Senior Design Presentation Spring 2016
-
Upload
huerta-joel -
Category
Documents
-
view
93 -
download
1
Transcript of Senior Design Presentation Spring 2016
Planetary Gear TransmissionFinal Presentation
May 27, 2016
Team Members: Joel HuertaMiguel AvilaJonathan VillamorRichie Aunchareonpornpat
SAE BAJA Liaison: Kevin KnarrFaculty Advisor: Ted Nye
California State University, Los Angeles
AGENDA
2
1. Background and Programmatics Joel
2. Design Options, Planetary Gear System, and Shifting Miguel
3. Transmission Box, Bearings, and Shafts Jonathan
4. Bolts, Screws, and Margin of Safety Richie
5. Design Challenges, Mechanical Assembly, and Conclusion Joel
WHAT IS BAJA?
• Annual Competition by Society of Automotive Engineers
• Small off-road cars that can withstand harsh terrain
• Judged based on various events (Hill Climbs, Rock Crawls, Endurance Race, etc.)
3
PROJECT BACKGROUND• All teams are given the same engine
• A lighter, smaller, and more efficient gearbox would help the team become more competitive
• A set up using a planetary gear system was proposed as a way to satisfy all three requirements
4
Current System Proposed System
SCOPE
• Design and analyze a prototype gearbox
• Provide a more efficient and lighter planetary gearbox
• Investigate if a more efficient gear ratio reduction in a more compact volume is reasonable
