Rotary hydraulic system and construction machinery

Abstract

The invention relates to the technical field of engineering machines and in particular discloses a rotary hydraulic system and an engineering machine. The rotary hydraulic system comprises a variable pump, a rotary motor, a revering valve and a damper valve; two oil ports of the variable pump are respectively connected with two oil ports of the rotary motor through a first oil circuit and a second oil circuit; the first oil circuit is connected with the second oil circuit through a third oil circuit; the reversing valve and the damper valve are arranged on the third oil circuit; and the reversing valve has connection and disconnection states. In the using process of the rotary hydraulic system disclosed by the invention, the connection or disconnection of the reversing valve can be controlled as required to ensure the rotary property of the rotary hydraulic system under different working conditions. Compared with the prior art, not only can the stable operation of the rotary hydraulic system be ensured during rotation starting and braking and in the rotating process, but also the rotary hydraulic system has a reverse rotation preventing function and favorable fine motion performance.

Description

technical field [0001] The invention relates to the field of construction machinery, in particular to a rotary hydraulic system and construction machinery. Background technique [0002] Slewing motion is one of the main movements of construction machinery such as cranes, and its performance is an important indicator to measure the operational performance of the whole machine. For example, as far as cranes are concerned, their operating environment is generally harsh, and they often need to be constructed in some uneven and narrow areas, so it is difficult for each leg to ensure that the frame is in a relatively horizontal state. In addition, when the crane is hoisting, the boom It often bears a large inclined load or partial load. Therefore, how to improve the slewing performance of the crane has always been a technical problem to be solved urgently by relevant technicians. [0003] When the slewing starts, brakes and during the slewing process, due to factors such as load...

AI Technical Summary

Problems solved by technology

However, the structure of this type of rotary buffer valve is usually relatively complicated and the cost is high; and during the hoisting operation of the crane, due to the existence of cable-stayed loads, unbalanced loads, or uneven ground, the phenomenon of rotary reversal is prone to occur; in addition , because the operator controls the rotary action through the control handle, when the control handle is in the small opening condition, the pressure oil flow and pressure in the system are not enough to push the load, that is, the rotary action cannot be performed normally

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