Abstract
Gear hydraulic machines are a type of volumetric hydraulic machines that are widely used in various industries. Their main purpose is to convert mechanical rotational energy into hydraulic energy (pumps) or vice versa (hydraulic motors). The performance of gear hydraulic machines depends on tribological properties such as hardness, wear resistance, strength, viscosity, surface roughness, lubricity. This article discusses the problems of gear pumps, namely their tribological properties associated with designs and materials of manufacture. There are several basic designs of gear pumps, each of which has its own characteristics, advantages and disadvantages. They ensure stable operation of systems that require fluid transfer with constant flow and pressure. However, their performance characteristics largely depend on the tribological properties of working elements such as gears, bearings and sealing devices. Wear and damage to these elements can significantly reduce the efficiency of the pump, lead to its breakdown or increased energy consumption. Various designs of gear pumps are considered, their characteristics, operating principles, liquid flows, advantages and disadvantages of various pump designs are studied.