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Is there a name for pulleys with the grub screw recessed into the groove?

catmanjan

Plastic
Joined
Feb 2, 2021
. . .is there a structural reason for the extra material?. . .

Naturally, if it is a stamped pulley or one with an especially thin web then a hub is a structural requirement if it is to be mounted to a cylindrical shaft. If it is made from a solid slug with straight sides and the load requirements do not mandate a long key, you can remove the hub and relocate the grub screw. The one you link to has a reduced center section so you would want to leave at least enough hub to be flush with the sides of the pulley rim. Depending on what the other side looks like you might also need to use a smaller grub screw.
 
catmanjan,

Another option is to use a pulley with a taper lock bush (if you have access to one end face of the pulley).

Taper lock pulleys have a bush which pulls up flush with the pulley face.

If you don't mind something a bit wider than the pulley, then the Bi-Loc (Biloc, Bi-Fit, Mi-Fit) pulleys are another option. On this system, there is a flange and bolt heads which are wider than the pulley.


Taper lock pulleys.jpg BI-FIT-RANGE.jpg
 
Thanks, I have used taper lock pulleys before - I am trying to find one that suits my needs, unfortunately I can't get a taper lock 2" V Belt A section with 1 inch bore, I think the taper lock is too big for a pulley this size

I will try and remanufacture mine into a hubless pulley
 
In the Dodge or Martin brand, the 1008 series taper lock bushing is the smallest one that goes up to 1” bore. Unfortunately, Martin does not appear to offer the size sheave you want that will accept it. You will likely just have to drill and tap a stock bore pulley to put the set screw in the bottom of the groove like you want it.
 
I haven't seen every sheave ever made but I have seen a whole bunch, and not one ever had a setscrew situated in a groove...I think it's poor engineering and something that a reputable manufacturer would never do. I've done it occasionally, but I'm just a hack.:eek:

Stuart
 
catmanjan,

Another option is to use a pulley with a taper lock bush (if you have access to one end face of the pulley).

Taper lock pulleys have a bush which pulls up flush with the pulley face.

If you don't mind something a bit wider than the pulley, then the Bi-Loc (Biloc, Bi-Fit, Mi-Fit) pulleys are another option. On this system, there is a flange and bolt heads which are wider than the pulley.


View attachment 313441 View attachment 313442

Peter, these are called taper locks and they are brilliant, but they are only available in larger sizes. However, check out Tsubaki's line of "Power Locks". They have several styles, many of which are very suitable to small shafts and pulleys, but be prepared for their very high cost. It makes your eyes water!
 
The need for a set screw in the crotch of V would indicate to me there is little or no hub to put an appropriate set screw or screws into. This would also indicate to me a single belt sheave which mean there is little axial support for the sheave. This is why I felt it was a bum deal and you would not see a sheave make for any real service with that construction. I could be all wrong on this though and would be happy to admit it.

Stuart
 
Alternatively, could I drill and tap the one I have and cut the wide part - or is there a structural reason for the extra material?

When you cut off extra hub leave as much on as will cover the shaft to give lateral support.

Would it be possible to run the hub toward the bearing or motor and adjust the system side to side to make the belt run true?

Paul
 
Because, if the belt is in contact with the bottom of the groove, then it is not gripping the sheaves and will be slipping!

I think we may be at cross purposes my statement was because an A section Vee belt is unsuited to a 2'' dia pulley as per the OPs quest. ***

Ref Page 26 here http://www.tecnicaindustriale.net/chiaravalli_cataloghi/manuale_calcolo_vbelts_gates.pdf

*** yes I know it's done - especially on ''low end'' machinery, but it ain't right nor is it efficient.
 








 
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