hydraulik - Jahns-Regulatoren

1. Technical defi nitions
1.1 Service factor
fS = service factor:
takes into account the gravity of the application; it depends on the:
working conditions and type,
type of operation,
start-up frequency.
fs • T2 < Tcont
Service factor
Type of load fs
Uniform U Moderate M Heavy H
Number of start- ups per hour 50 50 50
Hydraulic motors 1,0 1,0 1,2 1,0 1,2 1,4 1,2 1,4 1,6
Electric motors 1,1 1,2 1,4 1,2 1,4 1,6 1,4 1,6 1,8
1.2 Reduction ratio
ie = effective reduction ratio:
ratio between the input and output velocity of the gearbox;
ie = n1/n2 .
1.3 Correction factor kf
kf = output support lifetime correction factor:
used to obtain the theoretic duration of the support for values of n2 h different from those found in the
catalogue. For all gearboxes the external load curves are calculated for:
- n2 h = 100.000 for the output supports
- n1 h = 1.500.000 for the input supports
1.4 Torque arm length
Lmin= minimum advised torque arm length for shaft mounted applications.
1.5 Shrink disk torque
1.6 Speed
Mtmax= maximum torque transmittable by the shrink disk when supplied by Jahns.
Transmittable torque by the gearbox and the shrink disk must always be checked for compatibility.
n1 = input velocity
is the input velocity of the gearbox.
n2max = maximum output velocity
maximum output velocity of the gearbox for continuous operation; values of velocity near the maximum
can be achieved in compatibility with the work cycle; for further information please contact thetechnical
services.
1.7 Lifetime
n2 • h = output duration index:
product of the output velocity and the duration in hours.It represents a number proportional to the
stress applied to the element which limits the life of the gearbox. To correlate the velocity and the
duration, the torque Tcont is expressed as a function of the product n2 • h.
With the speed n2 and the torque Tcont required, the duration in hours can be calculated;or alternatively, if
the speed and the duration in hours required are known then the Tcont that the gearbox can transmit
can be calculated:
H Y D R A U L I K
Page B. 6
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