US1573319A - Reversing mechanism for opposed-piston engines - Google Patents

Description

Feb. 16 1926.

A. T. KASLEY REVERSING MECHANISM FOR OPPOSED PISTON ENGINES Filed July 2, 1921 U 8 w T A INVENTOR AITORNEY Patented Feb. 16, 1926.

ALEXANDER T. KASLEY, OF ESSINGTQN,

PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATIQN OF PENN- SYLVANIA.

REVERSING MECHANISM FOR OPPOSED-PISTON ENGINES.

Application filed July 2,

,ment of the oppositely moving pistons, and

it has for an object the provision of means whereby the pistons controlling the exhaust ports may be caused to lead the other pistons in both forward and reverse movements of the engine.

These and .other objects, which will be more manifest throughout the further description of my invention, are obtained by means of the apparatus described herein and illustrated in the accompanying drawing in which- Figure 1 is a longitudinal view, partially in section and partially in elevation, of a multiple cylinder engine embodying my invention, two engine units only being shown;

Figure 2 is a transverse sectional view thereof, taken on the line II-II of Figure 1; I

Figure 3 is a longitudinal view, partially in section and partially in elevation, of a modified form of the transmission mechanism illustrated in Figure 1;

struct the transmission mechanism in such a manner that the pistons controlling the exhaust ports lead the pistons controlling the air admission ports. This construction has the advantage of securing better scavenging of the exhaust gases from tle cylin- 'der and of permitting the cylinder to be 1921. Serial No. 482,231.

charged with pure air under a considerable pressure prior to the compression of the charge by the pistons. The leading pistons uncover the exhaust ports prior to the opening of the airadmission ports so as to permit the pressure within the cylinders to be reduced to substantially atmospheric pressure; the air then being admitted through inlet ports thoroughly sweeps out the exhaust gases. Moreover, on the compression stroke, the exhaust ports are covered prior to the air admission ports, allowing the cnteringair to build up a considerable pressure within the cylinder and thus increasing the amount of the air charge available for the power stroke. Such constructions, however, are not reversible, since the setting of the pistons controlling the exhaust ports in advance of the other pistons produces an arrangement in which the time of opening of the cylinder ports is unsuited for reverse operation.

It is the specific purpose of the 'present invention to provide a means whereby the pistons controlling the exhaust ports may lead the other pistons both during normal forward movement of the engine and during reverse movement thereof, thus enabling an engine of this type to operate efficiently in-either direction. In carrying out my invention, I provide for a suitable angular lost-motion in the pinion carried by the crank shaft to which the pistons controlling the exhaust ports are connected. During the normal forward movement of the multiple-cylinder engine, the rotational torque on the crank shafts is always positive in a single rotational direction, and hence permits a constantly effective rotational force, acting through the lost-motion device, to actuate the pinion, it being understood that the parts are so constructed that the pistons controlling the exhaust ports lead the pistons controlling the air-admission ports. Upon reversal of the engine, the rotational torque .being in the opposite direction, the lost-motion mechanism permits a suitable relative angular adjustment between the crankshaft and the pinion to effect, during the reverse movement, an angular lead of the cranks carny'ing the pistons controlling the exhaust ports. The change of the relative angular motion of the crank shafts is effected automatically upon each reversal of the engine and necessitates no operation other than that required in reversing an internal combustion engine of the usual construction.

A fuller understanding of a structure embodying my invention may be had from a reference to thedrawings in which I illustrate, in Figures 1 and 2, a multi-cylinder internal combustion engine 10, two cylinders 11 and 12 only of which are shown. It is to be understood, however, that the engine may be of a greater or lesser number of cylinders and that the particular engine disclosed is merely for the purpose of illustration. Each engine element comprises a cylinder 16, having open ends 17, and provided with a cooling jacket 18. Suitable fuel injection ports 20, air admission ports 21, and exhaust ports 22 are so disposed in the cylinder 15 that oppositely moving pistons 24, 25 form, at or near their extreme inner positions, a combustion chamber of limitedcapacity into which fuel is injected through the port 20, and serve, near the outer extent of their travel, to cover and uncover the air admission ports 21 and the exhaust ports 22. The pistons 24, 25 are directly connected by connecting rods 26, 27 to crank shafts 28, 29, which are located at opposite ends of the cylinders 15. The crank shafts are provided with offset crank portions 30, 31 having pitman bearings 32, 33, which are engaged by the outer ends of F the connecting rods 26, 27. Pinions 36, 37 are secured to the crank shafts 28, 29 and engage a co-acting gear 38 mounted upon a power shaft 13. The gears may be of any suitable construction, gears of the herringbone type being shown in Figures 1 and 2 and of the double helical type in Figures 3,

4 and 5, both types being particularly adapted for the transmission of ower from the crank shafts in the type of engine illustrated.

