Unmanned Systems Technology 023 I Milrem Multiscope I Wireless charging I Logistics insight I InterGeo, CUAV London & USA show reports I VideoRay Defender I OS Engines GR400U-FI I Ultrabeam Hydrographic Ultra-2 I IMUs

67 OS Engines GF40U-FI | Dossier used for the single valve return springs. The uncoated, heat-treated steel camshaft running in two bearings at the front of the crankcase is directly driven by a screwed gear on the crankshaft. The camshaft is inserted through the side of the crankcase with an O-ring seal and cover closing the assembly, the latter attached to the crankcase by a pair of M2.6 bolts. The cams each operate a solid steel, heat-treated, uncoated flat tappet with plain tappet bores formed by the crankcase. The tappets operate the pushrods through a ball-and-socket arrangement, the details of that being undisclosed. The pushrods are solid uncoated steel, and are 83 mm long and 2 mm in diameter. Each pushrod has a tubular housing running between the respective tappet bore and head channel, this being aluminium alloy and sealed top and bottom by O-rings. The pushrod is attached to its rocker using a screw to adjust clearance. The rockers are solid, heat-treated, uncoated steel and offer a rocker ratio of 1:1.3. The rockers articulate about a stationary steel support assembly that consists of a central block attached to the head via a single 12 mm M3 screw and an integral uncoated shaft either side, on the outer side of which is a rocker retention clip. The nose of the rocker acts directly on the uncoated tip of the respective valve. The oil contained in the blow-by gas lubricates the valvetrain. The PCV valve is fitted to the crankcase rear cover. This discharges the excessive oil accumulated in the crankcase and creates a good flow of oil to lubricate each part of the engine. With pre-mix lubrication there is no need for an oil pump, and with air cooling there is no need for a water pump. Cooling is taken care of by fins on the barrel and head, and additional ones on the side of the crankcase. The PM-02 electric fuel pump is of the roller vane type; this 12 V unit is capable of discharging 120 cc per minute at a pressure of 3 bar for only 5 W of electrical energy. It has a self-contained check valve to maintain that pressure, and a self-contained relief valve to guard against overload. Fuel runs through a filter between the tank and the fuel pump. Downstream of the pump is a fuel pressure sensor unit that includes a pressure relief valve. That valve is a manual method of releasing air in the fuel line. Unmanned Systems Technology | December/January 2019 Side view of the GF40U-FI