A piston for a heavy duty diesel engine including a composite layer forming at least a portion of a combustion surface is provided. The composite layer has a thickness greater than 500 microns and includes a mixture of components typically used to form brake pads, such as a thermoset resin, an insulating component, strengthening fibers, and an impact toughening additive. According to one example, the thermoset resin is a phenolic resin, the insulating component is a ceramic, the strengthening fibers are graphite, and the impact toughening additive is an aramid pulp of fibrillated chopped synthetic fibers. The composite layer also has a thermal conductivity of 0.8 to 5 W/m.Math.K. The body portion of the piston can include an undercut scroll thread to improve mechanical locking of the composite layer. The piston can also include a ceramic insert between the body portion and the composite layer.

A coating solution that contains 10 to 20% by weight of epoxy resin serving as a thermosetting resin, 20 to 30% by weight of MoS.sub.2, and 5 to 10% by weight of graphite, with a remainder thereof constituted by an organic solvent, is sprayed onto a wrap portion side face of an orbiting scroll from a spray nozzle. While spraying the coating solution, the orbiting scroll is rotated on a rotating table and the spray nozzle is moved along a rectilinear movement path toward a radial direction outer side of the orbiting scroll while maintaining an attitude thereof from the start of the spraying process. After applying the coating solution, the coating solution is dried by baking, whereupon a break-in operation is performed. As a result, an elastic coating is formed at a coating thickness that enables elastic deformation in accordance with a clearance between the wrap portion side faces.

A tapered roller bearing (31a) has a plurality of retainer segments (11a, 11d) each having a pocket to house a tapered roller (34a), and arranged so as to be continuously lined with each other in a circumferential direction between an outer ring (32a) and an inner ring (33a). The retainer segment (11a, 11d) is formed of a resin containing a filler material to lower a thermal linear expansion coefficient. In addition, a clearance (39a) is provided between the first retainer segment (11a) and the last retainer segment (11d) after the plurality of retainer segments (11a, 11d) have been arranged in the circumferential direction without providing any clearance. Here a circumferential range (R) of the clearance (39a) is larger than 0.075% of a circumference of a circle passing through a center of the retainer segment (11a, 11d) and smaller than 0.12% thereof at room temperature.

An electric compressor includes a housing accommodating a compression mechanism unit and an electric motor; an inverter; an inverter cover defining, in conjunction with the housing, an internal space accommodating the inverter; and a sealing member sealing the internal space. The inverter cover includes an outer cover portion formed of resin and having an outer surface exposed to an external space, an inner cover portion formed of resin and forming a resin interface where the inner cover portion is in close contact with the outer cover portion, and a metal plate interposed between the outer cover portion and the inner cover portion. The resin interface includes a first edge portion and a second edge portion and is arranged in such a manner that the first edge portion is located on the metal plate and that the second edge portion leads to the internal space.

The electric compressor includes a housing having electrical conductivity, an inverter, a cover having electrical conductivity, a sealing portion, and a shielding portion having electrical conductivity. The cover is attached to the housing, thereby defining an accommodating space in which the inverter is accommodated. The sealing portion has a main body portion made of resin and a metal portion having electrical conductivity. The sealing portion is provided in a gap between the housing and the cover. The shielding portion is joined to the metal portion and electrically grounded. The metal portion is provided in the accommodating space, and has an outer circumferential edge embedded in the main body portion. The shielding portion is arranged so as to face a third surface of the main body portion and so as to extend from the metal portion toward at least one of the first surface and the second surface.

A cylinder head for an engine may include an adiabatic coating layer having a polyamideimide resin and an aerogel dispersed in the polyamideimide resin with thermal conductivity of 0.60 W/m or less formed on a surface of a combustion chamber.

Methods for improving adhesion or bonding between materials used in forming components of directional drilling assemblies, such as rotors and stators, are provided. A surface of a component may be treated, such as through cleaning, etching and/or activating a surface. The use of plasma treatment may enhance the adhesion between the surfaces and/or materials to be bonded, thereby reducing the degradation or mechanical failure of these materials in oilfield applications.