Single-pump multi-motor closed hydraulic system and construction machinery including the hydraulic system

Abstract

The invention provides a single-pump multi-motor closed type hydraulic system and an engineering machine including the hydraulic system. The single-pump multi-motor closed type hydraulic system comprises a plurality of motors in series connection and one closed type pump (10) which is in series connection with the motors, wherein the closed type pump (10) comprises a closed type pump oil filling pump (14), and two adjacent motors of the motors are connected by a motor connection pipe; and the single-pump multi-motor closed type hydraulic system further comprises a first oil filling pipe (21), a first end of the first oil filling pipe (21) is connected with an operation oil opening of the closed type pump (10), a second end of the first oil filling pipe (21) is connected with the motor connection pipes, and the first oil filling pipe (21) is provided with a control valve for controlling the on and off of the first oil filling pipe (21). The single-pump multi-motor closed type hydraulic system disclosed by the invention can effectively prevent the motors from idling and immediately diagnoses a zero drift situation of the closed type pump.

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, this method requires an additional constant pressure source to be connected to the single-pump multi-motor closed hydraulic system, and when the constant pressure source is used for oil replenishment, the constant pressure source pressure must be detected and adjusted to ensure the constant pressure source. The pressure is the same as that of the closed pump

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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