Hybrid construction of a turbomachine rotor

Abstract

A hybrid rotor for a turbomachine, the hybrid rotor includes a rotor body including a first bearing surface, a second bearing surface, and an intermediate seal region formed as one unitary component. A first rotating element and a second rotating element are formed as part of the rotor body and operate to one of compress a fluid in response to a torque applied to the rotor body and expand a fluid to apply a first torque to the rotor body. The first rotating element and second rotating element are inseparable from the rotor body. A disk surface is formed as part of the rotor body and defines a first receiving surface having a first diameter and a second receiving surface having a second diameter. A first disk element formed separately from the rotor body has a first inner bore with a third diameter that is smaller than the first diameter, the first disk element shrunk-fit onto the rotor body such that the first inner bore engages the first receiving surface and the first disk element is operable to one of compress the fluid in response to the torque applied to the rotor body and expand the fluid to apply a third torque to the rotor body. A second disk element formed separately from the rotor body has a second inner bore with a fourth diameter that is smaller than the second diameter, the second disk element shrunk-fit onto the rotor body such that the second inner bore engages the second receiving surface and the second disk element is operable to one of compress the fluid in response to the torque applied to the rotor body and expand the fluid to apply a fourth torque to the rotor body.

Description

2024PF00593 Subsequent Filing VersionHYBRID CONSTRUCTION OF A TURBOMACHINE ROTORBACKGROUND

[0001] Industrial turbomachine rotors often include complex fluid interacting members including pump or compressor impellers, turbine impellers, blades, vanes, and the like. These fluid interacting members are selected to interact with a fluid that flows through the turbomachine to either compress, pressurize, pump, or extract energy to or from the fluid.

[0002] In some rotors, the fluid interacting members are able to be formed or machined as a unitary component with the remainder of the rotor. However, some rotors utilize more complex fluid interacting members that cannot be efficiently machined as part of the rotor.SUMMARY

[0003] In one aspect, a hybrid rotor for a turbomachine, the hybrid rotor includes a rotor body including a first bearing surface, a second bearing surface, and an intermediate seal region formed as one unitary component. A first rotating element formed as part of the rotor body operates to one of compress a fluid in response to a torque applied to the rotor body and expand a fluid to apply a first torque to the rotor body. The first rotating element is inseparable from the rotor body. A second rotating element formed as part of the rotor body operates to one of compress the fluid in response to the torque applied to the rotor body and expand the fluid to apply a second torque to the rotor body, the second rotating element being inseparable from the rotor body. A disk surface is formed as part of the rotor body and defines a first receiving surface having a first diameter and a second receiving surface having a second diameter. A first disk element formed separately from the rotor body has a first inner bore with a third diameter that is smaller than the first diameter, the first disk element shrunk-fit onto the rotor2024PF00593 Subsequent Filing Version body such that the first inner bore engages the first receiving surface and the first disk element is operable to one of compress the fluid in response to the torque applied to the rotor body and expand the fluid to apply a third torque to the rotor body. A second disk element formed separately from the rotor body has a second inner bore with a fourth diameter that is smaller than the second diameter, the second disk element shrunk-fit onto the rotor body such that the second inner bore engages the second receiving surface and the second disk element is operable to one of compress the fluid in response to the torque applied to the rotor body and expand the fluid to apply a fourth torque to the rotor body.

[0004] The hybrid rotor may also include a first bearing surface and a second bearing surface that are cylindrical surfaces arranged to engage a bearing to support the hybrid rotor for rotation about a rotational axis.

[0005] The hybrid rotor may also include an intermediate seal region positioned such that each of the first rotating element and the second rotating element are on a first side of the intermediate seal region and the first disk element and the second disk element are on a second side of the intermediate seal region.

[0006] The hybrid rotor may also include a first rotating element and a second rotating element that each include semi-enclosed centrifugal impellers.

[0007] The hybrid rotor may also include a first rotating element and a second rotating element that each include centrifugal compressor impellers.

