scholarly journals Application of Face-Gear Drives in Helicopter Transmissions

1994 ◽  
Vol 116 (3) ◽  
pp. 672-676 ◽  
Author(s):  
F. L. Litvin ◽  
J.-C. Wang ◽  
R. B. Bossler ◽  
Y.-J. D. Chen ◽  
G. Heath ◽  
...  
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Gear Ratio ◽  
Light Weight ◽  
Face Gear ◽  
Gear Design ◽  
Transmission Design ◽  
Torque Transmission ◽  
The Face ◽  
Gear Drives

The use of face-gears in helicopter transmissions was explored. A light-weight, split torque transmission design utilizing face-gears was described. Face-gear design is discussed. Topics included basic design geometry, tooth generation, limiting inner and outer radii, and recommendation for the gear ratio. Face-gear experimental studies were also included and the feasibility of face-gears in high-speed, high-load applications such as helicopter transmissions was demonstrated. Torque-split tests were performed and demonstrated an accurate split of torque using the face-gear concept.

scholarly journals Application of Face-Gear Drives in Helicopter Transmissions

1992 ◽  
Author(s):  
F. L. Litvin ◽  
J.-C. Wang ◽  
R. B. Bossler ◽  
Y.-J. D. Chen ◽  
G. Heath ◽  
...  
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Contact Ratio ◽  
Face Gear ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Transmission Design ◽  
Torque Transmission ◽  
Gear Drives ◽  
Split Torque

Abstract The use of face gears in helicopter transmissions was explored. A light-weight, split torque transmission design utilizing face gears was described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. Analytical study of transmission error showed face-gear drives were relatively insensitive to gear misalignment, but tooth contact was affected by misalignment. A method of localizing bearing contact to compensate for misalignment was explored. The proper choice of shaft support stiffness enabled good load sharing in the split torque transmission design. Face-gear experimental studies were also included and the feasibility of face gears in high-speed, high-load applications such as helicopter transmissions was demonstrated.

scholarly journals Numerical Simulation Investigation on the Windage Power Loss of a High-Speed Face Gear Drive

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2093 ◽  
Author(s):  
Yu Dai ◽  
Feiyue Ma ◽  
Xiang Zhu ◽  
Jifu Jia
Keyword(s):  
Power Loss ◽  
High Speed ◽  
Outer Radius ◽  
Face Gear ◽  
Optimal Distance ◽  
Inner Radius ◽  
Common Goals ◽  
Cfd Method ◽  
Gear Drives ◽  
The Impact

Reducing the energy consumption and improving the efficiency of high-speed transmission systems are increasingly common goals; the windage power loss is not negligible in these methods. In this work, the multi-reference frame (MRF) and periodic boundary conditions (PBC) based on the computational fluid dynamics (CFD) method were adopted to investigate the windage phenomena of a single face gear with and without a shroud, and the impact of the gear speed on the windage power loss was analyzed. Furthermore, the effects on the distribution of static pressure due to the distances between the shroud and the gear body in different directions, including the outer radius direction, the inner radius direction, and the addendum direction were investigated. The results indicate that the gear speed significantly affected the windage loss, as the higher the gear speed was, the greater the windage power loss. Additionally, the shroud could effectively reduce the windage power loss, where the optimal distance from the addendum to the shroud was not the minimum distance; however, for the distances from the shroud to the inner radius and the outer radius, the smaller the distance was, the smaller the windage loss. The results can provide a theoretical basis and technical reference for reducing the windage power loss of various face gear drives.

Two-Stage Precession Type Gear: Design, Geometric and Kinematic Analysis

2017 ◽  
Author(s):  
Łukasz Macyszyn ◽  
Adam Myszkowski ◽  
Roman Staniek ◽  
Stanisław Pabiszczak
Keyword(s):  
Gear Ratio ◽  
Original Method ◽  
Two Stage ◽  
Precession Angle ◽  
Gear Design ◽  
The Face ◽  
Gear Efficiency ◽  
Rotary Speed ◽  
Gear Wheels ◽  
Neodymium Magnets

The paper presents the theoretical bases, design and the principle of operation of two-stage precession type transmission with face meshing. Description and the principle of forming the face meshing which is modified by the original method have been shown as well. Dimensional relations between particular components of the gears are established and the analysis of optimal gear ratio, depending on the number of teeth or magnets on the circumferences of meshing gear wheels is also provided in the paper. For further analysis four prototypes of mechanical precession transmission with face meshing were designed, built and investigated. Those prototypes present different sizes, reduction ratio and precession angle. Investigations, described in the paper, helped to determine the gear efficiency rate as well as the maximal torque that could be transferred for the given rotary speed. This paper presents also the conception of the design of a novel double stage precession magnetic gear with face neodymium magnets. The results of the initial studies are the background of the further research in the field of magnetic precession type transmission.

Offset Face Gear Drives: Tooth Geometry and Contact Analysis

1997 ◽  
Vol 119 (1) ◽  
pp. 114-119 ◽  
Author(s):  
Y. Zhang ◽  
Z. Wu
Keyword(s):  
Contact Analysis ◽  
Tooth Surface ◽  
Generation Process ◽  
Surface Geometry ◽  
Face Gear ◽  
Tooth Contact Analysis ◽  
Tooth Contact ◽  
Gear Design ◽  
Gear Drives ◽  
Meshing Process

This paper presents a detailed investigation on the manufacturing, tooth geometry and contact characteristics of face gear drives with offset axes. In the paper, the tooth geometry of offset face gears is analytically determined by simulating the conjugate motion between the gear and the cutting tool in the generation process. Design criteria are established for the optimal tooth element proportions of offset face gears that avoid tooth undercutting and pointing. The tooth surface geometry of the gear member of the drive is modified by using a shaper that resembles the pinion in profile but has a few more teeth than the pinion to localize the tooth contact. The contact characteristics of the offset face gears are analyzed by a tooth contact analysis (TCA) program that simulates the meshing process of the gear drive assembled under misalignment. An example of offset face gear design and contact analysis is included in the paper.

Performance simulations of engine-gearbox combinations for lightweight passenger cars

2001 ◽  
Vol 215 (2) ◽  
pp. 259-271 ◽  
Author(s):  
P Soltic ◽  
L Guzzella
Keyword(s):  
Fuel Consumption ◽  
High Speed ◽  
Gear Ratio ◽  
Published Data ◽  
Passenger Cars ◽  
Gear Drive ◽  
Different Types ◽  
Variable Transmission ◽  
Low Efficiency ◽  
Gear Drives

This paper compares the fuel consumption of lightweight passenger cars with three different types of engine (one low speed and one high speed naturally aspirated spark ignited, one turbo-charged compression ignited) and two different types of transmission [continuously variable transmission (CVT) and automated gear drive]. All fuel consumption results are obtained using a quasi-static driving cycle simulator. The implemented models are described in detail. The engines are represented through their eficiency maps, which are obtained by scaling published data. Effciency of the transmission (CVT or gear drive) is modelled in dependence on speed, torque and gear ratio. The simulations show that low fuel consumption can be achieved with all those concepts. CVTs show similar results to automated gear drives. The CVT's theoretical advantage of operating the engine at its most fuel-efficient points is compensated by the relatively low efficiency.

Study on the Machining Mathematical Model and Simulation of Face-Gear with Curvilinear Shaped Teeth Based on the Local Conjugate Theory of Gearing

2012 ◽  
Vol 462 ◽  
pp. 105-108
Author(s):  
Wen Jin Wang ◽  
Jing Zhang ◽  
Jian Zhao ◽  
Ling Li Zhang ◽  
Tai Yong Wang
Keyword(s):  
Mathematical Model ◽  
Differential Geometry ◽  
Contact Ratio ◽  
Face Gear ◽  
Cutting Simulation ◽  
Model And Simulation ◽  
The Face ◽  
Bending Stresses ◽  
Gear Drives

A curvilinear-tooth face-gear has been developed in order to obtain a high contact ratio, reduced bending stresses and lower sliding velocities compared to the spur and helical involute face-gear drives. The machining method for this type of gear was studied based on the differential geometry and meshing theory in this paper. The cutting mathematical model of the face-gear was established, and then the cutting simulation of the face-gear was developed.

