Hello everyone, I am currently experiencing difficulty in pinpointing the frequency of bearing race defects in a Thrust ball bearing (specifically, SKF 51204). The attached file shows that the defect frequency is a multiple of the bearing speed frequency (5X), making it challenging to distinguish. Can anyone offer advice on how to address this issue? Thank you.
Dear Vips, I recommend posting your question in the Vibration Section for more specific feedback. Have you double-checked if the contact angle is truly at 90 degrees? It seems there may be a discrepancy in the rotation speed - 1 RPM is not equivalent to 60 Hz as indicated on your documentation; in fact, 60 rpm is equal to 1 Hz. If the calculated BPFO is indeed 5 times the shaft speed, make sure to investigate other potential sources of this frequency on the machine. Consider examining additional bearing fault indicators like high frequency acceleration (HFD) and demodulated (PeakVue) spectrum and waveform. It's crucial to ensure the accuracy of your data and calculations before delving into troubleshooting the fault issues. Embrace your inner detective to pinpoint and address the root cause effectively. Walt
Walt is right in suggesting to share this in the standard vibration forum found at http://maintenanceforums.com/e...s/a/frm/f/3751089011. In the realm of fault detection, it is important to note that issues are not always evident based solely on the fundamental frequency. Factors such as harmonics (including multiples of running speed) and floor noise contribute to the overall assessment. Bearing defects are generally straightforward to identify, particularly once an analyst has honed their pattern recognition skills. If you suspect a bearing issue, consider sharing the data for collective analysis. In my opinion (IMO), this approach can lead to valuable insights.
In the typical operation of bearings, the cage moves at a certain speed with respect to both the inner and outer rings. It is a common phenomenon in 90-degree contact thrust bearings for the cage to move at a speed equivalent to half the order. This is due to the equal pitch diameter of the races, which ensures that the ball travels at the same speed in relation to each race. This results in the ball making half a revolution with each shaft revolution, leading to a total of 0.5 revolutions relative to the rotating inner race. Consequently, the FTF is 0.5 and 1-FTF is also 0.5. This relationship ensures that the BPFO and BPFI are always whole number orders when the number of rolling elements is even. Therefore, it may be beneficial for OEMs to consider designing bearings with an odd number of rolling elements. It is recommended to investigate harmonics of 5x, consider factors such as twf and demod spectrum, and explore other potential causes of issues related to 5x, especially in cases involving 5-bladed impellers.
When analyzing thrust bearings, it is important to note that not all of them have a 90-degree contact angle. In my experience working on a thrust bearing for a small hydro turbine, I observed harmonics of 0.5xSS in the Demod spectrum. This led me to diagnose a fault in the bearing, which was confirmed after subsequent repairs. It is crucial to understand that various faults can present with similar vibration frequencies, making it necessary to thoroughly analyze all data to pinpoint the correct or most probable issue at hand. Walt.
Hey! Identifying bearing race defects can be tricky, especially with the frequency overlap like you're experiencing. One approach you might consider is using spectral analysis tools to isolate harmonics or energy peaks that are characteristic of the defects. Additionally, applying an envelope detection method could help highlight the defect frequencies amidst the background noise. If possible, try to collect data over varying loads or speeds, which may help differentiate the signals. Good luck!
Hey there! Identifying bearing race defects can definitely be tricky, especially with the harmonics coming into play. One approach you might consider is using a combination of vibration analysis techniques, like orbit analysis or spectral analysis, to isolate the defect frequencies from the operational frequencies. Employing a high-resolution FFT (Fast Fourier Transform) can help in distinguishing between the harmonics and providing a clearer picture of the defect frequency. Additionally, try to compare the results with baseline data to see if there's a shift that indicates a problem. Good luck!
Hey! It sounds like you're dealing with a tricky situation with the SKF 51204. One approach you could consider is using a frequency analysis tool like FFT (Fast Fourier Transform) to help isolate the defect frequency from the overall signal. It can be super effective for distinguishing between harmonics and identifying the specific defect frequencies. Additionally, try looking at the operational context—maybe changes in load or speed could help clarify things. Also, monitoring anything unusual in the vibration patterns, like sudden spikes, might give you a clearer picture. Good luck!
Hi there! It sounds like you're dealing with a tricky situation. To help isolate the bearing race defects, you might want to consider using advanced signal processing techniques like demodulation or envelop analysis, which can enhance the defect frequencies and help you separate them from the fundamental bearing frequencies. Additionally, if you haven't already, capturing data at different speeds could also provide insight into how the defect frequencies behave in relation to speed, which might make it easier to identify the patterns. Good luck!
Hi there! It sounds like you're dealing with a tricky diagnosis. One approach you might consider is using signal processing techniques, like envelope analysis or demodulation, which can help isolate those defect frequencies from the noise of the bearing speed. Additionally, try to utilize waveform analysis; sometimes, patterns in the vibration signal can give clues about the nature of the defect. If you can, take data at different operational speeds and conditions as well—this can help in identifying the defect frequency more clearly. Good luck!
✅ Work Order Management
✅ Asset Tracking
✅ Preventive Maintenance
✅ Inspection Report
We have received your information. We will share Schedule Demo details on your Mail Id.
Answer: 1. What is causing the difficulty in pinpointing the frequency of bearing race defects in SKF 51204 Thrust Ball Bearings? - The defect frequency is a multiple of the bearing speed frequency (5X), making it challenging to distinguish.
Answer: - One potential solution could involve applying techniques to separate the defect frequency from the bearing speed frequency to accurately pinpoint the issues.
Answer: - Utilizing vibration analysis, spectral analysis, or frequency domain analysis techniques could help in identifying and addressing bearing race defects in SKF 51204 Thrust Ball Bearings.
Join hundreds of satisfied customers who have transformed their maintenance processes.
Sign up today and start optimizing your workflow.