A cam shaft reduces noise produced by gears used to drive cams of a fuel injection pump. Conventionally, the gear noises are caused by negative torque of a cam shaft. A cam profile of each cam which lifts a plunger of the fuel injection pump is shaped like a fan. There are formed two cams in a single cam shaft. A lift increment segment of a first cam overlaps a lift decrement segment of a second cam to prevent a negative torque.
A drive for pump-nozzle injection elements and injection pumps of an internal combustion engine. The drive includes a crankshaft, a camshaft for actuating the injection elements, and form-locking traction member for drivingly connecting the crankshaft to the to the camshaft so that torque angles change in a synchronous manner. The camshaft has cams which are optimized in each case for an injection process with respect to stroke velocity and thus feed rate of fuel. The cams are configured so that the torque angle or a range of torque angles (.alpha..sub.VHmax) before TDC of the cams at which the cams produce a maximum fuel feed rate deviates by an angle .alpha..sub.a from an optimum angle before TDC (K). An amount by which the angle deviates from the optimum angle in a direction toward TDC is no more than an angular error (.alpha..sub.F) resulting from an increase in length of the traction means during operation.
A supply pump for a common rail fuel injection system applicable to a multi-cylinder engine, that exerts a smaller load on a drive power transmission mechanism connecting the engine to the supply pump. To this end, fuel delivery timing of the supply pump is optimized. The number of engine cylinders may be different from that of fuel delivery of the supply pump. A first fuel delivery end timing is 30.degree..+-.5.degree. after compression top dead center of #1 cylinder, and subsequent fuel delivery end timings come at constant intervals. The constant intervals are obtained by dividing 720.degree. by the number of fuel delivery per two rotations of an engine crankshaft.
