Multiport pumps with multi-functional flow paths

Abstract

Multiport pumps and associated pumping systems are described that provide a selective hydraulic or electrically powered pump/pump system. The pumps provide movement within a device or larger system. Movement can cause compression/expansion of a fluid and provide fluid movement within the same device or system. In this instance, the volume of fluid and the fluid flow path within, from, and to the pump(s) is kept constant to reduce or eliminate cavitation, seizure, and/or hydraulic lock. Use of at least one reservoir comprising; a compensator tank, a port allowing for operation at ambient pressure, and a pressure measuring device measuring pressure allowing for unbalanced flow to and from the multiport pumps along with thermal expansion or compression is detailed. In addition, use of a multiport swashplate pumps and associated valve plates that incorporate the features and functions of several valves not heretofore provided within the pump itself is also described.

Claims

1. At least one multiport pump that pumps fluid in either a single or bi-directional direction having multiple ports comprising; at least one inlet port, at least one outlet port, and at least one equilibrator port connected to a fluid reservoir wherein said equilibrator port equilibrates inlet and outlet flow such that a combination of said inlet port and said equilibrator port provide just enough fluid volume to fill one or more cavities of said at least one multiport pump so that fluid escapes through said outlet port to ensure overfill of said ports is prevented and so that a balanced equilibrium constant volume of fluid is maintained and resides within said at least one multiport pump during operation, wherein said at least one multiport pump withdraws and/or sends fluid into and out of said fluid reservoir to maintain a constant volume of fluid that reduces cavitation and hydraulic fluid lock and also provides and allows a balanced constant continuous fluid flow along a fluid flow path that contains fluid that flows in either a clockwise or counterclockwise direction into and out of said fluid reservoir that also acts as a constant volume compensator, such that an incremental volume of fluid is added or removed to maintain equal symmetric inflow and outflow of fluid into and out of said at least one multiport pump and wherein said fluid reservoir is vented, sealed, pressure compensated, preloaded and/or expandable thereby completing said fluid flow path and accomplishing an ability to control intermittent and/or continuous movement of moving devices.

2. The at least one multiport pump of claim 1, wherein said cavitation is eliminated unless an absence of enough fluid to completely fill one or more pump and/or port cavities enters or exits said at least one multiport pump at any time during start-up, operation, or shut down and wherein hydraulic fluid lock is eliminated unless an excess of fluid overfills one or more pump and/or port cavities as fluid enters or exits said at least one multiport pump at any time during start-up, operation or shut down.

3. The at least one multiport pump of claim 1, wherein one or more multiport pumps and are selected from the group consisting of; swashplate pumps, reciprocating pumps, scroll pumps, piston pumps, diaphragm pumps, injection pumps, centrifugal pumps, gear pumps, and metering pumps and wherein said fluid is air, a gas, a liquid, or any combination of air, gas, and liquid.

4. The at least one multiport pump of claim 1, wherein a constant volumetric balance of both said volume of fluid and said fluid flow occurs simultaneously during operation of said at least one multiport pump and wherein a fluid system operated by said at least one multiport pump may be a fluid system that is open to atmosphere or that is closed to atmosphere and wherein said at least one multiport pump can be primed with fluid during start-up and can be drained of fluid during shutdown and wherein said at least one multiport pump can operate in either a clockwise or counterclockwise direction so that when pressure into said at least one multiport pump is increased and then released no pressure is retained within said at least one multiport pump and wherein accordingly said at least one multiport pump can operate as both an hydraulic pump and as an hydraulic motor depending on which direction said fluid flows along said fluid path.

5. The at least one multiport pump of claim 1, wherein said at least one multiport is at least one multiport swashplate pump that includes a multi-port valve plate such that fluid flow into and out of said multiport swashplate pump is either unidirectional or bidirectional and wherein said multi-port valve plate includes at least three ports.

6. The at least one multiport swashplate pump of claim 5, wherein an at least three-port valve plate ensures a constant volumetric balanced fluid flow exists and is maintained within said at least one multiport pump in that said fluid flow volume remains constant throughout operation of said at least one multiport swashplate pump as said at least one multiport swashplate pump is utilized to operate and control movement of a hydraulic apparatus.

