple chopper and a third DC / DC triple chopper, wherein the lithium battery and the hydrogen fuel cell engine are respectively connected in parallel with the direct-current bus; the first DC / DC triple chopper takes power from the direct-current bus and supplies power to an armature winding of the first DC motor; the second DC / DC triple chopper takes power from the direct-current bus and supplies power to the armature winding of the second DC motor, and the third DC / DC triple chopper takes power from thedirect-current bus and supplies power to the excitation windings of the first DC motor and the second DC motor. The power control system adopts a hydrogen fuel engine and lithium battery hybrid energy system to replace the diesel generator set to provide power.

The invention discloses an asymmetrical excitation stator alternate-angle dual-salient-pole motor and a control method thereof, and belongs to the technical field of direct-current motors. The motor comprises a motor revolving shaft, a magnetic conductive material, a central electric excitation coil, two groups of salient pole stators, two groups of salient pole rotors and a stator winding, wherein four salient pole teeth are distributed on the rotors; six salient pole teeth are distributed on the stators; a second group of salient pole stators is staggered away from a first group of salient pole stators by a mechanical angle of 30 degrees; the stator winding is partitioned into a phase A, a phase B and a phase C; and the phases A, phases B and phases C of the salient pole stators on two sides are arranged in a staggered way. The method comprises the following steps: selecting a powered-on winding according to positions of the rotors; rotating the motor after powering on; performing phase change when a rotor tooth center line is deviated from a stator tooth center line on one side by 40 degrees; performing phase change at a phase change angle of 30 degrees; and rotating the motor continuously. The two groups of salient pole stators being staggered away by a certain mechanical angle are based on a torque overlapping principle, and torques generated by windings on both sides are overlapped, so that the torque of an axial excitation dual-salient-pole motor is increased, and the torque pulsation is reduced.

The invention provides a block rotor-type double-stator variable flux reluctance motor, which comprises an outer stator, an inner stator and an odd number-pole rotor, wherein the odd number-pole rotor is clamped between the outer stator and the inner stator and is prepared from an odd number of magnetic conductive materials; the inner stator is coaxially connected with the outer stator; each tooth of one of the inner stator and the outer stator is wound by an AC armature winding and a DC exciting winding which are driven by sine-wave current; an outer-layer air gap is arranged between the outer stator and the rotor; and an inner-layer air gap is arranged between the inner stator and the rotor. The number of rotor poles of the motor is the odd number; the output torque ripple is small; and the radial unbalanced magnetic pull of the odd number-pole rotor is obviously inhibited or even eliminated.

The invention belongs to the field of mining hydraulic motors, and particularly discloses a horizontal hydraulic cylinder type motor. The horizontal hydraulic cylinder type motor aims to achieve the technical purposes that the structure is simple, operation is convenient, safety coefficients are high, service life is long, and the underground coal mine accident rate can be effectively reduced. The horizontal hydraulic cylinder type motor comprises a box, three hydraulic cylinders, a crankshaft, a box front end assembly and a control system. An installing seat board is arranged at the bottom of the box, the hydraulic cylinders are arranged in the box side by side, the ends of pistons of the hydraulic cylinders are connected with the crankshaft through piston end covers, the output end of the crankshaft and the installing seat board are arranged on the same side, the hydraulic cylinders move in a reciprocating mode to drive the crankshaft to rotate, the crankshaft drives the control system to move, the control system controls reciprocating motion of the three hydraulic cylinders to drive the crankshaft to conduct continuous rotational motion, the hydraulic cylinders drive the crankshaft to rotate, the rotating speed is low, torque is large, and the horizontal hydraulic cylinder type motor meets the requirements for use of underground coal mine equipment.

The invention discloses a six-phase sine wave doubly salient motor and a control system thereof, a unit motor is of a 12 / 10 pole structure, each excitation element is wound across six stator poles, and the directions of magnetic fields generated by adjacent excitation coils are opposite. The armature coils are wound on the stator poles, the winding direction is consistent with the magnetic field of a magnet exciting coil of a turn chain, and the armature coils with the phase difference of 180 degrees are mutually combined and reversely connected in series to form a six-phase armature winding.A rotor is of a fan-shaped tooth or T-shaped tooth structure and adopts an eccentric air gap pole arc, and the motor rotor is of a skewed pole structure. After the excitation element generates excitation, during rotor rotation process, counter electromotive force of sine waves is induced in the armature winding. A vector control mode can be adopted, the problem that square wave control torque pulsation of a traditional doubly salient motor is large is effectively solved, a six-phase armature winding of the motor can flexibly form a three-phase, double three-phase redundancy and six-phase faulttolerance motor drive control system, and a new choice is provided for a high-reliability and low-torque pulsation drive motor.

