The evaluation of forces acting on excavator bucket and its capacity

Abstract

Excavators are commonly used machines in mining, material transport operations, ground levelling, agriculture, forestry applications and construction. The design of an excavator hoe type bucket is a critical task in the context of the digging forces developed by the actuators during the digging operation (Material Removing). The bucket is a highly essential component of the backhoe loader since it carries the entire load of excavated material. The important criteria for the design to be safe is that, the digging forces of the actuators must be greater than the resistive force offered by the terrain to be excavated. Due to an excessive quantity of resistive loads, an adverse effect on the bucket parts occurs, and it may fail during excavation operations. The bucket is being held back by a variety of forces that are preventing it from moving into the soil such as gravitational force and remolding force. This method can be used to predict digging forces and to run an excavation task autonomously. Bucket capacity, bucket life, poor design of tool, results in weak excavation of the ground, high wear of the tool, wastage of the time and power thus reducing the productivity and efficiency of a product. Prediction of resistive forces is a difficult task so soil tool interaction model plays an essential role also soil parameters such as density, cohesiveness differs as per material type. As the resistive forces are applied, steps such as penetration, separation, and escape are considered. The resistive forces for the worst soil condition characteristics have been estimated here. The reformulated basic Fundamental Earth Moving Equation,considers the terrain slope and interaction of the bucket as it moves through the soil. It is modified to support inclined soil surfaces and transient tool motion states. This paper focuses on the method of evaluating bucket capacity and digging forces, as well as the resistive forces provided by stiff soil, in accordance with ISO and SAE standards.