Single-pump multi-motor closed hydraulic system and engineering machinery including same

Abstract

The invention provides a single-pump multi-motor closed hydraulic system and engineering machinery including the same. The single-pump multi-motor closed hydraulic system comprises a plurality of motors connected in series and a closed pump (10) connected in series with the motors, wherein the closed pump (10) comprises a closed-pump oil supply pump (14); a first oil supply pipeline (21) is connected onto a hydraulic pipeline between the two adjacent motors in the motors respectively; the first oil supply pipelines (21) are arranged in parallel, joined at a first node and connected to an oil supply pressure hole of the closed-pump oil supply pump (14) through oil supply pressure pipelines (26); and each first oil supply pipeline (21) is provided with a first control valve for controlling each first oil supply pipeline (21) to be connected or disconnected. According to the single-pump multi-motor closed hydraulic system, the motors can be effectively prevented from idly running and the zero drift phenomenon of the closed-pump can be diagnosed in time.

Description

technical field [0001] The invention relates to a hydraulic system in construction machinery, in particular to a single-pump and multi-motor closed hydraulic system and construction machinery including the hydraulic system. Background technique [0002] At present, it is more common to use a single-pump multi-motor closed hydraulic system in the hydraulic system of road machinery and construction machinery products. Generally, one closed pump drives multiple hydraulic motors to rotate in both directions or in one direction. [0003] figure 1 Shown is a paver vibrating hydraulic system circuit, using a closed pump 10' to drive four motors of the same displacement (first motor 11', second motor 12', third motor 13', fourth motor 15'). The four motors are configured in groups of two to form a series circuit, and the two series circuits are connected to form a parallel circuit. The output oil flow of the high-pressure output port of the closed pump enters the parallel circuit...

AI Technical Summary

Problems solved by technology

[0013] Therefore, for machines using a single-pump and multi-motor closed hydraulic system, the current problem is that when the machine is idling and waiting for work, although the closed pump has already met the requirements that the multi-motor circuit cannot work at this time, there is no output working flow. To a multi-motor circuit, but in the case of a small motor load, there is often a slow and difficult to eliminate motor rotation phenomenon (hereinafter referred to as motor idling)

[0015] 1. The hydraulic system is equipped with a mechanical locking device. This method has the possibility of damaging the single-pump multi-motor hydraulic system due to the failure to release the lock in time when the machine is turned into normal work.

[0016] 2. The hydraulic system is equipped with a synchronous diverter valve. This method is not economical due to a large increase in production costs

[0018] However, the third method needs to connect a constant pressure source outside the single-pump multi-motor closed hydraulic system, and when the constant pressure source is used for oil replenishment, the constant pressure source must be tested and adjusted to ensure constant pressure The source pressure is the same as the closed pump pressure

In actual use, because the speed of the power source (such as the engine) is not necessarily exactly the same every time the machine is idling and waiting for work, the output flow of the charge pump is not the same, which makes the charge pressure change, which will make this pressure detection and Frequent adjustments will increase the workload and cause inconvenience

At the same time, the hydraulic system has no diagnostic ability for the output zero drift of the closed pump, which causes the pressure of the closed pump to exceed the pressure of the connected constant pressure source.

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