US3465161A - Reciprocating internal combustion electric generator - Google Patents

Description

Sept. 2, 1969 3,465,161

RECIPROGATING INTERNAL COMBUSTION ELECTRIC GENERATOR Filed June 30, 1967 H. C CUTKOSKY I 5 Sheets-Sheet 1 N QM 4rronmsys Sept. 2, 1969 H. c. CUTKOSKY RECIPROCATING INTERNAL COMBUSTION ELECTRIC GENERATOR Filed June 50, 1967 5 Sheets-Sheet INVIJNTOR. 664F040 C. Cum ask) firm/awry:

Sept. 2, 1969 H. c. CUTKOSKY 3,465,161

RECIPROCATING INTERNAL COMBUSTION ELECTRIC GENERATOR Filed June 30, 1967 5 Sheets-Sheet 4 INVENTOR 194F010 C. CUT/(05K) F123: .2 5 hwy,

United States Patent 3,465,161 RECIPROCATING INTERNAL COMBUSTION ELECTRIC GENERATOR Harold C. Cutkosky, 1227 Avenue D, Billings, Mont. 59102 Filed June 30, 1967, Ser. No. 650,424

Int. Cl. H02p 9/04 U.S. Cl. 290-1 27 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION This invention relates to energy conversion equipment and more particularly to an electric generator powered by an internal combustion engine in which rectilinear motion is employed rather than rotary motion. As well as generating electrical energy, thermal energy can be recovered from waste heat.

A variety of internal combustion electric generators of the reciprocating type have been previously proposed. A major deficiency of prior equipment is the vibration of the framework and supporting structure that results from alternate firing of spaced combustion chambers. While some of the prior generators of the type described are relatively simple in construction they will not operate reliably, particularly at low r.p.ms. where stalling is a problem. Other units are mechanically complex, expensive to construct and will not operate efiiciently for extended periods of time. Many of the problems inherent in the prior art result from poor combustion chamber scavenging, i.e., a loss of unexploded fuel and air mixture as well as the retention of combustion gases in the combustion chamber. In an attempt to reduce certain of these problems, hydraulic and air operated valves have been previously proposed for use in internal combustion engines of the free piston type. Valves of this kind, however, present difiicult and expensive machining problems as well as being relatively slow moving. Accordingly, high operating speeds cannot be obtained.

In addition to the problems already mentioned, the injection of fuel into the combustion chamber has been difficult to effectively accomplish without the requirement for complicated and specialized equipment for this purpose. The same problems are encountered with cooling and in some cases it is necessary to provide auxiliary cooling equipment such as an electric motor driven blower for the purpose of circulating cooling air over the cylinders.

Certain other problems of the prior art occur in the current generating portion of the equipment. The high current ripple produced in many prior units is objectionable for most applications. In other units, as the field windings are withdrawn from the armature, fewer and fewer coils are energized. This also produces a wave form having objectionable characteristics.

The fixed location of intake and exhaust passages in prior generators of the type described is objectionable 3,465,161 Patented Sept. 2, 1969 "ice since full stroke of the piston is required to keep the device in operation. This imposes conditions for the engine that are neither necessary nor economical since excess power is required to assure the completion of a cycle. Moreover, the high speed of a free piston engine precludes the use of linkages, cams, gears, etc., and thus ports in the cylinder walls have been resorted to. Although tapered poppet valves are well known as a means for rapid stoppage or release of the fluid, they are slow acting due to the reluctance of return springs, inertia of the mechanical train, and the requirement for frequent adjustment.

In view of these and other deficiencies of the prior art, it is one object to provide an improved reciprocating internal combustion generator of the type described wherein an effective provision is made for eliminating undesired vibration of the supporting framework, wires connected to the power output terminals, fuel lines, etc.

Another object of the invention is the provision of an improved generator of the type described which is troublefree, efficient, light in weight, flexible and economical to manufacture.

A further object of the present invention is the provision of a generator of the type described having improved scavenging of the combustion chambers whereby loss of the unexploded fuel and air mixture is minimized and the retention of exhaust gases within the combustion chambers is reduced.

Still another object of the present invention is the provision of an improved generator of the type described which is adapted to produce electrical current having a uniform, ripple-free, square wave pattern.

A further object of the present invention is the provision of an improved generator of the type described incorporating a relatively fast acting valving mechanism that does not require mechanical, hydraulic or an air-operated actuating mechanism.

A further object of the present invention is the provision of an improved generator of the type described wherein a single assembly functions for operating the valve mechanism as well as for injecting fuel into the combustion chamber. A still further object of the present invention is the provision of an improved generator of the type described wherein cooling air travels longitudinally of the cylinders in the opposite direction of the fuel flow and the circulation of cooling air is accomplished by the movement of the field portion of the generator.

Still another object of the present invention is the provision of an improved generator of the type described having a centrally located transversely extending axis of symmetry whereby economies are achieved through the use of duplicate parts on each side of the axis.

In brief terms, the present invention provides a reciprocating free piston, engine powered generator having two spaced combustion chambers defined by two axially aligned cylinders. A piston is mounted for reciprocation in each cylinder. The pistons are rigidly connected to opposite sides of an alternator field assembly. The alternator field assembly reciprocates with the piston inside of an armature structure. The armature and field pole pieces are oriented in oblique planes relative to one another for the purpose of preventing current ripple. A gas flow actuated fuel intake valve is located Within each piston. Movable exhaust valves are located in each cylinder head. A reciprocating electric motor armature is connected to each exhaust valve. Reciprocation of the alternator field assembly functions to cool the air through the cylinders. Reciprocation of the pistons and the motor armatures pumps a pressure generating fluid medium (typically a mixture of fuel and an oxidizer) hereinafter referred to simply for brevity as fuel axially and centrally through the cylinder. The cooling air is pumped axially and peripherally through bores provided within the cylinders, i.e., in a direction opposing the flow of fuel relative to the cylinder. The aligned cylinders are rigidly associated in a unitary engine frame which is mounted for reciprocation along the axis of the cylinders within an enclosure or casing whereby the combustion of a charge in one of the cylinders causes the piston assembly and the engine frame to travel in opposite direction at speeds which are inversely proportional to their masses. The apparatus may therefore be thought of as a generator of the moving cylinder type. Thus, during operation the generator exhibits reaction generated vibration compensating oppositely directed concurrent piston and cylinder motion.

The above mentioned and other more detailed and specific objects of the present invention will be apparent in view of the following specification and drawings which illustrate one form of the invention and wherein FIG. 1 is a central longitudinal cross sectional view of one form of the invention taken on line 11 of FIG. 3.

FIG. 2 is a central longitudinal cross sectional View taken on line 2-2 of FIG. 3.

FIG. 3 is a transverse sectional view taken on line 3-3 of FIG. 1.

FIG. 4 is a transverse cross sectional view taken on line 4-4 of FIG. 1.

FIG. 5 is a partial longitudinal cross sectional view of the alternator portion of the apparatus on an enlarged scale relative to FIGS. 1-4.

FIG. 6 is a partial plan view of the portion of the apparatus shown in FIG. 5.

FIG. 7 is a transverse sectional view taken on line 7-7 of FIG. 5.

FIG. 8 is a diagram of the left-hand end of the apparatus showing the position of various parts during the first stage of start up.

FIG. 9 is a diagram similar to FIG. 8 showing the second stage of the start up procedure.

FIGS. 10-14 are diagrams showing successive stages in the operating cycle of the apparatus with the shape of some of the parts being altered slightly so that the operating principle can be clearly seen.

FIG. is a schematic wiring diagram of the windings employed in the armature of the alternator and their external connections.

To the accomplishment of the foregoing and related ends the invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.

Refer now particularly to FIGS. 14. The apparatus includes four major component parts. The first of these is a hollow casing designated 10, the second is an engine frame 12 including the alternator armature and cylinders. The third is a piston assembly 14 which includes an alternator exciter or field pistons and intake valves. Finally, two identical exhaust valve assemblies are provided. These are designated 16 and 16 Each includes a linear electric motor field winding (solenoid) and an exhaust poppet valve. One such unit is provided at each end of the engine frame.

The generator casing 10 will now be described. The casing 10 comprises a hollow cylindrical enclosure having domed end walls 18 and 20, left-hand cooling air inlet and outlets 22 and 24 respectively, right-hand cooling air inlet and outlets 26 and 28 respectively, a left-hand fuel inlet 30, a right-hand fuel inlet 32, a left-hand exhaust duct 34 and a right-hand exhaust duct 36.

The top of the casing is suitably bored to receive a pair of longitudinally spaced power output terminals 38 and 40 which extend through insulators 42 and 44 and have secured to their inner ends resiliently mounted contacts or brushes 46 and 48 which engage the power output leads of the alternator armature as will be described more fully hereinbelow. The bottom wall of the casing 10 is suitably bored to receive insulated terminals 50 and 52 having resiliently mounted brushes 54 and 56 connected to their inward ends. The terminals 50 and 52 are used to provide current to the field winding of the alternator.

