Lubrication

of

Chains

The Chain

is one of the eldest traction and drive components,consisting of individual linksgripping movable into each other.

Open link chains – functioning without lubrication

normal open-link chain

stud-link or anchor chain

caterpillar-type drive chain(similar to track chains)

Base of the Chain Lubrication

All other Chains need an optimal Lubrication!

They never can work in the ideal state of hydrodynamic friction but always in the critical areasof boundary friction and mixed friction (see Stribeck diagram).

High loads restricted on linear surface contacts andno rotational motion but angular motion only prevails!

Therefore :Speciality lubricants are of especial importancefor the use at chains.

Link ChainsMakes and Shapes

Load chains

Drive chains

Load Chains

Liner chains

Fly-frame chains(without chain sprockets)

Drive Chains

Rotary chains

Bush chains

Roller chains

Construction of roller chains

Pin Bushing

Roller Side bar or plate

Types of Drive Chains

Single-rowroller chain

Double-rowroller chain

Triple-rowroller chain

Types of Conveyor Chains

Single row chain Double row chain Triple row chain

Failures and their Reasons

Dirtiness

At heavily soiled chains the oil only can partially and not completely penetrate into the chain joints.

Elongationof Chains

Even with optimal lubrication, chain stretching will occur afterlong operation time. However with an adequate lubrication the lifetime is 60 times longer than at dry running

Already with a 3% elongation, the sprockethas no more chance to gear in perfectly.

Broken Pins and Side Bars

The reason is often overloading or corrosion in the chain joint

Rust on Surface and Joint

Reasons are inadequate lubrication or insufficient corrosion protection.

Noise

Inadequate lubrication causes metallic friction which effectsgrating and squeaking.

Stiff Joints

After leaving the sprocket wheel thechain does not get back to its stretchedlength. Reasons are cold seizing, corrosion of the joint or residues of unsuitable lubricants, caused by insufficient or wrong lubrication.

Dependence of Wear, ChainElongation and kind of Lubrication

Graph 2: Lubrication only once a time,delay of wear occurrence until lubricantis used up.

Graph 3: Irregular lubrication, temporary dry running by hand lubricationif relubrication schedule is not followed.

Graph 4: Inadequate lubrication,irregular wear due to inferior, dirty, non-suitable or too small quantity of lubricant.

Graph 5: Perfect lubrication, strongly reduced wear, enhanced safety for longservice life of the chain.

Graph 1: Dry running, excessive wear,destruction of chain in very short time.

3

2

1

0

1 2

4

3

5

Ch

ain

elo

ng

ati

on

[%

]

Service time [h]

Ways of Lubrication

Depending on the speed of the chain v [m/s]

Hand lubrication

Drip lubrication

Slash lubrication

Pump lubrication

Hand Lubrication

Lubrication by oil can or brush is a very unsure method. It is not useful for continuous operation and therefore only suitable for driving units of minor importance and slow chain speeds.

Drip-feed Lubrication

Lubrication by wick, needle or drip oiler is suitable for driving units with low stress. In order that the lubricant will attain the linkages, the dripping pipesoutlets have to be placed above the pin row.

Splash Lubrication in Oil Bath

A chain protection case has a soundproofing effect. Its dimension should be such big, that the elongated chain does not beat against the walls. The chain pins should immerse into the bath not more than to the rollers orbushings. At the oil bath there is no loss of the lubricant.

Forced-feed circulatory Lubrication

Used for fast running chains and subject to high loads. Oil feeding may be carried out by connecting it to an already installed pressure oil pipe or a pump. The oil spurts from the pipe on the whole width of the chain on the inner side of the pulling strand and in direction of the course.

Requirements on the Lubricant

Lubricating performance

Wear protection

Penetrative andclearance fitting ability

Noise suppression

Corrosion protection

Adhesive ability

Temperature stability

Resistance to media

Food grade property

Environmentally safe

Service Temperature rangeof OKS Products

with MoS2

with Mox - Active

with MoS2 + Mox - Active

with white solid lubricants +Mox -Active

with graphite

with graphite

Thank You

for

Your Attention