Abstract:
The present disclosure provides systems for mitigating brake vibration. In various embodiments, a brake force distribution arrangement may comprise: a member in operable communication with an actuator having at least two contact surfaces such that as one of the at least two contact surfaces moves in a direction of actuation of the actuator the other moves in a direction opposite to the direction of actuation of the actuator.

Description:
FIELD 
       [0001]    The present disclosure relates to aircraft braking systems, and more specifically, to systems and methods for control over a plurality of electro-mechanical actuators with at least one load cell. 
       BACKGROUND 
       [0002]    Typically, an aircraft may comprise a plurality of electro-mechanical brake actuators (EBAs) that are configured to apply force to a brake stack on an aircraft wheel. Uneven loading of the brake stack during brake actuation may cause vibration. 
       SUMMARY 
       [0003]    Systems are provided herein for mitigating brake vibration. A brake force distribution arrangement may comprise: a member in operable communication with an actuator having at least two contact surfaces such that as one of the at least two contact surfaces moves in a direction of actuation of the actuator the other moves in a direction opposite to the direction of actuation of the actuator. 
         [0004]    In various embodiments, the member may extend from a first end to a second end. The at least two contact surfaces may comprise a first contact surface and a second contact surface. The first contact surface may comprise a first boss and the second contact surface may comprise a second boss, the first boss and the second boss extending from the member. The first contact surface may be located proximate the first end of the member and the second contact surface may be located proximate the second end of the member. The member may include an attachment feature located between the first end and the second end of the member, the member configured to pivot about the attachment feature. The attachment feature may be configured to be coupled to a ball screw. The attachment feature may be located closer to the first end than the second end. 
         [0005]    A brake arrangement may comprise: an actuator plate; an actuator coupled to the actuator plate, the actuator including a ball screw extending from the actuator; and a member including a first contact surface extending from the member in close proximity to a first end of the member, a second contact surface extending from the member in close proximity to a second end of the member, and an attachment feature located between the first end and the second end, the member coupled to the ball screw via the attachment feature. 
         [0006]    In various embodiments, the brake arrangement may further comprise a pressure plate. The first contact surface and the second contact surface may be configured to contact the pressure plate to apply a force to the brake arrangement. The first contact surface and the second contact surface may comprise at least one of a circular, rectangular, or elliptical geometry. The member may comprise a supporting plate defining a circular arc. The member may comprise at least one of a carbon/carbon material or a metal alloy, metal matrix composite (MMC), a medium carbon steel, a high carbon steel, or a composite ceramic. The member may be configured to pivot about the attachment feature. The member may comprise a flexural plate. The member may be configured to evenly distribute the first contact surface and the second contact surface about the actuator plate. 
         [0007]    A member for a brake arrangement may comprise: a first contact surface extending from a first end of the member; a second contact surface extending from a second end of the member, the member extending from the first end to the second end and comprising a circular arc, wherein an arc length of the member is between 5% and 35% of a circumference of an adjacent pressure member and an aspect ratio of the member is between 2 and 20; and an attachment feature located between the first end and the second end of the member, wherein the attachment feature is configured to be coupled to a ball screw. 
         [0008]    In various embodiments, the arc length of the member may be between 10% and 25% of the circumference of the adjacent pressure plate. A depth of the first contact surface and the second contact surface may be between 10% and 200% of a depth of the member. A width of the first contact surface and the second contact surface may be between 90% and 110% of a width of the member. 
         [0009]    The forgoing features and elements may be combined in various combinations without exclusivity, unless expressly indicated herein otherwise. These features and elements as well as the operation of the disclosed embodiments will become more apparent in light of the following description and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the detailed description and claims when considered in connection with the drawing figures, wherein like numerals denote like elements. 
           [0011]      FIG. 1  illustrates an aircraft brake in accordance with various embodiments; 
           [0012]      FIG. 2  illustrates a brake actuator plate assembly, in accordance with various embodiments; and 
           [0013]      FIG. 3  illustrates a perspective view of a brake force distribution arrangement, in accordance with various embodiments. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration. While these exemplary 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 changes and adaptations in design and construction may be made in accordance with this disclosure and the teachings herein. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. The scope of the disclosure is defined by the appended claims. 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. 
         [0015]    While described in the context of aircraft applications, and more specifically, in the context of brake control, the various embodiments of the present disclosure may be applied to any suitable application. 
