The rotary harrow is a machine for land-working, particularly to prepare sowing bed and to inter manures.
It is connected to the tractor by three point linkage.
It consists of a chassis that supports the horizontal transmission made out of the cylindrical gears, of the tine or blade holders, the tools, the clod crushing roller, the grader. The motion coming from the tractor through the P.T.O. drive shaft is vertically driven, through a one-speed gearbox or by the gear shift unit, to a set of horizontal cylindrical gears directly connected to the working units.
The required machine powers depend on the work width, on the involved depth and on the nature of the land.
The rotation speeds of the tools are around the following rates: 220/360 rev. per min.; with more practical interest for the mid rates.
Double machines are built as well (working width 6/8 meters); it’s a frame supporting two single harrow matched.
With a certain approximation, the requested power depending of the kind of land, the width and the work depth can be determinated according with the following formula:
N = i * L * h
where: N: requested power in KW.
i : experimental working index in KW/m*cm
- slimy sandy soil - i=0,3
- slimy soil - i=0,6
- argillaceous slimy soil - i=0,8
- argillaceous soil - i=1
L: width in meters
H: work depth in cm
Approximate working tractor speed 2-6 Km/h and working depth between 14-30 Km.
The range forecasts:
On the updated range of gearboxes and mainly on the multispeed units we have rationalized the project in order to use common parts as much as possible.
All the one speed gearboxes and “on demand”, also those with the gear shift, can be fitted with the input through shaft by which it is possible to control any other application of the harrow, such as localizer fertilizer spreader, weedkilling bar, seeding machine. The available gearboxes:
One speed unit:
Multispeed unit hand/lever: Power shift by hand shift by lever
HP=70 MV.814F DV.813F
HP=95 MV.819F DV.818F
HP=130 MV.824F DV.823F
HP=180 - DV.733F
HP=200 MV.826F -
HP=300/400 - DV.825A
The range of P.T.O. drive shafts normally used on this type of machine is:
Series: T e V Type: 40 – 60 – 80 – 90
Automatic limiter (L)