Strength and clearance optimization for Loader lift arm joint for Backhoe Loader 2020-28-0325
Product engineering organizations are committed to provide solutions with right quality and value to customers. Value improvement and efficient product engineering are key to the success of most organizations. Continuous improvement helps a product to be competitive in market in terms of performance.
In this paper, the Author summarizes about the detailed calculations which were carried out to take care of reduced clearances between engine enclosure and loader lift arm of Backhoe loader. The reduction in clearance was due to the transition from Interim Tier 4 engine canopy to Final Tier 4 engine canopy, and the size of engine enclosure increased whereas the loader lift arm structure kept same to avoid additional cost of change. The calculation includes detailed stack up analysis, sectional calculation on shear tear out, tension failure analysis and bearing stresses.
Due to the reduced clearance, when the loader lift arm is raised, it had the opportunity to contact the engine enclosure. While performing backhoe operation, with the loader lift arm in the downward position, the engine enclosure hits on the loader lift arm, which will limit the operational capability of backhoes. The study was challenged with constraints which did not allow to change any nearby or interacting assemblies like engine enclosure, loader lift arm cylinders, safety mechanical lock, and cylinder and Loader lift arm mounts on vehicle main frame etc.
Extensive study was conducted across all the backhoe loader variants and current and new design in terms of the clearances between the Loader lift arm and the engine enclosure. The study includes stack up analysis, sectional calculation on shear tear out, tension failure analysis and bearing stresses. The robust calculation and detailed part analysis helped the design and analysis team to skip Finite Element Analysis and field testing due to thorough use of solid engineering principles.
Based on the results from the sectional and stack-up calculations, decisions were taken on design directions and changes were implemented directly in field. The resolution is completed and post implementation no warranty cases were reported in this regard or due to any design changes that were made based on improvement strategy.
Ashwin Raveendran, Sandeep Dhotre, Kurtis Langner
John Deere Technology Center, John Deere C&F
International Conference on Advances in Design, Materials, Manufacturing and Surface Engineering for Mobility