US1282969A - Electrical starting system for internal-combustion engines. - Google Patents

Description

v c. A. SOANS. ELECTRICAL STARTING SYSTEM FOR INTERNAL COMBUSTION ENGINES.

APPLI CAT|ON FILED NOV. 7. I9l3. 4,282,969

tented 0015. 29, 1918;.

W/ T/VESSES CYRIL A. scams, or enter-tee, ILLINOIS, ASSIGNOR, MEsNE ASSIGNMENTS, To stairs. MOTOR APPLIANCE COMPANY, a CORPOBATION or DELAWARE.

V ELECTRICAE STARTING SYSTEM: FOR INTERNAL-COMBUSTION ENGINES.

essence.

Specification of Letters Patent.

Patented Dot. 29, 11918.

Application filed November 7, 1913. Serial 1105799392.

new and useful Improvements inElectrical Starting Systems for Internal-Combustion Engines, of which the following is a specification. i:

My invention relates to starting systems or devices for starting an internal combustion engine from a condition of rest, and

particularly to that type or class of starting device in which the engine is operated at starting by means of an electric motor. which receives current from a storage bats tery, and which batteryis in turn charged from a generator-or dynamo operated by the engine after it has been started. My improved starting device or system is designed with reference to use with and to form a part of the power system of a motor vehicle, and the object thereof is to provide such improvements in and relating to starting devices as are hereinafter more specifically and at length referred to and described.

The drawings accompanying and forming a part of this application illustrate the preferred embodiment of my invention, although it will be understood that the same includes such variations and modifications of the particularembodiment illustrated as will be obvious to those skilled in the art to which my invention relates. 35

arranged for operation as a generator; and

slightly modified withlreferenee to the connection of one of the shunt coils.

Fig. 3 is a view illustrating the motorgenerator of my device and the driving con n'ections between the same and the engine.

Referring to the drawing, the referencenumeral 5 designates the fly-wheel of an intern al combustion engine which is to be started by my improved starting device, the same having a series of gear teeth upon its periphery, and (l designates a pin on normally out.

of engagement with the teeth upon the fly- Wheel but which pinion'may be moved into engagement with saidteeth by means of any suitable operating mechanism such, for eX- ample. as the lever 0r pedal 7. The pinion (3 is driven by a gear 8 through an intermediate clutch which, while acting to transmit. motion to the pinion, allows the pinion to move ahead of and rotate faster than the gear when the engine starts under its own power. The pinion 6 and gear 8 slide upon a suitable shaft or support 9 as the lever 7 is operated, as will be understood.

My improved starting device includes a combined motor and generator, or dynamo, shown conventionally in Fig. 3 and the motor and generator armature windings or coils of which combined devices are located upon a single rotatable armature shown at 10. The reference numeral 1.1 designates the yoke, and 12 twoof the poles'of thefield magnet of the'combined motor and generator, from which it will be appreciated that the motor and generatorarmature windings will move in amagnetic'field irrespective ofever the armature 10 rotates in said field.

The motorand generator windings maybe arranged in any way so long as a device is I produced which will operate either as a generator or. as a motor, and said coilsare suitably connected with separate motor and generator commutators 13, 14.. The armature 10 is carried by a shaft 15 supported in suitable bearings notshown, which shaft is driven from the internal combustion. en

. ine'after the same has been started through ashaft 16 and clutch 17 which permits the armature to rotate independent of the shaft 16 when the combined motor and generator is operating as a motor in starting the engine. The shaft 15 is provided with a pinion 18- with which the gear 8 is made toengage by the lever 7, to thus connect the dynamo with the engine as will'be understood. The field magnet of the dynamo is provided with two separate windings or coils. one of coarse wire shown at 19 for use. when the device is used as amotor and which coil is commonly connected in series with the motor winding upon the armature, while the nected. combined motor and generator Will be opertor armatures of the combined motor and generator, and the starting devlce as a Whole is shown as arranged to operate ,as a motor.

The motor circuit 23 is closed by a two point switch 24, and the dynamo 1s operated by current from, a storage battery 25. At

