November 14, 2013Mechanical Engineering Tribology Laboratory (METL)

David ArseneauResearch Assistant

Sensor Development for a Wind Turbine Bearing Cage

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November 14, 2013Mechanical Engineering Tribology Laboratory (METL)

Outline

• Motivation• Schematic of a Wireless Strain Telemeter Circuit

Diagram• Placement of Wireless Strain Telemeter on a Wind

Turbine Bearing Cage• Future Work

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November 14, 2013Mechanical Engineering Tribology Laboratory (METL)

Motivation

• Costs ~$500,000 to replace each bearing in a wind turbine

• Current wind turbine bearing cage under investigation deforms 74mm

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November 14, 2013Mechanical Engineering Tribology Laboratory (METL)

Abaqus Results

Deformed shape plotted with the undeformed shape

Undeformed cage

Deformed cage (74mm at max point)

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November 14, 2013Mechanical Engineering Tribology Laboratory (METL)

Placement of Wireless Strain Telemeters

• Wireless strain telemeters will be mounted on the bearing cage– Strain gauge in the axial direction– Strain gauge in the tangential direction

• Printed Circuit Board (PCB) or Kapton will be used to populate the sensor

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November 14, 2013Mechanical Engineering Tribology Laboratory (METL)

Schematic of Wireless Strain Telemeter Circuit Diagram

R2= 1.5kΩ

C2= 8.2pF

Strain Gauge

C=8.2pFR4= 1.5kΩ

R5= 1.0kΩ R6= 1.0kΩ

R3= 5.0kΩ

Antenna

Transistors

Battery

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November 14, 2013Mechanical Engineering Tribology Laboratory (METL)

Strain Telemeter on a Wind Turbine Bearing Cage

BatteryAxial Strain Gauge

Circuit components on PCB or KaptonTangential Strain Gauge

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November 14, 2013Mechanical Engineering Tribology Laboratory (METL)

Future Work

• Develop new custom wireless strain telemeter • Install on wind turbine bearing cage

– Test under static condition– Evaluate in actual wind turbine