Tomislav Skračić, MA Undergraduate English Course for MARI NE ENGINEERS 3nd Semester

Essential reading:Essential reading:SPINČIĆ, A., PRITCHARD, B.,SPINČIĆ, A., PRITCHARD, B., An English Textbook For An English Textbook For

Marine Engineers 2Marine Engineers 2., Pomorski fakultet, Rijeka 2009.., Pomorski fakultet, Rijeka 2009.

LUZER, J., SPINČIĆ, A., LUZER, J., SPINČIĆ, A., Gramatička vježbenica engleskog Gramatička vježbenica engleskog jezika za pomorcejezika za pomorce, Pomorski fakultet, Rijeka 2003., Pomorski fakultet, Rijeka 2003.

Tomislav Skračić, MATomislav Skračić, MA

Undergraduate English Undergraduate English Course forCourse for

MARIMARINE ENGINEERSNE ENGINEERS3nd Semester3nd Semester

Lesson 3 – Lesson 3 – Connecting RodsConnecting Rods

Lesson 3Lesson 3Connecting RodsConnecting Rods

KEY WORDS

piston rod - klipnjača, stapajicaconnecting rod - ojnica: kod crosshead engine gdje su povezani

piston rod → crosshead → connecting rod → crankshaftconnecting rod - klipnjača, stapajica: kod trunk piston engine gdje je

njome direktno povezan piston → crankshaftcrosshead (n.) - križna glavain essence - u biti, u suštinithrust (n.) - potisak, porivchannel section - U-profilI-section - I-profil"marine" type design - ojnica s "brodskom" izvedbom donje glave, tj. ležaj

u dvodjelnom kućištu pričvršćenom za petu ojnicefixed centre design - ojnica s fiksnim središtem

Lesson 3Lesson 3Connecting RodsConnecting Rods

KEY WORDS

"crankpin end" - glava letećeg ležaja = big end bearingbolted - spojen vijcimarod shank - tijelo ojnicerod foot - peta ojnicedistant piece - podloška, distancioni element (npr. "shim")shim (n.) - podložna pločica, podložak za reguliranje zračnostitop dead centre (TDC) - gornja mrtva točka (GMT)thickness (n.) - debljinacompression ratio - omjer kompresijeclearance (n.) - zračnost, razmakpiston (n.) - klip, staptrunk piston - klip (s produženim plaštem kod

motora bez križne glave)

Lesson 3Lesson 3Connecting RodsConnecting Rods

KEY WORDS

bearing metal - ležajni metalgroove (n.) - žlijeb, utor, kanalbush (n.) - klipna očica, stapna očica, bukolabushing (n.) - rupa, otvor za osovinicu. "Bolcen" ulazi u bushing.interference (n) - rupice koje se nalaze i na bukoli i na osovinici

moraju se poklopiti radi podmazivanjafit (n.) - pristajanje, prijanjanjefit (v.) - postaviti, podesiti, ugraditi "it fits perfectly"rod eye - oko ojnicebored - izdubljen…bore (n.) - provrt, otvor, kalibar

The connecting rod connects the The connecting rod connects the crankshaft crankshaft directlydirectly to the pistonto the piston or, as in or, as in some other designs, some other designs, to the crossheadto the crosshead. . It is It is a running component connecting the a running component connecting the crankshaft to the piston (in crankshaft to the piston (in trunk piston trunk piston enginesengines) or to the crosshead (in ) or to the crosshead (in crosshead crosshead enginesengines). It has both ). It has both linearlinear (reciprocating, (reciprocating, up-and-down) and up-and-down) and rotationalrotational (rotary) (rotary) motion. motion.

Lesson 3Lesson 3Connecting RodsConnecting Rods

The connecting rod does this important task The connecting rod does this important task of of converting reciprocating motionconverting reciprocating motion of the of the piston into piston into rotary motion of the crankshaftrotary motion of the crankshaft.. I It t consists of an upper forked section which fits consists of an upper forked section which fits on on the crosshead bearingsthe crosshead bearings while the lower while the lower part fits on part fits on the crankpin bearingthe crankpin bearing..

Connecting RodsConnecting Rods

Connecting RodsConnecting Rods

1. DEFINITIONA running component connecting the crankshaft to the piston (in trunk piston engines) or to the crosshead (in crosshead engines).It has both linear (reciprocating, up-and-down) and rotational (rotary) motion.

2. FUNCTION Primary function: to transmit the push (pressure, thrust)

of the piston to the crankshaft, either directly or indirectly.

