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Nima shamsapourNima shamsapour(865211015)
Navid khakpayNavid khakpay(865211007)
Mehdi jebeliMehdi jebeli
845222017
Atta sojoodiAtta sojoodi(865211012)
Babak vajdiBabak vajdi(865211032)
Behnam sadriBehnam sadri(865211018)
Vakili. Dr
Mechanical Engineering DesignMechanical Engineering Design
:Contents
Preface ……………………………………4 What is a gearbox?………………………5Project description………………………..7Bulky characteristics of gearbox………..8Gear design……………………………….9Shaft design………………………………34Deflection consideration…………………37Bearing selection…………………………41Computer programming…………………54Acknowledgments………………………..55References………………………………..56
Preface:
The present work is a class project of mechanical engineering designThe present work is a class project of mechanical engineering design on Samand’s gearbox. The quad did as much as possible in order toon Samand’s gearbox. The quad did as much as possible in order to analyze ,collect, calculate and present the results. At first we have aanalyze ,collect, calculate and present the results. At first we have a historical vision on gearbox then all the parts of gearbox’shistorical vision on gearbox then all the parts of gearbox’s evaluations (some with more details) will be considered. we haveevaluations (some with more details) will be considered. we have
utilized some CAD soft wares like ANSYS,solidworks , catia &Mdesign utilized some CAD soft wares like ANSYS,solidworks , catia &Mdesign and the programming is MATLAB languageand the programming is MATLAB language..
We are really grateful of Dr.vakili on behalf of the recommendations We are really grateful of Dr.vakili on behalf of the recommendations and hope to satisfy him about the processand hope to satisfy him about the process..
?What is a gearbox
Gears are about as old as any ofGears are about as old as any of
the machinery of mankind. The oldest the machinery of mankind. The oldest machinemachine
is the potter's wheel. At first time over 3000is the potter's wheel. At first time over 3000 years ago primitive gears first meshedyears ago primitive gears first meshed
with each other and transmitted rotary motionwith each other and transmitted rotary motion. . Water wheels were used to convert energy ofWater wheels were used to convert energy of
moving water into energy that would powermoving water into energy that would power
machines. Wooden gears connected watermachines. Wooden gears connected water
wheels to machines that would grind wheatwheels to machines that would grind wheat
and hammer metalsand hammer metals..
A transmission or gear box provides speedA transmission or gear box provides speed
and torque conversion and from a rotatingand torque conversion and from a rotating
power source to another device using gearpower source to another device using gear
ratios. In British English the termratios. In British English the term
TRANSMISSION refers to the whole driveTRANSMISSION refers to the whole drive
train, including gearbox, clutch, prop shafttrain, including gearbox, clutch, prop shaft ), ),
for rear wheel drive), differential and finalfor rear wheel drive), differential and final
drive shafts. The most common use is indrive shafts. The most common use is in
motor vehicals,where the transmissionmotor vehicals,where the transmission
adapts the out put of the internal combustionadapts the out put of the internal combustion
engine to the drive wheelsengine to the drive wheels..
Often, a transmission will haveOften, a transmission will have
multiple gear ratios (or simplymultiple gear ratios (or simply
""gears"), with the ability to switchgears"), with the ability to switch
between them as speed variesbetween them as speed varies . .
This switching may be doneThis switching may be done
manually (by the operator), ormanually (by the operator), or
automatically. Directional automatically. Directional (forward(forward
and reverse) control may also beand reverse) control may also be
provided. Single-ratioprovided. Single-ratio
transmissions also exist, whichtransmissions also exist, which
simply change the speed and simply change the speed and torque (and sometimestorque (and sometimes
direction) of motor outputdirection) of motor output. .
Gearboxes have found use in a wide Gearboxes have found use in a wide variety of different—often variety of different—often stationary
—applications, such as—applications, such as wind turbines..Transmissions are also used in Transmissions are also used in agricultural, , industrial, , construction, , mining and and automotive equipment. In equipment. In addition to ordinary transmission addition to ordinary transmission equipped with gears, such equipped with gears, such equipment makes extensive use of equipment makes extensive use of the the hydrostatic drive and electrical and electrical adjustable-speed drives..
