The hydraulic pump consists of three parts: coupling, hydraulic oil tank and oil filter.
1. Coupling:
The hydraulic pump drive shaft cannot bear radial and axial forces, so it is not allowed to directly install pulleys, gears and sprockets on the shaft end. Usually, a coupling is used to connect the drive shaft and the pump drive shaft. If the coaxiality of the pump and the coupling exceeds the standard due to manufacturing reasons, and there is a deviation during assembly, the centrifugal force increases as the speed of the pump increases, and the coupling deforms. The large deformation increases the centrifugal force. This creates a vicious cycle, resulting in vibration and noise, which affects the service life of the pump. In addition, there are other influencing factors such as the coupling pin is loose and not tightened in time, and the rubber ring is worn and not replaced in time.
2. Hydraulic oil tank:
The main function of the hydraulic oil tank in the hydraulic system is to store oil, dissipate heat, separate the air contained in the oil and eliminate foam. When selecting an oil tank, we must first consider its capacity. Generally, mobile equipment takes 2 to 3 times the maximum flow of the pump, and fixed equipment takes 3 to 4 times; secondly, consider the oil level of the oil tank. When all the hydraulic cylinders of the system are extended, the oil level of the oil tank must not be lower than the minimum oil level, and when the cylinders are retracted, the oil level must not be higher than the maximum oil level; finally, consider the structure of the oil tank. The baffle in the traditional oil tank cannot play the role of sedimentation of dirt, and a vertical baffle should be installed along the longitudinal axis of the oil tank. There is a space between one end of this baffle and the end plate of the oil tank to connect the spaces on both sides of the baffle. The inlet and outlet of the hydraulic pump are arranged on both sides of the baffle at the unconnected end, so that the distance between the inlet and return oil is the farthest, and the hydraulic oil tank plays a more heat dissipation role.
3. Oil filter:
Generally, pollutants with a particle size of less than 10μm have little effect on the pump, but those larger than 10μm, especially those above 40μm, have a significant impact on the service life of the pump. Solid contamination particles in the hydraulic oil can easily aggravate the surface wear of the relatively moving parts in the pump, so it is necessary to install an oil filter to reduce the degree of oil contamination. Filtration accuracy requirements: 10-15μm for axial piston pumps, 25μm for vane pumps, and 40μm for gear pumps. The contamination and wear of the pump can be controlled within the allowable range. At present, high-precision oil filters are increasingly widely used, which can greatly extend the service life of hydraulic pumps.
