INSPECTING SHEAVES

A proper fitting sheave groove should support the rope over 135-150 degrees
of rope circumference. Observe the groove so that it may be clearly seen
whether the contour of the gauge matches the contour of the bottom of the groove.

A sheave badly corrugated by the rope's "print", a
condition which could seriously damage the wire rope.

Almost every rope installation has one or more sheaves ranging from traveling blocks with complicated reeving patterns to equalizing sheaves where only minimal rope movement is noticeable. Each sheave should receive an individual examination at periodic inspections.

Each sheave is to be examined for the following:

- Groove depth, width and contour.
- Groove smoothness.
- Broken or chipped flanges.
- Cracks in hubs, spokes, etc.
- Signs of rope contact with guards.
- Sheave bearings and shaft.
- Out-of-round condition.
- Alignment with other sheaves.

Assessing the general physical condition of a sheave, such as groove smoothness, freedom from cracks and knicks, existence of wear on guards, etc., is a matter of careful and knowledgeable observation.

Properly gauging and evaluating the width, depth and contour of grooves with a groove gauge, requires keen observation as well as knowledge of gauge design and use.

There are two types of wire rope groove gauges:

1. Those used by manufacturers of sheaves and drums, which make allowance for the maximum allowable oversize for wire rope and are used to determine the proper contour for new grooves.

2. Those used in the field, which are made to the nominal diameter of the rope plus one-half the allowable rope oversize. These are used to determine the minimum condition for worn grooves.

In a field inspection, when the gauge for worn grooves fits perfectly, the groove is at the minimum permissible contour. Anything narrower is unsuitable for use.

It is a good rule to keep in mind that under normal operating conditions, as a groove wears it tends to become deeper and narrower. Excessive wear in an over-width manner frequently indicates some operating abnormality such as alignment.

Sheave inspection should also include the condition of bearings and shaft. With the rope relaxed, the sheave should be rotated by hand to determine the fit of the bearing and effectiveness of its lubrication, whether the sheave runs true without wobbling on its shaft, whether the bottom of the groove is still concentric or round in relation to the shaft and whether the sheave and its shaft are in proper alignment with other sheaves or components of the system.