US20160123313A1

US20160123313A1 - Pneumatically-operated fluid pump with amplified fluid pressure, and related methods

Info

Publication number: US20160123313A1
Application number: US14/533,918
Authority: US
Inventors: Tom M. Simmons
Original assignee: Graco Fluid Handling A Inc
Current assignee: White Knight Fluid Handling Inc
Priority date: 2014-11-05
Filing date: 2014-11-05
Publication date: 2016-05-05
Also published as: WO2016073075A1; TW201629348A

Abstract

A fluid pump for pumping a subject fluid. The fluid pump including, a pump body, a first cavity within the pump body, a second cavity within the pump body, a flexible member, an incompressible fluid, a subject fluid chamber, and a piston. Piston may include a piston head and an elongated piston shaft. The piston may be configured to amplify a first pressure experienced on a first side of the piston head and exerted by a pressurized drive fluid to a second pressure experienced on an end surface of the elongated piston shaft and exerted on the incompressible fluid within the flexible member. The subject fluid may in turn be pressurized to a third pressure substantially equal to the second pressure.

Description

TECHNICAL FIELD

Embodiments of the present disclosure relate generally to positive displacement devices. More particularly, embodiments of the present disclosure relate to pneumatically-operated fluid pumps and related methods.

BACKGROUND

Reciprocating fluid pumps are used in many industries. Reciprocating fluid pumps generally include two at least one fluid chamber in a pump body. A reciprocating piston or shaft is driven back and forth within the pump body. One or more flexible members may be connected to the reciprocating piston or shaft. As the reciprocating piston moves in one direction, the movement of the flexible members results in subject fluid being drawn into a subject fluid chamber. As the reciprocating piston moves in the opposite direction, the movement of the flexible members results in fluid being expelled from the subject fluid chamber. A subject fluid inlet and a subject fluid outlet may be provided in fluid communication with the subject fluid chamber. Check valves may be provided at the subject fluid inlet and outlet of subject fluid chamber to ensure that fluid can only flow into the subject fluid chamber through the subject fluid inlet, and fluid can only flow out of the of the subject fluid chamber through the subject fluid outlet.
Conventional reciprocating fluid pumps operate by moving the reciprocating piston back and forth within the pump body. Moving the reciprocating piston from one direction to the other may be accomplished by using a shuttle valve, which provides drive fluid (e.g., pressurized air) to a first drive fluid chamber and moving the reciprocating piston in a first direction and then providing the drive fluid to a second drive fluid chamber and moving the reciprocating piston in a second opposite direction.
Examples of reciprocating fluid pumps and components thereof are disclosed in, for example: U.S. Pat. No. 5,558,506, which issued Sep. 24, 1996 to Simmons et al.; U.S. Pat. No. 5,893,707, which issued Apr. 13, 1999 to Simmons et al.; U.S. Pat. No. 6,106,246, which issued Aug. 22, 2000 to Steck et al.; U.S. Pat. No. 6,295,918, which issued Oct. 2, 2001 to Simmons et al.; U.S. Pat. No. 6,685,443, which issued Feb. 3, 2004 to Simmons et al.; and U.S. Pat. No. 7,458,309, which issued Dec. 2, 2008 to Simmons et al.; and U.S. Pat. No. 8,636,484, which issued Jan. 28, 2014 to Simmons et al. The disclosure of each of these patents and patent application is respectively incorporated herein in its entirety by this reference.

BRIEF SUMMARY

In some embodiments, the present disclosure includes a fluid pump for pumping a subject fluid. The fluid pump may include a pump body, a first cavity within the pump body, a second cavity within the pump body, a piston shaft hole extending from the first cavity to the second cavity, and a flexible member disposed within the second cavity. The flexible member may include a tubular body having a first closed end and a second open end opposite the first closed end, the second open end being proximate the piston shaft hole. The fluid pump may include an incompressible fluid chamber defined within the second cavity on a first side of the flexible member. The incompressible fluid chamber may include an incompressible fluid disposed therein. The fluid pump may further include a subject fluid chamber between a second cavity interior surface of the second cavity and an exterior surface of the flexible member. The flexible member may be configured to increase and decrease a volume of the subject fluid chamber. The fluid pump may further include a piston. The piston may include a piston head having a first side and an opposite second side. The first side of the piston head may have a first surface area. The piston head may be movable within the first cavity. The piston may further include an elongated piston shaft extending from the second side of the piston head and at least partially into the piston shaft hole. The elongated piston shaft may have an end surface opposite the piston head. The end surface may have a second surface area smaller than the first surface area of the first side of the piston head.
In additional embodiments, the present disclosure includes a pump body for pumping a subject fluid. The pump body may include a flexible member disposed within the pump body. The flexible member may include a tubular body having a first closed end and a second open end opposite the first closed end. The flexible member may further contain an at least substantially incompressible fluid. The pump body may further include a piston. The piston may include a piston head having a first side and an opposite second side, and an elongated piston shaft extending from the second side of the piston head. The elongated piston shaft may have an end surface on a distal end of the elongated piston shaft opposite the piston head. The piston may be configured such that a ratio of a first pressure experienced by the first side of the piston head and a second pressure experienced by the end surface of the elongated piston shaft is at least more than 1.
Yet further embodiments of the present disclosure include methods of pressurizing and pumping a subject fluid. In some embodiments, a method of the present disclosure may include inputting a pressurized drive fluid into a first drive fluid chamber of a first cavity of a pump body. The pressurized drive fluid may be input on a first side of a piston head of a piston. The pressurized drive fluid may exert a first pressure on the first side of the piston head. The method may further include moving the piston along an axial length of the first cavity of the pump body and exerting a second pressure on an incompressible fluid within an interior of a flexible member. The second pressure may be exerted on the incompressible fluid with an end surface of an elongated piston shaft extending from a second side of the piston head of the piston. The method may include pressurizing the incompressible fluid to a third pressure higher than the first pressure with the elongated piston shaft of the piston. The third pressure may be substantially equal to the second pressure. The method may also include pressurizing the subject fluid within a subject fluid chamber that least partially surrounds the flexible member to a fourth pressure higher than the first pressure and at least substantially equal to the second pressure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional side view of a pneumatically operated fluid pump according to an embodiment of the present disclosure.

