US20170226999A1

US20170226999A1 - Flushable pump fluid chamber

Info

Publication number: US20170226999A1
Application number: US15/490,692
Authority: US
Inventors: Jason J. Willoughby; David C. Polovitz; David M. Behrens
Original assignee: Graco Minnesota Inc
Current assignee: Graco Minnesota Inc
Priority date: 2015-07-16
Filing date: 2017-04-18
Publication date: 2017-08-10
Also published as: TW201708704A; WO2017011557A1

Abstract

A fluid cover for a displacement pump includes an inlet and an outlet oriented to provide desired flow characteristics to fluid entering a fluid chamber defined between the fluid cover and a diaphragm. The inlet is positioned to provide fluid to the fluid chamber at an oblique angle relative to the fluid cover. The oblique angle prevents the fluid from impinging on the fluid cover and the diaphragm, thereby maintaining a fluid velocity within the fluid chamber. The fluid velocity and rotational movement of the fluid facilitates flushing of the fluid chamber, as areas of low velocity or no velocity are eliminated from the fluid chamber, thereby preventing residuals from settling within the fluid chamber. The outlet is also positioned at an oblique angle to the fluid cover to maintain the rotational movement of the fluid flow.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Application No. 62/193,241 filed on Jul. 16, 2015, and entitled “FLUSHABLE DIAPHRAGM PUMP FLUID CHAMBER,” the disclosure of which is incorporated by reference in its entirety.

BACKGROUND

This disclosure relates to positive displacement pumps and more particularly to fluid covers for positive displacement pumps.
Positive displacement pumps discharge a process fluid at a selected flow rate. In a typical positive displacement pump, a fluid displacement member, usually a piston or diaphragm, drives the process fluid through the pump. When the fluid displacement member is drawn in, a suction condition is created in a fluid chamber between a fluid cover and the fluid displacement member, which draws process fluid into a fluid cavity from the inlet manifold. The fluid displacement member then reverses direction and forces the process fluid out of the fluid chamber through the outlet manifold.
After the process fluid has been applied, or when the positive displacement pump is going to be used to apply a different process fluid, the pump must be flushed to remove any residual process fluid remaining in the fluid chamber. The pump is operated in a typical fashion and drives a solvent or other cleaning fluid through the fluid chambers. The pump continues to drive the cleaning fluid through the fluid chambers until the fluid chambers are adequately cleaned. The volume of cleaning fluid required varies depending on the fluid flow paths within the fluid chambers, as areas of low or no fluid velocity allow contaminants to settle within the fluid chambers, thereby requiring additional flushing to ensure that the fluid chambers are adequately flushed.

SUMMARY

According to an aspect of the present disclosure, a pump includes a pump drive system, a first fluid displacement member disposed at a first end of the pump drive system, a first fluid cover attached to the first end of the pump drive system and securing the first fluid displacement member between the first end and the first fluid cover, an inlet manifold attached to the first fluid cover, and an outlet manifold attached to the first fluid cover. The first fluid cover includes a first cover body defined by a first inner wall and a first outer wall. The first inner wall and the first fluid displacement member define a first fluid chamber. A first fluid port and a second fluid port extend through the first cover body. The first fluid port includes a first inner orifice extending through the first inner wall and configured to direct a flow through the first inner orifice and into the first fluid chamber at a first oblique angle to the inner wall. The second fluid port includes a second inner orifice extending through the first inner wall and configured to direct a flow through the second inner orifice at a second oblique angle to the first inner wall. The first inner orifice is disposed a first radial distance from a center of the first inner wall and the second inner orifice is disposed at a second radial distance from the center. The inlet manifold is configured to provide a fluid to the first fluid chamber through the first inlet. The outlet manifold is configured to receive the fluid from the fluid chamber through the first outlet.
According to another aspect of the present disclosure, a fluid cover for a pump includes a cover body extending between a convex outer wall and a concave inner wall. A first fluid port extends through the body, and a second fluid port extends through the body. The first fluid port includes a first outer orifice, a first inner orifice extending through the concave inner wall, and a first flow path extending between the first outer orifice and the first inner orifice. The first inner orifice is positioned on the concave inner wall such that a pumped fluid is directed through the first inner orifice at a first oblique angle to the concave inner wall. The second fluid port is disposed opposite the first fluid port and includes a second inner orifice extending through the concave inner wall, a second outer orifice, and a second flow path extending between the second outer orifice and the second inner orifice. The second inner orifice is positioned on the concave inner wall such that the pumped fluid is directed through the second inner orifice at a second oblique angle to the concave inner wall.
According to yet another aspect of the present disclosure, a method of flushing a fluid chamber includes drawing a fluid into a fluid chamber defined between a fluid cover and a fluid displacement member through an inlet orifice, and driving the fluid out of the fluid chamber through a second inner orifice positioned to receive the fluid circulating within the fluid chamber. The inlet orifice is positioned to provide the fluid to the fluid chamber at a first oblique angle relative to an inner wall of the fluid cover, thereby imparting a rotational movement to the fluid entering the fluid chamber. The second inner orifice is positioned on the inner wall to direct the fluid at a second oblique angle relative to the inner wall.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a pump.

