FUNCTION
To hold 3 major engine components, that is cylinder block,A-frame and the crankcase in compression and transmit the firing load to the bed plate.
Provide for fatigue strength.
Aligns the running gear.
Helps reduce the bending stress to be transferred the tranverse girder
How bending moment of tie rods are reduced
As bending moment = force * distance of tie rods from centre line of crankshaft.
So, tie rods should be as close as possible to centreline of crankshaft
What are the Causes of Tie-Rod Breaking
- Tie rods are not properly tightened.
- The material and threading of tie rod are under rated and not properly machined.
- Aging of tie rod leading to failure or breakage.
- Tie rods bolts are over tightened by hydraulic pressure crossing its elasticity limit.
- Engine is over loaded or peak pressures of the cylinders are very high.
- Previous fretting of engine mating surface.
- Foundation bolts have become loose or chocks are damaged leading to transmission of vibration in to tie rods.
- Scavenge fire loosen the rods as they pass from the scavenge space and the heat leads to the expansion of the rods.
EFFECT OF BROKEN TIE ROD
1) Excess vibration
2) fretting of the mating surface
3) crankshaft deflection
4) unequal wear down of the main bearing surface
5) foundation bolts or chocks might get loose
Number of tie rod for engine up to the MC series
no of tie rod =2n+2Number of tie rod for engine MCC ME series
no of tie rod=4n
where n is the number of units