Safety devices and enclosures for balancing machines help to avoid accidents and are even prescribed by law for many applications. While United States Public Law 91-596 and the OSHA Standard does not specifically reference balancing machines, paragraphs 1910.212 “Machine Guarding,” and 1926.20 “Accident Prevention Responsibilities,” do apply. Schenck offers a complete line of enclosures that meet all regulations and applicable standards for all machine sizes.
A balancing machine may present a potential hazard to the operator or the surrounding workshop environment and must be protected from: |
| • |
Personnel coming into contact with machine components |
| • |
Unbalance correction masses detaching and flying off the rotor |
| • |
The rotor lifting off the supports, or
disintegrating |
Particularly dangerous are protruding rotor components, or
those which may become detached during rotation in the
balancing machine. These potential hazards may increase with
rotor size and balancing speed. |
| |
ISO 7475 (and the identical ANSI Standard S2.60) describe
possible safety hazards resulting from the operation of a
balancing machine, and classifications of safety barriers
and enclosures for different protection classes.
For low speed balancing, it may be sufficient to provide
guard rails, fences or barriers with drive interlocks to
keep personnel away from the rotating workpiece.
If the possibility exists that a small rotor particle
like a welding bead, bolt, key or correction mass is
separating from the rotor, safety glass or shielding (or a
protective enclosure on larger rotors) is required. A
protective enclosure must be fragment-proof, to prevent
penetration by fragments that may separate from the rotor.
|
Protection Class C enclosure for
vertical machines |
If a weight should fly off during
operation, an equal force will act upon the rotor itself,
which might be enough to lift the rotor from its mounting,
or from the supports. All standard horizontal machines are
equipped with safety hold-down brackets to restrain the
rotor. However, these hold-downs are not designed to
withstand separation of major rotor components, or rotor
disintegration.
High-speed applications usually require burst-proof
enclosures, pits, or bunkers, that are designed to contain
the complete rotor of major fragments during high-speed
balancing or over-speed testing. |
|
Protection Class B
enclosure with
wire mesh |