The invention discloses a balance-adjustable bilateral drive axial plunger motor which comprises a cylinder, an oil distribution disc, shells, a transmission shaft and a pressure intensity micro-adjustment device. Multiple rows of plunger holes evenly distributed around concentric circles are formed in the cylinder. The oil distribution disc is provided with multiple rows of oil suction ports and oil drainage ports. The oil drainage ports in each row of the oil distribution disc are communicated with an oil outlet through the corresponding shell. The oil suction ports in each row of the oil distribution disc are communicated with an oil inlet through the corresponding shell. The oil suction ports in the outer row or the oil outlets of the oil distribution disc are communicated with oil outlets of the pressure intensity micro-adjustment device. The stability of the bilateral drive axial plunger motor under high pressure and large loads can be well guaranteed, the design difficulty of the bilateral drive axial plunger motor can be greatly reduced, the service life of the bilateral drive axial plunger motor is prolonged, and the bilateral drive axial plunger motor is simple, feasible and good in application prospect and popularization value.

The invention discloses an adjustable and balanced double-sided drive axial plunger motor, which includes a cylinder body, an oil distribution plate, a housing, a transmission shaft and a pressure fine-tuning device. The plunger hole, the oil distribution plate is provided with multiple rows of oil suction ports and oil discharge ports, and the housing connects each row of oil discharge ports of the oil distribution plate to an oil outlet, and the oil distribution plate Each row of oil suction ports is connected to an oil inlet, and the outer oil suction ports or oil outlets of the oil distribution plate are connected to the oil outlet of the pressure fine-tuning device. The invention can well ensure the stability of the double-side driven axial plunger motor under high pressure and heavy load, and at the same time greatly reduce the design difficulty of the double-side driven axial plunger motor and increase its service life. application prospect and promotion value.

The invention discloses a three-phase doubly salient motor with non-uniform stator pole width distribution. The three-phase doubly salient motor comprises a stator iron core, a rotor iron core, an excitation element, an armature winding and a rotating shaft, and is characterized in that the rotor iron core is arranged inside the stator iron core, the rotating shaft is arranged inside the rotor iron core, the excitation element is arranged at the yoke part of the stator iron core, the armature winding is wound on the stator pole of the stator iron core, a rotor pole is arranged on the rotor iron core, the pole width of the stator pole is unevenly distributed, the pole width of the rotor pole is evenly distributed, the maximum pole width dmax of the stator pole is equal to the pole width of the rotor pole, the minimum pole width dmin is two thirds of the pole width of the rotor pole, the rotor iron core and the stator iron core are both of a salient pole structure, the number of the rotor poles is 4N, the pole-arc coefficient of the rotor is 0.5, the number of the stator poles is 6N, and N is a positive integer. According to the invention, approximate sine of the induction electromotive force of the armature winding of the doubly salient motor is realized, so that the doubly salient motor can adopt sine wave power supply, the torque ripple of the doubly salient motor is reduced, and the iron core loss of the motor is reduced.

The invention discloses subway tunnel wind power generating device with a double-wind wheel wind energy capture and spring energy storage structure. The device comprises double-wind wheel wind turbines, a speed reducing gearbox, a spring energy storage box, a mechanical energy sustained release device, a permanent magnet generator, a direct current converter and a direct current bus which are connected in series in a staggered manner. Double-wind wheel wind energy capture is realized through the double-wind wheel wind turbines which are connected in series in the staggered manner, and the windenergy utilization rate and the output torque are increased; high rotating speed of the wind turbines is converted into low rotating speed high torque output through the speed reducing gearbox, whichis beneficial for energy storage of a spring; the captured wind energy is stored as mechanical energy through the spring energy storage box; the conversion from the mechanical energy to electric energy is realized by the permanent magnet generator; and alternating current is converted into direct current and the direct current is output to the direct current bus through the direct current converter. The subway tunnel wind power generating device with the double-wind wheel wind energy capture and spring energy storage structure can realize the functions of tunnel wind energy capturing, mechanical energy storage and power generating, has the advantages of safety, high wind energy utilization rate and the like, and fills the technological gap of mechanical energy storage and renewable powergeneration of tunnel wind energy.

