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Transmission Error

TECHNICAL ARTICLES | 2023-02-21

Aspects of Gear Noise, Quality, and Manufacturing Technologies for Electromobility

In modern automotive vehicles, gear noise becomes more and more of an issue. The main reason is the reduced masking noise of the engine, which vanishes completely in the case of an electric driveline. Improved gear quality unfortunately does not correlate with a better noise performance in any case. High gear quality makes sure that the gear flanks are inside tight tolerances and that all teeth are nearly identical. Even if the running behavior of such gear sets shows a very low sound pressure level, the noise perception for human ears may be annoying.

INDUSTRY NEWS | 2022-05-06

Klingelnberg Examines Gear Grinding Challenges Today

Within the last decade, hard finishing technologies become highly relevant. Increasing the power density of a gearbox requires precisely machined gears without heat distortions. Especially in noise-sensitive applications, both honing and grinding are often applied.

TECHNICAL ARTICLES | 2021-06-01

Quasi-Static Transmission Error Behavior Under the Composite Effect of Temperature and Load

Given the lack of information on thermal distortion effects in small size steel gears, an experimental study of quasi-static transmission error behavior under thermomechanical conditions is presented.

TECHNICAL ARTICLES | 2019-09-01

Influence of Thermal Distortion on Spur Gear Tooth Contact

In this paper the effects of thermally induced geometry distortions on load distribution and transmission error have been analyzed.

TECHNICAL ARTICLES | 2019-08-01

Optimizing the Operational Behavior of Bevel Gears Using a Tolerance Field-Based Approach

The authors use data analysis to determine which tolerances have the greatest effect on transmission error, enabling them to make adjustments and reduce production costs.

FEATURE ARTICLES | 2019-07-01

Gear Noise Analysis: Design and Manufacturing Challenges Drive New Solutions for Noise Reduction

Gear noise is among the issues of greatest concern in today's modern gearboxes. Significant research has resulted in the application of enhancements in all phases of gear manufacturing, and the work is ongoing. With the introduction of Electric Vehicles (EV), research and development in this area has surged in recent years. Most importantly, powerful new noise analysis solutions are fast becoming available.

GEAR TALK WITH CHUCK | 2019-06-18

Claude Gosselin: Gears — Why Not?

When I graduated as a mechanical engineer in 1978, I landed a job in the “cold section” at Pratt & Whitney Canada (PWC) in Montreal. In those d...

ASK THE EXPERT | 2019-03-01

Relationship between Misalignment and Transmission Error in Cross- Axes Helical Gear Assemblies

Question: I am a gear engineer for a motor manufacturer in China. I am writing about noise generated from cross-helical gear assembly error. I want to learn the relationship between the misalignment (center distance change and cross-angle shift) and transmission error. It is better under the loading and theory conditions. What is the trend of cross-helical gear development (use ZI worm and involute helical gear, point contact)?

GEAR TALK WITH CHUCK | 2018-12-06

Out With the Old

No technology ...

GEAR TALK WITH CHUCK | 2018-05-24

The Right Stuff

Even the most brilliant gear design will fail if the wrong material is used to make the parts. Our understanding of metallurgy and alloying element...

GEAR TALK WITH CHUCK | 2017-11-02

Swag of the Expo Awards

My last blog covered the motivation for the Swag of the Expo award and my inspiration in creating it. Top contenders that did not quite qualify for...

TECHNICAL ARTICLES | 2017-03-01

Analysis and Optimization of Contact Ratio of Asymmetric Gears

This article presents an analysis of asymmetric tooth gears considering the effective contact ratio that is also affected by bending and contact tooth deflections. The goal is to find an optimal solution for high performance gear drives, which would combine high load capacity and efficiency, as well as low transmission error (which affects gear noise and vibration).

TECHNICAL ARTICLES | 2016-11-01

Influence of Topography Deviations on the Psychoacoustic Evaluation of Ground Bevel Gears

In the design process of transmissions, one major criterion is the resulting noise emission of the powertrain due to gear excitation. Within the past years, much investigation has shown that the noise emission can be attributed to quasi-static transmission error. Therefore, the transmission error can be used for a tooth contact analysis in the design process, as well as a characteristic value for quality assurance by experimental inspections.

