Electromechanical Rotary Valve to power multiple double acting reciprocating hydraulic cylinders

Abstract

An electromechanical rotary valve for reciprocating a plurality of double-acting hydraulic cylinders in multiples of two. The valve comprises a rotor spool 3 which is within a rotor sleeve 2 which in

Description

An Electromechanical Rotary Valve to power multiple double acting reciprocating hydraulic cylinders sequentially in a precisely timed pre-determined synchronisation. This invention is the result of a requirement to reciprocate multiple double acting hydraulic cylinders sequentially and at varying speeds with the greatest efficiency and within the smallest available space. This invention relates to an electromechanical compact rotary valve designed to supply the hydraulic drive fluid medium to a plurality of reciprocating double acting piston assemblies from a minimal number of ports and pipework with compact integration and high reversing frequency with a reduction in overall torque and power required to drive the spool and more economical to manufacture. Each pair of rotor spool segments is designed to power multiples of 2 separate reciprocating double acting pistons simultaneously and at precisely timed pre-determined intervals. Each pair of cylinder ports sharing a common spool valve pair are open to pressure and return independently of each other thus directing full flow and return to one or the other but not both at the same time. The proposed invention consists of a central rotating spool with oil flow and return reservoirs on each side of the valve discs, the valve discs having precisely placed grooves to direct the flow of fluid either to or from each cylinder in turn. When one side of a double acting cylinder is open to pressurised oil, the other side is simultaneously opened to the tank return. The spool is recessed each side of the control discs containing the directional flow grooves which forms a reservoir to dampen and evenly distribute the hydraulic load on the spool whilst lubricating it and providing a flow of oil to the elasto-hydrodynamic support bearings. The spool is housed within the valve sleeve which in turn contains grooves to reservoir high pressure and return oil and ports to direct the flow of oil to and from each hydraulic cylinder and to accept and return high pressure and low pressure oil from the pump and back to the storage tank accordingly. The rotating spool and fixed sleeve are each in turn housed within the valve case which has external ports for attachment of pipework to connect each side of the hydraulic cylinders and internal lines to supply the rotor sleeve with high pressure oil and to return low pressure oil to the tank. The frequency of operation is adjustable and made so in response to changes in rotational speed of the spool which is directly driven by the electric motor drive assembly mounted on one end of the valve case. The valve is modular in design so the capacity can be increased or reduced to suit an infinite variation in configuration of pairs of reciprocating hydraulic loads by the addition or removal of spool discs and associated ports and channelling. The example illustrated is configured to operate 4 double acting hydraulic cylinders. The invention will now be described solely by way of example and with reference to the accompanying drawings in which: The invention comprises of a valve body (1) with a plurality of external ports comprising a high pressure inlet port (4), a low pressure return port (5), ports (Oil ports LI, L2, L3, L4 and RI, R2, R3 and R4) to connect each end of a plurality of double acting hydraulic cylinders in multiples of 2 (Cylinders 1 and 3, cylinders 2 and 4), and internal ports (9,10,11,12,13,14, 15,16)to connect the high and low pressure drive medium to fixed orifices formed within an inner sleeve (2), a hollow fixed inner sleeve (2) is installed within the valve body (1) with a number of orifices formed along the length of the sleeve corresponding with high pressure feed and low pressure tank return and ports aligned with the external cylinder ports (Oil ports LI, L2, L3, L4 and RI, R2, R3 and R4) within the valve body (1). Housed within the fixed inner sleeve (2) is the rotating spool valve (3). One end of the spool (3) is enclosed and the other extends out of the valve case (1) where it is connected to the electric motor drive (7). Both ends of the spool (3) are supported in phosphor bronze bearings and the spool itself (3) has 3 integrated elasto-hydrodynamically supported bearings along its shaft. The spool (3) has grooves (6) machined into each of its timing discs (9) which when rotated expose internal ports (9,10,11,12,13,14,15,16) alternatively and sequentially to the high pressure drive medium and then the low pressure return in turn. Figure 1 shows a Complete Valve Assembly Figure 2 shows a Valve Sleeve Figure 3 shows a Valve Spool Principle of operation High pressure oil is piped to the high pressure inlet port (4) in valve case (1), whilst a low pressure conection back to the oil tank is connected to the tank return port (5) in valve case (1). High pressure oil flows into the valve case (1) through high pressure port (4) where it is channelled into the high pressure reservoir channels (17). As spool (3) rotates, grooves (6) align in turn with Ports (9,10,11,12,13,14,15 &16), exposing them alternatively to the high pressure reservoir chanels (17) and the low pressure chanels (18). At the same time, high pressure oil is fed into bearing surfaces (19) and drains into the low pressure chanels (18) forming an elastohydrodynamic contact.

Claims

1 An electromechanical rotary valve for reciprocating a plurality in multiples of two, double acting hydraulic cylinders sequentially in a precisely timed predetermined synchronisation with 2 hydraulic cylinders being driven from each single pair of rotor valves, having a source of pressurised oil and comprising a cylindrical valve body having a plurality of pairs of oil supply and discharge passageways for connection to hydraulic cylinders and a pair of common supply and discharge passageways contained within and terminating externally to supply and return oil from the hollow rotor sleeve mounted within with a plurality of oil passageways and distribution channels and ports to channel pressurised and return oil to and from the externally connected hydraulic cylinders and in response to instruction from the rotational rotor spool contained further within with grooves on the valve discs which open and close the passageways internally with laterally opposed grooves alternatively connecting each port in turn to either the high pressure side or the tank return side connecting the plurality of cylinders each in turn to pressurised and return oil feeds.2 An electromechanical rotary valve which in accordance with claim 1 for reciprocating a plurality in multiples of two, double acting hydraulic cylinders sequentially in a precisely timed pre-determined synchronisation with 2 hydraulic cylinders being driven from each single pair of rotor valves wherein the improvement comprises a set of sealing rings between the internal surface of the valve case and outer surface of the hollow distribution sleeve at each side of the distribution channels of the distribution sleeve, preventing cross flow of high pressure and return oil feeds.3 An electromechanical rotary valve which in accordance with claims 1 and 2 that supplies a reciprocating pressurised feed and low pressure return of oil to two separate cylinders from each pair of rotor valves thus reducing the overall size of the valve required, materials and machining costs.4 An electromechanical rotary valve for reciprocating a plurality in multiples of two, double acting hydraulic cylinders sequentially in a precisely timed predetermined synchronisation with 2 hydraulic cylinders being driven from each single pair of rotor valves which in accordance with claims 1 and 2 wherein the rotational spool runs in elasto-hydrodynamic bearings with a subsequent reduction in friction and maximising the useful life of the valve whilst reducing the torque and power consumption.

Images