FIG. 2 is cross-sectional side view of the fluid pump of FIG. 1, showing vectors representing forces exerted on various parts of the fluid pump.

FIG. 3 is a simplified flow chart demonstrating a method of pressurizing a subject fluid while pumping the subject fluid.

FIG. 4 is a cross-sectional side view of a pump system including a plurality of pneumatically operated fluid pumps as shown in FIG. 1 operably connected in parallel.

DETAILED DESCRIPTION

The illustrations presented herein are not meant to be actual views of any particular fluid pump 100 or component thereof, but are merely idealized representations that are used to describe embodiments of the disclosure.
As used herein, the term “substantially” in reference to a given parameter, property, or condition means and includes to a degree that one skilled in the art would understand that the given parameter, property, or condition is met with a small degree of variance, such as within acceptable manufacturing tolerances. For example, a parameter that is substantially met may be at least about 90% met, at least about 95% met, or even at least about 99% met.
Embodiments of the present disclosure include fluid pumps that include at least one drive fluid chamber, at least one subject fluid chamber, an incompressible fluid, a piston, and a flexible member for pressurizing a subject fluid to a pressure higher than a pressure to which a pressurized drive fluid is pressurized while pumping the subject fluid.
FIG. 1 is a cross-sectional side view of a pneumatically operated fluid pump according to an embodiment of the present disclosure. A fluid pump 100 is configured to pump a subject fluid, such as, for example, a liquid (e.g., water, oil, acid, etc.) or gas, using a pressurized drive fluid such as, for example, compressed gas (e.g., air). Thus, in some embodiments, the fluid pump 100 may comprise a pneumatically operated liquid pump. Furthermore, as described in further detail below, the fluid pump 100 may comprise a reciprocating pump in which the piston and flexible member cycle back and forth in a reciprocating manner during operation of the fluid pump 100.
The fluid pump 100 may include a pump body 102. The pump body 102 may comprise two or more components that are assembled together to form the pump body 102. The pump body 102 may comprise one or more of metals (including alloys), ceramics, polymers (e.g., PEEK, TEFLON, etc.), and composite materials. The pump body 102 may include therein a first cavity 104, a second cavity 106, a piston 118, and a flexible member 142. The first cavity 104 may have a first cavity interior surface 108, which may at least partially define a first drive fluid chamber 110 and a second drive fluid chamber 112. The second cavity 106 may have a second cavity interior surface 114, which may at least partially define a subject fluid chamber 116. The piston 118 may be positioned with the pump body 102. The piston 118 may have a piston head 120 and an elongated piston shaft 122 extending from the piston head 120. The piston head 120 and elongated piston shaft 122 may have a generally cylindrical shape. An outer diameter of the piston head 120 may be greater than an outer diameter of the elongated piston shaft 122. The piston 118 may be slidable back and forth (in the left and right directions from the perspective of FIG. 1) within the pump body 102 and may extend between the first cavity 104 and second cavity 106. The piston head 120 of the piston 118 may be disposed within the first cavity 104 and between the first drive fluid chamber 110 and the second drive fluid chamber 112.
The piston head 120 may have a first side 124, an opposite second side 126, and a cylindrical peripheral surface 128 extending from the first side 124 to the second side 126. The first side 124 of the piston head 120 may at least partially define the first drive fluid chamber 110. The second side 126 may at least partially define the second drive fluid chamber 112. The piston head 120 may include at least one annular seal cavity 130 formed along a circumference of the cylindrical peripheral surface 128 and between the first side 124 and the second side 126. The at least one annular seal cavity 130 may have at least one annular seal 132 (e.g., an O-ring seal) disposed therein. The elongated piston shaft 122 of the piston 118 may include a distal end 133 opposite the piston head 120 (the term “distal” meaning distal to the piston head 120). The distal end 133 may have an end surface 134. The first side 124 of the piston head 120 may have a first surface area SA1 (FIG. 2). The end surface 134 of the elongated piston shaft 122 may have a second surface area SA2 (FIG. 2). The pump body 102 may include a piston shaft hole 136 extending between the first cavity 104 and the second cavity 106. The piston shaft hole 136 may include a plurality of annular shaft seals 140 disposed along an interior surface 138 of the piston shaft hole 136 to provide a fluid-tight seal between the first cavity 104 and the second cavity 106 along the interface between the piston shaft hole 136 and the elongated piston shaft 122.
The flexible member 142 may be disposed at least partially within the second cavity 106. The flexible member 142 may comprise one or more of a bellows plunger, diaphragm, or any other known flexible member that can extend and retract. The flexible member 142 may divide the second cavity 106 into the subject fluid chamber 116 and an incompressible fluid chamber 156. The incompressible fluid chamber 156 may be at least partially disposed within an interior 144 of the flexible member 142. For example, the flexible member 142 may have an exterior surface 146 and an interior surface 148. The exterior surface 146 of the flexible member 142 may at least partially define the subject fluid chamber 116 while the interior surface 148 of the flexible member 142 may at least partially define the incompressible fluid chamber 156. A substantially incompressible fluid 176 may be disposed within the incompressible fluid chamber 156. In some embodiments, the incompressible fluid 176 may also be disposed within the piston shaft hole 136.
The flexible member 142 may comprise a tubular body 150 having a first closed end 152 and an opposite, second open end 154. The first closed end 152 may include a plunger head 158 integrally formed with or otherwise coupled to the tubular body 150. In other words, in some embodiments, the plunger head 158 may be formed integrally with the tubular body 150, and in other embodiments, the plunger head 158 may be formed separately from the tubular body 150 and attached to the first closed end 152 of the tubular body 150. For example, the plunger head 158 may be attached to the tubular body 150 using an adhesive, a fastener (e.g., bolts and screws), heat sealing (e.g., melt bonding), or with some other known means, as well as combinations thereof. The plunger head 158 may include a recess 160 on an interior side of the plunger head 158. At least one flexible member seal 162 may be provided between the pump body 102 and the flexible member 142. For example, a peripheral edge of the flexible member 142 at the second open end 154 thereof may be attached to the pump body 102 and a fluid tight seal may be provide between the pump body 102 and the flexible member 142. In some embodiments, the elongated piston shaft 122 of the piston 118 may extend from the piston head 120, through the piston shaft hole 136, through the second open end 154 of the flexible member 142, and into the interior 144 of the flexible member 142 within the incompressible fluid chamber 156. In other embodiments, the elongated piston shaft 122 of the piston 118 may extend from the piston head 120 and partially into the piston shaft hole 136. In other words, the elongated piston shaft 122 may not extend into the interior 144 of the flexible member 142. Furthermore, the distal end 133 of the elongated piston shaft 122 may not enter into the interior 144 of the flexible member 142 during operation of the fluid pump 100; rather, the elongated piston shaft 122 may push and pull at least some incompressible fluid 176 in and out of the flexible member 142. For example, the elongated piston shaft may pull liquid out of the interior 144 of the flexible member 142 and into the piston shaft hole 136 when retracting the flexible member 142 and may push liquid out of the piston shaft hole 136 and into the interior 144 of the flexible member 142 when extending the flexible member 142. For purposes of the current application, in some embodiments, the elongated piston shaft 122 will be described as entering into and withdrawing from the interior 144 of the flexible member 142 during operation of the fluid pump 100. However, it is understood that the elongated piston shaft 122 may not enter into the interior 144 of the flexible member 142 during operation of the fluid pump 100.
The incompressible fluid 176 (e.g., oil or water-based liquids) may be disposed within the incompressible fluid chamber 156 within the interior 144 of the flexible member 142. The flexible member 142 may be formed of and comprise a flexible polymer material (e.g., an elastomer, a thermoplastic material, or a fluoropolymer). The flexible member 142 may include one or more extending features 164 that enable the tubular body 150 of the bellow plungers to be longitudinally extended and compressed as the fluid pump 100 is cycled. For example, the extending features 164 may include accordion style bends or folds that enable the tubular body 150 of the flexible member 142 to extend and retract back and forth in the longitudinal direction (i.e., the horizontal direction from the perspective of FIG. 1) during operation of the fluid pump 100.
A subject fluid inlet 166 may be provided in the pump body 102 that leads into the subject fluid chamber 116 through the pump body 102. A subject fluid inlet check valve 168 may be provided proximate the subject fluid inlet 166 to ensure that subject fluid is capable of flowing into the subject fluid chamber 116 through the subject fluid inlet 166, but incapable of flowing out from the subject fluid chamber 116 through the subject fluid inlet 166. A subject fluid outlet 170 may be provided in the pump body 102 that leads out from the subject fluid chamber 116 through the pump body 102. A subject fluid outlet check valve 174 may be provided proximate the subject fluid outlet 170 to ensure that subject fluid is capable of flowing out from the subject fluid chamber 116 through the subject fluid outlet 170, but is incapable of flowing into the subject fluid chamber 116 through the subject fluid outlet 170.
A first drive fluid inlet 171 may be provided in the pump body 102 that leads into the first drive fluid chamber 110 through the pump body 102, and a second drive fluid inlet 172 may be provided in the pump body 102 that leads into the second drive fluid chamber 112. The first and second drive fluid inlets 171, 172 may have threaded portions for accepting a drive fluid hose or tubing (as depicted in FIG. 4). At least one vent may be provided in the pump body that leads into the first and second drive fluid chambers 110, 112.
To facilitate a complete understanding of the operation of the fluid pump 100, a complete pumping cycle of the fluid pump 100 (including a leftward stroke and a rightward stroke of the piston 118, from the perspective show in FIG.1) is described below.
