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Professional Engineering Exam Review Machinery Management. Gary Roberson. Topics for Discussion. Implement performance Draft and power estimation Fuel consumption Machine capacity. Documents to Review.
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Professional Engineering Exam ReviewMachinery Management Gary Roberson
Topics for Discussion • Implement performance • Draft and power estimation • Fuel consumption • Machine capacity
Documents to Review • ASAE S296.5 (DEC2003) General Terminology for Traction of Agricultural Traction and Transport Devices and Vehicles • terminology to assist in the standardized reporting of information on traction and transport devices and vehicles.
Documents to Review • ASAE S495.1 (NOV2005) Uniform Terminology for Agricultural Machinery Management • Uniform use of machinery management terms. • Definitions used in system analysis, economic analysis, and mechanical concepts.
Documents to Review • ASAE EP496.3 (FEB2006)Agricultural Machinery Management • Management decisions related to machine power requirements, capacities, cost, selection and replacement
Documents to Review • ASAE D497.6 (JUN2009) Agricultural Machinery Management Data • Data for use with decision tools from ASAE EP496.3
Books of Interest • Machinery Management, W. Bowers, Deere and Co. • Farm Power and Machinery Management, D. Hunt, Iowa State University Press. • Engineering Principles of Agricultural Machines, A. Srivastava, et al , ASABE • Engineering Models for Agricultural Production, D. Hunt, AVI Publishing Co. • Agricultural Systems Management, R. Peart and W. Shoup, Marcel Dekker
Implement Power Requirement • Drawbar power • Power developed by the drive wheels or tracks and transmitted through the hitch or drawbar to move the implement. • Power is the result of draft (force) and speed
Implement Draft • D is implement draft, N (lbf) • Rsc is soil and crop resistance, N (lbf) • MR is total implement motion resistance, N (lbf)
Implement Draft Where: • D=draft, N (lbf) • F=soil texture parameter • i=texture indicator: • 1=fine, 2=medium, 3=coarse • A, B, And C = machine parameters (Table 1, D497) • S=speed, km/h (mph) • W=width, m (ft) or number of tools • T=tillage depth, cm (in), • (1 for tools that are not depth specific)
Implement Draft Example • A 12 foot wide chisel plow with straight points and shanks spaced 1 foot apart is used at a depth of 6 inches in medium textured soil at a speed of 5 mph.
Implement Draft Example • Chisel plow with straight points • Table 1 in D497.5 • A = 52, B = 4.9, and C = 0 • Medium soil texture • Table 1 in D497.5 • F2 = .85 • S = 5 mph • W = 12 ft or 12 tools • T = 6 in
Implement Draft Example • D=Fi[A+B(S)+C(S)2]WT
Implement Draft Example • D=Fi[A+B(S)+C(S)2]WT • D=0.85x[52+4.9(5)]12x6
Implement Draft Example • D=Fi[A+B(S)+C(S)2]WT • D=0.85x[52+4.9(5)]12x6 • D= ?
Implement Draft Example • D=Fi[A+B(S)+C(S)2]WT • D=0.85x[52+4.9(5)]12x6 • D= 4682 lbf
Implement Draft Example • A 12 shank chisel plow with straight points and shanks spaced 0.3 meters apart is used at a depth of 0.15 meters in medium textured soil at a speed of 8 km/hr.
Implement Draft Example • Chisel plow with straight points • Table 1 in D497.5 • A = 91, B = 5.4, and C = 0 • Medium soil texture • Table 1 in D497.5 • F2 = .85 • S = 8 km/hr • W = 12 shanks • T = 0.15 meters = 15 cm
Implement Draft Example • D=Fi[A+B(S)+C(S)2]WT
Implement Draft Example • D=Fi[A+B(S)+C(S)2]WT • D=0.85x[91+5.4(8)]12x15
Implement Draft Example • D=Fi[A+B(S)+C(S)2]WT • D=0.85x[91+5.4(8)]12x15 • D= ?
Implement Draft Example • D=Fi[A+B(S)+C(S)2]WT • D=0.85x[91+5.4(8)]12x15 • D= 20,533 N
Implement Draft Exercise • A 4 shank subsoiler with straight points is used at a depth of 16 inches in coarse textured soil at a speed of 4 mph. • What’s the Draft?
Implement Draft Exercise • A 4 shank subsoiler with straight points is used at a depth of 16 inches in coarse textured soil at a speed of 4 mph. • What’s the Draft? 4959 LB
Implement Draft Exercise • A 4 shank subsoiler with straight points is used at a depth of 0.41 meters in coarse textured soil at a speed of 6.5 km/hr. • What’s the Draft?
Implement Draft Exercise • A 4 shank subsoiler with straight points is used at a depth of 0.41 meters in coarse textured soil at a speed of 6.5 km/hr. • What’s the Draft? 22,291 N
Drawbar Power • Pdb = Drawbar Power, HP • D = Draft, lbf • S = Speed, mph
Drawbar Power • Pdb = Drawbar Power, kW • D = Draft, kN • S = Speed, km/hr
Drawbar Power Example An Implement with a draft of 8,500 lbf is operated at a net or true ground speed of 5.0 MPH with 10 percent wheel slippage. What is the implement drawbar power?
PTO Power • PTO power is required from some implements and is delivered through the tractor PTO via a driveline to the implement. • The rotary power requirement is a function of the size and feed rate of the implement.
PTO Power • Ppto = PTO power • W = implement working width, ft • F = material feed rate. t/hr
Table 2, D497.5 kWh/t kW kW/m
PTO Power Example • A large round baler has a capacity of 10 tons per hour. The baler has a variable bale chamber
Implement PTO Example • Variable Chamber Round Baler • Table 2 in D497.5 • A = 5.4, B = 0, and C = 1.3 • 10 t/hr capacity
PTO Power Exercise • A rectangular baler has a capacity of 3 tons per hour. Bale dimensions (cross section) are 16” x 18”. • What’s the PTO power requirement?
PTO Power Exercise • A rectangular baler has a capacity of 3 tons per hour. Bale dimensions (cross section) are 16” x 18”. • What’s the PTO power requirement?
PTO Power Exercise • A rectangular baler has a capacity of 3 tons per hour. Bale dimensions (cross section) are 16” x 18”. • What’s the PTO power requirement? 6.3 Hp
Hydraulic Power • Fluid power requirement from the tractor for the implement • Hydraulic motors and cylinders used to drive implement functions
Hydraulic Power • Phyd = fluid power, HP • P = fluid pressure, psi • F = fluid flow, gpm