Hydrodynamic bearing alignment control systems and methods

Abstract

A system and method are provided for balancing a load received by a hydrodynamic bearing. The system comprises a base, a first pivot frame configured to rotate relative to the base along a first axis, a second pivot frame configured to rotate relative to the first pivot frame along a second axis, and a plurality of at least three sensors configured to measure at least one variable correlated to the alignment of the hydrodynamic bearing. The method involves using the sensors to detect misalignment and rotate at least one of the first and second pivot frames to adjust the alignment of the hydrodynamic bearing. Similar systems and methods using two sensors can be used to improve load balancing.

Description

Atty. Dkt. No. OU-23019WO HYDRODYNAMIC BEARING ALIGNMENT CONTROL SYSTEMS AND METHODS CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the filing benefit of U.S. Provisional Application No. 63 / 553,216 filed on February 14, 2024, the disclosure of which is incorporated herein by reference in its entirety. FIELD OF THE INVENTION

[0002] This disclosure relates to a system and method for actively balancing the distribution of hydrodynamic pressure acting on the pads of a thrust bearing. BACKGROUND OF THE INVENTION

[0003] Hydrodynamic thrust bearings, sometimes referred to as oil-film bearings, are designed to support axial loads in rotating shafts in the context of a mechanical assembly by separating the moving components with a thin film (i.e., layer) of oil or other suitable lubricant. Planar alignment between the smooth runner surface and the thrust face of the bearing is crucial for proper functionality. Alignment between the runner and bearing is typically achieved by virtue of high precision control applied to the mechanical components and their assembly. However, even the smallest deviation from the intended assembly alignment can cause uneven loading of the thrust bearing leading to wear and premature failure of the bearing. Accordingly, there is a need for improved systems and methods for maintaining alignment between the runner and the bearing. SUMMARY OF THE INVENTION

[0004] In a first aspect of the invention, a system configured to balance a load received by a hydrodynamic bearing is provided. The system comprises a runner; a base; the hydrodynamic bearing; a first pivot frame; a second pivot frame; and a plurality of sensors. With further respectAtty. Dkt. No. OU-23019WO to the runner, the runner includes a runner surface configured to interact with a first side of the hydrodynamic bearing. With further respect to the hydrodynamic bearing, the hydrodynamic bearing comprises: a plurality of bearing pads on the first side of the hydrodynamic bearing, each bearing pad comprising: a first bearing pad section comprising a taper depth; and a second bearing pad section that is configured to be planarly parallel to the runner surface when the hydrodynamic bearing is in operation. With further respect to the first pivot frame, it is configured to rotate the hydrodynamic bearing relative to the base along a first axis of rotation, wherein the first axis of rotation is perpendicular to the runner surface. With further respect to the second pivot frame, it is configured to rotate the hydrodynamic bearing relative to the first pivot frame along a second axis of rotation, wherein the second axis of rotation is perpendicular to the runner surface and the first axis of rotation. With respect to the plurality of sensors, each of the sensors is configured to measure at least one variable correlated to the alignment of the hydrodynamic bearing, comprising: a first sensor configured to measure a first measurement of the at least one variable at a first bearing pad; a second sensor configured to measure a second measurement of the at least one variable at a second bearing pad; and a third sensor configured to measure a third measurement of the at least one variable at a third bearing pad. It should be understood that, for the system set forth in this aspect of the invention, the first pivot frame and the second pivot frame are configured to rotate the hydrodynamic bearing in response to at least the first, second, and third measurements of the at least one variable until each measurement of the at least one variable is within a threshold of an average measurement of at least the first, second, and third measurement of the at least one variable.

[0005] In a second aspect of the invention, a method for balancing a load received by a hydrodynamic bearing comprising a plurality of bearing pads is provided. The method includesAtty. Dkt. No. OU-23019WO measuring, using a plurality of sensors, at least one variable at a plurality of bearing pads, comprising: measuring a first measurement of the at least one variable, using a first sensor, at a first bearing pad; measuring a second measurement of the at least one variable, using a second sensor, at a second bearing pad; and measuring a third measurement of the at least one variable, using a third sensor, at a third bearing pad. The method further involves determining, using a processor, an average measurement of the at least one variable using at least two of the measurements. The method further includes rotating the hydrodynamic bearing, using at least one of a first pivot frame configured to rotate along a first axis relative to a base and a second pivot frame configured to rotate relative to the first pivot frame along a second axis of rotation, in a manner selected from the group consisting of: (1) rotating the hydrodynamic bearing along the first axis of rotation, (2) rotating the hydrodynamic bearing along the second axis of rotation, and (3) rotating the hydrodynamic bearing along both the first axis of rotation and the second axis of rotation. With further respect to the second aspect of the invention, the first pivot frame is configured to rotate the hydrodynamic bearing along the first axis of rotation, and the second pivot frame is configured to rotate the hydrodynamic bearing along the second axis of rotation, wherein the first axis of rotation is perpendicular to the load received, and wherein the second axis of rotation is perpendicular to the load received and the first axis of rotation. Moreover, rotating the hydrodynamic bearing adjusts at least one of the first, second, and third measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement.

[0006] In a third aspect of the invention, a system configured to improve load balancing for a hydrodynamic bearing is provided. The system comprises a runner comprising a runner surface configured to interact with a first side of the hydrodynamic bearing. The system furtherAtty. Dkt. No. OU-23019WO comprises a base, the base comprising: the hydrodynamic bearing, wherein the hydrodynamic bearing comprises: a plurality of bearing pads on the first side of the hydrodynamic bearing, each bearing pad comprising: a first bearing pad section comprising a taper depth; and a second bearing pad section that is configured to be planarly parallel to the runner surface when the hydrodynamic bearing is in operation. At least one of the base or the system further comprises a first pivot frame configured to rotate the hydrodynamic bearing relative to the base along a first axis of rotation, wherein the first axis of rotation is perpendicular to the runner surface; and a second pivot frame configured to rotate the hydrodynamic bearing relative to the first pivot frame along a second axis of rotation, wherein the second axis of rotation is perpendicular to the runner surface and the first axis of rotation. The system further includes a plurality of sensors configured to measure at least one variable correlated to the alignment of the hydrodynamic bearing, comprising: a first sensor configured to measure a first measurement of the at least one variable at a first bearing pad of the plurality of bearing pads; and a second sensor configured to measure a second measurement of the at least one variable at a second bearing pad of the plurality of bearing pads; wherein the first pivot frame and the second pivot frame are configured to rotate the hydrodynamic bearing in response to the first and second measurements of the at least one variable until each measurement of the at least one variable is within a threshold of an average measurement of the first and second measurement of the at least one variable.

[0007] In a fourth aspect of the invention, a method for improving balance of a load received by a hydrodynamic bearing comprising a plurality of bearing pads is provided. The method includes measuring, using a plurality of sensors, at least one variable at a plurality of bearing pads, comprising: measuring a first measurement of the at least one variable, using a first sensor, received at a first bearing pad; and measuring a second measurement of the at least one variable,Atty. Dkt. No. OU-23019WO using a second sensor, received at a second bearing pad. The method further includes determining, using a processor, an average measurement of the at least one variable using the first and second measurements. The method further includes rotating the hydrodynamic bearing, using at least one of a first pivot frame configured to rotate along a first axis relative to a base and a second pivot frame configured to rotate relative to the first pivot frame along a second axis of rotation, in a manner selected from the group consisting of: (1) rotating the hydrodynamic bearing along the first axis of rotation; (2) rotating the hydrodynamic bearing along the second axis of rotation; and (3) rotating the hydrodynamic bearing along both the first axis of rotation and the second axis of rotation; wherein the first pivot frame is configured to rotate the hydrodynamic bearing along the first axis of rotation, and wherein the second pivot frame is configured to rotate the hydrodynamic bearing along the second axis of rotation; wherein the first axis of rotation is perpendicular to the load received, and wherein the second axis of rotation is perpendicular to the load received and the first axis of rotation, and wherein rotating the hydrodynamic bearing adjusts at least one of the first and second measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement.

[0008] While the present invention has been illustrated by the description of one or more aspects thereof, and while the aspects have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described in this brief summary.Atty. Dkt. No. OU-23019WO Accordingly, departures may be made from such details without departing from the scope or spirit of Applicants’ general inventive concept. DEFINITIONS

[0009] As used throughout the specification, the following terms and variables are to be understood as having the following meanings unless otherwise indicated explicitly when used.

[0010] As used herein, “between” is understood to mean “greater than or equal to the lower value and less than or equal to the higher value.”

[0011] As used herein, “pivot frame” is a term understood to encompass various devices capable of rotating a hydrodynamic bearing along an axis of rotation, including the pivot frames shown and described herein capable of rotating the hydrodynamic bearing indirectly (e.g., rotating a frame, which rotates a bearing carriage, which rotates the bearing), devices which rotate the hydrodynamic bearing directly, other similarly suitable devices capable of rotating a hydrodynamic bearing, devices capable of raising and lowering a height of a hydrodynamic bearing on both sides of an axis, other similarly suitable devices capable of raising and lowering a height of a hydrodynamic bearing on both sides of an axis, or a combination thereof. However, it would be understood by those having skill in the art that there are other means suitable for enabling rotating of the hydrodynamic bearing that could be used instead of the exemplary embodiment shown here.

[0012] As used herein, “MOFT” is understood to mean “minimum oil film thickness.” This term may be used interchangeably to support embodiments described or claimed herein using the broader term “MLLT”, which is understood to mean “minimum lubricant layer thickness” in embodiments of the invention where the broader category of lubricants is described or claimed.

[0013] As used herein, “x” is a variable that represents the length of a bearing pad.Atty. Dkt. No. OU-23019WO

[0014] As used herein, “P” is a variable that represents hydrodynamic pressure while “^^” is a variable that represents non-dimensional hydrodynamic pressure.

[0015] As used herein, “τ” is a variable that represents shear stress.

[0016] As used herein, “C” is a variable that represents mean oil film thickness. Alternatively, in embodiments referring more generally to a lubricant instead of oil, “C” is a variable that represents mean lubricant layer thickness.

[0017] As used herein, “η” is a variable that represents viscosity of the lubricant.

[0018] As used herein, “u” is a variable that represents velocity.

[0019] As used herein, “X” or “x” is a variable that represents circumferential length of the bearing pad while “^̅” is a variable that represents non-dimensional circumferential length of the bearing pad.

[0020] As used herein, “Y” or “y” is a variable that represents radial width of the bearing pad while “^^” is a variable that represents non-dimensional radial width of the bearing pad.

[0021] As used herein, “h” is a variable used to represent minimum oil film thickness (or, in embodiments referring more generally to a lubricant, minimum lubricant layer thickness) while “ℎ^” is a variable used to represent non-dimensional minimum oil film thickness (or, in embodiments referring more generally to a lubricant, non-dimensional minimum lubricant layer thickness).

[0022] As used herein, “t” is a variable that represents time while “^”̅is a variable that represents non-dimensional time. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general descriptionAtty. Dkt. No. OU-23019WO of the invention given above, and the detailed description given below, serve to explain the principles of the invention. Similar reference numerals are used to indicate similar features throughout the various figures of the drawings.

[0024] FIG. 1 is a perspective exploded view of the system according to an embodiment of the invention.

[0025] FIG. 2A is a cross-sectional view of the system according to an embodiment of the invention.

[0026] FIG. 2B is a cross-sectional view of the system according to another embodiment of the invention.

[0027] FIG.3 is a partial front view of a portion of the system with another enlarged partial view of the system according to an embodiment of the invention.

[0028] FIGS.4A-C show three different views of an embodiment of the invention. FIG.4A is a perspective view of a portion of the system. FIG. 4B is a top view of the hydrodynamic bearing and proximity sensor. FIG.4C is a bottom view of the same hydrodynamic bearing and proximity sensor.

[0029] FIGS. 5A-5D show various alternate embodiments of the hydrodynamic bearing according to illustrative embodiments of the invention. FIGS. 5A-5C are top views of hydrodynamic bearings showing various placements for sensor holes and proximity sensors according to embodiments of the invention. FIG. 5D is a bottom view showing placement of a plurality of thermocouple holes according to an embodiment of the invention.

[0030] FIGS. 6A-C show top views according to various illustrative alternate embodiments of the hydrodynamic bearings having different numbers of bearing pads and three sensors at various positions relative to the hydrodynamic bearing.Atty. Dkt. No. OU-23019WO

[0031] FIGS. 7A-D show top views according to various illustrative alternate embodiments of the hydrodynamic bearings having different numbers of bearing pads and sensors at various positions relative to each and every hydrodynamic bearing. FIG.7A shows an embodiment with four bearing pads and sensors. FIG.7B shows an embodiment with six bearing pads and sensors. FIG. 7C shows an embodiment with eight bearing pads and sensors. FIG. 7D shows an embodiment with twelve bearing pads and sensors.

[0032] FIGS. 8A-D show top views according to various illustrative alternate embodiments of the hydrodynamic bearings having different numbers of bearing pads and two sensors at various positions relative to the hydrodynamic bearing.

[0033] FIG. 9 is a simplified cross-sectional view demonstrating simplified linear operation of a single bearing pad and runner interface.

[0034] FIG. 10 is a system diagram showing the connection of the system to an oil control system and a user interface and control window according to an embodiment of the invention.

[0035] FIG. 11 is a graph showing real-time static load balancing data measuring both specific load and oil film pressure measured over time for a system according to the embodiment shown in FIGS.1 and 4A-C.

[0036] FIG. 12 is a graph showing real-time data measuring both specific load and oil film pressure for a varying load measured overtime for a system according to the embodiment shown in FIGS.1 and 4A-C without use of the load balancing system.

[0037] FIG. 13 is a graph showing real-time data measuring both specific load and oil film pressure for a varying load measured overtime for a system according to the embodiment shown in FIGS.1 and 4A-C using the load balancing system.Atty. Dkt. No. OU-23019WO

[0038] FIG. 14 is an array of measured pressure graphs, comparing analytically determined data (line) and experimentally derived data (3 data points) for pressure at a leading pressure sensor (L), a middle pressure sensor (M), and a trailing pressure sensor (T) measured during operation of the load balancing system at various taper depths arranged across the y axis (0.0005”, 0.0010”, 0.0015”, 0.0020”, and 0.0025”) and at various applied loads arranged across the y-axis (100lbf, 200 lbf, 300 lbf, 400 lbf, and 500 lbf) with a runner rotating at 1500 RPM.

[0039] FIG. 15 is an array of measured pressure graphs, comparing analytically determined data (line) and experimentally derived data (3 data points) for pressure at a leading pressure sensor (L), a middle pressure sensor (M), and a trailing pressure sensor (T) measured during operation of the load balancing system at various taper depths arranged across the y axis (0.0005”, 0.0010”, 0.0015”, 0.0020”, and 0.0025”) and at various applied loads arranged across the y-axis (100lbf, 200 lbf, 300 lbf, 400 lbf, and 500 lbf) with a runner rotating at 3000 RPM.

[0040] FIG. 16 is an array of measured pressure graphs, comparing analytically determined data (line) and experimentally derived data (3 data points) for pressure at a leading pressure sensor (L), a middle pressure sensor (M), and a trailing pressure sensor (T) measured during operation of the load balancing system at various taper depths arranged across the y axis (0.0005”, 0.0010”, 0.0015”, 0.0020”, and 0.0025”) and at various applied loads arranged across the y-axis (100lbf, 200 lbf, 300 lbf, 400 lbf, and 500 lbf) with a runner rotating at 4500 RPM.

[0041] FIG.17 is an array of measured pressure graphs, comparing analytically determined data (line) and experimentally derived data (3 data points) for pressure at a leading pressure sensor (L), a middle pressure sensor (M), and a trailing pressure sensor (T) measured during operation of the load balancing system at various taper depths arranged across the y axisAtty. Dkt. No. OU-23019WO (0.0005”, 0.0010”, 0.0015”, 0.0020”, and 0.0025”) and at various applied loads arranged across the y-axis (100lbf, 200 lbf, 300 lbf, 400 lbf, and 500 lbf) with a runner rotating at 6000 RPM. DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0042] As stated above, embodiments of systems and methods of the invention are designed to increase balancing of a load or to balance a load applied to a hydrodynamic bearing. As shown in FIGS.1-3, the system 10 comprises a base 12, a first axis pivot frame 14, a second axis pivot frame 16, a bearing carriage 18, and a bearing instrument assembly 20. As shown, the system 10 is configured to interact with a runner 22 having a runner surface 24 at the hydrodynamic bearing 26, specifically the hydrodynamic bearing surface 28. In one embodiment, the base 12 is connected to the first pivot frame 14, the first pivot frame 14 is connected to the second pivot frame 16, the second pivot frame is connected to the bearing carriage 18, and the bearing carriage is connected to the bearing instrument assembly 20. In such embodiments, there may be intermediate components or devices interspersed between the connection points described above. In another embodiment, the base 12 is directly connected to the first pivot frame 14, the first pivot frame 14 is directly connected to the second pivot frame 16, the second pivot frame is directly connected to the bearing carriage 18, and the bearing carriage is directly connected to the bearing instrument assembly 20.

[0043] With further respect to the system 10, the base 12 may be fixed relative to other adjacent components such that it does not significantly move during operation of the system 10. Additionally, as shown in FIGS.2A and 2B, the base 12 further comprises a force element 13a or 13b depending on configuration of the system 10. As shown in FIG.2A, the force element 13a is configured to receive an applied load during operation of the system 10. In one such embodiment, the runner 22 is configured to apply a load received at or by the force element 13a.Atty. Dkt. No. OU-23019WO As shown, the force element 13a is a spring. In embodiments wherein the spring 13a is used, it may be swapped out depending on the anticipated load requirement based on the spring constant and other relevant properties of the spring 13a. However, in alternate embodiments not shown here, other devices known in the art to be useful for resisting an applied force or receiving an applied force may be used. As shown in FIG.2B, the force element 13b is configured to apply a load during operation of the system 10, wherein the load is received at or by the runner 22. As shown, the force element 13b is a piston. However, in alternate embodiments of the invention not shown here, other devices known in the art to be useful for applying a force may be used.

[0044] With further respect to FIGS. 1-3, the first axis pivot frame 14 and the second axis pivot frame 16 are configured to rotate along a first axis 15 and a second axis 17 respectively. As shown, the first axis pivot frame 14 is configured to rotate relative to the base 12, and the second axis pivot frame 16 is configured to rotate relative to the first pivot frame 14. In one such embodiment, the first axis pivot frame 14 is an x-axis pivot frame configured to rotate along a first axis 15 that is an x-axis and the second axis pivot frame 16 is a y-axis pivot frame configured to rotate along a second axis 17 that is a y-axis. In an alternate embodiment, the first axis pivot frame 14 is a y-axis pivot frame configured to rotate along a first axis 15 that is a y- axis and the second axis pivot frame 16 is an x-axis pivot frame configured to rotate along a second axis 17 that is an x-axis.

[0045] Rotating at least one of the pivot frames 14, 16 is configured to rotate a component selected from the list consisting of the bearing carriage 18, the bearing instrument assembly 20, the hydrodynamic bearing 26, or a combination thereof in the same manner. The angle of tilt of these independent pivot axes 15, 17 is controlled by a first motor 5 configured to adjust the rotation of the first axis 15 and a second motor 7 configured to adjust the rotation of the secondAtty. Dkt. No. OU-23019WO axis 17. As shown, the first motor 5 is a stepper motor is configured to adjust the relative height of a portion of the first pivot frame 14 on a first wall perpendicular to a second wall, wherein the second wall comprises a plurality of pivot plates 2 connected to the first pivot frame 14, each pivot plate 2 having a pivot slot 4 and a pivot point 6, wherein the pivot slot 4 is configured to receive a pin (not shown), and wherein that pin is configured to travel along the pivot slot 4 as the first pivot frame 14 pivots about the pivot point 6. As shown, the second motor 7 is a stepper motor is configured to adjust the relative height of a portion of the second pivot frame 16 on the first wall perpendicular to the first wall, wherein the first wall comprises a plurality of pivot plates 2 connected to the second pivot frame 16, each pivot plate 2 having a pivot slot 4 and a pivot point 6, wherein the pivot slot 4 is configured to receive a pin (not shown), and wherein that pin is configured to travel along the pivot slot 4 as the first pivot frame 14 pivots about the pivot point 6. Although the motors 5 and 7 shown are stepper motors, this is not intended to be a limiting aspect of the present disclosure.

[0046] With further respect to the connection between the second pivot frame 16 and the bearing carriage 18, the second pivot frame 16 comprises at least one guide rail 21 and the bearing carriage comprises at least one linear bearing 23 configured to slidably receive the at least one guide rail 21. The slidable connection between the at least one guide rail 21 and the at least one linear bearing 23 allows the bearing carriage 18, bearing assembly 20, and hydrodynamic bearing 26 to move in line with the force received or applied by the force elements 13a, 13b, and the runner 22. In one embodiment, the second pivot frame 16 comprises a plurality of guide rails 21. In one embodiment, the bearing carriage 18 comprises a plurality of linear bearings 23. In an alternate embodiment, the bearing carriage 18 comprises a plurality of linear bearings 23, wherein a plurality of linear bearings 23 is configured to interact with each ofAtty. Dkt. No. OU-23019WO a plurality of guiderails 21. As shown, the bearing carriage 18 uses eight linear bearings 23, with four sets of two linear bearings 23 configured to receive each of four guide rails 21 attached to the second pivot frame 16, which dictate the orientation of the bearing carriage 18.

[0047] As shown in FIG. 2A, the force element 13a comprises springs seated in the base which are capped by load cells (not shown) which support the weight of the bearing carriage 18. As thrust load is introduced to the hydrodynamic bearing 26, the load cells measure the active force which is linearly proportional to the displacement of the springs. All thrust load is transmitted through the bearing carriage via steel support frame, so the T-slot aluminum does not transmit the thrust load.

[0048] With further respect to FIGS. 1-3, the bearing instrument assembly 20 is held in the bearing carriage 18 with a hydrodynamic bearing 26 at the top. In one embodiment, the hydrodynamic bearing 26 rests atop a bearing plate 25 that is directly connected to the bearing carriage 18. The hydrodynamic bearing surface 28 is configured to interface with the runner surface 24 with a lubricant layer separating the two during operation of the system and method (not shown). Accordingly, the bearing instrument assembly comprises a bearing instrument assembly lubricant inlet 30 configured to add lubricant to the interface between the runner surface 24 and the hydrodynamic bearing surface 28 and a hydrodynamic bearing lubricant outlet 32 configured to receive lubricant exiting the interface between the runner surface 24 and the hydrodynamic bearing surface 28. Optionally, the bearing plate 25 may comprise a lubricant gutter configured to collect lubricant exiting the interface between the runner surface 24 and the hydrodynamic bearing surface 28 and direct the flow of lubricant therefrom toward the hydrodynamic bearing lubricant outlet 32. In one embodiment, the bearing instrument assembly 20 comprises an optional lubricant shield 34 configured to contain oil runoff and / or splatter fromAtty. Dkt. No. OU-23019WO the hydrodynamic bearing. In a further embodiment thereof, the optional lubricant shield 34 comprises a transparent material, such as glass or plastic, allowing a user to view the lubrication interface during operation.

[0049] The bearing instrument assembly 20 may comprise one or more sensors. In one such embodiment, the bearing instrument assembly 20 comprises at least one proximity sensor 36. In one embodiment, the bearing instrument assembly comprises a plurality of proximity sensors 36. In such embodiments, each proximity sensor 36 comprises a sensor selected from the list consisting of an Eddy current sensor (capable of measuring relative height, oil film thickness, etc.), a laser sensor, an ultrasonic sensor, another suitable sensor for determining proximity, or a combination thereof. Additionally or alternatively, the bearing instrument assembly 20 comprises at least one pressure sensor 37. In one embodiment, the bearing instrument assembly 20 comprises a plurality of pressure sensors 37. In such embodiments, each pressure sensor 37 may be selected from the list consisting of a pressure transducer, some other suitable sensor for measuring pressure received, or a combination thereof. Additionally or alternatively, the bearing instrument assembly 20 comprises at least one temperature sensor 39. In one embodiment, the bearing instrument assembly 20 comprises a plurality of temperature sensors 39. In such embodiments, each temperature sensor 39 may be selected from the list consisting of a thermocouple, some other suitable sensor for measuring temperature, or a combination thereof.

[0050] With respect to sensors used in the bearing assembly 20, in one embodiment, the bearing assembly 20 consists of only at least one proximity sensor 36. In another embodiment, the bearing assembly 20 consists of only at least one pressure sensor 37. In another embodiment, the bearing assembly 20 consists of only at least one temperature sensor 39. In another embodiment, the bearing assembly 20 consists of only at least one proximity sensor 36 and atAtty. Dkt. No. OU-23019WO least one pressure sensor 37. In another embodiment, the bearing assembly 20 consists of only at least one proximity sensor 36 and at least one temperature sensor 39. In another embodiment, the bearing assembly 20 consists of only at least one proximity sensor 36, at least one pressure sensor 37, and at least one temperature sensor 39. In another embodiment, the bearing assembly 20 consists of only at least one temperature sensor 39 and at least one pressure sensor 37.

[0051] With respect to sensors used in the bearing assembly 20, in one embodiment, the bearing assembly 20 consists of only a plurality of proximity sensors 36. In another embodiment, the bearing assembly 20 consists of only a plurality of pressure sensors 37. In another embodiment, the bearing assembly 20 consists of only a plurality of temperature sensors 39. In another embodiment, the bearing assembly 20 consists of only a plurality of proximity sensors 36 and a plurality of pressure sensors 37. In another embodiment, the bearing assembly 20 consists of only a plurality of proximity sensors 36 and a plurality of temperature sensors 39. In another embodiment, the bearing assembly 20 consists of only a plurality of proximity sensors 36, a plurality of pressure sensors 37, and a plurality of temperature sensors 39. In another embodiment, the bearing assembly 20 consists of only a plurality of temperature sensors 39 and a plurality of pressure sensors 37.

[0052] With further respect to embodiments including at least one proximity sensor 36, a proximity sensor 36 may be positioned on the backing plate 25 proximate the hydrodynamic bearing. By proximate, what is meant is that the proximity sensor 36 is positioned in a manner that it is operable to measure the characteristic or at least one variable. The proximity sensor 36 may be a sensor selected from the list consisting of an Eddy current sensor, a laser sensor, an ultrasonic sensor, some other similarly suitable proximity sensor, or a combination thereof.Atty. Dkt. No. OU-23019WO

[0053] With further respect to embodiments including at least one pressure sensor 37, the pressure sensors 37 may be coupled to a portion of the backing plate 25, hydrodynamic bearing 26, hydrodynamic bearing pad 44 (discussed further below) where pressure is measured. The pressure sensor 37 could be selected from the list consisting of a pressure transducer, a strain gauge, a thin film pressure sensor, a flexible pressure sensor, some other similarly suitable pressure sensor, or a combination thereof.

[0054] With further respect to embodiments including at least one temperature sensor 39, temperature sensors 39 may be coupled to a portion of the backing plate 25, hydrodynamic bearing 26, hydrodynamic bearing pad 44 (discussed further below) where temperature is measured. Additionally or alternatively, a temperature sensor 39 may be coupled to a point proximate the hydrodynamic bearing instrument assembly lubricant inlet 30 to measure the temperature of lubricant entering the system 10 (not shown). Additionally or alternatively, a temperature sensor 39 may be coupled to a point proximate the hydrodynamic bearing lubricant inlet 29 (discussed further below) to measure the temperature of lubricant entering the interface between the runner surface 24 and the hydrodynamic bearing surface 28 (not shown). Additionally or alternatively, a temperature sensor 39 may be coupled to a point proximate the hydrodynamic bearing instrument assembly lubricant outlet 32 to measure the temperature of lubricant exiting the system 10 (not shown). Additionally or alternatively, a temperature sensor 39 may be coupled to a point proximate the hydrodynamic bearing lubricant outlet 31 to measure the temperature of lubricant exiting the interface between the runner surface 24 and the hydrodynamic bearing surface 28 (not shown).

[0055] With reference to FIGS. 4A-4C, the hydrodynamic bearing 26 is shown in more detail. The hydrodynamic bearing 26 comprises a recessed portion 38 and a raised portion 40.Atty. Dkt. No. OU-23019WO The recessed portion 38 comprises the hydrodynamic bearing lubricant inlet 29 and may optionally comprise at least one mounting hole 42 configured to allow for secure connection between the hydrodynamic bearing 26 and the bearing assembly 20 such as, for example, at the bearing plate 25. The raised portion 40 comprises a plurality of bearing pads 44, each bearing pad 44 comprising a tapered portion 46 and a flat portion 48. As shown, each of the bearing pads 44 are separated by a groove that functions as the hydrodynamic bearing lubricant outlet 31 during operation of the system 10. Additionally, the backing plate 25 comprises a temperature sensor location 57, wherein the temperature sensor location 57 is configured to measure the temperature of the lubricant.

[0056] Moreover, one or more of the bearing pads 44 may comprise a hole 50, 52, and / or 54 configured to enable operation of a sensor. For example, one or more bearing pad 44 may comprise a middle sensor hole 50 configured to enable operation of a sensor to measure at least one variable at an approximately central point of the bearing pad 44. Additionally or alternatively, one or more bearing pad 44 may comprise a leading sensor hole 52 configured to enable operation of a sensor to measure at least one variable at a point proximate a leading edge of the bearing pad 44 (i.e., a portion of the bearing pad 44 proximate a side configured to first receive a rotating portion of the runner 22). Additionally or alternatively, one or more bearing pad 44 may comprise a trailing sensor hole 54 configured to enable operation of a sensor to measure at least one variable at a point proximate a trailing edge of the bearing pad 44 (i.e., a portion of the bearing pad 44 proximate a side configured to last receive a rotating portion of the runner 22). As shown in FIGS. 4A-8D, leading sensor holes 52 are positioned at points proximate the lowest point of the tapered portion 46 and trailing sensor holes 54 are positioned at points proximate the flat portion 48 because, for the purposes of simplifying illustrations, theAtty. Dkt. No. OU-23019WO runner 22 is assumed to rotate in a clockwise direction and the hydrodynamic bearing pads 44 have a single tapered portion 46. In alternate embodiments of the invention depicted in FIGS. 4A-8D not shown here, the runner 22 could rotate in a counterclockwise direction and the tapering of the hydrodynamic pads 44 could rise in a counterclockwise direction (as opposed to raising in a clockwise direction as shown). In another alternate embodiment of the invention depicted in FIGS. 4A-8D not shown here, the runner 22 could be configured to rotate in either direction and the hydrodynamic pads 44 could have a middle flat portion 48 with tapered portions 46 on either side of the flat portion 48.

[0057] With further respect to FIGS.4A-4C, an embodiment of the hydrodynamic bearing 26 used in an embodiment the system 10 tested in the Experimental section below is shown in detail. With reference to FIGS. 4A and 4B, the hydrodynamic bearing 26 comprises eight equally sized and spaced bearing pads 44, each separated by a hydrodynamic bearing lubricant outlet 31, with three middle sensor holes 50 on a first, third, and fifth bearing pad 44 (i.e., at 90° angles or at 180° angles to each other), an optional leading sensor hole 52 on a second bearing pad 44, and an optional trailing sensor hole 54 on a fourth bearing pad 44. Moreover, proximate to the sixth bearing pad, there is a proximity sensor 36. With reference to the bottom view shown in FIG.4C, it can be seen that each of the middle sensor holes 50 and the optional leading and trailing sensor holes 52, 54, is configured to enable operation of a pressure sensor 37 (not shown) and have an o-ring situated on the backside of the hydrodynamic bearing 26. Moreover, there are a plurality of optional blind holes 58 on the backside of the hydrodynamic bearing 26 configured to permit insertion of a sensor to measure a variable related to the hydrodynamic bearing without boring completely through to the hydrodynamic bearing surface 28. In oneAtty. Dkt. No. OU-23019WO embodiment, such as in the Examples discussed further below, these blind holes 58 receive temperature sensors 39 (not shown) such as, for example, a thermocouple.

[0058] With respect to FIGS. 4A-4C, the three pressure sensors 37 (not shown) coupled to the three middle sensor holes 50 are used to measure three instances of the at least one variable (pressure) to enable the system 10 to balance the load received at the interface of the hydrodynamic bearing 26 and the runner 22. With respect to FIGS. 5A-5D, alternate embodiments of the hydrodynamic bearings enabling the system 10 to balance a load other than the embodiment used in the Examples below are shown to more generally illustrate important aspects of the invention. Generally speaking, it is important that the sensors used to measure the multiple instances of the at least one variable are positioned at relatively equivalent portions of the hydrodynamic bearing pads 44. As shown in FIG.5A, each of the middle sensor holes 50 of FIGS.4A-C are replaced with leading sensor holes 52. As shown in FIG.5B, each of the middle sensor holes 50 of FIGS. 4A-C are replaced with trailing sensor holes 54. As shown in FIG.5C, each of the middle sensor holes 50 of FIGS.4A-C are replaced with proximity sensors 36 at the periphery of the hydrodynamic bearing pads 44. As shown in FIG. 5D, each of the middle sensor holes 50 of FIGS. 4A-C are replaced with blind holes 58 on the back side of the hydrodynamic bearing 26. With reference to FIGS. 6A-8D below, any of the type of sensor adapting locations depicted in FIGS. 4A-5D (e.g., proximity sensor 36, middle sensor hole 50, leading sensor hole 52, trailing sensor hole 54, and / or blind hole 58) may be used for implementing sensors or sensor adapting locations for the embodiments shown in FIGS. 6A-8D instead of the embodiments explicitly disclosed.

[0059] In each of the embodiments shown in FIGS. 5A-5D, the three sensor adapting locations 52, 54, 58 or sensors 36 are separated by 90° or by 180° relative to the top and bottomAtty. Dkt. No. OU-23019WO views shown. However, as shown in FIGS. 6A-6C, a greater or lesser number of bearing pads 44 may be included, which may even impact the relative locations of the sensor adapting locations or sensors relative to the other sensors. As shown in FIG.6A, a hydrodynamic bearing 26 may only include 4 bearing pads, with three sensor locations 36 and / or sensor adapting locations 50 shown being separated by 90° or by 180° relative to the top view shown. As shown in FIG. 6B, a hydrodynamic bearing 26 may only include 6 bearing pads, with three sensor locations 36 and / or sensor adapting locations 50 shown being separated by 120° relative to the top view shown. As shown in FIG.6C, a hydrodynamic bearing 26 may include 12 bearing pads, with three sensor locations 36 and / or sensor adapting locations 50 shown being separated by 90° and / or 180° relative to the top view shown. Alternatively, the hydrodynamic bearing shown in FIG. 6C could have positioned the sensor or sensor adapting locations being separated by 120° instead and still have positional symmetry on different bearing pads. As a general rule, hydrodynamic bearings may have a number of bearing pads equal to a multiple of 4 (4, 8, 12, 16, 20, … 60, etc.). In such embodiments, the sensor locations and / or sensor adapting locations may be separated by 90° and / or 180° relative to the top view shown. Alternatively, as another general rule, hydrodynamic bearings may have a number of bearing pads equal to a multiple of 3 (3, 6, 9, 12, … 60, etc.). In such embodiments, the sensor locations and / or sensor adapting locations may be separated by 120° relative to the top view shown.

