Coefficient of friction stainless steel on bronze
Coefficient of friction stainless steel on bronze
(OP)
I am developing a worm gear assembly that uses a stainless steel worm and a bronze worm gear in combination. The closest thing I can find in my books or online is steel and bronze which only lists a lubricated value of 0.16.
1. Would you suggest using the steel and bronze value
2. Do you have a good source for a coefficient of friction values that do list a stainless steel and bronze coefficient of friction.
2. Do you know why there is no dry/ clean coefficient of friction value listed for bronze and steel?
1. Would you suggest using the steel and bronze value
2. Do you have a good source for a coefficient of friction values that do list a stainless steel and bronze coefficient of friction.
2. Do you know why there is no dry/ clean coefficient of friction value listed for bronze and steel?





RE: Coefficient of friction stainless steel on bronze
Link
Gives Aluminium Bronze on steel 0.45, Phosphor Bronze on Steel 0.35
je suis charlie
RE: Coefficient of friction stainless steel on bronze
For design purposes, you'll need both the static and dynamic friction values for clean/dry bronze on stainless. The specific bronze/stainless alloy composition can also make a difference. Some free machining alloys contain materials that might reduce friction. The relative surface roughness at the contact interface will also have an effect on friction characteristics. With smooth/clean/dry stainless steel on bronze I don't think you'll get a static friction below 0.30. A static friction of 0.16 for this combination with grease lube sounds like a reasonable number to use for design purposes.
RE: Coefficient of friction stainless steel on bronze
generally speaking stainless steel would not be the preferred choice to obtain low friction, both in dry and lubricated conditions. one of the prerequisites for lubrication is that the lubricant adheres well to the mating materials involved. adherence to stainless steel is less then with steel. in a wormgear due to the very high sliding between the gears adherence is even more important.
i would not consider stainless steel unless the environment really requires it - it will make lubrication, obtaining a acceptable lifespan and low friction a lot more difficult.
RE: Coefficient of friction stainless steel on bronze
As others said, running oil free will likely be a challenge.
Some machine design handbooks go so far as to say stuff like this -
[indent] " Why Not to Use Worm Gears -
There is one particularly glaring reason why one would not choose a worm gear over a standard gear: lubrication. The movement between the worm and the wheel gear faces is entirely sliding. There is no rolling component to the tooth contact or interaction. This makes them relatively difficult to lubricate. The lubricants required are usually very high viscosity (ISO 320 and greater) and thus are difficult to filter, and the lubricants required are typically specialized in what they do, requiring a product to be on-site specifically for that type of equipment. "
If the loads are low enough to consider running oil-free, maybe a self lubricating plastic would be an option.
There are lubricants designed for "open gearing" that stay put pretty well.
RE: Coefficient of friction stainless steel on bronze