8.4 Installation, Overhauling, Assembly Techniques and Dowel Pins

Installation of machines

1. Select the location – space for operation and maintenance, light, power supply.
2. Prepare a foundation (concrete) as per the manufacturer's drawing with pockets for foundation bolts.
3. Place the machine with a crane / rollers; fit foundation bolts and grout them.
4. Level the machine with a precision spirit level and wedges / levelling pads.
5. Tighten the bolts after the grout has set; check the level again.
6. Connect power, test run without load, then with load.

Overhauling

Overhauling is the complete dismantling, cleaning, inspection, repair or replacement of worn parts and re-assembly of a machine to bring it back to original condition.

• Study the manual and drawings; mark parts and keep them in order.
• Use proper pullers and tools – never hammer directly on finished parts.
• Replace bearings, seals, gaskets, worn gears; check alignment; re-test.

Assembly techniques

• Clean all parts; remove burrs.
• Check parts with the drawing before assembly.
• Lubricate mating surfaces.
• Tighten bolts evenly and in a criss-cross order, to the specified torque.
• Use correct fasteners and locking devices (spring washers, lock nuts, split pins).

Dowel pins

Dowel pins are hardened, accurately ground cylindrical (or taper) pins used to locate two parts in an exact position relative to each other.

• Screws hold the parts together; dowels locate them.
• Usually two dowels are used, placed as far apart as possible.
• The holes in both parts are drilled and reamed together after the parts are clamped in position.
• Fit: interference fit in one part, close (transition) fit in the other, so parts can be separated and re-assembled in the same position.