Vibration is the mechanical oscillation of an object at an equilibrium point. Vibration Analysis (VA) is the most effective method to find faults in gearboxes at the initial stage. In a nutshell, vibration analysis is a process that monitors the levels and patterns of vibration signals within a component, machinery, or structure, to detect abnormalities and evaluate the overall condition of the test object.
Moving on to Gearbox Vibration Analysis(GVA) is a predictive maintenance procedure. Generally, machines do not break down completely or fail without any sort of warning, which is often indicated by a change in the vibration level.
Let’s check how Gearbox Vibration Analysis helps in improving equipment health. In cases of damage, imbalance, misalignment, etc., symptoms are different. A field vibration analyzer is used to collect vibration data. To diagnose the cause and source of vibration, a detailed spectrum of analysis is the key for vibration analysts. Vibration analysis done in the gearbox helps in determining faults in the early stages. The maintenance department should schedule maintenance in advance to avoid potential problems with a proper plan, resources and tools.
Overview
Vibration Analysis collects details of vibrations detected and compares them against known failure-causing vibrations to identify potential failure points. Maintenance professionals are proactively using this technique to find out performance issues. Time and manpower are saved with the help of Vibration Analysis.
Different kinds of complicated vibration signals are observed and recorded in gearbox vibration analysis. They include random noise, inherent operating frequencies, and some failure frequencies. Based on these inputs and analysis, machine maintenance is performed.
In general, vibration is generated in a gearbox when the gear reducer is running. This occurs because of the effect of the gear pair dynamic mesh force. As a result, we can analyse the stability of the transmission system, but it will produce noise. The vibration is considered as a sound wave. There are a variety of instruments that can be used to capture machine vibration and this can be done by measuring changes in acceleration. Such devices are known as – accelerometers. This equipment will also measure frequency, a frequency-weighting network, and a display such as a metre, printer, or recorder.
What is a Gearbox?
A Gear Box is often called a transmission. Gearboxes simply refer to a set of gears and their casing, most commonly found in automobiles. A gearbox plays an important role in several industrial processes because it’s so critical. To prevent catastrophic failures and huge production losses, it should be monitored closely. It is an effective predictive maintenance approach for detecting faults in the Gearbox at the earliest stage to take the necessary steps to prevent failures. Different vibrations of each gear component create a distinct pattern. This pattern changes when there’s a fault.
Types of Gearboxes
In general, there are three different types of gearboxes.
- Concentric
- Parallel
- Right Angle
- Shaft Mount
Fundamentals of Gearbox Vibration
Vibration is simply the transfer of potential energy to kinetic energy. That means it is measured in terms of amplitude, frequency, and phase. So, when it comes to gearbox vibration analysis, based on the analysis of vibration signals picked up from the gearbox casing, there is an extensive number of concepts associated with the design, geometry, and construction of these machine elements. The common target is to detect abnormality, its type and intensity at an early stage of development and to monitor its evolution.
Reasons for Gearbox Failure:
- Improper Design
- Application Errors
- Manufacturing Errors
Types of Gearbox Faults
There are two types of gearbox faults:
- Shaft Turns Related Faults:
- Spectrum data is more effective for representing these faults.
- Amplitude changes in the gear mesh frequency (and/or 2xGM and 3xGM), with sidebands around the gear mesh peaks also changing in amplitude.
- Examples include misalignment and bent shafts.
- Gear Meshing Related Faults:
- Time waveform data is more effective for representing these faults.
- Vibration changes occur once per revolution, indicating a gear meshing issue.
- Spectrum changes are less predictable.
- Techniques like time synchronous averaging can help diagnose the extent of damage, even in complex gearboxes.
- Examples include cracked, broken, or worn teeth.
Types of vibration analysis techniques to detect gear faults.
- Time Domain Analysis
- Resonance Analysis
- Frequency Domain Analysis
- Envelope Analysis
- Phase Measurement Analysis
- Order Analysis
- Orbit Analysis
Damage, imbalance and misalignment are often the symptoms of failure. Manufacturing or application errors, poor design, or maintenance errors are probable causes of the failure. Methods used to assess pre- and post-failure are:
- Reactive Maintenance: It is done upon damage.
- Preventive Maintenance: It is routinely done to keep the machine in optimal condition.
- Predictive Maintenance: This includes planning for regular maintenance and tackling inevitable downtime.
Techniques for Gearbox Vibration Analysis
Let’s check with the gearbox vibration analysis, the possibility of failure can be identified easily. It gives more control and time for the maintenance processes. With a long history of reliability, VA is viable for more than just the common search for “bearing failure.”
