POWER TAKE-OFFS 4-3 E UROCARGO Euro 4/5 44444. General Specifications 4.1 General Specifications Different types of power takeoffs can be used dependine on the type of use and the performances required, the PTO can be fitted to: - the gearbox. - driveline. - the front of the engine. - the rear of the engine. The characteristics and performances are given in the paragraphs which follow and in the relevant documentation which will be supplied upon request.
For the definition of the power necessary for the apparatus to be controlled, particularly when the values requested are high, the absorbed power should also be considered during the drive transmission phase (5 to 10% for the mechanical transmissions, belts and gears, and greater values for the hydraulic controls). The choice of transmission ratio for the power take-off should be made so that the absorption of power occurs in a flexible engine operating range. Low r.p.m. (below 1000 r .p.m.) must be avoided to prevent irregular running. The power taken in relation to the number of revolutions of the power take-off at the required torque.
P(hp) = M ⋅ n P(kW) = M ⋅ n 7023 9550 P = Useable power M = Torque permitted for the power take-off n = power take-off r.p.m. Type of use Both occasional and continuous use should be considered. For occasional use periods of under 30 minutes are considered. The values for continuous use are those used for long periods. Whenever this is comparable tothat ofa stationary engine, thesuitabil- ity of reducing the scheduled values on the basis of the conditions of use (engine cooling, gearbox etc.) should be evaluated. The scheduled take-off values are also applicable for uses which do not involve large variations of torque either in frequency or magnitude.
To avoid overloading, in some cases (e.g. hydraulic pumps, compressors) it may be necessary to include the application of devices like clutches or safety valves. PTO transmissions The kinematic forces of the transmission from the power take-off to therelevant apparatusshould becarefully considered(angles, r.p.m., moment) during the design phase and the dynamic behaviour during operation in compliance with the transmission Manufac- turer’s instructions should be respected. The dimensions should take into consideration the forces which might occur under maxi- mum power and torque conditions.
To obtain a uniformity of kinetic forces angles of equal value, maximum of 7є, should be obtained at the extremities (Figure 4.1). Solution Z is preferred to solution W due to the lower loads on the bearings of the power take-off and the equipment being driven. When it is necessary to obtain different spatial inclinations ( ϕ ), the variations in r.p.m. should be compensated for with the arrange- ment of the forks shown in Figure 4.2. For transmissions employing multiple sections, the instructions given at point 2.8.2 should be followed. General Specifications Print 603.93.431 Base - January 2008