Abstract: A fluid filter assembly comprises a heater and a filter in series fluid flow relationship. A means for bypassing a fluid around the heater and the filter is provided which comprises ducts and a relief valve interposed between them. In normal operation the relief valve is closed so all the fluid flows through the heater and the filter. The fluid and any liquid impurities entrained therein are heated by the heater prior to passing through the filter. At low temperatures the heater cannot normally provide sufficient heat to prevent solidification of the liquid impurities entrained within the fluid which block the filter. The relief valve then opens to allow a proportion of fluid to flow through the bypass so a reduced amount of fluid flows through the heater and the filter. The heater heats the reduced flow of fluid therethrough to a temperature sufficiently high to melt the solidified liquid impurities blocking the filter.

Abstract: A rotary machine, having a casing and a rotor rotatable eccentrically in the casing to define an eccentric annulus divided into compartments by vanes, to function either as a compressor or an expansion engine has the vanes pivoted at the rim of the rotor and driven by a mechanical coupling to their operative positions. The vanes are driven by cranks lying in planes outside but parallel to the planes in which the vanes operate. The vanes operate with a minimal clearance between vane tip and casing in order, ideally, to provide zero friction at the vane tip.A power system is disclosed in which air is compressed, heated in a flame tube, expanded under volume confined conditions in a rotary machine as described to an intermediate pressure, and expanded to ambient under volume confined conditions in another rotary machine as described. The machine may drive auxiliaries in a vehicle.