Patent Description:
Wrap around or U-channel stator clips are used to increase the structural capability of the stator disk(s) of a brake assembly, such as an aircraft brake assembly, or to reduce stator slot enlargement in-service. In some cases, the increased strength is beneficial for loadings associated with in-service conditions. The use of stator clips may result in reduced braking performance at high aircraft landing energies. It is believed to be a result of stator clip drag on the torque plate spline. <CIT>, <CIT> and <CIT> relate to brake disk assemblies.

A stator disk assembly comprising a stator clip according to the invention as in claim <NUM> is disclosed herein. Further embodiments of the invention are also disclosed.

In various embodiments, the stator clip may comprise a first flange pair and second flange pair. The first flange pair may be orthogonal to a reverse side wall of the first face. In various embodiments, the first flange pair may comprise opposing flanges. In various embodiments, each flange may define a lug recess. In various embodiments, the second flange pair may be orthogonal to a reverse side wall of the second face. The second flange pair may comprise opposing flanges. In various embodiments, each flange may define a lug recess.

In various embodiments, the spline interface of the stator clip may be U-shaped. In various embodiments, the spline interface of the stator clip may be monolithic. In various embodiments, the stator clip may be configured to be riveted to a stator disk. The at least two ridges may be hemi-cylindrical.

A brake assembly is also disclosed herein, in accordance with various embodiments. The brake assembly may comprise a torque plate barrel. The torque plate barrel may comprise an outer surface disposed around a first reference axis. In various embodiments, the outer surface may comprise a first spline proceeding about the first reference axis. In various embodiments, the brake assembly may comprise a stator disk assembly mounted on the torque plate barrel.

In various embodiments, the torque plate barrel may further comprise a second spline. The second spline and the first spline may be spaced from one another proceeding about the first reference axis. In various embodiments, the inner perimeter may further comprise a second recess. The inner perimeter may comprise a third lug and fourth lug proximate the second recess. The third lug and fourth lug may be disposed on either side of the second recess.

In various embodiments, the brake assembly may comprise a second stator clip disposed within the second recess. In various embodiments, the second spline may be disposed within a spline interface of the second stator clip. In various embodiments, the first stator clip may be riveted to the first lug and the second lug of the inner perimeter. In various embodiments, the second stator clip may be riveted to the third lug and fourth lug of the inner perimeter.

A stator disk assembly is also disclosed herein, in accordance with various embodiments. In various embodiments, the stator disk assembly may comprise a stator disk comprising an inner perimeter disposed about a first aperture. The inner perimeter may comprise a first recess. In various embodiments, the inner perimeter may comprise a first lug and second lug proximate the first recess. The first lug and second lug may be disposed on either side of the first recess.

In various embodiments, the inner perimeter may further comprise a second recess. In various embodiments, the inner perimeter may comprise a third lug and fourth lug proximate the second recess. The third lug and fourth lug may be disposed on either side of the second recess. In various embodiments, the inner perimeter may further comprise a second stator clip disposed within the second recess.

The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in, and constitute a part of, this specification, illustrate various embodiments, and together with the description, serve to explain the principles of the disclosure.

The detailed description of various embodiments herein refers to the accompanying drawings, which show various embodiments by way of illustration.

For example, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. Also, any reference to attached, fixed, connected, or the like may include permanent, removable, temporary, partial, full, and/or any other possible attachment option.

For example, in the context of the present disclosure, methods may find particular use in connection with stator disc clips for aircraft brake systems. However, various aspects of the disclosed embodiments may be adapted for optimized performance with a variety of components, including bushings and rotor clips, and in a variety of systems. Accordingly, numerous applications of the present invention may be realized.

As used herein, a first component that is "radially outward" of a second component means that the first component is positioned at a greater distance away from a common axis (e.g., a rotational axis of a wheel assembly) than the second component. A first component that is "radially inward" of a second component means that the first component is positioned closer to the common axis than the second component. In the case of components that rotate about a common axis, a first component that is radially inward of a second component rotates through a circumferentially shorter path than the second component. As used herein, "distal" refers to the direction outward, or generally, away from a reference component. As used herein, "proximal" and/or "proximate" refer to a direction inward, or generally, towards the reference component. All ranges may include the upper and lower values, and all ranges and ratio limits disclosed herein may be combined. Unless specifically stated otherwise, reference to "a," "an" or "the" may include one or more than one and reference to an item in the singular may also include the item in the plural.

