Couplings in engine, Other Engineering

Couplings:

Because of the requirement to make maintenance tasks such as engine removal/refit, gearbox removal/refit easier, it is necessary to have a means of coupling the turboshafts output shaft to the helicopter main rotor gearbox input shaft together. This coupling must possess qualities which will allow movement of both the engine and the rotor gearbox independently of each other i.e. it must be flexible. It must also be finely balanced to reduce vibration.

One of the most common couplings in use is the ‘Thomas Coupling', sometimes referred to as the engine ‘high speed drive shaft'. The engine is joined to the main rotor gearbox by this high speed drive shaft. The shaft is belled at either end , one end being attached to the power take off shaft by means of Thomas flexible steel coupling. Each coupling consists of a number of steel discs, indexed by flats to ensure correct alignment when assembled. Two different numbered discs are used, each disc having a grain running either parallel to the flat or perpendicular to the flat. The discs are assembled alternately with the grains at 90° to each other. The bolts, nuts and washers securing the shaft to the engine are part of the fine balancing of the assembly and must always be replaced in the same position.

1352_coupling.png

Yet another method of coupling the engines power output to the main gearbox is shown in Figure.

The engine front mounting is bolted with the reduction gearbox to the hub of the air intake case; it supports the engine in the aircraft and serves as a torque reaction point. The mounting, which is of the gimbal type, is bolted to a gimbal ring, which is bolted to a similar mounting on the aircraft main gearbox, thus forming a gimbal coupling.

The engine output drive is transmitted to the aircraft main gearbox by a flanged coupling, which is secured via a flexible laminated disc coupling (Thomas Coupling) to a drive assembly. The drive assembly consists of an engine coupling and an aircraft main gearbox coupling bolted together, with a flexible laminated disc coupling (Thomas Coupling) at each end.

 

 

Posted Date: 9/12/2012 6:37:32 AM | Location : United States







Related Discussions:- Couplings in engine, Assignment Help, Ask Question on Couplings in engine, Get Answer, Expert's Help, Couplings in engine Discussions

Write discussion on Couplings in engine
Your posts are moderated
Related Questions
Electronic engine control systems : Advances in gas turbine technology have demanded more precise control of engine parameters than can be provided by hydromechanical fuel cont

State-estimators for continuous time linear systems The state space state and output equations of continuous time linear systems is of the form? x = Ax + Bu + v and y

The oil pressure indicator : The oil pressure indicator has a dial normally calibrated in pounds per square inch (psi). The indicator may have max. limit markers, but will alw

Internal Rate of Return: Multiple Alternatives To compare multiple alternatives using the IRR as measure of economic worth we must use the incremental approach. It is erroneou

Engine controls: Engine controls are very similar to flying controls, and the same types of equipment are used, such as rods, bellcranks and cables. Most control systems use ei

would you help with Evans diagram( draw and explain) for Iron in seawater,and how variability of Oxygen concentration affect the electrode potential vs.current?

how to work ever moll models

PITCH LOCK MECHANISM The pitch lock mechanism is necessary to cater for the two fine pitch position of 'flight fine pitch' and 'ground fine pitch'. It acts as a safety device

a hexagonal prism of 40mm side length of base and height 80mm is resting on HP on its base with two edges of base is parallel to horizontal plane. A square hall of equally inclined

Allowances for pattern : A pattern is always made larger than the required size of the casting in order to allow for various factor, such as shrinkage, machining, distortion and r