mechanical coupling with over-torque fuse
mechanical coupling with over-torque fuse
(OP)
I'm looking for a shaft coupling that will shear at around 150-200 in*lbs of force. I see Lovejoy makes one but it doesn't go down the the torque range I need. Any suggestions?
The application is between a gearmotor and a winch
The application is between a gearmotor and a winch





RE: mechanical coupling with over-torque fuse
There is also a spring-detent version, but I can't find it at the moment.
RE: mechanical coupling with over-torque fuse
RE: mechanical coupling with over-torque fuse
Another option is a magnetic coupling...but their not cheap.
These guys make some neat products. Non-contacting, constant torque, never needs adjustment, generates very little heat.
http://www.rimteccorporation.com/
RE: mechanical coupling with over-torque fuse
RE: mechanical coupling with over-torque fuse
However, if you have corrosiion problems then you potentially have the hub and shaft getting fused together by corrosion products. Thus the pin may never see any load.
Choose your materials for hub and shaft carefully.
Another option is a short section of hollow shaft with a designed failure point, installed between two flange couplings.
RE: mechanical coupling with over-torque fuse
As you probably know this would be easy if you were to use a hydraulic motor and set the pressure to correspond to your desired torque and then the motor would only stall if and when it reached that set point. maytag
RE: mechanical coupling with over-torque fuse
Right now I'm looking at a shear pin / calculated failure joint solution with a custom center element since an off the shelf solution is getting less likely. Because this is serving as a coupler as well as a failure point I'll be making the section between the two hubs out of a damping plastic material so I'm planning on not allowing the metallic elements to contact each other.
RE: mechanical coupling with over-torque fuse
There are various electronic overload devices (UST has a shock relay) that will shut down the power to the motor, but does nothing to stop the damaging inertia.
Russell Giuliano
Unique Technologies Associates - Cobra Solid Lubricant
www.uniquetechnologies.com
RE: mechanical coupling with over-torque fuse
RE: mechanical coupling with over-torque fuse
I am not sure if I completely understand your application, but how I am interpreting it, there is a spinning shaft. Does this shaft only spin one direction?
If so, could you make you coupling a 2 piece threaded male and female with either a left or right hand thread with hex flats to torque the two male and female pieces to 150-200 ft/lbs, thus when the forces are greater then the thread unscrews itself.
If the shaft spins both directions then make the couple out of 3 pieces with both left and right threads torque as above.
Tofflemire
RE: mechanical coupling with over-torque fuse
RE: mechanical coupling with over-torque fuse
Russell Giuliano
Unique Technologies Associates - Cobra Solid Lubricant
www.uniquetechnologies.com
RE: mechanical coupling with over-torque fuse
In a previous life we manufactured screw in plugs for a downhole tool that got welded after installation. They were designed similarly to the intermediate shaft idea above so that we had consistent seating torque. When the drive hex twisted off, you were fully seated.
RE: mechanical coupling with over-torque fuse
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: mechanical coupling with over-torque fuse
or possibly a clutch/brake motor, to disconnect and stop the motor upon overload. You may be better off with this route, as it is not the jam that causes the damage, but the motor inertia.
Russell Giuliano
Unique Technologies Associates - Cobra Solid Lubricant
www.uniquetechnologies.com
RE: mechanical coupling with over-torque fuse
RE: mechanical coupling with over-torque fuse
RE: mechanical coupling with over-torque fuse
http://www.rimteccorporation.com/ (and there are others tood)
RE: mechanical coupling with over-torque fuse