FIG. 2 is an elevation view of a pump cover.

FIG. 3A is a side elevation view of a pump cover with a fluid port exposed.

FIG. 3B is an isometric view of a fluid flow path through a fluid port.

DETAILED DESCRIPTION

FIG. 1 is an exploded perspective view of pump 10. Pump 10 includes drive system 12, fluid covers 14 a and 14 b, inlet manifold 16, outlet manifold 18, air valve 20, inlet check valves 22 a and 22 b, outlet check valves 24 a and 24 b, fluid displacement members 26 a and 26 b, pump shaft 28, and o-rings 30. Fluid cover 14 a includes cover body 32 a, inner surface 34 a, outer surface 36 a, first fluid port 38 a, and second fluid port 40 a. Inner surface 34 a includes circumferential edge 42 a. Fluid displacement member 26 a includes diaphragm 44 a and diaphragm plate 46 a. Fluid cover 14 b includes cover body 32 b, inner surface 34 b, outer surface 36 b, first fluid port 38 b, and second fluid port 40 b. Inner surface 34 b includes a circumferential edge, similar to circumferential edge 42 a. Fluid displacement member 26 b includes diaphragm 44 b and diaphragm plate 46 b.
Air valve 20 is connected to drive system 12 and is configured to direct compressed air to drive system 12. Pump shaft 28 extends through drive system 12 and is driven in a reciprocating manner along axis A-A by the compressed air provided by air valve 20. Fluid displacement member 26 a is connected to a first end of pump shaft 28. Diaphragm 44 a is directly connected to the first end of pump shaft 28, with diaphragm plate 46 a disposed between pump shaft 28 and diaphragm 44 a. Similar to fluid displacement member 26 a, fluid displacement member 26 b is connected to a second end of pump shaft 28. Diaphragm 44 b is directly connected to the second end of pump shaft 28, with diaphragm plate 46 b disposed between pump shaft 28 and diaphragm 44 b.
Fluid cover 14 a is attached to a first end of drive system 12 by cover fasteners 48 a. A peripheral edge of diaphragm 44 a is disposed between fluid cover 14 a and drive system 12, with fluid cover 14 a and drive system 12 securing diaphragm 44 a in place. The peripheral edge of diaphragm 44 a forms a fluid seal between fluid cover 14 a and drive system 12. Diaphragm 44 a and inner surface 34 a define fluid chamber 50 a. Fluid cover 14 b is attached to a second end of drive system 12 by cover fasteners 48 b. A peripheral edge of diaphragm 44 b is disposed between and secured in place by fluid cover 14 b and drive system 12. The peripheral edge of diaphragm 44 b forms a fluid seal between fluid cover 14 b and drive system 12. Diaphragm 44 b and inner surface 34 b define fluid chamber 50 b. It is understood that drive system 12 may be configured to drive pump shaft 28 in any suitable manner, such as pneumatically, electrically, hydraulically, or in any other suitable manner.
Inlet check valve 22 a and outlet check valve 24 a are disposed in fluid cover 14 a. Similarly, inlet check valve 22 b and outlet check valve 24 b are disposed in fluid cover 14 b. While inlet check valves 22 a and 22 b and outlet check valves 24 a and 24 b are shown as self-contained cartridges, which include all of the operating components of a check valve within a replaceable cartridge, it is understood that inlet check valve 22 a may be of any suitable configuration for allowing flow into fluid chamber 50 a from inlet manifold 16 a and outlet check valve 24 a may be of any suitable configuration for allowing flow out of fluid chamber 50 a to outlet manifold 18. For example, fluid cover 14 a may be configured to receive the individual components of inlet check valve 22 a and outlet check valve 24 a, such as a ball and a seat or poppet, without requiring a cartridge, or may include a permanently installed check valve.
First fluid port 38 a through cover body 32 a between inlet check valve 22 a and inner surface 34 a. First fluid port 38 a extends through inner surface 34 a proximate circumferential edge 42 a. First fluid port 38 a is configured to impart a swirl flow to the pumped fluid entering fluid chamber 50 a. To impart the swirl flow, first fluid port 38 a is positioned to introduce the pumped fluid to fluid chamber 50 a at an oblique angle to diaphragm 44 a and inner surface 34 a. The oblique angle prevents the pumped fluid from impinging on either diaphragm 44 a or inner surface 34 a as the pumped fluid enters fluid chamber 50 a.
