Limitations of Conjugate Gear Tooth Surfaces in Order to Avoid Undercutting and Appearance of Envelope of Lines of Contact

1988 ◽  
Author(s):  
F. L. Litvin ◽  
D. J. Kin ◽  
Y. Zhang
Keyword(s):  
Computer Graphics ◽  
Gear Tooth ◽  
Worm Gear ◽  
Singular Points ◽  
Line Contact ◽  
Gear Drive ◽  
Pressure Angle ◽  
Tooth Surfaces ◽  
Limiting Pressure

Abstract Gear tooth surfaces being in line contact at every instant are considered. The dimensions of the contacting surfaces must be limited in order to avoid: (i) the appearance of the envelope of lines of contact on the generating surface Σ1 and (ii) the appearance of singular points on the generated surface Σ2. The relations between the developed concepts and the Wildhaber’s concept of the limiting pressure angle are investigated. Applications to the worm-gear drive and the generation of a pinion of a formate gear drive are considered. Computer graphics have been used to illustrate the results of computation.

Limitations of Conjugate Gear Tooth Surfaces

1990 ◽  
Vol 112 (2) ◽  
pp. 230-236 ◽  
Author(s):  
F. L. Litvin ◽  
V. Kin ◽  
Y. Zhang
Keyword(s):  
Computer Graphics ◽  
Gear Tooth ◽  
Worm Gear ◽  
Singular Points ◽  
Line Contact ◽  
Gear Drive ◽  
Pressure Angle ◽  
Tooth Surfaces ◽  
Limiting Pressure

Gear tooth surfaces being in line contact at every instant are considered. The dimensions of the contacting surfaces must be limited in order to avoid: (a) the appearance of the envelope of lines of contact on the generating surface Σ1, and (b) the appearance of singular points on the generated surface Σ2. The relations between the developed concepts and Wildhaber’s concept of the limiting pressure angle are investigated. Applications to the worm-gear drive and the generation of a pinion of a Formate gear drive are considered. Computer graphics have been used to illustrate the results of computation.

Computerized Design, Generation and Simulation of Meshing and Contact of Modified Flender Worm-Gear Drives

1996 ◽  
Author(s):  
I. H. Seol ◽  
Faydor L. Litvin
Keyword(s):  
Gear Tooth ◽  
Worm Gear ◽  
Numerical Examples ◽  
Transmission Errors ◽  
Gear Drive ◽  
Bearing Contact ◽  
Tooth Surfaces ◽  
Design Generation ◽  
Computerized Simulation ◽  
Gear Drives

Abstract The worm and worm-gear tooth surfaces of existing design of Flender gear drive are in line contact at every instant and the gear drive is very sensitive to misalignment. Errors of alignment cause the shift of the bearing contact and transmission errors. The authors propose : (1) Methods for computerized simulation of meshing and contact of misaligned worm-gear drives of existing design (2) Methods of modification of geometry of worm-gear drives that enable to localize and stabilize the bearing contact and reduce the sensitivity of drives to misalignment (3) Methods for computerized simulation of meshing and contact of worm-gear drives with modified geometry The proposed approach was applied as well for the involute (David Brown) and Klingelnberg type of worm-gear drives. Numerical examples that illustrate the developed theory are provided.

Computerized Design, Generation and Simulation of Meshing and Contact of Modified Involute, Klingelnberg and Flender Type Worm-Gear Drives

1996 ◽  
Vol 118 (4) ◽  
pp. 551-555 ◽  
Author(s):  
I. H. Seol ◽  
F. L. Litvin
Keyword(s):  
Gear Tooth ◽  
Worm Gear ◽  
Numerical Examples ◽  
Transmission Errors ◽  
Gear Drive ◽  
Bearing Contact ◽  
Tooth Surfaces ◽  
Design Generation ◽  
Computerized Simulation ◽  
Gear Drives

The worm and worm-gear tooth surfaces of existing worm-gear drive designs are in line contact at every instant and the gear drive is very sensitive to misalignment. Errors of alignment cause shifting of the bearing contact and transmission errors. Methods for computerized simulation of meshing and contact of misaligned worm-gear drives of existing design are proposed. Also, modification of worm-gear drive geometry that provides a localized and stable bearing contact with reduced sensitivity to misalignment is described. Methods for computerized simulation of meshing and contact of worm-gear drives with the existing and modified geometry are represented. Numerical examples that illustrate the developed theory are provided. The proposed approach has been applied for modification of involute, Klingelnberg and Flender type worm-gear drives.

