A power tool includes a housing, a motor, and a drive mechanism. The drive mechanism includes a driven gear that is rotated by the motor. The driven gear is vertically-oriented within the housing and has an upper portion and a lower portion. The drive mechanism also includes a connecting rod coupled to the driven gear to translate rotary motion of the driven gear into reciprocating motion, and an output shaft coupled to the connecting rod to reciprocate relative to the housing through a cutting stroke and a return stroke. The drive mechanism further includes a counterweight coupled to the driven gear for rotation with the driven gear. The counterweight moves through the upper portion of the driven gear during the cutting stroke of the output shaft, and moves through the lower portion of the driven gear during a return stroke of the output shaft.

A power tool includes a housing, a motor, and a drive mechanism. The drive mechanism includes a driven gear that is rotated by the motor. The driven gear is vertically-oriented within the housing and has an upper portion and a lower portion. The drive mechanism also includes a connecting rod coupled to the driven gear to translate rotary motion of the driven gear into reciprocating motion, and an output shaft coupled to the connecting rod to reciprocate relative to the housing through a cutting stroke and a return stroke. The drive mechanism further includes a counterweight coupled to the driven gear for rotation with the driven gear. The counterweight moves through the upper portion of the driven gear during the cutting stroke of the output shaft, and moves through the lower portion of the driven gear during a return stroke of the output shaft.

A connecting rod for an internal combustion engine may include a big end passage for receiving a pin journal of a crankshaft, a small end passage for receiving a piston pin, and a beam extending between the big and small end passages. The small end passage may extend along a passage axis and be delimited by opposed edges. The small end passage may include an inner passage surface with a cylindrical surface portion having a first diameter. The small end passage may extend along the passage axis between the opposed edges. The inner passage surface may comprise profiled regions adjacent to the opposed edges and extending at least over a part of a circumference of the opposed edges. The profiled regions may begin from the cylindrical surface portion and increase into a maximum second diameter at the opposed edges. Further, a plurality of dimples may be positioned along the cylindrical surface portion of the inner passage surface.

A method for producing a connecting rod for an internal combustion engine, having a small connecting rod eye for holding a piston pin and having a large connecting rod eye for holding a crank pin, wherein at least one connecting rod eye has at least one geometric deviation from a cylindrical inner contour. It is provided according to the invention that the at least one connecting rod eye is formed by creating a bore with a cylindrical inner contour, and coating the bore with a coating comprising a resin with solid lubricant particles embedded therein. The coating forms the at least one geometric deviation from the cylindrical inner contour of the at least one connecting rod eye.

A method for producing a connecting rod for an internal combustion engine, having a small connecting rod eye for holding a piston pin and having a large connecting rod eye for holding a crank pin, wherein at least one connecting rod eye has at least one geometric deviation from a cylindrical inner contour. It is provided according to the invention that the at least one connecting rod eye is formed by creating a bore with a cylindrical inner contour, and coating the bore with a coating comprising a resin with solid lubricant particles embedded therein. The coating forms the at least one geometric deviation from the cylindrical inner contour of the at least one connecting rod eye.

The present disclosure provides a variable compression ratio device including a piston, a piston pin, an eccentric cam, a connecting rod, a crank pin, a hydraulic pump, an oil jet injection nozzle, an oil jet control valve, and a control unit. In addition, a groove formed in a rotating direction of the eccentric cam is divided into a first chamber and a second chamber. The piston pin receives a hydraulic pressure through a path formed inside the crank pin and the connecting rod and receives the oil injected from the oil jet injection nozzle to control the hydraulic pressure supplied to the first chamber and the second chamber of the eccentric cam, thereby controlling the rotation position of the eccentric cam.

An apparatus includes a connecting rod having a surface that defines an opening to receive a pin for coupling the connecting rod to a piston at a first end of the connecting rod. The surface includes a groove arrangement to collect, retain and distribute lubrication fluid in the space between the pin and the inner surface. The surface can be formed by the connecting rod or a bushing in an opening of the connecting rod.

An apparatus includes a connecting rod having a surface that defines an opening to receive a pin for coupling the connecting rod to a piston at a first end of the connecting rod. The surface includes a groove arrangement to collect, retain and distribute lubrication fluid in the space between the pin and the inner surface. The surface can be formed by the connecting rod or a bushing in an opening of the connecting rod.

The invention relates to a method for producing a piston rod unit, or a shaft, in lightweight construction, with a rod which is hollowly-drilled by means of a deep bore into the rod shank, and the resulting rod opening is closed subsequently by means of a forging process.

The invention relates to a method for producing a piston rod unit, or a shaft, in lightweight construction, with a rod which is hollowly-drilled by means of a deep bore into the rod shank, and the resulting rod opening is closed subsequently by means of a forging process.