One-way clutch train for preventing swiveling

Abstract

An ESP system, the ESP system having a drive shaft assembly; and an electric motor coupled with an end of the drive shaft assembly and rotating the drive shaft assembly in a first direction when energized. The ESP system also includes a pump coupled with an end of the driveshaft assembly remote from the motor, and a one-way clutch train in the driveshaft assembly that prevents rotation of the driveshaft assembly in the second direction. In this example, a drive shaft assembly includes a pump shaft having an end engaged with an end of a motor shaft; opposite ends of the pump shaft and the motor shaft are coupled with the pump and the motor, respectively. The one-way clutch train includes a shaft-to-shaft clutch coupled between inner and outer surfaces of the pump shaft and the motor shaft, and a shaft-to-housing clutch coupled between an outer surface of one of the pump shaft and the motor shaft and the outer housing.

Description

[0001] Related Applications

[0002] This application claims priority to and the benefit of co-pending U.S. application serial number 18 / 202,394, filed on May 26, 2023, and co-pending U.S. provisional application serial number 63 / 346,166, filed on May 26, 2022, which are incorporated herein by reference in their entirety and for all purposes. Background Art 1. Technical Field

[0003] The present disclosure relates to preventing backspin in an electric submersible pump system drive shaft having a series of one-way clutch assemblies.

[0004] 2. Description of the Prior Art

[0005] Electric submersible pumps ("ESPs") are commonly used in hydrocarbon producing wells. Typically, an ESP system includes an electric motor, a pump having an impeller and a diffuser, and a drive shaft connected between the motor and the pump. The drive shaft is attached to the impeller, and the shaft and impeller rotate when the motor is powered. The rotating impeller draws fluid from the well into the pump and forces the fluid through the diffuser, which pressurizes the fluid for delivery to the surface.

[0006] In some cases, such as when the motor is not powered and there is a column of well fluid above the impeller, the fluid in the column is driven by gravity through the impeller downhole and causes the impeller to rotate in a direction opposite to their rotation during pressurization. The connected drive shaft also rotates to cause the motor to swirl, thereby generating electricity that is conducted along the well along a power cable connected to the motor from the surface. This electricity produces undesirable effects, such as posing a hazard to personnel operating the well. Therefore, there is a need for a way to prevent swirl in an ESP motor that does not introduce frictional forces onto the drive shaft when operating the pump. Summary of the invention

[0007] An example of an electric submersible pump ("ESP") system is disclosed, the system including: a drive shaft assembly having an elongated section; an electric motor coupled to an end of the drive shaft assembly and causing the drive shaft assembly to rotate in a first direction when energized; a pump coupled to an end of the drive shaft assembly remote from the motor; and a one-way clutch system in the drive shaft assembly, the one-way clutch system being rotationally disengaged from the drive shaft assembly when the drive shaft assembly rotates in the first direction, and being rotationally engaged with the drive shaft assembly when the drive shaft assembly rotates in a second direction opposite to the first direction. In this example, the drive shaft assembly is composed of a shaft-to-shaft clutch coupled between adjacent segments on an outer surface of one of the segments and an inner surface of an adjacent segment, and a shaft-to-housing clutch coupled between one of the segments and an outer housing. The exemplary segments include a pump shaft and a motor shaft, the pump shaft having an end selectively coupled to an end of the motor shaft, and opposite ends of the pump shaft and the motor shaft being coupled to the pump and the motor, respectively. In this example, the shaft-to-housing clutch is selectively changeable between an engaged configuration and a disengaged configuration, wherein when in the engaged configuration, the housing is rotationally coupled to the pump shaft by the shaft-to-housing clutch, and wherein when in the disengaged configuration, the pump shaft is rotatable relative to the housing. Further, in this example, changing the rotational direction of the pump shaft causes the shaft-to-housing clutch to change between the engaged configuration and the disengaged configuration. In an alternative, the shaft-to-shaft clutch is selectively changeable between an engaged configuration and a disengaged configuration, wherein when in the engaged configuration, the motor shaft is rotationally coupled to the pump shaft by the shaft-to-shaft clutch, and wherein when in the disengaged configuration, the pump shaft is rotatable relative to the motor shaft; alternatively, changing the rotational direction of the motor shaft causes the shaft-to-shaft clutch to change between the engaged configuration and the disengaged configuration. The motor shaft optionally includes a receiver that receives an end of the pump shaft away from the pump, and wherein the shaft-to-shaft clutch is disposed in the receiver. In addition, in this example, the shaft-to-shaft clutch includes: an outer race that is press-fitted into the receiver; and an inner race that is press-fitted onto the outer surface of the pump shaft; and a sprag-type element that is located between the inner race and the outer race. The sprag-type element is an optionally substantially planar element that can pivot about an axis that is substantially parallel to the axis of the ESP assembly. In an alternative, the sprag-type element is strategically sized so that when the extended width of the sprag-type element is radially oriented from the axis, the opposite ends of the sprag-type element are wedged between the inner race and the outer race, wherein the sprag-type element is selectively radially oriented from the axis in response to the rotation of the outer race relative to the inner race in a first direction. In this example, when the sprag-type element is wedged between the inner race and the outer race, the clutch assembly is in an engaged configuration, and relative rotation of the outer race relative to the inner race in a first direction is prevented.In one embodiment, the sprag element is in sliding contact with the inner race and the outer race when the elongated width of the sprag element is oriented obliquely relative to the axis, and the sprag element is selectively oriented obliquely relative to the axis in response to rotation of the outer race relative to the inner race in a second direction opposite to the first direction. Optionally, the segments are in non-stop engagement when the segments are rotationally coupled to each other and can rotate about the axis, and wherein the segments are in stop engagement when the one-way clutch can selectively change between a locked configuration in which one of the segments is rotationally fixed in position and a rotating configuration in which adjacent segments can freely rotate relative to each other.

