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15th Dec 2015, 09:46 PM #1
Single revolution clutch- pin clutch or similar unit
I have been a member for some time, but no recent posts.
I have been developing a small agricultural seed drill, with a mechanical lift system. It is for the developing world.
I am looking for a small single revolution clutch, pin clutch or suchlike to lift the soil engaging parts.
As it must be simple, no hydraulics or electrics or suchlike.
The drive shaft rotates at 50 rpm, which is too slow for a wrap spring clutch, roller clutch or suchlike.
Gongli Africa 2 overall - tynes raise lo.jpg
Also the operating conditions in the field with dust etc. are too severe for most mechanisms.
This is from a 65 year old seed drill, which is barely satisfactory.
A Youtube clip of the unit in action can be seen at https://www.youtube.com/watch?v=m3eEqIBDXjg
Does any member have any ideas?
Can anyone direct me to plans or drawings on how to fabricate a small pin clutch or similar?
I can supply further details on request.
Thank you.
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16th Dec 2015, 06:50 AM #2Philomath in training
- Join Date
- Oct 2011
- Location
- Norwood-ish, Adelaide
- Age
- 59
- Posts
- 6,561
What sort of power transmission are you talking about? The clutch on some old machine tools is a pair of nesting cones (around 25 degree angle), held together with a spring.
You mention pin clutches - does it have to be positive location/ no slip?
Michael
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16th Dec 2015, 07:17 AM #3
Michael,
Thanks for the enquiry.
This is a drive from a ground wheel on the tractor which is travelling at 3-4 kph. The speed of rotation of the input shaft is around 50 rpm. There must be no slip, as it is a positive action to raise the soil engaging tools. Once raised the tools must be positively held up. When the operator trips the mechanism the soil engaging parts return to the down position. They then must be held positively down to hold them in the soil and plant the seeds.
Jeff E.
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16th Dec 2015, 08:24 AM #4Pink 10EE owner
- Join Date
- Aug 2008
- Location
- near Rockhampton
- Posts
- 6,218
Find an old massey ferguson combine and see how that lift mechanism works. We borrowed one once many years ago and it has a mechanical mechanism that lifted the undercarriage up automatically.
Gold, the colour of choice for the discerning person.
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16th Dec 2015, 08:55 AM #5
R.C.
Thanks for the advice.
Actually that is what is at preset fitted. I rescued two from farmers junk piles.
This 'rope trip lift' as it is nominally called is made from cast parts, and is too big and heavy for this application.
It works OK on the lift cycle. However on the lower cycle, when tripped, the undercarriage drops by gravity until it touches the ground.
The whole mechanism then starts to internally 'chatter' as various parts jump segments inside the unit. It will not exert positive down pressure.
My guess it is some some of overload system.
I consulted a retired Massey Ferguson Ag. Engineer who advised that extra down pressure springs were fitted to the old MF seed drills to overcome this.
It all gets too complicated for a small rig, and i am just looking for a compact pin clutch that will do the same job.
Check out the Youtube video.
https://www.youtube.com/watch?v=wcYKttiovDA
If something is not available 'off the shelf' I would appreciate it if a set of plans or drawings is available, and I can have something made up.
I have more detailed explanation that I can forward to interested folks if necessary.
Thanks for the interest.
R J E.
Tamworth NSW
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16th Dec 2015, 09:00 AM #6Mechanical Butcher
- Join Date
- Oct 2004
- Location
- Southern Highlands NSW
- Posts
- 1,898
Speedboats have dog clutches for their propeller shafts, I guess the water allowing the otherwise harsh action.
Your machine might need some shock absorbing system to survive, maybe some cush drive or torque-limiting?
A centrifugal clutch not an option?
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16th Dec 2015, 09:30 AM #7
Nadroj,
Thanks for the reply.
As previously mentioned the whole system only rotates at 50 rpm. So centrifugal clutch and similar set-ups are not applicable.
As R.C. noted, the old lift system from a 65 yr. old seed drill is the closest i have been able to locate.
The whole clutch normally free wheels.
