In recent years the structure of high viscosity gear pump has brought revolutionary changes. Comprehensive use of the material forced lubrication integral sliding bearing as the main characteristics of a number of new technologies, new materials, new technology application scope of the gear pump more and more widely, especially in the polymer melt conveying occasions such as high temperature, high pressure gear pump is almost unable to substitute other volume type pump. High viscosity gear pump has been successfully applied to Vigny Lun, acrylic, polyester, viscose fiber and other industries.

Now it seems ordinary high viscosity occasions in low temperature and low pressure using multiple tooth difference cycloid gear pump is ideal. The drive gear for gear claw type circular arc curve, the driven gear is embedded in the special cycloid tooth profile were 11 teeth and 8 teeth, separated by a crescent plate. The pump structure is compact, large flow, low noise, high efficiency and can adapt to changes in the viscosity of the medium in a large range.

Hardened face gear with high precision, gear and shaft machining and precision grinding and polishing of all, integral type sliding bearing end of tool steel open unloading groove, and the high pressure materials lead to bearing lubrication cooling (relatively) and then returns to the suction chamber. The pump precision, cut, volumetric efficiency and the size of stable performance and other indicators are very high, suitable temperature reached 450 ℃, apply pressure has reached 30MPa, suitable viscosity has reached 4 × l06cP.

In addition to the optimal design and the development direction of high viscosity gear pump and:

1) arc gear pump double circular arc tooth profile of involute gear pump as a supplement. The number of gear teeth of double circular arc tooth profile less, without undercutting, wear small, high efficiency and does not produce oil phenomena.

2) with helical, herringbone gear structure to replace the ordinary straight tooth structure not only can greatly reduce the flow and pressure fluctuation also has a self-cleaning function. Foreign companies have even in high temperature melt pump using herringbone gear.

3) with multiple sensors electric heating jacket to replace the heat insulation jacket can pump operation is simplified using.

4) the sun -- planetary gear structure is provided with a plurality of inlet outlet in order to achieve balance radial force, but also reduce the occurrence of cavitation of the stool. The structure has been adopted in spinning metering pump small.

5) the spiral seal (maze), the sealing structure of mechanical sealing, packing and other forms to completely solve pump leakage problems (especially in high vacuum condition).

6) for abrasive or corrosive media and other special occasions can be considered two leak outboard bearing gear pump, can also replace the cam rotor and synchronous gear through the gear special treatment.

High viscosity pump to sum up the various types of each has its own characteristics and shortcomings, but relatively speaking with its simple, reliable, high efficiency, low cost, wide range of application and many other advantages and come out on top in the field of development of high viscosity gear pump and continuous improvement has become increasingly evident.