Referring to <FIG>, in accordance with various embodiments, an aircraft <NUM> is illustrated. The aircraft <NUM> includes landing gear, which may include a left main landing gear <NUM>, a right main landing gear <NUM> and a nose landing gear <NUM>. The landing gear support the aircraft <NUM> when it is not flying, allowing the aircraft <NUM> to taxi, take off and land without damage. While the disclosure refers to the three landing gear configurations just referred, the disclosure nevertheless contemplates any number of landing gear configurations.

Referring to <FIG>, there is schematically depicted a brake assembly or a brake mechanism <NUM> that may be used by the aircraft <NUM> of <FIG> or any other appropriate aircraft. The brake mechanism <NUM> is mounted on an axle <NUM> for use with a wheel <NUM> disposed on and configured to rotate about the axle <NUM> via one or more bearing assemblies <NUM>. The wheel <NUM> includes a hub <NUM>, a wheel well <NUM> concentric about the hub <NUM> and a web portion <NUM> interconnecting the hub <NUM> and the wheel well <NUM>. A central axis <NUM> extends through the axle <NUM> and defines a center of rotation of the wheel <NUM>. A torque plate barrel <NUM> (sometimes referred to as a torque tube or barrel or a torque plate or back leg) is aligned concentrically with the hub <NUM>, and the wheel <NUM> is rotatable relative to the torque plate barrel <NUM>.

The brake mechanism <NUM> includes a piston assembly <NUM>, a pressure plate <NUM> disposed adjacent the piston assembly <NUM>, an end plate <NUM> positioned a distal location from the piston assembly <NUM>, and a plurality of rotor disks <NUM> interleaved with a plurality of stator disks <NUM> positioned intermediate the pressure plate <NUM> and the end plate <NUM>. The pressure plate <NUM>, the plurality of rotor disks <NUM>, the plurality of stator disks <NUM> and the end plate <NUM> together form a brake heat sink or brake stack <NUM>. The pressure plate <NUM>, the end plate <NUM> and the plurality of stator disks <NUM> are mounted to the torque plate barrel <NUM> and remain rotationally stationary relative to the axle <NUM>. Each stator disk <NUM> includes a pair of oppositely disposed sides 124a, 124b that each interface with a corresponding rotor disk <NUM> during a braking operation.

The torque plate barrel <NUM> may include an annular barrel or torque tube <NUM> and an annular plate or back leg <NUM>. The back leg <NUM> is disposed at an end distal from the piston assembly <NUM> and may be made monolithic with the torque tube <NUM>, as illustrated in <FIG>, or may be made as a separate annular piece and suitably connected to the torque tube <NUM>. The torque tube <NUM> has a plurality of circumferentially spaced and axially extending splines <NUM> disposed on an outer surface of the torque tube <NUM>. The plurality of stator disks <NUM> and the pressure plate <NUM> include notches or stator slots <NUM> on an inner periphery of the disks and the plate for engagement with the splines <NUM>, such that each disk and the plate are axially slidable with respect to the torque tube <NUM>.

The end plate <NUM> is suitably connected to the back leg <NUM> of the torque plate barrel <NUM> and is held non-rotatable, together with the plurality of stator disks <NUM> and the pressure plate <NUM>, during a braking action. The plurality of rotor disks <NUM>, interleaved between the pressure plate <NUM>, the end plate <NUM> and the plurality of stator disks <NUM>, each have a plurality of circumferentially spaced notches or rotor lugs <NUM> along an outer periphery of each disk for engagement with a plurality of torque bars <NUM> that is secured to or made monolithic with an inner periphery of the wheel <NUM>.

An actuating mechanism for the brake mechanism <NUM> includes a plurality of piston assemblies, including the piston assembly <NUM>, circumferentially spaced around an annular piston housing <NUM> (only one piston assembly is illustrated in <FIG>). Upon actuation, the plurality of piston assemblies affect a braking action by urging the pressure plate <NUM> and the plurality of stator disks <NUM> into frictional engagement with the plurality of rotor disks <NUM> and against the end plate <NUM>. Fluid or hydraulic pressure, mechanical springs or electric actuators, among other mechanisms, may be used to actuate the plurality of piston assemblies. Through compression of the plurality of rotor disks <NUM> and the plurality of stator disks <NUM> between the pressure plate <NUM> and the end plate <NUM>, the resulting frictional contact slows or stops or otherwise prevents rotation of the wheel <NUM>. The plurality of rotor disks <NUM> and the plurality of stator disks <NUM> are fabricated from various materials, such as, for example, carbon, carbon composites, and the like, that enable the brake disks to withstand and dissipate the heat generated during and following a braking action.

