How to Select Wheels and Casters
The first step is to correctly determine the load on each wheel or caster, according to the design and the conditions of use of the equipment where they will be assembled. Avoiding to exceed the limits of the load capacities of the casters and wheels shown in the catalog is important to achieve the best performance of the products. The formula below allows you to calculate the load on each wheel or wheel by considering some of the most important factors.
Pe = Weight of the equipment, cart or structure (kg)
Pmc = Maximum weight of the load to be transported (kg)
N = Number of wheels or castors
S = Safety coefficient The value of the safety factor S should be between 1.0 and 2.0 depending on the application conditions.
|Coefficient of Safety S
|CONDITION OF USE
|Practically static load
|Frequent use, smooth floor movements
|Frequent use, uneven floors
|Severe use, at speeds above 10km / h where with solid or liquid loads, or need to overcome obstacles
CONDITIONS OF THE ENVIRONMENT
The second step is to evaluate the working environment of the wheels or casters, such as maximum and minimum temperatures and the presence of chemicals that can cause contamination.
To help you choose the ideal material for the wheel, on pages 17 and 18 we have tables showing various types of chemicals and some of the materials used in the manufacture of Schioppa products.
Casters mounted with stainless steel forks provide excellent service life in damp environments and with harsh chemicals.
CONDITIONS OF THE FLOOR
It is essential to make an analysis of the type and conditions of the floor, to identify surface irregularities and the presence of obstacles. It must be chosen to the wheel with the most suitable material to not damage the floor, and with resistance to withstand the aggressiveness of the surface, the shocks and overcome with ease the obstacles. So that the noise level and vibrations during the movements are smaller, choose soft wheels and castors with springs.
TYPES OF ROLLING
We now set out for the third step which is to choose the ideal type of running.
The wheels can be supplied with five types of drives, which exert a great influence on their performance. They are: through hole, nylon bushing, bronze bushing, roller bearing and ball bearing.
For jobs with light loads and little movement, the wheels with a through hole or nylon bushing are the most suitable and provide an excellent cost-benefit ratio. Bronze bushings should be used in conditions of high humidity or extreme temperatures.
Roller bearings are suitable for light and medium loads, facilitate the handling of handheld equipment and the cost is low.
Ball bearings provide greater ease of movement in all load ranges, increased strength and durability. They must always be used on the wheels of equipment subjected to more severe uses, with mechanical traction and higher speeds. They are supplied with grease shielding for lubrication, or two shields with permanent lubrication. In the case of high severity applications (very high speeds and loads) where radial and axial forces are present, we can provide on request wheels with tapered roller bearings.
The main factors that contribute to better handling and ergonomics are the hardness of your tread material and its diameter. The harder the tread material the easier it will turn, and the larger its diameter, the more easily it rolls and overcomes obstacles.
Schioppa offers a complete line of accessories that further increase the efficiency of the wheels and castors.
Depending on the need, it is recommended to use brakes that block the wheel and the rotation of the head, body guard for feet protection or that also serve to unclog the passage, locking of rotation that direct the direction of displacement of the caster, and caps that prevent the entry of wires into the wheel hub.
Casters equipped with accessories may have their main dimensions changed and it is important to provide sufficient space in the design of the equipment for them to rotate freely.