CONNECTING ROD, CONNECTING ROD BEARING [SKYACTIV-G 2.0]

2016 – MX-5 – Engine

The connecting rod transmits pressure received by the piston during combustion to the crankshaft by engaging the piston pin and crank pin.

The connecting rod bearing forms an oil film on the outer surface of the crank pin to prevent wear due to sliding.

The connecting rod is located between the piston pin and crank pin.
High-strength, forged carbon steel has been adopted for weight reduction.
During manufacture of the connecting rods and connecting rod caps, a fracture splitting method ^*1 is employed for improved installation precision.
Weight has been reduced by optimizing the shape from the I shaft to the large end.
Reciprocating inertial weight, including the piston, has been reduced with the use of a full-float type for the connection with the piston and further tapering of the small end shape.
With the adoption of the plastic region tightening method^*2 for the connecting rod bolt, the stability of the axial force has been improved.

*1: Method which breaks off the large end portion of the connecting rod after it has been integrally molded to separate the connecting rod from the connecting rod cap. When assembling the connecting rod and connecting rod cap, dowel pins are not required to position the mating surface shape which was created during the breaking process due to the high precision installation.

*2: Plastic region tightening is a method of controlling the tightening using the rotation angle of a bolt and suppressing the variations in the axial force by tightening the bolt until its deformation does not return to its original condition (plastic region).