this time the external circuit 26 of the genage regulator and resistance short circuiting means opens a shunt around the resistance 3+. and inserts this resistance in a shunt field coil 20 of the generator portion, and wlnch coil serves to magnetize the field magnets of the dynamo when the same is used as a generator, all as more fully set forth below. This will break the shunt about a resistance 34 and thus weaken the current in the field circuit in which the latter is serially con- 1 t will therefore be obvious that the ated as a motor to start the engine, and that no flow of current can occur either in the external circuit above referred to of the generator portion of said device, nor any considerable current through the main shunt circuit thereof; althou, jh it will be appreciated that an electro-motive force is necessarily being generated in the armature winding of the generator portion because of the fact that it isrotating in the motor field. A slight flow of current will. however, occur in the arrangement shown in this figure, through the shunt coil 20, the high resistance coil 3% to be hereinafter described, and the coil 35 of the voltage regulator 29,'because of the fact that these coils are connected in series with one another across the external circuit 26. This flow, however, is so small as to be negligible. and is, moreover, incidental to the use of the coil 35 and is dependent upon the manner in which the coil 35 is connected in the system. Thus, in the arrangement shown in Fig. 2. no flow of current occurs through the coil 20 when the switch 31 opens a shunt around resistance 31% and inserts this resistance in'the shunt field and the dynamo being used as a motor, although at such times a small flow will occur th'rough the coil 3.3 of the voltage regulator as the same is shown as connected directly across the external circuit 26, in the scheme illustrated in this last-mentioned figure.

Referring now to the diagram, Fig. '2. the various parts of my improved starting device'are shown as arranged so that the combined motor and generator will operate as a generator (driven from the engine through the clutch 17 as above explained) to charge the storage battery 25, the switch 2+ having been moved into a. position to break the motor circuit and close the external generator circuit 26. The main shunt circuit 28 in which the shuntcoil 20 is included Will'be closed at the terminals of the combined 'voltage regulator and shunt coil cut-out 29,

and current will flow through the exterior generator circuit 26, the battery cut-out 27 and a common portion 28 f the'motor circuit, to thus charge the battery.

My improved starting device, as above stated, is designed with special reference for use for starting the engine of a motor-propelled vehicle, and, as the combined motor and generator are driven from the engine. it will be obvious that the speed at which the same is driven will vary within wide limits according to the speed of the engine.

The motor-generator must therefore be so constructed and arranged as to generate sufficient electro-motive force, when operating as a generator, to charge the battery at speeds of rotation of the dynamo armature varying between .wide limits, according to the speed at which the vehicle is being propelled by the engine, which electro-motive force should be constant or substantially constant.

The means provided for regulating the electro-motive.force generated by the combined motor and generator when the same is operating as a generator comprisesthe voltage regulator 29 hereinbefore referred to and which is designed and arranged to cause switch 31 to open a shunt around the resistance 34 and insert this resistance in the shunt .field whenever the said electromotive force exceeds a predetermined maximum; which maximum,.it will be appre-v ciated, is much below the electro-motive.

forcewhich might be generated by the dynamo when. operating as a generator; for

such maximum electro-motive force must be generated when the vehicle is being propelled slowly, andmay not be exceeded when the vehicle is being propelled rapidly. This action will reduce the. currentv flowing through the shunt coil 20 to a negligible amount; althou h it will be appreciated that .in the systemillustrated in both Figs. 1 and 2 a shghtcurrent will flow through the high resistance coil 3% when the dynamo is used as a generator, even thoughthe said circuit is broken at the terminals of the voltage regulator 29; because of the fact that the coil is connected in shunt across the terminals of the voltage regulator. It will be. appreciated. however, that this slight flow incidental to the use of the coil 35, which coil. as will hereinafter appear, isnot an indispensable element of my improved starting system, and may be dispensed with. The reduction of current flowing through the shunt coil :20 will be accompanied by a reduction of the magnetization of the field magnets of the dynamo, although said mag nets will in practice not be entirely demagnetized' because of magnetic hysteresis in the cores of the magnets, even though the the generator and which coil is arranged to act upon'a vibratlngspring-retracted armature 31 which carries one of thetwo cooperating terminals-Which make and break the main line of the circuit in; which the shunt coil is included as said armature vibrates, in the same Way as in an ordinary relay. The coil 30 is preferably placed upon a-suitable iron core 32' to thereby form an although it will be understood that the'coil may be used as a solenoid without a core, as in .eithercase the coil forms, in connection with the armature 31, an -electromagnetically operated device adapted to break the main line of the circuit in which the shunt coil 20 is includedandfthus in-. terrup't or greatly decrease the flow through imum. "Thisaction will be accompanied by ,a substantialreduction of the magnetization of the;field magnets'of the generator, and, consequently, by a reduction of. the

electro-motive force generated thereby to" a point below the constant electro-motive force to be maintained by the voltage regulator; Thus the; electro-motive "force generated is kept from rising above apiedetermined "maximum and asubstantially constant voltage is maintained; and it may be'remarked that when the dynamo is in useas' a generator the armature31 of the voltage regulator vibrates athigh speed, thus making and breaking the 'circuit in which it is includedmany times per second; The voltage regulator will in practice bemade adjustable as by varying the tension'of-a spring acting upon' the -spring retracted armature thereof, so that the magnitude of the con'stantvoltage main I tainedbyit may be varied.

