69results about How to "Improve vibration and noise" patented technology

The invention relates to an embedded sine-profile permanent motor rotor which solves the problem that permanent magnets in traditional motors in the prior art are generally attached to the outer sides of rotors and prone to shed in high-speed rotation of the rotors and the problem of vibration noise caused by instability in operation of the motors due to fluctuation in rotation of the rotors in normal shapes. A winding shaft on the surface of the rotor is provided with a plurality of arc protrusions in consecutive connection, the rotor is partitioned into a plurality of equal areas by the ligature of the rotor axis and the crosspoint of each two adjacent protrusions, two grooves in inverted splayed array are arranged in each area, and permanent magnets are inserted in the grooves. The embedded sine-profile permanent motor rotor has the advantages that the separation of the permanent magnets in high-speed rotation of the rotor is avoided, and reliability of the motor is improved while the service life of the motor is prolonged; salient pole rate is increased, larger salient pole torques can be generated, efficiency is improved, and the service life of the motor is prolonged; and the motor is more stable in operation, loss caused by harmonic waves is reduced, and vibration noise of the motor is improved to some extent.

The invention discloses a switch reluctance motor system. The switch reluctance motor system comprises a power supply, a power transformer which is connected with the power supply, a switch reluctance (SR) motor which is connected with a power variator, a load which is connected with the SR motor, an SR motor current detecting part, an SR motor position detecting part, a controller which is respectively connected with the SR motor current detecting part and the SR motor position detecting part and a phase compensation circuit. The switch reluctance motor system completely adopts a hardware circuit to form a digital angular control link, so that a conduction angle and a turn-off angle are translated forwards, the angle control is started when the rotation speed of the motor reaches a set rotation speed, the angle is conducted and turned off in advance, namely a conduction and turn-off waveform is translated forwards, thus the control method can well improve the motor torque and the motor vibration noise, and the operation performance of the switch reluctance motor at a high speed can be improved.

The invention relates to a variable displacement swash plate compressor. A swash plate driving mechanisms with a flexible driving balance design is provided, has proper flexibility during work, overcomes unbalanced force and moment acting on the swash plate, improves vibration, noise, kinematic pair blockage and excessive wear caused by the unbalanced force and moment, and reduces machining and assembly precision of related workpieces; a piston with a spiral linear oil groove is provided and stores oil, and through the reciprocation of the piston and the acceleration change of the piston, lubricating oil flows reasonably between the kinematic pair and is uniformly distributed on the cylindrical surface of the piston and the peripheral surface of the cylinder to improve the sealing and lubricating properties between the piston and the peripheral surface of the cylinder, improve the performance of the compressor and prolong the service life of the piston; and a cylinder cover capable of being formed at one time through die casting and having simple process is provided, and suction and discharge channels adopt a single-section or multi-section expansion chamber-type cavity consisting of alternate contraction sections and expansion sections to improve the vibration and air flow noise caused by suction and discharge pulsation.

The invention relates to an external rotor brushless permanent magnet motor and belongs to the motor technical field. The objective of the invention is to solve the technical problems of motor vibration and operating noises. The motor includes a rotor and a stator arranged in the rotor. The inner wall of the rotor is provided with a plurality of permanent magnetic poles at intervals along a circumferential direction. Chamfers are formed at the left edge portion and right edge portion of the inner side of each permanent magnetic pole. A plurality of stator teeth are formed on the stator. The stator teeth are distributed at intervals along the circumferential direction of the stator. The external rotor brushless permanent magnet motor is characterized in that a left stator auxiliary groove and a right stator auxiliary groove are formed in each stator tooth; and cut tooth tips are formed at the left edge portion and right edge portion of each stator tooth. According to the external rotor brushless permanent magnet motor provided by the invention, small vibration and operating noises are generated in the operation of the external rotor brushless permanent magnet motor.