The following techniques are used to perform gearbox vibration analysis:
- Data Collection: Reactive maintenance is used to collect data. Engineers set baselines because of varying changes in vibrations. Changes showing abnormal values are collected, which helps the analyst assess which part has defects.
- Data Processing: To eliminate the artefacts and noise from the raw vibration signal, pre-processing is required. Feature extraction is required to get meaningful and important characteristics from the vibrations. Time domain analysis, frequency domain analysis, and time-frequency domain analysis are the ways to perform factor extraction. With the extracted data, a feature vector is formed to diagnose the fault.
- Fault Diagnosis: For classifying faults, a set of algorithms is used, like support vector machines (SVM), artificial neural networks, Networks (ANN), K-nearest neighbours (KNN), etc. It leads to the diagnosis of faults in the machinery.
Benefits of Gearbox Vibration Analysis
To understand the benefits, let’s again revise where this technique is used. It is widely used in manufacturing units to inspect industrial gearboxes. This gearbox fault analysis is widely used because it will enable users to prevent breakdowns.
This method examines the noise produced by the gearbox. An industrial gearbox is made up of various parts, each generating distinct vibrations at specific frequencies during operation. Any damage will cause a complete change in the noise pattern. This shift in vibrations aids in identifying the nature and origin of the damage. For example, noise patterns vary depending on whether the issue is related to misalignment, damage, or imbalance. Turbines, pumps, conveyor parts, gears, fans, rotors, and other equipment can all reap the rewards of this analysis technique.
One of the main benefits is Predictive Maintenance. As this technique deals with machinery and equipment, timely maintenance can be done by engineers to prevent breakdowns and potential faults. The following are the other benefits of Predictive Maintenance:
- Enhanced Work Environment: By employing the predictive maintenance technique, faults in a gearbox can be detected and fixed at an early stage. This helps to create a safe working environment for the staff.
- Find Out the Required Repair Tasks: Early detection of potential problems improves maintenance practices. Management can take preventive measures to schedule maintenance.
- Reduce Labor & Repair Costs: Predictive Maintenance reduces the overall time required for repairing components because of its predictive nature. This may further help decrease labour costs.
- Extended Equipment Lifespan: Early diagnosis of problems gives maintenance personnel the time to take measures that may have a significant impact on increasing the lifespan of the equipment.
- Increase The Overall Production: With Predictive Maintenance, it is possible to increase production volumes, which in turn will increase revenue. Moreover, it can reduce labour costs, decrease potential problems, and lessen wrench time.
Steps to Follow in Gearbox Vibration Analysis
As we discussed, the process of finding anomalies and monitoring change from the established vibration signature of a system is known as Vibration Analysis (VA). The variations of amplitude, intensity, and frequency are calculated for VA. Integrated and synchronised gear trains in a huge box or container are known as gearboxes. It can change speed and torque between a driving device and a driven device. These gearboxes switch the direction of rotation and the direction of drive shafts.
According to some specific set of values for speed amplitude and acceleration, the gearboxes are standardised. Analysing gearbox failures is largely based on the detection of changes in patterns instead of analysing variables against absolute values. In short, VA in gearboxes are determined through the following steps:
- Calculate the Expected Vibration Spectrum
- Establish a Baseline
- Digitise the Signal
- Convert to Frequency Space
- Look at Harmonics
- Time-Waveform Analysis
- Phase Analysis
While choosing the trustworthy partner to check your gearbox vibration analysis, you can choose the best service provider – Ocean-Me.
How Does Ocean-Me Perform Gearbox Vibration Analysis
Gearbox vibration analysis is an excellent approach to keeping machines in optimal condition. Our key takeaways are:
It is highly effective in detecting faults at the earliest stages and mitigating problems and is widely used in industries because of its long history of reliability. These techniques include data collection, data processing, and fault diagnosis. Early detection of issues, improved maintenance practices, extended equipment lifespan, and enhanced operational safety are benefits of gearbox vibration analysis.
In the analysis, different complicated vibration signals are observed in the form of random noise, inherent operating frequencies, and failure frequencies. This is shown in the form of amplified frequencies in the sidebands. That difference in amplitude tells engineers about the exact problem.
Improvements in technology have made the gearbox technique formidable for detecting issues before they break down. A skilled vibration analyst can determine the causes of breakdowns within a few times using the basics of vibration analysis.
As the leading Engineering company in Oman, we provide reliable Gearbox Vibration Analysis Services. Our expertise also includes condition monitoring services such as partial discharge testing, laser shaft alignment services, vibration analysis, and more. With Ocean-Me, you can ensure the safety of your machines.