CWU | MET
AUTOJACK - POWERTRAIN DESIGN REQUIREMENTS
(1) The powertrain system of this AutoJack must be capable of lifting a 5000lb vehicle.
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(2) The powertrain system of this AutoJack must lift the vehicle at a rate of 1in/second.
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(3) The powertrain system of this AutoJack must have a vertical motion range from 4in (fully collapsed jack/open cylinder) to 35in (fully open jack/closed cylinder).
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(4) The automatic locking safety pin of this auto-jack must be capable of supporting a 5000lb load independently.
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(5) The powertrain system of this AutoJack must operate with no more than 3 gallons of hydraulic fluid.
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(6) The powertrain system of this AutoJack must weigh less than 70lbs.
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ANALYSES (A-1 THROUGH A-12)
There was total of 12 engineering (RADD) analyses performed during the design phase of the AutoJacks powertrain. These can be found in the "(2) DESIGN AND ANALYSES" and "APPENDIX A" sections of the complete project proposal. An example analysis has been included below for reference.
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EXAMPLE: HYDRAULIC CYLINDER ANALYSIS
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Green Sheet A-1 RADD: “Hydraulic Cylinder Force and Pressure Analysis”
(1) Requirement (G & F): Analysis A-1 was performed to address the design requirement of the powertrain lifting a 5000lb load. The goal here was to calculate the necessary dimensions for the hydraulic cylinder and then source the next available standard size.
(2) Analysis (S): In order to appropriately size the hydraulic cylinder for this specific situation, the bore diameter, rod diameter, working pressure and stroke length had to be calculated. These values were cross-referenced with NorTrac’s product catalog in order to confirm that the results were well under the working limit and therefore the design could be considered safe.
(3) Design (A & T): Analysis A-1 revealed that this design calls for a hydraulic cylinder with a 2in bore diameter, 1.125in rod diameter, a working pressure of at least 2350psi, and a minimum stroke length of 18in. It is important to remember that the cylinder effectively lifts the load directly with the connected link arms translating its horizontal motion into vertical motion. This can be treated as two separate 2500lb “pulls” or one 5000lb “pull” opposite to the fixed end of the cylinder.
(4) Documentation: Please see Appendix A, Analysis A-1 for this specific engineering analysis. Please see Appendix B, Drawing B-1 and B-2 for the corresponding engineering drawings
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Note: For more (12 total) engineering (RADD) analyses performed during the design phase of the AutoJack's powertrain, please see the "(2) DESIGN AND ANALYSES" and "APPENDIX A"sections in the linked MET489A-C Report.