Second fluid port 40 a also extends through cover body 32 a between outlet check valve 24 a and inner surface 34 a. Second fluid port 40 b similarly extends through cover body 32 b between outlet check valve 24 b and inner surface 34 b. Second fluid port 40 a is configured to receive the pumped fluid within fluid chamber 50 a and direct the fluid out to outlet manifold 18 through outlet check valve 24 a. Second fluid port 40 a is configured to impart and maintain a swirl flow throughout the pump cycle, and second fluid port 40 a is oriented such that second fluid port 40 a extends through inner surface 34 a at an oblique angle to inner surface 34 a and diaphragm 44 a. To ensure that the desired flow characteristics are achieved, second fluid port 40 a may be a mirror-image of first fluid port 38 a. Second fluid port 40 a extends through inner surface 34 a proximate circumferential edge 42 a, similar to first fluid port 38 a. Positioning both first fluid port 38 a and second fluid port 40 a proximate circumferential edge 42 a encourages the swirl flow at the periphery of fluid chamber 50 a, where diaphragm 44 a and fluid cover 14 a meet, thereby enhancing the flush properties when a solvent or other cleaning agent is pumped through fluid chamber 50 a. The flush properties are enhanced because the swirl flow maintains a constant fluid velocity in fluid chamber 50 a and removes more contaminants in a quicker manner.
First fluid port 38 b extends through cover body 32 b between inlet check valve 22 b and inner surface 34 b. Similar to first fluid port 38 a, first fluid port 38 b is configured to impart a swirl flow to the fluid entering fluid chamber 50 b. First fluid port 38 b is positioned to introduce the pumped fluid to fluid chamber 50 b at an oblique angle to diaphragm 44 b and inner surface 34 b, and first fluid port 38 b extends through inner surface 34 b proximate the circumferential edge of inner surface 34 b. Second fluid port 40 b also extends through cover body 32 b between outlet check valve 24 b and inner surface 34 b. Second fluid port 40 b is configured to receive the fluid within fluid chamber 50 b and to direct the fluid out to outlet manifold 18 through outlet check valve 24 b. Second fluid port 40 b extends through inner surface 34 b at an oblique angle to diaphragm 44 b and inner surface 34 b, similar to second fluid port 34 a. Second fluid port 40 b extends through inner surface 34 b proximate the circumferential edge of inner surface 34 b. To ensure that the desired flow characteristics are achieved, second fluid port 40 b may be a mirror-image of first fluid port 38 b.
Inlet manifold 16 is attached to both fluid cover 14 a and fluid cover 14 b by manifold fasteners 49. Inlet manifold 16 is configured to provide fluid to both fluid chamber 50 a, through first fluid port 38 a, and fluid chamber 50 b, through first fluid port 38 b. Outlet manifold 18 is also attached to both fluid cover 14 a and fluid cover 14 b by manifold fasteners 49. Outlet manifold 18 is configured to receive fluid from both fluid chamber 50 a, through second fluid port 40 a, and fluid chamber 50 b, through second fluid port 40 b. Outlet manifold 18 provides the fluid downstream to a downstream application, such as a paint applicator.
It is understood that fluid cover 14 a is configured such that pumped fluid may be provided to fluid chamber 50 a through either first fluid port 38 a or second fluid port 40 a, such that either first fluid port 38 a or second fluid port 40 a may function as the inlet. In such an instance, outlet manifold 18 may be connected to the other of first fluid port 38 a or second fluid port 40 a, such that either first fluid port 38 a or second fluid port 40 a function as the outlet. In this way, fluid covers 14 a and 14 b are reversible such that the inlet may function as the outlet and the outlet may function as the inlet. In addition, having fluid cover 14 a and fluid cover 14 b be reversible provides a mistake-proofing function, such that fluid cover 14 a may be installed on either the first end or the second end of drive system 12 and fluid cover 14 b may be installed on the opposite end of drive system 12 from fluid cover 14 a.
During operation, compressed air is introduced to drive system 12 through air valve 20 to pump shaft 28. The compressed air causes pump shaft 28 to reciprocate and pump shaft 28 alternatingly drives fluid displacement member 26 a to contract and expand fluid chamber 50 a, and fluid displacement member 26 b to contract and expand fluid chamber 50 b. The pumping operation for fluid pumped through fluid chambers 50 a and 50 b is substantially similar, thus the pumping operation for fluid chamber 50 a will be discussed in further detail. During a first stroke, pump shaft 28 drives fluid displacement member 26 b into fluid chamber 50 b and pump shaft 28 simultaneously pulls fluid displacement member 26 a drawing fluid displacement member 26 a away from fluid cover 14 a, thereby increasing a volume of fluid chamber 50 a. Pulling fluid displacement member 26 a causes inlet check valve 22 a to open and creates a suction condition in fluid chamber 50 a, thereby drawing fluid into fluid chamber 50 a. After pump shaft 28 completes the first stroke, pump shaft 28 transitions to a second stroke. During the transition, the movement of fluid displacement member 26 a is temporarily ceased, but the orientation of first fluid port 38 a and second fluid port 40 a maintains a swirl flow within fluid chamber 50 a during the transition. During the second stroke, pump shaft 28 drives fluid displacement member 26 a into fluid chamber 50 a, thereby decreasing a volume of fluid chamber 50 a. Driving fluid displacement member 26 a into fluid chamber 50 a causes inlet check valve 22 a to close and outlet check valve 24 a to open. With outlet check valve 24 a open, fluid displacement member 26 a drives the fluid out of fluid chamber 50 a through second fluid port 40 a and downstream through outlet manifold 18.