[0060] As shown in FIGS. 7A-7D, a number of sensors or sensor adapting locations greater than or equal to 3 may be used. In the embodiments shown in FIGS. 7A-7D, each bearing pad shows a sensor adapting location (the middle sensor hole 50) on each bearing pad 44. FIG. 7A shows an embodiment with four bearing pads and sensors. FIG. 7B shows an embodiment with six bearing pads and sensors. FIG. 7C shows an embodiment with eight bearing pads andAtty. Dkt. No. OU-23019WO sensors. FIG.7D shows an embodiment with twelve bearing pads and sensors. Each has both an optional middle sensor hole 50 and an optional proximity sensor 36 located proximate each bearing pad 44. In some embodiments of the above FIGS. 7A-7D, each of the bearing pads 44 have the same type of sensor. In other embodiments of the above FIGS. 7A-7D, some bearing pads 44 include one type of sensor while other bearing pads include another type of sensor. It should be understood that the exact number of bearing pads 44 is not a limiting aspect of the present invention provided that there are at least two bearing pads 44. While hydraulic bearings 26 having each exact number of bearing pads are not explicitly shown, hydraulic bearings 26 having 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, …, 60, … 120, or greater numbers still of bearing pads 44 having at least 3 sensors (or, alternatively, at least one sensor per bearing pad 44) may be used in accordance with the present invention.

[0061] With reference to FIGS. 8A-8D, hydrodynamic bearings 26 not useful for all embodiments of the invention are depicted. While embodiments of the hydrodynamic bearings 26 having at least 3 sensors or sensor adapting locations can be used to balance a load (discussed further below), the embodiments shown here only comprise two sensors or sensor adapting locations. Accordingly, it may not always be possible to measure enough variables to represent an entire planar surface which can be correlated with the planar orientation of the hydrodynamic bearing surface. However, it is possible to use two sensors or sensor adapting locations to measure the at least one variable to at least improve the balancing of a load as shown in the embodiments 8A-D. As shown in FIG. 8A, the two middle sensor holes 50 are located on opposite sides of the hydrodynamic bearing 26 (180°). As shown in FIG. 8B, the two middle sensor holes 50 are positioned at 90° relative to the top side view shown. As shown in FIG. 8C, the two middle sensor holes 50 are positioned at 45° relative to the top side view shown. AsAtty. Dkt. No. OU-23019WO shown in FIG.8D, the two middle sensor holes 50 are positioned at 120° relative to the top side view shown.

[0062] With reference to FIG. 10, the interconnection between the system 10, a lubricant conditioning system 60, and a user interface / control is shown. The lubricant conditioning system 60 comprises lubricant source 62 configured to pass through a heater 64 configured to heat the lubricant prior to entry into the system 10 at the bearing instrument assembly lubricant inlet 30 (not shown). The heater 64 may comprise any conventional means of heating a fluid, including but not limited to air heating, convection heating, surface heating, some other conventional means of heating a fluid, or a combination thereof. Subsequent to leaving the system 10 at the bearing instrument assembly lubricant outlet 32 (not shown), the lubricant is received by a heat exchanger 66 configured to cool the lubricant using the cooled fluid source 68. The cooled fluid source 68 used for the heat exchanger 66 may comprise a liquid (e.g., a water cooler) or a gas (e.g., an air cooler). Following the heat exchanger 66, the cooled lubricant is returned to the lubricant source 62 via a pump speed controller 70.

[0063] There is also a user interface and control 72 coupled to the system 10 and the lubricant conditioning system 60. The user interface 72 is coupled to a processor (not shown) which receives measurements of the at least one variable measured during operation of the system 10 and graphically displays relevant data 74 on the user interface and control. This relevant data 74 may include, but is not limited to, pressure received at one or more bearing pad, temperature of one or more bearing pad, temperature of the lubricant at the lubricant inlet 29 and / or 30, temperature of the lubricant at the lubricant outlet 31 and / or 32, lubricant pressure, bearing alignment data, thrust load, friction torque, current using an eddy current sensor, relative height of one or more bearing pad 44 using a proximity sensor 36, proximity of the runnerAtty. Dkt. No. OU-23019WO surface 24 relative to one or more bearing pad 44 using a proximity sensor 36, MOFT, MLLT, actual oil film thickness, actual lubricant layer thickness, an average of multiple instances of one of the above measurements, some other relevant data 74, or a combination thereof.

[0064] With reference again to the system 10, even small static misalignments between the runner surface 24 and thrust bearing surface 28 can result in significant variance of load distribution across the bearing pads 44. This misalignment leads to edge loading of the bearing which can result in accelerated wear and damage. Further, since numerical methods used typically rely on the assumption that the bearing is aligned with the runner and the thrust load is evenly distributed across the bearing after a certain period of time, the misaligned experimental results did not show consistent agreement to the numerical predictions. Thus, system 10 was designed to maintain even thrust load distribution resulting in mitigated surface wear and better agreement between experimental and numerical pressure data.

[0065] The system 10 works by manipulating the orientation of the thrust bearing surface 28 based on active measurements of at least one variable. The at least one variable may be any variable that is correlated with the alignment of the hydrodynamic bearing surface 28 with the runner surface 24. In one embodiment, the at least one variable is pressure received at a plurality of bearing pads 44. In another embodiment, the at least one variable is temperature measured proximate the surface of a plurality of bearing pads 44 (e.g., at a blind hole 58). In yet another embodiment, the at least one variable is proximity to the runner surface 24 measured from a location proximate to a plurality of bearing pads 44. In yet another embodiment, the at least one variable is relative height of a plurality of bearing pads 44 measured using a plurality of proximity sensors.Atty. Dkt. No. OU-23019WO

[0066] Where previous hydrodynamic thrust bearing alignment systems required independent spherical hydrostatic bearing system to balance load on the test bearing, this system uses one of the variables described above, motors 5, 7 configured to rotate at least one of the pivot frames 14, 16 along an axis of rotation 15, 17, and basic microcontroller programming. Figure 4A shows hydrodynamic bearing orientation and rotational degrees of freedom using the pivot frames 14, 16.

[0067] In one embodiment, the system 10 is configured to process using a processor three measurements from three measurement locations (M1, M2, M3) (e.g., middle sensor hole 50, leading sensor hole 52, trailing sensor hole 54, blind hole 58, proximity sensor 36). M1, M2, and M3 can be positioned in any of the locations disclosed above for FIGS. 4A-7D. In one such embodiment, M1, M2, and M3 are offset by 90 degrees and placed at the center of the respective bearing pads 44. This creates a 3-point balancing scheme to ensure that all bearing pads 44 are experiencing the same share of thrust load and thus closely aligned characteristic hydrodynamic pressure profiles. Rotational orientation of the bearing about the second axis 17 is controlled by the second motor 7 which pushes or pulls at the base of the bearing carriage 18 with respect to the first pivot frame 14 using a lead screw. Since the bearing carriage 18 translates vertically as load is changed, the second motor 7 is mounted on the guide rails 21 to follow the bearing carriage 18 while maintaining a push or pull force on the body. Orientation of the hydrodynamic bearing 26 about the first axis 15 is controlled by the first motor 5 which uses a lead screw to push or pull the first pivot frame 14 with respect to the base 12.

[0068] The precision of the bearing alignment system is reliant on accuracy of the motors 5, 7 and the at least one measurement, as well as the programmed misalignment condition threshold determination. In embodiments wherein the at least one variable is pressure, the threshold mayAtty. Dkt. No. OU-23019WO be an absolute value between ±0.5 PSI and ±100 PSI or a relative value between ±0.01% of the load and ±10% of the load. In embodiments wherein the at least one variable is relative height, the threshold may be an absolute value between ±0.5 µm and ±1 mm or a relative value between ±0.01% of the taper depth and ±10% of the taper depth. In embodiments wherein the at least one variable is lubricant layer thickness, the threshold may be an absolute value between ±0.00005” and ±0.05” or a relative value between ±0.01% of the MLLT and ±10% of the MLLT. In embodiments wherein the at least one variable is bearing pad 44 temperature, the threshold may be an absolute value between ±0.1°C and ±10°C or a relative value between ±0.01% of the average bearing temperature and ±10% of the average bearing temperature.

[0069] When misalignment was detected, such as when the threshold is exceeded for a period of time or for a number of consecutive measurements, at least one of the motors 5, 7 was sent a control signal via the processor to rotate either clockwise or counterclockwise depending on which sensor was indicating misalignment. Detecting misalignment may occur by measuring the at least one variable at a measurement frequency, wherein the measurement frequency is between 10 Hz and 100,000 Hz, and defining misalignment as a number of consecutive measurements between the plurality of sensors that indicate misalignment, such as between 2 and 100 measurements indicating misalignment. When misalignment is detected, the motors 5, 7 are configured to rotate incrementally and the processor is configured to repeatedly assess for misalignment until alignment was achieved. In one embodiment, rotating either clockwise or counterclockwise comprises rotating by a constant increment, which may be by an absolute value between ±0.01° and ±10°, or alternatively between ±1° and less than or equal to ±2°. In one embodiment, the constant rotational increment is 1.80˚ increments and misalignment condition threshold is based on measuring pressure and is ±3 PSI, which together were determined toAtty. Dkt. No. OU-23019WO provide adequate system stability such that the alignment system does not overshoot or undershoot the aligned position. The real-time control of the alignment system is dependent on the magnitude of misalignment. On average, alignment conditions were achieved in less than or equal to 5 minutes after reaching a desired static load, alternatively less than or equal to 3 minutes after reaching a desired static load, alternatively less than or equal to 1 minute after reaching a desired static load, alternatively less than or equal to 30 seconds after reaching a desired static load, or alternatively less than or equal to 10 seconds after reaching a desired static load.

[0070] Consider an embodiment where the hydrodynamic bearing 26 is initially operating under static misalignment. The end goal to balance the load and achieve alignment is to orient the hydrodynamic bearing such that the at least one variable measured at each bearing pad 44 is adjusted to the point where the at least one variable is measured on or relative to each pad at the same relative location (which must be at, relative to the center of the hydrodynamic bearing and the shape of the pad, the same location for each pad (e.g., middle, leading, trailing, etc.)). In an embodiment wherein M1 and M2 are aligned with the second axis 17, and wherein M3 is aligned with the first axis 15 (i.e., having a sensor distribution such as those shown in FIGS.5A-5D for example), the system 10 measures the three measurements as M1, M2 (180° from M1), and M3 (90° from both M1 and M2) takes the average value of the at least one measurement at M1 and M2 and commands the second motor 7 to tilt the bearing until the actual measurements are equivalent to their average value within the threshold to account for sensor noise. Simultaneously, the pressure measured at M2 is compared to the average of M1 and M3 and the first motor 5 is commanded to tilt the bearing until both values are within the threshold. Once both axes 15, 17 have been aligned, the value for each of the at least one measurement at allAtty. Dkt. No. OU-23019WO three measurements points M1, M2, M3 are equivalent and the characteristic hydrodynamic pressure profiles reflect a state of equal pressure distribution across the surface of the bearing pad 44. Since three bearing pads are used and do not form a single line, it implies that all bearing pads 44 are experiencing the same share of thrust load and thus produce closely aligned characteristic pressure distribution profiles, and the bearing is said to be aligned with the runner.

[0071] Alternatively, it is possible for at least one of the three sensors to not be aligned with either the first or second axis 15, 17. Consider, for example, an embodiment using a sensor array similar to that of FIG. 6B, wherein the sensors are spaced at 120° intervals about the hydrodynamic bearing and none of the sensors measuring the at least one variable are in line with either of the axes 15, 17 of rotation (despite it being possible for one of these sensors to be aligned with an axis of rotation). In such an embodiment, the end goal is to balance the load and achieve alignment by rotating the first and second axes 15, 17 to adjust orientation of the hydrodynamic bearing such that the at least one variable measured at or relative to each bearing pad 44 is adjusted to the point where the at least one variable is measured at or relative to each pad 44 at the same relative location (which must be at, relative to the center of the hydrodynamic bearing and the shape of the pad, the same location for each pad (e.g., middle, leading, trailing, etc.)) after adjustment. In such an embodiment, as is the case in the embodiment above, an average value for M1, M2, and M3 can be determined using the processor (instead of the average for only M1 and M2) to determine how to rotate the hydrodynamic bearing 26. Following this initial alignment determination, the processor determines a degree and direction of rotation for at least one of the first and second axes of rotation 15, 17 that adjusts the orientation of the hydrodynamic bearing in a manner configured to alter subsequently measured values of the M1, M2, and M3 values so that each value approached the determined average until each value isAtty. Dkt. No. OU-23019WO within the threshold of the average. Once all measured values are within the threshold, the value for each of the at least one measurement at all three measurements points M1, M2, M3 are equivalent and the characteristic hydrodynamic pressure profiles reflect a state of equal pressure distribution across the surface of the bearing pad 44.

[0072] In another example wherein only two sensors are used, such as any of the embodiments shown in FIGS. 8A-8D, the system 10 may instead be configured to improve balance as opposed to ensure that the load is balanced across the entire surface of the hydrodynamic bearing 26. In such embodiments, measuring the at least on variable at the two measurement points M1 and M2, determining, using a processor, an average of the at least one variable at M1 and M2, and rotating at least one of the first and second axes 15, 17 until the measured values are within the threshold of the average value.

[0073] EXAMPLES

[0074] Equipment and Materials

[0075] The system 10 used a Haas VF-13-axis CNC milling center to serve as the body and drive system and was connected to the runner 22 as shown in FIGS. 1 and 2A. Using a milling center as the test rig platform allows for a maximum achievable speed and thrust load of 15,000 rpm and 4,200 lbf, respectively.

[0076] The hydrodynamic bearing 26 had eight bearing pads using the collection of sensors, including all optional sensors, as shown in FIGS. 4A-4C. The OD of the bearing pads 44 was 2.75”, the ID of the bearing pads 44 was 1.375”, and the surface area for each bearing pad was 3.62 in2. As discussed in more detail below, the various bearing pads had varying taper depths as one of the variables, ranging from 0.0005”, 0.0010”, 0.0015”, 0.0020”, and 0.0025”.Atty. Dkt. No. OU-23019WO

[0077] The various sensors each had a sensor tolerance. The temperature sensors included in blind holes 58 were type-k thermocouples having a temperature range from -200°C to 1260°C, with a tolerance of ±2.5°C. The load cell for the force element 13a (not shown) had a range from 0 lbs. to 1000 lbs., a linearity of ±0.1% full scale output (FSO), a hysteresis of ±0.08% FSO, and a repeatability of ±0.03% FSO. The proximity sensor was an eddy current sensor having a range of 0.4 mm to 4 mm, having a resolution of 0.08 μm and a linearity greater than ± 4 μm. Finally, pressure transducers were used to measure the at least one variable, being pressure. The pressure sensors were positioned at the middle sensor holes 50, had a range from 0 PSI to 1000 PSI, and an accuracy value of ±0.25%.

[0078] The lubricant used at the interface between the runner surface 24 and the hydrodynamic bearing surface 28 was ISO VG 32 having an oil temperature of 104°F.

[0079] Derivation of the Reynolds Equation

[0080] The Reynolds equation is used to predict critical performance parameters for fixed geometry taper thrust bearings with variable taper angles. While it is not necessarily required to understand how to derive the version of the Reynolds equation used to practice all embodiments of the present invention, the derivation below is provided as one example of a way that pressure can be derived in a useful way to practice the invention using bearing pads disclosed herein. Other implementations of the invention using bearing pads having different shapes may require a modified form of the Reynolds equation derived below for embodiments using measured pressure to balance the load.

[0081] A numerical finite difference method (FDM) is used to solve the Reynolds equation giving a two-dimensional pressure distribution across a bearing pad 44. Pressure distribution is determined by input variables related to bearing geometry, oil viscosity, minimum oil filmAtty. Dkt. No. OU-23019WO thickness, speed, and applied load. The derivation of Reynolds equation is found widely in tribology literature [IIT Dehlhi, Department of Mechanical Engineering. Mechanical Tribology - Lectures 19-23, (Nov. 11, 2012). Accessed: Feb. 02, 2023. [Video Lecture]. Available: https: / / www.youtube.com / playlist?list=PLbMVogVj5nJRCfyN1QEiBsNFek8d00kWw; B. Bhushan, Principles and applications of tribology, Second edition. in Tribology series. Hoboken: Wiley, John Wiley & Sons Inc, 2013.] and is adapted here to model the bearing geometry and operating conditions tested experimentally in this study. Reference [IIT Dehlhi, Department of Mechanical Engineering. Mechanical Tribology - Lectures 19-23, (Nov. 11, 2012). Accessed: Feb. 02, 2023. [Video Lecture]. Available: https: / / www.youtube.com / playlist?list=PLbMVogVj5nJRCfyN1QEiBsNFek8d00kWw] derives a general form of the Reynolds equation for a bearing surface that does not have a flat land portion at the trailing edge, but since the bearing tested in this study have flat lands on the bearing pads 44 the equation had to be modified. To generate a source of pressure on the flat portion of the bearing, a state of vibrational change in oil film thickness is considered in the equation called squeeze action.