7. The at least one multiport swashplate pump of claim 6, wherein said at least three-port valve plate includes at least three corresponding valves and wherein at least one port is designated for counterclockwise flow, at least one port is designated for clockwise flow and at least one port is designated as a reservoir port, wherein said reservoir port allows for constant volumetric fluid flow balancing by utilizing said reservoir to either add or remove a volume of fluid as needed during operation of said at least one multiport swashplate pump.

8. The at least one multiport swashplate pump of claim 5, wherein said at least one multiport swashplate pump includes an at least four-port valve plate and includes at least four corresponding valves wherein at least one port is designated for counterclockwise flow, at least one port is designated for clockwise flow, at least one port is designated as a reservoir port, and at least one port is designated as a sensor port.

9. The at least one multiport swashplate pump of claim 8, wherein said sensor port provides a portion of said at least one multiport swashplate pump for including a sensor within or attached to said port that measures volume, pressure, and temperature of both fluid and fluid flow along a fluid flow path.

10. The at least one multiport swashplate pump of claim 9, wherein said sensor port is a monitor port, wherein said monitor port monitors fluid, fluid volume, and fluid flow and can also provide hydraulic actuators.

11. The at least one multiport pump of claim 1, wherein when said at least one multiport pump moves in a clockwise direction, it delivers fluid to a clockwise port and withdraws fluid from a counterclockwise port.

12. The at least one multiport pump of claim 1, wherein when said at least one multiport pump moves in counterclockwise direction, it delivers fluid to a counterclockwise port and withdraws fluid from a clockwise port.

13. The at least one multiport pump of claim 5, wherein said at least one multiport pump and/or said three-port valve plate that includes a swashplate pump are fully submersed.

14. The at least one multiport pump of claim 5, wherein said at least one multiport pump and/or said at least four-port valve plate that includes said swashplate pump are fully submersed.

15. The at least one multiport pump of claim 5, wherein said at least one multiport pump and/or said swashplate pump provides and allows for fluid flow into and out of at least one reservoir.

16. At least one multiport pump that pumps fluid in either a single or bi-directional direction having multiple ports comprising; at least one inlet port, at least one outlet port, and at least one equilibrator port connected to a fluid reservoir wherein said equilibrator port equilibrates inlet and outlet flow such that a combination of said inlet port and said equilibrator port provide just enough fluid volume to fill one or more cavities of said at least one multiport pump without an overfill of fluid that escapes through said outlet port so that a rate of change of volume of fluid is constant and prohibits cavitation and hydraulic fluid lock and also provides and allows a balanced constant continuous fluid flow along a flow path in either a clockwise or counterclockwise direction into and out of said fluid reservoir such that an incremental volume of fluid is added or removed to maintain equal symmetric inflow and outflow of fluid into and out of said at least one multiport pump.

17. At least one multiport pump that pumps fluid in either a single or bi-directional direction having multiple ports comprising; at least one inlet port, at least one outlet port, and at least one equilibrator port connected to a fluid reservoir wherein said equilibrator port equilibrates inlet and outlet flow such that a combination of said inlet port and said equilibrator port provide for a balanced equilibrium constant volume and/or rate of change of volume of fluid that is constant so that fluid is maintained within said at least one multiport pump during operation, wherein said at least one multiport pump withdraws and/or sends fluid into and out of said fluid reservoir to maintain a constant volume and/or rate of change of volume of fluid which is constant and reduces cavitation and hydraulic fluid lock and also provides and allows a balanced constant continuous fluid flow along a flow path in either a clockwise or counterclockwise direction into and out of said fluid reservoir such that an incremental volume of fluid is added or removed to maintain equal symmetric inflow and outflow of fluid into and out of said at least one multiport pump.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A is a cross sectional side view of a known design for a swashplate pump.

(2) FIG. 1B is a front and back view of a current valve plate design for the same swashplate pump shown in FIG. 1A.

(3) FIG. 1C is front and back view of a three (3)-port swashplate pump as described in this disclosure.

