1. Date of download: 5/28/2016 Copyright © ASME. All rights reserved. From: Ultrasonic Measurement of Rolling Bearing Lubrication Using Piezoelectric Thin Films J. Tribol. 2008;131(1):011502-011502-8. doi:10.1115/1.3002324 Configuration of ball bearing outer-raceway and ball in contact Figure Legend:

2. Date of download: 5/28/2016 Copyright © ASME. All rights reserved. From: Ultrasonic Measurement of Rolling Bearing Lubrication Using Piezoelectric Thin Films J. Tribol. 2008;131(1):011502-011502-8. doi:10.1115/1.3002324 Schematic of the piezo thin film transducer on a ball bearing Figure Legend:

3. Date of download: 5/28/2016 Copyright © ASME. All rights reserved. From: Ultrasonic Measurement of Rolling Bearing Lubrication Using Piezoelectric Thin Films J. Tribol. 2008;131(1):011502-011502-8. doi:10.1115/1.3002324 Photograph of the instrumented ball bearing Figure Legend:

4. Date of download: 5/28/2016 Copyright © ASME. All rights reserved. From: Ultrasonic Measurement of Rolling Bearing Lubrication Using Piezoelectric Thin Films J. Tribol. 2008;131(1):011502-011502-8. doi:10.1115/1.3002324 Reflection coefficient profile measured as the bearing rotates. The center of the lubricated contact occurs at x=0. The horizontal dashed lines indicate the predictions based on Eq.. Figure Legend:

5. Date of download: 5/28/2016 Copyright © ASME. All rights reserved. From: Ultrasonic Measurement of Rolling Bearing Lubrication Using Piezoelectric Thin Films J. Tribol. 2008;131(1):011502-011502-8. doi:10.1115/1.3002324 The undeformed and deformed shape of the contact surfaces; (a) outer-raceway and (b) ball Figure Legend:

6. Date of download: 5/28/2016 Copyright © ASME. All rights reserved. From: Ultrasonic Measurement of Rolling Bearing Lubrication Using Piezoelectric Thin Films J. Tribol. 2008;131(1):011502-011502-8. doi:10.1115/1.3002324 The tangent angle as a function of distance across the outer-raceway for a range of bearing loads Figure Legend:

7. Date of download: 5/28/2016 Copyright © ASME. All rights reserved. From: Ultrasonic Measurement of Rolling Bearing Lubrication Using Piezoelectric Thin Films J. Tribol. 2008;131(1):011502-011502-8. doi:10.1115/1.3002324 Simulated geometrical reflection coefficient (Rg) caused by the surface deformation alone Figure Legend:

8. Date of download: 5/28/2016 Copyright © ASME. All rights reserved. From: Ultrasonic Measurement of Rolling Bearing Lubrication Using Piezoelectric Thin Films J. Tribol. 2008;131(1):011502-011502-8. doi:10.1115/1.3002324 The reflection coefficient profiles obtained when an assumed reflection coefficient (given by Eq. ) is distorted by the reflection effect caused by surface deformation. The dashed lines indicate the theoretical values based on the oil-film thickness calculated from Eq.. Figure Legend:

9. Date of download: 5/28/2016 Copyright © ASME. All rights reserved. From: Ultrasonic Measurement of Rolling Bearing Lubrication Using Piezoelectric Thin Films J. Tribol. 2008;131(1):011502-011502-8. doi:10.1115/1.3002324 A comparison of experimentally measured oil-film thickness (including a correction for surface deformation) with EHL theoretical solution (Eq. ) for a range of bearing loads (W) and speeds (w). Note that label AlN refers to measurements made using the piezo thin film transducer and label Focsd refers to data from Ref. obtained using a highly focused 50 MHz transducer. Figure Legend: