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Using one way bearing in cable reel

Using one way bearing in cable reel

(OP)
I am developing a motorized cable reel. I am using a geared DC motor to drive central cable drum on which the cable rests. This cable reel is only used to automatically retract the cable back once the cable is pulled out. The cable is pulled out manually by hand from the cable reel. I am using a one way bearing coupled to my DC motor shaft to make it easy to pull out the cable manually. The one way bearing housing is in turn connected to a small sprocket. The small sprocket is connected to the bigger sprocket (attached to the cable drum) via a chain. Now, the problem that I am facing is that the whenever I power on the motor, the entire assembly rotates in the direction that the one way bearing moves. But what I need is the assembly needs to rotate in the direction opposite to which the bearing moves. On the side where the bearing rotates freely , I pull the cable out manually (as the bearing makes it easy to pull cable out), and I dont turn on the motor in this case. In the other direction where the bearing doesn't move, I need the entire assembly to rotate in order to pull the cable in, but what happens is that just the motor shaft rotates, the bearing, bearing housing, sprocket, etc dont move. What modifications should I make to achive my goal or any other alternatives for this ? I cannot use an electromagnetic clutch here.




The motor with shaft, sprocket, one way bearing and housing.



The motor with shaft, one way bearing and housing.



The motor with shaft and one way bearing.

RE: Using one way bearing in cable reel

It's hard to understand the problem with words. Your pictures do not seem to communicate the issue. Please show the complete assembly and denote some rotation directions. I don't understand why you don't reverse rotation of the motor if the reel is not rotating correctly.

Below is your long paragraph broken up to track easier -
I am developing a motorized cable reel. I am using a geared DC motor to drive central cable drum on which the cable rests. This cable reel is only used to automatically retract the cable back once the cable is pulled out.
  1. The cable is pulled out manually by hand from the cable reel.
  2. I am using a one way bearing coupled to my DC motor shaft to make it easy to pull out the cable manually.
  3. The one way bearing housing is in turn connected to a small sprocket. The small sprocket is connected to the bigger sprocket (attached to the cable drum) via a chain.
  4. whenever I power on the motor, the entire assembly rotates in the direction that the one way bearing moves.
  5. But what I need is the assembly needs to rotate in the direction opposite to which the bearing moves.
  6. On the side where the bearing rotates freely , I pull the cable out manually (as the bearing makes it easy to pull cable out), and I dont turn on the motor in this case.
  7. In the other direction where the bearing doesn't move, I need the entire assembly to rotate in order to pull the cable in,
  8. but what happens is that just the motor shaft rotates, the bearing, bearing housing, sprocket, etc dont move.
  9. What modifications should I make to achive my goal or any other alternatives for this ? I cannot use an electromagnetic clutch here.

RE: Using one way bearing in cable reel

I cannot follow your description either. That is probably because what you want to do cannot be done with a one-way bearing (more correctly called a one-way clutch), alone. You need an on/off clutch.

RE: Using one way bearing in cable reel

Yes, it sounds like freewheeling the cable drum clockwise is the same relative motion as the drive shaft rotating CCW to pull the cable back in.
There needs to be a pin or something to lock the shaft to the sprocket to let the motor pull back the cable.

RE: Using one way bearing in cable reel

(OP)
@dvd @Tmoose @Compositepro
Guys, I have added a video explaining the problem I am facing. Hope this gives a clear picture.

Also, the one way bearing is connected to the motor shaft via a keyway slot on the bearing and a key on the shaft. I am trying to use the same cycle chain and sprocket concept here and I am trying to understand where I am going wrong here.

Link to the video,

Link

RE: Using one way bearing in cable reel

What you are trying to do is not possible. All that the one way clutch does is allow you to manually turn the drum to wind-up slack in the cable without using the motor. The forces on your clutch are the same when winding the cable with the motor or when trying to unwind the cable manually.

RE: Using one way bearing in cable reel

Maybe if there was a centrifugal clutch on the motor which would only engage and drive the drum to haul in the cable when the motor was revved up.

RE: Using one way bearing in cable reel

As others have pointed out, you cannot achieve what you want without some fundamental changes to your mechanism. You should first turn your one-way bearing around so that when the motor is energized, it turns the sprockets and retracts the cable. Then you need to solve the problem of how to manually feed the cable out, since the one-way bearing will now prevent the sprockets from turning in reverse. One typical way to do this is with a manual release lever that decouples the cable drum from the drive sprocket system. There are probably dozens of ways to design this mechanism.

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