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Water Hydraulic Conversion by Dan Pitstick Dan Sellers Nathan Schoonover

Water Hydraulic Conversion by Dan Pitstick Dan Sellers Nathan Schoonover. Introduction. The purpose of this project is to convert an oil hydraulic turf mower into a water hydraulic turf mower. The key systems are drive train, steering, and mower drive. Hydrostat Design Calculations .

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Water Hydraulic Conversion by Dan Pitstick Dan Sellers Nathan Schoonover

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  1. Water Hydraulic Conversion by Dan Pitstick Dan Sellers Nathan Schoonover

  2. Introduction The purpose of this project is to convert an oil hydraulic turf mower into a water hydraulic turf mower. The key systems are drive train, steering, and mower drive.

  3. Hydrostat Design Calculations • Tractive Effort (TE) TE = (RR + GR + Fa + DP) * 1.1 RR = Rolling Resistance = Gross Vehicle Weight(GVW) * Rolling Radius GR= Grade Resistance = 0.01 * GVW * Grade % Fa = Acceleration Force = (Velocity * GVW) / (time * 32.16) DP = Drawbar Pull) = 0 since no drawbar pull TE = 390 lbs

  4. Hydrostat Design Calculations • Required Torque Treq = (TE * r) / (G*N) G = Gear Ratio = 4 N = Number of Motors = 2 Treq = 487 in-lbs • Maximum Required Motor Speed S = (168 * V * G)/ r = 500 rpm

  5. Motor Selection • Old Motor Parker TJ 0165 Low Speed High Torque Motor Displacement = 163 cc/rev • New Motor Nessie MVM 160 Water Hydraulic Motor Displacement = 160 cc/rev Max Torque = 100 N-m = 885 in-lbs

  6. Design Problems • Maximum Motor Speed • Max Speed of Nessie Motor is 200 rpm • Required Motor Speed of 511 rpm to reach 7.6 mph • Max ground speed using Nessie Motor 3 mph • Axial Loading • Motor cannot handle any axial loading • Fairfield planetary final drive solves this problem • S07A • Reduction Ratio of 4:1

  7. List of Fittings and Hoses

  8. Lift Hydraulics

  9. Hydraulic Lift • Hydraulic Cylinders • Volume Displaced • Rod End • V = A * L • A = Outside – Inside • L = Length of Rod • V = .994 * 5.870 = 5.835 in3 • Cylinder End • V = A * L • A = Cyl. Area • L = Length of Cyl • V = 2.76 * 5.87 = 16.2 in2

  10. Hydraulic Lift • Hydraulic Cylinders • Flow required • Q = V / s • V = Volume Displaced • S = time displaced • For Rod End • Q = 5.835 in3 / 2s = 2.92 in3/s • Q = .758 gpm = 2.87 L/min • For Cylinder End • Q = 16.2 in3 / 2s = 8.1 in3/s • Q = 2.1 gpm = 7.96 L/min • Total Flow • For Cylinders • 2 Cylinders * Max Flow = 2 * 2.1 gpm = 4.2 gpm

  11. Reel Hydraulics

  12. Reel Motors • Reel Description • 11 Blade Reels with Cutting Frequency of .047 in / mph • Maximum Mowing Speed of 3.7 mph • Reel Diameter = 5 inches • Reel Motor Speed Calculation • Reel Circumference = Pi * D = 3.14 * 5 = 1.309 ft = 2.44792 E-4 miles • 3.7 mph * (1rev / 2.44792 E-4 miles) = 250 rpm • Required Flow • Q = N * D = 250 rpm * 10cc/rev = 2.5 L/min • Total Flow = 3 * 2.5 = 7.5 L/min = 1.98 gpm

  13. Reel Mounting Problems • Oil Hydraulic Motor • Smaller Shaft • Splined Shaft • Water Hydraulic Motor • Larger Shaft • Smooth Shaft with Keyway • Solution • Design adapter incorporating Splined shaft with smooth shaft of water hydraulic motor

  14. Front Reel Hydraulics

  15. Rear Reel and Return Hydraulics

  16. Lift Hydraulics

  17. Goals of steering • To develop a steering valve design for water use • Be able to steer effectively with small user input. • Be able to produce the valve for use in Jacobsen turf mower.

  18. 4 design possibilities • Chrome plate existing design • Convert to electric steering • Design completely new valve • Use 3 position 4-way valve at cylinder with toggle switch to control.

  19. Chrome plating • Use of electroless nickel plating provided by Millcreek metal finishing of Erie, PA • May be free of charge depending on size of parts and other specifications. • Good resistance to corrosion. • May have tolerance problem.

  20. Electric steering • Use electric solenoid with screw type gear to produce force. • Not much information on parts and components. • No knowledge of how system works. • Costs?

  21. New design • Simple so shop can manufacture it. • Will be able to build prototype for sure. • Will not have functionality of original. (It will be a jerk steer design).

  22. Chrome plate existing design…maybe Find out more on electric steering. Make new design out of plastic. Maybe test if Dan Pitstick finishes Hydro-drive. If other possibilities fail implement new valve design. Final design: use two ideas so if one doesn’t work, have the other.

  23. Most critical equation: P=(T/R)/A • P=Pressure required to turn • T=experimental torque • R=radius of turn from cylinder to kingpin. • A= functional cross-sectional area of cylinder. • In this case: P=(612lb-in/3in)/1.63in2 • Pressure required =125 psi.

  24. Other important calculations • Swept volume (SV) = stroke*A • Valve disp. (HD) = SV/n. Note: n is number of turns. • Minimum pump flow (Q) = HD*SS*60/231. Q=1.9 approximately.

  25. Pump Flow • Hydrostatic Drive Max = 17 gpm • Steering Max = 2 gpm • Reel Drive Max = 2 gpm • Lift Cylinder Max = 5 gpm • Total Flow = 26 gpm

  26. Contacts • Motors, Valves, and Pump • Danfoss – Nessie • Fenner • Fittings • Parker • Swagelok • Faster • Hoses • Parker • Swagelok

  27. Time Line • March 9 • Have all Motors, Valves, and Cylinders ordered • Contact fitting suppliers to see what is available and place orders • Make list of hose length and size needed and contact suppliers • March 23 – April 6 • Upon arrival of parts, begin assembly • April 20 • Finalize poster • April 27 • Turn in project report

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