The invention discloses a rotor permanent magnet type hybrid excitation axial flux switching permanent magnet motor, and belongs to the field of hybrid excitation synchronous motors. The motor comprises a first stator, a rotor and a second stator arranged in a coaxial manner, the rotor is clamped between the first stator and the second stator, each stator is formed by six E-type iron cores, six centralized armature windings, and six centralized excitation windings, and the rotor is formed by ten pairs of rotor poles and ten aluminium-nickel-cobalt permanent magnets. According to the motor, theaxial length is short, the structure is compact, the size is small, and the power and torque densities can be increased; the aluminium-nickel-cobalt permanent magnets are arranged on the rotor so that the torque output capability is great, and the overload capability of the motor is improved; the torque ripple is small, the dynamic and steady-state performances of the system are enhanced, and theoperation is more stable; the reactance of armature reaction is low, an excitation magnetic field and a permanent magnetic field are in a parallel connection relation, and the magnetic adjustment isflexible and convenient; and the permanent magnets are located on the rotor so that a stator magnetic circuit is not easily saturated, and the constant-power speed regulation range of the motor is greatly extended.

The invention discloses a method for reducing the torque ripple of a five-phase embedded permanent magnet motor. According to the invention, a stator magnetomotive force model is established. An equivalent magnetic circuit diagram of the motor is extracted, and an odd harmonic part in the rotor magnetomotive force is converted into an even harmonic part according to the interaction principle between the stator magnetomotive force and the rotor magnetomotive force of the motor. In this way, the permanent magnet torque ripple is reduced. Meanwhile, an optimal extreme arc coefficient ratio underthe condition of an asymmetric magnetic pole structure is solved. On the basis of the asymmetric magnetic pole structure, the repeated units of a permanent magnet magnetic pole are determined. The angle of one-time offset is calculated, and a proper offset method is selected for carrying out the magnetic pole deviation. The performances of the reluctance torque and the cogging torque are reduced.According to the invention, the equivalent magnetic circuit method is used for analyzing and calculating an optimal extreme arc coefficient. Not only the optimal permanent magnet torque performance isobtained, but also the design period is shortened. By adopting the magnetic pole offset method, the pulsation of the output torque of the embedded motor is further reduced.

The invention belongs to the field of mining hydraulic motors, particularly discloses a walking type hydraulic cylinder motor. The hydraulic cylinder motor with equal distributed angles is simple in structure, convenient to operate, high in safety coefficient, long in service life, is capable of effectively reducing the accident rate under a coal mine. The hydraulic cylinder motor comprises a box body, three hydraulic cylinders, a crank shaft, a box body front end component and a control system, wherein an installing plate fixed together with a tractor is arranged at one side of the box body; the hydraulic cylinders are arranged in the box body side by side; the hydraulic cylinders do reciprocating motion to drive the crankshaft to do rotating motion and the crankshaft drives the control system to move; the control system is used for controlling the three hydraulic cylinders to do reciprocating motion so as to drive the crankshaft to do continuous rotating motion; the hydraulic cylinders drives the crankshaft to rotate and can be used as left and right input devices of the tractor and a crane so as to drive the tractor and the crane to move simultaneously.

The invention discloses a built-in alternative-pole permanent-magnet motor based on a rotor complementary structure. In the motor, a permanent magnet pole S (7), a permanent magnet pole N (8) and an iron core pole (9) are respectively disposed in a first rotor (2), a second rotor (3) and a third rotor (4) in a heteropolar alternative-pole mode. The three-rotor structure is nested in a stator (1),and is coaxial with the stator (1). The stator (1) comprises armature teeth (5) and fault-tolerant teeth (6), wherein the armature teeth (5) and fault-tolerant teeth (6) are alternately arranged alongthe periphery of the stator (1). The armature teeth (5) is provided with an armature winding (10), and the armature winding (10) is wound in a mode of single-layer fractional-slot centralized winding. Compared with a multi-stator structure and a distributed winding, the alternative-pole rotor complementary structure is simple and reliable, is low in cost, has no magnetic circuit coupling, is small in copper loss, and is high in efficiency. Because the stator (1) is just provided with one single-layer fractional-slot centralized winding, a motor end part is small in loss, and the torque and power density are high.

The invention belongs to the field of mining hydraulic motors, and in particular discloses an equal distribution angle hydraulic cylinder motor with an emulsion filter under the mine; the technical problem to be solved is to provide a motor with simple structure, convenient operation, high safety factor, and Equidistributed angle hydraulic cylinder motor with an underground emulsion filter that has a long life and can effectively reduce the accident rate in coal mines; the technical solution adopted: includes an oil tank, a filter device, an oil pump and a hydraulic cylinder motor, the supply of the oil tank The oil port is connected to the oil inlet port of the oil pump through a filter device, and the oil outlet port of the oil pump is connected to the oil return port of the oil tank through a hydraulic cylinder motor, which converts the horizontal reciprocating motion of the hydraulic cylinder into the crankshaft Rotary movement, the underground emulsion filter can provide different filtration accuracy, to ensure the clean emulsion provided to the hydraulic cylinder of the hydraulic cylinder motor, and to improve the service life of the hydraulic cylinder motor.