Linkage model and manufacturing process of shaping non-circular gears

As the current research of face gear drive cannot realize fluctuating gear ratio, a design method of orthogonal fluctuating gear ratio face gear drive is proposed. The mathematical model of orthogo...

Geometry design, three-dimensional modeling and kinematic analysis of orthogonal fluctuating gear ratio face gear drive

The mathematical model and mechanical properties of variable center distance gears based on screw theory

Design and manufacture of new type of non-circular cylindrical gear generated by face-milling method

Prevention of resonance oscillations in gear mechanisms using non-circular gears

A simple and accurate numerical method was proposed for calculating the tooth profile of a noncircular gear. This method is directly based on the real gear shaping process, rather than deducing and solving complicated meshing equations used in the traditional method. The tooth profile is gradually obtained from the boundary produced by continuously plotting the cutter profile on the gear transverse plane. The key point of the method is picking up the graph boundaries. The relative position of the cutter profile on the gear transverse plane is determined by the given pitch line of the noncircular gear, parameters of the shaper cutter, and the shaping process data. In comparison with the traditional method, it is universal and is much more efficient and accurate, especially for noncircular gears, which have nontrivial pitch lines. Special problems in gear design and manufacturing, such as tooth pointing, undercut, and fillet interference, are included in the process. As an application example of the numerical method, a square internal gear is chosen from a new type of hydraulic motor with noncircular planetary gears, and the tooth profile of that gear is computed. The gear is successfully machined by electromagnetic discharge (EMD) using the resulting data.

Numerical computing method of noncircular gear tooth profiles generated by shaper cutters

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

The influences of tool setting errors on skiving accuracy are discussed in this paper. Firstly, a method for the calculation of error-free cutting edge of skiving cutter is proposed. Based on the theories of cutter enveloping gear, the gear profile deviations, which are affected by the tool position and orientation errors in skiving, are analyzed. Results show that the profile deviations are insensitive to this kind of setting error of the cutter. Then, the effects of tool eccentricity error on skiving accuracy are analyzed. Results show that the waves on the tooth flanks, which are caused by the tool eccentricity error, have obvious influences on the helix deviations and the profile deviations of the workpiece. The waves on the tooth flanks are periodic ones and can be obviously affected by the number of teeth of the cutter.

Influences of tool setting errors on gear skiving accuracy

The invention discloses a bevel gear machining method. According to the geometric parameters and the required tooth system of a gear to be machined, the method comprises the following steps that: (1) the parameters of a shaping gear wheel are determined; (2) the tooth traces of the shaping gear wheel are determined; (3) the parameters of a cutter are determined; (4) the cutter movement on the tooth surface of the shaping gear wheel is determined; (5) the basic tooth surface modification of the shaping gear wheel is determined; (6) the movement of the shaping gear wheel generating the gear is determined; (7) the movement of the gear generated by the shaping gear wheel is corrected; and (8) the generation of the gear to be machined is completed. The invention has the advantages that: (1) the cutting and the grinding of bevel gears with straight teeth, curved teeth, cycloidal teeth, quasi-involute teeth and the like can be implemented on one machine tool; (2) the dimension of the cutter is determined only by the module of the gear to be machined and has nothing to do with the diameter of the gear to be machined and the tooth width; (3) the diameter of the cutter or the grinding wheel is small, the torque of the machine tool spindle is small, the force applied to the machine tool is small, the deformation of the machine tool is small and the machining accuracy is high; (4) the position, the dimension and the shape of the contact spots on the tooth surface can be conveniently controlled and all kinds of theoretically full-conjugated bevel gear pairs can be machined; and (5) the transmission ratio function required by the gear pairs to be machined can be accurately realized.

Bevel gear machining method

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.

Shimin Mao

Papers

Numerical computing method of noncircular gear tooth profiles generated by shaper cutters

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

Influences of tool setting errors on gear skiving accuracy

Bevel gear machining method

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