In the hydraulic system, the hydraulic pump is the core component of energy conversion, and whether its selection is reasonable or not directly affects the performance, efficiency and service life of the whole system. Therefore, the correct selection of hydraulic pump is very important for the design and application of hydraulic system. This paper will systematically introduce the selection method of hydraulic pump from the aspects of job demand analysis, pump type selection, parameter calculation and use environment.
First, clear system work requirements
Before selecting the type, the overall working requirements of the hydraulic system should be made clear first. Including the pressure, flow rate, working cycle time, load type (constant load or variable load), environmental temperature of system operation, medium type, etc. These basic parameters are the basis of subsequent selection.
Second, choose the appropriate type of hydraulic pump
According to system requirements, common hydraulic pumps mainly include gear pumps, vane pumps and piston pumps:
1. Gear pump: simple structure, low cost and strong anti-pollution ability, but low pressure and average efficiency, suitable for medium and low pressure systems.
2. Vane pump: It runs smoothly and has low noise. It is suitable for medium-pressure systems and is commonly used in machine tools and automation equipment.
3. Piston pump: high pressure, complex structure and high efficiency, suitable for high-pressure and high-power systems, such as construction machinery and heavy equipment.
In addition, it can be divided into quantitative pump and variable pump according to whether it is variable or not. Variable displacement pump can automatically adjust the flow according to the load change, which is better in energy saving and high efficiency.
Third, the calculation and matching of key parameters
1. Determine the working pressure: Determine the rated pressure of the hydraulic pump according to the maximum working pressure of the actuator (such as oil cylinder and motor) and considering the pipeline loss.
2. Calculate the required flow: According to the speed and structural size of the actuator, calculate the total flow required by the system with a certain margin.
3. Calculation of power: According to the formula $ p = frac {p cdot q} {60 cdot eta} $ (where $ p $ is pressure, $ q $ is flow and $ eta $ is efficiency), estimate the driving power of the pump, so as to reasonably select the driving motor or engine.
Fourth, consider the use environment and maintenance factors
The installation space, working environment (such as temperature, humidity and dust), oil cleanliness and maintenance convenience should also be considered when selecting the type. For example, in high temperature or high pollution environment, pumps with high temperature resistance and corrosion resistance should be selected, and suitable filtration system should be equipped to prolong the service life.
V. Comprehensive evaluation and type selection verification
After the initial selection, it is suggested to verify it by system simulation or prototype test to ensure that the selected pump can meet the stable operation of the system under various working conditions. At the same time, it is necessary to consider the cost performance ratio to avoid the waste of resources caused by blind pursuit of high performance.
To sum up, the selection of hydraulic pump is a systematic project, which needs to comprehensively consider system requirements, pump types, parameter matching, environmental adaptability and other aspects. Only on the basis of fully understanding the system characteristics and pump performance can we make scientific and reasonable selection decisions and ensure the efficient and stable operation of the hydraulic system.