The invention discloses a permanent magnet synchronous motor vibration noise active suppression method, which is based on a DSP + FPGA embedded control system architecture. On the basis that a DSP timer is interrupted to complete sampling processing and closed-loop control and obtain a modulation degree and an angle real-time instruction, an angle jump quantity between adjacent sampling points isextracted, and an angle stepping value is calculated by adopting a virtual high-frequency method; a modulation instruction is sent to an FPGA through a high-speed data bus, the amplitude of a modulation wave in a control period is equivalently linearized and stepped to an instruction value by utilizing high running speed of the FPGA, reliable zero clearing of a counter and a stepper cache is guaranteed through clock synchronization, a smooth modulation wave is generated and compared with a triangular carrier, and then a PWM pulse is output; and a driving inverter converts a direct-current busvoltage into a three-phase alternating-current voltage to drive a motor to operate, so that multi-sampling fine control of key variables is realized, the variable updating frequency and the control precision are remarkably improved, the variable jump is avoided, and the torque ripple and the electromagnetic vibration noise of the motor are effectively improved.

The invention discloses a rotor auxiliary slot optimization design method for reducing the vibration noise of a built-in permanent magnet motor, and the method specifically comprises the steps of determining the size of the built-in motor according to the actual design requirements, wherein the built-in motor in the specification employs a single-layer V-shaped embedded structure; adopting a double-auxiliary-slot structure on the surface of the rotor, and optimizing the double-auxiliary-slot structure by using a multi-objective optimization algorithm. According to the invention, the rotor auxiliary slot structure is utilized to locally adjust the air-gap flux density distribution, so that the harmonic content which plays a main role in the vibration noise in the air-gap flux density can be remarkably reduced, and the electromagnetic harmonic content in an air-gap magnetic field is further improved; and then the optimal auxiliary slot structure and position point are selected in combination with a multi-target backbone particle swarm algorithm, the optimal electromagnetic force distribution condition is obtained, the vibration noise condition of the built-in permanent magnet motor in the multi-working-condition and wide-speed-domain operation process is obviously improved, and thus the operation stability of the motor is improved.

The present invention provides a control method for inhibiting single-phase capacitor run motor vibration noise. The circuit of the method comprises a primary winding, a secondary winding, a start capacitor and an adjustable run capacitor. The induction electromotive force of the secondary winding when the primary winding is powered and the secondary winding is disconnected and the induction electromotive force of the primary winding when the secondary winding is powered and the primary winding is disconnected are detected when a motor is in a no-load operation, and the effective turn ratio of the primary winding and the secondary winding is obtained. Rated voltage is applied to the motor to allow the motor to drive a load to run, a start capacitor is disconnected after normal running, the adjustable run capacitor is connected, the voltage of the primary winding, the secondary winding and the adjustable run capacitor at that time are detected, the ovality information of a gap magnetic field is obtained, the capacitance value of the adjustable run capacitor is changed according to the information, the vibration noise in common single-phase capacitor run motor load running can be effectively inhibited, the adjustable run capacitor can be changed according to different loads dragged by the motor, and the vibration noise is small when multiple types of loads are dragged by the motor.

The invention discloses a radialskewed slot rotor and a motor applying the same. The motor applying the radial skewed slot rotor comprises theradial skewed slot rotor. Theradial skewed slot rotorcomprises a rotating shaft, a plurality of rotor punching sheets and conducting bars, and the radial skewed slot rotor is mainly formed by coaxially laminating the plurality of rotor punching sheets, wherein a shaft hole is formed in the axis position of each rotor punching sheet, the position of a rotor notch is not changed, the center line of the rotor groove of the outer circle inclines by a certain angle along the radial direction of the rotor punching sheet to form an inclined rotating groove, and the plurality of rotating grooves are uniformly distributed along the circumference. The radial skewed slot rotor and the motor applying the radial skewed slot rotor can be directly applied to an existing asynchronous motor, and compared with an axial skewed slot rotor motor which is widely used at present, the equivalent slot depth and the equivalent guide bar length of the manufactured radial skewed slot rotor motor are reduced, so that the total leakage reactance value of the radial skewed slot rotor motor is reduced, the loss and the size of reactive current in the rotor are reduced, and the effects of improving the efficiency and the power factor and increasing the overload capacity are achieved.

