High pressure intensifier system

Abstract

A hydraulic pressure intensifier system ( 10 ) for developing a high pressure fluid jet that utilizes an electric motor ( 84 ) for both pressurizing a hydraulic fluid and for controlling the pressure and/or flow of the high pressure fluid jet developed by the system. The intensifier system also utilizes a return spring for retraction of the piston which allows the hydraulic fluid and the high pressure fluid to be separated by an air gap to minimize the potential for cross-fluid contamination. A high pressure hose ( 66 ) connected to the output of the intensifier includes a check valve ( 70 ) at its distal end rather than at the outlet of the intensifier to allow fluid to be drained out of the hose and into the intensifier upon system shut down for instantaneous stoppage of the jet.

1 . A pressure intensifier for developing a high pressure flow of liquid comprising:
 a high pressure liquid intensifier piston displaceable within a chamber of a high pressure intensifier cylinder between first and second positions to respectively discharge pressurized liquid from the chamber through an outlet on a delivery stroke and to intake liquid into the chamber through an inlet on a recharge stroke;   a low pressure hydraulic drive piston supported for sliding movement within a low pressure cylinder and operatively coupled with the high pressure intensifier piston for displacing the high pressure intensifier piston towards the second position during the delivery stroke; and   a return spring operatively coupled to at least one of the high pressure piston and the low pressure piston and configured to urge at least the high pressure piston towards the first position during the recharge stoke.   
     
     
         2 . A pressure intensifier as set forth in  claim 1 , further comprising a sleeve operatively coupled to the low pressure piston for movement therewith, the sleeve adapted for telescoping movement over an exterior surface of the high pressure intensifier cylinder during displacement of the high pressure piston by the low pressure piston. 
     
     
         3 . A pressure intensifier as set forth in  claim 2 , wherein the return spring at least partially surrounds the sleeve, the sleeve thereby acting as a spring guide for guiding the spring during movement of the pistons. 
     
     
         4 . A pressure intensifier as set forth in  claim 2 , wherein the sleeve, low pressure piston, and high pressure intensifier cylinder together form an air gap that can vary in size depending on the position of the low pressure cylinder, whereby the air gap separates hydraulic fluid acting on the low pressure piston and liquid in the high pressure intensifier cylinder. 
     
     
         5 . A pressure intensifier as set forth in  claim 1 , wherein the return spring is interposed between the low pressure piston and the high pressure intensifier cylinder, the spring being configured to be compressed during the delivery stroke when the low pressure piston is displaced towards the high pressure intensifier cylinder. 
     
     
         6 . A pressure intensifier as set forth in  claim 1 , wherein the high pressure intensifier cylinder is supported within the low pressure cylinder. 
     
     
         7 . A pressure intensifier as set forth in  claim 1 , wherein the pressurized liquid includes water. 
     
     
         8 . A pressure intensifier system for developing a high pressure flow of fluid comprising:
 a high pressure intensifier piston displaceable within a high pressure chamber between first and second positions to respectively discharge high pressure fluid from the chamber through an outlet on a delivery stroke and to intake fluid into the chamber through an inlet on a recharge stroke;   a low pressure drive piston displaceable within a low pressure chamber separate from the high pressure chamber, the low pressure drive piston being supported for sliding movement within a cylinder including the low pressure chamber and operatively coupled with the high pressure intensifier piston for displacing the high pressure intensifier piston towards the second position during the delivery stroke in response to low pressure fluid being supplied thereto;   a pump for supplying the low pressure fluid to the low pressure drive piston;   a motor for driving the pump; and   a controller configured to control the motor in response to pressure sensed by a pressure sensor that senses the pressure of at least one of the high pressure fluid or the low pressure fluid.   
     
     
         9 . A pressure intensifier system as set forth in  claim 8 , wherein the controller controls a torque output of the motor to modulate the pressure of at least one of the high pressure fluid or the low pressure fluid. 
     
     
         10 . A pressure intensifier system as set forth in  claim 8 , wherein the controller controls a speed output of the motor to modulate the pressure of at least one of the high pressure fluid or the low pressure fluid. 
     
     
         11 . A pressure intensifier system as set forth in  claim 8  further comprising an electrical limit switch associated with the low pressure drive piston the limit switch configured to limit the advance of the low pressure drive piston on the delivery stroke. 
     
     
         12 . A pressure intensifier system as set forth in  claim 8 , further comprising a conduit fluidly coupled to the outlet for receiving the high pressure fluid from the chamber, the conduit having at a distal dispensing end thereof a check valve permitting flow through the conduit from the chamber and restricting backflow into the conduit. 
     
     
         13 . A pressure intensifier system as set forth in  claim 8 , wherein the fluid includes water. 
     
     
         14 . A pressure intensifier system for delivering a fluid comprising:
 an intensifier unit for developing a high pressure flow of fluid, the unit including a high pressure piston displaceable within an intensifier chamber to discharge high pressure fluid through an outlet on a delivery stroke, and on a recharge stroke to admit fluid into the chamber through an inlet to refill the chamber; and   a fluid conduit fluidly coupled to the outlet of the intensifier chamber for receiving the high pressure fluid from the intensifier unit and for dispensing the high pressure fluid at a dispensing end thereof connectable to nozzle;   wherein the fluid conduit has a check valve at the terminal dispensing end thereof remote the outlet of the intensifier chamber for restricting backflow of fluid into the conduit when fluid is not being dispensed therefrom.   
     
     
         15 . A pressure intensifier system as set forth in  claim 14 , further comprising the nozzle, wherein the check valve restricts backflow of fluid from the nozzle into the conduit. 
     
     
         16 . A pressure intensifier system as set forth in  claim 14 , wherein the check valve is a ball check valve. 
     
     
         17 . A pressure intensifier system as set forth in  claim 14 , further comprising an inlet check valve for restricting flow of fluid from the chamber out the inlet during the delivery stroke, and to permit flow of fluid through the inlet during the recharge stroke. 
     
     
         18 . A pressure intensifier system as set forth in  claim 14 , further comprising a linear actuator operatively coupled to the high pressure intensifier piston for advancing the piston on the delivery stroke and retracting the piston on the recharge stroke. 
     
     
         19 . A pressure intensifier system as set forth in  claim 18 , wherein the linear actuator includes a ball screw. 
     
     
         20 . A pressure intensifier system as set forth in  claim 19 , wherein the output shaft has a screw portion having threads engaged with mating threads associated with the high pressure piston, and wherein the high pressure piston is fixed against rotation such that rotation of the output shaft in a first direction advances the piston and rotation of the shaft in an opposite direction retracts the piston. 
     
     
         21 . A pressure intensifier system as set forth in  claim 14 , further comprising a controller configured to control the motor in response to sensed condition. 
     
     
         22 . A pressure intensifier system as set forth in  claim 21 , wherein the sensed condition includes at least one of a pressure sensed by a pressure sensor that senses the pressure of the high pressure fluid, or a position of the linear actuator. 
     
     
         23 . A pressure intensifier system as set forth in  claim 14 , wherein the intensifier unit is removable from the intensifier assembly as a unit. 
     
     
         24 . A pressure intensifier system as set forth in  claim 14 , wherein the intensifier unit releasably attachable to the intensifier assembly. 
     
     
         25 . A pressure intensifier system as set forth in  claim 14 , wherein the intensifier unit is attached to the intensifier assembly by a quick-release mechanism.