The torque plate barrel <NUM> is secured to a stationary portion of the landing gear such as the axle <NUM>, preventing the torque plate barrel <NUM> and the plurality of stator disks <NUM> from rotating during braking of the aircraft. The torque tube <NUM> portion of the torque plate barrel <NUM> may be attached to the annular piston housing <NUM> via an annular mounting surface <NUM>, wherein bolt fasteners <NUM> secure the torque plate barrel <NUM> to the annular piston housing <NUM>. A spacer member or pedestal <NUM> is positioned between an inner diameter surface <NUM> of the torque tube <NUM> and an outer diameter surface <NUM> of the axle <NUM>. The pedestal <NUM> includes a radially inner surface or foot <NUM> for engaging the axle <NUM>, a web portion <NUM> radially outward of the foot <NUM> and a head portion <NUM> for engaging the inner diameter surface <NUM> of the torque tube <NUM>. The pedestal <NUM> augments support of the torque plate barrel <NUM> within the brake mechanism <NUM> generally and, more particularly, against the axle <NUM>. The pedestal <NUM> may be made monolithic with the torque tube <NUM> portion of the torque plate barrel <NUM>.

A heat shield <NUM> is secured directly or indirectly to the wheel <NUM> between a radially inward surface of the wheel well <NUM> and the plurality of torque bars <NUM>. As illustrated in <FIG>, the heat shield <NUM> is concentric with the wheel well <NUM> and may have a plurality of heat shield sections <NUM> disposed between respective, adjacent pairs of the plurality of torque bars <NUM>. The heat shield <NUM>, or heat shield sections <NUM>, is spaced from the radially inward surface of the wheel well <NUM> and secured in place by heat shield tabs <NUM>, such that the heat shield <NUM>, or heat shield sections <NUM>, is disposed generally parallel to the axis of rotation or central axis <NUM> of the wheel <NUM> and intermediate the plurality of torque bars <NUM> and the radially inward surface of the wheel well <NUM>. In various embodiments, including for heavy-duty applications, the heat shield <NUM>, or heat shield sections <NUM>, may be further secured in place by heat shield carriers <NUM>.

The plurality of torque bars <NUM> is attached at axially inboard ends to the wheel <NUM> by torque bar bolts <NUM>. The torque bar bolts <NUM> extend through respective holes in a flange <NUM> provided on the wheel <NUM> as shown, which flange <NUM> for purposes of the present description is intended to be considered as part of the wheel well <NUM>. Each of the plurality of torque bars <NUM> may include a pin <NUM> or similar member at its axially outboard end (i.e., the end opposite the torque bar bolts <NUM>) that is received within a hole <NUM> disposed proximate the web portion <NUM> of the wheel <NUM>. The heat shield <NUM>, or heat shield sections <NUM>, is positioned adjacent a radially inward surface of the wheel well <NUM> and secured in place by the heat shield tabs <NUM>.

<FIG> illustrates a stator disk <NUM> that may be used as the stator disks <NUM> addressed above with regard to the brake assembly <NUM> of <FIG>. Although the stator disk <NUM> may be formed from any appropriate material or combination of materials, the stator disk <NUM> may be formed from carbon in various embodiments. An inner perimeter <NUM> of the stator disk <NUM> (or more generally for an inner perimeter <NUM> of a stator disk assembly that utilizes the stator disk <NUM>) is illustrated in <FIG>, is annularly disposed about a first reference axis <NUM> (e.g., extends a full <NUM>° about the axis <NUM>), and defines an outer boundary of a first aperture or a first mounting aperture <NUM> (e.g., for receipt of a torque plate). A plurality of lugs <NUM> are incorporated by the inner perimeter <NUM>, and these lugs <NUM> may be characterized as being disposed in radially-spaced or circumferentially-spaced relation to one another about/relative to the first reference axis <NUM>. A recess <NUM> is disposed between each adjacent pair of lugs <NUM>. As such, the stator disk <NUM> also includes a plurality of recesses <NUM> and these recesses <NUM> may be characterized as being disposed in radially-spaced or circumferentially-spaced relation to one another about/relative the first reference axis <NUM>. These lugs <NUM> and recesses <NUM> will be addressed in more detail below in relation to <FIG> and <FIG>. The stator disk <NUM> may include any appropriate number of lugs <NUM> and recesses <NUM>.

