Does anyone know what the final frive ratio is on a 320c pab serial number prefix. Thinking about building a gear reduction system and wondered what the final output would be .
Who likes a math challenge ? Google helps these days So you’ll be driving a 13 tooth sun, driving 44 tooth planets on a 104 tooth ring. That planet carrier is driving a 17 tooth sun with 30 tooth planets on a 79 tooth ring.....
So what does google tell you . I was hoping somebody knew what it was. Somebody always has the answer on this site. Don't they?
51 to 1 as near as makes no difference.
Thank you kindly
I was figuring about 53 to 1 on my fingers and toes . . .but I ran out of toes. . . . . . . .
Calculating the ratio of a planetary use the formula: - (# of teeth on the ring gear divded by the number of teeth on the sun gear) + 1 So for our firend's final drive the 1st reduction is 104 divided by 13 (8) + 1 = 9. 2nd reduction is 79 divided by 17 (4.65) + 1 = 5.65 Total reduction multiply the two together - 9 x 5.65 = 50.82 - 51 give or take.
Does it matter that in the first reduction the planet carrier is the output and second reduction the ring gear is the output ?
Not AFAIK. The only options in a planetary gear set are for the planetary carrier to be fixed (i.e. the ring gear rotates) or the ring gear to be fixed (i.e. the planetary carrier rotates). The overall gear ratio ought not to change whichever one of the two options is fixed in a particular gear set where the sun gear is the input. As you point out it's typical on a double reduction planetary set to have the 1st reduction carrier driving the sun gear for the input of the 2nd reduction.
According to our records, the final drive ratio for that 320C should be 49.82.