[0082] FIG.9 shows the technical illustration used as the reference diagram for deriving the Reynolds equation for numerical FDM. The bearing pad 44, having a tapered section 46 and a flat section 48, is held stationary while the runner 22 having a runner surface 24 that slides from left to right. In the real-world setup, the runner 22 rotates in a circular motion against the bearing pad 44 having an annular sector shape. To simplify calculation of the Reynolds equation, linear motion has been assumed in this derivation with the bearing pad shape being simplified to a rectangular shape. The length of the simplified bearing pad shown in FIG.9 is oriented along the x-axis and reflects the circumferential length of the real bearing at the mean radius. The width ofAtty. Dkt. No. OU-23019WO the bearing pad is along the y-axis and is chosen to preserve the same surface area as the real bearing pad.

[0083] Axial load is introduced vertically in the direction that is normal to the bearing pad 44 and runner 22 interface. Accordingly, the load may be applied in the direction from the runner 22 towards the bearing 44 (see FIG. 2A) or the load may be applied in the direction from the bearing pad 44 toward the runner 22 (see FIG.2B). The MOFT is measured at the flat portion 48 of the bearing pad 44 near the trailing edge or outlet. The oil film thickness across the pad (h) is a linear function of pad length (x) and invariant in pad width (y). Following the derivation process outlined in [IIT Dehlhi, Department of Mechanical Engineering. Mechanical Tribology - Lectures 19-23, (Nov. 11, 2012). Accessed: Feb. 02, 2023. [Video Lecture]. Available: https: / / www.youtube.com / playlist?list=PLbMVogVj5nJRCfyN1QEiBsNFek8d00kWw], a general form of the Reynolds equation, shown in equation (1) below, is used as a starting point for the present analysis. ^ (1)^^^ ^^ ^ ^^^ ^ ^^^ ^h^^^^^^ + ^^ ^^^ ^h^^^^^ = ^^ ^^^ ^^^ + 2 ^^^^̅^

[0084] Equation 1 above is numerically discretized using Taylor series expansion to algebraically represent the differential terms. A discrete grid is applied on the bearing surface such that pressure is iteratively solved at each node on the grid. Equation 2 below shows the numerical expression for the first derivative of pressure where “i” and “j” represent the coordinates of the nodal position upon the discrete cartesian grid and “Δx” is the distance between said nodes. Then, the second derivative of pressure with respect to x takes the form of equation 3 below. ^^ ^ ^(2)^^, = ^^!", #^^$",^^^ %&^Atty. Dkt. No. OU-23019WO ^^^^,^'(')^^ '(^^^^!* #^')^^(3)^^^ ^ ^^^ ^ =.,, ^$*.,,&^^

[0085] Above is theseries line of reasoning to get a pressure gradient in the x-direction. The same method can be used to get an expression for the y-direction. This numerical approach is referred to as the finite difference method (FDM) and is applied to the Reynolds equation presented in eq. (1). Note that the right-hand side terms in eq. (1) include pressure and the term for oil film thickness (ℎ), so the resulting FDM treatment results in the full expression given in eq. (4). ^^ -(4)^!*.,, ^^^!", .^^ -^$*.,, ^^^$", #^^^ - -^!*.,, .^^^$*.,, ^^^^,+ ^^ ^^- ^, !*.,^^ - - -^, !".^^^, $*., ^^^, $"#^^^^, !*., .^^^, !*., ^^^^, / &^^0^ ^^ / &^^0^=because the change in oil film thickness over time is treated as a constant value in this case. The source material used as a reference for deriving the Reynolds equation omits this last term for simplicity, however, the analysis presented here is modified to include this term as it is the only way to generate pressure on the flat portion 48 of the bearing pad 44. The left side of eq. (4) contains all terms related to the unknown parameter of pressure, and the right-hand side shows the source terms for pressure. The source term for pressure is called wedge action as it describes how the change in MOFT converges into a wedge shape thus producing hydrodynamic pressure. On the tapered portion 46 of the bearing pad 44, this source term gives a non-zero value, however, on the flat portion 48 of the bearing pad 44, this term yields a value of zero since the MOFT does not change along the flat portion 48. The second source term, known as squeeze action, provides a non-zero pressure source for the flat portion 48 of the bearing pad. If an incompressible fluid separates two flat surfaces and these surfaces are brought closer together atAtty. Dkt. No. OU-23019WO a faster rate than the fluid can freely exit the space, then pressure is developed hence the term squeeze action. Inclusion of the squeeze action term is required for developing pressure on the flat portion 48 of the bearing pad 44.

[0087] The result obtained by this method gives a snapshot in the time domain, so a constant value based on speed and estimated vibration is assigned to this term as described later in this section. After rearranging eq. (4) to solve for^P2,3the resulting equation takes the form of eq. (5). ^ (5) ^ P = 4 ^^-^!*., ^ ^^-6^$*., ^ ^^ ^^: 7^^-^2,3 ^- ^- ^6^^- P2.9,3 +- - ^6^ -P2#9,3 +- - ^6^^^-<P^2,3.9 +The flat portion 48 of the bearing pad 44 is a design feature which provides a greater stability of bearing performance under fluctuating or sudden increases in thrust loads. Even when the bearings tested in this study are held at static loading conditions, mechanical vibration within the system is unavoidable and is therefore represented in this numerical analysis using the term “^^^^^̅”.The magnitude and rate of simulated vibration is based on the sinusoidal nature ofinduced by the runner 22. The vibration is simplified to take on a triangular waveform where the amplitude is the approximate value of the total runout of the physical runner 22 and the wave period is equivalent to the time of one revolution of the runner 22. This vibration is the physical representation of the change in MOFT over time and is used to provide a value for the squeeze action term.

[0089] Representing the sinusoidal nature of squeeze action occurring between the bearing and runner as a triangle waveform gives a linear slope to give a value to the term “^^^^̅”, and theAtty. Dkt. No. OU-23019WO revolutions represented on the x-axis can be changed to time by taking the speed of the runner 22 in revolutions per minute and converting that to seconds per revolution. Then, the time sample occurring during the negatively sloping portion of the vibration waveform is used and the change in oil film thickness is taken as the amplitude of the vibration wave.

[0090] The static load-carrying capacity of the bearing pad 44 is equivalent to the volume under the pressure curve under static loading conditions. The varying load-carrying capacity of the bearing pad 44, meaning the ability of the load to be changed from a first load to a second load by, for example, a stepwise process or a constant increase, is equivalent to the volume under the pressure curve at a specific point in time during varying loading conditions. Numerical integration is used to calculate the volume under the pressure contour to provide the magnitude of thrust load which the bearing pad 44 is currently supporting. This fact is leveraged to develop a method for numerically determining MLLT given an applied thrust load as discussed in the next section.

[0091] Numerical Determination of MOFT or MLLT

[0092] To support the functionality of the bearing alignment system, all numerical and experimental results for minimum oil film thickness (MOFT) and hydrodynamic pressure distribution are compared and analyzed at various speeds and applied loads. The procedure for numerically predicting the MOFT or MLLT is semi-empirical in that the input value for lubricant viscosity is calculated from experimental temperature data while the other input variables including speed, applied load, and bearing geometry are taken at nominal value. The method for calculating a value for viscosity used in the numerical analysis was based on the measured lubricant temperature. Two K-type thermocouples were used to determine the temperature of the lubricant at the interface between the bearing pad 44 and the runner 22. The first thermocoupleAtty. Dkt. No. OU-23019WO was placed directly inline of the hydrodynamic bearing lubricant inlet 29 as it exited the inlet 29. The second thermocouple was placed near the periphery of the bearing pad 44 as lubricant exited the hydrodynamic bearing lubricant outlet 31. The lubricant entered the hydrodynamic bearing lubricant inlet 29 at the desired temperature set by the lubricant conditioning system 60 and, due to sheering of the lubricant between the hydrodynamic bearing surface 28 bearing and runner surface 24, exited at an elevated temperature. The average of these two temperatures was taken as the assumed temperature of the lubricant at the interface.

[0093] This method of experimental determination of lubricant temperature may be somewhat limited in that the outlet lubricant may cool rapidly as it contacts the backing plate 25 which supports the hydrodynamic bearing 26. Furthermore, heat transfer in the bearing instrument assembly lubricant inlet may have worked to cool the lubricant slightly before it entered the hydrodynamic bearing. Since the gap separating the hydrodynamic bearing surface 28 and runner surface 24 is too thin to place a thermocouple in the interface, it was not possible to directly measure the lubricant temperature at the interface. Further, since the Reynolds equation relies on an accurate value of lubricant viscosity to solve for pressure, this method may be a source of error. Despite these limitations and potential sources of error, using a constant value for lubricant viscosity for all test conditions would have neglected the effect that taper depth has on bearing friction torque and consequently resulted in a greater error. The relationship between lubricant temperature and viscosity is given below in eq. (6), where viscosities A and ABcorrespond to temperatures C and CB, respectively, and the coefficient, D, is the temperature- viscosity coefficient for ISO 32 oil used as the lubricant in the examples below. (6) A = A 9 9BE^F GD ^Atty. Dkt. No. OU-23019WO

[0094] Since the load capacity of the hydrodynamic bearing 26 can only be determined after the numerical simulation has converged, while also being dynamically dependent on multiple semi-empirical input variables, an initial guess for MOFT or MLLT must be supplied.

[0095] When determining the MOFT or MLLT for a hydrodynamic bearing 26 under a given set of operating conditions, including a known applied load, the overall thrust load is first divided by the number of bearing pads 44 to get the evenly distributed load acting on each bearing pad 44. This introduces a key assumption that, when the hydrodynamic bearing 26 and runner are perfectly aligned, this is sufficient to assume that each bearing pad 44 is carrying an equal and evenly distributed portion of the total thrust load. For example, if a hydrodynamic bearing 24 with 8 bearing pads 44 was subjected to a total thrust load of 800 lbf and the hydrodynamic bearing surface 28 was perfectly aligned with the runner surface 24, then each bearing pad 44 would be carrying exactly 1 / 8thor 100 lbf individually. The resulting hydrodynamic pressure distribution acting on the bearing pad 44 would support this load and the resulting MOFT or MLLT would be dynamically dependent on the applied load, speed, viscosity, and bearing taper geometry. Since load, speed, viscosity, and bearing taper geometry are all known, the Reynolds equation can be back solved for MOFT or MLLT.

[0096] However, to initiate the numerical pressure distribution calculation, an arbitrary but reasonable guess for MOFT or MLLT must first be given. Then, using the initial guess for MOFT or MLLT, the simulation is run to convergence and the resultant load capacity is determined. The convergence of the iterative solver is defined by a difference function which compares the sum of pressure in the current iteration to that of the previous iteration. When the difference between the current and previous iteration falls under a threshold, which could be as low as ±0.001 PSI, the iterative solver may be configured to stop, and the pressure solution of theAtty. Dkt. No. OU-23019WO current iteration is returned. Alternatively, the iterative solver could be run for a period of time sufficient to converge on an acceptably accurate value of the solution. The integrated volume under the pressure curve is calculated using numerical integration and a load capacity is determined. Based on the resulting load capacity as compared to the nominal target load capacity, the MOFT or MLLT guess is then incremented higher or lower. If the resulting numerically predicted load capacity is higher than the target load capacity, the MOFT or MLLT is increased and vice versa if the resulting numerically predicted load capacity is lower than the target load capacity.

[0097] Manually augmenting the MOFT or MLLT input value presented a challenge in the implementation of this numerical approach due to the precision of the MOFT or MLLT required to produce a load capacity within the desired tolerance of the target load capacity (±0.5 lbf). For example, if the initial MOFT or MLLT resulted in a large difference between numerically predicted load capacity on the scale of 10-100 lbf, then the MOFT had to be adjusted on the scale of 0.001” increments. However, as the numerically predicted load capacity approached the target value within 1-10 lbf, the adjustments to the MOFT or MLLT input value had to be iterated on a scale as small as 0.000001”.

[0098] The dynamic relationship between applied load and MOFT or MLLT is leveraged here to numerically predict MOFT or MLLT values for the entire variable taper test matrix which is performed experimentally in this study. The resulting MOFT or MLLT values are presented in the examples below and directly compared to the experimentally determined values and a percent deviation is given. Further, the MOFT values are then used as inputs to the FDM pressure distribution solver which gives the numerically determined hydrodynamic pressureAtty. Dkt. No. OU-23019WO distribution which is directly compared to experimental values and a percent deviation is given. Full output and detailed plots can be found in the results section of this study.

[0099] EXAMPLE 1

[0100] Method

[0101] FIG. 11 shows an implementation of static load during operation of the system 10 under static load. FIGS. 12-13 shows comparable implementations of the system under varying loads, wherein the specific load is stepwise adjusted to higher specific loads at constant intervals. In FIG.12, the balancing system is not used. In FIG.13, the balancing system is used.

[0102] Results and Discussion

[0103] As can be seen from FIG. 11, the system was able to achieve an initially balanced state relatively quickly (less than 2 minutes. While on the right pressure sensors had a pressure spike starting at about 3 minutes, peaking at about 5 minutes, and reconverging to a balanced state due to operation of the system at about 8 minutes. Once the right sensor reconverged to the balanced state, the system 10 was able to maintain the balanced state for the remainder of the duration.

[0104] As can be seen from the comparison of FIGS.12 and 13, the system 10 has a clearly beneficial effect on the balancing of the loads. With reference to FIG. 12, without implementation of the system, the alignment quickly significantly deviates by the second step of changing the applied load, momentarily approaches an almost balanced state at about 65 minutes until about 75 minutes (back and front sensors), but then quickly and significantly deviates again. With reference to FIG.13, the difference is stark—the lines for the actual measured pressures are so balanced that it is nearly impossible to see different lines except where a little noise appears.

[0105] EXAMPLE 2Atty. Dkt. No. OU-23019WO

[0106] Method

[0107] The runner 22 was configured to apply loads equal to 100lbf, 200 lbf, 300 lbf, 400 lbf and 500 lbf to test how the different applied pressures impacted the balancing function of the system 10. The runner was also configured to rotate at several speeds, including 1500 RPM, 3000 RPM, 4500 RPM, and 6000 RPM. FIGS.14-17 show 1500 RPM, 3000 RPM, 4500 RPM, and 6000 RPM respectively, and at those rotational speeds compare graphs comparing analytically expected pressures across the bearing pad surface to leading (L), middle (M), and trailing (T) actual experimental data points generated at an array of taper depths (0.0005”, 0.0010”, 0.0015”, 0.0020”, and 0.0025”) on the y-axis of the array and applied loads (100lbf, 200 lbf, 300 lbf, 400 lbf and 500 lbf) on the x-axis of the array.

[0108] Results and Discussion

[0109] As can be seen, generally speaking, the experimental results measured at the leading and middle sensors agreed with the analytically expected data for these points. Generally speaking, across all rotational speeds, some deviation of the leading and middle sensor pressure readings happened at low taper depth (0.0005”) and increased with increasing applied loads. However, these deviations were relatively small and experimentally derived data generally agreed well with analytical expectations.

