Design and application of hydraulic force manual boosters

In recent years, the pressure requirements of hydraulic supports have continued to rise. However, the deficiency of initial supporting force has become a common problem in fully mechanized working faces, often leading to roof subsidence, premature separation, and a series of safety issues such as advanced break lines and coal wall spalling. To address this, a manual pressurizer was designed to achieve the required initial force through manual fluid pressurization. The device is arranged in parallel with the hydraulic control one-way valve, ensuring that it does not interfere with the normal lifting function of the hydraulic support. Based on the designed pressurization circuit, this study integrates hydraulic and mechanical technologies to design the main components, including the pressurizing cylinder, pressure control structure, one-way conduction mechanism, safety mechanism, and coordinated action system. The device is capable of achieving rapid and reliable pressurization within the emulsion system. Field tests were conducted on the ZY8500/21/45 hydraulic support bracket at the Guotun coal mine. Results show that the device significantly enhances the initial supporting force, reduces resistance build-up time, prevents roof subsidence and premature separation, and substantially improves the overall safety of the mining face. This study proposes a low-cost and high-reliability technical solution to address insufficient initial support force in deep mines, filling the application gap of mechanical booster devices in mine pressure control.