Page 73 - CITS - Fitter Trade Practical - Volume -2

FITTER - CITS

• Apply light pressure with the ram on the mandrel gradually so that the shaft is extracted out of the pulley. Apply
same pressure on the ram still the shaft is completely ejected out from the pulley.
• Bring back the ram to its original position gradually and remove the mandrel.
Assemble pulley and shaft
• Deburr the keyway in the shaft and the hub and clean the keyways.

• Check the dimensions of the shaft and the hub and the keyways.
• Check, by inserting the hub on the shaft, so that it is a tight push fit with the hands on to the shaft. Polish the
shaft or scrap bore of the workpiece until this fit is obtained.
• Select a Gib head key of the correct section and length.
• Check the key for width by inserting into the keyway of the shaft, draw file the key until it is a light tap fit in the
keyway. Similarly, check the key in the keyway of the hub. (Fig 4)

Fig 4

• Fit the hub on to the shaft by taping slightly with a soft hammer.
• Tap the key in to the keyway. Remove the key and check for any high spots, and file away the high spots.
Repeat the above operation until the key head is approximately 15mm away from the boss of the hub.
(Fig 5).
• Remove the key and check the fit on the faces.
• Fit key with a firm blow with a hammer.

Fig 5

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CITS : C G & M - Fitter - Exercise 65