First fluid port 38 a introduces the fluid into fluid chamber 50 a at an oblique angle to inner surface 34 a and diaphragm 44 a, which promotes swirling of the fluid within fluid chamber 50 a. In addition, first fluid port 38 a is positioned such that the fluid entering fluid chamber 50 a through is prevented from impinging on inner surface 34 a and diaphragm 44 a. Preventing the fluid from impinging on inner surface 34 a and diaphragm 44 a maintains a desired fluid velocity in fluid chamber 50 a, thereby preventing areas of low or no fluid velocity. In addition, first fluid port 38 a is positioned proximate circumferential edge 42 a. Positioning the first inner orifice proximate circumferential edge 42 a encourages swirl flow about a periphery of fluid chamber 50 a, thereby providing for quicker, more efficient flushing of fluid chamber 50 a when a solvent is pumped to flush fluid chamber 50 a.
As the fluid is driven out of fluid chamber 50 a during the second stroke, second fluid port 40 a receives the fluid from fluid chamber 50 a. Second fluid port 40 a is positioned at an oblique angle to inner surface 34 a and diaphragm 44 a. The oblique angle of second fluid port 40 a promotes the swirl flow within fluid chamber 50 a throughout the pump cycle, including the first stroke, the transition, and the second stroke. For example, unlike an outlet port aligned with an axis of pump shaft 28, which would cause a drop in flow velocity producing undesirable flow characteristics and areas of no flow velocity, positioning second fluid port 30 a at the oblique angle, proximate circumferential edge 42 a of inner surface 34 a promotes the swirl flow and ensures that the flow has desirable characteristics. Positioning second fluid port 40 a at the oblique angle and proximate circumferential edge 42 a thus eliminates areas of low flow velocity or no flow velocity. In addition, having second fluid port 40 a enter through inner surface 34 a proximate circumferential edge 42 a further encourages the maintenance of the swirl flow about a periphery of the fluid chamber 50 a, thereby facilitating the flushing of fluid chamber 50 a and preventing residual process fluid from settling in fluid chamber 50 a.
Pump 10 is configured to drive a fluid, such as paint, to a downstream application. After applying the fluid, fluid chambers 50 a and 50 b must be flushed with a solvent or other cleaning fluid before storage or reuse. Flushing fluid chambers 50 a and 50 b both maintains the useful life of various components of pump 10 and ensures the quality of the next fluid pumped, such as a paint of a different pigment. To flush pump 10, the solvent is pumped through fluid chambers 50 a and 50 b in the same manner as other pumped fluids, described above. First fluid port 38 a imparts a swirl flow on the solvent and prevents the solvent from having low velocity or no velocity when in fluid chamber 50 a. The swirl flow of the solvent prevents pumped fluid, such as paint, from settling within fluid chamber 50 a. In addition, the constant velocity maintained in fluid chamber 50 a prevents solids, such as fillers and additives from the paint, from settling in fluid chamber 50 a. Second fluid port 40 a is configured to maintain the swirl flow in fluid chamber 50 during the transition and the second stroke. Second fluid port 40 a receives the solvent and provides the solvent to outlet manifold 18. Both first fluid port 38 a and second fluid port 40 a are disposed proximate the circumferential edge 42 a of inner surface 34 a. Positioning both first fluid port 38 a and second fluid port 40 a proximate the periphery of inner surface 34 maintains the swirl flow about a periphery of fluid chamber 50 a, which is also proximate a periphery of diaphragm 44 a. Maintaining the swirl flow proximate a perimeter of diaphragm 44 a and fluid chamber 50 a facilitate flushing of fluid chamber 50 a, thereby reducing both the volume of solvent and the time required to flush fluid chamber 50 a.
