US2696343A

US2696343A - Internal-combustion engine with compressor

Info

Publication number: US2696343A
Application number: US361545A
Authority: US
Inventors: Mallory Marion
Original assignee: Mallory Research Co
Current assignee: Mallory Research Co
Priority date: 1953-06-15
Filing date: 1953-06-15
Publication date: 1954-12-07
Anticipated expiration: 1971-12-07

Description

D 1954 M. MALLORY INTERNAL-COMBUSTION ENGINE WITH COMPRESSOR Original Filed May 21, 1948 B/NE EX FOR COOL! M W n 0 M United States Patent f INTERNAL-COMBUSTION ENGINE WITH COMPRESSOR assignor to The Mallory Mich a corporation of No. 28,444, 1953, Serial 7 Claims. (Cl. 230-48) This invention relates to a combined internal cornbustion engine and fluid compressor, and has for its primary object to improve the construction and operation of units of this character to enhance the practicability and commercial value thereof.

Another object is to provide such an arrangement, construction and operation of the movable parts of the unit as to reduce to a minimum the thrust action of the ignited charges on the crankshaft, and to utilize the crankshaft mainly as a timing means for the pistons, the ignition and the valve mechanism.

Other objects of the invention will be apparent from the following description, and from the accompany ng drawing, illustrating one em odiment thereof, in WhlCh Fig. l is a central vertical longitudinal section of an apparatus embodying the invention, with parts in full and with the engine piston approximately in firing position;

Fig. 2 is a fragmentary section with the engine piston at the end of its firing stroke and the compressor p1ston at the end of its compressing stroke, and

Fig. 3 is an enlarged detail, partly in section, of the floating connection of the piston connecting rods with each other and with the crankshaft.

Referring to the drawing, 1 designates a cylinder unit having at one end an engine cylinder 2 and at 1ts other end a compressor cylinder 3, with a crank case 4 therebetween. A crankshaft 5 is journaled in the sides of the crank case 4 and has a wrist-pin 6 in the case. A power piston 7 is mounted in the cyl1nder 2 and cooperates with its outer end to form a combustlon chamberS. A compressor piston 9 is mounted in the cylinder 3 and cooperates with its outer end to form a compressor chamber 10. The pistons 7 and 9 are connected at their inner ends to the wrist-pin 6 by respective connecting rods 11 and 12, the connection being such that when the engine piston is at the limit of its out or compression stroke, the compressor piston 9 is at the lnn t of its in or suction stroke, as shown in Fig. 2.

Each connecting rod 11, 12, has a loose or floatlng connection with the wrist-pin 6, and the rods are connected without play to each other. This is accompl shed by rotatably mounting the inner ends of the two connecting rods without clearance, other than to provide a free turning fit, on a bearing sleeve 13, which in turn is mounted with a clearance 14 for limited floating movements on the wrist-pin 6. This permits one or the other of the sleeve and piston to have lagging movements relative to the other during running of the apparatus for the purpose hereinafter described.

The engine operates on the two-cycle principle and its cylinder 2 has the intake port 15 and the exhaust port 16 located to be uncovered to the combustion chamber by the piston at the inner end of its stroke, the exhaust port being uncovered preferably slightly in advance of the intake port, as is customary. The cylinder 2 is provided at the outer end of the combustion chamber with a sparkplug 17 for igniting the charges. Carbureted fuel charges are introduced into the cylinder through the port 15 from a line 18 which is opened to an air supply source, and has a fuel jet 19 discharging in a restricted portion thereof toward the port 15. A throttle 20 is disposed between the fuel jet and the port.

The outer or compression end of the compressor cylinder has a rotary valve 21 mounted therein and pro- 2,696,343 Patented Dec. 7, 1954 vided diametrically therethrough with a port 22, which during rotation opens connection first between the compressor cylinder 10 and an air inlet port 23 and then between the compressor cylinder and an outlet port 24. The valve 21 is connected to the crankshaft 5 to operate in synchronism therewith, in the present instance at a one to two ratio, so that the crank makes two revolutions to one of the valve. The arrangement is such that the valve port 22 opens communication between the intake port 23 and the cylinder 10 during approximately the full in or suction stroke of the compressor piston, and then closes such port and opens communication between the cylinder 10 and the outlet port 24 during substantially the entire out or compression stroke of the piston.

