Comparison of high temperature and high viscosity gear oil pump

High temperature gear pump is a polyester melt conveying , pressurization and melt metering essential equipment. Than other types of heat pump melt pump , compact structure, reliable operation, low energy consumption, high volumetric efficiency , the melt shear cut the role of small , high-pressure flow when high viscosity stability, no outlet pressure fluctuations. the pump has the unique advantage and a key role in the process , it has played an irreplaceable role in the polyester production.

A complete gear pump includes a motor , reducer , coupling and pump head parts , head part of the pump casing , front and rear side cover , gear shafts, bearings and shaft seal . Temperature gear pumps are positive displacement pumps, working volume changes depend working intermeshing driving and driven gears to cause melt conveyance . working volume by the pump, and the gear splines with the side plate bearing function composition.

Generally high viscosity pump bearings sliding bearings and the inner wall of the non-load bearing surface of the spiral flow channel is designed , rotation of the spiral groove gear to the steering shaft with the same . Outer end bearing the inlet communicating with the pump , the bearing the inner end of the spiral groove and tooth root ( vacuum portion) communication when the shaft is rotated by the coil and the bearing effect of the pressure difference between the ends of the bearing outside the cryogenic liquid into the bearing , the bearing lubrication and cooling , immediately flows into the disengaging meshing teeth , constitute a sufficient lubrication , cooling quickly spiral self-priming advantage of the low-pressure lubrication system lubrication is: enter the bearing lubrication fluid media are all low , easy to form a viscous lubricating fluid dynamic pressure bearing ability of the film a large number of lubricating fluid circulating constantly bearing away the heat , to play a good bearing lubrication and cooling effect due to sufficient liquid to fill the tooth roots emerging from the engagement , greatly improving the performance of self-priming gear pumps , avoiding the suction air phenomenon , not only can improve the volumetric efficiency, but also help reduce cavitation, noise reduction. using the sliding bearings immersed in the medium, and through special Kongdao Jiang lubrication system , the technology has been in polyvinyl alcohol , polyester , rubber , resins , fertilizers and other areas of the gear pump successfully applied .

Bearing materials commonly used tool steel and surface hardening treatment to improve its anti-bonding capability if the transmission medium containing abrasive particles should be used very hard bearing materials , such as ceramics in recent years , GS-1 PTFE vinyl composite steel is considered ideal sliding bearing material which cold-rolled steel sheet ( substrate) , spherical porous sintered bronze powder or copper mesh ( middle layer ) , polytetrafluoroethylene ( surface layer ) of composite material and three-layer Cheng, both metal and plastic polytetrafluoroethylene advantages on the basis of this material , Shanghai Research Institute of Materials has developed a better performance of the SF -type three-layer composite self-lubricating materials , it bronze wire mesh instead of bronze powder layer , the surface of the plastic formulations have been carefully screened . such bearing material fatigue resistance , high load capacity , low friction , long service life , is to improve the technical performance of the new gear pump bearing material .