Abstract: A flexible diaphragm coupling is disclosed which includes a radially inner hub portion, a radially outer rim portion, and a flexible diaphragm portion extending between the radially outer rim portion and the radially inner hub portion. The flexible diaphragm portion includes a radially inner diaphragm section having a maximum axial thickness adjacent the radially inner hub portion and a radially outwardly tapering axial thickness extending to a point of minimum axial thickness of the diaphragm portion, and a radially outer diaphragm section having a maximum axial thickness adjacent the radially outer rim portion and a radially inwardly tapering axial thickness extending to the point of minimum axial thickness of the diaphragm portion. By design, the point of minimum axial thickness of the diaphragm portion is closer to the radially outer rim portion than to the radially inner hub portion.

Abstract: A flexible diaphragm coupling is disclosed which includes a radially inner hub portion, a radially outer rim portion, and a flexible diaphragm portion extending between the radially outer rim portion and the radially inner hub portion. The flexible diaphragm portion includes a radially inner diaphragm section having a maximum axial thickness adjacent the radially inner hub portion and a radially outwardly tapering axial thickness extending to a point of minimum axial thickness of the diaphragm portion, and a radially outer diaphragm section having a maximum axial thickness adjacent the radially outer rim portion and a radially inwardly tapering axial thickness extending to the point of minimum axial thickness of the diaphragm portion. By design, the point of minimum axial thickness of the diaphragm portion is closer to the radially outer rim portion than to the radially inner hub portion.

Abstract: A variable displacement piston pump includes a plurality of axially aligned pumping cylinders with a drive shaft extending therebetween having a pivotable swash plate disposed in a relatively dry cavity at one end of the drive shaft for operating the pumping cylinders, and a reaction thrust plate on the other end of the drive shaft for providing a reaction force on the drive shaft opposite that provided by the swash plate. An inlet shaft seal prevents fluid, which enters the pump at the inlet port, from filling the mounting housing and submerging the mount shaft portion of a rotating assembly supporting the swash plate. Two needle roller bearings support the swash plate and transmit torque from the drive coupling to the swash plate. A high pressure fluid restrictor meters hydraulic control fluid to the two needle bearings.