Heat sink configurations for eddy current brake applications

Abstract

A heat sink configuration for an eddy current brake having a rotor (120) configured to be operably coupled to a wheel (102) of an aircraft is provided. The rotor (120) can include an annular central disc portion (126) and a plurality of heat sinks (122) arranged circumferentially around an outer radial edge. The plurality of heat sinks (122) can each have first and second detachable flanges on opposite axial sides of the heat sinks (122). The rotor (120) may further include grooves (124) arranged between two circumferentially adjacent heat sinks to receive a clamp (140) for operably coupling the brake rotor assembly (110) to the wheel (102) of the aircraft. An axial thickness of the annular central disc portion (126) can be less than an axial thickness of the plurality of heat sinks (122) to promote heat transfer from the annular central disc portion (126) into the plurality of heat sinks (122) during use.

Description

[0001] HEAT SINK CONFIGURATIONS FOR EDDY CURRENT BRAKE APPLICATIONS

[0002] FIELD OF DISCLOSURE

[0003] The present disclosure relates to eddy current braking architectures. More particularly, the present disclosure relates to improved heat sink configurations for axial- flux eddy current braking architectures, such as those associated with aircraft landing gear.

[0004] BACKGROUND

[0005] A braking alternative to friction brakes uses electromagnetic effects, notably "eddy current" brakes, which generate a resistive torque due to the interaction of a fixed or variable magnetic field and a rotating conductor. The magnetic field can be generated by electromagnets or by permanent magnets. The resistive torque that results from the brake depends on the speed of rotation of the conductor, the conductivity of the conductor, and the magnetic flux density (among other parameters). Conventional eddy current brake designs modulate the resistive torque by altering the magnetic flux density. In configurations using an electromagnet, the magnetic flux density is altered by varying the current applied to the magnet coil. In configurations with a permanent magnet, the magnetic flux density is altered by varying the airgap between the magnet and the conductor. Eddy current brakes can be used in various machinery, such machinery for use in the aircraft, automotive, industrial, aerospace, and rail industries.

[0006] In one example, aircraft landing gear commonly utilize wheel brakes to slow and stop the aircraft during ground maneuvers and to assist other braking systems (thrust reversers, spoilers, etc.) to decelerate the aircraft after touch-down during landing. Typical wheel brakes employ friction materials to provide a resistive torque and to convert kinetic energy to heat. A variety of configurations are possible, but all friction brakes impart wear, requiring regular maintenance and replacement of worn components. Additionally, the worn material is typically ejected from the brake as dust, which can contaminate surrounding components and, depending on the wear material, can represent a health hazard. Eddy current brakes can address these and other negative aspects of friction brakes. U.S. Patent No. 9,638,273, issued to Schmidt, and currently assigned to Safran Landing Systems UK Ltd., the disclosure of which is expressly incorporated herein, discloses an electromagnet eddy current brake assembly in which the electromagnets are also used as a form of electronically commutated motor. The brake assembly has a stator that includes at least one electromagnetic coil and is moveable in a direction parallel to the rotational axis of the wheel between a first position and a second position. In the first position, the electromagnetic coil is inductively coupled to the first portion of the rim when the wheel is rotating relative to the at least one electromagnetic coil. In the second position, the electromagnetic coil is inductively coupled to the second portion of the rim. When the rotor is in the first position, the brake assembly provides a braking force on the wheel. When the rotor is in the second position, the brake assembly generates power due to rotation of the wheel.

[0007] U.S. Patent App. No. 17 / 695,442, filed March 15, 2022, and currently assigned to Safran Landing Systems Canada Inc., the disclosure of which is expressly incorporated herein, discloses an electromagnet eddy current brake assembly having a rotor configured to rotate about an axis with a rim of the aircraft. The rotor has a first frustoconical rotor surface and either a conductive element or a magnet. The brake assembly further includes a stator fixed in rotation about the axis and configured for selective translation in a direction along the axis. The stator has a first frustoconical stator surface proximate to the first frustoconical rotor surface and either a conductive element (when the stator has a magnet) or a magnet (when the stator has a conductive element). These brake assemblies utilize the relative motion between adjacent stators and rotors to induce eddy currents that result in resistive braking torque. The resulting braking torque varies in part on the distance (airgap) between the stator and the rotor. Embodiments of the disclosed braking assembly utilized rotors and stators with corresponding frustoconical surfaces.

[0008] Eddy current brake systems face certain challenges, particularly related to heat dissipation. During operation of the eddy current brake system, kinetic energy is converted to thermal energy, which must be effectively dissipated. Improper dissipation of the generated heat can lead to performance degradation (e.g., reduced braking efficiency, premature wear of brake components, etc.) and potential safety hazards (e.g., system failure). Therefore, heat management must be considered in eddy current brake system designs to maintain optimal braking performance and ensure safe and reliable operation of eddy current brake systems.

[0009] Eddy current brake systems can include various heat dissipation systems, such as fans, cooling fluids, and thermal insulation materials. In these examples, fans can facilitate airflow to enhance heat dissipation, cooling fluids, such as oil or water, can remove heat from the braking system, and thermal insulation materials can minimize heat transfer to other components within or near the eddy current brake system. Embodiments of heat sink configurations for eddy current brake applications for aircraft in accordance with aspects of the present disclosure provide an eddy current braking system with improved efficiency and performance as compared to known eddy current aircraft braking systems.

