Patent Publication Number: US-2023133000-A1

Title: System architecture for operation of aircraft flaps

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to European Patent Application No. 21275155.6 filed Nov. 3, 2021, the entire contents of which is incorporated herein by reference. 
     FIELD 
     The present disclosure relates to system architecture for an aircraft. In particular, the present disclosure related to a system electrical architecture for operation of aircraft flaps. 
     BACKGROUND 
     Individual flap panels on aircraft wings require two motor drive units to operate the individual flap panels. Therefore, eight motor drive units are required per aircraft in order to ensure all flap panels can be operated in the event of electronic failures. 
     SUMMARY 
     There is provided a system architecture for operation of aircraft flaps. The system architecture includes a first pair of motor drive units, the first pair comprising a first motor drive unit and a second motor drive unit, and a second pair of motor drive units, the second pair comprising a third motor drive unit and a fourth motor drive unit. The system architecture further includes a first plurality of switches connected between the first motor drive unit and the second motor drive unit, said first plurality of switches configured to operate a first electric motor and a second electric motor, and a second plurality of switches connected between the third motor drive unit and the fourth motor drive unit, said second plurality of switches configured to operate a third electric motor and a fourth electric motor. 
     The first motor drive unit and the second motor drive unit may be connected in series, and the first plurality of switches may include a first switch, a second switch, a third switch and a fourth switch. The first switch and the second switch may be arranged in parallel with the third switch and the fourth switch. The first electric motor may be connected between the first switch and the second switch, and the second motor may be connected between the third switch and the fourth switch. The first electric motor may further be configured to operate a left hand outboard flap panel and the second electric motor may be configured to operate a left hand inboard flap panel. 
     The third motor drive unit and the fourth motor drive unit may be connected in series, and the second plurality of switches may include a fifth switch, a sixth switch, a seventh switch and an eighth switch. The fifth switch and the sixth switch may be arranged in parallel with the seventh switch and the eighth switch. The third electric motor may be connected between the fifth switch and the sixth switch, and the fourth motor may be connected between the seventh switch and the eighth switch. The third electric motor may be configured to operate a right hand inboard flap panel and the fourth electric motor may be configured to operate a right hand outboard flap panel. 
     There is also provided an aircraft that includes a left hand outboard flap panel, a left hand inboard flap panel, a right hand inboard flap panel, and a right hand outboard flap panel. The aircraft also includes the system architecture as described above. The first electric motor may be configured to operate a left hand outboard flap panel and the second electric motor may be configured to operate a left hand inboard flap panel. The third electric motor may be configured to operate a right hand inboard flap panel and the fourth electric motor may be configured to operate a right hand outboard flap panel. 
     There is further provided a method of operation of aircraft flaps. The method includes providing a first pair of motor drive units, the first pair comprising a first motor drive unit and a second motor drive unit, providing a second pair of motor drive units, the second pair comprising a third motor drive unit and a fourth motor drive unit, providing a first plurality of switches connected between the first motor drive unit and the second motor drive unit, said first plurality of switches configured to operate a first electric motor and a second electric motor, and providing a second plurality of switches connected between the third motor drive unit and the fourth motor drive unit, said second plurality of switches configured to operate a third electric motor and a fourth electric motor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows an example of an ordinary system architecture for a distributed lift system of an aircraft and operation of aircraft flaps. 
         FIG.  2   a    shows an example of a system architecture in accordance with this disclosure. 
         FIG.  2   b    shows an example of the system architecture of  FIG.  2   a    in use. 
         FIG.  2   c    shows an example of the system architecture of  FIG.  2   a    during a failure. 
         FIG.  2   d    shows an example of the system architecture of  FIG.  2   a    during the failure. 
         FIG.  2   e    shows an example of the system architecture of  FIG.  2   a    during a further failure. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    shows an example of an ordinary system architecture for operation of aircraft flaps. As can be seen in  FIG.  1   , there are provided two motor drive units for each flap panel. For example, on the left hand side wing of the aircraft, there is provided an outboard flap panel (flap panel  2 ) with two motor drive units MD 1  and MD 2  to operate the left hand side outboard flap panel. There is also provided a left hand side inboard flap panel (flap panel  1 ) with two motor drive units MD 3  and MD 4  to operate the left hand side inboard flap panel. On the right hand side wing, there is provided a right hand side inboard panel (flap panel  1 ) with a further two motor drive units MD 5  and MD 6  to operate the right hand side inboard flap panel. There is also provided a right hand side outboard flap panel (flap panel  2 ) with a further two motor drive units MD 7  and MD 8  to operate the right hand side outboard flap panel. As an example, each flap panel is operated by two motor drive units, which results in a total of eight motor drive units along the wings to operate the four flap panels. This is expensive and weighty for an aircraft. Further, if there is a failure in the motor drive units, there is a risk that the flap panels will not operate at all. For example, if MD 3  and MD 4  fail, the left hand side inboard flap panel will not operate, which can lead to consequences for the flight crew. 
       FIG.  2   a    shows a system architecture  20  in accordance with the present disclosure. The system architecture  20  generally allows for fail safe mechanisms during operation of the flap panels. As shown in  FIG.  2   a   , there may be provided a first motor drive unit MD 1  connected in series with a second motor drive unit MD 3 . Connected between the first motor drive unit MD 1  and second motor drive unit MD 3  is a plurality of switches SW 1 , SW 2 , SW 5  and SW 6 . As shown in  FIG.  2   a   , a first switch SW 1  and a second switch SW 5  are in parallel with a third switch SW 2  and a fourth switch SW 6 , and all of these switches SW 1 , SW 2 , SW 5 , SW 6  are connected to the first motor drive unit MD 1  and the second motor drive unit MD 3 . A first electric motor  201  for operation of a left hand outboard flap panel is shown connected between the first and second switches SW 1  and SW 5 . A second electric motor  202  for operation of a left hand inboard flap panel is shown connected between the third and fourth switches SW 2  and SW 6 . All of the first, second, third and fourth switches SW 1 , SW 5 , SW 2  and SW 6  are shown to be open. 
     As shown in  FIG.  2   a   , there may be provided a third motor drive unit MD 2  connected in series with a fourth motor drive unit MD 4 . Connected between the third motor drive unit MD 2  and fourth motor drive unit MD 4  is a plurality of switches SW 3 , SW 4 , SW 7  and SW 8 . As shown in  FIG.  2   a   , a fifth switch SW 3  and a sixth switch SW 7  are in parallel with a seventh switch SW 4  and an eighth switch SW 8 , and all of these switches SW 3 , SW 4 , SW 7 , SW 8  are connected to the third motor drive unit MD 2  and the fourth motor drive unit MD 4 . A third electric motor  203  for operation of a right hand inboard flap panel is shown connected between the fifth and sixth switches SW 3  and SW 7 . A fourth electric motor  204  for operation of a right hand outboard flap panel is shown connected between the seventh and eighth switches SW 4  and SW 8 . All of the fifth, sixth, seventh and eighth switches SW 3 , SW 7 , SW 4  and SW 8  are shown to be open. 
     In the example shown in  FIG.  2   a   , all of the flap panels can be controlled by a system architecture that has only four motor drive units. 
       FIG.  2   b    shows an example of the system architecture of  FIG.  2   a    during a safe operation. As can be seen in  FIG.  2   b   , the first switch SW 1  and the fourth switch SW 6  are closed such that the first motor drive unit MD 1  and second motor drive unit MD 3  can operate the electric motors  201  and  202 . Therefore, the first motor drive unit MD 1  and the second motor drive unit MD 3  are able to operate the left hand side inboard and outboard flap panels. Similarly, the fifth switch SW 3  and the eighth switch SW 8  are closed such that the third motor drive unit MD 2  and fourth motor drive unit MD 4  can operate the electric motors  203  and  204 . Therefore, the third motor drive unit MD 2  and the fourth motor drive unit MD 4  are able to operate the right hand side inboard and outboard flap panels. 
