# US 10,246,955 B2 · Self-aligning mud pump assembly

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- Number: US 10,246,955 B2
- Document ID: US10246955B2
- Status: Granted
- Kind: B2
- Application number: 15/227,807
- Filed: 2016-08-03
- Published: 2018-01-11
- Granted: 2019-04-02
- Earliest claimed: 2016-07-07
- Assignees: Cameron International Corporation
- Applicants: Cameron International Corporation
- Inventors: Pascal Berthaud; Robert Berthaud
- Web page: https://patentgrep.com/patent/US10246955B2

## CPC

- E21B 21/01: Arrangements for handling drilling fluids or cuttings outside the borehole, e.g. mud boxes
- F04B 1/00: Multi-cylinder machines or pumps characterised by number or arrangement of cylinders (machines or pumps with pistons coacting within one cylinder F04B3/00)
- F04B 9/02: the means being mechanical
- F04B 15/02: the fluids being viscous or non-homogeneous
- F04B 19/22: of reciprocating-piston type
- F04B 23/06: the pumps being all of reciprocating positive-displacement type
- F04B 49/035: Bypassing
- F04B 53/04: Draining
- F04B 53/08: Cooling; Heating; Preventing freezing
- F04B 53/14: Pistons, piston-rods or piston-rod connections
- F04B 53/143: {Sealing provided on the piston}
- F04B 53/18: Lubricating
- F16C 5/00: Crossheads; Constructions of connecting-rod heads or piston-rod connections rigid with crossheads (piston-rods, i.e. rods rigidly connected to the piston, F16J7/00)
- F16C 11/0614: {the female part of the joint being open on two sides}
- F16C 11/0628: {with linings}
- F05B 2230/60: Assembly methods
- F16C 7/023: {for piston engines, pumps or the like}
- F16C 2360/42: Pumps with cylinders or pistons
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F)
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F05B: INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G

## Abstract

A self-aligning mud pump apparatus is provided. In one embodiment, the mud pump includes a rotatable crankshaft, a crosshead, a crosshead guide, and a hub disposed in a housing. The hub is disposed on the crankshaft and is operable to convert rotating motion of the crankshaft to reciprocating motion of the crosshead within the crosshead guide. The hub is coupled to the crosshead via a connecting rod, which is connected the crosshead such that the connecting rod has five degrees of freedom with respect to the crosshead guide. The mud pump may also or instead include a piston coupled to the crosshead with five degrees of freedom between the piston and the crosshead. Additional systems, devices, and methods are also disclosed.

## Claims

### Claim 1

A self-aligning mud pump apparatus, comprising:
a housing;
a rotatable crankshaft disposed in the housing;
a crosshead disposed in the housing;
a crosshead guide disposed in the housing to constrain movement of the crosshead; and
a hub disposed in the housing and disposed on the crankshaft for converting a rotating motion of the crankshaft to a reciprocating motion of the crosshead within the crosshead guide via a connecting rod having a first end coupled to the hub and a second end coupled to the crosshead;
wherein the connecting rod is coupled to the crosshead via a bearing mounted on a retention component received in a spherical seat such that the second end of the connecting rod pivots in three rotational degrees of freedom within the crosshead and the connecting rod has two translational degrees of freedom with the crosshead guide;
wherein the retention component is fixedly coupled to a pin, and the pin is moveably coupled to the crosshead so as to allow the pin, along with the retention component, the bearing, and the connecting rod to translate together in a direction perpendicular to the direction of reciprocating motion of the crosshead within the crosshead guide.

### Claim 2 (depends on 1)

The mud pump apparatus according to claim 1, wherein play between the bearing and the connecting rod allows the second end of the connecting rod to translate with respect to the bearing in a direction perpendicular to the direction of reciprocating motion of the crosshead within the crosshead guide.

### Claim 3 (depends on 1)

The mud pump apparatus according to claim 1, further comprising a plunger piston coupled to the crosshead with five degrees of freedom between the plunger piston and the crosshead.

### Claim 4 (depends on 3)

The mud pump apparatus according to claim 3, wherein the five degrees of freedom between the plunger piston and the crosshead include three rotational degrees of freedom and two translational degrees of freedom.

### Claim 5 (depends on 3)

The mud pump apparatus according to claim 3, wherein the plunger piston is a headless piston and includes a spherical knob, and the crosshead includes a socket that receives the spherical knob.

### Claim 6 (depends on 5)

The mud pump apparatus according to claim 5, comprising a bearing including the socket.