Gearing principle and geometric design of conical involute gear pairs with crossed axes

Author(s):  
J He ◽  
X Wu ◽  
Y Cui

A group of formulae for the geometric parameters, such as the gear mounting distance, crossed-axes angle, centre distance and helix angle of the tooth projection on the reference plane of a reference rack, of a crossed-axes gear drive of different arrangements are derived based on the analysis of the spatial mesh relationship between conjugate gears and their reference rack. A set of geometrical design methods for conical involute gear pairs with crossed axes (non-intersecting and non-parallel axes) is presented. The formulae can be applied not only to all of the possible independent forms of crossed-axes gear drives but also to the case of gearing with parallel axes and intersecting axes. The design methods consist of two parts, the sequential and the reverse methods. The former is used to determine the mounting dimensions when the basic dimensions of a pair of conical involute gears are given, while the latter is used to determine basic dimensions of a pair of gears when the mounting dimensions are known. The formulae and the methods are verified through the design and manufacture of a set of testing gears.

2019 ◽  
Vol 287 ◽  
pp. 01006
Author(s):  
Ognyan Alipiiev

An important part of “Generalized theory”, developed by the author of this article, is the “bidirectional modification” of involute gears. The main point of the proposed modification is that together with the traditional “radial modification” of the basic rack, an additional “tangential modification” of the side profiles of the rack-cutters is introduced. As a result, the area of possible existence of involute gear drives in the generalized theory is considerably extended. Based on the bidirectional modification, a new classification of involute gears at their meshing with a rack cutter is proposed. The classification is characterized by a significant variety, which is composed of thirteen different types of gears: a zero gear; two radially modified gears; two tangentially modified gears and eight two-way modified gears. Based on the bidirectional modification in radial and tangential directions, a new classification of the involute gear drives is proposed. The classification is composed of sixteen different types of gear drives: a zero gear drive, three equally-modified gear drives; two balanced gear drives; five positive gear drives and five negative gear drives.


2016 ◽  
Vol 68 (6) ◽  
pp. 671-675 ◽  
Author(s):  
Zhimin Fan ◽  
Wanfeng Zhou ◽  
Ruixue Wang ◽  
Na Wang

Purpose The purpose of this paper is to derive a new lubrication model of double involute gears drive and study the effect of the tooth waist order parameters of double involute gears on lubrication performance. Design/methodology/approach The new lubrication model of double involute gears drive was established according to the meshing characteristics of double involute gears drive and the finite length line contact elastohydrodynamic lubrication theory. Numerical calculation of the lubrication model of gear drive was conducted using the multigrid method. Findings The results show that the oil film necking phenomenon and the oil film pressure peak emerged at the tooth waist order area and the tooth profile ends, and when compared with involute gear, the lubrication performance at the tooth waist order area is better than that at the tooth profile ends. The effect of tooth waist order parameters on lubrication performance at the tooth waist order area was greater than that at other areas. Originality/value This research will promote the application of the double involute gear as soon as possible, and it has the reference value for other types of gears.


2012 ◽  
Vol 155-156 ◽  
pp. 1050-1055
Author(s):  
Lei Liu ◽  
Zhu Qing Huang

A novel torus-involute gear transmission is presented in this paper. There are two types of tooth profiles for torus-involute gears: convex tooth and concave tooth. Torus-involute gears are non-sensitive to axial misalignments and allow variable shaft angle without meshing interference. Based on revealing of essence for tooth profiles, introducing the parameter t and discretizing this type of gear into tiny linear continuous corrected gears, a design method is proposed. To testify whether the transmission ratio of torus-involute gear transmission is constant, simulation is implemented in commercial codes ADAMS. The computed results show that this novel gear drive can achieve a constant transmission ratio with variable shaft angle.


1973 ◽  
Vol 95 (4) ◽  
pp. 1131-1138 ◽  
Author(s):  
E. I. Radzimovsky ◽  
A. Mirarefi ◽  
W. E. Broom

In this work the authors, using a testing machine designed for this investigation, determined experimentally the variation in the friction losses in gearing during an individual tooth engagement period. Based upon the obtained data “instantaneous efficiency” of various gear drives and the variation of “apparent coefficient of friction” during the engagement period were evaluated. This “apparent” or “effective” coefficient of friction is a coefficient which represents the effect of the friction due to rolling or a combination of rolling and sliding motion between the engaged teeth in the gear drives. The instantaneous coefficients of friction in the gearing during the engagement cycle were obtained for a large number of different operational conditions. The following factors were used as variable parameters: the torque transmitted by the gears, the speed of gear rotation, the diametral pitch, and the contact ratio of the gearing.


Author(s):  
S H Wu ◽  
S J Tsai

A novel design for skew conical involute gear drives in approximate line contact is proposed. Such a drive has a contact ellipse with a large major-to-minor-axis ratio, which allows it to overcome the weakness of conical gear drives for application in power transmission. This gearing design approach is characterized by reduced edge contact sensitivity and increased surface durability. The edge contact sensitivity that can arise with this kind of gear drive due to assembly or manufacturing errors is evaluated by analysing the value of the shift of the line of action caused by such errors. The surface durability is evaluated by calculating the Hertz stress. Some guidelines are developed based on the analysis of the influence of the gearing parameters on the edge contact sensitivity and the surface durability made possible using this design approach for conical gear drives in the approximate line contact. The guidelines are summarized and, finally, a practical example is given to demonstrate the feasibility of the approximate line contact design.


2010 ◽  
Vol 20-23 ◽  
pp. 1385-1390
Author(s):  
Hong Bin Yang ◽  
Xiao Hong Wang ◽  
Zong De Fang

To develop a good quality of hypoid gear drive, the authors test the vibration and noise of two kinds of hypoid gear drives under different working conditions. The test object is a pair of hypoid gear drive used in the back axle of one minivan and a designed hypoid gear drive with high teeth based on the former. The results indicate that the hypoid gear drive with high teeth has lower vibration and noise.


2016 ◽  
Vol 46 (2) ◽  
pp. 3-26 ◽  
Author(s):  
Valentin Abadjiev ◽  
Emilia Abadjieva

Abstract Hyperboloid gear drives with face mating gears are used to transform rotations between shafts with non-parallel and non-intersecting axes. A special case of these transmissions are Spiroid and Helicon gear drives. The classical gear drives of this type are the Archimedean ones. The objective of this study are hyperboloid gear drives with face meshing, when the pinion possesses threads of conic convolute, Archimedean and involute types, or the pinion has threads of cylindrical convolute, Archimedean and involute types. For simplicity, all three types transmis- sions with face mating gears and a conic pinion are titled Spiroid and all three types transmissions with face mating gears and a cylindrical pinion are titled Helicon. Principles of the mathematical modelling of tooth contact synthesis are discussed in this study. The presented research shows that the synthesis is realized by application of two mathematical models: pitch contact point and mesh region models. Two approaches for synthesis of the gear drives in accordance with Olivier’s principles are illustrated. The algorithms and computer programs for optimization synthesis and design of the studied hyperboloid gear drives are presented.


Author(s):  
I. H. Seol ◽  
Faydor L. Litvin

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.


2012 ◽  
Vol 215-216 ◽  
pp. 974-977 ◽  
Author(s):  
Li Ming Lian ◽  
Gui Min Liu

The dynamic performance of asymmetric involute gear transmission system is analyzed by the MSC.ADAMS software during the paper. By comparative analyzed with the traditional dynamic characteristics of symmetrical involute straight gear transmission, it can be summarized that the asymmetric involute gear transmission system has better vibration characteristics in the course of transmission.


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