DIAPHRAGM CARTRIDGE AND PUMP HAVING A DIAPHRAGM CARTRIDGE
A diaphragm pump includes a diaphragm cartridge assembly. The diaphragm cartridge is a self-contained unit having a diaphragm defining a pumped fluid side and a hydraulic fluid side and a seat receiving the hydraulic fluid side of the diaphragm and having a center opening. A biasing rod mounts to the diaphragm on the hydraulic fluid side and extending through the opening of the seat. A valve guide at an extended end of the biasing rod and a valve spool slidably mounts on the valve guide. A biasing element engages the seat and the valve guide. The pump may also include valve cartridges including a combined inlet check valve and discharge check valve.
1. Field of the Invention
The present invention is related to a diaphragm pump and in particular to a hydraulically driven diaphragm pump with a removable self-contained diaphragm cartridge.
2. Description of the Prior Art
Diaphragm pumps are hydraulically driven pumps in which the pump fluid is displaced by a diaphragm that is deflected by hydraulic fluid pressure. Such pumps provide good value and efficiency while being reliable. Such diaphragm pumps utilize a valve system that controls the volume of oil on the hydraulic side of the diaphragm. Such systems are shown for example in U.S. Pat. No. 7,425,120 to Hembree and assigned to Wanner Engineering, Inc. The valve system of the diaphragm pump is configured with the center of the diaphragm attached to a rod, generally referred to as a bias rod that actuates a valve spool and also provides attachment for a spring that applies a biasing force to the diaphragm.
Although such pump systems provide good performance and reliability, further improvements are possible. Diaphragm pumps need to be serviced periodically and in pumps with such valve systems, the diaphragm must be detached from the rod to gain access to the valve components and other pump components. The spring of such a valve system must be supported or attached to a non-moving surface behind the diaphragm and requires further disassembly and assembly to remove the diaphragm. Therefore, if the diaphragm must be replaced, it also requires removal of the rod attachment. In such a pump, the diaphragm must be pulled forward to detach the diaphragm from the bias rod in order to gain access to the rod. Moreover, if the spool valve and bias rod assembly are removed, the plate behind the diaphragm must also be removed. Other known designs require a fastener that passes through the diaphragm but which still requires access to the rod behind the diaphragm so that it can be held while the fastener is unscrewed. All of these configurations require removal and disassembly of multiple components for servicing and may raise difficulties in accessing and/or gripping the components to remove them. The assembly and disassembly of the components is compounded by having a tensioned spring that must be attached and detached and may be propelled from the assembly or could propel other components from the pump or diaphragm, thereby raising the possibility that parts may be lost.
Therefore, it can be seen that a new and improved diaphragm pump with a diaphragm cartridge is needed that allows a simpler system for removing the diaphragm and valve without detaching the diaphragm from the rod. Moreover, such a diaphragm pump and valve system should avoid having to disassemble the pump further than removal of the fluid head to gain access to the diaphragm. The present invention addresses these as well as other problems associated with diaphragm pumps and valve systems.
SUMMARY OF THE INVENTIONThe present invention is directed to a diaphragm pump having a self-contained removable diaphragm cartridge. The diaphragm cartridge may be removed as an assembly and serviced or simply replaced with another diaphragm cartridge. Removal of the diaphragm cartridge does not require removal of other elements and also does not require special tools for manipulating the diaphragm. The diaphragm cartridge includes a diaphragm connected to a bias rod, which is connected to a valve guide. A valve spool slides within a decreased thickness section of the valve guide and moves between shoulders at opposite ends of the narrowed section. The valve spool moves to open or close an overfill valve and an underfill valve. Under normal operating conditions, the valve spool covers both the overfill valve and the underfill valve.
The diaphragm and bias rod are held against the diaphragm seat by a spring. The diaphragm cartridge is properly oriented by an alignment pin to ensure that a passage at the top of the diaphragm aligns with an air bleed line. The diaphragm deflects in a reciprocating motion between a forward position at top dead center and a retracted position to provide a fluid pumping action. The diaphragm cartridge is positioned between a hydraulic plate and a leak detection plate in one embodiment with the leak detection plate clamped between a manifold and a hydraulic plate.
The diaphragm cartridge includes the self contained assembly with the diaphragm, bias rod, valve guide, valve spool, diaphragm seat and springs. Therefore, the entire cartridge may be removed without any disassembly of the various elements of the cartridge. Moreover, the diaphragm cartridge avoids use of a spring attachment or separate valve that requires connection to a hydraulic plate. The diaphragm seat may be easily accessed and engaged so that the cartridge does not require access behind the diaphragm and special tools as is typically required with prior art designs. A further advantages is that the hydraulic plate may be left in place and therefore oil may be left in the crankcase when changing or servicing diaphragms.
