Lubrication mechanism for piston pin and snap ring
AssigneeNKG Spark Plug Co., Ltd.
InventorsTakio Kojima, Mitsuyoshi Kawamura, Shigeaki Akao
Life of this patent
Estimating the term…
Abstract
A piston boss is formed with an oil inlet hole for collecting oil flowing downward along a piston and allowing it to flow toward a snap ring and an end of a ceramic piston pin in contact with the snap ring. The oil having lubricated the snap ring and the end of the piston pin is collected by an oil outlet hole formed in the piston boss and allowed to flow downward therethrough.
Claims16
A lubrication mechanism for an internal combustion engine comprising:
- a piston having a piston boss formed with a bearing surface;
- a piston pin journalled in said bearing surface;
- a groove cut in said bearing surface;
- means installed in said groove in contact with an end of said piston pin for preventing endwise movement of said piston pin;
- said piston boss having an oil inlet hole formed therein for collecting oil flowing downward along said piston and allowing it to flow toward said groove;
- and
- said groove being semi-circular in crosssection and having a maximum diameter portion, said oil inlet hole having an outlet end communicating in part with a portion of said groove offset from said maximum diameter portion inwardly of said piston, and communicating in part with said bearing surface.
A piston pin and snap ring lubrication mechanism comprising:
- a piston having piston bosses respectively formed with bearing surfaces;
- a ceramic piston pin journalled in said bearing surfaces;
- said bearing surfaces being respectively formed with snap ring grooves;
- snap rings respectively installed in said snap ring grooves in contact with opposite ends of said piston pin for preventing endwise movement of said piston pin;
- means for forming an oil inlet hole in at least one of said piston bosses for collecting oil flowing downward along an outer periphery of said piston and allowing it to flow toward one of said snap ring grooves;
- and
- said one snap ring groove being semi-circular in cross-section and having a maximum diameter portion, said oil inlet hole having an outlet end communicating in part with a portion of said one snap ring groove offset from said maximum diameter portion inwardly of said piston, and communicating in part with said bearing surfaces.
A piston pin and snap ring lubrication mechanism comprising:
- a piston having piston bosses respectively formed with bearing surfaces;
- a ceramic piston pin journalled in said bearing surfaces;
- snap rings respectively installed in said snap ring grooves in contact with opposite ends of said piston pin for preventing endwise movement of said piston pin;
- means for forming an oil inlet hole said piston bosses for collecting oil flowing downward along an inner circumferential periphery of said piston and allowing it to flow toward said snap ring grooves;
- and
- said snap ring grooves being semi-circular in cross-section and having a maximum diameter portion, said oil inlet hole having an outlet end communicating in part with a portion of said snap ring grooves offset from said maximum diameter portion toward the inside of said piston, an communicating in part with said bearing surfaces.
A piston pin and snap ring lubrication mechanism as set forth in claim 16, further comprising means for forming an oil outlet hole in said one piston boss for collecting oil having lubricated said snap ring and said end of said piston pin and allowing it to flow downward therethrough.
Dependencies are inferred from the claim text.