United States Patent [19] [11] 4,918,677 Hofmann [45] ‘ Dec. 6, 1983

[54] ALTERNATOR FOR IGNITION SYSTEM 4,111,174 9/ 1978 Fitzner et al...... 123/602

AND AUXILIARY POWER 4,160,435 7/1979 Sloder ...... 123/599

_ 4,213,436 7/1980 Burson ...... _ . . . .. 123/599 [75] Inventor: Gloris R. Hofmann, Fond du Lac, 4,259,938 4/1981 1011111185011 ...... 123/599 Wis. _ ‘ _ Sk k_ In FOREIGN PATENT DOCUMENTS [73] Ass‘gneez Brunswlck corporatmn’ 0 1e’ ' 732888 11/1933 United Kingdom ...... 123/599 [21] Appl. No.: 317,827 . _ Primary Examiner—Raymond A. Nelli [22] Flled: Nov‘ 3' 1981 Attorney, Agent, or Firm-O. T. Sessions [51] Int. c1.3 ...... F02P 1/02; F02P 5/04; F021, 3/06 [57] ABSTRACT [52] US. Cl...... 123/599; 123/602; The invention provides an alternator driven by an en 123/ 605 gine crankshaft (11). A stator mounted on the [58] Field of Search ...... 123/599, 602, 418, 655, (10) includes circumferentially spaced power coils (19) 123/ 149 D, 605; 310/741 70 lying in the plane of and radially inward of the power [56] References Cited (20) mounted on the engine flywheel (12). Ignition coils (18) are mounted circumferentially spaced U'S‘ PATENT DOCUMENTS from the power magnets (20), but axially offset there 3,465,739 9/1969 Burson ...... 123/599 from to couple with the fringe flux of the power mag €:1mlerm?"n ct al~ ------~ nets, thus allowing a high output from the power coils 3,955,550, , 5/1976 Carlssonat ey, r...... 123/599 (19) wlthout- overloadlng~ the igmtlon1 - - coils- (18). 3,961,618 6/1976 Swift ...... 123/602 4,061,121 12/1977 MacLeod ...... 123/599 4 Claims, 4 Drawing Figures

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(A(11111111111 I US. Patent Dec. 6, 1983 Sheet 1 of3 4,418,677

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SHUNT SHUNT 36 REGULATOR REGULATOR

