scholarly journals Influence of Optimal Tooth Modifications on Dynamic Characteristics of a Vehicle Gearbox

2019 ◽  
Vol 16 (1) ◽  
pp. 6319-6331
Author(s):  
Najeeb Ullah ◽  
T. Cong ◽  
B. Huan ◽  
H. Yucheng
Keyword(s):  
Contact Stress ◽  
Gear Tooth ◽  
Transmission Error ◽  
Optimum Level ◽  
Contact Pattern ◽  
Gear Noise ◽  
Tooth Modification ◽  
Proposed Modification ◽  
The Impact ◽  
Central Gear

Considering the practical problems of gear noise and vibration, this work focuses on the gearbox of the electric vehicle as the research object to analyse the impact of gear micro-tooth modification. First of all, the effort centres itself on minimising the contact stress and making the load distribution better by implementing the tooth modification on both upper and central speed phases. The procedural analysis of gear tooth modification is executed to make the contact pattern better, so edge contact has been avoided and the load is distributed over a wide area of the tooth for both upper and central gear sets. The contact pattern is positioned in the centre of teeth and contact stress is lowered by 20% to 837 MPA. Then, the peak to peak transmission error is decreased under three proposed modification approaches. Also, contact and bending safety factors are improved as a result of tooth modification. Meanwhile, it was noticed by performing dynamic analysis that right bearings of both upper and central phases have a higher radial response for first two orders which is further decreased to an optimum level as a result of micro-tooth modification strategies.

Effects of the Gear Tooth Modification on the Nonlinear Dynamics of Gear Transmission System

2010 ◽  
Vol 97-101 ◽  
pp. 2764-2769
Author(s):  
Si Yu Chen ◽  
Jin Yuan Tang ◽  
C.W. Luo
Keyword(s):  
Nonlinear Dynamics ◽  
Gear Tooth ◽  
Simulation Method ◽  
Transmission Error ◽  
Dynamic Responses ◽  
Meshing Stiffness ◽  
Gear Transmission System ◽  
Tooth Modification ◽  
Static Transmission Error ◽  
Misalignment Error

The effects of tooth modification on the nonlinear dynamic behaviors are studied in this paper. Firstly, the static transmission error under load combined with misalignment error and modification are deduced. These effects can be introduced directly in the meshing stiffness and static transmission error models. Then the effect of two different type of tooth modification combined with misalignment error on the dynamic responses are investigated by using numerical simulation method. The numerical results show that the misalignment error has a significant effect on the static transmission error. The tooth crowning modification is generally preferred for absorbing the misalignment error by comparing with the tip and root relief. The tip and root relief can not resolve the vibration problem induced by misalignment error but the crowning modification can reduce the vibration significantly.

Whine Noise Development of Engine Timing Gear System in Heavy Duty Vehicle

2011 ◽  
Author(s):  
Sukil Oh ◽  
Koo-Tae Kang ◽  
Kang-Young Soh ◽  
Jung-Ho Kim
Keyword(s):  
Error Analysis ◽  
Gear Tooth ◽  
Transmission Error ◽  
Gear Train ◽  
Source Control ◽  
Heavy Duty ◽  
Diesel Vehicles ◽  
Tooth Modification ◽  
Heavy Duty Diesel ◽  
Vehicle Test

Gear train is the most applied in the heavy duty engine timing system on the benefit of reliability, durability, timing accuracy, maintenance, and high torque transmission. But the gear train is vulnerable to rattle and whine noise due to many serial gear connections, which lead to more possibility for gear backlash impact and gear transmission errors compared with chain and toothed meshed belt timing systems. Furthermore, normal heavy duty diesel vehicles like truck and bus are well vibration isolated from engine at gear noise frequency range. Therefore, noise source control is inevitable in the developing process in heavy duty diesel vehicles. The objective of this paper is to reduce timing gear whine noise in the engine developing process for heavy duty vehicles. Main focus is modification of gear tooth shape in the proto engine developing process considering vehicle driving modes. To investigate engine timing gear whine noise, transmission error analysis was executed in accordance with proto type gears and optimal gear tooth modification was induced by transmission error analysis, engine bench, and vehicle test.

Recent Progress and Prospect on Tooth Modification of Involute Cylindrical Gear

2021 ◽  
Vol 14 ◽  
Author(s):  
Lin Han ◽  
Yang Qi
Keyword(s):  
Load Distribution ◽  
Power Transmission ◽  
Gear Tooth ◽  
Transmission Error ◽  
Gear Pair ◽  
Cylindrical Gear ◽  
Tooth Width ◽  
Modification Method ◽  
Power Transmission Systems ◽  
Tooth Modification

Background: Recent reviews on tooth modification of involute cylindrical gear are presented. Gear pairs are widely employed in motion and power transmission systems. Manufacturing and assembling errors of gear parts, time-varying mesh stiffness and transmission error of gear pair, usually induce vibration, noise, non-uniformly load distribution and stress concentration, resulting in earlier failure of gear. Tooth modification is regarded as one of the most popular ways to suppress vibration, reduce noise level, and improve load distribution of gear pairs. Objective: To provide an overview of recent research and patents on tooth modification method and technology. Methods: This article reviews related research and patents on tooth modification. The modification method, evaluation, optimization and machining technology are introduced. Results: Three types of modifications are compared and analyzed, and influences of each on both static and dynamic performances of gear pair are concluded. By summarizing a number of patents and research about tooth modification of cylindrical gears, the current and future development of research and patent are also discussed. Conclusion: Tooth modification is classified into tip or root relief along tooth profile, lead crown modification along tooth width and compound modification. Each could be applied in different ways. In view of design, optimization under given working condition to get optimal modification parameters is more practical. Machining technology and device for modified gear is a key to get high quality performance of geared transmission. More patents on tooth modification should be invented in future.

A Study on Planetary Gear Dynamics With Tooth Profile Modification

2011 ◽  
Author(s):  
Cheon-Jae Bahk ◽  
Robert G. Parker
Keyword(s):  
Dynamic Response ◽  
Gear Tooth ◽  
Planetary Gear ◽  
Transmission Error ◽  
Tooth Profile ◽  
Peak Amplitude ◽  
Profile Modification ◽  
Tooth Profile Modification ◽  
Static Transmission Error ◽  
The Impact

This study investigates the impact of tooth profile modification on planetary gear dynamic response. Micro-scale geometric deviations from an involute gear tooth profile add an additional excitation source, potentially reducing gear vibration. In order to take account of the excitation, tooth profile modification is included in an analytical planetary gear model. Nonlinearity due to tooth contact loss is considered. Time-varying mesh stiffness and both rotational and translational gear motions are modeled. The accuracy of the proposed model for dynamic analysis is correlated against a benchmark finite element analysis. Perturbation analysis is employed to obtain a closed-form approximation of planetary gear dynamic response with tooth profile modification. Mathematical expressions from the perturbation solution allow one to easily estimate the peak amplitude of resonant response using known parameters. Variation of the peak amplitude with the amount and the length of profile modification illustrates the effect of tooth profile modification on planetary gear dynamic response. For a given external load, the tooth profile modification parameters for minimal response are readily obtained. Static transmission error and dynamic response are minimized at different amounts of profile modification, which contradicts common practical thinking regarding strong correlation between static transmission error and dynamic response. Contrary to the expectation of further reduced vibration, the combination of the optimum sun-planet and ring-planet mesh tooth profile modifications that minimizes response when applied individually increases dynamic response.

Transmission Error as Gear Noise Excitation

2009 ◽  
Author(s):  
Mats Henriksson ◽  
Yuet-Yan Pang
Keyword(s):  
Transmission Error ◽  
Gear Pair ◽  
Bending Moments ◽  
Contact Pattern ◽  
Gear Noise ◽  
Correlate Noise ◽  
Edge Contact ◽  
Measurement Result ◽  
Static Transmission Error ◽  
The Difference

Traditionally, transmission error (TE) has been used in order to asses the noise properties of gears. Measurements of gear noise for a complete truck gearbox have been used to correlate noise from a gear pair with the concept of calculated static transmission error as noise excitation. Two gear pairs with very similar macro geometry but different micro geometry was used. Both transmission error as excitation and the excitation proposed by P. Velex and M. Ajmi which is the difference between the loaded and unloaded transmission error, are compared with measured noise. The result shows that the difference between the loaded and unloaded TE correlates well with measure noise for gear pair A but no excitation correlates with the measurement result gear pair B. A big difference between gear pair A and B can be seen in the contact pattern. The contact pattern of gear pair B shows that despite a large tip relief, edge contact occurs where the tip relief starts. This can be one explanation to the lack of correlation between TE and the measurement result for gear pair B. Another explanation can be other excitations such as friction and bending moments. The results show the limitations of only considering transmission error when designing quiet gears.

A Study on Tooth Modification for Spur Gear for Articulated Hauler

2011 ◽  
Author(s):  
Qi Zhang ◽  
Zhezhu Xu ◽  
Sungki Lyu
Keyword(s):  
Load Distribution ◽  
Transmission Error ◽  
Spur Gear ◽  
Normal Operation ◽  
Noise Levels ◽  
Gear Noise ◽  
Before And After ◽  
Tooth Modification ◽  
Final Drive ◽  
Root Stress

Construction equipment is heavily loaded during normal operation. In recent years, there is a trend that lower gear noise levels are demanded for driver to avoid annoyance and fatigue of operation. For articulated haulers, meshing transmission error (T.E.) is the excitation that leads the tonal noise known as gear whine, and radiated gear whine is also the dominant source of noise in gearbox. This paper presents a method for the analysis of the tooth modification, and the prediction of transmission error under the loaded torque for the spur gear pair of the articulated hauler’s final drive. And the transmission error, contact stress, root stress and load distribution are also calculated and compared before and after tooth modification under one torque. The simulation result shows that the transmission error and stress under the load can be minimized by the appropriate tooth modification. It is a good approach where the simulated result is used to improve the design before the prototype is available for the test.

A Methodology to Experimentally Investigate the Impact of Wobble Errors on the Contact Pattern and Static Transmission Error of Helical Gear Pairs

2019 ◽  
Author(s):  
Michael Benatar ◽  
Michael Handschuh ◽  
Ahmet Kahraman ◽  
David Talbot
Keyword(s):  
Transmission Error ◽  
Helical Gear ◽  
Experimental Results ◽  
Gear Pair ◽  
Contact Pattern ◽  
Gear Mesh ◽  
Face Width ◽  
The Face ◽  
Static Transmission Error ◽  
The Impact

Abstract For a gear pair, both the contact pattern and the transmission error (TE) significantly impact durability and fatigue life. Design and manufacturing processes are often aimed at improving the contact pattern and reducing the overall TE. Other errors, such as runout and wobble, are often induced during the installation of power transmission systems, and they can alter the contact pattern and TE of an otherwise well-designed gear pair. This study provides a methodology to experimentally investigate the impact of wobble errors on the contact pattern and static transmission error (STE) of helical gears. It first provides a description of the modifications to an existing test machine. Next, it describes the gear specifications, preliminary testing matrix, data acquisition and processing procedure, as well as the experimental results obtained with regards to both the contact pattern and STE. The following are observed while describing the experimental results. For a test with no wobble and no runout, the contact pattern remains the same at every rotational position. However, by introducing even a small amount of wobble, the contact will shift from one side of the face width of the gear to the opposite side of the face width of the gear within one revolution. Introduction of wobble may increase the STE and sideband activity around gear mesh harmonics, especially as torque increases. Yet the modest increases in STE and sideband activity seen with the introduction of wobble are not enough to make definitive conclusions. The feasibility of the modified test setup has been demonstrated, and preliminary results have been presented. However, additional data collection should be completed in order to study the impact of runout and wobble on both spur and helical gear pairs with various microgeometry modifications and manufacturing errors.

scholarly journals An Experimental Investigation of the Impact of Random Spacing Errors on the Dynamic Transmission Error of Spur Gear Pairs

2019 ◽  
Author(s):  
Muhammad Nevin Anandika ◽  
Ahmet Kahraman ◽  
David Talbot
Keyword(s):  
Frequency Spectrum ◽  
Gear Tooth ◽  
Random Sequence ◽  
Transmission Error ◽  
Spur Gear ◽  
Engineering Industry ◽  
Gear Pair ◽  
Gear Mesh ◽  
Dynamic Transmission Error ◽  
The Impact

