Various embodiments of the teachings herein include an actuator for a flap or for a valve for adjusting a gaseous or fluid volume flow. The actuator may include: a housing; an electric motor disposed in the housing; a downstream reduction gear; and a positioning element with an actuator connection for the flap or the valve. There is an electromagnet adjacent to an outer side of the rotor with a coil arrangement with a magnetic core. There is an electrical circuit arrangement for activating the electromagnet, providing a first brief current pulse, so a remanent magnetic field remains in the coil core. In a holding position of the actuator, while a mechanical pre-tensioning is set up, there is a holding torque with contact to the outer side of the rotor. The circuit arrangement provides a second brief current pulse to extinguish the remanent magnetic field still present in the coil core for releasing the holding torque with contact, forming an air gap between the electromagnet and the outer side of the rotor.

An electric motor includes an angle sensor, and the angle sensor includes a main body, a hood part, a holding part, a first circuit board, an intermediate flange, a second circuit board, a disk part, e.g., with a dimensional scale, and a hollow shaft. The rotor shaft of the angle sensor is connected to a rotor of the electric motor for conjoint rotation. The disc part is slid onto the hollow shaft and bears against a shaft step and/or a flat surface region of the hollow shaft. The second circuit board has conducting tracks acting and/or formed as coil winding and is held clamped between the main body and the intermediate flange. The intermediate flange is pressed towards the main body by the screw head of another screw screwed into a threaded bore of the main body. The first circuit board is held clamped between the intermediate flange and the holding part. The screw head of a screw screwed into a threaded bore of the intermediate flange presses the holding part towards the intermediate flange, and an elastically preloaded sheet-metal part supported on the hood part is disposed between the holding part and the hood part.

Provided is a drive control mechanism of a geared motor capable of executing a stopping operation between a start point and an end point in a drive range, maintaining this stopping operation, and smoothly and reliably executing respective operations that start from this stopped state without applying any external force other than a drive input of the electric motor. The drive control mechanism of a geared motor 1 according to the present invention includes the geared motor 1 formed by integrating an electric motor 2 with a speed change unit 3 including an input shaft that is a drive shaft 21 of the electric motor 2, and braking means 4, 14 for controlling braking in each of driven and stopped states in an output shaft 32 of the speed change unit 3, and the braking means 4, 14 includes a rotating part 40, 140 rotatably and pivotally supported by the drive shaft 21 of the electric motor 2, and including a permanent magnet 43, 143 disposed in an annular shape, and a fixing part 41, 141 fixed to a case 20 of the electric motor 2, and including a permanent magnet 45, 146 disposed facing the permanent magnet 43, 143 of the rotating part 40, 140 with a different polarity in the stopped state, and disposed in an annular shape.

Systems and methods for braking a power tool motor using a magnetically susceptible fluid. One power tool includes a housing, a motor within the housing, a drive train coupled to the motor, a magnetically susceptible fluid located within the drive train, and an inductor within the housing and configured to introduce a magnetic field to the magnetically susceptible fluid. An electronic controller is connected to the motor and to the inductor and is configured to receive a signal to initiate a braking process, generate, in response to the initiation of the braking process, a control signal for the inductor, and provide the control signal to the inductor to control a viscosity of the magnetically susceptible fluid located within the drive train.

Provided is a drive control mechanism of a geared motor capable of executing a stopping operation between a start point and an end point in a drive range, maintaining this stopping operation, and smoothly and reliably executing respective operations that start from this stopped state without applying any external force other than a drive input of the electric motor. The drive control mechanism of a geared motor 1 according to the present invention includes the geared motor 1 formed by integrating an electric motor 2 with a speed change unit 3 including an input shaft that is a drive shaft 21 of the electric motor 2, and braking means 4, 14 for controlling braking in each of driven and stopped states in an output shaft 32 of the speed change unit 3, and the braking means 4, 14 includes a rotating part 40, 140 rotatably and pivotally supported by the drive shaft 21 of the electric motor 2, and including a permanent magnet 43, 143 disposed in an annular shape, and a fixing part 41, 141 fixed to a case 20 of the electric motor 2, and including a permanent magnet 45, 146 disposed facing the permanent magnet 43, 143 of the rotating part 40, 140 with a different polarity in the stopped state, and disposed in an annular shape.

An actuator includes a movable body provided with a magnet, a support body provided with a case and a coil assembly, a connecting body to be connected to the movable body and the support body, and a magnetic drive circuit. The coil assembly includes a first plate. The case includes a first case member, and a second case member. The coil assembly is positioned in a Z direction by fitting a protruding plate portion protruding from an edge of the first plate to an outer peripheral side into a first cutout concave portion provided in an edge of the first case member, and a second cutout concave portion provided in an edge of the second case member, and abutting a curved portion provided on an edge of each of the cutout concave portions against the protruding plate portion from both sides in the Z direction.

An electric actuator includes a motor portion including a rotor rotatable about a motor shaft and a stator opposing the rotor, a reduction gear to decelerate and output rotation of the rotor, a brake to brake rotation of the rotor, a position detector to detect a position change of the rotor, and a cover that accommodates the motor portion. The reduction gear, the brake, the motor portion, and the position detector are sequentially arranged in an axial direction from one side in the axial direction. The brake includes a first brake portion that includes a magnetic material; and a second brake portion that rotates in synchronization with the rotor, is in contact with the first brake portion at a braking position, and is in non-contact with the first brake portion at the non-braking position, and a solenoid.