[0010] SUMMARY

[0011] The present disclosure provides examples of heat sink configurations for eddy current braking architecture, e.g., for aircraft. Embodiments of the present disclosure can include eddy current brakes that include an annular central disc portion that has a performance thickness specified based on skin depth of the magnetic flux and a thicker heat sink portion for heat dissipation.

[0012] In accordance with an aspect of the present disclosure, an eddy current brake rotor configured to be operably coupled to a wheel of an aircraft is provided. In an embodiment, the brake rotor includes an annular central disc portion having a central opening; and a plurality of heat sinks arranged circumferentially around an outer radial edge of the annular central disc portion, the plurality of heat sinks having grooves arranged therebetween configured to receive a clamp assembly for operably coupling the brake rotor to the wheel of the aircraft. An axial thickness of the annular central disc portion can be less than an axial thickness of the plurality of heat sinks to promote heat transfer from the annular central disc portion into the plurality of heat sinks during use.

[0013] In accordance with an aspect of the present disclosure, an eddy current brake splitrotor configured to be operably coupled to a wheel of an aircraft is provided. In an embodiment, the brake split-rotor includes a first rotor half, comprising: a first annular central disc portion having a first central opening; and a first plurality of heat sink portions arranged circumferentially around an outer radial edge of the first annular central disc portion; and a second rotor half that is mirror symmetrical to the first rotor half and configured to abut the first rotor half, the second rotor half comprising: a second annular central disc portion having a second central opening; and a second plurality of heat sink portions arranged circumferentially around an outer radial edge of the second annular central disc portion. The plurality of first and second heat sink portions can have grooves arranged therebetween configured to receive a clamp for operably coupling the brake splitrotor to the wheel of the aircraft, and, when the first rotor half is assembled to the second rotor half, an axial thickness of the first and second annular central disc portions can be less than an axial thickness of the first and second plurality of heat sinks to promote heat transfer from the first and second annular central disc portions into the first and second plurality of heat sink portions during use.

[0014] In accordance with an aspect of the present disclosure, an eddy current brake having a rotor assembly configured to be operably coupled to a wheel of an aircraft is provided. In an embodiment, the rotor assembly includes an annular central disc portion having a central opening; and a plurality of heat sinks arranged circumferentially around an outer radial edge of the annular central disc portion, the plurality of heat sinks each having: a first detachable flange on a first axial side of the heat sink; a second detachable flange on a second axial side of the heat sink opposite the first axial side; and grooves arranged between two circumferentially adjacent heat sinks, the grooves configured to receive a clamp assembly for operably coupling the brake rotor assembly to the wheel of the aircraft. An axial thickness of the annular central disc portion can be less than an axial thickness of the plurality of heat sinks to promote heat transfer from the annular central disc portion into the plurality of heat sinks during use.

[0015] In accordance with another aspect of the present disclosure, each of the plurality of heat sinks can further include: a first detachable flange on a first axial side of the heat sink; and a second detachable flange on a second axial side of the heat sink opposite the first axial side.

[0016] In accordance with another aspect of the present disclosure, each of the first and second detachable flanges can be operably coupled to the respective heat sink with dowel pins, screws, bolts, welding, clamps, dovetail joints, or a combination thereof.

[0017] In accordance with another aspect of the present disclosure, the eddy current brake rotor can include fillets and / or chamfers to reduce the stress risers within the grooves and between the plurality of heat sinks and the annular central disc portion.

[0018] In accordance with another aspect of the present disclosure, a ferromagnetic core can be positioned within the annular central disc portion and configured to draw magnetic flux into the annular central disc portion during use.

[0019] In accordance with another aspect of the present disclosure, the clamp assembly can include a clamp body configured to be operably coupled to the wheel and a clamp head configured to be operably coupled to the clamp body, wherein the clamp assembly extends through each of the grooves arranged between the plurality of heat sinks to operably couple the brake rotor to the wheel.

[0020] In accordance with another aspect of the present disclosure, the axial thickness of the annular central disc portion can be less than or equal to double a minimum skin depth determined based on a resistivity (p), absolute magnetic permeability (p), and angular velocity (co) of the annular central disc portion during use. In accordance with another aspect of the present disclosure, the first rotor half can include a first circular indentation and a first tab indentation in the first annular central disc portion, and the second rotor half can include a second circular indentation and a second tab indentation in the second annular central disc portion.

[0021] In accordance with another aspect of the present disclosure, the ferromagnetic core can include a tab protrusion configured to be received within the first and second tab indentations to prevent the ferromagnetic core from spinning independently relative to either of the first and second rotor halves during use.

