公开(公告)号：US20180058218A1

公开(公告)日：2018-03-01

申请号：US15250312

申请日：2016-08-29

Applicant: Caterpillar Inc.

Inventor： Sunil J. Bean ,  Alan R. Stockner ,  Mingchun Dong

IPC: F01B23/08 ,  F04B9/103 ,  F04B15/08 ,  F04B23/02 ,  F01B1/01 ,  F01B25/00 ,  F01B31/28

CPC classification number: F04B23/021 ,  F04B9/103 ,  F04B15/08 ,  F04B2015/081

Abstract: A cryogenic fluid pump includes a drive assembly and a pumping assembly. The drive assembly includes a cylinder. The cylinder includes an annular dump channel formed in and extending about an interior wall of the cylinder. A piston is reciprocatable within the cylinder between a first and second position. A hydraulic pressure chamber is defined by the cylinder and the piston. The piston includes an axial spill passage in communication with the pressure chamber and a transverse spill passage in communication with the axial spill passage. The transverse spill passage includes a piston dump port which is sealed to the cylinder in the first position and in the second position unsealed to the cylinder to permit fluid exit from the pressure chamber. The second position includes an over travel state and the dump area of the piston dump port when unsealed to the cylinder increases as the piston advances.