Multidisciplinary Engineering Senior DesignProject 06445 Alternator Test Stand

Preliminary Design Review02/24/06

Sponsor/Mentors/Members

Project SponsorCenter for Integrated Manufacturing Systems

Team Members Aaron Wright - Project Manager Dan Guerand - Mechanical Engineer Kevin Lloyd – Mechanical Engineer Tim Marvin - Mechanical/Electrical Engineer Dave Schuele - Mechanical Engineer

Team Mentors Mike Thurston Omar Anbari Cyril Gaillard Abhijit Mukherjee

Alternator Test Stand Background

CIMS development of Reliability Centered Maintenance

RCM focuses on predicting failure

CIMS would like to predict the failure of military and domestic alternators

Prediction of failure in alternators allows preventative maintenance to save time, money, life, and equipment.

Project Overview

Project Overview

Test Stand Requirements

Apply a load capable of failing an alternator

Failure must occur in an accelerated time frame

Acquire valuable data for life of alternator

Flexible system design

Test stand must be safe to operate

Self-sustaining for life of alternator

Breakdown of Team Process

1. Project sponsor meetings determined needs

2. Assessed member interests

3. Task list compiled

4. Members assigned to tasks based on interests

5. Concepts for each component categorized by task

6. Gantt chart compiled to provide time requirements for tasks

7. Component feasibility determined by budget and physical constraints

Needs Assessment

100% load must be applied to 14 or 28 volt alternator continuously for life of alternator

Load must be capable of battery configurations of 12 or 24 volts

Data collection must be available for life of alternator

System components must provide maximum safety

ATS must be easily set up by one person

ATS must be self-governing for duration of testing

Project Tasks

Systems Integration - Aaron

Frame/Safety – Kevin

Drive motor – predetermined by CIMS

Battery Bank – predetermined by CIMS

Alternator & Mounting – Dave

Load Bank / Cooling – Dan

Data Acquisition – Tim

Alternator and Battery Load System

The alternator is loaded using 6 banks of low resistance, high power, helical wound resistors.

All resistors are placed in parallel so as to decrease the total amount of resistance with each bank step.

Each bank steps up the amount of current drawn from the alternator or battery.

Resistors will dissipate at most 85% of their rated load.

Load Stepping

BANK RESISTANCE RATED POWER MAX POWER USE 14V % LOAD CURRENT STEP 1 2.8 560 78 14 5 2 2.8 560 78 14 10 3 0.45 2280 485 21 41 4 0.45 2280 485 21 72 5 0.375 3750 580 16 110 6 0.6 1710 360 21 133

BANK RESISTANCE RATED POWER MAX POWER USE 28V % LOAD CURRENT STEP 1 2.8 560 280 56 10 2 2.8 560 280 56 20 3 0.45 2280 1740 85 82 4 0.45 2280 1740 85 145 5 0.375 3750 2090 62 220 6 0.6 1710 1305 85 265

* Resistors have a +/- 10% tolerance on resistance values

Thermal System

The thermal system uses forced convection to dissipate the heat

produced by the resistors.

Advantages Allows for heat transfer rates that are much higher than those

for natural convection. Maintains the ambient temperature of the air surrounding the

resistor bank to levels that the resistors can operate within.

Disadvantages Use of fans requires more power to operate the test stand. Mounting and space constraints within the frame.

Varying the Parameters

Staggered array

Air velocity

Number of rows of resistors

Transverse pitch

Heat Rate versus Velocity

Varying the Number of Resistor Rows

Varying the Transverse Pitch

Amount of Power Dissipation

Maximum power that must be dissipated from resistors is 7.5 kilowatts.

Theoretical maximum power that can be dissipated through the bank of tubes is 150 kilowatts per meter.

Thermal System Final Design

Safety

Prevention of Burns ASTM E1509 used as a guideline

Load Bank & Ambient Exhaust

Prevention of Pinch & Crush Points 4 Fans (Sever Points)

Steel Fan Guards 2 Belts (Crush Points & Belt Break Concern)

Belt Guards – 16 gauge Steel

Internal Frame Concerns Automatic Soft-Stop (Software Shuts Down)

Overheat (Load, Batteries, Electronic Components) Doors, Access Panels, Safety Guards In-Place

Manual Hard Stop (Complete Power Disconnect) Emergency Stop On Side

Visual Monitoring of Frame Internals Transparent Front and Top

Safety

Battery Ventilation & Spill Minimal Hydrogen Out Gassing

Vent Through Wire Access Slots – Frame Fans Spill Protection – Sulfuric Acid

Polypropylene Lining

Identification of Hazards

Aesthetics

Professional Appearance Specified Placement for Subassemblies Electronic Components Board Bundle & Harness Wires Conceal Rough Edges

Visually Appealing to CIMS Vendors & Customers Display Components

Transparent Front & Top

Frame Design

Key Aspects Given Angle-Iron Frame, Motor, and Motor Controller Place Sub-Assemblies To:

Maximize Performance Maximize Efficiency Meet Safety Specifications Meet Aesthetics Requirements

Subassemblies Battery Unit

Stock Cabinet Transparent Doors Sulfuric Acid Resistant Easy Access

Frame Design

Subassemblies Electronic Components Board

Electronic Insulator - Polypropylene Accessible Position Adjustable

Rear Door Track System Accessibility Low Cost Removable

Front Panels Transparent Easy & Quick Access Low Cost

Frame Design

Other Frame Components Top

Transparent Sealed

Sides Moderately Rigid

Placement Limited Option:

Battery Unit – Front Left Load Bank – Horizontal

Other Components Based on Requirements (Previously Mentioned)

Frame Design

Alternator Drive System

Requirements Ability to turn alternator at maximum RPM

Intermediate Shaft Allow for proper belt tensioning Accept wide range of alternators

Physical Mounting Drive Type Electrical Interface

Alternator Drive System

Intermediate Pulley Assembly

From Front of Case

From Rear of Case

Alternator Drive System

Alternator Mounting

System Component Cost

Alternator Fixture $938.15

Data Acquisition $1024.77

Frame & Safety $1074.84

Intermediate Pulley $443.62

Load & Load Cooling $3494.67

Grand Total $6976.05

Financial Investment

Questions

Backup Slides and References