I don’t quite understand the use of a gearbox. What is the purpose of it?
Say for example some machine use a gearbox for some reason is it possible to replace it with a motor and a speed contorller?
Thank You.
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An electrical motor is strong in relation to its physical size. It’s not entirely that simple, but almost. A large ass motor is strong. A small motor ain’t.
But you can use a gear box to make it strong, as long as you also accept a lower rotational speed secondary to the gearbox.
In other words, this comes in handy every time you have an application where the physical size of the motor is limited by the location where you intend to put it.
A very typical example of this is electrical trains or diesel-electrical trains. The motor is located, literally, between the wheels. And has a gearbox.
A motor on a train ALSO has electronics controlling the rotational speed by frequency, so this is a hybrid solution where you typically use both gears AND electronics.
But it proves my point; sometimes you can’t fit the motor you want, so you are going to have to accept gear losses to reach your goal.
It also works in the opposite direction, of course. When you can’t find a motor that is fast enough, you can gear up one that is strong enough.
To be fair, frequency controllers have been undergoing a lot of development in the past decade or two and was a bit of a new era when they showed up on the market in affordable, tiny encapsulations. There are a lot of applications that you today wouldn’t build with a gearbox at all, that you more or less HAD to have a gearbox on in the 70’s because you didn’t really have a choice on the matter.
Some industry applications consider the electronics a source of unnecessary potential faults. Pump installations in waterworks COULD be such an application, since the environment very obviously is going to contain water (and we all know that water and electronics is not a splendid combination) and likely a lot more more so when the pump is failing. If you intend to run the motor at its full speed for the entire duration of its life span…what do you need the electronics for? They are just an unnecessary potential breakdown that adds nothing to the application. The gearbox, you grease it at the same time as the motor, a few times a year on a schedule.
Another part of it is that it’s easier to cater to a market with gear boxes: you can bundle the same motor with several different gear boxes, effectively selling products for several different user cases with just one product.
Or, the gear box belongs to the machine. But when the motor fails, nearly any supplier you can think of has one available off the shelf. Because the gear boxes makes it easier for the motor manufacturers to concentrate on a few standard sizes. Just send someone to fetch the right size, install it and you are good to go again. (in reality, the suppliers still have hundreds of sizes, but they would have had at least tenfold need for stock if we didn’t also utilise gearboxes…)
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