The casing 10 includes a pair of longitudinally spaced cylindrical bearings 60 and 62 within which the engine frame 12 is mounted for reciprocatory sliding motion. Accordingly, the mating surfaces of the engine frame 12 are machined to just fit within the bearings 60 and 62 and to slide freely therein.

-Rigidly mounted within the domed ends of the casings 18 and 20 are a plurality of buffers 64 each having a flat endwardly facing surface 64 which engages or almost engages the end surface of the engine frame during operation to limit its longitudinal motion as will be described below.

The engine frame 12 will now be described. It has the form of an elongated cylinder and includes end pieces 70 and 72 which contain the exhaust valve assemblies 16" and 16 and left as well as right-hand engine cylinders 74 and 76. The cylinders are spaced longitudinally within the engine frame on aligned axes and are bored concentrically within the surfaces of the engine frame engaging the bearings 60 and 62. Located between the end pieces 70 and 72 is the armature assembly of the alternator 78.

The exhaust valve assemblies 16 and 16 and the associated duct work for providing fuel-air mixture to the combustion chambers will be described next. Since both sides of the generator are symmetrical, only the left-hand valve assembly 16 and its associated duct work will be described.

The engine casing 10 is provided with a chamber at each end within which the linear acting valve actuating motor (solenoid) armature 82 is mounted. The armature 82 consists of a multiplicity of longitudinally extending aligned iron laminates 84 within which a pair of longitudinally spaced solenoid armature coils 86 and 88 are located. Current is supplied to the armature coils through conductors 90 and 92.

Mounted concentrically within the coils 86 and 88 is a solenoid field assembly composed of a soft iron spool 94 which is rigidly connected to a support rod 96 that is mounted for longitudinal sliding motion within the engine frame 12. The field winding 98 of the spool 94 has current supplied to it through conductors 100 and 102 (FIG. 1). An exhaust valve 104 is slidably and concentrically mounted within each of the spools. Each exhaust valve 104 is provided with a flange 104 mounted withing a cylindrical opening 106 such that it engages one end of the opening 106 just before the spool 94 reaches its extreme position of travel either to the right or left.

Fuel supplied through the lines 30 and 32 enters the engine cylinder 10 through an inlet port 110 and then passes to the right and left through a duct 112, thence through radially extending ducts 114 and 114 which communicate at their inner ends with the chamber 80 on one side of the spool 94. Within these ducts are provided one way flap valves 115 and 115 Fuel is exhausted through ducts 116 and 118 which are provided with one Way flap valves 119 and 119 Because of the close tolerance between the outside diameter of the spool 94 and the coils 86 and 88, the reciprocation of the spool 94 during operation acts to pump the fuel from the cham- 'ber 80 through the radially extending outlet ducts 116 and 118 to a longitudinally extending supply duct 120 that communicates with the cylinder 74 at its extreme inward end on the side of the piston opposite the combustion chamber.

The exhaust valve 104 is a poppet type valve mounted within a tapered annular valve seat 122 which communicates with an exhaust duct 124 that is connected at its lower end to one of the exhaust pipes 34 or 36 as the case may be. It will thus be seen that during operation the fuel-air mixture entering through the duct 30 will flow through the ducts 112, 114 and 11-4 into the chamber 80 and will be pumped from chamber 80 through ducts 116, 118 and duct 120 into the cylinders 74 and 76. Exhaust gases will pass from the combustion chamber through the exhaust duct 124 and the exhaust pipes 34 and 36.

The flow of cooling air through the cylinders will now be described with particular reference to FIG. 2. As can be seen in the figure, cooling air enters the casing through inlet ducts 22 and 26. It then flows circumferentially around the engine frame 12, thence centrally through a plurality of circumferentially distributed check valves 126 constructed to enable the cooling air to flow from the enclosure into a chamber 128 within the alternator assembly 78. The cooling air flows from chamber 128 axially and peripherally through any one of a plurality of circumferentially arranged check valves 130, thence through circumferentially distributed longitudinally extending cooling channels 132. The channels 132 communicate with the endmost portion of the casing 10 and with the cooling air outlet duct 24 and 28 through ports provided on the end of the engine frame 12 in axial alignment with the buffers 64. Thus, during operation the cooling air will flow out through the end of the engine frame into the casing 10 and will be exhausted through the ducts 24 and 28. The gases exhausted through the ends of the ducts 132 will cause the reciprocation of the engine frame 12 to be resisted by the air cushion provided between the outward fiow of the cooling air and the buffers 64. In this way the buffers function to dynamically center the engine frame 12 without contacting it under normal conditions and the greater flow of cooling air through the ducts 132 at high engine speeds will provide a greater centering force, i.e., the centering force will be in proportion to the speed of the engine.

