62results about How to "Small torque fluctuation" patented technology

A current sensor for detecting a power supply current is commonly used for detecting a current of a stator winding to detect a rotational position of a magnet rotor, so that a sinusoidal driving is realized without adding two current sensors for detection of a phase current, and also a phase shift circuit and a comparator needed in the conventional 120-degree current feeding are not required, and the number of components can be reduced. Therefore, an inverter device with a low noise and low vibration, having a small size, light weight and high reliability is obtained.

The invention discloses a model prediction-based doubly salient permanent magnet synchronous motor direct torque control method. The model prediction-based doubly salient permanent magnet synchronous motor direct torque control method comprises the following steps that: stator current and rotor angular speed of a doubly salient permanent magnet synchronous motor are acquired; under eight groups of inverter switching vector signals, and based on the stator current and the rotor angular speed, the output current of the motor at a next moment of each kind of inverter switching vector is predicted according to constraint relationships between current variation quantity, micro components and voltage, current under eight kinds of switching states; based on a direct torque control theory, motor torque and motor magnetic flux linkage at the next moment of each kind of inverter switching vector can be further predicted; and related voltage vectors are selected reasonably with realizing minimum total quantity of the torque and the magnetic flux linkage adopted as a target, and therefore, the operation of an inverter can be controlled real time. With the model prediction-based doubly salient permanent magnet synchronous motor direct torque control method of the invention adopted, switching frequency and loss can be effectively decreased, and torque fluctuation of the motor can be decreased.

An exhaust gas purifying system causes less torque fluctuation and is capable of preventing the occurrence of white smoke in a regeneration control operation for regenerating a continuous regeneration DPF 3. When the continuous regeneration DPF 3 with an oxidation catalyst 3Aa on the upstream side of a filter 3Ab is controlled to regenerate, an exhaust throttle valve 31 provided in an exhaust passage 2 is closed and a delay multi-step injection control is performed to increase the temperature of the exhaust gas if an exhaust temperature T1 at the inlet of the oxidation catalyst 3Aa is less than the activation temperature Ta of the oxidation catalyst. After the exhaust temperature T1 at the inlet of the oxidation catalyst 3Aa has risen to the activation temperature Ta of the oxidation catalyst or higher, the exhaust throttle valve 31 is opened in a stepwise or continuous manner so that the exhaust temperature T2 at the inlet of the filter 3Ab rises to a lower limit temperature of PM forced combustion Tb1 or higher.

The invention discloses a double salient permanent magnet (DSPM) current control method, which comprises the following steps: obtaining eight groups of inverter switching vector signal; at the current time k, predicting p-phase stator current of next time k+1 in each group of inverter switching vector signal (img file='DDA0000448969140000011.TIF' wi='88' he='65' /), wherein p represents A, B and C phases of a motor; in each group of inverter switching vector signal, obtaining the current predicted value of d -axis and q -axis according to (img file='DDA0000448969140000012.TIF' wi='96' he='64' /); in each group of inverter switching vector signal, calculating d-axis current prediction error (img file='DDA0000448969140000013.TIF' wi='72' he='64' /) and q-axis current prediction error (img file='DDA0000448969140000014.TIF' wi='104' he ='68' /) of the next time k +1; according to (img file='DDA0000448969140000015.TIF' wi='72' he ='66' /) and (img file='DDA0000448969140000016.TIF' wi='112' he='64'/ ), selecting the switching vector signal of the minimum total amount of torque fluctuation and flux fluctuation as a drive signal of the inverter switch, thereby real-time controlling on-off of a inverter switch tube. The method by accurately controlling the DSPM motor output current, accurately control the inverter switching vector change, so that the motor torque fluctuation and flux fluctuation are minimum, the requirement for electrode parameters is low, and the response speed is fast.

The invention discloses an asymmetric permanent magnet motor for a new energy automobile, relates to the technical field of motors, and aims to lower torque fluctuation. The motor comprises rotors and a stator, wherein a plurality of permanent magnet units are arranged on the rotors; and the permanent magnet units comprise permanent magnet grooves and magnetic steel embedded into the permanent magnet grooves. The asymmetric permanent magnet motor is characterized in that magnetic pole axes of the rotors partition the permanent magnet units into left halves and right halves; and the left halves and the right halves of the permanent magnet units have different structures. Through adoption of the motor provided by the invention, the comprehensive performance of the motor can be enhanced.

There is provided an efficient compressor which is simple in structure and small in torque fluctuation. The compressor comprises a compression element which comprises a cylinder having a compression space formed therein, a suction port and a discharge port which communicate with the compression space in the cylinder, a compression member which comprises continuous thick and thin parts, one surface of which inclines, which is arranged in the cylinder to rotate, and which compresses fluids sucked through the suction port and discharges the compressed fluids through the discharge port, and a vane which is arranged between the suction port and the discharge port to abut on one surface of the compression member, and which partitions the compression space of the cylinder into a low pressure chamber and a high pressure chamber.

