| 摘要 |
A deflection system for the arm of longwall coal shearers contains a hydraulic cylinder, with one end secured to the shearer arm and the other end - to the shearer body. The hydraulic cylinder is connected through a three-position two-way divider to a hydraulic pump and to a hydraulic medium tank. It is characterised in that it is equipped with two-position one-way valves (5) in the main conduits (1, 2), connecting the hydraulic cylinder (3) to the three-position two-way divider (4). The valves (5) are hydraulically operated and contain the non-return valve (6) in one of the ducts. The controllers (7) of the two-position one-way valves (5) are connected through the controlling conduits (8) respectively to the main conduit (1, 2) at the place between the two-position one-way valve (5) and the hydraulic cylinder (3). They are also connected alternately through the controlling conduits (9) to the main conduits (1, 2) between the two-position one-way valve (5) and the three-position two-way divider (4). Moreover, both main conduits (1, 2) are connected to the hydraulic pump (10) through the auxiliary conduit (11), connected at the places between the two-position one-way valves (5) and the hydraulic cylinder (3) by means of the non-return valves (12) arranged into a push-pull system, and by means of the pressure reducing valve (13). |
