Piston assembly and associated components, systems, and method
A piston assembly includes a piston head. The piston assembly further includes an upper connecting rod rotatably coupled to the piston head. The piston assembly also includes a shoe positioned between the upper connecting rod and an inner wall of the piston head.
1 . A piston assembly comprising:
a piston head;
an upper connecting rod rotatably coupled to the piston head; and
a shoe positioned between the upper connecting rod and an inner wall of the piston head, the shoe having a convex piston interface surface in contact with the inner wall of the piston head and a convex rod interface surface in contact with the upper connecting rod, wherein a surface area of the convex piston interface surface is greater than a surface area of the convex rod interface surface.
2 . The piston assembly of claim 1 , wherein the convex piston interface surface is in sliding contact with the inner wall of the piston head.
3 . The piston assembly of claim 1 , wherein the inner wall of the piston head comprises an inner wall of a piston skirt.
4 . The piston assembly of claim 3 , wherein the shoe is configured to distribute a lateral force across the inner wall of the piston skirt.
5 . The piston assembly of claim 1 , wherein the convex rod interface surface is in sliding contact with the upper connecting rod.
6 . The piston assembly of claim 5 , wherein the upper connecting rod comprises a complementary recess in sliding contact with the convex rod interface surface of the shoe.
7 . The piston assembly of claim 6 , wherein the complementary recess comprises a curved surface.
8 . The piston assembly of claim 1 , wherein the shoe has a first width proximate the upper connecting rod and a second width proximate the inner wall of the piston head and wherein the second width is greater than the first width.
9 . An engine comprising:
a cylinder;
a crankshaft; and
a piston assembly disposed within the cylinder, the piston assembly comprising:
a piston head;
an upper connecting rod rotatably coupled to the piston head;
a lower connecting rod coupled between the upper connecting rod and the crankshaft; and
a shoe slidably coupled between a recess in the upper connecting rod and a skirt of the piston head, where a rod interface surface of the shoe slidably connected to the recess is smaller than a skirt interface surface of the shoe slidably connected to the skirt;
wherein the upper connecting rod is configured to rotate in small increments relative to the shoe.
10 . The engine of claim 9 , wherein the shoe comprises a skirt interface surface slidably connected to the skirt of the piston head.
11 . The engine of claim 10 , wherein the skirt interface surface has a radius that substantially matches a radius of an inner surface of the skirt of the piston head.
12 . The engine of claim 9 , wherein the recess comprises a curved surface complementary to a rod interface surface of the shoe.
13 . The engine of claim 9 , wherein the recess further comprises a bearing insert.
14 . The engine of claim 9 , wherein the recess is positioned closer to a piston connection between the upper connecting rod and the piston head than a lower rod connection between the upper connecting rod and the lower connecting rod.
15 . An upper connecting rod of a piston assembly, the upper connecting rod comprising:
a piston connection point;
a lower rod connection point; and
a curved recess defined in an outer edge of the upper connecting rod, the curved recess defining an arc having an angle greater than 60 degrees, the curved recess configured to receive an interfacing element between the upper connecting rod and a piston, the curved recess positioned between the piston connection point and the lower rod connection point and positioned closer to the piston connection point than the lower rod connection point.
16 . The upper connecting rod of claim 15 , wherein the piston connection point comprises a gudgeon pin assembly.
17 . The upper connecting rod of claim 16 , wherein the lower rod connection point comprises a connector pin assembly.
18 . The upper connecting rod of claim 15 , wherein the curved recess comprises an arc of at least 90 degrees.