[0008] Another example of an electric submersible pump ("ESP") system is disclosed, including a housing, an electric motor that generates a rotational force in a first direction when energized, a pump, and a drive shaft assembly coupled between the motor and the pump. The drive shaft assembly includes a pump shaft having an end coupled to the pump; a motor shaft having an end coupled to the motor; and a shaft-to-shaft clutch including a plurality of sprag-type elements disposed in an annulus between the pump shaft and the motor shaft, the sprag-type elements being capable of changing between a radial orientation, in which rotational torque is transmitted between the pump shaft and the motor shaft through the plurality of sprag-type elements, and an inclined orientation in which the pump shaft and the motor shaft are capable of rotating relative to each other. In one alternative, the plurality of brace-type elements is a first plurality of brace-type elements, and the system further has a shaft-to-housing clutch having a second plurality of brace-type elements disposed in an annulus between the pump shaft and the housing, the second plurality of brace-type elements being capable of changing between a radial orientation, in which rotational torque is transmitted between the pump shaft and the housing through the second plurality of brace-type elements, and an inclined orientation, in which the pump shaft is capable of rotating relative to the housing. In one example, when the motor shaft is rotated in a first direction by the motor so that the pump shaft also rotates in the first direction, the first plurality of brace-type elements are in a radial orientation, and wherein when the pump shaft rotates in the first direction, the second plurality of brace-type elements are in an inclined configuration such that when the motor is energized, rotational torque from the motor is transmitted to the pump through the drive shaft assembly. In an embodiment, when a rotational torque is applied to the pump shaft in a second direction opposite to the first direction, the second plurality of brace-type elements are in a radial configuration, thereby rotationally coupling the pump shaft to the housing and preventing rotation of the pump shaft, wherein when the motor shaft is rotated in a first direction by the motor so that the pump shaft also rotates in the first direction, the first plurality of brace-type elements are in a radial orientation, and such that when the motor is energized, the rotational torque from the motor is transmitted to the pump through the drive shaft assembly. The pump shaft optionally includes an axial passage, a port extending radially from the passage to an outer surface of the pump shaft, and an opening in the passage at a downhole end of the pump shaft, and wherein a magnetic reservoir is disposed proximate the opening such that when the pump shaft rotates, a fluid flow is introduced into the opening, through the passage and out of the port, and wherein metal particles are pulled from the fluid flow and retained in the reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Having stated certain features and benefits of the present invention, other features and benefits will become apparent when described in conjunction with the accompanying drawings, in which:

[0010] Figure 1 is a side partial cross-sectional view of an example of an electric submersible pump ("ESP") system disposed in a well.

[0011] Figure 2 is used with Figure 1A side cross-sectional view of an example of a reverse rotation stop sub for use with an ESP system.

[0012] Figure 3 is with Figure 1 Exploded view of the drive shaft assembly used with the ESP system.

[0013] Figure 4 It is taken along line 4-4 Figure 2 An axial cross-sectional view of a portion of a reverse rotation stop aid.

[0014] Figure 5 It is taken along line 5-5 Figure 2 An axial cross-sectional view of a portion of a reverse rotation stop aid.

[0015] Figure 6 yes Figure 2 Magnified view of the auxiliary parts.

[0016] Fig. 7A and Figure 7B are schematic axial views of a clutch in free-spinning and locked configurations, respectively.

[0017] Figure 8 yes Figure 2 A side cross-sectional view of an alternative example of a reverse rotation stop aid.

[0018] While the subject matter is described in conjunction with the embodiments disclosed herein, it should be understood that the scope of the present disclosure is not limited to any particular embodiment. On the contrary, the disclosure is intended to cover all alternatives, modifications, and equivalents thereof. DETAILED DESCRIPTION

[0019] The methods and systems of the present disclosure are now described more fully below with reference to the accompanying drawings showing embodiments. The methods and systems of the present disclosure may be in many different forms and should not be construed as being limited to the exemplary embodiments listed herein; on the contrary, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. Similar numbers throughout the specification represent similar elements. In one embodiment, the use of the term "about" includes + / -5% of the quoted value. In one embodiment, the term "substantially" includes + / -5% of the quoted value, comparison or description. In one embodiment, the use of the term "roughly" includes + / -10% of the quoted value.

[0020] It should be further understood that the scope of the present disclosure is not limited to the exact details of the architecture, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to those skilled in the art. In the drawings and specification, exemplary embodiments have been disclosed, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

[0021] Figure 1 1 shows an example of an electric submersible pump ("ESP") system 11 disposed in a well 12 in a front elevational, partial cross-sectional view. The ESP system 11, described in more detail below, has a pump 13 to lift a fluid F from within the well 12 to the surface S, the fluid F being generated from a formation 14 surrounding the well 12. The pump 13 includes an inlet 15 for drawing the fluid F into the pump 13, where the fluid F is pressurized. The pump 13 is driven by a motor 17, which is shown mounted on an end of the ESP system 11 remote from the pump 13; in one example, the motor 17 is powered by a cable (not shown) that is connected to a power source at the surface S to deliver power and operate the ESP system 11. The ESP system 11 includes a seal portion 19, which is shown disposed between the pump 13 and the motor 17, which selectively provides pressure equalization between a fluid (e.g., a dielectric fluid, a lubricating fluid, or a cooling fluid) within the motor 17 and environmental conditions in the well 12.

[0022] exist Figure 1 In the example of , the reverse rotation stop aid 21 is shown as being mounted to the upper end of the motor 17 and between the motor 17 and the seal 19. The drive shaft assembly 23 is shown in dashed outline and is rotationally coupled between the motor 17 and the pump 13. In the example, the pump 13 is a centrifugal pump having an impeller (not shown) stacked within the housing of the pump and coupled to the drive shaft assembly 23. In this example, a diffuser (not shown) stacked within the housing is included, the diffuser having a channel that selectively aligns with and receives fluid from the channel in the impeller when the impeller rotates. The corresponding channels form a fluid flow path within the pump 13, wherein the fluid in the well 12 is pressurized as it travels along the fluid flow path. As described in more detail below, the aid 21 selectively blocks rotation of the drive shaft assembly 23 to prevent swirl within the motor 17.

[0023] Figure 1The motor 17 of the embodiment includes an elongated rotor stack (not shown) mounted to a drive shaft assembly 23, the rotor stack being disposed within the motor 17 and capable of rotating relative to a stator (not shown) within the motor. The rotor stack of this example optionally includes a permanent magnet having magnetic poles spaced angularly around the circumference of the drive shaft assembly 23. Electricity from the cable to the stator generates a rotating electromagnetic field that causes the rotor stack to rotate in a first direction, thereby rotating the drive shaft assembly 23 and the impeller to pressurize the well fluid, as described above. In a non-limiting example of operation, gyration describes the rotation of the drive shaft assembly 23 and the rotor in the motor 17 in a second direction opposite to the first direction. When the rotor stack rotates in the second direction, the motor 17 may generate electricity. When viewed from the wellhead, the first direction is clockwise and the second direction is counterclockwise, and in an alternative, when viewed from the wellhead, the first direction is counterclockwise and the second direction is clockwise.

[0024] Figure 1 Also included in the well 12 is a production line 25, which is shown connected to the ESP system 11 at the wellhead end (i.e., closer to the surface S) of the pump 13. In the example shown, the tubing 25 provides a conduit for directing the fluid pressurized by the pump 13 to the surface S, such as to a wellhead assembly (not shown), from which the fluid is transmitted for processing or refining. The fluid F is shown entering the well 12 through perforations 26, which extend radially from the well 12 through casing 27, which is shown as lining the sidewall of the well 12, and into the formation 14. The casing 27 is shown as a solid metal tubular and provides isolation between the well 12 and the surrounding formation 14.

[0025] Reference now Figure 2 , shows an exemplary portion of an ESP system 11 with an auxiliary component 21 in a side cross-sectional view. In this example, the drive shaft assembly 23 includes a pump shaft 28 having a connection with the pump 13 ( Figure 1 ) is rotatably attached to the uphole end 29 and a downhole end 30 opposite the uphole end 29, which is selectively rotatably engaged with a motor shaft 31. The motor shaft 31 includes a receiver 32, which has a diameter larger than the diameter of the downhole end 30 and receives the downhole end 30. The shaft 31 includes a lower end 33 shown on the side opposite to the receiver 34, and protrudes axially from an outer housing 34 covering the auxiliary member 21 and surrounding the shafts 29, 31. The housing 34 is shown as being composed of multiple sections, in an alternative, the housing 34 is a single piece.

[0026] The pump shaft 28 and the motor shaft 31 are selectively rotationally coupled to each other by a shaft-to-shaft clutch 35, which is shown as being disposed in an annular space between the inner surface of the receiver 32 and the outer surface of the downhole end 30. The clutch 35 includes an annular inner race 37 attached to the outer surface of the downhole end 30 and an annular outer race 39 coupled to the inner surface of the receiver 32. In the alternative, the races 37, 39 are press-fitted to the end 30 and the receiver 32, respectively. In the example shown, the races 37, 39 are substantially coaxial and circumscribed to the axis AX of the ESP assembly 11. Between the inner race 37 and the outer race 39 is a clutch assembly 40 having clutch members 41 that are configured to allow the downhole shaft 30 to rotate relative to the shaft 31 when either of the shafts 30, 31 rotates in one direction, and to rotationally couple the shafts 30, 31 when either of the shafts 30, 31 rotates in the opposite direction. In one example, the clutch assembly 40 is in a disengaged configuration when the shafts 30, 31 are able to rotate relative to each other, and the clutch assembly is in an engaged configuration when the shafts 30, 31 are coupled. Further, in this example, the clutch assembly 40 is in an engaged configuration when the races 37, 39 are rotationally coupled or attached to each other, and the clutch assembly is in a disengaged configuration when the races 37, 39 are able to rotate relative to each other. Within the clutch assembly 40 is a clutch member 41 that provides a selective coupling between the inner race 37 and the outer race 39; a bearing 43 is also shown as part of the clutch assembly 40 that facilitates rotation between the inner race 37 and the outer race 39.

[0027] A shaft-to-housing clutch 45 is also included in the auxiliary member 21 and is disposed in an annular gap between a portion of the pump shaft 28 and the inner surface of the housing 34. Similar to the clutch 35, the shaft-to-housing clutch 45 includes an annular inner race 47 coupled to the outer surface of the pump shaft 28, an annular outer race 49 coupled to the inner surface of the housing 34, and a clutch assembly 50 disposed between the inner race 47 and the outer race 49. As shown, the inner race 47 is coupled to a portion of the pump shaft 28 near its wellhead end 29. In an alternative, the races 47, 49 are press-fitted to the shaft 28 and the housing 34, respectively. In this example, the clutch assembly 50 also includes a clutch member 51 and a bearing 53 similar to those in the clutch 35. The ridge 54 is shown as protruding radially inward from the inner surface of the housing 34 and circumscribed to the axis AX. In an alternative embodiment, the shaft-to-shaft clutch 35 includes two or more sets of clutch assemblies 40 that are stacked substantially coaxially in the annular space between the shaft 28 and the housing 34 and are optionally in abutting contact with each other; and / or, the shaft-to-housing clutch 45 includes two or more sets of clutch assemblies 50 that are stacked substantially coaxially in the annular space between the shaft 28 and the inner surface of the receiver 32 and are optionally in abutting contact with each other.

[0028] Still reference Figure 2 , defining a downward facing shoulder 55 where the diameter of the pump shaft 28 transitions radially inwardly near its downhole end 30 and adjacent the uphole end of the clutch 35, with the upward facing radial surface of the inner race 37 being shown abutting the shoulder 55. Similarly, defining an upward facing shoulder 57 where the inner diameter of the receiver 32 transitions radially outwardly adjacent the end of the clutch 35 distal from the shoulder 55, with the shoulder being shown supporting the lower radial surface of the outer race 39. The combination of the shoulders 55, 57 provides axial support for the pump shaft 28, and in the example shown, the location of the shoulders 55, 57 and the axial dimensions of the races 37, 39 form a gap 59 between the lower extremity of the downhole end 30 and the lowermost portion of the receiver 32. Figure 2 Also shown in the figure is a skirt 61 formed on the downwardly facing surface of the receiver 32 and spaced radially outward from the outer surface of the motor shaft 31 adjacent the receiver 32. A thrust bearing 63 is shown disposed between the end of the skirt 61 facing away from the shaft 28 and a base portion 64 of the auxiliary member 21. A journal bearing 65 is shown formed between the housing 34 and a portion of the shaft 31 located below the receiver 32.

[0029] Figure 3 , which depicts each of the pump shaft 28 and the motor shaft 31 adjacent to each other. The end of the shaft 31 adjacent the shaft 28 is enlarged with a receiver 32 for receiving the lower end of the shaft 28. The shoulder 55 is shown facing downward.

[0030] Reference now Figure 4 , showing that along Figure 2 4-4 of the example of the shaft-to-housing clutch 45. Here, the clutch assembly 50 is schematically represented in the annular gap between the inner race 47 and the outer race 49. When a rotational force is applied to one or both of the races 47, 49 to rotate the two races 47, 49 in one direction, the clutch assembly 50 selectively rotationally couples the inner race 47 and the outer race 49; and allows relative rotation in a direction opposite to one direction. As shown, the shaft 28 is rotationally attached to the inner race 47, and the housing 34 is rotationally attached to the outer race 49, so that the clutch assembly 50 rotationally attaches the shaft 28 to the housing 34 when the shaft 28 rotates in one direction, and allows the shaft 28 to rotate freely in the opposite direction. For the purposes discussed herein, the clutch assembly 50 is in an engaged configuration when the races 47, 49 are rotationally coupled or attached to each other, and the clutch assembly is in a disengaged configuration when the races 47, 49 are able to rotate relative to each other. Thus, when the clutch assembly 50 is in the engaged configuration, the shaft 28 is rotationally coupled with the housing 34 and is not free to rotate relative to the housing 34. When the clutch assembly 50 is in the disengaged configuration, the shaft 28 is able to rotate relative to the housing 34.

[0031] Figure 5 Shown along Figure 25-5 of the shaft-to-shaft clutch 35. In this example, the clutch assembly 40 is disposed in the annular space between the inner race 37 and the outer race 39, and rotationally couples the races 37, 39 when either of the races 37, 39 rotates in one direction, and allows relative rotation between the races 37, 39 when relative rotation occurs in the opposite direction. In a non-limiting example of operation, as shown by arrow CW37, the clutch assembly 40 allows the inner race 37 to rotate in a clockwise direction relative to the outer race 39; and restricts the inner race 37 from rotating in a counterclockwise direction relative to the outer race 39 (as shown by arrow CCW37), thereby rotationally attaching or coupling the races 37, 39. In this example, the outer race 39 is capable of rotating in a counterclockwise direction relative to the inner race 37 (as shown by arrow CCW39), and is restricted from rotating in a clockwise direction relative to the inner race 37 (as shown by arrow CW39). Alternatively, in this example, the clutch assembly 50 allows the inner race 47 to rotate in a clockwise direction relative to the outer race 49 (as shown by arrow CW47); and limits the inner race 47 from rotating in a counterclockwise direction relative to the outer race 49 (as shown by arrow CCW47), thereby rotationally attaching or coupling the races 47, 49. In this alternative, the outer race 49 is able to rotate in a counterclockwise direction relative to the inner race 47 (as shown by arrow CCW49), and is limited to rotating in a clockwise direction relative to the inner race 47 (as shown by arrow CW49). Optionally, these rotational directions are reversed in one or both of the clutch assemblies 40, 50.

