The loader's digging and unloading operations are achieved through the movement of its working device. The loader's working device consists of a bucket (1), boom (2), connecting rod (3), rocker arm (4), bucket tilt cylinder (5), and boom cylinder (6). The entire working device is hinged to the chassis (7). The bucket is hinged to the bucket tilt cylinder via the connecting rod and rocker arm for loading and unloading materials. The boom is hinged to the chassis and boom cylinder for raising and lowering the bucket. The bucket tilting and boom raising/lowering are hydraulically controlled.
During loader operation, the working device should ensure that: when the bucket tilt cylinder is locked and the boom cylinder is raised or lowered, the connecting rod mechanism causes the bucket to move vertically or nearly vertically to prevent the bucket from tilting and spilling material; when the boom is in any position and the bucket rotates around the boom hinge point for unloading, the bucket tilt angle is not less than 45°; and after unloading, when the boom lowers, the bucket automatically levels itself. Based on the structural types of loader working devices both domestically and internationally, there are seven main types. These are categorized by the number of linkage components: three-bar, four-bar, five-bar, six-bar, and eight-bar, etc.; and by whether the input and output rods rotate in the same direction: forward and reverse linkage mechanisms, etc. The bucket structure of earthmoving loaders typically uses low-carbon, wear-resistant, high-strength steel plates welded together. The cutting edge is made of wear-resistant medium-manganese alloy steel, while the side cutting edges and reinforcing angle plates are made of high-strength, wear-resistant steel. The shape of the bucket cutting blade is divided into four types. The selection of the tooth shape should consider factors such as insertion resistance, wear resistance, and ease of replacement. Tooth shapes are divided into pointed and blunt teeth; wheeled loaders mostly use pointed teeth, while tracked loaders mostly use blunt teeth. The number of bucket teeth depends on the bucket width, and the tooth spacing is generally 150-300mm. Bucket teeth structures are divided into two types: integral and split. Small and medium-sized loaders mostly use integral types, while large loaders often use split types due to poor working conditions and severe wear of the bucket teeth. Split bucket teeth consist of two parts: basic tooth 2 and tooth tip 1. After wear, only the tooth tip needs to be replaced.
