Generally speaking, caster wheels short life is not due to the design or defect in the caster itself. It is generally because some key characteristics were not considered when the caster was purchased and/or installed. Here are the top 10 reasons casters short life:
1. Caster Capacity Overload
Overloading is one of the main reasons for the short life of casters. Under normal circumstances, except for professional forklifts and trolleys, users seldom know the maximum load-bearing weight of casters. This is mainly due to the manufacturer’s identification and explanation of the maximum load-bearing capacity of the casters, and there is a lack of communication.
Have you ever seen a shopping cart marked with a carrying weight? Does the sofa in your home indicate how many people can sit on? On the other hand, the user lacks knowledge of the load capacity of casters. It is like a car with a load of 2 tons but a load of 5 tons. Such a car will accelerate and twist, but the slope that can be climbed is overloaded. In some factories, there are often 2 tons of trolleys that carry 3 tons of goods. As a result, the outer skin (polyurethane) of the wheels falls off and breaks, and the frame is deformed. The impact of overload on the casters: the small turntable is severely deformed, the steel ball falls off, and the bearing wears quickly, which causes the caster bracket to deform and affects the steel ball running track, and even the bracket is overwhelmed and deformed to contact and jam the wheel. Leading to the wheel, deformation, cracking, and degumming .
2. Impact Loading
Impact loading occurs when a caster hits a large obstacle or bump and experiences the resulting g-forces. This means that if a caster with a load capacity of 100 lbs. hits a bump and experiences 5 g, it’s as if the caster is carrying 500 lbs. at that moment.
This impact load can cause a catastrophic failure of the caster due to the peak g-forces which cause the caster to bear a higher load than its rated load capacity.
Brinelling is the dent or “wear” that is pressed into a hard surface. Brinelling occurs in a caster when the ball bearings in the swivel head begin to develop grooves in the hard cap. Brinelling affects the performance of the swivel of the caster by increasing the swivel force. Swivelling forces are typically the largest mobility force that a material handling cart will experience.
4.Excess Swivel Offset
A design flaw can result in too big a distance between the centre of the axel and the centre of the kingpin or main rivet. This could cause the legs of the yoke to break away from the swivel when a load is applied.
Avoid by ensuring the design and engineering teams collaborate to find the optimum balance between a large enough offset for ergonomic efficiency and a short enough offset to ensure joint strength.
5. Wrong Bearing Type
Bearings are the part of the caster that limits movement to preferred motion and reduces friction between the moving parts within the caster. Using the wrong bearing type for a specific application can also be a cause of failure. For example, an application experiencing high side thrust. A tapered bearing would best be utilized. Improper bearing selection will cause premature failure of the caster. Various considerations should be made such as; bearing material, race construction and accessibility for maintenance if required.
6. Environmental Conditions
The different work condition need the casters with different materials. Therefore, the user should fully consider the environment of the place the casters working when using it, and use different casters according to the environment. In acid and alkaline occasions, cast iron wheels are not suitable for use. Cast iron wheels will quickly rust and corrode, resulting in failure to rotate normally. In textile mills and garment factories with many windings or thread ends, it is advisable to use casters with anti-winding function to prevent winding or thread ends from getting entangled in the bearings or entering the steering steel ball track when the wheels are rotating. Casters made of high-temperature phenolic resin should be used in high-temperature workplaces
Or use cast iron wheels or high temperature resistant nylon wheels to avoid thermal deformation of the casters and failure of normal operation due to high ambient temperature. In cold places, casters with larger assembly tolerances should be used to avoid cold bursting of the wheels due to cold shrinkage. Cast iron casters should not be used in places with a lot of iron nails or glass. It is suitable to use casters with larger wheel diameters on uneven ground; if the wheel diameter is too small, the impact resistance will be poor, and the service life of the casters will be naturally shorter in such places.
7. High speeds
High speeds can cause many issues with casters that weren’t designed for that specific application. Catastrophic failures can occur due to caster overheating, damage to the caster wheel hub, or damage to the bearings. Understanding the speed at which the caster will be used in its intended application will help you choose the right caster. For instance, you would need a much different caster for a manual material handling cart vs. a towable cart which can experience speeds in excess of 5 miles per hour.
8. Soft Top Plates
The function of the top plate of a caster is to provide secure attachment to the structure, protect the wheel and ensure the wheel direction is maintained. Having a thin top plate or one that isn’t hardened steel can make it very easy for it to bend out of shape potentially compromising both the load capacity and the directional intent of the caster. This condition mainly occurs when a caster goes over an obstacle and is damaged by the resultant impact. More robust and hardened top plates eliminate this issue.
9. King Bolt/Rivet Failure
Many casters are designed with the use of a rivet or kingpin bolt. These components generally have much of the stress concentrated on them when a high load is applied. Because of this, they are prone to failure when used in the wrong application. The solution to this potential issue is to use a Kingpinless caster that distributes the stress over a larger area on the caster.
10. Extreme Temperatures
Industrial castors used at temperatures exceeding 1000F can cause the material to fail. Softer materials like polymers and rubbers can flat spot or even melt.
Avoid by using temperature-resistant materials, such as hard-wearing phenolic resin or high-temperature rubber wheels. These materials can typically stand up to temperatures ranging from -40° to +280°.
Choose the Right Caster the First Time to Reduce Caster Changeover and Costs
Caster changeover can be costly and can impact your business operations. Your business needs to cut costs and keep downtime low in order to improve. Choosing the right caster may seem like a minor decision, but by doing it right the first time, you can avoid costly caster maintenance and replacement down the road.
By considering the 10 caster pitfalls, you can avoid them in order to choose the right caster for your specific application.
To get some guidance on how to choose the right caster for your particular application, check out caster solutions by industry to help you understand how different industry applications require different caster solutions.