Project description
It is desired to design a gearbox To get this we first anaylzedIt is desired to design a gearbox To get this we first anaylzed the forces and power generated in the internal combustion enginethe forces and power generated in the internal combustion engine then according to the inpute data like the maximum torque and then according to the inpute data like the maximum torque and maximum power gears designed Then by considering the maximum power gears designed Then by considering the shasfts distans and gears diameters the critical gear mated shasfts distans and gears diameters the critical gear mated during the engaging identified Then all diameters of shafts during the engaging identified Then all diameters of shafts were found out It is important to note that we used some steps were found out It is important to note that we used some steps through the shafts inorder to reduce the material used in through the shafts inorder to reduce the material used in manufacturingmanufacturing At last all the bearings were selected for the most criticalAt last all the bearings were selected for the most critical condition and all the data and informations were wrote condition and all the data and informations were wrote besides .the figuresbesides .the figures
Bulky characteristics of gearbox
Total weight 39.15Kg
length420mm
width240mm
height310mm
Occupied volume
0.0312m^3
Approximate cost
195$
Normal distance of
shafts
150(mm)
Upper shaft length
360mm
Lower shaft length
410mm
Distance of gear 5,4
40mm
Distance of gear 4,3
5mm
Distance of gear 3,2
20mm
Distance of gear 2,REV
5mm
Distance of gear REV,1
60mm
Gear design
There are some important notes to be informed. First we calculated the There are some important notes to be informed. First we calculated the power generated ,from some principle physics and fluid mechanics. power generated ,from some principle physics and fluid mechanics. During the engaging of the gears to the higher speeds, the power During the engaging of the gears to the higher speeds, the power increases and the torque reduces. For the rear gear we assumed the increases and the torque reduces. For the rear gear we assumed the conditions as well as 1conditions as well as 1sttstt gear,inorder to have the worst situation. the gear,inorder to have the worst situation. the assumption for the overload factor was according to the speed of the assumption for the overload factor was according to the speed of the shaft. when we have low speeds it should be less than 1.5 and when shaft. when we have low speeds it should be less than 1.5 and when the speed increases ,the unbalanced forces increases and the the speed increases ,the unbalanced forces increases and the overload factor shouldn’t be less than 2.The gear strength for live overload factor shouldn’t be less than 2.The gear strength for live assumed 10^8 cycles & the reliability was set 99%.Temperture factor assumed 10^8 cycles & the reliability was set 99%.Temperture factor was not considered. The surface condition factor was almost 1 was not considered. The surface condition factor was almost 1 because of our gear materials. All the gears are from steel but different because of our gear materials. All the gears are from steel but different
hard nesseshard nesses . .
Gear1(pinion):
MMnn 2.52.5
DD 70mm70mm
NN 2424
FF 40mm40mm
MaterialMaterialSt,grade2St,grade2
,,550HB550HB
WW 3000rpm3000rpm
HH 64.5hp64.5hp
WWtt*n*ndd 13128N13128N
nn 2020
3030
KKoo11
SSFF1.21.2
SSHH1.21.2
QQvv88
)more details(
SH948.05.1562
206.04070
115.106.1377.1113128191
2.1SH
SF
0928500
48.088.240
115.106.1377.1113128
2.1SF
Gear1(gear):
MMnn 2.52.5
DD 230mm230mm
NN 8080
FF 40mm40mm
MaterialMaterialSt,grade2St,grade2
,,550HB550HB
WW 913rpm913rpm
HH 64.5hp64.5hp
WWtt*n*ndd 13128N13128N
nn 2020
3030
KKoo11
SSFF1.41.4
SSHH1.31.3
QQvv88
)more details(
SH965.05.1562
206.04070
115.1047.1377.1113128191
3.1SH
SF
965.0560
52.088.240
115.1047.1377.1113128
4.1SF
Rear gear (pinion):MMnn
2.52.5
DD 70mm70mm
NN 2828
FF 40mm40mm
MaterialMaterialSt,grade2St,grade2
Carburized & Carburized & hardenedhardened
WW 3000rpm3000rpm
HH 64.5hp64.5hp
WWtt*n*ndd 13128N13128N
nn 2020
00
KKoo1.251.25
SSFF1.51.5
SSHH1.21.2
QQvv88
)more details:(
SH948.01619
01374070
115.1049.1377.125.113128191
2.1SH
SF
0928500
6.3.05.240
115.1049.1377.125.113128
5.1SF
Rear gear (gear):MMnn
2.52.5
DD 230mm230mm
NN 9292
FF 40mm40mm
MaterialMaterialSt,grade2St,grade2
Carburized & Carburized & hardenedhardened
WW 913rpm913rpm
HH 64.5hp64.5hp
WWtt*n*ndd 13128N13128N
nn 2020
00
KKoo1.251.25
SSFF1.021.02
SSHH1.11.1
QQvv88
)More details(
SH974.01619
01374070
115.104.1377.125.113128191
SF
94.0500
46.05.240
115.104.1377.125.113128
02.1SF
1.1SH
2nd gear (pinion):
WW 3700rpm3700rpm
HH 70hp70hp
WWtt*n*ndd 7700N7700N
nn 2020
3030
MMnn 44
DD 105mm105mm
NN 2222
FF 40mm40mm
MaterialMaterialSt,grade2St,grade2
Carburized & Carburized & hardenedhardened
KKoo1.51.5
SSFF22
SSHH1.21.2
QQvv88
)more details(
SH948.01619
1.040105
1136.1074.15.15.17700191
2.1SH
SF
976.0500
458.061.440
1136.1074.15.15.17700
2SF
2nd gear (gear):MMnn
44
DD 195mm195mm
NN 4242
FF 40mm40mm
MaterialMaterialSt,grade2St,grade2
Carburized & Carburized & hardenedhardened
WW 2000rpm2000rpm
HH 70hp70hp
WWtt*n*ndd 7700N7700N
nn 2020
3030
KKoo1.51.5
SSFF22
SSHH1.21.2
QQvv88
)More details(
SH962.01619
1.040105
1136.1079.15.15.17700191
2.1SH
SF
988.0500
488.061.440
1136.1079.15.15.17700
2SF
3rd gear (pinion):MMnn
44
DD 130mm130mm
NN 3030
FF 30mm30mm
MaterialMaterialSt,grade2St,grade2
450HB450HB
WW 4500rpm4500rpm
HH 80hp80hp
WWtt*n*ndd 5845N5845N
nn 2020
3030
KKoo1.51.5
SSFF22
SSHH1.121.12
QQvv99
)more details(
SH948.01311
112.030130
112.1059.144.15.15845191
2SFSF
976.0430
49.061.430
112.1059.144.15.15845
12.1SH
3rd gear (gear):MMnn
44
DD 170mm170mm
NN 4040
FF 30mm30mm
MaterialMaterialSt,grade2St,grade2
450HB450HB
WW 3440rpm3440rpm
HH 80hp80hp
WWtt*n*ndd 5845N5845N
nn 2020
3030
KKoo1.51.5
SSFF22
SSHH1.121.12
QQvv99
)more details(
SH954.01321
112.030130
112.1062.144.15.15845191
12.1SH
2SFSF
981.0430
5.061.430
112.1062.144.15.15845
4th gear (pinion):MMnn
44
DD 152mm152mm
NN 3333
FF 30mm30mm
MaterialMaterialSt,grade1St,grade1
300HB300HB
WW 5300rpm5300rpm
HH 90hp90hp
WWtt*n*ndd 4775N4775N
nn 2020
3030
KKoo22
SSFF1.11.1
SSHH22
QQvv99
)More details(
SH948.0866
674.030152
112.106.132.124775191
SF
976.02.248
48.061.430
112.106.132.124775
2SH
1.1SF
4th gear (gear)MMnn
44
DD 148mm148mm
NN 3232
FF 30mm30mm
MaterialMaterialSt,grade1St,grade1
300HB300HB
WW 5443rpm5443rpm
HH 90hp90hp
WWtt*n*ndd 4775N4775N
nn 2020
3030
KKoo22
SSFF1.11.1
SSHH22
QQvv99
SH976.0866
674.030152
112.106.132.124775191
)More details(
SF
96.02.248
48.061.430
112.106.132.124775
1.1SF
2SH
5th gear (pinion)MMnn
44
DD 172mm172mm
NN 3838
FF 20mm20mm
MaterialMaterialSt,grade1St,grade1
350HB350HB
WW 6000rpm6000rpm
HH 100hp100hp
WWtt*n*ndd 4140N4140N
nn 2020
3030
KKoo22
SSFF1.11.1
SSHH2.52.5
QQvv9-109-10
)More details(
SH948.0977
561.020172
112.1039.115.24140191
SF
971.05.221
49.061.420
112.1039.15.24140
2SH
1.1SF
5th gear (gear)
WW 8062rpm8062rpm
HH 100hp100hp
WWtt*n*ndd 4140N4140N
nn 2020
3030
MMnn 44
DD 128mm128mm
NN 2828
FF 20mm20mm
MaterialMaterialSt,grade1St,grade1
350HB350HB
KKoo2.52.5
SSFF1.11.1
SSHH2.52.5
QQvv9-109-10
)More details(
SH948.0977
561.020172
112.1039.115.24140191
2SH
SF
971.05.221
49.061.420
112.1039.15.24140
1.1SF
Shaft design:
Now it is the time to design the shafts. The most important note is the Now it is the time to design the shafts. The most important note is the gears weight. For the upper shaft, we assumed concentrated weight at gears weight. For the upper shaft, we assumed concentrated weight at the center of the gears but at the lower shaft because of their large the center of the gears but at the lower shaft because of their large size, we assumed uniform distributed force. The other note is the size, we assumed uniform distributed force. The other note is the steps. During the calculation, we saw that there are some parts that steps. During the calculation, we saw that there are some parts that can be manufactured with less diameters. saw we considered some can be manufactured with less diameters. saw we considered some steps and used 3mm fillet radius. The fatigue failure was one of the steps and used 3mm fillet radius. The fatigue failure was one of the important factor. this is stated after evaluating the other parameters important factor. this is stated after evaluating the other parameters like critical frequency and defelction.the SODERBERG was the relation like critical frequency and defelction.the SODERBERG was the relation for the fatigue failure. The deflection would result in larger diameters, for the fatigue failure. The deflection would result in larger diameters,
so we used one more bearing in each shaft to reduce the deflectionso we used one more bearing in each shaft to reduce the deflection . .The calculations resulted in the critical condition when engaging the rear The calculations resulted in the critical condition when engaging the rear or the 1or the 1stst gear. so we examined the gear 4 in order to reject it as the gear. so we examined the gear 4 in order to reject it as the bad condition then we solved the problem on the base of rear and 1bad condition then we solved the problem on the base of rear and 1stst geargear..
