# Generating a back and forth movement of an axle

• Lobotomy
In summary, to have an axle rotate back and forth from one position to the other, a mechanism can be created using a motor with a crank or eccentric that drives a connecting link, such as a Pitman arm or radius arm, which is then engaged to the rotating shaft. This can be seen in action in a washing machine transmission.
Lobotomy
Goal: To have an axle rotate back and forth from one position to the other.

We have a motor rotating in one direction

How so solve this in a smart/simple way?

I'm thinking having
1. one cog on the motor axle, rotating the same way as the motor
2. a second cog connected to the above cog that would then rotate in the other direction.
3. having one "camshaft" each, roughly L-shaped part, connected to each cog. The cams will then rotate in different direction.
4. The axle that should rotate back and forth is roughly Z-shaped with an "offset" part that will be touched by the cams.
5. This will generate a movement back and forth when the cams, revolving in different direction touches the offset part of the axle.

See my extremely silly drawing attached =)

*will this work in principle?
*is there a better/simpler way to do it?

Would there for instance be a cleverly designed cam shape that can singlehandedly do the same job if just put on the motor axle?

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Lobotomy said:
Goal: To have an axle rotate back and forth from one position to the other.
I don't understand.
Does the axle have two wheels?
Are those wheels free to rotate on the axle, or are they driven?
What do you mean by "back and forth", aim in a different direction, or rotate the axle about it's axis, forwards and backwards?
Why ?

Baluncore said:
I don't understand.
Does the axle have two wheels?
Are those wheels free to rotate on the axle, or are they driven?
What do you mean by "back and forth", aim in a different direction, or rotate the axle about it's axis, forwards and backwards?
Why ?

No it has nothing to do with wheels. There's no purpose.
The axle rotates like 90 degrees in one direction, and then it should rotate 90 degrees back to where it began. Thats the "requirement".

Problem is that the motor only rotates in one direction, otherwise you could just drive the engine in one direction and then put it in reverse and drive it back. Therefore you need some kind of mechanism in betweeen

If you only want 90° then a crank on the motor, linked to a longer crank on the shaft will do that.

If you want more than 90°, maybe several turns, then mount a crank or an eccentric on the motor shaft, that pushes and pulls a Pitman arm.
A gear rack on the Pitman arm, is engaged to a pinion gear on the rotating shaft.
The throw of the motor crank, and the size of the pinion, sets the angle of shaft rotation.

Baluncore said:
If you only want 90° then a crank on the motor, linked to a longer crank on the shaft will do that.

OK, I am not really following, do you have an illustration, video or so on something similar in principle?

Baluncore said:

ok so somewhat like pistons in an engine: first "piston" goes up, and the other piston down, and pushes the axle one way. Then the second piston goes up and the first down, pushing it the other way?
The axle would have like a U-shaped horsewhoe at the end.

Lobotomy said:
The axle would have like a U-shaped horsewhoe at the end.
Not necessarily. The motor could have a simple crank, or an eccentric.
https://en.wikipedia.org/wiki/Eccentric_(mechanism)

Since shaft rotation is not beyond about 120°, the connecting link does not need to cut the shaft axis. A radius arm clamped to the straight shaft, would be driven by one end of the link.

Just Google washing machine transmission. No need to reinvent the wheel.

berkeman

## 1. What is the purpose of generating a back and forth movement of an axle?

The purpose of generating a back and forth movement of an axle is to convert rotational motion into linear motion. This can be used in various mechanical devices such as pumps, pistons, and conveyor belts.

## 2. How is a back and forth movement of an axle achieved?

A back and forth movement of an axle is achieved through the use of a crank and connecting rod mechanism. The crank rotates the axle, while the connecting rod translates this rotation into linear motion.

## 3. What factors affect the back and forth movement of an axle?

The back and forth movement of an axle can be affected by various factors such as the length and angle of the connecting rod, the speed and torque of the crank, and the friction between the moving parts.

## 4. Can the back and forth movement of an axle be controlled?

Yes, the back and forth movement of an axle can be controlled by adjusting the parameters mentioned above. By changing the length or angle of the connecting rod, or the speed and torque of the crank, the motion of the axle can be altered.

## 5. What are some real-world applications of generating a back and forth movement of an axle?

Generating a back and forth movement of an axle has various real-world applications, such as in car engines, where the crankshaft converts the rotational motion of the pistons into linear motion to power the vehicle. It is also used in pumps to move fluids, and in manufacturing processes for conveyor belts and other automated machinery.

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