Thrust Bearing System and Method For Operating The Same

Abstract

A fluid machine and method of operating the same includes a pump portion having a pump impeller chamber, a pump inlet and a pump outlet, a turbine portion having a turbine impeller chamber, a turbine inlet and a turbine outlet and a shaft extending between the pump impeller chamber and the turbine impeller chamber. The fluid machine also includes a first bearing and a second bearing spaced apart to form a balance disk chamber. A balance disk is coupled to the shaft and is disposed within the balance disk chamber and a turbine impeller coupled to the impeller end of the shaft disposed within the impeller chamber. A first thrust bearing is formed between the balance disk and the first bearing. The thrust bearing receives fluid from at least one of the pump inlet or the turbine outlet.

Claims

1. A fluid machine comprising: a pump portion having a pump impeller chamber, a pump inlet and a pump outlet; a turbine portion having a turbine impeller chamber, a turbine inlet and a turbine outlet; a shaft extending between the pump impeller chamber and the turbine impeller chamber; a first bearing and a second bearing spaced apart to form a balance disk chamber; a balance disk coupled to the shaft and disposed within the balance disk chamber; a turbine impeller coupled to the shaft disposed within the turbine impeller chamber; and a first thrust bearing formed between the balance disk and the first bearing, said thrust bearing receiving fluid from at least one of the pump inlet or the turbine outlet.

2. A fluid machine as recited in claim 1 further comprising a filter filtering the fluid from the pump inlet into the first thrust bearing.

3. A fluid machine as recited in claim 1 further comprising a proximity sensor generating a proximity signal corresponding to a distance between the balance disk and the first bearing or the second bearing.

4. A fluid machine as recited in claim 1 further comprising a heat exchanger coupling in fluid communication with the balance disk chamber.

5. A fluid machine as recited in claim 4 wherein the heat exchanger communicates fluid between the balance disk chamber to a thrust bearing inlet port.

6. A fluid machine as recited in claim 1 wherein the balance disk is coupled disposed between the pump portion and the turbine portion.

7. A fluid machine as recited in claim 1 wherein the first bearing comprises a turbine bearing and the second bearing comprises a pump bearing.

8. A fluid machine as recited in claim 1 further comprising a first valve selectively coupling either the turbine inlet or the pump outlet to the balance disk chamber.

9. A fluid machine as recited in claim 8 further comprising a second valve receiving fluid from the first valve and selectively coupling the fluid to the first thrust bearing or a second thrust bearing; wherein the first thrust bearing is formed on a first side of the balance disk and the second thrust bearing is formed on a second side of the balance disk.

10. A fluid machine as recited in claim 9 further comprising a first channel and a second channel through a casing, said first channel and said second channel selectively coupled to the second valve.

11. A fluid machine as recited in claim 10 further comprising a third channel disposed between the first channel and the second channel, said third channel directed adjacent to a peripheral edge of the balance disk.

12. A fluid machine as recited in claim 11 wherein the second valve simultaneously communicates the fluid through the second channel and third channel or simultaneously through the first channel and the third channel.

13. A fluid machine as recited in claim 1 wherein the balance disk is disposed adjacent to the turbine portion.

14. A fluid machine as recited in claim 13 wherein the balance disk is disposed within a disk casing.

15. A fluid machine as recited in claim 14 wherein the balance disk is disposed between a turbine outlet and a bearing casing

16. A fluid machine as recited in claim 15 wherein the turbine outlet is perpendicular to the shaft.

17. A fluid machine as recited in claim 16 wherein the balance disk is coupled to the shaft using a shaft extension.

18. A fluid machine as recited in claim 1 wherein the balance disk comprises a first side and a second side and a flow channel fluidically coupling the first side and the second side through the balance disk.

19. A fluid machine as recited in claim 18 wherein the first side corresponds to a pump side and the second side corresponds to a turbine side within the first thrust bearing.

20. A fluid machine as recited in claim 18 wherein the first side corresponds to a turbine side and the second side corresponds to a pump side within the first thrust bearing.

21. A fluid machine as recited in claim 18 wherein the flow channel comprises a first axial portion disposed adjacent to the shaft at the first side, a radial portion extending radially within the balance disk and a second axial portion extending axially to the second side radially outward from the shaft relative to the first axial portion.

22. A method of operating a fluid machine comprising: communicating fluid from a pump outlet or a turbine inlet to a thrust bearing formed by a balance disk coupled to a shaft; rotating the balance disk between a first bearing and a second bearing; and generating an axial force in response to communicating fluid in response to communicating and generating.

23. A method as recited in claim 22 wherein communicating fluid comprises communicating fluid to a bearing cavity between a pump portion and turbine portion of a hydraulic pressure booster.

