Oleh: Rozan Haqi Pratama, ST.
1. Introduction
1.1. Theory of Balancing
Balancing of a rotating machinery is an important step to ensure of reliability of the machine so it will operate much longer. The balancing process generally take a process of the addition and removal of particular amount of weight which take location at its axial location or angular position along the rotor. so it can contribute the centrifuge forces of the rotor [1].
Centrifuge force of a rotating component consisting of mass ( m ) and eccentricity ( e ) which run at particular rotating angular speed ( w ) normally given by following equation:
Balancing is performed when such a rotating part have its center of mass does not coincide with the axis of rotation [2]. The phenomenon which met this condition is so called unbalance. The reason behind what causing the unbalance include the following:
- Improper of design such as forging, casting etc.
- Wear of particular rotating part.
- Addition of the new component to a rotating devices.
In early days of balancing process, it was difficult to get the phase data required to perform balancing. The problem may come from bad data reading of the sensor such as due to oil covering the reflective tape (which used as the input feedback of the RPM information). This situation forces engineer to perform balancing using only amplitude information.
The amplitude information required to conduct balancing could be acquired using only accelerometer. Although, the vibration should be filtered out to 1X RPM [1]. This is required to neglect the other problem which is not caused by unbalance. The example of techniques were developed to balancing using only the amplitude information is four run balancing.