Title: Ultrasonic Reflections from the Multi-Frequency bearing in the Full-Scale Wind turbine Bearing Test Rig
Instituation: The University of Sheffield, UK
Date of Collection: 15/05/2019 - 07/06/2019
Keywords: Bearing, meniscus, oil lubrication, grease lubrication
Rig: Multilife - owned by Riccardo

Overview:

This test data was captured on the multi-frequency bearing, installed in the full-scale wind turbine bearing test rig, and has test data for the bearing lubricated with Hyspin VG 32 oil and Alpha SP 320 oil.

During the VG320 test 4 sensors were active. Chn1 - 2MHz, Chn2 - 5MHz, Chn3 - 10MHz, Chn4 - 15MHz. The 5MHz sensor was damaged when stripping the rig down between tests and so for VG 32 tests Chn1 - 2MHz, Chn2 - 10MHz, Chn3 - 15MHz. When excited these sensors send ultrasonic waves through the raceway which reflect from the inner raceway-roller contact face. A bearing carrier supports the instrumented inner raceway which is in turn shaft mounted. This inner raceway then remains stationary during the test and the outer raceway is belt driven at 5 different speeds of 20, 40, 60, 80, 100rpm. The tests were run at applied loads of 000kN, 100kN, 200kN and 400kN.

For oil tests an oil pump and scavenger pump worked to constantly circulate oil. During the VG320 test the oil pump was turned off due to a concern of flooding the bearing, and prior knowledge that the inlet flow rate is quicker than the outlet flow rate.

The recordings are of these raw reflections. The data was capturered using the Film Measurement System from Tribosonics Ltd.

Notes on data:

No temeprature measurmement was available for these tests. However, from repeats whith a different bearing instrumented with a thermocouple, the inner raceway temperature is assumed between 30C - 35C during the tests.

For oil tests, three 10s captures were taken. Then end of the file name refers to the test number. For example, 20190515_Multilifetest_0200kN_080RPM_2 is the VG320 oil (known via date) testsed under 200kN of total radial load, with the outer raceway spinning at 80rpm, and is the second capture.

Units:
In the file, there are unit themes throughout:
-pulse rate (Hz)
-temperature (Celcius)
-range and delay (microseconds)
-reflection units (millivolt)
-Filter (mode 5, centred around 10MHz)