Mechanism to Reverse Rotating Axle with Friction: Ideas Needed

In summary, the individual is seeking a mechanism to reverse the direction of rotation on a rotating axle when there is too much friction. They prefer to use purely mechanical parts such as springs and gears. The conversation includes various suggestions and ideas, including using a torque-limiting clutch and planetary gear system with a pawl to shift or lock the gears. Another suggestion is to use tumbler gears or over-centre spring loading to toggle the direction of rotation. The individual expresses gratitude for the suggestions and states that they have found what they needed.
  • #1
Chris184
3
1
Hello,

for my current physics-project i am searching a mechanism:
When there is to much friction on a rotating axle, it should reverse the direction and go on, till the mechanism starts all over again. I would love to solve this with pure mechanical parts, like springs gears etc...

If you have any ideas on how to realize this mechanism, or even an existing mechanism, please share your thoughts with me. I am happy about every idea.

Thanks, Chris

p.s.: and sorry for my english, I am from Austria ;)
 
Engineering news on Phys.org
  • #2
Welcome to the PF.
Chris184 said:
When there is to much friction on a rotating axle, it should reverse the direction and go on, till the mechanism starts all over again. I would love to solve this with pure mechanical parts, like springs gears etc...
Can you describe the behavior a bit more? What is applying frictional torque to the axle? What is driving the axle against that frictional torque? Will reversing the direction of axle rotation zero out the frictional torque, or will it remain just as strong after the reversal?
 
  • #3
I don't know how practical, but this concept comes to mind.
  • concentric shafts, one the drive the other driven
  • a torque-limiting clutch, as used in some battery operated screwdrivers
  • planetary gear system coupling the two shafts
  • when the torque-limiting clutch slips it drives a pawl that shifts (or locks?) the planetary gear train
Still lots of details to work out!

Cheers,
Tom
 
  • #4
"...drives a pawl that shifts (or locks?) the planetary gear train"

thus reversing the rotation of the driven shaft. (Is this what you mean to say?)
 
  • Like
Likes Chris184
  • #5
berkeman said:
Welcome to the PF.

Can you describe the behavior a bit more? What is applying frictional torque to the axle? What is driving the axle against that frictional torque? Will reversing the direction of axle rotation zero out the frictional torque, or will it remain just as strong after the reversal?

Yes sure. There is a torqueslip built into a linear actuator. The linearactuator shall be driven in and out by this mechanism. When reversing the direction the friction will remain as strong as before the reversal.
Thanks for your comment.
Tom.G said:
I don't know how practical, but this concept comes to mind.
  • concentric shafts, one the drive the other driven
  • a torque-limiting clutch, as used in some battery operated screwdrivers
  • planetary gear system coupling the two shafts
  • when the torque-limiting clutch slips it drives a pawl that shifts (or locks?) the planetary gear train
Still lots of details to work out!

Cheers,
Tom

Hey Tom, thanks for your idea. It was helpful. Even tho i did not completely understand the pawl. The problem which comes in my mind is that the pawl has to be unlocked again, since i want the mechanism to be repeatet more than twice. Do you understand my concerns, or did i misunderstand you?

Thanks for your comment!
 
Last edited:
  • #6
AZFIREBALL said:
"...drives a pawl that shifts (or locks?) the planetary gear train"

thus reversing the rotation of the driven shaft. (Is this what you mean to say?
Yes.

Chris184 said:
Do you understand my concerns, or did i misunderstand you?
Probably a bit of both!

Chris184 said:
When reversing the direction the friction will remain as strong as after before? the reversal.
I think that shoots down my (shadow of an) approach. But I do wonder how the driven element doesn't immediately switch back to the first direction.
 
  • #7
Google 'Tumbler gears'.
Two gears that act forward or one of which reverses. Used on the lead screw on a lathe when thread cutting.
Take a look at a thread cutting lathe to see how Left/Right thread is selected.
You could over-centre spring load the gear mount plate so that when it is overloaded it toggles or flips to the other mode and reflects direction.
 
  • #8
Baluncore said:
Google 'Tumbler gears'.
Two gears that act forward or one of which reverses. Used on the lead screw on a lathe when thread cutting.
Take a look at a thread cutting lathe to see how Left/Right thread is selected.
You could over-centre spring load the gear mount plate so that when it is overloaded it toggles or flips to the other mode and reflects direction.

Thank you very much, that's exactly what i needed!
 

1. How does friction affect the rotation of an axle?

Friction is a force that resists the motion between two surfaces in contact. In the case of rotating axles, friction can slow down or stop the rotation, depending on the direction of the force.

2. What is the purpose of reversing the rotation of an axle?

The purpose of reversing the rotation of an axle can vary depending on the specific application. In some cases, it may be desired to change the direction of movement, while in others it may be necessary for safety reasons or to prevent wear and tear on the axle or surrounding components.

3. What are some potential ways to reverse the rotation of an axle with friction?

There are several potential ideas for reversing the rotation of an axle with friction. Some possibilities include using a gear mechanism, changing the direction of the applied force, or implementing a braking system to slow down and change the direction of rotation.

4. What factors should be considered when designing a mechanism to reverse rotating axles with friction?

When designing a mechanism to reverse rotating axles with friction, it is important to consider the amount of friction between the axle and its surrounding components, the direction and strength of the applied force, and the desired speed and direction of rotation. Additionally, the durability and efficiency of the mechanism should be taken into account.

5. Are there any potential drawbacks or challenges associated with using friction to reverse the rotation of an axle?

One potential drawback of using friction to reverse the rotation of an axle is that it can cause wear and tear on the axle and its surrounding components if not properly managed. Additionally, factors such as temperature and lubrication can impact the effectiveness of using friction for this purpose. It is important to carefully consider and address these potential challenges when designing a mechanism for reversing rotating axles with friction.

Similar threads

Analyzing the Mechanics of a Wobble Plate in a Cranked Axle Mechanism
    • Mechanical Engineering
Replies
10
Views
2K
Translating reciprocating motion into a 45 degree rotation
    • Mechanical Engineering
Replies
5
Views
1K
My weird geneva mechanism doesn't work. Looking for suggestions
    • Mechanical Engineering
Replies
3
Views
948
Insights for a Mechanical Engineering student
    • Mechanical Engineering
Replies
11
Views
2K
Seeking ideas for how to achieve an adjustably damped shaft connector
    • Mechanical Engineering
Replies
6
Views
1K
Film Advance system research for DIY Camera
    • Mechanical Engineering
Replies
3
Views
1K
How good are automatic watch winding mechanisms?
    • Mechanical Engineering
Replies
22
Views
2K
What kind of pump can do this?
    • Mechanical Engineering
Replies
22
Views
1K
Is a Larger DC Motor Needed for Low Wind Speed Power Generation?
    • Mechanical Engineering
Replies
34
Views
2K
Slowly Rotating Device For a Camera Pan Timelapse
    • Mechanical Engineering
Replies
12
Views
2K

Hot Threads

Recent Insights

Back
Top