Patent Application
20250020061
This disclosure relates generally to rotary engines for aircraft and, more particularly, to a seal assembly for a rotary engine housing.
A rotary engine for an aircraft may be configured, for example, as a Wankel engine. The rotary engine includes one or more rotors configured to eccentrically rotate within an engine housing. The engine housing may include one or more seals or seal assemblies configured to provide fluid seals between various components and chambers of the rotary engine. Various seal and seal assembly configurations for engine housings are known for rotary engines. While these known seal and seal assembly configurations have various advantages, there is still room in the art for improvement.
It should be understood that any or all of the features or embodiments described herein can be used or combined in any combination with each and every other feature or embodiment described herein unless expressly noted otherwise.
According to an aspect of the present disclosure, an engine housing for an aircraft rotary engine includes a rotor housing and a side housing assembly. The rotor housing includes a rotor housing body. The rotor housing body extends about an axis to form a rotor cavity of the engine housing. The rotor housing body extends between and to a first axial end and a second axial end. The side housing assembly includes a side housing body, a side plate, and a seal assembly. The side housing body is disposed at the first axial end. The side plate is disposed axially between the rotor housing body and the side housing body. The side plate includes an inner side, an outer side, and a perimeter edge extending from the inner side to the outer side. The inner side further forms the rotor cavity. The seal assembly includes a support ring and a spacer. The support ring and the spacer extend about the axis. The support ring is mounted to the perimeter edge by a braze joint between the support ring and the side plate. The support ring circumscribes the side plate. The spacer extends between and to a first axial spacer end and a second axial spacer end. The first axial spacer end is disposed at the support ring and the outer side. The second axial spacer end is disposed at the side housing body.
In any of the aspects or embodiments described above and herein, the rotor housing body and the side housing body may form a coolant passage. The support ring may be disposed between the rotor cavity and the coolant passage.
In any of the aspects or embodiments described above and herein, the support ring, the spacer, and the side plate may further form the coolant passage.
In any of the aspects or embodiments described above and herein, the seal assembly may further include a seal. The seal may contact the rotor housing body and the support ring.
In any of the aspects or embodiments described above and herein, the support ring may extend between and to a first axial support ring end and a second axial support ring end. The first axial support ring end may be disposed at the rotor housing body. The second axial support ring end may be disposed at the spacer. The rotor housing body may form a recess at the first axial end, and the first axial support ring end is disposed within the recess.
In any of the aspects or embodiments described above and herein, the rotor housing body may form a dovetail seal groove and the seal may be disposed in the dovetail seal groove.
In any of the aspects or embodiments described above and herein, the support ring may be formed by a single ring body extending completely around the axis.
In any of the aspects or embodiments described above and herein, the support ring may include a plurality of discrete ring body segments assembled to form the support ring.
In any of the aspects or embodiments described above and herein, the inner side may be axially spaced from the first axial end by a gap.
In any of the aspects or embodiments described above and herein, the support ring may extend between and to a first radial end and a second radial end. The first radial end may contact the side housing body. The second radial end may contact the perimeter edge.
In any of the aspects or embodiments described above and herein, the side housing body may include a side housing body material. The side plate may include a side plate material. The side housing body material may be different than the side plate material.
In any of the aspects or embodiments described above and herein, the spacer may include a spacer material. The spacer material may be different than the side housing body material and the side plate material.
In any of the aspects or embodiments described above and herein, the second axial spacer end may include an outer radial end portion and an inner radial end portion. The outer radial end portion may contact the side housing body. The inner radial end portion may be spaced from the side housing body.
According to another aspect of the present disclosure, an engine housing for an aircraft rotary engine includes a rotor housing and a side housing assembly. The rotor housing includes a rotor housing body. The rotor housing body extends about an axis to form a rotor cavity of the engine housing. The rotor housing body extends between and to a first axial end and a second axial end. The rotor housing body forms a coolant passage. The side housing assembly includes a side housing body, a side plate, and a seal assembly. The side housing body is disposed at the first axial end. The side housing body further forms the coolant passage. The side plate is disposed axially between the rotor housing body and the side housing body. The side plate further forms the rotor cavity. The seal assembly includes a support ring and a spacer. The support ring and the spacer extend about the axis. The support ring is mounted to the side plate by a braze joint. The braze joint extends circumferentially about the axis. The support ring is disposed between the rotor cavity and the coolant passage. The spacer is disposed axially between the support ring and the side housing body. The spacer is further disposed axially between the side plate and the side housing body.
