Load capacity
calculation
Load capacity criteria
Dynamic load capacity is defined by bench tests according to DIN EN 12527–12533 and depends on trolley weight, maximum load, and the number of Wheels, with a safety factor applied. Static load capacity evaluates tread deformation under stationary conditions. For calculation, the formula P = (P1 + P2)/3 is applied, since often only three Wheels are in full contact with the ground.
Dynamic load capacity
The load rating specified for a Wheel or a castor indicates the maximum load the component can withstand, determined by rotary bench testing in compliance with DIN EN 12527–12533 (ISO 22878–22884).
To establish the required load capacity, it is necessary to know the tare weight of the transport equipment, the maximum additional load, and the number of Wheels or castors used. If four or more units are installed, the load distribution on each Wheel or castor may not be uniform.
The required load capacity is calculated using the following formula:
P = (P1 + P2)/3
P1 = Payload to be supported
P2 = Weight of the trolley/machine or equipment
Division by 3 is justified by the fact that in practice only 3 out of 4 Wheels are often in full ground contact.
Wheels and castors with ball bearings can achieve speeds above 4 km/h, but only with a reduced load capacity.
Static load capacity
When a Wheel or castor is primarily subjected to static loads, its static load capacity is determined according to ISO 22878. The test assesses, among other aspects, the degree of tread flattening after a specified time.
Static load data for our products are provided in the technical datasheets, which can be downloaded from the product detail pages or requested directly from our team.
Load capacity of Wheel and castor assemblies
The load capacity of Wheel–castor assemblies indicates the maximum load the unit can withstand under correct operating conditions. This value depends on several factors: Wheel material and dimensions, type of bracket (fixed or swivel), type of bearing, material quality, and operating conditions (running surface, speed, temperature).
When selecting a product, it is essential to consider not only the nominal load capacity indicated by the manufacturer but also the number of Wheels used, weight distribution, and possible dynamic stresses. Incorrect calculation may cause premature wear, deformation, or failure, compromising safety and functionality of the application.
For further technical details or to request tailored advice: