Abstract: A method of controlling an electric machine that includes sequentially exciting and freewheeling a winding of the electric machine. The winding is excited by an excitation voltage and is freewheeled over a freewheel angle. The method then includes varying the freewheel angle in response to changes in the excitation voltage. Additionally, a control system for an electric machine, and a product incorporating the control system and electric machine.

Abstract: A device and method for matching the rates of speed at which an electric motor that is drivingly connected to a worm gear raises and lowers a window in an automobile power window assembly. By axially displacing the motor's armature, and/or by varying the thread and tooth profiles of the worm and the gear, the amount of torque produced by the motor and transmitted through the worm gear can be altered. In order to compensate for the effect of gravity on the motor load and on the window's speed of ascent and descent, more torque is provided when the window is being raised and less torque is provided when the window is being lowered.

Abstract: A drive unit includes a rotating electrical machine; a rotation sensor that detects a rotational position of a rotor of the rotating electrical machine, and a storage medium. In an inspecting step of measuring a counter electromotive force by mechanically driving the rotating electrical machine after the rotating electrical machine and the rotation sensor are assembled together, positional error information of the rotation sensor obtained based on information of the counter electromotive force and output information from the rotation sensor is stored in the storage medium. The storage medium is integrally provided to the drive unit in such a state that the storage medium is readable upon assembling a control device that controls the rotating electrical machine.

Abstract: A device and method for matching the rates of speed at which an electric motor that is drivingly connected to a worm gear raises and lowers a window in an automobile power window assembly. By axially displacing the motor's armature, and/or by varying the thread and tooth profiles of the worm and the gear, the amount of torque produced by the motor and transmitted through the worm gear can be altered. In order to compensate for the effect of gravity on the motor load and on the window's speed of ascent and descent, more torque is provided when the window is being raised and less torque is provided when the window is being lowered.

Abstract: In an electric vehicle drive apparatus having an electric motor and a motor drive device, the electric motor having a stator, a rotor and a moving mechanism capable of changing a relative distance between the stator and the rotor to vary an effective magnetic flux of the motor, the motor drive device compares a regenerative current with a target current during a regenerative control of the motor, and when it is found that the regenerative current is larger than the target current, the distance between the stator and the rotor is increased to reduce the effective magnetic flux.

Abstract: A motor drive assembly includes a stationary housing, a shaft rotatably carried by the housing for driving a load, a gear box rotatably carried by the shaft, and an electric motor in the gear box having a rotor coupled by a gear train to the shaft. A switch in the housing near the gear box is operated when the gear box rotates against a spring bias in response to the rotor's exerting an increased predetermined torque. The motor may have an auxiliary winding in circuit with the switch to reduce power consumed by the motor when the switch is operated. Alternatively, a solenoid may be connected to the switch to hold the rotor stationary when the motor stops. The motor may have a main drive winding which is de-energized by the switch.

Abstract: Alternating Current (A.C.) Motors are modified in such a way as to provide zero to full nameplate torque, by inserting magnetic rods into elongate control-rod-receptive channelways in the stator. By moving the rods in and out of their respective channelways the magnetic path of the stator flux will change. With the rods all the way out of the stator full nameplate torque is achieved. As the rods are inserted deeper into the stator, the output torque of the rotor will decrease proportionally to a minimum value.