Erection

The important points requiring attention are as follows :

Whenever possible, make provision for adjustment of centre distance.

Mount all drives as close to bearings as possible.

The two wheels must be in alignment.

The shafts must be parallel and both lie in horizontal plane.

End play of shafts should be reduced to about 1 /16th in.

Lubrication

It is as important to oil the bearings (joints) of a chain as it is to oil the bearings of any machine. The importance of this is evident when it is realised that the normal bearing pressures upon the wearing surfaces run from 1,000 lbs. to 2,000 lbs. per square inch.

Hence, it is essential always to arrange for some means of lubrication.

For efficient lubrication the alternative methods are :

(1) To run the chain continually through oil, by using a gear case or a splash guard with an oil well.

(2) ;To enclose the chain in a gear case and lubricate by means of a pump and sump or an oil thrower disc.

(3) ;Drip lubrication. Fix a drip lubricator so that the oil drips regularly upon the inside of the running chain. It may be necessary to erect a splashguard round the drive.

When speeds are higher than normal, or when both wheels are small or centres less than 30 chain pitches, the pump and sump arrangement is strongly to be recommended.

Chains should be taken down periodically and cleaned thoroughly in paraffin or kerosene.

Maintenance

Chains should not be allowed to run too slack. When excessive slackness develops, evidenced by whipping, adjust centres where this is possible, or take out one link of the chain.

Impulsive Drives

It is important to maintain a chain free from slackness in all cases when it is subject to an impulsive load. Otherwise slackness permits whipping, which increases the rate of wear. (Messrs. Hans Renold Ltd.)

Utilising Old Chains

A novel use for old chains is to make handles for doors of outhouses or for heavy boxes. A length of the chain, say about 9 in., is cut off by sawing through one of the links, and this is then secured to the work by means of a stout staple through each end of the end links. In order to prevent the chain from becoming rusty a coat of paint or enamel is desirable.