The configuration of first fluid ports 38 a and 38 b and second fluid ports 40 a and 40 b provide significant advantages. Positioning first fluid port 38 a and second fluid port 40 a at oblique angles to inner surface 34 a and diaphragm 44 a encourages the rotational flow of solvent and promotes flushing of fluid chambers 50 a and 50 b, thereby reducing the material cost and the time cost associated with flushing pump 10. In addition, positioning both first fluid port 38 a and second fluid port 40 a proximate circumferential edge 42 a promotes the swirl flow at a periphery of fluid chamber 50 a. Promoting the swirl flow at the periphery of fluid chamber 50 a provides for quicker, more efficient flushing of fluid chamber 50 a. The swirl flow at the periphery of fluid chamber 50 a removes paint or other fluid disposed at the interface of diaphragm 44 a and fluid cover 14 a, which is traditionally the most difficult portion of fluid chamber 50 a to flush. Having a quicker, more efficient flush reduces both the volume of solvent required and the downtime required for flushing. Reducing the volume of solvent required reduces the material costs associated with pump 10 a. In addition, reducing the downtime required to clean pump 10 increases the return on investment for pump 10. Furthermore, fluid covers 14 a and 14 b being interchangeable provides a cost savings to the end user, as the end user requires a single replacement fluid cover in the event either fluid cover 14 a or fluid cover 14 b requires replacement.
FIG. 2 is an elevation view of a fluid cover 14 a. As discussed above, fluid cover 14 a and fluid cover 14 b are substantially similar. As such, fluid cover 14 a will be discussed in further detail, and the discussion of fluid cover 14 a applies to fluid cover 14 b as well. Fluid cover 14 a includes cover body 32 a, inner surface 34 a, first fluid port 38 a, second fluid port 40 a, first check housing 52 a, and second check housing 54 a. Inner surface 34 a includes circumferential edge 42 a. First fluid port 38 a includes first inner orifice 56 a, first outer orifice 58 a, and first flow path 60 a. Second fluid port 40 a includes second inner orifice 62 a, second outer orifice 64 a, and second flow path 66 a.
Cover body 32 a extends between inner surface 34 a and outer surface 36 a (shown in FIG. 1). Inner surface 34 a is preferably a concave surface while outer surface 36 a is preferably a convex surface. Point A is disposed at a center of inner surface 34 a, which is aligned along axis A-A (shown in FIG. 1). First check housing 52 a extends into cover body 32 and is configured to receive inlet check valve 22 a (shown in FIG. 1). Similar to first check housing 52 a, outlet check housing extends into cover body 32 a and is configured to receive outlet check valve 24 a (shown in FIG. 1).
First fluid port 38 a extends through cover body 32 a between first check housing 52 a and inner surface 34 a. First flow path 60 a extends between first outer orifice 58 a and first inner orifice 56 a. First outer orifice 58 a opens to first check housing 52 a, and first inner orifice 56 a opens through inner surface 34 a of fluid cover 14 a. First inner orifice 56 a is disposed proximate circumferential edge 42 a of inner surface 34 a at a radial distance R1 from point A.
Second fluid port 40 a extends through cover body 32 a between second check housing 54 a and inner surface 34 a. Second flow path 66 a extends between second outer orifice 64 a and second inner orifice 62 a. Second outer orifice 64 a is open to second check housing 54 a, and second inner orifice 62 a opens through inner surface 34 a of fluid cover 14 a. Similar to first inner orifice 56 a, second inner orifice 62 a is disposed proximate circumferential edge 42 a of inner surface 34 a. Second inner orifice 62 a is disposed at a radial distance R2 from point A. Radial distance R1 is approximately equal to radial distance R2, and both R1 and R2 are preferably greater than half of the radial distance between point A and circumferential edge 42 a. It is understood that first inner orifice 58 a and second inner orifice 62 a may be positioned at any desired location on inner surface 34 a to provide fluid to fluid chamber 50 a tangential to circumferential edge 42 a and at an oblique angle to inner surface 34 a. For example, first inner orifice 56 a may be disposed approximately adjacent second inner orifice 62 a, may be disposed opposite second inner orifice 62 a, or may be disposed at any other angle of displacement relative to second inner orifice 62 a.
During a first stroke of a pump, such as pump 10 (shown in FIG. 1), first fluid port 38 a provides fluid into a fluid chamber, such as fluid chamber 50 a (shown in FIG. 1), that is at least partially defined by fluid cover 14 a. First outer orifice 58 a is configured to receive a fluid provided through the check valve housed in first check housing 52 a. The fluid flows through first flow path 60 a and is provided into the fluid chamber through first inner orifice 56 a. First inner orifice 56 a is positioned on inner surface 34 a to introduce flow at an oblique angle to inner surface 34 a. The oblique angle imparts a swirl flow on the fluid entering the fluid chamber, shown by flow lines F. The oblique angle also prevents the fluid entering the fluid chamber through first inner orifice 56 a from impinging on inner surface 34 a. The swirl flow imparted on the fluid entering the fluid chamber encourages a constant flow velocity throughout the fluid chamber, and particularly at a periphery of inner surface 34 a, which facilitates the efficient removal of solids and other residue from the fluid chamber. In addition, directing the fluid exiting first inner orifice 56 a such that the fluid does not impinge on inner surface 34 a prevents the fluid from losing velocity, thereby aiding in the elimination of areas of low velocity or no velocity and preventing solids and other residue from settling within the fluid chamber.