The alternator armature will now be described with particular reference to FIGS. 1 and 5. As shown in the figures, the alternator armature consists of a plurality of longitudinally extending circumferentially spaced iron laminates having a helically disposed inwardly opening channel 136 on its inward surface. The armature windings are mounted within the channel 136. As can be seen in FIG. 15, the armature windings are divided into four coils designated 138, 140, 142 and 144. One end of coil 138 is connected to the brush 46 and the other end is connected to coil 140 by means of a conductor 141. The opposite end of coil 140 is connected by means of a con ductor 143 to a coil 144. The inward end of coil 144 is connected by means of conductor 145 to the outward end of coil 142. The inward end of coil 142 is connected to the brush 48. Thus, in a half cycle of operation, current will fiow into the alternator through the brush 46 clockwise through the coil 138, thence through coil 140 via conductor 141. In this way the induced current flow is in the same direction adjacent both poles of the field assembly which will be described below. Current leaves the left half of the alternator armature by way of the conductor 143, then flows counterclockwise through outer coil 144 to the inner coil 142 by means of external conductor 145 and again flows counterclockwise through coil 142 to the brush 48.

The piston and alternator field assembly 14 will now be described in connection with FIGS. 1 and 5. Mounted concentrically within the alternator 78 is an alternator field structure comprising a spool 150 having a circumferentially extending recess 152 within which the armature field winding 154 is located. Integral with the spool 150 are longitudinally extending aligned piston rods 156 and 158 to the ends of which are secured right and lefthand pistons 160 and 162 respectively. Positioned over the connecting rods are conductive sleeves 164 and 166, best seen in FIG. 5, which are wired to the ends of the coil 154 by means of conductors 168 and 170. The sleeves are spaced from the piston rods by insulators 172 and 174 and are conductively engaged by brushes 176 and 178 which are in turn wired to the terminals 50 and 52 respectively.

As clearly shown in FIGS. 1 and 2 the piston rods extend through bores 180 and 182 provide-d within end walls 184 and 186 which define the compartment in each cylinder on the opposite side of the piston from the combustion chamber and it is into this chamber that the fuel mixture enters the cylinder before passing into the combustion chamber. As shown in FIGS. 1 and 2, the pistons 160 and 162 include centrally located annular intake valve ports 190 and 192 which are provided with cooperating poppet valves 194 and 196. The valve stem of each valve is mounted for sliding motion within a central bore provided at the end of each of the connecting rods. The valves 194 and 196 are operated partially by inertia and partially by gas flow. Accordingly, their motion during operation is entirely automatic. Each of the combustion chambers is provided with suitable igniting devices such as a capacitor discharge type spark plug 198 and 199.

The mechanical aspects of the operation of the generator will now be described particularly with reference to FIGS. 8-14. Since the piston assembly 14 is initially at rest and there is no recoil force present prior to firing, some means must be provided to initiate oscillation. This is done by energizing the field coil 98 of one of the linear valve actuating motors by providing a current through conductors 101 and 102, then reversing the current flow and repeating the operation with the solenoid winding 98 at the opposite end of the engine. The first stage of this operation is shown in FIG. 8 wherein the spool 94 is shown traveling from the dotted line position to the solid line position thereby opening the exhaust valve 104. Although most of the motion will be imparted to the spools, a small but definite amount of motion will be experienced by the engine frame and the piston assembly 14. As a result of this motion, a small amount of fuel will enter the combustion chamber and be ignited by the spark plug. With the advent of firing, a recoil or reaction force is present in the engine frame 12. This recoil force is complementary to the magnetic force of the solenoid 98 so that the electrical energy required for solenoid operation decreases after firing. The net wattage required for each solenoid will depend upon the degree that the electric pulses to the solenoids are out of phase with the firing or recoil pulses and therefore can be either a plus or a minus value.

It should be noted that the length of the stroke of each of the spools 94 is made equal to the maximum distance of recoil of the engine frame 12. It should also be noted that the displacement of the spools 94 is utilized in charging each combustion chamber with fuel since the laminates 82 and the coils 86, 88 form a cylinder and the reciprocation of the spool 94 therein serves as a metering device and pump for the fuel.

The fuel enters the combustion chamber behind the piston, i.e., on the opposite side from the combustion chamber. If desired, additional air can be forced into the chamber behind the piston as shown in FIGS. 10-14 and admix with the fuel mixture entering from duct 120. From its location behind the piston, the fuel passes into the combustion chamber through the intake openings 190, 192, the poppet valves 194, 196 being unseated by a combination of gas pressure and inertia.

When the exhaust valves are first opened by the solenoid spools as depicted in FIG. 8, the gas pressure within the combustion chamber causes fuel and air to flow through the combustion chamber and a condition for ignition is established even if the alternator field and piston assembly 14 is at rest. The solenoid spool 94 is then energized so as to travel in the opposite direction, i.e., outwardly as shown in FIG. 9 thereby closing the exhaust valve. When this step has been performed the igniter can be energized to set off the charge in the combustion chamber.

It should be understood that allowance should be made for the time required for the spool to travel to its extreme inward position and the time elapsed between the actuation of the solenoid field winding 98 and the time that the exhaust valve is to close. Since the exhaust valve must not open, the full travel of the spool 98 must be allowed to take place to make sure that the exhaust valve is closed thereby permitting compression of the fuel and air mixture. This is accomplished by allowing a proper clearance as described above between the flange 104 of the valve stem and the solenoid spool 94.

As shown in sequence in FIGS. 10-14 which illustrate the normal operation of the apparatus after the starting procedure has been terminated, the combustion of the fuel-air mixture takes place alternately in right and lefthand combustion chambers. As each charge is exploded, the pressure of the gases closes the intake valve and causes the piston to travel away from the exploded gases in the opposite direction thereby compressing the charge in the opposite combustion chamber. As described hereinabove, the masses 12 and 14 will travel in opposite directions within the stationary casing 10. When the charge in the combustion chamber containing the fuel and air mixture is at a state of maximum compression, the igniter will be energized thereby causing the engine frame 12 to travel in one direction and the alternator field and piston assembly 14 to travel in the other direction. After the charge has been exploded and the mass 14 has reached one extreme end of its travel, as shown in FIGS. 12 and 14, the exhaust valve in that cylinder is opened by energizing the appropriate linear valve actuating motor solenoid. The cylinder is then scavenged by the fuel-air mixture entering through the intake valve from the opposite side of the piston.

Referring specifically to FIG. 10 it will be seen that the ignition has just taken place in the left-hand combustion chamber. The exhaust valve at the left has been closed and the intake valve is just about to be closed by the gas pressure. The fuel-air mixture is at this stage entering the combustion chamber through the intake valve of the right-hand piston. The right-hand exhaust valve has just closed.

In FIG. 11 combustion continues in the left-hand combustion chamber and the left-hand exhaust valve remains closed with the left-hand spool 94 at its extreme right position. The movement of the piston assembly 14 to the right compresses the mixture in the right-hand combustion chamber and the alternator field begins to move cooling air toward the right-hand cylinder. In this stage of the operating cycle, both of the intake valves are closed. It should also be noted that the recoil of the engine frame '12 causes the left-hand solenoid spool 94 to begin to move toward the left relative to the engine frame 12.

Refer now to FIG. 12 which shows the exhaust of combustion gases taking place in the left-hand cylinder and the ignition of a charge in the right-hand cylinder. At this point in the cycle the masses 12 and 14 have begun to travel in the directions opposite those shown in FIGS. 10 and 11.

Refer now to FIG. 13 showing the next succeeding stage, viz., the compression of the fuel-air mixture charged in the left-hand cylinder and combustion in the right-hand cylinder. It should be noted during this stage of operation that the cooling air is forced peripherally toward the left through the cooling ducts of the cylinder by the alternator field member. It should also be seen that the sticking action of the magnetic field in the lefthand solenoid spool closes the exhaust valve. It can also be noted in this stage of operation that the solenoid spools 94 are coming into phase with one another.

Refer now to FIG. 14 which shows ignition in the left-hand cylinder and exhaust in the right-hand cylinder. It will be seen during this stage of operation that both of the solenoid spools 94 are in their extreme left-hand position and that the left-hand exhaust valve is closed while the right-hand exhaust valve is open. These stages of operation are repeated continuously while the generator continues to run.

During operation, the field winding 154 of the alternator is excited by the application of current to terminals 50 and 52. With the winding 154 energized a magnetic field is produced. The two flanges of the spool form its poles. The overall length of the spool 150 is preferably equal to the maximum stroke of the pistons and the length of the armature assembly 78 is twice the length of the piston stroke.

The generation of current without excessive current ripple is accomplished in accordance with the invention by orienting the pole pieces of the spool 150 at an oblique angle relative to the windings of the armature assembly 78. Specifically, the windings in the armature 78 are spirally wound.