         [0016]      FIG. 1  illustrates an aircraft brake arrangement  100  in accordance with various embodiments. Aircraft brake arrangement  100  may include a plurality of actuator motors  102 , a plurality of electromechanical brake actuators  104 , a plurality of ball screws  106 , an end plate  111  and a pressure plate  110 , and a plurality of rotating discs  112  and stators  114  positioned in an alternating fashion between end plate  111  and pressure plate  110 . Rotating discs  112  may rotate about an axis  115  and the stators  114  may have no angular movement relative to axis  115 . Wheels may be coupled to rotating discs  112  such that a linear speed of the aircraft is proportional to the angular speed of rotating discs  112 . As force is applied to pressure plate  110  towards end plate  111  along the axis  115 , rotating discs  112  and stators  114  are forced together in an axial direction. This causes the rotational speed of rotating discs  112  to become reduced (i.e., causes braking effect) due to friction between rotating discs  112 , stators  114 , end plate  111  and pressure plate  110 . In response to sufficient force being exerted on rotating discs  112  via pressure plate  110 , the rotating discs  112  will stop rotating. 
         [0017]    In order to exert this force onto pressure plate  110 , actuator motor  102  may cause electromechanical brake actuator  104  to actuate. Although referred to herein as electromechanical brake actuator  104 , it is contemplated that, in various embodiments, electromechanical brake actuator  104  may be an electrohydraulic actuator or a hydraulic actuator. In various embodiments, actuator motor  102  may be a brushless motor, such as a permanent magnet synchronous motor (PMSM), a permanent-magnet motor (PMM) or the like. In various embodiments, electromechanical brake actuator  104  may be coupled to or otherwise operate a motor shaft and a pressure generating device, such as, for example, a ball screw, a ram, and/or the like. In response to actuation, electromechanical brake actuator  104  causes the motor shaft to rotate. Rotation of the motor shaft may cause rotation of a ball nut, and rotational motion of the ball nut may be transformed into linear motion of a ball screw  106 . Linear translation of ball screw  106  towards pressure plate  110  applies force via member (also referred to herein as a supporting plate)  108  on pressure plate  110  towards end plate  111 . Thus, ball screw  106  may extend from brake actuator  104 . Accordingly, supporting plate  108  may be in operable communication with actuator  104 . Supporting plate  108  may be located adjacent to pressure plate  110 . 
         [0018]    Pressure plate  110  may comprise a diameter. Pressure plate  110  may comprise a circumference, wherein the circumference is equal to the product of pi (π) and the diameter. 
         [0019]    With reference to  FIG. 2 , elements with like element numbering as depicted in  FIG. 1  are intended to be the same and will not be repeated for the sake of clarity. 
         [0020]    With reference to  FIG. 2 , brake actuator plate assembly  200  may include actuator plate  210 , at least one actuator  104 , ball screw  106 , and supporting plate  108 . In various embodiments, supporting plate  108  may include first contact surface (also referred to herein as first boss)  212  and second contact surface (also referred to herein as second boss)  214 . First boss  212  and second boss  214  may extend from supporting plate  108 . First boss  212  may be located at first end  216 . First boss  212  may be located in close proximity to first end  216 . Second boss  214  may be located at second end  218 . Second boss  214  may be located in close proximity to second end  218 . Supporting plate  108  may comprise a circular arc. Stated another way, supporting plate  108  may define a circular arc. Supporting plate  108  may extend from first end  216  to second end  218 . 
         [0021]    Supporting plate  108  may include attachment feature  220 . In various embodiments, attachment feature  220  may be located between first end  216  and second end  218 . Attachment feature  220  may be configured to couple or attach supporting plate  108  to ball screw  106 . Attachment feature  220  may comprise a pivot. Attachment feature  220  may be configured to attach to ball screw  106  such that supporting plate  108  may be able to pivot about attachment feature  220 . Attachment feature  220  may be configured to attach to ball screw  106  such that supporting plate  108  may be able to pivot about attachment feature  220  in the x-z plane. Attachment feature  220  may be configured to attach to ball screw  106  such that supporting plate  108  may be able to pivot about attachment feature  220  in the y-z plane. Attachment feature  220  may be configured to attach to ball screw  106  such that supporting plate  108  may be able to pivot about attachment feature  220  in any direction similar to the configuration of a ball joint. Supporting plate may pivot about ball screw  106  via attachment feature  220  such that first boss  212  moves in a first direction, such as the positive z-direction for example, and in response to first boss  212  moving in the first direction, second boss moves in a second direction, for example the negative z-direction. In various embodiments, as illustrated in  FIG. 2 , the positive z-direction may be the direction of actuation of actuator  104  and consequently ball screw  106 . In various embodiments, supporting plate  108  may comprise a flexural plate  109 . Flexural plate  109  may be a plate which is configured to flex in response to a force exerted from ball screw  106  to pressure plate  110  via flexural plate  109 , first boss  212 , and/or second boss  214  (see  FIG. 1 ). In various embodiments, supporting plate  108  may be configured to extend and retract with ball screw  106 . 