[0110] Trailing sensor data tended to agree well at lower taper depths (0.0015” and lower), lower applied loads (300 lbf and lower). However, there were large exceptions to the expected values at 0.0020” ± 0.0005” taper depths at higher applied loads (300-500 lbf), where experimental data deviated significantly from expected values Accordingly, in such conditions, it may be preferable to use middle and trailing sensors where load bearing distribution is more likely to conform with analytical expectations.Atty. Dkt. No. OU-23019WO

[0111] While the present invention has been illustrated by the description of one or more embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicants’ general inventive concept. ASPECTS OF THE INVENTION 1. A system configured to balance a load received by a hydrodynamic bearing, comprising: a runner comprising a runner surface configured to interact with a first side of the hydrodynamic bearing; a base; the hydrodynamic bearing, wherein the hydrodynamic bearing comprises: a plurality of bearing pads on the first side of the hydrodynamic bearing, each bearing pad comprising: a first bearing pad section comprising a taper depth; and a second bearing pad section that is configured to be planarly parallel to the runner surface when the hydrodynamic bearing is in operation; a first pivot frame configured to rotate the hydrodynamic bearing relative to the base along a first axis of rotation, wherein the first axis of rotation is perpendicular to the runner surface; a second pivot frame configured to rotate the hydrodynamic bearing relative to the first pivot frame along a second axis of rotation, wherein the second axis of rotation is perpendicular to the runner surface and the first axis of rotation; and a plurality of sensors configured to measure at least one variable correlated to the alignment of the hydrodynamic bearing, comprising:Atty. Dkt. No. OU-23019WO a first sensor configured to measure a first measurement of the at least one variable at a first bearing pad; a second sensor configured to measure a second measurement of the at least one variable at a second bearing pad; and a third sensor configured to measure a third measurement of the at least one variable at a third bearing pad; wherein the first pivot frame and the second pivot frame are configured to rotate the hydrodynamic bearing in response to at least the first, second, and third measurements of the at least one variable until each measurement of the at least one variable is within a threshold of an average measurement of at least the first, second, and third measurement of the at least one variable. 2. The system of aspect 1, wherein the at least one variable is pressure, wherein the first sensor comprises a first pressure sensor configured to measure pressure approximately equal to a first portion of the load received by the first bearing pad, wherein the second sensor comprises a second pressure sensor configured to measure pressure approximately equal to a second portion of the load received by the second bearing pad, and wherein the third sensor comprises a third pressure sensor configured to measure pressure approximately equal to a third portion of the load received by the third bearing pad. 3. The system of aspect 2, wherein the threshold is an absolute value. 4. The system of aspect 3, wherein the threshold is ±100 PSI. 5. The system of aspect 3, wherein the threshold is ±0.5 PSI. 6. The system of aspect 2, wherein the threshold is a relative value. 7. The system of aspect 6, wherein the threshold is ±10% of the load. 8. The system of aspect 6, wherein the threshold is ±0.01% of the load.Atty. Dkt. No. OU-23019WO 9. The system of aspect 2, wherein the first, second, and third pressure sensors are leading pressure sensors. 10. The system of aspect 2, wherein the first, second, and third pressure sensors are middle pressure sensors. 11. The system of aspect 2, wherein the first, second, and third pressure sensors are trailing pressure sensors. 12. The system of aspect 1, wherein the at least one variable is height of the flat portion of each of the bearing pads relative to the runner surface, wherein the first sensor comprises a first proximity sensor configured to measure height of the flat portion of the first bearing pad relative to the runner surface, wherein the second sensor comprises a second proximity sensor configured to measure height of the flat portion of the second bearing pad relative to the runner surface, and wherein the third sensor comprises a third proximity sensor configured to measure height of the flat portion of the third bearing pad relative to the runner surface. 13. The system of aspect 12, wherein the threshold is an absolute value. 14. The system of aspect 13, wherein the threshold is ±1 mm. 15. The system of aspect 13, wherein the threshold is ±0.5 µm. 16. The system of aspect 12, wherein the threshold is a relative value. 17. The system of aspect 16, wherein the threshold is ±10% of the taper depth. 18. The system of aspect 16, wherein the threshold is ±0.01% of the taper depth. 19. The system of aspect 1, wherein the hydrodynamic bearing comprises a lubricant inlet and a plurality of lubricant outlets, wherein the runner surface and the first side of the hydrodynamic bearing are configured to be separated by a lubricant layer during operation of the system, and wherein the lubricant layer comprises:Atty. Dkt. No. OU-23019WO a lubricant layer thickness; a minimum lubricant layer thickness (MLLT); and a lubricant temperature. 20. The system of aspect 19, wherein the at least one variable is lubricant layer thickness, wherein the first sensor comprises a first proximity sensor configured to measure lubricant layer thickness at the first bearing pad, wherein the second sensor comprises a second proximity sensor configured to measure lubricant layer thickness at the second bearing pad, and wherein the third sensor comprises a third proximity sensor configured to measure lubricant layer thickness at the third bearing pad. 21. The system of aspect 20 wherein the threshold is an absolute value. 22. The system of aspect 21, wherein the threshold is ±0.05”. 23. The system of aspect 21, wherein the threshold is ±0.00005”. 24. The system of aspect 20, wherein the wherein the threshold is a relative value. 25. The system of aspect 24, wherein the threshold is ±0.01% of the MLLT. 26. The system of aspect 24, wherein the threshold is ±10% of the MLLT. 27. The system of aspect 1, wherein the at least one variable is bearing pad temperature, wherein the first sensor comprises a first thermocouple configured to measure bearing pad temperature at the first bearing pad, wherein the second sensor comprises a second thermocouple configured to measure bearing pad temperature at the second bearing pad, and wherein the third sensor comprises a third thermocouple configured to measure bearing pad temperature at the third bearing pad. 28. The system of aspect 27 wherein the threshold is an absolute value. 29. The system of aspect 28, wherein the threshold is ±0.1°C”.Atty. Dkt. No. OU-23019WO 30. The system of aspect 28, wherein the threshold is ±10°C”. 31. The system of aspect 27, wherein the wherein the threshold is a relative value. 32. The system of aspect 31, wherein the threshold is ±0.01% of the average bearing pad temperature at the sensor location. 33. The system of aspect 31, wherein the threshold is ±10% of the average bearing pad temperature at the sensor location. 34. The system of aspect 1, further comprising a plurality of secondary sensors configured to measure at least one secondary variable at a plurality of secondary bearing pads, comprising: a first secondary sensor configured to measure the at least one secondary variable at a first secondary bearing pad; a second secondary sensor configured to measure the at least one secondary variable at a second secondary bearing pad; and a third secondary sensor configured to measure the at least one secondary variable at a third secondary bearing pad; wherein the first, second, and / or third secondary bearing pad may comprise the first, second, and / or third bearing pad, wherein the at least one secondary variable is different from the at least one variable, and wherein the first, second, and third secondary sensors are selected from the list consisting of a pressure sensor, a proximity sensor, and a temperature sensor. 35. The system of aspect 34, wherein the first, second, and third sensors comprise pressure sensors, and wherein the first, second, and third secondary sensors comprise proximity sensors. 36. The system of any of aspects 12, 20, 34, and 35, wherein the proximity sensor is selected from a list consisting of an Eddy current sensor, a laser sensor, and ultrasonic sensor, or a combination thereof. 37. The system of aspect 1, wherein the plurality of sensors consists of only the first, second, and third sensors.Atty. Dkt. No. OU-23019WO 38. The system of aspect 1, wherein at least one of the first pivot frame and the second pivot frame is configured to rotate by a constant rotational increment each time at least one of the first, second, and third measurement exceeds the threshold by a positive or negative amount. 39. The system of aspect 38, wherein the constant rotational increment is greater than or equal to ±0.01°. 40. The system of aspect 38, wherein the constant rotational increment is less than or equal to ±10°. 41. The system of aspect 38, wherein the constant rotational increment is greater than or equal to ±1° and less than or equal to ±2°. 42. The system of aspect 1, wherein each of the first, second, and third sensors are configured to measure the first, second, and third measurement at a measurement frequency. 43. The system of aspect 42, wherein the measurement frequency is greater than or equal to 10 Hz. 44. The system of aspect 42, wherein the measurement frequency is less than or equal to 100,000 Hz. 45. The system of aspect 42, wherein the measurement frequency is approximately equal to 1000Hz. 46. The system of aspect 1, wherein the system is configured to balance a static load. 47. The system of aspect 1, wherein the system is configured to adjust a varying load, and wherein the average measurement is an average measurement of the varying load. 48. The system of aspect 1, wherein the plurality of bearing pads is radially distributed along an outer edge of the hydrodynamic bearing at a constant interval.Atty. Dkt. No. OU-23019WO 49. The system of aspect 48, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads. 50. The system of aspect 48, wherein the plurality of bearing pads is equal to a multiple of 4. 51. The system of aspect 50, wherein the first bearing pad is radially separated by 180° from the second bearing pad, and wherein the third bearing pad is radially separated from both the first and second bearing pads by 90°. 52. The system of aspect 48, wherein the plurality of bearing pads is equal to a multiple of 3. 53. The system of aspect 52, wherein the first bearing pad is radially separated from both the second and third bearing pads by 120°, and wherein the second bearing pad is radially separated from the third bearing pad by 120°. 54. The system of aspect 48, wherein the plurality of sensors includes greater than or equal to 4 sensors, wherein each additional sensor is configured to measure the at least one variable, wherein the first pivot frame and the second pivot frame are further configured to rotate the hydrodynamic bearing in response to each of the additional measurements of the at least one variable until each measurement of the at least one variable is within a threshold of an average measurement of the first, second, third, and each additional measurement of the at least one variable. 55. The system of aspect 54, wherein each bearing pad comprises one of the additional sensors configured to measure the at least one variable, and wherein each bearing pad is radially separated from each adjacent bearing pad by 360° / n, wherein n equals the number of bearing pads. 56. The system of aspect 55, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads. 57. A method for balancing a load received by a hydrodynamic bearing comprising a plurality of bearing pads, the method comprising:Atty. Dkt. No. OU-23019WO measuring, using a plurality of sensors, at least one variable at a plurality of bearing pads, comprising: measuring a first measurement of the at least one variable, using a first sensor, at a first bearing pad; measuring a second measurement of the at least one variable, using a second sensor, at a second bearing pad; and measuring a third measurement of the at least one variable, using a third sensor, at a third bearing pad; determining, using a processor, an average measurement of the at least one variable using at least two of the measurements; and rotating the hydrodynamic bearing, using at least one of a first pivot frame configured to rotate along a first axis relative to a base and a second pivot frame configured to rotate relative to the first pivot frame along a second axis of rotation, in a manner selected from the group consisting of: rotating the hydrodynamic bearing along the first axis of rotation, rotating the hydrodynamic bearing along the second axis of rotation, and rotating the hydrodynamic bearing along both the first axis of rotation and the second axis of rotation; wherein the first pivot frame is configured to rotate the hydrodynamic bearing along the first axis of rotation, and wherein the second pivot frame is configured to rotate the hydrodynamic bearing along the second axis of rotation wherein the first axis of rotation is perpendicular to the load received, and wherein the second axis of rotation is perpendicular to the load received and the first axis of rotation, wherein rotating the hydrodynamic bearing adjusts at least one of the first, second, and third measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement. 58. The method of aspect 57, wherein the at least one variable is pressure, wherein measuring the first measurement comprises using a first pressure sensor configured to measure pressure approximately equal to a first portion of the load received by the first bearing pad, wherein measuring the second measurement comprises using a second pressure sensor configured toAtty. Dkt. No. OU-23019WO measure pressure approximately equal to a second portion of the load received by the second bearing pad, and wherein measuring the third measurement comprises using a third pressure sensor configured to measure pressure approximately equal to a third portion of the load received by the third bearing pad. 59. The method of aspect 58, wherein the threshold is an absolute value. 60. The method of aspect 59, wherein the threshold is ±100 PSI. 61. The method of aspect 59, wherein the threshold is ±0.5 PSI. 62. The method of aspect 58, wherein the threshold is a relative value. 63. The method of aspect 62, wherein the threshold is ±10% of the load. 64. The method of aspect 62, wherein the threshold is ±0.01% of the load. 65. The method of aspect 58, wherein the first, second, and third pressure sensors are leading pressure sensors. 66. The method of aspect 58, wherein the first, second, and third pressure sensors are middle pressure sensors. 67. The method of aspect 58, wherein the first, second, and third pressure sensors are trailing pressure sensors. 68. The method of aspect 57, wherein the at least one variable is height of the flat portion of each of the bearing pads relative to the runner surface, wherein measuring the first measurement comprises using a first proximity sensor configured to measure height of the flat portion of the first bearing pad relative to the runner surface, wherein measuring the second measurement comprises using a second proximity sensor configured to measure height of the flat portion of the second bearing pad relative to the runner surface, and wherein measuring the third measurement comprises using a third proximity sensor configured to measure height of the flat portion of the third bearing pad relative to the runner surface.Atty. Dkt. No. OU-23019WO 69. The method of aspect 68, wherein the threshold is an absolute value. 70. The method of aspect 69, wherein the threshold is ±1 m. 71. The method of aspect 69, wherein the threshold is ±1 µm. 72. The method of aspect 68, wherein the threshold is a relative value. 73. The method of aspect 72, wherein the threshold is ±10% of the taper depth. 74. The method of aspect 72, wherein the threshold is ±0.01% of the taper depth. 75. The method of aspect 57, further comprising flowing a lubricant between the plurality of bearing pads and a runner, wherein the hydrodynamic bearing comprises a lubricant inlet and a plurality of lubricant outlets, wherein the runner and the hydrodynamic bearing are configured to be separated by a lubricant layer, and wherein the lubricant layer comprises: a lubricant layer thickness; a minimum lubricant layer thickness (MLLT); and a lubricant temperature. 76. The method of aspect 75, wherein the at least one variable is lubricant layer thickness, wherein measuring the first measurement comprises using a first proximity sensor configured to measure lubricant layer thickness at the first bearing pad, wherein measuring the second measurement comprises using a second proximity sensor configured to measure lubricant layer thickness at the second bearing pad, and wherein measuring the third measurement comprises using a third proximity sensor configured to measure lubricant layer thickness at the third bearing pad. 77. The method of aspect 76 wherein the threshold is an absolute value. 78. The method of aspect 77, wherein the threshold is ±0.05”.Atty. Dkt. No. OU-23019WO 79. The method of aspect 77, wherein the threshold is ±0.0005”. 80. The method of aspect 76, wherein the wherein the threshold is a relative value. 81. The method of aspect 80, wherein the threshold is ±0.01% of the MLLT. 82. The method of aspect 80, wherein the threshold is ±10% of the MLLT. 83. The method of aspect 75, wherein the at least one variable is bearing pad temperature, wherein measuring the first measurement comprises using a first thermocouple configured to measure bearing pad temperature at the first bearing pad, wherein measuring the second measurement comprises using a second thermocouple configured to measure bearing pad temperature at the second bearing pad, and wherein measuring the third measurement comprises using a third thermocouple configured to measure bearing pad temperature at the third bearing pad. 84. The method of aspect 83 wherein the threshold is an absolute value. 85. The method of aspect 84, wherein the threshold is ±0.1°C”. 86. The method of aspect 84, wherein the threshold is ±10°C”. 87. The method of aspect 83, wherein the wherein the threshold is a relative value. 88. The method of aspect 87, wherein the threshold is ±0.1% of an average lubricant temperature. 89. The method of aspect 87, wherein the threshold is ±10% of an average lubricant temperature. 90. The method of aspect 57, further comprising measuring, using a plurality of secondary sensors, at least one secondary variable at a plurality of secondary bearing pads, comprising: measuring the at least one secondary variable, using a first secondary sensor, at a first secondary bearing pad;Atty. Dkt. No. OU-23019WO measuring the at least one secondary variable, using a second secondary sensor, at a second secondary bearing pad; measuring the at least one secondary variable, using a third secondary sensor, at a third secondary bearing pad; wherein the first, second, and / or third secondary bearing pad may comprise the first, second, and / or third bearing pad, wherein the at least one secondary variable is different from the at least one variable, and wherein the first, second, and third secondary sensors are selected from the list consisting of a pressure sensor, a proximity sensor, and a temperature sensor. 91. The method of aspect 90, wherein the first, second, and third sensors comprise pressure sensors, and wherein the first, second, and third secondary sensors comprise proximity sensors. 92. The method of any of aspects 68, 76, 90, and 91, wherein the proximity sensor is selected from a list consisting of an Eddy current sensor, a laser sensor, and ultrasonic sensor, or a combination thereof. 93. The method of aspect 57, wherein the plurality of sensors consists of only the first, second, and third sensors. 94. The method of aspect 57, wherein rotating the hydrodynamic bearing pad comprises rotating at least one of the first pivot frame and the second pivot frame by a constant rotational increment each time at least one of the first, second, and third measurement exceeds the threshold by a positive or negative amount. 95. The method of aspect 94, wherein the constant rotational increment is greater than or equal to ±0.01°. 96. The method of aspect 94, wherein the constant rotational increment is less than or equal to ±10°. 97. The method of aspect 94, wherein the constant rotational increment is greater than or equal to ±1° and less than or equal to ±2°.Atty. Dkt. No. OU-23019WO 98. The method of aspect 57, wherein measuring the first, second, and third measurements occurs at a measurement frequency. 99. The method of aspect 98, wherein the measurement frequency is greater than or equal to 10 Hz. 100. The method of aspect 98, wherein the measurement frequency is less than or equal to 100,000 Hz. 101. The method of aspect 98, wherein the measurement frequency is approximately equal to 1000Hz. 102. The method of aspect 57, wherein the method balances a static load. 103. The method of aspect 57, wherein the method adjusts to a varying load, and wherein the average measurement is an average measurement of the varying load. 104. The method of aspect 57, wherein the plurality of bearing pads is radially distributed along an outer edge of the hydrodynamic bearing at a constant interval. 105. The method of aspect 104, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads. 106. The method of aspect 104, wherein the plurality of bearing pads is equal to a multiple of 4. 107. The method of aspect 106, wherein the first bearing pad is radially separated by 180° from the second bearing pad, and wherein the third bearing pad is radially separated from both the first and second bearing pads by 90°. 108. The method of aspect 107, wherein rotating the hydrodynamic bearing pad adjusts at least one of the first, second, and third measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement comprises:Atty. Dkt. No. OU-23019WO wherein determining, using the processor, the average measurement of the at least one variable comprises using the first and second measurements; determining, using the processor, the difference between each of the first, second, and third measurements and the average measurement; and rotating the hydrodynamic bearing using at least one of the first pivot frame and the second pivot frame until the first, second, and third measurements are adjusted to a value within the threshold of the average measurement. 109. The method of aspect 104, wherein the plurality of bearing pads is equal to a multiple of 3. 110. The method of aspect 109, wherein the first bearing pad is radially separated from both the second and third bearing pads by 120°, and wherein the second bearing pad is radially separated from the third bearing pad by 120°. 111. The method of aspect 110, wherein rotating the hydrodynamic bearing pad adjusts at least one of the first, second, and third measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement comprises: wherein determining, using the processor, the average measurement of the at least one variable comprises using the first, second, and third measurements; determining, using the processor, the difference between each of the first, second, and third measurements and the average measurement; and rotating the hydrodynamic bearing using at least one of the first pivot frame and the second pivot frame until the first, second, and third measurements are adjusted to a value within the threshold of the average measurement. 112. The method of aspect 104, wherein the plurality of sensors includes greater than or equal to 4 sensors; wherein measuring, using the plurality of sensors, the at least one variable comprises measuring an additional measurement of the at least one variable using each additional sensor; and wherein rotating the hydrodynamic bearing, using at least one of the first pivot frame and the second pivot frame, are further comprises adjusting each of the additionalAtty. Dkt. No. OU-23019WO measurements of the at least one variable until each measurement of the at least one variable is within a threshold of the average measurement. 113. The method of aspect 112, wherein each bearing pad comprises one of the additional sensors configured to measure the at least one variable, and wherein each bearing pad is radially separated from each adjacent bearing pad by 360° / n, wherein n equals the number of bearing pads. 114. The method of aspect 113, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads. 115. A system configured to improve load balancing for a hydrodynamic bearing, comprising: a runner comprising a runner surface configured to interact with a first side of the hydrodynamic bearing; a base; the hydrodynamic bearing, wherein the hydrodynamic bearing comprises: a plurality of bearing pads on the first side of the hydrodynamic bearing, each bearing pad comprising: a first bearing pad section comprising a taper depth; and a second bearing pad section that is configured to be planarly parallel to the runner surface when the hydrodynamic bearing is in operation; a first pivot frame configured to rotate the hydrodynamic bearing relative to the base along a first axis of rotation, wherein the first axis of rotation is perpendicular to the runner surface; a second pivot frame configured to rotate the hydrodynamic bearing relative to the first pivot frame along a second axis of rotation, wherein the second axis of rotation is perpendicular to the runner surface and the first axis of rotation; and a plurality of sensors configured to measure at least one variable correlated to the alignment of the hydrodynamic bearing, comprising: a first sensor configured to measure a first measurement of the at least one variable at a first bearing pad of the plurality of bearing pads; andAtty. Dkt. No. OU-23019WO a second sensor configured to measure a second measurement of the at least one variable at a second bearing pad of the plurality of bearing pads; wherein the first pivot frame and the second pivot frame are configured to rotate the hydrodynamic bearing in response to the first and second measurements of the at least one variable until each measurement of the at least one variable is within a threshold of an average measurement of the first and second measurement of the at least one variable. 116. The system of aspect 115, wherein the at least one variable is pressure, wherein the first sensor comprises a first pressure sensor configured to measure pressure approximately equal to a first portion of the load received by the first bearing pad, and wherein the second sensor comprises a second pressure sensor configured to measure pressure approximately equal to a second portion of the load received by the second bearing pad. 117. The system of aspect 116, wherein the threshold is an absolute value. 118. The system of aspect 117, wherein the threshold is ±100 PSI. 119. The system of aspect 117, wherein the threshold is ±0.5 PSI. 120. The system of aspect 116, wherein the threshold is a relative value. 121. The system of aspect 120, wherein the threshold is ±10% of the load. 122. The system of aspect 120, wherein the threshold is ±0.01% of the load. 123. The system of aspect 116, wherein the first and second pressure sensors are leading pressure sensors. 124. The system of aspect 116, wherein the first and second pressure sensors are middle pressure sensors. 125. The system of aspect 116, wherein the first and second pressure sensors are trailing pressure sensors.Atty. Dkt. No. OU-23019WO 126. The system of aspect 115, wherein the at least one variable is height of the flat portion of each of the bearing pads relative to the runner surface, wherein the first sensor comprises a first proximity sensor configured to measure height of the flat portion of the first bearing pad relative to the runner surface, and wherein the second sensor comprises a second proximity sensor configured to measure height of the flat portion of the second bearing pad relative to the runner surface. 127. The system of aspect 126, wherein the threshold is an absolute value. 128. The system of aspect 127, wherein the threshold is ±1 mm. 129. The system of aspect 127, wherein the threshold is ±0.5 µm. 130. The system of aspect 126, wherein the threshold is a relative value. 131. The system of aspect 130, wherein the threshold is ±10% of the taper depth. 132. The system of aspect 130, wherein the threshold is ±0.01% of the taper depth. 133. The system of aspect 115, wherein the hydrodynamic bearing comprises a lubricant inlet and a plurality of lubricant outlets, wherein the runner surface and the first side of the hydrodynamic bearing are configured to be separated by a lubricant layer during operation of the system, and wherein the lubricant layer comprises: a lubricant layer thickness; a minimum lubricant layer thickness (MLLT); and a lubricant temperature. 134. The system of aspect 133, wherein the at least one variable is lubricant layer thickness, wherein the first sensor comprises a first proximity sensor configured to measure lubricant layer thickness at the first bearing pad, and wherein the second sensor comprises a second proximity sensor configured to measure lubricant layer thickness at the second bearing pad. 135. The system of aspect 134 wherein the threshold is an absolute value.Atty. Dkt. No. OU-23019WO 136. The system of aspect 135, wherein the threshold is ±0.05”. 137. The system of aspect 135, wherein the threshold is ±0.00005”. 138. The system of aspect 134, wherein the wherein the threshold is a relative value. 139. The system of aspect 138, wherein the threshold is ±0.01% of the MLLT. 140. The system of aspect 138, wherein the threshold is ±10% of the MLLT. 141. The system of aspect 115, wherein the at least one variable is bearing pad temperature, wherein the first sensor comprises a first thermocouple configured to measure bearing pad temperature at the first bearing pad, and wherein the second sensor comprises a second thermocouple configured to measure bearing pad temperature at the second bearing pad. 142. The system of aspect 141 wherein the threshold is an absolute value. 143. The system of aspect 142, wherein the threshold is ±0.1°C”. 144. The system of aspect 142, wherein the threshold is ±10°C”. 145. The system of aspect 141, wherein the wherein the threshold is a relative value. 146. The system of aspect 145, wherein the threshold is ±0.01% of the average bearing pad temperature at the sensor location. 147. The system of aspect 145, wherein the threshold is ±10% of the average bearing pad temperature at the sensor location. 148. The system of aspect 115, further comprising a plurality of secondary sensors configured to measure at least one secondary variable at a plurality of secondary bearing pads, comprising: a first secondary sensor configured to measure the at least one secondary variable at a first secondary bearing pad; andAtty. Dkt. No. OU-23019WO a second secondary sensor configured to measure the at least one secondary variable at a second secondary bearing pad; wherein the first and / or second secondary bearing pad may comprise the first and / or second third bearing pad, wherein the at least one secondary variable is different from the at least one variable, and wherein the first and second secondary sensors are selected from the list consisting of a pressure sensor, a proximity sensor, and a temperature sensor. 149. The system of aspect 148, wherein the first and second sensors comprise pressure sensors, and wherein the first and second secondary sensors comprise proximity sensors. 150. The system of any of aspects 126, 134, 148, and 149, wherein the proximity sensor is selected from a list consisting of an Eddy current sensor, a laser sensor, and ultrasonic sensor, or a combination thereof. 151. The system of aspect 115, wherein the plurality of sensors consists of only the first and second sensors. 152. The system of aspect 115, wherein at least one of the first pivot frame and the second pivot frame is configured to rotate by a constant rotational increment each time at least one of the first and second measurement exceeds the threshold by a positive or negative amount. 153. The system of aspect 152, wherein the constant rotational increment is greater than or equal to ±0.01°. 154. The system of aspect 152, wherein the constant rotational increment is less than or equal to ±10°. 155. The system of aspect 152, wherein the constant rotational increment is greater than or equal to ±1° and less than or equal to ±2°. 156. The system of aspect 115, wherein each of the first, second, and third sensors are configured to measure the first, second, and third measurement at a measurement frequency.Atty. Dkt. No. OU-23019WO 157. The system of aspect 156, wherein the measurement frequency is greater than or equal to 10 Hz. 158. The system of aspect 156, wherein the measurement frequency is less than or equal to 100,000 Hz. 159. The system of aspect 156, wherein the measurement frequency is approximately equal to 1000Hz. 160. The system of aspect 115, wherein the system is configured to improve balancing of a static load. 161. The system of aspect 115, wherein the system is configured to adjust a varying load, and wherein the average measurement is an average measurement of the varying load. 162. The system of aspect 115, wherein the plurality of bearing pads is radially distributed along an outer edge of the hydrodynamic bearing at a constant interval. 163. The system of aspect 162, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads. 164. The system of aspect 162, wherein the plurality of bearing pads is equal to a multiple of 4. 165. The system of aspect 164, wherein the first bearing pad is radially separated by 180° from the second bearing pad. 166. The system of aspect 162, wherein the plurality of bearing pads is equal to a multiple of 3. 167. The system of aspect 166, wherein the first bearing pad is radially separated from the second bearing pad by 120°.Atty. Dkt. No. OU-23019WO 168. A method for improving balance of a load received by a hydrodynamic bearing comprising a plurality of bearing pads, the method comprising: measuring, using a plurality of sensors, at least one variable at a plurality of bearing pads, comprising: measuring a first measurement of the at least one variable, using a first sensor, received at a first bearing pad; and measuring a second measurement of the at least one variable, using a second sensor, received at a second bearing pad; determining, using a processor, an average measurement of the at least one variable using the first and second measurements; and rotating the hydrodynamic bearing, using at least one of a first pivot frame configured to rotate along a first axis relative to a base and a second pivot frame configured to rotate relative to the first pivot frame along a second axis of rotation, in a manner selected from the group consisting of: rotating the hydrodynamic bearing along the first axis of rotation, rotating the hydrodynamic bearing along the second axis of rotation, and rotating the hydrodynamic bearing along both the first axis of rotation and the second axis of rotation; wherein the first pivot frame is configured to rotate the hydrodynamic bearing along the first axis of rotation, and wherein the second pivot frame is configured to rotate the hydrodynamic bearing along the second axis of rotation wherein the first axis of rotation is perpendicular to the load received, and wherein the second axis of rotation is perpendicular to the load received and the first axis of rotation, wherein rotating the hydrodynamic bearing adjusts at least one of the first and second measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement. 169. The method of aspect 168, wherein the at least one variable is pressure, wherein measuring the first measurement comprises using a first pressure sensor configured to measure pressure approximately equal to a first portion of the load received by the first bearing pad, and wherein measuring the second measurement comprises using a second pressure sensorAtty. Dkt. No. OU-23019WO configured to measure pressure approximately equal to a second portion of the load received by the second bearing pad. 170. The method of aspect 169, wherein the threshold is an absolute value. 171. The method of aspect 170, wherein the threshold is ±100 PSI. 172. The method of aspect 170, wherein the threshold is ±0.5 PSI. 173. The method of aspect 169, wherein the threshold is a relative value. 174. The method of aspect 173, wherein the threshold is ±10% of the load. 175. The method of aspect 173, wherein the threshold is ±0.01% of the load. 176. The method of aspect 169, wherein the first and second pressure sensors are leading pressure sensors. 177. The method of aspect 169, wherein the first and second pressure sensors are middle pressure sensors. 178. The method of aspect 169, wherein the first and second pressure sensors are trailing pressure sensors. 179. The method of aspect 168, wherein the at least one variable is height of the flat portion of each of the bearing pads relative to the runner surface, wherein measuring the first measurement comprises using a first proximity sensor configured to measure height of the flat portion of the first bearing pad relative to the runner surface, and wherein measuring the second measurement comprises using a second proximity sensor configured to measure height of the flat portion of the second bearing pad relative to the runner surface. 180. The method of aspect 179, wherein the threshold is an absolute value. 181. The method of aspect 180, wherein the threshold is ±1 m.Atty. Dkt. No. OU-23019WO 182. The method of aspect 180, wherein the threshold is ±1 µm. 183. The method of aspect 179, wherein the threshold is a relative value. 184. The method of aspect 183, wherein the threshold is ±10% of the taper depth. 185. The method of aspect 183, wherein the threshold is ±0.01% of the taper depth. 186. The method of aspect 168, further comprising flowing a lubricant between the plurality of bearing pads and a runner, wherein the hydrodynamic bearing comprises a lubricant inlet and a plurality of lubricant outlets, wherein the runner and the hydrodynamic bearing are configured to be separated by a lubricant layer, and wherein the lubricant layer comprises: a lubricant layer thickness; a minimum lubricant layer thickness (MLLT); and a lubricant temperature. 187. The method of aspect 186, wherein the at least one variable is lubricant layer thickness, wherein measuring the first measurement comprises using a first proximity sensor configured to measure lubricant layer thickness at the first bearing pad, wherein measuring the second measurement comprises using a second proximity sensor configured to measure lubricant layer thickness at the second bearing pad, and wherein measuring the third measurement comprises using a third proximity sensor configured to measure lubricant layer thickness at the third bearing pad. 188. The method of aspect 187 wherein the threshold is an absolute value. 189. The method of aspect 188, wherein the threshold is ±0.05”. 190. The method of aspect 188, wherein the threshold is ±0.0005”. 191. The method of aspect 187, wherein the wherein the threshold is a relative value. 192. The method of aspect 191, wherein the threshold is ±0.01% of the MLLT.Atty. Dkt. No. OU-23019WO 193. The method of aspect 191, wherein the threshold is ±10% of the MLLT. 194. The method of aspect 186, wherein the at least one variable is bearing pad temperature, wherein measuring the first measurement comprises using a first thermocouple configured to measure bearing pad temperature at the first bearing pad, and wherein measuring the second measurement comprises using a second thermocouple configured to measure bearing pad temperature at the second bearing pad. 195. The method of aspect 194 wherein the threshold is an absolute value. 196. The method of aspect 195, wherein the threshold is ±0.1°C”. 197. The method of aspect 195, wherein the threshold is ±10°C”. 198. The method of aspect 194, wherein the wherein the threshold is a relative value. 199. The method of aspect 198, wherein the threshold is ±0.1% of an average lubricant temperature. 200. The method of aspect 198, wherein the threshold is ±10% of an average lubricant temperature. 201. The method of aspect 168, further comprising measuring, using a plurality of secondary sensors, at least one secondary variable at a plurality of secondary bearing pads, comprising: measuring the at least one secondary variable, using a first secondary sensor, at a first secondary bearing pad; measuring the at least one secondary variable, using a second secondary sensor, at a second secondary bearing pad; wherein the first and / or second secondary bearing pad may comprise the first and / or second third bearing pad, wherein the at least one secondary variable is different from the at least one variable, and wherein the first, second, and third secondary sensors are selected from the list consisting of a pressure sensor, a proximity sensor, and a temperature sensor.Atty. Dkt. No. OU-23019WO 202. The method of aspect 201, wherein the first and second sensors comprise pressure sensors, and wherein the first and second secondary sensors comprise proximity sensors. 203. The method of any of aspects 179, 187, 201, and 202, wherein the proximity sensor is selected from a list consisting of an Eddy current sensor, a laser sensor, and ultrasonic sensor, or a combination thereof. 204. The method of aspect 168, wherein the plurality of sensors consists of only the first, second, and third sensors. 205. The method of aspect 168, wherein rotating the hydrodynamic bearing pad comprises rotating at least one of the first pivot frame and the second pivot frame by a constant rotational increment each time at least one of the first and second measurement exceeds the threshold by a positive or negative amount. 206. The method of aspect 205, wherein the constant rotational increment is greater than or equal to ±0.01°. 207. The method of aspect 205, wherein the constant rotational increment is less than or equal to ±10°. 208. The method of aspect 205, wherein the constant rotational increment is greater than or equal to ±1° and less than or equal to ±2°. 209. The method of aspect 168, wherein measuring the first and second measurements occurs at a measurement frequency. 210. The method of aspect 209, wherein the measurement frequency is greater than or equal to 10 Hz. 211. The method of aspect 209, wherein the measurement frequency is less than or equal to 100,000 Hz.Atty. Dkt. No. OU-23019WO 212. The method of aspect 209, wherein the measurement frequency is approximately equal to 1000Hz. 213. The method of aspect 168, wherein the method improves balance for a static load. 214. The method of aspect 168, wherein the method adjusts to a varying load, and wherein the average measurement is an average measurement of the varying load. 215. The method of aspect 168, wherein the plurality of bearing pads is radially distributed along an outer edge of the hydrodynamic bearing at a constant interval. 216. The method of aspect 215, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads. 217. The method of aspect 215, wherein the plurality of bearing pads is equal to a multiple of 4. 218. The method of aspect 217, wherein the first bearing pad is radially separated by 180° from the second bearing pad. 219. The method of aspect 218, wherein rotating the hydrodynamic bearing pad adjusts at least one of the first and second measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement comprises: wherein determining, using the processor, the average measurement of the at least one variable comprises using the first and second measurements; determining, using the processor, the difference between each of the first and second measurements and the average measurement; and rotating the hydrodynamic bearing using at least one of the first pivot frame and the second pivot frame until the first and second measurements are adjusted to a value within the threshold of the average measurement. 220. The method of aspect 215, wherein the plurality of bearing pads is equal to a multiple of 3.Atty. Dkt. No. OU-23019WO 221. The method of aspect 220, wherein the first bearing pad is radially separated from the second bearing pad by 120°. 222. The method of aspect 221, wherein rotating the hydrodynamic bearing pad adjusts at least one of the first and second measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement comprises: wherein determining, using the processor, the average measurement of the at least one variable comprises using the first and second measurements; determining, using the processor, the difference between each of the first and second measurements and the average measurement; and rotating the hydrodynamic bearing using at least one of the first pivot frame and the second pivot frame until the first, second, and third measurements are adjusted to a value within the threshold of the average measurement.

Claims

Atty. Dkt. No. OU-23019WO WHAT IS CLAIMED IS:

1. A system configured to balance a load received by a hydrodynamic bearing, comprising: a runner comprising a runner surface configured to interact with a first side of the hydrodynamic bearing; a base; the hydrodynamic bearing, wherein the hydrodynamic bearing comprises: a plurality of bearing pads on the first side of the hydrodynamic bearing, each bearing pad comprising: a first bearing pad section comprising a taper depth; and a second bearing pad section that is configured to be planarly parallel to the runner surface when the hydrodynamic bearing is in operation; a first pivot frame configured to rotate the hydrodynamic bearing relative to the base along a first axis of rotation, wherein the first axis of rotation is perpendicular to the runner surface; a second pivot frame configured to rotate the hydrodynamic bearing relative to the first pivot frame along a second axis of rotation, wherein the second axis of rotation is perpendicular to the runner surface and the first axis of rotation; and a plurality of sensors configured to measure at least one variable correlated to the alignment of the hydrodynamic bearing, comprising: a first sensor configured to measure a first measurement of the at least one variable at a first bearing pad; a second sensor configured to measure a second measurement of the at least one variable at a second bearing pad; and a third sensor configured to measure a third measurement of the at least one variable at a third bearing pad; wherein the first pivot frame and the second pivot frame are configured to rotate the hydrodynamic bearing in response to at least the first, second, and third measurements of the at least one variable until each measurement of the at least one variable is within a threshold of an average measurement of at least the first, second, and third measurement of the at least one variable.Atty. Dkt. No. OU-23019WO 2. The system of claim 1, wherein the at least one variable is pressure, wherein the first sensor comprises a first pressure sensor configured to measure pressure approximately equal to a first portion of the load received by the first bearing pad, wherein the second sensor comprises a second pressure sensor configured to measure pressure approximately equal to a second portion of the load received by the second bearing pad, and wherein the third sensor comprises a third pressure sensor configured to measure pressure approximately equal to a third portion of the load received by the third bearing pad.

3. The system of claim 2, wherein the threshold is an absolute value.

4. The system of claim 3, wherein the threshold is ±100 PSI.

5. The system of claim 3, wherein the threshold is ±0.5 PSI.

6. The system of claim 2, wherein the threshold is a relative value.

7. The system of claim 6, wherein the threshold is ±10% of the load.

8. The system of claim 6, wherein the threshold is ±0.01% of the load.

9. The system of claim 2, wherein the first, second, and third pressure sensors are leading pressure sensors.

10. The system of claim 2, wherein the first, second, and third pressure sensors are middle pressure sensors.

11. The system of claim 2, wherein the first, second, and third pressure sensors are trailing pressure sensors.

12. The system of claim 1, wherein the at least one variable is height of the flat portion of each of the bearing pads relative to the runner surface, wherein the first sensor comprises a first proximity sensor configured to measure height of the flat portion of the first bearing pad relative to the runner surface, wherein the second sensor comprises a second proximity sensor configured to measure height of the flat portion of the second bearing pad relative to the runner surface, andAtty. Dkt. No. OU-23019WO wherein the third sensor comprises a third proximity sensor configured to measure height of the flat portion of the third bearing pad relative to the runner surface.

13. The system of claim 12, wherein the threshold is an absolute value.

14. The system of claim 13, wherein the threshold is ±1 mm.

15. The system of claim 13, wherein the threshold is ±0.5 µm.

16. The system of claim 12, wherein the threshold is a relative value.

17. The system of claim 16, wherein the threshold is ±10% of the taper depth.

18. The system of claim 16, wherein the threshold is ±0.01% of the taper depth.

19. The system of claim 1, wherein the hydrodynamic bearing comprises a lubricant inlet and a plurality of lubricant outlets, wherein the runner surface and the first side of the hydrodynamic bearing are configured to be separated by a lubricant layer during operation of the system, and wherein the lubricant layer comprises: a lubricant layer thickness; a minimum lubricant layer thickness (MLLT); and a lubricant temperature.

20. The system of claim 19, wherein the at least one variable is lubricant layer thickness, wherein the first sensor comprises a first proximity sensor configured to measure lubricant layer thickness at the first bearing pad, wherein the second sensor comprises a second proximity sensor configured to measure lubricant layer thickness at the second bearing pad, and wherein the third sensor comprises a third proximity sensor configured to measure lubricant layer thickness at the third bearing pad.

21. The system of claim 20 wherein the threshold is an absolute value.

22. The system of claim 21, wherein the threshold is ±0.05”.Atty. Dkt. No. OU-23019WO 23. The system of claim 21, wherein the threshold is ±0.00005”.

24. The system of claim 20, wherein the wherein the threshold is a relative value.

25. The system of claim 24, wherein the threshold is ±0.01% of the MLLT.

26. The system of claim 24, wherein the threshold is ±10% of the MLLT.

27. The system of claim 1, wherein the at least one variable is bearing pad temperature, wherein the first sensor comprises a first thermocouple configured to measure bearing pad temperature at the first bearing pad, wherein the second sensor comprises a second thermocouple configured to measure bearing pad temperature at the second bearing pad, and wherein the third sensor comprises a third thermocouple configured to measure bearing pad temperature at the third bearing pad.

28. The system of claim 27 wherein the threshold is an absolute value.

29. The system of claim 28, wherein the threshold is ±0.1°C”.

30. The system of claim 28, wherein the threshold is ±10°C”.

31. The system of claim 27, wherein the wherein the threshold is a relative value.

32. The system of claim 31, wherein the threshold is ±0.01% of the average bearing pad temperature at the sensor location.

33. The system of claim 31, wherein the threshold is ±10% of the average bearing pad temperature at the sensor location.

34. The system of claim 1, further comprising a plurality of secondary sensors configured to measure at least one secondary variable at a plurality of secondary bearing pads, comprising: a first secondary sensor configured to measure the at least one secondary variable at a first secondary bearing pad;Atty. Dkt. No. OU-23019WO a second secondary sensor configured to measure the at least one secondary variable at a second secondary bearing pad; and a third secondary sensor configured to measure the at least one secondary variable at a third secondary bearing pad; wherein the first, second, and / or third secondary bearing pad may comprise the first, second, and / or third bearing pad, wherein the at least one secondary variable is different from the at least one variable, and wherein the first, second, and third secondary sensors are selected from the list consisting of a pressure sensor, a proximity sensor, and a temperature sensor.

35. The system of claim 34, wherein the first, second, and third sensors comprise pressure sensors, and wherein the first, second, and third secondary sensors comprise proximity sensors.

36. The system of any of claims 12, 20, 34, and 35, wherein the proximity sensor is selected from a list consisting of an Eddy current sensor, a laser sensor, and ultrasonic sensor, or a combination thereof.

37. The system of claim 1, wherein the plurality of sensors consists of only the first, second, and third sensors.

38. The system of claim 1, wherein at least one of the first pivot frame and the second pivot frame is configured to rotate by a constant rotational increment each time at least one of the first, second, and third measurement exceeds the threshold by a positive or negative amount.

39. The system of claim 38, wherein the constant rotational increment is greater than or equal to ±0.01°.

40. The system of claim 38, wherein the constant rotational increment is less than or equal to ±10°.

41. The system of claim 38, wherein the constant rotational increment is greater than or equal to ±1° and less than or equal to ±2°.Atty. Dkt. No. OU-23019WO 42. The system of claim 1, wherein each of the first, second, and third sensors are configured to measure the first, second, and third measurement at a measurement frequency.

43. The system of claim 42, wherein the measurement frequency is greater than or equal to 10 Hz.

44. The system of claim 42, wherein the measurement frequency is less than or equal to 100,000 Hz.

45. The system of claim 42, wherein the measurement frequency is approximately equal to 1000Hz.

46. The system of claim 1, wherein the system is configured to balance a static load.

47. The system of claim 1, wherein the system is configured to adjust a varying load, and wherein the average measurement is an average measurement of the varying load.

48. The system of claim 1, wherein the plurality of bearing pads is radially distributed along an outer edge of the hydrodynamic bearing at a constant interval.

49. The system of claim 48, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads.

50. The system of claim 48, wherein the plurality of bearing pads is equal to a multiple of 4.

51. The system of claim 50, wherein the first bearing pad is radially separated by 180° from the second bearing pad, and wherein the third bearing pad is radially separated from both the first and second bearing pads by 90°.

52. The system of claim 48, wherein the plurality of bearing pads is equal to a multiple of 3.

53. The system of claim 52, wherein the first bearing pad is radially separated from both the second and third bearing pads by 120°, and wherein the second bearing pad is radially separated from the third bearing pad by 120°.Atty. Dkt. No. OU-23019WO 54. The system of claim 48, wherein the plurality of sensors includes greater than or equal to 4 sensors, wherein each additional sensor is configured to measure the at least one variable, wherein the first pivot frame and the second pivot frame are further configured to rotate the hydrodynamic bearing in response to each of the additional measurements of the at least one variable until each measurement of the at least one variable is within a threshold of an average measurement of the first, second, third, and each additional measurement of the at least one variable.

55. The system of claim 54, wherein each bearing pad comprises one of the additional sensors configured to measure the at least one variable, and wherein each bearing pad is radially separated from each adjacent bearing pad by 360° / n, wherein n equals the number of bearing pads.

56. The system of claim 55, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads.

57. A method for balancing a load received by a hydrodynamic bearing comprising a plurality of bearing pads, the method comprising: measuring, using a plurality of sensors, at least one variable at a plurality of bearing pads, comprising: measuring a first measurement of the at least one variable, using a first sensor, at a first bearing pad; measuring a second measurement of the at least one variable, using a second sensor, at a second bearing pad; and measuring a third measurement of the at least one variable, using a third sensor, at a third bearing pad; determining, using a processor, an average measurement of the at least one variable using at least two of the measurements; and rotating the hydrodynamic bearing, using at least one of a first pivot frame configured to rotate along a first axis relative to a base and a second pivot frame configured to rotate relative to the first pivot frame along a second axis of rotation, in a manner selected from the group consisting of:Atty. Dkt. No. OU-23019WO rotating the hydrodynamic bearing along the first axis of rotation, rotating the hydrodynamic bearing along the second axis of rotation, and rotating the hydrodynamic bearing along both the first axis of rotation and the second axis of rotation; wherein the first pivot frame is configured to rotate the hydrodynamic bearing along the first axis of rotation, and wherein the second pivot frame is configured to rotate the hydrodynamic bearing along the second axis of rotation wherein the first axis of rotation is perpendicular to the load received, and wherein the second axis of rotation is perpendicular to the load received and the first axis of rotation, wherein rotating the hydrodynamic bearing adjusts at least one of the first, second, and third measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement.

58. The method of claim 57, wherein the at least one variable is pressure, wherein measuring the first measurement comprises using a first pressure sensor configured to measure pressure approximately equal to a first portion of the load received by the first bearing pad, wherein measuring the second measurement comprises using a second pressure sensor configured to measure pressure approximately equal to a second portion of the load received by the second bearing pad, and wherein measuring the third measurement comprises using a third pressure sensor configured to measure pressure approximately equal to a third portion of the load received by the third bearing pad.

59. The method of claim 58, wherein the threshold is an absolute value.

60. The method of claim 59, wherein the threshold is ±100 PSI.

61. The method of claim 59, wherein the threshold is ±0.5 PSI.

62. The method of claim 58, wherein the threshold is a relative value.

63. The method of claim 62, wherein the threshold is ±10% of the load.

64. The method of claim 62, wherein the threshold is ±0.01% of the load.Atty. Dkt. No. OU-23019WO 65. The method of claim 58, wherein the first, second, and third pressure sensors are leading pressure sensors.

66. The method of claim 58, wherein the first, second, and third pressure sensors are middle pressure sensors.

67. The method of claim 58, wherein the first, second, and third pressure sensors are trailing pressure sensors.

68. The method of claim 57, wherein the at least one variable is height of the flat portion of each of the bearing pads relative to the runner surface, wherein measuring the first measurement comprises using a first proximity sensor configured to measure height of the flat portion of the first bearing pad relative to the runner surface, wherein measuring the second measurement comprises using a second proximity sensor configured to measure height of the flat portion of the second bearing pad relative to the runner surface, and wherein measuring the third measurement comprises using a third proximity sensor configured to measure height of the flat portion of the third bearing pad relative to the runner surface.

69. The method of claim 68, wherein the threshold is an absolute value.

70. The method of claim 69, wherein the threshold is ±1 m.

71. The method of claim 69, wherein the threshold is ±1 µm.

72. The method of claim 68, wherein the threshold is a relative value.

73. The method of claim 72, wherein the threshold is ±10% of the taper depth.

74. The method of claim 72, wherein the threshold is ±0.01% of the taper depth.

75. The method of claim 57, further comprising flowing a lubricant between the plurality of bearing pads and a runner, wherein the hydrodynamic bearing comprises a lubricant inlet and aAtty. Dkt. No. OU-23019WO plurality of lubricant outlets, wherein the runner and the hydrodynamic bearing are configured to be separated by a lubricant layer, and wherein the lubricant layer comprises: a lubricant layer thickness; a minimum lubricant layer thickness (MLLT); and a lubricant temperature.

76. The method of claim 75, wherein the at least one variable is lubricant layer thickness, wherein measuring the first measurement comprises using a first proximity sensor configured to measure lubricant layer thickness at the first bearing pad, wherein measuring the second measurement comprises using a second proximity sensor configured to measure lubricant layer thickness at the second bearing pad, and wherein measuring the third measurement comprises using a third proximity sensor configured to measure lubricant layer thickness at the third bearing pad.

77. The method of claim 76 wherein the threshold is an absolute value.

78. The method of claim 77, wherein the threshold is ±0.05”.

79. The method of claim 77, wherein the threshold is ±0.0005”.

80. The method of claim 76, wherein the wherein the threshold is a relative value.

81. The method of claim 80, wherein the threshold is ±0.01% of the MLLT.

82. The method of claim 80, wherein the threshold is ±10% of the MLLT.

83. The method of claim 75, wherein the at least one variable is bearing pad temperature, wherein measuring the first measurement comprises using a first thermocouple configured to measure bearing pad temperature at the first bearing pad, wherein measuring the second measurement comprises using a second thermocouple configured to measure bearing pad temperature at the second bearing pad, and wherein measuring the third measurement comprises using a third thermocouple configured to measure bearing pad temperature at the third bearing pad.Atty. Dkt. No. OU-23019WO 84. The method of claim 83 wherein the threshold is an absolute value.

85. The method of claim 84, wherein the threshold is ±0.1°C”.

86. The method of claim 84, wherein the threshold is ±10°C”.

87. The method of claim 83, wherein the wherein the threshold is a relative value.

88. The method of claim 87, wherein the threshold is ±0.1% of an average lubricant temperature.

89. The method of claim 87, wherein the threshold is ±10% of an average lubricant temperature.

90. The method of claim 57, further comprising measuring, using a plurality of secondary sensors, at least one secondary variable at a plurality of secondary bearing pads, comprising: measuring the at least one secondary variable, using a first secondary sensor, at a first secondary bearing pad; measuring the at least one secondary variable, using a second secondary sensor, at a second secondary bearing pad; measuring the at least one secondary variable, using a third secondary sensor, at a third secondary bearing pad; wherein the first, second, and / or third secondary bearing pad may comprise the first, second, and / or third bearing pad, wherein the at least one secondary variable is different from the at least one variable, and wherein the first, second, and third secondary sensors are selected from the list consisting of a pressure sensor, a proximity sensor, and a temperature sensor.

91. The method of claim 90, wherein the first, second, and third sensors comprise pressure sensors, and wherein the first, second, and third secondary sensors comprise proximity sensors.Atty. Dkt. No. OU-23019WO 92. The method of any of claims 68, 76, 90, and 91, wherein the proximity sensor is selected from a list consisting of an Eddy current sensor, a laser sensor, and ultrasonic sensor, or a combination thereof.

93. The method of claim 57, wherein the plurality of sensors consists of only the first, second, and third sensors.

94. The method of claim 57, wherein rotating the hydrodynamic bearing pad comprises rotating at least one of the first pivot frame and the second pivot frame by a constant rotational increment each time at least one of the first, second, and third measurement exceeds the threshold by a positive or negative amount.

95. The method of claim 94, wherein the constant rotational increment is greater than or equal to ±0.01°.

96. The method of claim 94, wherein the constant rotational increment is less than or equal to ±10°.

97. The method of claim 94, wherein the constant rotational increment is greater than or equal to ±1° and less than or equal to ±2°.

98. The method of claim 57, wherein measuring the first, second, and third measurements occurs at a measurement frequency.

99. The method of claim 98, wherein the measurement frequency is greater than or equal to 10 Hz.

100. The method of claim 98, wherein the measurement frequency is less than or equal to 100,000 Hz.

101. The method of claim 98, wherein the measurement frequency is approximately equal to 1000Hz.

102. The method of claim 57, wherein the method balances a static load.Atty. Dkt. No. OU-23019WO 103. The method of claim 57, wherein the method adjusts to a varying load, and wherein the average measurement is an average measurement of the varying load.

104. The method of claim 57, wherein the plurality of bearing pads is radially distributed along an outer edge of the hydrodynamic bearing at a constant interval.

105. The method of claim 104, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads.

106. The method of claim 104, wherein the plurality of bearing pads is equal to a multiple of 4.

107. The method of claim 106, wherein the first bearing pad is radially separated by 180° from the second bearing pad, and wherein the third bearing pad is radially separated from both the first and second bearing pads by 90°.

108. The method of claim 107, wherein rotating the hydrodynamic bearing pad adjusts at least one of the first, second, and third measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement comprises: wherein determining, using the processor, the average measurement of the at least one variable comprises using the first and second measurements; determining, using the processor, the difference between each of the first, second, and third measurements and the average measurement; and rotating the hydrodynamic bearing using at least one of the first pivot frame and the second pivot frame until the first, second, and third measurements are adjusted to a value within the threshold of the average measurement.

109. The method of claim 104, wherein the plurality of bearing pads is equal to a multiple of 3.

110. The method of claim 109, wherein the first bearing pad is radially separated from both the second and third bearing pads by 120°, and wherein the second bearing pad is radially separated from the third bearing pad by 120°.Atty. Dkt. No. OU-23019WO 111. The method of claim 110, wherein rotating the hydrodynamic bearing pad adjusts at least one of the first, second, and third measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement comprises: wherein determining, using the processor, the average measurement of the at least one variable comprises using the first, second, and third measurements; determining, using the processor, the difference between each of the first, second, and third measurements and the average measurement; and rotating the hydrodynamic bearing using at least one of the first pivot frame and the second pivot frame until the first, second, and third measurements are adjusted to a value within the threshold of the average measurement.

112. The method of claim 104, wherein the plurality of sensors includes greater than or equal to 4 sensors; wherein measuring, using the plurality of sensors, the at least one variable comprises measuring an additional measurement of the at least one variable using each additional sensor; and wherein rotating the hydrodynamic bearing, using at least one of the first pivot frame and the second pivot frame, are further comprises adjusting each of the additional measurements of the at least one variable until each measurement of the at least one variable is within a threshold of the average measurement.

113. The method of claim 112, wherein each bearing pad comprises one of the additional sensors configured to measure the at least one variable, and wherein each bearing pad is radially separated from each adjacent bearing pad by 360° / n, wherein n equals the number of bearing pads.

114. The method of claim 113, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads.

115. A system configured to improve load balancing for a hydrodynamic bearing, comprising: a runner comprising a runner surface configured to interact with a first side of the hydrodynamic bearing; a base; the hydrodynamic bearing, wherein the hydrodynamic bearing comprises:Atty. Dkt. No. OU-23019WO a plurality of bearing pads on the first side of the hydrodynamic bearing, each bearing pad comprising: a first bearing pad section comprising a taper depth; and a second bearing pad section that is configured to be planarly parallel to the runner surface when the hydrodynamic bearing is in operation; a first pivot frame configured to rotate the hydrodynamic bearing relative to the base along a first axis of rotation, wherein the first axis of rotation is perpendicular to the runner surface; a second pivot frame configured to rotate the hydrodynamic bearing relative to the first pivot frame along a second axis of rotation, wherein the second axis of rotation is perpendicular to the runner surface and the first axis of rotation; and a plurality of sensors configured to measure at least one variable correlated to the alignment of the hydrodynamic bearing, comprising: a first sensor configured to measure a first measurement of the at least one variable at a first bearing pad of the plurality of bearing pads; and a second sensor configured to measure a second measurement of the at least one variable at a second bearing pad of the plurality of bearing pads; wherein the first pivot frame and the second pivot frame are configured to rotate the hydrodynamic bearing in response to the first and second measurements of the at least one variable until each measurement of the at least one variable is within a threshold of an average measurement of the first and second measurement of the at least one variable.

116. The system of claim 115, wherein the at least one variable is pressure, wherein the first sensor comprises a first pressure sensor configured to measure pressure approximately equal to a first portion of the load received by the first bearing pad, and wherein the second sensor comprises a second pressure sensor configured to measure pressure approximately equal to a second portion of the load received by the second bearing pad.

117. The system of claim 116, wherein the threshold is an absolute value.

118. The system of claim 117, wherein the threshold is ±100 PSI.Atty. Dkt. No. OU-23019WO 119. The system of claim 117, wherein the threshold is ±0.5 PSI.

120. The system of claim 116, wherein the threshold is a relative value.

121. The system of claim 120, wherein the threshold is ±10% of the load.

122. The system of claim 120, wherein the threshold is ±0.01% of the load.

123. The system of claim 116, wherein the first and second pressure sensors are leading pressure sensors.

124. The system of claim 116, wherein the first and second pressure sensors are middle pressure sensors.

125. The system of claim 116, wherein the first and second pressure sensors are trailing pressure sensors.

126. The system of claim 115, wherein the at least one variable is height of the flat portion of each of the bearing pads relative to the runner surface, wherein the first sensor comprises a first proximity sensor configured to measure height of the flat portion of the first bearing pad relative to the runner surface, and wherein the second sensor comprises a second proximity sensor configured to measure height of the flat portion of the second bearing pad relative to the runner surface.

127. The system of claim 126, wherein the threshold is an absolute value.

128. The system of claim 127, wherein the threshold is ±1 mm.

129. The system of claim 127, wherein the threshold is ±0.5 µm.

130. The system of claim 126, wherein the threshold is a relative value.

131. The system of claim 130, wherein the threshold is ±10% of the taper depth.Atty. Dkt. No. OU-23019WO 132. The system of claim 130, wherein the threshold is ±0.01% of the taper depth.

133. The system of claim 115, wherein the hydrodynamic bearing comprises a lubricant inlet and a plurality of lubricant outlets, wherein the runner surface and the first side of the hydrodynamic bearing are configured to be separated by a lubricant layer during operation of the system, and wherein the lubricant layer comprises: a lubricant layer thickness; a minimum lubricant layer thickness (MLLT); and a lubricant temperature.

134. The system of claim 133, wherein the at least one variable is lubricant layer thickness, wherein the first sensor comprises a first proximity sensor configured to measure lubricant layer thickness at the first bearing pad, and wherein the second sensor comprises a second proximity sensor configured to measure lubricant layer thickness at the second bearing pad.

135. The system of claim 134 wherein the threshold is an absolute value.

136. The system of claim 135, wherein the threshold is ±0.05”.

137. The system of claim 135, wherein the threshold is ±0.00005”.

138. The system of claim 134, wherein the wherein the threshold is a relative value.

139. The system of claim 138, wherein the threshold is ±0.01% of the MLLT.

140. The system of claim 138, wherein the threshold is ±10% of the MLLT.

141. The system of claim 115, wherein the at least one variable is bearing pad temperature, wherein the first sensor comprises a first thermocouple configured to measure bearing pad temperature at the first bearing pad, and wherein the second sensor comprises a second thermocouple configured to measure bearing pad temperature at the second bearing pad.

142. The system of claim 141 wherein the threshold is an absolute value.Atty. Dkt. No. OU-23019WO 143. The system of claim 142, wherein the threshold is ±0.1°C”.

144. The system of claim 142, wherein the threshold is ±10°C”.

145. The system of claim 141, wherein the wherein the threshold is a relative value.

146. The system of claim 145, wherein the threshold is ±0.01% of the average bearing pad temperature at the sensor location.

147. The system of claim 145, wherein the threshold is ±10% of the average bearing pad temperature at the sensor location.

148. The system of claim 115, further comprising a plurality of secondary sensors configured to measure at least one secondary variable at a plurality of secondary bearing pads, comprising: a first secondary sensor configured to measure the at least one secondary variable at a first secondary bearing pad; and a second secondary sensor configured to measure the at least one secondary variable at a second secondary bearing pad; wherein the first and / or second secondary bearing pad may comprise the first and / or second third bearing pad, wherein the at least one secondary variable is different from the at least one variable, and wherein the first and second secondary sensors are selected from the list consisting of a pressure sensor, a proximity sensor, and a temperature sensor.

149. The system of claim 148, wherein the first and second sensors comprise pressure sensors, and wherein the first and second secondary sensors comprise proximity sensors.

150. The system of any of claims 126, 134, 148, and 149, wherein the proximity sensor is selected from a list consisting of an Eddy current sensor, a laser sensor, and ultrasonic sensor, or a combination thereof.

151. The system of claim 115, wherein the plurality of sensors consists of only the first and second sensors.Atty. Dkt. No. OU-23019WO 152. The system of claim 115, wherein at least one of the first pivot frame and the second pivot frame is configured to rotate by a constant rotational increment each time at least one of the first and second measurement exceeds the threshold by a positive or negative amount.

153. The system of claim 152, wherein the constant rotational increment is greater than or equal to ±0.01°.

154. The system of claim 152, wherein the constant rotational increment is less than or equal to ±10°.

155. The system of claim 152, wherein the constant rotational increment is greater than or equal to ±1° and less than or equal to ±2°.

156. The system of claim 115, wherein each of the first, second, and third sensors are configured to measure the first, second, and third measurement at a measurement frequency.

157. The system of claim 156, wherein the measurement frequency is greater than or equal to 10 Hz.

158. The system of claim 156, wherein the measurement frequency is less than or equal to 100,000 Hz.

159. The system of claim 156, wherein the measurement frequency is approximately equal to 1000Hz.

160. The system of claim 115, wherein the system is configured to improve balancing of a static load.

161. The system of claim 115, wherein the system is configured to adjust a varying load, and wherein the average measurement is an average measurement of the varying load.

162. The system of claim 115, wherein the plurality of bearing pads is radially distributed along an outer edge of the hydrodynamic bearing at a constant interval.Atty. Dkt. No. OU-23019WO 163. The system of claim 162, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads.

164. The system of claim 162, wherein the plurality of bearing pads is equal to a multiple of 4.

165. The system of claim 164, wherein the first bearing pad is radially separated by 180° from the second bearing pad.

166. The system of claim 162, wherein the plurality of bearing pads is equal to a multiple of 3.

167. The system of claim 166, wherein the first bearing pad is radially separated from the second bearing pad by 120°.

168. A method for improving balance of a load received by a hydrodynamic bearing comprising a plurality of bearing pads, the method comprising: measuring, using a plurality of sensors, at least one variable at a plurality of bearing pads, comprising: measuring a first measurement of the at least one variable, using a first sensor, received at a first bearing pad; and measuring a second measurement of the at least one variable, using a second sensor, received at a second bearing pad; determining, using a processor, an average measurement of the at least one variable using the first and second measurements; and rotating the hydrodynamic bearing, using at least one of a first pivot frame configured to rotate along a first axis relative to a base and a second pivot frame configured to rotate relative to the first pivot frame along a second axis of rotation, in a manner selected from the group consisting of: rotating the hydrodynamic bearing along the first axis of rotation, rotating the hydrodynamic bearing along the second axis of rotation, and rotating the hydrodynamic bearing along both the first axis of rotation and the second axis of rotation;Atty. Dkt. No. OU-23019WO wherein the first pivot frame is configured to rotate the hydrodynamic bearing along the first axis of rotation, and wherein the second pivot frame is configured to rotate the hydrodynamic bearing along the second axis of rotation wherein the first axis of rotation is perpendicular to the load received, and wherein the second axis of rotation is perpendicular to the load received and the first axis of rotation, wherein rotating the hydrodynamic bearing adjusts at least one of the first and second measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement.

169. The method of claim 168, wherein the at least one variable is pressure, wherein measuring the first measurement comprises using a first pressure sensor configured to measure pressure approximately equal to a first portion of the load received by the first bearing pad, and wherein measuring the second measurement comprises using a second pressure sensor configured to measure pressure approximately equal to a second portion of the load received by the second bearing pad.

170. The method of claim 169, wherein the threshold is an absolute value.

171. The method of claim 170, wherein the threshold is ±100 PSI.

172. The method of claim 170, wherein the threshold is ±0.5 PSI.

173. The method of claim 169, wherein the threshold is a relative value.

174. The method of claim 173, wherein the threshold is ±10% of the load.

175. The method of claim 173, wherein the threshold is ±0.01% of the load.

176. The method of claim 169, wherein the first and second pressure sensors are leading pressure sensors.

177. The method of claim 169, wherein the first and second pressure sensors are middle pressure sensors.Atty. Dkt. No. OU-23019WO 178. The method of claim 169, wherein the first and second pressure sensors are trailing pressure sensors.

179. The method of claim 168, wherein the at least one variable is height of the flat portion of each of the bearing pads relative to the runner surface, wherein measuring the first measurement comprises using a first proximity sensor configured to measure height of the flat portion of the first bearing pad relative to the runner surface, and wherein measuring the second measurement comprises using a second proximity sensor configured to measure height of the flat portion of the second bearing pad relative to the runner surface.

180. The method of claim 179, wherein the threshold is an absolute value.

181. The method of claim 180, wherein the threshold is ±1 m.

182. The method of claim 180, wherein the threshold is ±1 µm.

183. The method of claim 179, wherein the threshold is a relative value.

184. The method of claim 183, wherein the threshold is ±10% of the taper depth.

185. The method of claim 183, wherein the threshold is ±0.01% of the taper depth.

186. The method of claim 168, further comprising flowing a lubricant between the plurality of bearing pads and a runner, wherein the hydrodynamic bearing comprises a lubricant inlet and a plurality of lubricant outlets, wherein the runner and the hydrodynamic bearing are configured to be separated by a lubricant layer, and wherein the lubricant layer comprises: a lubricant layer thickness; a minimum lubricant layer thickness (MLLT); and a lubricant temperature.

187. The method of claim 186, wherein the at least one variable is lubricant layer thickness, wherein measuring the first measurement comprises using a first proximity sensor configured toAtty. Dkt. No. OU-23019WO measure lubricant layer thickness at the first bearing pad, wherein measuring the second measurement comprises using a second proximity sensor configured to measure lubricant layer thickness at the second bearing pad, and wherein measuring the third measurement comprises using a third proximity sensor configured to measure lubricant layer thickness at the third bearing pad.

188. The method of claim 187 wherein the threshold is an absolute value.

189. The method of claim 188, wherein the threshold is ±0.05”.

190. The method of claim 188, wherein the threshold is ±0.0005”.

191. The method of claim 187, wherein the wherein the threshold is a relative value.

192. The method of claim 191, wherein the threshold is ±0.01% of the MLLT.

193. The method of claim 191, wherein the threshold is ±10% of the MLLT.

194. The method of claim 186, wherein the at least one variable is bearing pad temperature, wherein measuring the first measurement comprises using a first thermocouple configured to measure bearing pad temperature at the first bearing pad, and wherein measuring the second measurement comprises using a second thermocouple configured to measure bearing pad temperature at the second bearing pad.

195. The method of claim 194 wherein the threshold is an absolute value.

196. The method of claim 195, wherein the threshold is ±0.1°C”.

197. The method of claim 195, wherein the threshold is ±10°C”.

198. The method of claim 194, wherein the wherein the threshold is a relative value.

199. The method of claim 198, wherein the threshold is ±0.1% of an average lubricant temperature.Atty. Dkt. No. OU-23019WO 200. The method of claim 198, wherein the threshold is ±10% of an average lubricant temperature.

201. The method of claim 168, further comprising measuring, using a plurality of secondary sensors, at least one secondary variable at a plurality of secondary bearing pads, comprising: measuring the at least one secondary variable, using a first secondary sensor, at a first secondary bearing pad; measuring the at least one secondary variable, using a second secondary sensor, at a second secondary bearing pad; wherein the first and / or second secondary bearing pad may comprise the first and / or second third bearing pad, wherein the at least one secondary variable is different from the at least one variable, and wherein the first, second, and third secondary sensors are selected from the list consisting of a pressure sensor, a proximity sensor, and a temperature sensor.

202. The method of claim 201, wherein the first and second sensors comprise pressure sensors, and wherein the first and second secondary sensors comprise proximity sensors.

203. The method of any of claims 179, 187, 201, and 202, wherein the proximity sensor is selected from a list consisting of an Eddy current sensor, a laser sensor, and ultrasonic sensor, or a combination thereof.

204. The method of claim 168, wherein the plurality of sensors consists of only the first, second, and third sensors.

205. The method of claim 168, wherein rotating the hydrodynamic bearing pad comprises rotating at least one of the first pivot frame and the second pivot frame by a constant rotational increment each time at least one of the first and second measurement exceeds the threshold by a positive or negative amount.

206. The method of claim 205, wherein the constant rotational increment is greater than or equal to ±0.01°.Atty. Dkt. No. OU-23019WO 207. The method of claim 205, wherein the constant rotational increment is less than or equal to ±10°.

208. The method of claim 205, wherein the constant rotational increment is greater than or equal to ±1° and less than or equal to ±2°.

209. The method of claim 168, wherein measuring the first and second measurements occurs at a measurement frequency.

210. The method of claim 209, wherein the measurement frequency is greater than or equal to 10 Hz.

211. The method of claim 209, wherein the measurement frequency is less than or equal to 100,000 Hz.

212. The method of claim 209, wherein the measurement frequency is approximately equal to 1000Hz.

213. The method of claim 168, wherein the method improves balance for a static load.

214. The method of claim 168, wherein the method adjusts to a varying load, and wherein the average measurement is an average measurement of the varying load.

215. The method of claim 168, wherein the plurality of bearing pads is radially distributed along an outer edge of the hydrodynamic bearing at a constant interval.

216. The method of claim 215, wherein the plurality of bearing pads consists of greater than or equal to 3 bearing pads and less than or equal to 12 bearing pads.

217. The method of claim 215, wherein the plurality of bearing pads is equal to a multiple of 4.

218. The method of claim 217, wherein the first bearing pad is radially separated by 180° from the second bearing pad.Atty. Dkt. No. OU-23019WO 219. The method of claim 218, wherein rotating the hydrodynamic bearing pad adjusts at least one of the first and second measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement comprises: wherein determining, using the processor, the average measurement of the at least one variable comprises using the first and second measurements; determining, using the processor, the difference between each of the first and second measurements and the average measurement; and rotating the hydrodynamic bearing using at least one of the first pivot frame and the second pivot frame until the first and second measurements are adjusted to a value within the threshold of the average measurement.

220. The method of claim 215, wherein the plurality of bearing pads is equal to a multiple of 3.

221. The method of claim 220, wherein the first bearing pad is radially separated from the second bearing pad by 120°.

222. The method of claim 221, wherein rotating the hydrodynamic bearing pad adjusts at least one of the first and second measurements so that, after the adjustment, each measurement has a value within a threshold of the average measurement comprises: wherein determining, using the processor, the average measurement of the at least one variable comprises using the first and second measurements; determining, using the processor, the difference between each of the first and second measurements and the average measurement; and rotating the hydrodynamic bearing using at least one of the first pivot frame and the second pivot frame until the first, second, and third measurements are adjusted to a value within the threshold of the average measurement.

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