Advanced Manufacture of Spiral Bevel Gears on CNC Hypoid Generating Machine

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Vilmos V. Simon

An algorithm is developed for the execution of motions on the computer numerical control (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. The algorithm is applied for the execution of motions on the CNC hypoid generator for the manufacture of spiral bevel gears, based on the machine tool setting variation on the cradle-type hypoid generator conducted by optimal polynomial functions up to the fifth-order. By using the corresponding computer program, the motion graphs of the CNC hypoid generator are determined for the manufacture of spiral bevel gears, based on the optimal variation in the velocity ratio in the kinematic scheme and on the variation in the cradle radial setting on a cradle-type generator.

Author(s):  
Vilmos V. Simon

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. The algorithm is applied for the execution of motions on the CNC hypoid generator for the manufacture of spiral bevel gears, based on the machine-tool setting variation on the cradle-type hypoid generator conducted by optimal polynomial functions up to 5th order. By using the corresponding computer program, the motion graphs of the CNC hypoid generator are determined for the manufacture of spiral bevel gears based on the optimal variation of the velocity ratio in the kinematic scheme and of the cradle radial setting on a cradle-type generator.


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.


2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Joël Teixeira Alves ◽  
Michèle Guingand ◽  
Jean-Pierre de Vaujany

The design of spiral bevel gears remains complex since tooth geometry and the resulting kinematic performance stem directly from the manufacturing process. Spiral bevel gear cutting up to now has relied on the works of several manufacturers. Recent advances in milling machine technology and computer aided manufacturing (CAM) now make it possible to manufacture good quality spiral bevel gears on a standard 5-axis milling machine. This paper describes the computer aided design (CAD) definition and manufacturing of spiral bevel gear tooth surfaces. Process performance is assessed by comparing the resulting surfaces after machining with the predefined CAD surfaces. This manufacturing process makes it possible to obtain geometry analytically, making design easier than with standard spiral bevel gears.


1991 ◽  
Vol 113 (2) ◽  
pp. 174-181 ◽  
Author(s):  
Z. H. Fong ◽  
Chung-Biau Tsay

A complete tooth geometry of the circular-cut spiral bevel gears has been mathematically modeled. The mathematical model has been divided into several independent modules, each representing an individual kinematic relation or tool-setting, with examples included. A comparison with the spiraloid model has also been made in this paper. The mathematical model can be applied to simulate and calculate the tooth profiles for the Duplex Method, Helical Duplex Method, Formate Method, and Modified Roll Method for circular-cut spiral bevel gears. It can also be applied to the computer numerical controlled (CNC) machining, computer-aided finite element stress analysis, and tooth contact analysis (TCA) for the spiral bevel gear.


Author(s):  
Vilmos V. Simon

In this study, a method is proposed for the advanced manufacture of face-hobbed spiral bevel gears on CNC hypoid generators with optimized tooth surface geometry. An optimization methodology is applied to systematically define optimal head-cutter geometry and machine tool settings to introduce optimal tooth modifications. The goal of the optimization is to simultaneously minimize tooth contact pressures and angular displacement error of the driven gear (the transmission error). The optimization is based on machine tool setting variation on the cradle-type generator conducted by optimal polynomial functions. An algorithm is developed for the execution of motions on the CNC hypoid generator using the relations on the cradle-type machine. Effectiveness of the method was demonstrated by using a face-hobbed spiral bevel gear example. Significant reductions in the maximum tooth contact pressure and in the transmission errors were obtained.


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.


2018 ◽  
Vol 939 ◽  
pp. 63-72
Author(s):  
Xi Ning Jiang ◽  
Yue Hai Sun ◽  
Xiao Hu Xie

A new type of machining method called half-spread-out helix modified roll is used to carry out numerical control machining and simulation of spiral bevel gears in this paper. The transformation from traditional machine tool adjustment parameters into processing input parameters of five-axis CNC machining center was realized. The simulated gear model of this machining method is obtained, and the coordinates of its tooth surface points are compared with points coordinates of theoretical tooth surface which are generated according to the traditional machining method. From the comparison, the correctness of this numerical control machining model is verified.


Author(s):  
Vasiliy V. Akimov ◽  
Sergey A. Lagutin ◽  
Andrey E. Volkov

The generating of two spiral bevel gears by the plane-top generating wheel with essentially different parameters of the head-cutter installation and motion is considered. For this case the necessary and sufficient conditions providing coincidence of normal vectors and surface curvatures in the designed point are presented as the vector equations system. The relations among blade pressure angle, head-cutter radius, radial distance, tool installation angle, machine centre to back, blank offset and velocity ratio are obtained. The developed methods make the opportunity to design equivalent machine-tool settings, to extend manufacturing possibilities of gear-cutting machines and to raise the load rating of the gear drive.


Friction ◽  
2021 ◽  
Author(s):  
Zongzheng Wang ◽  
Wei Pu ◽  
Xin Pei ◽  
Wei Cao

AbstractExisting studies primarily focus on stiffness and damping under full-film lubrication or dry contact conditions. However, most lubricated transmission components operate in the mixed lubrication region, indicating that both the asperity contact and film lubrication exist on the rubbing surfaces. Herein, a novel method is proposed to evaluate the time-varying contact stiffness and damping of spiral bevel gears under transient mixed lubrication conditions. This method is sufficiently robust for addressing any mixed lubrication state regardless of the severity of the asperity contact. Based on this method, the transient mixed contact stiffness and damping of spiral bevel gears are investigated systematically. The results show a significant difference between the transient mixed contact stiffness and damping and the results from Hertz (dry) contact. In addition, the roughness significantly changes the contact stiffness and damping, indicating the importance of film lubrication and asperity contact. The transient mixed contact stiffness and damping change significantly along the meshing path from an engaging-in to an engaging-out point, and both of them are affected by the applied torque and rotational speed. In addition, the middle contact path is recommended because of its comprehensive high stiffness and damping, which maintained the stability of spiral bevel gear transmission.


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