7/21/2019 Customer Requirement

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Speed reducer gearbox for tractor

Customer Requirement

This project is to design a small size speed reducer gearbox that is used in a small

tractor. The tractor uses a 4-cylinder SI engine with power rating 50kW. It is operated 9hours per day, 5 days per week  and with a high rotational speed of ~ 100 rad/s.

However, the drive for the wheels of the tractor is desired to rotate more slowly ~20 rad/s

and transmit a higher torque than is available at the output of the engine.In order to reduce fuel consumption, the design of the gearbox has to be light

weight. Besides that, as part of the customer requirement, the designer must ensure that

the gearbox is good in performance, safe to use, low production cost and ease to

manufacture.

Functions

1. 

To receive power from the tractor’s engine through a rotating shaft. 2.  To transmit the power through machine elements that reduce the rotational speed

to a desired value3.  To deliver the power at the lower speed to an output shaft that ultimately drives

the wheels of the tractor.

Design requirements

1.  The reducer must transmit 50 kW.

2.  To reduce speed with a ratio of 5:1.

3.  The input is from a 4 cylinder SI engine with a rotational speed of ~100 rad/s.4.  The output delivers the power at a rotational speed ~20 rad/s.

5.  The tractor is expected to operate 9 hours (h) per day, 5 days per week.

Evaluation Criteria

1. Safety2. Performance

3. Low cost

4. Ease to manufacture

5. Light weight6. Small size

7. Reliable