Gearbox torque calculation - input/output

In summary, the conversation discusses a problem with calculating the input torque of a gearbox, which has an output torque of 0.12348 Nm, an output speed of 80 rpm, and an input speed of 4 rpm. The gearbox has a ratio of 1:20 and is composed of four gears, two pairs each consisting of a driver and a driven gear. The solution involves multiplying the output torque by the gear ratio to obtain the input torque. The application in question is a concept design involving a power spring driving a pump.
  • #1
karl8695
5
0
Hi all,

Please help me to solve this fairly simple problem (i think):

Gearbox output torque driving the input shaft to pump = 0.12348 Nm
Gearbox output speed - 80 rpm
Gearbox input speed - 4 rpm

Gearbox is compound consisting of x4 gears arranged in two pairs -

Gear A, driver = 100 teeth
Gear B, driven = 20 teeth
Gear C, driver = 80 teeth
Gear D, driven = 20 teeth

Gearbox Ratio = 1:20

How do I calculate the input torque?

Thanks in advance
 
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  • #2
It seems to me your gearbox is working from low speed to high speed, meaning your gear ratio is speeding up the rotation, which means it is reducing the torque by the same ratio.

take your 'output' torque and multiply this by the ratio to get the input torque.

What's your application? This is opposite of how I use gearboxes.
 
  • #3
Hi Huntoon,

The question is related to a concept design where a power spring will be driving the input to a pump; think along the lines of the Baylis wind-up radio.

And thanks for your response, i was hoping it was that simple.
 
  • #4
double check your math and my logic. you get what you pay for, you know what I mean... happy to help though, cheers.
 

FAQ: Gearbox torque calculation - input/output

1. What is torque and why is it important in gearbox calculations?

Torque is a measure of the force that causes an object to rotate around an axis. In gearbox calculations, it is important because it determines the amount of force that the gearbox can handle and the amount of power it can transmit.

2. How is torque calculated for a gearbox?

To calculate torque for a gearbox, you need to know the input torque of the motor or engine, the gear ratio of the gearbox, and the efficiency of the gearbox. The output torque can then be calculated by multiplying the input torque by the gear ratio and dividing by the efficiency.

3. What is the difference between input torque and output torque in a gearbox?

Input torque is the torque coming from the motor or engine that is driving the gearbox, while output torque is the torque being transmitted from the gearbox to the load. The gear ratio and efficiency of the gearbox determine the relationship between input and output torque.

4. How does the gear ratio affect the torque in a gearbox?

The gear ratio is the ratio between the number of teeth on the input gear and the number of teeth on the output gear. It determines how much the output shaft will rotate compared to the input shaft and therefore affects the amount of torque that can be transmitted.

5. What factors can affect the accuracy of gearbox torque calculations?

Some factors that can affect the accuracy of gearbox torque calculations include variations in gear tooth profile, backlash, lubrication, and load variations. It is important to consider these factors when designing and selecting gearboxes for specific applications.

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