Multi-leaved core brake disks and assemblies

The present disclosure provides a multi-leaved core damping disk comprising an annular-shaped first disk half, an annular shaped second disk half, and a multi-leaved core axially aligned with, and disposed therebetween.

FIELD

The present disclosure relates to aircraft braking systems and, more particularly, to a vibration damping brake disk of an aircraft brake assembly.

BACKGROUND

Aircraft brake systems typically employ a series of friction disks that, when forced into contact with each other, help to stop the aircraft. Friction disks splined to a non-rotating wheel axle are interspersed with friction disks splined to the rotating wheel. The friction disks are configured to withstand and dissipate the heat generated from contact between the friction disks during braking. Due to high speed landings and rejected takeoffs, over time, the amount of heat generated can be enough to destroy friction disks made of formerly commonly used materials, such as steel. Carbon composite materials are better suited for high temperature use and are now the standard for friction disks in aircraft brake assemblies. However, carbon composite disks may vibrate in use and may generate significant brake noise.

SUMMARY

In various embodiments, the present disclosure provides a multi-leaved core damping disk comprising a first disk half, a second disk half, and a multi-leaved core axially aligned with, and disposed therebetween. In various embodiments, the first disk half comprises a first friction surface at a first axial end of the first disk half and a first non-friction surface at a second axial end of the first disk half, and the second disk half comprises a second friction surface at a third axial end of the second disk half and a second non-friction surface at a fourth axial end of the second disk half. In various embodiments, the first friction surface is disposed at a fifth axial end of the multi-leaved core damping disk and the second friction surface is disposed at a sixth axial end of the multi-leaved core damping disk.

In various embodiments, the multi-leaved core comprises a plurality of disk leaves. In various embodiments, the plurality of disk leaves comprise a carbon composite material. In various embodiments, the plurality of disk leaves comprise a refractory metal. In various embodiments, at least one of the plurality of disk leaves comprises an axial thickness of between about 1.27 millimeters (about 0.05 inches) and about 15.24 millimeters (about 0.6 inches). In various embodiments, the multi-leaved core further comprises a plurality of spacers, wherein each one of the plurality of spacers is disposed alternately with each one of the plurality of disk leaves along an axis. In various embodiments, at least one of the plurality of disk leaves comprises a contact surface at an axial end of the at least one of the plurality of disk leaves, and a non-contact surface recessed from the contact surface. In various embodiments, the multi-leaved core further comprises a floating core.

In various embodiments, the present disclosure provides a disk brake assembly comprising a pressure plate coupled to a first rotor friction disk of a plurality of rotor friction disks, and a plurality of stator friction disks located between the pressure plate and an end plate, wherein each one of the plurality of stator friction disks is disposed alternately with each one of the plurality of rotor friction disks along an axis, and wherein at least one of the plurality of rotor friction disks and the plurality of stator friction disks comprises a solid friction disk. In various embodiments, the end plate is coupled to a second rotor friction disk of the plurality of rotor friction disks, and at least one stator friction disk comprises a multi-leaved core damping disk. In various embodiments, the end plate is coupled to a second rotor friction disk of the plurality of rotor friction disks, and at least one rotor friction disk comprises a multi-leaved core damping disk.

DETAILED DESCRIPTION

The detailed description of various embodiments herein makes reference to the accompanying drawings, which show various embodiments by way of illustration. While these various embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that logical, chemical, and mechanical changes may be made without departing from the spirit and scope of the disclosure. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation.

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. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected, or the like may include permanent, removable, temporary, partial, full, and/or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact.

For example, in the context of the present disclosure, devices and systems may find particular use in connection with aircraft brake disks. However, various aspects of the disclosed embodiments may be adapted for optimized performance with a variety of brake disks and/or disk brake assemblies. As such, numerous applications of the present disclosure may be realized.

In various embodiments, multi-leaved core damping disks comprising a multi-leaved core are disclosed. In various embodiments, the multi-leaved core damping disk may comprise friction disks, including rotors and/or stators. In various embodiments, the multi-leaved core damping disk may comprise a first disk half and a second disk half, and a multi-leaved core disposed axially therebetween. In various embodiments, first disk half, second disk half, and/or multi-leaved core may comprise a generally annular shape. However, in various embodiments, first disk half, second disk half, and/or multi-leaved core may comprise any suitable shape.

In various embodiments, the first disk half may comprise a first friction surface located at a first axial end and a first non-friction surface located at a second axial end. In various embodiments, first axial end and second axial end may comprise opposite axial ends of the first disk half. In various embodiments, the second disk half may comprise a second friction surface located at a third axial end and a second non-friction surface located at a fourth axial end. In various embodiments, third axial end and fourth axial end may comprise opposite axial ends of the second disk half. In various embodiments, the first friction surface and the second friction surface may be disposed at opposite axial ends of the multi-leaved core damping disk. Stated differently, first friction surface may be disposed at a fifth axial end of the multi-leaved core damping disk and second friction surface may be disposed at a sixth axial end of the multi-leaved core damping disk.

In various embodiments, the multi-leaved core may comprise a plurality of thin disk leaves configured to damp noise and vibration generated from contact between friction disks during braking. In various embodiments, each disk leaves may comprise a generally annular shape. However, in various embodiments, disk leaves may comprise any suitable shape. In various embodiments, each one of the plurality of disk leaves may comprise non-friction surfaces at opposite axial ends of the disk leaves. In various embodiments, non-friction surfaces of the disk leaves may physically contact other portions of the multi-leaved core damping disk, but may not form a continuous structure. While not intending to be bound by theory, this structural discontinuity may serve to damp vibration.

In various embodiments, disk brake assemblies comprising a combination of multi-leaved core damping disks and solid friction disks are disclosed. These multi-leaved core damping disks and/or solid frictions disks may be arranged together in any suitable pattern or position. In various embodiments, a disk brake assembly may comprise a single, “dead” disk configured to damp vibration and noise, and a plurality of solid friction disks.

According to various embodiments, and with reference toFIG. 1, a cross-sectional view of wheel10supported for rotation around axle12by bearings14is depicted. In various embodiments, wheel10includes rims16for supporting a tire and a series of axially extending rotor splines18(one shown). In various embodiments, rotation of wheel10is modulated by disk brake assembly20. In various embodiments, disk brake assembly20includes torque flange22, torque tube24, a plurality of pistons26(one shown), pressure carbon disk30, and end plate32. In various embodiments, torque tube24is an elongated annular structure that includes reaction plate34and a series of axially extending stator splines36(one shown). In various embodiment, reaction plate34and stator splines36may be integral with torque tube24as shown inFIG. 1, or attached as separate components.

In various embodiments, disk brake assembly20also includes at least one multi-leaved core damping disk and at least one solid friction disk (and/or solid friction disk assembly). In various embodiments, multi-leaved core damping disks90,95may be a non-rotatable friction disk40, or a rotatable friction disk42. In various embodiments, solid friction disks80,85may be a non-rotatable friction disk40, or a rotatable friction disk42. In various embodiments, solid friction disks80,85may comprise a continuous or unitary annular-shaped disk. As used herein, a non-rotatable friction disk40(such as disks85,95) may be referred to as a stator friction disk. At times a rotatable friction disk42(such as disks80,90) may be referred to as a rotor friction disk. In various embodiments, each one of multi-leaved core damping disks90,95and/or solid friction disks80,85includes an attachment structure. In various embodiments, non-rotatable friction disk40may include a plurality of stator lugs44at circumferentially spaced positions around non-rotatable friction disk40as an attachment structure. Similarly, in various embodiments, rotatable friction disk42may include a plurality of rotor lugs46at circumferentially spaced positions around rotatable friction disk42at an attachment structure. The disk brake assemblies contemplated herein may have any number of rotatable friction disks and/or non-rotatable friction disks, such as 5,4; 4,3; and 3,2, respectively. For convenience, the friction disk positions referred to herein are labeled61,62,63,64,65,66,67,68, and69from the pressure carbon disk30to the end plate32. For instance, position61is adjacent to the pressure carbon disk30while position69is adjacent to the end plate32. In various embodiments, pressure carbon disk30, end plate32, solid friction disks80,85and multi-leaved core damping disks90,95are all generally annular structures comprising a carbon composite material.

In various embodiments, torque flange22is mounted to axle12. In various embodiments, torque tube24is bolted to torque flange22such that reaction plate34is near an axial center of wheel10. In various embodiments, end plate32is connected to a surface of reaction plate34facing axially towards pressure carbon disk30. Thus, in various embodiments, end plate32is non-rotatable by virtue of its connection to torque tube24. In various embodiments, stator splines36support pressure carbon disk30so that pressure carbon disk30is also non-rotatable. In various embodiments, stator splines36also support non-rotatable friction disks40. In various embodiments, non-rotatable friction disks40engage stator splines36with gaps formed between stator lugs44. Similarly, in various embodiments, rotatable friction disks42engage rotor splines18with gaps formed between rotor lugs46. Thus, in various embodiments, rotatable friction disks42are rotatable by virtue of their engagement with rotor splines18of wheel10.

As shown inFIG. 1, in various embodiments, rotatable friction disks42are arranged with end plate32on one end, pressure carbon disk30on the other end, and non-rotatable friction disks40interleaved so that rotatable friction disks42are adjacent to non-rotatable friction components. In various embodiments, pistons26are connected to torque flange22at circumferentially spaced positions around torque flange22. In various embodiments, pistons26face axially toward wheel10and contact a side of pressure carbon disk30opposite rotatable friction disks42. In various embodiments, pistons26may be powered electrically, hydraulically, pneumatically and/or combinations thereof.

With reference toFIG. 2, a cross-sectional view of multi-leaved core damping disk90, which is a rotatable friction disk42, is depicted. In various embodiments, multi-leaved core damping disk90comprises a first disk half82and a second disk half83. In various embodiments, first disk half82and second disk half83may comprise annular-shaped disks. In various embodiments, first disk half82and second disk half83may comprise an attachment structure in the form of rotor lug46, friction surface56, and non-friction surface58. In various embodiments, friction surface56may be disposed at an axial end of first disk half82and second disk half83. In various embodiments, friction surface56may be configured for operationally engaging a corresponding friction surface of another disk brake assembly component, such as a non-rotatable friction disk40. In various embodiments, non-friction surface58may be located at an axial end of first disk half82and second disk half83on a side opposite of friction surface56. In various embodiments, non-friction surface58may be configured for contacting a non-friction surface of another disk brake assembly component.

In various embodiments, first disk half82and second disk half83further comprise inner diameter surface84and outer diameter surface86and outer attachment surface52. In various embodiments, inner diameter surface84may be located at a radially inward facing edge of first disk half82and second disk half83. In various embodiments, outer diameter surface86and outer attachment surface52may be located at a radially outward facing edge of first disk half82and second disk half83. In various embodiments, friction surface56may extend radially between inner diameter surface84and outer diameter surface86. In various embodiments, non-friction surface58may extend radially between inner diameter surface84and outer attachment surface52.

In various embodiments, first disk half82and second disk half83may comprise an attachment structure in the form of rotor lug46. In various embodiments, rotor lug46may project radially outward from outer diameter surface86. As shown inFIG. 2, in various embodiments, multi-leaved core210may be disposed between first disk half82and second disk half83such that their respective non-friction surfaces58are in contact with multi-leaved core210to form multi-leaved core damping disk90. In various embodiments, multi-leaved core210may comprise a plurality of disk leaves212.

In various embodiments, first disk half82and second disk half83may be coupled by a fastening device87. In various embodiments, fastening device87may comprise a rivet, spring-loaded rivet, clamp, or other assembly hardware. However, in various embodiments, fastening device87may comprise any attachment mechanism suitable for use in multi-leaved core damping disk90. In various embodiments, while the first disk half82and second disk half83may be held in contact with multi-leaved core210, they may form a non-continuous structure. That is, the non-friction surfaces58are not bonded to multi-leaved core210, but are merely held together by, for example, fastening device87. In various embodiments, first disk half82and second disk half83may be coupled by a plurality of fastening devices disposed circumferentially about multi-leaved core damping disk.

In various embodiments, disk leaves212may comprise thin, generally annular-shaped disks. In various embodiments, disk leaves212may be oriented about axis102(with momentary reference toFIG. 1) and disposed substantially parallel to first disk half82and second disk half83. As shown inFIG. 2, in various embodiments, multi-leaved core210may comprise four disk leaves212. However, a multi-leaved core may comprise any number of disk leaves suitable for a particular embodiment. In various embodiments, disk leaf212may comprise an axial thickness of between about 1.27 millimeters (about 0.05 inches) and about 15.24 millimeters (about 0.6 inches), wherein the term about in this context only refers to +/−0.635 millimeters (about 0.025 inches). However, in various embodiments, disk leaf212may comprise any suitable axial thickness.

