Gearbox design-Is this design possible to make the output shaft thin?

Click For Summary

Discussion Overview

The discussion revolves around the feasibility of a gearbox design that allows for a thin output shaft. Participants explore various design considerations, including bearing arrangements, torque requirements, and the implications of belt tension on shaft diameter. The scope includes technical explanations and design challenges related to mechanical engineering.

Discussion Character

  • Technical explanation, Debate/contested

Main Points Raised

  • Some participants question the correctness of the design without visual aids or detailed specifications, such as bearing types and arrangements.
  • One participant emphasizes that there is no singular correct design and discusses the importance of proper bearing positioning and alignment to manage forces and stresses on the shaft.
  • Concerns are raised about the practicality of supporting the output shaft on both sides of the pulley, suggesting that quick belt changes may be hindered by such a design.
  • A proposal is made for a compression strut supported by self-aligning bearings to counter belt tension while allowing for easy belt replacement.
  • Participants are encouraged to specify key parameters like power transmission, output shaft RPM, torque, pulley diameter, and belt tension to determine the minimum shaft diameter needed.
  • Another solution is suggested involving a coupling between the output shaft and an independent shaft, which would be supported by bearings and allow for cantilever mounting for easier belt replacement.
  • Alignment of both shafts is noted as critical for extending the life of the coupling.

Areas of Agreement / Disagreement

Participants express differing views on the design's feasibility and the best approach to achieving a thin output shaft. There is no consensus on a single solution, and multiple competing ideas are presented.

Contextual Notes

Participants note the need for specific parameters and conditions to be defined, such as torque requirements and alignment considerations, which are essential for evaluating the proposed designs.

a61098417
Messages
1
Reaction score
0
TL;DR
The output shaft of the gearbox undergoes torque and bending force(tensile force of the belt)(I use belt after gearbox). If I mount/fix the pulley on other things instead of the output shaft, the belt won't bend the shaft. Thus, the output shaft gets torque only. Is my design correct?
Is this design correct?
 
Engineering news on Phys.org
Welcome to PhysicsForums. Can you post a drawing or picture of your arrangement, and comment on what kind of bearings you are using at each joint? You can use the "Attach files" link below the Edit window to upload PDF or JPEG files.
 
  • Like
Likes   Reactions: Lnewqban and Dr.D
a61098417 said:
Is this design correct?
There are many solutions. There is no one correct design.

Where an additional bearing is provided, it must be positioned and aligned correctly, or it will not carry the required forces without increasing stresses in the shaft. Will you have a flexible coupling between the gearbox and the pulley shaft?

The problem with supporting the output shaft on both sides of the belt pulley is that you are restricted to a mounting that enables you to change the belts quickly, without special tools.

What does the belt drive? A compression strut, floating in spherical self-aligning bearings, between two shafts, can counter the belt tension, while making it possible to change the belt quickly.

Specify the power to be transmitted.
Specify the RPM of the output shaft.
Compute the torque in the shaft.
Specify the pulley diameter and the tension in the belt.

The minimum possible shaft diameter to consider must satisfy that torque requirement.
Now analyse the bending due to belt tension with one or two support pulleys.
 
  • Like
Likes   Reactions: Lnewqban and berkeman

Similar threads

  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 16 ·
Replies
16
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
Replies
2
Views
1K
  • · Replies 24 ·
Replies
24
Views
2K
Replies
2
Views
3K
  • · Replies 27 ·
Replies
27
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K