Because the tooth profile of the gear rack is straight, the pressure angle at all points on the tooth profile is the same, equal to the inclination angle of the tooth profile. This angle is called ...
PP board is a semi-crystalline material. It is harder and has a higher melting point than PE. Because the homopolymer PP temperature is very brittle above 0C, many commercial PP materials are rand...
Coal bunkers in coal mine production are basically made of concrete, and their surface is not smooth, the coefficient of friction is large, and the water absorption is high, which are the main reas...