阅读说明：本技术 液压系统 (Hydraulic system ) 是由 邹爱标 邹云斌 陈云涛 于 2021-06-19 设计创作，主要内容包括：本发明公开了一种液压系统。包括主泵,以及先导泵,还包括循环齿轮泵,所述循环齿轮泵设于主泵与先导泵之间,所述循环齿轮泵的主动齿轮轴分别与主泵和先导泵传动连接,所述循环齿轮泵包括泵体和泵盖,设于泵体内腔的、相互啮合的主从动齿轮,及其分别连接于所述主从动齿轮的主从动齿轮轴,所述循环齿轮泵还包括力平衡装置。该液压系统在解决其回油漏油问题的基础上,可避免液压油高温故障。(The invention discloses a hydraulic system. Including the main pump to and the guide pump, still include circulating gear pump, circulating gear pump locates between main pump and the guide pump, circulating gear pump's driving gear axle is connected with main pump and guide pump transmission respectively, circulating gear pump includes the pump body and pump cover, locates pump body inner chamber, intermeshing's principal and subordinate moving gear, and connect respectively in principal and subordinate moving gear axle of principal and subordinate moving gear, circulating gear pump still includes power balancing unit. The hydraulic system can avoid high-temperature fault of hydraulic oil on the basis of solving the problem of oil return and oil leakage.)

1. The utility model provides a hydraulic system, includes the main pump to and guide's pump, characterized by still includes circulating gear pump, circulating gear pump locates between main pump and the guide's pump, circulating gear pump's driving gear axle is connected with main pump and guide's pump transmission respectively, circulating gear pump includes the pump body and pump cover, locates pump body inner chamber, intermeshing's the primary and secondary moving gear, and connect respectively in the primary and secondary moving gear axle of primary and secondary moving gear, circulating gear pump still includes power balancing unit.

2. The hydraulic system as recited in claim 1 wherein the drive gear shaft and the driven gear shaft of the gerotor pump are supported by deep groove ball bearings and DU bearings, respectively.

Technical Field

The invention relates to a hydraulic system of engineering machinery.

Background

Due to the structural problem of a hydraulic system of an engineering machine such as an excavator, the existing excavator has the fault of oil leakage of a radiator under the broken working condition. Aiming at the fault, the broken return oil is directly returned to the hydraulic oil tank, so that the damage to a radiator caused by the high broken return oil pressure peak value is avoided, but if the broken return oil is directly returned to the hydraulic oil tank, the oil temperature in the hydraulic oil tank is easily increased and cannot be effectively cooled, and further the high-temperature fault of the hydraulic oil of the excavator is caused. In addition, the gear shaft of the related gear pump can be flexibly deformed under the condition of load or high-pressure load, the journal of the gear shaft and the bearing are changed from cylindrical surface contact into line contact, and the pressure load is in long-term line contact, so that the bearing and the shaft are certainly damaged and deformed, and the normal operation and the service life of the pump are influenced.

Disclosure of Invention

The present invention is directed to a hydraulic system that solves the above-mentioned problems of the prior art. The hydraulic system can avoid high-temperature fault of hydraulic oil on the basis of solving the problem of oil return and oil leakage.

The technical scheme of the hydraulic circulation system comprises a main pump, a pilot pump and a circulating gear pump, wherein the circulating gear pump is arranged between the main pump and the pilot pump, a driving gear shaft of the circulating gear pump is in transmission connection with the main pump and the pilot pump respectively, the circulating gear pump comprises a pump body, a pump cover, a main driven gear and a secondary driven gear, the main driven gear and the secondary driven gear are arranged in an inner cavity of the pump body and are meshed with each other, the main driven gear shaft and the secondary driven gear are respectively connected with the main driven gear and the secondary driven gear, and the circulating gear pump further comprises a force balancing device.

And a driving gear shaft and a driven gear shaft of the circulating gear pump form supports through a deep groove ball bearing and a DU bearing respectively.

The hydraulic system is simple and reasonable in structure, and the high-temperature oil in the hydraulic oil tank is cooled circularly by connecting the circulating gear pump in series between the main pump and the pilot pump. The circulating gear pump has the advantages of strong bearing capacity, long service life, simple and reasonable structure, small volume, large displacement, stable and reliable operation, good adaptability, strong applicability and low manufacturing cost.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of a hydraulic system according to the present invention; FIG. 2 is a schematic structural view of an embodiment of the gerotor pump of FIG. 1; fig. 3 is a schematic structural diagram of a force balancing apparatus according to an embodiment of the present invention.

Detailed Description

In order to facilitate a better understanding of the invention, the invention is further illustrated by the following examples in conjunction with the accompanying drawings.

As shown in fig. 1 and 2. The hydraulic system of the present invention includes a main pump 13, a pilot pump 15, a circulating gear pump 14 provided between the main pump 13 and the pilot pump 15, and the like.