After completing the first stroke, the pump transitions to a second stroke, in which the fluid is driven downstream from the fluid chamber. During the transition from the first stroke to the second stroke, the pump momentarily stops moving, such that the diaphragm is neither expanding nor contracting the volume of the fluid chamber. During the transition, the positioning of second inner orifice 62 a and first inner orifice 56 a ensure that the rotational flow of the fluid is maintained within the fluid chamber. Second inner orifice 62 a is positioned on inner surface 34 a at an oblique angle to inner surface 34 a, similar to first inner orifice 56 a. In addition, second inner orifice 62 a is positioned on inner surface 34 a at radial distance R2, which is approximately equal to radial distance R1, such that second inner orifice 62 a and first inner orifice 56 a are disposed at approximately the same radial distance from point A. Positioning first inner orifice 56 a and second inner orifice 62 a at approximately the same radial distance from point A ensures that the swirl flow imparted on the fluid by first inner orifice 56 a is maintained throughout the pump cycle.
During the second stroke, the diaphragm is driven into the fluid chamber, thereby reducing the volume of the fluid chamber and driving the fluid downstream through second fluid port 40 a and outlet check valve 24 a. The orientation of second inner orifice 62 a relative to inner surface 34 a facilitates the removal of fluid and any contaminants carried by the fluid from the fluid chamber. The orientation of second inner orifice 62 a also encourages the swirl flow to continue throughout the second stroke. Ensuring that the rotational flow continues throughout the pump cycle prevents solids from settling in the fluid chamber; as such, the position on first inner orifice 56 a and second inner orifice 62 a enhances the flow characteristics within the fluid chamber.
FIG. 3A is a side elevation view of fluid cover 14 a with first fluid port 38 a exposed. FIG. 3B is a perspective view of first fluid port 38 a. FIGS. 3A and 3B will be discussed together. Fluid cover 14 a includes cover body 32 a, inner surface 34 a, first fluid port 38 a, and second fluid port 40 a. Inner surface 34 a includes circumferential edge 42 a. First fluid port 38 a includes first inner orifice 56 a, first outer orifice 58 a, and first flow path 60 a. Second fluid port 40 a includes second inner orifice 62 a.
Cover body 32 a extends between inner surface 34 a and outer surface 36 a (shown in FIG. 1). Inner surface 34 a is preferably a concave surface while outer surface 36 a is preferably a convex surface. Inner surface 34 a partially defines fluid chamber 50 a. Fluid chamber 50 a is defined between inner surface 34 a and a fluid displacement member, such as diaphragm 44 a (shown in FIG. 1). Point A is disposed at a center of inner surface, which is aligned along axis A-A (shown in FIG. 1). First fluid port 38 a extends through cover body 32 a with first inner orifice 56 a extending through inner surface 34 a. Similar to first fluid port 38 a, outlet extends through cover body 32 a with second inner orifice extending through inner surface 34 a. First inner orifice 56 a is positioned at a radial distance R1 from point A, and second inner orifice 62 a is positioned at a radial distance R2 from point A. Radial distance R1 is preferably approximately equal to radial distance R2.
First fluid port 38 a provides a fluid to fluid chamber 50 a. First inner orifice 56 a is positioned to provide a flow of fluid into fluid chamber 50 a at an oblique angle to inner surface 34 a, such that a swirl flow is imparted to the fluid entering fluid chamber 50 a. First inner orifice 56 a is positioned proximate circumferential edge 42 a of inner surface 34 a. Positioning first inner orifice 56 a proximate circumferential edge 42 a encourages the swirl flow proximate circumferential edge 42 a. First inner orifice 56 a is thus positioned to purge any solids residing proximate circumferential edge 42 a. While the rotational flow facilitates the purge of fluid chamber 50 a, the rotational flow also actively prevents solids from settling anywhere within fluid chamber 50 a by ensuring that the fluid within fluid chamber 50 a is constantly flowing within fluid chamber 50 a throughout the entire pump cycle, regardless of whether the pump is pumping a fluid for application, such as a paint, or a cleaning fluid, such as a solvent.
