Electric drill

Abstract

This application relates to an electric drill, comprising: an output shaft; a torque adjustment assembly including an adjusting sleeve, an adjusting nut, a biasing component, and a shift washer. Rotating the adjusting sleeve causes the adjusting nut to reciprocate along the axial direction of the output shaft. The adjusting nut presses against the shift washer via the biasing component. The shift washer adjusts the clutch torque of the clutch mechanism to interrupt the transmission connection between the motor and the output shaft when the clutch torque is reached. The adjusting sleeve has an internal thread, and the adjusting nut has an external thread adapted to the internal thread. The helix angle between the internal and external threads is denoted as θ. The static friction coefficient between the adjusting sleeve and the adjusting nut is denoted as μ, and the electric drill satisfies tanθ < μ. This ensures that the adjusting sleeve and the adjusting nut form a self-locking structure, preventing the adjusting sleeve from rotating unexpectedly due to vibration or load changes during non-human operation, thereby maintaining a stable set torque value. This self-locking feature replaces the elastic deformation anti-reverse function of traditional sound plate, significantly reducing the dependence on the deformation of the sound plate.

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