US2786459A - Internal combustion engine - Google Patents

Description

March 26, 1957 EMBURY 2,786,459

' INTERNAL COMBUSTION ENGINE Filed Feb. 17, 1955 2 Sheets-Sheet l i I111)! "II/77127121)!!! lnvzntor LLOYD ELLIOTT EMBURY.

2 Sheets-Sheet 2 L. E. EMBURY INTERNAL COMBUSTION ENGINE FIG.3

March 26, 1957 Filed Feb. 17', 1955 Inventor u.or0 ELLIOTT EMBURY I A 'ys INTERNAL COMBUSTION ENGINE Lloyd E. Embury, Toronto, Ontario, Canada Application Fehruary 17, 1955, Serial No. 488,873

3 Claims. (Cl. HES-=56 This invention relates to an internal combustion engine of the double acting type, that is, the type wherein combustion chambers are provided in the block at each end of the power cylinder. Means are, of course,- provided for igniting the fuel in the combustion chamber at the required point in the compression cycle and for carburetion and admission of the fuel to the combustion chambers. Double acting engines are not of themselves new. The novelty in my invention resides in the manner in which I interconnect my piston and my crank shaft.

Generally speaking, my engine has a block and a power piston which reciprocates in the bore thereof. The power piston is formed with a cross bore which latter bore in turn has a second piston that reciprocates therein. The second piston is formed with a through bore to slidably and r'otatably accommodate an enlarged bearing section of the crank shaft. The crank shaft is journalled in the block and extends through the bores in both the first and second pistons. The longitudinal axes of the second and third bores are arranged with respect to the longitudinal axis of the crankshaft in such a way that reciprocation of both pistons takes place with rotation of the crankshaft.

Passage means are provided in the block for admitting fuel mixture to the combustion chambers. Flow through these passage means is controlled by the reciprocation of the principal or power piston.

My invention will be clearly understood after reference to the following detailed specification read in conjunc' tion with the drawings.

In the drawings:

Figure 1 is a cut-away view of a block of an engine according to my invention; and

Figure 2 is a sectional view along the line 2 2 of Figure 1. i

Figure 3 is a schematic indication of the fuel travel in my motor.

Figure 4 is an enlargement of one of the elements of ends of the piston 12 define together with the closed ends of the bore 1 1 combustion chambers 15 and 160i a two-cycle engine. sparkplu'gs not shown,- are pro vided for igniting. compressed fuel in the" combustion chambers 15- and 16 respectively, in operation. the ignition system is not illustrated in this specification since it is capable of'considerable variation and does not form a part of this invention.

This invention is concerned with the inter-connection of the crankshaft 19 whiclris journalled in the sides ofthe block. to as indicated at 20 arr-d 21, and its intercon ection with thepower piston 12'- asthe latter reciprocates" during operation.

Detailof atent I principal axis of which is preferably at right angles to the principal axis of the power piston 12. If the principal axis of the bore 22 is not at right angles to such axis,

then the full piston movement will not be transmitted to.

the shaft since some of the movement will be absorbed by the pumping piston 23.

Pumping piston 23 is adapted to reciprocate within the bore 22. the principal axis of which is at an incline to the principal axis of the bore through the power cylinder.

The shaft 19 is formed with an enlarged eccentric cylindrical bearing section 24 which acts as an eccentric crank shaft hearing which slidably contacts the inner surface of the bore 25 in the piston 23, so that as the shaft 19 rotates through a complete rotation the piston 23 'is given a reciprocal component of translation both at right angles to and parallel to the main piston bore.

The bore 25 of piston 23, as indicated above, is inclined with respect to the principal axis thereof, i. e. the axis of the bore 22 in the main piston 12, which isthe axis of reciprocation of piston 23 and as a result of the wedging action taking place between the shaft bearing section 24 and the wall of bore 22, the piston 23 will reciprocate within the bore 22 in the powercyl-in'der as it is actuated by the piston 12 during operation.

