VARMGASMOTOR

A multi-cylinder self-starting hot gas engine according to the present invention consists of two parallel pairs of opposed displacer cylinders with respective displacer members mounted for movement therein and two parallel pairs of opposed work cylinders disposed parallel to the displacer cylinders and having respective pistons arranged to reciprocate therein; each work cylinder communicating with a respective displacer cylinder to provide a cold end chamber. First transmission connects the displacers for synchronized movement offset in phase within the cylinders and a second transmission interconnects the pistons for synchronized movement offset in phase within the cylinders. An output drive is connected to the pistons. An adjustable phase displacer interconnects the first and second transmission means for adjusting the phase relation of the displacers with respect to their associated pistons from an in-phase condition in which no torque is applied to or from the output drive to an optimum-phase displacement position in which the maximum torque is applied to or from the output drive. A fluid heat source enclosure completely surrounds displacer cylinder hot end chambers to put the gaseous medium in an intimate heat transfer relationship with the heating fluid so that when the engine is at rest with the displacers in the in-phase condition, movement of the displacers, in response to operation of the adjustable phase displacer away from the in-phase condition causes an immediate imbalance in pressure applied to the pistons to provide an immediate self-start. Cooling means is provided at the cold end for cooling the gaseous medium therein.