Drilling Mud Pump Parts

The power and fluid ends are shown below in more detail.

Power End

Figure 05 gives a cut-away view of a complete power end. An eccentric shaft converts the rotating motion of a one-piece pinion and shaft into a reciprocating motion. All the shafts are supported by roller bearings.

The crosshead, which slides inside a crosshead guide to sustain the true linear movement of the extension rod, is visible, as well as the stuffing box assembly, which is also shown in detail in Figure 6.

The connection between the extension rod and piston rod is a finely tapered tread with a jam nut (in a double-acting pump) or butted with a clamp (in a single-acting pump), as shown in the figure below.

Fluid End

Figure 8 shows an example of the fluid end of a duplex mud pump.

• Item # 1 Fluid Module Only (Studded Included Items 1 – 6)

• Item # 2 Stud – Frame, Threaded Ring

• Item # 3 Stud – Discharge Manifold

• Item # 4 Stud – Threaded Ring

• Item # 5 Threaded Ring

• Item # 6 Discharge Manifold

• Item # 7 Threaded Plug Retainer

• Item # 8 Threaded Ring

• Item # 9 Cylinder Head Plug

• Item # Cylinder Head Plug – Top (Included Items 9 & 17)

• Item # 10 Threaded Liner Retainer

• Item # 11 Lower Valve Guide

• Item # 12 Retainer – Lower Valve Guide

• Item # 13 Seal – Cylinder Head Plug, Liner

• Item # 14 Discharge Manifold

• Item # 15 Seal – Suction Manifold

• Item # 16 Valve Guide Bushing

• Item # 17 Upper Valve Guide

Special attention should be paid to the oil flood stuffing box (Figure 9) to withstand the full pump pressure. The stuffing box is cooled and lubricated by an independent lubricating system.

A closed cooling system protects the pistons of the single-acting  pump from overheating (see Figure 10). The cooling liquid is usually a mixture of oil and potable water circulated by a small pump. If the pistons were not cooled, the sleeves would become hot and overheat within a few minutes. The cylinder surface must also be lubricated.

The splash baffle on the extension rod prevents the cooling water from being carried to the pump crank-case by the extension rod.