A method of repairing a piston seal assembly comprises removing worn material from a piston seal groove to generate a worked seal groove, applying a groove buildup member to the worked seal groove, and disposing a seal member proximate the groove buildup member.

A power cylinder system for a reciprocating engine includes a piston configured to move within a cylinder of the reciprocating engine. The system also includes a groove extending circumferentially about the piston and configured to support a ring. An axially-facing surface of the groove has circumferential undulations at ambient temperatures that are configured to compensate for distortions to the groove caused by operation of the reciprocating engine.

A power cylinder system for a reciprocating engine includes a piston configured to move within a cylinder of the reciprocating engine. The system also includes a groove extending circumferentially about the piston and configured to support a ring. An axially-facing surface of the groove has circumferential undulations at ambient temperatures that are configured to compensate for distortions to the groove caused by operation of the reciprocating engine.

A compressor may include a shell, first and second scroll members, a floating seal, a muffler plate, and a wear ring. The shell defines a discharge chamber and a suction chamber. The floating seal may sealingly engage the second scroll member. The muffler plate defines the discharge chamber and the suction chamber. The wear ring may sealingly engage the muffler plate and the floating seal such that the wear ring, the muffler plate, and the floating seal fluidly isolate the discharge chamber from the suction chamber. The muffler plate may include an axially facing surface that contacts the wear ring. The axially facing surface may include an annular recess. The wear ring may at least partially cover the annular recess. The annular recess may provide clearance between the muffler plate and the wear ring to allow the wear ring to deflect relative to the muffler plate during compressor operation.

A compressor may include a shell, first and second scroll members, a floating seal, a muffler plate, and a wear ring. The shell defines a discharge chamber and a suction chamber. The floating seal may sealingly engage the second scroll member. The muffler plate defines the discharge chamber and the suction chamber. The wear ring may sealingly engage the muffler plate and the floating seal such that the wear ring, the muffler plate, and the floating seal fluidly isolate the discharge chamber from the suction chamber. The muffler plate may include an axially facing surface that contacts the wear ring. The axially facing surface may include an annular recess. The wear ring may at least partially cover the annular recess. The annular recess may provide clearance between the muffler plate and the wear ring to allow the wear ring to deflect relative to the muffler plate during compressor operation.

A power cylinder system for a reciprocating engine includes a steel piston configured to move within a cylinder of the reciprocating engine. The system also includes a groove extending circumferentially about the piston beneath a top land of the piston and configured to support a ring having an inner circumferential face. One or more channels are formed in the top land and are configured to facilitate transfer of combustion gases to a space between a portion of the groove and the inner circumferential face of the ring.

A piston for an internal combustion engine may include a piston crown, a piston body, and a ring portion. The piston body may have a radially outermost piston outer surface, which may emanate from the piston crown and extend axially and in a circumferential direction. The ring portion may be disposed axially spaced apart from the piston crown. The ring portion may extend axially and in the circumferential direction. The ring portion may include a ring carrier with a ring groove configured to receive a piston ring. The ring portion may further include a radially outer ring portion outer surface that extends in the circumferential direction. The ring portion outer surface may be disposed radially to an inside relative to the piston outer surface. The piston outer surface may extend elliptically in the circumferential direction. The ring portion outer surface may extend rotation-symmetrically in the circumferential direction.

A piston for an internal combustion engine may include a ring belt, a groove, and an additional groove. The ring belt may extend along an axial direction. The groove may be arranged on the outer circumference of the ring belt and may be configured to receive an oil scraper ring. The additional groove may be arranged on the outer circumference spaced apart from the groove with respect to the axial direction. The additional groove may include a first groove side axially facing away from the groove and a second groove side axially facing the groove. The first groove side may include an axial step.

The present invention addresses the problem of providing a piston ring covered with a DLC coating that has excellent wear resistance and shows a low attacking property on a cylinder bore sliding surface. The problem is solved by a piston ring which is used in the presence of an engine lubricating oil and includes a DLC coating on an outer peripheral sliding surface. The DLC coating has an sp.sup.2 component ratio of 0.5 to 0.85 as determined from a TEM-EELS spectrum obtained by a combination of a transmission electron microscope (TEM) and electron energy loss spectroscopy (EELS), as well as a coating hardness of 12 GPa to 26 GPa and a Young's modulus of 250 GPa or less as measured by a nanoindentation method.

The present invention addresses the problem of providing a piston ring covered with a DLC coating that has excellent wear resistance and shows a low attacking property on a cylinder bore sliding surface. The problem is solved by a piston ring which is used in the presence of an engine lubricating oil and includes a DLC coating on an outer peripheral sliding surface. The DLC coating has an sp.sup.2 component ratio of 0.5 to 0.85 as determined from a TEM-EELS spectrum obtained by a combination of a transmission electron microscope (TEM) and electron energy loss spectroscopy (EELS), as well as a coating hardness of 12 GPa to 26 GPa and a Young's modulus of 250 GPa or less as measured by a nanoindentation method.