Similar to first inner orifice 56 a, second inner orifice 62 a positioned at an oblique angle to inner surface 34 a. Second inner orifice 62 a is configured such that the swirl flow of the fluid in fluid chamber 50 a is maintained throughout the pump cycle. In addition, second inner orifice 62 a is disposed on inner surface 34 a at radial distance R2, which is preferably approximately equal to radial distance R1. Positioning first inner orifice 56 a and second inner orifice 62 a at approximately equal radial distances from point A encourages the rotational flow of the fluid in fluid chamber 50 a throughout the pump cycle, such that no areas of low velocity or no velocity form within fluid chamber 50 a. For example, unlike an outlet orifice aligned with axis A-A of pump shaft 28 (shown in FIG. 1), which would cause a drop in flow velocity thereby producing undesirable flow characteristics and areas of low flow velocity, positioning the second inner orifice 62 a an oblique angle proximate circumferential edge 42 a of inner surface 34 a promotes swirl flow and ensures that the flow has desirable characteristics, including the elimination of areas of low flow velocity or no flow velocity.
In FIG. 3B, first fluid port 38 a is shown separated from fluid cover 14 a. As discussed above, second fluid port 40 a is preferably a mirror-image of first fluid port 38 a. As such, while the discussion of FIG. 3B is directed towards first fluid port 38 a, it is understood that the discussion of first fluid port 38 a is equally applicable to second fluid port 40. First fluid port 38 includes first flow path 60 a extending between first inner orifice 56 a and first outer orifice 58 a. First outer orifice 58 a is configured to receive a fluid and provide the fluid to first flow path 60 a. First inner orifice 56 a is configured to receive the fluid from first flow path 60 a and to provide the fluid into fluid chamber 50 a.
First inner orifice 56 a is configured to impart a rotational flow to the fluid exiting first inner orifice 56 a into fluid chamber 50 a. First flow path 60 a extends between first outer orifice 58 a and first inner orifice 56 a and enhances the flow characteristics of the fluid entering fluid chamber 50 a by imparting swirl to the flow of the fluid entering fluid chamber 50 a. First flow path 60 a may extend helically between first inner orifice 56 a and first outer orifice 58 a, such that first flow path 60 a may impart additional rotational flow to the fluid. It is understood, however, that first flow path 60 a may take any suitable configuration for supplying fluid between first outer orifice 58 a and first inner orifice 56 a, such as a direct path, a curved path, or any other desired configuration. First fluid port 38 a and second fluid port 40 a produce significant advantages. First fluid port 38 a introduces fluid to the fluid chamber 50 a in a manner that produces rotational movement of the fluid within fluid chamber 50 a. The swirl flow of the fluid within fluid chamber 50 a enhances cleaning of the pump when a solvent or other cleaning solution is pumped through fluid chamber 50 a. As stated above, second fluid port 40 a is preferably a mirror-image of first fluid port 38 a. Second fluid port 40 a similarly enhances the cleaning of the pump as the orientation of second fluid port 40 a encourages swirl flow throughout the pump cycle.
The orientation and positioning of first fluid port 38 a and second fluid port 40 a enhances the flow of fluid through fluid chamber 50 a, thereby enhancing residue removal from fluid chamber 50 a. First fluid port 38 a and second fluid port 40 a ensure a constant, fast fluid velocity throughout fluid chamber 50 a. In addition, first fluid port 38 a and second fluid port 40 a promote flow at a perimeter of inner surface 34 a, thereby enhancing flushing of the perimeter, which is typically the most difficult portion of fluid chamber 50 a to flush. The oblique angle of first inner orifice 56 a promotes swirling of the fluid within fluid chamber 50 a and prevents the fluid from striking inner surface 34 a, which would cause the fluid velocity to slow. The oblique angle of second inner orifice 62 further promotes swirling by encouraging the rotational flow throughout the pump cycle, including the first stroke, the transition, and the second stroke.
By introducing a swirl flow to fluid chamber 50 a, and by maintaining the swirl flow throughout the pump cycle, first fluid port 38 a and second fluid port 40 a reduce the volume of flushing material required to flush fluid chamber 50 a and provide for faster flush time. Using less flushing material reduces the material cost associated with flushing the fluid chamber. The faster flush time decreases the downtime of pump required for flushing, allowing for more efficient, effective use of the pump.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

1. A pump comprising:

a pump drive system;

a first fluid displacement member disposed at a first end of the pump drive system;

a first fluid cover attached to a first end of the pump drive system, wherein the first fluid displacement member is secured between the pump drive system and the first fluid cover, wherein the first fluid cover comprises:

a first cover body defined by a first inner wall and a first outer wall, wherein the first inner wall and the first fluid displacement member define a first fluid chamber;

a first fluid port extending through the first cover body, wherein the first fluid port includes a first inner orifice extending through the first inner wall, wherein the first fluid port is configured to direct a flow through the first inner orifice and into the first fluid chamber at a first oblique angle to the inner wall; and

a second fluid port extending through the first cover body, wherein the second fluid port includes a second inner orifice extending through the first inner wall and configured to direct a flow through the second inner orifice at a second oblique angle to the first inner wall; and

wherein the first inner orifice is disposed a first radial distance from a center of the first inner wall and the second inner orifice is disposed at a second radial distance from the center;

an inlet manifold attached to the first fluid cover and configured to provide a fluid to the first fluid chamber through the first inlet; and

an outlet manifold attached to the first fluid cover and configured to receive the fluid from the fluid chamber through the first outlet.

2. The pump of claim 1, wherein the first fluid port further comprises:

a first outer orifice configured to receive the pumped fluid from the inlet manifold; and

a first flow path extending from the first outer orifice to the first inner orifice.

3. The pump of claim 2, wherein the second fluid port further comprises:

a second outer orifice configured to provide the pumped fluid to the outlet manifold; and

a second flow path extending from the second outer orifice to the second inner orifice.

4. The pump of claim 1, wherein the first radial distance is approximately equal to the second radial distance.

5. The pump of claim 1, wherein the first inner orifice is disposed proximate a circumferential edge of the inner wall, and the second outer orifice is disposed proximate the circumferential edge of the inner wall.

6. The pump of claim 5, wherein the first inner orifice is a mirror-image of the second inner orifice.

7. The pump of claim 6, wherein the first fluid port is a mirror-image of the second fluid port.

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

a second fluid displacement member disposed at a second end of the pump drive system; and

a second fluid cover attached to a second end of the pump drive system, wherein the second fluid displacement member is secured between the second fluid cover and the second end of the pump drive system, wherein the second fluid cover comprises:

a second cover body defined by a second inner wall and a second outer wall, wherein the second inner wall and the second fluid displacement member define a second fluid chamber;

a third fluid port extending through the second cover body, wherein the third fluid port includes a third inner orifice extending through the second inner wall and configured to direct the pumped fluid into the second fluid chamber through the third inner orifice at a third oblique angle to the inner wall; and

a fourth fluid port extending though the second cover body, wherein the fourth fluid port includes a fourth inner orifice extending through the second inner wall and positioned to direct a flow through the fourth inner orifice at a fourth oblique angle to the second; and

wherein the third inner orifice is disposed at a third radial distance from a center of the second inner wall, and the fourth inner orifice is disposed at a fourth radial distance from the center.

9. The pump of claim 8, and wherein:

the first fluid displacement member comprises a first diaphragm; and

the second fluid displacement member comprises a second diaphragm.

10. A fluid cover for a pump, the fluid cover comprising:

a cover body extending between a convex outer wall and a concave inner wall;

a first fluid port extending through the body, wherein the first fluid port comprises:

a first outer orifice;

a first inner orifice extending through the concave inner wall; and

a first flow path extending between the first outer orifice and the first inner orifice;

wherein the first inner orifice is positioned on the concave inner wall such that a pumped fluid is directed through the first inner orifice at a first oblique angle to the concave inner wall;

an second fluid port extending through the body and disposed opposite the first fluid port, wherein the second fluid port comprises:

a second inner orifice extending through the concave inner wall;

a second outer orifice; and

a second flow path extending between the second outer orifice and the second inner orifice;

wherein the second inner orifice is positioned on the concave inner wall such that a pumped fluid is directed through the second inner orifice at a second oblique angle to the concave inner wall.

11. The fluid cover of claim 10, wherein the first inner orifice is disposed a first radial distance from a center of the concave inner wall, and wherein the second inner orifice is disposed a second radial distance from the center of the concave inner wall.

12. The fluid cover of claim 11, wherein the first radial distance is approximately equal to the second radial distance.

13. The fluid cover of claim 10, wherein the first inner orifice is disposed proximate a circumferential edge of the concave inner wall, and wherein the second inner orifice is disposed proximate the circumferential edge of the concave inner wall.

14. The fluid cover of claim 13, wherein the first inner orifice is a mirror-image of the second inner orifice.

15. A method of flushing a fluid chamber, the method comprising:

drawing a fluid into a fluid chamber defined between a fluid cover and a fluid displacement member through a first inner orifice, wherein the first inner orifice is positioned to provide the fluid to the fluid chamber at a first oblique angle relative to an inner wall of the fluid cover, thereby imparting a rotational movement to the fluid entering the fluid chamber; and

driving the fluid out of the fluid chamber through an second inner orifice positioned to receive the fluid circulating within the fluid chamber, wherein the second inner orifice is positioned on the inner wall to direct the fluid at a second oblique angle relative to the inner wall.

16. The method of claim 15, wherein the fluid displacement member comprises a diaphragm.

17. The method of claim 15, wherein the first inner orifice is disposed proximate a circumferential edge of the inner wall, and the second inner orifice is disposed proximate a circumferential edge of the inner wall.

18. The method of claim 17, wherein the first inner orifice is configured to provide the fluid to the first fluid chamber tangentially to a circumferential edge of the fluid chamber.

19. The method of claim 15, wherein the first inner orifice is disposed at a first radial distance from a center of the inner wall, and the second inner orifice is disposed at a second radial distance from the center of the inner wall.

20. The method of claim 15, and wherein the first oblique angle is positioned such that the pumped fluid entering the fluid chamber through the first inner orifice does not impinge on the inner wall or the fluid displacement member.