[0008] The hybrid rotor may also include a first disk element and a second disk element that each include closed centrifugal impellers.

[0009] The hybrid rotor may also include a first disk element and a second disk element that each include centrifugal compressor impellers.

[0010] The hybrid rotor may also include a first diameter and a second diameter that are equal. Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.2024PF00593 Subsequent Filing VersionBRIEF DESCRIPTION OF THE DRAWINGS

[0011] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0012] FIG. l is a longitudinal view of a hybrid turbine rotor.

[0013] FIG. 2 is a cross-section of the hybrid rotor of FIG. 1 taken in a plane that passes through the longitudinal axis.DETAILED DESCRIPTION

[0014] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in this description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0015] Various technologies that pertain to systems and methods will now be described with reference to the drawings, where like reference numerals represent like elements throughout. The drawings discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged apparatus. It is to be understood that functionality that is described as being carried out by certain system elements may be performed by multiple elements. Similarly, for2024PF00593 Subsequent Filing Version instance, an element may be configured to perform functionality that is described as being carried out by multiple elements. The numerous innovative teachings of the present application will be described with reference to exemplary non-limiting embodiments.

[0016] It should be understood that the words or phrases used herein should be construed broadly, unless expressly limited in some examples. For example, the terms “including,” “having,” and “comprising,” as well as derivatives thereof, mean inclusion without limitation. The singular forms “a”, “an” and “the” are intended to include the plural forms as well (i.e., one or more), unless the context clearly indicates otherwise. Further, the term “and / or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. The term “or” is inclusive, meaning and / or, unless the context clearly indicates otherwise. The phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like. Furthermore, while multiple embodiments or constructions may be described herein, any features, methods, steps, components, etc. described with regard to one embodiment are equally applicable to other embodiments, absent a specific statement to the contrary.

[0017] Also, terms such as “first”, “second”, “third” and so forth may be used herein to refer to various elements, information, functions, or acts, but should not be considered as limiting in any way. Rather these numeral adjectives are used to distinguish different elements, information, functions or acts from each other. For example, a first element, information, function, or act could be termed a second element, information, function, or act, and, similarly, a second element, information, function, or act could be termed a first element, information, function, or act, without departing from the scope of the present disclosure.

[0018] In addition, the term “adjacent to” may mean that an element is relatively near to but not in contact with a further element or that the element is in contact with the further portion unless the context clearly indicates otherwise. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Terms “about” or2024PF00593 Subsequent Filing Version“substantially” or like terms are intended to cover variations in a value that are within normal industry manufacturing tolerances for that dimension. If no industry standard is available, a variation of twenty percent would fall within the meaning of these terms unless otherwise stated.

[0019] Increased power density of a turbomachine rotor can be accomplished by using integrally machined semi-open impellers with very high surface speed capability. Such semiopen impellers typically have lower efficiency than similar closed impellers. The shrink fit of closed impellers allows for these more complicated machining operations to take place separately from the rest of the rotor, and the closed impeller design allows for higher efficiencies than a similar application using semi-open impellers.

[0020] Compared to a design where all the impellers are shrunk fit to a separate cylindrical shaft, this solution can achieve similar performance in a smaller size. This reduces material cost, machining costs, and package costs. Additionally, the integrally machined impellers result in cost savings over the same size rotor with all shrunk fit impellers.

[0021] FIG. 1 illustrates a hybrid rotor 100 that includes a rotor body 102 suitable for use in a number of different turbomachines. For example, the hybrid rotor 100 could be used as a turbine rotor or a compressor rotor as will be discussed in greater detail. Of course, other uses of the hybrid rotor 100 beyond those explicitly described herein are possible.

[0022] The rotor body 102 includes various surfaces such as a first bearing surface 110 and a second bearing surface 112 that each engage a bearing that in turn support the rotor body 102 for rotation about a rotational axis 108. Other surfaces may be provided for sealing, engagement with a thrust bearing, and other purposes commonly needed with the particular type of machine that is using the hybrid rotor 100.