[0032] Reference now Figure 6 , showing Figure 2 , and shows in more detail an embodiment of the elements of the clutch assemblies 40A, 50A that make up the clutch 35A, 45A. For convenience, the clutch assemblies 40A, 50A are superimposed in a single example and their corresponding elements are referenced in the figure. The clutch assemblies 40A, 50A in this example include bearings 43A1, 53A1, which are depicted as spherical members or ball bearings; and bearings 43A2, 53A2, which are depicted as needle bearings or roller bearings. It is further shown that the clutch members 41A, 51A are represented as sprag-type elements and are capable of pivoting about an axis AS, which is shown as being generally parallel to the axis AX ( Figure 1 ). In the example shown, the sprag-type element is generally planar, with a length extending along the axis AS, and a width and thickness (or height) each transverse to the axis AS and to each other. In an embodiment, the clutch assembly 40A, 50A includes a plurality of bearings 43A1, 53A and a clutch member 41A, 51A circumscribing the axis AX.

[0033] Along the Figure 6 The line 7A, B-7A, B is intercepted Fig. 7A and Figure 7B Schematically illustrates an example of how the orientation of the clutch members 41A, 51A changes the relative rotation of the outer race 39A, 49A relative to the inner race 37A, 47A; and an example of how the orientation of the clutch members 41A, 51A affects the engagement and disengagement between the outer race 39A, 49A and the inner race 37A, 47A. For the purposes discussed herein, the clutch members 41A, 51A have a length substantially parallel to the axis AS and a width W and a thickness transverse to the axis AS, wherein the width is greater than the thickness. Fig. 7A , which shows an example of a clutch 35A, 45A in a disengaged configuration that allows the outer race 39A, 49A to rotate counterclockwise relative to the inner race 37A, 47A while the inner race 37A, 47A is stationary, or the inner race 37A, 47A to rotate clockwise relative to the outer race 39A, 49A. In this scenario of rotation by the race 37A, 47A, 39A, 49A, the clutch members 41A, 51A pivot in the annular space between the race 37A, 47A and the race 39A, 49A so that their width W is inclined to the line L shown as extending radially from the axis AX; in this orientation, the clutch members 41A, 51A do not hinder the rotation of the race 37A, 47A relative to the race 39A, 49A, and vice versa. When in Fig. 7A In the orientation shown, the lateral edges of the clutch members 41A, 51A are in sliding contact with the races 37A, 47A and the races 39A, 49A; alternatively, the clutch members 41A, 51A are outside the respective rotational paths of any of the races 37A, 47A and the races 39A, 49A; thereby leaving gaps G1, G2 between the clutch members 41A, 51A and the inner races 37A, 47A and the outer races 39A, 49A, respectively. When there is sliding contact between the clutch members 41A, 51A and the races 37A, 47A, 39A, 49A or when there are gaps G1, G2, the clutch 35A, 45A is in a disengaged configuration.

[0034] Figure 7B, which does prevent relative rotation of the inner race 37A, 47A relative to the outer race 39A, 49A. The transition to the engaged configuration can be initiated when all of the races 37A, 47A, 39A, 49A are stationary, or immediately after relative rotation occurs between the races 37A, 47A, 39A, 49A, or when relative rotation occurs between the races 37A, 47A, 39A, 49A. In this example, the clutch members 41A, 51A are oriented so that their width W extends along a line substantially parallel to the line L shown as extending radially from the axis AX. The width W is sized so that when the clutch members 41A, 51A are as shown, the inner race 37A, 47A, 39A, 49A is engaged. Figure 7B When in the radial orientation shown, the opposing lateral edges of the clutch members 41A, 51A contact the respective outer and inner surfaces of the races 37A, 47A, 39A, 49A. This contact between the clutch members 41A, 51A and the races 37A, 47A, 39A, 49A wedges the clutch members 41A, 51A between the races 37A, 47A, 39A, 49A so that radial forces are transmitted between the races 37A, 47A, 39A, 49A through the width W of the clutch members 41A, 51A. Wedging the clutch member 41A between the races 37A, 39A causes the inner race 37A to rotationally engage the outer race 39A, which in turn couples the shaft 28 to the housing 34. Similarly, wedging clutch member 51A between races 47A, 49A rotationally engages inner race 47A with outer race 49A, which in turn couples shaft 28 with shaft 31. In the alternative and as described in detail below, the relative rotational direction for engaging / disengaging clutches 35, 35A is opposite to the rotational direction for engaging / disengaging clutches 45, 45A.

[0035] In one example, the clutch assembly 40 is configured such that rotation of the motor shaft 31 in a first direction results in an engaged configuration, causing the motor shaft 31 to be rotationally coupled to the pump shaft 28, and correspondingly causing the pump shaft 28 to rotate in the same first direction. Further, in this example, the clutch assembly 50 is configured such that rotation of the pump shaft 28 in the first direction results in a disengaged configuration, and wherein the pump shaft 28 is capable of rotating in the first direction relative to the housing 34, i.e., the inner race 47 and the outer race 49 are capable of rotating in the first direction relative to each other. Still in this example, rotation of the pump shaft 28 (such as caused by reverse rotation of the fluid flowing through the impeller, which reverse rotation causes the pump shaft 28 to rotate in a second direction opposite to the first direction) causes the clutch assembly 50 to be in an engaged configuration to rotationally couple the pump shaft 28 with the housing 34, and thereby prevent rotation of the drive shaft assembly 23, thereby preventing backspin in the motor shaft 31. In the configuration of this example, the clutch assembly 50 does not hinder the rotation of the pump shaft 28 relative to the housing 34 (or hinder the relative rotation of the races 47, 49) in the first direction of rotation of the pump shaft 28 (i.e., the rotation of the pump shaft 28 caused by factors other than the rotation of the motor shaft 31) because the clutch assembly 50 is in the disengaged configuration for rotation in the first direction. In addition, when the pump shaft 28 rotates in the first direction due to a force other than the rotation of the motor shaft 31, the pump shaft is able to rotate relative to the motor shaft 31 because the relative rotation of the pump shaft 28 and the motor shaft 31 is in the opposite direction to the direction that caused the clutch assembly 40 to enter the engaged configuration, thereby rotationally coupling the pump shaft 28 and the motor shaft 31. In this scenario, the rotation of the drive shaft assembly 21 is prevented by configuring the clutch assembly 40 so that the rotational torque is not transmitted between the shafts 28, 31 when the rotational force is applied to the pump shaft 28 in the first direction by factors other than the rotation of the motor shaft 31. Examples of preventing / impeding rotation or preventing / impeding rotational forces include selectively coupling a component to a fixed structure to prevent rotation of the component (e.g., coupling pump shaft 28 to housing 34), and selectively configuring a component in the drive train to be in a disengaged mode so that rotational forces are not transmitted across the drive train (e.g., allowing free rotation between shafts 28, 30 when one or both of the two shafts are rotating in a specified direction relative to each other).

