A method for preventing motion of an output shaft (401), of an electromagnetic motor comprising a coil assembly, when a mechanical brake (400) is released, comprising the steps of: determining the position of the output shaft (401); correlating the position of the output shaft (401) with a current such that when applied in the coil assembly induces a force on the output shaft (401) to prevent motion of the output shaft (401) when the mechanical brake (400) is released.

A mechanical brake for arresting movement of the output shaft of a linear electric motor, comprising a pivotally mounted plate having a space for receiving the output shaft of the motor; an electrically operated holding device contacting a free end of the plate and arranged to hold the plate in a condition to permit movement of the output shaft and to permit the plate to pivot to a jamming position; wherein the electrically operated holding device comprises a solenoid to control the movement of the plate.

An electromagnetic brake device presses a pressing plate against a brake rotor along an axis via a friction material by the electromagnetic force of an electromagnetic actuator. The electromagnetic brake device includes a support member that is disposed on the opposite side of the pressing plate to the brake rotor and that is supported by a housing so as to be displaceable along the axis and non-rotatable around the axis, and a shaft member that transmits a force in the direction along the axis between the pressing plate and the support member. An electromagnetic coil and an armature of the electromagnetic actuator are spaced apart from the pressing plate between the pressing plate and the support member, the electromagnetic coil is supported by the housing, and the armature is supported by the support member.

A method for controlling an electromagnetic brake (1) having a coil carrier (2), a solenoid (5), an armature disc (7), and at least one further force-exerting element. The internal and external poles (3, 4) of the coil carrier each have a front surface with a varying gradient that fits, in a complementary fashion, the front surfaces of the respective internal and external poles (8, 9) of the armature disc. The brake has an air gap (11) which varies in size and forms a stroke region (21). When excitation occurs, the solenoid generates a magnetic force, and the force-exerting element generates an opposing force, wherein the ratio of the solenoid's magnetic force and the opposing force varies at least once between greater than and smaller than one during the movement of the armature disc in the stroke region owing to the variation of the excitation of the solenoid.

An electric motor comprising: a stator; a rotor having a magnet mounted thereto; an electric circuit comprising a plurality of phases or windings for driving rotation of a rotor, in a drive mode; and a controller configured to control the electric circuit, in a motor braking mode, to short at least one of said phases or windings such that the magnet is able to generate a braking current in the shorted phase or winding wherein the motor is configured to operate at a rated current in the drive mode and to have a reactance such that the amplitude of the braking current is the same or lower than the amplitude of the rated current.

A torque generation apparatus includes a magnetic disc rotatable about a rotation axis, a first yoke, a second yoke, a magnetic viscous fluid placed between the magnetic disc and the first yoke and the second yoke, a coil, and a third yoke. The coil overlaps with the magnetic disc as viewed along the rotation axis. The third yoke constitutes a magnetic path of a magnetic field generated by the coil together with the first yoke and the second yoke. The magnetic disc includes a torque increasing portion at at least one of a surface facing the first yoke and a surface facing the second yoke. The torque increasing portion is provided in an outer circumferential area of the magnetic disc in a radial direction and causes a shearing force to a cluster of the magnetic viscous fluid to become larger than that in the inner circumferential area.

An automatic descent control device includes a line configured to be attached to a load. A line system retracts slack from the line when the line is not loaded and extends the line when the line is loaded. At least one braking system provides a braking force when the line is loaded so as to control extension of the line and a descent rate of the load. The at least one braking system is operable in at least two configurations, a first configuration that the at least one braking system lowers the load at a first descent rate, and a second configuration that the at least one braking system lowers or locks the load at a second descent rate. The load being a constant and the first descent rate is greater than the second descent rate.

A method for dynamic braking of a permanent magnet motor, and an elevator utilizing thereof, are presented. The arrangement includes a corresponding number of phase legs and input connectors relative to a number of the plurality of motor windings, wherein each one of the input connectors is coupled to a respective one of the phase legs. At least some of the phase legs comprise at least two semiconductor devices. Second terminals of the phase legs are connected to each other, wherein the arrangement includes a number of semiconductor switches configured for forming a short-circuit between each of the plurality of motor windings.

An eddy current braking system for a wheel of a vehicle, the vehicle including a chassis and the wheel being rotatably mounted to the chassis, the wheel including a wheel rim made of an electrically-conductive material and extending annularly around a wheel cavity, the system comprising: a magnetic field generating member secured to the chassis and disposed annularly within the wheel cavity and proximal to the wheel rim, the magnetizable member being operable for generating a magnetic field towards the wheel rim to generate eddy current within the wheel rim upon rotation of the wheel; and a magnetic field controller operatively connected to the magnetic field generating member for selectively controlling an intensity of the magnetic field applied by the magnetic field generating member on the wheel rim.

This braking control device comprises a differential mechanism, a first electric motor that generates assisting force in a braking operation member, a second electric motor that adjusts output rod shift of the differential mechanism, and a controller that controls the first and second electric motors. In the controller, the first electric motor is controlled on the basis of an assistance map in which the assisting force is calculated, and the second electric motor is controlled on the basis of a displacement map in which the output rod shift is calculated. When the displacement map is changed, the assistance map is corrected as well.