108 results about "Torque constant" patented technology

The present invention provides a hybrid field excitation flux switching electric motor. On one hand, a stator part adopts a centralized armature winding, an exciting winding, a straight channel rotor, and a permanent magnet arranged in the stator. On the other hand, the rotor part is a salient pole and is not provided with a permanent magnet or a winding. The structure is extraordinary simple and durable. The electromagnetic capability of four centralized armature coils which are designed to form a single-phase armature winding is controlled by the corresponding exciting winding coil through the exciting current. On structure, the advantages of compactness, simpleness, good robustness and suitability for operation with high speed of the permanent magnet flux switching electric motor are kept. The function of hybrid field excitation can be realized without additionally adding the volume of the electric motor. The electric motor is guaranteed to have stronger torque output capability and higher power density. The electric motor is especially suitable for the application occasion with high volume and large output. The functions of large torque in torque-constant area and broad velocity modulation in power-constant area can be realized.

A controller and a control system capable of estimating inertia of an article to be driven in a short period of time, with a small operation range of an electric motor. The controller for the motor has an inertia estimating part which includes a sine-wave command generating part which adds a sine-wave command to a torque command for the motor; a current feedback sampling part which obtains a current value of the motor; a speed feedback sampling part which obtains a speed feedback of the motor; an acceleration calculating part which calculates an acceleration value based on the speed feedback; and an estimated inertia calculating part which estimates the inertia of the article, based on a representative current value, a representative acceleration value and a torque constant of the motor, which are calculated from current and acceleration values in a plurality of cycles of the sine-wave command and stored in a sampling data storing part.

The invention discloses a virtual signal injection-based maximum torque current ratio control method of a synchronous motor. A tidy signal is injected to a stator current angle to obtain a derivativeof an electromagnetic torque on the stator current angle, and then a stator current angle reference value is obtained; and next, a stator current amplitude reference value is obtained by a fixed torque constant and an open loop compensation integrator, and then a d-q-axis current reference value is obtained. By virtue of the more accurate formula disclosed in the invention, the steady state precision is ensured; and by virtue of square wave injection and processing method, dynamic response is improved.

The invention discloses a method for restraining the flux-adjusting torque ripple of a memory motor based on current decoupling, including setting given values of d, q-axis current, Both and d, The deviation from the q-axis current setpoint is input to the PI regulator, the output of the d-axis current PI regulator is subtracted from omega eLqiq to obtain the d-axis voltage given value, To the output of q-axis current PI regulator, [omega]e(Ldid + [psi]r) is added to get the given value of q-axis voltage. D, q-axis voltage is controlled by coordinate transformation and SVPWM modulation to drive the inverter motor. When the rotational speed of the motor is higher than the base speed, the magnetization state of the permanent magnet is adjusted discretely by using the memory magnetization method, and the d-axis current weakening method is used to continuously adjust the magnetization state in each magnetization state, and the q-axis decoupling current is applied at the same time as the d-axis current is applied, so as to keep the torque constant during the magnetization adjustment period and suppress the torque ripple during the magnetization adjustment period.

Energization stages are formed by first and second sensor groups and a torque constant is defined for each of the stages. A target current value is computationally determined so as to drive a motor under control. As a torque command showing a target torque of the motor is input to the controller, the target current value is computationally determined for each stage according to a torque constant map, which provides a table of torque constants for different phases and different stages. The rotor angle of the motor is detected by Hall sensors and the current stage is computationally determined on the basis of the detected rotor angle. Then, a target current value is defined as a function of the target torque for each stage on the basis of the current stage and the motor is driven by the driver under PID control based on the target current value.

A sinusoidal command is added to a torque command of a controller to acquire a velocity and a current value of an electric motor. An estimated coupling torque value is calculated by calculating an input torque value from the current value and a torque constant of the electric motor and further calculating a coupling torque value from a velocity difference, motor inertia, and the input torque. An estimated torque error is then calculated from the estimated coupling torque value and the coupling torque value, and inertia, friction, and a spring constant are estimated from the estimated torque error, the velocity, and the coupling torque value.

An electromechanical rotary actuator includes a rotor and a stator having one or more slots into which one or more coils are placed. The stator includes a rotor position restoring means which overcomes cogging outside a desired rotation range. The rotor position restoration means may include one or more restoring magnets or optionally include a contoured cavity within the stator proximate the rotor. One stator includes teeth having contoured ends forming a portion of the aperture within which the rotor operates. Distal ends of the teeth form a relatively large gap compared to typical actuators, wherein the gap is sized to the rotor magnet. An actuator desirably having a high torque constant, low coil resistance and a low coil inductance is provided.