[0022] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0023] DESCRIPTION OF THE DRAWINGS

[0024] The foregoing aspects and many of the attendant advantages of the claimed subject matter will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

[0025] FIGURE 1 A depicts one example of a wheel assembly having an eddy current brake rotor, such as a wheel assembly for landing gear of a passenger or cargo aircraft, shown in perspective view, in which technologies and / or methodologies of the present disclosure may be employed;

[0026] FIGURE IB is an exploded perspective view of the wheel assembly of FIGURE 1A;

[0027] FIGURE 1C is a perspective view of the eddy current brake rotor of the wheel assembly of FIGURE 1A; FIGURE ID is a side view of the eddy current brake rotor of the wheel assembly of FIGURE 1A;

[0028] FIGURE IE is a cross-sectional view of the eddy current brake rotor of the wheel assembly of FIGURE 1 A, taken along line 1E-1E in FIGURE ID;

[0029] FIGURE 2A is a perspective view of an eddy current brake rotor assembly in accordance with embodiments of the present disclosure;

[0030] FIGURE 2B is an exploded perspective view of the eddy current brake rotor assembly of FIGURE 2 A;

[0031] FIGURE 3 A is a perspective view of an eddy current brake split-rotor assembly in accordance with embodiments of the present disclosure; and

[0032] FIGURE 3B is an exploded perspective view of the eddy current brake split-rotor assembly of FIGURE 3A.

[0033] DETAILED DESCRIPTION

[0034] The detailed description set forth above in connection with the appended drawings, where like numerals reference like elements, are intended as a description of various embodiments of the present disclosure and are not intended to represent the only embodiments. Each embodiment described in this disclosure is provided merely as an example or illustration and should not be construed as preferred or advantageous over other embodiments. The illustrative examples provided herein are not intended to be exhaustive or to limit the disclosure to the precise forms disclosed.

[0035] As will be described in more detail below, the present disclosure provides examples of heat sink configurations for eddy current braking systems, e.g., for aircraft landing gear, rail machinery, etc. Eddy current brakes can be used in various applications where controlled deceleration of rotating components is required. Eddy current brakes generate heat by converting kinetic energy into thermal energy during braking operation. The generated heat must be effectively dissipated to avoid performance degradation (e.g., reduced braking efficiency, premature wear of brake components, warping, etc.) and potential safety hazards (e.g., system failure). The braking torque of an eddy current brake is proportional to the speed of rotation, strength of the magnetic field, and the material properties of the rotor. For an eddy current brake system using passive magnets, the brake torque can be actively controlled by adjusting the air gap between the rotor and stator where the magnetic fields pass and as a function of the rotation speed of the rotor. For an eddy current brake system using electromagnets, the electromagnets can be switched on / off or reversed to modify the braking torque.

[0036] Embodiments of the present disclosure provide improved heat sink configurations to control heat dissipation of eddy current brakes. The eddy current brake rotor configurations can include material specifications and / or geometry to maximize heat transfer efficiency into the heat sink portions, thereby improving the overall performance and durability of the eddy current braking system. Embodiments of the present disclosure are expected to improve the efficiency of heat dissipation in an eddy current brake system, among other advantages, which can provide increased braking performance and safety across various applications and operating conditions.

[0037] Embodiments of the present disclosure include heat sink features that can increase thermal performance of the eddy current brake rotor, thereby improving overall performance. The geometry of the eddy current brake rotors of the present disclosure include a relatively thin central section positioned towards the center of the rotor and a thicker outer section positioned towards the outer circumference of the rotor. The central section can have a thickness that allows constructive interference of magnetic fields on either side of the brake rotor. In these embodiments, the thickness of the central section is specified such that a skin depth is optimized to promote interaction of these two magnetic fields to increase the strength of the eddy currents generated, which increases braking and thermal performance. Although the central section also conducts heat, the outer section can have a heat sink flange geometry that promotes the dissipation of heat energy. In the eddy current brake rotors of the present disclosure, the relatively thin central section promotes at least a portion of the heat energy generated in the rotor to travel towards the thicker outer flanges, where the heat sinks are configured to absorb the thermal energy more effectively due their higher mass.

[0038] The operational thickness of the central section of the brake rotor can be optimized such that two magnetic arrays on either side of the rotor can create constructive interference across the central section of the brake rotor, increasing the strength of the magnetic field. This increased magnetic field strength thereby increases the eddy currents generated in the brake rotor, which in turn increases braking performance of the eddy current brake. In some embodiments, the flanges of the brake rotors described herein can be removable from the rotor body to improve manufacturability and reduce costs. In further embodiments, a split-rotor configuration can include a central iron core to draw in magnetic flux from the stators, increasing the density of the eddy currents generated by the brake system.

[0039] In the context of the eddy current brakes of embodiments of the present disclosure, skin depth refers to the depth at which the alternating currents in a conductor penetrate when exposed to a changing electromagnetic field. The skin depth phenomenon occurs primarily at high frequencies of electromagnetic field. As the frequency of the electromagnetic field increases, the skin depth decreases such that the induced alternating currents are closer to the surface of the conductor. The performance of an eddy current brake is partially dependent on this skin depth. In specifying the combination of frequency of the electromagnetic field and the conductivity of the material of the brake rotor, the available maximum braking torque and efficiency of the system can be tailored to specific applications. In a further aspect, the skin depth can determine how effectively the eddy currents penetrate the conductor (i.e., the brake rotor) and, by extension, how effectively the eddy currents generate a braking torque.

