Drive system for hydraulic fracturing pump

A hydraulic fracturing pump comprising:

• a crankcase housing having a first side at a first end of the crankcase housing and a second side at a second end of the crankcase housing, an upper surface extending between the first and second sides and a base and, the crankcase housing formed along a crankcase axis extending between the two ends, the crankcase housing further having a plurality of crosshead apertures formed in the crankcase housing, each crosshead aperture formed about a crosshead axis that is generally perpendicular to the crankcase axis;
• a crankshaft extending along the crankcase axis from a first end to a second end;
• a plurality of piston arms spaced apart from one another along the crankshaft;
• and a corresponding plurality of crossheads;
• wherein each piston arm is pivotally coupled to the crankshaft at a first end of a corresponding piston arm, and each piston arm is pivotally coupled to a crosshead at a second end of the piston arm, each crosshead moving reciprocal along a crosshead axis;
• a crankshaft gear mounted on each end of the crankshaft;
• a pinion assembly extending along a pinion axis extending between the first end and second end of the crankcase housing, the pinion axis parallel with, but spaced apart from the crankcase axis, the pinion assembly having a first pinion shaft extending along the pinion axis between a first end and a second end of the first pinion shaft, a second pinion shaft extending along the pinion axis between a first end and a second end of the second pinion shaft, an input pinion gear disposed along each pinion shaft adjacent the first end of each pinion shaft;
• a power source coupled to a single input shaft connected to one of the first and second pinion shafts and used to drive both of the first and second pinion shafts;
• and
• a keyless coupler interconnecting the second ends of the first and second pinion shafts.

A hydraulic fracturing pump comprising:

• a crankcase housing having a first side at a first end of the crankcase housing and a second side at a second end of the crankcase housing, an upper surface extending between the first and second sides and a base and, the crankcase housing formed along a crankcase axis extending between the two ends, the crankcase housing further having a plurality of crosshead apertures formed in the crankcase housing, each crosshead aperture formed about a crosshead axis that is generally perpendicular to the crankcase axis;
• a crankshaft extending along the crankcase axis from a first end to a second end;
• a plurality of piston arms spaced apart from one another along the crankshaft;
• and a corresponding plurality of crossheads;
• wherein each piston arm is pivotally coupled to the crankshaft at a first end of a corresponding piston arm, and each piston arm is pivotally coupled to a crosshead at a second end of the piston arm, each crosshead moving reciprocal along a crosshead axis;
• a crankshaft gear mounted on each end of the crankshaft;
• a pinion assembly extending along a pinion axis extending between the first end and second end of the crankcase housing, the pinion axis parallel with, but spaced apart from the crankcase axis, the pinion assembly having a first pinion shaft extending along the pinion axis between a first end and a second end of the first pinion shaft, a second pinion shaft extending along the pinion axis between a first end and a second end of the second pinion shaft, an input pinion gear disposed along each pinion shaft adjacent the first end of each pinion shaft, each input pinion gear having a diameter D1;
• a keyless coupler interconnecting the second ends of the first and second pinion shafts;
• first and second intermediate gear assemblies, each intermediate gear assembly extending along an intermediate axis and within the crankcase housing between the pinion gears and the crankshaft gears, the intermediate axis extending parallel with, but spaced apart from the crankcase axis and the pinion axis, each intermediate gear assembly having an intermediate shaft extending along the intermediate axis between a first end and a second end of the intermediate shaft, each intermediate gear assembly further having a first intermediate gear having a diameter D2 and mounted adjacent the first end of the intermediate shaft and a second intermediate gear having a diameter D3 and mounted adjacent the second end of the intermediate shaft, the first intermediate gear meshed with an input pinion gear and the second intermediate gear meshed with a crankshaft gear, wherein the diameter D3 is less than the diameter D2.