In order to facilitate the analysis of excavator hydraulic system, the oil circuit is simplified and divided into several basic circuits. The basic principle of simplification is not to change the overall performance and the working relationship between each connection. Because the excavator requires compound action in the working process, different circuits will work at the same time
Analysis of rotary hydraulic system of Kobelco excavator
The rotary hydraulic system is composed of constant power series pump, three position six way directional valve, rotary motor, manual proportional pilot valve, etc. When the three position six way directional valve is in the left position, the swing motor rotates to the right, the excavator rotates, and the upper frame rotates to the right; When the three position six way directional valve is in the middle position, the middle position adopts the o-rod function, the rotation motor stops rotating, and the upper frame of the excavator stops rotating; When the three position six way directional valve is in the right position, the swing motor rotates to the left, the excavator rotates, and the upper frame rotates to the left; The rotary motor device is composed of overload oil makeup valve, anti cavitation valve, planetary deceleration mechanism, braking device, etc. The output torque of the rotary hydraulic motor is transmitted to the rotary gear ring through the planetary reduction mechanism, so as to drive the rotary upper frame to rotate at a low speed, and the speed is generally 10R / min. The overload oil replenishment valve can protect the overload of the high-pressure side of the swing motor and replenish oil to the low-pressure side to prevent cavitation. The braking device plays the role of parking braking and can accurately locate and unload materials. Because the throttle circuit is adopted inside the three position six way multi-channel valve, the swing start and stop can be stable without impact
