US 3,995,974 A · Internal combustion assisted hydraulic engine

Abstract

This hydraulic engine utilizes two sets of hydraulic cylinders connected to a shaft so as to be alternately pressurized as the shaft is reciprocally driven by a pair of conventional internal combustion chambers. The outlets of all hydraulic cylinders are connected to a common output line via valves. During each power stroke certain of the hydraulic cylinders being pressurized are selectively disconnected (depressurized) from the output line. This effectively decreases the load on the driving chamber, and insures a relatively constant, high pressure hydraulic fluid output level despite changes in supplied force during each power stroke. The selective cylinder disconnection may be implemented programmatically in response to changes in engine parameters such as combustion chamber pressure. The engine also includes a pump for supplying input hydraulic fluid to each set of cylinders while that set is not being pressurized. The input fluid force is additive to the power supplied by the operative combustion chamber. The pump is driven by pressurized fluid from the output line, and includes a flywheel with sufficient inertia to maintain pumping, and hence continue engine operation, in the event of a misfire in one of the combustion chambers.

Claims15

Dependent claims

An internal combustion assisted hydraulic engine comprising:

an internal combustion chamber having a piston,
a set of at least two hydraulic cylinders each connected to said piston for pressurization during each power stroke of said chamber,
a common output line for pressurized hydraulic fluid from said set of cylinders, and
hydraulic load control means, responsive to the force exerted on said piston, for selectively disconnecting the hydraulic cylinders from said common output line during said chamber power stroke to maintain the hydraulic fluid pressure in said output line at a substantially constant preselected level notwithstanding changes in force exerted on said piston during said power stroke.

1 more element

An internal combustion assisted hydraulic engine comprising:

a pair of internal combustion chambers each having a piston,
a common shaft connecting said pistons, alternate combustion strokes of said chambers imparting reciprocation to said shaft,
first and second pluralities of hydraulic cylinders having plungers attached to said shaft for pressurizing hydraulic fluid in said first plurality as said shaft reciprocates in one direction and for pressurizing hydraulic fluid in said second plurality as said shaft reciprocates in the opposite direction,
a common output line,
a one-way valve connecting the outlet of each hydraulic cylinder to said common output line, said one-way valves permitting passage to said output line only of hydraulic fluid having a pressure at least equal to that in said output line, and
selective venting means for venting the outlet of selected hydraulic cylinders to a reservoir pressure substantially lower than said output line pressure for a portion of the chamber power stroke causing pressurization in that cylinder, said venting means being responsive to the force exerted on each piston during the power stroke of the respective combustion chamber and operative to maintain the hydraulic pressure in said output line at a substantially constant level notwithstanding changes in the force exerted on that piston during said respective power stroke.

3 more elements

A hydraulic engine comprising;

first and second sets of hydraulic cylinders, each set containing more than one cylinder, the pressurized fluid outlet of each cylinder being connectable to a common output line, the pistons of all cylinders being mechanically attached to a common shaft,
drive means for reciprocating said shaft alternately to pressurize the hydraulic fluid in said first and second sets,
means for selectively, effectively connecting to the output line the outlets of certain hydraulic cylinders in the set being pressurized in response to changes in force exerted by said drive means so that only the pressurized fluid from connected cylinders is supplied to said output line, whereby the output line pressure remains substantially constant despite changes in force exerted by said drive means during the pressurization cycle.

Dependencies are inferred from the claim text.

Internal combustion assisted hydraulic engine

Life of this patent

Internal combustion assisted hydraulic engine

Life of this patent

Abstract

Claims15