Controlled hydraulic systems

Abstract

There is herein described a controlled hydraulic systems for operating machinery. More particularly, there is described a controlled hydraulic system ( 200 ) comprising a variable drive ratio device ( 214 ) interposed between a prime mover ( 210 ) and a fixed displacement pump ( 112 ) for controlling the operating speed of the pump ( 212 ) and hence the output flow in the hydraulic system.

1 . A controlled hydraulic system comprising:
 a prime mover;   a pump; and   a variable drive ratio device interposed between the prime mover and the pump;   wherein the variable drive ratio is capable of controlling the operating speed of the pump and hence the output flow in the hydraulic system.   
     
     
         2 . A controlled hydraulic system according to  claim 1 , wherein the prime mover is of a fixed or variable speed. 
     
     
         3 . A controlled hydraulic system according to  claim 1 , wherein the pump is a fixed displacement pump. 
     
     
         4 . A controlled hydraulic system according to  claim 1 , wherein the ratio of the variable ratio drive is capable of being controlled remotely. 
     
     
         5 . A controlled hydraulic system according to  claim 1 , wherein the controlled hydraulic system comprises a flow control device. 
     
     
         6 . A controlled hydraulic system according to  claim 1 , wherein the controlled hydraulic system comprises a system of cables capable of allowing the hydraulic fluid to flow. 
     
     
         7 . A controlled hydraulic system according to  claim 1 , wherein there is provided a sensing system for measuring and/or sensing the pressure difference across one orifice (e.g. a spool metering notch), at least one orifice, three orifices or a plurality of orifices in the hydraulic system. 
     
     
         8 . A controlled hydraulic system according to  claim 1 , wherein the hydraulic system comprise one orifice (e.g. a spool metering notch), at least one orifice, three orifices or a plurality of orifices which are formed from poppet valves. 
     
     
         9 . A controlled hydraulic system according to  claim 1 , wherein the hydraulic system is remotely controlled thereby providing a remote interactive control system. 
     
     
         10 . A controlled hydraulic system according to  claim 1 , wherein the hydraulic system comprises a controller (e.g. a joystick controller), an electronic control package and a main control valve. 
     
     
         11 . A controlled hydraulic system according to  claim 1 , wherein the controller is connected to the electronic control package which is capable of allowing the controller to send a signal to the electronic control package which allows the output signal from the electronic control package to be modified and changed in response to any change in signal from the pressure monitors on at least one or both sides of an orifice. 
     
     
         12 . A controlled hydraulic system according to  claim 1 , wherein a user is capable of automatically using a controller (e.g. a given joystick position) to constantly modify spool position in response to any change in pressure loss or increase across a selected orifice and thereby maintain the required flow and actuator speed. 
     
     
         13 . A controlled hydraulic system according to  claim 1 , wherein a monitoring and/or sensing system is capable of continuously monitoring and sensing hydraulic flow and transferring this information to an Engine Management System to control engine speed and hence pump flow. 
     
     
         14 . A controlled hydraulic system according to  claim 1 , wherein the hydraulic system comprises pressure transducers capable of monitoring the pressures at different parts of the hydraulic system in order to adjust spool position and maintain a specific pressure difference and hence maintain an operating speed of an actuator. 
     
     
         15 . A controlled hydraulic system according to  claim 1 , wherein there is a pressure monitor across an orifice or a series of pressure monitors across (e.g. on both sides) of a plurality of orifices. 
     
     
         16 . A method of controlling the operating speed of a pump and hence the output flow in a hydraulic system, the method comprising:
 providing a prime mover;   providing a pump; and   providing a variable drive ratio device interposed between the prime mover and the pump.   
     
     
         17 . A method of controlling the operating speed of a pump according to  claim 16 , wherein the method comprises comprise using a pressure monitor across an orifice or a series of pressure monitors across (e.g. on both sides) of a plurality of orifices in the hydraulic system. 
     
     
         18 . A method of controlling the operating speed of a pump according to  claim 17 , wherein the pressure monitors are capable of forming a sensing system and are capable of sensing pressure in the hydraulic system and transmitting this information to facilitate a user in using the hydraulic system and hence in the operation of a hydraulic machine. 
     
     
         19 - 20 . (canceled)