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 Tractive Effort (TE) 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

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

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

Design Problems Maximum Motor Speed 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 Axial Loading –Motor cannot handle any axial loading –Fairfield planetary final drive solves this problem –S07A »Reduction Ratio of 4:1

List of Fittings and Hoses

Lift Hydraulics

Hydraulic Lift Hydraulic Cylinders Hydraulic Cylinders –Volume Displaced »Rod End V = A * L V = A * L –A = Outside – Inside –L = Length of Rod V =.994 * = in 3 V =.994 * = in 3 »Cylinder End V = A * L V = A * L –A = Cyl. Area –L = Length of Cyl V = 2.76 * 5.87 = 16.2 in 2 V = 2.76 * 5.87 = 16.2 in 2

Hydraulic Lift Hydraulic Cylinders Hydraulic Cylinders –Flow required »Q = V / s V = Volume Displaced V = Volume Displaced S = time displaced S = time displaced »For Rod End Q = in 3 / 2s = 2.92 in 3 /s Q = in 3 / 2s = 2.92 in 3 /s Q =.758 gpm = 2.87 L/min Q =.758 gpm = 2.87 L/min »For Cylinder End Q = 16.2 in 3 / 2s = 8.1 in 3 /s Q = 16.2 in 3 / 2s = 8.1 in 3 /s Q = 2.1 gpm = 7.96 L/min Q = 2.1 gpm = 7.96 L/min –Total Flow »For Cylinders 2 Cylinders * Max Flow = 2 * 2.1 gpm = 4.2 gpm 2 Cylinders * Max Flow = 2 * 2.1 gpm = 4.2 gpm

Reel Hydraulics

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

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

Front Reel Hydraulics

Rear Reel and Return Hydraulics

Lift Hydraulics

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

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

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

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

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

Final design: use two ideas so if one doesn’t work, have the other. Chrome plate existing design…maybe Chrome plate existing design…maybe Find out more on electric steering. 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.

Most critical equation: P=(T/R)/A P=Pressure required to turn P=Pressure required to turn T=experimental torque T=experimental torque R=radius of turn from cylinder to kingpin. R=radius of turn from cylinder to kingpin. A= functional cross-sectional area of cylinder. A= functional cross-sectional area of cylinder. In this case: P=(612lb-in/3in)/1.63in 2 In this case: P=(612lb-in/3in)/1.63in 2 Pressure required =125 psi. Pressure required =125 psi.

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

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

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

Time Line March 9 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 March 23 – April 6 –Upon arrival of parts, begin assembly April 20 April 20 –Finalize poster April 27 April 27 –Turn in project report