WO2010119043A1

WO2010119043A1 - Offset-driveshaft connecting rod construction for reciprocating piston engines

Info

Publication number: WO2010119043A1
Application number: PCT/EP2010/054852
Authority: WO
Inventors: Lenin Capalbo
Original assignee: Lenin Capalbo
Priority date: 2009-04-17
Filing date: 2010-04-14
Publication date: 2010-10-21
Also published as: ITMI20090630A1

Abstract

A connecting rod for reciprocating piston engines comprises a connecting rod body, having a connecting rod body foot associated with a piston pin and a connecting rod body head associated with a driveshaft crank pin, the driveshaft having a rotary axis, the connecting rod being characterized in that the connecting rod body has a substantially L-shape including a long arm and a short arm arranged at an angle therebetween, said angle being preferably included in a range from 45° to 135°.

Description

OFFSET-DRIVESHAFT CONNECTING ROD CONSTRUCTION FOR RECIPROCATING PISTON ENGINES

BACKGROUND OF THE INVENTION

The present invention relates to a reciprocating piston engine comprising a novel connecting rod construction.

As is known, an internal combustion reciprocating piston engine comprises one or more engine cylinders, therewithin corresponding plungers or pistons coupled by connecting rods to the engine crankshafts slide.

The cylinders are encompassed by a cooling liquid jacket, are provided with air cooling fin arrangements, and are closed at the top thereof by a refrigerated cylinder head holding therein distributing, igniting, and injection members. In an opposite cylinder construction, a plunger or piston operates as a head for the other plunger or piston.

The forces transmitted by the driving fluid to the engine movable members are discharged on the engine block, coupled to the cylinders by the engine framework and closed at the bottom thereof by a closing casing forming a lubricating oil cup.

The plunger or piston, coupled to the connecting rod by a piston pin, discharges cross efforts directly at this connection or by a crosshead arrangement.

The engine construction further comprises drive fluid distributing and fuel supplying members and optional comburent medium feeding elements, for a scavenging and/or supercharging type of operation, to ignite the carbureted mixture, and for lubricating and refrigerating purposes.

To allow the engine crankshaft to properly operate, said engine construction further comprises crankshaft balancing and torque vibration damping devices .

In prior reciprocating plunger or piston engines, each connecting rod is coupled to the engine crankshaft through a coupling head mounted on the crank pin and is coupled to the piston through a pin coupled foot element.

A problem affecting the above engine construction is that the combustion should occur as the piston is at the top dead center thereof, thereby generating a very high stress since, at this position, the connecting rod head and foot are arranged on a same axis passing through the driveshaft rotary axis, thereby the combustion actually occurs with a combustion delay, with an offset between the connecting rod axis and driveshaft rotary axis, with a consequent decreasing of engine efficiency.

SUMMARY OF THE INVENTION

Thus, the aim of the present invention is to provide such a connecting rod construction, for reciprocating piston engines adapted to overcome the above mentioned drawback.

Within the scope of the above mentioned aim, a main object of the invention is to provide such a connecting rod construction allowing the combustion phase of the engine to occur as the engine piston is precisely arranged at the top dead center thereof, while reducing to a minimum any dangerous mechanical stress thereon.

Another object of the present invention is to provide such a connecting rod construction which may be easily fitted to any existing piston engines.

Another object of the present invention is to provide such a connecting rod construction which is very reliable and safe in operation. Yet another object of the present invention is to provide such a connecting rod construction which may be easily made starting from easily available elements and materials and which, moreover, is very competitive from a mere economic standpoint. According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a connecting rod for reciprocating piston engines, said connecting rod comprising a connecting rod body having a connecting rod body foot associated with a piston pin, and a connecting rod body head associated with a driveshaft pin, said connecting rod being characterized in that said connecting rod body has a substantially L-shape configuration including a long arm and a short arm defining an angle therebetween.

The long arm of the connecting rod body comprising the connecting rod body foot and the short arm of the connecting rod body comprising the connecting rod head.

