Patent Description:
Air cycle machines are used in environmental control systems in aircraft to condition air for delivery to an aircraft cabin. Conditioned air is air at a temperature, pressure, and humidity desirable for aircraft passenger comfort and safety. At or near ground level, the ambient air temperature and/or humidity is often sufficiently high that the air must be cooled as part of the conditioning process before being delivered to the aircraft cabin. At flight altitude, ambient air is often far cooler than desired, but at such a low pressure that it must be compressed to an acceptable pressure as part of the conditioning process. Compressing ambient air at flight altitude heats the resulting pressurized air sufficiently that it must be cooled, even if the ambient air temperature is very low. Thus, under most conditions, heat must be removed from air by the air cycle machine before the air is delivered to the aircraft cabin.

Air cycle machines typically include rotating components mounted to a tie rod and a static housing surrounding the rotating components. The static housing can include multiple pieces that are fastened together. A seal plate can be positioned between the static housing pieces to limit the leakage of air between differently pressurized regions of the air cycle machine. Seal plates are known from <CIT> and <CIT>.

A seal plate for a rotary machine is provided according to claim <NUM>.

A rotary machine is provided as defined in claim <NUM>.

<FIG> is a cross-sectional view of air cycle machine <NUM>, which includes fan section <NUM>, compressor section <NUM>, first turbine section <NUM>, second turbine section <NUM>, tie rod <NUM>, fan and compressor housing <NUM>, seal plate <NUM>, first turbine housing <NUM>, and second turbine housing <NUM>. Fan section <NUM> includes fan inlet <NUM>, fan duct <NUM>, fan outlet <NUM>, and fan rotor <NUM>. Compressor section <NUM> includes compressor inlet <NUM>, compressor duct <NUM>, compressor outlet <NUM>, compressor rotor <NUM>, diffuser <NUM>, and compressor rotor shroud <NUM>. First turbine section <NUM> includes first turbine inlet <NUM>, first turbine duct <NUM>, first turbine outlet <NUM>, first turbine rotor <NUM>, and first turbine rotor shroud <NUM>. Second turbine section <NUM> includes second turbine inlet <NUM>, second turbine duct <NUM>, second turbine outlet <NUM>, and second turbine rotor <NUM>. Air cycle machine <NUM> further includes first journal bearing <NUM>, first rotating shaft <NUM>, second journal bearing <NUM>, and second rotating shaft <NUM>. Also shown in <FIG> is axis Z.

Fan section <NUM>, compressor section <NUM>, first turbine section <NUM>, and second turbine section <NUM> are all mounted on tie rod <NUM>. Tie rod <NUM> rotates about axis Z. Fan and compressor housing <NUM> is connected to seal plate <NUM> and first turbine housing <NUM> with fasteners. Seal plate <NUM> separates flow paths in fan and compressor housing <NUM> from flow paths in first turbine housing <NUM>. First turbine housing <NUM> is connected to second turbine housing <NUM> with fasteners. Fan and compressor housing <NUM>, first turbine housing <NUM>, and second turbine housing <NUM> together form an overall housing for air cycle machine <NUM>. Fan and compressor housing <NUM> houses fan section <NUM> and compressor section <NUM>, first turbine housing <NUM> housing first turbine section <NUM>, and second turbine housing <NUM> houses second turbine section <NUM>.

Fan section <NUM> includes fan inlet <NUM>, fan duct <NUM>, fan outlet <NUM>, and fan rotor <NUM>. Fan section <NUM> typically draws in ram air from a ram air scoop or alternatively from an associated gas turbine or other aircraft component. Air is drawn into fan inlet <NUM> and is ducted through fan duct <NUM> to fan outlet <NUM>. Fan rotor <NUM> is positioned in fan duct <NUM> adjacent to fan outlet <NUM> and is mounted to and rotates with tie rod <NUM>. Fan rotor <NUM> draws air into fan section <NUM> to be routed through air cycle machine <NUM>.

Compressor section <NUM> includes compressor inlet <NUM>, compressor duct <NUM>, compressor outlet <NUM>, compressor rotor <NUM>, and diffuser <NUM>. Air is routed into compressor inlet <NUM> and is ducted through compressor duct <NUM> to compressor outlet <NUM>. Compressor rotor <NUM> and diffuser <NUM> are positioned in compressor duct <NUM>. Compressor rotor <NUM> is mounted to and rotates with tie rod <NUM> to compress the air flowing through compressor duct <NUM>. Diffuser <NUM> is a static structure through which the compressor air can flow after it has been compressed with compressor rotor <NUM>. Air exiting diffuser <NUM> can then exit compressor duct <NUM> through compressor outlet <NUM>. Compressor rotor shroud <NUM> is positioned radially outward from and surrounds compressor rotor <NUM>.

First turbine section <NUM> includes first turbine inlet <NUM>, first turbine duct <NUM>, first turbine outlet <NUM>, first turbine rotor <NUM>, and first turbine rotor shroud <NUM>. Air is routed into first turbine inlet <NUM> and is ducted through first turbine duct <NUM> to first turbine outlet <NUM>. First turbine rotor <NUM> is positioned in first turbine duct <NUM> and is mounted to and rotates with tie rod <NUM>. First turbine rotor <NUM> will extract energy from the air passing through first turbine section <NUM> to drive rotation of tie rod <NUM>. First turbine rotor shroud <NUM> is positioned radially outward from and surrounds first turbine rotor <NUM>.

Second turbine section <NUM> includes second turbine inlet <NUM>, second turbine duct <NUM>, second turbine outlet <NUM>, and second turbine rotor <NUM>. Air is routed into second turbine inlet <NUM> and is ducted through second turbine duct <NUM> to second turbine outlet <NUM>. Second turbine rotor <NUM> is positioned in second turbine duct <NUM> and is mounted to and rotates with tie rod <NUM>. Second turbine rotor <NUM> will extract energy from the air passing through second turbine section <NUM> to drive rotation of tie rod <NUM>.

<FIG> is a front plan view of seal plate <NUM> of air cycle machine <NUM>. <FIG> is a back plan view of seal plate <NUM> of air cycle machine <NUM>. <FIG> is a cross-sectional view of a portion of seal plate <NUM> taken along line <NUM>-<NUM> of <FIG>. Seal plate <NUM> includes body <NUM> and bore <NUM> (shown in <FIG>). Body <NUM> includes first side <NUM>, second side <NUM>, radially inner end <NUM>, radially outer end <NUM>, hub <NUM>, first disk portion <NUM>, second disk portion <NUM>, third disk portion <NUM>, fourth disk portion <NUM>, first plurality of holes <NUM>, second plurality of holes <NUM>, third plurality of holes <NUM>, and groove <NUM> (shown in <FIG>). As shown in <FIG>, body <NUM> further includes exterior surface <NUM> and lattice structure <NUM>, which includes first region <NUM>, second region <NUM>, third region <NUM>, and fourth region <NUM>.

Seal plate <NUM> includes body <NUM> with bore <NUM> extending through a center of body <NUM>. Body <NUM> has a plate shape and includes first side <NUM> and second side <NUM> opposite of first side <NUM>. Body <NUM> also has radially inner end <NUM> and radially outer end <NUM> opposite of radially inner end <NUM>. Radially inner end <NUM> of body <NUM> defines bore <NUM> extending through body <NUM> of seal plate <NUM>.

Body <NUM> includes hub <NUM> extending from radially inner end <NUM> and positioned adjacent to bore <NUM>. Hub <NUM> is a center portion of body <NUM>. First disk portion <NUM> of body <NUM> extends radially outward from hub <NUM>. Second disk portion <NUM> of body <NUM> extends radially outward from first disk portion <NUM>. Third disk portion <NUM> of body <NUM> extends radially outward from second disk portion <NUM>. Fourth disk portion <NUM> of body <NUM> extends radially outward from third disk portion <NUM> to radially outer end <NUM>. First plurality of holes <NUM> are positioned around and extend through second disk portion <NUM> of body <NUM>. Second plurality of holes <NUM> are positioned around and extend through third disk portion <NUM> of body <NUM>. Third plurality of holes <NUM> are positioned around and extend through fourth disk portion <NUM> of body <NUM>. Groove <NUM> is positioned on fourth disk portion <NUM> of body <NUM> and extends into body <NUM> from second side <NUM> of body <NUM>. Groove <NUM> is configured to receive an o-ring to seal against other components of air cycle machine <NUM>.

Body <NUM> further includes exterior surface <NUM> that surrounds lattice structure <NUM> in an interior of body <NUM>. Exterior surface <NUM> is a solid, continuous surface. Lattice structure <NUM> is a varying lattice structure. Lattice structure <NUM> has regions with varying densities. As shown in <FIG>, lattice structure <NUM> has first region <NUM>, second region <NUM>, third region <NUM> and fourth region <NUM>. Lattice structure <NUM> may vary gradually or abruptly between regions. Lattice structure <NUM> includes members arranged in a 3D crisscrossing pattern with voids between the members. As shown in <FIG>, lattice structure <NUM> varies in density by having a varying distribution of the members and voids of lattice structure <NUM>. In alternate embodiments, lattice structure <NUM> can vary in density by varying the thickness of the members, by having varying geometrical configurations, and/or by varying fillet radii on joints between the members.

First region <NUM> is a region of lattice structure <NUM> positioned in hub <NUM> of body <NUM>. Second region <NUM> is a region of lattice structure <NUM> in first disk portion <NUM> of body <NUM>. Third region <NUM> is a region of lattice structure <NUM> in second disk portion <NUM> of body <NUM> that surrounds first plurality of bolt holes <NUM>. Fourth region <NUM> is a region of lattice structure <NUM> in third disk portion <NUM> and fourth disk portion <NUM> of body <NUM>.

In the embodiment shown in <FIG>, first region <NUM> and third region <NUM> of lattice structure <NUM> have a greater density than second region <NUM> and fourth region <NUM> of lattice structure <NUM>. Seal plate <NUM> is additively manufactured, allowing lattice structure <NUM> to be manufactured with different densities in different areas of seal plate <NUM>. Any suitable additive manufacturing process (also known as a 3D printing process) can be used to manufacture seal plate <NUM>, including, for example, direct metal laser sintering, electron beam freeform fabrication, electron-beam melting, selective laser melting, or selective laser sintering. Seal plate <NUM> can be made out of any material that can be used in an additive manufacturing process, includes any of stainless steel, corrosion-resistant steel, nickel-chromium alloy, aluminum, titanium, synthetic fiber, fiberglass, composites, carbon fiber, thermosetting bismaleimide (BMI) resins, and combinations thereof.

Traditional seal plates for rotary machines have solid cross-sections and can be manufactured by subtractive manufacturing processes, such as hogout, or compression molding. Additively manufacturing seal plate <NUM> allows lattice structure <NUM> to be used in seal plate <NUM>. Using lattice structure <NUM> in seal plate <NUM> allows seal plate <NUM> to have a reduced weight compared to traditional seal plates, as there are voids between lattice structure <NUM>. At the same time, seal plate <NUM> will have an equivalent strength as traditional seal plates due to the increased strength of lattice structure <NUM>.

Lattice structure <NUM> in seal plate <NUM> can also improve the thermal resistance of seal plate <NUM>. Seal plate <NUM> is used as a heat transfer barrier between components of air cycle machine <NUM>. Manufacturing seal plate <NUM> with lattice structure <NUM> improves the thermal resistance of seal plate <NUM>, as there are voids in lattice structure <NUM> that improve the insulating abilities of seal plate <NUM>.

Further, the density of lattice structure <NUM> is varied to optimize mechanical properties of seal plate <NUM> locally and generally. Mechanical properties of seal plate <NUM>, such as stress, strain, stiffness, and energy absorption, can be optimized to improve the performance of seal plate <NUM> by reducing stress in high stress regions of seal plate <NUM>, reducing strain and increasing stiffness in deflection regions of seal plate <NUM>, and increasing energy absorption capacity at energy containment regions of seal plate <NUM>. Reducing stress and strain in local regions of seal plate <NUM> can also reduce stress and strain in seal plate <NUM> generally. Reducing the stresses in high stress regions can reduce the failure rate of seal plate <NUM> and, thus, the failure rate of air cycle machine <NUM>. Reduced failure rates result in reduced down time, reduced repairs, and reduced costs. Reducing the strain and increasing the stiffness in deflection regions can reduce the tolerances between rotors in air cycle machine <NUM> and surrounding components. Reducing the tolerances between the rotors and surrounding components can increase the compression efficiency of air cycle machine <NUM>. Increased energy absorption capacity can improve the safe operation of air cycle machine <NUM>. Should a rotor fail, seal plate <NUM> and other components in air cycle machine <NUM> can contain this energy to protect other components of air cycle machine <NUM>.

<FIG> is a cross-sectional view of seal plate <NUM> positioned in air cycle machine <NUM>. <FIG> shows fan and compressor housing <NUM>, seal plate <NUM>, first turbine housing <NUM>, compressor duct <NUM>, compressor rotor <NUM>, diffuser <NUM>, compressor rotor shroud <NUM>, first turbine duct <NUM>, first turbine rotor <NUM>, first turbine rotor shroud <NUM>. Seal plate <NUM> includes body <NUM> and bore <NUM>. Body <NUM> includes first side <NUM>, second side <NUM>, radially inner end <NUM>, radially outer end <NUM>, hub <NUM>, first disk portion <NUM>, second disk portion <NUM>, third disk portion <NUM>, fourth disk portion <NUM>, first plurality of holes <NUM>, second plurality of holes <NUM>, third plurality of holes <NUM>, and groove <NUM>. As shown in <FIG>, body <NUM> further includes exterior surface <NUM> and lattice structure <NUM>, which includes first region <NUM>, second region <NUM>, third region <NUM>, and fourth region <NUM>.

Air cycle machine <NUM> has the structure and design as described above in reference to <FIG>. Seal plate <NUM> has the structure and design as described above in reference to <FIG>. Hub <NUM> of seal plate <NUM> abuts a seal that interfaces with rotating components, including compressor rotor <NUM> and first turbine rotor <NUM> of air cycle machine <NUM>. A first side of first disk portion <NUM> of seal plate <NUM> is positioned adjacent first rubine rotor <NUM>, and a second side of first disk portion <NUM> of seal plate <NUM> is positioned adjacent compressor rotor <NUM>. A first side of second disk portion <NUM> of seal plate <NUM> abuts first turbine rotor shroud <NUM>. Bolts extend through first plurality of holes <NUM> in second disk portion <NUM> to bolt seal plate <NUM> to first turbine rotor shroud <NUM>. A second side of second disk portion <NUM> of seal plate <NUM> is positioned adjacent to a radially outer end of compressor rotor <NUM>. A first side of third disk portion <NUM> of seal plate <NUM> abuts a flange of first turbine housing <NUM>, and a second side of third disk portion <NUM> of seal plate <NUM> abuts diffuser <NUM>. Bolts extend through second plurality of holes <NUM> to bolt seal plate <NUM> between diffuser <NUM> and first turbine housing <NUM>. Fourth disk portion <NUM> of seal plate <NUM> is positioned between and fan and compressor housing <NUM> and first turbine housing <NUM>. Bolts extends through third plurality of holes <NUM> to bolt seal plate <NUM> between fan and compressor housing <NUM> and first turbine housing <NUM>.

Seal plate <NUM> has first region <NUM> of lattice structure <NUM> in hub <NUM>. First region <NUM> is a deflection region of seal plate <NUM>, which is a region of seal plate <NUM> that is subject to deflection. As compressor rotor <NUM> and first turbine rotor <NUM> rotate, first region <NUM> of hub <NUM> is subject to deflection. First region <NUM> of lattice structure <NUM> is an area of increased density that aids in deflection management of seal plate <NUM> to reduce and prevent deflection of seal plate <NUM>. By reducing and preventing deflection of seal plate <NUM>, the efficiency of air cycle machine <NUM> can be increased.

Seal plate <NUM> has third region <NUM> of lattice structure <NUM> in second disk portion <NUM> of seal plate <NUM>. Third region <NUM> is a deflection region of seal plate <NUM>, which is a region of seal plate <NUM> that is subject to deflection. As air cycle machine <NUM> operates, third region <NUM> of hub <NUM> is subject to deflection. Third region <NUM> of lattice structure <NUM> is an area of increased density that aids in deflection management of seal plate <NUM> to reduce and prevent deflection of seal plate <NUM>. By reducing and preventing deflection of seal plate <NUM>, the efficiency of air cycle machine <NUM> can be increased.

There are gaps between compressor rotor <NUM> and surrounding components, such as compressor rotor shroud <NUM>, and between first turbine rotor <NUM> and surrounding components, such as first turbine rotor shroud <NUM>, to prevent contact between compressor rotor <NUM> and first turbine rotor <NUM> and surrounding components. Contact between compressor rotor <NUM> and first turbine rotor <NUM> and surrounding components may damage the components and cause failure of air cycle machine <NUM>. The gaps between compressor rotor <NUM> and first turbine rotor <NUM> and surrounding components have to account for deflections that compressor rotor <NUM> and first turbine rotor <NUM> and surrounding components, such as seal plate <NUM>, can be subjected to during operation of compressor rotor <NUM> and first turbine rotor <NUM>. Thus, the more deformation that compressor rotor <NUM>, first turbine rotor <NUM>, and seal plate <NUM> are subjected to during operation of compressor rotor <NUM> and first turbine rotor <NUM>, the larger the gaps need to be to ensure component safety. However, air can leak from air cycle machine <NUM> through the gaps, which leads to inefficiencies in air cycle machine <NUM>. Thus, it is desirable to minimize the gaps between compressor rotor <NUM> and first turbine rotor <NUM> and surrounding components. Identifying deflection regions of seal plate <NUM> and increasing the density of lattice structure <NUM> in the deflection regions (for example, first region <NUM> and third region <NUM>) reduces and prevents the deflections and strain that seal plate <NUM> is subjected to during operation of compressor rotor <NUM> and first turbine rotor <NUM> by increasing the stiffness in these areas. This reduced deflection and strain and increased stiffness means that the parts deform less when in operation. If seal plate <NUM> undergoes less deflection, the gaps between compressor rotor <NUM> and first turbine rotor <NUM> and surrounding components can be reduced. Reducing the gaps increase the efficiency of air cycle machine <NUM>.

Seal plate <NUM> has third region <NUM> of lattice structure <NUM> in second disk portion <NUM> of seal plate <NUM>. Third region <NUM> is a stress region of seal plate <NUM>, which is a region of seal plate <NUM> that is subject to high stress during operation of air cycle machine <NUM>. The high stress in stress regions of seal plate <NUM>, such as third region <NUM>, is a higher stress than stresses present in other regions of seal plate <NUM>. Third region <NUM> of lattice structure <NUM> is an area of increased density that aids in stress reduction during operation of air cycle machine <NUM> to reduce the stress in third region <NUM> of seal plate <NUM>. Stress reduction at critical points of seal plate <NUM> leads to increased longevity of seal plate <NUM>.

Reducing stress in stress regions of seal plate <NUM> will improve the longevity of seal plate <NUM>. Reducing the stresses at stress regions can reduce the failure rate of seal plate <NUM>, as well as the failure rate of air cycle machine <NUM> overall. During operation, these failures can damage components surrounding seal plate <NUM>, as these components are required to contain the energy of the failure for safety of the aircraft and its passengers. Reduced failure rates result in reduced down time, reduced repairs, and reduced costs.

Seal plate <NUM> has third region <NUM> of lattice structure <NUM> in second disk portion <NUM> of seal plate <NUM>. Third region <NUM> is an energy containment region of seal plate <NUM>, which is a region of seal plate <NUM> that is designed to absorb energy. Third region <NUM> in second disk portion <NUM> is positioned adjacent to a radially outer end of compressor rotor <NUM> and needs to be designed to absorb energy from compressor rotor <NUM> in the event of a failure of compressor rotor <NUM>. Third region <NUM> of lattice structure <NUM> is an area of increased density that aids in energy containment during operation of air cycle machine <NUM>. Energy containment at critical points of seal plate <NUM> ensures safe operation of air cycle machine <NUM>.

Increased energy containment is important to the safe operation of air cycle machine <NUM>. If compressor rotor <NUM> fails, seal plate <NUM> is designed to absorb the energy to protect and prevent serious damage to other components of air cycle machine <NUM>. Third region <NUM> of lattice structure <NUM> is positioned near compressor rotor <NUM> to contain the energy from compressor rotor <NUM> in seal plate <NUM>.

Seal plate <NUM> is one example of a seal plate in which variable lattice structure <NUM> can be used. In alternate embodiments, variable lattice structure <NUM> can be used in any suitable seal plate having any design. Further, air cycle machine <NUM> is one example of a turbomachinery or rotary machine in which seal plate <NUM> or any other seal plate with variable lattice structure <NUM> can be used. In alternate embodiments, seal plate <NUM> or any other seal plate with variable lattice structure <NUM> can be used in any other rotary machine having a seal plate.

<FIG> is a flow chart showing a method of manufacturing seal plate <NUM>. Step <NUM> includes laying down a layer of powder. Step <NUM> solidifying a portion of the layer of powder. Step <NUM> includes repeating steps <NUM> and <NUM> until seal plate <NUM> is completed. Step <NUM> includes processing seal plate <NUM>.

Seal plate <NUM> can be manufactured using an additive manufacturing process. Additive manufacturing involves manufacturing seal plate <NUM> layer by layer. Additive manufacturing processes allow complex internal and external shapes and geometries to be manufactured that are not feasible or possible with traditional manufacturing. A typical additive manufacturing process involves using a computer to create a three-dimensional representation of seal plate <NUM>. The three-dimensional representation will be converted into instructions which divide seal plate <NUM> into many individual layers. These instructions are then sent to an additive manufacturing device. This additive manufacturing device will print each layer, in order, and one at a time until all layers have been printed. Any additive manufacturing process can be used, including direct metal laser sintering, electron beam freeform fabrication, electron-beam melting, selective laser melting, selective laser sintering, or other equivalents that are known in the art.

Step <NUM> includes laying down a layer of powder. The powder can be made of a material selected from the group consisting of stainless steel, corrosion-resistant steel, nickel-chromium alloy, aluminum, titanium, synthetic fiber, fiberglass, composites, carbon fiber, thermosetting bismaleimide (BMI) resins, and combinations thereof. This powder may be laid down by a roller, pressurized gas, or other equivalents that are known in the art. This powder may have any grain size, wherein the grain size of the powder affects the unprocessed surface properties of seal plate <NUM>.

Step <NUM> includes solidifying a portion of the layer of powder. A portion of the layer of powder can be solidified by applying energy to layer of powder. Any energy source can be used, including laser beam, electron beams, or other equivalents that are known in the art. The application of this energy will solidify the powder in a specific configuration. The specific configuration of solidified metal will be entirely dependent on which layer the process is currently at. This specific configuration will be in a specific shape and distribution so that when combined with the other layers, it forms seal plate <NUM>.

Step <NUM> includes repeating steps <NUM> and <NUM> until seal plate <NUM> is completed. These two steps together lead to seal plate <NUM> being built layer by layer to completion. The specific configuration of step <NUM> consists of exterior surface <NUM>, which is continuous and solid, and lattice structure <NUM>, which has a varying density. The density of lattice structure <NUM> can be locally optimized to reduce stress or strain in specific regions and improve energy containment in specific regions. Reducing the stresses at high stress regions can reduce the failure rate of seal plate <NUM> and thus the failure rate of air cycle machine <NUM>. Reduced failure rates result in reduced down time, reduced repairs, and reduced costs. Reduced strain, and thus reduced deflection, at deflection regions means that the parts deform less when in operation. If seal plate <NUM> undergoes less deflection, the tolerances between components of air cycle machine <NUM> can be reduced. Reducing tolerances between components increases the efficiency of air cycle machine <NUM>. Improving energy containment in energy containment regions of seal plate <NUM> ensures the safe operation of air cycle machine <NUM>.

Step <NUM> includes processing seal plate <NUM>. Step <NUM> is an optional step. Processing seal plate <NUM> can include post processing steps, such as smoothing of exterior surface <NUM> of seal plate <NUM> or removal of powder from an interior of seal plate <NUM>. Since an additive manufacturing process is used, exterior surface <NUM> of seal plate <NUM> may be rougher than desired. Through sanding, brushing, buffing, grinding, and combinations thereof, exterior surface <NUM> of seal plate <NUM> may be made smoother. Removal of the powder from an interior of seal plate <NUM> can involve the process of removing the unsolidified powder between lattice structure <NUM> through high pressure gas, mechanical movements, or other methods know in the art.

A seal plate for a rotary machine includes a hub centered on a central axis of the rotary machine, a disk portion extending radially outwards from the hub, and a variable lattice structure in an interior of the seal plate. The variable lattice structure includes a first region of the seal plate having a first lattice structure, and a second region of the seal plate having a second lattice structure. The second lattice structure of the second region is denser than the first lattice structure of the first region. The second region is a deflection region, a stress region, or an energy containment region of the seal plate.

The seal plate of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
The seal plate has a continuous exterior solid surface surrounding the variable lattice structure.

The stress region of the seal plate is a region of the seal plate that is subject to higher stress than other regions of the seal plate.

The stress region of the seal plate is a region surrounding a bolt hole in the disk portion of the seal plate.

The deflection region of the seal plate is a region of the seal plate that is subject to deflections.

The deflection region of the seal plate is a region surrounding a bolt hole in the disk portion of the seal plate.

The deflection region of the seal plate is the hub of the seal plate.

The energy containment region of the seal plate is a region of the seal plate that is configured to contain energy.

The energy containment region of the seal plate is a region surrounding a bolt hole in the disk portion of the seal plate.

The seal plate is made of a material selected from the group consisting of stainless steel, corrosion-resistant steel, nickel-chromium alloy, aluminum, titanium, synthetic fiber, fiberglass, composites, carbon fiber, thermosetting bismaleimide (BMI) resins, and combinations thereof.

A rotary machine includes a tie rod extending through the rotary machine along a central axis, a compressor rotor mounted on the tie rod, a turbine rotor mounted on the tie rod, a compressor housing surrounding the compressor rotor, and a turbine housing surrounding the turbine rotor. A seal plate is positioned between the compressor housing and the turbine housing. The seal plates includes a hub centered on the central axis of the rotary machine, a disk portion extending radially outwards from the hub, and a variable lattice structure in an interior of the seal plate. The variable lattice structure includes a first region of the seal plate having a first lattice structure, and a second region of the seal plate having a second lattice structure. The second lattice structure of the second region is denser than the first lattice structure of the first region. The second region is a deflection region, a stress region, or an energy containment region of the seal plate.

The rotary machine of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:
The seal plate has a continuous exterior solid surface surrounding the variable lattice structure.

The deflection region of the seal plate is the hub of the seal plate that abuts rotating components mounted on the tie rod.

Claim 1:
A seal plate (<NUM>) for a rotary machine, the seal plate comprising:
a hub (<NUM>) centered on a central axis of the rotary machine;
a disk portion (<NUM>) extending radially outwards from the hub; and
a continuous exterior solid surface (<NUM>); and
a variable lattice structure (<NUM>) including intersecting members and voids between the intersecting members in an interior of the hub (<NUM>) and the disk portion (<NUM>), wherein the variable lattice structure (<NUM>) is surrounded by the exterior solid surface (<NUM>), and characterized in that the variable lattice structure (<NUM>) comprises:
a first region (<NUM>) of the seal plate having a first lattice structure; and
a second region (<NUM>) of the seal plate having a second lattice structure;
wherein the second lattice structure of the second region (<NUM>) is denser than the first lattice structure of the first region (<NUM>); and
wherein the second region (<NUM>) is a deflection region, a stress region, or an energy containment region of the seal plate (<NUM>).