The circulating gear pump 14 comprises a pump body 4, a pump cover 1, a main driven gear shaft and the like. The pump cover 1 is fixedly connected to one end of the pump body in a centering manner through a sealing ring 9 and a plurality of positioning pins 2. The driving and driven gears which are meshed with each other are arranged in the inner cavity of the pump body, the driving and driven gears are respectively and fixedly connected to the driving and driven gear shaft, and two ends of the driven gear shaft 3 are respectively supported and connected to the pump cover and the pump body through DU bearings 5. Two ends of the driving gear shaft 7 are respectively supported and connected to the pump cover 1 and the pump body 4 through deep groove ball bearings 6.

Two ends of a driving gear shaft 7 of the circulating gear pump are respectively connected with corresponding transmission shafts of a main pump A and a pilot pump C through an external spline 13 and an internal spline 8.

The front end of the circulating gear pump is provided with an outer positioning spigot 12, the rear end of the circulating gear pump is provided with an inner positioning spigot 11, and the circulating gear pump is connected with the main pump and the pilot pump through the outer positioning spigot 12 and the inner positioning spigot 11 respectively.

The circulating gear pump is driven by the main pump to rotate to generate self-suction force, high-temperature oil in the oil tank of the main pump is pumped out and is pressurized and injected into a corresponding radiator, the high-temperature oil returns to the oil tank after being cooled by the radiator and is circulated and reciprocated, and the oil temperature in the hydraulic oil tank is further reduced to a reasonable range.

The circulating gear pump can reduce the influence of the jumping factor brought by the transmission part and has the characteristics of small friction coefficient, low noise and the like. The bearing (such as a deep groove ball bearing) and the shaft sleeve (such as a UD bearing) are respectively arranged on the driving gear shaft and the driven gear shaft, so that the centering can be met, the concentricity of the driving gear shaft and the two positioning spigots at the front end and the rear end is ensured, meanwhile, the limitation of the structural size can be well realized, the occupied space is small, the structure is simple, and the bearing capacity is improved.

In example 2. As shown in fig. 3. The circulating gear pump also comprises a force balancing device. The force balance device comprises an outer part a of the driven gear shaft 3 near the two ends DU bearings 5 to an inner part b of the two ends DU bearings 5, the diameters of the parts are respectively gradually reduced, and the parts are formed into conical cylinder shapes which are opposite to each other. That is, the diameters of the outer portions a of the journals on both sides of the driven gear shaft 3 to the inner portions b of the journals are gradually reduced, and the outer portions and the inner portions are tapered cylinders facing each other. The gear pump can not generate flexible deformation when no load, the shaft neck of the driven gear shaft 3 is respectively in line contact with the inner holes of the DU bearings of the gear pump at two points of Ca and Da, when the circulating gear pump is under the condition of pressure load, the shaft neck of the driven gear shaft 3 is respectively in cylindrical surface contact with the inner holes of the DU bearings of the gear pump, and the bearing capacity of the driven gear shaft is finally supported by the corresponding inner holes of the bearings in a large area. The rest of the structure and the corresponding operation of this example can be similar to the above-mentioned embodiment.

In example 3. The force balancing device comprises two side journal parts of a driving driven gear and a driven gear of a driving driven gear shaft, which are respectively arranged in conical cylinders which are opposite to each other. The diameters of the outer side part of the driving gear shaft 7 close to the deep groove ball bearings at the two ends to the inner side part of the deep groove ball bearings 6 at the two ends are respectively reduced gradually, and the driving gear shaft is in a conical cylinder shape opposite to each other. Similarly, the driven gear shaft 3 has tapered cylindrical shapes that gradually decrease in diameter from the outer side of the bearings 5 at both ends to the inner side of the bearings at both ends. That is, the diameters of the outer portions of the journal to the inner portions of the journal on both sides of the corresponding driving gear and driven gear of the driving gear shaft and driven gear shaft are gradually reduced to form opposite tapered cylinders.

When the circulating gear pump is in no-load, the driving gear shaft and the driven gear shaft do not generate flexible deformation, and the journals of the driving gear shaft and the driven gear shaft are respectively in line contact with corresponding four points of deep groove ball bearings and DU bearing inner holes of the deep groove ball bearings; when the gear pump is under the load condition, driving gear shaft 7 and 3 journals of driven gear shaft are all face contact with face of cylinder rather than corresponding deep groove ball bearing 6 and DU bearing hole respectively, and its bearing capacity is finally supported by corresponding bearing hole large tracts of land, and driving gear shaft and driven gear shaft all can reduce or avoid the influence that flexural deformation produced, have strengthened the bearing capacity of bearing relatively, effectively improve the easy fatigue failure phenomenon that appears in bearing later stage to extension gear pump life-span. The rest of the structure and the corresponding operation of this example can be similar to the above-mentioned embodiment.