Tractor Systems and Control
Course Objective:
After studying the course, the student shall be able to:
- Understand tractor developing patterns and principles.
- Apply appropriate engineering principles, concepts, theories, definitions, laws, models and patterns to understand and present tractor control systems in a clear and logical form.
- Apply knowledge and understanding of power transmission and control in familiar and unfamiliar situations of tractor application.
- Analyze the result of experiments accurately and clearly, draw conclusion and make generalization from experiment, and
- Appreciate the scientific, social, economic, environmental and technological contributions and applications of tractor.
- Tractor as Source of Mechanical Farm Power[3 hours]
- History of Development of Tractors
- Classification of Tractors
- Essential Features of Farm Tractors
- Ranges and Availability in the Country
- Tractor Selection Criteria
- Systems and Controls in Farm Tractors
- Types of Power Transmission [3 hours]
- Two and Four Wheeled Drive
- Hydrostatic and Hydrodynamic Drives
- Design Principles for Power Transmission
- Clutch System [2 hours]
- Purpose and Type
- Principle of operation
- Functional Requirements
- Design Parameters and Procedure
- Gear Box [3 hours]
- Purpose and Types
- Principle of Operation
- Functional Requirements
- Design Parameters and Procedure
- Differential and Final Drive [2 hours]
- Purpose and Types
- Principle of Operation
- Functional Requirements
- Design Parameters and Procedure
- Steering System [2 hours]
- Purpose and Types
- Principle of Operation
- Components Involved in Mechanical Steering
- Functional Requirements
- Adjustments: Camber, Caster, Toe-in, Toe-out, Kingpin Inclination, Tie-Rod Locking
- Design Parameters and Procedure in Reference to Mechanical Steering
- Brake System [2 hours]
- Purpose and Types
- Principle of Operation
- Functional Requirements
- Design Parameters and Procedures
- Hydraulic System [3 hours]
- Purpose and Types
- Hydraulic Circuit Symbol
- Principle of Operation
- Functional Requirements
- Design Parameters and Procedures (Pump, Motor and Cylinder)
- Automatic Position and Draft Controls
- Auxiliary Power Transmission and Power Outlets [2 hours]
- P.T.O. System
- Belt, Pulley and Drawbar - functional requirements and design parameters
- Special Power Drives for Front and Side Mounted Implements
- Traction and Traction Theory [4 hours]
- Mechanics of a Rigid Wheel (Traction and Towed)
- Construction of Tractor Tyre
- Inflation Pressure
- Theoretical Soil Thrust on Traction Device
- Rolling Resistance and Travel Reduction
- Coefficient of Traction and Tractive Efficiency
- Tractive Effort, Rim Pull, Drawbar Pull
- Traction Parameters and Design of Traction Device
- Traction Aids and Wheel Ballasting - types and selection criteria
- Soil Compaction in Tillage and Traction
- Mechanics of Tractor Chassis[4 hours]
- Static and Dynamic Forces Acting on Tractor Chassis
- Location of Center of Gravity and Moment of Inertia
- Static Equilibrium Analysis
- Longitudinal Stability and Stability at Turns
- Tractor Hitching [3 hours]
- Terminology Used in Tractor Hitching
- Types: Single Axis Hitching, Two-Axes Hitching, Automatic Hitching
- Weight Transfer and Stability
- Break-away Principle and Other Safety Devices
- Power Tiller [4 hours]
- Purpose and Types
- Range and Availability
- Control Systems of Power Tillers
- Ergonomic Principles in Tractor Design [3 hours]
- Human Factors in Tractor Design
- Human Tolerance to Temperature, Noise and Vibration
- Design of Operators' Seat, Controls and Control Panel
- Tractor Testing [3 hours]
- Introduction and Purpose
- Tractor Test Codes
- Engine and Drawbar Performance at Full and Part Load
- Performance Data of Major Makes and Models of Tractors Used in Nepal
- Economics of Tractor Use [2 hours]
Practical
- Dissembling and Assembling of Clutch System, Components Involved and Maintenance Operation (One practical)
- Dissembling and Assembling of Gear Box, Components Involved and Maintenance Operation (One practical)
- Dissembling and Assembling of Differential and Final Drive, Components Involved and Maintenance Operation (Two practical)
- Dissembling and Assembling of Steering System, Components Involved and Adjustments of Camber, Caster, Toe-in and Toe-out (Two practical)
- Dissembling and Assembling of Brake System, Components Involved and Maintenance Operation (One practical)
- Dissembling and Assembling of Hydraulic System, Components Involved and Maintenance Operation (One practical)
- Study on Wheel Parameters and Ballasting in Farm Tractors (One practical)
- Hitching of Mounted, Semi-Mounted and Trailed Type Farm Implements and Stability Analysis (Two practical)
- Study on Control Systems of Power Tillers (One practical)
Tutorials:
Tutorial classes shall be devoted to design problem solving on: - Gear Box
- Differential and Final Drive
- Steering System
- Brake System
- Hydraulic System
- Hitch System
References:
- Tractors and their Power Units by J. B. Liljedahl, W. M. Carleton, P. K. Turnquist and D. W. Smith. John Wiley & Sons, New York
- Goering, Carroll E. and Alan C. Hansen. 2004. Engine and Tractor Power, 4th edition, ASABE, St. Joseph, Michigan, USA.
- Test Codes of Bureau of Indian Standards, New Delhi for Agricultural Implements, I.C. Engines and Tractors.
- Soil Dynamics in Tillage and traction (US Hand Book) by Gill and Vandenberg.
- Power Hydraulics by Michael J. Pinches and John G. Ashby. Prentice Hall International (U. K.) Ltd.
- Tractors and Crawlers by Irving Frazee and V.E. Philip.
- Design of Automotive Engines by Kolchin and Demidov.
Evaluation Scheme
The questions will cover all the chapters in the syllabus. The evaluation for the final theory examination is indicated as follows:
|
Chapter |
Hours |
Marks Distribution* |
1 |
3 |
10 |
2.1 |
3 |
2.2 |
2 |
10 |
2.3 |
3 |
2.4 |
2 |
10 |
2.5 |
2 |
2.6 |
2 |
2.7 |
3 |
10 |
2.8 |
2 |
3 |
4 |
20 |
4 |
4 |
5 |
3 |
6 |
4 |
10 |
7 |
3 |
8 |
3 |
10 |
9 |
2 |
Total |
45 |
80 |
*Note: There may be minor deviation in marks distribution.
|
