Robert Boschgmbh

Gerhard Pfluger

Manfred Frister

Herbert Franz

Reinhold Wamsler

Martin Scholpp

Burkhardt Schmidt

To improve resistance to vibration and shock, while permitting ready access for replacement of brushes of an alternator, the remote end shield (8) is formed as a reinforced plastic injection-molded or pressure-cast structure, integral with a hub for the remote bearing of the rotor and the brush holder for the brushes engaging slip rings (10, 11) on the rotor shaft. An opening (33) extending from approximately the radially outermost part of the brush holder to the end of the remote bearing plate permits access to the brushes for maintenance or replacement. The surface region of the end plate is formed with an engagement surface (35) against which a voltage regulator can be attached, having a projecting terminal blade electrically connected with one of the brushes by a compression spring and/or an eyelet rivet and a pigtail attached thereto.

Easily serviceable alternator, particularly for vehicular use

To simplify assembly of automotive-type alternators, the end or bearing shield (20) at the slip ring side thereof--that is remote from the drive side--is formed as a unitary plastic element, fitted into the housing and forming, at the same time:

Alternator with unitary brush-holder and bearing hub

To limit the maximum speed of the fan blade of an automotive-type alternator, the fan blade (21) is secured to the outer race (23) of a ball bearing (22) having a two-part inner race (24, 25), one of the parts being an axially slidable sleeve (25) which is spring-pressed by a cup spring (26) in engagement with a drive pulley (18) against the first race (24). Until a certain limiting reactive pneumatic force or frictional force is reached, the cup spring (26) will clamp the balls (22) between the inner and outer races, so that the fan blade (21) will rotate with the pulley; when the reactive force and speed are exceeded, however, the fan blade can rotate about the balls (22), and hence slip with respect to the rotation of the pulley (18).

Vehicular-type alternator with speed-responsive fan coupling

Insulation between a rotor shaft and slip rings for electrical connection to a rotary winding is provided by a layer coating the shaft that is sintered in place from fluidized bed material, providing a thin layer that is sufficiently tough for slip rings to be mounted on top so that the layer provides the insulation from the shaft. The slip rings may be quite thin, thus keeping the active surface of the slip ring to a very small diameter. Brass and bronze slip rings may be press-fitted onto the shaft while maintaining the insulation of the layer, but carbon slip rings, which are desirable for long life are best secured by means of an adhesive. The slip ring assembly is particularly useful for three-phase alternators of motor vehicles.

Growing community of inventors

Markgroningen, Germany

Gerhard Pfluger