A rightward stroke of a cycle of the pump body 102 assembly begins by inputting pressurized drive fluid into the second drive fluid chamber 112 through the second drive fluid inlet 172, which urges the piston head 120 of the piston 118 to the right (from the perspective of FIG. 1). The pressurized drive fluid may be input using a shuttle valve arrangement. For example, pressurized drive fluid may be input using a shuttle valve arrangement as described in in U.S. Pat. No. 5,567,118 to Grgurich et al., issued Oct. 22, 1996, or U.S. Pat. No. 6,012,377 to Hung, issued Jan. 11, 2000, the disclosure of each of which is incorporated herein by reference. As the piston head 120 moves to the right, the elongated piston shaft 122 may be pulled to the right. Furthermore, by moving the piston head 120 of the piston 118 to the right, a volume of the second drive fluid chamber 112 may increase, and a volume of the first drive fluid chamber 110 may decrease. As the volume of the first drive fluid chamber 110 decreases, drive fluid present within the first drive fluid chamber 110 may be vented out from the pump body 102 through the first drive fluid inlet 171 and/or at least one valve.
During the rightward stroke, in some embodiments, the elongated piston shaft 122, the distal end of which may be disposed within the interior 144 of the flexible member 142, may be at least partially withdrawn from the incompressible fluid chamber 156. As discussed above, in other embodiments, the distal end 133 end the elongated piston shaft 122 may not be disposed within the interior of the flexible member 142 and may pull at least some of the incompressible fluid out of the interior 144 of the flexible member 142 and into the piston shaft hole 136. Withdrawal of at least some of the incompressible fluid 176 from the incompressible fluid chamber 156 causes the flexible member 142 to retract and move to the right (from the perspective of FIG. 1) during the rightward stroke of the piston 118. As the flexible member 142 refracts, the plunger head 158 of the flexible member 142 moves to the right (from the perspective of FIG. 1). Refraction of the flexible member 142 and movement of the plunger head 158 to the right increases a volume of the subject fluid chamber 116, which causes subject fluid to be drawn through the subject fluid inlet 166 and into the subject fluid chamber 116. Furthermore, increasing the volume of the subject fluid chamber 116 may cause the subject fluid inlet check valve 168 to open, which may allow subject fluid to flow into the subject fluid chamber 116 and may cause the subject fluid outlet check valve 174 to close, which may prevent any subject fluid that may have been already been dispensed from the subject fluid chamber 116 from being drawn back into the subject fluid chamber 116 through the subject fluid outlet 170.
In some embodiments, the piston 118 may be moved to the right until the flexible member 142 is fully refracted. By fully refracting the flexible member 142, a maximum volume of the subject fluid chamber 116 may be achieved, which may assist in maximizing an amount of subject fluid pumped through the pump body 102 during a single cycle. In other embodiments, the flexible member 142 may not be fully retracted during a cycle but may be only partially extended. How much the flexible member 142 retracts during a cycle of the fluid pump 100 may be adjusted as desired.
Upon completing the rightward stroke of the piston 118, a leftward stroke begins by inputting pressurized drive fluid into the first drive fluid chamber 110, which urges the piston head 120 of the piston 118 to the left (from the perspective of FIG. 1). As discussed above, pressurized drive fluid may be input using a shuttle valve arrangement. As the piston head 120 moves to the left, the elongated piston shaft 122 may be pushed to the left. By moving the piston head 120 of the piston 118 to the left, a volume of the second drive fluid chamber 112 may decrease, and a volume of the first drive fluid chamber 110 may increase. As the volume of the second drive fluid chamber 112 decreases, drive fluid present within the second drive fluid chamber 112 may be vented out from the pump body 102 through the second drive fluid inlet 172 and/or at least one vent.
During the leftward stroke, in some embodiments, the distal end of the elongated piston shaft 122 inserted into or farther into the incompressible fluid chamber 156. As discussed above, in other embodiments, the elongated piston shaft 122 may not be inserted into the incompressible fluid chamber 156 and may push at least some incompressible fluid 176 into the incompressible fluid chamber 156 from the piston shaft hole 136. As the elongated piston shaft 122 moves into the incompressible fluid chamber 156, or pushes at least some incompressible fluid 176 into the incompressible fluid chamber 156, the elongated piston shaft 122 displaces at least some of the incompressible fluid 176 disposed within the incompressible fluid chamber 156, which generates pressure therein as the incompressible fluid 176 pushes against the interior surface 148 of the flexible member 142. The pressurization of the incompressible fluid 176 within the incompressible fluid chamber 156 causes the flexible member 142 to extend. As the flexible member 142 extends, the plunger head 158 of the flexible member 142 moves to the left (from the perspective of FIG. 1) within the second cavity 106.
Extension of the flexible member 142 causes subject fluid to be dispensed out of the subject fluid chamber 116 through the subject fluid outlet 170 responsive to the decrease in the volume of the subject fluid chamber 116. Furthermore, dispensing subject fluid out of the subject fluid chamber 116 through the subject fluid outlet 170 may cause the subject fluid inlet check valve 168 to close, which may prevent any subject fluid from being dispensed out of the subject fluid chamber 116 through the subject fluid inlet 166 and may cause the subject fluid outlet check valve 174 to open, which may allow subject fluid to be dispensed out of the subject fluid chamber 116 through the subject fluid outlet 170. In some embodiments, the flexible member 142 may be extended until the flexible member 142 substantially fills the second cavity 106 and dispenses substantially all of the subject matter fluid out of the subject fluid chamber 116 through the subject fluid outlet 170. In other embodiments, the flexible member 142 may be only partially extended and may dispense only a portion of the subject fluid out of the subject fluid chamber 116 through the subject fluid outlet 170.
