| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a fluid pump suitable for a fuel high pressure injection pump of a diesel engine by preventing abnormal wear or seizure in a sliding part between the cam and the plunger. SOLUTION: In this fluid pump with a plunger operated by a cam mechanism, the cam mechanism consists of a cam, a roller which slidingly contacts with the cam, and a shoe which slidingly contacts with the cam and abuts on the plunger. Either of the roller or the shoe is made of ceramics with coefficients of thermal expansion nearly equal to that of the other part. For example, one part is made of a ferrous metal, while the other part is made of zirconia ceramics. In the fluid pump having the same structure as the above, at least one of the roller and the shoe is made of silicon nitride ceramic or silicon carbide ceramic. Both ends of the roller are formed into a crown shape, so that the variation of the surface pressure caused by sliding contact between the roller and the cam, in the longitudinal direction of the roller lies in a prescribed range.</p> |
