Dynamic Balancing: the key to efficiency and performance

A world without balance would result in chaos. The same principle applies to machinery and rotating equipment. 

What are the components of dynamic balancing?

The balancing machine

The balancing machine is a specialised piece of equipment used to measure and correct the unbalance in rotating components. Its purpose is to:

• Reduce or eliminate vibration in rotating components ensuring smoother and more efficient operation. 
• Extend the operational life of machinery and its components
• Improve product quality where reliability and precision are crucial in industries such as automotive and aerospace

How does the balancing machine work?

Balancing machines measure, analyse, and correct unbalance in rotating components. The general process includes:

• Component is mounted on the support system: the machine can accommodate different sizes and shapes of components
• Component vibration is measured: sensors, such as accelerometers or laser sensors are used to collect data regarding the amplitude and phase of the vibrations
• Data is analysed: this analysis helps to determine the type and amount of unbalanced in the component, as well as the location and magnitude of the heavy spot
• Unbalance correction: the amount of weight which needs to be added or removed to achieve balance is calculated typically by adding counterweights
• Balancing is carried out: balance weights are applied (using bolts, welding, adhesive or balance putty) at specific locations on the component to achieve balance 
• Component is remeasured: once weight has been added or removed, the component is re-measured to check the unbalance has been reduced to an acceptable level. This may be repeated to achieve desired balance

Balancing weights

Balancing weights reduce or eliminate unbalanced by compensating for the uneven mass distribution within the component. When properly placed and adjusted, they effectively counteract the unbalanced forces to reduce vibration and improve operation.

So, how are they used?

• Type and location of unbalance is identified: the balancing machine will do just this through measurements and analysis
• Counterweights are put in place: based on the previous analysis, the counterweights (usually small masses made of metal), are attached to the component’s surface to offset the unbalance via fastening using bolts, welding, using adhesive or balance putty
• Unbalance is re-measured: the component is re-measured once the counterweights have been applied to verify whether the unbalance has been corrected. If not, the weight or placement of the weights will be adjusted until the desired balance is achieved

Detecting unbalance and its effects: what are the symptoms of unbalance?

• Excessive vibration
• Premature bearing/machine failure
• Excessive noise
• Structural damage due to vibration
• Risk to the safety of personnel

What are some of the measurement techniques?

Vibration analysis

A critical measurement technique for assessing vibrational behaviour, vibration analysis is widely used to monitor, measure and analyse amplitude, frequency and phase in order to understand the condition and performance of equipment and structures. Accelerometers are commonly used to measure the acceleration experienced by a point on a vibrating object. These vibrations are converted into electrical signals which are analysed to understand the level of vibration.

Phase analysis

Phase analysis is used to determine the timing and synchronisation of different signals or waveforms and to provide insight into the relationship between them. 

Both vibration analysis and phase analysis are essential measurement techniques for gathering insights into the behaviour and performance of equipment. These are also valuable for machine condition monitoring, quality control and creating a proactive maintenance programme. 

What are the consequences of unbalance?

Unbalance in machinery or rotating equipment can have a number of negative consequences, causing critical damage to other components and bearings, as well as for the surrounding environment. Some key examples of the consequences include:

• Excessive vibration: causing wear and tear, premature failure and detrimental effects on the quality of the equipment’s operation
• Reduced lifespan of equipment: continual excessive vibration and mechanical stresses can accelerate wear and tear on components including bearings, seals and gears, resulting in breakdowns and the need for more frequent maintenance
• Increased maintenance costs: more frequent maintenance can result in costly downtime as well as increased labour and material costs to repair and replace faulty or damaged components
• Higher energy consumption: unbalanced equipment is often less efficient due to the increased vibrations and friction which can result in higher energy usage, resource consumption and increased operating costs
• Quality issues: irregularities in quality can be caused by unbalance
• Excessive noise: vibrations caused by unbalanced can generate a lot of noise which can be detrimental for both the working environment and for wider noise-pollution regulations
• Safety risk: vibrations and/or mechanical failure may result in accidents for those working with or near the equipment
• Environmental issues: unbalanced equipment means increased energy consumption and frequent replacements, resulting in higher energy usage, resource consumption and increased wastage

The Dynamic Balancing Process

1. Pre-balancing preparations

Prior to carrying out dynamic balancing, it’s imperative to carry out some pre-balancing preparations to ensure accuracy and safety. Some of the key steps involve:

