Compositions of the Hydraulic Pumps

Ⅰ. About the hydram pump

The hydraulic pump is the power component of the hydraulic system. It is driven by an engine or an electric motor, sucks oil from the hydraulic oil tank, forms the pressure oil and discharges it, and sends it to the actuator. Hydraulic pumps are divided into gear pumps, plunger pumps, vane pumps and screw pumps according to their structures.

Ⅱ. The composition of the hydram pump

The hydram pump consists of three parts: coupling, hydraulic oil tank and oil filter.

1. Coupling: The hydram pump drive shaft cannot withstand radial force and axial force, 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 due to manufacturing reasons, the coaxiality of the pump and the coupling exceeds the standard, and there are deviations during assembly, as the pump speed increases, the centrifugal force increases, and the coupling deforms, the deformation increases the centrifugal force. A vicious circle is created, which results in vibration and noise, which affects the service life of the pump. In addition, there are other influencing factors such as the looseness of the coupling pin and the failure to fasten it in time, and the wear of the rubber ring and the failure to replace it 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 a fuel tank, first consider its capacity. Generally, mobile equipment should take 2 to 3 times the maximum flow rate of the pump, and fixed equipment should take 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 should not be low. At the lowest oil level, the oil level should not be higher than the highest oil level when the oil cylinder is retracted; finally, considering the structure of the oil tank, the diaphragm in the traditional oil tank cannot play the role of depositing dirt, and a vertical diaphragm should be installed along the longitudinal axis of the oil tank. There is a space between one end of the diaphragm and the end plate of the fuel tank so that the space on both sides of the diaphragm is connected. The oil inlet and outlet of the hyd pump are arranged on both sides of the diaphragm at the disconnected end, so that the distance between the oil inlet and the oil return is the farthest. The hydraulic oil tank has more cooling effect.

3. Oil filter: Generally, pollutants with a particle size below 10 μm have little effect on the pump, while those larger than 10 μm, especially above 40 μm, have a significant impact on the service life of the pump. The solid pollution particles in the hydraulic oil can easily aggravate the surface wear of the relatively moving parts in the pump. Therefore, it is necessary to install an oil filter to reduce the pollution degree of the oil. Filtration accuracy requirements: 10 to 15 μm for axial piston pumps, 25 μm for vane pumps, and 40 μm for gear pumps. The pollution and wear of the pump can be controlled within the allowable range. At present, high-precision oil filters are widely used, which can greatly extend the service life of hydraulic pumps.