HYDRAULIC DRIVE OF SELF-PROPELLED BOOM CRANE Russian patent published in 1999 - IPC

FIELD: transport engineering; high-capacity boom cranes. SUBSTANCE: drive has hydraulic cylinders of boom extension and lifting mechanisms and hydraulic motors of turntable slewing mechanism and load winch provided with brakes with hydraulic cylinders and communicating through three-position distributors with supply source and tank. Control spaces of three-position hydraulic distributors are placed in communication with control pump through servovalve units and lines. Both control spaces of three-position hydraulic distributors of boom extension mechanism hydraulic cylinders, turntable slewing and load winch hydraulic motors and one of control spaces of three-position hydraulic distributors of boom lifting hydraulic cylinder are placed in communication with tank by additional line, each through its two-position distributor with electromagnetic control in one position and electromagnetically controlled two-position distributor are coupled with load torque safeguard. Control spaces of three-position hydraulic distributors are placed in communication with corresponding electromagnetically-controlled two-position distributors through at least one OR valve. Supply source is made in form of two axial piston pumps. EFFECT: possibility of combination of working operations irrespective to value of load, provision of overload protection of drive, increased efficiency of drive. 3 cl, 3 dwg