The invention provides a compressor and a refrigeration device. The compressor comprises a shell, a pump body assembly which is arranged in the shell and comprises a crankshaft and an upper bearing,and a motor assembly which is arranged in the shell configured to be suitable for driving the pump body assembly. The motor assembly comprises a stator assembly which is fixed on the upper bearing, and a rotor assembly which is connected with the crankshaft. The rotor assembly drives the crankshaft to perform rotary compression, and the rotor assembly is arranged in the axial direction of the stator assembly. According to the compressor provided by the invention, the stator assembly is directly fixed on the upper bearing, so that the stress of the stator assembly is reduced; the electromagnetic noise is reduced, and the performance of the motor assembly is improved; the performance of the compressor is improved; the rotor assembly is arranged in the axial direction of the stator assembly,and the rotor assembly and the stator assembly are designed to be flat, so that the height of the motor assembly is low; and the flat stator assembly and the flat rotor assembly are similar to plates,so that the miniaturization design of products is realized.

The invention relates to a rotor torsion inclination method suitable for a permanent magnet synchronous motor, the permanent magnet synchronous motor comprises a stator and a rotor core which are coaxial, and the method comprises the following steps: the rotor core is axially divided into five sections of rotors with the same length, and according to the number of pole pairs of the motor and the order of magnetic field harmonic waves needing to be weakened, one section of rotor is taken as a reference; and the other four sections of rotors are respectively twisted clockwise or anticlockwise by an angle alpha 1 or alpha 2 to form an arrangement mode for weakening specific-order magnetic field harmonic waves. Compared with the prior art, the five rotors can be freely combined to be distributed in the axial direction, rich torsion inclination angles are generated to be matched to weaken magnetic field harmonic waves of specific orders, and when the multiple rotors are axially and symmetrically distributed in a staggered mode, vibration noise can be optimal.

The invention discloses a rotor punching sheet, which comprises a plurality of magnetic pole areas distributed along the circumference, first magnetic steel grooves and second magnetic steel grooves are arranged in the magnetic pole areas, the first magnetic steel grooves are located at the outer sides of the second magnetic steel grooves, and the midperpendicular of the first magnetic steel grooves and the midperpendicular of the second magnetic steel grooves coincide, and the rotor punching sheet also comprises two third magnetic steel grooves, the two third magnetic steel grooves are distributed at the two ends of the second magnetic steel groove and are symmetrically arranged in a V shape, values of the width L1 of the first magnetic steel groove, the width L2 of the second magnetic steel groove and the width L3 of the third magnetic steel grooves meet the following relation, r1 is the radius of the outermost circle of the rotor punching sheet, and p is the number of pole pairs of the motor; the value of the thickness W1 of the first magnetic steel groove, the value of the thickness W2 of the second magnetic steel groove and the value of the thickness W3 of the third magnetic steel groove meet the following relation: 0.16 * L1 < = W1 < = 0.2 * L1 < = W2 < = 2 * W1 < = W3 < = W2; and on the basis of ensuring the output torque of the motor, the production cost of the motor can be reduced, the sine degree of an air-gap magnetic field is effectively improved, harmonic waves are reduced, and the vibration noise problem is improved, so that the high-performance and low-cost motor design is realized.

The invention discloses a marine energy-saving stator which comprises an X shaft, a propeller is arranged on the outer side of the X shaft, a paddle disc face is arranged on one side of the propeller, a movable block is arranged on one side of the paddle disc face, a movable hook is arranged on one side of the movable block, a first blade is arranged on one side of the movable hook, and a second blade is arranged on one side of the first blade. And a third blade is arranged on one side of the second blade. According to the marine energy-saving stator, the paddle efficiency can be improved within the full navigational speed range, the purposes of energy conservation and emission reduction are achieved, meanwhile, the vibration noise problem is solved, and through CFD simulation and ship model pool tests, the energy-saving effect is improved by 20%-80% compared with a traditional stator. When the three-blade scheme is used, the construction cost can be additionally saved, in order to improve the propelling efficiency and consider the line type of the tail of the ship body, the blades are arranged in front of the propeller, the blades are reasonably arranged in the rotating range of the whole propeller, and the blades are arranged in the first quadrant, the fourth quadrant and the third quadrant in front of the propeller disc face respectively.