Secondary function: (in most designs) to convey cooling oil to the pistons which demands for a quite a large diameter passage.

Connecting RodsConnecting Rods

TYPES

a) Marine type: The large end bearing is seperate from

the rod which has a palm end (T-shaped end)

b) Fixed centre design: The upper half of the crankpin

box makes part of of the connecting rod.

c) Fork and blade type: Vee engine connecting rods.

d) Articular type: Vee engine connecting rods.

In the In the marine type designmarine type design the rod large the rod large end, called “crankpin end”, consists of a end, called “crankpin end”, consists of a separate bearing housing (or box) divided separate bearing housing (or box) divided in two partsin two parts, bolted to a foot on the rod , bolted to a foot on the rod shank. A distanshank. A distancece piece, known as piece, known as compression plate or shimcompression plate or shim, is interposed , is interposed between the foot and the box to permit between the foot and the box to permit the piston to be moved nearer to or farther the piston to be moved nearer to or farther from the cylinder head at top dead centre. from the cylinder head at top dead centre. Its thickness is chosen so as Its thickness is chosen so as to ensure to ensure correct compression ratiocorrect compression ratio. .

Types of Connecting Rods – MARINE DESIGNTypes of Connecting Rods – MARINE DESIGN

Types of Connecting RodsTypes of Connecting Rods– MARINE DESIGN– MARINE DESIGN

Types of Connecting RodsTypes of Connecting Rods– MARINE DESIGN– MARINE DESIGN

The simpler construction of The simpler construction of the fixed the fixed centre rodcentre rod does not have this adjustment does not have this adjustment and relies on accuracy to ensure correct and relies on accuracy to ensure correct clearances. With a few exceptions clearances. With a few exceptions medium medium speed diesel engines have trunk pistonsspeed diesel engines have trunk pistons with the result that pistons and connecting with the result that pistons and connecting rods have to be fitted together before rods have to be fitted together before being assembled into the cylinder. The being assembled into the cylinder. The methods of methods of assemblyassembly and and overhauloverhaul tend tend to influence the design of the large end. to influence the design of the large end.

Types of Connecting Rods – FIXED CENTRETypes of Connecting Rods – FIXED CENTRE

The connecting rod does thThe connecting rod does thee important task important task of of ____________ . ____________ .

IIt consists of an upper forked section which t consists of an upper forked section which fits on fits on ____________ ____________ while the lower part fits while the lower part fits on on ____________ ____________ ..

Connecting RodsConnecting RodsExercise 1 – Complete the sentences:Exercise 1 – Complete the sentences:

The connecting rod connects the crankshaft The connecting rod connects the crankshaft directly directly ____________ ____________ or, as in some other or, as in some other designs, to designs, to ____________ .____________ .

It connects the crankshaft to the piston (in It connects the crankshaft to the piston (in ____________ piston engines) or to the ____________ piston engines) or to the crosshead (in ____________ engines). crosshead (in ____________ engines).

It has two motions: ____________ It has two motions: ____________ (reciprocating, up-and-down) and (reciprocating, up-and-down) and _____________ motion. _____________ motion.

Connecting RodsConnecting RodsExercise 2 – Complete the sentences:Exercise 2 – Complete the sentences:

In the marine type design the rod large end, called “crankpin end”, consists of a ____________ divided in two parts, bolted to a foot on the rod shank.

A distance piece, known as ____________ or shim, is interposed between the ____________ and the box to ____________ the piston to be moved nearer to or farther from the cylinder head at ____________.

Its thickness is chosen so as to ensure correct compression ____________.

Connecting RodsConnecting RodsExercise 3 – Complete the sentences:Exercise 3 – Complete the sentences:

The simpler construction of the fixed centre rod does not have this adjustment and relies on accuracy to ensure ____________ .

With a few exceptions medium speed diesel engines have trunk pistons with the result that pistons and connecting rods have to be fitted together before ____________ .

The methods of assembly and ____________ tend to influence the design of the large end.

Connecting RodsConnecting RodsExercise 4 – Complete the sentences:Exercise 4 – Complete the sentences:

The primary function of the connecting rod is to transmit _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ , either directly or indirectly.

Its secondary function is to _ _ _ _ _ _ _ _ _ _ _ _ , which demands for a quite a large ____________ passage.

Connecting RodsConnecting RodsExercise 5 – Complete the sentences:Exercise 5 – Complete the sentences: