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UPPER PART SUPPORT OF EXCITER OF ELECTRICAL MACHINES HAVING PEDESTAL BEARINGS LOADED WITH INTENSIVE MECHANICAL VIBRATIONS

IP.com Disclosure Number: IPCOM000244164D
Publication Date: 2015-Nov-18
Document File: 3 page(s) / 183K

Publishing Venue

The IP.com Prior Art Database

Related People

Joonas Helander: AUTHOR [+2]

Abstract

Loose support of exciter of especially fame size 1600 generators having pedestal bearingsincorporated on the same base with internal combustion engine have been found out themajor source of axial direction vibrations of N end bearings Exciter is supported from itslower part to bearing pedestal used in this frame size generators Insufficient support of upper part of exciter may cause intensive mechanical vibrations inaxial direction As a solution a new support structure is designed It is manufactured bywelding and it is fastened to other generator structure by bolts New design is giving much more structural stiffness in axial direction than old one whenpedestal bearings are used for power plant generator incorporated on the same base withinternal combustion engine EXCITER SUPPORT MOUNTING VIBRATIONS STIFFNESS GENERATOR INTERNAL COMBUSTION ENGINE PEDESTAL BEARING

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UPPER PART SUPPORT OF EXCITER OF ELECTRICAL MACHINES HAVING PEDESTAL BEARINGS LOADED WITH INTENSIVE

MECHANICAL VIBRATIONS

Joonas Helander, Ari S Vartiainen, both of ABB Oy Motors & Generators Helsinki

TECHNICAL FIELD

Upper part support of exciter of electrical machines having pedestal bearings designed for especially power plant generators incorporated on the same steel base construction with internal combustion engine.

BACKGROUND OF THE DISCLOSURE AND TECHNICAL PROBLEM TO BE SOLVED

Power plant generators incorporated on the same steel base construction with internal combustion engine are exposed to intensive mechanical vibrations. Responses to vibrations may increase to problematic levels if there is local resonance existing in the structure of generator. Four stroke internal combustion engine generates substantial impulses in multiplicity of rotational speed halves. In order to avoid resonances the natural frequencies of parts of generator structure should be located in structural design between those multiplicities of rotational speed halves. In practise it is very difficult to design the structure of generator that resonances can be avoided in all parts of generator structure.

Above certain multiplicities of the rotational speed the excitations have been found out to attenuate considerably in many practical cases when local natural frequencies of generator structure have been designed to be higher than several times of multiplicities of rotational speed.

Loose support of exciter of especially fame size 1600 generators having pedestal bearings incorporated on the same base with internal combustion engine have been found out the major source of axial direction vibrations of N-end bearings. Exciter is supported from its lower part to bearing pedestal used in this frame size generators. The bearing pedestal itself is very rigid structure. The major challenge to avoid axial direction vibrations of N-end bearings is to develop support that can fix exciter upper part rigidly to generator structure.

SUMMARY

Loose support of exciter of especially fame size 1600 generators having pedestal bearings incorporated on the same base with internal combustion engine have been found out the major source of axial direction vibrations of N-end bearings. Exciter is supported from its lower part to bearing pedestal used in this frame size generators.

Insufficient support of upper part of exciter may cause intensive mechanical vibrations in axial direction. As a solution a new support structure is designed. It is manufactured by...