Motorola Corporation

Raymond E Nordbrock

Kirk A Sievers

Richard L Spears

Alfred G Ocken

An inexpensive semi enclosed alternator provides high power prolonged operation in environments having particle contamination in the ambient atmosphere. An alternator housing has front and rear housing portions, and a drive shaft carrying a rotor assembly is within the housing. A drive shaft extension from the housing holds a fan assembly. The rear housing portion has cylindrical sidewalls joined to a closed end portion 27 and forms an air sealed cavity except for an open end facing the front housing portion. The front housing portion comprises cylindrical sidewalls, having through-openings therein, which terminate in a first end opening 31, facing rear housing open end 28, and a substantially open second end opening 30 facing the fan assembly and the ambient atmosphere. Preferably rotor and stator assemblies, and rectifying diodes, are positioned within the housing substantially between the through openings and the closed end portion of the rear housing. During normal drive shaft rotation, the fan assembly draws cooling ambient air into the housing through the through-openings 33, and this air is then drawn out of the housing through the second end opening 30 of the front housing portion. This causes cooling air turbulence within the housing, while not directly exposing most internal alternator components to particle contamination in the ambient atmosphere. A voltage regulator is provided in a sealed protective cavity external to the internal cavity. A heatsink which is part of the voltage regulator is utilized to form part of the walls that create the protective cavity.

Semi enclosed alternator

A single alternator having multiple isolated windings provides multiple outputs as for charging 12 and 24 volt batteries. A main regulator controls the field coil current and a secondary regulator controls the charging current for the second battery by controlling the second rectifier.

Multiple output alternator system

A charging system for amplifying AC output voltages induced in at least one stator winding of an alternator by residual magnetism from a low carbon steel rotor to self-excite the charging system by means of the residual magnetism at low engine RPM. An electronic voltage regulator is responsive to small AC output voltages from the stator winding, even below voltage levels required to forward bias a silicon semiconductor junction, to fully energize the field winding of the alternator. Since the voltage regulator is responsive to alternator signal developed at low engine RPM, the regulator can also be used as a sensor to indicate an operative engine condition, such as start up.

Growing community of inventors

West Chicago, IL, United States of America

Raymond E Nordbrock