Abstract Noise and vibration performance of a gear system is critical in any engineering industry. Excessive vibrational amplitudes originated by the excitations at the gear meshes propagate to the transmission housing to cause noticeable noise, while also increasing gear tooth stresses to degrade durability. As such, gear designers must generate designs that are nominally quiet with low-vibration amplitudes. This implies a gear pair fabricated exactly to the specifications of its blue print will be acceptable for its vibration behavior. Achieving this, however, is not sufficient. As the manufacturing of gears require them to be subject to bands of tolerances afforded by the manufacturing processes employed, the designers must be concerned about variations to the performance of their presumably quite baseline designs within these tolerance bands. This research aims at demonstrating how one type of manufacturing error, random tooth spacing errors, alter the vibratory behavior of a spur gear pair. Two pairs of spur gears are tested for their dynamic transmission error performance. One gear pair with no tooth spacing errors form the baseline. The second gear pair contain an intentionally induced random sequence of spacing errors. The forced vibration responses of both gear pairs are compared within wide ranges of speed and torque. This comparison shows that there is a clear and significant impact of random spacing errors on spur gear dynamics, measurable through examination of their respective transmission error signatures. In the off-resonance regions of speed, vibration amplitudes of the random error pair are higher than the no-error baseline spur gear pair. Meanwhile, at or near resonance peaks, the presence of random spacing errors tends to lower the peak amplitudes slightly as compared to the no-error baseline spur gear pair. The presence of random spacing errors introduces substantial harmonic content that are non-mesh harmonics. This results in a broadband frequency spectrum in addition to an otherwise well-defined frequency spectrum with gear-mesh order components, pointing to an additional concern of noise quality.

Compensated Conjugation and Gear Tooth Modification Design

2016 ◽  
Vol 138 (7) ◽  
Author(s):  
Bowen Yu ◽  
Kwun-lon Ting
Keyword(s):  
Differential Geometry ◽  
Loading Condition ◽  
Gear Tooth ◽  
Transmission Function ◽  
Practical Method ◽  
Transmission Error ◽  
Fundamental Issue ◽  
Gear Design ◽  
Modification Method ◽  
Tooth Modification

This paper addresses the fundamental issue on the conjugation for any gearing systems after tooth modification. It presents a rigorous theory on compensated conjugation for gear transmission error (TE) balance. The basic idea is that conjugation impaired by the loading condition can be compensated by modifying the transmission function. Thus, conjugation holds true after tooth modification. Because the modification is based on the universal concept of transmission rather than the tooth geometry, the proposed tooth modification method is universal rather than limited to involute or even planar gearing. A theorem about the continuity of motion and conjugate geometries is presented and proved for any desirable modification. The proposed theory is consistent with the standard manufacturing process for tooth modification. Tooth geometries and cutter geometries can be obtained after the theoretical TE function is designed. The proposed method is highlighted and demonstrated with an involute gear design, in which a convenient and practical method with a direct rack-cutter modification is presented and rigorously analyzed based on kinematics and differential geometry. Examples are presented to show the effectiveness of the methodology.

Research on the Tooth Modification in Gear Skiving

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Fangyan Zheng ◽  
Mingde Zhang ◽  
Weiqing Zhang ◽  
Xiaodong Guo
Keyword(s):  
Mathematical Model ◽  
Transmission Error ◽  
The Other ◽  
Contact Pattern ◽  
Tooth Contact Analysis ◽  
Cylindrical Gear ◽  
Left Behind ◽  
Angle Correction ◽  
Tooth Modification ◽  
Offset Correction

As a prospective machining method for cylindrical gear, gear skiving has been promoted by many commercial companies, such as Gleason, Mitsubishi, and Prawema recently. Although the principle and mathematical model for gear skiving has been discussed by many works, the tooth modification was left behind in the literature. In fact, machine kinematics correction and tooth contact analysis (TCA) are widely used for tooth modification in gear processing, such as hobbing, grinding, and milling. Focusing on this, the paper generalizes machine kinematics correction and TCA to gear skiving. The influence of the modification parameters on tooth deviation, contact path, and transmission error are all investigated, showing that localized contact pattern and polynomial transmission error can be realized through cutter offset correction for one gear and cutter tilted (or crossed angle) correction for the other gear.

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