Below are the most frequently asked questions from customers and our answers about the lubrication used in anti-friction linear guides and slides.
Lubrication in linear guides and slides is often underestimated. It plays a vital role in the lifetime of linear guides and linear slides than thought by many. Lack of lubrication and the wrong use of lubricants are the most common causes of linear guides failures. Fortunately, PM precision linear guides and frictionless slides require tiny amounts of lubricant during their operating life.
Please note we give our advice based on experience, but no rights can be derived from it. For advice based on your particular application, please contact us.
In general, we advise using lubrications like:
For most applications, grease is a better option, because it adheres better to the raceway surfaces and lasts longer than oil.
Since every application is different, we advise consulting our application specialists. They will be able to give you the right recommendations.
A corrosion protection oil is an oil that protects the guideways (components) during transport and storage against corrosion. Before installation, this corrosion protection film must be removed.
For linear guides which are used in linear slides, the standard lubrication provided at delivery is sufficient, and they are ready-to-use.
Yes, it is essential to have an ultra-thin film of lubrication between the moving parts to minimise wear and to reduce friction. PM can deliver the products with customised lubrication. Regularly lubrication of the linear guides is advisable, especially after a large number of cycles. Routinely monitoring the operating condition is required to determine the lubrication interval and prevent dry-running.
There are two general types of lubricants used for precision linear guides, such as cross roller linear bearings: grease and oil.
Greases used in linear guides are typically lithium-based greases, with no solid additives such as MoS2 (molybdenum disulfide) or PTFE (Teflon). These greases perform well in high-load applications and offer good stability against corrosion. Also, greases are longer-lasting, making them ideal for applications that have no easy access for service. Grease also helps to prevent the ingress of contaminants in the linear bearing. The consistency class of grease indicates how it will flow within the linear bearing.
Oil lubrication is recommended by light to medium loads and high-speed applications, as it flows better than grease. It also dissipates heat more readily than grease. However, you will have to consider the mounting orientation of the linear bearings or slides when you apply oil. That is because when you mount vertically or sideways, the oil will flow to the bottom and might start to drip.
We prefer to use lubrication by CLP oil, such as DIN 51519 or HLP oil, such as DIN 51524, assuming viscosity values between ISO-VG15 and ISO-VG100 according to DIN 51519.
PM linear slides are supplied pre-lubricated with a small amount of oil. Miniature roller slides PMMR and MSR with anti-cage creep technology are pre-lubricated with grease for high-speed, short stroke and dynamic applications. As a result, both types of slides are ready to use. Details on lubrication are available in the product catalogues.
Lubrication can be applied using the gap between a pair of guideways.
During service-lubrication, it is important to check the compatibility of lubes. Mixing different oils or greases can reduce the performance of the linear bearings, resulting in reduced running smoothness, cage creep and, at worst, damage to the linear guides.