Monster Transmission?
Melting Slicks
Joined: Feb 2003
Posts: 2,677
Likes: 812
From: Saskatoon Sask.
I hear what you are saying. The teeth of first planetary gear will determine the relative position of sun, ring and planetary gears.
The center of each following planetary gear can only be placed in positions that allow both ring and sun gear to engage.
I totally agree.
But why should the carrier be forced to use 'even spacing' between gears? Having planetary gears a fraction offset to engage closest tooth is not a problem.
The center of each following planetary gear can only be placed in positions that allow both ring and sun gear to engage.
I totally agree.
But why should the carrier be forced to use 'even spacing' between gears? Having planetary gears a fraction offset to engage closest tooth is not a problem.
Even spacing promotes even loading I would assume. Most things in this world are symmetrical unless there is a specific reason not to. This is all very simple. Let's look at real world instead of hypothetical and guessing.
1. GM only makes one rear ring gear for the 4l60
2. Due to the fact that the ratios don't change(stock), by default the sun gear is the same for both the 5 planet and the 4 planet trans.
3. This gives way to the planets having to be the same diameter and tooth count to maintain proper gear mesh.
4. The 4 planet carrier gears are 90° apart. The 5 planet carrier gears are 72° apart. How does GM get this to work like a charm when Dogs said in post #37 that this wasn't possible - it would lock up?
Melting Slicks
Joined: Mar 2001
Posts: 2,150
Likes: 304
From: Timra, Sweden
From this link
In your basic setup, your ring gear will have teeth equal to the number of the teeth in the sun gear, plus two planets (though there may be advantages to modifying this slightly), simply because a line straight across the center from one end of the ring gear to the other will span the sun gear at the center, and room for a planet on either end. The planets will typically be spaced at regular intervals around the sun. To accomplish this, the total number of teeth in the ring gear and sun gear combined divided by the number of planets has to equal a whole number. Of course, the planets have to be spaced far enough from each other so that they do not interfere.
In your basic setup, your ring gear will have teeth equal to the number of the teeth in the sun gear, plus two planets (though there may be advantages to modifying this slightly), simply because a line straight across the center from one end of the ring gear to the other will span the sun gear at the center, and room for a planet on either end. The planets will typically be spaced at regular intervals around the sun. To accomplish this, the total number of teeth in the ring gear and sun gear combined divided by the number of planets has to equal a whole number. Of course, the planets have to be spaced far enough from each other so that they do not interfere.
The special case is using one ( =1 ) planetary gear on a regular interval. The total number of teeth in ring gear and sun gear combined divided by 1 is a whole number.
Last edited by JoBy; Mar 12, 2021 at 04:03 PM.
