Belarus 892 - Use of Safety Clutches When PTO and Cardan Shaft Are Applied

892-0000010B OM
206
5.5 Use of safety clutches when PTO and cardan shaft are applied
To avoid failures of PTO shaft and PRS in several implements with active working
attachments mechanical safety clutches are used.
Functional purpose of the safety clutch is automated gear deactivation or limitation of
the torque value transmitted from the PTO shaft to PRS under overloads caused by large
starting moment, overload of (locks) the working attachments and loads fluctuations on the
PRS drive.
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ATTENTION: THE IMPLEMENT COUPLED SAFETY CLUTCH RESPONSE TIME
SHALL EXCEED THE NOMINAL OPERATING TORQUE ACTING FOR A LONG TIME IN
THE IMPLEMENT DRIVE, BUT BE ALWAYS EQUAL TO OR LESS THAN THE MAXIMUM
PERMISSIBLE PTO SHAFT TORQUE! IF THE IMPLEMENT SAFETY CLUTCH RE-
SPONSE TIME EXCEEDS THE PERMISSIBLE PTO SHAFT TORQUE SUCH IMPLEMENT
MUST NOT BE COUPLED WITH THE TRACTOR.
Among safety clutches there are cam clutch, frictional clutch, disk clutch, they can be
subdivided to two basic types – with destructible and indestructible working components.
Clutches with a destructible component are used as unlikely overload control device.
In several implements freewheeling clutches are used. The freewheeling clutches
(sprag clutches) are automatically closed if the rotating direction is straight, and are unclosed
if the rotating direction is opposite. The freewheeling clutches ensure operation of the imple-
ments with the increased inertia moment of the implement rotating masses to prevent it from
the drive failure when the PTO shaft is switched off.
There are also combination safety clutches. A combination safety clutch is the safety
clutch which is structurally combined with a clutch of other type, for example with a freewheel-
ing clutch.
ATTENTION: MANUFACTURER OF THE IMPLEMENT CARDAN-DRIVEN FROM
THE TRACTOR PTO SHAFT SHALL INFORM YOU IN ADVANCE ABOUT THE NECES-
SITY OF APPLICATION OF A SAFETY CLUTCH, CLUTCH DESIGN FEATURES AND
CONSEQUENCES OF THE IMPLEMENTS APPLICATIONS WITHOUT THE SAFETY
CLUTCH!
When you need to decide on the purchase or operation of the cardan shaft follow the
implements and cardan shaft manufacturers’ guidelines first of all. It is recommended to
apply with the tractor the implements with active working attachments where the length be-
tween the articulations of the fully off-set cardan shaft does not exceed 1 m.