Rotary piston combustion engine with oil-cooled piston

Claim 1

A rotary piston combustion engine comprising: a housing, a shaft mounted in the housing, shaft bearings interposed between the shaft and the housing, an eccentric on the shaft, a rotary piston carried by the eccentric, a piston bearing interposed between the eccentric and the piston, the piston including hollow spaces through which a coolant flows to cool the piston, a first oil circulating system for lubricating the shaft and piston bearings, the first system including first passages for conducting lubricating oil to the bearings, a first pump for pumping lubricating oil from a source through the first passages to the bearings, said first pump having a capacity to deliver oil in small volume and at a high pressure, a second independent oil circulating system for directing an oil coolant to the piston, the second system including second passages for conducting the coolant to the piston hollow spaces to cool the piston, a second pump for pumping the coolant from a source through the second passages to the piston hollow spaces, said second pump having a capacity to deliver the coolant in large volume and at low pressure, a return passage for receiving and directing the coolant from the piston hollow spaces, a valve in one of the second passages and being adapted to be shifted to an adjusted position to regulate the amount of coolant passing through the second passages, a condition responsive control means coupled with the valve for shifting the valve to an adjusted position for adjusting the amount of coolant passing through the second passages into the piston hollow spaces to thereby permit throttling the amount of coolant passing into the piston hollow spaces, and the condition responsive means being coupled with the return passage for sensing temperature of the coolant in the return passage for adjusting the valve.