US2237823A - Magneto generator - Google Patents

Description

p 1941- E. BFNOWO SIELSKI 2237.823

' HAGNETO GENERATOR Filed March 6, 1937 3 Sheets-Sheet 1 f BY vjelsk/ 1. TTORNEY.

April 8, 1941. E. a. NowosnzLsKi IAGNETO GENERATOR Filed March 6, 1937 3 Sheets-Sheet 2 INVENTOR.

April 8, 1941- E. B. NowosnzLskl IAGNETO GENERATOR Filed March 6, 1937 3 Sheets-Sheet 3 Patented Apr. 8, 1941 v MAGNETO GENERATOR Edward B. Nowosielski, Sidney, N. Y., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Application March 6, 1937, Serial No. 129,397

3 Claims.

The present invention relates to a magneto generator for ignition or internal combustion' Fig. 3 is a section taken substantially on the line 3--3 of Fig. 1:

engines and more particularly to a multi-polar magneto oi the concentric type especially adapted for operation at high rotative speeds.

As the operative speeds of ignition magnetos are raised to keep pace with the development of high speed multi-cylinder engines, the inertia of the magneto rotor becomes more important, and the desirability of using small, light rotors conflicts'with the demands for powerful multi-polar magnets. It is, of course, possible to use stationary magnets and rotate the induction coil with respect thereto, but this entails the necessity of constructing the coil so as to withstand the severestresses due to such high speed rotation, and making provision for maintaining the rotor in dynamic balance.

It is an object of the present invention to provide a novel magneto which is simple and economical' in construction and eflicient and reliable in operation at high rotativaspeeds.

It is another object to provide such a device incorporating alight, easily balanced rotor which is particularly well adapted for rotation at high It is a further object to provide such a device in which the number of sparks produced per revolution of the rotor is a multiple of the number of the magnetic poles.

it is another object to provide such a device in which both the coil and the magnets are stationary, the reversals of flux from the magnets through the coil being secured by rotation of an inguctor member in the magnetic circuit of the co it is another object to provide such a device in which the flux from all the magnets is emcientiy utilized i'or the production of each ignition discharge irom the coil.

It is another object to provide such a device in which the magnets, coil and distributor are all arranged coaxial with the inductor rotor, thus permitting the use of a small housing concentric with the drive shaft,

Further objects and advantages will be apparents from the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a longitudinal substantially mid-sectional view oi a preferred embodiment of the invention taken substantially on line i-l of Fig. 2;

Fig. 2 is a section taken substantially on the line 2-2 of Fig. 1;

Fig. 4 is a section taken substantially on the line 4-4 of Fig. 1; and

Fig. is a detail in perspective showing the elements of the magnetic circuits in disassembled relation, partly broken away.

Referring first to Fig. 1 of the drawings, there is illustrated a housing i of substantially cylindrical form having journalled therein as indicated at 2 and 3 a rotor shaft 4 provided with a coupling member 5 arranged to be driven from a suitable member of the engine to be ignited.

According to the present invention, a circular magnet member 6 (Fig. 3) is arranged adjacent one end of the casing i The member 6 is magnetized in segments to form a plurality of arcuate magnets as indicated by the letters "N and S, provided with axially extending pole shoes i. An induction coil indicated generally at 8 is substantially centrally located within the housing 0 and is provided with a hollow magnetic core 9 surrounding concentrically the rotor shaft 4, spaced therefrom. Radially extending rings or spiders ii and i2 oi magnetic material are mounted on the projecting ends of the core 9 and connect respectively with two groups of axially extending stationary inductor members i3 and M respectively, which inductors are equally spaced circumferentially or the spiders and extend longttudinally into overlapping or interdigitating relation with the pole shoes 7 of magnet 8, the stationary inductors and pole shoes being arranged alternately and having their inner surfaces coincident with a common cylindrical surface.

Means are provided for alternately connecting each group of stationary inductors to the oppositely magnetized pole shoes in the form of a rotor it comprising a body iii of non-magnetic material suitably fixed on the rotor shaft 5 having a series of cylindrically arranged rotary inductors it embedded therein, the rotary inductors being arcuate in shape and subtending a sufficient angle to include one pole shoe and one fixed inductor. The rotary inductors thus act as bridgingmembars to complete magnetic circuits from the pole shoes of each polarity through the groups of stationary inductors and the core of the coil.

The casing i is provided with a cap I! in which is located suitable breaker mechanism l8 and a distributor block i9, and a cam 2i and distributor rotor 22 are mounted on the end of the rotor shaft l for actuating the breaker and distributor devices.

The primary winding of coil 8 is connected by a lead 28 to the breaker mechanism, and the secondary of the coil is connected by a lead 2 5 to the central electrode 25 of the breaker mechanism.

In the operation of this device, rotation of the shaft 6 causes the rotary inductors it carried thereby to alternately connect the pole shoes 7 of one polarity to one of the groups of stationary inductors as it, and the pole shoes l of opposite polarity to the other group of stationary inductors as M, reversing such connections .each time that a rotary inductor leaves one pole shoe and comes into operative relation with another. In' the structure illustrated, the magnet member 6 is magnetized in four segments. There are consequently four pole shoes El, two stationary inductors 53, two stationary inductors M and four rotary inductors it. It will thus be seen that there is a flux reversalthrough the induction coil for each forty-five degrees of rotation of the rotor shaft, or eight reversals per revolution, which is double the number of magnets used.

The currents in the primary of the coil gendeparting from the spirit of the invention as defined in the claimsappended hereto.

What is claimed is:

1. Ih a high tension magneto, a housing, a

'drive shaft journalled therein, a plurality of arcuate magnets arranged in a circle about ,the

shaft with like poles adjacent, an induction coil having a hollow core traversed by said shaft, two groups of fixed inductors connected to the ends of said core and extending axially toward the magnets, pole shoes extending axially from the magnets between theends of the fixed inductors, and a rotor having arcuate inductors arranged to connect the pole shoes of opposite polarity selectively to said groups of fixed inductors.

2. In a magneto, a cylindrical casing, a rotor shaft axially journalled therein, an induction coil located medially in said casing having a hollow core traversed by said shaft, a circular series of arcuate magnets arranged adjacent one end of said casing. pole shoes extending axially therefrom, stationary inductor members extending from the ends of said core positioned between the pole shoes, and a rotor having arcuate inductors arranged, to connect the pole shoes alternately with the fixed inductors from the opposite ends of the core.

3. In a magneto, a cylindrical casing, a rotor shaft axially journalled therein, an induction coil located medially in said casing having a hollow core traversed by said shaft, a circular series of arcuate magnets arranged adjacent one end of said casing, pole shoes extending axially therefrom, stationary inductor members extending from the ends of said core positioned between the pole shoes, a rotor having arcuate inductors arranged to connect the pole shoes alternately with the fixed inductors from the opposite ends of the core, breaker and distributor mechanism arranged adjacent the other end of the casing, a cam and a distributor rotor on the

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