LAUSR

High pressurisation is one of the important developmental techniques for piston pumps. Given that press-fit cylinder blocks of instruction machinery develop cracks or breakage; based on the DIN 7190(2001) and GB/T 5371-2004, the amounts of interference in the press-fit cylinder block were calculated. The maximum, minimum, and average amounts of interference were 0.1689, 0.0576, and 0.1133 mm, respectively. Finite-element analysis of interference force as a single applied force and interference force in conjunction with hydraulic pressure was investigated in this study as multiple applied forces in order to investigate the causes of cracks. The results indicate that at the maximum interference, the weak section where cracks easily develop is the thin wall between the cylinder bore and the spring hole. The analysis results are consistent with the observed positions of the cracks, thereby providing a reference for the future design and production of piston pumps.