Fourth-Order Kinematic Synthesis for Face-Milling Spiral Bevel Gears With Modified Radial Motion (MRM) Correction

2005 ◽  
Vol 128 (2) ◽  
pp. 457-467 ◽  
Author(s):  
Pei-Yu Wang ◽  
Zhang-Hua Fong

The use of a fourth-order motion curve is proposed by Stadtfeld and Gaiser to reduce the running noise of a bevel gear set recently. However, the methodology of synthesizing the tooth surfaces was not clearly shown in the literature. In this work, we proposed a methodology to synthesize the mating tooth surfaces of a face-milling spiral bevel gear set transmitting rotations with a predetermined fourth-order motion curve and contact path. A modified radial motion (MRM) correction in the machine plane of a computer numerical control (CNC) hypoid generator is introduced to modify the pinion tooth surface. With MRM correction, an arbitrary predetermined contact path on the pinion tooth surface with predetermined fourth-order motion curve can be achieved. Parameters of MRM correction are calculated according to the predetermined contact path and motion curve. As shown by the numerical examples, the contact path and the motion curve were obtained as expected by applying the MRM correction. The results of this work can be applied to the pinion, which is generated side-by-side (for example, fixed setting method, formate method, and Helixform method) and can be used as a basis for further study on the motion curve optimizations.

1992 ◽  
Vol 114 (2) ◽  
pp. 317-325 ◽  
Author(s):  
Zhang-Hua Fong ◽  
Chung-Biau Tsay

Undercutting is a serious problem in designing spiral bevel gears with small numbers of teeth. Conditions of undercutting for spiral bevel gears vary with the manufacturing methods. Based on the theory of gearing [1], the tooth geometry of the Gleason type circular-cut spiral bevel gear is mathematically modeled. The sufficient and necessary conditions for the existence and regularity of the generated gear tooth surfaces are investigated. The conditions of undercutting for a circular-cut spiral bevel gear are defined by the sufficient conditions of the regular gear tooth surface. The derived undercutting equations can be applicable for checking the undercutting conditions of spiral bevel gears manufactured by the Gleason Duplex Method, Helical Duplex Method, Fixed Setting Method, and Modified Roll Method. An example is included to illustrate the application of the proposed undercut checking equations.


2017 ◽  
Vol 873 ◽  
pp. 48-53
Author(s):  
Kazumasa Kawasaki ◽  
Isamu Tsuji

A machining method of large-sized spiral bevel gears in cyclo-palloid system has been developed using a computer numerical control (CNC) machining center. As a result of trial machining, the tooth surfaces were rough and leprous tool mark occurred. Therefore, the tooth surfaces were polished using a poly-vinyl alcohol (PVA) elastic grindstone after machining in order to improve the surface roughness and the occurrence of leprous tool mark. However, the wear and clogging of the elastic grindstone occurred after polishing. In this paper, the tooth surfaces of the large-sized spiral bevel gears are polished using a radial bristle brush instead of a PVA elastic grindstone. The swarf cutting that was machined by the side of a tool was carried out in polishing in order to make the life of the radial bristle brush. After polishing, the tooth surface was observed and the surface roughness was measured. Afterwards, the surface roughness and the occurrence of leprous tool mark before and after polishing were compared. As a result, the surface roughness and the occurrence of leprous tool mark were improved.


Author(s):  
Fangyan Zheng ◽  
Lin Hua ◽  
Dingfang Chen ◽  
Xinghui Han

Noncircular bevel gears are applied in variable-speed transmissions with intersecting axes. Since dedicated machines for manufacturing noncircular bevel gears are not available, noncircular bevel gears are normally manufactured using universal computer numerically controlled (CNC) machining centers, resulting in poor productivity. This paper describes a face-milling method for generation of noncircular spiral bevel gears, which is analogous to the generation of spiral bevel and hypoid gears using CNC hypoid gear generators, such as Gleason free-form hypoid generators. As a result, the productivity is significantly improved. Based on the theory of gearing, this paper first describes the basic concept of generation of conjugate noncircular spiral bevel gears. Generation of the tooth surfaces using crown-gear generation concept is analytically discussed with association to the face-milling process of generation of the proposed noncircular spiral bevel gears. The tooth surface geometries are represented by the position vectors and normals. The kinematical model of free-form machines is developed. The machine motion parameters are determined based on the theoretically defined tooth surfaces using the crown-gear generation concept. The developed method is verified by manufacturing a real pair of noncircular spiral bevel gears with satisfactory contact patterns which agree well with those modeled using a commercial cae software program.


2018 ◽  
Vol 10 (7) ◽  
pp. 168781401879065 ◽  
Author(s):  
Shuai Mo ◽  
Shengping Zhu ◽  
Guoguang Jin ◽  
Jiabei Gong ◽  
Zhanyong Feng ◽  
...  

High-speed heavy-load spiral bevel gears put forward high requirement for flexural strength; shot peening is a technique that greatly improves the bending fatigue strength of gears. During shot peening, a large number of fine pellets bombard the surface of the metal target material at very high speeds and let the target material undergo plastic deformation, at the same time strengthening layer is produced. Spiral bevel gear as the object of being bombarded inevitably brought the tooth surface micro-morphology changes. In this article, we aim to reveal the effect of microtopography of tooth shot peening on gear lubrication in spiral bevel gear, try to establish a reasonable description of the microscopic morphology for tooth surface by shot peening, to reveal the lubrication characteristics of spiral bevel gears after shot peening treatment based on the lubrication theory, and do comparative research on the surface lubrication characteristics of a variety of microstructures.


