Fig. 35. Elevation of Argyll Single Sleeve Motor from The Motor, London.
In diagram 10, the inlet is nearly closed, the sleeve port passing away from the cylinder ports to the water jacketed portion of the cylinder above.
Fig. 36. Valve Motion Diagram of Argyll Motor Showing the Valve Positions at Different Parts of the Working Stroke.
This series of diagrams shows the operation of the duplicated port of the sleeve (which port is the one shown dotted) in relation with one of the inlet ports and one of the exhaust ports in the cylinder wall, the latter ports being marked respectively I and E. The elliptical movement referred to in the text can be traced by following the different positions of the dotted port in the sleeve. In the top row of diagrams it is seen to come downwards and also to move over to the left, whilst in the lower set it rises—bearing still to the left—until, after Fig. 10, it goes higher up for the compression and explosion strokes, during which it bears over to the right and comes down again ready to commence once more the cycle, as in Fig. 1. The other ports in the cylinder wall are the same as those shown, and the other ports in the sleeve are akin in shape to half of the dotted port, but they are without the little tongue cut in the base of this double purpose port. This little tongue in the duplicated port is designed to give as much lead to the exhaust opening as possible, without interfering with the correct timing of the inlet port. The way in which it just misses interfering with the closing of the inlet port is seen in Fig. 10. We are indebted to “The Motor” for these cuts.
(53) Sturtevant Aeronautical Motor.
The cylinders of the Sturtevant aeronautical motor are of the “L” type and are cast separately with the cylinder barrel and water jacket in one integral casting. A special iron is used for these castings that has an ultimate tensile strength of 40,000 pounds per square inch. The valves which are easily accessible through valve covers, are operated directly from the cam shaft without valve rockers. A hollow cam shaft is used with integral cams to insure a maximum of strength with a minimum of weight, and bearings are placed between each set of cams. A bronze gear fitted on the cam shaft meshes with a gear on the crank shaft without intermediate idlers.
Fig. 41. Six Cylinder Sturtevant Aero Motor.
Like the cam shaft, the crank is bored out from end to end with a propeller flange applied on a taper at one end of the shaft. A bearing is provided between each throw with an additional thrust bearing at the forward end of the shaft which may be arranged to take either the thrust or the pull of the propeller. Lubricating oil is applied to all the bearings under a pressure of twenty pounds per square inch, this pressure being maintained by a gear pump attached directly to the end of the cam shaft. The oil is transferred from the pump to the bearings through passages cast in the base, no piping being used. Oil enters the hollow crank shaft at the main bearings and is conducted through the arms to the connecting rod bearings. The oil flying from the crank shaft falls into the oil sump at the bottom of the case where it is cooled before being used again. A second gear pump in tandem with the first takes the oil from the sump and forces it through a filter into the tank.