Author Topic: Auto reversing winch  (Read 397 times)

Offline Brian Rupnow

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Auto reversing winch
« on: September 11, 2019, 04:49:20 PM »
After completing the vertical hit and miss engine, I have tried three or four different ways to make the engine go in and out of "hit and miss" no load operation and "only hit-no miss" loaded operation. Some of the things I tried were successful, but they demanded that I be part of the operation. I wanted something totally automatic to do this job, where I wouldn't have to be involved. My absolute best video of the engine doing what I wanted was with the engine turning a winch to raise a load. I have done a great deal of thinking how this could be done without needing me to engage and disengage the winch. So---I'm a bit early into the game here, but far enough to share a concept. Last year I designed and built a mechanism that would reverse a flat belt drive, in order to mimic the reversing of a belt drive from a line shaft. It worked. It was rather crude and "sorta" worked but after making a couple of videos of it in operation it has set on a shelf in my office and never been touched again.  However--there was a little bit of magic at work there, because when the lower shaft was driven by a motor, the two semi transparent drums turned in opposite directions. Now, imagine a winch drum that sets between the two outside drums and is not keyed to the shaft. It is actually a bit narrower than the space. Think "dog clutch". If I had a mechanism that would slide the drum to the left or to the right, it would rotate clockwise when forced up against the driven drum on one side, and counterclockwise when it was forced up against the other drum. Now think of two  mechanical "bobs" attached to the winch line, that contact an arm at maximum height and forces the moveable winch drum against the opposite driven drum. This reverses the rotation of the winch drum and pays out line until at minimum height the second "bob" contacts the same arm and swings it over against the other driven drum. There won't be enough force to make the faces a friction drive. It will have to be a dog clutch that engages very easily. Will share more with you fellows after I have thought this out a bit more clearly in my head.---Brian

Offline Brian Rupnow

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Re: Auto reversing winch
« Reply #1 on: September 11, 2019, 04:51:09 PM »
I have worked out all the design of the self reversing winch. When the "bobs" on the string hit the arm which is attached to the bevel gear, the bevel gear rotates (only a little bit)  and causes the second bevel gear to rotate. The carrier rotates (again only a little bit) and the bearings attached to it cause the winch drum to move to either the right or to the left. As soon as the winch drum rides up against either semi transparent drums, the built in dog clutch (which you can't see in the models) engage and turn the winch drum either clockwise or counterclockwise until the other "bob" attached to the string hits the arm and moves the winch over against the other drum which is rotating in the opposite direction.



Offline Ye-Ole Steam Dude

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Re: Auto reversing winch
« Reply #2 on: September 11, 2019, 04:59:44 PM »
Hello Brian,

If I understand what you are looking for I believe you need to look at a cut-away of the lower unit on an outboard motor. That is where the "reversing" mechanism is and a simple "lever" slides a double bevel gear in both directions, thus engaging Forward or Reverse for the propeller. Hope this will help.

Have a great day,
Thomas

Offline Brian Rupnow

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Re: Auto reversing winch
« Reply #3 on: September 11, 2019, 06:12:24 PM »
Thomas--I have seen that, and you are correct. I do not have the capacity to easily make bevel gears at home. I have made a set, "just to see if I could" and they  are what I will be using here. About 90 percent of this thing is already built, from a job I done last year.--Brian

Offline Brian Rupnow

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Re: Auto reversing winch
« Reply #4 on: September 12, 2019, 04:53:07 PM »
I've been rethinking this mechanism. This picture shows the current state of what I am starting with. I have spent a few hours this morning rethinking the design to let me use more of the parts that I already have. The model shows my change in design direction.


Offline Brian Rupnow

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Re: Auto reversing winch
« Reply #5 on: September 14, 2019, 11:47:32 PM »
Today I made the winch drum and put the groove in each side that gives me the "dog clutch". The knurled round part setting beside the new winch drum is one of the original parts that has been drilled and had a piece of 1/4" shaft Loctited into it. (the other existing drum is laying at the front of the mechanism.) Due to the gearing, the two knurled drums rotate in opposite directions--they are locked to the shaft which is actually three individual shafts--right shaft fixed to right knurled drum, left shaft attached to the left knurled drum, and a floater shaft between the two which is not powered. The winch drum is shifted from one side to the other to reverse it. There is going to end up being a very small gap between the winch drum and the 1/4" shafts that are mounted in the existing knurled drums because the winch drum must not engage both drums at the same time.

Offline Brian Rupnow

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Re: Auto reversing winch
« Reply #6 on: September 19, 2019, 09:08:55 PM »
The reversing winch mechanism is finished. It operates very smoothly on the test bench. The pivot for the gear segment got changed from a shoulder bolt to a 3/8" shaft with ball bearings, to prevent binding at the pivot. Tomorrow I will do a dynamic test. If it is successful, then I will post a video.

Offline Brian Rupnow

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Re: Auto reversing winch
« Reply #7 on: September 19, 2019, 10:26:03 PM »
I think I am going to have to add a counterweight to the other side of the gear segment axis.  I have tried to make everything very "free" so that nothing will bind. I've succeeded so well that the weight of the offset arm makes the winch drum change sides.

Offline Brian Rupnow

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Re: Auto reversing winch
« Reply #8 on: September 20, 2019, 03:54:38 PM »
This morning  was the first "trial run" of the system, and I am quite happy with the results at this time. The winch drum does reverse as I had hoped, and does so quite smoothly. I am going to add something similar to a ball indent pin to hold the mechanism in forward or reverse gear so it doesn't move from vibration as it runs. Thanks for having a  look.---Brian

Offline Ye-Ole Steam Dude

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Re: Auto reversing winch
« Reply #9 on: September 20, 2019, 04:11:33 PM »
Hello Brian,

That unit seems to operated very smoothly, great job of design work  :NotWorthy: :ThumbsUp:

Have a great day,
Thomas

Offline Brian Rupnow

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Re: Auto reversing winch
« Reply #10 on: September 20, 2019, 07:22:29 PM »
This "add on" will be my version of a "detent" system" for the mechanism. The purple rod is spring steel.

Offline Johnmcc69

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Re: Auto reversing winch
« Reply #11 on: September 20, 2019, 07:25:32 PM »
Great job Brian! A really smooth transition between forward/reverse.
 Nice design.

 John