Pressure differential pumps

Abstract

Embodiments of the present disclosure relate generally to pumps and systems that use a differential pressure gradient to transfer fluids. In one example, the pumps may use available differential pressure that exists due to outside pressure and cabin pressure due to altitude on-board a vehicle such as an aircraft.

What is claimed is: 
     
         1 . A pump system configured to use differential pressure, comprising:
 a pump body comprising at least one vacuum/air inlet, at least one fluid inlet, at least one fluid outlet, a reservoir configured for containing a fluid, and a vacuum control member for controlling application of vacuum to the reservoir;   at least one piston element housed within the pump body, the at least one piston element configured to move in response to a pressure differential created by application or removal of vacuum to the reservoir through the at least one vacuum/air inlet.   
     
     
         2 . The system of  claim 1 , wherein the at least one piston is moved via a vacuum created, via a spring, via magnetic force, or any combination thereof. 
     
     
         3 . The system of  claim 1 , wherein the at least one piston is comprised of one or more shape memory alloys. 
     
     
         4 . The system of  claim 1 , wherein the at least one piston comprises a hydraulic cylinder. 
     
     
         5 . The system of  claim 1 , wherein the at least one piston comprises a spring piston under compression when vacuum is applied. 
     
     
         6 . The system of  claim 1 , wherein the at least one piston is configured to contract upon application of vacuum to the at least one vacuum inlet as fluid is pulled into the reservoir via the at least one fluid inlet. 
     
     
         7 . The system of  claim 6 , wherein the at least one piston is configured to extend upon removal of vacuum to push the fluid out of the reservoir, through the at least one fluid outlet. 
     
     
         8 . The system of  claim 1 , wherein the at least one piston comprises a piston head and a piston yoke, and further comprising a sleeve around the piston yoke. 
     
     
         9 . The system of  claim 1 , further comprising one or more piston seals maintained via a low-friction sleeve. 
     
     
         10 . The system of  claim 1 , wherein the at least one piston is guided via internal rails. 
     
     
         11 . The system of  claim 1 , further comprising a first valve at the at least one inlet, a second valve at the at least one outlet, and a third valve at the vacuum control member. 
     
     
         12 . The system of  claim 1 , wherein the at least one piston comprises two pistons that extend into the reservoir to force fluid out through the outlet. 
     
     
         13 . The system of  claim 12 , wherein the two pistons are timed for multi-stroke action. 
     
     
         14 . The system of  claim 1 , wherein the at least one piston is physically isolated from pumped fluids. 
     
     
         15 . The system of  claim 1 , wherein the pump body is comprised of a high-density plastic polymer. 
     
     
         16 . The system of  claim 1 , wherein the at least one vacuum/air inlet comprises a first vacuum inlet and a second vent air inlet. 
     
     
         17 . A method of using differential pressure to move fluid through a pump system, comprising:
 providing a pump body comprising a vacuum inlet, a fluid inlet, an outlet, a vacuum control member, and a reservoir configured for containing a fluid;   at least one piston housed within the pump body, the at least one piston configured to move in response to a pressure differential;   applying a first pressure to the vacuum inlet to create a first movement of the piston and to cause fluid to enter the reservoir through the at least one fluid inlet;   venting the first pressure through the vacuum control member to create a second movement of the at least one piston, forcing fluid out the outlet.   
     
     
         18 . The method of  claim 17 , wherein the at least one piston comprises a spring, and wherein the first movement comprises compression of the spring, and wherein the second movement comprises expansion of the spring. 
     
     
         19 . The method of  claim 17 , further comprising a first valve at the inlet, a second valve at the outlet, and a third valve at the vacuum control member, and further comprising causing fluid to enter the reservoir by opening the first valve when the second valve is closed; and opening the third valve to vacuum. 
     
     
         20 . The method of  claim 17 , further comprising a first valve at the inlet, a second valve at the outlet, and a third valve at the vacuum control member, and further comprising causing fluid to exit the reservoir by closing the first valve when the second valve is opened; and opening the third valve to vent. 
     
     
         21 . The method of  claim 17 , wherein the at least one tension-compression element comprises two pistons that extend into the reservoir to force fluid out through the outlet.