Patent Application
20200096064
The present disclosure relates to aircraft brake systems, and more particularly to an aircraft brake system with angled stator lugs.
Conventional aircraft brake assemblies comprise rotating and stationary discs that slow an aircraft upon landing. Stationary friction discs splined to a non-rotating torque tube are interspersed with rotating friction discs splined to the rotating wheel. The friction discs withstand and dissipate the heat generated from contact between one another during braking. During high speed landings and rejected takeoffs (“RTOs”) a significant amount of heat and force are generated. There is a need for an improved friction disc brake system.
The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosure. The summary is not an extensive overview of the disclosure. It is neither intended to identify key or critical elements of the disclosure nor to delineate the scope of the disclosure. The following summary merely presents some concepts of the disclosure in a simplified form as a prelude to the description below.
Aspects of the disclosure are directed to a multiple disc brake system, comprising an annular disc stack that includes interleaved sets of rotor discs and stator discs; an axially extending torque tube; and an actuator that axially moves the rotor discs into engagement with an axially adjacent stator disc. Where each of the stator discs includes a plurality of circumferential arranged stator lugs that secure the stator discs to the torque tube, where each of the plurality of circumferential stator lugs comprises tapered side walls that taper inwardly transverse to the axially extending torque tube.
Each of the plurality of circumferential stator lugs may comprise beveled axial edges.
The tapered side walls may taper 1° to 45° inwardly with respect to a radial axis.
The tapered side walls may taper inwardly 5° to 15°.
The torque tube may comprise a plurality of stator splines that each engage an associated one of the plurality of stator lugs to prevent the stator discs from rotating in response to a torque being applied to the stator discs during braking.
Each of the plurality of stator lugs may comprise a planar tip surface at a distal end of the stator lug.
Each of the plurality of stator lugs may comprise a tip surface having a radii at a distal end of the stator lug.
Each of the plurality of stator lugs may comprise a tip surface having a chamfer at a distal end of the stator lug.
Aspects of the disclosure are also directed to a disc brake system, comprising interleaved sets of rotor discs and stator discs; an axially extending torque tube; and at least one piston that axially moves the rotor discs into engagement with axially adjacent one of the stator discs. Each of the stator discs includes a plurality of circumferential stator lugs that secure the stator discs to the torque tube, where each of the plurality of circumferential stator lugs each comprise tapered side walls that taper inwardly transverse to the axially extending torque tube.
The disk brake system may comprise a pressure plate and an end plate that sandwich the interleaved sets of rotor discs and stator discs, where the at least one piston axially moves the pressure plate.
Each of the plurality of circumferential stator lugs may comprise beveled axial edges.
The tapered side walls may taper inwardly 1° to 45° with respect to a radial axis.
The tapered side walls may taper inwardly 5° to 15°.
The torque tube may comprise a plurality of stator splines that each engage an associated one of the plurality of stator lugs to prevent the stator discs from rotating in response to a torque being applied to the stator discs during braking.
Each of the plurality of stator lugs may comprise a planar tip surface at a distal end of the stator lug.
Each of the plurality of stator lugs may comprise a tip surface having a radii at a distal end of the stator lug.
Each of the plurality of stator lugs may comprise a tip surface having a chamfer at a distal end of the stator lug.
The brake system 20 also includes a plurality of friction discs 38, each of which may comprise a friction disc core. The plurality of friction discs 38 (also referred to as annular disk stack) may include at least one friction disc 40 with a non-rotatable core, also known as a stator 40, and at least one friction disc with a rotatable core, also known as a rotor 42. The stators 40 and the rotors 42 may be located adjacent to one another in the multi-disc brake system 20, forming a plurality of adjacent stator-rotor pairs. The stators 40 may comprise a stator core 48 and floating stator wear liners 50. The rotors 42 may comprise a rotor core 49 and floating rotor wear liners 60. Of course, the brake system may include a stator disk and a rotor disk comprised of one component made entirely of a single component (e.g., carbon) rather than a core and a liner. Referring still to
The piston housing 22 is mounted to the axle 12. The torque tube 24 may be bolted to the piston housing 22 such that the reaction plate 34 is near an axial center of the wheel 10. The end plate 32 is connected to a surface of the reaction plate 34 facing axially inward. Thus, the end plate 32 is non-rotatable by virtue of its connection to the torque tube 24. The stator splines 36 support the pressure plate 30 so that the pressure plate is also non-rotatable. The stator splines 36 also support the stators 40 via the stator cores 48. The stator cores 48 engage the stator splines 36 with gaps formed between the stator lugs 44. Similarly, the rotors 42 engage the rotor splines 18 via a rotor core 49 with gaps formed between the rotor lugs 46. Thus, the rotor cores 49 of the rotors 42 are rotatable by virtue of their engagement with the rotor splines 18 of the wheel 10.
