Geometry model of roller bit's sphere tooth, wedgy tooth and bucket shape tooth were established;

建立了牙轮钻头的球形齿、楔形齿和勺形齿三维空间的几何模型；

New type piston ring synthetic measurement instrument is the instrument which can measure both the height and trapezoid Angle of the keystone piston ring and wedgy piston ring.

新型活塞环综合检测仪就是一种能同时测量梯形或楔形活塞环的环高与梯形角的综合测量仪。