Speed-adjustable direct current motor

The speed-adjustable direct current motor comprises a base, an installation sleeve is arranged right above the base, a plurality of supporting blocks are fixedly connected between the installation sleeve and the base, a machine body is arranged in the installation sleeve, the two ends of the machine body penetrate through the installation sleeve respectively, and the supporting blocks are fixedly connected with the installation sleeve. A plurality of mounting grooves are formed in the side wall of the inner bottom end of the mounting sleeve, damping shock absorbers are fixedly connected to the side walls of the inner bottom ends of the mounting grooves, the upper ends of the damping shock absorbers penetrate through the mounting grooves and abut against the lower end of the machine body, an arc-shaped clamping plate is arranged at the upper end of the machine body, and the lower end of the arc-shaped clamping plate abuts against the upper end of the machine body; the upper end of the arc-shaped clamping plate