Patent ID: 7284528
Filing Date: 2007-10-23
Classification: F02F,F16C,F16M,Y10T

Abstract:
1. A crank shaft support assembly for increasing stiffness and reducing thermal mismatch distortion in a crank shaft bore of an engine comprising different metals, the assembly comprising: a cylinder block comprising a first material; at least two crank journal inserts that are insert-molded into respective crank journal regions of the cylinder block, that comprise a second material having greater stiffness and a lower thermal coefficient of expansion than the first material, and that are shaped to provide a cross-planar mechanical lock between each crank journal insert and the cylinder block, the shape of each crank journal insert including one or more features selected from the group of features consisting of cross-planar ribbing, undercuts, and through-holes; at least two bearing caps bolted to the respective crank journal inserts and defining, along with the crank journal inserts, at least two crank shaft support rings defining a crank shaft bore coaxially aligned with a crank shaft axis; each of the bearing caps comprises a material having higher stiffness and a lower thermal coefficient of expansion than the first material and is supported on the respective crank journal inserts independently of any direct connection to the cylinder block; and each crank journal insert including a plurality of posts connected across respective post tops by an upper arched beam and across respective post bases by a lower arched beam, the lower arched beam including a semi-cylindrical cut-away that defines an upper portion of a crank shaft support ring.