Gerotor compressor and gerotor expander

An engine includes a compressor, and combustor, and an expander. The compressor compresses ambient air. The combustor burns the compressed air, and produces exhaust gasses. The expander receives the exhaust gases from the combustor, and expands the exhaust gasses. The compressor may be a gerotor compressor or a piston compressor having variable-dead-volume control. The expander may be a gerotor expander or a piston expander having variable-dead-volume control. Moreover, the engine may include a regenerative brake. The regenerative brake may include one or more valves coupled to the compressor, an expander clutch, and a compressor clutch. Specifically, during braking, the expander clutch is disengaged and the compressor clutch is engaged.