| 摘要 |
A piston (10, 10′) includes a piston body (12, 12′) having an upper crown portion (16, 16′) with an upper combustion dome (18, 18′) against which combustion forces act. The underside of the upper combustion dome (18, 18′) comprises an under-crown region (60, 60′). The piston body (12, 12′) also includes a lower crown portion (26, 26′) with a pair of pin bosses (36, 38) spaced apart for pivotally adjoining a connecting rod. An outer oil gallery (31, 31′) is formed as an inclusion between the upper (16, 16′) and lower (26, 26′) crown portions. The outer oil gallery (31, 31′) has an oil inlet (50, 50′) and an oil outlet (52, 52′). A tubular cooling nozzle (54, 54′) is affixed in fluid communication with the oil outlet (52, 52′) and extends toward the under-crown region (60, 60′) where oil is discharged during reciprocation of the piston (16, 16′). Cooling oil from the outer oil gallery (33) is channeled by the cooling nozzle (54, 54′) to the under-crown region (60, 60′) providing supplemental cooling in a passively actuated system.
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