Tunnel-style crankshaft with counterweights of increased radial profile

摘要

A tunnel-style crankshaft assembly is provided having counterweights that serve the purposes of retaining the axial motion of bearings and improving the balance of the crankshaft assembly as a result of having a structure of an increased radial profile. The counterweights can include a mass section and a bearing retaining section. When the counterweight is secured to a crank web, the mass section of the counterweight is axially spaced from a bearing assembly disposed around the web. Therefore, the mass section of the counterweight may extend radially beyond an inner race of the bearing assembly without contacting the bearing assembly's cage. The mass section of the counterweight does not extend radially beyond a radial envelope of a crankshaft support surface thereby permitting the crankshaft assembly to be slidingly inserted into the crankcase.

主权项

1. A crankshaft assembly comprising:
a first crank web having a first outer bearing support surface; a second crank web having a second outer bearing support surface; a crank pin extending between and directly connecting the first web and the second web; a first bearing assembly forming at least a portion of a main bearing, the first bearing assembly disposed around the first outer bearing support surface; and a first counterweight carried by said first crank web, said first counterweight including a first bearing retaining section that extends radially beyond said first bearing support surface, said first bearing retaining section retaining said first bearing assembly in an axial direction and said first counterweight including a first mass section that extends radially beyond said first outer bearing support surface and has a first surface which overlaps at least a portion of said first bearing assembly, the first surface being axially spaced from said portion of said first bearing assembly that is overlapped.