Three element diaphragm damper for fuel pump

A pressure damper assembly for a fuel inlet passage in a single piston high pressure fuel pump, comprising:

• an inlet fitting;
• a cover attached to the fitting and having a substantially cylindrical sidewall defining an internal damping chamber in fluid communication with the fuel inlet passage of the pump, and a bottom sealingly attached to the pump;
• a pair of upper and lower diaphragm assemblies supported within the damping chamber by a retainer assembly wherein
• each said diaphragm assembly includes first and second metal diaphragms having diaphragm rims sealingly secured to respective first and second sides of an imperforate central plate and convex central regions spaced from the central plate, thereby defining first and second independent closed gas volumes radially inward of a surrounding diaphragm assembly periphery;
• said retainer assembly includes a distinct first retainer having a portion that bears on and biases the periphery of the upper diaphragm assembly, a distinct second retainer having a portion that bears on and biases the periphery of the lower diaphragm assembly, a distinct spacer between the first and second retainers, having a portion that bears on the periphery of the upper diaphragm assembly in opposition to the first retainer and another portion that bears on the periphery of the lower diaphragm assembly in opposition to the second retainer, with each of the first and second retainers including tabs that engage the spacer, said tabs being situated in slots in the spacer;
• whereby feed fuel delivered to the pump through the inlet fitting flows through said damping chamber at a pressure that acts on the first and second diaphragms of each diaphragm assembly before entry into the inlet passage of the pump.