(4) FIG. 1D is a format and back view of a three (3)-port valve plate directly vented to and/or for immersion into a reservoir as described in the present disclosure.

(5) FIG. 1E is front and back view of a four (4)-port swashplate pump as described in the present disclosure.

(6) FIG. 1F is a front and back view of a four (4)-port valve plate directly vented to and/or for immersion into a reservoir as described in the present disclosure

DETAILED DESCRIPTION

(7) FIGS. 1A and 1B represent known swashplate pump designs with valve plates (prior art) representative of state-of-the-art devices. These pumps were initially designed to simplify other older pump designs in that these pumps have no moving valves, no cam shafts, no crankshafts, and no connecting rods, thereby minimizing the number of parts that can fail due to wear or improper use of the pump. This compact design also leads to better efficiency and lower costs during the lifetime of the pump. In FIG. 1A, valve plate (1010) directs the fluid to the user device through ports. These ports include a cw port (1015) which is connected to a valve plate kidney (1011) and ccw port (1016) that connects with a valve plate kidney (1012). Rotating cylinder bore barrel (1060) includes cylinder bores for each piston. Piston (1061) shown in a top dead center position (TDC) and piston (1065) shown in the bottom dead center (BDC) position are illustrative of the entire piston set residing in the rotating cylinder bore barrel (1060). This barrel (1060) is a rotated with drive shaft (1070) in either a cw or ccw direction at a speed appropriate for delivering fluid and a torque appropriate for delivering the desired pressure. Swashplate (1080) is stationary while the piston angled contact surface (1066) functions as the dwell cam which actuates the entire piston set that allows for translating the rotary drive shaft into an axial piston movement in the rotating cylinder bore barrel (1060).

(8) The valve plate, shown in FIG. 1B includes both a front and back view (1010 F—front view and 1010B—back view) of a state-of-the-art design. This valve plate functions by directing flow between the cw valve plate kidney (1011) and the ccw valve plate kidney (1012). The cw valve plate kidney (1011) is connected through the plate to the cw port (1015). The ccw valve plate kidney (1012) is connected through the plate to the ccw port (1016).

(9) In operation of this specific swashplate pump (which is illustrated using only two pistons—1061 and 1065, representative of swashplate pumps with 2 or more pistons), starting from the illustrated position of the rotating barrel (1060) with pistons, piston (1061) is located at TDC and is driven clockwise engaging with counterclockwise valve plate kidney (1012). Next, as the barrel (1060) rotates clockwise, the piston (1061) moves toward a BDC position during a 180 degree rotation, ending at a BDC position. During that rotation, the piston (1061) moves away from the valve plate thereby pulling fluid into the piston cylinder resulting in pulling fluid from the user device connected to the ccw—counterclockwise—port (1016).

(10) Simultaneously, starting from the illustrated position of the rotating barrel (1060) with pistons, piston (1065) which is initially located at a BDC position and is driven clockwise engaging with clockwise valve plate kidney (1011). Next, as the barrel (1060) rotates clockwise, the piston (1065) moves toward a TDC position during a 180 degree rotation, ending at a TDC position. During that rotation, the piston (1065) moves toward the valve plate thereby displacing fluid from the piston cylinder resulting in displacing fluid toward the user device connected to cw—clockwise—port (1015).

(11) The pistons as illustrated in the TDC and BDC positions described above allow no flow to move into or out of the rotating cylinder bore barrel (1060). In other words, any piston which passes across these regions causes the valve cylinder bores in the barrel to close.