3 U.S. Patent Dec. 6, 1983 Sheet 3 of3 4,418,677

I _.25 4,418,677 1 2

ALTERNATOR FOR IGNITION SYSTEM AND BRIEF DESCRIPTION OF THE DRAWINGS AUXILIARY POWER FIG. 1 is partial sectional view of an alternator appa ratus according to the invention. DESCRIPTION FIG. 2 is a top view of the stator and includes a sche matic diagram of the power circuit. 1. Technical Field FIG. 3 is a detail drawing of the cam operated switch This invention relates to an electrical alternator appa employed in the invention. ratus for internal combustion and, more particu FIG. 4 is a perspective view. of the stator incorpo larly, to such apparatus for powering an ignition system rated in the invention. and auxiliary electrical equipment. 2. Background Art BEST MODE FOR CARRYING OUT THE Internal combustion engine powered devices such as INVENTION outboard motors, snowmobiles, lawn tractors, and simi Shown in FIG. 1 of the drawings is the upper portion lar devices frequently use capacitor discharge ignition 5 of an outboard motor engine 10. The engine 10 is of any systems and have auxiliary electrical equipment such as suitable construction such as a two-cycle internal com lights, starters, and batteries. Further, the different na bustion engine widely employed in the outboard motor ture of the ignition system and the auxiliary equipment industry, and in the preferred embodiment is a large generally place distinctly different requirements on the multi-cylinder outboard motor engine having six cylin power source. Space limitations in such applications ders in a V arrangement. The engine 10 has a vertical require a compact, lightweight construction for the crankshaft 11 with a ?ywheel assembly 12 attached at electrical power source. Consequently an alternator the upper end and is connected by any suitable means to may frequently be incorporated into the ?ywheel struc drive a , not illustrated. ture of the engine to generate electrical power. The ?ywheel assembly 12 is attached to the upper One prior alternator, disclosed in US. Pat. No. end of the crankshaft 11 to reduce the ?uctuation in 4,160,435, uses two sets of magnets mounted on the rotational speed of the crankshaft 11. The ?ywheel ?ywheel, axially spaced apart, and coupled with two assembly 12 includes a central hub 13, attached to the sets of axailly spaced stator coils. This arrangement thus output shaft 11 by a nut 14 and key, not illustrated. An outer rim 15 is connected to the hub 13 by a plate 16 provides two axially spaced alternators, one to power which is attached to both the rim 15 and the hub 13. A the engine’s ignition system and another to provide ring gear 17 attached to the outer periphery of the auxiliary power. ?ywheel rim 15 may be selectively engaged by a gear Other alternators have used a single set of magnets on driven by an , not illustrated, for starting the ?ywheel coupled with two sets of stator coils in the the engine 10. same plane to power the ignition system and to provide Generally, in the preferred embodiment, an alterna auxiliary power. The output of the auxiliary power coils tor is mounted within the structure of the ?ywheel in such systems has been limited, since increasing mag assembly 12‘. The alternator includes a set of ignition net size to increase power will overload the ignition stator coils 18 and a set of power stator coils 19, both power coils. ?xed to the engine 10. Six radially polarized power 40 magnets 20 are ?xed about the inner circumference of DISCLOSURE OF INVENTION the ?ywheel rim 15 to generate electrical power in the The invention provides an alternator apparatus for coils as the ?ywheel turns. supplying electrical power to both a capacitor ignition The ignition coils 18 are connected to a capacitor system for an internal combustion engine and to a sepa discharge ignition unit 21 to supply power for charging rate auxiliary power load. A plurality of circumferen 45 the power capacitors. The capacitor discharge ignition tially spaced magnets are mounted on an engine driven unit 21 may be of ‘any suitable type and typically will rotor and all lie in a plane perpendicular to the axis of include a trigger coil to generate timed trigger pulses to the rotor. A power coil means, which may include a control the discharge of the capacitors and thus the plurality of circumferentially spaced power coils, is firing of the spark plugs. In the embodiment illustrated, secured in radial alignment with the magnets while an the trigger coil, not illustrated, is positioned adjacent ignition coil means is coupled to the fringe ?ux of the the ?ywheel hub and is coupled with magnets 22 magnets, possibly by having at least two ignition coils mounted on the hub 13 to generate the timed trigger axially offset from the plane of the magnets. This ar pulses. rangement permits the use of stronger magnets without In the preferred embodiment, both the ignition coils 55 18 and the power coils 19 are mounted on radial poles overloading the ignition circuits. extending outwardly from a single laminated iron core By offsetting two ignition coils to opposite sides of 23. The core 23 is supported on the engine block with the plane of the magnets two ignition coils can occupy the crankshaft 11 projecting upward therethrough. All the same circumferential space required by one, thus of the ten power coils 19 lie in a single plane perpendic allowing space for an additional power coil. The coils ular to the crankshaft axis and coincident with the plane may stillbe compactly placed within the circle of the in which the power magnets 20 lie. The poles 24 sup magnets. porting the power coils 19 each terminate in a T-shaped Preferably, the magnets are mounted on the engine’s pole shoe 25 having a slightly curved outer radius con ?ywheel and the coil means includes a core having centric with the crankshaft 11 and ?ywheel 12 to couple radial poles for both the ignition and power windings. 