In any of the aspects or embodiments described above and herein, the coolant passage may include a coolant channel and a plurality of coolant conduits. The side housing body and the side plate may form the coolant channel. The coolant channel may extend about the axis. The side housing body and the rotor housing body may form the plurality of coolant conduits. The plurality of coolant conduits may be connected in fluid communication with the coolant channel.
In any of the aspects or embodiments described above and herein, the spacer may further form the coolant channel.
In any of the aspects or embodiments described above and herein, the support ring may further form the plurality of coolant conduits.
According to another aspect of the present disclosure, an engine housing for an aircraft rotary engine includes a rotor housing and a side housing assembly. The rotor housing includes a rotor housing body. The rotor housing body extends about an axis to form a rotor cavity of the engine housing. The rotor housing body extends between and to a first axial end and a second axial end. The side housing assembly includes a side housing body, a side plate, and a seal assembly. The side housing body is disposed at the first axial end. The side plate is disposed axially between the rotor housing body and the side housing body. The side plate further forms the rotor cavity. The seal assembly includes a support ring and a spacer. The support ring and the spacer extend about the axis. The support ring extends between and to a first axial support ring end and a second axial support ring end. The support ring further extends between and to a first radial support ring end and a second radial support ring end. The first axial support ring end is disposed at the first axial end. The first radial support ring end is disposed at the side housing body. The second radial support ring end is mounted to the side plate by a braze joint. The spacer extends between and to a first axial spacer end and a second axial spacer end. The spacer further extends between and to a first radial spacer end and a second radial spacer end. The first axial spacer end is disposed at the second axial support ring end and the side plate. The second axial spacer end is disposed at the side housing body. The first radial spacer end is disposed at the side housing body.
In any of the aspects or embodiments described above and herein, the rotor housing body may form a recess at the first axial end. The first axial support ring end may be disposed within the recess.
In any of the aspects or embodiments described above and herein, the rotor housing body may form a seal groove at the recess. The seal assembly may further include a seal disposed in the seal groove. The first seal may contact the rotor housing body and the first axial support ring end.
The present disclosure, and all its aspects, embodiments and advantages associated therewith will become more readily apparent in view of the detailed description provided below, including the accompanying drawings.
The engine 12 of
The rotor assembly 24 is coupled to the engine shaft 26 and configured to drive the engine shaft 26 for rotation about a rotational axis 28. The engine shaft 26 is coupled to the rotational load 14 such that rotation of the engine shaft 26 by the rotor assembly 24 drives rotation of the rotational load 14. The engine shaft 26 may be coupled to the rotational load 14 by a speed-reducing gear assembly 30 of the engine 12. The speed-reducing gear assembly 30 may be configured to effect rotation of the rotational load 14 at a reduced rotational speed relative to the engine shaft 26. The rotational load 14 of
The rotational assembly 20 of
Referring to
The engine housing 46 of
The rotor housing body 56 of
The side housing assemblies 54 may be mounted to or otherwise disposed at (e.g., on, adjacent, or proximate) the first end 58 and the second end 60. For example, the side housing assemblies 54 may include a first side housing assembly 54A disposed at the first end 58 and a second side housing assembly 54B disposed at the second end 60. The side housing assemblies 54 further form the rotor cavity 62 (e.g., axial bounds of the rotor cavity 62). Each of the first side housing assembly 54A and the second side housing assembly 54B may include a respective shaft aperture (not shown) through which the engine shaft 26 may extend along the rotational axis 28 through the rotor cavity 62.
The rotor 48 of
Briefly, the rotor 48 of
In operation of the engine 12, the fuel system 50 is configured to effect rotation of the rotor 48 by directing a fuel into the rotor cavity 62 and igniting the fuel in a defined sequence. During each orbital revolution of the rotor 48, each working chamber 80 varies in volume and moves about the rotor cavity 62 to undergo four phases of intake, compression, expansion, and exhaust, thereby driving rotation of the rotor 48 and the shaft 26.
