Damping device and method

Abstract

The method and device of the present invention reduces the pulsation of fluid from a pump. The damping device and method works on either the positive pressure or negative pressure side of the pump. Under positive pressure the device is attached downstream from the outlet port of a pump, the device having an input port in fluidic communication with the outlet port of the pump, an outlet port, an outer wall with an opening, and a membrane covering the opening, the outer wall of the device and the membrane forming a contained volume. As fluid from the outlet port of the pump passes into the device, it enters the contained volume which expands and contracts, thereby vitiating the pulsations in the fluid flow downstream of the device. Alternatively, under negative pressure the device is attached upstream from the inlet port of a pump.

I claim: 
     
         1 . A device comprising:
 an outer casing with an opening in an exterior wall, wherein said opening is covered by a membrane, said membrane and said outer casing creating a constrained volume, wherein said membrane is configured to expand when pressure inside said constrained volume is greater than pressure outside said constrained volume and to retract when pressure outside said constrained volume is greater than pressure inside said constrained volume;   an inlet port configured to allow fluid into said constrained volume; and   an outlet port configured to allow fluid out of said constrained volume.   
     
     
         2 . The device of  claim 1 , further comprising a restrictive orifice downstream of said outlet port. 
     
     
         3 . The device of  claim 1 , wherein said membrane is natural rubber. 
     
     
         4 . The device of  claim 1 , wherein said membrane is latex. 
     
     
         5 . The device of  claim 1 , wherein said membrane is silicone. 
     
     
         6 . A method of damping fluid pulsations from the outlet port of a pump comprising:
 passing fluid through an inlet port into a contained volume, said contained volume created by an outer casing with an opening in an exterior wall and a membrane covering said opening;   configuring said membrane such that it protrudes beyond said exterior wall when pressure of said fluid inside said contained volume is greater than pressure outside said contained volume and recedes into said contained volume when pressure outside said contained volume exceeds pressure of said fluid inside said contained volume; and   thereafter passing said fluid through an outlet port.   
     
     
         7 . The method of  claim 6 , further comprising passing said fluid through a restrictive orifice downstream of said outlet port. 
     
     
         8 . The method of  claim 6 , wherein said membrane is natural rubber. 
     
     
         9 . The method of  claim 6 , wherein said membrane is latex. 
     
     
         10 . The method of  claim 6 , wherein said membrane is silicone. 
     
     
         11 . A device damping fluid pulsations from the outlet port of a pump comprising:
 means for containing fluid with an opening in an exterior wall, wherein said opening is covered by a membrane, said membrane and said means for containing fluid creating a constrained volume;   means for allowing fluid into said constrained volume;   means for allowing fluid out of said constrained volume; and   wherein said membrane is configured to expand when pressure inside said constrained volume is greater than pressure outside said constrained volume and to retract when pressure outside said constrained volume is greater than pressure inside said constrained volume.   
     
     
         12 . The device of  claim 11 , further comprising means for restricting flow of said fluid into said inlet port. 
     
     
         13 . The device of  claim 11 , wherein said membrane is natural rubber. 
     
     
         14 . The device of  claim 11 , wherein said membrane is latex. 
     
     
         15 . The device of  claim 11 , wherein said membrane is silicone.