Sealing structure of valve rod of thermal expansion valve

The utility model discloses a sealing structure of a valve rod of a thermal expansion valve, which comprises an air box head, a diaphragm, a valve body, the valve rod and a transmission block, wherein the air box head is divided into two parts of an upper cavity and a lower cavity by the diaphragm, the valve rod extends into the valve body, the top of the valve rod is matched with the transmission block below the diaphragm, and a modified polytetrafluoroethylene seal ring with ripples on the inner wall is adopted between the valve body and the valve rod for sealing. As the modified polytetrafluoroethylene seal ring with the ripples on the inner wall is adopted between the valve body and the valve rod for sealing, the sealing effect is very good, and the sealing structure can prevent pressure in the valve body from leaking and entering into the lower cavity of the air box head, ensure that the pressure in the lower cavity of the air box head is free of interference of the pressure of an inner cavity of the val