The invention relates to a novel rotary table driven by a DC motor. The motor stator is mounted on a frame, windings and an iron core are mounted on the inner side of the stator, and a commutator is arranged at the lower end of the windings. The wire inlet terminal and the brush of the conducting ring are fixed on the lower end of the stator; the motor stator is fixed on the main shaft; the worktable face is connected to the main shaft by bolts; an alnico is fixed on the stator, the brush with a conducting ring is mounted on the bottom of the stator by a frame; the brush of the commutator is mounted on the brush frame provided with a conducting ring, and the brush of the commutator contacts with the commutator; and the conducting-ring brush contacts with the conducting ring arranged on the brush frame provided with a conducting ring. The part between the main shaft and the frame is supported by a thrust ball bearing and an angular-contact ball bearing, and the part between the worktable face connected with the main shaft and the frame is supported by a tapered roller bearing. The rotary table with such structure has the advantages of that the rotor has small moment of inertia, the fluctuation of moment is small, the speed is low, the performance is sound, and the cost is low; particularly when load acceleration requires relatively high control accuracy, such structure is easy to meet the technical requirements of the rotary table and reduce the cost.

The invention discloses a permanent magnet and direct current brush motor for an automobile air conditioner. The motor comprises a casing (2), a permanent magnet (3), a rotor (4), an electrical brush (6) and a commutator (8), wherein the permanent magnet (3) is fixed in the cavity of the casing (2); the permanent magnet (3) has a tile-shaped irregular section which is asymmetrical; the outer arc (3R) and the inner arc (3r) of the tile-shaped irregular section of the permanent magnet are not concentric; and the radius (r) of the inner arc of the tile-shaped irregular section of the permanent magnet is larger than the radius (R) of the outer arc of the tile-shaped irregular section of the permanent magnet. By adopting the technical scheme, the permanent magnet with the tile-shaped irregular section is adopted, so that the distribution form of a magnetic field is closer to the form of a sine wave, and the odd harmonics of the magnetic field are effectively reduced; and a chute structure is adopted by the rotor to reduce the relative magnetic resistance fluctuation in the axial magnetic fields of the permanent magnet and the tooth sockets of the rotor, so that tooth socket moment fluctuation is effectively reduced, the noise of the motor is reduced, and the service life of the motor is prolonged.

The invention discloses a permanent magnet synchronous motor back potential harmonic suppressing method. The method comprises the steps that a function containing a sine forms a salient pole; the salient pole forms the excircle of a motor rotor through a circumferential array, or the excircle of the motor rotor is composed of a line which cannot be described by a function; the back potential waveform of a motor is tested; the harmonic order and amplitude are decomposed through Fourier transform; the sinusoidal function subtracts a harmonic function to form a new salient pole; and the new salient pole finally forms the excircle of the motor rotor through the circumferential array. Motor air gaps made by the method are sinusoidally distributed. An excircle function subtracts the back potential harmonic function. The back potential harmonic result is suppressed. The method has the advantages of simple and effective principle, strong operability, low motor back potential harmonic content,small torque fluctuation and low vibration noise.

The invention relates to a high-precision low-fluctuation permanent magnetic brushless servomotor for a solar tracking system, which comprises a machine shell as well as a stator and a rotor in the machine shell, wherein the stator comprises a stator core fixed on the inner wall of the machine shell and a stator winding; the rotor comprises a main shaft and a rotor core; the outer circumference of the rotor core is sleeved with an annular magnetic pole consisting of radial magnetized magnetic steels which are evenly arranged along the circumferential direction and adjacent oblique angled magnetized magnetic steels; one radial magnetized magnetic steel and two adjacent oblique angled magnetized magnetic steels in the annular magnetic pole form a rotor magnetic pole; the radial magnetized magnetic steels are main magnetic poles; and the two adjacent oblique angled magnetized magnetic steels on both sides are auxiliary magnetic poles. Radial and oblique angled mixed anisotropic magnetized magnetic poles in the annular magnetic pole of the rotor ensure that the motor can also remarkably improve air gap flux density waveform of the motor even if the even air gap is adopted, obtain a sinewave magnetic field, does not reduce power output, can also reduce moment fluctuation, and improve the precision of the solar tracking system. The motor can perform steady operation with high efficiency, low fluctuation, low noise, quick response and high precision.

The invention discloses a numerical control shaping gear grinding machine tool, which comprises a numerical control system, a machine tool body and an upright column vertical to the machine tool body, wherein a longitudinal workbench and a transverse workbench are arranged on the machine tool body. The machine tool is characterized in that a work piece spindle box is arranged on the longitudinal workbench; the upright column is fixed on the transverse workbench, a vertical workbench is arranged along the upright column, and a grinding wheel spindle box is arranged on the vertical workbench; a circular grating ruler which is in feedback connection with the numerical control system and is used for detecting angular displacement is arranged on a motor shaft in the work piece spindle box; furthermore, the numerical control system is respectively in feedback connection with straight grating rulers arranged in the feeding directions of the longitudinal workbench, the transverse workbench and the vertical workbench. The numerical control shaping gear grinding machine tool can adapt to the machining of gears with different moduli, is simple and convenient to operate, facilitates the improvement on the production efficiency, meanwhile can perform real-time feedback of feeding amount and achieves accurate control so as to improve machining precision.

