Free piston engine pump including variable energy rate and acceleration-deceleration controls

A free piston engine pump operative in response to the energy or work rate of a free piston engine, comprising pump means driven by such engine during power strokes of such engine for generating at least one fluid output work rate, said pump means having a pumping chamber and piston means therein;

• valve means for delivering fluid to said pumping chamber during a return or compression stroke of said piston means to return the same to an initial position ready for the next power stroke;
• return means operative at a beginning portion of the return or compression stroke for delivering to said pump means to expedite the return stroke a predetermined relatively high input work rate that during a normal operation is independent of the output work rate or rates of the preceding power stroke;
• said piston means comprising primary piston means for pumping fluid to generate such one fluid output work rate during at least of the power stroke, and said return means comprising secondary piston means coupled to said primary piston means responsive to a fluid input for delivering such relatively high input work rate to said primary piston means to accelerate the same toward an initial position in preparation for a succeeding power stroke;
• fluidically responsive transfer means having fluid coupling means between said primary and secondary piston means for transfering work between said primary and secondary piston means;
• and control orifice means for providing from a source of pressurized fluid a controlled flow of fluid to said transfer means during the return stroke to return said transfer means to an initial position ready for the next power stroke.

A free piston engine pump operative in response to the energy or work rate of a free piston engine, comprising pump means driven by such engine during the power stroke for generating plural fluid output work rates, including at least an initial relatively high output work rate and an intermediate relatively low output work rate, secondary pumping means for producing a predetermined independent relatively high output work rate after such intermediate relatively low output work rate, and coupling means for coupling energy from such engine to said secondary pumping means at only a portion of such power stroke after such initial relatively high output work rate near the end of the power stroke to cause said secondary pumping means to produce such relatively high output work rate, independently of the initial relatively high output work rate of said pump means, said pump means comprising a pump outlet, primary piston means for pumping fluid at a relatively high output work rate to said pump outlet during at least part of the power stroke, and said secondary pumping means comprising secondary piston means coupled to said primary piston means movable a predetermined distance at least near the end of the powwer stroke for pumping fluid during such movement, and said pump means further including a transfer flow control means operable during at least an intermediate portion of the power stroke for transferring at least some of the fluid pumped by said primary piston means from reaching said pump outlet and supplemental piston means movable with said primary piston means for pumping fluid during the power stroke at a relatively low output work rate, and said transfer flow control means comprising means for transferring fluid from the outlet side of said primary piston means to the inlet side thereof during an intermediate portion of the power stroke.

A free piston engine pump operative in response to the energy or work rate of a free piston engine, comprising pump means driven by such engine during the power stroke for generating plural fluid output work rates including at least an initial relatively high fluid output work rate;

• secondary pumping means for producing a predetermined relatively high output work rate at least near the end of the power stroke;
• means for coupling energy from such engine to said secondary pumping means via said pump means at only a portion of such power stroke near the end of the power stroke to cause said secondary pumping means to produce such relatively high output work rate independently of such initial relatively high fluid output work rate of said pump means;
• a fluid outlet;
• said pump means comprising a cylinder, supply means for supplying fluid to said cylinder, and primary piston means movable in said cylinder in response to energy produced by such engine during a power stroke for pumping fluid to said fluid outlet during one part of the power stroke;
• and said secondary pumping means comprising a secondary cylinder, secondary piston means movable in said secondary cylinder, and boundary means for limiting movement of said secondary piston means in said secondary cylinder to a predetermined distance between initial and extreme positions.

