PURPOSE: To improve lubrication of a bearing by forming a groove in width total length of the bearing on the bearing internal peripheral surface of a connecting rod small end part, and setting a vertical sectional area in a groove lengthwise direction in groove both ends smaller than that in the groove lengthwise directional center.
CONSTITUTION: A linear groove 12 is extended in the width direction of a pin bearing 8 and tilted relating to a direction of the center axial line B of a piston pin 9. The bottom of the linear groove 12 is in fixed height, but since a diameter in an internal peripheral surface of the pin bearing 8 is increased in accordance with advancing toward both ends in the width direction of the pin bearing 8, a depth of the linear groove 12 is shallowed from D1 to D2, and a width of the linear groove 12 is narrowed from W1 to W2 in accordance with advancing to both ends from the center. That is, an area of a V-shaped section vertical in the lengthwise direction of the linear groove 12 is decreased in accordance with advancing to both ends from the width direction center of the pin bearing 8. Consequently, oil in the linear groove 12 can be suppressed from flowing out from both ends of the linear groove 12, and holdability of oil in the linear groove 12 can be improved.
| JP6166950 | Bearing structure of an internal-combustion engine |
| JP6184977 | The piston pin for heat dissipation |
| WO/1998/009752 | METHOD FOR PRODUCING A SINTERED PART |
KIDO YOSHIO
IIZUKA TERUHIRO
OKADO ATSUSHI
DAIDO METAL CO LTD