Piston cooling configurations utilizing lubricating oil from a bearing reservoir in an opposed-piston engine

A piston cooling configuration for an opposed-piston engine, comprising:

• a piston with a crown having an end surface shaped to form a combustion chamber with an end surface of an opposing piston;
• the crown including an undercrown;
• a bearing mounted in the piston between the undercrown and a small end of a connecting rod;
• the bearing including a wristpin and a bearing surface;
• an oil reservoir in the wristpin in fluid communication with one or more wristpin oil outlet passages positioned to pass oil through the wristpin into a lubrication interface between the wristpin and the bearing surface;
• at least one oiling groove in the bearing surface which is in fluid communication with a wristpin oil outlet passage of the oil reservoir;
• a wristpin oil inlet passage in fluid communication with the reservoir;
• and,
• at least one cooling jet outlet in a part of the bearing that does not move relative to the undercrown;
• in which the cooling jet outlet is in fluid communication with the oil reservoir via the at least one oiling groove and is aimed toward an undercrown portion, further in which the oil reservoir is an annular recess with opposing ends and has an axis that corresponds to an axis on which the wristpin oscillates.