Hydraulic fluid pump and stuffing box assembly for same

1. A stuffing box assembly for a fluid end of a hydraulic fluid pump, the stuffing box assembly comprising:

a stuffing box unit having a plunger bore configured to receive a plunger of the hydraulic fluid pump and a plurality of seals, wherein the plunger includes a plunger end that enters an interior volume of a fluid end housing during operation of the hydraulic fluid pump, wherein the plunger bore extends from a first axial end of the stuffing box unit to a second axial end of the stuffing box unit, the second axial end being positionable adjacent the interior volume of the fluid end housing, and wherein the plunger bore includes a first portion configured to receive the plurality of seals and a second portion extending between the first portion and the second axial end; and

a sensor coupled to the stuffing box unit and configured to determine a fluid pressure within the second portion of the stuffing box unit.

2. The stuffing box assembly of claim 1 , wherein the sensor is a pressure sensor in fluid communication with a fluid within the second portion of the plunger bore.

3. The stuffing box assembly of claim 1 , wherein the sensor is a strain gage coupled to the stuffing box unit and configured to detect a value indicative of the fluid pressure within the second portion of the stuffing box unit.

4. The stuffing box assembly of claim 3 , wherein the stuffing box unit includes a flat cut into a cylindrical outer surface of the stuffing box unit, wherein the flat cut defines a planar surface oriented perpendicular to a radial direction of the stuffing box unit, and wherein the strain gage is coupled to the flat cut.

5. The stuffing box assembly of claim 1 , wherein the stuffing box assembly includes a cylindrical outer surface, and wherein a channel extends from the cylindrical outer surface to the second portion of the plunger bore, and wherein the sensor is coupled to the channel at the cylindrical outer surface.

6. The stuffing box assembly of claim 5 , wherein the interior volume of the fluid end housing is defined between an inlet valve and an outlet valve, and wherein the channel is defined entirely by the stuffing box unit and does not extend through the fluid end housing.

7. The stuffing box assembly of claim 5 , wherein an opening of the channel at the second portion of the plunger bore is located axially nearer the second axial end of the plunger bore than the sensor.

8. The stuffing box assembly of claim 1 , wherein the fluid pressure that is determined by the sensor is representative of a pressure within the interior volume of the fluid end housing.

9. The stuffing box assembly of claim 1 , wherein the plunger bore further comprises a third portion, wherein the first portion is located between the second portion and the third portion, and wherein the third portion is threaded.

10. The stuffing box assembly of claim 9 , further comprising a stuffing nut, wherein the stuffing nut is threaded and configured to engage the third portion of the plunger bore, and wherein the stuffing nut is configured to compress the plurality of seals within the first portion.

11. The stuffing box assembly of claim 1 , further comprising a monitoring device programmed to record the fluid pressure determined by the sensor and to compare the fluid pressure to a predefined pressure range or a previously measured fluid pressure.

12. A stuffing box assembly for a fluid end of a hydraulic fluid pump, the stuffing box assembly comprising:

a stuffing box unit having an axial bore, wherein the axial bore is defined by a first portion configured to support a plurality of seals, a second portion configured to be positioned adjacent an interior volume of a fluid end housing into which an end of a plunger extends during operation of the hydraulic fluid pump, and a third portion configured to engage a stuffing nut, wherein the first portion is positioned between the second portion and the third portion, and

sensing means configured to determine a fluid pressure within the second portion of the axial bore.

13. The stuffing box assembly of claim 12 , wherein the stuffing box unit is configured to be removably coupled to the fluid end housing and the interior volume is defined between an inlet valve and an outlet valve.

14. The stuffing box assembly of claim 13 , wherein the sensing means is coupled to an outer surface of the stuffing box unit, and wherein the sensing means is accessible when the stuffing box unit is removably coupled to the fluid end housing.

15. The stuffing box assembly of claim 12 , wherein the third portion of the axial bore extends between a first axial end of the stuffing box unit and the first portion of the axial bore, and wherein the second portion extends between a second axial end of the stuffing box unit and the first portion of the axial bore.

16. The stuffing box assembly of claim 12 , further comprising a monitoring device programmed to monitor or record the fluid pressure determined by the sensing means and to compare the fluid pressure to a predefined pressure range, a predefined pattern of pressures, a dynamically generated pattern of pressures, or a previously measured fluid pressure.

17. A stuffing box assembly for a fluid end of a hydraulic fluid pump, the stuffing box assembly comprising:

a stuffing box unit having an axial bore configured to support a plurality of seals in a first portion, wherein the axial bore includes a second portion axially spaced apart from the first portion so that the second portion can be positioned adjacent an interior volume of a fluid end housing into which an end of a plunger extends during operation of the hydraulic fluid pump, and wherein the stuffing box unit further comprises a channel branching from the axial bore at the second portion, and

a sensor in fluid communication with the channel and configured to determine a fluid pressure within the second portion of the stuffing box unit.

18. The stuffing box assembly of claim 17 , wherein the stuffing box unit is configured to be removably coupled to the fluid end housing and the interior volume is defined between an inlet valve and an outlet valve, and wherein the sensor is in fluid communication with the interior volume via the channel.

19. The stuffing box assembly of claim 17 , wherein an opening of the channel at the second portion of the axial bore is located axially nearer an axial end of the axial bore than the sensor.

20. The stuffing box assembly of claim 19 , wherein the plunger is a reciprocating plunger that reciprocates within a reciprocating range, and wherein the opening of the channel at the second portion of the axial bore is located outside of the reciprocating range.