-The reference numeral 34 des gnates an auxiliary shunt coil of high resistance connected across the switch 31 and the auxiliary sh-untyco-il 33 of high resistance is connected in parallel with. the coil'20. v

' These coils, however, are not indispensable to the operation of my device' and may be dispensed with if thespar king at, the ter-' minals iii-question is found to be not objejctiona-ble -'or injurious to. a prohibitive extent.

lator, as all of'thes'e circuits are open Assuming that the starting device is operating as a motor as shown in Fig. l, and remembering that the armature winding of the combined motor and generator which is "used when the device operates as a generator is rotating in the .motor field (and usually at excessive speed as the dynamo armature is commonly driven as a motor at a much higher speed when the'engine is being started than it is driven as a generator from the engine in charging the storage battery) .it willibe appreciated that an electro-moive force will be generated in the generator armature winding ofthe dynamo much greater and commonly several times the constant electroniotiveforce maintained by the electronagnet which is magnetized by the l l g g vHIIOW t n h Ch coil and in. turn attracts thearmature 31 15 an important feature of my invention,

were not present, it will be appreciated that the spring-retracted armature 3110f the voltage regulator would close the main shunt circuit 28 in whichthe shunt'tcoil 20 is in' 'cluded at the terminals of the voltage regulator; but no'current would'fiow through either the shunt coil 20 of the' generator portion of the dynamo, the externalcircuit 26 thereof, or the coil 30 of the voltage regug because of the position of the switch 2%.; If

,u'nder such conditions theswitch 24 were the current which normally flows therein,

and the'result would be that excessive sparking or arcing would occur at the terminals of Ithe, voltage regulator each time the dynamo was converted from a motor to a generator.

- In order to prevent excessive sparking at the terminals of the voltage regulatorwhen' the dynamo is converted from a motor to a. generator I provide means for breaking the main shunt circuit 28 in which the shunt coil 20 isincluded when the dynamo operates as a motor, and for keeping said circuit broken at such times; said means being illustrated electro-motive force generated when the same operates as'a generator; from which it follows that no rush of current can occur through the shunt coil and terminals of the 'voltage regulator when the dynamo is converted from a motor to a generator because of the fact that the main shunt circuit in which the coil and terminals are included will then be broken. Thiscircuit breaking device is preferably combined with the voltage regulator and acts to break the circuit trically connected with the dynamo in such a way that a flow of current may occur therethrough when the motor-generator is used as a motor. Thus in Fig. 1 the coil 35 is connected in series with the voltage regulator coil 30 when the dynamo operates as a motor, whereby the coils reinforce one another. and a current will flow through both coils due to the high electro-niotive force generated in. the generator armature winding when the dynamo is used as a motor, notwithstanding the fact that the external generator circuit is broken at the switch 24 at such times. The tllll'ltltlll'03l of the voltage regulator will therefore be attracted, and the circuit in which the shunt coil 20 is included will be broken at the terminals of the voltageregulator. lhe same result will be secured with the arrangement shown in Fig.- 2 in which the coil 35 is connected in parallel with the coil 30. In this last-mentioned arrangement, when the dynamo operates as a generator very little current flows through the coil 35, because of its high resistance and the low-electro-motive force maintained at such times by the voltage regulator; so that while the coils 30 and 35 reinforce one another when the dynamo op crates as a generator, the magnetization of the core 32 is due for the most part to the coil 30. hen the dynamo operates as a motor, however, the magnetizing effect of the coil 35 is greatly increased because of the increased electro-motive force then generated in the generator armature winding, and is sufficient to break the main line of the circuit in which the shunt coilQO is included, notwithstanding the, fact that no current is then flowinfl' in the. coil 30.

It will beunderstood that the functions performed by the voltage regulator and by the circuit breaker responsive to the excessive electro-motive force generated in the generator armature winding when the dy namo'is used as a motor. are independentof one another, and utilize in part a single concrete structure merely for the purpose of convenience. Thus, if the coil 30 were omitted, the voltage regulating function would no longer be performed, but the circuit'in which the shunt coil 20 is included would.

generator would not be maintained constant in such a case, but a storage'battery could nevertheless be charged with a considerable degree of success, particularly if the battery used was of a type which may be charged at widely varying rates, or if the speed at which the dynamo was driven from the. engine as fairly constant as is the case in stationary and marine work, and in motor-driven trucks for comparatively heavy service.

