A cryopump includes: a cryopump container including a cryopump intake port; a radiation shield that is cooled to a first cooling temperature and extends from the cryopump intake port into the cryopump container; a cryopanel unit that is cooled to a second cooling temperature lower than the first cooling temperature and is disposed to be surrounded by the radiation shield in the cryopump container; and an intake port shield that is cooled to the first cooling temperature and is disposed at the cryopump intake port such that the cryopanel unit is not visible from an outside of the cryopump, in which the radiation shield includes a first gas inlet formed at a height between the intake port shield and the cryopanel unit.

A cryopump has a simple-to-manufacture frontal baffle plate with improved gas distribution and has a large-area second-stage array plate to capture Type II gases. The cryopump has a first-stage frontal baffle plate having orifices and flaps bent from and attached to the orifices. The cryopump has a second-stage top plate that is larger in area than cooling baffles of the second stage array.

A cryopump has a simple-to-manufacture frontal baffle plate with improved gas distribution and has a large-area second-stage array plate to capture Type II gases. The cryopump has a first-stage frontal baffle plate having orifices and flaps bent from and attached to the orifices. The cryopump has a second-stage top plate that is larger in area than cooling baffles of the second stage array.

A cryopump includes a top cryopanel that partitions a shield cavity into a shield cavity upper portion and a shield cavity lower portion. A radiation shield includes a shield main slit that communicates a shield outside gap into the shield cavity lower portion. The radiation shield may include a shield auxiliary slit that is formed at a different position from that of the shield main slit in an axial direction of the cryopump and that communicates the shield outside gap into the shield cavity lower portion. The shield auxiliary slit may be formed between the top cryopanel and the shield main slit in the axial direction.

A cryopump includes a top cryopanel that partitions a shield cavity into a shield cavity upper portion and a shield cavity lower portion. A radiation shield includes a shield main slit that communicates a shield outside gap into the shield cavity lower portion. The radiation shield may include a shield auxiliary slit that is formed at a different position from that of the shield main slit in an axial direction of the cryopump and that communicates the shield outside gap into the shield cavity lower portion. The shield auxiliary slit may be formed between the top cryopanel and the shield main slit in the axial direction.

Gaseous fuel downstream of a heat exchanger can be too cold for fuel system components when the temperature of engine coolant employed as a working fluid in the heat exchanger is too low to elevate gaseous fuel temperature, and it is possible for the engine coolant to freeze. A method of operating a cryogenic pump for controlling discharge temperature of a heat exchanger that vaporizes a process fluid received from the cryogenic pump with heat from a working fluid, where the cryogenic pump includes a piston reciprocatable in a cylinder between a proximate cylinder head and a distal cylinder head, includes monitoring at least one of process fluid temperature and working fluid temperature; retracting the piston during an intake stroke from the proximate cylinder head to the distal cylinder head; and extending the piston in a plurality of incremental discharge strokes until the piston travels from the distal cylinder head back to the proximate cylinder head. At least one of the number of incremental discharge strokes, a length of incremental discharge strokes and a rest period between incremental discharge strokes is selected such that at least one of the process fluid temperature and working fluid temperature is maintained above a predetermined level.

Gaseous fuel downstream of a heat exchanger can be too cold for fuel system components when the temperature of engine coolant employed as a working fluid in the heat exchanger is too low to elevate gaseous fuel temperature, and it is possible for the engine coolant to freeze. A method of operating a cryogenic pump for controlling discharge temperature of a heat exchanger that vaporizes a process fluid received from the cryogenic pump with heat from a working fluid, where the cryogenic pump includes a piston reciprocatable in a cylinder between a proximate cylinder head and a distal cylinder head, includes monitoring at least one of process fluid temperature and working fluid temperature; retracting the piston during an intake stroke from the proximate cylinder head to the distal cylinder head; and extending the piston in a plurality of incremental discharge strokes until the piston travels from the distal cylinder head back to the proximate cylinder head. At least one of the number of incremental discharge strokes, a length of incremental discharge strokes and a rest period between incremental discharge strokes is selected such that at least one of the process fluid temperature and working fluid temperature is maintained above a predetermined level.

A drive system for a cryogenic pump is provided including a spool housing having a plurality of valves disposed therein about a pump axis and a tappet housing including a plurality of tappet bores, each tappet bore in communication with a respective one of the plurality of valves. A collection cavity collects hydraulic fluid from the tappet bores. A pump flange includes a fluid inlet and a fluid outlet. An inlet manifold directs hydraulic fluid received through the fluid inlet to each of the plurality of valves. An outlet manifold directs hydraulic fluid from each of the valves and the collection cavity to the fluid outlet.

A drive system for a cryogenic pump is provided including a spool housing having a plurality of valves disposed therein about a pump axis and a tappet housing including a plurality of tappet bores, each tappet bore in communication with a respective one of the plurality of valves. A collection cavity collects hydraulic fluid from the tappet bores. A pump flange includes a fluid inlet and a fluid outlet. An inlet manifold directs hydraulic fluid received through the fluid inlet to each of the plurality of valves. An outlet manifold directs hydraulic fluid from each of the valves and the collection cavity to the fluid outlet.

A cryogenic pump comprising a shaft disposed in a bearing. The shaft rotates with respect to the bearing housing, and the shaft includes an end with an angled face. The pump includes a drive at one end of the bearing housing. A tappet passage is formed through the drive housing. A pushrod housing connects to the drive housing. The pump includes a piston and a tappet sliding within the tappet passage. The tappet has a base end disposed within the tappet passage and a rod end extending below the tappet end of the drive housing. A fluid cavity is in the tappet passage between the piston and the tappet. The pump includes a pushrod connected to the tappet. The angled face of the shaft rotates and drives the piston toward the drive housing, pushing fluid within the fluid cavity against the tappet, driving the pushrod away from the drive housing.