The cooling jacket 18 may be constructed in any conventional way but is preferably constructed to cool the entire engine element and, hence, surrounds not only the portion of the cylinder subjected to the heat of the combustible gases but embraces, as well, the air inlet and exhaust ports and the manifolds leading thereto. As shown, portions of the cooling jacket adjacent the manifolds are flanged as at 42, the flanges of the adjacent cylinders serving to aline the manifolds and to unite, by means of the bolts 43, the several cylinders of the engine unit.

The pinion 37 is actuated from the shaft 29 through a hub 45 which is secured to the shaft 29 by a key 46. The hub is provided with two diametrically opposedly-ex tending lugs 47, which are capable of limited angular movement within cooperating recesses 48 formed in the pinion 37. Cover tion thereof is as follows:

other. The recesses 48 thus form dash pots.

for the lugs 47 and prevent sudden movements or slamming of the pinion upon the hub. Oil, for purposes of lubrication, which in some installations may be made to fill the recesses 4.8, may be introduced through the ducts 52 and 53. The air within the recesses 48 affords sufficient resistance to the relative movements of the pinion and hub, where a sutlicient number of cylinders are employed, since the rotational torque is always in one direction and the lugs 47 are, consequently, held at one end of the recess, as shown in Figure 2. In case a small number of cylinders comprise an engine unit, however, the recesses 48 are preferably filled with oil, sincea certain amount of back lash between the shaft and pinion may occur at times, as when a cylinder misses fire. In such cases the movement of the lugs 47 within the recesses is much retarded by the necessary movement of the oil from one side of the piston to the other and destructive shocks are in this manner obviated.

Having described the arrangement of apparatus embodying my invention, the opera- In a normal forward operation of the engine, the pistons 25 controlling the exhaust ports 22, are arranged to lead the pistons 24 controlling the air admission ports 21 by providing a relative angular displacement of the cranks 31 and 30, which displacement is effected by the proper disposition of the hub 45 upon the shaft '29 and is maintained through the gear train 36, 37 and 38. Assuming that the rotational torque in each crank shaft is contra-clockwise in the forward movement of the engine, the lugs 47 are held at the ends of the recesses 48 shown in Figure 2 by the constant uni-directional ,rotational torque of the shafts 28 and 29.

When the engine is reversed, as by the application of compressed air to the cylinders in a manner common in the internal combustion engine art, the rotational torque of the shafts 28, 29 is reversed in direction and the tons 25 associated with the cranks 31 lead the pistons 24 associated with the cranks 30 during the reverse rotational movement of the engme, and, consequently, secure the advantageous conditions of scavenging and charging inherent in th1s relation of op- -positely moving pistons. As has been ingoverning pump, may, if desired, be maintained within the pinion recesses.

The construction illustrated in Figures 3, 4 and 5 is adaptable to double helical reduction gearing when employed with an internal combustion engine of the type shown in Figure 1. As illustrated, the crank shaft 28 carries a double helical pinion 57, the driving shaft 13, a double helical gear 58 and the crank shaft 29, a specially construct-- ed double helical pinion 60. The pinion 69 is constructed of two members 61 and 62, each of which is slidably keyed to the crank shaft 29, as by keys 63. Suitable stops 64 integrally secured to the shaft 29 hunt the sliding movement of the pinion members upon the shaft. A fluid-tight cylindrical chamber 65 is formed between the pinion members 61 and 62 which, as shown, comprises a cylinder 66 secured to the inner side of the pinion 61 and a cooperating cylinder 67 secured to the pinion member 62. The cylinders 66 and 67 are arranged to move telescopically one within the other, the cylinder 67 being provided with packing rings 68 to prevent leakage of fluid from chamber 65. An oil passage 69 may be provided in the shaft 29 and branch passages 70 may lead from the passage 69 into a cylindrical chamber 65.

The operation of the construction illustrated in Figures 3, 4 and 5 is carried out in the following manner. It is apparent that when the pinion members 61 and 62 are rotating in the contra-clockwise direction indicated by the arrows (see Figure 5), the lateral components of force created by the engaging teeth of the helical pinion members driving the double helical gear 58 is exerted to drive the pinion members apart. The pinions being slidable on the shaft 29 are thus forced outwardly to contact with the outer stops 64, with which they are held in contact during the forward rotational movement of the engine by the constant uni-directional rotational torque acting through the crank shaft 29, and the pinion 60. In

this position of the pinion, the cranks upon the shafts 28, 29 are arranged to be so disposed that the pistons associated with the crank 29 lead the pistons associated with the crank 28 and thus secure in operation. the advatanges inherent in this method of operating an internal combustion engine. If now, the internal combustion engine is reversed, the rotational direction of the crank shafts is likewise reversed and the lateral component of force created by the engaging teeth of the pinion members driving the double helical gear 58 is exerted inwardly and the pinion members 61, 62 slide along the shaft 29 and abut the inner stops 64 where they are held by the constant unidirectional rotational torque of the shaft 29, now acting in a reverse direction. The movement of the pinion members from the outer to the inner position, due to the angular arrangement of the engaging teeth of the pinion 69 and gear 58, causes the relative rotation of the shaft 29 without effecting a corresponding rotation of the shafts 13, or crank shaft 26. This rotational movement is designed to be sufiicient in amount to give the crank shaft 2:)and the associated pistons 25 the desired lead over the pistons 24, associated with the crank 28 so as to secure the advantages derived from this arrangement of pistons in the reverse operation of the engine.

