Calculation

BRECO® and CONTI® SYNCHROFLEX polyurethane timing belts in the transport area

Transport timing belts are to be designed preferably as head drive. The goods to be transported can consist of one or more individual loads. A lot of individual loads can be seen as line load.

Calculation of circumferencial force FU

From the overall transport load, the required haul-off force or the circumferential force FU for the drive pulley assemblies can be derived:

FU = 9,81 * m * μ

Circumferential force in the drive pulley station ... FU [N]
Mass of the transported product ... m [kg]
Friction factor of the timing belt in relation to the bed plate ... µ

As friction factor µ (slide friction), the following values can be assumed:

Steel/PUR 92 Shore A ... 0,6 - 0,7
Steel/PAZ ... 0,2 - 0,4
PE/PUR ... 0,3 - 0,4

In general, friction factors show large ranges. Trials should be carried out, if necessary. Information without obligation.

Information on the force/elongation behaviour

The grid surface in the picture shows the force/elongation behaviour in the timing belt under operating conditions. The individual spacing between the transported products increase towards to the drive pulley assembly.

Spacing s1 < s2

Pre-tension force

We recommend to set the pre-tension force in the transport timing belt such that a residual pre-tension force is always maintained on the slack span side under operating conditions. Apply a pre-tension force of:

FV > 0,5 * FU

Calculation of belt width b:

\[b={F_U \over z_e \cdot F_{Uspez}}\]

FU ... Circumferencial force (calculated)
FUspez ... specific load of the belt teeth
ze ... meshing number of teeth of endless joined belts:
zemax = 6