Enveloping worm gear quieter?
Enveloping worm gear quieter?
(OP)
Hi everyone,
I have a pretty basic question and haven't really ever done a gear design before, so excuse me if the question is ignorant. I've been asked to reduce noise in a hand held pump system that uses a worm gear on a small DC motor to turn a gear to get the pumping action. The worm and gear are both non-enveloping (not throated). I've read in many places that a single or double enveloped (worm or worm+gear) is more efficient, but does that mean it's quieter too, or is that completely unrelated?
The worm is reducing speed 100:1, and a ballpark torque for the worm is 0.01 N-m, with a brass worm and nylon gear. The output gear turns just about 60 rpm. Given this "flavor" and scale of gear train, is it even worth considering an enveloping design?
Thanks in advance!
-Adam
I have a pretty basic question and haven't really ever done a gear design before, so excuse me if the question is ignorant. I've been asked to reduce noise in a hand held pump system that uses a worm gear on a small DC motor to turn a gear to get the pumping action. The worm and gear are both non-enveloping (not throated). I've read in many places that a single or double enveloped (worm or worm+gear) is more efficient, but does that mean it's quieter too, or is that completely unrelated?
The worm is reducing speed 100:1, and a ballpark torque for the worm is 0.01 N-m, with a brass worm and nylon gear. The output gear turns just about 60 rpm. Given this "flavor" and scale of gear train, is it even worth considering an enveloping design?
Thanks in advance!
-Adam





RE: Enveloping worm gear quieter?
The 6000 rpm motor may be the primary source.
Ted
RE: Enveloping worm gear quieter?
The first thing that comes to mind is ball bearings. If any are present on that shaft, use better ones, or if life and load limitations allow it, use Oilite(r) bearings.
Also, if neither gear is enveloping, only one gear wheel tooth at a time is carrying the load, and some noise will be produced when the load transfers from one tooth to the next. You may have to retool both gears in order to add throat to even one; it may be easier to isolate/damp the noise than to prevent it.
Mike Halloran
Pembroke Pines, FL, USA
RE: Enveloping worm gear quieter?
RE: Enveloping worm gear quieter?
MikeHalloran: We're using bushings throughout the drive train. To my knowledge, the motor manufacturer indicated that their bushing motor was quieter than their bearing motor.
plasgears: I just learned about acetal as a possible gear material while investigating this problem yesterday. Is the loss of accuracy in a nylon worm outweighed by it's damping properties? Also, what constitutes a light load?
Thanks to all of you for your input!
-Adam
RE: Enveloping worm gear quieter?
Here's a way to calculate the gear mesh frequency.
http://w
I don't know, nor could find much about worm gear pumps tp speculate if there is are pressure pulses at the gear mesh frequency, but other pumps can make a lot of hydraulic noise at their various meshing frequencies
RE: Enveloping worm gear quieter?
-Adam
RE: Enveloping worm gear quieter?
Case study. We had a design of sub fractional gearmotor that went into stall. Option of slip clutch was not avail. We changed the last stage pinion and gear to neat nylon and added a thermistor in the circuit. Results were very satisfactory. We got this advice from a plastic mfr. They see all kinds of designs and solutions.