Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B41/00—Engines characterised by special means for improving conversion of heat or pressure energy into mechanical power
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
  • F02F7/00—Casings, e.g. crankcases or frames
  • F02F7/0002—Cylinder arrangements
  • F02F7/0019—Cylinders and crankshaft not in one plane (deaxation)
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
  • F02B75/00—Other engines
  • F02B75/02—Engines characterised by their cycles, e.g. six-stroke
  • F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
  • F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• This invention relates to improvements in internal combustion engines, and most especially relates to so- called two-cycle engines.
• crankshaft is offset to one side of the central longitudinal plane of the engine cylinders, in the direction of the crank-
• crankshafts there are two crankshafts offset on either side of the central plane of the cylinder which rotate in opposite directions.
• the crank ⁇ shaft is offset in the direction of rotation of the crank-
• Fels utilizes an intermediate rocker arm between the crankshaft and the piston connecting rod in order to maintain a more nearly constant torque delivery during the engine cycle.
• a two- 0 cycle engine can be operated efficiently at a higher engine speed by increasing the period during which the inlet ports are open during each cycle.
• the crankshaft is offset laterally from a common plane including the longitudinal axis of each cylinder.
• crankshaft rotation is in a direction opposite that of the direction of the off-set.
• Figure 1 is a side elevation view of the crankshaft of a three-cylinder engine according to this invention, with attendant reduction gears and showing one of the pistons attached to the crankshaft;
• Figure 2 is a front elevation view showing the for- ward end of the crankshaft and main drive, together with the attendant reduction gears of the engine of Figure 1;
• Figure 3 is a transverse section through a cylinder and crankshaft of a two-cycle engine of the type of Figure 1;
• Figure 4 is a top plan view of the cylinder of Figure 3;
• Figure 5 is a plan view of the three-cylinder engine illustrated.
• Figure 6 is a cross-section through a piston showing a further embodiment of this invention.
• OMPI except for the significant advantages of decreased size and weight for given power output obtainable by the present invention, it is believed to be sufficient to illustrate only those portions set forth herein; these include a cross-section of a single cylinder, with the connecting rod and crankshaft connections being only diagrammatically shown.
• the invention deals primarily with the relationship of these parts to each other and not to any specific structural features.
• The. engine shown is of the two-cycle diesel type, although this is merely exemplary and the invention is equally adaptable to a spark ignition engine, or even other modes or type of engine power cycles possible with reciprocating piston engines, that can function with an inlet port located through the side wall of the cylinder that is alternate ⁇ ly opened and closed directly by the movement of the pis ⁇ ton.
• the cylinder As shown in the drawings, the cylinder, generally indicated by the numberal 10, has a piston 12 reciprocally movable therewithin.
• the piston 12 includes a relatively thick head portion 13 and skirt 14 extending ou wardly therefrom.
• a wrist pin 16 is mounted within the skirt 14 at a location adjacent the outer end thereof.
• a piston connecting rod 18 is journaled around the wrist pin 16, at the upper end of the connecting rod 18.
• the piston head 13, as depicted in the drawing, presents a substantially convex surface, which is conventionally used for diesel engines. Similarly, a flat head surface could be provided if the engine were to be used in a spark ignition cycle.
• Other configurations can be utilized, which are well known in the art, or which may be developed in the future, without affecting the present invention.
• any particular combustion chamber design e.g., the com ⁇ bination of valves, fuel inlets, and apark plugs, if any are used.
• the in-line, two-cycle engine dipicted in the drawings is shown as having three cylinders in accordance with Fig. 1. It must be understood that this number is not limiting and either a smaller or greater number of cylinders can be present in any operating engine in accordance with this in vention.
• the crankshaft in all cases is located such that its longitudinal axis is parallel to but laterally offset to a substantial extent from, the common plane extending longitudinally of the cylinder block and including the longitudinal axis of each cylinder in the block.
• crankshaft generally indicated by the numeral 24, is de ⁇ signed for a three-cylinder engine and thus includes three cranks 25, 26 and 27, which are separated from each other by the same distances as separate the center lines of the cylinders, and are angularly spaced apart about the cir ⁇ cumference of the crankshaft, 120 degrees. As is shown in Fig. 1, the crank 25 is journaled within the second end of the connecting rod 18.
• the crank 24 operates the exhause poppet valves and the various other accessories which may be utilized with this engine, such as for example an air turbo-charger, through the reduction gears shown in Fig. 2.
