Multi-objective optimization of hypoid gears to improve operating characteristics

In this paper, the influence of the manufacturing parameters on the conditions of mixed elastohydrodynamic lubrication is investigated. On the basis of the obtained results, recommendations are for...

Improvements in the mixed elastohydrodynamic lubrication and in the efficiency of hypoid gears

This paper proposes a function-oriented form-grinding approach to obtain excellent and stable contact performance of cylindrical gears by designing modification forms based on a predesigned controllable fourth-order transmission error (TE) function and error sensitivity evaluation. First of all, a predesigned fourth-order TE polynomial function is assigned to the gear drive. Mathematical models of modified tooth surfaces that can describe their local deviation and ease-off topography are then obtained with the predesigned fourth-order TE function. The corresponding error sensitivity analysis is applied for investigation that reflects inherent relationships between contact attributes of modified tooth surfaces and misalignments. Moreover, the form-grinding wheel’s profile equation, the coordinate transformation matrix during form-grinding, and settings of computer numerical control (CNC) form-grinding programs for this active design method can be determined. This approach is ultimately conducted on three involute cylindrical gear pairs to demonstrate its feasibility and effectiveness.

A function-oriented active form-grinding method for cylindrical gears based on error sensitivity

https://iopscience.iop.org/article/10.1088/1361-6501/aa8dd7/pdf

A new digitized reverse correction method for hypoid gears based on a one-dimensional probe

Improved mixed elastohydrodynamic lubrication of hypoid gears by the optimization of manufacture parameters

To eliminate the tooth edge contact and improve the distribution of the tooth contact stress for face-hobbed spiral bevel gears in the case of heavy load and misalignment considered, optimizing the cutter blade profile is one of the most effective solutions. Generally, a segment of circle arc is used to substitute the straight line to get a desired theoretical tooth contact pattern, however, which is not sufficient for a heavy-loaded gear pair. A multi-segment cutter blade profile with Toprem, Flankrem, and cutter tip is introduced to obtain the ideal load and contact stress distribution. First, the structure of cutter head is described geometrically, the mathematical model of new cutter blade profile is built, and the equation for each section is given in detail. Then, the calculations of all design parameters are represented step by step. Finally, a contrast experiment between the original cutter and new optimal cutter, including tooth contact analysis, finite element analysis, and practical rolling check, is carried out for Oerlikon hypoid gears to verify effectiveness.

Optimization of cutter blade profile for face-hobbed spiral bevel gears

This paper proposes a pinion development approach in order to obtain excellent transmission performance of the face-milled spiral bevel and hypoid gears. First, the flank form of the gear pair is determined based on the original designed ease-off topography by adjusting the contact attributes. After the gear pair is finished and measured, the deviation sum can be established by converting the wheel flank deviations into the equivalent pinion flank deviations. Then, the real ease-off topography is obtained, which is an important indicator to evaluate the transmission performance. Next, the real ease-off topography is redesigned with the target of the original designed ease-off topography to compensate the deviation sum by readjusting the contact attributes. Thus, the pinion flank form is redesigned and the corresponding machine-tool settings can be calculated by the active design method. According to which, the pinion is recut/reground and the wheel remains unchanged. Finally, the approach is conducted on a face-milled hypoid gear pair to demonstrate its effectiveness.

Pinion development of face-milled spiral bevel and hypoid gears based on contact attributes

To satisfy the requirement of high precision of aero spiral bevel and hypoid gears, considering some inevitable error sources during machining, as well as easy operation and cost saving, a novel tooth surface deviation correction method is proposed. With this method, the mathematical model of the modified theoretical gear tooth surface is established to restore the real gear member via measurement data. According to which, subsequently, the theoretical pinion is redesigned so as to provide the nominal values of pinion tooth surface for correction. Then, to compensate the deviations of the real pinion tooth surface from the redesigned one, the corrective machine settings are optimized. By this, the correction can be conducted on the pinion only. At last, a numerical example of a hypoid gear set by SGM (spiral generated modified-roll) method is presented to demonstrate the proposed approach.

Correction of tooth surface deviations for aero spiral bevel and hypoid gears

Tool path active design for tooth modification of face-hobbed spiral bevel gears

Skiving is an efficient gear cutting technology with relatively high machining accuracy, especially for internal gears. Nevertheless, the machining accuracy can hardly be satisfied if the skived gear is modified, so we try to extend the definition and hypotheses domain of the previous works. In this paper, fundamental research is conducted to further improve the skiving accuracy. Firstly, a new type of skiving tool with double rake faces is proposed for flexibly meeting different modification requirements of the two flanks of the work gear teeth. Secondly, the mathematical model of curve-surface conjugated cutting edges of the skiving tool for enveloping the tooth flanks of the working gear with profile modification is established. Then, the algorithm of the skiving tool path with alterable shaft angle in the cutting process is proposed for eliminating the twist of gear tooth flanks with lead modification. Finally, machining simulations are carried out to verify the feasibility of the proposed improved skiving methods.

/pdf/a-novel-method-for-improving-the-skiving-accuracy-of-gears-4288fhnx.pdf

Wenchao Guo

Papers

Optimization of cutter blade profile for face-hobbed spiral bevel gears

Pinion development of face-milled spiral bevel and hypoid gears based on contact attributes

Correction of tooth surface deviations for aero spiral bevel and hypoid gears

Tool path active design for tooth modification of face-hobbed spiral bevel gears

A Novel Method for Improving the Skiving Accuracy of Gears with Profile and Lead Modifications