Loader is a kind of earth and stone construction machinery widely used in highway, railway, construction, hydropower, port, mine and other construction projects. It is mainly used for shoveling and loading soil, sand, lime, coal and other bulk materials. It can also be used for light shoveling and excavation of ore, hard soil and so on. Loading different auxiliary working devices can also carry out bulldozing, lifting and other materials such as wood loading and unloading operations. In road construction, especially in high-grade highway construction, loaders are used for filling and excavation of subgrade works, aggregate and loading of asphalt mixture and cement concrete yard. In addition, it can also be used for pushing and transporting soil, scraping the ground and pulling other machines. Because the loader has the advantages of high speed, high efficiency, good mobility, light operation and so on, it has become one of the main machines of earthwork construction in engineering construction.
The shoveling and loading and unloading operation of loader is realized by the movement of its working device. The working device of loader consists of bucket, boom, connecting rod, rocker arm, turning bucket cylinder, boom cylinder, etc. The whole working device is hinged on the frame. The bucket is hinged with the bowl cylinder through the connecting rod and rocker arm to load and unload materials. The boom is hinged with the frame and boom cylinder to lift the bucket. The turning of the bucket and the lifting of the boom are hydraulically controlled.
During the operation of loader, the working device shall be able to ensure that: when the rotating bucket oil cylinder is locked and the boom oil cylinder is lifted or lowered, the linkage mechanism can make the bucket move up and down or close to the horizontal movement, so as to prevent the bucket from tilting and scattering materials; when the boom is at any position and the bucket is rotating around the pivot point of the boom for unloading, the bucket tilt angle shall not be less than 45 °, and when the boom is lowered after unloading, the bucket can be automatically leveled.
At present, the domestic loaders are transiting from low level, low quality, low price, functional to high level, high quality, middle price, and economical. In the transition from imitation to independent development, major manufacturers continue to invest in technology, adopt different technical routes, innovate in key components and systems, get rid of the current situation of the same product design, no own characteristics and advantages, stand out from the strange circle of low-level disordered competition, and become the leader of loader industry. Gears play an important role in the working process of loaders. This paper focuses on the selection of materials for spiral bevel gears of loaders and their manufacturing process.