Contact Characteristics Control And Processing Adjustment Method Of Spiral Bevel Gear Based On Ease-off Surface

Spiral bevel gears are widely used in automobiles,aircraft,ships and other mechanical systems due to their high load-bearing capacity and smooth operation.With the upgrading of China’s manufacturing industry,the requirements for high performance bevel gears are getting higher and higher,and the requirements for the control of their tooth contact characteristics are also getting higher and higher.However,due to the complex shape of the spiral bevel gear tooth surface,its tooth contact characteristics are not easy to control.Currently,the commonly used tooth contact characteristic control method is the local synthesis method,which mainly controls the contact state of tooth surface indirectly by controlling the curvature parameter of the contact reference point,and its calculation is complicated and not intuitive enough.Moreover,this method can only control the tooth contact characteristics near the reference point,but cannot control the tooth contact characteristics far from the reference point,and usually requires repeated adjustments to obtain the ideal tooth contact characteristics.To address the above problems,this paper investigates the control and machining adjustment method of spiral bevel gears based on the ease-off surface.With the intuitive geometric characteristics of the ease-off surface,the contact characteristics of spiral bevel gear teeth can be well controlled.1)The method of defining contact characteristics of spiral bevel gears is studied,the tooth surface equations of spiral bevel gears are derived,and the mathematical model for solving the conjugate pinion tooth surface according to the equations of the gear tooth surface is established.The connection between the contact characteristic parameters and the ease-off surface is established while solving the conjugate pinion tooth surface.The ease-off surface of the gear and pinion can be constructed by presetting the contact characteristic parameters,and the target surface of the pinion satisfying the contact characteristics of the preset gear pair can be obtained by superimposing it with the conjugate pinion tooth surface.2)The method of solving the machine tool adjustment parameters for the target tooth surface of the pinion satisfying the preset contact characteristics is investigated.The initial actual face of the pinion is determined by the machine tool adjustment parameters calculated according to the principle of local synthesis,and the deviation surface of the actual face of the pinion from the target face of the pinion is obtained by comparing it with the target face of the pinion.Based on the principle of differential geometric surface theory,the deviation surface is transformed into a geometric quantity that can reflect the deviation of tooth surface pressure angle,helix angle,bulge amount and torque angle,etc.,and the mathematical model for the optimal solution of the target tooth surface approximation of the pinion is established with this objective.The influence of the machine tool adjustment parameters on the tooth geometry deviation is analyzed,the independent variables of the optimization solution are determined by combining the characteristics of the tooth deviation,and the LM nonlinear least squares optimization algorithm is studied to realize the optimization solution of the machine tool adjustment parameters for the final machining of the target tooth surface of the pinion.3)Based on the research of the above methods,the control program of the contact characteristics of the spiral bevel gear tooth surface and the optimization solution program of the machine tool adjustment parameters for the target tooth surface of the pinion are compiled.The program is applied to calculate the target pinion face of the example gear with the given contact characteristics,and the theoretical contact analysis is performed between the pinion face and the gear face to verify the consistency of the contact area pattern and transmission error magnitude with the preset contact characteristics.The actual tooth surface of the pinion determined by this set of parameters is very close to the target tooth surface,and the reasonableness of the requested machine adjustment parameters is verified by simulation machining.In summary,this paper explores an intuitive control method based on the contact characteristics of conjugate differential surface spiral bevel gear teeth,and verifies the accuracy and effectiveness of the method in controlling the contact characteristics of the gear teeth during the whole meshing cycle through arithmetic examples,which is of good practical value for the transmission performance improvement of spiral bevel gears.