The bore of the ring has workings (1a) suitable to act as a grease reserve at the friction area. A self-lubricating coating (3) with low wettability is applied to the entire surface of the said bore, including in the workings (1a) suitable to act as a grease reserve, such that after wearing of the layer of self-lubricating coating at the friction surface of the bore, the difference in wettability between the said friction surface and the workings still having the coating, enables the grease to be drawn out of the said workings in order to lubricate the said friction surface.

A method for grease purification is disclosed. The method comprises steps of: S1, feeding crude grease into a grease hydrolysis column to be hydrolysed so as to obtain aqueous phase, organic phase, and middle layer substances between the aqueous phase and the organic phase; S2, feeding the organic phase and the middle layer substances in the grease hydrolysis column into a flash stripping column to be flashed so as to obtain vaporized products and non-vaporized products; and S3, feeding the vaporized products in the flash stripping column into a separation column to be separated so as to obtain fatty acid. By this method, fatty acid with a high purity can be obtained; glycerin can be obtained as a co-product; and high value-added nutrients in the grease can be collected. Therefore, the use value of grease can be greatly improved.

The bore of the ring has workings (1a) suitable to act as a grease reserve at the friction area. A self-lubricating coating (3) with low wettability is applied to the entire surface of the said bore, including in the workings (1a) suitable to act as a grease reserve, such that after wearing of the layer of self-lubricating coating at the friction surface of the bore, the difference in wettability between the said friction surface and the workings still having the coating, enables the grease to be drawn out of the said workings in order to lubricate the said friction surface.

Provided is a grease containing a base oil and a hydrophilic nanofiber, the hydrophilic nanofiber having a thickness (d) of 0.01 to 500 nm being dispersed therein. The grease is low in an environmental load and excellent in safety on the human body and also has an appropriate worked penetration and has a high dropping point, and therefore, it is also excellent in heat resistance.

The bore of the ring has workings suitable to act as a grease reserve at a friction area. A self-lubricating coating layer with a low wettability is applied to the entire surface of the bore, including in the workings suitable to act as a grease reserve, such that after wearing of the layer of self-lubricating coating at the friction surface of the bore, the difference in wettability between the friction surface and the workings still having the coating layer, enables the grease to be drawn out of the workings in order to lubricate the friction area.

This disclosure relates to a process for extracting a perfluoropolyether. The process involves: (a) contacting a solvent comprising a liquid or supercritical carbon dioxide with a lubricating grease comprising a thickener and the perfluoropolyether in an extraction zone to form an extraction solution comprising an extracted perfluoropolyether; and (b) recovering the extracted perfluoropolyether from the extraction solution; wherein the recovered extracted perfluoropolyether comprises no more than about 2 wt % of the thickener.

This disclosure relates to a process for extracting a perfluoropolyether. The process involves: (a) contacting a solvent comprising a liquid or supercritical carbon dioxide with a lubricating grease comprising a thickener, an extraction aid material, and the perfluoropolyether in an extraction zone to form an extraction solution comprising an extracted perfluoropolyether; and (b) recovering the extracted perfluoropolyether from the extraction solution; wherein the recovered extracted perfluoropolyether comprises no more than about 2 wt % of the thickener.

Provided is a grease containing a base oil and a hydrophilic nanofiber, the hydrophilic nanofiber having a thickness (d) of 0.01 to 500 nm being dispersed therein. The grease is low in an environmental load and excellent in safety on the human body and also has an appropriate worked penetration and has a high dropping point, and therefore, it is also excellent in heat resistance.