In various embodiments, disk leaves212may comprise at least one of a carbon composite material, a refractory metal, or a refractory metal alloy. For example, in various embodiments, disk leaves212may comprise at least one of carbon, silicon carbide, silicon nitride, boron carbide, aluminum nitride, titanium nitride, boron nitride, zirconia, SiCxNy (wherein x is a number in the range from about zero to about 1, and y is a number in the range from about zero to about 4/3), silica, alumina, titania (TiO2), or a combination of at least two of the foregoing. However, in various embodiments, disk leaves212may comprise any suitable material capable of withstanding operational temperatures of a disk brake assembly.

Although the embodiment ofFIG. 2is described in terms of multi-leaved core damping disk90, which is a rotatable friction disk42(with momentary reference toFIG. 1), it is understood that the same description and features apply generally to either type of multi-leaved core damping disk90,95and thus, to a non-rotatable friction disk40(with momentary reference toFIG. 1), except that rotor lug46at outer diameter surface86is replaced by stator lug44at inner diameter surface84.

With reference toFIGS. 1 and 2, in various embodiments, prior to operation of disk brake assembly20, pistons26are not actuated and gaps exist between each of rotatable friction disks42and each of the non-rotatable friction components, namely pressure carbon disk30, end plate32, and non-rotatable friction disks40. In various embodiments, the gaps are formed by the axial spreading of the rotatable friction disks42along rotor splines18; and the non-rotatable friction disks40, and pressure carbon disk30along stator splines36due to the movement of rotatable friction disks42adjacent to the non-rotatable friction components. In various embodiments, during operation of disk brake assembly20, pistons26are actuated, forcing pressure carbon disk30to move along stator splines36against at least one of a plurality of multi-leaved core damping disks90and/or solid friction disks80, forcing them axially toward end plate32and reaction plate34. In various embodiments, squeezed between pressure carbon disk30and reaction plate34, the gaps are eliminated as friction surfaces contact other, mating friction surfaces. In various embodiments, drag generated by the contact of the friction surfaces acts to slow rotatable friction disks42and wheel10. In various embodiments, the drag also generates significant heat which is absorbed by multi-leaved core damping disks90,95and/or solid friction disks80,85of disk brake assembly20.

In various embodiments, brake vibration is significantly damped by multi-leaved core damping disks90,95. In various embodiments, multi-leaved core damping disks90,95are assembled such that non-friction surfaces therein are in physical contact, but do not form a continuous structure. Thus, in various embodiments, vibration is damped at non-friction surfaces, even though brake pressure is satisfactorily transmitted to and from all multi-leaved core damping disks90,95. Without wishing to be bound by theory, it is believed that the non-continuous structure of multi-leaved core damping disks causes increased absorption of vibrational energy.

In various embodiments, performance variation of the brake assembly/heat sink may be controlled through placement of one or more multi-leaved core damping disks90,95in various locations within the brake assembly/heat sink. For instance, and with reference toFIG. 1, in various embodiments, one multi-leaved core damping disk may be disposed at any one of friction disk position61,62,63,64,65,66,67,68, or69. In such an embodiment, the single multi-leaved core damping disk may be referred to as a “dead” disk and may provide damping for an entire disk brake assembly. In various embodiments, however, a multi-leaved core damping disk may be disposed at two or more of friction disk positions61,62,63,64,65,66,67,68, and/or69.

In various embodiments a multi-leaved core damping disk may provide damping through additional features. With reference toFIG. 3, a multi-leaved core300may comprise a plurality of disk leaves312. In various embodiments, multi-leaved core300may further comprise at least one spacer320interleaved between the plurality of disk leaves312. In various embodiments, spacer320may comprise a carbon composite and/or carbon fiber-reinforced carbon, a composite material consisting of carbon fiber reinforcement in a matrix of graphite. In various embodiments, spacer320may comprise a refractory metal. In various embodiments, spacer320may comprise a different material than the plurality of disk leaves312and/or may comprise the same material as the plurality of disk leaves312. In various embodiments, spacer320may provide additional damping.

