Detailed Design Review of Magnetic Field Centering Device Project # P08028 “Develop a Design and Methodology to Ensure the Concentricity between the Magnetic Field and Bushings of a Magnetic Bearing.”

Team Organization

Project Background Need for project produced from the LVAD Heart Pump experiments being conducted by Dr. Steven Day. LVAD Heart Pump utilizes magnetic bearings to alleviate mechanical wear. Magnetic bearing assemblies consist of a magnets permanently adhered between bushings. Proper functionality of magnetic bearing assemblies relies on the concentricity between both bushings and the magnetic field.

LVAD Heart Pump

Rotor Assembly of the LVAD

Hall Magnet Assembly

Purpose of Project. The magnetic field is not concentric to the physical diameter of the magnet The concentricity of the bushings and magnetic field need to be within customer’s specifications Be adaptable for other magnets of the LVAD Heart Pump

IDEAL MAGNETIC BEARING Red = Magnet Grey = Bushing Blue = Magnetic Field Green = Hall Effect Sensor

Red = Magnet Grey = Bushing Blue = Magnetic Field Green = Hall Effect Sensor

PROPERLY ADJUSTED MAGNETIC BEARING Red = Magnet Grey = Bushing Blue = Magnetic Field Green = Hall Effect Sensor

Current Method of Assembling Magnetic Bearings

Associated Problems High level of maintenance and calibration required. Low level of automation in process. Amount of time required for proper assembly of magnetic bearing Repeatability Not the dedicated function of device.

Statement of Problem Develop a highly autonomous device capable of repeatedly ensuring concentricity between the magnetic field and bushings of the rotor assembly.

Customer Needs and Engineering Correlations Customer NeedsCustomer SpecificationsEngineering Needs Concentricity of Magnetic Bearings Within ± 12 µm in Radial Direction Tolerances of Device Components must Stack up to ≤ 12 µm. Device Components must Provide High Resolution and Repeatability. Low Level of Maintainability NA Easily Calibrated Device Components Device Stand/Enclosure must Dampen Minor Vibrations. Higher Level of Automation Maximum Number of User Interactions = 10 Device Components must be capable of interaction with computer Non-Contact Sensors Adaptability0.5 – 1.0 in. Adjustable Radial and/or Axial Positioning of Sensors/Holding Components Adequate Measuring Ranges of Sensors/ Travel of Positioning Components Budget $ 12, Simplicity of System COTS

High Level System Concept

Final Design Concept and Methodology

Flow of System

Schedule for Senior Design II

Current State of Design Selected design expected to meet high level customer needs and specifications. - Verification through additional testing and feasibility assessment. Design fulfills all engineering specifications - Further tolerance analysis of system components necessitated. Current design selection on target to exceed budget - Revising of off-shelf component selection in progress.

Schedule for Senior Design II