Gear surface hardness: HRC 62-65. Synchronous gears, composed of a gear ring and a gear hub, are positioned with a cone pin after the impeller clearance is adjusted. The gear hub and shaft are fitted with a 1:30 cone fit for easy disassembly and maintenance. The three-blade Roots blower synchronous gears are made of alloy steel 20CrMoTi, with carburized and quenched gear surfaces. After high-frequency quenching treatment, they are ground to achieve five-grade accuracy. The gear clearance, precision, and movement accuracy are crucial for the uniform and smooth engagement of the impeller. One of the main sources of equipment friction and noise is the roughness of the gear surface. Since the synchronous gears of the Roots blower serve both as a transmission and as a positioning for the impeller, their precision and wear resistance, as well as the wear condition, directly affect the impeller engagement. Therefore, there is a high requirement for the precision and wear resistance of the synchronous gears.