The ELPEX coupling is especially suitable for rough operation. An application factor different from that in catalog section 3 is therefore sufficient for all applications. In the case of machines which excite torsional vibration, FLENDER urgently recommends carrying out a torsional vibration calculation or measuring the coupling load occurring in the drive.

Coupling selection

Coupling load in continuous operation

The operating principles of the driving and driven machines are divided into categories and the application factor FB derived from these in accordance with DIN 3990-1.

Examples of torque characteristic in driven machines:

• uniform with moderate shock loads: generators, fans, blowers
• non uniform: reciprocating compressors, mixers,
  conveyor systems
• very rough: crushers, excavators, presses, mills

NR: Natural rubber mixture

Select size with: T_KN ? T_N · FB · FT

Coupling load at maximum and overload conditions

The maximum torque is the highest load acting on the coupling in normal operation.
Maximum torques at a frequency of up to 25 times an hour are permitted and must be lower than the maximum coupling torque. Examples of maximum torque conditions are: Starting operations, stopping operations or usual operating conditions with maximum load.

T_Kmax ? T_max · FT

Overload torques are maximum loads which occur only in combination with special, infrequent operating conditions. Examples of overload torque conditions are: Motor short circuit, emergency stop or blocking because of component breakage. Overload torques at a frequency of once a month are permitted and must be lower than the maximum overload torque of the coupling. The overload condition may last only a short while, i.e. fractions of a second.

T_KOL ? T_OL · FT

Coupling load due to dynamic torque load

Applying the frequency factor FF, the dynamic torque load must be lower than the coupling fatigue torque.

Dynamic torque load
T_KW ? T_W · FT · FF · 0.6 / (FB – 1.0)

Frequency of the dynamic torque load
f_err ?10 Hz frequency factor FF = 1.0

Frequency of the dynamic torque load
f_err >10 Hz frequency factor FF = v(f_err / 10 Hz)

Checking the maximum speed:

The following must apply to all load situations: n_Kmax ? n_max

Checking permitted shaft misalignment and restorative forces

For all load situations the actual shaft misalignment must be less than the permitted shaft misalignment.

Checking bore diameter, mounting geometry and coupling design

The check must be made on the basis of the dimension tables. On request, couplings with adapted geometry can be provided.

Checking shaft-hub connection

Please refer to catalog section 3 for instructions.

Checking temperature and chemically aggressive environment

The permitted coupling temperature is specified in the Temperature Factor FT table. In the case of chemically aggressive environments, please consult the manufacturer.