The gear and shaftReducer is a dynamic communication agencies, the use of gear speed converters, motor rotational speed reducer to the Rotary to be few, and have greater torque institutions. General helical gear reducer has reducer (including parallel shaft helical gear reducer, a worm reducer, bevel gear reducer, etc.), planetary gear reducer, Cycloid reducer, a worm reducer, a planetary friction CVT mechanical machines.The important position of the wheel gear and shaft can't falter in the design of he passing to process to make them can is divided into many model numbers , using for many situations respectively .So we must be the multilayer to the understanding of the wheel gear and shaft in reducer.In the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three dimensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel to each other. There are also other reasons, as we shall learn.Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an involutes helicoids. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an involutes curve. The surface obtained when every point on the edge generates an involutes is called an involutes helicoids.The initial contact of spur-gear teeth is...