By means, then, of providing an eccentric bearing sec-' tion 24 on the shaft 19 which contacts the inner surface of the pumping piston 23 bore, it will be seen that reciprocal movement of the pumping piston 23 axially relative to the main piston 12 bore will actuate the shaft 19 to rotate. Although the pumping piston 23 is free to reciprocate at right angles to the main piston 12 axis, movement of the pumping piston 23 axially relative to said main piston 12 must correspond to a main piston 12 movement in such axial direction. Thus reciprocation of said main piston 12 in an axial direction causes consequent reciprocation of said pumping piston 23 in the same direction, the reciprocation of said pumping piston 23 driving said shaft 19. At the same time the reciprocat- 7 ing pumping piston 23 in said main piston 19 bore suppower heads of the engine.

Fuel is admitted to the end 15 of the engine by the following path. it flows from the carburetor 28 through a passage means in the block 19 indicated by the numeral 2?, the out-put end of which communicates with the open exhaust stroke by the piston 23 and open during the remainder of the cycle. Transfer chamber 26 is in constant communication with a passage 4G connecting transfer chamber 26 with combustion chamber i5 'butpassage 40 ha's'a port 42 closed by the side walls of the piston 12 when it isabove its median position. However, when the Piston 23 is formed with a through bore 25,.

I intend to employ them as a portion of the passage means for admitting fuel to the piston 12 goes below such median position, combustion chamber 15 then comes into communication with port 42. In passage 40 is placed a one way valve 43 adapted to open to allow passage of the fuel upward through the passage 40 under the pressure conditions which exist when pumping piston 23 is half way across bore 22 and moving in a direction to decrease the volume of transfer chamber 26. Thus fuel transfer through passage 40 takes place, only during the travel of the piston from its lowest to its median position and such transfer takes place under the impulsion of pumping piston 23. A similar passage with a similar one way valve (not shown) is provided for similar fuel transfer from transfer chamber 27 to combustion chamber 15. ignition takes place after compression in the combustion chamber has taken place to the predetermined extent, and after ignition the power piston is forced back again and the exhaust gases escape through the exhaust port 35.

Reference may now 'be had to Figure 3, for the operation of the engine. Taking the uppermost disposition of the eccentric bearing section as (i. e. top dead centre for chamber 15) the graphical. operation of the various ports is laid out for two complete rotations of the shaft. For each port or passage listed an upward location of the graph indicates an open port or passage, while the lowermost position indicates the closed position of such port. Thus it will be seen that passages 29 and 30 are aligned from 270 to 90 while the free exit of port 30 is clear of the piston 23 for pumping from approximately 0 to 180. Thus the open operation of ports 29 and 30 takes place in those angular distributions where port 30 is both aligned with passage 29 and free of the piston 23. Port 42 is the upper end of passage 40, the lower end of which is always open while the top is cyclically closed by the main piston. The main piston blocks off at the upper half of the piston rotation, namely from 270 to 90. From 90 to 270 the port is open and pumping piston 23 is moving to compress the fuel in the appropriate transfer chamber to force fuel into the combustion chamber through passage 40. Exhaust ports 45 open at 180 for a short period to allow emission of the gases. Just before the completion of the compression stroke, ignition takes place. The one way valve 1-3 in port 39 operates to close the port in any time when there is an excess of pressure in the combustion chamber over the transfer chamber and does not open until there is a predetermined pressure excess in the transfer chamber over the combustion chamber.

The operation of the fuel supply system is as follows:

With the shaft turning counter-clockwise as seen in Figure 1, let 0 be top dead centre. Then it will be obvious that the piston as shown in Figures 1 and 2 is at 270. Considering the operations on fuel from carburettor 28 to the exhaust then by reference to Figures 1, 2 and 3 it will be seen that passages 29 and 3t? are constructed to align between 270 and 90. During this time, transfer chamber 27 is being enlarged by piston 23 and when the port of passage 30 is uncovered by piston 23 fuel is sucked in by the piston 23. At 90 the piston 12 has lowered to its median position so that port 42 representing the opening of the transfer chamber 26 combustion chamber 15 passage is opened by the downward passage of the upper surface of the main piston. However, a one way valve is placed in the passage to only open under the pressure conditions which exist when the fuel in transfer chamber 27 is compressed to half its volume, i. e. when piston 23 is moving to diminish the volume of transfer chamber 27 and when transfer chambers 26 and 27 are of equal size. Thus although port opening 42 is open at 90, no fluid travels through the passageway into the combustion chamber until the piston reaches 180. Fluid therefore is pushed by the pumping piston 23 into the combustion chamber from 180 to 270, and ceases then, since the piston 12 moving upwardly past the median position closes opening 42. As the main piston continues to move upwardly the fuel pumped into chamber is compressed, the compression increasing to a maximum at top dead centre or 0. Ignition, see graph E, is timed to take place in chamber 15 just before 0. The combustion stroke moves the piston from 0 to with the exhaust port (not shown) opening at 170 and staying open to It will be obvious that each part referred to contributing to the fuel supply to, and combustion in, chamber 15 has its counterpart for performing similar functions with respect to chamber 16. As indicated by graph G, the graphs with respect to chamber 16 are similar to graphs AF but the operations in the two chambers take place 130 out of phase to each other. Thus when pumping piston "is moving to the right in Figure l to pump fuel from transfer chamber 27 into combustion chamber, it is creating a suction in transfer chamber 26 to draw fuel thereinto through passage 31 from the carburettor 28.

I claim:

1. In an internal combustion engine a block having a bore, a first piston reciprocable in said first bore of said block, said first piston being double-acting and partly defining in said block a first combustion chamber and a second combustion chamber, one at each end of the bore in said block, said first piston having a second bore extending thereacross, a second piston reciprocable within said second bore the ends thereof defining therewith and with the walls of said first bore a first transfer chamber and a second transfer chamber, one at each end of the said second bore, said first transfer chamber being operatively related to said first combustion chamber and said second transfer chamber being operatively related to said second combustion chamber, fuel intake passage means to said first combustion chamber including passage means through said block and said first transfer chamber, fuel intake passage means to said second combustion chamber including passage through said block and said second transfer chamber, said second piston being formed with a third bore extending therethrough having its longitudinal axis at an angle to the longitudinal axis thereof, a crank shaft journalled in said block and extending through said second bore in said first piston and said third bore in said second piston, said crank shaft having an enlarged eccentric portion that is translatably and rotatably slidably relative to said third bore in said second piston whereby said first and second pistons reciprocate in their bores when said crank shaft rotates, ignition means for said first and second combustion chambers, exhaust passage means in said block from said first combustion chamber, exhaust passage means in said block from said second combustion chamber, said first piston being adapted to control the opening and closing of said intake passage means and said exhaust passage means cyclically as it reciprocates in operation.

2. A cylinder having a bore, a first piston rcciprocable within said bore, said first piston being formed with a second bore having a longitudinal axis that intersects the longitudinal axis of said first bore but is at an angle of greater than 45 thereto, a second piston in said second bore, a crank shaft journalled in said first cylinder and extending through said second cylinder with its longitudinal axis at an angle to and intersecting the longitudinal axis of said second cylinder, a portion of the part of said crank shaft .that'extends through said second cylinder having an increased diameter and being eccentric relative to the main extent of the shaft whereby said second piston reciprocates as said crank shaft rotates.

3. An internal combustion engine comprising: a block containing a bore in which reciprocates a main piston which defines a combustion chamber at each end of said main piston; a transverse bore in said main piston, relative to the direction of reciprocation of said main piston; a shaft journaled in said main block extending through saidtransverse block and provided with a cylindrical ec- 5 6 centric bearing section, a pumping piston having an outer from each pumping chamber to a respective combustion diameter to slide in said transverse bore and an inner dichamber synchronized with said main piston reciprocatameter to receive said bearing section, whereby a pair ion, whereby said pumping piston supplies a pumping acof transfer chambers are defined on each side of said tion to cause the supply of fuel to said combustion champumping chamber in said transverse bore, fuel entrance 5 her. passageways to said pumping chamber, fuel passageways No references cited.

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