The battery cut-out 27 hereinbefore..referred to maybe of usual or ordinary construction. and forms no part of the invention to which this application relates. As shown, it comprises a core 36 of iron upon which a coil 37 of high resistance is .wound and which coil is connected in parallel with the storage battery 25 when the dynamo is charging-the battery. The core 36, when magnetized by the coil .37, will attract a pivotally supported spring-retracted armature 38 which *arries one of the terminals of the cut-out, the other being stationary, and thus close the circuit 23' in which'the battery is included when it is being charged, and which circuit includes a coil 39 also wound upon the core 36 of the battery cutout.

It therefore. follows that when the motorgenerator commences to operate as a generator andwhen the electro-motive force thereof has become sutliciently high to charge the storage battery, a current, small in amount because of the high resistance of the coil. will flow through the coil 37 and magnetize the core 36 of the battery cut-out; whereupon th 2 armature 38 will be attracted, the circuit 23 in which the battery is included will be closed at .the terminals or" the battery cut-out. and current will flow through the coil 9 andcircuit 23 to charge the battery. wound as to reinforce one. another. from which it followsthat the terminals of the cut-out are held in contact with increased force after the current. begins to flow through the coil 8!). if the speed ofthe motor-generator falls to such an extent that the elcctro-motive force generated by the gene 'ator armature winding is less than the electro-motive force of the battery, a current in a'reverse direction will he established through the coil 3.) of the battery cutout. thus releasing the armature 38 and breaking the circuit in which the battery is included, as will be understood.

The reference numeral 40 designates a The coils b7 and 39 are soswitch used preliminary to startingthe engine for the purpose of facilitating the bringing of the gears intermediate the motor-generator armature shaft and the fly'- in the position shown in- Fig. 2. If now the= switch 40 be moved to close the circuit-41 controlled by it,'current will flow from the storage battery through the generator'arma- E ture Winding and shunt field coil of the 15 dynamo, which current, however, will be small "in quantity because of the high re 'sistance of the generator portion of the 1 motor-generator, that is, the generator armature winding thereof and the shunt coil 20.

The armature of the dynamo, however, will be rotated slowly, and with little power, and, while this is occurring, the lever 7 is operated to move the pinion 16 and gear 8 as hereinbe- .fore explained, whereupon the train of gearing between the dynamo armature and the fly-wheel of the engine is brought into engagement at. low speed and quietly and without shock ordanger of stripping the teeth. After the gears are in mesh, the switch 24 is moved into the positionshown in Fig. land the dynamo operates as a motor as hereinbefore explained.

Having tlrus described and explained my invention, I claim and desire to secure by LettersPatent:

1. In apparatus ofthe class described, in

combinatlon, 'a dynamo machine, a battery, the dynamo being provided with, a motor winding for-starting and a generator windmg for charging and means controlled by the generator winding during motor operation to protect the generator winding against the high voltage developed therein due to the operation of the machine as a motor. I

2. In apparatus of the class described, in combination, a dynamo machine, a battery,

' said dynamo inc uding a motor armature winding for starting. and a generator armature winding .for charging, and electromagnetic means energized by said generator winding during motor operation to weaken the field of said dynamo preparatory to generator action.

3.111 apparatus of the class described, in

' combination, a dynamo electric machine,

conducting means comprising a shunt field circuit adapted to lead current from said machine as a generator',,said circuit provid- 'ing excitation during generator operation and including an automatic regulating switch, a storage battery, conducting means conductin weaken said shunt field winding when said -machineis connected with-said battery as a conducting means comprising-a shunt held circuit adaptedto lead current from said machine as a generator,,l'said circuit pro viding excitation during. generator operation, a storagebattery, conducting means comprising a series fie'ld winding adapted to lead current to said machine as a motor, means adapted alternatively to connect said battery-with said first and with said second means, and means adapted to motor, said last means comprising a normally shunted resistance In series with said shunt field winding, and means adapted to break the shunt.

5. In apparatus of the class described, in

combination, a single dynamo electric machine, lncludinga motor armature wlndlng and a generator armature windlng, a motor field and a generator field, means for shifting from a motor to a generator connection, an automatic regulating switch associated with said latter field, and an electromagneticcoil actuated by said generator winding during motor operation to maintain said regulating switch in open position when the motor connection is shifted to a generator connection. I

6. In apparatus-of the class described, in combination,- a dynamo electric machine, a storage battery, conducting means adapted to lead current from said machine as a generator, an automatic switch associated with said means, conducting'means adapted to lead current to said machine as a motor, means alternatively connecting said battery with. said first and with said second conducting-means, means adapted-to maintain said automatic switch in open position while said machine is operating as a motor, and

means to render said last means inoperative when said machine is operating as a generator.

Signed, at Chicago in the county of Cook-.-

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