![DESIGN PROCEDURE BASED ON GEAR LIFE
SL.
NO
SPUR GEAR HELICAL GEAR BEVEL GEAR WORM GEAR
1. Step-1 Gear ratio (i)...Gear ratio value is initially given
2
Step-2 .Selection of material
Respective material is given in the data. If not given based on application select the material
3.
Step-3 .Gear Life
The given gear life is in hours. Convert to minutes.
Life in no of hours N=Gear life in minutes x N1= cycles.
[If not given assume as 20,000 hrs.]
4.
Step-4 Calculation of Initial Design Torque [Mt]:
[Mt]= Mt. K. Kd , Mt = P x 60/2ПN , Assume K. Kd = 1.3 , PSGDB 8.15
Assume K. Kd = 1
[PSGDB-8.44]
5.
Step-5 Calculation of Eequ , [σb] & [σc] :
Eequ –PSGDB 8.14, [ σb] – 1.4 Kbl x σ-1
/n. K σ PSGDB-8.18, Kbl-PSGDB 8.20, n- PSGDB
8.19, K σ –PSGDB 8.19 , [σc]- CR.HRC.Kcl ,–PSGDB 8.16 ,CR.HRC.Kcl –PSGDB 8.17
(CB.HB.Kcl –PSGDB 8.17 for bevel gear)
[σb] & [σc]-PSGDB-8.45
6.
Step-6, Calculation of Centre Distance (a)/ For bevel & worm Cone distance (R)
For Designing Refer PSGDB-8.13,ψ- b/a-PSGDB-8.14, ψy-R/b-PSGDB 8.15
PSGDB-8.44, for d2
Assume q=11
PSGDB-8.44](https://image.slidesharecdn.com/unit-23basedongearlife-230615045244-f21bfbb3/85/UNIT-2-3-based-on-gear-life-pdf-1-320.jpg)
![STEP
NO
SPUR GEAR HELICAL GEAR BEVEL GEAR WORM GEAR
12.
Step-12 Revision of Design Torque of Gear [Mt]
Re-Calculation of [σc],
K,Kd
Revise K, Kd from PSGDB 8.15, 8.16. Then find [Mt]
Based on Vs, σc is
selected.
13.
Step-13 Check for Bending. [σb]
If [σb] > σb , Then the Design is safe
σb = . . .
x[Mt]
For Checking PSGDB 8.13A
Y= for Z1,PSGDB 8.18
σb =
.
. . .
x[Mt]
For Checking PSGDB 8.13A
Y= for Z1,PSGDB 8.18
σb =
[ ( )][ ]
( . ) . .
For Checking PSGDB 8.13A
for Zv1,for yv PSGDB 8.53
σb =
. [ ]
. . .
[PSGDB8.44]
for Z2,for yv PSGDB 8.18
14.
Step-14 Check for wear Strength. [σc]
If [σc] > σc , Then the Design is safe
σc =
0.74 .
. . [ ]
PSGDB-8.13
σc =
0.7 .
. . [ ]
PSGDB-8.13
σc =
.
[ . ]
( )
.
. . [ ]
PSGDB-8.13
σc =
. [ ]
PSGDB-8.44
15
Check For Efficiency (Only For Worm Gear) - PSGDB-8.49
η actual = ( )
Based on Vs select µ, then ρ = tan-1
(µ)..
If η actual > η Desired , Then design is safe
16
Step-15 .Basic Dimensions
Refer PSGDB 8.22 for determining the basic dimensions Refer PSGDB 8.38 for
determining the basic
dimensions
Refer PSGDB 8.43 for
determining the basic
dimensions](https://image.slidesharecdn.com/unit-23basedongearlife-230615045244-f21bfbb3/85/UNIT-2-3-based-on-gear-life-pdf-3-320.jpg)
UNIT- 2&3 based on gear life.pdf
- 1. DESIGN PROCEDURE BASED ON GEAR LIFE SL. NO SPUR GEAR HELICAL GEAR BEVEL GEAR WORM GEAR 1. Step-1 Gear ratio (i)...Gear ratio value is initially given 2 Step-2 .Selection of material Respective material is given in the data. If not given based on application select the material 3. Step-3 .Gear Life The given gear life is in hours. Convert to minutes. Life in no of hours N=Gear life in minutes x N1= cycles. [If not given assume as 20,000 hrs.] 4. Step-4 Calculation of Initial Design Torque [Mt]: [Mt]= Mt. K. Kd , Mt = P x 60/2ПN , Assume K. Kd = 1.3 , PSGDB 8.15 Assume K. Kd = 1 [PSGDB-8.44] 5. Step-5 Calculation of Eequ , [σb] & [σc] : Eequ –PSGDB 8.14, [ σb] – 1.4 Kbl x σ-1 /n. K σ PSGDB-8.18, Kbl-PSGDB 8.20, n- PSGDB 8.19, K σ –PSGDB 8.19 , [σc]- CR.HRC.Kcl ,–PSGDB 8.16 ,CR.HRC.Kcl –PSGDB 8.17 (CB.HB.Kcl –PSGDB 8.17 for bevel gear) [σb] & [σc]-PSGDB-8.45 6. Step-6, Calculation of Centre Distance (a)/ For bevel & worm Cone distance (R) For Designing Refer PSGDB-8.13,ψ- b/a-PSGDB-8.14, ψy-R/b-PSGDB 8.15 PSGDB-8.44, for d2 Assume q=11 PSGDB-8.44
- 2. STEP NO SPUR GEAR HELICAL GEAR BEVEL GEAR WORM GEAR 7. Step-7, Selection of Z1 & Z2 Assume (Z1 17-21), Z2 =I x Z1 Zv1= Z1/cos ᵟ1, Zv2= Z1/cos ᵟ2 } Based on efficiency value select the Z1. Refer PSGDB-8.46 Z2 =I x Z1 8 Step-8,Calculation of Module = -PSGDB-8.22 m n=2a.COSβ / (Z1 + Z2) PSGDB-8.22 = /0.5 + PSGDB-8.38 mx =2a/q+Z2+ẕ PSGDB-8.43 9. Step-9,Revised Center distance(a)/For bevel and Worm Cone Distance(R) = -PSGDB-8.22 a =( mn/ cosβ). (Z1 + Z2)/2 PSGDB-8.22 = 0.5 + PSGDB-8.38 R =0.5 mx(q+Z2+ẕ) PSGDB-8.43 10. Step-10 Calculation of b,d1,V & ψp Calculation of bav, mav ,d1av,V & ψp Calculation of d,V,γ,Vs .b= ψ.a d1= m.Z1 V= ПDN/60 ψp= b/d1 b= ψ.a d1= (mn/cosβ).Z1 V= ПDN/60 ψp= b/d1 PSGDB 8.15 ψy-R/b mav = mt-(b.sinδ1/Z1) d1av= mav x Z1 ψp= b/d1av d1= q. mx d2= Z2. mx γ=tan-1 (Z1/q) Vs=V1 x cos γ 11 Step-11, Selection of Quality of Gear From PSGDB 8.3, Based on Module the Preferred quality is selected. NA
- 3. STEP NO SPUR GEAR HELICAL GEAR BEVEL GEAR WORM GEAR 12. Step-12 Revision of Design Torque of Gear [Mt] Re-Calculation of [σc], K,Kd Revise K, Kd from PSGDB 8.15, 8.16. Then find [Mt] Based on Vs, σc is selected. 13. Step-13 Check for Bending. [σb] If [σb] > σb , Then the Design is safe σb = . . . x[Mt] For Checking PSGDB 8.13A Y= for Z1,PSGDB 8.18 σb = . . . . x[Mt] For Checking PSGDB 8.13A Y= for Z1,PSGDB 8.18 σb = [ ( )][ ] ( . ) . . For Checking PSGDB 8.13A for Zv1,for yv PSGDB 8.53 σb = . [ ] . . . [PSGDB8.44] for Z2,for yv PSGDB 8.18 14. Step-14 Check for wear Strength. [σc] If [σc] > σc , Then the Design is safe σc = 0.74 . . . [ ] PSGDB-8.13 σc = 0.7 . . . [ ] PSGDB-8.13 σc = . [ . ] ( ) . . . [ ] PSGDB-8.13 σc = . [ ] PSGDB-8.44 15 Check For Efficiency (Only For Worm Gear) - PSGDB-8.49 η actual = ( ) Based on Vs select µ, then ρ = tan-1 (µ).. If η actual > η Desired , Then design is safe 16 Step-15 .Basic Dimensions Refer PSGDB 8.22 for determining the basic dimensions Refer PSGDB 8.38 for determining the basic dimensions Refer PSGDB 8.43 for determining the basic dimensions