[0040] Although embodiments of the present disclosure may be described with reference to heat sink configurations for eddy current brake architectures for aircraft, one skilled in the relevant art will appreciate that the disclosed embodiments are illustrative in nature and therefore should not be construed as limited to such an application. It should therefore be apparent that the disclosed technologies and methodologies have wide application, and therefore may be suitable for use with many types of vehicle braking architectures, including automobiles, buses, trains, heavy equipment, and the like. Accordingly, the following descriptions and illustrations herein should not limit the scope of the claimed subject matter.

[0041] FIGURE 1A depicts one example of a wheel assembly 100 (“assembly 100”) having an eddy current brake rotor 120 (“rotor 120”), such as a wheel assembly for landing gear of a passenger or cargo aircraft, shown in perspective view, in which technologies and / or methodologies of the present disclosure may be employed. The assembly 100 can include a wheel 102 and an eddy current brake rotor assembly 110 (“rotor assembly 110”) operably coupled to the wheel 102. The rotor assembly 110 can include attachment components to operably couple the rotor 120 to the wheel 102 for operation of the eddy current brake system. In some embodiments, the assembly 100 can be integrated at least partially into a nose landing gear system, a left main landing gear system, and / or a right main landing gear system of an aircraft. As noted above, the assembly 100 can also be suitable for use with many types of vehicle braking architectures. The attachment components of the rotor assembly 110 can include clamp heads 130 distributed around an outer circumference of the rotor 120, as will be described in greater detail below.

[0042] FIGURE IB is an exploded perspective view of the assembly 100, showing an embodiment of the rotor assembly 110 having an attachment component system configured to operably couple the rotor 120 to the wheel 102. In the illustrated embodiment, the rotor 120 has a generally annular disc shape and can be operably coupled to the wheel 102 with a series of eight clamps 140 arranged circumferentially around an outer radial edge of the rotor 120 and configured to be received within grooves 124 (see FIGURE 1C) of the rotor 120. The clamps 140 can each be coupled to the clamp heads 130, e.g., with bolts 132, to capture a portion of the rotor 120 therebetween. The clamps 140 can in turn be coupled to the wheel 102, e.g., with bolts 142. Although the illustrated embodiments show eight clamp 140 and clamp head 130 combinations corresponding to the eight grooves 124 of the rotor 120, in other embodiments, the rotor 120 can have any suitable number of grooves 124 and corresponding clamp 140 and clamp head 130 combinations to operably couple the rotor 120 to the wheel 102. Other attachment schemes of the rotor 120 to the wheel 102 are also within the scope of the present disclosure, such as welding, integrated rotor mounting components, friction fit, etc.

[0043] FIGURE 1C is a perspective view and FIGURE ID is a side view of the rotor 120. The rotor 120 can include a plurality of heat sinks 122 arranged circumferentially around an outer radial edge of the rotor 120. As noted above, the plurality of heat sinks 122 can be separated by the grooves 124 which are configured to receive the clamps 140 therein. The grooves 124 can be formed by machining (milling, cutting, etc.), casting, or otherwise formed, and can include smoothing features (e.g., fillets and chamfers) to reduce stress risers within the grooves 124. The heat sinks 122 can be arranged to surround an annular central disc portion 126 (“central portion 126”) of the rotor 120 and can further include the smoothing features (e.g., fillets and chamfers) therebetween. While the central portion 126 can be maximized to increase the surface area for eddy current generation, the central portion 126 can include a central opening 128 to reduce the mass of the rotor 120 in an area where the generated braking torque would be minimal, e.g., near the central axis of rotation where the torque vector moment arm is relatively short. In the eddy current brake system, the central portion 126 can be positioned axially adjacent to the magnets (permanent or electro-, not shown) and configured to receive the magnetic field to produce the eddy currents braking effect, thereby counteracting rotation of the wheel 102. Although one example of a ratio of central portion surface area to central opening is shown, in other embodiments, the central opening can be larger or smaller depending on performance requirements of the braking system. As described above, the thicknesses of the heat sinks 122 and the central portion 126 can determine the performance parameters (braking force, heat dissipation, etc.) of the rotor 120 of the eddy current brake system. FIGURE IE is a cross-sectional view of the rotor 120, taken along line 1E-1E in FIGURE ID. In the illustrated embodiment, the central portion 126 has a thickness T1 (referred to herein as a “performance thickness”) and the heat sinks 122 have a thickness T2 (referred to herein as a “thermal thickness”). The performance thickness T1 can be specified such that the stators operating on either side create constructive magnetic interference to increase the strength of the magnetic field the rotor 120 passes through during rotation. Although the central portion 126 is shown as having a constant thickness T1 from the central opening 128 to the radially inward base of the heat sinks 122, other embodiments can include a variable thickness, such as a linearly increasing thickness from the central opening 128 radially outward, a series of steps, oscillating features, radial and / or circumferential ridges, or the like. Similarly, the thickness T2 of the heat sinks 122 can be variable in the radial and / or circumferential directions along the heat sinks 122.