• the main drive 30, driven by the pinion gear 29 connects to the main cam drive gear 32 which, in turn, is connected by conventional means to the other camming gears including the right cam gear 38 and accessory gear 34, the left cam idler 35, the lef accessory drive ' 36, the right accessory drive 37, the right cam gear 38, and the left cam gear 29.
• the shaft connections between these various gears and the exhaust valves or accessories are not shown here but are conventional in the art, not having direct effect on the present invention. It is useful to note, however, that preferred mechanical operating characteristics are obtained when the axis about which the main drive 30 rotates, passes through the common longitudinal plane of the cylinders in the piston block.
• each cylinder 10 is formed within a cylinder block 100, as by casting, there being a water jacket defined between the internal surfaces of the engine block 100 and the external surfaces of the individual cylinders 10. Air inlet ports defined by lateral surfaces 40 are formed in the middle area of each cylinder 10, below the water jacket 10.
• a sleeve liner 42 is press fit into the cylinder bore, so as to remain stationary during engine operation. This sleeve 42 can also be cast in place o the interior surface of the cylinder wall can be suitably finished so that the piston rides directly on the cylinder 10.
• the cylinder liner 42 includes ports defined by lateral surfaces 43, the ports 43 being so located on the sleeve such that when the sleeve is slip fit within the cylinder 10, each port 43 is aligned with a complementary port 40 through the cylinder wall 41.
• the internal circumferential surface of the cylin ⁇ der liner 42 is so sized as to form a pressure-tight fit with the external circumferential surface of the piston skirt 14 during operation, and most specifically with the sealing rings 45 located circumferentially about the piston skirt 14.
• the inlet ports 40 are ar ⁇ ranged about the circumference of each cylinder symmetricall relative to the common plane of the engine. Each port 40 is open between the cylinder 10 and an inlet plenum defined by the lower wall 140 of the water jacket 100 and the curved surface 142.
• the substantially straight surface 141 and curved surface 142 are convergent such that the inlet plenum has a venturi-like cross-section, as shown in Fig. 3.
• the invention as embodied in the above-described engine allows greater engine speed (rpm) and efficiency in operation by providing asymmetrical timing for the opening of the air inlet ports 40, 43, and increased ef ⁇ fective port height for greater flow area cross-section, and, therefore, greater mass flow.
• rpm engine speed
• a great advantage is obtained by the increased delay in the opening of the exhaust valve during each cycle, made possible by the offsetting of the crankshaft. This increases the period of expansion during each cycle of the engine, resulting in improved mechanical and thermodynamic efficiency.
• each piston 12 reciprocates within a cylinder 10, al ⁇ ternately opening and closing the air inlet ports 40, 43.
• the present invention permits an increase in the intake of air per operating cycle of the engine by increasing the expansion period during each cycle. This is accomplished by permitting an increase in the height of the ports 40, 43, i.e., the distance parallel to the center line of the cylinder as shown in Figure 3, and by increasing the period of time during which the port is open during each cycle of the engine.
• the offset distance should be at least equal to about 10 percent of the radius of the piston, and optimally at least about 20 percent of the radius.
• This angle C is maximized by maintaining the length of the connecting rod, i.e., the distance between the wrist pin 16 axis and the crank axis 25, 27, as short as possible. This can be shortened, e.g., by placing the wrist pin 16 axially outwardly from the piston head 13, i.e., as close to the outer end of the skirt 14 as is possible with ⁇ out mechanically interfering with the operation of the crankshaft at bottom dead center (as shown in Figures 3 and 6) .
• the angle ⁇ can be further increased by radially offsetting the pivoting connection between the piston and the connecting rod, e.g., wrist pin 16, in the direction, opposite from the offset direction of the crankshaft (as shown in Figure 6) .
• the effectiveness of the present invention can per ⁇ haps best be seen from the following specific example of an operating engine.
• the cylinder liner, or sleeve 42 has a bore diameter of 5-1/8 inches, the piston stroke length is increased to about 3-7/16 inches and the air intake port height is about 11/16 inch.
• the length of the connecting rod, from the center axis of the piston wrist pin to the center axis of the crankshaft is approximately 6 inches.
• the lateral offset of the axis of the crankshaft to the right of the common longitudinal plane of the cylinders is about 1-5/8 inches, i.e., approximately equal to 1/2 the stroke of the piston, and the lateral offset of the wrist pin 16 to the left of the common plane is about 1/2 inch.