By fully extending the flexible member 142, a maximum amount of subject fluid may be pumped out from the pump body 102 during a single cycle. How much the flexible member 142 extends during a cycle of the fluid pump 100 may be adjusted as desired. The piston 118 may be moved to the left until the piston 118 is in a starting position of the rightward stroke, thereby completing one full cycle of the fluid pump 100, at which point, a new cycle begins. This reciprocating action may be continued, which may result in at least substantially continuous flow of the subject fluid through the fluid pump 100.
Thus, to drive the pumping action of the fluid pump 100, the first drive fluid chamber 110 and the second drive fluid chamber 112 may be pressurized in an alternating manner to cause the piston 118, elongated piston shaft 122, and flexible member 142 to reciprocate back and forth within the pump body 102, as discussed above. For example, the fluid pump 100 may use the shuttle valve arrangement to facilitate pressuring the first and second drive fluid chambers 110, 112 in an alternating manner. The cycle discussed above is not intended to indicate an order of operations of the fluid pump 100. It is understood that the pumping action of the fluid pump 100 may be started with the piston 118 at any position.
FIG. 2 is cross-sectional side view of the fluid pump 100 of FIG. 1, showing vectors representing forces exerted on various parts of the fluid pump 100 during a pumping cycle of the fluid pump 100.The fluid pump 100 may pressurize the subject fluid to a pressure higher than a pressure to which the pressurized drive fluid is pressurized. For example, in some embodiments, during a leftward stroke, the pressurized drive fluid may be pressurized to a first pressure in the first drive fluid chamber 110. The first pressure of the pressurized drive fluid, as depicted in FIG. 2 as vectors P₁, may be exerted on the first surface area SA1 of the first side 124 of the piston head 120. During the leftward stroke, the end surface 134 of the elongated piston shaft 122 of may exert a second pressure, as depicted in FIG. 2 as vectors P₂, on the incompressible fluid 176 within the incompressible fluid chamber 156 within flexible member 142. In some embodiments, a force exerted on the first surface area SA1 of the first side 124 of the piston head 120 may be substantially equal to a force exerted by the end surface 134 of the elongated piston shaft 122 on the incompressible fluid 176. Furthermore because pressure is equal to force per area (P=F/A) and because the second surface area SA2 of the end surface 134 of the elongated piston shaft 122 may be smaller than the first surface area SA1 of the first side 124 of the piston 118, the second pressure P₂may be larger than the first pressure P₁. Thus, the incompressible fluid 176 may be subject and pressurized to the second pressure P₂, which may be higher than the first pressure P₁of the pressurized drive fluid. Put another way, the piston 118 may be configured to amplify the first pressure P₁experienced on the first side 124 of the piston head 120 to the second pressure P₂experienced by the end surface 134 of the elongated piston shaft 122. Pressuring the incompressible fluid 176 to the second pressure, may cause a third pressure, as depicted in FIG. 2 as vectors P₃, to be exerted on the interior surface 148 of the flexible member 142.
In some embodiments, the third pressure P₃exerted by the incompressible fluid 176 on the interior surface 148 of the flexible member 142 is substantially equal to a fourth pressure, as depicted in FIG. 2 as vectors P₄, exerted by the exterior surface 146 on the subject fluid within the subject fluid chamber 116. Furthermore, a third surface area of the interior surface 148 of the flexible member 142 and a fourth surface area of the exterior surface 146 of the flexible member 142 may be substantially equal. Therefore, a the third pressure P₃exerted on the third surface area of the interior surface 148 of the flexible member 142 may be substantially equal to the fourth pressure P₄exerted on the subject fluid by the exterior surface 146 of the flexible member 142. Thus, the subject fluid may be subject and pressurized to the fourth pressure P₄substantially equal to the second pressure P₂of the incompressible fluid 176. Accordingly, the subject fluid may be pressurized to the fourth pressure P₄, which may be higher than the first pressure P₁of the pressurized drive fluid. In some embodiments, the subject fluid may experience a fourth pressure P₄that is at least two times the first pressure P₁experienced by the pressurized drive fluid. In other embodiments, the subject fluid may experience a fourth pressure P₄that is at least four times the first pressure P₁experienced by the pressurized drive fluid. In yet other embodiments, the subject fluid may experience a fourth pressure P₄that is at least six times the first pressure P₁experienced by the pressurized drive fluid.
A ratio of the first surface area SA1 of the first side 124 of the piston head 120 to the second surface area SA2 of the end surface 134 of the elongated piston shaft 122 may be adjusted to achieve different increases in pressure. Subject fluids having increased pressure may be used when performing tasks, such as, generating a spray of the subject liquid.
