LV EN RU DE FR

Ground Motor Vehicles

Course developer

Prior knowledge

LauZ4251, Ground Motor Vehicles II

Course abstract

The aim of the study course is to strengthen the acquired theoretical knowledge and skills about the calculation of technical indicators of tractors. Within the framework of project students have to make following calculations: rolling resistance, road adherence, motive and traction forces, transfer number of transmission, theoretical and actual speed of motion. It is necessary to determine slipping of wheels on definite ground. Students have to construct governor characteristics and have to make graphoanalytical construction of tractor traction curves.

Learning outcomes and their assessment

Knowledge - of the traction capacity of the tractor, of the speed of movement, of the fuel mass, of the fuel consumption and of the efficiency factor.
Skills - Use the tractive properties of vehicles (tractors) when designing and assembling farm machinery units and setting optimal operating modes for them.
Competence - the acquired knowledge and skills shall be used in the development of new technological options for agricultural aggregates, such as the efficient provision of agricultural machinery units in accordance with agro-technical and quality requirements.
Evaluation up to 10 points.

Course Content(Calendar)

The individual task of the course project is issued by the lecturer. The lecturer also introduces the course project implementation requirements.
The student gets acquainted with the technical characteristics of the tractor prototype independently. The following calculations are performed:
• Calculation of motion resistance force.
• Calculation of the operating weight of the tractor.
• Calculation of the effective motor power and the theoretical speed of movement.
• Engine control curves as a function of crankshaft rotation speed, torque.
• Calculation of load characteristics.
• Construction of load characteristics.
• Tractor propulsion.
• Dynamic and kinematic wheel radii.
• Designing the engine for the selected gear.
• Slip calculation and slip curve construction.
• Calculation of theoretical and actual velocities, construction of characteristics.
• Calculation of traction power and hourly fuel consumption.
• Traction efficiency calculation, characteristic curve construction.
• Graphoanalytical construction and analysis of tractor traction characteristics.

At the end, the work is designed according to the instructions and defended.

Requirements for awarding credit points

The course project is designed and presented in accordance with the methodological rules and defended.

Description of the organization and tasks of students’ independent work

The course project is developed independently, consultation with the lecturer.

Criteria for Evaluating Learning Outcomes

The accuracy of the calculations, the quality of the diagrams, the presentation are evaluated.
A student can get a successful mark if at least the tractor's power, torque and fuel consumption curves are correctly calculated and constructed.

Compulsory reading

1. Introduction to Internal Combustion Engines. Stone. Basingstoke: Palgrave Macmillan, 2012.
2. Internal Combustion Engine Handbook. Basshuysen. 2004. SAE

3. Cikovskis V. Iekšdedzes motori. 1 daļa. Rīga: Jumava, 2010. 286 lpp.

Further reading

1. Miķelsons Z., Pīrs V. Spēkratu konstrukcijas. Jelgava, 2008. 199 lpp.
2. Blīvis J., Gulbis V. Traktori un automobiļi. Rīga: Zvaigzne, 1991. 517 lpp.
3. Cikovskis V. Motori. Rīga: Jumava, 2000. 224 lpp.

4. Duffy J.E. Modern automotive technology. Illinois: Goodheart-Willcox, 2009. 1613 p.

Periodicals and other sources

1. LUBE Magazine, United Kingdom Lubricants Association Limited lube-media.com | ukla.org.uk, Registered in the UK: No. 936857 VAT Reg No. GB 240 8376 65
2. Profi: Magazin fur Agrartechnik. -1997- Münster-Hiltrup Landwirtschaftsverlag GmbH -1997- ISSN 0937-1583.

Notes

Compulsory course project for students of the sub-program "Agricultural Technique" of the academic bachelor study program "Agricultural Engineering".