Abstract: A propulsion assembly for an unmanned aerial vehicle (UAV) includes a motor configured to rotate in a first direction, a propeller seat configured to be driven by the motor to rotate in the first direction and to receive a propeller, and a sensor configured to collect sensing data useful for determining whether the propeller is locked to the propeller seat, without requiring operation of the motor.

Abstract: A control method for a power tool and a power tool is disclosed. The control method has an operating mode and a safety mode. In the operating mode, a motor drives a tool receptacle in a rotating manner. In the operating mode, the motor has a power consumption in the amount of at least an operating value. The safety mode is triggered if a sensor device detects a rotational blockade of the tool receptacle. In the safety mode, a clutch that is switchable by electrical signals located in the drive train between the motor and tool receptacle is periodically opened and closed and a power consumption of the motor is reduced as compared to the operating value.

Abstract: An overload protection device for protecting a motor from overload is disclosed. The overload protection device includes a shaft and a load carrying member driven by the driving portion of the shaft. The shaft includes a shaft body and a driving portion on an end of the shaft body. The load carrying member includes at least one magnetic member corresponding to the driving portion. Each of the at least one magnetic member includes a first magnetic member fixed on the load carrying member and a second magnetic member rotatably fixed on the load carrying member. The first magnetic member is located between the second magnetic member and the driving portion of the shaft and the same poles of the first and second magnetic member are opposite to each other. The driving portion is engaged with the first magnetic member and impels the first magnetic member to rotate the load carrying member under the rated load of the motor.

Abstract: The clutch includes a drive disk, a follower disk and a brake disk. When current flows, the follower disk is connected with the drive disk to transmit a power from a driving unit to a door-opening/closing mechanism. When no current flows, the follower disk is separated from the drive disk to cut off the power transmission from the driving unit to the door-opening/closing mechanism. In a state that the drive disk and the follower disk are separated from each other, the brake disk is connected to the follower disk to brake the door-opening/closing mechanism in the opening direction of the door, and to allow the door-opening/closing mechanism to move in the closing direction of the door.

Abstract: An overload protection arrangement for a portable power tool includes a magnetic clutch (5) arranged in a drive train of the power tool between an electromotor (1) and a tool chuck (3), control electronics (6) for controlling the magnetic clutch (5), a self-actuated torque-dependent overload clutch (7) likewise arranged in the drive train, and a sensor (8) for detecting an open condition of the overload clutch (7) upon the overload of the drive train and connected with the control electronics (6).

Abstract: A mechanical clutch with two elements (11, 21) which, for the purpose of positively engaging one another, are provided with opposed end toothings which are adapted to one another, the first element (11) being rotatably mounted and axially supported, the second element (21) also being rotatably mounted and axially supported, and further being axially blocked in a first position for the purpose of being non-rotatably engaged with the first element (11), and being axially moveable into a position in which it is freely rotatably and disengaged from the first element (11), with a device for selectively axially blocking the second element (21), the clutch further comprising: a cavity system whose shape is variable and which is filled with a magneto-rheological fluid; a displacing member which can be moved between a first position and a second position, which delimits the cavity system and which is connected to the second element (21); and an electro-magnet (37) which can magnetize at least part of the magneto-rheol