An outer perimeter <NUM> of the stator disk <NUM> is disposed outwardly of the inner perimeter <NUM>, relative to the first reference axis <NUM>. The stator disk <NUM> includes a first side <NUM> (e.g., corresponding with the first side 124a of one of the stator disks <NUM> shown in <FIG>), where this first side <NUM> may interface with a rotor disk during a braking operation. The stator disk <NUM> includes an oppositely disposed second side <NUM> (e.g., corresponding with the second side 124b of one of the stator disks <NUM> shown in <FIG>), where this second side <NUM> may interface with a different rotor disk during a braking operation. The thickness of the stator disk <NUM> corresponds with the spacing between these two sides <NUM>, <NUM>. Each of the first side <NUM> and second side <NUM> of the stator disk <NUM> include what may be characterized as a braking surface <NUM> that extends from an inner braking surface boundary <NUM> to the outer perimeter <NUM> of the stator disk <NUM>. Each braking surface <NUM> would engage a different corresponding rotor disk (e.g., rotor disk <NUM> - <FIG>) during a braking operation.

<FIG> illustrates a portion of a brake assembly <NUM> (e.g., brake assembly <NUM> of <FIG>) that includes the above-described stator disk <NUM>. Only an inward portion of the stator disk <NUM> (relative to the first reference axis <NUM>) is illustrated in <FIG>. The brake assembly <NUM> further includes a torque plate barrel or a torque plate <NUM>. The torque plate barrel <NUM> includes an outer surface <NUM> that is disposed about the first reference axis <NUM>. This outer surface <NUM> may be cylindrical. A plurality of splines, ribs, or protrusions <NUM> are disposed on the outer surface <NUM> of the torque plate barrel <NUM>. The splines <NUM> may be disposed parallel with the first reference axis <NUM> and may be disposed about this same first reference axis <NUM> (e.g., the splines <NUM> may be characterized as being disposed in radially-spaced or circumferentially-spaced relation to one another about/relative the first reference axis <NUM>). Each spline <NUM> of the torque plate barrel <NUM> is disposed in a corresponding recess <NUM> of the stator disk <NUM>. Accordingly, typically, the brake assembly will include an equal number of splines <NUM> (torque plate barrel <NUM>) and recesses <NUM> (stator disk <NUM>).

In various embodiments, the stator disk <NUM> may be part of a stator disk assembly, which may comprise stator clips disposed within the recesses <NUM> of the stator disk <NUM>.

<FIG> and <FIG> illustrate a stator clip <NUM> according to the present invention Stator clips <NUM> may improve lug strength and the structural integrity of the stator disk. The stator clip <NUM> may comprise a spline interface <NUM>. The spline interface <NUM> may include a first face <NUM> and a second face <NUM> opposite the first face <NUM>. In various embodiments, the spline interface <NUM> may comprise a third face <NUM> bridging between the first face <NUM> and the second face <NUM>. The third face <NUM> may be substantially orthogonal to the first face <NUM> and the second face <NUM>. In various embodiments, the spline interface <NUM> may be U-shaped. In various embodiments, the spline interface <NUM> may be a monolithic structure.

With additional reference to <FIG>, and with further reference to <FIG> and <FIG>, in various embodiments, the spline interface <NUM> of the stator clip <NUM> may be disposed in a corresponding recess <NUM> of the stator disk <NUM>. Accordingly, each spline <NUM> of the torque plate barrel <NUM> may be disposed in the spline interface <NUM>. In various embodiments, the first face <NUM> and the second face <NUM> of the spline interface <NUM> may each comprise a ridge (e.g., raised pad). In various embodiments, and as shown in <FIG>, the spline interface <NUM> may comprise at least two ridges 310a/310b. Two ridges may be advantageous to provide increased loading stability, such that rotation is not dependent on a single ridge. The ridges 310a/310b may reduce the contact area between the torque plate barrel spline <NUM> and the stator clip <NUM>, while maintaining the overall integrity of the stator clip <NUM>. This may be advantageous since the greater the contact area between the spline and the stator clip, the greater the drag force. Moreover, having the ridges 310a/310b along the first <NUM> and also having ridges 310a/310b along the second face <NUM> would orient the ridges perpendicular to the drag force (e.g., the direction of the drag), which may further reduce drag.

