diesel generator

No.

Dear Sir,

The Flexible coupling normally used from 5 KVA and above.

In the Question the kVA rating is absent.

Below the above rating you can have direct coupling otherwise you can have Tapered shaft coupling (Commonly known as J type Coupling)

Actually the flexible coupling is better over the direct coupling - in case of direct coupling you need to shrink fit the coupling hub on the alternator shaft & then you need to aling the alternator coupling hub with the engine hub within 100 microns ( Max), this alingement involves expert operators.

Where as in case of Flexible coupling you have coupling disc (Flex Plate) on the Alternator shaft
& the Single Bearing Housing. The dimensions of the Coupling disc & Single bearing housing needs to be in match with the engine flywheel & flywheel housing ( Bell Housing). The dimensions tolerance is governed by the standard known as SAE standards.

The Single bearing Housing of alternator gets coupled with engine Bell Housing & the coupling disc gets coupled with the Engine Flywheel.

Comparing to Direct coupling this flexible coupling needs lesser expertise & you do not need to measure the alingement.

I suppose this will clarify your doubt, If still in doublt pls mention the kva rating of the Alternator & engine type to explain further..

Bye..

With all due respect, this answer is wrong in so many ways that I do not know where to start. I suggest that it is ignored.

dear kaisan,

could you do me a favor, and letting me know more about your previus discussion.

thanks