Crankshaft construction

In a reciprocating piston triplex mud pump having three connecting rods mounted with a crankshaft, and improvement in the crankshaft thereof, comprising

• a. an elongated cross-sectional circular shaft;
• b. first, second and third circular journal discs rigidly mounted on said shaft in a spaced relation, each of said journal discs having a mounting opening therethrough which is offset from the geometric center of the respective journal disc such that each of the respective mounting openings is within the perimeter of the respective journal disc such that said journal discs are eccentrically mounted on said shaft;
• said journal discs having crankshaft mounting end portions of said connecting rods rotatably mounted around the outer periphery thereof;
• c. a fourth substantially flat circular disc is rigidly mounted directly to said shaft between two of said journal discs and having a mounting opening through the center thereof such that said disc is substantially concentrically mounted on said shaft;
• d. an annular drive gear rigidly mounted around the outer peripheral portion of said fourth disc with said gear having teeth around the outer periphery thereof adapted for operable engagement with a source of rotative power in order to operably rotate said crankshaft;
• and
• e. said shaft, having a plurality of radially enlarged peripheral portions therearound at spaced intervals along the length thereof with said discs being mounted on said shaft at said enlarged peripheral portions.