Example of gearbox calculation.

Table of Content:

• Input conditions
• Predistribution of transmission ratio
• Used calculations

Example of gearbox calculation.

In this chapter we will present a complete design of a one-speed gearbox driven by a belt transmission and driving a chain transmission.

Input conditions.

Transmitted power output 10 kW, electric motor speed 1450 /min, required output speed 30 /min. Load type - static, slight impacts, service life 20,000 hours. Material requirements are not defined.

Gearbox concept

Note: In the displayed drawing, the objects (2D) are shown as you can insert and set them up in the drawing (accurate dimensions). The following modifications are not solved to make a drawing complying with the recognized and the specified conditions of an engineering drawing.

Predistribution of transmission ratio.

• Belt transmission: V-belt, transmission 1:3, output speed 1450 / 3 = 483.33
• One-speed gearbox: External spur gear with helical toothing, transmission 1:4, output speed 483.33 / 4 = 120.83
• Chain transmission: Roller chain transmission, transmission 1:4, output speed, 120.83 / 4 = 30.21

Used calculations.

A total of twelve calculations, by means of which not only gearing, but also shafts, bearings, shaft connections, belt transmission and chain transmission can be designed and checked, have been used for the design. Relations between the individual calculations can also be created in calculating. This enables the creation of a comprehensive solution, which makes it possible to design various power options very fast through a simple change in input parameters and recalculation of all nodes.

It is evident that the result of calculations cannot be a complete design. However, the present calculations will make it possible to design the dimensions very fast (several hours), including the basic concept of the designed solution and including the basic optimization. Thus, it is possible to assess the suitability of the designed structure very quickly.

The individual calculations are numbered (see figure) and a list of them is shown hereinafter. By clicking on the link a full calculation listing is displayed.

1. V-Belt.

Specification and calculation results: vbelt_01_example1_en.pdf

2. External spur gear.

Specification and calculation results: Gear1_01_example1_en.pdf

3. Shaft No 1.

Specification and calculation results: Shaft_No1_example1_en.pdf

4. Shaft-hub connection.

Specification and calculation results: ShaftCon_No1_Example1_en.pdf

5. Bearing No 1.

Specification and calculation results: BearingSKF_No1_ShaftNo1_example1_en.pdf

6. Bearing No 2.

Specification and calculation results: BearingSKF_No2_ShaftNo1_example1_en.pdf

7. Roller chains transmission.

Specification and calculation results: Chains_01_example1_en.pdf

8. Shaft No 2.

Specification and calculation results: Shaft_No2_example1_en.pdf

9. Shaft-hub connection.

Specification and calculation results: ShaftCon_No2_Example1_en.pdf

10. Shaft-hub connection.

Specification and calculation results: ShaftCon_No3_Example1_en.pdf

11. Bearing No 1.

Specification and calculation results: BearingSKF_No1_ShaftNo2_example1_en.pdf

12. Bearing No 2.

Specification and calculation results: BearingSKF_No2_ShaftNo2_example1_en.pdf