Mazda CX-5 Service & Repair Manual: Connecting Rod, Connecting Rod Bearing

Purpose, Function

Connecting rod

• The connecting rod transmits the reciprocating movement of the piston to the crankshaft by engaging the piston pin and crank pin.

Connecting rod bearing

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

Construction

Connecting rod

• The connecting rod is installed between the piston pin and crank pin.

• High-strength, forged carbon steel has been adopted for weight reduction.

• A cracking method*1 for breaking off and separating the connecting rod from the connecting rod cap has been adopted for improved accuracy.

• 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*2 method for the connecting rod bolt, the stability of the axial force has been improved.

  

  
  

*2 Plastic region tightening is a method of controlling the tightening using the rotation angle of a bolt. By tightening to the region (plastic tightening region) in which bolt deformation does not become irreversible, variation in axial force is suppressed.

Connecting rod bearing

• The connecting rod bearing is installed on the outer surface of the crank pin.

• The upper and lower connecting rod bearing are made of aluminum alloy.