Bevel gear ordinary gear is the shape of a cylinder. The pitch angle of a gear is the angle between the face of the pitch surface and the axis. The most familiar kinds of bevel gears have pitch angles of less than 90 degrees and therefore are cone-shaped. This type of bevel gear is called external because the gear teeth point outward. The pitch surfaces of meshed external bevel gears are coaxial with the gear shafts; the apexes of the two surfaces are at the point of intersection of the shaft axes. Bevel gears that have pitch angles of greater than ninety
Type 90 75 mm field gun and Battle of Okinawa, often deployed together with armored units. The Type 90 continued to be used as field artillery until the surrender of Japan. The Type 90 formed the basis for the Type 3 75 mm tank gun used in the Type 3 Ho-Ni III Gun tank and Type 3 Chi-Nu medium tank. Type 90 75 mm field gun The was a field gun used by the Imperial Japanese Army during the Second Sino-Japanese War, Soviet-Japanese Border Wars and World War II. The Type 90 designation was given to this gun as it was accepted in the year 2590