5
ORGANIZATION CHART DEFINED PROJECT RESPONSIBILITIES
6
Student LeadJoel Huerta
Technical Review
Theodore Nye
Project Review Authority
Kevin Knarr
Design of Gear and Shifting Systems
Miguel Avila
Gear Box and OverviewRichie A. and Joel Huerta
Shaft and Bearing Analysis
Jonathan Villamor
PROJECT CONSTRAINTS WERE MET WITH SCHEDULE
7
WBS 4 11 18 25 1 8 15 22 29 6 13 20 27 3 10 17 24 31 7 14 21 28 6 13 20 27 3 10 17 24 1 8 15 22 29 5 12 19 26
1 Program Milestons SRR/CoDR PDR Deliver CDR/Expo
1.1 Program Key Events Order Parts Receive Parts Baja Competition
1.2 Phase 1-Requirements and Concept Design
1.3 Transmission Requirements
1.4 Reviews
2 Phase 2-Detail Design and Fabrication
2.1 Design of Transmission
2.2 Analysis of Transmission
2.3 Concept Design of Transmission Box
Select Appropriate Shaft Lengths and Diameters
2.4 Stress and Loading Analysis of Gears
2.5 Stress and Loading Analysis of Shafts and Sizing of Bearings
2.6 Design of Prototype
3 Phase 3-Final Assembly and Evaluation
3.1 Fabrication of Prototype
3.2 Assembly of Gear Box
3.3 Testing of Gear Box
3.4 Evaluation of Output Gear Ratio
3.5 Failure Modes and Effects Analysis
4 Program Management
4.1 Weekly Meetings Agendas and Minutes
4.2 Oral Presentation and Written Report
4.3 Reviews
Nov
Fall Quarter 2015
Dec JanActivity
Apr May JuneOct
Winter Quarter 2016 Spring Quarter 2016
MarFeb
PROJECT CONSTRAINTS DEFINED BY REQUIREMENTS
8
No. Requirement Name Performance Objective Capabilities
1 Gear Ratio 7:1 7.01:1
2 Weight <39lbs 51 lbs
3 Volume 4 in. x 12 in. x 8 in. 6.41 in.x 15.05 in. x 10.16 in.
4 Transmission Modes Forward, Neutral, Reverse Forward, Neutral, Reverse
5 Max Continuous Torque >42 lb-ft 180.28 lb-ft
6 Max Shock Torque >293.02 lb-ft 306.37 lb-ft
7 Moisture Environment Sealed Gearbox and Bearings Comply
8 Interface Shall Meet MICD Non Compliant
AGENDA
9
1. Background and Programmatics Joel
2. Design Options, Planetary Gear System, and Shifting Miguel
3. Transmission Box, Bearings, and Shafts Jonathan
4. Bolts, Screws, and Margin of Safety Richie
5. Design Challenges, Mechanical Assembly, and Conclusion Joel
CONCEPT DESIGN OPTIONS
10
Design 2 Design 1 Design 3
• Most Efficient• Heaviest Design
• Hard to achieve reverse• Expensive Ring Gear
• Lightest Design• Spur Gears Easy to Design
PLANETARY GEAR SYSTEM
• Forward, neutral, and reverse were obtained
• Gear system still needs to be optimized for mass
11
GEAR TEETH DETAILS
12
Output Spur Gear: 68
Ring Gear: 46 Planet Gears:16
Sun Gear:14
Carrier Spur Gear: 42
Idler Input Gear: 18
Output Idler Gear: 25 Output spur gear:
1.0 inch
Planetary system: 1.1 inch
Idler gear: 1.0 inch
Carrier spur gear: 1.0 inch
Reverse gear: 1.0 inch
GEAR RATIOS BETWEEN GEARS
13
Output forward gear ratio: 7.01
Output reverse gear ratio: 4.96
Gear ratio of planetary system: 4.34
Equation used for Planetary Gear Analysis:
SHIFTER DESIGN MODES
14
Forward7.01:1
Neutral Reverse4.96:1
SHIFTER DESIGN
15
AGENDA
16
1. Background and Programmatics Joel
2. Design Options, Planetary Gear System, and Shifting Miguel
3. Transmission Box, Bearings, and Shafts Jonathan
4. Bolts, Screws, and Margin of Safety Richie
5. Design Challenges, Mechanical Assembly, and Conclusion Joel
TRANSMISSION BOX
17
*Transmission Box Material is Aluminum Alloy 2024 T-4Dimensions are in inches.
6.41
10
.16
SHAFTS AND BEARINGS
18
BearingsShafts
19
Shaft Bearing # Bore Dynamic Load Static Load Material Margin of Safety
Input 7206-2RS 1.1811 in 4,875 lbs. 3,165 lbs. 52100 Chrome
Steel
0.98
Output 7206-2RS 1.1811 in 3,435 lbs. 2,020 lbs. 52100 Chrome
Steel
1.58
Idler 7205-2RS 0.9842 in 4,875 lbs. 3,165 lbs. 52100 Chrome
Steel
1.31
BEARING ANALYSIS
Ball Bearing : 𝐿10𝐶
𝑃
3
SHAFT ANALYSIS
20
Shaft Length Diameter Margin of safety
Input 8.44 in. 1.18 in. 1.32
Output 10.41 in. 1.18 in. 1.50
Idler 6.41 in. 0.98 in. 2.01
𝑑=32 𝑁𝑓
𝜋𝑘𝑓
𝑀𝑎
𝑆𝑓
2
+3
4
𝑇𝑚
𝑆𝑦
21/2 1/3
*Factor of Safety Factor Assumption, N=1.1
AGENDA
21
1. Background and Programmatics Joel
2. Design Options, Planetary Gear System, and Shifting Miguel
3. Transmission Box, Bearings, and Shafts Jonathan
4. Bolts, Screws, and Margin of Safety Richie
5. Design Challenges, Mechanical Assembly, and Conclusion Joel
BOLTS AND SCREWS
22
Bolts Screws
MARGIN OF SAFETY TABLE
Face
Width
Number
of Teeth
Bending
Stress
Margin of
Safety
Gear F (in) N σb (psi) Bending
Sun 1.1 14 74749.15 0.37
Planet 1.1 16 76410.24 0.34
Ring 1.1 46 44082.83 1.32
Carrier 1 42 83913.81 0.22
Idler 1 18 25923.03 2.94
Reverse 1 25 81228.26 0.26
Output 1 68 94766.31 0.08
Margin of Safety:
𝑀𝑆 =𝜎𝑦
𝜎𝑝𝑟𝑒𝑑′ ∗ 𝑁
− 1
*Factor of Safety Factor Assumption, N=1.1
Bending Endurance Strength (SFB)=112400 psi
OLD VS. NEW
24
AGENDA
25
1. Background and Programmatics Joel
2. Design Options, Planetary Gear System, and Shifting Miguel
3. Transmission Box, Bearings, and Shafts Jonathan
4. Bolts, Screws, and Margin of Safety Richie
5. Design Challenges, Mechanical Assembly, and Conclusion Joel
DESIGN CHALLENGES
26
Fixed Clutch and U-Joint Distance
6.41 inches
Volume Requires Frame Modifications
(Old Design)
PRINTED GEARBOX
27
11.81 in.
3D PRINTED GEARBOX
28
GEAR RATIO TESTING AND SCHEMATIC
TestRatio
Obtained
Turn Test 7:1
Speed Test 6.56:1
Torque Test 3.79:1
29
Speed Test
POWER SOURCE
MOTORGEAR
SYSTEMTACHOMETER
BRAKE
GEAR SYSTEM
TORQUE WATCH
SENSORTORQUE
TRANSDUCERMULTIMETER
POWER SUPPLY
Torque Test
SUMMARY AND REVIEW
30
• Forward, neutral, and reverse were achieved by prototype• 7:1 gear ratio achieved by design• Basic design shows feasibility, ready for future optimization
31
QUESTIONS?