The rotor housing 52 and the side housing assemblies 54 of
The side housing body 82 extends (e.g., axially extends) between and to an inner side 96 of the side housing body 82 and an outer side 98 of the side housing body 82. The side housing body 82 includes an outer radial body portion 100 and an inner radial body portion 102. The outer radial body portion 100 is disposed radially outward of the coolant passage 88. The inner radial body portion 102 extends radially inward from the outer radial body portion 100. The inner radial body portion 102 forms portions of the coolant passage 88 (e.g., the coolant channel 92 and the coolant conduits 94) at (e.g., on, adjacent, or proximate) the inner side 96. The engine housing 46 of
The side plate 84 extends (e.g., axially extends relative to the rotational axis 28) between and to an inner side 106 of the side plate 84 and an outer side 108 of the side plate 84. The side plate 84 includes a perimeter edge 110 circumscribing the inner side 106 and the outer side 108. The side plate 84 (e.g., the perimeter edge 110) may have an epitrochoid shape similar to that of the rotor cavity 62. The side plate 84 is disposed axially between the rotor housing body 56 and the inner radial body portion 102 of the side housing body 82. The inner side 106 faces the rotor 48 and forms a portion of the rotor cavity 62. For example, the inner side 106 (e.g., at the perimeter edge 110) may be disposed in contact with the first end 58 or the second end 60 of the rotor housing body and the outer side 108 may be disposed in contact with the inner side 96. The outer side 108 faces and forms a portion of the coolant channel 92. The side plate 84 forms a shaft aperture for the engine shaft 26 along the rotational axis 28 (not shown). The side plate 84 includes a side plate material. The side plate material may form all or a substantial portion of the side plate 84. The side plate material may be different than the side housing body material. For example, the side plate material may be a harder material relative to the side housing body material. The side plate material may alternatively be a ceramic material such as, but not limited to, silicon carbide (SiC). The present disclosure, however, is not limited to the use of a particular material or combination of materials for the side plate material.
In at least some conventional rotary engine housings of which we are aware, the engine housing may include an O-ring forming an inner coolant seal between a rotor housing body and a side plate of the engine housing. This inner coolant seal may be disposed in contact with the rotor housing body and the side plate at a position radially between a rotor cavity and a coolant passage of the engine housing to prevent coolant from the coolant passage from leaking into the rotor cavity. To limit structural loading (e.g., axial clamping load) and resultant degradation experienced by the side plate, the rotary engine housing may be configured with a gap (e.g., an axial gap) between the side plate and the rotor housing body. The gap may close during operation of the rotary engine due to thermal expansion of the engine housing components. We have observed that to further reduce structural loading experienced by the side plate, a size (e.g., axial span) of the gap may be increased. However, increasing a size of the gap may expose the inner coolant seal to hot combustion gas from the rotor cavity, thereby causing degradation of the inner coolant seal and an increased likelihood of coolant escaping the coolant passage into the rotor cavity.
The support ring 112 extends (e.g., axially extends) between and to a first axial end 122 of the support ring 112 and a second axial end 124 of the support ring 112. The support ring 112 extends (e.g., radially extends) between and to a first radial end 126 of the support ring 112 and a second radial end 128 of the support ring 112. The support ring 112 extends about (e.g., completely around) the rotational axis 28. The support ring 112 may be formed by a single ring body extending completely around the rotational axis 28. For example,
The first axial end 122 may contact or otherwise be disposed at (e.g., on, adjacent, or proximate) the rotor housing body 56 (e.g., the first end 58 or the second end 60). The first axial end 122 may be positioned in contact with the seal 116 (e.g., an O-ring), which seal 116 may be positioned between and in contact with the rotor housing body 56 and the support ring 112 to form a fluid seal between the rotor housing body 56 and the support ring 112. The rotor housing body 56 (e.g., at the first end 58 or the second end 60; see
The second axial end 124 may contact or otherwise be disposed at (e.g., on, adjacent, or proximate) the spacer 114. The second axial end 124 may be disposed coincident with the outer side 108.
