1. 1. Link Analysis Williams, Davis, Kirby - ER33 Nomenclature Drag Link Crank Shaft Transmission Link
2. 2. Link Analysis Williams, Davis, Kirby - ER33 Linkage system is the force transferring mechanism Transmission link will transfer motion and force from the piston and spring assemblies into the system Drag link will transfer the opening and closing forces of the transmission link into the crank shaft Crank shaft is connected to the valve shaft at the key hole and will receive the force and motion inputs from the system and impart them as torque to the valve shaft
3. 3. Williams, Davis, Kirby - ER33 Link Analysis Pin Sizing Pin Sizing The minimum diameter of the pin. d=P/Tt t= thickness P = force T= 32000 lbf is the max allowable shear for AL7075 with a F.S. of 1.5 d= diameter of pin Fixed point 2988 lbf/32000lbf * 1in=0.07 in Spring 6310lbf /32000lbf * 1 in= 0.18 in Piston 3635 lbf /32000 lbf * 1 in= 0.11 in Drag link 353 lbf /3200 lbf * 1 in= 0.0091 in
4. 4. Link Analysis- Connection point Williams, Davis, Kirby - ER33 calculations Y = 0.18sin11 + y = 0.25 in Ys= y + 0.18+1.375/2 = 1.12 in Y2=0.18sin11 + 0.11sin11 + .2 = 0.27 in Yp= Ys + 0.11 + 1.125/2 + Y2 + 1.375/2 = 2.75 in Point Placements The places are based on the fixed point to each hole center Ys= spring distance Yp= Piston distance
5. 5. Williams, Davis, Kirby - ER33 Link Analysis- Stress Analysis Governing Equations Moment M = F*d Normal Stress = Mb*d/I Double Shear Stress = F / (D * t) Shear Stress max= 3/2 F/A
6. 6. Link Analysis Williams, Davis, Kirby - ER33
7. 7. Williams, Davis, Kirby - ER33 Link Analysis- Transmission Link System Inputs Force from Valve: 313lbf Force from Piston : 3635lbf Force from Spring: 6310 lbf Force at Fixed Point: 2988lbf Moment at Fixed Point: 432.74 in*lbf The Transmission Link experiences the most stress throughout the system, due to it having a direct connection to the mechanisms applying force.
8. 8. Williams, Davis, Kirby - ER33 Link Analysis- Transmission Link 313 9530.51 6623 2112.75 The Shear and Bending Moment Diagrams are used to find were the part is like to fail given the forces.
9. 9. Williams, Davis, Kirby - ER33 Link Analysis- Transmission Link Drag link Analysis Results Normal stress n = 553/0.0759 n = 4123.6 lbf Shear stress = 10,016lbf Spring Point Analysis calculations n = 432.74 * 0.875/ .0558 n= 6785.8lbf = (3/2) 6623/ 1*.875 = 11687.76 lbf
10. 10. Link Analysis Williams, Davis, Kirby - ER33
11. 11. Transmission Link- Dimensions Williams, Davis, Kirby - ER33 The lower part of the transmission links cross-sectional area is not be constant and was determined by the calculated values based on the Spring connection point Selected Bearing Characteristics for Connection Points Along the Transmission Link Spring OD: 1.375 in ID: 0.875 in Piston OD: 1.125 in ID: 0.625 in The constant cross-sectional of the lower part of the transmission link will be equal to that of the point at which the spring attaches. Using the W = 2D standard, the width of the link is 1.75 in. thickness is 1.0 in
12. 12. Drag Link and Crank Shaft -Sizing Williams, Davis, Kirby - ER33 The Drag like and Crank Shaft have the same Hole diameter and width. This is due to force calculations bearings will not be present in the connection points for these two links. Crank Shaft Hole d: 0.25 in t: 0.125 in w:0.5 in Load: 313 lbf Drag Link sizing Hole: 0.25 in t= 1.0 in Load: 313 lbf The Crank shafts square key dimensions were driven by the existing shaft geometry.
13. 13. Drag Link Williams, Davis, Kirby - ER33
14. 14. Crank Shaft Williams, Davis, Kirby - ER33