Gear pump type and development trend

The early gear pumps were all hydraulic type. Due to the need of environmental protection and energy saving, and the mature application of servo motors and the sharp decline in prices, more and more all-electric precision gear pumps have been used in recent years in order to analyze this trend. , I will compare the features listed:

1. All-hydraulic gear pump has many unique advantages in forming precision and complex shape products. It develops from the traditional single-cylinder liquid-filled, multi-cylinder liquid-filled type to the current two-plate direct pressure type, in which two plates are used. The most representative of the direct pressure type, but its control technology is difficult, high precision machining, hydraulic technology is difficult to grasp.

2, all-electric gear pump has a series of advantages, especially in environmental protection and energy saving advantages, it is reported that the current more advanced all-electric gear pump can save up to 70%, in addition, due to the use of servo motor injection control accuracy High, speed is also more stable, but also multi-level adjustment. However, the all-electric gear pump is not as good as a full-hydraulic gear pump in service life, and a full-hydraulic gear pump must use a servo valve with closed-loop control to ensure accuracy, and the servo valve is expensive and brings about an increase in cost.

3. The electric-hydraulic gear pump is a new type of gear pump integrated with hydraulic and electric drive. It combines the advantages of full-hydraulic gear pump's high-performance and all-electric energy-saving advantages. This kind of electric-hydraulic combined type Gear pumps have become the development direction of gear pump technology.

In the cost components of injection molding products, electricity costs account for a considerable proportion. According to the demand for the gear pump equipment technology, the ratio of power consumed by the gear pump oil pump motor to the total power consumption of the equipment is as high as 50% to 65%, and therefore has great potential for energy saving. All-electric injection machines have inherent advantages in terms of energy-saving effect. However, as mentioned above, the cost of such models is high, which results in a very limited range of applications. At the same time, it is difficult to develop the technology. Currently, the field is almost It is monopolized by Japanese companies. Although China Haitai, Donghua, and other press companies have launched fully self-developed all-electric injection machines, but the technical reliability of their products still needs to be tested in the market. The author believes that: within a short time, domestic all-electric machine is difficult to compete with Japanese equipment.

The introduction of energy-saving technologies on universal injection machines to develop energy-saving injection machines is an important trend in the development of skills and technologies for international and domestic injection machines. Such technologies include frequency conversion energy-saving, variable-capacity pump energy-saving and servo control energy-saving, etc. Energy-saving effects can also reach the range of 30 to 70%.