[0044] The thermal thickness T2 between the outer flange surfaces of the heat sinks 122 is configured to be greater than the performance thickness T1 to promote transfer of the heat generated on the operating surfaces of the central portion 126 radially outward to the heat sinks 122, and in turn dissipated by convection to the surrounding air. The heat sinks 122 increase the mass of the rotor 120, permitting it to store more heat energy, thereby reducing heat buildup in the rotor 120 while maintaining an optimal performance thickness T1 in view of the mass required to absorb the kinetic energy of the object, e.g., the aircraft.

[0045] The value of the performance thickness T1 is related to the skin depth (5, see the equation reproduced below) of the eddy currents induced by the surrounding stators (not shown). The skin depth (5) refers to the distance into the central portion 126 of the rotor 120 at which eddy currents are generated. If the eddy currents induced by the stators on both sides of the central portion 126 overlap in the center, constructive interference occurs which in turn increases the eddy current density and the performance of the eddy current brake. To obtain an overlap of the eddy currents, the performance thickness T1 must be equal to or less than double the minimum skin depth (5) on each side of the central portion 126. The skin depth (5) of the system can be calculated from the design parameters of the eddy current brake based on the equation reproduced below, with the following variables: resistivity (p) of the rotor, absolute magnetic permeability (p) of the rotor material, and the angular velocity (co) of the rotor.

[0046] During operation of the eddy current brake, the above-noted variables change as the increasing temperature of the rotor causes a change in resistivity (p) and the angular velocity (co) decreases as the rotor slows down due to braking action on the object, e.g., the aircraft. The performance thickness T1 can therefore be specified based on the relevant design requirements that define the operating temperature and angular velocity (co). The following table lists varying resistivities (p) and angular velocities (co), along with their corresponding skin depth (5) and maximum performance thickness Tl. In some embodiments, the maximum performance thickness Tl is from about 9mm to about 62mm. In some embodiments, an example of an optimized performance thickness Tl for a copper rotor operating at a temperature of 250°C and an angular velocity (co) of 1000 RPM is 15.71 mm. Other embodiments of the performance thickness Tl can produce other advantageous results based on the application of the eddy current brake system.

[0047] Table 1. Maximum performance thicknesses Tl for different design parameters.

[0048] FIGURE 2A is a perspective view and FIGURE 2B is an exploded perspective view of an eddy current brake rotor assembly 220 (“rotor assembly 220”) in accordance with embodiments of the present disclosure. The rotor assembly 220 is similar in function to the rotor 120 shown in FIGURES 1 A-1E, except that the embodiment of the rotor assembly 220 includes a heat sink body 222 having detachable flanges 223. The rotor assembly 220 can include the heat sink body 222, a first detachable flange 223a, a second detachable flange 223b arranged opposite across the heat sink body 222 from the first detachable flange 223a, grooves 224, a central portion 226, and a central opening 228. In some embodiments, the dimensions, ratios, layout, and thicknesses can be the same as those of the rotor 120, which would result in a similar performance in an eddy current brake system. In the embodiment of the rotor assembly 220, the detachable flanges 223 a and 223b can improve manufacturability and reduce cost of materials, and can further allow a different material specification for the first and second detachable flanges 223a and 223b, among other differences.

[0049] As shown most clearly in FIGURE 2B, the first detachable flange 223a can be operably coupled to the heat sink body 222 by first dowel pins 236a being cooperatively received within apertures 234 of the heat sink body 222 and corresponding apertures (not shown) within the first detachable flange 223a. Similarly, the second detachable flange 223b can be operably coupled to the heat sink body 222 by second dowel pins 236b being cooperatively received within apertures (not shown) of the heat sink body 222 and corresponding apertures 235 within the second detachable flange 223b. In the illustrated configuration using the dowel pins 236a and 236b, the operable coupling of the first and second detachable flanges 223a and 223b can be a press fit, interference fit (e.g., by thermal expansion during assembly), or the like. In these embodiments, the dowel pins 236a and 236b can be formed from a similar material as the heat sink body 222 and the first and second detachable flanges 223a and 223b to avoid dissimilar material issues (corrosion, coefficient of thermal expansion, etc.). In other embodiments, the first and second detachable flanges 223a and 223b can be operably coupled to the heat sink body 222 with other suitable fasteners (screws, bolts, etc.), welding, dovetail joints, clamps, etc., or a combination thereof.

[0050] FIGURE 3 A is a perspective view and FIGURE 3B is an exploded perspective view of an eddy current brake split-rotor assembly 320 (“split-rotor assembly 320”) in accordance with embodiments of the present disclosure. The split-rotor assembly 320 is similar in function to the rotor 120 shown in FIGURES 1 A-1E and the rotor assembly 220 shown in FIGURES 2A and 2B, except that the embodiment of the split-rotor assembly 320 includes halved portions with a ferromagnetic core. The split-rotor assembly 320 can include first and second heat sink portions 322a and 322b, grooves 324, first and second central portions 326a and 326b, and first and second central openings 328a and 328b. In some embodiments, the dimensions, ratios, layout, and thicknesses can be the same as those of the rotor 120 and the rotor assembly 220, which would result in a similar performance in an eddy current brake system. In the embodiment of the split-rotor assembly 320, the halved portions can improve manufacturability and reduce cost of materials, and can further allow a different material specification for the ferromagnetic core, which is expected to increase the eddy current braking effect, among other differences.

