Sealing elements for rotating shafts: in general, PTFE is the plastic material that has the best friction characteristics. It is also called Teflon.
It has the consistency of a kind of butter, for which it is loaded with bronze or other materials such as graphite, depending on the material with which it is to be coupled. PU, polyurethane, is similar to an elastomer, so no bronze is needed.
These gaskets are loaded in 2 ways:
- Preload, given by the throat bottom Ø
- Energization, given by the pressure of the oil that goes to contain. Something similar to the ailerons in F1: The stronger you go, the more you can go strong. In our case the p is quite low and the energization is accordingly. To keep them you must use the other way.
In general it is the shape of the gasket that makes the application (roto-translating or only translating). In our case, given the shape of the throat, we can not get any better.
We chose the PU instead of the PTFR because it behaves better at p ↙, speed ↙, driving games ↙.
MQL is a lubrication system through which an oil-air aerosol is created at the tool work point. It allows to use the minimum quantity of oil in the current state of the technology.
- Only use original oils (they are such as to allow perfect micronization, do not contain solid molecular additives, are polarized, offer poor adhesion to machine surfaces_for easier cleaning_, are not aggressive for valves and aerosol pipes, have excellent lubricating capabilities ).
The F110 Lubrix is recommended, but samples of other oils can be submitted for evaluation.
- 20 liters a week (real – expected consumption) is a consumption above all limits “acceptable”: already 1 liter every 10 hours of continuous and effective lubrication is to be considered very unusual. “Normal” consumption is from 5 to 140 ml / hour; average 20-25 ml / hour. One piece (eg connecting rod) can be turned and finished with 1-2 ml of oil (per piece).
- TRC04 has 4,5 vs 3 ml/piece, 115l each 2 wks and 84 parts/h
- Verify that appropriate nozzles are adopted and directed where necessary; the nozzles (1, 2, 4 .. it does not matter) must be positioned at a maximum distance of 20 mm from the cutting edge. Single-phase aerosol nozzles are recommended, with a terminal sprayer having a max. 1.1-1.2 mm diameter outlet hole
- Lubrix offers the ultimate in technology and performance for MQL from within. With internal MQL, an excessive consumption of oil is an indication of non-compliant use of the system, for example: wrong MQL parameter for a given tool (or set of tools with similar lubrication needs), or incorrect tools because – for example – with internal raceways with a diameter greater than 1.8 mm-max 2. In addition .. Which tools? Provided by whom? With which dimensions and which diameter ducts? Etc … they are all crucial information.
The aerosol system is based on Bernoulli: a converging nozzle increases speed and decreases pressure. The decrease in p causes the oil to condense.
I remember that a pressure drop in a nozzle corresponds to a drop in T (and the consequent creation of aerosol, or fog):