Hydraulic pump station is the power source of the hydraulic system. It can provide corresponding pressure and flow according to the mechanical equipment’s working conditions.
The hydraulic pump station has a wide range of uses and is classified in many ways.
1. According to the Driving Mode
Electric type:
It uses an electric motor as the primary power source, which is suitable for fixed mechanical equipment with stable power supply. It has low noise during operation, and electric drive is generally used in industrial hydraulics, making it the most widely used application.
Mobile type:
It uses a diesel engine as the primary power source and does not need electricity, making it convenient for remote areas without power supply or with short circuits, and all kinds of construction equipment used for field work. The noise is relatively high, and the utilization rate is low.
Most mobile machinery is driven by diesel engines.
2. According to the Output Pressure
According to the high and low output pressure of the hydraulic pump group, the hydraulic pump station can be divided into low-pressure, medium-pressure, medium-high-pressure, high-pressure, and ultra-high-pressure, with their pressure ranges as follows:
- Low-pressure pump station: p ≤ 2.5 MPa
- Medium-pressure pump station: p > 2.5 ~ 8 MPa
- Medium-high-pressure pump station: p > 8 ~ 16 MPa
- High-pressure pump station: p > 16 ~ 32 MPa
- Ultra-high-pressure pump station: p > 32 MPa
3. According to the Output Flow Characteristics
Based on the output flow characteristics of hydraulic pump groups, the hydraulic pump station can be divided into fixed-displacement hydraulic pump stations and variable-displacement hydraulic pump stations.
Different output pressure and flow characteristics can be applied to different host operating conditions and work requirements.
If a fixed-displacement hydraulic pump station is used, according to the hydraulic system’s demand for flow, a single fixed-displacement pump or multiple fixed-displacement pumps can be configured.
If a variable-displacement hydraulic pump station is used, it can be further divided into constant power type, constant pressure type, constant flow type, pressure limiting type, and pressure-cutting type according to the adjustment characteristics of pressure-flow.
In practical engineering applications, more pressure-compensated variable pumps are used for oil supply. When the hydraulic system reaches the predetermined pressure, the hydraulic oil is not discharged through the high-pressure relief valve but achieves safe protection by reducing the pump’s flow output.
4. According to the Mechanism Form of the Pump Device
Upper horizontal type:
The pump device is horizontally installed on the oil tank cover plate and is mainly used for variable vane pump systems, making it convenient for flow regulation.
Side horizontal type:
The pump device is horizontally installed on a separate foundation beside the oil tank, and the side installation type can be equipped with standby pumps.
It is mainly used for systems with an oil tank capacity of more than 250 liters and an electric motor power of 7.5 kilowatts or more.
Upper vertical type:
The pump device is vertically installed on the oil tank cover plate and is mainly used for fixed-displacement pump systems.
Lower type:
The pump is installed below the oil level in the oil tank, which can improve the suction conditions of the hydraulic pump. The oil tank can be a rectangular oil tank or a cylindrical oil tank.
5. According to the Scale of the Hydraulic Station
According to the size of the hydraulic station, it can be divided into three types:
Small-scale single-machine hydraulic stations
Small-scale single-machine hydraulic stations are usually power-type or composite-type integral hydraulic stations. Generally, what we call hydraulic pump stations refer to small hydraulic stations.
Compact hydraulic stations
Compact hydraulic stations, also known as power units, have a compact design and occupy a small space, which is their main advantage.
Medium-sized unit-type hydraulic stations
Medium-sized unit-type hydraulic stations mostly use a composite type of separated structure.
Large-scale central hydraulic stations
Large-scale central hydraulic stations are set high, which enables centralized management of the hydraulic system.
6. According to the Degree of Universality
According to the degree of universality, hydraulic stations can be divided into two types: specialized hydraulic stations and general-purpose hydraulic stations.
Specialized hydraulic stations
Specialized hydraulic stations are mainly used for industrial equipment, specifically designed and manufactured according to the main machine’s specific technological purpose and generally do not have versatility.
General-purpose hydraulic stations
General-purpose hydraulic stations integrate most of the control elements with hydraulic pumps and their driving motors, oil tanks, etc. This type of hydraulic device generally has a portable structure. Their small volume and weight are usually produced by hydraulic component factories specializing in such products.