[0023] A first rotating element 104 and a second rotating element 106 are formed as part of the rotor body 102 with additional rotating elements formed as part of the rotor body 102 being possible. In the illustrated construction, four rotating elements formed as part of the rotor body 102 are illustrated. In some constructions, the rotor body 102, including the first rotating element 104, the second rotating element 106, and any additional rotating elements is a forged2024PF00593 Subsequent Filing Version component that is then finish machined to complete the necessary seal surfaces, bearing surfaces, other surfaces, and rotating elements.

[0024] In the illustrated construction, the first rotating element 104, the second rotating element 106, and the additional rotating elements formed as part of the rotor body 102 each include an impeller and specifically, a semi-closed centrifugal impeller. In compressors (e.g., centrifugal compressors), the impellers 120 operate to compress a fluid as it passes through the impeller in response to a torque being applied to the hybrid rotor 100. In turbines, the impellers 120 convert energy within the flow of fluid as it passes through the impeller 120 to apply a torque to the hybrid rotor 100.

[0025] Other constructions may include different types of impellers 120 such as closed or open centrifugal impellers 120 or may replace the impellers 120 with other rotating elements such as blades or vanes.

[0026] In addition to the integrated rotating elements, the hybrid rotor 100 also includes a first disk element 114, and a second disk element 116, with additional disk elements being possible depending on the application of the hybrid rotor 100. Each of the first disk element 114, the second disk element 116, and any additional disk elements are formed separately from the rotor body 102 and are either permanently or removably attached to the rotor body 102 as part of the assembly of the hybrid rotor 100. In the illustrated construction, and as will be described in greater detail with regard to FIG. 2, the first disk element 114, the second disk element 116, and any additional disk elements are shrunk on disks.

[0027] Each disk element of the illustrated construction includes an impeller that is formed as part of the disk or attached to the disk. In the illustrated construction, the first disk element 114, the second disk element 116, and any additional disk elements include a closed impeller 122 with other arrangements of the impeller being possible. As with the rotating elements, in compressors, the closed impellers 122 operate to compress a fluid as it passes through the impeller in response to a torque being applied to the hybrid rotor 100. In turbines, the closed impellers 122 convert energy within the flow of fluid as it passes through the impeller 120 to apply a torque to the hybrid rotor 100.2024PF00593 Subsequent Filing Version

[0028] Due to the complexities involved in manufacturing a closed impeller 122, it is advantageous to form such closed impellers 122 on separate disks rather than attempt to form them as part of the rotor body 102. Of course, other impeller arrangements or even different components entirely (e.g., blades or vanes) could be used in place of or in conjunction with the closed impellers 122.

[0029] FIG. 2 is a cross-sectional view of the hybrid rotor 100 of FIG. 1 which better illustrates the arrangement between the rotor body 102, the first disk element 114, the second disk element 116, and any additional disk elements that may be present.

[0030] The rotor body 102 includes a first receiving surface 202, a second receiving surface 204, and a corresponding receiving surface for any additional disk elements beyond the first disk element 114 and the second disk element 116. The first receiving surface 202 defines a first diameter. In the illustrated construction, the first receiving surface 202 includes two separate surfaces having different diameters. However, for simplicity, the first receiving surface 202 will be described as a single surface that defines a single diameter.

[0031] The corresponding first disk element 114 includes a first inner bore 206 that corresponds to the first receiving surface 202. Thus, if the first receiving surface 202 includes more than one surface, the first disk element 114 may include corresponding surfaces or clearance bores. Similarly, the second receiving surface 204 defines a second diameter. Like the first receiving surface 202, the second receiving surface 204 may include more than one surface if desired. It is also important to note that the first receiving surface 202 may be larger than the second receiving surface 204 to assure that the first disk element 114 can move past the second receiving surface 204 and engage the first inner bore 206 during assembly.

[0032] The first inner bore 206 defines a third diameter that is slightly smaller than the first diameter to define an interference or shrink fit therebetween. The difference between the first diameter and the third diameter is selected to provide the level of compression between the first disk element 114 and the rotor body 102 to assure that the first disk element 114 will not slip or otherwise move during normal operation. Typically, the first disk element 114 is heated to a predetermined temperature to increase the size of the first inner bore 206 to a size larger than2024PF00593 Subsequent Filing Version the third diameter. The first disk element 114 is then positioned in its desired operating position and the temperatures of the first disk element 114 and the rotor body 102 equalize. Once equalized, the first inner bore 206 engages the first receiving surface 202 to define a shrink fit therebetween.

[0033] The second inner bore 208 defines a fourth diameter that is slightly smaller than the second diameter to define an interference or shrink fit therebetween. The difference between the second diameter and the fourth diameter is selected to provide the level of compression between the second disk element 116 and the rotor body 102 to ensure that the second disk element 116 will not slip or otherwise move during normal operation. Typically, the second disk element 116 is heated to a predetermined temperature to increase the size of the second inner bore 208 to a size larger than the fourth diameter. The second disk element 116 is then positioned in its desired operating position and the temperatures of the second disk element 116 and the rotor body 102 equalize. Once equalized, the second inner bore 208 engages the second receiving surface 204 to define a shrink fit therebetween.

[0034] The relationships between additional receiving surfaces and inner bores of any additional disk elements are arranged as described with regard to the first disk element 114 and the second disk element 116. In addition, the process of installing any additional disk elements is substantially the same as described with regard to the installation of the first disk element 114 and the second disk element 116.

[0035] Once the hybrid rotor 100 is assembled it can be installed in a casing to largely enclose the hybrid rotor 100 and specifically each of the disk elements and the rotating elements for operation. If the hybrid rotor 100 is being used in a compressor, a motor or other drive member is coupled to the hybrid rotor 100 to produce rotation at a desired speed. A fluid to be compressed is delivered to one or more of the rotating elements or disk elements in parallel or in series. For example, in one arrangement, the fluid enters the hybrid rotor 100 at the first rotating element 104. The first rotating element 104 and the associated stationary components (e.g., casings, seals, housings, diffusers, etc.) cooperate to compress the fluid and discharge the compressed fluid from the first rotating element 104. The compressed fluid is then directed to the second rotating element 106 which operates in a similar manner to further compress the2024PF00593 Subsequent Filing Version fluid. This process repeats until the fluid passes through each of the rotating elements and is discharged from the Nth or last of the rotating elements. The fluid is then directed to the first disk element 114 which operates in a manner similar to that described with regard to the rotating elements to further compress the fluid. In the illustrated construction, the disk elements include closed impellers 122 that are more efficient at the higher pressure of the fluid. Again, this process is repeated for the second disk element 116 and any additional disk elements before the fully compressed fluid is discharged from the compressor.

[0036] It should be noted that the first rotating element 104, the second rotating element 106, the first disk element 114, and the second disk element 116 are selected for convenience of illustration and do not represent an actual order of the elements or stages. Thus, any rotating element could be the first rotating element 104 and any disk element could be the first disk element 114.

[0037] The arrangements illustrated and described herein allow for a portion of the hybrid rotor 100 to be manufactured as a single component with another portion being stacked or attached. While forming the hybrid rotor 100 as a single unitary component provides a stable and strong component, the machining of the flow elements in each stage of the hybrid rotor 100 can be challenging. In some cases, such as when using closed impellers 122, the machining when formed as part of the rotor body 102 is too challenging and it is better to form the closed impellers 122 on separate disks. The arrangement illustrated herein thus allows for rotors that include both impellers 120 formed as part of the rotor body 102 and closed impellers 122 formed separately from the rotor body 102.