Since the windings of the armature are center tapped and connected as described in connection with FIG. 15, the induced current under one pole piece will not be neutralized by that induced under the other pole piece when the coils are series wound. Accordingly, the polarity of the current and the potential at the terminals 38 and 40 remains constant as long as the field assembly moves at a constant speed in the same direction. The current generated has an alternating rectangular wave form.

The internal cooling of the alternator is accomplished through the pumping action of the spool 150 within the alternator armature assembly 78. The check valves in the engine frame assure a positive flow of cooling air into the alternator from the inlet ducts past the combustion chamber through the cooling passages. The opening and closing of the check valves is assisted by the recoil action (reciprocation) of the supporting frame resulting from combustion.

Refer again to FIG. 15 which illustrates one preferred arrangement for coordinating the operation of the linear acting exhaust valve operating motors and igniters. It will, however, be apparent to those skilled in the art that other methods of timing the impulses to the solenoids and synchronizing the igniters with the solenoids can be employed.

The brushes 46 and 48 are connected to a power storage unit 200 through a full wave rectifier 202 by means of conductors 204 and 206. The brushes are also connected to the spark plugs 198 and 199 through a selector pulse sending unit 208 via conductors 210 and 212 and conventional ignition coils 113 and 115. The selector pulse sending unit functions to split the square wave into positive and negative components as shown. The terminals of the power storage unit 200 are connected to suitable solenoid switching units 21 and 203 via conductors 214 and 216. The switching units 201 and 203 are triggered during operation by pulses transmitted from the sending unit 208 through conductors 218 and 220. During the starting operation, current is supplied to conductors 210 and 212 by conductors 228 and 230 which are wired to the output of a low frequency oscillator or multivibrator 232. Current is supplied to the multivibrator 232 from the power storage unit 200 by conductors 234 and 236 and starting switch 238.

Upon closing the starting switch 238, the low frequency oscillator 232 sends signals alternately first to the right solenoid and left spark plug, then to the left solenoid and right spark plug. This initiates combustion. After firing starts, the movement of the alternator produces a square wave current. The selector 208 splits this current into positive and negative components. The decaying portion of the resultant half wave components trigger the proper solenoid switching units 201 and 203 which in turn operate the solenoids 86 and 88. The low frequency oscillator 232 is then turned off.

A generator in accordance with the present invention was constructed without the requirement for gears, levers, springs and other slow-acting and expensive components.

It was found that it could be manufactured inexpensively and exhibited good reliability. The linear acting motor solenoids functioned both for opening and exhaust valves and for metering and pumping fuel to the combustion chambers. The movement of the alternator field windings in addition to inducing a current into the armature acted to pump cooling air through the cylinders. In addition, vibration is compensated and the destruction of wires and other parts is eliminated through the reaction generated oppositely directed concurrent piston and cylinder motion. The scavenging of the combustion chamber was good at all engine speeds. The unit was symmetrical and accordingly the same parts could be used at each end thereby effecting the manufacturing economies. The current generated was uniform and does not exhibit objectionable ripple. Neither hydraulic, air-operated mechanisms or spring were required for actuating exhaust valves.

The engine portion of the apparatus described herein is capable of providing a variable stroke since it is possible for the valves to be closed and ignition to be accomplished with the pistons in any position. As a result, stalling at low engine speeds is not a problem. Since the intake valves function without the application of an external force they may be thought of as being automatic.

The charges of fuel are trapped behind the piston prior to ignition to assure good cooling of the piston. scavenging of the combustion chamber is assisted by the toroidal flow of the fresh charge as it enters the combustion chamber.

A great many variations can be made in the invention, for example the fields can be electrically powered by batteries as described or permanent magnets can be used.

It is apparent that many other modifications and variations of this invention as hereinbefore set forth may be made without departing from the spirit and scope thereof. The specific embodiments described are given by way of example only and the invention is limited only by the terms of the appended claims.

What is claimed is:

1. A reciprocating internal combustion engine electric generator comprising in combination an enclosure having bearing means therein, an engine frame slidably supported on the bearings for reciprocatory motion, said engine frame including spaced cylinders and an alternator armature assembly, a unitary alternator field and piston assembly including an alternator field structure operatively associated with the alternator armature and pistons mounted for reciprocation within the cylinders of the engine frame, means for introducing a fuel into the combustion chamber, and means for exhausting the fuel from the combustion chamber, whereby reaction generated by oppositely directed concurrent piston and engine frame motion at least partially compensates for the vibration generated by the expansion of gases in the combustion chamber.

2. The apparatus of claim 1 wherein the alternator field assembly includes pole pieces and the alternator armature assembly includes windings which are oriented at an oblique angle relative to the pole pieces whereby current amplitude is stabilized.

