Lubrication (Oiling)

Lubrication is extremely important for roller chain transmission. Improper lubrication could shorten the service life of a roller chain. Lubrication for roller chain transmission is also extremely important because chains have recently been used under more severe conditions such as high speeds and heavy loads.
The following is a list of lubrication points, lubrication methods, and types of lubricants, so be sure to lubricate chains with reference to this list.

Lubrication points

Lubricating oil

In general, use a high-grade industrial lubricant. Select a lubricant with appropriate viscosity according to the ambient temperature, lubrication type, and chain size from the table below.

Commercial lubricating Oil (for reference)

Maintenance/Inspection

Maintenance

(1) Caution during installation

• Chain elongation is caused by the wear between the pin and the bushing.
• Each chain is coated with anti-rust lubricant at the time of shipment. Do not wash or wipe off the lubricant when installing chains. Also, be careful not to place the chain directly on the floor to prevent sand or dust from adhering to it.

(2) Timing of replacement

• When the chain elongation reaches +1.5%. (When the number of teeth is 60 or more, the allowable elongation becomes smaller as shown in the graph below.)
• When the link plate is significantly damaged, cracked, or deformed.
• When the chain is found to have significant scratches, cracks, or rotation defects.
• When a bent pin or warped link plate is observed.
• Significant rusting and chain bending defects are observed.

Number of sprocket teeth and allowable elongation

(3) Check Oil Lubrication

• Remove the chain periodically and clean it with kerosene. After that, fully lubricate the chain.

• Powders and foreign matter that accelerate wear must be completely removed.
• Metal surfaces cleaned with solvents are prone to rusting, and should be lubricated immediately to prevent rusting.
• Inspect the contact surfaces of the pins and the bushings, and if they are shiny, this indicates that the lubrication was proper. Apply oil again and use the chain.

(4) Chain elongation measurement procedure (caliper measurement)

• Chain length is usually measured by applying a load of approximately 1% of the average tensile strength. To measure an existing chain, measure the inner and outer dimensions between the rollers on the tension side as shown in the figure below.
• To minimize measurement error, measure at least 6 links.

Figure of 10links measuring

(5) Chain elongation measurement procedure (measurement with a measuring tape)

• To avoid measurement error, remove the chain and measure a distance close to the number of all links in a straight line.

Inspection

When roller chains and sprockets are installed, perform the trial run inspection shown below before operation. In addition, since conditions may change over time during operation, perform daily and regular inspections to ensure safe use.

(1) Trial Run Inspection

• Check the chain is correctly installed
• Check the clips, split pins, etc. at the chain joint are correctly installed
• Check the split pins at the chain joint are correctly spread
• Check the appropriate take-up tension (Not too loose or too tight)。
• Check that the chain doesn’t touch chain cover
• Check that chain is lubricated properly

(2) Daily Inspection

• Check for abnormal vibrations, noises, etc.
• Check obstacles that may interfere with the chain and sprocket
• Check the chain components, dirt, corrosion, improper lubrication etc.
• Check each components for scratches, deformation, damage or other abnormalities.
• Check the roller rotation, bending, or gaps in each part
• Check the condition of the contact area with the sprocket
• Check the chain wear elongation
• Check abnormality of the joints, clips, or split pins
• Check rusting of the chain (Red rust due to poor lubrication or rust due to environmental deterioration)
• Check lubricating oil carbonization or other deterioration
• Check adhesive powder or forging matter that accelerates wear

(3) Periodic Inspection

• Check the paragraphs (1) and (2) above visually or with a measuring device while the machine is running, stopped, and with the chain removed.
• Perform regular inspections according to the usage conditions and environment. If the usage conditions are severe, increase the number of inspections.

(4) Other

• Predict failures are take measures to prevent accident according to the inspection result.

Clarification of problems and Countermeasures