When one trips the system, It lifts the undercarriage of the seeder, taking 1-3 seconds to do so. Once up, a release mechanism operates after a cycle, and the undercarriage is latched up. It stays latched (again free wheeling) until tripped again, when it goes though the other half of the cycle and drops the undercarriage down.
All of this was superseded when hydraulics appeared in the late 1940's, and a double acting 8 inch hydraulic ram now does the job.
However the seeder is designed for he developing world, where no hydraulic expertise available (it costs too much anyway).
Something simple that can be repaired in the village blacksmith shop is what I am looking for.
The Youtube video ( as shown in previous post) is the closest I can come to it.
Thanks again for your comments.
R J E.
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16th Dec 2015, 11:47 AM #8Banned
- Join Date
- Aug 2015
- Location
- QLD
- Posts
- 735
Have you tried a Trove search?
There may very well be an old horse drawn equipment cataloge available...
Home - Trove
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16th Dec 2015, 11:53 AM #9Golden Member
- Join Date
- Nov 2010
- Location
- Gippsland Victoria
- Posts
- 733
Maybe have a look here ?
507 Mechanical Movements, 47
there are approx half a dozen clutch mechanisms if you go to the directory above.
and just a general trawl through the whole site might "plant the seed" of an idea
Bill
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16th Dec 2015, 02:54 PM #10
Pin clutch.mp4
Thanks to all for the ideas.
I have attached an mp4 8 sec. video which may show up. Being a newbie on this forum I am not sure.
It is also at https://www.youtube.com/watch?v=wcYKttiovDA
If anyone has any plans for something like this I would be pleased to hear.
Apparently this system was on old power presses.
Regards to all.
R J E.
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16th Dec 2015, 03:01 PM #11Senior Member
- Join Date
- Jan 2012
- Location
- Melbourne
- Posts
- 149
Guessing you have already Googled?
https://www.google.com.au/search?q=S...=1600&bih=1041
Single rev clutches were also used on crank operated presses, where the flywheel would be engaged for one turn only. May be worth checking scrappers?
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16th Dec 2015, 03:29 PM #12
Neil,
Thanks for the reply.
The unit I am envisaging would be around 200mm diameter, along the same lines as the video.
If there is an enterprising member who would like to take it on, then I will give full co-operation.
I have a small lathe, but am what is called in Aussie slang - a 'bush mechanic'
All assistance appreciated.
R J E.
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16th Dec 2015, 04:01 PM #13Most Valued Member
- Join Date
- Jul 2010
- Location
- Melbourne
- Posts
- 9,088
I'm not sure that is your answer. As I understand it, those clutches like to be unloaded when disengaging. What that video doesnt show is a brake on the crank. If the crank "falls backwards" the pin reengages, if it doesn't have enough momentum the pin will almost disengage "clack clack clack clack". If the brake doesnt stop and hold the crank the pin reengages(you can easily get to a point when it just keep running, which means you need more brake). Some of the bigger presses release the brake for say 270 degrees, to stop the brake getting to hot, not likely to be an issue for you but you might like to release it to save power.
Having said all that, if you keep the above in mind you might be able to make it work. Good luck.
Stuart
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16th Dec 2015, 04:25 PM #14Pink 10EE owner
- Join Date
- Aug 2008
- Location
- near Rockhampton
- Posts
- 6,218
Is this device supposed to be a direct drill or for planting crops into prepared soil. It looks to be more for planting trees or something into hard soil as it is only two runs quite a distance apart with quite robust tynes. The mechanism you have is probably designed for typical combine work of planting into prepared ground where pretty much gravity is all you need to get the tynes to the correct depth.
Gold, the colour of choice for the discerning person.
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16th Dec 2015, 04:49 PM #15
Stustoys,
Thanks for the post. I trust that if it is turning at 50 rpm that there will not be those challenges.
Having said that, I intend probably fitting a sprag clutch or similar on the drive shaft so that it cannot turn backwards.
I already have a pair of them on the drive wheels of the tractor, and if the operator reverses the rig for any reason all of the drives freewheel and not travel in reverse and wreck something.
R J E.
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