Integrated Cab Suspension System for Versatile L4WD Tractor
Date
2014-12-01
Authors
Grossart, Andrew
Hammouz, Ahmad
Martel, Brent
Plourde, Daniel
Sun, Pengkai
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
This report outlines the design and analysis procedure followed in designing a cab suspension system for Buhler Versatile’s L4WD tractor. Buhler Versatile received complaints stating that vibrations were being transmitted to the operator when the tractor was operated on hard surfaces. As a result, the client has commissioned Versateam Engineering to design a marketable and functional cab suspension system. Buhler Versatile determined that the offending vibrations originated from the interaction of the tracks with hard road surfaces while travelling at speeds above 20km/h. Since the cab is not isolated from the frame, certain offending frequencies were being transmitted to the cab, causing operator discomfort. The client specified that the goal for the new system was to reduce vibration by 25-50% when compared to the current mounting system. The main design constraint is that the system must satisfy all applicable safety standards and regulations. Low cost, durability and low maintenance were also desired features, as well as the ability to manufacture the system in house or purchase the necessary components from a supplier. The key requirement of the new design is that it must be marketable in order for the L4WD tractor to remain competitive in the marketplace. The final design consists of a combination of a coil spring and shock absorber mounted at both rear corners of the cab. This design provides the best ability to isolate the cab from the offending vibrations and damp any cab oscillations. It is estimated that the proposed cab suspension system will reduce vibrations by 79%, thereby improving operator comfort. Additionally, this design is comprised of components known to provide successful suspension characteristics, legitimizing the design in the eyes of consumers and aiding its marketability. CAD model drawings have been created for each individual component as well as for the complete system assembly. Additionally, the overall tractor model provided by the customer has been updated with the suspension system retrofitted into the existing model. Engineering drawings have been produced for the components to be fabricated in house and product requirements have been provided for the components to be purchased from outside suppliers.