The invention discloses a built-in permanent magnet synchronous motor, relates to the technical field of a motor and aims to solve the technical problem of improving the comprehensive quality of the motor. Multiple permanent magnet slots are axially and symmetrically arranged in a rotor of the motor along the central axis of the rotor at intervals, three permanent magnets distributed in an arc band shape are arranged in each permanent magnet slot, wherein one permanent magnet is a middle steel magnet, and the other two permanent magnets are side steel magnets; the built-in permanent magnet synchronous motor is characterized in that each middle steel magnet adopts the normal magnetization vertical to the surface of the steel magnet, and each two side steel magnets in one slot adopt the non-normal magnetization, so that the arc center of a magnet arrangement arc of each permanent magnet slot is enabled not to coincide with the magnetization orientation point of permanent magnets in the corresponding permanent magnet slot. According to the motor provided by the invention, the comprehensive quality of the motor is greatly improved.

The invention discloses a steering shaft, an automobile steering mechanism and an automobile. The steering shaft comprises a first shaft and a second shaft which are connected through a universal joint, wherein one of the first shaft and the second shaft is used for being connected with an automobile steering column and the other of the first shaft and the second shaft is used for being connected with an automobile steering gear. The steering shaft provided by the invention comprises the first shaft and the second shaft which are connected through the universal joint, so that an included angle between the first shaft and the second shaft can be adjusted, an included angle between the first shaft and the steering column and an included angle the second shaft and the steering gear can be adjusted, an included angle condition which does not generate moment fluctuation is easy to achieve because of the adjustable included angles, and the moment fluctuation generation probabilities of the automobile steering mechanism during the transmission process of the rotating force are reduced by adjusting the above included angles compared with an ungovernable rotary shaft in the prior art.

The invention relates to an integrated air-supply unit (1), in particular for air-suspension systems for motor vehicles, said unit comprising an air compressor (2) having an electric motor (3) and an air dryer (4). The air compressor (2) together with the electric motor (3), air dryer (4) and a number of pneumatic connections (8) form a functional unit.

The invention provides a pump body structure, a compressor and an air conditioner. The pump body structure comprises an exhaust cavity. The exhaust cavity is provided with a first exhaust channel anda second exhaust channel, and the first exhaust channel and the second exhaust channel can communicate with the exhaust cavity or be separated from the exhaust cavity. The opening and penetrating pressure of the second exhaust channel is higher than the opening and penetrating pressure of the first exhaust channel. By means of the pump body structure, the compressor and the air conditioner, when the exhaust resistance is too large during running of the compressor or overcompression exists, the exhaust resistance and the overcompression losses of the compressor are reduced through opening and penetrating and the second exhaust channel, torque fluctuation caused by unsmooth exhausting when exhausting is over is reduced, and airflow pulsation is reduced.

The invention provides a crank type piston pneumatic engine apparatus comprising a plurality of dual-action air cylinders and a plurality of crank power output units connected with adjacent air cylinders, a variable platen, an inertia wheel, and a pressure control loop. Each crank power output unit has a piston rod connection head, a piston rod connection shaft, a first crank, a second crank, a crank output shaft and an inertia wheel shaft; one end of the piston rod connection head is fixedly connected with an air cylinder piston and the other end is fixedly connected with the middle part of the piston rod connection shaft; two ends of the piston rod connection shaft are respectively connected with the upper end of the first crank and the upper end of the second crank via bearings; the lower end of the first crank is connected with the crank output via a bearing; the lower end of the second crank is connected with the inertia wheel shaft via a bearing; the adjacent air cylinders are connected via the crank output shaft or the inertia wheel; the variable platen is arranged the outermost crank output shaft and fixed thereon; the inertia wheel is arranged on the outermost inertial wheel shaft and fixed thereon; and the pneumatic control loop controls the air cylinder to work.

The invention relates to a method for filtering a position signal (S) of a positions sensor of a clutch actuation device of a friction clutch in a drive train of a motor vehicle. In order to eliminatevibrations occurring in an in particular hydrostatically designed clutch actuation device due to a non-linear arrangement, the position signal (S) is filtered by means of a low pass filter (12), theposition signal (S) is additionally filtered in a first filter element (13) having a sliding average and in a second filter element (14) as a hysteresis filter (15), wherein both filtered position signals (S(m), (S(h)) are weighted in a decision module (16) in order to minimize deviations of the filtered position signal (S(s)) from the actual position.

The invention provides a structure design method of a torque motor with low torque fluctuation, which comprises the following steps: determining the number of auxiliary grooves, the groove type and the grooving angle, wherein the number Nn of auxiliary grooves in a single crown part is the smallest integer value satisfying the condition that Nn+1 is not equal to Np/k, the auxiliary grooves are semicircular grooves, and the grooving angle is obtained from the set range by using the simulation calculation method when the torque fluctuation is minimum. The structure designed by the invention reduces the cogging torque of the motor and is very effective in reducing the torque fluctuation of the motor. Moreover, the scheme is simple in structure, good in manufacturability and easy to implement.