[0051] As shown in FIGURE 3B, the first half of the split-rotor assembly 320 having the first heat sink portion 233a, the groove 324, the first central portion 326a, and the first central opening 328a can be mirror symmetrical to the second half of the split-rotor assembly 320 having the second heat sink portion 233b, the groove 324, the second central portion 326b, and the second central opening 328b. In this regard, certain features of the inner surface of the first half of the split-rotor assembly 320 are not shown for clarity in FIGURE 3B, but are described with reference to the inner surface of the second half of the split-rotor assembly 320, which includes a circular indentation 344b and a corresponding tab indentation 346b. The size and shape of the circular indentation 344b and the tab indentation 346b corresponding to the size and shape of a ferromagnetic core 350 (which fits within the circular indentation 344b) including tab protrusions 352 (which fit within the tab indentations 346b).

[0052] The ferromagnetic core 350 of the split-rotor assembly 320 can increase the effectiveness of drawing in magnetic flux from the stators, thereby reducing the power required, increasing the maximum thickness of the central portion, and / or increasing maximum braking torque. As a secondary effect, the material of the ferromagnetic core can provide an additional heat sink mass for the split-rotor assembly 320. The interface of the tab protrusions 352 with the tab indentations 346b and the corresponding tab indentations of the first half (not shown) are a torque transfer mechanism that prevents the ferromagnetic core from spinning independently from either of the first and second halves. Further, the magnetic fields urge the first and second halves together during use, ensuring torque transfer between the halves.

[0053] A collection of example embodiments, including at least some explicitly enumerated as “ECs” (Example Combinations), providing additional description of a variety of embodiment types in accordance with the concepts described herein are provided below. These examples are not meant to be mutually exclusive, exhaustive, or restrictive; and the claimed subject matter is not limited to these example embodiments but rather encompasses all possible modifications and variations within the scope of the issued claims and their equivalents.

[0054] EC A. An eddy current brake rotor configured to be operably coupled to a wheel of an aircraft, the brake rotor comprising: an annular central disc portion having a central opening; and a plurality of heat sinks arranged circumferentially around an outer radial edge of the annular central disc portion, the plurality of heat sinks having grooves arranged therebetween configured to receive a clamp assembly for operably coupling the brake rotor to the wheel of the aircraft, wherein an axial thickness of the annular central disc portion is less than an axial thickness of the plurality of heat sinks to promote heat transfer from the annular central disc portion into the plurality of heat sinks during use.

[0055] EC B. The brake rotor of EC A, wherein each of the plurality of heat sinks further comprises: a first detachable flange on a first axial side of the heat sink; and a second detachable flange on a second axial side of the heat sink opposite the first axial side.

[0056] EC C. The brake rotor of EC B, wherein each of the first and second detachable flanges are operably coupled to the respective heat sink with dowel pins, screws, bolts, welding, clamps, dovetail joints, or a combination thereof.

[0057] EC D. The brake rotor of EC C, wherein the grooves include fillets and / or chamfers to reduce stress risers within the grooves.

[0058] EC E. The brake rotor of EC A, further comprising a ferromagnetic core positioned within the annular central disc portion and configured to draw magnetic flux into the annular central disc portion during use.

[0059] EC F. The brake rotor of EC A, wherein the clamp assembly comprises a clamp body configured to be operably coupled to the wheel and a clamp head configured to be operably coupled to the clamp body, wherein the clamp assembly extends through each of the grooves arranged between the plurality of heat sinks to operably couple the brake rotor to the wheel.

[0060] EC G. The brake rotor of any of EC A, wherein the axial thickness of the annular central disc portion is less than or equal to double a minimum skin depth determined based on a resistivity (p), absolute magnetic permeability (p), and angular velocity (co) of the annular central disc portion during use.

[0061] EC H. An eddy current brake split-rotor configured to be operably coupled to a wheel of an aircraft, the brake split-rotor comprising: a first rotor half, comprising: a first annular central disc portion having a first central opening; and a first plurality of heat sink portions arranged circumferentially around an outer radial edge of the first annular central disc portion; and a second rotor half that is mirror symmetrical to the first rotor half and configured to abut the first rotor half, the second rotor half comprising: a second annular central disc portion having a second central opening; and a second plurality of heat sink portions arranged circumferentially around an outer radial edge of the second annular central disc portion, wherein the plurality of first and second heat sink portions have grooves arranged therebetween configured to receive a clamp assembly for operably coupling the brake splitrotor to the wheel of the aircraft, and wherein, when the first rotor half is assembled to the second rotor half, an axial thickness of the first and second annular central disc portions is less than an axial thickness of the first and second plurality of heat sinks to promote heat transfer from the first and second annular central disc portions into the first and second plurality of heat sink portions during use.

[0062] EC I. The brake split-rotor of EC H, wherein each of the first and second plurality of heat sink portions further comprises a detachable flange.

[0063] EC J. The brake split-rotor of EC I, wherein each of the detachable flanges are operably coupled to the respective heat sink portion with dowel pins, screws, bolts, welding, clamps, dovetail joints, or a combination thereof. EC K. The brake split-rotor of EC H, wherein the grooves include fillets and / or chamfers to reduce stress risers within the grooves.

[0064] EC L. The brake split-rotor of EC H, wherein the first rotor half includes a first circular indentation and a first tab indentation in the first annular central disc portion, and wherein the second rotor half includes a second circular indentation and a second tab indentation in the second annular central disc portion.

[0065] EC M. The brake split-rotor of EC L, further comprising a ferromagnetic core positioned between the first and second annular central disc portions within the first and second circular indentations and configured to draw magnetic flux into the annular central disc portion during use.

[0066] EC N. The brake split-rotor of EC M, wherein the ferromagnetic core includes a tab protrusion configured to be received within the first and second tab indentations to prevent the ferromagnetic core from spinning independently relative to either of the first and second rotor halves during use.

[0067] EC O. The brake split-rotor of EC H, wherein the clamp assembly comprises a clamp body configured to be operably coupled to the wheel and a clamp head configured to be operably coupled to the clamp body, wherein the clamp assembly extends through each of the grooves arranged between the first and second plurality of heat sink portions to operably couple the brake split-rotor to the wheel.

[0068] EC P. The brake split-rotor of EC H, wherein the axial thickness of the first and second annular central disc portions is less than or equal to double a minimum skin depth determined based on a resistivity (p), absolute magnetic permeability (p), and angular velocity (co) of the first and second annular central disc portions during use.

[0069] EC Q. An eddy current brake having a rotor assembly configured to be operably coupled to a wheel of an aircraft, the rotor assembly comprising: an annular central disc portion having a central opening; and a plurality of heat sinks arranged circumferentially around an outer radial edge of the annular central disc portion, the plurality of heat sinks each having: a first detachable flange on a first axial side of the heat sink; a second detachable flange on a second axial side of the heat sink opposite the first axial side; and grooves arranged between two circumferentially adjacent heat sinks, the grooves configured to receive a clamp assembly for operably coupling the brake rotor assembly to the wheel of the aircraft, wherein an axial thickness of the annular central disc portion is less than an axial thickness of the plurality of heat sinks to promote heat transfer from the annular central disc portion into the plurality of heat sinks during use.

[0070] EC R. The brake rotor assembly of EC Q, wherein each of the first and second detachable flanges are operably coupled to the respective heat sink with dowel pins, screws, bolts, welding, clamps, dovetail joints, or a combination thereof.

[0071] EC S. The brake rotor of EC Q, further comprising a ferromagnetic core positioned within the annular central disc portion and configured to draw magnetic flux into the annular central disc portion during use.

[0072] In the foregoing description, specific details are set forth to provide a thorough understanding of exemplary embodiments of the present disclosure. It will be apparent to one skilled in the art, however, that the embodiments disclosed herein may be practiced without embodying all of the specific details. In some instances, well-known process steps have not been described in detail in order not to unnecessarily obscure various aspects of the present disclosure. Further, it will be appreciated that embodiments of the present disclosure may employ any combination of features described herein.

[0073] The present application may reference quantities and numbers. Unless specifically stated, such quantities and numbers are not to be considered restrictive, but exemplary of the possible quantities or numbers associated with the present application. Also in this regard, the present application may use the term “plurality” to reference a quantity or number. In this regard, the term “plurality” is meant to be any number that is more than one, for example, two, three, four, five, etc. The terms “about,” “approximately,” “near,” etc., mean plus or minus 10% of the stated value. For the purposes of the present disclosure, the phrase “at least one of A and B” is equivalent to “A and / or B” or vice versa, namely “A” alone, “B” alone or “A and B.”. Similarly, the phrase “at least one of A, B, and C,” for example, means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C), including all further possible permutations when greater than three elements are listed.

[0074] It should be noted that for purposes of this disclosure, terminology such as “upper,” “lower,” “vertical,” “horizontal,” “fore,” “aft,” “inner,” “outer,” “front,” “rear,” etc., should be construed as descriptive and not limiting the scope of the claimed subject matter. Further, the use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings.

[0075] Throughout this specification, terms of art may be used. These terms are to take on their ordinary meaning in the art from which they come, unless specifically defined herein or the context of their use would clearly suggest otherwise.

[0076] The principles, representative embodiments, and modes of operation of the present disclosure have been described in the foregoing description. However, aspects of the present disclosure, which are intended to be protected, are not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. It will be appreciated that variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present disclosure. Accordingly, it is expressly intended that all such variations, changes, and equivalents fall within the spirit and scope of the present disclosure as claimed.

Claims

CLAIMSThe embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An eddy current brake rotor configured to be operably coupled to a wheel of an aircraft, the brake rotor comprising: an annular central disc portion having a central opening; and a plurality of heat sinks arranged circumferentially around an outer radial edge of the annular central disc portion, the plurality of heat sinks having grooves arranged therebetween configured to receive a clamp assembly for operably coupling the brake rotor to the wheel of the aircraft, wherein an axial thickness of the annular central disc portion is less than an axial thickness of the plurality of heat sinks to promote heat transfer from the annular central disc portion into the plurality of heat sinks during use.

