A fastener driving tool with a working cylinder and a piston, the piston outer surface having a lubricant-saturated foam material that stores and dispenses lubricant into the piston-cylinder wall interface, thereby increasing the performance and lifespan of the tool. Another embodiment discloses a two-part piston in which the bottom portion is made of metal and absorbs the main mechanical loading forces of the piston drive and return strokes, and the top portion is made of a non-metallic material that has surfaces that act as sliding bearings against the inner wall of the cylinder.

A fastener driving tool with a working cylinder and a piston, the piston outer surface having a lubricant-saturated foam material that stores and dispenses lubricant into the piston-cylinder wall interface, thereby increasing the performance and lifespan of the tool. Another embodiment discloses a two-part piston in which the bottom portion is made of metal and absorbs the main mechanical loading forces of the piston drive and return strokes, and the top portion is made of a non-metallic material that has surfaces that act as sliding bearings against the inner wall of the cylinder.

The present disclosure provides a piston for an internal combustion engine, the piston having a piston body including a first bearing saddle defining a first axis and a second bearing saddle defining a second axis, the first axis being parallel to and spaced from the second axis. A bearing is also provided, the bearing having a first journal having a first body, longitudinal ends, and lateral edges, the first journal defining a first axis, the first journal disposed about approximately 180 degrees of the first axis and a second journal having a second body and defining a second axis, the second journal disposed about approximately 180 degrees of the second axis, the second journal operable to be positioned abutting one of the lateral edges of the first journal when the first and second journals are positioned with the piston.

The present disclosure provides a piston for an internal combustion engine, the piston having a piston body including a first bearing saddle defining a first axis and a second bearing saddle defining a second axis, the first axis being parallel to and spaced from the second axis. A bearing is also provided, the bearing having a first journal having a first body, longitudinal ends, and lateral edges, the first journal defining a first axis, the first journal disposed about approximately 180 degrees of the first axis and a second journal having a second body and defining a second axis, the second journal disposed about approximately 180 degrees of the second axis, the second journal operable to be positioned abutting one of the lateral edges of the first journal when the first and second journals are positioned with the piston.

The invention in question relates, in particular, to a hydraulic variable compression ratio piston comprising a full floating eccentric mounted in the body of said piston, wherein the eccentric accepts a piston pin, with the pin in turn, accepting the small end of the connecting rod. The eccentric moves in a circular manner against the force of preloaded springs installed at the bottom of the piston, thereby allowing the piston to move up or down relative to the connecting rod. An adjustment mechanism within the piston comprising of a combination of said preloaded springs and a lifter acting against the movement of the eccentric, holds the piston's current position relative to the connecting rod until an increase or decrease in combustion forces act upon the piston and changes the compression ratio.

The invention in question relates, in particular, to a hydraulic variable compression ratio piston comprising a full floating eccentric mounted in the body of said piston, wherein the eccentric accepts a piston pin, with the pin in turn, accepting the small end of the connecting rod. The eccentric moves in a circular manner against the force of preloaded springs installed at the bottom of the piston, thereby allowing the piston to move up or down relative to the connecting rod. An adjustment mechanism within the piston comprising of a combination of said preloaded springs and a lifter acting against the movement of the eccentric, holds the piston's current position relative to the connecting rod until an increase or decrease in combustion forces act upon the piston and changes the compression ratio.

The invention in question relates, in particular, to a hydraulic variable compression ratio piston comprising a full floating eccentric mounted in the body of said piston, wherein the eccentric accepts a piston pin, with the pin in turn, accepting the small end of the connecting rod. The eccentric moves in a circular manner against the force of preloaded springs installed at the bottom of the piston, thereby allowing the piston to move up or down relative to the connecting rod. An adjustment mechanism within the piston comprising of a combination of said preloaded springs and a lifter acting against the movement of the eccentric, holds the piston's current position relative to the connecting rod until an increase or decrease in combustion forces act upon the piston and changes the compression ratio.

The invention in question relates, in particular, to a hydraulic variable compression ratio piston comprising a full floating eccentric mounted in the body of said piston, wherein the eccentric accepts a piston pin, with the pin in turn, accepting the small end of the connecting rod. The eccentric moves in a circular manner against the force of preloaded springs installed at the bottom of the piston, thereby allowing the piston to move up or down relative to the connecting rod. An adjustment mechanism within the piston comprising of a combination of said preloaded springs and a lifter acting against the movement of the eccentric, holds the piston's current position relative to the connecting rod until an increase or decrease in combustion forces act upon the piston and changes the compression ratio.

A lubricating mechanism of a pin connection pair of an internal combustion engine having a piston, a pin, and a connecting rod. The pin may be mounted in two pin seat portions of the piston such that the pin and one of the two pin seat portions form the pin connection pair. The lubricating mechanism may include a lubricating passage through which a lubricating medium is flowable and an oil outlet orifice communicating with the lubricating passage. The lubricating passage and the oil outlet orifice may be disposed in a piston top portion of the piston. An opening of the oil outlet orifice may face in an axial direction and may be disposed directly below a corresponding portion of the lubricating passage such that the lubricating medium is flowable via the opening directly to a gap defined between the connecting rod and a pin seat portion.

A lubricating mechanism of a pin connection pair of an internal combustion engine having a piston, a pin, and a connecting rod. The pin may be mounted in two pin seat portions of the piston such that the pin and one of the two pin seat portions form the pin connection pair. The lubricating mechanism may include a lubricating passage through which a lubricating medium is flowable and an oil outlet orifice communicating with the lubricating passage. The lubricating passage and the oil outlet orifice may be disposed in a piston top portion of the piston. An opening of the oil outlet orifice may face in an axial direction and may be disposed directly below a corresponding portion of the lubricating passage such that the lubricating medium is flowable via the opening directly to a gap defined between the connecting rod and a pin seat portion.