US2223898A

US2223898A - Two-stroke internal combustion engine

Info

Publication number: US2223898A
Application number: US230868A
Authority: US
Inventors: Petersen Ove; Solver Einar
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-09-27
Filing date: 1938-09-20
Publication date: 1940-12-03
Anticipated expiration: 1957-12-03

Description

Dec. 3, 1940. o. PETERSEN ET AL I I TWO-STROKE INTERNAL COMBUSTION ENGINE Filed Sept. 20, 1938 P, W g f t R 0. w 3 or 0; v g K w w a 6 MW e 6 I f i 5w; i j T I i- .8 I W i J hf K v 6 Patented Dec. 3, 1940 TWO-STROKE INTERNAL COMBUSTION ENGINE Ove Petersen and Einar salver, Gentofte, near Copenhagen, Denmark Application September 20, 1938, Serial No. 230,868 In Denmark September 2'7, 1937 4 Claims.

This invention relates to two-stroke stationary or marine internal combustion compression-ignition engines having a main piston and two exhaust pistons all operating in a common cylinder and operatively connected to a crank-shaft for the transmission of power thereto.

It is a primary object of the invention to to provide large internal combustion engines of the above indicated type having pistons of equal diameter with any desired number of cylinder units without materially exceeding the over-all length of corresponding engines of known construction.

It is another object of the invention to provide engines of the type above referred to with a considerably smaller weight than the weight of engines of known construction and having the same power output.

Still another object of the invention is to provide an engine of the type described in which the crank-shaft is of a particularly light and rigid design thus permitting comparatively high rotating speed, and in which the cylinder lining and the engine frame is substantially relieved of vertical forces originating from the combustion pressures and of stresses originating from heat distortions.

With these and other secondary objects in view the invention consists in the novel combinations of features disclosed in the following specification and the annexed drawing.

In the drawing:

Fig. 1 is a vertical partial section through a double acting engine according to the invention with part of a connecting rod between upper and lower yokes for the exhaust pistons removed; and

Fig. 2 is a partial section taken on the line IIII of Fig. 1 and drawn to a considerably larger scale.

In the drawing, I is the main piston of the double acting engine which piston is connected to a crank 5 on the crank shaft 6 through a piston rod 2, cross head 3 and connecting rod 4.

- The crank shaft 6 is mounted in main bearings I on the bed plate (not shown) of the engine.

The main piston I reciprocates in a long tubular cylinder composed of two cylinder portions 8 and 8, between which is inserted a shorter annular cylinder portion 9 in which the scavenging air ports it) are arranged so that the scavenging air inlet into the upper and lower ends of the cylinder is controlled by the main piston when the latter moves respectively down below and up over the ports.

The outlet of the exhaust gases from each end of the cylinder takes place through exhaust ports 20 and 20' respectively near the outer ends of the cylinder portions 8 and 8 and the outlet is controlled by-exhaust pistons II and I9 respectively having the same diameter as the main piston. The exhaust pistons are secured to an upper and a lower cross beam I2 and I4 respectively interconnected through vertical rods I3 so that the exhaust pistons are moved as a united assembly approximately in inverse timing relatively to the main piston but with a substantially shorter stroke than the latter. The exhaust pistons are connected with the crank shaft through a pair of vertical connecting rods I5 connected by pins IS with excentric straps I! each of which enclose one of a pair of excentrics I8 disposed on the crank shaft one at each side of the crank 5.

In this construction the cylinder and the engine frame are entirely released of Vertical combustion pressure forces.

The annular scavenging port portion 9 is provided with an outwardly directed flange 26 serving to support the same on a shoulder on a boxshaped scavenging air manifold 23 which surrounds or encloses the scavenging port portion and part of the lower cylinder portion 8. The scavenging air manifold 23 is supported upon a light frame 2|, 22 which may be made of cast iron or consist of a welded structure composed of steel plates and bars. The frame is supported upon the bed plate (not shown) of the engine.

The outer wall of the scavenging air manifold is extended upwards beyond the shoulder supporting the scavenging port portion and thus between the cylinder and the scavenging air manifold is thereby formed a scavenging air space 25 which communicates with the interior space 24 of the scavenging air manifold by way of apertures in the upper Wall of the manifold.

Exhaust manifolds 21 surround the

exhaust ports

20 and 20 and are constructed in such manner that they do not prevent the upper and lower end respectively of the cylinders from longitudinal displacements due to heat extensions. For this purpose the cylinder ends may be slidable in the exhaust manifolds or the latter may be slidable relatively to the remaining engine frame.

We claim:

1. A double-acting two-stroke cycle stationary or marine internal combustion compression-ignition engine having in combination, a main piston and two exhaust pistons opposed to and having the same diameter as the main piston but an essentially shorter stroke than the main piston, a common tubular cylinder provided with scavenging ports at the middle controlled by the main piston and a set of exhaust ports in the vicinity of each open cylinder end controlled by the exhaust pistons, a crank shaft having a crank for the main piston and at either side of the same an eccentric for transmitting the power from the exhaust piston to the crank shaft.

2. A double-acting two-stroke cycle stationary or marine internal combustion compression-ignition engine having, a main piston and two exhaust pistons opposed thereto and having the same diameter as the main piston but an essentially shorter stroke than the main piston, a common tubular cylinder provided with scavenging ports at the middle portion and a set of exhaust ports in the vicinity of each open cylinder end, said cylinder having in the immediate vicinity of the scavenging ports an outwardly directed flange resting on and secured to supporting parts of the engine frame, the cylinder ends projecting upwardly and downwardly respectively having only yieldable connections with fixed parts of the engine frame.

3. A double-acting two-stroke cycle stationary or marine internal combustion compression-ignition engine having, a main piston and two exhaust pistons opposed thereto and having the same diameter as the main piston but an essentially shorter stroke than the main piston, a common tubular cylinder provided with scavenging ports at the middle portion and a set of exhaust ports in the vicinity of each open cylinder end, said cylinder having in the immediate vicinity of the scavenging ports an outwardly directed flange resting on and secured to a generally boxlike scavenging air manifold enclosing the scavenging portion of the cylinder and resting upon fixed parts of the engine frame.

4. An internal combustion engine as claimed in claim 3 in which said cylinder is composed of a central annular portion provided with said scavenging air ports and said supporting flange, and an upper and a lower tubular portion secured thereto.

OVE PETERSEN. EINAR SQLVER.