FIG. 3 is a simplified flow chart demonstrating a method 300 of pressurizing a subject fluid while pumping the subject fluid. An embodiment of the present disclosure includes a method 300 of pressuring a subject fluid while pumping the subject fluid using the fluid pump 100 of FIG. 1. Referring to FIGS. 1 and 3, the method 300 may include action 301 of inputting pressurized drive fluid into the first drive fluid chamber 110. The pressurized drive fluid may be pressurized to a first pressure and may be input into the first drive fluid chamber 110 through the first drive fluid inlet 171. The pressurized drive fluid may comprise compressed gas (e.g., air). The method 300 may also include action 302 of moving the piston 118 along an axial length of the first cavity 104 in a first direction with the pressurized drive fluid. In some embodiments, the first direction may be to the left along an axial length of the first cavity 104 (from perspective of FIG. 1). Moving the piston 118 to the left may also include moving the elongated piston shaft 122 of the piston 118 to the left. The method 300 may also include action 304 of increasing a volume of the first drive fluid chamber 110 while decreasing a volume of the second drive fluid chamber 112. The volume of the first drive fluid chamber 110 may be increased by moving the piston head 120 of the piston 118 to the left (from perspective of FIG. 1).
The method 300 may further include action 306 of pressurizing the incompressible fluid 176 to a second pressure, which may be higher than the first pressure to which the pressurized drive fluid is pressurized. The incompressible fluid 176 may be pressurized to the second pressure by pushing the elongated piston shaft 122 into the interior 144 of the flexible member 142 with the piston 118 the piston head 120. The first surface area SA1 of the first side 124 of the piston head 120 may be larger than the second surface area SA2 of the end surface 134 of the elongated piston shaft 122, which may result in the incompressible fluid 176 being subject to the second pressure which is higher than the first pressure to which the pressurized drive fluid is pressurized.
The method 300 may include action 308 of extending the flexible member 142 to at least partially fill the second cavity 106. In some embodiments, the flexible member 142 may be extended by inserting the elongated piston shaft 122 at least partially into the interior 144 of the flexible member 142 and displacing at least some of the incompressible fluid 176 disposed in the interior 144 of the flexible member 142. In other embodiments, the flexible member 142 may be extended by pushing at least some incompressible fluid 176 from the piston shaft hole 136 and into the incompressible fluid chamber 156 with the elongated piston shaft 122. In other words, by inserting the elongated piston shaft 122 into the interior 144 of the flexible member 142 or by pushing at least some incompressible fluid 176 into the interior 144 of the flexible member 142, an internal volume of the flexible member 142 is increased, which may cause the flexible member 142 to extend to accommodate a larger internal volume. In some embodiments, the amount the flexible member 142 extends during a cycle of the fluid pump 100 may be adjusted by adjusting a distance traveled by the piston 118 during the leftward stroke within the pump body 102. The distance traveled by the piston 118 during the leftward stroke may be adjusted by inputting more or less pressurized drive fluid into the first drive fluid chamber 110.
The method 300 may also include action 310 of pressuring the subject fluid to a fourth pressure substantially equal to the second pressure to which the incompressible fluid 176 is pressurized and higher than the first pressure to which the pressurized drive fluid is pressurized. The subject fluid may be pressurized by the incompressible fluid 176. As discussed above, the third surface area of the interior surface 148 of the flexible member 142 may be substantially equal to the fourth surface area of the exterior surface 146 of the flexible member 142. Furthermore, the third pressure exerted by the incompressible fluid 176 on the interior surface 148 of the flexible member 142 may be transferred with about a 1:1 ratio by the exterior surface 146 to the subject fluid. Furthermore, because the third and fourth surface areas are substantially equal, the fourth pressure experienced by the subject fluid may be substantially equal to the third pressure exerted by the incompressible fluid 176. Thus, the subject fluid may be pressurized to the fourth pressure substantially equal to the second pressure to which the incompressible fluid 176 is pressurized. Furthermore, as discussed above in regard to action 306, because the second pressure of the incompressible fluid 176 is higher than the first pressure of the pressurized drive fluid, the fourth pressure of the subject fluid may be higher than the first pressure of the pressurized drive fluid. In some embodiments, the method 300 includes pressurizing the subject fluid to a fourth pressure that is at least two times higher than the first pressure of the pressurized drive fluid. In other embodiments, the method 300 includes pressurizing the subject fluid to a fourth pressure that is at least four times higher than the first pressure of the pressurized drive fluid. In yet other embodiments, the method 300 includes pressurizing the subject fluid to a fourth pressure that is at least six times higher than the first pressure of the pressurized drive fluid.
