The development prospects of the hydraulic power unit industry

The development prospects of the hydraulic power unit industry

The hydraulic power unit is the "core" of the hydraulic transmission system. Nowadays, hydraulic power units with motors as the transmission device often adopt a discrete structural design, which is composed of independent components such as motors, couplings, hydraulic pumps and oil tanks connected together. This design is characterized by complex construction, low productivity, high noise pollution and uncertain external leakage paths.

Therefore, in recent years, the integration and unification of electric-hydraulic power units have received increasingly close attention and development. After the development and expansion of motor oil pump groups and hydraulic motor pumps, hydraulic power stations (integrated hydraulic power stations) that highly integrate motors, hydraulic pumps, oil tanks and accessories have emerged, significantly reducing the volume of electric hydraulic power units, minimizing leakage and greatly lowering noise pollution. The integrated electric hydraulic power unit ADAPTS to the future development trend of hydraulic technology towards quietness and energy conservation, low-carbon manufacturing, and human-machine friendliness, and has significant research and application value as well as broad application prospects.

Low efficiency. Due to the connection of independent components such as the motor, hydraulic pump and oil tank, the structure of the hydraulic power device is relatively complex. There are many links in energy conversion and power transmission, which are prone to mechanical friction losses, pipeline pressure losses and leakage losses.

(2) It is prone to leakage. Under long-term working conditions, the sealing devices at the connection points of the pipelines between the hydraulic pump and the oil tank and the shaft extension part of the hydraulic pump are subject to corrosion and wear, resulting in leakage, environmental pollution, and inconvenience in management and maintenance.

(3) It is prone to generating cavitation noise and vibration. In discrete power units, the motor and the hydraulic pump are connected by couplings, but the coaxiality cannot be guaranteed, and mechanical vibration and noise are prone to occur during operation. Complex pipeline connections lead to increased fluid resistance, which can easily cause local negative pressure, resulting in bubble sedimentation and thus generating cavitation noise and vibration. The noise control of traditional hydroelectric generating units usually takes independent motors and hydraulic pumps as the research objects. The noise reduction space is not large enough, and further noise reduction is very difficult. The overall noise reduction effect is not very obvious.

(4) The forming process of shell parts such as hydraulic pumps and motors is rather complex. The hydraulic pump and motor are independent components. The shell structure is complex and requires separate casting, which increases the casting and processing costs and also raises the carbon emissions during the casting process. Compared with the structural form that combines an independent electro-hydraulic power unit with an oil tank, the integration of the electro-hydraulic power unit will result in less energy loss, does not require a large number of seals, and can achieve tubeless connection.