QUOTE(oe_kintaro @ Feb 13 2014, 08:17 PM)
Put it this way... probability for a system to fail is the product of the components.
If as you say, belt driven is a 3 component system, then you have 3 potential points of failure. Mind you, these are not independent redundant systems, but 3 interlinked ones. So you have 3 chances to fail.
In a DD there's only 1. (this is oversimplifying, but I hope you get the idea of what I am talking about)
Put it in another way, we would be playing a game of Russian roulette where one person pulls the trigger 3 times vs person who pulls it once.
As an engineering concept DDs have their own engineering problems to solve, but all being equal, there's less chance to fail because of the mechanical simplicity.
It's a general rule that the higher the mechanical complexity, the more chance for failure.
Sorry, your concept are wrong totally. In heavy industry equipment, just take power plant for example, their generator is driven by steam turbine(Tuanku Jaafar power plant at PD).
And it is using 3 parts also, generator, turbine and coupling.
Or take another more simple example, a pump, again, it is divided to 3 main parts, a motor, coupling and pump.
If follow your logic, why the engineers never design the pump and generator under 1 single package for simplicity sake?
Just before you can't answer and say I off topic, for washing machine, it is the same. For margin wise, changing a new set will be way better than doing repair work. DD when the tube failed, we have to change the whole set, unlike the split type, as every equipment are split, so the tube won't fail but the belt or motor will fail.
Do you see old school WM being send back to service center? How about DD type?