WO2020198260A1

WO2020198260A1 - Novel hinged plunger clamp with latch lock

Info

Publication number: WO2020198260A1
Application number: PCT/US2020/024515
Authority: WO
Inventors: Gideon N. SPENCER
Original assignee: SPM Flow Control Inc
Current assignee: SPM Oil and Gas Inc
Priority date: 2019-03-25
Filing date: 2020-03-24
Publication date: 2020-10-01
Anticipated expiration: 2021-09-25

Abstract

A positive displacement pump (100) includes a pony rod (204) having first and second ends and which is disposed in the power end (102) of the pump, and a plunger (202) having first and second ends where the first end of the plunger is coupled to the second end of the pony rod and the second end of the plunger is configured to move into a fluid chamber in the fluid end to displace the fluid in the chamber. The second end of the pony rod and the first end of the plunger are coupled together to form a rigid connection using a hinged quick-release clamp (200) secured with a locking latch (206).

Description

NOVEL HINGED PLUNGER CLAMP WITH LATCH LOCK

RELATED APPLICATION

The present application claims the benefit of U.S. Provisional Patent Application No. 62/823,624 filed on March 25, 2019, incorporated herein by reference.

FIELD

The present disclosure relates to hydraulic fracturing pumps, and in particular, to a novel hinged clamp with a latch lock for connecting the plunger and pony rod.

BACKGROUND

Hydraulic fracturing (a.k.a. fracking) is a process to obtain hydrocarbons such as natural gas and petroleum by injecting a fracking fluid or slurry at high pressure into a wellbore to create cracks in deep rock formations. The hydraulic fracturing process employs a variety of different types of equipment at the site of the well, including one or more positive displacement pumps, slurry blender, fracturing fluid tanks, high-pressure flow iron (pipe or conduit), wellhead, valves, charge pumps, and trailers upon which some equipment are carried.

Positive displacement pumps are commonly used in oil fields for high pressure hydrocarbon recovery applications, such as injecting the fracking fluid down the wellbore. A positive displacement pump typically has two sections, a power end and a fluid end. The power end includes a crankshaft powered by an engine that drives the plungers. The fluid end of the pump includes cylinders into which the plungers operate to draw fluid into the fluid chamber and then forcibly push out at a high pressure to a discharge manifold, which is in fluid communication with a well head. A seal assembly, also called a packing assembly or stuffing box, is disposed in the cylinder chamber of the pump housing and used to prevent leakage of frac fluid from around the plunger during pumping operations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a positive displacement pump according to the teachings of the present disclosure; FIG. 2 is a partial cross-sectional side view of an example embodiment of a novel clamp with a quick-release latch lock connecting a plunger and pony rod for the fluid end of a positive displacement frac pump according to the teachings of the present disclosure;

FIG. 3 is a perspective view of an example embodiment of a novel clamp with a quick- release latch lock for connecting a plunger and pony rod for the fluid end of a positive displacement frac pump according to the teachings of the present disclosure; and

FIG. 4 shows perspective views of representative latching locks that may be incorporated in the novel plunger clamp according to the teachings of the present disclosure.

DETAILED DESCRIPTION

Positive displacement pumps 100, such as the one shown in FIG. 1, are commonly used in oil fields for high pressure hydrocarbon recovery applications, such as injecting the fracking fluid down the wellbore. The positive displacement pump 100 has two sections, a power end 102 and a fluid end 104. The fluid end 104 of the pump includes a fluid end block or fluid cylinder, which is connected to the power end housing via a plurality of stay rods 106. In operation, the crankshaft (not explicitly shown) reciprocates a plunger rod assembly between the power end 102 and the fluid end 104. The crankshaft is powered by an engine or motor (not explicitly shown) that drives a series of plungers (not explicitly shown) to create alternating high and low pressures inside a fluid chamber. The plungers operate to draw fluid into the fluid chamber from the suction manifold 108 and then discharge the fluid at a high pressure to a discharge manifold 110. The discharged liquid is then injected at high pressure into an encased wellbore. The injected fracturing fluid is also commonly called a slurry, which is a mixture of water, proppants (silica sand or ceramic), and chemical additives. The pump can also be used to inject a cement mixture down the wellbore for cementing operations. The pump may be freestanding on the ground, mounted to a skid, or mounted to a trailer. The crankshaft in the power end 102 of the pump 100 is typically mechanically connected to a motor (not explicitly shown). In one embodiment, a gear is mechanically connected to the crankshaft (not explicitly shown) and is rotated by the motor through additional gears. A connector rod connects to a crosshead (not explicitly shown) through a crosshead pin, which holds the connector rod (not explicitly shown) longitudinally relative to the crosshead. The connector rod pivots about the crosshead pin as the crankshaft rotates with the other end of the connector rod.

FIG. 2 is a partial cross-sectional side view of an example embodiment of a novel clamp 200 with a quick-release latch lock connecting a plunger 202 and pony rod 204 for the fluid end 104 of a positive displacement frac pump 100. As shown in FIG. 2, the pony rod 204 extends from the crosshead in a longitudinally opposite direction from the crankshaft. The connector rod 204 and the crosshead convert the rotational movement of the crankshaft into the longitudinal movement of the pony rod, which is in turn connected to a plunger 202 that draws and pushes the frac fluid passing through the cylinder housing in the fluid end 104 of the pump 100.

In a conventional frac pump, the plunger in the fluid end and the pony rod in the power end are held together using a plunger clamp that has two halves held together about the ends of the pony rod and plunger by two fasteners, such as socket head cap screws or bolts. This conventional clamp requires tools (pneumatic, electric, or battery-powered) to assemble and disassemble, and the fasteners can be easily dropped and become lost during the process. If assembly is done incorrectly, it may lead to premature failure of the clamp. During installation, the plunger may be difficult to drive fully into place. The plunger must be positioned close to the pony rod to allow the plunger clamp to be installed. The plunger, clamp or plunger packing may become damaged while installing the clamp. During operation the pony rod and plunger can become fused together, making disassembly difficult. The use of force, using additional tools, and spending more time are often required to separate the two components for maintenance.

As shown in FIGS. 2 and 3, a generally cylindrical clamp 200 with a locking latch 206, also known as a toggle latch, may be used to close around the pony rod end and plunger end and secure them together. The clamp 200 has two halves 208 and 209 that are rotatably coupled by a hinge 210. Each of the clamp halves 208 and 209 having a half annular shape or profile. At the free end of the two halves is a locking latch 206 that enables the clamp to be secured around the pony rod 204 and plunger 202 to achieve a rigid connection between them. Also named draw latch or draw catch, the locking latch 206 is a mechanical fastener that has a claw or a loop 212 that is rotatably coupled to the free end of one half 208. The claw 212 is configured to hook onto a catch plate 214 that is disposed at the end of the other half of the clamp 209. A locking lever 216 can then be flipped down over the claw 212 and catch plate 214 to lock down the latch. In the embodiment shown in FIG. 3, the claw 212 is rotatably coupled to the locking lever 216, which is in turn rotatably coupled to the free end of the clamp half 208. FIG. 4 shows a number of locking latches that may be incorporated in the plunger clamp.

Therefore, by eliminating the use of a clamp that has disconnected components that have to be fastened together by fasteners that require tools, the connection between the plunger and pony rod ends have been greatly simplified. Having to properly position both components of the conventional clamp and fasten or remove two threaded fasteners using a tool for the assembly requires more skill and more personnel. The use of the quick-release clamp that incorporate a locking latch means savings in time and labor costs. Further, no tool is needed to assemble or disassemble the connection, and there are no loose parts to keep track of.

The clamp may have the same generally cylindrical shape and profile as current clamps that require closure using threaded fasteners. Therefore, the deployment of the new clamp does not require any change to the design of the pony rod and plunger.