(12) For the present disclosure, the valve plate design for the multiport swashplate pump has been changed as shown in FIGS. 1C, 1D, 1E, and 1F. Specifically, FIG. 1C and FIG. 1D illustrate 3-port valve configurations. FIG. 1C indicates 1020F which is the front view of a 3-port valve plate and 1020B is the back view the same 3-port valve plate. The cw kidney (1021) and ccw kidney (1022) as well as the cw port (1025) and ccw port (1026) have the same functionality as those shown above as (1011, 1012—the kidneys and 1015 and 1016—the ports) shown in FIG. 1B. The purpose of the third valve port which is a third center kidney port (1023) is to momentarily and remotely connect each cylinder to the reservoir through a reservoir port (1027) during operation of the pump at either TDC or BDC. This is to ensure balanced volume within the pump as well as balanced volumetric flow to the user device regardless of imbalances in the flow requirements to and from the user device. If there is more fluid returning from the user device than is being sent to the user device, the excess fluid is returned to the reservoir as the pistons pass over third center reservoir kidney port (1023). Conversely if there is less fluid returning from the user device than is being sent to the user device, the deficit fluid will be supplied by the reservoir to the user device through the third center reservoir kidney (1023).

(13) FIG. 1D indicates 1030F which is the front view of a 3-port valve plate and 1030B is the back view the same 3-port valve plate. The cw kidney (1031) and ccw kidney (1032) as well as the cw port (1035) and ccw port (1036) have the same functionality as those shown above as (1011, 1012—the kidneys and 1015 and 1016—the ports) shown in FIG. 1B. The purpose of the third valve port which is a third center kidney immersion port (1033) is to momentarily and directly connect each cylinder to the reservoir through a reservoir port (1037) designed for direct immersion of the pump in the reservoir during operation of the pump at either TDC or BDC. This is still to ensure balanced volume within the pump as well as balanced volumetric flow to the user device regardless of imbalances in the flow requirements to and from the user device. If there is more fluid returning from the user device than is being sent to the user device, the excess fluid is returned to the reservoir as the pistons pass over third center immersion kidney port (1033). Conversely if there is less fluid returning from the user device than is being sent to the user device, the deficit fluid will be supplied by the reservoir to the user device through the third center immersion kidney port (1033).

(14) Specifically, FIG. 1E and FIG. 1F illustrate 4-port valve configurations. FIG. 1E indicates 1040F which is the front view of a 4-port valve plate and 1040B is the back view the same 4-port valve plate. The cw kidney (1041) and ccw kidney (1042) as well as the cw port (1045) and ccw port (1046) have the same functionality as those shown above as (1011, 1012—the kidneys and 1015 and 1016—the ports) shown in FIG. 1B. The third port is the reservoir kidney port (1043) connected to the reservoir port (1047) located at BDC which serves the same function as (1023) above but only in the BDC position. The purpose of the fourth valve sensor kidney (1044) is to momentarily and remotely connected each cylinder through a sensor port (1048) during operation of the pump at TDC so that the sensor kidney (1044) and sensor port (1048) are both connected to the highest pressure that occurs within the pump. The functionality of the fourth valve kidney (1044) and the sensor port (1048) is to monitor and control operation of the one or more pumps and user devices that comprise a pumping system.

(15) Specifically, FIG. 1E and FIG. 1F illustrate 4-port valve configurations. FIG. 1F indicates 1050F which is the front view of a 4-port valve plate and 1050B is the back view the same 4-port valve plate. The cw kidney (1051) and ccw kidney (1052) as well as the cw port (1055) and ccw port (1056) have the same functionality as those shown above as (1011, 1012—the kidneys and 1015 and 1016—the ports) shown in FIG. 1B. The third port is the reservoir kidney immersion port (1053) connected to the reservoir immersion port (1057) located at BDC so that each piston is momentarily and directly connected to the reservoir through the reservoir port (1057) designed for direct immersion of the pump in the reservoir during operation of the pump at BDC. This is still to ensure balanced volume within the pump as well as balanced volumetric flow to the user device regardless of imbalances in the flow requirements to and from the user device. If there is more fluid returning from the user device than is being sent to the user device, the excess fluid is returned to the reservoir as the pistons pass over the third center immersion kidney port (1053). Conversely if there is less fluid returning from the user device than is being sent to the user device, the deficit fluid will be supplied by the reservoir to the user device through the third center immersion kidney port (1053). The purpose of the fourth valve sensor kidney (1054) is to momentarily and remotely connect each cylinder through a sensor port (1058) during operation of the pump at TDC so that the sensor kidney (1054) and sensor port (1058) are both connected to the highest pressure that occurs within the pump. The functionality of the fourth valve kidney (1054) and the sensor port (1058) is to monitor and control operation of the one or more pumps and user devices that comprise a pumping system.

