What Is a Caster?
A caster is mainly used as moving wheel parts attached to carts and shelves. Various types of caster exist, depending on differences in installation methods and tire materials, and they are used for different purposes.
Some of them are equipped with a stopper mechanism, which is useful when it is necessary to secure the cart during transportation.
Uses of Casters
Casters are mainly used for different types of terrain and different load capacities depending on the material of the tire. Typical materials and their main applications are shown below.
Elastic Material
Since casters can move smoothly even if there are some bumps, they are mainly used in situations where casters need to be used on bumpy road surfaces. Typical materials include rubber, urethane, and elastomer. Some of these materials are susceptible to oil and chemicals and deteriorate over long periods of use, so care must be taken when selecting materials for factory carts. There are also casters that use tires filled with air, similar to automobile tires, and are often used for outdoor applications.
Rigid Materials
Compared to elastic materials, rigid materials have lower shock absorption performance and are prone to vibration on bumpy surfaces, but they have the advantage of being able to move even heavy objects smoothly and are used for transporting heavy objects in warehouses. Typical materials include “nylon,” and “phenol.” Compared to elastic materials, many of them have higher resistance to oil and chemicals, so they are sometimes employed for the convenience of the place of use.
Principle of Casters
Casters are mainly composed of three parts: the “mounting part,” “the body part,” and the “wheel part.”
Mounting Part
The type of mounting part should be selected depending on how to attach the casters to the object. The main types are “flat type with a plate fixed by screws,” “type with a caster itself screwed in,” “type inserted into a square pipe or round pipe,” etc.
Main Body Part
This part is used to connect the mounting section and the wheel section and is generally made by bending sheet metal. Since the load capacity varies greatly depending on the material and shape, special consideration should be given when handling heavy objects.
Wheel Part
This is the key part of casters. Various materials exist, and the size of the wheel also affects performance. In general, the larger the wheel diameter, the less rolling resistance, allowing smooth movement even on bumpy, unpaved surfaces. For this reason, if there are no restrictions on the overall size of the equipment, it is advantageous to choose a wheel diameter. In reality, however, there are almost always restrictions on the overall size of the device after the installation of casters, so the optimal one is often selected by weighing ease of use and size.