667results about "Stopping arrangements" patented technology

A motorized surgical instrument is disclosed. The surgical instrument includes a control circuit configured to control the movement of an end effector. If the end effector moves outside a predetermined acceptable range, the control circuit may create a dynamic brake to resist the undesired movement of the end effector. The control circuit may apply pulse width modulated (PWM) current to resist the undesired movement of the end effector outside a predetermined acceptable range.

A disk drive is disclosed comprising a disk, a head actuated over the disk, and a spindle motor for rotating the disk, the spindle motor comprising a plurality of windings. Disk control circuitry executes a spin-down operation of the spindle motor by estimating an angular position of the spindle motor by applying a voltage to at least one of the windings and evaluating a rise time of current flowing through the winding. The windings are commutated in response to the estimated angular position, and a driving current is applied to the windings to brake the spindle motor.

A motor including an outside rotor having a rotor disc with plural magnets alternating polarities flush mounted in the disc, an inside stator assembly with a ring of pole pieces forming a channel to house a transversely wound stator windings, and a controller coupled with feedback electronics for monitoring a timing, speed and direction and coupling a signal to a processing unit for adjusting the drive electronics driving the phase windings. A u-shaped gap above the channel to receive the rotor disc and focus the captured magnetic flux in the pole pieces toward the magnets. In an embodiment the molded magnetic flux channel pole pieces of the inside stator are sets of molded magnetic flux channel pole pieces, each set forming a channel and corresponding to one phase of the motor; and a section of each one of the transverse windings passing through one channel, the remaining section folding back outside the set in close proximity to the outer base of the set of molded magnetic flux channel pole pieces.

In a discharge control section of an inverter control device, when the connection of the battery and the smoothing capacitor is disconnected by means of a contactor, the charge accumulated on the smoothing capacitor is discharged by applying high-frequency voltage to the stator windings of the motor by controlling the main inverter circuit.

A safety circuit for providing protection against failures that impact safety of an inverter circuit driving a Permanent Magnet Synchronous Motor (PMSM) including high and low side switches connected in a bridge and driven by a gate driver circuit during operation of the PMSM in a field weakening mode, the gate driver circuit including stages for driving the high and low side switches, the safety circuit comprising a main power supply and a back-up power supply for supplying voltage to the gate driver circuit driving the switches of the bridge of the inverter circuit, wherein if the main power supply fails to deliver adequate power to the gate driver circuit, the back-up power supply provides power to the gate driver circuit to allow the gate driver circuit to turn ON the low side switches and turn OFF the high side switches.

The invention provides a method, device and system for controlling a PMSM (Permanent Magnet Synchronous Motor) to put into operation again at the belt speed. The counter EMF of the PMSM is obtained by the speed of a trailer, and is compared with the voltage on the inverter side, if the counter EMF is higher than the voltage on the inverter side, the PMSM is not allowed to be put into operation again at the belt speed, otherwise, the PMSM is put into operation again at the belt speed. When the PMSM is allowed to be put into operation again at the belt speed, a separation contactor is closed; when the PMSM is not allowed to be put into operation again at the belt speed, the separation contactor is switched off. Therefore, the method, the device and the system can be used for computing the rotor position angles through dividing the working conditions into low-speed working conditions and medium-high speed working conditions according to Omega e, and the PMSM is started through the rotor position angles; the overall control method is provided from the view of system, the PMSM at the high speed section is not allowed to be put into operation again at the belt speed, the position for the PMSM at the medium-high speed section to be put into operation again is determined through adopting a one-step short-circuit method to compute the rotor position angles, the position for the PMSM at the low speed section to be put into operation again is determined through adopting an INFORM (Indirect Flux detection by On-line Reactance Measurement) method to compute the rotor position angles.

A device is provided for detecting inadequate electric braking and commutation to a safety brake is intended for a vehicle with electric traction, in particular a rail vehicle, which is provided with a traction chain, the system including a first electric, non-safety brake which is integrated in the traction chain and a second safety brake.

