- #1
hollidca
- 13
- 0
This is the solution to a question. I have followed it through with my own calculations and I'm getting good numbers. However I don't understand how the numbers for 8. are decided. Why is the last one 1/4? I need to work this out because it is putting my lifting speed 0.06m/s below the limit for my project.
1. Calculate lifting load: W=mg=21600 N
2. Calculate power: Plan VL = 0.1 m/s P=W VL = 2160 Watt
3. Motor selection: Dayton AC motor catalogue Selected Motor: 4LX07 Dayton 2240 Watt
@1725 rpm (=180 rad/s)
4. Check for lifting speed: VL = Pmotor/W= 2240/ 21600= 0.104 m/s (OK in the range)
5. Calculate cable speed: For the cable-pulley configuration shown: Vcable =2VL=0.2m/s
6. Select: ddrum=25cm
7. Calculate gearbox speed ratio: ωdrum= Vcable /rdrum=0.2/0.125=1.6 rad/s λ= ωdrum / ωmotor
=1/112
8. Distribute the speed ratio: (1/3) x(1/3)x(1/3)x(1/4)=1/108 (speed reduction over 5 shafts)
9. Check for lifting speed for λ= 1/108 : ωdrum= 1/108 xωmotor =1.67 rad/s Vcable =rdrumωdrum
=0.125x1.67=0.208m/sVL= Vcable/2=0.104 m/s (OK in the range)
10. Select number of teeth for pinions and calculate number of teeth for gears: [Note: In
your project select N=14 for pinions]
11. Calculate gear pitch diameters: [ Note: In your project use helical gears with module
M=2mm, pressure angle φt=20 and helix angle ψ=30 degrees, for simplicity].
Any help would be greatly appreciated.
1. Calculate lifting load: W=mg=21600 N
2. Calculate power: Plan VL = 0.1 m/s P=W VL = 2160 Watt
3. Motor selection: Dayton AC motor catalogue Selected Motor: 4LX07 Dayton 2240 Watt
@1725 rpm (=180 rad/s)
4. Check for lifting speed: VL = Pmotor/W= 2240/ 21600= 0.104 m/s (OK in the range)
5. Calculate cable speed: For the cable-pulley configuration shown: Vcable =2VL=0.2m/s
6. Select: ddrum=25cm
7. Calculate gearbox speed ratio: ωdrum= Vcable /rdrum=0.2/0.125=1.6 rad/s λ= ωdrum / ωmotor
=1/112
8. Distribute the speed ratio: (1/3) x(1/3)x(1/3)x(1/4)=1/108 (speed reduction over 5 shafts)
9. Check for lifting speed for λ= 1/108 : ωdrum= 1/108 xωmotor =1.67 rad/s Vcable =rdrumωdrum
=0.125x1.67=0.208m/sVL= Vcable/2=0.104 m/s (OK in the range)
10. Select number of teeth for pinions and calculate number of teeth for gears: [Note: In
your project select N=14 for pinions]
11. Calculate gear pitch diameters: [ Note: In your project use helical gears with module
M=2mm, pressure angle φt=20 and helix angle ψ=30 degrees, for simplicity].
Any help would be greatly appreciated.