Balance wheel

Abstract

The invention relates to a balance wheel for rotating machines, especially combustion engines, including, for example, outboard motors. Hitherto, such balance wheels or flywheels have been manufactured from different non-ferrous metals as zinc or aluminum alloys, and in one embodiment they have the shape of an inverted pot having low side walls. On the inner side of the walls balance wheel magnets, that is, permanent magnets for the ignition or generator system of the motor, are attached, and the other elements of the ignition or generator systems are disposed outwardly around the output shaft of the engine and inside the "pot". However, for obtaining a suitable magnetic field, the permanent magnets are not attached directly to the balance wheel of a non-magnetic material--zinc or aluminum--but on a ring of magnetic material, for instance steel, which in its turn is attached to the balance wheel. As known, the object of a balance wheel is to act as an accumulator of mechanical energy. The efficiency or inertia of the balance wheel in this respect is determined by the relation G.times.D.sup.2, were G stands for the mass and D for the diameter. The larger the rotating machine is, the higher value is necessary for the expression G.times.D.sup.2. However, the larger the mass of an object is, the higher is also the weight thereof. Therefore, efficient balance wheels are relatively heavy, which is regarded as a drawback, especially what concerns more or less carriable or transportable motors, as for instance outboard motors or the like. But also in connection with stationary rotating machines, too heavy balance wheels have an adverse effect on the lifetime of the crank shaft and crank shaft main bearings.

Dependencies are inferred from the claim text.