Elastomer Couplings EK Servomax® and TX Ecolight®
Jaw Couplings / Elastomer Coupling: Faktors and sizing calculations
Temperature
factor S |
|||
Temperature ( ) |
Sh 98 A | Sh 64 D | Sh 80 A |
| > -30° to -10° | 1,5 | 1,7 | 1,4 |
| > -10° to +30° | 1,0 | 1,0 | 1,0 |
| > +30° to +40° | 1,2 | 1,1 | 1,3 |
| > +40° to +60° | 1,4 | 1,3 | 1,5 |
| > +60° to +80° | 1,7 | 1,5 | 1,8 |
| > +80° to +100° | 2,0 | 1,8 | 2,1 |
| > +100° to +120° | – | 2,4 | – |
| Start factor SZ | |||
| Zh | up to 120 | up to 240 | above 240 |
| SZ | 1,0 | 1,3 | on request |
| Shock- oder load factor SA | |||
| Uniform load | SA = 1,0 | ||
| Non-uniform load |
SA = 1,8 | ||
| High dynamics, frequent reversing loads | SA = 2,5 | ||
Wording:
| TKN | = | Rated torque of the coupling (Nm) |
| TKmax | = | Max. torque of the coupling (Nm) |
| TS | = | Existing peak torque of the coupling (Nm) |
| TAS | = | Peak torque of the drive element (Nm) |
| TAN | = | Rated torque of the drive element (Nm) |
| TLN | = | Rated torque of the driven element (Nm) |
| PLN | = | Power of the driven element (KW) |
| n | = | Speed (rpm) |
| JA | = | Motor´s moment of inertia (kgm2) |
| JL | = | Machine´s moment of inertia (kgm2) (Spindle + slide + workpiece) |
| J1 | = | Moment of inertia of a coupling half at the driving end (kgm2) |
| J2 | = | Moment of inertia of a coupling half at the driven end (kgm2) |
| m | = | Ratio of the moments of inerta driving to driven element |
|
= | Temperature of the area around the coupling (observe radiant heat) |
| S |
= | Temperature factor |
| SA | = | Shock or load factor |
| SZ | = | Start factor (factor for the number of starts/hour) |
| Zh | = | Cycle of starts (1/h) |
Sizing of a Servomax® or Ecolight® Elastomer Coupling
1. Calculation example without shock or reversing loads
The rated torque of the coupling (TKN) needs
to be higher than the rated torque of the driven element
(TLN)
times the temperature factor S at
the coupling for the application. If TLN is
not known,
TAN can be used for the calculation instead.
Condition: 
Auxiliary
calculation: 
Calculation example: (No loads and shocks)
| Drive face: DC - motor TAN = 119 Nm |
Coupling conditons: = 70° C S =
1,7 (for 70°/Type A)) |
Driven face: Pump TLN = 85 Nm |
|
| Bedingung: | TKN > TLN
x S TKN > 85 Nm x 1,7 TKN > 144,5 Nm  |
Result: A coupling type EK 2/150/A (TKN = 160 Nm) is selected. | |
2. Calculation example with shock loads
In all cases the maximum rated torque (TKmax). of the coupling can not be exceeded. First calculate the rated torque (TKN) of the coupling same as above. Compare this result to the peak torque (TS) times the start factor (SZ ) times the temperature factor (SU ) for the application. The greater of the two values must be less than (TKmax) of the coupling.
Condition: 
Auxiliary
calculation: 
Condition: 
Auxiliary
calculation: 