Upper shaft:
Diameters Diameters from left to from left to
rightright
45mm50mm36mm
MaterialMaterial1030HR1030HR1030HR
Critical situationCritical situation is when rearis when rear
gear is engagedgear is engaged..
Lower shaft:
Diameters from Diameters from left to rightleft to right
34mm47mm50mm
MaterialMaterial1045 CD1045 CD1045 CD
Critical situationCritical situation is when rearis when rear
gear is engagedgear is engaged
Deflection considerations(ANSYS)
Other gears just Other gears just vanishedvanished..
ModelingModeling
Showing Showing the fillets of the fillets of
the stepsthe steps..
Uniform load Uniform load distribution of distribution of
the gearthe gear..
Stress Stress distributiondistribution..
))before middle before middle bearingbearing((
Stress Stress distributiondistribution..
))after middle after middle bearingbearing((
Stress Stress distributiondistribution..
))after middle after middle bearingbearing((
Stress Stress distributiondistribution..
))after middle after middle bearingbearing((
Bearing selection:
We were supposed to select 4 bearings ,two for the upper shaft We were supposed to select 4 bearings ,two for the upper shaft and two for the lower shaft. But when evaluating the and two for the lower shaft. But when evaluating the deflections we saw that it is worth to try the 3deflections we saw that it is worth to try the 3rdrd bearing for each bearing for each shaft and reduce the undesirable deflection which can cause shaft and reduce the undesirable deflection which can cause force increased during the engaging. So we did it andforce increased during the engaging. So we did it and
According to the critical forces, we selected the suitable bearing According to the critical forces, we selected the suitable bearing from SKF online bearing selection for a long life.Ofcourse in from SKF online bearing selection for a long life.Ofcourse in bearing selection, its diameters ,mass and cost were bearing selection, its diameters ,mass and cost were consideredconsidered.
Upper shaft (right side):
Upper shaft (right side):
Upper shaft (Left side):
Upper shaft (Left side):
Upper shaft (middle)
Upper shaft (middle)
Lower shaft( right side)
Lower shaft( right side)
Lower shaft( left side)
Lower shaft( left side)
Lower shaft (middle)
Lower shaft (middle)
Computer programming:
In order to computerize the evaluations ,we wrote the In order to computerize the evaluations ,we wrote the program which gets some input data like program which gets some input data like m,Np,Ng,Wt,speed and some others and predicts the m,Np,Ng,Wt,speed and some others and predicts the coefficient of safety for pitting and bending.Ofcourse coefficient of safety for pitting and bending.Ofcourse we are really grateful of Mr.milanchiyan for his prior we are really grateful of Mr.milanchiyan for his prior program which we have extended it .There is an program which we have extended it .There is an animation which shows the operationanimation which shows the operation..
Acknowledgment:
At first we really thanks GOD which provided the At first we really thanks GOD which provided the conditions in order to work on the project as much conditions in order to work on the project as much as possible. Then we are really grateful of our wise as possible. Then we are really grateful of our wise master,Dr.vakili on behalf of the recommendations. master,Dr.vakili on behalf of the recommendations. We really thanks from TAKARAN CO(ISACO bureau We really thanks from TAKARAN CO(ISACO bureau in TEHARAN) , our dear engineer ,Mr.Ghorbani and in TEHARAN) , our dear engineer ,Mr.Ghorbani and our classmate Mr.milanchiyan.We hope to develop our classmate Mr.milanchiyan.We hope to develop
our performance in future works.enshalahour performance in future works.enshalah.….…
References:
1.Budynas,Nisbett,shigley’s mechanical engineering design,6th,7th,8th edition,Mc graw Hill,
افزار . 2 نرم توسط طراحی و رحیمیان،تحلیل محمد ANSYS دکتر
در. 33 در. طراحی نارنجی ANSYSANSYSطراحی مثلث کتابهای جمشیدی،مجموعه نارنجی ،نیما مثلث کتابهای جمشیدی،مجموعه ،نیما
44..www.SKF.COMwww.SKF.COM
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