CN-116136924-B - Variable-thickness gear three-dimensional entity parameterization modeling method

Abstract

The invention relates to a three-dimensional manufacturing technology of a thickened gear, in particular to a three-dimensional solid parametric modeling method of the thickened gear based on Solidworks, which can effectively improve the three-dimensional modeling efficiency of the gear and reduce the repeated modeling time, the variable-thickness gear parametric model is designed based on the involute forming principle, variable-thickness gears with various sizes can be obtained by modifying basic parameters in an equation of a design tree, repeated modeling time in scientific research is greatly saved by parametric modeling of the variable-thickness gears, design efficiency is improved, and design resources are liberated.

Inventors

• WEN JIANMIN

Assignees

• 哈尔滨工业大学（威海）

Dates

Publication Date

20260512

Application Date

20211116

Claims (5)

1. 1. The three-dimensional solid parametric modeling method for the thickened gear is characterized by comprising the following steps of: Step 1, setting parameters, namely establishing a global variable at the beginning of modeling, uniformly adopting a variable name to replace a specific numerical value in the subsequent modeling, wherein a parameter calculation formula of a thickened gear is adopted when the global variable is established, and the method comprises the following steps of H at * , the tooth top coefficient of the end face; h an * , a French face tooth top coefficient; beta-helix angle (rad); delta-cone angle (rad); wherein α tl -left flank pressure angle (rad); Alpha tr -right flank pressure angle (rad); alpha n -pressure angle (rad); beta l in the middle-left tooth surface indexing cylindrical helix angle (rad); beta r -right flank indexing cylinder helix angle (rad); The basic parameter calculation formula of the thickened gear has universality, and is a basic parameter calculation formula of the deflection bevel gear when the cone angle delta=0°, and is a basic parameter calculation formula of the straight thickened gear when the spiral angle beta=0°; Step 2, generating an involute profile: wherein r b is the radius (mm) of the base circle of the gear; r k -radius at the tooth profile K point (mm); alpha k -pressure angle at the tooth profile K point (rad); θ k -the spread angle (rad) at the tooth profile K point, The coordinates (x k ,y k ) of any point K on the involute are written as By combining the formula (4) and the formula (5), the left tooth profile equation from the base circle to the top circle can be written as R a in the formula, namely the radius (mm) of the gear tooth top circle; The right tooth profile expression is changed from the ordinate to the negative number, and the right tooth profile is rotated anticlockwise around the origin by an angle gamma, which is S-gear indexing circular tooth thickness (mm); By combining the formula (6) and the formula (7), the tooth profile equation from the base circle to the top circle is written as Wherein i represents the left and right tooth profiles of the gear, 1 is the right tooth profile, and 2 is the left tooth profile; Gamma i -left and right tooth profiles counter-clockwise rotation angle, when the value is negative, representing clockwise rotation, and gamma 1 -γ 2 = gamma, (rad); r bi -base radius (mm) of left and right tooth profile At the small displacement end, when the radius of the root circle is smaller than that of the base circle, the involute profile is prolonged into the base circle by a straight line, and the equation of the extension line is that T is a dimensionless parameter, is proportional to the length of an extension line, and is taken to be 0 to 2; step 3, generating a spiral line, namely, entering a sketch drawing base circle in the Solidworks, defining the diameter of the base circle to be 2r bl , opening the function of the spiral line, selecting the definition mode to be height and pitch, setting the rotation direction of the spiral line to be anticlockwise, setting the height to be tooth width h and the pitch to be Setting the initial angle as The right spiral line is drawn in the same way, and only parameters need to be changed.
2. 2. The method for three-dimensional solid parametric modeling of a thickened gear according to claim 1, wherein the thickened gears with different sizes are obtained by modifying basic parameters such as tooth number, normal modulus, pressure angle, helix angle, cone angle and maximum end face deflection coefficient and tooth width.
3. 3. The method for modeling three-dimensional solid parameters of a thickened gear according to claim 1, wherein if the deflection bevel gears with different sizes are to be generated, the cone angle is set to be 0, and then the tooth number, the normal modulus, the pressure angle, the helix angle, the maximum deflection coefficient of the end face and the tooth width are modified to obtain the variable bevel gear.
4. 4. The method for three-dimensional parametric modeling of a thickened gear according to claim 1, wherein if the thickened gears with different sizes are to be generated, the basic parameters are modified by setting the helix angle to 0, adding a negative sign to the formula of the right tooth surface indexing cylinder helix angle.
5. 5. The method for three-dimensional parametric modeling of a thickened gear according to claim 1, wherein if the thickened gears with different sizes are to be generated, the spiral line is modified to be clockwise after a negative sign is added in front of a formula of a spiral angle and a left and right tooth surface indexing cylinder spiral angle, and finally basic parameters are modified.