[0036] In a non-limiting example of operation, the clutch assembly 40 ( Figure 2): (1) is configured to enter or be in an engaged structure by rotation of the motor shaft 31 in a first direction counterclockwise relative to the motor shaft 31 (when viewed from the ground S); and (2) is configured to enter or be in a disengaged structure by rotation of the motor shaft 31 in a second direction clockwise relative to the motor shaft 31 (when viewed from the ground S); and (3) the clutch assembly 50 in the shaft-to-housing clutch 45 is configured to enter or be in a disengaged structure by rotation of the pump shaft 28 in a direction counterclockwise relative to the housing 34 (when viewed from the ground S); and (4) is configured to enter or be in an engaged structure by rotation of the pump shaft 28 in a clockwise direction relative to the housing 34 (when viewed from the ground S). With the clutch assembly 40 in the engaged configuration and the clutch assembly 50 in the disengaged configuration, the motor shaft 31 is rotationally coupled with the pump shaft 28, and the pump shaft 28 is able to rotate relative to the housing 34; and continuity along the drive shaft assembly 23 is maintained (i.e., the rotational force applied to the end or a portion of the drive shaft assembly 23 is substantially transmitted along the entire length of the drive shaft assembly 23). In this example, when the motor 17 is energized, the output shaft (not shown) of the motor 17 rotates in a first direction, so that when power is transmitted from the surface S to the well 12 ( Figure 1 ), this energizes the motor 17, thereby rotating the motor shaft 31 and the pump shaft 28 in a first direction, which in turn rotates the impeller in the pump 13. Furthermore, in this example, when the motor 17 is idling and not energized, and the column of liquid is at the wellhead of the impeller and is collected on the impeller, the motor shaft 31 is prevented from rotating in the second direction (i.e., the swirling direction) from the stationary head of the liquid on the impeller by the clutch assembly 50 being transformed into an engaged configuration by the rotation of the pump shaft 28 in the second direction relative to the housing 34. Preventing the rotation of the pump shaft 28 interrupts the rotational continuity of the drive shaft assembly 23, and prevents the induced rotation of the impeller in the pump 13 (due to the stationary head of the column of liquid) from being transmitted along the drive shaft assembly 23 to the motor shaft 31 and the motor 17. When the pump shaft 28 rotates in the second direction, the rotational continuity along the drive shaft assembly 23 is also interrupted by the clutch assembly 40; the clutch assembly is transformed into a disengaged configuration by the rotation of the pump shaft 28 in the second or clockwise direction, so that any rotational torque in the pump shaft 28 (such as caused by a fault in the clutch assembly 50) in the second direction is not transmitted to the motor shaft 31. In one example, the auxiliary member 21 defines a one-way clutch system that connects the drive shaft assembly 23 between the motor 17 and the pump 13 ( Figure 1 ) is restricted to a single direction of rotation.

[0037] Figure 8 The side cross-sectional view in FIG. 1 shows the well 12 ( Figure 1 ) is an alternative example of an ESP component 111 used in FIG. ESP component 111 is similar to Figure 2The assembly 11 includes a reverse rotation stop assist member 121 and a drive shaft assembly 123. The drive shaft assembly 123 includes a pump shaft 128 having a downhole end 130 and a pump shaft for connecting to the pump 13 ( Figure 1 ) wellhead end 129, the drive shaft assembly 123 also includes a motor shaft 131 having a receiver 132 shown coupled to end 130. An end 133 of the motor shaft 131 opposite to the receiver 132 is selectively coupled to the motor 17 ( Figure 1 ) connection. The outer housing 134 covers the drive shaft assembly 123. The shaft-to-shaft clutch 135 is shown as being located in an annulus between the pump shaft 128 and the inner surface of the receiver 132, and it provides selective coupling between the pump shaft 128 and the motor shaft 131. The shaft-to-shaft clutch 135 includes an inner race 1371-3 that is press-fit to the outer surface of the pump shaft 128, and an outer race 1391-3 that is press-fit to the inner surface of the receiver 132. The clutch 135 also includes a clutch assembly 1401-3 formed by mounting a clutch member 1411-3 and bearings 142, 143 between the races 1371-3, 1391-3. In one embodiment, the clutch assemblies 1401-3 are substantially coaxial with each other and are in axially adjacent contact. As shown, the clutch member 1411-3 is a sprag-type element and is similar to members 41A, 51A ( Figure 6 , Fig. 7A , Figure 7B ), bearing 142 is a spherical bearing or a ball bearing, and bearing 143 is a needle bearing or a roller bearing. Figure 8 In the example of , clutch assembly 1401,2 consists of a single row of clutch members 1411-3 between races 1371,2, 1391,2, and clutch assembly 1403 is shown as consisting of clutch members 1413 and bearings 142,143 axially stacked in an annulus between races 1373,1393.