3. The apparatus according to claim 1 wherein said means for introducing and exhausting fuel from the combustion chamber comprises at least one movable valve mefnber operatively associated with a linear acting electric motor solenoid, said motor solenoid being movable between two extreme positions whenenergized with current of the opposite polarity for opening or closing said valve member.

4. The apparatus according to claim 3 wherein the linear acting motor includes a solenoid spool slidably mounted relative to the valve member for limited axial movement thereon and a means on the spool for engaging a portion of the valve when slid a predetermined distance in either direction relative to the valve member.

5. The apparatus according to claim 4 wherein valve means is operatively associated with the armature field assembly and communicatively associated with a cooling air inlet and outlet valve whereby the reciprocation of the alternator field assembly is thereby adapted to pump cooling air into the proximity of the combustion chamber to remove heat therefrom during operation of the generator.

6. The apparatus according to claim 1 wherein a movable intake valve is provided in each of the pistons, an exhaust valve is provided at the end of the combustion chamber opposite the piston and a means is provided for actuating the exhaust valve in timed relationship to the oscillatory movement of the alternator field and piston assembly relative to the engine frame.

7. The apparatus according to claim 1 wherein the alternator armature includes a spirally disposed inwardly opening recess, windings located in the recess, said alternator field assembly including a cylindrical spool having a circumferentially extending recess therein to define pole pieces oriented at an oblique angle with relation to the spiral recess in the armature whereby undesired current ripple in the power generated is avoided.

8. The apparatus according to claim 1 wherein a linear acting motor solenoid is operatively associated with a movable valve member for opening and closing the valve, said solenoid member being mounted for reciprocation within a chamber in the engine assembly, fuel ducts communicating between the chamber on either side of the solenoid for introducing fuel to the chamber and outlet ducts communicating between the chamber and the engine cylinders whereby the reciprocation of the linear acting motor solenoid within the chamber pumps fuel through the chamber into the cylinders.

9. A reciprocating internal combustion electric generator comprising in combination an engine frame having an alternator armature and a piston assembly having an alternator field assembly mounted for reciprocation therein, said engine frame including cylinders defining a pair of spaced combustion chambers, said piston assembly having pistons mounted for reciprocation in the engine frame in communication with the combustion chambers, and a means in the engine frame for introducing fuel to the combustion chambers, an exhaust valve mounted in the head of each combustion chamber opposite the piston, a linear acting motor solenoid operatively associated with each of the exhaust valves for opening the exhaust valve in one extreme position thereof and for closing the exhaust valve in the other extreme position thereof, conductors operatively associated with the solenoid to provide energizing current to the solenoid whereby the opening of the exhaust valve can be timed independently of the motion of the pistons to thereby enable the said fuel to be exploded in the combustion chambers at any position of the pistons relative to the engine frame whereby stalling at low engine speeds is lessened.

10. The apparatus of claim 9 wherein the alternator field assembly includes a pole piece and the alternator armature assembly includes windings which are oriented at an oblique angle relative to the pole pieces.

11. The apparatus according to claim 9 wherein said valve means is provided comprising at least one valve operatively associated with a linear acting electric motor solenoid, said motor solenoid being movable between two extreme positions when energized with current for opening and closing said valve.

12. The apparatus according to claim 11 wherein the linear acting motor includes a solenoid spool slidably mounted relative to the valve member for limited axial movement thereon and a means on the spool for engaging a portion of the valve when slid a predetermined distance in either direction relative to the valve member.

13. The apparatus according to claim 9 wherein valve means are operatively associated with the armature field assembly and communicatively associated with cooling air inlet and outlet valves whereby the reciprocation of the alternator field assembly is adapted to pump cooling air into the proximity of the combustion chamber to rcmove heat therefrom.

14. The apparatus according to claim 9 wherein an intake valve is provided in each of the pistons, an exhaust valve is provided at the end of each combustion chamber opposite the piston and a means is provided for actuating the exhaust valve in timed relationship to the oscillatory movement of the alternator field and piston assembly relative to the engine frame.

15. The apparatus according to claim 9 wherein the alternator armature includes a spirally disposed inwardly opening recess, windings located in the recess, said alternator field assembly includes a cylindrical spool having a circumferentially extending recess therein to define pole pieces oriented at an oblique angle with relation to the helical grooves in the armature whereby the amplitude of the current generated is stabilized.