The method 300 may include action 312 of dispensing at least some subject fluid out of the subject fluid chamber 116 thought the subject fluid outlet 170. Extending the flexible member 142 and at least partially filling the second cavity 106 with the flexible member 142 may dispense the subject fluid out of the subject fluid chamber 116. Furthermore, extending the flexible member 142 may decrease the volume of the subject fluid chamber 116 and may dispense some subject fluid out of the subject fluid chamber 116 through the subject fluid outlet 170. Moreover, dispensing subject fluid out of the subject fluid chamber 116 through the subject fluid outlet 170 may cause the subject fluid inlet check valve 168 to close, which may prevent any subject fluid from being dispensed out of the subject fluid chamber 116 through the subject fluid inlet 166. Dispensing subject fluid out of the subject fluid chamber 116 through the subject fluid outlet 170 may also cause the subject fluid outlet check valve 174 to open, which may allow subject fluid to be pushed out of the subject fluid chamber 116 through the subject fluid outlet 170. In some embodiments, substantially all of the subject fluid may be dispensed out of the subject fluid chamber 116. In other embodiments, only a portion of the subject fluid may be dispensed out the subject fluid chamber 116.
The method 300 may further include action 314 of inputting pressurized drive fluid into the second drive fluid chamber 112 to initiate a rightward stroke. As discussed above, the pressurized drive fluid may be input using a shuttle valve arrangement. The pressurized drive fluid may be input through the second drive fluid inlet 172. The method 300 may include an action 316 of moving the piston 118 along an axial length of the first cavity 104 in a second direction with the pressurized drive fluid. In some embodiments, the second direction may be to the right along an axial length of the first cavity (from the perspective of FIG. 1). Moving the piston 118 to the right may also include moving the elongated piston shaft 122 to the right. The method 300 may also include an action 318 of increasing a volume of the second drive fluid chamber 112 while decreasing a volume of the first drive fluid chamber 110. The volume of the second drive fluid chamber 112 may be increased by moving the piston head 120 of the piston 118 to the right (from the perspective of FIG. 1) within the first cavity 104.
The method 300 may include action 320 of retracting the flexible member 142. In some embodiments, the flexible member 142 may be retracted by withdrawing the elongated piston shaft 122 at least partially out of the interior 144 of the flexible member 142. In other embodiments, the flexible member 142 may be refracted by pulling at least some incompressible fluid 176 out of the interior 144 of the flexible member 142 with the elongated piston shaft. In other words, by withdrawing the elongated piston shaft 122 out of the interior 144 of the flexible member 142 or by pulling at least some incompressible fluid 176 out of the interior 144 of the flexible member 142, the internal volume of the flexible member 142 is decreased causing the flexible member 142 to retract to accommodate a smaller internal volume. Retracting the flexible member 142 may increase a volume of the subject fluid chamber 116, which may initiate action 322 of drawing subject fluid into the subject fluid chamber 116 through the subject fluid inlet 166. By drawing subject fluid into the subject fluid chamber 116 through the subject fluid inlet 166 the subject fluid inlet check valve 168 may be caused to open, which may allow subject fluid to be drawn into the subject fluid chamber 116 through the subject fluid inlet 166. Furthermore, dispensing subject fluid out of the subject fluid chamber 116 through the subject fluid outlet 170 may cause the subject fluid outlet check valve 174 to close, which may prevent subject fluid that has already be dispensed from the subject fluid chamber 116 from being drawn back into to the subject fluid chamber 116 through the subject fluid outlet 170.
The above discussed method 300 of pressuring a subject fluid and pumping the subject fluid may be repeated to perform a reciprocating action. This reciprocating action may be continued, which may result in at least substantially continuous flow of the subject fluid through the fluid pump 100.
FIG. 4 is a cross-sectional side view of a pump system including a plurality of pneumatically operated fluid pumps fluid pumps as shown in FIG. 1 operably connected in parallel. In some embodiments, a plurality of fluid pumps may be connected together in a parallel with a first subject fluid tube 480 connecting the subject fluid outlet 470 of a first fluid pump 400 with the subject fluid outlet 472 of a second fluid pump 401. Furthermore, the first subject fluid tube 480 may connect the subject fluid outlet 470 of the first fluid pump 400 and the subject fluid outlet 472 of the second fluid pump 401 to a first common source 473. The plurality of pumps may further be connected in parallel with a second subject fluid tube 481 connecting a subject fluid inlet 475 of the first fluid pump 400 with a subject fluid inlet 471 of the second fluid pump 401. The second subject fluid tube 481 may also connect the subject fluid inlet 475 of the first fluid pump 400 and the subject fluid inlet 471 to a second common source 474. Placing multiple fluid pumps in parallel may allow for maintaining a stable pressure in the subject fluid while pumping the subject fluid.
The example embodiments of the disclosure described above do not limit the scope of the invention, since these embodiments are merely examples of embodiments of the invention, which is defined by the scope of the appended claims and their legal equivalents. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the disclosure, in addition to those shown and described herein, such as alternate useful combinations of the elements described, will become apparent to those skilled in the art from the description. Such modifications and embodiments are also intended to fall within the scope of the appended claims.

