Design Review 2 Team AES

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Domenic Fleming
5 years ago
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1 Design Review 2 Team AES Andy Hughes Jesse Shoup Barry Poechmann Eric Jackson

2 Complete Assembly OVERVIEW Features and Operation Motor Selection and Performance Stress Analysis Screw Main Arm Gear System Cost / Weight Considerations Manufacturing and Materials Schedule

3 Features and Basic Operation No Assembly Required User activates jack by holding down a button on the wired remote control Adjustable saddle aids in lifting high vehicles Alignment link keeps saddle parallel with ground Performance 5,500 lb capacity Lift Range: 5 in to 15 inches Estimated Lift Time: 5 minutes (under normal operating conditions)

Verified Leeson PMDC Motor Performance Tested Performance in Stocker 011 on 1-31-04 Source Power (HP) Compare Data with

4 Verified Leeson PMDC Motor Performance Tested Performance in Stocker 011 on Source Power (HP) Compare Data with Expected Performance Current (A) Torque (in-lb) Efficiency (%) Dynamometer Test Leeson Data 1/ N/A

Stress Analysis of Screw Load Case: 5,500 lbs @ 5 in 0.

583 in diameter cylinder (screw minor diameter) 19,100 lb: axial

5 Stress Analysis of Screw Load Case: 5,500 5 in 0.75 inch ACME Threaded Screw (8 TPI) Approximated as in diameter cylinder (screw minor diameter) 19,100 lb: axial compressive load from vehicle 1,044 in-lbs: torque from motor (at 8 Amps) τ max = Tr J σ x = P A 1044 in-lbs 19,100 lbs

6 Stress Analysis of Screw von Mises effective stress for the 2-D case in terms of the applied stresses σ = σ x + σ y σ x σ y + τ xy Worst Load Case: 5,500 5 in FOS S = y σ 125,000 = 86,100 Important considerations = 1.5 5,500 lb load used includes FOS (ie. loading = GVW) FOS increases as car is lifted due to jack geometry Normal Operation: 2,400 5 in FOS S = y σ 125,000 = = ,300 Additional Failure Modes FOS Screw Threads Shearing 10.4 Nut Threads Shearing 1.7 Screw Buckling 2.0

7 Applied Loads on Main Arm 4140 Steel -Forged and Machined Boundary Conditions: Constrained at Pins 8,250 lb Proof Load 20,500 lb Reaction at 22 19,100 lb Pin Reaction

8 von Mises Stress Hand Calculations (average stress) 157,000 psi 60,000 psi

9 Stress Concentration Cutout to allow device to fully collapse.

10 Stress Concentration Course of Action Original Modified Shape has been optimized to reduce stress concentration Increased side thickness to 5/16

11 Transmission 2 Speed Transmission Uses worm and spur gears 170:1 Normal operating range 530:1 Assumes 70% Transmission Efficiency Plan Finish Design Outsource to Qualified Vendor

12 Manufactured Components Part Main Arm Manufacturing Method Forged and Machined Material Weight (lb) 4140 Steel 5 Track Alignment Links Support Arm Slider Wheels Saddle Machined Forged and Machined Sand Cast and Machined Sand Cast and Machined Forged Forged and Machined 1 ¼ x ¾ 12L14 Steel 4140 Steel 6061 Aluminum 4140 Steel 1040 Steel 4140 Steel

13 Purchased Components Part Cost Subtotal Estimated Weight (lb) Pins $3 2.1 Motor $50 4 Transmission $80 6 Screw / Nut $5 1.2 Thrust Bearing $5 0.2 Electronics $2 0.5 Manufactured Totals $ Totals $170 ±

14 Roller Slider Bearing Weight Analysis Individual Part Percentage Cumulative Percentage Wt. Percentage of Total Base Frames Motor Alignment Link Slider Main Arm Transmission Saddle Fixed Link Thrust Support Saddle Base Pins Screw Component Name Pareto Graph of Component Weight.

15 Critical Path Finish Stress Analysis on Base, Arm, and Slider (3/4/04) Order Raw Materials (3/8/04) Create Prototype Process Plans (3/13/04) Machine Structure (4/12/04) Test Structure (4/16/04) Determine Gear Box Specs and Select Vendor (3/8/04) Order Gears, Bearings and Shafts (3/12/04) Machine Gearbox Housing (4/8/04) Assemble (4/12/04) Test (4/14/04)

16 Potential Problems / Priorities Higher transmission losses than expected Transmission cost Weight Reduction Accurate Analysis on Complex Parts (FEA)

17 References: Machine Design (Norton): Screw Selection Schaum s Outlines: Machine Design: Transmission Machinery s Handbook: Screw + other components ASME PALD: Safety Standards

18 Questions???

19 Estimated Lift 70% 50% Normal Operating Conditions with 4000 lb GVW Vehicle 4 min 5 min Worst Case Loading (5,500 lb) 12 min 16 min

20 Worm Gear Calculations Our Tangential Load = 168 lbs Allowable Tangential Load: 300 lbs Dynamic Load Rating: 314 lbs Wear Load Rating: 200 lbs 1 f tanα Efficiency = = 78% f 1+ tanα where: f = coeff. of friction = α = lead angle = 6

21 Stress Analysis Slider Applied Loads 7475 lb 7475 lb lb Pin lb Nut

22 Purchased Components Specifications Unit Cost Sub Estimated Weight (lb) Pins and Shafts 5/8" 1045 Chrome-Plated Steel $29.56/36" $30 2 Snap Rings 5/8" Heavy Duty Retaining Ring $0.20 $4 0.1 Motor 1/14 hp, 12vdc, 2.88 in-lbs, 7.7 A $91.00 $91 4 Worm Gear 12 Pitch, 60 t, 5/8" bore, 5" Pitch dia $70.05 $ Worm 12 Pitch, 1/2" bore, 1" Pitch dia $19.52 $ Spur Gear 16 DP, 1" PD, 5/8" Bore, 20 PA?? 0.1 Spur Gear 16 DP, 2" PD, 5/8" Bore, 20 PA?? 0.4 Spur Gear 16 DP, 3" PD, 5/8" Bore, 20 PA?? 1 Screw 3/4"-8 Acme Threaded Rod $0.50/inch $8 1 Nut 3/4"-8 Acme Coupling Nut $3.29 $3 0.2 Thrust Bearing " x 2.469" x.75", lb $32.04 $ Ball Bearing 5/8" x 7/16" x 1 3/8" Shielded $5.67 $ Plug Cigarette Adapter w/8 Amp Fuse $8.00 $8 0.1 Switch DPDT Heavy Duty Rocker $5.00 $ Wire 22 Gauge Stranded Wire $0.25/foot $3 0.2 Saddle Lining 3/8" Neoprene $1.00/in^2 $9 0.1

24 PINS Slider Track

Sheet 1 Variable loading

Sheet 1 Variable loading 1. Estimate S e for the following materials: a. AISI 1020 CD steel. b. AISI 1080 HR steel. c. 2024 T3 aluminum. d. AISI 4340 steel heat-treated to a tensile strength of 1700 MPa.