A free piston engine pump operative in response to the energy or work rate of a free piston engine, comprising pump means driven by such engine during power strokes of such engine for generating at least one fluid output work rate, said pump means having a pumping chamber and piston means therein, valve means for delivering fluid to said pumping chamber during a return or compression stroke of said piston means to return the same to an initial position ready for the next power stroke, and return means operative at a beginning portion of the return or compression stroke for delivering to said pump means to expedite the return stroke a predetermined relatively high input work rate that during a normal operation is independent of the output work rate or rates of the preceding power stroke, said piston means comprising primary piston means for pumping fluid to generate such one fluid output work rate during at least part of the power stroke, and said return means comprising secondary piston means coupled to said primary piston means responsive to a fluid input for delivering such relatively high input work rate to said primary piston means to accelerate the same toward an initial position in preparation for a succeeding power stroke, said pump further comprising a chamber, said secondary piston means being positioned in said chamber and movable a predetermined distance with respect to the latter during a beginning portion of the return stroke to deliver such high input work rate to said pump means exclusively while moving over such predetermined distance.

A free piston engine pump operative in response to the energy or work rate of a free piston engine, comprising pump means driven by such engine during power strokes of such engine for generating at least one fluid output work rate, said pump means having a pumping chamber and piston means therein;

• valve means for delivering fluid to said pumping chamber during a return or compression stroke of said piston means to return the same to an initial position ready for the next power stroke;
• return means operative at a beginning portion of the return or compression stroke for delivering to said pump means to expedite the return stroke a predetermined relatively high input work rate that during a normal operation is independent of the output work rate or rates of the preceding power stroke;
• said piston means comprising primary piston means for pumping fluid to generate such one fluid output work rate during at least part of the power stroke, and said return means comprising secondary piston means coupled to said primary piston means responsive to a fluid input for delivering such relatively high input work rate to said primary piston means to accelerate the same toward an initial position in preparation for a succeeding power stroke;
• and transfer means for transferring work between said primary and secondary piston means, said transfer means comprising transfer piston means for transferring such work, including a first means for directing mechanically transferring forces with respect to said primary piston means and a second means for transferring forces with respect to said secondary piston means via a fluid.

A free piston engine pump operative in response to the energy or work rate of a free piston engine, comprising pump means driven by such engine during the power stroke for generating plural fluid work rates, said pump means including primary piston means movable during the power stroke over a normal predetermined stroke distance and capable of movement into an overtravel region in response to excess engine energy, outlet means for delivering fluid pumped by said primary piston means during at least part of such predetermined stroke distance, start means for moving said piston means substantially fully into such overtravel region prior to start up the pump and engine, and return means for returning said primary piston means fully from such overtravel region and at least substantially completely over such normal predetermined stroke distance to obtain substantially maximum compression in the engine prior to an initial power stroke at start-up thereof, said return means including means operative at the beginning of a return or compression stroke for delivering a predetermined relatively high input work rate to said pump means, including secondary piston means coupled to said primary piston means for delivering such high input work rate and means for limiting the travel distance of said secondary piston means enabling the latter to expedite the return stroke independently of the output work rate or rates of the preceding power stroke, and said start means including means for moving said secondary piston means to its extreme position thereby to obtain such expedited return of said primary piston means.

A free piston engine pump operative in response to the energy of work rate of a free piston engine, comprising pump means driven by such engine during the power stroke for generating plural fluid output work rates, including at least an initial relatively high output work rate and an intermediate relatively low output work rate;

• secondary pumping means for producing a predetermined independent relatively high output work rate after such intermediate relatively low output work rate;
• coupling means for coupling energy from such engine to said secondary pumping means at only a portion of such power stroke after such initial relatively high output work rate near the end of the power stroke to cause said secondary pumping means to produce such relatively high output work rate independently of the initial relatively high output work rate of said pump means;
• said pump means comprising a pump outlet, primary piston means for pumping fluid at a relatively high output work rate to said pump outlet during at least part of the power stroke, and said secondary pumping means comprising secondary piston means coupled to said primary piston means movable a predetermined distance at least near the end of the power stroke for pumping fluid during such movement;
• energy absorbing means for absorbing overtravel work produced by said pump means at the end of the power stroke;
• and transfer means for transferring work between said primary and secondary piston means, including flow relief means for permitting controlled outflow of fluid from between said transfer means and secondary piston means when the latter has moved to its extreme position during the power stroke and said primary piston means continues to move said transfer means in an overtravel mode.