• Inspecting and cleaning the equipment: thoroughly check the rotor for any visible damage including cracks or irregularities, as well as making sure it’s clean and free of debris 
• Checking the bearings and mountings: ensure they’re in good condition and aligned properly
• Verifying operating conditions: understand the rotor’s speed, temperature and environmental factors to help select the appropriate balancing method and tolerances
• Selecting the appropriate balancing equipment: it may require portable balancing machines, vibration analysers or software-based solutions depending on the type and size of the rotor
• Preparing the balancing area: make sure the space is clean, well-lit with sufficient clearance around the motor and tools and equipment are readily accessible
• Calibrating the equipment: ensure the balancing equipment is calibrated to the manufacture specifications to ensure accurate measurements
• Establishing baseline data: the rotor’s vibration levels and imbalance characteristics data will help assess the effectiveness of the balancing adjustments
• Planning the balancing procedure: create a systematic plan which takes into account the location and magnitude of the balancing tolerances and correction methods 
• Securing the rotor: use appropriate clamping or fastening methods to ensure the rotor is mounted on the balancing machine securely to avoid any movement

2. The balancing procedure

The balancing process involves several key steps to accurately identify and correct imbalance:

• • Mount the object on the balancing machine: Securely mount the rotor onto the balancing machine according to the manufacturer’s instructions. The mounting must be stable and the rotor must be aligned properly with the machines axis of rotation
  • Conduct initial measurements and analyse: use the balancing machine or vibration analyser to gain an initial measurement of the rotor’s vibration levels. Then analyse this data to determine the magnitude and location of imbalance in the rotor
  • Add trial weights: add trial weights to the rotor in specific locations determined by the initial analysis – start conservatively to avoid overcompensation. Run the balancing machine and observe the effect of the trial weights on the rotor’s vibration levels, then adjust the position or magnitude based on these observations. Continue adding, adjusting and retesting until the levels of vibration are minimised with acceptable tolerances. Ensure a record of the trial weigh additions and adjustments are documented for future reference
  • Final measurement and verification: conduct a final measurement of the rotor’s vibration levels once the optimal weight and placement have been determined. Verify that the vibration levels have been reduced to within the specified tolerances. Make sure the rotor remains stable and balanced during this final measurement and make any minor adjustments to fine-tune the balance if needed.

3. Post-balancing measures

• Secure the weights: make sure the added balancing weights are properly and securely fastened
• Reassemble and test: ensure the equipment operates smoothly post-balancing

What are the advantages of dynamic balancing?

Dynamic balancing contributes to improved performance, efficiency and longevity of rotating equipment by:

• Reducing vibration to ensure smooth operation, reduce noise levels and prevents premature wear and tear of components 
• Enhancing performance and efficiency by operating at its optimal level and reducing energy consumption and operating costs
• Preventing costly downtime and improving operational continuity

Industries and applications

Dynamic balancing is widely used across various industries and applications to improve the performance, reliability, and longevity of rotating machinery and components, making it an essential process for ensuring the reliability and efficiency of various mechanical systems. These industries include:

• Automotive: crankshafts, camshafts, drive shafts, and rotating assemblies in engines and transmissions. Balanced components contribute to smoother operation, reduced vibration, and improved fuel efficiency
• Aerospace: aircraft engines, propellers, turbines, and other rotating systems. Balanced components help ensure safe and efficient operation of aircraft by minimising vibration-induced fatigue and enhancing performance
• Industrial machinery: pumps, compressors, fans, turbines, and rotating shafts. Balanced machinery operates more efficiently, experiences less downtime due to maintenance, and has an extended service life
• Manufacturing processes: precision machining operations, such as grinding wheels, spindles, and tooling. Balanced tools and machinery produce higher-quality products with tighter tolerances and reduce the risk of tool wear and breakage
• Consumer products: home appliances, power tools, and recreational equipment. Balanced components, such as motors, rotors, and blades, improve the performance, reliability, and user experience of these products including washing machine drums, ceiling fan blades, and lawnmower blades to minimise vibration, noise, and wear, thereby enhancing product efficiency and lifespan.

Balancing the world of rotating machinery

Dynamic balancing isn’t just about improving individual processes; it’s about shaping a smoother, more efficient, and productive future for industries and society as a whole. By embracing dynamic balancing as a fundamental aspect of maintenance and optimisation, businesses can pave the way for innovation, sustainability, and growth. Let’s strive towards a future where balanced machinery powers progress, enabling us to achieve greater heights of efficiency, reliability, and success.

To learn more about our dynamic balancing services and how we can help you, please contact us today