24. A method as recited in claim 22 wherein communicating fluid comprises communicating fluid to a bearing cavity formed in a casing extension at a turbine end of a hydraulic pressure booster.

25. A fluid machine as recited in claim 22 further comprising coupling fluid from a first side of the balance disk to a second side of the balance disk through the balance disk

26. A fluid machine as recited in claim 25 wherein coupling fluid comprises coupling fluid through a flow channel comprising a first axial portion disposed adjacent to the shaft at the first side, a radial portion extending radially within the balance disk and a second axial portion extending axially to the second side radially outward from the shaft relative to the first axial portion

Description

DRAWINGS

[0036] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

[0037] FIG. 1 is a cross-sectional view of a first turbocharger according to the prior art.

[0038] FIG. 2 is a cross-sectional view of a first fluid machine according to the prior art.

[0039] FIG. 3 is an end view of an impeller of FIG. 2.

[0040] FIG. 4 is a cross-sectional view of a second fluid machine according to the prior art.

[0041] FIG. 5 is a cross-sectional view of a third example of a turbine portion according to the prior art.

[0042] FIG. 6 is a cross-sectional view of a fourth example of a turbine portion according to the prior art.

[0043] FIG. 7 is a cross-sectional view of an alternative example of an impeller of the prior art.

[0044] FIG. 8A is a cross-sectional view of a first example according to the present disclosure.

[0045] FIG. 8B is a front view of the balance disk of FIG. 8A.

[0046] FIG. 8C is a cross-sectional view of the balance disk relative to a bearing surface of FIG. 8A.

[0047] FIG. 8D is a cross-sectional view of a second example according to the present disclosure.

[0048] FIG. 8E is a cross-sectional view of a third example according to the present disclosure

[0049] FIG. 9 is a fourth example of a hydraulic pressure booster according to a second example of the disclosure.

DETAILED DESCRIPTION

[0050] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical OR. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure.

[0051] In the following description, a hydraulic pressure booster having a turbine portion and pump portion is illustrated. However, the present disclosure applies equally to other fluid machines. The present disclosure provides a way to deliver pumpage to a thrust bearing over the operating range of the device. Debris entering the turbine is also reduced.

[0052] Referring now to FIG. 8A, a hydraulic pressure booster 910 according to the present disclosure is set forth. In this example, the components with the same reference numerals described above in FIGS. 1-7 are set forth. In this example, the hydraulic pressure booster 910 includes a first bearing 912 and a second bearing 914 that are spaced apart. In this example, the bearing 912 may be referred to as a turbine bearing and the bearing 914 may be referred to as a pump bearing. The pump bearing 914 and turbine bearing 912 define a balance disk chamber 916. The balance disk chamber 916 houses a balance disk 918 which is rotatably coupled to the common shaft 20. The bearing 912 has a first side 912A that is disposed adjacent to the turbine impeller 40 and a second side 912B within the balance disk chamber 916. The bearing 914 has a first side 914A adjacent to the pump impeller 22 and a second side 914B within the balance disk chamber 916. The bearings 912 and 914 provide radial support for the shaft 920. The turbine outlet 44 is coaxial with the shaft 20.

[0053] The balance disk 918 has a first surface 918A that faces surface 912B and a second surface 918B that faces the second surface 914B. Surface 918A has a land 930. The second surface 918B has a second land 932. The lands 930 and 932 are annular in shape. In an alternate example, the land 930 may be disposed on the surface 912B. Land 932 may also be disposed on the surface 914B.

[0054] A first thrust bearing 940 is defined by the volume between the first surface 912B, surface 918A and the first land 930. A second thrust bearing 942 is defined between the surface 914B, surface 918B and the land 932. The thrust bearing and the land 932. The thrust bearings 940, 942 are provided with process fluid from either the turbine flow or the feed flow as will be defined below. Fluid is communicated to the first thrust bearing 940 through an inlet port 944. Fluid is communicated to the second thrust bearing 942 through a port 946. The port 944 is in fluid communication with a channel 948 that extends through the bearing 912 and the casing 26. A channel 950 is in fluid communication with the port 946 through the bearing 914 and the casing 26. Another channel 952 may extend through the casing 26 and provide fluid adjacent to the balance disk 918.

[0055] A first pipe 954 may communicate fluid to the first channel 948. A second pipe 956 communicates processed fluid to the channel 950. Pipe 958 communicates fluid to the channel 950.

[0056] Each of the pipes 954, 956 and 958 may be in communication with a four-way valve 960. The four-way valve 960 selectively communicates fluid to the pipes 954-956. It should be noted that the four-way valve 960 may receive fluid from a filter 962. The filter 962 filters out contaminants from the process fluid before reaching the pipes 954-958. Fluid from the filter 962 is communicated through a pipe 964.

