Jd Gear Options

drom68

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I have a gear that I need to make. The gear has damage and is not running true and makes a lot of noise. The gear will not see hard use, but it is part of the final gearing and will see torque to drive the tractor.

The gear:
31 teeth
14.5deg PA
6 DP
5.64" dia

The issue, the customer wants the noise to be nonexistent. I explained that spur gears are noisy, he wants a quite gear, so- no guarantees and the gear needs to be remade anyway.

Any suggestions on what type of material to use to reduce noise?

Options I have come up with so far:
- Other material: Cast Iron or bronze. They reduce sound, bronze being expensive. Delrin, little to no sound, but not sure if it will hold up.
- 20 PA vs 14.5 PA Requires both gears to be made.
- Accuracy, probably the most important part to reduce backlash and improve meshing.
- Profile tips of teeth, time intensive.

Looking for suggestions/recommendations, thanks. 20150514_165946_resized.jpg
 
I think after making both gears accurately there are special lubricants you can use that will smooth and quiet the gears while running----Dave
 
Thanks Dave. I thought about lubricants, but wasn't sure if they would make a difference with a splash system. The gear set is above the oil level.
Dan
 
Hi Dan, I take it that the gear is from the transmission or PTO. A good gear oil will make a world of difference even being above the level.
I have also had a lot of success lapping straight cut gears.
Brendan
 
Hi Dan, I take it that the gear is from the transmission or PTO. A good gear oil will make a world of difference even being above the level.
I have also had a lot of success lapping straight cut gears.
Brendan

Yes it is in the tranny. I will definitely take a look at the gear oil, thanks to both you and Dave. As for the lapping of the gear, can you provide more info on this. Thanks!
 
I have a gear that I need to make. The gear has damage and is not running true and makes a lot of noise. The gear will not see hard use, but it is part of the final gearing and will see torque to drive the tractor.

The gear:
31 teeth
14.5deg PA
6 DP
5.64" dia

The issue, the customer wants the noise to be nonexistent. I explained that spur gears are noisy, he wants a quite gear, so- no guarantees and the gear needs to be remade anyway.

Any suggestions on what type of material to use to reduce noise?

Options I have come up with so far:
- Other material: Cast Iron or bronze. They reduce sound, bronze being expensive. Delrin, little to no sound, but not sure if it will hold up.
- 20 PA vs 14.5 PA Requires both gears to be made.
- Accuracy, probably the most important part to reduce backlash and improve meshing.
- Profile tips of teeth, time intensive.

Looking for suggestions/recommendations, thanks. View attachment 103302
 
I have a gear that I need to make. The gear has damage and is not running true and makes a lot of noise. The gear will not see hard use, but it is part of the final gearing and will see torque to drive the tractor.

The gear:
31 teeth
14.5deg PA
6 DP
5.64" dia

The issue, the customer wants the noise to be nonexistent. I explained that spur gears are noisy, he wants a quite gear, so- no guarantees and the gear needs to be remade anyway.

Any suggestions on what type of material to use to reduce noise?

Options I have come up with so far:
- Other material: Cast Iron or bronze. They reduce sound, bronze being expensive. Delrin, little to no sound, but not sure if it will hold up.
- 20 PA vs 14.5 PA Requires both gears to be made.
- Accuracy, probably the most important part to reduce backlash and improve meshing.
- Profile tips of teeth, time intensive.

Looking for suggestions/recommendations, thanks. View attachment 103302
 
5-15-15 Dear drom68. Perhaps purchasing a new gear would save some money. If you should cut a gear a - 6DP pitch cuttter
would be quite expensive. Also are 2 gears needed? Diametral Pitch must be the same for both gears. I did not quite understand
what was needed. As for gear material I would suggest 4140 or 8620 steel. In the interim if you have any questions please feel
free to contact me on this website at any time. Cordially, jbollman
 
Jbollman, thanks for the input and conversation. I think I am going to go with cast iron for the gear and the way it is going to be used.
 
Yes it is in the tranny. I will definitely take a look at the gear oil, thanks to both you and Dave. As for the lapping of the gear, can you provide more info on this. Thanks!
Hi Dan, Lapping gears- Years ago I was doing a lot of work on Mack quad boxes. The old fitter that I worked with showed me how . All you do is start medium valve grinding paste a little smear on each side of the teeth and rotate the gears slowly back and forth (you can hear the paste crunching) keep doing this until you cant hear the crunching and then wipe the teeth. then change to the fine paste and repeat. Me being a very smart young fitter thought he was mad but it cut the noise by 25%.
Just spin the transmission by hand and use water based valve grinding paste (it dries on the teeth were oil based drips). For gear oil I would use a 80 w /90 mineral. Hope this helps.
Regards
Brendan
 
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