PRONAR T900, Operator'S Manual, Page: 54 / 153

Pronar T900 SECTION 3
3.14
3.2.6 HYDRAULIC STEERING SYSTEM
As standard, Pronar T900 trailer is equipped with hydraulic steering system for controlling the
wheels of the first axle and the third axle of the trailer.
Two external axles (1) and (2) are steering axles. They are equipped with cylinder (3) that is
connected through hydraulic conduits and pipes with double-acting hydraulic cylinders (4)
located on both sides of the drawbar, forming a closed circuit. The drawbar's cylinders (4) are
connected with the strings (5) by means of the lever (6). The strings' ball-shaped ends (5) are
connected with the tractor's hitch which meets the requirements of ISO 26402 standard.
FIGURE 3.9 Design of the hydraulic steering system
(1) front steering axle, (2) rear steering axle, (3) axle cylinder, (4) drawbar cylinder, (5) string,
(6) lever, (7) hydraulic steering accumulator, (8) hand pump
The system is filled with oil in the amount of approximately 10 litres. The reference list of oils
is included in ANNEX C TO THIS PUBLICATION. During movement of cylinder rods (4), oil
flows to steering cylinders (3) located on the external axles and causes turning the trailer's
wheels. Rods of cylinders (4) move when the trailer's drawbar changes its angular position
with regard to tractor hitch when manoeuvring. Thanks to this solution, tyre wear is reduced,
power required to manoeuvre the trailer is smaller and damage to soil is reduced when