Change search
ReferencesLink to record
Permanent link

Direct link
Logarithmical Crowning for Spur Gears
KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.ORCID iD: 0000-0003-4447-3363
KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.ORCID iD: 0000-0002-2578-9453
2010 (English)In: Strojniski vestnik, ISSN 0039-2480, Vol. 56, no 4, 239-244 p.Article in journal (Refereed) Published
Abstract [en]

Gear tooth modifications, such as lead crowning, are often recommended to compensate for misalignment (e.g. assembly deviations). Lead crowning means that the tooth centre is slightly thicker than the tooth edges and is usually described as a circular arc profile. The use of crowning shifts the peak load from the tooth flank edges and, therefore, reduces the risk for high contact pressures at the edges, which can otherwise result in a shortened service life. In this study a logarithmical lead profile was compared with traditional lead profile modifications for gears. The profiles were applied on a spur gear pair and a numerical method for contact analysis was used to calculate the contact pressure distribution at the pitch diameter. All lead profiles were optimised with respect to low contact pressure at a specific normal load, a specified maximum misalignment in the plane of action and a tooth flank edge contact criteria. The results show that the logarithmical profile responds differently to misalignments compared to the traditional lead profile modifications. The logarithmical profile resulted in lower maximum contact pressures for small misalignments and is, therefore, of further interest in terms of achieving a robust gear design. (C) 2010 Journal of Mechanical Engineering. All rights reserved.

Place, publisher, year, edition, pages
2010. Vol. 56, no 4, 239-244 p.
Keyword [en]
spur gear, lead crowning, misalignment, contact pressure
National Category
Mechanical Engineering
URN: urn:nbn:se:kth:diva-27228ISI: 000279265400003ScopusID: 2-s2.0-77952772204OAI: diva2:379434
QC 20101217Available from: 2010-12-17 Created: 2010-12-09 Last updated: 2012-09-25Bibliographically approved
In thesis
1. On tribological design in gear tooth contacts
Open this publication in new window or tab >>On tribological design in gear tooth contacts
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The correct tribological design will have a considerable effect on a gear’s service life and efficiency. The purpose of this thesis is to clarify the impact of variation in the gear tooth flank tribological system on the gear contact load capacity – to increase the understanding of how surface topography and lubricant interact.

In this thesis the variation in surface topography inherent in the manufacturing method has been shown, by experimental work and computer simulations, to be an important factor for the contact condition in the early life of gears. Surface analysis revealed that the formation and composition of surface boundary layers depends strongly on the chemical composition of the lubricant, but also on pre-existing surface boundary layers. Additionally, surface boundary layers play a major role in frictional behaviour, wear and in allowing the lubricant to react properly with the surfaces.

Paper A presents the current ISO 6336 calculation of surface durability. A robust design approach was used to investigate the extent to which the current standard for calculation of surface durability allows for manufacturing variations and the choice of lubricant.

Paper B investigates the extent to which a logarithmical profile modification can increase gear contact pressure robustness compared to traditional lead profiles for gears.

Paper C compares different gear manufacturing methods and their as-manufactured (fresh unworn) surface topographies, using measured surface topographies as input to a contact simulation program.

Paper D examines surface boundary layer formation and the corresponding wear in relation to different anti-wear additives in an environmentally adapted base oil.

Papers E and F make use of specimens with surface topographies imitating two gear manufacturing methods (grinding and superfinishing) to be used in a twin-disc and barrel-on-disc machine respectively. The contacts are analysed by friction measurements and simulations combined with methods for surface analysis.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2012. 40 p.
Trita-MMK, ISSN 1400-1179 ; 2012:18
friction, gear contact, gear manufacturing, surface boundary layers, surface topography, wear
National Category
Mechanical Engineering Other Mechanical Engineering Tribology
urn:nbn:se:kth:diva-102742 (URN)978-91-7501-493-7 (ISBN)
Public defence
2012-10-15, Studion Gladan, Brinellvägen 85, KTH, Stockholm, 10:00 (English)

QC 20120925

Available from: 2012-09-25 Created: 2012-09-24 Last updated: 2012-09-25Bibliographically approved

Open Access in DiVA

No full text


Search in DiVA

By author/editor
Bergseth, EllenBjörklund, Stefan
By organisation
Machine Elements
In the same journal
Strojniski vestnik
Mechanical Engineering

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 202 hits
ReferencesLink to record
Permanent link

Direct link