An electric machine includes a stator and a rotor energizable by magnetic fields produced by the stator when receiving a stator current to produce relative motion between the rotor and the stator. A controller is configured to send the stator current through the stator at a current angle measured from the closest one of a pole of the rotor, determine a desired operational output of the electric machine, and determine a desired rotor motion corresponding to the desired operational output of the electric machine. The controller is further configured to calculate a vector control modulation applied to the stator that elicits the desired rotor motion, and adjust the current angle of the stator current based on the vector control modulation to cause the rotor to perform the desired rotor motion and achieve the desired operational output of the electric machine.

A multi-phase electric motor includes a stator winding. The multi-phase electric motor is controlled by regulating a current flowing in the multi-phase electric motor in response to an applied voltage. An overload condition of the multi-phase electric motor is detected by monitoring a thermal increase of the value of a stator resistance of the stator winding of the multi-phase electric motor during a steady state condition of said multi-phase electric motor in which the current flowing in the motor has constant phase, and the motor is operating at constant load with constant speed.

A generator system having a dynamo that contains an armature, a stator and a housing. The armature rotates about a first axis of rotation. The stator is concentrically positioned around the armature. Both the armature and the stator are free to rotate in opposite directions about the first axis of rotation. The housing of the dynamo is connected to a motor that can rotate the dynamo around a second axis of rotation. There is an angle of inclination between the first axis of rotation and the second axis of rotation. This angle of inclination is selectively altered during operation. By changing the angle of inclination between the two axes of rotation, a precession can be created that adds rotational energy to both the armature and the stator. This increases the output of the dynamo and creates a highly efficient electrical generator.

A generator system having a dynamo that contains an armature, a stator and a housing. The armature rotates about a first axis of rotation. The stator is concentrically positioned around the armature. Both the armature and the stator are free to rotate in opposite directions about the first axis of rotation. The housing of the dynamo is connected to a motor that can rotate the dynamo around a second axis of rotation. There is an angle of inclination between the first axis of rotation and the second axis of rotation. This angle of inclination is selectively altered during operation. By changing the angle of inclination between the two axes of rotation, a precession can be created that adds rotational energy to both the armature and the stator. This increases the output of the dynamo and creates a highly efficient electrical generator.

This clutch includes an annular clutch housing, a rotationally driven drive-side rotating body, a driven-side rotating body, a rolling body, and a support member. The clutch is configured such that, when the drive-side rotating body starts to rotate when driven, the drive-side rotating body comes into contact with the support member in a rotational direction and presses the rolling body in the rotational direction through the support member, thereby releasing the rolling body from gripping effected by the clutch housing and the driven-side rotating body. The support member includes a load generation section for generating a load which makes it difficult for the support member to rotate about the rotation axis of the drive-side rotating body when at least the drive-side rotating body starts to rotate when driven.

This clutch includes an annular clutch housing, a rotationally driven drive-side rotating body, a driven-side rotating body, a rolling body, and a support member. The clutch is configured such that, when the drive-side rotating body starts to rotate when driven, the drive-side rotating body comes into contact with the support member in a rotational direction and presses the rolling body in the rotational direction through the support member, thereby releasing the rolling body from gripping effected by the clutch housing and the driven-side rotating body. The support member includes a load generation section for generating a load which makes it difficult for the support member to rotate about the rotation axis of the drive-side rotating body when at least the drive-side rotating body starts to rotate when driven.

Provided is a motor control device generating a torque command such that a detection speed of a motor matches a command speed, and controlling the motor. The motor control device includes: a torque command differential component taking a differential of the torque command and obtaining a torque command differential value; a motor actual speed second order differential component taking a second order differential of the detection speed of the motor and obtaining a motor jerk; and a runaway detection component determining that the motor is in a runaway state in a case where an abnormal state in which a sign of the motor jerk and a sign of the torque command differential value do not match continues for a predetermined time or more. Accordingly, the runaway of the motor can be detected in a short time while the erroneous detection can be suppressed.

The invention relates to an electric motor comprising: (A) a ring-like rotor which comprises: a plurality of electromagnets that are equi-angularly spaced and equi-radially disposed in a ring-like manner; and, (B) a stator which comprises: a plurality of solenoids that are equi-angularly spaced and equi-radially disposed, each of said solenoids having a solenoid core, which in turn has a rectangular shape in cross-section, and a cavity; and a solenoid coil within each of said solenoids; wherein said electromagnets are arranged such that they can move through said cavities of the solenoid cores in a rotational manner, wherein negative and positive ends, respectively, of the plurality of said electromagnets are connected in parallel to respective negative and positive peripheral strips, and wherein current to the electromagnet coils is supplied from a power supply via two brushes, respectively to the negative and positive strips.

The invention relates to an electric motor comprising: (A) a ring-like rotor which comprises: a plurality of electromagnets that are equi-angularly spaced and equi-radially disposed in a ring-like manner; and, (B) a stator which comprises: a plurality of solenoids that are equi-angularly spaced and equi-radially disposed, each of said solenoids having a solenoid core, which in turn has a rectangular shape in cross-section, and a cavity; and a solenoid coil within each of said solenoids; wherein said electromagnets are arranged such that they can move through said cavities of the solenoid cores in a rotational manner, wherein negative and positive ends, respectively, of the plurality of said electromagnets are connected in parallel to respective negative and positive peripheral strips, and wherein current to the electromagnet coils is supplied from a power supply via two brushes, respectively to the negative and positive strips.

A linear electric actuator system, preferably for patient lifters, comprising at least one linear electric actuator and a controller having a power limiting circuit for limiting the power to the at least one linear electric actuator. The actuator system is arranged such that the threshold value of the maximum permissible power in the power limiting circuit may be changed, and that this change may be performed via reference to the position of the spindle nut on the spindle as a look up in a table showing a corresponding value for the power limit.