[0057] In operation, the four-way valve 960 may be eliminated if the hydraulic pressure booster 910 is used in one or selected operating conditions. That is, the loads acting on the shaft from the turbine impeller 40 or the pump impeller 22 may always act in a constant direction during operation. Thus, one of the channels 948-952 may be provided in the design while eliminating the others.

[0058] A three-way valve 970 is in communication with the turbine inlet 42 and the pump outlet 32 through pipes 972 and 974, respectively.

[0059] In operation, a counter thrust to balance the thrust of the rotor is provided with the balance disk 918 and the thrust bearings 940 and 942 associated therewith. As mentioned above, only one thrust bearing need be formed in certain design conditions. When the thrust indicated by arrow 50, which is toward the turbine portion, is present, lubrication flow may be admitted through the pipe 954 and into the channel 948 where it enters to form a thrust bearing through the port 944. Fluid enters the pipe through the four-way valve 960, the pipe 958 and the filter 962. Fluid may be communicated into the filter 962 through the three-way valve 970 which operates to provide fluid from either the turbine inlet 42 or the pump outlet 32. The three-way valve 970 may be controlled by a controller 980 which may be microprocessor-based. The controller 980 may also control the operation of the four-way valve 960.

[0060] If the thrust is directed toward the pump side of the HPB 910, lubrication flow may be admitted through channel 950 and pipe 956. Fluid is communicated through the four-way valve 960, the three-way valve 970 and from one of the turbine inlet 42 or the pump outlet 32.

[0061] As briefly mentioned above, it may also be desirable to communicate fluid simultaneously through the pipes 948 and 958. Likewise, it may be desirable to communicate fluid through pipes 950 and 958. The pipe 958 communicates fluid to the channel 952. The channel 952 provides fluid adjacent to the peripheral edge of the balance disk 918.

[0062] Referring now to FIG. 8B, to increase the thrust force, hydrodynamic action of the balance disk 918 may be used. The balance disk 918 may be provided with a plurality of radially oriented surface recesses that generate hydrodynamic lift that increases in strength as the gap between the balance disk and the adjacent bearing face decreases. In this example, a first plurality of recesses 982A extends from the outer periphery of the balance disk 918 to just short of a groove 984. The groove 984 is a reduced thickness portion. It should be noted that each surface 918A, 918B of the balance disk may include such surfaces. However, only one surface in various designs may be used. The recesses 982B extend from the groove 984 to just short of the outer periphery of the balance disk 918. The recesses 982A and 982B are interspersed. That is, when traversing around the balance disk 918, the recesses 982A alternate with recesses 982B. In this example, there are four recesses 982A and four recesses 982B.

[0063] Referring now to FIG. 8C, a cross-sectional view of the balance disk relative to one of the surfaces 912B or 914B is set forth. In this example, the balance disk is moving in the direction indicated by the arrow 986. Each of the recesses 982A or 982B may be formed according to the following. The recesses 982A or 982B include a tapered portion 988. The groove 990 is on the leading edge and thus pressure is built up in the tapered portion 988 due to the movement of the balance disk 918 in the direction indicated by the arrow 986.

[0064] Because the lubrication flow to the thrust bearings are filtered, the clearance between the surfaces 912B or 914B and the balance disk 918 may be small. The clearance is smaller than the distance between the wear rings 232.

[0065] Referring now to FIG. 8D, the balance disk 918 includes a flow channel 992 therethrough. The flow channel 992 extends within the balance disk 918 and communicates fluid from a first side of the balance disk to a second side of the balance disk 918. In FIG. 8D, fluid is communicated from the pump side 918B of the balance disk 918 to the turbine side 918A of the balance disk 918.

[0066] The flow channel 992 has a first axial portion 992A that extends from the pump side 918B proximate to or adjacent to the shaft 20. A radial portion 992B extends in a radial direction from the first axial portion 992A. The radial portion 992B extends away from the shaft 20 in a radial direction direction. A second axial portion 992C couples the radial 992B to the second side of the balance disk 918.

[0067] In operation, fluid flows from the first side 918B of the balance disk 918 which corresponds to the pump side through the first axial portion 992A, through the radial portion 992B where the centrifugal forces cause an increase in the pressure of the fluid. The centrifugal force is caused by the high rate of rotation of the shaft 20 and the rotor associated therewith. Fluid exits to the second side 918A of the balance disk 918 through the second axial portion 992C into the thrust bearing formed on the first side 918A. The second axial portion 992C is located a further distance from the shaft 20 than the first axial portion 992A (radially outward). The flow channel 992 consequently increases the capacity of the thrust bearing at the turbine side of the balance disk 918.

