The characteristics of commonly used vane pumps and gear pumps
There are various types of pumps, which are mainly used to transport liquids such as water, oil, acid-base liquid, emulsion, suspoemulsion and liquid metal, as well as liquid and gas mixtures and liquids containing suspended solids. This article will focus on the working principle and performance characteristics of vane pumps and gear pumps that we often use.
vane pump
According to the different types are divided into:
1. Specifically refers to the sliding vane pump in the positive displacement pump.
2. Refers to the three pumps (centrifugal pump, mixed flow pump, axial flow pump) of the power pump or other special pumps.
According to whether its theoretical displacement per revolution is a fixed value or a variable value, it can be divided into:
1. Vane variable displacement pump.
2. Vane type quantitative pump.
Performance characteristics of vane pump:
1. Advantages:
①The output flow rate is more uniform than that of the gear pump, the operation is stable and the noise is small.
② Higher working pressure and higher volumetric efficiency.
③Single-acting vane pump is easy to realize flow adjustment, while double-acting vane pump has long service life due to the balance of radial hydraulic pressure on the rotor.
④Compact structure, small outline size and large flow rate.
2. Disadvantages:
①The self-priming performance is worse than that of the gear pump, and the requirements for the oil-absorbing conditions are stricter, and the speed range must be within the range of 500-1500r/min.
②It is sensitive to oil pollution, the blades are easily killed by impurities in the oil, and the work reliability is poor.
③The structure is more complicated, the parts manufacturing precision is higher, and the price is higher.
④ Vane pumps are generally used in medium pressure (6.3 MPa) hydraulic systems, mainly for machine tool control, especially double-acting vane pumps, which are widely used in precision machine tools because of their small flow fluctuations.
gear pump
The teeth of the two gears of the gear pump separate from each other to form a low pressure, and the liquid is sucked in, and the two gears on the other side close together to form a high pressure to discharge the liquid.
Performance characteristics of gear pump:
1. Advantages:
①Simple and compact structure, small size, light weight, good workmanship and cheap price;
② Strong self-priming, not sensitive to oil pollution;
③ Wide speed range, impact load resistance, easy maintenance and reliable operation.
2. Disadvantages:
①The radial force is unbalanced, the flow pulsation is large, the noise is large, and the efficiency is low;
② The interchangeability of parts is poor, and it is not easy to repair after wear and tear, so it cannot be used as a variable displacement pump.