TECHNICAL ARTICLES | 2016-07-01

Hybrid Hertzian and FE-Based Helical Gear-Loaded Tooth Contact Analysis and Comparison with FE

Gear-loaded tooth contact analysis is an important tool for the design and analysis of gear performance within transmission and driveline systems. Methods for the calculation of tooth contact conditions have been discussed in the literature for many years. It's possible the method you've been using is underestimating transmission error in helical gears. Here's why.

TECHNICAL ARTICLES | 2016-06-01

Worm Gear Efficiency Estimation and Optimization

This paper outlines the comparison of efficiencies for worm gearboxes with a center distance ranging from 28 - 150 mm that have single reduction from 5 to 100:1. Efficiencies are calculated using several standards (AGMA, ISO, DIN, BS) or by methods defined in other bibliographic references. It also deals with the measurement of torque and temperature on a test rig — required for the calibration of an analytical model to predict worm gearbox efficiency and temperature. And finally, there are examples of experimental activity (wear and friction measurements on a blockon- ring tribometer and the measurements of dynamic viscosity) regarding the effort of improving the efficiency for worm gear drivers by adding nanoparticles of fullerene shape to standard PEG lubricant

INDUSTRY NEWS | 2015-06-01

Industry News

News from Around the Gear Industry

INDUSTRY NEWS | 2012-10-18

Dayton Progress Celebrates National Manufacturing Day

Dayton Progress Corporation participated in National Manufacturing Day on October 5th by opening its doors and hosting educational open h...

TECHNICAL ARTICLES | 2012-01-01

Evaluation of Methods for Calculating Effects of Tip Relief on Transmission Error, Noise and Stress in Loaded Spur Gears

The connection between transmission error, noise and vibration during operation has long been established. Calculation methods have been developed to describe the influence so that it is possible to evaluate the relative effect of applying a specific modification at the design stage. These calculations enable the designer to minimize the excitation from the gear pair engagement at a specific load. This paper explains the theory behind transmission error and the reasoning behind the method of applying the modifications through mapping surface profiles and determining load sharing.

TECHNICAL ARTICLES | 2010-08-01

Optimizing Gear Geometry for Minimum Transmission Error, Mesh Friction Losses and Scuffing Risk Through Computer- Aided Engineering

Minimizing gear losses caused by churning, windage and mesh friction is important if plant operating costs and environmental impact are to be minimized. This paper concentrates on mesh friction losses and associated scuffing risk. It describes the preliminary results from using a validated, 3-D Finite Element Analysis (FEA) and Tooth Contact Analysis (TCA) program to optimize cylindrical gears for low friction losses without compromising transmission error (TE), noise and power density. Some case studies and generic procedures for minimizing losses are presented. Future development and further validation work is discussed.

TECHNICAL ARTICLES | 2010-07-01

Effects of Profile Corrections on Peak-to-Peak Transmission Error

Profile corrections on gears are a commonly used method to reduce transmission error, contact shock, and scoring risk. There are different types of profile corrections. It is a known fact that the type of profile correction used will have a strong influence on the resulting transmission error. The degree of this influence may be determined by calculating tooth loading during mesh. The current method for this calculation is very complicated and time consuming; however, a new approach has been developed that could reduce the calculation time.

TECHNICAL ARTICLES | 2008-11-01

A Further Study on High-Contact-Ratio Spur Gears in Mesh with Double-Scope Tooth Profile Modification

This paper will demonstrate that, unlike commonly used low-contact-ratio spur gears, high-contact-ratio spur gears can provide higher power-to-weight ratio, and can also achieve smoother running with lower transmission error (TE) variations.

TECHNICAL ARTICLES | 2007-03-01

Transmission Error and Noise Emission of Spur Gears

Transmission error (TE) is recognized as one of the most important causes of gear acoustic emissions...

FEATURE ARTICLES | 2005-01-01

Tooth Flank Corrections of Wide Face Width Helical Gears that Account for Shaft Deflections

This paper discusses the influence of tip relief, root relief, load modification, end relief and their combinations on gear stresses and transmission errors due to shaft deflections.

TECHNICAL ARTICLES | 1998-05-01

Hobs & Form Relived Cutters: Common Sharpening Problems

Fig. 1 shows the effects of positive and negative rake on finished gear teeth. Incorrect positive rake (A) increase the depth and decreases the pressure angle on the hob tooth. The resulting gear tooth is thick at the top and thin at the bottom. Incorrect negative rake (B) decreases the depth and increases the pressure angle. This results in a cutting drag and makes the gear tooth thin at the top and thick at the bottom.