The invention provides a PMSM position servo system high-order object controller design and parameter determination method. A position controller adopts a PID adjustor, and PID adjustor parameters aredesigned based on pole assignment; a current ring adopts the PI adjustor and is corrected into an I type system to determine the parameters of the PI adjustor; the current loop is provided with a PWMinverter; and the characteristic equation of a PID closed-loop system is as follows: JTqs4+Js3+KtKds2+KtKps+KtKi=0, wherein J is a rotational inertia, Tq=1/K, K+KpkPWMKa/Ta, KPWM is the proportionalgain of the PWM inverter, Ka=1/R, R is a motor sator resistance, Ta is a motor electric time constant, s is a controlled time variable, Kt is a torque constant, Kp, Kd and Ki are controller control parameters, Ki=Kp/taui, and taui is an integral time constant of the PID adjustor. As contrastive analysis is carried out for different step responses of the high-order object control system when pole parameters change, a selection range of related parameters is given out, and engineering significance is obtained.

A speed control apparatus for varying the speed of an AC motor while maintaining the torque and power constant over a range of angular speeds The AC motor is driven by a D.C. source. A universal conmutator capable of providing two symmetrical non-contending signals with a frequency that can be selectively varied. A microprocessor unit for monitoring the frequency of the signals and control proportionally varying the duty cycle of the signals calculates the necessary duty cycle to maintain the torque constant over a range of angular speeds.

An estimated torque constant calculation unit calculates an estimated torque constant relating to the permanent magnet synchronous motor from a current representative value and an acceleration representative value acquired from a plurality of current values and a plurality of acceleration values in the same operation state over a plurality of periods of a sinusoidal command signal and a predetermined inertia relating to the permanent magnet synchronous motor. A demagnetization detection unit detects whether or not irreversible demagnetization has occurred in the permanent magnet of the permanent magnet synchronous motor based on a difference between the estimated torque constant and a predetermined torque constant relating to the permanent magnet synchronous motor.

A optical scanner control method and a optical scanner capable of positioning a mirror at a high speed independently of a rocking angle, and a laser machining apparatus for irradiating a printed circuit board with a laser beam by use of the optical scanner to thereby perforate the printed circuit board. In order to operate an actuator for rocking the mirror based on a deviation of a current position from an commanded value, a change in gain of the actuator is measured in accordance with each rocking angle in advance, and the manipulated variable of the actuator is corrected to cancel the change in gain. Thus, the influence of the alteration of a torque constant in accordance with the rocking angle can be suppressed so that the response characteristic becomes uniform all over a scanning region, and the positioning speed can be improved.

The invention discloses a modal testing method of a numerical control machine tool feed system based on built-in sensors. The method comprises the following steps: a numerical control machine tool worktable is moved in accordance with given excitation signals, and at the same time servo motor current signals, motor coder signals and grating scale signals are acquired synchronously by using a signal acquisition device; the motor current signals are multiplied by the torque constant of a motor to produce the torque of the motor; second order difference is performed on the coder signals and the grating scale signals to produce acceleration signals of the worktable and angular acceleration of a screw rod; a frequency response function of the torque of the motor and an acceleration of the worktable and a frequency response function of the torque of the motor and an angular acceleration of the screw rod are calculated; fitting is performed on the two frequency response functions to obtain a fitted frequency response function; and axial modal parameters and torsional modal parameters are calculated finally. Compared with conventional modal testing methods, the novel method provided in the invention reduces cost of tests, and can realizes on-line testing of feed system modal parameters.

A variable magnetic flux-type rotary electric machine includes a stator and a rotor. The stator includes a stator coil wound on teeth. The rotor defines an air gap between the rotor and the stator. The rotor has at least one permanent magnet arranged in the d-axis magnetic path. The stator and the rotor are arranged relative to the permanent magnet to set a characteristic of d(Kt(I))/dI≧0 in a range of at or below magnetic saturation of a core material of at least one of the stator and the rotor, where KT represents a torque constant, and I represents an applied current, and a function of KT with respect to I is represented by KT=Kt(I) for a torque Tr acting on the rotor that is represented by Tr=KT×I.

