Bilateral connecting rod apparatus
An apparatus and method provide a true bilateral connecting rod apparatus having a crankshaft defining an axis of rotation and a rod journal eccentrically mounted for circular rotation about the axis, and a pair of connecting rods attached to the rod journal for reciprocating motion in a common plane extending perpendicularly through the rod journal. One or more retaining rings engage the pair of connecting rods and secure the pair of connecting rods to the journal. A common bearing insert is disposed between the pair of connecting rods and the rod journal.
1. A bilateral connecting rod apparatus comprising:
a crankshaft defining an axis of rotation and a rod journal eccentrically mounted for circular rotation about the axis;
a pair of connecting rods attached to the rod journal for reciprocating motion in a common plane extending perpendicularly through the rod journal, cach connecting rod including:
a shank portion defining a longitudinal midplane of the connecting rod,
a bearing saddle, the bearing saddle having a cylindrical surface bisected by the longitudinal midplane and subtended by an angle of less than 180 degrees centered at a radius of the cylindrical surface along the longitudinal midplane for engaging the rod journal, and
an arcuate surface extending parallel to the cylindrical surface of the bearing saddle,
wherein the crankshaft includes a first and a second axially facing wall respectively defining a first and a second end of the rod journal separated by a length of the rod journal;
a retaining ring, the retaining ring engaging the bearing saddles of the connecting rods and having a first bearing surface thereof configured for bearing against the arcuate surface of each connecting rod, a second bearing surface thereof configured for bearing against the rod journal, and an axial bearing surface thereof for bearing against one of the first and second axially facing walls of the crankshaft; and
a bearing insert disposed between the cylindrical surfaces of the bearing saddles of the connecting rods and the rod journal.
2. The apparatus of claim 1 wherein the bearing insert is disposed between the rod journal and both the cylindrical surfaces of the bearing saddles of the connecting rods and the second bearing surfaces of the retaining ring.
3. The apparatus of claim 2 wherein the second surface of the retaining ring and the bearing insert extend 360 degrees around the rod journal.
4. The apparatus of claim 3 wherein:
each connecting rod includes a second arcuate surface extending parallel the cylindrical surface of the bearing saddle; and
the apparatus includes a second retaining ring having a first bearing surface thereof configured for bearing against the arcuate surface of the connecting rod, a second bearing surface thereof for bearing against the rod journal, and an axial bearing surface thereof for bearing against the other of the first and second axial surfaces of the crankshaft.
5. The apparatus of claim 4 wherein the bearing insert is further disposed between the second surface of the second retaining ring and the rod journal.
6. The apparatus of claim 5 wherein the second surface of the second retaining ring extends 360 degrees around the rod journal.