         [0022]    In various embodiments, attachment feature  220  may be located at the center of supporting plate  108 . Accordingly, attachment feature  220  may be located at an equal distance from first end  216  as it is to second end  218 . However, attachment feature  220  may be located at a location other than the center of supporting plate  108 .  FIG. 2  illustrates second boss  214  located further away from attachment feature  220  than first boss  212 . In various embodiments, attachment feature  220  may be located more proximate to first end  216  than second end  218  as illustrated in  FIG. 2 . Thus, brake actuator plate assembly  200  may be configured to evenly distribute points of contact across pressure plate  110  (see  FIG. 1 ) to compensate for brake actuators  104  that are unevenly distributed or spaced around the circumference of actuator plate  210 . Thus, supporting plate  108  may be configured to prevent vibration by evenly distributing points of contact (i.e., first boss  212  and second boss  214 ) with pressure plate  110  about the circumference of pressure plate  110  (see  FIG. 1 ). 
         [0023]    In various embodiments, first boss  212  and second boss  214  may be configured to contact pressure plate  110  to apply a force (braking) to aircraft brake arrangement  100  (see  FIG. 1 ). Supporting plate  108  may comprise a plate. Supporting plate  108  may be flexible such that supporting plate  108  may flex in response to force exerted from pressure plate  110  (see  FIG. 1 ). Accordingly, with momentary reference to  FIG. 1 , supporting plate  108  may be configured to flex to help evenly distribute forces exerted from pressure plate  110  and/or ball screw  106 . For example, first end  216  may be configured to flex away from pressure plate  110  in the positive z-direction in response to a larger force being exerted on first boss  212  than second boss  214 . Accordingly, vibration may be dampened in response to supporting plate  108  flexing. Furthermore, supporting plate  108  may be configured to pivot about attachment feature  220  to help evenly distribute forces exerted from pressure plate  110 . For example, first end  216  may be configured to pivot away from pressure plate  110  in response to a greater for being exerted on first boss  212  than second boss  214 . Accordingly, vibration may be dampened in response to supporting plate  108  pivoting. 
         [0024]    With reference to  FIG. 3 , elements with like element numbering as depicted in  FIG. 2  are intended to be the same and will not be repeated for the sake of clarity. 
         [0025]    With reference to  FIG. 3 , a perspective view of a brake force distribution arrangement is illustrated, in accordance with various embodiments. Brake force distribution arrangement  300  may include supporting plate  108  and ball screw  106 . First boss  212  and the second boss  214  may comprise a circular geometry as illustrated in  FIG. 3 . However, first boss  212  and the second boss  214  may comprise a rectangular, elliptical, or any other suitable geometry. 
         [0026]    In various embodiments, supporting plate  108 , first boss  212 , and second boss  214  may be additively manufactured. In various embodiments, supporting plate  108 , first boss  212 , and second boss  214  may be manufactured via a subtractive manufacturing method. In various embodiments, supporting plate  108 , first boss  212 , and second boss  214  may comprise a single, unitary member manufactured from a single part. Supporting plate  108  may support first boss  212  and second boss  214 . In various embodiments, supporting plate  108 , first boss  212 , and second boss  214  may comprise carbon/carbon material. Supporting plate  108 , first boss  212 , and/or second boss  214  may comprise a high heat capacity metal alloy, such as steel, layered steel, or cast iron for example. In various embodiments, supporting plate  108 , first boss  212 , and second boss  214  may comprise a metal matrix composite (MMC). In various embodiments, supporting plate  108 , first boss  212 , and second boss  214  may comprise a medium carbon steel. In various embodiments, supporting plate  108 , first boss  212 , and second boss  214  may comprise a high carbon steel. In various embodiments, supporting plate  108 , first boss  212 , and second boss  214  may comprise a composite ceramic. 
         [0027]    In various embodiments, with temporary reference to  FIG. 1 , the arc length  352  of supporting plate  108  may be between 5% and 35% of the circumference of pressure plate  110 . In various embodiments, the arc length  352  of supporting plate  108  may be between 10% and 25% of the circumference of pressure plate  110 . 
         [0028]    In various embodiments, supporting plate  108  may comprise an aspect ratio defined by the ratio of the width  354  of supporting plate  108  and the arc length  352  of supporting plate  108 . In various embodiments, the aspect ratio of supporting plate  108  may be between 2 and 20. In various embodiments, depth  358  of first boss  212  and depth  359  of second boss  214  may be between 10% and 200% of depth  356  of supporting plate  108 . In various embodiments, width  362  of first boss  212  and width  364  of second boss  214  may be between 90% and 110% of width  354  of supporting plate  108 . 
         [0029]    Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. 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 disclosure. The scope of the disclosure 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.” Moreover, where a phrase similar to “at least one of A, B, or C” is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. 
         [0030]    Systems, methods and apparatus are provided herein. 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. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments. 
         [0031]    Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f), unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.