Piston assembly having a wrist pin bolted therein
AssigneeCaterpillar Inc.
InventorWillibald G. Berlinger
Life of this patent
Estimating the term…
Abstract
The design and construction of past piston assemblies having a wrist pin bolted to a connecting rod have excessive weight and structural components, and requires more complex machining techniques and tooling. The present invention overcomes these problem by providing a piston assembly (30) with a wrist pin (36) attached to a piston member (32). Thus, the length of the leg members (80) are short and do not require a portion surrounding the wrist pin (36). The results being reduced piston member (32) and piston assembly (30) weight and lower inertia, a simplified forging or casting process, a more easily machinable cavity (86) within the piston member (32) and a higher quality piston assembly (30).
Claims16
A piston assembly (30), comprising:
- a piston member (32) including a crown (52) having a top surface (54), a bottom surface (56), a tubular member (58) depending away from the top surface (54) and having an outer surface (62) defining a plurality of grooves (68,72) therein, a pair of leg members (76) being positioned radially inwardly of the tubular member (58) and being spaced therefrom forming a cavity (86) therebetween, extending from the bottom surface (56) and being spaced one from the other a preestablished distance, each of said leg members (76) having a mounting surface (80) thereon positioned at an end of the leg members (76) opposite the bottom surface (56) of the crown (52) and having a threaded bore (84) therein;
- a wrist pin (36) including an outer surface (122) having at least a portion thereof in contacting relationship to the mounting surfaces (80) of the piston member (32) and an inner surface (120), said wrist pin (36) having a pair of bores (126) therethrough each of said pair of bores (126) having an enlarged end (127) passing between the outer surface (122) and the inner surface (120);
- and
- means for fastening (130) the wrist pin (36) to the piston member (32), said means for fastening (130) being positioned in the bores (126).
A piston assembly (30) adapted for use with an internal combustion engine (10) including a block (12) having a bore (18) therein, a crankshaft (20) rotatably mounted in the block (12), a connecting rod (22) rotatably connected to the crankshaft (20) and said piston assembly (32) being connected to the connecting rod (22) and positioned in the bore (18), said piston assembly (32) comprising:
- a piston member (32) including a crown (52) having a top surface (54), a bottom surface (56), a tubular member (58) depending away from the top surface (54) and having an outer surface (62) defining a plurality of grooves (68,72) therein, a pair of leg members (76) being positioned radially inwardly of the tubular member (58) and being spaced therefrom forming a cavity (86) therebetween, extending from the bottom surface (56) and being spaced one from the other a preestablished distance, each of said leg members (76) having a mounting surface (80) thereon positioned at an end of the leg members (76) opposite the bottom surface (56) of the crown (52) and having a threaded bore (84) therein;
- a wrist pin (36) including an outer surface (122) having at least a portion thereof in contacting relationship to the mounting surfaces (80) of the piston member (32) and an inner surface (120), said wrist pin (36) having a pair of bores (126) therethrough each of said pair of bores (126) having an enlarged end (127) passing between the outer surface (122) and the inner surface (120);
- and
- means for fastening (130) the wrist pin (36) to the piston member (32), said means for fastening being positioned in the bores (126).
An articulated piston assembly (30), comprising:
- a piston member (32) including a crown (52) having a top surface (54), a bottom surface (56), a tubular member (58) depending away from the top surface (54) and having an outer surface (62) defining a plurality of grooves (68,72) therein, a pair of leg members (76) being positioned radially inwardly of the tubular member (58) and being spaced therefrom forming a cavity (86) therebetween, extending from the bottom surface (56) and being spaced one from the other a preestablished distance, each of said leg members (76) having a mounting surface (80) thereon positioned at an end of the leg members (76) opposite the bottom surface (56) of the crown (52) and having a threaded bore (84) therein;
- a wrist pin (36) including an outer surface (122) having at least a portion thereof in contacting relationship to the mounting surfaces (80) of the piston member (32) and an inner surface (120), said wrist pin (36) having a pair of bores (126) therethrough;
- a skirt (34) removably attached to the wrist pin (36) and being positioned in pivotal working relationship to the piston member (32) by the wrist pin (36);
- means for retaining the wrist pin (36) within the skirt (34);
- and
- means for fastening (130) the wrist pin (36) to the piston member (32), said means for fastening being positioned in the bores (126).
Dependencies are inferred from the claim text.