BEARING FAILURE DETECTION WITH WI-CARE 200 SERIES
The following case study reports how the Wi-care installation has allowed to detect a bearing failure and avoid the production downtime.
CUSTOMER’S PROFILE AND NEED
The client followed by MIPU is a company that works in the chemical industry. This company owns a production plant and it has an internal maintenance department.
The main reason that brought the client to contact MIPU and require a consulting of our Predictive Maintenance Team was the necessity to monitor the functioning of their extruder with the purpose of detecting failures.
The internal staff responsible for predictive maintenance have measured this equipment for several years, but they could not find any irregularity in the machine operation. Consequently, the customer was pretty sure that they could keep to use this machine until their turnaround in September 2020.
Nevertheless, they decided to install six Wi-care 240 modules in October 2019 to properly monitor the equipment.
OUR SOLUTION
We proposed to install the Wi-care sensor in order to collect vibration data easily and accurately. In fact, thanks to vibrations analysis, it is possible to constantly monitor the machine state of health and detect anomalies with a great level of accuracy.
We placed four sensors on the engine and twenty on the gearbox of the extruder. The RPM (Revolutions Per Minute) is measured via an active inductive tachometer near the coupling between the motor and the gearbox. Input/output: 1383/360.
WI-CARE 240 MEASUREMENTS
Below we show part of the report of the Wi-care measurements after the installation in October 2019.
The first peak hold measurement revealed a relatively high impact level on the coupling side of the input shaft (Figure 5). This could be a symptom of a problem specific to this part.
The corresponding spectrum contained asynchronous energy at 7.59xRPM which seems to come from the inner ring of the FAG QJ326-N2-MPA bearing, as the figure 6 shows. This formula, known as BPFI (Ball Pass Frequency of Inner Ring), is used to calculate bearing frequencies and it indicates an inner ring defect.
What made this data alarming is that this BPFI energy at 7.59x RPM is clearly visible in the low frequency area of the normal vibration measurement (see figure 9). These amplitudes are the highest in axial direction, measured on the input shaft – non drive end. The BPFI energy, which is visible in the low frequency area, indicates that the inner ring fault is at an advanced stage. However, the defect is not so critically high to make further operation dangerous.
If we hypothetically had opened and cleaned the bearing in that moment, we could have seen a damaged inner ring.
The customer had planned to produce with this extrusion line until their scheduled stop in September 2020, but the detection of this problem revealed a damage quite severe.
Based on that, they decided that the risk of producing until September 2020 was too high and they planned to overhaul the gearbox during a brief stop in January 2020.
Images below show the damage found on the input shaft FAG QJ326-N2-MPA bearing.
CONCLUSION
In conclusion, the damage of the bearing was easily detectable in both low and high frequency measurements by using the appropriate predictive maintenance tools. Our customer can now detect failures before they occur and reduce production stops.
If you want to receive the complete datasheet of the Wi-care or you want to know more about how you can reduce your downtime, contact us!
