Quasi-hyperbolic gear manufacturers talk about the basic parameters of gears and their design

What are the basic parameters of a gear? In order to constrain the entire gear, the basic parameters that must be dimensioned include the number of teeth, the normal module, the normal pressure angle, the helix angle, the tooth width, the tooth tip circle, the number of teeth, the number of intersecting teeth, the regular line (the number of teeth and the regular line can be directly replaced by the distance between the measuring bar and the intersecting bar), and the center distance. It's going to be weird looking here. Why is there no displacement coefficient? The manufacturer of quasi-hyperbolic gears will introduce the meaning of each parameter separately and answer why the common normal line is marked instead of the displacement coefficient.

In addition to the normal module, code, normal module, there are end face module, code mt. In straight teeth, the middle normal coefficient and the end face coefficient are the same. In bevel gears, their quasi-hyperbolic gear manufacturers believe that the relationship is as follows:

The vertical module is a module where the tool processes gears on a plane perpendicular to the spiral angle generatrix. The end face module means a module of a gear on a plane parallel to the end faces of the gear.

The module M itself has no physical meaning and functions as a substitute for the gear pitch P. FIG. The module M substantially determines the thickness of a single tooth of the gear, and the size of the gear in combination with the number of teeth Z is also substantially determined. The module M can improve gear strength, breakage and wear by adding modules.

normal pressure angle, chord n. The pressure angle is the angle between the direction of motion of the involute and the direction of the force, and the pressure angle at each point on the involute is different. The farther away from the reference circle, the greater the pressure angle. The pressure angle of the reference circle is 0, and the pressure angle of the pitch circle in most countries in the world is 20.

There is a concept here. Some people say that at different points of the gear, the pressure angle is different. Changing the pressure angle can change the coincidence and change the strength. But the principle is to adjust the involute shape and optimize the gear transmission. In general, the method of adjusting the displacement coefficient can be used to achieve the same effect. Adjusting the pressure angle needs to replace the tool, and the displacement coefficient only needs to adjust the tool position. Therefore, in general, the adjustment displacement coefficient of gear optimization can be realized by adjusting the displacement coefficient, and the pressure angle cannot be adjusted by adjusting the displacement coefficient. If the pressure angle changes, the knife must be reordered, so the cycle is long and the price is high.

The helix angle, the chord, the tangent of the helical gear pitch spiral and the acute angle of the corresponding shaft clamping are called the pitch cylindrical helix angle (pitch helix angle or helix angle). Helical gears have a greater degree of matching than spur gears and have the advantage of improving gear strength and stability. Therefore, under the same processing accuracy, the helical gear is suitable for faster speed. The spur gear helix angle is zero. Of course, the disadvantage of bevel gears is that meshing produces axial splitting forces, and the axial positioning requirements of bevel gears are much higher than those of spur gears.

Tooth width, chord B, the width of the tooth part of the gear measured along the direction of the linear generatrix of the pitch cylindrical surface.

Quasi-hyperbolic gear manufacturers believe that the size of the tooth width affects the matching degree of the bevel gear, affects the size of the contact area, and therefore also affects the strength of the gear. In an ideal state, the longer the tooth width, the higher the strength, but in fact there are processing errors. The longer the tooth width, the greater the error, the more serious the meshing impact of the gear, and the lower the gear strength. Therefore, quasi-hyperbolic gear manufacturers believe that it is very necessary to choose the appropriate two width, and the longer the two width, the better the strength is the wrong idea. The addendum circle, the chord da, the circle passing through each addendum of the gear, the diameter is represented by da, and the radius is represented by ra. The tooth tip circle is very important in the gear parameters, and its value will affect the coincidence degree, sliding speed, tooth tip thickness, etc. Improper value will also cause gear meshing interference.

The root circle, the chord df, the circle tangent to the bottom of each gear groove in the gear, the diameter is denoted by df, and the radius is denoted by RF. The root circle affects the top clearance of the gear. The influence of the stress concentration position of the tooth root on the bending strength of the thin-walled gear is obvious. Many people think that this value can not be marked, but we strongly recommend that it be marked on the drawing. If there is a problem, it is easy to investigate. However, quasi-hyperbolic gear manufacturers feel that the processing control of the root circle need not be strict. Because the root circle is determined by the tool and the common normal. After the first processing is correct, the possibility of processing errors is very small. But if you ignore this value, if there is a problem, the responsibility of you and the manufacturer will be uncertain.