Author(s):  
Zhen Chen ◽  
Ming Zeng

In this paper, an active design method of meshing line for a spiral bevel gear mechanism with nonrelative sliding is presented. First, the general meshing line equations for a nonrelative sliding transmission mechanism between two orthogonal axes are proposed based on the active design parameters. Then, parametric equations for contact curves on the drive and driven spiral bevel gears are deduced by coordinate transformation of the meshing line equations. Further to this, parametric equations for the tooth surface of each bevel gear are derived according to the conical spiral motion of a generatrix circle along the calculated contact curves. Finally, a set of numerical examples is presented based on two types of motion equation of the meshing points. Material prototypes are fabricated and experimentally tested to validate the kinematic performance of the functionally designed spiral bevel gear set.


Author(s):  
Zhang-Hua Fong ◽  
Chung-Biau Tsay

Abstract Kinematical optimization and sensitivity analysis of circular-cut spiral bevel gears are investigated in this paper. Based on the Gleason spiral bevel gear generator and EPG test machine, a mathematical model is proposed to simulate the tooth contact conditions of the spiral bevel gear set. All the machine settings and assembly data are simulated by simplified parameters. The tooth contact patterns and kinematic errors are obtained by the proposed mathematical model and the tooth contact analysis techniques. Loaded tooth contact patterns are obtained by the differential geometry and the Hertz contact formulas. Tooth surface sensitivity due to the variation of machine settings is studied. The corrective machine settings can be calculated by the sensitive matrix and the linear regression method. An optimization algorithm is also developed to minimize the kinematic errors and the discontinuity of tooth meshing. According to the proposed studies, an improved procedure for development of spiral bevel gears is suggested. The results of this paper can be applied to determine the sensitivity and precision requirements in manufacturing, and improve the running quality of the spiral bevel gears. Two examples are presented to demonstrate the applications of the optimization model.


2013 ◽  
Vol 415 ◽  
pp. 636-641
Author(s):  
Xiao Zhong Deng ◽  
Geng Geng Li ◽  
Bing Yang Wei

In order to solve the small cutting strip width and poor surface quality problems when spiral bevel gears are CNC machined by ball-end mills£¬a machining method of face milling spiral bevel gears by using a disc cutter with a concave end is presented. Based on the researches of spiral bevel gears geometry structure, through a bigger diameter disc cutter with a concave end selected, the setting order of cutter orientation angles changed, and the functions of cutter tilt and yaw angle separated, tooth surfaces machined with big cutting strip width and no bottom land gouge can be expected. Finally, taking a spiral bevel gear pair as an example, through machining and measurement experiments, the method feasibility and correctness are verified


Author(s):  
V. Simon

The design and advanced manufacture of face-hobbed spiral bevel gears on computer numerical control (CNC) hypoid generating machines is presented. The concept of face-hobbed bevel gear generation by an imaginary generating crown gear is established. In order to reduce the sensitivity of the gear pair to errors in tooth-surfaces and to the mutual position of the mating members, modifications are introduced into the teeth of both members. The lengthwise crowning of teeth is achieved by applying a slightly bigger lengthwise tooth flank curvature of the crown gear generating the concave side of pinion/gear tooth-surfaces, and/or by using tilt angle of the head-cutter in the manufacture of pinion/gear teeth. The tooth profile modification is introduced by the circular profile of the cutting edge of head-cutter blades. An algorithm is developed for the execution of motions on the CNC hypoid generating machine using the relations on the cradle-type machine. The algorithm is based on the condition that since the tool is a rotary surface and the pinion/gear blank is also related to a rotary surface, it is necessary to ensure the same relative position of the head cutter and the pinion on both machines.


2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Ligang Yao ◽  
Bing Gu ◽  
Shujuan Haung ◽  
Guowu Wei ◽  
Jian S. Dai

The purpose of this paper is to propose a pair of external and internal spiral bevel gears with double circular-arc in the nutation drive. Based on the movement of nutation, this paper develops equations of the tooth profiles for the gear set, leading to the mathematical modeling of the spiral bevel gear with a constant helical angle gear alignment curve, enabling the tooth surface to be generated, and permitting the theoretical contacting lines to be produced in light of the meshing function. Simulation and verification are carried out to prove the mathematical equations. Numerical control (NC) simulation of machining the external and internal double circular-arc spiral bevel gears is developed, and the spiral gears were manufactured on a NC milling machine. The prototype of the nutation drive is illustrated in the case study at the end of this paper.


1982 ◽  
Vol 104 (4) ◽  
pp. 743-748 ◽  
Author(s):  
R. L. Huston ◽  
J. J. Coy

An analysis of the surface geometry of spiral bevel gears formed by a circular cutter is presented. The emphasis is upon determining the tooth surface principal radii of curvature of crown (flat) gears. Specific results are presented for involute, straight, and hyperbolic cutter profiles. It is shown that the geometry of circular cut spiral bevel gears is somewhat simpler than a theoretical logarithmic spiral bevel gear.


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