The device includes a member for commutation from the first brake to the second brake, a device for monitoring the braking performance of the first brake using data for measurement of the intensity of a current, a decision device for commutating from the first brake to the second brake when a predetermined threshold value is exceeded and a device for transmitting a commutation command to the at least one commutation member.

The invention relates to a motor device of a top opening barrel washing machine for accurately halting and positioning. A washing barrel of a washing machine consists of an outer barrel positioned on an outer layer and an inner barrel positioned in the outer barrel; both the inner barrel and the outer barrel are positioned in the shell of the washing machine; a motor is arranged beside the inner barrel and drives the inner barrel to rotate; a locking piece is arranged on the inner wall of the outer barrel; the motor is provided with a controller for controlling the locking piece to be at the locking position; and the inner barrel is controlled by the controller to be kept at a position in which clothes and articles are put into or taken out. A small block of magnetic steel is additionally arranged on a motor rotor and matched with a fourth Hall sensor on a motor stator, thus the motor can stop in the same posture; and when a direct current brushless motor is used on the top opening washing machine, the cover-opening position of the inner barrel faces upward and stops at the position at which the clothes and articles are put into or taken out by people, thereby realizing the humanized design of the washing machine and enabling the operation of the washing machine to become simple, comfortable and convenient.

Provided is a motor control circuit for controlling the energization of a coil on the basis of the detection result of the position of a rotor. The motor control circuit performs controls to make a stop for a short time by suppressing continuous rotations by inertia and to cause no reverse rotation. When an external control signal (CTL) changes from L to H, a steady rotation control changes to a reversing control so that a reversing brake state comes in. The rotating speed of the motor is monitored, and when the rotating speed attenuates to a set rotating speed, a brake control signal (SPSB) changes from L to H so that a short brake state comes in. However, the motor is caused to continue rotations by inertia, and a position detecting signal (HALL) changes, so that the reversing brake control is performed temporarily (for a time period corresponding to a pulse width (TRB)). This short-pulse reversing brake control is interruptedly performed till the motor stops completely. Thus, the stop can be done for a shorter time period than in the case in which the stop is done only by the short brake control after the motor was decelerated to a rotating speed just before the stop.

A method controls an electric vehicle which is so constituted as to drive a synchronous motor by way of a switch and an inverter circuit. A battery acts as a source of driving a controlling power. The synchronous motor has a permanent magnet acting as an outer rotor. The method includes the following operations of: 1) detecting that the electric vehicle has an acceleration signal of zero; 2) detecting that an actual speed of the electric vehicle is less than a predetermined percent of a rated speed; 3) supplying a current to a winding of a fixed phase of the synchronous motor, by way of the inverter circuit; and 4) generating a braking force.

A system and method are presented for aligning a rotor in a motor. The motor may include the rotor and a plurality of pairs of electromagnets. One or more pairs of electromagnets may be excited at a first excitation level. The one or more pairs of electromagnets may be less than all of the plurality of pairs of electromagnets. The excitation of the one or more pairs of electromagnets may be increased to a second excitation level over a first period of time. The excitation of the one or more pairs of electromagnets may be decreased to a third excitation level over a second period of time. Exciting the one or more pairs of electromagnets, increasing the excitation, and decreasing the excitation may cause the rotor to stop in a known position.

A drive device has a break circuit. The break circuit inputs phase-current values transferred from phase-current sensors mounted on an electrical path of a motor generator. A power switching element is equipped with a freewheel diode connected in parallel with each other. An inverter has pairs of the power switching elements. In each pair, the power switching element in a high voltage side and the power switching element in a low voltage side are connected in series. It is detected for the freewheel diode to be in a freewheel mode when a forward current flows in the freewheel diode. The break circuit detects the freewheel mode when the phase-current value is not less than a predetermined threshold value. The break circuit detects the freewheel mode where the current flows in the freewheel diode in an upper arm when the phase-current value is not more than the threshold current value.