The angle formed between the axis of the long arm and axis of the short arm being preferably selected in a range from 45° to 135°.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will become more apparent hereinafter from the following disclosure of a preferred, though not exclusive, embodiment of the invention, which is illustrated, by way of an indicative, but not limitative, example in the accompanying drawings, where :

Figure 1 is an elevation view of a piston, connecting rod and crank assembly of a reciprocating piston engine including a connecting rod construction according to the present invention;

Figure 2 is a side elevation view, as partially cross-sectioned, showing an application example of the inventive connecting rod construction being applied to a reciprocating piston engine; and Figure 3 is a front elevation view, as partially cross-sectioned, of the engine shown in figure 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the number references of the above mentioned figures, the reciprocating piston engine connecting rod construction according to the present invention, which has been generally indicated by the reference number 1, comprises, as main component elements thereof, a connecting rod body 2 having a connecting rod body foot 3 associated with a piston 5 pin 4 and a connecting rod body head β associated with a crank pin 7 of a driveshaft 10 having a rotary axis 11.

According to the present invention, the connecting rod 2 has a substantially L-shape including long arm 8 and a short arm 9, said long and short arms being arranged at an angle with respect to one another, the angle between the long arm 8 and short arm 9 being selected depending on the connecting rod application.

By way of an example, said angle is preferably included in the 45° to 135° range.

The above disclosed angled construction of the inventive connecting rod 2 allows to achieve an offset arm between the longitudinal axis of said connecting rod and the driveshaft rotary axis 11, with the piston being arranged at the top dead center thereof, thereby as the combustion expansion force is applied to the piston, a very large power will be applied to the crank pin, to improve in turn the engine efficiency and greatly reducing the fuel consume. Thus, the above mentioned offset of the driveshaft from the connecting rod foot portion represents the main feature of the inventive connecting rod, owing to which the combustion and expanding forces will follow a linear pattern and will apply a high power on the driveshaft crank pin, while preventing any force losses from occurring.

Yet another important advantage of the inventive connecting rod is that, since the driveshaft is offset by a length equal to that of the short arm, the long arm will be a swingably displaced through an overall revolution angle range, thereby greatly reducing the size of the engine. It has been found that the invention fully achieves the intended aim and objects.

In fact, the invention has provided an angled connecting rod construction allowing the engine to operate with a very high operating efficiency, while greatly reducing wear to basic components thereof.

As stated, the inventive connecting rod construction may be easily fitted to any existing reciprocating piston engines. In practicing the invention, the used materials, as well as the contingent size and shapes, can be any, depending on requirements.

Claims

1. A reciprocating piston engine connecting rod comprising a connecting rod body having a connecting rod body foot associated with a piston pin and a connection rod body head associated with a driveshaft crank pin, said driveshaft having a driveshaft rotary axis, said connecting rod construction being characterized in that said connecting rod body has a substantially L-shape including a long arm and a short arm defining an angle therebetween.

2. A connecting rod, according to claim 1, characterized in that said connecting rod body long arm comprises the connection rod body foot and said connecting rod body short arm comprises the connecting rod body head.

3. A connecting rod, according to claim 1, characterized in that said angle varies from 45° to 135°.

4. A connecting rod, according to claim 1, characterized in that said connecting rod body provides an offset between a longitudinal middle axis of said long arm and said driveshaft rotary axis as a piston of said engine is arranged at a top dead center thereof.

5. A connecting rod, according to claim 4, characterized in that said L-shape connecting rod body causes, as on said piston is applied a combustion expanding force of said engine, said connecting rod to apply to said crank pin a larger operating power.

6. A connecting rod, according to claim 1, characterized in that said connecting rod provides said engine with an improved operating efficiency and fuel saving.

7. A connecting rod, according to claim 1, characterized in that said connecting rod is so arranged as to offset said driveshaft from said connecting rod foot.

8. A connecting rod, according to claim 1, characterized in that, with the driveshaft being offset by a length equal to a length of said short arm, said long arm is swingably displaced through a full revolution of said engine, thereby reducing to a minimum an occupied space thereof within said engine.