Crankshaft and connecting rod assemblies for hydraulic fracturing pumps
Crankshaft and connecting rod assemblies for hydraulic fracturing pumps and related methods may enhance the flow of fracturing fluid into a wellhead during a high-pressure fracturing operation. The assemblies and methods may include a crankshaft having a crankpin between first and second journals. The crankpin may include first and second longitudinally spaced ridges at least partially extending circumferentially around the crankpin. The assemblies and methods further may include first and second connecting rods connected to the crankpin. The first connecting rod may include first and second crankpin connectors connected to the crankpin and at least partially defining therebetween a connecting rod clearance between and positioned to at least partially receive therein an end of a second connecting rod. The assemblies and methods also may include first and second rod clamps connected to the first crankpin connector, thereby to rotatably connect the first and second connecting rods to the crankpin.
1 . A crankshaft for a hydraulic fracturing pump, the crankshaft comprising:
a first journal configured to be rotatably supported in a first frame section of the pump;
a second journal configured to be rotatably supported in a second frame section of the pump, the first journal and the second journal defining therebetween a longitudinal crankshaft axis;
a crankpin between the first journal and the second journal and defining a longitudinal crankpin axis extending substantially parallel to and offset from the longitudinal crankshaft axis, the crankpin configured to receive one or more connecting rods, the one or more connecting rods including a first connecting rod having first and second crankpin connectors spaced along the crankpin and a rod body with a crank end and a plunger end opposite the crank end, the crank end including at least one connector connected to the crankpin, and including:
a crankpin body extending along the longitudinal crankpin axis and defining a crankpin surface, the crankpin surface being substantially cylindrical;
a first ridge at least partially extending circumferentially around the crankpin surface; and
a second ridge longitudinally spaced from the first ridge and at least partially extending circumferentially around the crankpin surface,
wherein each of the first ridge and the second ridge includes a ridge extension, the ridge extension extending between:
a first ridge base extending radially outward from a first side of the ridge extension, and
a second ridge base extending radially outward from a second side of the ridge extension; and
a second connecting rod having a crank end with a third crankpin connector configured to be rotatably mounted on the crankpin between the first and second crankpin connectors of the first connecting rod.
2 . The crankshaft of claim 1 , wherein the crankpin body defines a first end and a second end between which the crankpin surface extends, the first ridge is spaced from and adjacent to the first end of the crankpin body, and the second ridge is located between the first ridge and the second end of the crankpin body.
3 . The crankshaft of claim 2 , wherein the crankpin body defines a first rod receiver portion between the first end of the crankpin body and the first ridge, a second rod receiver portion between the first ridge and the second ridge, and a third rod receiver portion between the second ridge and the second end of the crankpin body.
4 . The crankshaft of claim 2 , wherein one or more of the ridge base or the ridge extension at least partially defines a concave ridge radius.
5 . The crankshaft of claim 4 , wherein the ridge radius is a first ridge radius, the first ridge radius is on a first side of the one or more of the first ridge or the second ridge, and the one or more of the first ridge or the second ridge further includes a second side longitudinally opposite the first side, the second side at least partially defining a concave second ridge radius.
6 . The crankshaft of claim 4 , wherein the ridge base is a first ridge base, the ridge radius is a first ridge radius, the one or more of the first ridge or the second ridge includes a second ridge base extending radially outward to the ridge extension, and one or more of the second ridge base or the ridge extension at least partially defines a concave second ridge radius.
7 . The crankshaft of claim 6 , wherein each of the one or more of the first ridge or the second ridge includes the first ridge radius and the second ridge radius.
8 . The crankshaft of claim 7 , wherein one or more of the first journal or the first end at least partially defines a concave first journal radius, and one or more of the second journal or the second end defines a concave second journal radius.
9 . The crankshaft of claim 8 , wherein the first ridge radius, the second ridge radius, the first journal radius, and the second journal radius have at least one substantially equal dimension.
