The CBJ3 series high pressure gear pumps adopt special large diameter needle bearing rings with high loading capacity and large module gear. The axial clearance can be compasated through double metal floating sideplates and the special seals on the compassation faces. The best sweep-bore seal in radial and advanced technique of the pure low pressure side radial hydraulic force region expanding balance are used. So the bearing force loaded will reduce near 20%. The seal on the joint surface is good in reliability. So the pressure is stability for a long term and the volumetric efficiency and mechanical efficiency are higher. They are mainly used loaders, cranes, bulldozers and other engineering machinery.