The invention discloses an intermediate supporting structure for rigidity improving and shock absorption. The structure includes an upper bracket, a lower bracket, a rubber widget and a bearing; the upper bracket and the lower bracket are semicircular and arranged in a buckled mode, the rubber widget is annular, the outer annular surface of the rubber widget is connected in a circular space formed after the upper bracket and the lower bracket are buckled in a clamping mode, the inner annular surface of the rubber widget is provided with a first groove, the bearing is arranged in the first groove, and raised ribs are uniformly arranged between the inner annular surface and the outer annular surface of the rubber widget. According to the intermediate supporting structure for rigidity improving and shock absorption, the situation that vibration of rear axles, a drive system and a vehicle body is intensified due to the vibration of a transmission shaft and the intermediate supporting structure is avoided, fire coupling with a road surface is avoided, on low-speed and high-speed road sections, the vibration noise of the whole vehicle is significantly reduced, and the purpose of reducing the vibration noise is achieved.

The invention relates to a shock absorption unit special for a hydropower station. The shock absorption unit comprises a bottom plate. Two unit bodies which are connected with each other are mounted at the upper end of the bottom plate. Four shock absorption branch chains are symmetrically arranged on the lower end face of the bottom plate and mounted on a mounting plate. Four lower limiting columns are symmetrically welded to the lower end of the bottom plate and connected with the mounting plate through lower limiting springs. Two upper limiting columns are symmetrically welded to the two sides of the middle portion of the mounting plate. All the upper limiting columns are connected with the bottom plate through upper limiting springs. Each shock absorption branch chain comprises a substrate welded to the lower end face of the bottom plate. Two upper lug seats are symmetrically welded to the two ends of each substrate. Each upper lug seat is connected with the top end of a first extending-and-contracting rod through a pin shaft. The bottom end of each first extending-and-contracting rod is connected with a lower lug seat through a pin shaft. Each lower lug seat is obliquely welded to a mounting block. The shock absorption unit special for the hydropower station can achieve the good shock absorption effect and has the beneficial effects that the structure is simple, the shock absorption effect is good, and vibration noise is small.

The invention relates to a two-gear speed changing power system of an electric automobile. The two-gear speed changing power system comprises a driving motor, a differential mechanism, a right half shaft and a left half shaft, and further comprises a planetary gear speed reducing mechanism, a synchronizer and two sets of wheel rim speed reducing mechanisms, wherein the planetary gear speed reducing mechanism and the synchronizer are located in a shell of the driving motor to form an integrated structure. The two-gear speed changing power system has extremely high integration degree; the wheel rim speed reducing mechanisms are used as the final stage of a transmission chain of a main speed reducing mechanism so that the load of the front-stage part of the transmission chain is greatly reduced and the part size of the front-grade part of the transmission chain is reduced, and a miniaturization and light-weight principle is met; a rotor rotary shaft of the driving motor is directly connected with a speed changer gear so that coaxial tolerance caused by matched installation is avoided; the quantities of duplex planetary gears and differential mechanism driving gears are the same and the duplex planetary gears and the differential mechanism driving gears are arranged around the central line at equal angles; the whole structure is centrally symmetrical, the weight distribution is uniform, the dynamic balance property is good, the transmission efficiency is higher, and the vibration noise condition is better.

The invention provides a stator core, a stator, a permanent magnet synchronous motor, a compressor and refrigeration equipment. The stator core comprises a plurality of stator punching sheets, the plurality of stator punching sheets are stacked in the axial direction of an inner hole, each stator punching sheet comprises a plurality of stator teeth distributed in the circumferential direction, each stator tooth comprises a tooth part and a tooth boot connected to the tooth part, and the plurality of tooth boots form the inner hole in an enclosing mode; the plurality of stator punching sheets comprise at least one first stator punching sheet, the inner circumferential wall of at least one tooth boot of the first stator punching sheet is provided with a concave part, the tooth boot comprisesa first tooth boot part, and a part of the concave part is located in an area, facing one side of the first tooth boot part, of the symmetric center line of the tooth part. Therefore, radial electromagnetic force waves generated by the interaction of armature magnetic field harmonics and rotor magnetic field harmonics are reduced, the deformation of the stator core is reduced, the vibration noiseof a motor key frequency band is remarkably improved, and the hearing feeling of the compressor is effectively improved.

