Will worm gear/worm back drive?
Will worm gear/worm back drive?
(OP)
I am designing a simple fixture and would like to use a worm and worm gear arrangement for rotatation . I need to ratate the load +/- 5 degrees from zero
1. Can I move the load by turning the hand knob on top?
2. Any chance the worm gear will back-drive the worm?
Any help on this would be greatly appreciated
1. Can I move the load by turning the hand knob on top?
2. Any chance the worm gear will back-drive the worm?
Any help on this would be greatly appreciated





RE: Will worm gear/worm back drive?
Short answers no you can't back drive the worm
regards
desertfox
RE: Will worm gear/worm back drive?
RE: Will worm gear/worm back drive?
It definately won't back drive with a single start worm of 168:1 ratio.
If the load has to be raised vertically check out this link for some calculations:
http://www
Trevor Clarke. (R & D) Scientific Instruments.Somerset. UK
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RE: Will worm gear/worm back drive?
RE: Will worm gear/worm back drive?
RE: Will worm gear/worm back drive?
For a good general discussion of worm drives, "Machinery design" by Deutschman et al has a nice chapter.
Cheers
Greg Locock
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RE: Will worm gear/worm back drive?
Thanks so much for the input. First time using this forum but it is awesome.
My fixture see`s no vibration. Only static load. The worm/worm gear I have picked pout has a lead angle of 14 1/2 degree ( 180:1 ratio, 48 pitch). Have not see any lesser L,A..
Anybody have experience with this smaller worm/worm gear arrangement?
I understand MOST worm gears will not back drive but some will.
Again, Thanks for all the help.
RE: Will worm gear/worm back drive?
RE: Will worm gear/worm back drive?
The worm gear has a pressure angle of 14 1/2 degrees..
Thanks for your help
RE: Will worm gear/worm back drive?
Regards,
Lcubed
RE: Will worm gear/worm back drive?
I did the preiminary design of an optical scanner which had a 20" diameter worm gear. I cannot remember the gear ratio, but it was well over 50:1. I had to design an oversized worm to get the lead angle down to the point where it was self locking.
Rules of thumb are not 100% reliable.
JHG