Bearing system for reciprocating pump and method of assembly

1. A power end frame assembly for a reciprocating pump, the power end frame assembly, comprising:

a first and second end plate segment, the first and second end plate segments each including an annular bearing support surface configured to support a first crankshaft bearing assembly having an outer race and an inner race;

at least two middle plate segments disposed between the first and second end plate segments, the at least two middle plate segments each including an annular bearing support surface configured to support a second crankshaft bearing assembly having an outer race and an inner race;

the annular bearing support surfaces of the first and second end plate segments and the at least two middle plate segments each having a diameter and being coaxially aligned;

wherein the diameters of the annular bearing support surfaces of the first and second end plate segments are larger than the diameter of the annular bearing support surfaces of the at least two middle plate segments; and

a crankshaft having at least four journals, at least two of the journals sized to support the inner races of the second crankshaft bearing assemblies, the at least two journals having an outer diameter different from the outer diameters of the remaining journals.

2. The frame assembly of claim 1 , wherein the diameters of the bearing support surfaces of the at least two middle plate segments is from about 0.762 mm and 7.62 mm (0.03 inches and 0.3 inches) smaller than the diameter of the bearing support surface of at least one of the first and second end plate segments.

3. The frame assembly of claim 1 , wherein the diameter of the bearing support surface of at least one of the first and second end plate segments is about 641.35 mm (25.25 inches).

4. The frame assembly of claim 1 , wherein the diameters of the bearing support surfaces of the at least two middle plate segments is from about 50.8 mm to 889 mm (2 inches to 35 inches).

5. The frame assembly of claim 1 , wherein the diameters of the bearing support surfaces of the first and second end plate segments are the same.

6. The frame assembly of claim 1 , where the at least two middle plate segments comprises a pair of inner middle plate segments disposed between a pair of outer middle plate segments, each middle plate segment having a coaxially aligned bearing support surface, the diameters of the bearing support surfaces of the inner middle plate segments being smaller than the diameters of the bearing support surfaces of the outer middle plate segments.

7. The frame assembly of claim 6 , wherein the diameters of the bearing support surfaces of the inner middle plate segments are substantially equal.

8. The frame assembly of claim 6 , wherein the diameters of the bearing support surfaces of the outer middle plate segments are substantially equal.

9. The frame assembly of claim 1 , further comprising:

a bearing race disposed in each of the bearing support surfaces, wherein the bearing races corresponding to the bearing support surfaces of the at least two middle plate segments comprises a thickness that is different than a thickness of the bearing race corresponding to the bearing support surfaces of the first and second end plate segments.

10. The frame assembly of claim 1 , wherein each outer race includes an outer surface contacting a respective bearing support surface and an inner surface contacting a respective inner race, wherein the outer races are each formed having a thickness such that an inner diameter of the outer race of the second crankshaft bearing assemblies are substantially equal to an inner diameter of the outer race of the first crankshaft bearing assemblies.

11. A power end for a reciprocating pump, the power end comprising:

a housing having a first pair of middle annular bearing support surfaces and a second pair of middle annular bearing support surfaces, the first and second middle annular bearing support surfaces disposed between a pair of end annular bearing support surfaces, the pair of end annular bearing support surfaces and the first and second pair of middle annular bearing support surfaces each having a diameter and being co-axially aligned to support an outer bearing race of a respective crankshaft bearing assembly;

wherein the diameter of each of the end annular bearing support surfaces is larger than the diameters of the first pair of middle annular bearing support surfaces, and the diameters of the first pair of middle annular bearing support surfaces are larger than the diameter of the second pair of middle annular bearing support surfaces to facilitate insertion of the outer bearing races of the crankshaft bearing assembly into the power end; and

wherein each outer bearing race on the second pair of middle annular bearing support surfaces is formed of a first thickness, each outer bearing race on the first pair of middle annular bearing support surfaces is formed of a second thickness different from the first thickness such that the inner diameters of each of the outer bearing races are substantially the same diameter.

12. The power end of claim 11 , wherein the diameter of the first pair of middle annular bearing support surface is from about 0.762 mm and 7.62 mm (0.03 inches and 0.3 inches) smaller than the diameter of the pair of end annular bearing support surfaces.

13. The power end of claim 11 , wherein the diameter of at least one of the end annular bearing support surfaces is about 641.35 mm (25.25 inches).

14. The power end of claim 11 , wherein the diameter of the first pair of middle annular bearing support surfaces is from about 50.8 mm to 889 mm (2 inches to 35 inches).

15. The power end of claim 11 , wherein the diameters of the end annular bearing support surfaces are the same.

16. The power end of claim 11 , wherein the diameters of the first pair of middle annular bearing support surfaces are substantially equal.

17. The power end of claim 11 , wherein the diameters of the end annular bearing support surfaces are substantially equal.

18. The power end of claim 11 , wherein the crankshaft bearing assembly includes the outer bearing race and an inner bearing race, wherein the inner bearing race includes bearing rollers thereon.

19. A power end frame assembly for a reciprocating pump, the power end frame assembly, comprising:

a plurality of crankshaft bearing assemblies each including an inner bearing race and an outer bearing race;

a first and second end plate segment, the first and second end plate segments each including annular bearing support surfaces configured to support a respective outer bearing race;

a first pair of middle plate segments and a second pair of middle plate segments, the first and second pair of middle plate segments disposed between the first and second end plate segments, the first and second pair of middle plate segments each including an annular bearing support surface configured to support a respective outer bearing race;

the annular bearing support surfaces of the first and second end plate segments and the first and second pair of middle plate segments each having a diameter and being coaxially aligned;

wherein the diameter of the annular bearing support surfaces of at least one of the first and second end plate segments is larger than diameters of the second pair of middle plate segments and the diameters of the second pair of middle plate segments is larger than the diameters of the first pair of middle plate segments to facilitate insertion of the outer bearing races into the power end frame; and

a crankshaft having a plurality of journals corresponding to the annular bearing support surfaces on the first and second pair of middle plate segments each supporting an inner bearing race of a respective crankshaft bearing assembly thereon, a diameter of the journals corresponding to the second pair of middle plate segments is larger than a diameter of the journals corresponding to the first pair of middle plate segments.

20. The power end frame assembly of claim 19 , wherein the diameters of the annular bearing support surfaces of the first and second end plate segments are substantially equal.

21. The power end frame assembly of claim 19 , wherein the diameters of the annular bearing support surfaces of the first pair of middle plate segments are substantially equal.

22. The power end frame assembly of claim 19 , wherein each outer bearing race on the second pair of middle annular bearing support surfaces is formed of a first thickness, each outer bearing race on the first pair of middle annular bearing support surfaces is formed of a second thickness different from the first thickness such that the inner diameters of each of the outer bearing races are substantially the same.

23. A power end for a reciprocating pump, the power end comprising:

a housing having a plurality of middle annular bearing support surfaces disposed between a pair of end annular bearing support surfaces, the pair of end annular bearing support surfaces and the plurality of middle annular bearing support surfaces each having a diameter and being co-axially aligned to support an outer bearing race of a respective crankshaft bearing assembly;

wherein the diameter of at least one of the end annular bearing support surfaces is larger than the diameter on an adjacent middle annular bearing support surface, the diameter on the adjacent middle annual bearing support surface is larger than the diameter of an adjacent second middle annular bearing support surface to facilitate insertion of the outer bearing races of the crankshaft bearing assembly into the power end; and

wherein each outer bearing race disposed on the middle annular bearing support surfaces are formed of a different thickness such that the inner diameters of each of the outer bearing races are substantially the same diameter.