Sheave Assemblies and Towers (Ch.3) - Main parts of Sheave Assebly (5)

1. Tower->mounting frame->the main sheave frame->the secondary sheave frame->sheaves

2. axles and shafts

2.1. primary/secondary pivot shafts

3. bushings

3.1. a bushing reduces sliding friction

3.2. sheave beams(frames) pivot on their exles as they react to and distribute the loads on the assembly.

3.3. nylon, brass, fibre

3.4. needs lubrication

4. secondary sheave frames

4.1. frame=beam support the sheaves

4.2. mounted on axles that attach to the main sheave beam

4.3. allow the secondary frame elements to pivot and distribute the load to between sheaves

5. main sheave assembly frame

5.1. frame=beam that holds axles on which the secondary sheave frames are mounted.

5.2. it is mounted on the main sheave assembly axle which attached to tower crossarm.

6. mounting frame