[0038] The shaft-to-housing clutch 145 is shown as being located in an annulus between the pump shaft 128 and the inner surface of the housing 134, and it provides selective coupling between the pump shaft 128 and the housing 134. The shaft-to-housing clutch 145 includes an inner race 1471-3 that is press-fit to the outer surface of the pump shaft 128, and an outer race 1491-3 that is press-fit to the inner surface of the housing 134. The clutch 145 includes a clutch assembly 1501-3 formed by mounting a clutch member 1511-3 and bearings 152, 153 between the races 1471-3, 1491-3. As shown, the clutch member 1511-3 is a sprag type element and similar to the clutch member 1411-3, the bearing 152 is a spherical bearing or a ball bearing, and the bearing 153 is a needle bearing or a roller bearing. Figure 8In the example of , clutch assembly 1501,2 consists of a single row of clutch members 1511-3 between races 1471,2, 1491,2, and clutch assembly 1503 is formed by axially stacking clutch members 1513 and bearings 152,153 in the annular space between races 1373,1393.

[0039] exist Figure 8 In the embodiment of the present invention, the axial dimension of the clutch assembly 1403, 1503 exceeds the axial dimension of the clutch assembly 1401, 2, 1501, 2, and optionally, the clutch assemblies 1401-3, 15013 are substantially coaxial and axially abutting contact with each other. The advantage achieved by clutches 135, 145 having different types of clutch assemblies 1401-3, 1501-3 (i.e., some having only sprag-type elements and others having a combination of bearings and sprag-type elements) is that the size of the clutch 135, 145 can be reduced without reducing the structural capacity.

[0040] exist Figure 8 In the ESP component 111, similar to Figure 2 1, a downwardly facing shoulder 155 is formed in the pump shaft 128, thereby defining an axial rear stop for the clutch 135. A snap ring 156 is shown disposed in a groove 157 circumscribing the inner surface of the housing 134 and is used to axially support the clutch 145 within the housing 134. Figure 2 54. In the example shown, the clutch 145 can be removed from the housing by removing the snap ring 156. The ring 158 is shown as circumscribing the lower edge within the recess 132 and axially adjacent to the downhole end of the clutch 135. Figure 8 The space 159, the skirt 161, the thrust bearing 163, the base portion 164 and the journal bearing 165 are similar to Figure 2 The gap 59, skirt 61, thrust bearing 63, base portion 64 and journal bearing 65.

[0041] exist Figure 8Also shown in the example of the embodiment of the present invention is a passage 167, which is shown extending axially within a portion of the pump shaft 128 and intersecting a port 169 extending radially from the passage 167 through the outer surface of the pump shaft 128. An enlarged diameter portion of the passage 167 is formed in an end portion of the pump shaft 128 disposed in the recess 132 and adjacent to the space 159. The port 169 and the opening 170 provide communication between the passage 167 and the exterior of the pump shaft 128. A reservoir 171 is shown formed on the lower surface of the receiver 132 and facing the opening 170. A magnet 173 is retained in the reservoir 171 by a fastener 175. In the example, a cooling and / or lubricating fluid is circulated through the passage 167, wherein the flow of the fluid is caused by the rotation of the shaft 128; and metal particles in the fluid are captured by the magnet 173 and retained in the reservoir 171. Inner race 1471-3 is shown rotationally coupled to pump shaft 128 via an extended key 181 that fits into grooves formed axially in race 1471-3 and pump shaft 128. A hole 183 is shown formed through the bottom of recess 132; hole 183 includes threads 185 for inserting a bolt (not shown) to remove clutch 135 from within recess 132. Coupler 187 is shown for coupling motor shaft 131 to motor 17 ( Figure 1 ) of the output shaft (not shown), the connector 187 has a spline end 189 engaged with the end 133 of the motor shaft 131 and an opposite spline end 191 for engaging with the motor output shaft.

[0042] Therefore, the invention described herein is well adapted to accomplish these objectives and to achieve the objects and advantages mentioned, as well as other objects and advantages inherent therein. Although only the presently preferred embodiments of the invention are given for the purpose of disclosure, there are many changes in the details of the process for achieving the desired results. These and other similar modifications will be apparent to those skilled in the art and are intended to be encompassed within the spirit of the invention disclosed herein and within the scope of the appended claims.

Claims

1. An electric submersible pump ("ESP") system comprising: a drive shaft assembly, the drive shaft assembly comprising an elongated section; an electric motor coupled to an end of the drive shaft assembly and causing the drive shaft assembly to rotate in a first direction when energized; a pump coupled to an end of the drive shaft assembly distal from the motor; and a one-way clutch system located in the drive shaft assembly, wherein when the drive shaft assembly rotates in the first direction, the one-way clutch system is rotationally disengaged from the drive shaft assembly, and when the drive shaft assembly rotates in a second direction opposite to the first direction, the one-way clutch system is rotationally engaged with the drive shaft assembly, and the one-way clutch system comprises, a shaft-to-shaft clutch coupled between adjacent segments on an outer surface of one of the segments and an inner surface of an adjacent segment, A shaft-to-casing clutch is coupled between one of the sections and an outer casing.