• the crankshaft rotates to the left, as is indicated by the curved arrows in Figure 3.
• This provides an offset angle ⁇ ( , i.e., between a line drawn from the center point of the piston wrist pin 16 to the longitudinal axis of the crankshaft 24 relative to the com ⁇ mon longitudinal plane, (designated as ⁇ in Figure 6) of about 14 degrees. If the wrist pin 16 is located on the
• c* in Figu 3
• the operating cycle of the engine provides for the air intake ports 40, 43 to be open, that is, not covered by the piston skirt 14, for a period of 117 degrees of the total cycle of the piston. That is, the piston drops to below the level of the intake port 12 degrees after top dead center (TDC) and does not close until 115 degrees before TDC, i.e., when the piston has r turned moving upwardly above the level of the intake port 40, 43. Because of the offset _c( ) angle, the bottom dea center of the engine operation is 190 degrees after TDC. Accordingly, it is believed that the effective increase i the time during which the intake port is open is equal to approximately 1/2 of the angle d in each cycle.
• this invention is particularly adaptable to the so-called “square” or “over-square” engi design, that is, where the cylinder bore is equal to or larger than the piston stroke.
• Such engines provide a larger bore for a given volumetric capacity and thus are better able to accommodate the angled connecting rod with out interference with its movement.
• the cylinder walls extend a substan ⁇ tial distance below bottom dead center of the piston, to avoid obstruction for the present invention
• the cylinder side walls 42 should be made as-shorfas"possible;alterna ⁇ tively, indentations or notches can be formed in the cylinder wall extending axially to the bottom dead center position of the piston during operation, to eliminate as much as possible any mechanical interference with the angled connecting rod 18, without disturbing the pressure seal of the cylinder/piston interface.
• crank ⁇ shaf be offset in the direction opposite to the " rotation of the crankshaft, in order to obtain the desirable asvmmetr cal port timing, which results in an increased open, or in ⁇ take, period for the intake ports. Offsetting the crank- shaft in the same direction as the rotation of the crank ⁇ shaft, will not have this effect, and in fact should have the diametrically opposite effect of reducing the period of time during which the port is open.
• air can be pressurized, i.e., supercharged, prio to the intake into the engine, ' by means that are well known to the art.
• a pressurizer, or supercharger can be operated by, for example, the accessory gears as defined above.
• any type of supercharger, or intake air pressurizing means can be used: exhaust gas driven turbochargers or so-called complex, or pulsed, superchargers.
• fuel i.e., petroleum hydrocarbons
• fuel can be fed into the engine by any of a variety of known methods.
• the fuel can be fed either by a conventional carburetor or by a conventional fuel injector, both of which are well known to the art, or improvements or modifications thereof which may be developed in the futur
• the conventional means for feeding fuel is by use of a fuel injection system; however, again, other presently known means or other means which may in the future be developed can be utilized.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Cylinder Crankcases Of Internal Combustion Engines (AREA)
• Valve Device For Special Equipments (AREA)
• Output Control And Ontrol Of Special Type Engine (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=22789535

Family Applications (1)

Country Status (14)

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• 1981
  • 1981-12-01 CA CA000391237A patent/CA1184125A/en not_active Expired
  • 1981-12-01 IT IT49810/81A patent/IT1144517B/it active
  • 1981-12-01 ES ES507601A patent/ES8301323A1/es not_active Expired
  • 1981-12-02 DD DD81235332A patent/DD201927A5/de unknown
  • 1981-12-02 DE DE813152567A patent/DE3152567A1/de not_active Withdrawn
  • 1981-12-02 WO PCT/US1981/001602 patent/WO1982001913A1/en not_active Application Discontinuation
  • 1981-12-02 AU AU80820/82A patent/AU549837B2/en not_active Ceased
  • 1981-12-02 BR BR8108902A patent/BR8108902A/pt unknown
  • 1981-12-02 IN IN762/DEL/81A patent/IN157675B/en unknown
  • 1981-12-02 PL PL23405881A patent/PL234058A1/xx unknown
  • 1981-12-02 JP JP50040182A patent/JPS57502264A/ja active Pending
  • 1981-12-02 GB GB08221383A patent/GB2104151B/en not_active Expired
  • 1981-12-02 EP EP19820900411 patent/EP0065988A4/de not_active Withdrawn
• 1982
  • 1982-07-30 SE SE8204519A patent/SE8204519D0/xx not_active Application Discontinuation

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