Field Balancing

Unbalance is the most common reason for improper machine vibrations at rotating machinery which can easily lead to machine failure and unplanned downtime.

By using field balancing, unbalance can be removed from your machinery directly in the field, fast and cost-saving.

Brüel & Kjær Vibro is leading in portable solutions for field balancing for years now. Not only for maintenance, also for production, testing and mounting of machines field balancing is essential.

The latest generation of measurement instruments, such as VIBROTEST 80 and VIBROPORT 80, further improved the field balancing:

  • Polar plots show the machine behaviour during static and dynamic balancing
  • Balancing prognosis functions enable a more efficient removal of the unbalance
  • Of course, storage and report functions are available for documentation of the process

Types of unbalance

The ISO 1925 standard  defines single-plane balancing as:

"A procedure by which the mass distribution of a rigid rotor is adjusted in order to ensure that the residual static unbalance is within specified limits." (abridged)

As a rule this type of balancing is sufficient only for narrow rotors which have no axial swash motion.

Typical rotors which often require only single-plane balancing are:

  • Fans, ventilators and air separators,
  • grinding discs, die chucks,
  • pulleys, flywheels, clutches,
  • gears,
  • impellers, atomizer discs

Two-plane balancing is defined in ISO 1925 as:

"A procedure by which the mass distribution of a rigid rotor is adjusted in order to ensure that the residual dynamic unbalance is within specified limits." (abridged)

As a rule two-plane balancing is required in all elongated, rigid rotors and all disc-shaped rotors where the permissible balancing tolerances cannot be achieved by single-plane balancing.

Typical rotors which should be balanced in two planes are: 

  • paper machine rolls,
  • centrifuge drums and decanter rotors,
  • electric motors and generator armatures,
  • crushing and cutting rotors,
  • machine tool spindles,
  • grinding rolls,
  • fans and blowers with elongated impellers and
  • compressor rotors