Hydraulic speed governor
OwnerHarold Goldinventor
Life of this patent
Estimating the term…
Abstract
Flow from a pressure source is bidirectionally conducted to a prime-mover driven, bidirectional, positive displacement pump and in-series flow restrictions; the pressure source and flow restrictions functioning to provide the reference flow rate; the pressure gradient across said pump bidirectionally signaling the error in prime-mover speed. Means responsive to said pressure gradient provide proportional plus integral control of the prime-mover speed.
Claims8
A mechanism for controlling the speed and the direction of a machine, said machine including a throttle for varying the speed and the direction of said machine, said mechanism comprising a first and a second flow restriction means and a positive displacement, bidirectional pump means conduited between said flow restriction means, said flow restriction means and said pump means defining a series array, selector means operative to communicate one side of said series array with a pressure source and the opposite side with a drain, or to communicate said opposite side with a pressure source and said one side with a drain, means driving said pump means at a speed proportional to the speed of said machine and in the corresponding direction, actuator means responsive to the pressure gradient across said pump means, and means coupling said actuator means to said throttle.
A valve responsive to a first and a second pressure, said valve comprising a housing, a first bore in said housing, a valve sleeve operating in said first bore, openings in said sleeve, annuluses in said first bore, said openings and said annuluses defining separate fluid passages, a second bore, said second bore being coaxial with said first bore and contained within said sleeve, a valve spool operating freely in said second bore, lands on said spool, second annuluses in said second bore, said lands and said second annuluses defining variable orifices, means in said housing defining first and second chambers between the ends of said first bore and the ends of said sleeve, a third bore in said housing, said third bore being of equal diameter with and coaxial with said second bore and opening into said first chamber, a fourth bore in said housing, said fourth bore being of equal diameter with and coaxial with said second bore and opening into said second chamber, the end lands of said spool projecting out of said sleeve and extending through said first and second chambers and into said third and fourth bores, said spool operating freely in said third and fourth bores, springs engaging the ends of said spool and restraining the longitudinal displacement of said spool relative to said housing, a first conduit freely communicating said first pressure with said first chamber through a first flow restriction means, a second conduit freely communicating said first pressure with the end of said spool in said fourth bore, a third conduit freely communicating said second pressure with the end of said spool in said third bore, a fourth conduit communicating said second pressure with said second chamber through a second flow restriction means, said spool and said sleeve being thereby responsive to the difference between said first and second pressures to make the displacement of said spool relative to said sleeve proportional to the sum of a displacement proportional to said pressure difference and a displacement proportional to the time integral of said pressure difference.
An actuator responsive to a first and a second pressure comprising a first piston operating freely in a first bore, a second piston operating freely in a second bore, said second piston being longitudinally restrained by springs, said first piston being in communication with said first and said second pressures through flow restrictions, said second piston being in free communication with said first and said second pressures, and linkage means coupled to said pistons, said linkage means providing an output displacement that is the sum of displacements proportional to the displacement of said first and of said second piston, said actuator being thereby responsive to the difference between said first and second pressures to make the said output displacement proportional to the sum of a displacement proportional to said pressure difference and a displacement proportional to the time integral of said pressure difference.
Dependencies are inferred from the claim text.