65 with the power magnets 20 across a small air gap and The invention thus provides a compact alternator reduce the leakage ?ux. Each of the power coils 19 power source for an internal combustion engine which carried on the poles 24 has twenty six turns of seventeen permits increased power output for auxiliary loads. gage copper wire. 4,418,677 3 4 The four ignition coils include two low speed coils 26 FIG. 3. By switching the power coils 19 from a series and two high speed coils 27. The low speed coils have connection at low speeds to a parallel connection at a very large number of turns of ?ne wire, 15,000 turns of high speed, the higher output of the series connected 42 gage wire in the preferred embodiment, while the coils at low speed can be utilized along with the higher high speed coils have a substantially smaller number of output of the parallel connected coils at higher speeds. turns of heavier wire, 2,000 turns of 35 gage wire in the . I claim: preferred embodiment. Each of the low speed coils 26 is 1. An alternator apparatus for supplying electrical connected in parallel with one of the high speed coils 27 power to a capacitor discharge ignition system of an to effectively charge the power capacitors, as shown in internal combustion engine and for supplying electrical U.S. Pat. No. 3,874,349 to Fitzner. The four ignition power to a separate power load, said alternator appara charging coils 18 are arranged on four poles 28 formed tus comprising: on the axial edges of the stator core 23. With two coils (A) an engine driven flywheel mounted for rotation occupying each of two circumferentially spaced posi ' on said engine, said ?ywheel including a circumfer tions, the four ignition charging coils 18 occupy the ential ?ange; same circumferential space as two of the power cells, (B) a plurality of circumferentially spaced magnets thus allowing additional space for the power coils. Fur mounted on the flange of said flywheel and lying in ther, with the ignition charging coils axially offset from a common plane; and the plane of the magnets and power coils, the ignition (C) a stator assembly mounted on said engine concen charging coils are coupled to the fringe ?ux of the trically with said ?ywheel and radially inward of power magnets 20. Thus more powerful magnets may 20 said ?ange, said stator assembly including be used to increase the output of the power coils with (1) a circular magnetic core having a plurality of out overloading the ignition coils 18. circumferentially spaced radial power poles As most clearly seen in FIG. 2, the power coils 19 are lying in the plane of said magnets and at least connected in two groups of ?ve coils, with the coils in two radial ignition poles offset from said plane, each group connected in electrical series. In the pre 25 (2) power windings mounted on each of said power ferred embodiment each group of power coils is con poles, and nected to a bridge circuit 29 made up of four diodes to (3) ignition windings on each of said ignition poles, provide full wave recti?cation. A switch 30 provided said ignition windings including a high speed between the groups of coils allows them to be con winding and a low speed winding with said high nected to the electrical load, represented by the battery 30 speed winding having a substantially smaller 31 in FIG. 2, in either series or parallel relationship. number of turns of heavier wire than said low With the switch 30 open as shown in FIG. 2, the groups speed winding, all of said windings responding 7 of coils are connected in parallel with each bridge cir to the magnetic field created by said magnets to cuit-29'supp1ying to the battery 31. With the switch 30 closed, the coils are effectively connected generate electrical outputs. in series and the diodes 32, 33, 34 and 35 serve as a 2. The alternator apparatus de?ned in claim 1 bridge circuitto-rectify the current generated. A pair of wherein said ignition poles include at least two ignition shunt type voltage regulators 36, such as that described poles offset to opposite sides of said plane and axially in the U.S. patent application of Staerzl, Ser. No. aligned. _ _, 06-059,054, ?led on July 19, 1979 and assigned to the 3. The alternator apparatus de?ned in claim 2 same assignee as this application, are‘ connected across wherein said power windings include substantially the bride recti?er circuits 29 to provide regulated fewer turns of heavier wire than does said high speed power to charge the battery 31. winding. . The switch 30 of the preferred embodiment is actu 4. The alternator apparatus de?ned in claim 3 ated by a cam 37 driven by the engine’s linkage 45 wherein each of said power poles include a vT-shaped 38. The cam lobe 39 holds the switch 30 closed below a pole shoe adjacent said magnets. ~ predetermined throttle setting as most clearly shown in * 1k * * *

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