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Two-stroke gasoline engines are known to benefit from using in-cylinder fuel injection which improves their ability to meet the strict fuel economy and exhaust emissions requirements. A conventional method of in-cylinder fuel injection involves application of plunger-type positive displacement pumps. Two-stroke engines are usually smaller and lighter than their 4-stroke counterparts of equal power and need a pump that should also be small and light and, preferably, simple in construction. Because a 2-stroke engine fires every crankshaft revolution, its fuel injection pump must run at crankshaft speed (twice the speed of a 4-stroke engine pump). An electronically controlled fuel injection system has been designed to satisfy the needs of a small automotive 2-stroke engine capable of running at speeds of up to 6000 rpm.

Several types of hybrid-electric vehicles have been developed at Ford Research Laboratory. Among the parallel hybrid systems with a single electric motor, two types were studied. In the first type, the electric motor was attached directly to the crankshaft (mild hybrid) [1], to enable the engine start-stop and regeneration functions. In the second type (full hybrid) the electric motor was connected to the engine through the use of a clutch to allow electric launch of the vehicle and pure electric driving at low speeds. The full hybrid powertrain described in this paper uses a more powerful electric motor for enhanced regenerative braking and engine power assist. An engine-disconnecting clutch saves energy during both the electric propulsion and during vehicle braking. When the clutch is disengaged the engine is shut-off, which eliminates the energy otherwise spent on motoring the engine during electric propulsion.

With the advent of electronic controls and development of electromagnetically controlled fuel injection pumps, the cost of fuel systems using plunger-type pumps was substantially reduced. Further reduction in cost can be achieved if fewer solenoid valves are used. A new type of injection pump combining electromagnetic spill control principle with distributor-type operation is described. Only one solenoid valve is required for a multi-cylinder engine. The pump was designed for port injection of gasoline, but with some modifications could be adapted to direct fuel injection. The fuel injection system includes a controller capable of electronic trimming of port-to-port fuel distribution for tight control of air to fuel ratios in all engine cylinders. A review of the basic concept and operating principles is given, and test results as well as cost considerations are discussed.

The idea of using a single electrical machine for both starting the engine and generating electrical power is not new. However, the real benefits, that justify the higher cost of a combined starter-alternator, become apparent when it is used as part of a hybrid powerplant. This powerplant allows a substantial improvement in fuel economy by a variety of methods (i.e. the engine shut-down during deceleration and idle, regenerative braking, etc.), as well as enhancements to engine performance, emissions, and vehicle driveability. This paper describes the analysis of the structure supporting the starter-alternator on the end of the engine crankshaft (Figure 1). It deals with the requirement to maintain a small radial gap between the rotor and stator, and it discusses how the rotor affects the loading on the crankshaft. In addition, thermal deformations of the rotor/clutch assembly are analyzed with three light-weight materials.