| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a pump capable of being assembled at ordinary temperature and usable at an ultra-low temperature without causing a seizure in a sliding part by forming a cylinder and a piston base material by use of the same material, subjecting the surface of the piston to a self-lubricating composite plating, and setting the space between the piston and the cylinder to a prescribed precision. SOLUTION: A liquid hydrogen pump has a suction opening 2 formed on the bottom of a bottomed cylindrical pump housing 1, and the upper part of the housing 1 is fixed to a liquid hydrogen storage vessel. A piston 10 fitted to a cylinder 11 within the housing 1 is reciprocated through a connection rod 15 by the operation of a pump driving mechanism arranged in the upper part of the housing 1. In this case, the circumferential surface of the piston 10 is nickeled by use of a suspension obtained by dispersing a material having self- lubricating function such as polytetrafluoroethylene or molybdenum disulfide in a metal matrix, and the plating layer is polished, whereby the clearance between the cylinder 11 and the piston 12 is set to 1-3μm.</p> |
