To get a patent, an invention needs to be new, useful and non-obvious. New means no one knows about it. Useful means the invention must work. Non-obvious means someone skilled in the art wouldn't find the invention readily apparent.
A snarky answer to your question is that because you have publicly disclosed your inventions they are known and not now patentable. However, in the US there is a grace period and I'm assuming these are just examples and not real inventions you want to patent.
One thing to remember is just because you might get a patent on something doesn't mean you have a right to use the invention. There might be another patent that covers the invention. I think this is the problem with several of your ideas. For example lets consider your gear using gasoline. You might attempt to get a patent on the use of gasoline to cool a gear. I'd say this would be obvious since evaporative cooling is well known and cooling a gear train is also well known. However, even if you did get a patent the original patent with covers a gear using gasoline to lubricate would be infringed. You might say "I'm using the gasoline to cool", but the gasoline doesn't magically lose its ability to lubricate. If you implement all the aspects of a patent's claim, you infringe it. Similarly if sugar prevents wear and oxidation, you might get a patent on the oxidation prevention, but the sugar doesn't lose its anti-wear properties so you are probably infringing on the existing patent.
Similarly using antibodies for infection control and lubrication. Assuming the antibodies actually have both properties, if you make contact lenses with antibodies and claim to use them for lubrication, they still prevent infection. However, you might work around the infringement if you devise a particular antibody that can be proven ineffective as an infection control but still has its lubrication properties.
This all boils down to patentability versus freedom to operate. I am not a lawyer and patentability and freedom to operate analyses are highly dependent on the particulars of the invention. I highly recommend working with a patent attorney or agent with experience in the specific field.