In various embodiments, the ridges 310a/310b may be hemi-cylindrical, extending longitudinally across the first face <NUM> and second face <NUM>. Hemi-cylindrical ridges may be well suited to accommodate high torque, especially during high energy braking operations such as aircraft landing. However, the ridges 310a/310b may be of any desired shape suitable for accommodating torque load. In various embodiments, the ridges 310a/310b may be sized to accommodate the highest peak torque that may be generated by the brake assembly without damaging the brake assembly. In various embodiments, and as further shown in <FIG> and <FIG>, the ridges 310a/310b may comprise rounded ends <NUM> or may be rounded to prevent edge loading that may contribute to dynamic instability. Accordingly, the ridges 310a/310b may reduce the likelihood of degraded braking performance or dynamic instability associated with edge loading.

In various embodiments, the stator clip <NUM> may comprise a first flange pair <NUM>. The first flange pair <NUM> may be substantially orthogonal to a reverse side wall <NUM> of the first face <NUM>. The first flange pair <NUM> may comprise opposing flanges 314a/314b. Each flange 314a/314b may define a lug recess 315a/315b. The stator clip <NUM> may further comprise a second flange pair <NUM>. The second flange pair <NUM> may be substantially orthogonal to a reverse side wall <NUM> of the second face <NUM>. The second flange pair <NUM> may comprise opposing flanges 316a/316b. Each flange 316a/316b may define a lug recess 317a/317b. The stator clip <NUM> may be riveted to a stator disk (e.g., <FIG>, <NUM>) at the lug recesses 315a/315b/317a/317b of the flange pairs <NUM>/<NUM>. Stator disk lugs (<FIG>, <NUM>) may be disposed within the lug recesses 315a/315b/317a/317b, securing the stator clip <NUM> to the stator disk (<FIG>, <NUM>). The flange pairs <NUM>/<NUM> may be substantially U-shaped, enabling the flanges to slide onto a stator disk.

A method <NUM> of rearranging a brake assembly is illustrated in <FIG>. The method <NUM> may comprise removing (step <NUM>) a first stator disk from the brake assembly. The method <NUM> may further comprise disposing (step <NUM>) a stator clip in a recess of a second stator disk. In various embodiments, a plurality of stator clips may be disposed in any number of recesses of the second stator disk. The method <NUM> may comprise reassembling (step <NUM>) the brake assembly by disposing (step <NUM>) the second stator disk on a torque plate barrel. In various embodiments, the second stator disk may be disposed between an adjacent pair of rotor disks.

However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the invention. The scope of the invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more.

In the detailed description herein, references to "various embodiments", "one embodiment", "an embodiment", "an example embodiment", etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic.

Claim 1:
A stator disk assembly, comprising:
a stator disk (<NUM>) comprising an inner perimeter disposed about a first aperture (<NUM>), wherein the inner perimeter comprises:
a first recess (<NUM>); and
a first lug (<NUM>) and second lug (<NUM>) proximate the first recess, wherein the first lug and the second lug are disposed on either side of the first recess; and
a first stator clip (<NUM>) disposed within the first recess, the first stator clip comprising a spline interface (<NUM>), the spline interface comprising:
a first face (<NUM>);
a second face (<NUM>), wherein the first face is opposite the second face,
wherein the first face and the second face each comprises a ridge; and
a third face (<NUM>) bridging between the first face and the second face, wherein the third face is orthogonal to the first face and the second face;
a first flange pair (<NUM>), the first flange pair being orthogonal to a reverse side wall (<NUM>) of the first face, the first flange pair comprising opposing flanges (314a, 314b), each flange defining a lug recess (315a, 315b); and
a second flange pair (<NUM>), the second flange pair being orthogonal to a reverse side wall (<NUM>) of the second face, the second flange pair comprising opposing flanges (316a, 316b), each flange defining a lug recess (317a, 317b), characterised in that
the first face (<NUM>) and the second face (<NUM>) each comprise at least two ridges (310a, 310b), and wherein the at least two ridges (310a, 310b) comprise rounded ends (<NUM>) to prevent edge loading that contributes to dynamic instability.