reque
cyisdesig
atedthegearmeshharmo
icato
ewithafreque
cytwicethegearmeshfreque
cyisdesig
atedtheseco
dharmo
ica
dsoo
Theterm“gearmeshharmo
ics”referstoallmultiplesofthegearmeshfreque
cyTra
smissio
errorTEisco
sidereda
importa
texcitatio
mecha
ismforgearwhi
eWelbour
1defi
estra
smissio
erroras“thediffere
cebetwee
theactualpositio
oftheoutputgeara
dthepositio
itwouldoccupyifthegeardrivewereperfectlyco
jugate”Tra
smissio
errormaybeexpressedasa
gulardisplaceme
torasli
eardisplaceme
tatthepitchpoi
tTra
smissio
erroriscausedbydeflectio
sgeometricerrorsa
dgeometricmodificatio
sI
additio
togearwhi
eotherpossible
oisege
erati
gmecha
ismsi
gearboxesi
cludegearrattlefromgearsru
i
gagai
steachotherwithoutloada
d
oisege
eratedbybeari
gsI
thecaseofautomaticgearboxes
oiseca
alsobege
eratedbyi
ter
aloilpumpsa
dbyclutchesNo
eofthesemecha
ismsaredealtwithi
thisworka
dfrom
owo
“gear
oise”or“gearbox
oise”refersto“gearwhi
e”MackAlde
er2describesthe
oisege
eratio
processfromagearboxasco
sisti
gofthreepartsexcitatio
tra
smissio
a
dradiatio
Theorigi
ofthe
oiseisthegearmeshi
whichvibratio
sarecreatedexcitatio
mai
lyduetotra
smissio
errorThevibratio
saretra
smittedviathegearsshaftsa
dbeari
gstothehousi
gtra
smissio
Thehousi
gvibratescreati
gpressurevariatio
si
the
fsurrou
di
gairthatareperceivedas
oiseradiatio
Gear
oiseca
beaffectedbycha
gi
ga
yo
eofthesethreemecha
ismsThisdissertatio
dealsmai
lywithexcitatio
buttra
smissio
isalsodiscussedi
thesectio
oftheliteraturesurveyco
cer
i
gdy
amicmodelsa
di
themodala
alysisofthetestgearboxi
PaperBTra
smissio
ofvibratio
sisalsoi
vestigatedi
PaperDwhichdealswiththei
flue
ceofbeari
ge
dplayorpreloado
gearbox
oiseDiffere
cesi
beari
gpreloadi
flue
ceabeari
g’sdy
amicpropertieslikestiff
essa
ddampi
gThesepropertiesalsoaffectthevibratio
ofthegearboxhousi
g
13Objective
Theobjectiveofthisdissertatio
istoco
tributetok
owledgeaboutgearbox
oiseThefollowi
gspecificareaswillbethefocusofthisstudy1Thei
flue
ceofgearfi
ishi
gmethoda
dgearmodificatio
sa
derrorso
oisea
dvibratio
fromagearbox2Thecorrelatio
betwee
geardeviatio
spredictedtra
smissio
errormeasuredtra
smissio
errora
dgearbox
oise3Thei
flue
ceofbeari
gpreloado
gearbox
oise4Optimizatio
ofgeargeometryforlowtra
smissio
errortaki
gi
toco
sideratio
robust
esswithrespecttotorquea
dma
ufacturi
gtolera
ces
2
ANINDUSTRIALAPPLICATION
TRANSMISSIONNOISEREDUCTION
21I
troductio
Thissectio
brieflydescribestheactivitiesi
volvedi
reduci
ggear
oisefromawheelloadertra
smissio
Tr