Diffuser assembly for upward, downward and radial pump protection

Patent metadata

Field	Value
Publication number	US-11293455-B2
Application number	US-201816346967-A
Country	US
Kind code	B2
Filing date	May 31, 2018
Priority date	May 31, 2018
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

A diffuser subassembly for use in downhole submersible pump assemblies includes a bearing set for supporting a drive shaft of the pump assemblies. The bearing set includes a sleeve for supporting the drive shaft in upward, downward and radial directions. The sleeve includes a central flange captured axially between a pair of bushings fixed to a diffuser body. Axial loads from the drive shaft may be transferred through the central flange of the sleeve to one or the other of the bushings into the diffuser body to accommodate upward and downward thrust forces. The bushings may be keyed to discourage rotational motion with respect to the diffuser body.

First claim

What is claimed is:

1. A diffuser subassembly for a wellbore pump, the diffuser subassembly comprising:
a diffuser body defining a bore extending along a longitudinal axis, the diffuser body including a fluid flow path around the bore arranged to reduce a velocity of a fluid flowing therethrough while increasing a static pressure of the fluid;
a first bushing pressed into the bore and secured within the bore, the first bushing defining a first thrust surface on a lower surface thereof within the bore;
a second bushing pressed into the bore and secured within the bore, the second bushing defining a second thrust surface on an upper surface thereof within the bore; and
a sleeve for receiving a drive shaft, the sleeve defining upper and lower thrust surfaces thereon disposed axially between the first and second thrust surfaces of the first and second bushings, the sleeve captured between the first bushing and the second bushing independent of the sleeve being coupled to the drive shaft.

2. The diffuser subassembly of claim 1 , wherein the upper and lower thrust surfaces are defined on a flange extending radially from a sleeve body portion.

3. The diffuser subassembly of claim 2 , wherein the flange intersects an axial center of the sleeve body portion.

4. The diffuser subassembly of claim 1 , wherein the diffuser body defines a circumferential rim extending radially into the bore, and wherein at least one gap is defined within the circumferential rim for receiving a tab of at least one of the first and second bushings to prohibit free rotation of the first and second bushings with respect to the diffuser body.

5. The diffuser subassembly of claim 4 , wherein the first and second bushings are pressed into the diffuser body such that a perimeter of at least one of the first or second thrust surfaces engages the circumferential rim.

6. The diffuser subassembly of claim 1 , further comprising a pair of lock rings disposed on opposite axial sides of the first and second bushings and engaged with the diffuser body so as to retain the first and second bushings within the diffuser body.

7. The diffuser subassembly of claim 1 , wherein the diffuser body includes a fluid flow passage therein, the fluid flow passage extending at an oblique angle with respect to the longitudinal axis into the central bore.

8. A wellbore pump, comprising:
an electrical motor;
a drive shaft operably coupled to the electrical motor for selective rotation of the drive shaft about a longitudinal axis;
an impeller coupled to the drive shaft such that rotation of the drive shaft about the longitudinal axis rotates the impeller about the longitudinal axis;
a diffuser body adjacent the impeller, the diffuser body defining a bore extending along the longitudinal axis and receiving the drive shaft therein;
an upper bushing disposed within the bore, the upper bushing defining a first thrust surface on a lower surface thereof within the bore;
a lower bushing disposed within the bore, the lower bushing defining a second thrust surface on an upper surface thereof within the bore; and
a sleeve receiving the drive shaft therein such that the sleeve is axially spaced from the impeller; the sleeve defining upper and lower thrust surfaces thereon disposed axially between the first and second thrust surfaces of the upper and lower bushings.

9. The wellbore pump of claim 8 , wherein the drive shaft is rotationally coupled to the sleeve by a keyed slot defined on at least one of the drive shaft and the sleeve.

10. The wellbore pump of claim 8 , wherein at least one of the bushings is rotationally fixed to the diffuser body by a tab defined on one of the diffuser body and the at least one of the bushings extending into a gap defined on the other of the diffuser body and the at least one of the bushings.

11. The wellbore pump of claim 8 , further comprising an impeller and diffuser stack including the impeller and diffuser body and at least one additional impeller coupled to the drive shaft and at least one additional diffuser body circumscribing the drive shaft.

12. The wellbore pump of claim 8 , wherein the sleeve is axially captured within the bore by the upper and lower bushings.

13. The wellbore pump of claim 12 , wherein the sleeve includes a central flange extending radially from a sleeve body portion, and wherein the central flange defines the upper and lower thrust surfaces thereon disposed axially between the upper and lower bushings.

14. The wellbore pump of claim 8 , wherein the upper and lower bushings are secured in the diffuser body by at least one of an interference fit with the diffuser body and a lock ring disposed on axial sides of the first and second bushings.

15. A method of assembling a wellbore pump, the method comprising:
securing a first bushing within a bore of a diffuser body;
disposing a sleeve within the bore of the diffuser body such that an upper thrust surface on the sleeve is adjacent to a complementary thrust surface defined on the first bushing;
securing a second bushing within the bore of the diffuser body such that a thrust surface on the second bushing is adjacent a complementary lower thrust surface defined on the sleeve opposite the upper thrust surface to thereby capture the sleeve within the bore of the diffuser body; and
coupling, after securing the second bushing, the sleeve to a drive shaft of the submersible pump.

16. The method according to claim 15 , wherein coupling the sleeve to the drive shaft comprises rotationally coupling the drive shaft to the sleeve by engaging a key on one of the drive shaft and the sleeve with a keyslot defined on the other of the drive shaft and the sleeve.

17. The method according to claim 15 , wherein securing the first bushing within the bore of the diffuser body comprises rotationally coupling the first bushing with the diffuser body by inserting a tab defined on the first bushing with a gap defined within the diffuser body.

18. The method according to claim 15 , wherein disposing the sleeve within the bore comprises aligning a central flange of the sleeve with the thrust surface defined on the first bushing.

19. The method according to claim 18 , wherein securing the second bushing within the bore comprises aligning the thrust surface on the second bushing with the central flange of the sleeve to thereby axially capture the central flange between the first and second bushings.

20. The method according to claim 19 , wherein securing the first and second bushings within the bore comprises at least one of forming an interference fit between the first and second bushing with the diffuser body and securing a pair of lock rings on opposite axial sides of the first and second bushings.

Assignees

• Halliburton Energy Services Inc

Inventors

• Nowitzki Wesley John
• Webster Joshua W

Classifications

• F04D29/046 Primary

  Bearings · CPC title

• F04D13/10

  adapted for use in mining bore holes · CPC title

• F04D29/62

  of radial or helico-centrifugal pumps · CPC title

• E21B43/128

  Adaptation of pump systems with down-hole electric drives · CPC title

• F04D29/0413

  hydrostatic; hydrodynamic thrust bearings · CPC title