Dust gets everywhere.
We see it across the surfaces of our homes and even in our workplaces, especially when the light shines through to show it in its full glory!
However, dust that seeps and builds up within engineering equipment can be disastrous.
Causing damage to cylinder walls, dust can also cause significant damage and disruption to rods and seals.
It’s not just dust either; mud, debris, dirt, and even excess water can cause severe mechanical systems problems if they aren’t properly maintained and seal bearings housed.
Problems such as friction, surface wear, and an imperfect seal contact can all occur.
This is why many different types of applications need to stay clean both on the outside and inside. Equipment like hydraulic cylinders, snow ploughs, seals in logging, earthmovers, etc.
Top tips to keep systems and machinery dust-free
For seals and bearings and protecting them from the elements, we have various components at our disposal to help keep dust and dirt at bay.
The three main components which we’ll be talking about below all attach to the exterior side of the main seal in the system, and the component you require will depend on what you’re protecting your machinery from.
Wipers – used across lighter applications to seal fine material, dust, water, and wet mud. Wipers are made from rubber (a firm elastomer) or soft plastic and are ideal if you’re looking for easy assembly and low friction.
Scrapers – used for more aggressive applications, sealing out hard, solid debris such as ice and dry mud. Scrapers are manufactured from hard plastic or, most commonly, brass. Unfortunately, scrapers still let finer material slip through the net, and piston and rod lubrication leakage can still occur, attracting further dust.
Excluders – these tend to be the middle ground between wipers and scrapers regarding the level of protection they provide. Sealing out medium level materials, excluders are most commonly found in hydraulic cylinders and can help prevent contamination due to their prolonged seal life. Excluders are great for more rugged applications i.e., keeping mud out of brake cylinders, for example.
Note: Excluders can also be combined within the pneumatic cylinders’ inner seal, helping to provide a quality fit and low friction.
Scrapers, wipers, and excluders come in all shapes and sizes depending on your requirements – make sure to speak to one of the expert team at SSP to find out more.
Dust seals for bearings
To help keep your bearings clean within applications, you firstly need to keep the surrounding environment clean.
You then need to choose the best shaft seal and shaft configuration to protect bearings from dust and moisture ingress (shaft seals help close the gap between the housing where your bearing is contained and the shaft). Rubber seals are the most common and durable in this respect.
However, rubber or labyrinth seals will work well in dusty environments.
Labyrinth seals do require a straight shaft, whereas rubber seals allow for more flexibility.
If dust is a big contamination problem, the seal shaft arrangement may need to be redesigned to increase the level of protection.
Solutions in these instances include:
- Parallel configuration for seals and combination seals
- The use of wiping devices that are spring-loaded.
- Installing a stuffing box in the gap between the housing and the end of the equipment.
- Using a felt seal throughout the equipment and the housing, cleaning the shaft via brushing.
- Creating a barrier by greasing the two seals, flushing out any past seals.
- Fitting mechanical seals, or auxiliary seals, as these seals can come into contact with the dust and water first.
A point to note: It is essential that the assembly of the bearings and the housing is 100% clean because even with all of the best external protection bearings will still suffer premature failure if the bearing is contaminated at the assembly stage.
A note about Breathers
Breathers found on housings will allow some dust and moisture to get inside the bearing, adding to its premature failure.
To avoid such situations, you could opt to replace breathers with air filters that are low micron, as these remove dust particles up to two microns and greater in size.
Our team is on hand at Specialist Sealing Products to help you with all of your gaskets and sealing equipment and products.