Maximum torque, maximum power

In summary, the torque developed at maximum power is less than the maximum torque of 165 Nm at 4300 rev/min and its maximum power 88 kW at 5500 rev/min.
  • #1
phigit
2
0
Explain why the torque developed at maximum power is less than the maximum torque

maximum torque of 165 Nm at 4300 rev/min and its maximum power 88 kW at 5500 rev/min

Torque developed at maximum power
T = bp x 60
2pN
= 88000 x 60
2 x p x 5500
= 152.8 Nm

Power developed at maximum torque
bp = 2pNT
60
= 2 x p x 4300 x 165
60
= 74298.66626 ÷ 1000
= 74.3 kW

please help I'm really not sure!:cry:
 
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  • #2
phigit said:
Torque developed at maximum power
T = bp x 60
2pN
= 88000 x 60
2 x p x 5500
= 152.8 Nm

I don't know what the problem is.

152 is less than 165,

isn't it? There's no need to do anything with the second equation here, you're done.
 
  • #3
it's necessary to explain why and why the loss occurs though.
 
  • #4
The rotational speed is still low when the maximum torque is applied at a lower gear ratio. As the speed picks up you change over to a higher gear and you can then apply less torque.
 
  • #5
The answer (as given by andrevdh) cannot be deduced through the math in this particular problem, so there is no formula to prove it. Motors and machines will have several factors that affect their efficiency of energy transfer.
 
  • #6
Could it be due to (rotational) inertia - that is the rotational speed peaks at a later stage than the applied torque?

Am sure the motor enthusiasts have discussed this to great lengths ... and still have not come to a conclusion.
 
  • #7
andrevdh said:
Could it be due to (rotational) inertia - that is the rotational speed peaks at a later stage than the applied torque?

Am sure the motor enthusiasts have discussed this to great lengths ... and still have not come to a conclusion.

I think you were right with your previous post. I meant to say to the OP that your answer was not observable by looking at the given quantities; rather, it required knowledge of how motors and gears worked.
 
  • #8
phigit said:
Explain why the torque developed at maximum power is less than the maximum torque

maximum torque of 165 Nm at 4300 rev/min and its maximum power 88 kW at 5500 rev/min

Torque developed at maximum power
T = bp x 60
2pN
= 88000 x 60
2 x p x 5500
= 152.8 Nm

Power developed at maximum torque
bp = 2pNT
60
= 2 x p x 4300 x 165

60
= 74298.66626 ÷ 1000
= 74.3 kW

please help I'm really not sure!:cry:

maximum torque is develo

the torque developed is low at maximum power because of many other thing that helps your torque reduce when power is increased,
one example is when you start the engine, during starting you need more torque to turn your engine, but once your engine is running the torque is reduce because of to many factors, first is the momentum of your flywheel that helps the shaft to turn faster, second is friction will be reduce between shafts and bearing, and third is the speed, once your speed is built up your shaft is almost floating from the bearing which reduces the friction a lot.
 
  • #9
LOL phigit you got a exact same question at my, r u doing IMI course?

and your answers above are same as me.

p/s:eek:ps, not seeing the date from 2007
 
Last edited:

What is maximum torque?

Maximum torque is the maximum amount of rotational force that an engine or motor can produce. It is typically measured in units of Newton-meters (Nm) or foot-pounds (ft-lbs) and is an important factor in determining the overall performance of a machine.

What is maximum power?

Maximum power is the maximum rate at which work can be done, or energy can be converted, by an engine or motor. It is typically measured in units of watts (W) or horsepower (hp) and is a crucial factor in determining the speed and acceleration of a machine.

What is the relationship between maximum torque and maximum power?

Maximum torque and maximum power are interrelated, but not necessarily directly proportional. In simple terms, an engine or motor with a high maximum torque will be able to produce a high maximum power, but the specific power output will depend on the engine's speed. This means that an engine with a lower maximum torque but a higher maximum power may actually have better performance in certain situations.

How do you measure maximum torque and maximum power?

Maximum torque and maximum power can be measured using a dynamometer, which applies a load to the engine or motor and measures the resulting output. The engine is typically run at different speeds and loads to determine the maximum values. These measurements are then used to create a torque and power curve, which shows the maximum values at different speeds and loads.

What factors can affect maximum torque and maximum power?

The maximum torque and maximum power of an engine or motor can be affected by a variety of factors, including the engine design, fuel type, air intake, exhaust system, and operating conditions. Changes in any of these factors can lead to changes in the torque and power output of the engine. Additionally, the efficiency of the drivetrain and transmission can also impact the overall torque and power of a machine.

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