Hydraulic circuit

摘要

The hydraulic circuit serves to control the hydraulic motors (5, 7) associated with a friction (1) preceded by a storage drum (2). A brake valve (25) and a 4/2 directional control valve (11) controllable in dependence on the direction are incorporated in the hydraulic lines leading to the drum motor (7) from a pump (8). The brake valve (25) is influenced by the pressure in the hydraulic line (14) leading to the hydraulic motor (5) of the friction winch (1). When a steel rope is drawn off the drum (2), the motor (7) acts as a pump and additionally feeds hydraulic fluid into the hydraulic circuit The valve (11) so switches the hydraulic circuit that the load pressure (DL) is available against the pump pressure (p1). As the coil diameter reduces, the speed of the drum motor (7) increases, so that drawing-off can take place at increasing speed. The circuit is such that there is a constant shift of the absorption volumes towards the hydraulic motor (5, 7), which calls for a greater absorption volume due to the change of the coil diameter (dx) at the storage drum (2). The circuit also provides automatic adjustment of the braking and stopping torques at the storage drum (2). <IMAGE>