(16) The devices and systems described herein can be implemented in a wide range of sizes and operating configurations. In other words, the physics and fluid mechanics of the system do not depend on a particular system size. The estimated power range results from a system design constrained to use current commercially available components, manufacturing processes, and transportation processes. Larger and/or smaller system power may be preferred if the design uses a greater fraction of custom, purpose-designed components. Moreover, system power also depends on the end-use of the system. In other words, the size of the system may be affected by whether the system is implemented in the compressor/expander mode or whether the system is being used to deliver only compression or only expansion via one or more pumps.

(17) Devices and systems used to compress and/or expand a gas can be configured to operate in a compression mode to compress fluids up to at least 10,000 psi. Devices and systems used to compress and/or expand a gas can be configured to operate in an expansion mode to expand a gas such that the compressed gas from the compressed gas storage chamber has a pressure ratio to that of the expanded gas of 250:1. In some embodiments, a compression/expansion device is configured to expand a gas through two or three stages of expansion.

(18) Devices and systems used to compress and/or expand a fluid including air, and gas, and/or to pressurize and/or pump a fluid, such as water, can release and/or absorb heat during, for example, a compression or expansion cycle. In some embodiments, one or more pneumatically or electrically actuated valves can include a heat capacitor for transferring heat to and/or from the gas as it is being compressed/expanded. In some embodiments, the heat transfer element can be a thermal capacitor that absorbs and holds heat released from a gas that is being compressed, and then releases the heat to a gas or other fluid at a later time. In some embodiments, the heat transfer element can be a heat transferring device that absorbs heat from a liquid that is being compressed, and then facilitates the transfer of the heat outside of the device.

(19) In another example, heat can be transferred from and/or to gas that is compressed and/or expanded by adding and/or removing liquid (e.g., water) to/from within a pneumatic cylinder. A gas/liquid or gas/heat element interface may move and/or change shape during a compression and/or expansion process in a pneumatic cylinder. This movement and/or shape change may provide a compressor/expander device with a heat transfer surface that can accommodate the changing shape of the internal areas of a pneumatic cylinder in which compression and/or expansion occurs. This movement and/or shape change may provide a compressor/expander device with a heat transfer surface that optimizes its heat transfer performance with respect to the current conditions within the pneumatic cylinder, for example, with respect to gas density, gas temperature, and/or relative temperature of gas and liquid, among others. In some embodiments, the liquid may allow the volume of gas remaining in a pneumatic cylinder after compression to be nearly eliminated or completely eliminated (i.e., zero clearance volume).

(20) A liquid (such as water or oil or other hydraulic fluids) can have a relatively high thermal capacity as compared to a gas (such as air) such that a transfer of an amount of heat energy from the gas to the liquid avoids a significant increase in the temperature of the gas, but only incurs a modest increase in the temperature of the liquid. This allows buffering of the system from substantial temperature changes. In other words, this relationship creates a system that is resistant to substantial temperature changes. Heat that is transferred between the gas and liquid, or components of the vessel itself, may be moved from or to (for example) a pneumatic cylinder through one or more processes. In some embodiments, heat can be moved in or out of the cylinder using mass transfer of the compression liquid itself. In other embodiments, heat can be moved in or out of the cylinder using heat exchange methods that transfer heat in or out of the compression liquid without removing the compression liquid from the cylinder. Such heat exchangers can be in thermal contact with the compression liquid, components of the cylinder, a heat transfer element, or any combination thereof. Furthermore, heat exchangers may also use mass transfer to move heat in or out of the cylinder. Thus, the liquid within a cylinder can be used to transfer heat from gas that is compressed or compressing (or to gas that is expanded or expanding) and can also act in combination with a heat exchanger to transfer heat to an external environment (or from an external environment). Any suitable mechanism for transferring heat out of the device during compression and/or into the device during expansion may be incorporated into the system.