Referring still to
The stator core 48 may comprise a spine 202 and an inner core 204. The inner core 204 may comprise the angled/tapered stator lugs 44. The inner core 204 may also comprise stator gaps 210 between an inner portion of the stator lugs 44. The stator gaps 210 with tapered sidewalls may be located to align with the stator splines 36. The engagement between the stator splines 36 and the stator lugs 44 prevents the stator core 48 from rotating in response to a torque being applied to the stator 40 during braking. The stator core 48 may also include a stator retention ring 244 that is located at a radially outer portion of the inner core 204. The stator retention ring 244 may comprise an annular feature extending axially from the stator core 48 relative to a contact surface plane of the stator core. The stator retention ring 244 may be substantially concentric with the stator core 48.
Referring still to
The retention ring 244 of the stator may have an identical or substantially similar configuration. For example, the stator core 48 may be bilaterally symmetrical in a transverse cross-section, as illustrated, with the stator retention rings 244 having substantially similar cross sections and stator retention ring outer diameters. This may enable interchangeable use of the wear liners 50 on either side of the stator core 48.
The outer wall 346 may define a centration surface of the stator retention ring 244. The centration surface may be defined by the outer wall 346 that may have a substantially frustoconical profile, with the radial diameter of the outer wall 346 of the stator retention ring 244 decreasing from a maximum radius at the base of the outer wall 346 where the wall intersects the stator contact surface 306 to a minimum radius at a maximum first angled outer wall axial distance from the contact surface 306 (i.e., the point of maximum axial distance of the outer wall 346 from the stator contact surface 306).
The wear liner 50 may comprise an annular ring configured to contact the stator core 48. Each wear liner 50 may have a first primary wear surface 352 and a second primary wear surface 354 opposite the first primary wear surface. The first primary wear surface 352 may contact stator contact surface 306. The second primary wear surface 354 may contact an adjacent friction component of a multi-disc brake system, such as rotor 42. The floating stator wear liners 50 may comprise a substantially uniform thickness in an axial dimension. Each floating stator wear liner 50 may further comprise walls extending between primary wear surfaces 352 and 354. An exterior wall 355 defines an outside diameter and an interior wall 356 defines a secondary wear surface. The interior wall 356 that defines the secondary wear surface may have a profile and dimensions complementary to the profile and dimensions of the outer wall 346 and be configured to receive the outer wall 346 of stator retention ring 244, thereby permitting the floating stator wear liner 50 to be fitted about the outer wall 346. When fitted about the outer wall 346, the first primary wear surface 352 may be in contact with the stator contact surface 306, and the secondary wear surface defined by the interior wall 356 may be in contact with the centration surface of the outer wall 346.
During aircraft braking, a torque may be applied to the wear liners 50. For example, and with reference now also to
It is contemplated that rather than a planar tip surface, the edges may have a radii or chamfers. This would be beneficial to keep sharp edges on the planar splines from edge loading the carbon stator lugs. For example, the entire tip may be a full radius, but such a tip may be difficult to machine.
Although the different non-limiting embodiments have specific illustrated components, the embodiments are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments.
It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom.
The foregoing description is exemplary rather than defined by the features within. Various non-limiting embodiments are disclosed herein, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims. It is therefore to be understood that within the scope of the appended claims, the disclosure may be practiced other than as specifically described. For that reason the appended claims should be studied to determine true scope and content.
