Woodruff Key Fit
Woodruff Key Fit
(OP)
What type of fit would you expect to see (width wise) on a woodruff key?
I'm detailing up some drawings to hold a pulley onto a camshaft, our company standard is based on DIN 6888 but I'm not convinced we've interpreted it correctly, for a 5mm wide key I'm meant to use the tolerances shown below:
Key Way Width = 5 P9 (-0.012/-0.042)
Key Width = 5 h9 (0/-0.03) (Tols of standard part)
These values will give anything between 18 microns clearance and 42 microns interference and its the interference part that I'm questioning. If the key to pulley interface had this amount of interference then its going to take a fair old push to get the pulley onto the shaft.
There is nothing to suggest that the pulley slot should be any wider than the shaft slot.
Any comments or suggestions? Am I worrying about nothing?
I only have a copy of the standard in German so despite my efforts with Google Translate I may have missed something.
Cheers.
I'm detailing up some drawings to hold a pulley onto a camshaft, our company standard is based on DIN 6888 but I'm not convinced we've interpreted it correctly, for a 5mm wide key I'm meant to use the tolerances shown below:
Key Way Width = 5 P9 (-0.012/-0.042)
Key Width = 5 h9 (0/-0.03) (Tols of standard part)
These values will give anything between 18 microns clearance and 42 microns interference and its the interference part that I'm questioning. If the key to pulley interface had this amount of interference then its going to take a fair old push to get the pulley onto the shaft.
There is nothing to suggest that the pulley slot should be any wider than the shaft slot.
Any comments or suggestions? Am I worrying about nothing?
I only have a copy of the standard in German so despite my efforts with Google Translate I may have missed something.
Cheers.





RE: Woodruff Key Fit
RE: Woodruff Key Fit
"Bearings and other Machine elements"
Table 5
'British Standard woodruff keys and keyways',
shows the clearances shaft/sheave to be slightly greater for the sheave (or pully) for all sizes of woodruff keys.
eg, for a 1/16" T key, the shaft is cut to .062/.063, and the pulley to .063/.065".
for a 1/4" T key, the shaft is cut to .249/.251", and the pulley to .0252/.0253".
For the largest key in the table, the clearance is .002" for the pulley.
I guess these guys don't want to work too hard installing the pulleys.
Having said all that, the illustration for table 5 shows a tapered shaft.
RE: Woodruff Key Fit