ZF – widely known in the agricultural machinery sector as a supplier of transmissions and axles – has created something of a ‘buzz’ with its drive-line electrification technology.
One of its leading ideas in this area is the use of an electrically-driven wheel on an implement – a plough, for example – to help the tractor along and to boost overall traction.
According to ZF, there are other applications for electric-drive technology; the company also says that it could be used on trailers or slurry tankers. It says that, by sharing the drive requirement between the tractor and the trailer or implement, there are “substantial advantages in difficult driving situations”.
The video (below) shows a single-wheel, electric-drive system in use on a large plough.
In this example, ZF proposes that a “standard” 240hp tractor can pull a six-furrow, reversible plough in a given set of conditions. But it wouldn’t be able for eight furrows.
However, the same 240hp tractor can do better – if it’s equipped with a high-voltage generator (ZF Terra+) and if it’s coupled to a plough with an electrically-driven land wheel (ZF eTrac). ZF says in that case – in otherwise similar conditions – the outfit can manage two extra furrows.
The tractor pulls (the plough) from up front as normal. However, when excessive wheel-spin is detected, the generator kicks in – sending electrical power to the single-wheel, electric-drive system (on the land wheel on the plough).
This, in turn, prompts a visible improvement – with less wheel-slip and dramatically less nashing of teeth.
ZF’s eTRAC – GPE 50. This is a single-wheel electric-drive unit
Certainly, the footage within this ZF-produced video would suggest that the addition of the generator and electric-drive system makes a very significant difference to the outfit’s forward speed – when the going gets tough.
Alternative thinking
ZF says that traditional power boost facilities (on modern, common-rail diesel engines) are typically not available for heavy-duty (slow-moving) field-work.
They are usually restricted to transport operations or PTO work; that’s because routing additional torque through a tractor’s transmission – when tugging a heavy implement at slower speeds in the field – may exceed the approved loading.
That, in turn, could lead to – at best – voiding of the tractor’s warranty or – at worst – an expensive gearbox or drive-line failure.
ZF’s electric-drive approach enables extra muscle to be brought to bear, without putting additional stress on the tractor’s own transmission.
It’s an interesting development. I was tempted to even say that it is a potentially shocking move, but that would be little more than a cheap pun!