According to a further aspect of the invention, check valve cartridges may also be employed in conjunction with a diaphragm cartridge. Multiple check valve cartridges may be used in a single pump with each diaphragm having an associated check valve cartridge. Each check valve cartridge is configured as a combination inlet check valve and discharge check valve. As with the diaphragm cartridge, the check valve cartridge is a completely self-contained assembly and configured and accessed so that no additional elements need to be removed in order to service and access the inlet check valve and/or the discharge check valve.
The present invention provides a system that is more reliable, easier and much simpler for access and maintenance, especially when performing maintenance in the field that is not possible with prior art diaphragm pumps that require disassembly of the multiple various elements by using a system configured with cartridges.
These features of novelty and various other advantages that characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof. However, for a better understanding of the invention, its advantages, and the objects obtained by its use, reference should be made to the drawings that form a further part hereof, and to the accompanying descriptive matter, in which there is illustrated and described a preferred embodiment of the invention.
Referring now to the drawings, wherein like reference letters and numerals indicate corresponding structure throughout the several views:
Referring now to the drawings and in particular to
Referring now to
The manifold (26) houses inlet and discharge check valves. In one embodiment, the pump (20) includes a combined inlet valve and discharge check valve assemblies, which as explained hereinafter, may be configured as a check valve cartridge (100) including an inlet check valve (102) and a discharge check valve (104) for each of the diaphragms (52). The check valves and provide for suction and discharge of the pump fluid into the inlet passage (146) and out through the outlet passage (148).
Referring now to
The diaphragm (52) and bias rod (54) are held against a diaphragm seat (62) by a spring (64). The diaphragm seat (62) defines a center opening for the bias rod (54) and includes a passage (66) located at the top of the diaphragm (52). The passage (66) therefore acts to vent air so that any air trapped at the top of the diaphragm chamber is vented and leaves the system through an air bleed (78) as shown in
In one embodiment, a pin (68) is utilized to properly orient the diaphragm cartridge (50) with the passage (66) located at the top of the diaphragm (52) when the cartridge (50) is inserted in the pump (20). The diaphragm cartridge (50) is shown positioned with the diaphragm (52) at an extended position in
The diaphragm cartridge (50) is clamped between a hydraulic plate (80) and a leak detection plate (82), as shown in
In one embodiment of the present invention, the pump (20) includes one or more check valve cartridges, generally designated (100) mounting in the manifold (26) as shown in
Referring now to
Between the valves (102) and (104), the center housing (120) forms a passage (122) connecting to the pumping chamber passage (152) formed in the manifold (26). The center housing (120) forms a seat (128) receiving an 0-ring type gasket (150) and the cylindrical insert (138) holding the gasket in place. The discharge valve ball (126) engages the gasket (150) when the discharge check valve (104) is in the closed position. The pin (132) connects the center housing (120) to the upper housing (130) and acts as a travel limiter for the discharge valve ball (126).
The upper housing (130) includes the hex top (106) or other shape allowing engagement with a conventional wrench, socket or similar tool that allows for applying the tool to turn the cartridge (100). The upper housing (130) also includes a threaded portion (134) mating with complementary threads (142) of the manifold (26) to secure the cartridge (100). Such a configuration provides for easy and simple removal and interchanging of the entire check valve cartridge (100) with conventional tools if maintenance or replacement is required. The upper housing (130) also forms an orifice (136) that aligns with the outlet passage (56) formed in the manifold (26).
The check valve cartridge (100) includes both the inlet check valve (102) and discharge check valve (104) that are automatically actuated by the pumping action of the diaphragm (52). During the suction portion of the diaphragm stroke, the valve ball (116) and the valve ball (126) are positioned as shown in
During this portion of the pumping stroke of the diaphragm (52), the discharge valve ball (126) remains in engagement with the discharge check valve seat (128) and the gasket (150). This configuration prevents pumped fluid from being drawn back in by the diaphragm (52).
Referring now to
During the pumping portion of the stroke of the diaphragm (52), the inlet check valve (102) is closed with the inlet valve ball (116) engaging the inlet valve seat (114) and its respective gasket (150).
It can be seen that the check valve cartridge (100) provides a simple and reliable operation with only the valve balls (116, 126) moving and having geometry that automatically limits the travel of each of the valve balls (116) and (126) in response to pressure changes from the suction or discharge stroke of the pump (20). The entire cartridge (100) can be removed and replaced or removed and serviced or maintained by simply unscrewing the cartridge (100) with a conventional wrench or socket. Moreover, the cartridge (100) is a completely self-contained assembly and configured and accessed so that no additional elements need to be removed in order to service and access the inlet check valve (102) and/or the discharge check valve (104).