The invention discloses emulsified lubricating oil for machining, and relates to the technical field of machining. The emulsified lubricating oil is prepared from, by weight, 6-20 parts of sodium hydroxide mother liquor, 25-55 parts of 3# naphthenic acid, 1 part of emulsifier benzene-80, 1 part of emulsifier tween-80, 2-8 parts of middle molecular anolamines, 13-35 parts of basic oil, 1 part of Ta and Tb composite rust inhibitor, 5 parts of phosphate ester, 0.5 part of titanium dioxide nano-particle, 1 part of dithiopyro phosphate, 0.5 part of sodium metaborate, 5 parts of poly a-alkene T803A, 0.2 part of calcium alkyl salicylate T109, 0.3 part of sulfurized calcium alkyl phenolate T115A, 0.3 part of diaIk eny I succinimide T152, 0.2 part of succinic acid pentaerythritol ester L117, 3 parts of zinc dialkyl dithiophate (ZDDP), 1 part of benzotriazole T706 and 1 part of molybdenum dialkyl dithiophate (Mo DDP). High-qualified emulsified lubricating products can be provided for machining industries such as metal cutting and metal rolling.

The invention discloses a continuously-variable transmission system for electrically driven vehicles. The continuously-variable transmission system comprises a continuously-variable transmission mechanism and a hydraulic actuating system used for adjusting the variable speed ratio of the continuously-variable transmission mechanism, wherein the continuously-variable transmission mechanism comprises a driving belt pulley, a driven belt pulley and a driving belt arranged on the driving belt pulley and the driven belt pulley; the hydraulic actuating system comprises an oil pump, a first pressureoil circuit and a second pressure oil circuit; the first pressure oil circuit and the second pressure oil circuit are connected with the oil pump; a first pressure regulating valve for regulating oilpressure is arranged in the first pressure oil circuit; and a second pressure regulating valve for regulating oil pressure is arranged in the second pressure oil circuit. According to the continuously-variable transmission system of the invention, through the arrangement of the hydraulic actuating system, the variable speed ratio of the continuously-variable transmission mechanism can be adjusted;and therefore, the whole continuously-variable transmission system can achieve high efficiency and energy saving, the application cost of a finished automobile can be reduced, and not only the low-speed power performance and the grade ability but also the energy efficiency of the finished automobile is improved.

The invention provides a brushless permanent magnet motor comprising a rotor, a magnet group nested on the rotor, a stator sleeved on the magnet group and coaxial with the rotor, and a sleeve barrel coaxial with the rotor and the stator and positioned between the magnet group and the stator; the stator comprises a plurality of tooth portions arranged along an inner periphery surface; one ends, far away from the inner periphery surface, of the tooth portions are respectively provided with a front end portion; a card stopping zone is formed along the front end portions; the sleeve barrel is provided with a plurality of card stopping portions respectively matched with positions of each card stopping zones; each card stopping portion is nested between the card stopping zones. The brushless permanent magnet motor is stable in structure, can effectively reduce magnetic flux density instant changes, can reduce cogging torque and ripples of the torque, and greatly reduces noise vibrations.

The invention discloses a test apparatus for simulating the whole-vehicle working state of a heating ventilation case. The test apparatus comprises a horizontally arranged workbench, and an air inlet voltage stabilization box, an air outlet voltage stabilization box and an airflow distribution box which are arranged on the workbench, and is mainly technically characterized in that the air inlet voltage stabilization box and the air outlet voltage stabilization box are connected through an orifice plate, the air inlet voltage stabilization box is provided with a trumpet-shaped air inlet, the air outlet voltage stabilization box is provided with an air outlet and a pressure gauge which is connected through a connecting pipe for monitoring air pressure in the air outlet voltage stabilization box, the air outlet is connected with the air inlet end of a blower through an air outlet pipe, the air outlet voltage stabilization box is internally provided with a vibration sensor, the airflow distribution box is provided with a microphone I, and a microphone II is arranged on the surface of the volute of the blower; and the air outlet end of the blower is linked to the airflow distribution box, and the airflow distribution box is provided with an air exit. The test apparatus provided by the invention fundamentally solves the problem of difficult evaluation of heating ventilation vibration noise level at the early stage of automobile development and controls vibration noise through simulating a real-vehicle working condition.