scholarly journals DETERMINATION OF DYNAMIC LOADS IN TRANSMISSIONS TRACKED FOREST MACHINE WHILE OVERCOMING OBSTACLES

2017 ◽  
Vol 7 (1) ◽  
pp. 185-196
Author(s):  
Клубничкин ◽  
Vladislav Klubnichkin ◽  
Клубничкин ◽  
Evgeniy Klubnichkin ◽  
Бухтояров ◽  
...  
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Dynamic Loads ◽  
Pilot Studies ◽  
Torque Transmission ◽  
Characteristic Species ◽  
Final Drive

The theoretical analysis of dynamic phenomena in transmission tracked forest machine is much more difficult in the absence of experimental data on the effects of the input characteristic of the machine. The most characteristic species in the transmission effects that arise under real operating conditions allow to evaluate the results of experimental studies, they also provide an opportunity to assess the quality of theoretical studies. To determine the loading of the transmission in the experiment involves the measurement of a number of kinematic and power parameters characterizing the speed and stress state of the transmission. In the course of the research used a special measuring equipment made in Germany includes the high-speed digital telemetry system for strain "TEL1-PCM-HS" company KMT. This article describes how to determine the dynamic load transmission elements tracked forest machine LZ-5 in overcoming individual barriers in experimental studies (tests). The paper presents a program of pilot studies tracked forest machine. Presented curves change the time settings on the final drives and cardan shaft, depending on the speed of the engine and drive sprockets in overcoming obstacles GLZM with different gears. histograms were constructed on the distribution of the torque transmission shafts for various modes of overcoming obstacles in order to analyze the influence of operational factors on the magnitude of dynamic loads. The article presents the distribution curve of the moments on the driven shaft final drive to overcome obstacles tracked forest machine with a pack assortments in the volume of 12m3. It was noted that there are no less than 20 times the dynamic point values, which exceed the estimated time for the overcoming of obstacles. From the studies that the transmission level of at least dynamic forces having height obstacles.

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

2012 ◽  
Vol 227 (4) ◽  
pp. 779-793 ◽  
Author(s):  
Chao Lin ◽  
Hai Gong ◽  
Ning Nie ◽  
Qinlong Zen ◽  
Lei Zhang
Keyword(s):  
Design Method ◽  
Angular Displacement ◽  
Three Dimensional ◽  
Angular Acceleration ◽  
Gear Ratio ◽  
Tooth Surface ◽  
Coordinate Systems ◽  
Face Gear ◽  
Gear Drive ◽  
The Face

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 orthogonal fluctuating gear ratio face gear drive is found based on the space engagement theory. The equation of the pitch curve, addendum curve and dedendum curve of face gear are derived. The design method of tooth surface of the face gear is available based on the envelope method. The conversion relationship of enveloping coordinate systems is obtained during the enveloping process of orthogonal fluctuating gear ratio face gear drive after the establishment of enveloping coordinate systems. Then combining with equation of generating surface, the tooth surface equation of the face gear is obtained. The three-dimensional model of orthogonal fluctuating gear ratio face gear is acquired on the basis of a modeling program, which is developed under the environment of VB and Solidworks (API). Furthermore, localization of the bearing contact is achieved by the manufacturing method and it is justified by the finite element method analysis result. Finally, the kinematics of the orthogonal fluctuating gear ratio face gear drive is analyzed, and the change laws of transmission ratio, angular displacement and angular acceleration of the face gear are acquired.

Design, Generation and Bending Stress Analysis of Face-Gear with Curvilinear Shaped Teeth

2012 ◽  
Vol 472-475 ◽  
pp. 74-77
Author(s):  
Wen Jin Wang ◽  
Jing Zhang ◽  
Jian Zhao ◽  
Ling Li Zhang ◽  
Tai Yong Wang
Keyword(s):  
Stress Analysis ◽  
Tooth Surface ◽  
Surface Model ◽  
Bending Stress ◽  
Contact Ratio ◽  
Face Gear ◽  
The Face ◽  
Bending Stresses ◽  
Design Generation ◽  
Gear Drives

A curvilinear-tooth face-gear has been developed in order to obtain a high contact ratio, reduced bending stresses and lower sliding velocities compared to the spur and helical involute face-gear drives. The generation of the face gear is based on application of a tilted head-cutter whereas the conventional method of generation is based on application of a hob. The tooth surface model of the face-gear is established, and then bending stress analysis is performed by using Finite Element Method. The developed theory is illustrated with numerical examples.

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