Lubrication Effects on Chain Operation
The majority of chain drives and conveyors will perform better and last longer when timely and adequate lubrication is provided. One rule-of-thumb is that proper lubrication can extend chain life by as much as 100 times.
Even if overall chain life is acceptable, lack of proper lubrication can cause other problems. When a chain is starved for lubrication, wear from one joint to another can vary greatly, causing erratic action. Rapid joint wear can cause early loss of timing in a conveyor. Lack of lubrication can increase friction and power consumption and cause a harmful temperature rise.
Need for Lubrication
Chain lubrication is needed mainly to slow the wear between the pins and bushings in the chain joints, to flush out wear debris and foreign materials, and to smooth the chain’s engagement with the sprocket. Additionally, lubrication may be needed to inhibit rust and corrosion, to carry away heat, and to cushion impact forces.
In manual lubrication, oil is applied to the chain with a brush or spout can. The preferred frequency is at least once each day, but the interval may be longer if experience shows it is adequate for that particular application. The amount of oil and the frequency of its application must be adequate to prevent the formation of a reddish brown discoloration in the chain joints. That discoloration indicates that red iron oxide is generated in the chain joints because they are not receiving sufficient lubrication.
In brush lubrication, oil is continuously brushed on the lower span of the chain from the inside of the loop. The amount of oil and the frequency of its application must be adequate to prevent the formation of a reddish brown discoloration in the chain joints.
In drip lubrication, oil is dripped between the link plate or sidebar edges at a rate from four to 20 drops per minute, depending on speed. Again, the amount of oil and the frequency of its application must be adequate to prevent the formation of a reddish brown discoloration in the chain joints.
Oil Stream or Spray Lubrication
In oil stream lubrication, the oil is pumped to nozzles that deliver a stream or spray onto the lower span of the chain from the inside of the loop. The oil spray should be distributed uniformly across the entire width of the chain.
The same guidelines given for periodic maintenance of manual and drip lubrication of chain drives apply to chain conveyors.
For oil stream lubrication, check the oil level in the reservoir at least daily and add oil as necessary. Ensure that all orifices and nozzles are clear and that oil is properly directed onto the chain.