The invention discloses a method for reducing the undulatory wear of steel rails. The steel rails are supported by sleepers and fixed to the sleepers through fasteners in fastened and pressed modes. Tracks of the steel rails guide wheels, and the steel rails and the wheels interact with each other to form a wheel rail system. According to the method for reducing the undulatory wear of the steel rails, the wheel rail flexibility difference and steel rail vibration, particularly in the wheel rail system transverse direction, are reduced. Through the method for reducing the undulatory wear of thesteel rails, vibration noise can be reduced, the undulatory wear of the steel rails is reduced, the wheel rail relation is improved accordingly, wheel rail vibration and noise are reduced, the service lives of the steel rails and the wheels are prolonged, the effectiveness of the track fasteners is improved, and the travelling safety is improved finally.

The invention belongs to the technical field of car spare parts, and relates to a novel heavy truck car hub unit. The unit mainly comprises a hub, a first bearing and a second bearing. The first bearing and the second bearing are located at the two ends of the hub correspondingly. The first bearing and the second bearing are each comprises a retainer, an inner collar, an outer collar and a plurality of rolling bodies. A combined sealing ring, an O-shaped ring, a single sealing ring, a sing sealing ring, an O-shaped ring and a combined sealing ring are sequentially arranged at the right end in the hub from right to left. The combined sealing rings are arranged between a large flange of an inner ring of the first bearing and the hub as well as between a large flange of an inner ring of the second bearing and the hub correspondingly. The single sealing rings are located between inner and outer rings of the first bearing as well as between the inner and outer rings of the second bearing. The O-shaped rings are located between the first bearing and a shaft as well as between the second bearing and the shaft. According to the novel heavy truck car hub unit, the bearing base planes and a shaft shoulder are used positioning, an original space ring structure is omitted, and the assembling process can be simplified; and the structure is simple, the unit has the advantages of being convenient to mount and replace, the mounting efficiency can be improved, and the unit has high market popularization value.

The invention relates to the field of household electrical appliances, and provides a microwave oven housing and a microwave oven. The microwave oven housing includes a housing body, the housing bodycomprises a top plate arranged horizontally, a first side plate and a second side plate, wherein the first side plate and the second side plate are arranged on the two opposite sides of the top plate,the first side plate is arranged close to a microwave oven transformer, the inner side of the first side plate is provided with an acoustic sound absorption structure or a multi-layer composite soundabsorption board, or the housing body is integrally formed by the multi-layer composite sound absorption board. According to the microwave oven housing and the microwave oven, vibration and 'buzzing'sound of the side plates can be lowered, thus the vibration noise of the microwave oven is improved, the sound quality is improved, and the user experience of the microwave oven is promoted.

The present application provides a rotor core, a rotor structure, a motor and a compressor, and an electrical appliance having the same, including: an iron core body; a groove group is arranged on the outer peripheral wall of the iron core body; the groove group includes n grooves; In the groove group, each groove is different in size from any other groove; the n grooves are all located in the direction of the q-axis; where n≧2. According to the rotor core, the rotor structure, the motor and the compressor and the electric appliance with the rotor core of the present application, the problem of noise and vibration of the permanent magnet synchronous motor can be improved.

The invention relates to the field of manufacturing of dust collector motors, and aims to provide a dust collector motor press fitting device and a dust collector motor press fitting method. The dust collector motor press fitting device comprises a machine base, a supporting seat, a support frame, a compression cylinder, a transition block and a pressure block, wherein the supporting seat is provided with an outer cover accommodating countersink in the upper end face, and is pivoted to the machine base; the support frame is provided with a transverse plate, and is connected with the machine base; the compression cylinder is connected with the transverse plate; the pressure block is provided with a machine shell countersink in the lower end face, and is pivoted to the transition block; the transverse plate is provided with a first guide hole which is matched with a piston rod of the compression cylinder; the piston rod of the compression cylinder passes through the guide hole, and is connected with the upper end of the transition block; the lower end face of the pressure block is vertical to the rotating axis of the pressure block; the upper end face of the supporting seat is vertical to the rotating axis of the supporting seat; the axis of the compression cylinder and the rotating axis of the pressure block are coaxial with the rotating axis of the supporting seat respectively. The dust collector motor press fitting device has high press fitting efficiency and high coaxiality among a fan, a stator and a rotor of the press-fitted dust collector motor, and has low vibration noise during use.

