Engineering Principles of Agricultural Machines 2nd Edition

Chapter 12
Grain Harvesting____________________________________ 403
Introduction................................................................................................................ 403
12.1 Methods and Equipm ent................................................................................. 403
12.1.1 Direct harvesting.......................................................................................403
12.1.2 Cutting and windrowing........................................................................... 408
12.2 Functional Processes........................................................................................409
12.2.1 Gathering, cutting, pickup, and feeding................................................. 410
12.2.2 Threshing...................................................................................................415
12.2.3 Separation..................................................................................................420
12.2.4 Cleaning.....................................................................................................427

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12.2.5 Power requirements...................................................................................433
12.3 Combine Testing.............................................................................................. 433
Problems...................................................................................................................... 435
Chapter 13
Fruit, Nut, and Vegetable Harvesting 
437
Introduction................................................................................................................ 437
Natural constraints................................................................................................. 438
Economic constraints............................................................................................. 438
13.1 The Functional Processes................................................................................ 43 9
13.1.1 Removal.....................................................................................................439
13.1.2 Control.......................................................................................................440
13.1.3 Selection..................................................................................................... 440
13.1.4 Transportation........................................................................................... 441
13.2 Methods and Equipm ent................................................................................. 441
13.2.1 Root crops..................................................................................................442
13.2.2 Surface crops............................................................................................. 447
13.2.3 Bush and trellis crops............................................................................... 452
13.2.4 Tree crops...................................................................................................459
13.3 Theoretical Considerations.............................................................................. 464
13.3.1 Aerodynamic concepts............................................................................. 464
13.3.2 Fundamentals of bush and tree shakers.................................................. 468
13.3.3 Vibrational detachment during harvest.................................................. 475
13.3.4 Impact models and mechanical damage................................................. 476
13.4 Performance Factors.........................................................................................483
13.4.1 Damage......................................................................................................484
13.4.2 Efficiency................................................................................................... 484
13.4.3 Reliability.................................................................................................. 484
Problems...................................................................................................................... 486