In practice, it is preferable to close the valve port 22 to the intake port 23 slightlybefore the piston completes its in or suction stroke and at approximately the same time, but after such closing, to open the cylinder to the outlet port, this latter opening taking place at approximately the same time as the ignition of the power charge.

The inlet port 23 preferably opens to the atmosphere, and the outlet port 24 preferably connects through a pipe 25 with an air charge storage tank 26. The tank 26, in the present instance, has connection with the air charge line 18 to serve as its supply source and is also shown as having connection through a line 27 with an air turbine 28, the rotor of which is mounted on the crankshaft 5 so that air pressure from the tank is utilized to assist in the driving of the shaft. In addition to the air turbine 28, the usual flywheel (not shown) is preferably provided on the crankshaft. The tank may also have a valve controlled outlet 29 whereby the compressed storage air may be used for any desired purpose.

In the use of the present apparatus, the main power of the combustion in the engine cylinder is not transferred through the crankshaft to deliver power to the compressor unit, as is customarily the case with apparatus of this type, but most of the power generated by the combustion is transferred through the

piston connections

11, 12 and 13 directly to the compressor piston 9 instead of through the crankshaft. The crankshaft plays more the function of timing the piston, the ignition and the valve mechanism. Naturally, due to thefloating action of the sleeve 13 on the crankshaft, there is little stress on the bearings of the shaft and on the connecting rod bearings, and a small crankshaft and bearings therefor and for the connecting rods can be used.

Assuming, in operation, that the compressor piston 9 has reached the end of its intake stroke, an atmospheric charge has been drawn through port 23 and rotary valve port 22, but as the piston 9 reaches the end of its intake stroke, port 22 ceases communication with port 23 and makes communication with the outlet port 24. The pressure in tank 26 being higher than atmospheric pressure immediately flows back into the atmospheric pressure or the existing pressure drawn into the cylinder through port 23 on the intake stroke of the piston. The explosion then takes place in the engine cylinder and the explosive force on the engine piston 7 is directly against the maximum air pressure in the tank 26, which is now open to the compressor cylinder 10, especially after the engine crank has moved slightly past dead center. The explosive force is communicated directly through the pistons and connecting rods instead of to the crankshaft and then to the compressor piston due to the sleeve bearing 13 being mounted for limited play or clearance on the crankshaft while its bearing in the inner ends of the connecting rods 11 and 12 is without clearance. This explosive force is also against the air pressures or tank pressures in the compressor chamber 10 at the beginning of the explosion, inasmuch as the rotary valve 21 will at the time of explosion be in a position to connect the air pressure in the tank 26 with the compression cylinder 10. Therefore, the air pressure in the tank will be directly against the combustion pressure in the engine-cylinder, thus relieving much of the load from the crankshaft. This eliminates to a great extent dead center of the engine unit. In other words, if the crankshaft was not used and the connecting rods 11 and 12 were solidly connected together, the entire explosive force would be against the air pressure and there would beno dead center. Of course, however, with such a eonstructiomdifficulties would arise due to proper timing of the pistons, the igntion and the valve. The crankshaft is used for timing and, of course, to store energy ;to cause compression in engine cylinders and to complete scavenging of 'the aircornpressor cylinder during starting of the engine and to assist in the starting operation.

With'the clearance provided between the connecting rod bearing sleeve 13 and the crankshaft, once the crankshaft is started, the flywheel speed will not be delivering the load-of the engine, but will be running more freely and tend to travel ahead or lead the pistons. If the load increases, that is, the air pressure builds up in the tank 26 and compression cylinder 10, to oppose combustion to the-extent that the pistons would tend to slow down, the flywheel speed, or the airturbine speed, will take the lead. If an air turbine 28 is employed in addition to the'flywheel, the tank or other pressure for actuating the turbine will always keep the flywheel pullingagainst the pistons, and of'course if the air pressure is from the storage tank 26, there is no loss of power because the power used from the tank to keep the turbine turning is added back to the engine power.

It is important for proper operation that the area of the compressor cylinder be larger than that of the combustion cylinder. The reason for this is that the combustion pressures are much higher than the compression pressures. For instance, supposing the combustion pressures to be 400 pounds per square inch and the cylinders had an area ratio of two to one with the compression cylinder the larger, the air compression piston having twice the areaof the combustion piston would cause practically a balance. If the cylinders were one to one, the volume of air handled would be low. The idea is to use a large volume of air under a lower pressure than the combustion pressures. Naturally, the combustion piston would be smaller than the compression piston, and the air pressure obtained depends-on the area ratio of the two pistons.

I wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous modifications and changes without departing from the spirit of the claims.

This application is a continuation of my application Serial No; 28,444, filed May 21, 1948, now abandoned.

I claim:

1. Aninternal combustion engine and fluid compressor unit comprising in combination opposed engine and compressor cylinders, a piston in each cylinder, a direct connectlon between said pistons for driving the compressor piston from the engine piston and constructed and arranged so that the engine piston is at the end of its compression stroke when the compressor piston is at the end of its suction stroke and the engine piston travels on its power stroke as the compressor piston travels on its compression stroke, said compressor cylinder having fluid inlet and outlet ports, valve means cooperating with said ports for'selectively opening and closing said ports, a fluid reservoir in communication with said outlet port, and means loosely connected to and driven by said engine piston and connected to said valve means for moving said valve means to open or closed position with respect to said ports in timed relation with the reciprocating compressor piston whereby upon the suction stroke of said compressor piston the inlet port is open and the outlet port is closed and upon the compression stroke of said compressor piston the inlet port is closed and the outlet port is open to place the compressor cylinder and fluid reservoir in communication, said direct connection between said pistons and said means loosely connected to said engine piston being adapted to admit substantially the full pressure of the fluid charge in the reservoir against the compressor piston whereby the explosive force on the engine piston during the power stroke will be exerted directly against the fluid under pressure in said compressor cylinder and reservoir.

2. The internal combustion engine and fluid compressor unit claimed in claim 1 wherein the inlet port of said compressor cylinder opens directly to atmosphere so that the compressor piston on its suction stroke draws in a charge of atmospheric air.

3. The internal combustion engine and fluid compressor unit comprisingthe-means loosely 'connected to said engine piston defined in claim 2 including a crankshaft driven by said connection and timing means driven ofl said crankshaft and connected to said valve means for opening and closing the said valve means which controls the inlet and outlet ports of said compressor cylinder, substantially allof the explosiveforce on the engine piston being transferred directlythrough said connection to the compressor. piston and said crankshaft serving primarily to time the opening and closingof said valve means.

4. The internal combustion engine and fluid compressor unit as defined in claim 3 wherein said valve means comprises a rotary valve which opens the inlet port-as it closes the :outlet .port and closes the .inlet port as it opens the outlet port.

5. An internal combustion engine construction comprising, an engine-crankshaft, an engine cylinder with a power piston therein, a connecting rod pivotally connected at oneend to thepower piston, anzair-compressing cylinder with .a compression piston therein, a connecting rod pivotally connected at one end to the compressorpiston, means pivotally connecting the opposite-end of each connecting rod to a throw of the crankshaft, the compressing cylinder having an inlet: port to the atmosphere and having anoutle'tporbfor compressed air, a reservoir for compressed air, conduit means connecting the reservoir to the outlet port,rnotor means operable by compressed air and connected tothe zreservoir {and arranged to apply torque to the crankshaft, the two pistons being so related that when the power piston is substantially at-the limit of its compression stroke'the compressor piston? is substantially at the limit'of its intake stroke and the throw of the crankshaft approximates a dead center position, valve means for controlling said inlet and .outlet ports, valve-operatingmeans connected with saidvalve means and operable by the crankshaft and timed by the crankshaft to operate said valve means to open the exhaust portand establish an open connection between the reservoir and the compressing cylinder when the two pistons are substantially in the stated positions, so that the substantially full, pressure of the compressed air inthe reservoir is active upon the compressor piston substantially immediately at .the start of the power stroke of the power piston, whereby the peak pressure of the powerstroke is utilized for further compression of theairzand the crankshaft is relieved of the peak pressure whensthe throw of'thecrankshaft approximates a dead center position.

6. The engine construction as recited in claim 5 characterized in that there is means which connects :the. said opposite ends of the connecting rods to each other with a snug pivotal connection. and" additionally connects said ends of'the connecting rods to the .throw of the crankshaftwith a loose pivotal connection, whereby the throw of the crankshaft may lead themovement of the power piston.

7. The engine construction as recited in claim 6 characterized in that the means which connects the said opposite ends of the connecting rods is a sleeve to which the said ends of the connecting rods are pivotally connected, said sleeve-being mounted on a throw of the crankshaft and having an internal diameter in excess of the diameter-of the throw to provide the loose connection.

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