Selection According to the Environment

Lubrication

When using an LM system, it is necessary to provide effective lubrication. Without lubrication, the rolling elements or the raceway may be worn faster and the service life may be shortened. A lubricant has effects such as the following. (1) Minimizes friction in moving elements to prevent seizure and reduce wear. (2) Forms an oil film on the raceway to decrease stress acting on the surface and extend rolling fatigue life. (3) Covers the metal surface to prevent rust formation. To fully bring out the functions of the LM Guide, it is necessary to provide lubrication according to the operating conditions. If the mounting orientation is other than horizontal, the lubricant may not reach the raceway completely. Be sure to let THK know the mounting orientation and the exact position in each LM block where the grease nipple or the piping joint should be attached.
For lubrication, see Setting Conditions and Accessories for Lubrication. Even with an LM Guide with seals, the internal lubricant gradually seeps out during operation. Therefore, the system needs to be lubricated at an appropriate interval according to the operating conditions.

Corrosion Prevention

Determining a Material

Any LM System requires a material that suits the operating environment. For use in environments where corrosion resistance is required, some LM System models can use martensitic stainless steel. (Martensitic stainless steel can be used for LM Guide models SHS, SSR, SHW, SRS, HSR, SR, HRW, RSX, RSR, and HR.) The HSR series includes HSR-M2, a highly corrosion-resistant LM Guide using anti-corrosive austenitic stainless steel. For details, see Corrosion-Resistant LM Guide Model HSR-M2 .

Surface Treatment

The surfaces of the rails and shafts of an LM System can be treated for anti-corrosive or aesthetic purposes. THK offers THK-AP treatment, which is the optimum surface treatment for the LM System. There are roughly three types of THK-AP treatment: AP-HC, AP-C, and AP-CF.

Contamination Protection

It is necessary to prevent foreign materials from getting inside the product, as it will lead to abnormal wear and a shortened service life. Therefore, when entrance of dust or other foreign material is a possibility, it is necessary to select a sealing device or contamination protection option suited to the operating environment and conditions.
THK offers contamination protection accessories for each model of the LM Guide, such as end seals made of a special synthetic rubber with high wear resistance, and side seals and inner seals that provide further contamination protection.
In addition, for applications in adverse environments, a Laminated Contact Scraper LaCS and dedicated bellows are available for various model numbers. Also, THK offers dedicated caps designed to prevent cutting chips from entering the LM rail mounting holes.
When it is necessary to provide contamination protection for a ball screw in an environment exposed to cutting chips and moisture, we recommend using a telescopic cover that protects the whole system or a large bellows. For the options, see For the options, see Options: Contamination Protection.