Description

Variable-thickness gear three-dimensional entity parameterization modeling method Technical field: the invention relates to a three-dimensional manufacturing technology of a thickened gear, in particular to a three-dimensional parametric modeling method of a thickened gear based on Solidworks, which can effectively improve the three-dimensional modeling efficiency of the gear and reduce the repeated modeling time. The background technology is as follows: The thickened gears were originally proposed by us a.s.beam and are characterized by different end section deflection coefficients in the axial direction. When the displacement coefficient on the end face linearly changes along with the distance of the end face in the axial direction, the thickened gear is similar to the bevel gear in appearance, and when the tooth side gap occurs, the tooth side gap can be adjusted without changing the gear and only adjusting the axial position of the gear, so that the transmission without the side gap is realized, and the service life of the gear is prolonged. The advantages of good reliability, long service life and the like of the thickened gear lead the thickened gear to have wide application, so that more and more students develop the thickened gear without three-dimensional modeling of the thickened gear with different parameters. The traditional gear modeling has the defects of large workload, more repeated steps and the like, and the partial gear modeling method adopts spline curve approximation to replace asymptote, so that the modeling precision is insufficient. At present, a plurality of open gear three-dimensional modeling plug-in tool boxes exist, but the three-dimensional modeling plug-in tool boxes cannot directly generate three-dimensional models of the deflection gears and the thickened gears, and certain limitations still exist. The invention comprises the following steps: aiming at the defects and shortcomings in the prior art, the invention provides a Solidworks-based three-dimensional solid parametric modeling method for a thickened gear, which can effectively improve the three-dimensional modeling efficiency of the gear and reduce the repeated modeling time. In order to save modeling time, the variable-thickness gear is subjected to parameterization modeling based on an involute forming principle in Solidworks three-dimensional modeling software, and after modeling is finished, variable-thickness gears and deflection bevel gears with various sizes can be generated by only changing basic parameters of the variable-thickness gear, such as normal face modulus, tooth number, cone angle, spiral angle and the like. The invention can be achieved by the following measures: The three-dimensional solid parametric modeling method for the thickened gear is characterized by comprising the following steps of: Step 1, setting parameters, namely establishing a global variable at the beginning of modeling, uniformly adopting a variable name to replace a specific numerical value in the subsequent modeling, wherein a parameter calculation formula of a thickened gear is adopted when the global variable is established, and the method comprises the following steps of H at*, the tooth top coefficient of the end face; h an*, a French face tooth top coefficient; beta-helix angle (rad); delta-cone angle (rad); wherein α tl -left flank pressure angle (rad); Alpha tr -right flank pressure angle (rad); alpha n -pressure angle (rad); beta l in the middle-left tooth surface indexing cylindrical helix angle (rad); beta r -right flank indexing cylinder helix angle (rad); The basic parameter calculation formula of the thickened gear has universality, and is a basic parameter calculation formula of the deflection bevel gear when the cone angle delta=0°, and is a basic parameter calculation formula of the straight thickened gear when the spiral angle beta=0°; Step 2, generating an involute profile: wherein r b is the radius (mm) of the base circle of the gear; r k -radius at the tooth profile K point (mm); alpha k -pressure angle at the tooth profile K point (rad); θ k -the spread angle (rad) at the tooth profile K point, The coordinates (x k,yk) of any point K on the involute are written as By combining the formula (4) and the formula (5), the left tooth profile equation from the base circle to the top circle can be written as R a in the formula, namely the radius (mm) of the gear tooth top circle; And the right tooth profile expression is only needed to change the ordinate into a negative number. To form reasonable left and right tooth profiles, the right tooth profile is rotated counterclockwise around the origin by an angle gamma, gamma being S-gear indexing circular tooth thickness (mm); By combining the formula (6) and the formula (7), the tooth profile equation from the base circle to the top circle is written as Wherein i-represents the left and right tooth profile of the gear, 1 is the right tooth profile, 2 is the left tooth p