Connecting rod and crosshead assembly for enhancing the performance of a reciprocating pump

A method of assembling a crosshead and a connecting rod for a reciprocating pump, the method comprising:

• providing the crosshead, the crosshead comprising:
• a main body;
• a cylindrical bore formed through, and at least partially defining a first bearing surface in, the main body, the first bearing surface extending about a first axis;
• and a window formed in the main body transversely to the first axis, wherein, at the location of the window, the first bearing surface of the crosshead extends more than 180 degrees but less than 360 degrees about the first axis;
• positioning a cylindrical small end of the connecting rod within the cylindrical bore, the cylindrical small end defining opposing end portions and a cylindrical second bearing surface extending between the opposing end portions, and the cylindrical small end extending about a second axis;
• connecting a beam portion of the connecting rod to the cylindrical small end at the second bearing surface, the beam portion and the cylindrical small end being separately formed;
• and
• connecting a clamp to the main body of the crosshead to prevent, or at least reduce, axial displacement of the cylindrical small end along the second axis and relative to the crosshead;
• wherein, when the cylindrical small end is positioned within the cylindrical bore and the beam portion is connected to the cylindrical small end, the first and second axes are substantially coaxial and the beam portion extends through the window;
• and
• wherein the clamp is sized and shaped so that, when the cylindrical small end is positioned within the cylindrical bore and the clamp is connected to the main body of the crosshead, the clamp engages both the main body and the respective opposing end portions of the cylindrical small end.

A reciprocating pump assembly, comprising:

• a fluid end comprising a plunger bore and a plunger adapted to reciprocate within the plunger bore;
• a power end comprising a tubular guide member, a crank shaft adapted to rotate about a first axis, and a crank throw offset from the first axis and connected to the crankshaft;
• and a mechanical linkage operably coupling the power end to the fluid end, the mechanical linkage comprising:
• a crosshead comprising:
• a main body;
• a cylindrical bore formed through, and at least partially defining a first bearing surface in, the main body, the first bearing surface extending about a first axis;
• and a window formed in the main body transversely to the first axis, wherein the first bearing surface of the crosshead extends more than 180 degrees but less than 360 degrees about the first axis;
• and
• a connecting rod comprising a cylindrical small end defining opposing end portions and a cylindrical second bearing surface extending between the opposing end portions, the cylindrical small end extending about a second axis and within the cylindrical bore, and a beam portion connected to the cylindrical small end at the second bearing surface, the beam portion and the cylindrical small end being separately formed;
• and
• a clamp connected to the main body of the crosshead to prevent, or at least reduce, axial displacement of the cylindrical small end along the second axis and relative to the crosshead;
• wherein the beam portion extends through the window and the first and second axes are substantially coaxial;
• and
• wherein the clamp is sized and shaped to engage both the main body and the respective opposing end portions of the cylindrical small end.