The present invention is one combined stator structure with flat winding. When great work current is needed, the combined stator structure has high duty ratio, correct winding turn number, and precisely controlled torque constant or counter electromotive force, and this makes the motor or generator in fixed volume obtain accurately designed maximum rotation speed or counter electromotive force.The flat winding has low copper wire impedance, and this makes the motor or generator possess high operation efficiency.

A damping assembly for the actuator of high performance disk drive assembly is formed from multiple materials. The damping assembly is added to the actuator to dampen vibration that occurs during operation of the drive. The damping assembly is connected to an exterior portion of a coil region of the actuator. The damping assembly helps dampen vibration modes for coil torsion and coil bending, thereby improving dynamics settling performance to improve overall file input/output throughput performance. This also allows for a higher voice coil motor torque constant by increasing the magnet radius, thereby also improving move time, which further improves file input/output throughput performance. The overall file performance is improved by reducing settling times associated with coil torsion and coil bending modes, and allowing a higher torque constant to also improve move time. Both of these effects contribute to improving file performance.

A method for controlling a motor by an inverter and by a vectorial technique, comprising the following steps: determining the value of a quadrature current Iq necessary for said motor to generate the desired torque; calculating the value of a direct current to be supplied to the motor by an equation as a function of the phase of the current vector on which the torque constant of the motor depends; calculating the power current of said motor from the direct current and the quadrature current; supplying the power current to the motor through the inverter.

The invention relates to a cogging-torque test method for an alternating-current permanent-magnet synchronous servo motor. According to the cogging-torque test method, a servo driver is utilized to drive a tested motor to stably rotate at a lower rotating speed, an encoder is utilized to detect the speed and the position information of the motor, and the cogging torque of the motor can be tested through the combination of recorded feedback currents at different positions with the torque constant of the electric current. According to the cogging-torque test method disclosed by the invention, no special tool or work equipment needs to be prepared, all that is needed is to connect the motor with the driver and regulate the control parameters to proper values, so that the motor can stably run at a lower rotating speed, then data can be acquired, and the cogging torque can be calculated; the cogging-torque test method is simple and convenient in usage.

A spindle motor of a disk drive apparatus includes a base unit, a stator, a covered cylindrical rotor hub, a rotor magnet, and a bearing mechanism. The rotor magnet is an Nd—Fe—B bond magnet. The thickness of the rotor magnet in the radial direction is about 0.7 mm or more and about 1.0 mm or less. The distance between the rotor magnet and the stator core in the radial direction is about 0.15 mm or more and about 0.20 mm or less. A torque constant Kt of torque generated between the stator and the rotor magnet is about 4 mN·m/A or more and about 6 mN·m/A or less. A motor constant Km is about 2 mN·m/(A·√Ω) or more and about 4 mN·m/(A·√Ω) or less.

The invention provides a method for identifying parameters of a brushless direct current motor. Phase currents and a motor rotating angle generated when the brushless direct current motor stably operates are collected to obtain a motor pole pair number, and motor resistance and the back electromotive force coefficient are obtained in an identification mode. The bus current of the brushless direct current motor generated when an open cycle operates in a full duty ratio mode to reach a steady state and the time period used by the bus current for reaching the steady state are collected to obtain the inductance of the motor, and the torque constant and the no-load friction torque of the motor are obtained in an identification mode. The motor rotating angle in the process that the motor enters the braking process from the steady state revolving speed is collected, and the rotation inertia parameters are obtained in an identification mode. The method is simple and practicable in theory, and the engineering practice is easy to achieve.

A scanner has a rotor, and a stator disposed in the outside of the rotor. The rotor includes a shaft, and a permanent magnet mounted on the outer circumferential side of the shaft. The stator includes a casing, a yoke held in the inner circumferential side of the casing, and coils disposed in the inner circumferential side of the yoke. The permanent magnet of the rotor has radially depressed grooves formed in its outer circumferential portion. The torque constant of the scanner is circumferentially equalized by the grooves. Thus, positioning accuracy is improved.

The invention proposes a direct voltage sine wave driving method for a DC brushless motor, and the sine wave driver can completely replace the square wave driver. The sine wave drive DC brushless motor system has the characteristics of constant torque, low noise, large starting torque, excellent low-speed performance, good dynamic performance and adjustable torque. Compared with the traditional square wave drive, it has great advantages, especially in terms of precision requirements. Higher servo control system. Especially in low-speed operating systems, sine wave drives have incomparable advantages.