10 . An assembly, comprising:
a crankshaft including:
a first journal configured to be rotatably supported in a first frame section of a pump;
a second journal configured to be rotatably supported in a second frame section of the pump, the first and the second journals defining therebetween a longitudinal crankshaft axis; and
a crankpin between the first journal and the second journal and defining a longitudinal crankpin axis extending substantially parallel to and offset from the longitudinal crankshaft axis, the crankpin including:
a crankpin body extending along the longitudinal crankpin axis and defining a crankpin surface, the crankpin surface being substantially cylindrical;
a first ridge at least partially extending circumferentially around the crankpin surface; and
a second ridge longitudinally spaced from the first ridge and at least partially extending circumferentially around the crankpin surface;
a first connecting rod including:
a first elongated rod body defining a first longitudinal rod axis and having a first crank end and a first plunger end opposite the first crank end, the first crank end including:
a first crankpin connector connected to the crankpin between the first journal and the first ridge; and
a second crankpin connector connected to the crankpin between the second ridge and the second journal, the first crank end defining a connecting rod clearance between the first crankpin connector and the second crankpin connector; and
a second connecting rod including a second elongated rod body defining a second longitudinal rod axis and having a second crank end and a second plunger end opposite the second crank end, the second crank end including a third crankpin connector connected to the crankpin between the first crankpin connector and the second crankpin connector of the first connecting rod.
11 . The assembly of claim 10 , wherein the third crankpin connector is connected to the crankpin in the connecting rod clearance of the first connecting rod.
12 . The assembly of claim 10 , wherein the first longitudinal rod axis of the first connecting rod and the second longitudinal rod axis of the second connecting rod lie in a common rod plane.
13 . The assembly of claim 10 , wherein the crankpin body defines a first end and a second end between which the crankpin surface extends, the first ridge is spaced from and adjacent to the first end of the crankpin body, the crankpin body defines a first rod receiver portion between the first end of the crankpin body and the first ridge, the second ridge is located between the first ridge and the second end of the crankpin body, the crankpin body defines a second rod receiver portion between the first ridge and the second ridge, and the crankpin body defines a third rod receiver portion between the second ridge and the second end of the crankpin body.
14 . The assembly of claim 13 , wherein the first crankpin connector is connected to the crankpin at the first rod receiver portion; the second crankpin connector is connected to the crankpin at the third rod receiver portion; and the third crankpin connector is connected to the crankpin at the second rod receiver portion.
15 . The assembly of claim 13 , wherein each of the first ridge and the second ridge includes a first ridge base, a second ridge base, and a ridge extension; the first ridge base and the ridge extension define a concave first ridge radius; and the second ridge base and the ridge extension define a concave second ridge radius.
16 . The assembly of claim 15 , further including:
a first crankpin bushing associated with the first crankpin connector and acting as a first bearing between the first crankpin connector and the crankpin;
a second crankpin bushing associated with the second crankpin connector and acting as a second bearing between the second crankpin connector and the crankpin; and
a third crankpin bushing associated with the third crankpin connector and acting as a third bearing between the third crankpin connector and the crankpin.
17 . The assembly of claim 16 , wherein one or more of:
the first crankpin bushing includes a first interior surface facing the crankpin and first outboard edges having first lateral surfaces, one or more of the first outboard edges at least partially defining a convex first bushing radius extending between the first interior surface and one or more of the first lateral surfaces;
the second crankpin bushing includes a second interior surface facing the crankpin and second outboard edges having second lateral surfaces, one or more of the second outboard edges at least partially defining a convex second bushing radius extending between the second interior surface and one or more of the second lateral surfaces; or
the third crankpin bushing includes a third interior surface facing the crankpin and third outboard edges having third lateral surfaces, one or more of the third outboard edges at least partially defining a convex third bushing radius extending between the third interior surface and one or more of the third lateral surfaces.
18 . The assembly of claim 17 , wherein one or more of the first journal or the first end at least partially defines a concave first journal radius and one or more of the second journal or the second end defines a concave second journal radius.
19 . The assembly of claim 18 , wherein each of the first bushing radius, the second bushing radius, or the third bushing radius nests between two of the ridge radii or one of the ridge radius and one of the journal radius.
20 . The assembly of claim 19 , wherein at least one of the first ridge radius or the second ridge radius is greater than one or more of the first bushing radius, the second bushing radius, or the third bushing radius.