Bearings and mechanical seals enhanced with microstructures

A shaft-thrust bearing comprising a shaft and a thrust bearing, said shaft having a face in contact with said thrust bearing, and said thrust bearing having a face in contact with said shaft, wherein at least one of said faces:

• (a) comprises a plurality of microstructures covering between about 10% and about 70% of the area of said face, wherein each of said microstructures comprises a distal end and a proximal end;
• (b) the proximal end of each of said microstructures is connected to said face;
• (c) the distal end of each of said microstructures is not connected to a shield, wall, or other object that inhibits heat transfer,
• (d) the distance between the proximal and distal ends of each of said microstructures is between about 0.05 mm and about 1.0 mm, and the aspect ratio of each of said microstructures is between about 0.2 and about 20;
• wherein the aspect ratio of a microstructure is the ratio of the distance between the proximal end and the distal end to the characteristic dimension of the microstructure;
• wherein the characteristic dimension of the microstructure is the diameter of the microstructure in a plane perpendicular to a line between the proximal end and the distal end of the microstructure;
• and
• (e) wherein, if a lubricant is applied to said face, then in the presence of a load between said shaft and said thrust bearing, said microstructures and the spaces between adjacent microstructures are adapted to cause the lubricant to flow to substantially all portions of said face subject to the load;
• whereby heat transfer at the interface of said shaft and said thrust bearing is substantially greater than would be the heat transfer between an otherwise identical shaft and an otherwise identical thrust bearing, both of which lacked said microstructures;
• and
• whereby, if a lubricant is applied to said face, the friction between said shaft and said thrust bearing is substantially less than would be the friction between an otherwise identical shaft and an otherwise identical thrust bearing, both of which lacked said microstructures.

A heat transfer device for heating or cooling an apparatus, comprising a first face and a second face, wherein:

• (a) said first face is in thermal contact with the apparatus to be heated or cooled, or is adapted to be placed in thermal contact with the apparatus, or is part of the apparatus;
• (b) the device additionally comprises a plurality of microstructures connecting said first and second faces, and covering between about 10% and about 70% of the area of each of said faces;
• (c) the distance between said first and second faces is between about 0.05 mm and about 1.0 mm, and the aspect ratio of each of said microstructures is between about 0.5 and about 75;
• wherein the aspect ratio of a microstructure is the ratio of the distance between said faces to the characteristic dimension of the microstructure;
• wherein the characteristic dimension of the microstructure is the diameter of the microstructure in a plane perpendicular to a line between said faces;
• and
• (d) wherein the space between said faces and said microstructures is adapted for circulation of a refrigerant fluid to carry heat to or from the apparatus.

A ball bearing comprising a first race, and a second race interior to said first race, and a plurality of load-bearing balls between said first and second races, each of said races having a face in contact with said balls, wherein at least one of said faces:

• (a) comprises a plurality of microstructures covering between about 10% and about 70% of the area of said face, wherein each of said microstructures comprises a distal end and a proximal end;
• (b) the proximal end of each of said microstructures is connected to said face;
• (c) the distal end of each of said microstructures is not connected to a shield, wall, or other object that inhibits heat transfer;
• (d) the distance between the proximal and distal ends of each of said microstructures is between about 0.05 mm and about 1.0 mm, and the aspect ratio of each of said microstructures is between about 0.2 and about 5.0;
• wherein the aspect ratio of a microstructure is the ratio of the distance between the proximal end and the distal end to the characteristic dimension of the microstructure;
• wherein the characteristic dimension of the microstructure is the diameter of the microstructure in a plane perpendicular to a line between the proximal end and the distal end of the microstructure;
• and
• (e) wherein, if a lubricant is applied to said face, then in the presence of a load between said races, said microstructures and the spaces between adjacent microstructures are adapted to cause the lubricant to flow to substantially all portions of said face subject to the load;
• whereby heat transfer at the interface of said races is substantially greater than would be the heat transfer between otherwise identical races, both of which lacked said microstructures;
• and
• whereby, if a lubricant is applied to said face, the friction between said races is substantially less than would be the friction between otherwise identical races, both of which lacked said microstructures.

A bearing comprising a first member and a second member, wherein each of said members has a surface in contact with the other said member, and wherein said first member is adapted to movably support said second member under a load, wherein at least one of said surfaces:

• (a) comprises a plurality of microstructures covering between about 10% and about 70% of the area of said first surface, wherein each of said microstructures comprises a distal end and a proximal end;
• (b) the proximal end of each of said microstructures is connected to said first surface;
• (c) the distal end of each of said microstructures is not connected to a shield, wall, or other object that inhibits heat transfer;
• (d) the distance between the proximal and distal ends of each of said microstructures is between about 0.05 mm and about 1.0 mm, and the aspect ratio of each of said microstructures is between about 0.5 and about 75;
• wherein the aspect ratio of a microstructure is the ratio of the distance between the proximal end and the distal end to the characteristic dimension of the microstructure;
• wherein the characteristic dimension of the microstructure is the diameter of the microstructure in a plane perpendicular to a line between the proximal end and the distal end of the microstructure;
• and
• (e) wherein, if a lubricant is applied to said first surface, then in the presence of a load between said first and second surfaces, said microstructures and the spaces between adjacent microstructures are adapted to cause the lubricant to flow to substantially all portions of said first surface subject to the load;
• whereby heat transfer at the interface of said first and second surfaces is substantially greater than would be the heat transfer between otherwise identical surfaces lacking said microstructures;
• and
• whereby, if a lubricant is applied to said first surface, the friction between said first and second surfaces is substantially less than would be the friction between otherwise identical surfaces lacking said microstructures.