Tractors 2

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If the original tractor and many after it have very little sheet metal, then there will probably be a lot of cast parts and precision machining of rotating parts, i.e. classic mechanical engineering.
The variations in clutches are striking, all of which prepare the vehicle for the comparatively large number of starts in difficult terrain. A multi-plate clutch, for example, provides more friction surface. We only know it from the
automatic transmission, but here it is foot-operated.
And while in 'Tractor 1' we talked about the auxiliary drive in the form of a roll, later on the most important unit is the power take-off shaft, which transports the torque to the outside. There is also an extra clutch that releases
the drive when the pedal is half pressed and the power take-off shaft when the pedal is fully pressed.
It doesn't necessarily have to be a foot pedal, it can also be a hand lever. A lot of work for the release bearing. If there are two, the two functions can be switched separately. This is also referred to as the 'PTO' clutch.
But what exactly is a power take-off shaft? Basically a removed cardan shaft, of course without a center bearing. Here too, the two cardan joints are moved as far to the ends as possible because the power take-off shaft
also
uses the bearings of the connecting pieces. To eliminate the uneven transmission of such joints when bent, the joints are rotated by 90° against each other.
Often enough, it is lightly protected along its entire length by a fixed and chained plastic tube, which is particularly necessary when the shaft that actually transmits torque is not a smooth tube. But of course the construction
directly next to the roller bearings is protected against the leakage of grease and the ingress of dirt by seals.
The transmitting shaft usually has a coarse bush toothing towards the tractor and ends in a flange to the machine to be driven. For smooth running, the angle to the driving and driven shaft should be as equal as possible.
It
is certainly possible to buy such shafts and then shorten them to suit your own needs.
Of course, special accident prevention regulations apply to a thing that rotates freely in the countryside at 1000 rpm and more, e.g. that the angular defection of the drive must not exceed 70°. Maximum torque and power,
including the speed, are also specified. There are locking devices that disengage in the case of an overload.
Power take-off shafts are necessary for all attachments and coupled vehicles where machinery needs to be set in motion that cannot be ensured by connecting it to any existing wheels. Of course, all of this can also be
necessary for attachments to the front.
Rear PTOs are particularly spectacular when they are connected to a drive axle on the trailer. A tractor to which an additional driving rear axle is added for particularly steep or difficult terrain. Otherwise, the possible
applications for PTOs are incredibly wide.

There is even the option of using spacers for specific tasks. In the case of the video above, this is a freewheel (picture). This allows the tractor engine to drive an attachment via the PTO shaft, but does not allow the
attachment to disturb the engine's operation. A slip clutch is sometimes used here, e.g. to prevent overloading.
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