The features of the present invention which are believed to be novel are set forth below with particularity in the appended claims. However, modifications, variations, and changes to the exemplary embodiments described above will be apparent to those skilled in the art, and the novel valve having a novel clamp with locking latch for the pony rod and plunger described herein thus encompasses such modifications, variations, and changes and are not limited to the specific embodiments described herein.

Claims

WHAT IS CLAIMED IS:

1. A positive displacement pump having a power end coupled to a fluid end, comprising:

a pony rod having first and second ends and disposed in the power end;

a plunger having first and second ends where the first end of the plunger is coupled to the second end of the pony rod and the second end of the plunger is configured to move into a fluid chamber in the fluid end to displace the fluid in the chamber; and

where the second end of the pony rod and the first end of the plunger are coupled together to form a rigid connection using a hinged clamp secured with a locking latch.

2. The positive displacement pump of claim 1, wherein the hinged clamp comprises:

a first half annular part having a first end and a second end;

a second half annular part having a first end and a second end; and

where the first ends of the first and second half annular parts are rotatably joined by a hinge, and the second ends of the first and second half annular parts being configured to securely latch together so that the first and second half annular parts are securely clamped about the plunger and pony rod to form the rigid connection.

3. The positive displacement pump of claim 1, wherein the hinged clamp comprises:

a first half annular part having a first end and a second end;

a second half annular part having a first end and a second end; and

where the first ends of the first and second half annular parts are rotatably joined by a hinge, and the second ends of the first and second half annular parts being configured to securely latch together using a locking lever so that the first and second half annular parts are locked about the plunger and pony rod to form the rigid connection.

4. The positive displacement pump of claim 1, wherein the hinged clamp comprises:

a first half annular part having a first end and a second end;

a second half annular part having a first end and a second end; and

where the first ends of the first and second half annular parts are rotatably joined by a hinge, and the second ends of the first and second half annular parts having a catch member and a catch plate that can securely engage so that the first and second half annular parts are locked about the plunger and pony rod to form the rigid connection.

5. A hinged clamp to form a rigid connection between a plunger and a pony rod in a positive displacement pump, comprising:

a first half annular part having a first end and a second end;

a second half annular part having a first end and a second end; and

where the first ends of the first and second half annular parts are rotatably joined by a hinge, the second end of the second half annular part having a catch, and the second end of the first half annular part having a catch member for latching the catch and a locking lever for locking the clamp securely around the plunger and pony rod and form a rigid coupling.

6. The hinged clamp of claim 5, wherein the locking lever is rotatably coupled to the second end of the first half annular part, and the catch member is rotatably coupled to the locking lever.

7. The hinged clamp of claim 5, wherein the catch member is a claw configured to lockingly engage the catch disposed on the second end of the second half annular part.

8. The hinged clamp of claim 5, wherein the catch member includes a loop configured to lockingly engage the catch disposed on the second end of the second half annular part.

9. A hinged clamp to form a rigid connection between a plunger and a pony rod in a frac pump, comprising:

a first half clamp part having a first end and a second end;

a second half clamp part having a first end and a second end; and

wherein the first ends of the first and second half clamp parts are rotatably joined by a hinge, and the second ends of the first and second half clamp parts being configured to lockingly latch together so that the first and second half clamp parts are securely clamped about the plunger and pony rod to form a rigid connection.

10. The hinged clamp of claim 9, further comprising a locking lever coupled to the second end of the first half clamp part configured to lockingly secure the second ends of the first and second half clamp parts.

11. The hinged clamp of claim 9, wherein the second ends of the first and second half clamp parts have a catch member and a catch that can securely engage.

12. The hinged clamp of claim 9, wherein the second end of the second half clamp part includes a catch, and the second end of the first half clamp part includes a catch member for latching the catch, and further comprising a locking lever rotatably coupled to the second end of the first half clamp part, and the catch member is rotatably coupled to the locking lever.

13. The hinged clamp of claim 12, wherein the catch member is a claw configured to lockingly engage the catch disposed on the second end of the second half clamp part.

14. The hinged clamp of claim 12, wherein the catch member includes a loop configured to lockingly engage the catch disposed on the second end of the second half clamp part.