Traction and Power Transmission in Agricultural Tractors

1. Traction and Power Transmission in Agricultural Tractors Claude Laguë, P.Eng., Ph.D. Professor & Chair Holder Sask Pork Chair in Environmental Engineering for the Pork Industry Department of Agricultural & Bioresource Engineering University of Saskatchewan

2. Outline • ASAE’s ¼ Scale Tractor Design Competition • Analysis of a power transmission system between the engine and the drive axle of a ¼ scale 2-wheel drive tractor to maximize the net pulling force of the tractor

3. ASAE’s ¼ Scale Tractor Design Competition What is ASAE (source http://asae.org/about.html): • The American Society of Agricultural Engineers (ASAE) is a professional and technical organization dedicated to theadvancement of engineering applicable to agricultural, food, and biological systems. • ASAE members serve in industry, academia, and public service. They each have broad training in various engineeringdisciplines, and they all share a key commonality: agricultural engineers are uniquely qualified to determine anddevelop more efficient and environmentally sensitive methods of cultivating food and fibre for an ever-increasing worldpopulation. • Founded in 1907 and headquartered in St Joseph, Michigan, ASAE comprises 9,000 members (including many students) representing morethan 90 countries. • Check out student and preprofessionals information at http://asae.org/membership/students/index.html

4. ASAE’s ¼ Scale Tractor Design Competition What is the ASAE’s ¼ Scale Tractor Design Competition (source http://asae.org/membership/students/index.html): • Since 1997, ASAEorganizes a National Student Design Competition based upon the concept of designing a ¼Scale Tractor to provide students professional experience, education and fun . • There are four main judging categories: a Written Design Report (25%), a Team Presentation (25%), Individual DesignJudging (10%) and a Performance Competition (40%). The performance competition, the highlight of the event,is comprised of a multi-stage tractor pull using a progressive sled and is held in May at East Moline, IL. • Through involvement in the competition, students gain practical experience in the design ofdrivetrain systems, tractor performance, manufacturing processes, analysis of tractive forces,weight transfer and strength of materials. In addition, they also develop skills incommunication, leadership, teamwork, fundraising and test & development.

5. ASAE’s ¼ Scale Tractor Design Competition Past competitions: • 1997-1998: 17 teams including one from Canada (U. of Manitoba) that finished in 13th position . • 1998-1999: 25 teams including two from Canada (U. Laval (21st position) and U. of Manitoba (18th position)) • 1999-2000: 28 teams including three from Canada (Mc Gill U. (21st position), U. Laval (10th position) and U. of Manitoba (25th position)) • U. Laval won 1st place in the Written Design Report category • In 2001 – 2002, the U. of Saskatchewan should enter the competition; it is up to you!!!

6. ASAE’s ¼ Scale Tractor Design Competition Design and fabrication Teamwork Fundraising and sponsorships Test and performance

7. ASAE’s ¼ Scale Tractor Design Competition Main Objective: To design, fabricate and test a 2-wheel drive tractor that will produce the maximum pulling force (tractive force – wheel slip and rolling resistance losses) while meeting a number of design constraints and criteria (9 pages of rules!!!).

8. ASAE’s ¼ Scale Tractor Design Competition • Potential design project topics for ABE 395 and 495: • Optimizing the power transmission system for a ¼ scale 2-wheel drive tractor • Optimizing the frame and chassis design for a ¼ scale 2-wheel drive tractor • Design of a performance data acquisition system for a ¼ scale 2-wheel drive tractor • Design of a control system to optimize dynamic weight transfer on a ¼ scale 2-wheel drive tractor • And more…

9. Today’s Lab Problem • Purpose: To analyze the mechanics of traction for a 2WD ¼ scale tractor with the objective of maximizing the net pulling force of the tractor.