2. The system of claim 1 , wherein one of the segments includes a pump shaft and another of the segments includes a motor shaft, the pump shaft having an end selectively coupled to an end of the motor shaft, wherein opposite ends of the pump shaft and the motor shaft are coupled to the pump and the motor, respectively.

3. The system of claim 2 wherein the shaft-to-housing clutch is selectively changeable between an engaged configuration and a disengaged configuration, wherein when in the engaged configuration the housing is rotationally coupled to the pump shaft via the shaft-to-housing clutch, and wherein when in the disengaged configuration the pump shaft is rotatable relative to the housing. 4 . The system of claim 3 , wherein changing the rotational direction of the pump shaft changes the shaft-to-housing clutch between the engaged configuration and the disengaged configuration.

5. The system of claim 2 wherein the shaft-to-shaft clutch is selectively changeable between an engaged configuration and a disengaged configuration, wherein when in the engaged configuration the motor shaft is rotationally coupled to the pump shaft via the shaft-to-shaft clutch, and wherein when in the disengaged configuration the pump shaft is rotatable relative to the motor shaft.

6. The system of claim 5, wherein changing the direction of rotation of the motor shaft changes the shaft-to-shaft clutch between the engaged configuration and the disengaged configuration.

7. The system of claim 2, wherein the motor shaft includes a receiver that receives an end of the pump shaft distal from the pump, and wherein the shaft-to-shaft clutch is disposed in the receiver.

8. The system of claim 7, wherein the shaft-to-shaft clutch comprises: an outer race press-fitted within the receiver; and an inner race press-fitted onto an outer surface of the pump shaft; and a sprag-type element located between the inner race and the outer race.

9. The system of claim 8, wherein the sprag-type element is a generally planar element pivotable about an axis substantially parallel to an axis of the ESP assembly.

10. A system according to claim 9, wherein the dimensions of the brace-type element are strategically designed so that when the extended width of the brace-type element is radially oriented from the axis, the opposite ends of the brace-type element are wedged between the inner race and the outer race, wherein in response to rotation of the outer race relative to the inner race in a first direction, the brace-type element is selectively oriented radially from the axis.

11. The system of claim 10, wherein the clutch assembly is in an engaged configuration when the sprag element is wedged between the inner race and the outer race and relative rotation of the outer race with respect to the inner race in a first direction is prevented.

12. A system according to claim 10, wherein the brace-type element is in sliding contact with the inner race and the outer race when the extended width of the brace-type element is oriented obliquely relative to the axis, and wherein in response to the outer race rotating relative to the inner race in a second direction opposite to the first direction, the brace-type element is selectively oriented obliquely relative to the axis.

13. A system according to claim 1, wherein the segments are in non-stop engagement when the segments are rotationally coupled to each other and are capable of rotating about an axis, and wherein the segments are in stop engagement when the one-way clutch is capable of selectively changing between a locked configuration in which one of the segments is rotationally fixed in position and a rotational configuration in which adjacent segments are able to rotate freely relative to each other.

14. An electric submersible pump ("ESP") system comprising: case; an electric motor that generates a rotational force in a first direction when energized; Pumps; and a drive shaft assembly coupled between the motor and the pump, And include, a pump shaft having an end coupled to the pump, a motor shaft having an end coupled to the motor, A shaft-to-shaft clutch comprising a plurality of sprag-type elements disposed in an annulus between the pump shaft and the motor shaft, the sprag-type elements being capable of changing between a radial orientation in which rotational torque is transmitted between the pump shaft and the motor shaft through the plurality of sprag-type elements and an inclined orientation in which the pump shaft and the motor shaft are capable of rotating relative to each other.

15. The system of claim 14, wherein the plurality of sprag-type elements comprises a first plurality of sprag-type elements, the system further comprising a shaft-to-housing clutch comprising a second plurality of sprag-type elements disposed in an annulus between the pump shaft and the housing, the second plurality of sprag-type elements being capable of changing between a radial orientation and an inclined orientation, wherein rotational torque is transmitted between the pump shaft and the housing through the second plurality of sprag-type elements, and wherein the pump shaft is capable of rotating relative to the housing in the inclined orientation.

16. The system of claim 15, wherein the first plurality of brace-type elements are in the radial orientation when the motor shaft is rotated in a first direction by the motor so that the pump shaft also rotates in the first direction, and wherein the second plurality of brace-type elements are in the inclined configuration when the pump shaft rotates in the first direction such that when the motor is energized, rotational torque from the motor is transmitted to the pump through the drive shaft assembly.

17. The system of claim 15, wherein when rotational torque is applied to the pump shaft in a second direction opposite to the first direction, the second plurality of brace-type elements are in the radial configuration, thereby rotationally coupling the pump shaft to the housing and preventing rotation of the pump shaft, wherein when the motor shaft is rotated in a first direction by the motor so that the pump shaft also rotates in the first direction, the first plurality of brace-type elements are in the radial orientation and such that when the motor is energized, rotational torque from the motor is transmitted to the pump through the drive shaft assembly.

18. The system of claim 14, wherein the pump shaft includes an axial passage, a port extending radially from the passage to an outer surface of the pump shaft, and an opening in the passage at a downhole end of the pump shaft, and wherein a magnetic reservoir is disposed proximate the opening such that as the pump shaft rotates, a fluid flow is introduced into the opening, through the passage, and out of the port receiving thermal energy from a bearing, and wherein metallic particles are drawn from the fluid flow and retained in the reservoir.

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