Innovative solution for the LHD loader intended for operation in low workings of underground mines

The article presents the results of comparative numerical tests of typical operating systems of LHD loaders with a proprietary solution based on a patent. LHD loaders belong to the group of basic machines working in various operating systems, including room-and-pillar systems. Due to the thickness of the deposits, mining is frequently carried out in low workings. In the case of typical T-kinematic or Z-kinematic systems, the operation of LHD loaders is more difficult. Due to the low height of the excavation, the excavated material is loaded in several cycles. A smaller machine generates less thrust force, which also negatively affects loading efficiency. Additionally, there are typical operational problems associated with the use of hydraulic actuators, the piston rods of which are exposed to mechanical damage and loss of tightness. In the presented proprietary solution of the working system, the bucket is attached to a telescopic boom system moved by hydraulic rotary actuators (Saga et al., 2019). Moreover, the loader is equipped with spreaders to stabilize the machine. The use of rotary actuators and a lowered pivot point of the bucket, together with a telescopic arm and spreaders, allows the bucket to be loaded in one cycle. In the article, the results of simulation tests of three kinematic systems have been presented. The analysis included, among others, the movement of the bucket, the duration of the cycle, and the related demand for hydraulic oil, as well as the load on the most important structural elements and nodes. The research has shown that the proposed solution can successfully compete with classic systems in terms of load and oil demand while offering an advantage in terms of functionality.