Balancing

STATIC AND DYNAMIC BALANCING

Static and dynamic balancing of a plane is a technique used to distribute the mass of a plane, rotor or other rotary motion mechanisms (e.g. fans, impellers, turbines, shafts). Balancing is necessary to avoid vibrations, uneven wear and other problems caused by an unbalanced centre of mass.

Static balancing

Static balancing means balancing a rotor or other object when it is stationary. This procedure aims to ensure that the centre of mass is on the axis of rotation of the object. If an object is properly statically balanced by placing it on an axis of free rotation, it will remain stable and will not rotate on its own due to gravity.

How static balancing is performed

  • The object is rotated about its axis and the position of its centre of mass is measured
  • If the object’s centre of mass is off axis, weights are added or removed from the object until the centre of mass is on the axis

For example, a car wheel is balanced statically so that it doesn’t tilt freely to one side when turning

Static balancing

ADVANTAGES

  • Simple and fast technique
  • Suitable for smaller or slower machines where dynamic loads are minimal

How dynamic balancing is performed

  • The object is rotated at a high speed, as it would be used under real working conditions
  • Measurements are taken with special SKF Microlog equipment to determine where and what kind of imbalance exists
  • Adding or removing weights on the surface of the object to reduce vibrations and inertial forces

ADVANTAGES

  • Ensures balance at high rotational speeds
  • Essential for large mechanical systems such as turbines, boiler fans, transport fans, propellers, aircraft engines

Main differences between static and dynamic balancing

Static balancing only measures the position of the centre of mass when the object is stationary, while dynamic balancing takes into account the movement of the object (rotation) at high speed

Static balancing is simpler and often used for slower, less complex systems, while dynamic balancing is necessary for high speed and complex systems

Both techniques are important for the smooth operation of mechanical systems, but are used in different situations depending on the speed and design of the mechanism.