In various embodiments, and with reference toFIG. 4, a multi-leaved core400may comprise a plurality of disk leaves412and a floating core430. In various embodiments, floating core430may be located radially inward of disk leaves412. In various embodiments, floating core430may comprise an annular component having floating core keys432extending radially outward from an outer circumference434of floating core430. In various embodiments, each floating core key432may correspond to a plurality of disk leaf notches414. In various embodiments, floating core430may be positioned such that floating core keys432fit within the plurality of disk leaf notches414. Thus, in various embodiments, floating core keys432may contact lateral walls of the plurality of disk leaf notches414and prevent relative rotational movement between floating core430and the plurality of disk leaves412. In various embodiments, a material of floating core430may be selected for its frictional and/or vibrational damping properties. In various embodiments, the material of floating core430may be selected for its wear resistance, thermal conductivity, heat capacity, structural, and/or oxidation resistance properties. In various embodiments, floating core430may comprise a carbon composite. In various embodiments, floating core430may provide additional damping.

In various embodiments, and with reference toFIG. 5, a multi-leaved core500may comprise at least one cavity510configured to provide additional damping. In various embodiments, at least one disk leaf512of multi-leaved core500may comprise at least one contact surface92A,92B and non-contact surface94. In various embodiments, non-contact surface94may be recessed from contact surface92A, and/or92B. In various embodiments, contact surface92B is substantially parallel to non-contact surface94. In various embodiments, contact surface92A,92B may be configured for contacting a non-friction surface of another disk brake assembly component, for example, an adjacent disk leaf512.

In various embodiments, non-contact surface94may extend radially at least partially between inner diameter surface84and outer diameter surface86. In various embodiments, non-contact surface94extends circumferentially around at least a portion of disk leaf512. In various embodiments, non-contact surface94extends circumferentially around the entirety of disk leaf512to form a complete annulus. According to various embodiments, the surface of the non-contact surface, may not be parallel to the contact surfaces of disk leaf512and, instead, may be oriented in any desired angle, and comprise a curve or any desired shape.

In various embodiments, each of at least two disk leaves512may comprise a circumferentially extending recess on an axial side of the disk leaf512. In various embodiments, the at least two disk leaves512may be disposed in multi-leaved core500such that their recesses face each other, forming a cavity510. In various embodiments, disk leaves512are in physical contact with each other at contact surfaces92A,92B, but do not form a continuous structure. While not intending to be bound by theory, in various embodiments, this structural discontinuity at contact surfaces92A,92B may serve to damp vibration. In various embodiments, cavity510limits the area of contact between disk leaves512, which may also damp vibration and/or reduce brake noise of a disk brake assembly. According to various embodiments, improved braking performance under certain conditions and decreased variability in braking performance may be achieved. In various embodiments, multi-leaved core500may further comprise at least one spacer520.

In various embodiments and with reference toFIG. 6, a multi-leaved core600may comprise a plurality of disk leaves612, at least one cavity610, and/or a floating core630. In various embodiments and with reference toFIG. 7, a multi-leaved core700may comprise a plurality of disk leaves712, at least one cavity710, a floating core730, and/or at least one spacer720.

Solid friction disks may be referred to as “thick” or “thin” solid friction disks. In various embodiments, thick disks may be approximately twice as thick as thin disks. In general, a rotor (rotatable friction disk42) comprises a thick friction disk while a stator (non-rotatable friction disk40) comprises a thin friction disk; however, a rotor may comprise a thin friction disk while a stator may comprise a thick friction disk. As previously described, due to the high cost of the materials involved, such as the high cost of the carbon/carbon materials, reuse of materials may be important. For instance, thick friction disks may be used in the field within a braking system for a period of time, such as a first tour. A thick friction disk may be removed from service and then through machining be formed into a thin friction disk. This thin friction disk may be used in the field within a braking system for a period of time, such as a second tour. This thin friction disk may be removed from service and then through machining be formed into a split thick disk and/or half of a split thick disk. This thick split friction disk may be used in the field within a braking system for a period of time, such as a third tour. The thick split friction disk may be removed from service and through machining be formed into a thin split friction disk. This thin split friction disk may be used in the field within a braking system for a period of time, such as a fourth tour. Thus, in various embodiments, a disk brake assembly which uses a variety of thin and thick and solid and split friction disks may extend the life span of the friction disks as these parts may be reused in other brake system applications, as compared with an all split disk brake assembly which may be limited to one or two tours. In various embodiments, use of multi-leaved core damping disks and/or a single “dead” disk to provide damping may improve cost efficiencies through reuse and repurposing of friction disks and carbon composite materials.