(21) In some embodiments, a hydraulic actuator includes a hydraulic ram (a component familiar to those skilled in the art of hydraulic actuation) that connects to a pneumatic piston using a piston rod. Piston motion results when a hydraulic pump urges hydraulic fluid into and/or out of a chamber or chambers of the hydraulic ram. Component sizes depend on the power desired for the complete system, on fluid pressures, and on the hydraulic fluid pressures. The fluid pressures in the pneumatic portion of the system, and hydraulic fluid pressure in the hydraulic pump/motor are considered simultaneously in order to configure the relative sizes of hydraulic ram pistons and the pneumatic cylinder pistons. In general, the ratio of the cross-sectional area of the hydraulic ram piston, to the cross-sectional area of the pneumatic cylinder piston must be in proportion to the ratio of the hydraulic pump/motor operating pressure, to the pneumatic cylinder operating pressure. For example, a hydraulic pump/motor may have a maximum operating pressure of 10,000 psi, if the maximum desired fluid pressure is 2500 psi, then the ratio between hydraulic ram piston cross sectional area to the pneumatic cylinder piston may be no less than 100 divided by 400, and in fact should be greater than this ratio figure in order to overcome machine aspects such as component friction and the like. In addition, the ratio of hydraulic ram piston cross section area to pneumatic piston cross section area can be modified during system operation configuring a hydraulic actuation system with more than one hydraulic ram, a concept which is described in more detail below.

(22) In the present disclosure, the system operation may be controlled by a hydraulic controller and/or electric controller. The controller coordinates: valve actuation, pump/motor operation, fluid direction, and compression/expansion operation. During expansion operation, the controller determines the volume of fluid to admit from a reservoir into the system. By way of example, the controller may collect and evaluate system status information such as the temperatures and pressures of: the fluid storage chambers, cylinders, the fluid source and determine a preferred volume of fluid to admit from the reservoir into or out of the system. The controller may admit a fluid volume calculated to expand such that the fluid achieves a pressure roughly equivalent to the pressure of the fluid source. It is understood that it may be desirable to expand the fluid to pressures that may be greater than, or less than the pressure of the fluid source. The controllers may be used with any of many control paradigms to define overall machine operation such as: a time-based schedule for fluid volume, a time-based schedule for fluid pressure, a time-based schedule for fluid temperature, a parametrically described and controlled position evolution, pressure evolution, temperature evolution, or power consumption/generation. Those skilled in the art of controller design will understand that the possible control algorithms are virtually unlimited.

(23) The present disclosure is specific to the use of one or more multiport pumps to insure a constant volume of fluid remains within the pumps. One such pump is an axial piston type hydraulic pump, and more specifically a hydraulic pump wherein a plurality of pistons are arranged within a liquid tight slidable engagement within cylinders driven for endwise reciprocation by a swash plate. This pump type is known as a “swashplate pump” described in full detail in U.S. Pat. No. 4,007,663. The present disclosure provides a valve plate design for these swashplate pumps that also enables fluid volume to remain constant or nearly constant during operation of the apparatus and system described herein. When needed, fluid volume is adjusted by either adding or removing fluid from the apparatus/system/pump by use of the previously described reservoir. By designing the pump with a multi-port valve plate design, it is possible to continuously access the reservoir as needed. This results in reducing the complexity and cost associated with providing the apparatus and system with the required fluid flow and fluid flow path without the need for an inverse shuttle valve (3-port valve plate design) and in some cases without the need for both a detented shuttle valve and an inverse shuttle valve (4-port valve plate design).

(24) While various embodiments of the invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Where methods and steps described above indicate certain events occurring in certain order, those of ordinary skill in the art having the benefit of this disclosure would recognize that the ordering of certain steps may be modified and that such modifications are in accordance with the variations of the invention. Additionally, certain of the steps may be performed concurrently in a parallel process when possible, as well as performed sequentially as described above. Additionally, certain steps may be partially completed before proceeding to subsequent steps. The embodiments have been particularly shown and described, but it will be understood that various changes in form and details may be made.

(25) Although various embodiments have been described as having particular features and/or combinations of components, other embodiments are possible having any combination or sub-combination of any features and/or components from any of the embodiments described herein.