LO 6-6 Identify and describe the hazards associated with rotating components and outline control practices

1. Rotating Hazards

Rotating Hazards

Broken hands and arms or severed fingers are a few of the injuries caused by rotating hazards. Mechanical power, transmitted through drive belts, gears, and pulleys, can impart tremendous force to body parts, causing severe injuries Figure 29. An open turbocharger compressor housing, containing sharp impeller wheel blades, is another common component on a running engine that can quickly and cleanly cut fingertips. Using the housing as a grab handle or inadvertently making contact with the blades can happen while performing engine repairs with the turbocharger intake pipe disconnected. Rotating machine parts are primarily hazardous because they form nip points, places where parts of fingers are gripped and then squeezed or pulled with great force Figure 30. Other rotating hazards include flywheels, shaft couplings, cams, spindles, chains, cranks, and meshing gears. The danger increases when items such as set screws, bolts, nicks, abrasions, and projecting keys are exposed on rotating parts. Rotating motion can be dangerous even when smooth, slowly rotating shafts grip clothing or, through skin contact, twist an arm or hand into a dangerous position. Rotating components can even turn falling tools or fasteners into dangerous projectiles if they make contact with rotating items (like fan blades) when they fall.

FIGURE 06-29: Fan blades and belt drive systems are common rotating hazards when performing engine service work.

FIGURE 06-30: Rotating hazards create nip points where parts of fingers, clothing, jewelry, and hair can be trapped and either pulled or squeezed.

1.1. Rotating Hazards (continued)

To avoid rotating hazards on diesel engines, the following precautions should be practiced:

• Always shut off an engine before performing any measuring or cleaning or making any adjustments or other service work.
• Install a finger guard or clamp wire mesh over the turbocharger inlet anytime the engine is operated and the air intake pipe is removed.
• Verify that any guards to protect against rotating hazards are in place on an engine.
• Do not wear loose clothing or jewelry (rings) that can be caught in the rotating parts.
• Tie back long hair to prevent it from becoming caught in machinery.
• Place tools, fasteners, and small parts on a cart or workbench. Do not use the area around the engine to store these items; rotating parts can convert falling items into projectiles.
• If adjustments are made when the engine is rotating, use extreme caution to keep hands and body parts away from rotating components.