Computerized Simulation of Transmission Errors and Shift of Bearing Contact for Hypoid Gear Drive With Conjugate Gear Tooth Surfaces

1994 ◽  
Author(s):  
Faydor L. Litvin ◽  
Jui-Sheng Chen ◽  
Thomas M. Sep ◽  
Jyh-Chiang Wang
Keyword(s):  
Gear Tooth ◽  
Low Noise ◽  
Linear Functions ◽  
Hypoid Gear ◽  
Transmission Errors ◽  
Gear Drive ◽  
Bearing Contact ◽  
Parabolic Function ◽  
Tooth Surfaces ◽  
Computerized Simulation

Abstract Computerized investigation of the influence of alignment errors on the transmission errors and the shift of the bearing contact is proposed. The investigation is performed for an imaginary hypoid gear drive with conjugate tooth surfaces. It is proven that the transmission functions caused by misalignment are periodic discontinues almost linear functions with the frequency of cycle of meshing. The above functions can be totally absorbed by a predesigned parabolic function. The shift of the bearing contact caused by misalignment has been determined as well. The performed investigation is based on computerized simulation of meshing and contact of gear tooth surfaces. The machine-tool settings for the generation of the designed gear drive have been determined. Numerical example that illustrates the developed theory is given. The performed investigation allows to determine the influence of gear misalignment on transmission errors, and design a low-noise hypoid gear drive by a properly predesigned parabolic function of transmission errors.

Tooth Undercutting of Beveloid Gears

2000 ◽  
Author(s):  
Chia-Chang Liu ◽  
Chung-Biau Tsay
Keyword(s):  
Gear Tooth ◽  
Singular Points ◽  
Tooth Surface ◽  
Involute Gear ◽  
Beveloid Gears ◽  
Tooth Surfaces

Abstract A beveloid gear can be viewed as an involute gear of which the profile-shifted coefficient linearly decreases from the heel to the toe. Therefore, tooth undercutting occurs and singular points appear on the tooth surfaces near the toe. When undercutting occurs, the gear tooth is comparatively weak. In this study, the conditions of tooth undercutting of beveloid gears were derived and specific phenomena were also investigated by numerical illustrated examples. In addition, according to the characteristics of tooth undercutting on the beveloid gear tooth surface, a novel type hob cutter with varying cutting depths was designed to avoid tooth undercutting of the beveloid gear.

scholarly journals Geometry and design of spur gear drive associated with low sliding ratio

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110125
Author(s):  
Wei Sheng ◽  
Zhengminqing Li ◽  
Hong Zhang ◽  
Rupeng Zhu
Keyword(s):  
Gear Tooth ◽  
Tooth Wear ◽  
Spur Gear ◽  
Transmission Efficiency ◽  
Contact Ratio ◽  
Gear Drive ◽  
Solid Models ◽  
Tooth Surfaces ◽  
The Relationship ◽  
Cubic Function

The relative sliding between tooth surfaces is the main cause of tooth wear and power loss, which directly affects the transmission efficiency and durability of gear. The aim of this paper is to provide a method to design such spur gear with low sliding ratio (LSR). Based on kinematics, differential geometry and contact path, the general mathematical models of the generating rack, the pinion and the mating gear tooth profiles are established in turn. Then, according to the relationship between the contact path and sliding ratio, a contact path described by a cubic function is proposed to construct a spur gear drive with low sliding ratio. In order to ensure the continuity of action and non-interference, solid models of the mated gear pair are established, and the motion simulation is carried out by an example. Moreover, the effects of the contact path function coefficients on sliding ratio, tooth shape, and contact ratio are analyzed. Meshing efficiency and tooth wear of LSR gear drive are evaluated by comparing with those of the involute gear drive. The results show that, this LSR spur gear drive has higher transmission efficiency and better anti-wear performance.

Tooth Undercutting of Beveloid Gears

2000 ◽  
Vol 123 (4) ◽  
pp. 569-576 ◽  
Author(s):  
Chia-Chang Liu ◽  
Chung-Biau Tsay
Keyword(s):  
Gear Tooth ◽  
Singular Points ◽  
Tooth Surface ◽  
Involute Gear ◽  
Beveloid Gears ◽  
Tooth Surfaces

A beveloid gear can be viewed as an involute gear of which the profile-shifted coefficient linearly decreases from the heel to the toe. Therefore, tooth undercutting occurs and singular points appear on the tooth surfaces near the toe. When undercutting occurs, the gear tooth is comparatively weak. In this study, the conditions of tooth undercutting of beveloid gears were derived and specific phenomena were also investigated by numerical illustrated examples. In addition, according to the characteristics of tooth undercutting on the beveloid gear tooth surface, two practicable methods were also proposed to avoid the tooth undercutting of beveloid gears.

