In situ blocked force measurement in gearboxes with potential application for condition monitoring
type: CreativeWork
description: The use of gearboxes for power transfer is widespread throughout industry. However, machines today are operating at higher speeds than ever before and gear failures such as wear or tooth breakage is serious and legitimate concerns. Incipient fault detection in gears has thus become the subject of intensive investigation and at this stage of development, there are many competing condition monitoring methods based on vibration signal analysis. This thesis summarizes the research steps taken after a review of (i) current maintenance strategies, (ii) gearbox condition monitoring techniques and gear vibration fundamental and common gearbox failure modes, (iii) new approach called in-situ blocked force. A test rig was built, designed and fabricated for experimental data collection. The experimental work was carried out using a healthy spur gear and one suffering from tooth breakage with two levels of faults; 25% and 85%. This study reports the use of the blocked force to characterize the gear mesh interactions; the advantage is to remove the effect of the housing, and to get a signal, which is more representative of the source mechanisms from which it is generated. Under certain assumptions the blocked forces are an intrinsic property of the vibration source. For example, a given vibration source, such as gear, hypothetically operating in the same conditions could produce different vibration signals when installed in different housings, however, the blocked forces theoretically are the same in both cases. The blocked force represents a property independent of the noise generating mechanisms and is therefore invariant to the gearbox housing. It is proposed that this invariance yields a signal more amenable to fault detection. In this thesis, assessment of the condition of a gearbox in a test rig is based on vibration analysis but, contrary to standard condition monitoring techniques, this research uses the blocked force signal instead of acceleration signals. FFT has appli…
abstract: The use of gearboxes for power transfer is widespread throughout industry. However, machines today are operating at higher speeds than ever before and gear failures such as wear or tooth breakage is serious and legitimate concerns. Incipient fault detection in gears has thus become the subject of intensive investigation and at this stage of development, there are many competing condition monitoring methods based on vibration signal analysis. This thesis summarizes the research steps taken after a review of (i) current maintenance strategies, (ii) gearbox condition monitoring techniques and gear vibration fundamental and common gearbox failure modes, (iii) new approach called in-situ blocked force. A test rig was built, designed and fabricated for experimental data collection. The experimental work was carried out using a healthy spur gear and one suffering from tooth breakage with two levels of faults; 25% and 85%. This study reports the use of the blocked force to characterize the gear mesh interactions; the advantage is to remove the effect of the housing, and to get a signal, which is more representative of the source mechanisms from which it is generated. Under certain assumptions the blocked forces are an intrinsic property of the vibration source. For example, a given vibration source, such as gear, hypothetically operating in the same conditions could produce different vibration signals when installed in different housings, however, the blocked forces theoretically are the same in both cases. The blocked force represents a property independent of the noise generating mechanisms and is therefore invariant to the gearbox housing. It is proposed that this invariance yields a signal more amenable to fault detection. In this thesis, assessment of the condition of a gearbox in a test rig is based on vibration analysis but, contrary to standard condition monitoring techniques, this research uses the blocked force signal instead of acceleration signals. FFT has appli…
author: Abohnik, AA
language: en
date published: 2026
date modified: 2026-07-24T04:26:30Z
provider: U. of Salford
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: U. of Salford