TECHNICAL ARTICLES | 1996-07-01

Noise Reduction in Plastic & Powder Metal Gear Sets

The data discussed in this article was taken from an upright vacuum cleaner. This was a prototype cleaner that was self-propelled by a geared transmission. It was the first time that the manufacturer had used a geared transmission in this application.

TECHNICAL ARTICLES | 1994-07-01

Effect of Extended Tooth Contact on the Modeling of Spur Gear Transmissions

In some gear dynamic models, the effect of tooth flexibility is ignored when the model determines which pairs of teeth are in contact. Deflection of loaded teeth is not introduced until the equations of motion are solved. This means the zone of tooth contact and average tooth meshing stiffness are underestimated, and the individual tooth load is overstated, especially for heavily loaded gears. This article compares the static transmission error and dynamic load of heavily loaded, low-contact-ratio spur gears when the effect of tooth flexibility has been considered and when it has been ignored. Neglecting the effect yields an underestimate of resonance speeds and an overestimate of the dynamic load.

TECHNICAL ARTICLES | 1994-05-01

Designing Hardened & Ground Spur Gears to Operate With Minimum Noise

When designing hardened and ground spur gears to operate with minimum noise, what are the parameters to be considered? should tip and/or root relief be applied to both wheel and pinion or only to one member? When pinions are enlarged and he wheel reduced, should tip relief be applied? What are the effects on strength, wear and noise? For given ratios with enlarged pinions and reduced wheels, how can the gear set sized be checked or adjusted to ensure that the best combination has been achieved?

TECHNICAL ARTICLES | 1990-07-01

Transmission Errors and Bearing Contact of Spur, Helical, and Spiral Bevel Gears

An investigation of transmission errors and bearing contact of spur, helical, and spiral bevel gears was performed. Modified tooth surfaces for these gears have been proposed in order to absorb linear transmission errors caused by gear misalignment and to localize the bearing contact. Numerical examples for spur, helical, and spiral bevel gears are presented to illustrate the behavior of the modified gear surfaces with respect to misalignment and errors of assembly. The numerical results indicate that the modified surfaces will perform with a low level of transmission error in non-ideal operating environments.

TECHNICAL ARTICLES | 1988-07-01

The Uses and Limitations of Transmission Error

The concept of "transmission error" is relatively new and stems from research work in the late 1950s by Gregory, Harris and Munro,(1) together with the need to check the accuracy of gear cutting machines. The corresponding commercial "single flank" testing equipment became available in the 1960s, but it was not until about ten years ago that it became generally used, and only recently has it been possible to test reliably at full load and full speed.

TECHNICAL ARTICLES | 1988-01-01

The Relationship of Measured Gear Noise to Measured Gear Transmission Errors

Vehicle gear noise testing is a complex and often misunderstood subject. Gear noise is really a system problem.(1) most gearing used for power transmission is enclosed in a housing and, therefore, little or no audible sound is actually heard from the gear pair.(2) The vibrations created by the gears are amplified by resonances of structural elements. This amplification occurs when the speed of the gear set is such that the meshing frequency or a multiply of it is equal to a natural frequency of the system in which the gears are mounted.

VOICES | 1987-05-01

Viewpoint

Joe Arvin comments on his recent trip to Scandinavia and how U.S. defense dollars are being spent overseas. J.D. Smith responds to an article on gear noise from the previous issue.

TECHNICAL ARTICLES | 1987-01-01

Gear Noise and the Sideband Phenomenon

Gear noise can be a source of intense annoyance. It is often the primary source of annoyance even when it is not the loudest noise component. This is because of the way it is perceived. Gear noise is a collection of pure tones which the human ear can detect even when they are 10dB lower than the overall noise level. Another reason for our sensitivity to transmission noise is that we associate it with impending mechanical failure.

TECHNICAL ARTICLES | 1986-05-01

Identification of Gear Noise with Single Flank Composite Measurement

Anyone involved in the design, manufacture and use of gears is concerned with three general characteristics relative to their application: noise, accuracy, and strength or surface durability. In the article, we will be dealing with probably the most aggravating of the group, gear noise.

TECHNICAL ARTICLES | 1984-05-01

Single Flank Testing of Gears

Presumably, everyone who would be interested in this subject is already somewhat familiar with testing of gears by traditional means. Three types of gear inspection are in common use: 1) measurement of gear elements and relationships, 2) tooth contact pattern checks and 3) rolling composite checks. Single Flank testing falls into this last category, as does the more familiar Double Flank test.