Claims

What is claimed is:

1. A fluid pump for pumping a subject fluid, the fluid pump comprising:

a pump body;

a first cavity within the pump body;

a second cavity within the pump body;

a piston shaft hole extending from the first cavity to the second cavity;

a flexible member disposed within the second cavity, the flexible member comprising a tubular body having a first closed end and a second open end opposite the first closed end, the second open end being proximate the piston shaft hole, the flexible member configured to extend and retract within the second cavity during operation of the fluid pump;

an incompressible fluid chamber defined within the second cavity on a first side of the flexible member;

an incompressible fluid disposed within the incompressible fluid chamber;

a subject fluid chamber defined within the second cavity on a second side of the flexible member, the flexible member configured to increase and decrease a volume of the subject fluid chamber; and

a piston comprising:

a piston head having a first side and an opposite second side, the first side of the piston head having a first surface area, the piston head movable within the first cavity; and

an elongated piston shaft extending from the second side of the piston head and at least partially into the piston shaft hole, wherein the elongated piston shaft has an end surface opposite the piston head, the end surface having a second surface area smaller than the first surface area of the first side of the piston head.

2. The fluid pump of claim 1, wherein the piston is configured to amplify a first pressure experienced on the first surface area of the first side of the piston head to a second pressure experienced by the second surface area of the end surface of the elongated piston shaft.

3. The fluid pump of claim 2, wherein the elongated piston shaft of the piston is configured to pressurize the incompressible fluid to a third pressure substantially equal to the second pressure experienced by the second surface area of the end surface of the elongated piston shaft.

4. The fluid pump of claim 3, wherein the flexible member is configured to pressurize the subject fluid disposed within the subject fluid chamber to a fourth pressure substantially equal to the third pressure of the incompressible fluid.

5. The fluid pump of claim 4, wherein a ratio of the first pressure experienced on the first surface area of the first side of the piston head and the fourth pressure of the subject fluid is at least more than 1.

6. The fluid pump of claim 4, wherein a ratio of the first pressure experienced on the first surface area of the first side of the piston head and the fourth pressure of the subject fluid is at least 3.

7. The fluid pump of claim 4, wherein a ratio of the first pressure experienced on the first surface area of the first side of the piston head and the fourth pressure of the subject fluid is at least 6.

8. The fluid pump of claim 1, further comprising:

a first drive fluid chamber located between the first side of the piston head of the piston and a first cavity interior surface of the first cavity; and

a second drive fluid chamber located between the second side of the piston head of the piston and the first cavity interior surface of the first cavity.

9. The fluid pump of claim 8, further comprising:

a first drive fluid inlet extending through the pump body to the first drive fluid chamber;

a second drive fluid inlet extending through the pump body to the second drive fluid chamber;

a subject fluid inlet extending through the pump body to the subject fluid chamber; and

a subject fluid outlet extending through the pump body to the subject fluid chamber.

10. A pump body for pumping a subject fluid, the pump body comprising:

a flexible member disposed within the pump body, the flexible member comprising a tubular body having a first closed end and a second open end opposite the first closed end, the flexible member containing an incompressible fluid; and

a piston comprising:

a piston head having a first side and an opposite second side; and

an elongated piston shaft extending from the second side of the piston head, the elongated piston shaft having an end surface on a distal end of the elongated piston shaft opposite the piston head, and wherein the piston is configured such that a ratio of a first pressure experienced by the first side of the piston head and a second pressure experienced by the end surface of the elongated piston shaft is at least more than 1.

11. The pump body of claim 10, wherein a first surface area of the first side of the piston head is larger than a second surface area of the end surface of the elongated piston shaft.

12. The pump body of claim 10, wherein the ratio of the first pressure experienced by the first side of the piston head and the second pressure experienced by the end surface of the elongated piston shaft is at least 3.

13. The pump body of claim 10, wherein the ratio of the first pressure experienced by the first side of the piston head and the second pressure experienced by the end surface of the elongated piston shaft is at least 6.

14. The pump body of claim 10, wherein a fourth pressure experienced by the subject fluid is at least substantially equal to third pressure experienced by the incompressible fluid, and wherein the third pressure is at least substantially equal to the second pressure experienced by the end surface of the elongated piston shaft.

15. A method of pressurizing and pumping a subject fluid, the method comprising:

inputting a pressurized drive fluid into a first drive fluid chamber of a first cavity of a pump body, wherein the pressurized drive fluid is input on a first side of a piston head of a piston, the pressurized drive fluid exerting a first pressure on the first side of the piston head;

moving the piston along an axial length of the first cavity of the pump body;

exerting a second pressure on an incompressible fluid within an interior of a flexible member, wherein the second pressure is exerted on the incompressible fluid with an end surface of an elongated piston shaft extending from a second side of the piston head of the piston;

pressurizing the incompressible fluid to a third pressure higher than the first pressure with the elongated piston shaft of the piston and substantially equal to the second pressure;

pressurizing the subject fluid within a subject fluid chamber that least partially surrounds the flexible member to a fourth pressure higher than the first pressure and at least substantially equal to the third pressure.

16. The method of claim 15, further comprising:

extending the flexible member;

decreasing a volume of the subject fluid chamber in the pump body; and

dispensing at least some of the subject fluid out of the subject fluid chamber through a subject fluid outlet in the pump body.

17. The method of claim 16, further comprising:

inputting the pressurized drive fluid into a second drive fluid chamber of the first cavity of the pump body, wherein the pressurized drive fluid is input on the second side of the piston head of the piston;

pulling at least some of the incompressible fluid out of the interior of the flexible member with the elongated piston shaft of the piston;

retracting the flexible member;

increasing the volume of the subject fluid chamber; and

drawing at least some subject fluid into the subject fluid chamber through a subject fluid inlet in the pump body.

18. The method of claim 15, wherein pressurizing the subject fluid to a fourth pressure comprises pressurizing the subject fluid to the fourth pressure that is at least 2 times the first pressure experienced by the first side of the piston head.

19. The method of claim 15, wherein pressurizing the subject fluid to a fourth pressure comprises pressurizing the subject fluid to the fourth pressure that is at least 4 times the first pressure experienced by the first side of the piston head.

20. The method of claim 15, wherein pressurizing the subject fluid to a fourth pressure comprises pressurizing the subject fluid to the fourth pressure that is at least 6 times the first pressure experienced by the first side of the piston head.