The invention provides a stator core, a stator, a permanent magnet synchronous motor, a compressor and refrigeration equipment, and the stator core comprises a stator inner hole which is used for thepenetration of a rotor and a plurality of stator punching sheets; each stator punching sheet has a thickness, the plurality of stator punching sheets are stacked along the axial direction of the stator inner hole, and each stator punching sheet comprises a stator yoke and a plurality of stator teeth distributed along the circumferential direction of the stator yoke; each stator tooth comprises a tooth root connected with the stator yoke, and a tooth crown connected with one end, deviating from the stator yoke, of the tooth root; each stator punching sheet has a thickness along the axial direction of the stator inner hole, at least one tooth crown on at least one stator punching sheet is provided with a magnetic conduction hole, and along the axial direction of the tooth root, the projection of the magnetic conduction hole on the tooth crown divides the surface, deviating from the tooth root, of the tooth crown into a first tooth crown surface and a second tooth crown surface; the areaof the first tooth crown face is smaller than that of the second tooth crown face. According to the embodiment of the invention, the vibration noise of the key frequency band of the motor can be significantly improved, and the hearing of the motor and the compressor is improved.

The invention belongs to the technical field of automobile parts, and relates to a novel light truck hub unit. The novel light truck hub unit mainly comprises a hub, a first bearing and a second bearing. The first bearing and the second bearing are located at the two ends of the hub correspondingly. The first bearing and the second bearing each comprise a holder and a plurality of rolling bodies, and the hub is further connected with a plurality of hub bolts. A combined seal, an O-shaped ring, a single seal, a single seal and a combined seal are arranged in the hub, wherein the combined seals and the single seals are both located between the inner rings and the outer rings of the first bearing and the second bearing, and the O-shaped ring is located between the inner ring large end face of the second bearing and a shaft. It is guaranteed that pre-tightening of the hub unit is proper through matching of the first bearing and the second bearing with the hub, and backlash self-adjustment between the bearings is achieved; and through usage of the double combined seals, the double single seals and the O-shaped ring, the cleanliness in the hub is improved, the cleanliness of the bearing operating environment is guaranteed, and therefore the service life of the bearings is prolonged.

The invention relates to a non-clogging sewage pump, and provides a vortex forward-extended double blade impeller sewage pump. The sewage pump is characterized in that a double blade structure is adopted, the hub arranged at the centre of the inlet and outlet of an impeller passage is half the size of an ordinary impeller hub. The impeller is in a semi-open type. The stream lines of a front shroud and a back shroud of the blades extend forward to the direction of the inlet. Compared with an ordinary impeller, a forward-extension angle of the stream line of the back shroud is about 120 degrees, and a forward-extension angle of the stream line of the front shroud is about 45 degrees. A wrap angle theta of the blades is about 360 degrees. The vortex forward-extended double blade impeller sewage pump has the advantages that vortex forward-extended and double blades mode are adopted, the impeller passage is widened, the through capacity of sundries with long fiber and large particles is improved, the whole operating efficiency of the sewage pump is improved, the passage capacity and the anti winding performance are good, and the operating is stable.

The invention provides a low-torque pulsation high-speed axial flux surface-mounted permanent magnet motor, which comprises two axially arranged rotors and a stator located between the two rotors, andthe distances between the two rotors and the stator are unequal, i.e., the lengths of air gaps between the two rotors and the stator are unequal. Due to the structure of the high-speed axial flux permanent magnet motor, the centrifugal force borne by the rotor is orthogonal to the electromagnetic tensile stress direction, that is, the permanent magnet sheath part does not influence the axial effective air gap length, the design of the permanent magnet and the sheath thereof is more diversified, and the optimal design scheme can be found.

A piping structure of refrigeration device is prepared as setting combined structure formed by two sections of arc pipes being not in the same plane on said device as winding one section around peripheral direction of compressor to form U form pipe at vertical plane and setting another section to be arc pipe in plane with included angle being less than 60 degree to level.