It may be desirable to supply oil, under pressure, to the cylindrical chamber 65 during the forward operation of the engine, especially where a back lash of the crank shaft is likely to occur. The oil may be supplied from the oil governor pump or other suitable source, and serves, when introduced into the cylindrical chamber 65 between the pinion members 61 and 62, to prevent shocks and slamming of the pinion members, due to the sudden changes in the direction of rotational torque of the crank shafts, should such occur. During the reverse periods of operation, which are generally of short duration, no prcssu re is maintained upon the oil within the cylinders 61, 62. The cylindrical chamber 65, however, serves as a dash pot and effectively prevents the outward slamming of the pinon mem bers when the engine is again actuated in normal forward movement.

It is apparent from the above description that I have provided a simple, compact, and rugged construction for employment in connection with the transmission mechanism of an opposed-piston internal combustion engine, in which the pistons control the air admission and exhaust ports, which construction insures the opening of the exhaust ports prior to the opening of the air admission ports and the closing of the exhaust ports priorto the closing of the "air admission ports in both forward and reverse movements of the engine, an arrangement which particularly adapts an engine of the character designated to be employed in marine propulsion.

\Vhile I have shown my invention in but two forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In an internal combustion engine, the combination of a cylinder, oppositely moving pistons therein, scavenging and exhaust ports controlled by the pistons, cranks to which the pistons are connected, and means automatically operative for adjusting the relative angular disposition of the cranks to each other so that the piston controlling the exhaust ports may lead the other piston in both forward and reverse operations of the engine. a

2. In an internal combustion engine, the combination of an open-ended cylinder provided with scavenging ports and exhaust ports, two oppositely moving pistons in said cylinder, one of said pistons controlling the exhaust port, the other piston controlling the scavenging port, and means for automatically causing the piston controlling the exhaust port to lead the other piston in both forward and reverse operation of the engine.

3. In an internal combustion engine, the combination of a cylinder, oppositely moving pistons therein, scavenging and exhaust ports controlled by the pistons, crank shafts spaced from each end of the cylinder, rods directly connecting each piston with the adjacent crank shaft, gears for synchronizing the rotational movements of the crank shafts, and automatically operative means associated with one of the gears for causing the piston controlling the exhaust ports to lead the other piston in both forward and reverse operations of the engine.

4. In an internal combustion engine, the combination of a cylinder, oppositely moving pistons therein, scavenging and exhaust ports controlled by the pistons, crank shafts spaced from each end of the cylinder, rods directly connecting each piston with the adjacent crank shaft, pinions secured to each crank shaft, a driving shaft, a gear on the driving shaft engaging the pinions, and automatically operative means associated with one of the pinions for causing the crank shafts to be angularly displaced relative to each other in such manner that the piston controlling the exhaust ports leads the other piston in both forward and reverse operations of the engine,

In an internal combustion engine, the combination of a cylinder, oppositely moving pistons therein, scavenging and exhaust ports controlled by the pistons, crank shafts spaced from each end of the cylinder, rods directly connecting each piston With the adjacent crank shafts, gears for synchronizing the rotational movements of the crank shafts, and a lost-motion device associated with one of the gears for causing the piston controlling the exhaust ports to lead the other piston in both forward and reverse operation of the engine.

6. In'an engine installation, the combination of two substantially parallel and spaced apart crank shafts, a plurality of open-ended cylinders disposed between the crank shafts, opposed-pistons in each cylinder, inlet and exhaust ports controlled by said pistons, gears for synchronizing the rotational movements of the crank shafts, and automatically operative means associated with one of the gears for causing the pistons controlling the exhaust ports in the several cylinders to lead the other pistons in both forward and reverse operation of the engine.

7. In an engine installation, the combination of two substantially parallel and spaced apart crank shafts, a plurality of open-ended cylinders having their center lines in the plane of the center lines of the crank shafts, opposed pistons in each cylinder, inlet and exhaust ports controlled by said pistons, a driven element, transmission mechanism between the crank shafts and the driven element, and automatically operative means for adjusting the relative angular disposition of the cranks to each other so that the pistons controlling the exhaust ports may lead the other pistons in both forward and reverse operations of the engine.

8. lln an engine installation, the combination of two substantially parallel and spaced apart crank shafts, a plurality of open-ended cylinders having their center lines in the plane of the center lines of the crank shafts, opposed pistons in each cylinder, inlet and exhaust ports controlled by said piston, and automatically operative means for adjusting the relative angular disposition of the cranks to each other so that the pistons controlling the exhaust ports may lead the other pistons in both forward and reverse operations of the engine,

In testimony whereof, I have hereunto subscribed my name this 30th day of June,

ALEXANDER T. KASLEY.

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