Load Distribution in Cylindrical Worm Gears

2000 ◽  
Author(s):  
Vilmos V. Simon
Keyword(s):  
Load Distribution ◽  
Gear Tooth ◽  
Point Contact ◽  
Transmission Error ◽  
Worm Gear ◽  
Gear Teeth ◽  
Total Transmission ◽  
Transmission Errors ◽  
Gear Drive ◽  
Worm Gears

Abstract A method for the determination of load sharing between the instantaneously engaged worm threads and gear teeth, for the calculation of load distribution along the teeth and transmission errors in different types of cylindrical worm gears is presented. The method covers both cases — that of the theoretical line and point contact. The bending and shearing deflections of worm thread and gear tooth, the local contact deformations of the mating surfaces, the axial deformations of worm body, gear body bending and torsion, deflections of the supporting shafts, and the manufacturing and alignment errors of worm and gear are included. Based on the real load distribution the tooth contact pressure is calculated, in the case of point contact in two different ways, and the obtained results are compared. Also, the total transmission error, consisting of the kinematical transmission error due to the mismatch of the worm gear drive and of the transmission error caused by the deflections of worm thread and gear teeth, is calculated. The method is implemented by a computer program. By using this program the influence of the type of worm gear drive and of design and manufacturing parameters on load distribution and transmission errors is investigated and discussed.

Load Distribution in Cylindrical Worm Gears

2003 ◽  
Vol 125 (2) ◽  
pp. 356-364 ◽  
Author(s):  
Vilmos Simon
Keyword(s):  
Load Distribution ◽  
Gear Tooth ◽  
Point Contact ◽  
Transmission Error ◽  
Worm Gear ◽  
Gear Teeth ◽  
Total Transmission ◽  
Transmission Errors ◽  
Gear Drive ◽  
Worm Gears

A method for the determination of load sharing between the instantaneously engaged worm threads and gear teeth, for the calculation of load distribution along the teeth and transmission errors in different types of cylindrical worm gears is presented. The method covers both cases—that of the theoretical line and point contact. The bending and shearing deflections of worm thread and gear tooth, the local contact deformations of the mating surfaces, the axial deformations of worm body, gear body bending and torsion, deflections of the supporting shafts, and the manufacturing and alignment errors of worm and gear are included. Based on the real load distribution the tooth contact pressure is calculated, in the case of point contact in two different ways, and the obtained results are compared. Also, the total transmission error, consisting of the kinematical transmission error due to the mismatch of the worm gear drive and of the transmission error caused by the deflections of worm thread and gear teeth, is calculated. The method is implemented by a computer program. By using this program the influence of the type of worm gear drive and of design and manufacturing parameters on load distribution and transmission errors is investigated and discussed.

Computerized Simulation of Transmission Errors and Shift of Bearing Contact for Face-Milled Hypoid Gear Drive

1995 ◽  
Vol 117 (2A) ◽  
pp. 262-268 ◽  
Author(s):  
F. L. Litvin ◽  
Jui-Sheng Chen ◽  
T. M. Sep ◽  
Jyh-Chiang Wang
Keyword(s):  
Gear Tooth ◽  
Transmission Error ◽  
Linear Functions ◽  
Hypoid Gear ◽  
Transmission Errors ◽  
Gear Drive ◽  
Bearing Contact ◽  
Tooth Surfaces ◽  
Computerized Simulation ◽  
Alignment Errors

A computerized investigation of the influence of alignment errors on the transmission errors and the shift of the bearing contact is performed. The investigation is performed for an imaginary hypoid gear drive with conjugate tooth surfaces. The transmission error functions caused by misalignment are shown to be periodic discontinuous almost linear functions with the frequency of the cycle of meshing. The above functions can be totally absorbed by a predesigned parabolic function. The shift of the bearing contact caused by misalignment has been determined as well. The investigation is based on computerized simulation of meshing and contact of gear tooth surfaces. The machine-tool settings for the generation of the designed gear drive have been determined. A numerical example that illustrates the developed theory is given.

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