The first radial end 126 may contact or otherwise be disposed at (e.g., on, adjacent, or proximate) the side housing body 82. For example, the first radial end 126 of
The second radial end 128 is disposed radially inward of the first radial end 126. The second radial end 128 circumscribes the side plate 84 (e.g., the perimeter edge 110). The second radial end 128 is mounted to the perimeter edge 110 by a braze joint 144 formed between the support ring 112 and the side plate 84. The braze joint 144 may extend about (e.g., completely around) the rotational axis 28 along the second radial end 128 and the perimeter edge 110. In addition to retaining the support ring 112 on the side plate 84 for sealing with the rotor housing body 56, the braze joint 144 may form a fluid seal between the support ring 112 and the side plate 84. The braze joint 144 may alternatively be formed by a plurality of braze joint segments (e.g., circumferential segments), for example, corresponding to respective ring body segments for a plurality of discrete ring body segments forming the support ring 112. For some embodiments of the support ring 112 and the side plate 84, the support ring 112 may have a substantially different thermal coefficient of expansion relative to the side plate 84. This different thermal coefficient of expansion may expose the braze joint 144 to excessive amounts of stress during certain operating conditions of the rotor assembly 24 (see
The spacer 114 extends (e.g., axially extends) between and to a first axial end 136 of the spacer 114 and a second axial end 138 of the spacer 114. The spacer 114 extends (e.g., radially extends) between and to a first radial end 140 of the spacer 114 and a second radial end 142 of the spacer 114. The spacer 114 extends about (e.g., completely around) the rotational axis 28. The spacer 114 is disposed axially between the side housing body 82 on one side and the support ring 112 and the side plate 84 on the other side. The spacer 114 includes a spacer material. The spacer material may form all or a substantial portion of the spacer 114. The spacer material may be a metal or metal alloy material such as, but not limited to, steel, brass, or bronze, which metal or metal alloy material is different than the side housing body material. The spacer material may alternatively be a non-metal material such as, but not limited to, a polyimide-based plastic material or a fiber-reinforced polyimide-based plastic material. Because the spacer 114 does not circumscribe the side plate 84, in contrast to the support ring 112, the spacer material may be selected with less concern for thermal expansion coefficient in comparison to the support ring material. Instead, the spacer material may be selected to reduce wear between the spacer 114 (e.g., the first axial end 136) and the side plate 84 (e.g., the outer side 108). The spacer 114 may include a coating or other material disposed on the spacer material. The coating or other material may be configured, for example, to reduce wear between the spacer 114 and the side plate 84.
The first axial end 136 may contact or otherwise be disposed at (e.g., on, adjacent, or proximate) the side plate 84 (e.g., outer side 108) and the support ring 112 (e.g., the second axial end 124).
The second axial end 138 includes an outer radial end portion 148 and an inner radial end portion 150. The outer radial end portion 148 extends (e.g., radially extends) from the first radial end 140 to the inner radial end portion 150. The inner radial end portion 150 extends from the outer radial end portion 148 to the second radial end 142. The outer radial end portion 148 may contact or otherwise be disposed at (e.g., on, adjacent, or proximate) the side housing body 82. The inner radial end portion 150 may not contact the side housing body 82 (e.g., the inner radial end portion 150 is spaced from the side housing body 82). For example, the inner radial end portion 150 may form a portion of the coolant channel 92.
The first radial end 140 may contact or otherwise be disposed at (e.g., on, adjacent, or proximate) the side housing body 82. For example, the first radial end 140 of
The second radial end 142 is disposed radially inward of the first radial end 140. The second radial end 142 may be disposed radially coincident with the side plate 84 and within the coolant channel 92.
While the principles of the disclosure have been described above in connection with specific apparatuses and methods, it is to be clearly understood that this description is made only by way of example and not as limitation on the scope of the disclosure. Specific details are given in the above description to provide a thorough understanding of the embodiments. However, it is understood that the embodiments may be practiced without these specific details.
It is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a block diagram, etc. Although any one of these structures may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc.
The singular forms “a,” “an,” and “the” refer to one or more than one, unless the context clearly dictates otherwise. For example, the term “comprising a specimen” includes single or plural specimens and is considered equivalent to the phrase “comprising at least one specimen.” The term “or” refers to a single element of stated alternative elements or a combination of two or more elements unless the context clearly indicates otherwise. As used herein, “comprises” means “includes.” Thus, “comprising A or B,” means “including A or B, or A and B,” without excluding additional elements.
It is noted that various connections are set forth between elements in the present description and drawings (the contents of which are included in this disclosure by way of reference). It is noted that these connections are general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. Any reference to attached, fixed, connected, or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option.
No element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprise”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
While various inventive aspects, concepts and features of the disclosures may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts, and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present application. Still further, while various alternative embodiments as to the various aspects, concepts, and features of the disclosures—such as alternative materials, structures, configurations, methods, devices, and components, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts, or features into additional embodiments and uses within the scope of the present application even if such embodiments are not expressly disclosed herein. For example, in the exemplary embodiments described above within the Detailed Description portion of the present specification, elements may be described as individual units and shown as independent of one another to facilitate the description. In alternative embodiments, such elements may be configured as combined elements.
