Supports & Retainment of Rotating Parts

1. Wherever Gears, belts, pulleys, electric motors and other rotating parts are used two basic rules should be followed. These rules are :

a) Every part of rotating assembly must be supported radially.b) Every part of rotating assembly must be retained or held axially.

2. Provide shoulder or spacer (sleeve) to avoid sliding of rotating machine parts.3. Shaft may be supported on sliding or roller bearing at appropriate position.4. Provide shoulder in bearing housing to avoid side slipping of bearing in housing.5. Step down the shaft at bearing to avoid slipping of shaft sideways.6. Provide retaining rings and locknuts to retain bearings in shaft.7. Provide removal caps on bearing.8. Provide shims in space between housing and cap of bearings to compensate for manufacturing tolerances.9. Provide seals where shafts enter or leave a housing to hold the lubricant in and to keep dirt out.10. The overhang rotating parts mount the bearing close to hub.11. For bevel gears and pinion cartridge mounting allows shims to be used between cartridge flange and housing to adjust the position of pinion to obtain correct gear tooth clearance.12. For worm gears shimmed caps should be used to adjust gear axially.

Assembly Consideration in Design

1. Provide proper relationship and orientation of assemble parts with respect to other parts of machine.

2. Provide proper mating surfaces.3. Design of assembly should be less costly.4. Replacement of worn out parts should be with minimum cost.5. Provide datum point so that assembly can be based properly.6. Provide easy access to each part so that they can be assembled easily.7. Product design should ensure assembly by placing the parts one over the other.8. Minimize side fastening of assembly.9. Design the assembly to have number of subassembly.