In operation, the crankshaft (36) rotates to cause the piston or plunger (42) to reciprocate. Hydraulic oil in the hydraulic chamber (30) is forced against the diaphragm (52) to cause the diaphragm to reciprocate and provide pumping action. The deflection of the diaphragm (52) to extend and then retract suctions and discharges the pumped fluid.
The diaphragm cartridge (50) includes the diaphragm (52), the bias rod (54), the valve guide (56), the valve spool (60), the diaphragm seat (62) and the springs (64) all in a self-contained assembly. Therefore, the entire diaphragm cartridge (50) may be removed as a single unit without being disassembled. There is no spring attachment or separate valve that requires connection to a hydraulic plate (50). Moreover, the cartridge (50) can be removed without requiring access to the area behind the diaphragm or removal of other pump elements. Therefore the hydraulic plate (80) can be left in place and the crankcase (22) can be left full of oil when changing diaphragms or providing other maintenance or service to the diaphragm cartridge assembly (50). Moreover, the check valve cartridge (100) is a completely self-contained assembly and configured and accessed so that no additional elements need to be removed in order to service and access the inlet check valve (102) and/or the discharge check valve (104). This configuration is much simpler and achieves less time consuming maintenance that eliminates the possibility of losing small parts under the biasing force of a spring as may occur when providing service or maintenance of the prior art diaphragm pumps.
It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.
Claims
1. A diaphragm pump comprising:
- a diaphragm cartridge assembly; a diaphragm defining a pumped fluid side and a hydraulic fluid side; a seat receiving the hydraulic fluid side of the diaphragm and having a center opening; a biasing rod mounted to the diaphragm on the hydraulic fluid side and extending through the opening of the seat; a valve guide at an extended end of the biasing rod; a valve spool slidably mounted on the valve guide;
- a biasing element engaging the seat and the valve guide.
2. A diaphragm pump according to claim 1, further comprising an air bleed line at an upper portion of the seat in fluid communication with the hydraulic fluid side.
3. A diaphragm pump according to claim 2, further comprising an air bleed device on the diaphragm assembly to facilitate air removal through the air bleed line.
4. A diaphragm pump according to claim 1, further comprising an alignment element.
5. A diaphragm pump according to claim 3, further comprising an alignment element on the diaphragm assembly to align the air bleed device with the air bleed line.
6. A diaphragm pump according to claim 1, wherein the pump comprises a plurality of the diaphragm cartridge assemblies.
7. A diaphragm pump according to claim 1, wherein the pump comprises a crankshaft driving a plunger impelling hydraulic fluid against the diaphragm.
8. A diaphragm pump according to claim 1, further comprising a leak detection system.
9. A diaphragm pump according to claim 1, further comprising a check valve cartridge including an inlet check valve and an outlet check valve.
10. A diaphragm pump according to claim 10, further comprising a manifold including an inlet and an outlet.
11. A diaphragm pump according to claim 1, comprising a plurality of diaphragm cartridge assemblies and a manifold including an inlet and an outlet. wherein the manifold includes a of check valve cartridges.
12. A diaphragm pump according to claim 11, wherein the manifold includes a plurality of check valve cartridges including an inlet check valve and an outlet check valve.
13. A diaphragm pump according to claim 12, wherein each of the plurality of diaphragm cartridge assemblies is in fluid communication with an associated one of the plurality of check valve cartridges.
14. A diaphragm pump according to claim 1, wherein the pump comprises a crankshaft driving a plurality of plungers impelling hydraulic fluid against an associated diaphragm of the plurality of diaphragm cartridge assemblies.
15. A diaphragm cartridge assembly for a diaphragm pump comprising:
- a diaphragm defining a pumped fluid side and a hydraulic fluid side;
- a seat receiving the hydraulic fluid side of the diaphragm and a center opening;
- a biasing rod mounted to the diaphragm on the hydraulic fluid side and extending through the center opening of the seat;
- a valve guide at an extended end of the biasing rod;
- a valve spool slidably mounted on the valve guide;
- a biasing element engaging the seat and the valve guide.
16. A diaphragm cartridge assembly according to claim 15, wherein the diaphragm cartridge assembly is a self-contained removable cartridge.
17. A diaphragm cartridge assembly according to claim 15, further comprising an air bleed line at an upper portion of the seat.
18. A diaphragm cartridge assembly according to claim 15, further comprising an alignment element.
Type: Application
Filed: Oct 31, 2014
Publication Date: Apr 30, 2015
Inventor: Richard D. Hembree (Port Coquitlam)
Application Number: 14/529,966
International Classification: F04B 43/073 (20060101); F04B 43/067 (20060101);