Automatic opening and closing phase change clutch and one-way cold guide pile

The utility model provides an automatic on-off phase change clutch. The automatic on-off phase change clutch comprises a rotary drum; a transmission shaft; the transmission shaft is arranged in the rotary drum and is coaxial with the rotary drum; the shell part is positioned between the rotary drum and the transmission shaft; the end, facing the rotary drum, of the shell is fixed to the inner side of the rotary drum, and an opening is formed in the end, facing the transmission shaft, of the shell. An elastic cavity is formed in the shell; and phase change liquid is arranged in the elastic cavity. Under the condition that the temperature is reduced, the phase change liquid is changed into a solid state from a liquid state, the volume is expanded, then the elastic cavity is enlarged and makes contact with the transmission shaft and is pressed tightly, and the transmission shaft drives the rotating drum to rotate through friction force. When the temperature rises, the phase change liquid is changed from a solid