Stress limiting diaphragm for diaphragm and bellows pumps and actuators

The diaphragm profile 10 is defined by a computer generated compound radius 10d beginning at 10f and ending at 10g. The compound radius is generally governed by the equation: ( t 2 ) R = E where, t=Diaphragm Thickness R=Radius of Curvature of Diaphragm Profile =Stress from Flexure of Radius "R" E=Modulus of Elasticity The profile limits diaphragm stresses to a prescribed and controlled level dictated by the initial formed profile of the diaphragm. As the bellows compresses, the gaps between adjacent diaphragm spans begin to close, thereby supporting the diaphragm and limiting further increases in stress. The remaining and shortened free span of each diaphragm is able to withstand the elevated pressures achieved during the compression process, ultimately offering a stable structure to the increase in loading. A lubricious wear strip 11 is used to protect the diaphragm from undesired wear that could result from metal to metal contact between the diaphragms. A wear strip offset 13 accommodates the placement of the strip. The close spacing facilitated by the offset maintains a clearance given by Item 12 when the diaphragm is fully compressed, resulting in higher compression ratios where compressible fluids are pumped, and higher flow efficiencies where incompressible fluids are pumped.