A motor drive apparatus 1 having a dynamic braking circuit 5 for producing a deceleration torque utilizing a braking force caused by a synchronous motor 4 acting as a generator when the synchronous motor 4 is deenergized, is equipped with a dynamic braking circuit fault detection capability, and comprises: a DC power supply 2 which is obtained by rectifying input AC power; voltage application means 2, 3, 10, 11 for applying a voltage to the windings of the synchronous motor 4 and to the dynamic braking circuit 5 for a predetermined length of time by switching power transistors A to F connected to the DC power supply 2; current detection means 6 for detecting the value of a current flowing from the power transistors A to F; and fault checking means 11 for checking the dynamic braking circuit 5 for the presence or absence of a fault, based on the current value detected by the current detection means 6 and on a predefined threshold value. With this configuration, detection of faults in the dynamic braking circuit is accomplished without requiring the addition of a contact signal or a control circuit.

A method of controlling a power converter (20) of a motor drive system (10)controls the power converter (20) during a first operating mode by applying a current control scheme, which sets power converter commands to control torque current flowing from the power converter (20) to the motor (30) to achieve desired motor speed; and initiates a second operating mode when power supply to the power converter (20) is interrupted. The second operating mode includes controlling negative torque current between the power converter (20) and the motor (30) so that mechanical energy from the motor (30) charges an element (58) on a power supply side of the power converter (20). The first operating mode is resumed when the input power recovers. Torque current between the power converter (20) and the motor (30) is also controlled to limit a maximum transient DC bus voltage.

A traction drive, in particular for rail cars, includes a permanent-excited synchronous motor, a traction converter with a pulsed inverter for powering the motor, and ohmic brake resistors. Cross-over switches are connected with a corresponding input terminal of the motor and can switch the input terminal between a corresponding output terminal of the pulsed inverter (for travel) and a terminal of a corresponding brake resistor (for braking). The brake resistors are electrically connected in a star configuration. The traction drive can operate with different supply voltages. There is no longer a need for a mechanical brake, and flat spots on the wheels can be prevented.

The invention relates to a motor drive system and an energy feedback brake control method of the motor drive system. The motor drive system comprises a storage battery, a motor controller and a permanent magnet brushless direct current motor. The motor controller comprises a control module and a triphase full-bridge inversion circuit, wherein the control module comprises an electric control unit and a brake control unit; the brake control unit is used for confirming a first upper half bridge switch tube and a second lower half bridge switch tube turned on by a wave transmission sequence corresponding to a position signal of the current rotor in the electric control process when brake is conducted, and sending a PWM (pulse-width modulation) signal to control the on and off of the first lower half bridge switch tube corresponding to a branch where the first upper half bridge switch tube is located, so that a return circuit is formed to generate brake current in a motor coil, and the storage battery is charged. According to the system and the method, half bridge modulation energy feedback can be conducted according to a reversibility principle of the motor in the brake process of the permanent magnet brushless direct current motor, and the service time of the storage battery can be prolonged.

In a motor-driven shift position switching device, when the difference between a target position and the rotation position of a rotor has become smaller than a prescribed value in a motor feedback control, a transition is made to a deceleration control. A phase lead correction amount for correcting the phase lead of the current supply phase with respect to the rotor rotation phase is set in accordance with the rotor rotation speed. Thus, proper braking force suitable for the rotor rotation speed is exerted on the rotor and the rotor can be decelerated smoothly as it approaches the target position. Further, in the period when the current supply to the motor is kept off, the shift position switching determination ranges are set wider than in the period when the current supply to the motor is on.

A braking action of movement of a support surface on an examination may be accomplished with a motor. The examination table includes a base, a support surface moveable with respect to the base, and a motor having a rotor and a stator. The motor is coupled to the support surface and configured to move the support surface. A motor controller of the examination table is in electrical communication with the motor. The motor controller is configured to brake the movement of the support surface by terminating power to a plurality of windings of the stator of the motor for a predetermined amount of time, and, selectively activating a subset of windings of the plurality of windings of the stator for a predetermined amount of time.