Mechanical Engineering Gurus?

[EvanH]

Ok, I think I am correct in thinking and function, but I would like some help to make sure I am right.

I have two gears. One gear is 6" in diameter. One is 2" in diameter. The 6" gear is driven at 300 RPM.

The 2" gear is not driven by the 6" gear. Instead I have a 2" gear on the 6", connecting it to said 2" gear via chain.

The 6" gear and the adjacent 2" gear have three points, each located at 120 degrees.

Since the 6 and 2 are connected by a seperate 2" gear. The 6" gear and the adjacent 2" gear(driven by the 2" that is on the 6") will rotate the same direction, at 300 rpm each, and will have the ability to match the three points every time because the drive ratio for the 2" gear is a 1:1.

And even if they were some hair brained sizes like 5.387 and 1.276, as long as the connecting gear was even they would still turn the same rate and direction.

Thanks!

[AdamVR4]

Since the 6 and 2 are connected by a seperate 2" gear. The 6" gear and the adjacent 2" gear(driven by the 2" that is on the 6") will rotate the same direction, at 300 rpm each, and will have the ability to match the three points every time because the drive ratio for the 2" gear is a 1:1.

And even if they were some hair brained sizes like 5.387 and 1.276, as long as the connecting gear was even they would still turn the same rate and direction.

I think you've got it. Neglecting inertia, the 6" gear is essentially useless.

[DocWalt]

The 6" gear is useless. Not really sure if that's what you were asking, but yeah...

[19Eclipse90]

You've got it right. Gears on the same shaft rotate at the same speed.

[lawdogg]

[Lithium]

The 6" gear is useless. Not really sure if that's what you were asking, but yeah...

Not entirely, If this machine is using the 6" gear to rotate this assembly then It would give the machine more leverage over the 2" gears. For example if the machine was using an electric motor, an electric motor is limited by its voltage supply. The only way to change that motors output characteristics is to increase/ decrease voltage or increase/ decrease a particular gear set that the motor could be rotating. Long story short, Just like a bicycle, bigger gear in the back allows your feet to have more leverage over the tire but not much speed and vise versa. Small gear in the back allows for more speed but less leverage. So really in his example the size of the 6" gear could be used for regulating the speed of this said rotating assembly.

[DocWalt]

Not entirely, If this machine is using the 6" gear to rotate this assembly then It would give the machine more leverage over the 2" gears. For example if the machine was using an electric motor, an electric motor is limited by its voltage supply. The only way to change that motors output characteristics is to increase/ decrease voltage or increase/ decrease a particular gear set that the motor could be rotating. Long story short, Just like a bicycle, bigger gear in the back allows your feet to have more leverage over the tire but not much speed and vise versa. Small gear in the back allows for more speed but less leverage. So really in his example the size of the 6" gear could be used for regulating the speed of this said rotating assembly.

Which is true, but completely unrelated to the question he's asking. He's only asking if the dots would stay "in time", which they would.

[Lithium]

Which is true, but completely unrelated to the question he's asking. He's only asking if the dots would stay "in time", which they would.

most likely true because I didnt read the OP lol.

[blindmist]

Now just to land it.....


Lets put this into a real world use here.

Your crank gear that turns the timing belt is exactly HALF the size of the cams (ratio being the factor which is 1:2). Therefore, your crank turns two times for every one rotation of the cam. So, if you have 1 mark that aligns on all of them, it will only happen once every other rotation of the crank.

[i3igpete]