To reduce a friction, and to provide an excellent seizing resistance. Provided is a cast iron cylinder liner including an inner peripheral sliding surface made of cast iron, and an internal combustion engine including a cylinder bore including an inner peripheral sliding surface made of cast iron, wherein the inner peripheral sliding surface includes a region satisfying Expression (1) to Expression (3),

Rvk/Rk1.0 Expression (1)

0.08 mRk0.3 m Expression (2)

RkRpk>0 Expression (3)

[Rk is the core roughness depth based on JIS B0671-2:2002, Rpk is the reduced peak height based on JIS B0671-2:2002, and Rvk is the reduced valley depth based on JIS B0671-2:2002 in Expression (1) to Expression (3)].

Disclosed is lubrication for a slow-running two-stroke engine, especially marine diesel engines. The lubrication uses Swirl Injection Principle by locating the lubricant injectors closer to the TDC than of the full stroke of the piston, which is closer than in typical marine diesel engines. This can be achieved by reconstructing cylinder liners or by adding new mounting holes to the cylinder. In case that such reconstruction is not possible, an improvement of SIP principles can also be achieved by directing the spray towards the TDC or to a location on the cylinder liner closer to the TDC as compared to the location of the SIP valves, for example under an angle of more than 30 degrees or even more than 60 degrees when measured from a plane normal to the cylinder axis.

Disclosed is lubrication for a slow-running two-stroke engine, especially marine diesel engines. The lubrication uses Swirl Injection Principle by locating the lubricant injectors closer to the TDC than of the full stroke of the piston, which is closer than in typical marine diesel engines. This can be achieved by reconstructing cylinder liners or by adding new mounting holes to the cylinder. In case that such reconstruction is not possible, an improvement of SIP principles can also be achieved by directing the spray towards the TDC or to a location on the cylinder liner closer to the TDC as compared to the location of the SIP valves, for example under an angle of more than 30 degrees or even more than 60 degrees when measured from a plane normal to the cylinder axis.

A structural frame is provided herein. The structural frame may provide a lubrication passage that feeds a lubricant to a cylinder block. The structural frame may increase cylinder block strength while allowing a cylinder block to be constructed of less material.

The invention relates to a cylinder bore and a method. The cylinder bore is configured to receive a piston for reciprocating movement therein and has a pressure side and a counter-pressure side. The cylinder bore includes a bore surface having a first roughness value in a first longitudinal region on the pressure side and a second roughness value different from the first roughness value in the first longitudinal region on the counter-pressure side.

The invention relates to a cylinder bore and a method. The cylinder bore is configured to receive a piston for reciprocating movement therein and has a pressure side and a counter-pressure side. The cylinder bore includes a bore surface having a first roughness value in a first longitudinal region on the pressure side and a second roughness value different from the first roughness value in the first longitudinal region on the counter-pressure side.

Methods and systems are provided for a bore. In one example, a system includes a bore portion for receiving a reciprocating piston, the bore portion having first and second ends between which the piston travels in an axial direction. The bore portion comprises a plurality of recesses, axially spaced apart, and formed in a piston facing surface of the bore portion at a plurality of axial positions, with at least one recess being provided at each axial position. Widths of the plurality of recesses decrease in the axial direction away from a mid-stroke position toward the first and second ends, and depths of the plurality of recesses increase in the axial direction away from the mid-stroke position toward the first and second ends.

This application discloses a cylinder block structure including: a cylinder block surrounding a cylinder array formed by a plurality of cylinders lined up in a first direction; a reinforcement plate including: a first fastening portion fastened to the cylinder block; and a second fastening portion fastened to the cylinder block at a position separated from the first fastening portion in a second direction that intersects with the first direction; and an oil pump that supplies oil to the cylinder block. The oil pump is fastened to the cylinder block together with the reinforcement plate. The reinforcement plate is interposed between the cylinder block and the oil pump, and has a length that is equal to or more than half of the cylinder array in the first direction.

This application discloses a cylinder block structure including: a cylinder block surrounding a cylinder array formed by a plurality of cylinders lined up in a first direction; a reinforcement plate including: a first fastening portion fastened to the cylinder block; and a second fastening portion fastened to the cylinder block at a position separated from the first fastening portion in a second direction that intersects with the first direction; and an oil pump that supplies oil to the cylinder block. The oil pump is fastened to the cylinder block together with the reinforcement plate. The reinforcement plate is interposed between the cylinder block and the oil pump, and has a length that is equal to or more than half of the cylinder array in the first direction.

A member having a sliding contact surface that exerts a reduced frictional force when making sliding contact with a prescribed member and retains the lubricating oil more uniformly is provided. The sliding contact surface is a honed surface having flat plateau parts and groove parts. As calculated in regard to the sliding contact surface by using a mean line derived from a cross-sectional curve of the sliding contact surface in accordance with ISO 13565-1, a ten-point average roughness is 0.6-7.0 m, a load length ratio at a cut level of 20% is 60-98%, an effective load roughness is 0-1 m, and a mean value of intervals between the groove parts having a depth of 0.2 m or greater from the mean line is 79-280 m.