Sealed and pressure balanced oil lubricating system

Abstract From the Canadian patent

A sealed and pressure balanced lubricating system for high pressure rotary equipment includes a housing with a bore divided by a slidable piston into a lubricant chamber and a gas chamber. The gas chamber communicates with an area of the equipment which is exposed to high gas pressure and the lubricant chamber communicates with bearings within the equipment. During operation gas pressure forces the piston against the lubricant to pressure feed the bearings. A relief valve in the piston is opened, after the equipment stops and the pressure therein returns to atmospheric in the event that, pressurized gas has become entrained in the lubricant due to leakage past shaft seals. Such gas forces …