[0038] To form the hybrid rotor 100 of FIG. 1, a rough rotor piece if first procured. The rough rotor piece is sized and arranged to allow for the machining of any integrally machined impellers as well as other rotor features (e.g., bearing surfaces). Each disk element is separately machined before being installed on the rotor body 102.

[0039] FIG. 1 and FIG. 2 show back-to-back configurations with semi-open, integrally machined impellers in one process section (one side of the intermediate seal region 118) and closed, shrink fit impellers in the other process section with the intermediate seal region 1182024PF00593 Subsequent Filing Version operable to form a seal therebetween and define a portion of a balance piston located between the sections. Of course, other arrangements such as straight through configurations or parallel flow configurations are possible.

[0040] As discussed, the rotating elements are illustrated as including integrally-machined semi-open impellers and the disk elements are shown as including closed impellers, other constructions may include different impeller arrangements in one or both of these sections as desired.

[0041] Although an exemplary embodiment of the present disclosure has been described in detail, those skilled in the art will understand that various changes, substitutions, variations, and improvements disclosed herein may be made without departing from the spirit and scope of the disclosure in its broadest form.

[0042] None of the description in the present application should be read as implying that any particular element, step, act, or function is an essential element, which must be included in the claim scope: the scope of patented subject matter is defined only by the allowed claims. Moreover, none of these claims are intended to invoke a means plus function claim construction unless the exact words "means for" are followed by a participle.

Claims

2024PF00593 Subsequent Filing VersionCLAIMSWhat is claimed is:

1. A hybrid rotor for a turbomachine, the hybrid rotor comprising: a rotor body including a first bearing surface, a second bearing surface, and an intermediate seal region formed as one unitary component; a first rotating element formed as part of the rotor body and operable to one of compress a fluid in response to a torque applied to the rotor body and expand a fluid to apply a first torque to the rotor body, the first rotating element being inseparable from the rotor body; a second rotating element formed as part of the rotor body and operable to one of compress the fluid in response to the torque applied to the rotor body and expand the fluid to apply a second torque to the rotor body, the second rotating element being inseparable from the rotor body; a disk surface formed as part of the rotor body and defining a first receiving surface having a first diameter and a second receiving surface having a second diameter; a first disk element formed separately from the rotor body and having a first inner bore having a third diameter that is smaller than the first diameter, the first disk element shrunk-fit onto the rotor body such that the first inner bore engages the first receiving surface and the first disk element is operable to one of compress the fluid in response to the torque applied to the rotor body and expand the fluid to apply a third torque to the rotor body; and a second disk element formed separately from the rotor body and having a second inner bore having a fourth diameter that is smaller than the second diameter, the second disk element shrunk-fit onto the rotor body such that the second inner bore engages the second receiving surface and the second disk element is operable to one of compress the fluid in response to the torque applied to the rotor body and expand the fluid to apply a fourth torque to the rotor body.

2. The hybrid rotor of claim 1, wherein the first bearing surface and the second bearing surface are cylindrical surfaces arranged to engage a bearing to support the hybrid rotor for rotation about a rotational axis.2024PF00593 Subsequent Filing Version3. The hybrid rotor of claim 1, wherein the intermediate seal region is positioned such that each of the first rotating element and the second rotating element are on a first side of the intermediate seal region and the first disk element and the second disk element are on a second side of the intermediate seal region.

4. The hybrid rotor of claim 1, wherein the first rotating element and the second rotating element include semi-enclosed centrifugal impellers.

5. The hybrid rotor of claim 1, wherein the first rotating element and the second rotating element include centrifugal compressor impellers.

6. The hybrid rotor of claim 1, wherein the first disk element and the second disk element include closed centrifugal impellers.

7. The hybrid rotor of claim 1, wherein the first disk element and the second disk element include centrifugal compressor impellers.

8. The hybrid rotor of claim 1, wherein the first diameter and the second diameter are equal.

Images