[0068] It should be noted that a plurality of flow channels may be included in the balance disk. To provide balanced forces, the flow channels may be symmetrically disposed about the balance disk 918. It should also be noted that in FIG. 8D, the thrust forces that act on the shaft are in the direction toward the turbine side.

[0069] Referring now to FIG. 8E, another embodiment of a flow channel within a balance disk 918 is set forth in a similar manner as that of FIG. 8D. However, in FIG. 8E, the predominant forces are in the direction of the pump portion 16. Therefore, a flow channel 994 is communicating fluid from the first side 918A of the balance disk which corresponds to the turbine portion to the second side 918B of the balance disk which corresponds to the pump side of the balance disk 918. In this example, the flow channel 994 includes a first axial portion 994A that is fluidically coupled to the first side 918A of the balance disk 918. A radial portion 994B communicates fluid from the first axial portion 994A to a second axial portion 994C. The second axial portion 994C communicates fluid to the second side 918B of the balance disk. In a similar manner to that described above with respect to FIG. 8D, fluid enters the first axial portion 994A adjacent to or proximate to the shaft 20. The pressure of the fluid within the flow channel 994 is increased by the centrifugal forces acting on the rotating balance disk 918. The fluid pressure increases within the radial portion 994B as the fluid traverses in the direction illustrated by the arrow toward the outward direction of the balance disk 918 away from the shaft 20. Higher pressure fluid then enters the thrust bearing located at the pump side of the balance disk 918. As mentioned above, the increased high pressure fluid into the thrust bearing increases the capacity of the thrust bearing, in this case, on the pump side of the hydraulic pressure booster 910.

[0070] Referring now to FIG. 9, an alternative fluid machine 1010 is set forth. In this example, fluid is communicated from the pump outlet 32 to the filter 1011 disposed within a pipe 1012. A pipe 1014 may communicate fluid from the pump outlet to the shaft 20 between the turbine portion 18 and the pump portion 16 of the fluid machine 1010 such as a hydraulic pressure booster. In this example, the balance disk 1030 and balance disk chamber 1042 have been relocated outboard and adjacent to the turbine portion 18 of the fluid machine. The casing 26 may be supplemented with a casing extension or outer cap 1020 that is fastened with a bolt 1022 to a turbine end of the casing 26. The casing 26 and the outer cap 1020 may have a hollow space therebetween to house a first bearing 1024 and a second bearing 1026. The bearings 1024 and the bearings 1026 have inner surfaces 1024A and 1026A, respectively. The surface 1024A may form thrust bearing 1040 between surfaces 1030A of the balance disk 1030 within the volume defined by the wear ring 1080 disposed on the surface 1030A.

[0071] The flow channels 992, 994 illustrated in the balance disks illustrated in FIGS. 8D and 8E may also be incorporated within the balance disk 1030 to increase the capacity of the thrust bearings 1040.

[0072] A shaft extension 1032 may extend from the turbine portion 18 and the shaft 20 so that the balance disk 1030 and the wear ring 1080 rotates therewith. A shaft seal 1034 seals the shaft extension 1032 from leakage with the turbine outlet 44. The turbine outlet 44 is perpendicular to the shaft 20.

[0073] The pipe 1014 and the channel 1014A are provided closer to the pump impeller 22 than the turbine impeller 40. That is, the distance between the pump impeller 22 and the channel 1014A is less than the distance between the channel 1014A and the turbine impeller 40.

[0074] In operation, the rate of flow to the thrust bearing 1040 formed by a volume within the balance disk chamber 1042 between the bearing casing 1020, the balance disk 1030 and wear ring 1080.

[0075] A temperature sensor 1044 and a proximity sensor 1046 may be disposed within the bearing 1024 to generate a temperature signal corresponding to a temperature at the bearing 1024 and a proximity signal of the balance disk 1030 relative distance to the bearing 1024. The output of the temperature sensor 1044 may be used to control the heat exchanger 1050 and thus cool the fluid within the thrust bearing 1040. The fluid from the thrust bearing 1040 may be communicated through the heat exchanger 1050 and to the inlet pipe 1052 in a cooled state. The circulation through the heat exchanger 1050 is driven by the higher pressure caused by the rotating balance disk 1030. That is, a higher pressure exists at the outer diameter of the balance disk 1030 and thus the fluid may be communicated through the heat exchanger and back through the inlet pipe 1052.

[0076] The speed sensor 1060 may be used to monitor the rotational speed of the shaft extension 1032 which also corresponds to the rotational speed of the shaft 20. The speed sensor 1060 may be located within the turbine outlet 44 or adjacent to the temperature sensor 1044 and the proximity sensor 1046. A tooth or other indicator on the balance disk may provide the sensor with the rotational speed of the shaft.

[0077] Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims.