POWER TAKE-OFFS 4-5 E UROCARGO Euro 4/5 Power Take---off from Gearbox 4.2 Power take-off from gearbox Depending on the type of gearbox power can be taken from the layshaft through the flange or spline located on the rear, side or lower part of the gearbox. The technical characteristics necessary are given in the documentation supplied upon request for the various gearboxes. The types of power take-off and the torque values obtained with the ratio between the number of output revolutions and engine r.p.m. are shown in Table 4.1. The values refer to the conditions indicated in the table. Higher values for occasional use must be agreed upon as each occasion arises depending on the type of use.
Check the vehicle to ascertain whether it is possible to fit a power take-off suitable to its size. The power take-off applied to the gearbox must only be used when the vehicle is stationary and must be engaged and disengaged when the clutch is disengaged to avoid excessive stress on the synchronisers during gear change. For special situations when the power take-off is used and the vehicle is moving the gear must not be changed. For gearboxes equipped with a torque converter, the same power take- offs used for normal gearboxes are, as a rule, used. It should be carefully noted that, when the engine r.p.m. is below 60% of the max.
value the converter will be in the phase of hydraulic r.p.m.; in this phase, depending on the absorbed power, the r.p.m. of the power take-off is subject to oscillation despite the fact that the engine r.p.m. is constant. Direct Application of Pumps When the application of pumps of other equipment (e.g.
for tippers or cranes) is carried out directly from the power take-off, without the use of intermediate shafts and after checking that the size of the pump permits margins of safety with chassis and engine unit (cross member, transmission shaft etc.), the static and dynamic torques exerted by the mass of the pump and by the power take-off should be checked for compatibility with the resistance of the walls of the gearbox. By way of an example, the moment due to the additional masses must not have values of over 3% approx. of the maximum engine torque.
In cases where the gearbox is applied in a single unit with the engine, the value of the additional masses must be verified with regard to the inertial effects in order to avoid the induction of resonance conditions in the engine unit within the field of operational engi- ne r.p.m. When fitting power take-offs the torque values shown in Table 4.1 must not be exceeded. ! Transmission oil temperature must not exceed 120єC during prolonged use. Coolant temperature must not exceed 100 ° C. Not all types of power take-off available on the market are suitable for continu- ous use.
When in use the specifications (working periods, pauses etc.) specific to the power take-off in question should be respected. Power Take-off from Gearbox Print 603.93.431 Base - January 2008