       FIG.  2   c    shows an example of the system architecture of  FIG.  2   a    during a failure event in which the left hand side inboard panel and right hand side inboard panel can operate as normal. As an example shown in  FIG.  2   c   , the first motor drive unit MD 1  has failed. As can be seen in  FIG.  2   c   , the left hand inboard flap panel can be operated by closing the fourth switch SW 6  and operating the second electric motor  202  for the left hand inboard flap panel via the second motor drive unit MD 3 . The right hand side inboard flap panel is unaffected by the failure of the first motor drive unit MD 1  and, as shown in  FIG.  2   c   , the sixth switch SW 7  can be closed so as to operate the third electric motor  203  for the right hand inboard flap panel. 
       FIG.  2   d    shows an example of the system architecture of  FIG.  2   a    during a failure event in which the left hand side outboard panel and right hand side outboard panel can operate as normal. As an example shown in  FIG.  2   d   , the first motor drive unit MD 1  has failed. As can be seen in  FIG.  2   d   , the left hand outboard flap panel can be operated by closing the second switch SW 5  and operating the first electric motor  201  for the left hand outboard flap panel via the second motor drive unit MD 3 . The right hand side outboard flap panel is unaffected by the failure of the first motor drive unit MD 1  and, as shown in  FIG.  2   d   , the eighth switch SW 8  can be closed so as to operate the fourth electric motor  204  for the right hand outboard flap panel. 
       FIG.  2   e    shows an example of the system architecture of  FIG.  2   a    during a failure event in which the left hand side outboard panel and right hand side outboard panel can operate as normal. As an example shown in  FIG.  2   e   , the first motor drive unit MD 1  and the first switch SW 1  have failed. As can be seen in  FIG.  2   e   , the left hand outboard flap panel can be operated by closing the second switch SW 5  and operating the first electric motor  201  for the left hand outboard flap panel via the second motor drive unit MD 3 . The right hand side outboard flap panel is unaffected by the failure of the first motor drive unit MD 1  and the first switch SW 1 , and as shown in  FIG.  2   e   , the eighth switch SW 8  can be closed so as to operate the fourth electric motor  204  for the right hand outboard flap panel. 
     The examples of failures shown in  FIGS.  2   c  to  2   e    are merely examples. It is understood that if the second motor drive unit MD 3  fails, then the first motor drive unit MD 1  could operate the inboard and outboard flap panels by closing the first and third switches SW 1  and SW 2  to operate the first and second electric motors  201  and  202 . Similarly, if the third motor drive unit MD 2  fails, the fourth motor drive unit MD 4  can operate the inboard and outboard flap panels by closing the sixth and eighth switches SW 7  and SW 8  to operate the third and fourth electric motors  203  and  204 . If any of the switches fail, as an example, the current could be re-routed to drive any of the electric motors from the pairs of motor drive units (e.g. motor drive units MD 1  and MD 3  as one pair and MD 2  and MD 4  as another pair). 
     Likewise, if there are more than one failure in the system, the system architecture provides for an electrical routing for the flaps to be operated. For example, if the first motor drive unit MD 1  and the third motor drive unit MD 2  both fail, the second motor drive unit MD 3  and the fourth motor drive unit MD 4  may operate the switches. For example, the second motor drive unit MD 3  may operate the second switch SW 5  and fourth switch SW 6  and the fourth motor drive unit MD 4  may operate the sixth switch SW 7  and the eighth switch SW 8 . Therefore, the inboard and outboard flap panels may still be operated even in the event of a dual failure of motor drive units. 
     Reducing the number of motor drive units required in operations of flap panels for aircraft from eight to four significantly reduces the complexity and weight of the system architecture, and provides a fail-safe mechanism should one or more motor drive units fail during flight by utilising switches within the system architecture. 
     Although this disclosure has been described in terms of preferred examples, it should be understood that these examples are illustrative only and that the claims are not limited to those examples. Those skilled in the art will be able to make modifications and alternatives in view of the disclosure which are contemplated as falling within the scope of the appended claims.