GB 02923 - Edition 05 - 03/2013
3/5
B 300
Pump connections to an installation
Axial loads (a)
Bending moment (b)
Torque (c)
Rotor
Pump fixed to
system : valve
Pendulum plate
Front view
Pump
Top view
Torque (c)
Loads :
Bending
moment (b)
Axial load (a)
Worst Case Turbo
Pump Crash Scenario
Definitions
The kinetic energy of the rotor has to be absorbed by the installation
if the pump seizes suddenly
.
The maximum resulting loads have been measured on a test bench
by simulating a worst case Turbo pump crash with
a rotor split into
2 parts at nominal speed
. The impact of the rotor parts creates the
following
transient loads
.
The rotor parts can be ejected out of the pump inlet flange and can
impact on the plate of the valve or any other part of the system. If
this is placed close to the turbo pump and if it has high stiffness the
impact can create a high axial load on the system. Such axial force has
not been observed on a standard pendulum valve.
The impact of the rotor parts on the housing will create a radial force
on the housing. This radial force will create a bending moment on
the system as a function of the distance to the pump.
The deceleration of the rotor parts creates a torque value on the
pump housing, which is transmitted to the system.
The maximum values of the axial force and the bending moment
occur at approximately the same time. A delay of up to several ms has
been observed for the maximum torque value.
Pump
adixen Vacuum Products - Operating Instructions - ATP 2300 M
