Hello,(adsbygoogle = window.adsbygoogle || []).push({});

I'm stuck on what should be a fairly simple problem. Trying to calculate the size of motor required to rotate steel pipe at 0.33RPM around its axis, on 2 sets of rollers, 4 wheels total (hard rubber).

Pipe

48" OD Mild Steel pipe 0.5WT

24m in Length

Rollers

4 x 12" Rubber wheels (40" Center to Center) on bearings

This is where is stand.

Torque required to accelerate the system (0.00 RPM to 0.33 RPM in 1 sec)

Ta=Iα

I=(∏/32)ρL(D1^4-D2^4)

1.219 D1 – External diameter of the disc [m]

1.194 D2 – Internal diameter of the disc [m]

7,850.000 ρ – Density of the load [kg/m3]

9,069.050 m – Weight of the load [kg]

24.000 L – Length of the load [m]

I=3,300.689

α=(w1-w0)/t

0.000 ω0 – Initial velocity of the motor [rad/s]

0.035 ω1 – Final velocity of the motor [rad/s] or 0.33 RPM

1.000 t – Time for velocity change

α=0.035

Ta=114.064 N*m

Now the next part i am not too sure about,

Torque required to overcome rolling resistance :

Rolling resistance coefficient - f = 0.0077m Hard Rubber on Steel

http://www.roymech.co.uk/Useful_Tables/Tribology/co_of_frict.htm

F = f x W/R

Fr=(0.0077m*9069.050kg*9.81 kg/s^2)/0.610m

Trr= 1123.031 N *.610m = 685.049 N*m

Total Torque required to rotate the pipe at 0.33rpms in 1 sec.

T=Ta+Trr=799 N*m

or

589 Lb*ft

This seems low to me and this is only the torque at the pipe, once geared that torque will be significantly lower. will I know i'm missing the bearing friction torque required but that cant be that much.

What else should I be calculating?, if anything.

I have attached a drawing of the system, once I find the torque required for rotate the pipe I should have the required input torque dividing that Torque by the gear ratios.

One more thing, Bonus question. Some of these types of pipe have a seam welded down the middle along the length of the pipe, it projects from the pipe a few mm sort of like a speed bump on the pipe. Is there a way to calculate the torque required to over come the rollers once the seams comes in contact with the roller wheels?

Thanks in advance.

**Physics Forums - The Fusion of Science and Community**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Torque required to rotate steel pipe on rollers

Loading...

Similar Threads - Torque required rotate | Date |
---|---|

What is the torque required for a track to climb over a step | Jan 27, 2018 |

Calculating the torque required to rotate a ski on snow | Dec 29, 2017 |

Torque required to rotate 5 flywheels connected with 1 belt | Dec 2, 2015 |

How can we calculate the required torque to rotate 1200 kg? | Mar 28, 2015 |

Torque Required to Rotate a Drum | Mar 25, 2015 |

**Physics Forums - The Fusion of Science and Community**