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Lubrication and Handling Precautions

Lubrication

The objective of Lubrication and Handling Precautions includes the reduction of friction among the rolling elements as well as between the rolling elements and the raceway, prevention of sintering, reduction of wear, and the prevention of rust by forming a film over the surfaces. To maximize the performance of a linear system, the lubricant type and a lubrication method appropriate for the operating environment should be selected.
There are two types of lubrication: oil lubrication and grease lubrication. For oil lubrication, turbine oil conforming to ISO standard VG32 to 68 is recommended.
For grease lubrication, lithium soap based grease No.2 is recommended. For slide bush and some other products, anti-rust oil that does not adversely affect the lubricant is applied prior to shipment. Please apply a lubricant before using these products. Products with raceway grooves, such as slide guide, are delivered pre-lubricated with grease for immediate use. Please relubricate with a similar type of grease periodically depending on the operating conditions. The recommended relubrication period is about 6 months or 1,000km of travel distance under normal conditions.

NB provides the following optional greases.
Please select one in accordance with the use conditions of your linear system.

KGL Grease (Low Dust Generation Grease)

KGL Grease has an excellent property of low dust generation with a lithium-type thickening agent used. It is ideal for use in a clean room.

KGU Grease (Low Dust Generation Grease)

With urea-type thickening agent used, KGU Grease has features including a superior low dust generation property and the reduced dynamic frictional resistance during low-speed operation.

item
grease name
KGL Grease
KGU Grease
appearance
light yellowish-white
light brown
base oil
synthetic oil and refined oil mixed
synthetic oil and refined oil mixed
kinematic viscosity of base oil (mm2/s, 40℃ )
32
approx. 85
thickening agent
lithium soap
urea
mixture viscosity
237
246
drop point (℃ )
201
250 or higher
copper plate corrosion (100℃ , 24hrs)
passed
passed
evaporation (mass%)
0.8 (99℃ 22h)
0.61 (150℃ 22h)
oil separation (mass% 100℃ , 24hrs)
0.9
0.1
oxidation stability (MPa99℃ , 100hrs)
0.04
0.015
bearing corrosion prevention (52℃ , 48hrs)
passed
passed
operating temperature range (℃ )
-20~120
-20~150

Handling Precautions

Please follow the instructions below to maintain the accuracy of NB linear system as a precision part and for a safety use.

Notes on Handling

  • Any shock load caused by rough handling (such as dropping or hitting with hammer) may cause a scar or dent on the raceway which will hinder smooth movement and shorten expected travel life. Also be aware that such impact may damage the resin parts.
  • Never try to disassemble the product. Doing so may cause an entry of contamination or deterioration of assembly accuracy.
  • The blocks or the outer cylinders may move just by tilting the rail or the shaft. Be careful not to let them fall off from the rail or the shaft by mistake.
  • The accuracy on the mounting surface and parallelism of the rails or the shafts after assembly are important factors to optimize the performance of the linear system. Exercise adequate care for mounting accuracy.

Notes on Use

  • Be careful not to let dust or foreign particles enter the linear system during use.
  • When using the linear system under an environment where dust or coolant may scatter, protect the system with a cover or bellows.
  • When the NB linear system is used in a manner that its rail is fixed to the ceiling and downward load is applied to the block (s) or the outer cylinder (s), if the block or the outer cylinder breaks, it may fall off from the rail and drop to the floor. Provide additional measures for preventing dropping of the block or the outer cylinder, such as a safety catch.

Instructions in considering the "Life Time" of a Linear System

  • When the load applied to a block or an outer cylinder exceeds 0.5 time of the basic dynamic load rating (P > 0.5C), the actual life of the system may become shorter than a calculated life time. Therefore, it is recommended to use the system with 0.5C or lower.
  • In the repetition of very minute stroke, where the rolling element, a steel ball or a cylindrical roller, makes only less than a half turn, early wear called fretting occurs at the contact points between the rolling elements and the raceway. There is no perfect measure to avoid this, but the life of the system can be extended by using anti-fretting grease and moving the blocks or the outer cylinders for the full stroke length once in a few thousand times of use.
    Anti-fretting grease is available as an option. Please select it for applications with very minute stroke length.
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