16. In a reciprocating internal combustion electric generator of the type having an engine frame including at least a pair of spaced cylinders and a piston assembly operatively associated therewith, an alternator field as sembly operatively connected to the piston assembly and an alternator armature assembly operatively associated with the engine frame and said alternator field having a pair of pole pieces thereon, the improvement comprising providing windings in the alternator armature assembly which are oriented at an oblique angle relative to the pole pieces whereby the pole pieces will cut some of the windings at all times to thereby stabilize the amplitude of the current generated.

17. The apparatus according to claim 16 wherein a linear acting motor solenoid member is operatively associated with a movable valve means for opening and closing said valves, said solenoid member being mounted for reciprocation within a chamber in the engine assembly, fuel ducts communicating between the chamber on either side of the solenoid member for introducing fuel to the chamber and outlet ducts communicating between the chamber and the engine cylinders whereby the reciprocation of the linear acting motor solenoid within the chamber pumps fuel through the chamber into the cylinders.

18. The apparatus of claim 16 wherein the alternator field assembly includes a pole piece and the alternator armature assembly includes windings which are oriented at an oblique angle relative to the pole pieces.

19. The apparatus according to claim 16 wherein said valve means is provided comprising at least one valve operatively associated with a linear acting electric motor solenoid, said motor solenoid being movable between two extreme positions when energized with current for opening and closing said valve.

20. The apparatus according to claim 19 wherein the linear acting motor includes a solenoid spool slidably mounted relative to the valve member for limited axial movement thereon and a means on the spool for engaging a portion of the valve when slid a predetermined distance in either direction relative to the valve member.

21. The apparatus according to claim 16 wherein valve means are operatively associated with the armature assembly and communicatively associated with cooling air inlet and outlet valves whereby the reciprocation of the alternator field assembly is adapted to pump cooling air into the proximity of the combustion chamber to remove heat therefrom.

22. The apparatus according to claim 21 wherein the engine frame is slidably supported in an enclosure for reciprocatory motion, said engine frame having cooling air outlet ports opening endwise from the frame in a direction parallel to said reciprocatory motion, and buffer means on the enclosure opposite said port openings for cushioning such motion of the frame within the enclosure.

23. The apparatus according to claim 16 wherein an intake valve is provided in each of the pistons, an exhaust valve is provided at the end of each combustion chamber opposite the piston and a means is provided for actuating the exhaust valve in timed relationship to the oscillatory movement of the alternator field and piston assembly relative to the engine frame.

24. The apparatus according to claim 16 wherein the alternator armature includes a spirally disposed inwardly opening recess, windings located in the recess, said alternator field assembly includes a cylindrical spool having a circumferentially extending recess therein to define pole pieces oriented at an oblique angle with relation to the helical grooves in the armature whereby the amplitude of the current generated is stabilized.

25. In a reciprocating internal combustion electrlc generator of the type having an engine frame including at least a pair of spaced cylinders and a piston assembly operatively associated therewith, a generator field assembly operatively connected to the piston assembly and an alternator armature assembly operatively associated with the engine frame and said alternator field having a pair of pole pieces thereon, the improvement comprising providing windings in the alternator armature assembly which are oriented at an oblique angle relative to the pole pieces whereby the pole pieces will cut some of the windings at all times to thereby stabilize the amplitude of the current generated.

26. The apparatus according to claim 25 wherein a linear acting motor solenoid member is operatively associated with a movable valve means for opening and closing said valves, said solenoid member being mounted for reciprocation within a chamber in the engine assembly, fuel ducts communicating between the chamber on either side of the solenoid member for introducing fuel to the chamber and outlet ducts communicating between the chamber and the engine cylinders whereby the reciprocation of the linear acting motor solenoid within the chamber pumps fuel through the chamber into the cylinders.

27. A reciprocating internal combustion electnc generator of the free piston type including an engine frame 'having two longitudinally spaced aligned cylinders therein defining combustion chambers at their ends, a piston assembly mounted for reciprocation in the engine frame including a pair of spaced apart aligned pistons mounted for sliding movement within the cylinders, said piston assembly also including an alternator field assembly rigidly associated with the pistons and located therebetween, an alternator armature assembly mounted in the center of the engine frame positioned immediately exteriorly of the alternator field assembly and being operatively associated therewith, a fuel intake valve located in each of the pistons, an exhaust valve located at the end of the cylinder opposite the piston, a valve actuating means operatively associated with each of the exhaust valve s, said generator including a means for pumping cooling air in the proximity of the combustion chamber for removing heat therefrom and a means within the engine frame for pumping fuel to the cylinders in timed relationship to the motion of the exhaust valve.

References Cited UNITED STATES PATENTS 9/1963 James 290-1 2/1966 Colgate 290-1 US. Cl. X.R. 310l5; 322-3

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