2. The brake rotor of Claim 1, wherein each of the plurality of heat sinks further comprises: a first detachable flange on a first axial side of the heat sink; and a second detachable flange on a second axial side of the heat sink opposite the first axial side.

3. The brake rotor of Claim 2, wherein each of the first and second detachable flanges are operably coupled to the respective heat sink with dowel pins, screws, bolts, welding, clamps, dovetail joints, or a combination thereof.

4. The brake rotor of Claim 3, further comprising fillets and / or chamfers to reduce stress risers within the grooves and between the plurality of heat sinks and the annular central disc portion.

5. The brake rotor of any of Claims 1-4, further comprising a ferromagnetic core positioned within the annular central disc portion and configured to draw magnetic flux into the annular central disc portion during use.

6. The brake rotor of any of Claims 1-5, wherein the clamp assembly comprises a clamp body configured to be operably coupled to the wheel and a clamp head configured to be operably coupled to the clamp body, wherein the clamp assembly extends through each of the grooves arranged between the plurality of heat sinks to operably couple the brake rotor to the wheel.

7. The brake rotor of any of Claims 1-6, wherein the axial thickness of the annular central disc portion is less than or equal to double a minimum skin depth determined based on a resistivity (p), absolute magnetic permeability (p), and angular velocity (co) of the annular central disc portion during use.

8. An eddy current brake split-rotor configured to be operably coupled to a wheel of an aircraft, the brake split-rotor comprising: a first rotor half, comprising: a first annular central disc portion having a first central opening; and a first plurality of heat sink portions arranged circumferentially around an outer radial edge of the first annular central disc portion; and a second rotor half that is mirror symmetrical to the first rotor half and configured to abut the first rotor half, the second rotor half comprising: a second annular central disc portion having a second central opening; and a second plurality of heat sink portions arranged circumferentially around an outer radial edge of the second annular central disc portion,wherein the plurality of first and second heat sink portions have grooves arranged therebetween configured to receive a clamp assembly for operably coupling the brake splitrotor to the wheel of the aircraft, and wherein, when the first rotor half is assembled to the second rotor half, an axial thickness of the first and second annular central disc portions is less than an axial thickness of the first and second plurality of heat sinks to promote heat transfer from the first and second annular central disc portions into the first and second plurality of heat sink portions during use.

9. The brake split-rotor of Claim 8, wherein each of the first and second plurality of heat sink portions further comprises a detachable flange.

10. The brake split-rotor of Claim 9, wherein each of the detachable flanges are operably coupled to the respective heat sink portion with dowel pins, screws, bolts, welding, clamps, dovetail joints, or a combination thereof.

11. The brake split-rotor of any of Claims 8-10, wherein the grooves include fillets and / or chamfers to reduce stress risers within the grooves.

12. The brake split-rotor of any of Claims 8-11, wherein the first rotor half includes a first circular indentation and a first tab indentation in the first annular central disc portion, and wherein the second rotor half includes a second circular indentation and a second tab indentation in the second annular central disc portion.

13. The brake split-rotor of Claim 12, further comprising a ferromagnetic core positioned between the first and second annular central disc portions within the first and second circular indentations and configured to draw magnetic flux into the annular central disc portion during use.

14. The brake split-rotor of Claim 13, wherein the ferromagnetic core includes a tab protrusion configured to be received within the first and second tab indentations to prevent the ferromagnetic core from spinning independently relative to either of the first and second rotor halves during use.

15. The brake split-rotor of any of Claims 8-14, wherein the clamp assembly comprises a clamp body configured to be operably coupled to the wheel and a clamp head configured to be operably coupled to the clamp body, wherein the clamp assembly extends through each of the grooves arranged between the first and second plurality of heat sink portions to operably couple the brake split-rotor to the wheel.

16. The brake split-rotor of any of Claims 8-15, wherein the axial thickness of the first and second annular central disc portions is less than or equal to double a minimum skin depth determined based on a resistivity (p), absolute magnetic permeability (p), and angular velocity (co) of the first and second annular central disc portions during use.

17. An eddy current brake having a rotor assembly configured to be operably coupled to a wheel of an aircraft, the rotor assembly comprising: an annular central disc portion having a central opening; and a plurality of heat sinks arranged circumferentially around an outer radial edge of the annular central disc portion, the plurality of heat sinks each having: a first detachable flange on a first axial side of the heat sink; a second detachable flange on a second axial side of the heat sink opposite the first axial side; and grooves arranged between two circumferentially adjacent heat sinks, the grooves configured to receive a clamp assembly for operably coupling the brake rotor assembly to the wheel of the aircraft,wherein an axial thickness of the annular central disc portion is less than an axial thickness of the plurality of heat sinks to promote heat transfer from the annular central disc portion into the plurality of heat sinks during use.

18. The brake rotor assembly of Claim 17, wherein each of the first and second detachable flanges are operably coupled to the respective heat sink with dowel pins, screws, bolts, welding, clamps, dovetail joints, or a combination thereof.

19. The brake rotor of Claims 17 or 18, further comprising a ferromagnetic core positioned within the annular central disc portion and configured to draw magnetic flux into the annular central disc portion during use.

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