Abstract:
The present disclosure relates to an electromagnetic rotary shock absorber for damping a wheel suspension component associated with a motor vehicle. The electromagnetic rotary shock absorber has a flywheel and at least one damper. The damper has a first element operably associated with the flywheel for driving the flywheel rotationally, and a second element operably associated with the wheel suspension component. The damper operates to dampen relative movement of the wheel suspension component using an inertia of the flywheel.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present disclosure claims priority from U.S. Provisional Patent Application Ser. No. 62/030,752, filed Jul. 30, 2014, the entire contents of which is hereby incorporated by reference into the present disclosure. 
     
    
     FIELD 
       [0002]    The present disclosure relates to a rotary damper, and more particularly, to an electromagnetic rotary damper for a vehicular wheel suspension system. 
       BACKGROUND 
       [0003]    This section provides background information related to the present disclosure which is not necessarily prior art. 
         [0004]    The wheel suspension system for a vehicle may include an electromagnetic rotary damper which reduces vehicular vibrations generated at the wheel. The electromagnetic rotary damper includes an electric motor having a rotor and a stator, which are connected to a vehicle body. Such dampers are also used as an energy harvester for generating energy from the movement of the wheel suspension system. The electromagnetic rotary damper should be capable of handling low and high frequency disturbances experienced by the wheel suspension system. 
       SUMMARY 
       [0005]    In one aspect the present disclosure relates to an electromagnetic rotary shock absorber for damping a wheel suspension component associated with a motor vehicle. The electromagnetic rotary shock absorber comprises a flywheel and at least one damper. The damper has a first element operably associated with the flywheel for driving the flywheel rotationally, and a second element operably associated with the wheel suspension component. The damper operates to dampen relative movement of the wheel suspension component using an inertia of the flywheel. 
         [0006]    In another aspect the present disclosure relates to an electromagnetic rotary shock absorber for damping a wheel suspension component associated with a motor vehicle. The electromagnetic rotary shock absorber comprises a flywheel, a damper and an electronic controller. The damper is operatively disposed between the flywheel and the wheel suspension component and operates to dampen relative movement of the wheel suspension component using an inertia of the flywheel. An electronic controller is used for controlling the damper. 
         [0007]    In still another aspect the present disclosure relates to a method for damping a wheel suspension component associated with a motor vehicle. The method comprises providing a damper in the form of an electric motor having a rotor and a stator. The method further involves operatively coupling a flywheel to the rotor to enable the flywheel to be driven rotationally by the rotor. The method also involves operatively coupling the stator to the wheel suspension component, and using a mass of the rotating flywheel to dampen movement of the wheel suspension component. 
     
    
     
       DRAWINGS 
         [0008]    The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
           [0009]      FIG. 1  is a schematic view of an electromagnetic rotary flywheel damper (EF damper) for a vehicle suspension system; 
           [0010]      FIG. 2A  illustrates a connection of a wheel of the vehicle and a suspension link which is coupled to a stator of the EF damper; 
           [0011]      FIG. 2B  depicts an angular speed of the suspension link (ω 1 ) and a nominal angular speed of the rotor (ω 2 ); 
           [0012]      FIG. 3  illustrates characteristics of a semi-active system having the EF damper without a clutch; and 
           [0013]      FIG. 4  illustrates characteristics of an active system having the EF damper with the clutch. 
       
    
    
       [0014]    Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION 
       [0015]    The present disclosure will now be described more fully with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application or uses.  FIG. 1  illustrates an electromagnetic rotary flywheel damper  10  (hereinafter “EF damper  10 ”) for a suspension system of a vehicle. The vehicle may be any type of vehicle such as, without limitation, an automobile, van, light truck, truck or SUV. 
         [0016]    The EF damper  10  includes an electric motor  12 , a flywheel  14 , first and second gearboxes  16  and  18 , and a clutch  19 . The gearboxes  16  and  18  may be any kind of speed multiplier (e.g., harmonic drives). The electric motor  12  includes a rotor  20  and a stator  22 . The stator  22  is connected to a suspension link  24  of the vehicle via the first gearbox  16 . The rotor  20  is connected to the flywheel  14  via the second gearbox  18 . The rotor  20  and the flywheel  14  are connected such that the rotor and the flywheel spin freely around one axis  26  independent of the vehicle body. The rotor  20  turns at a speed for maximum electromagnetic coupling. The flywheel  14  may be made of steel or any other suitable material. 
         [0017]    A bearing  20   a  of the rotor  20  is connected to, or otherwise partially supported from, a chassis  28  of the vehicle to carry the force of the suspension system. The clutch  19  may be used to couple the flywheel  14  to the chassis  28  via the second gearbox  18 . The gearboxes  16  and  18  are reduction gears such as planetary gears. The first gearbox  16  amplifies the relative movement of the suspension system to improve the resolution of the movement of the rotor  20  relative to the stator  22 . 
         [0018]      FIG. 2A  illustrates a connection of a wheel  30  and the suspension link  24 , and where the suspension link is coupled to the stator  22  (shown in diagrammatic form). Movement of the wheel  30  is transferred to the suspension link  24  as an angular speed ω 1 .  FIG. 2B  depicts the angular speed of the suspension link  24  (ω 1 ) and the nominal angular speed of the rotor  20  (ω 2 ).  FIG. 3  illustrates a chart of various loads placed on the EF damper  10  plotted as current or torque vs. angular speed. 
         [0019]    At static operation, the flywheel  14  is controlled to spin at a set speed by a controller of the electric motor  12 . The set speed of the flywheel  14  is seen by the stator  22  as a nominal angular speed ω 2  (i.e., the nominal angular speed of the rotor  20 ). Motion of the suspension system is transferred to the stator  22  creating a relative rotation of the stator (i.e., a wheel event). More particularly, the relative movement of the suspension system is seen by the stator  22  as a relative variation in speed by the rotor  20 . Depending on a plurality of factors that include the strength of the magnetic coupling between the stator  22  and rotor  20 , the rotating speed of the flywheel  14 , and the impact energy of the suspension movement, the force of the relative movement is either accelerating the flywheel  14  or acting as a force against the rotor and/or flywheel ( FIG. 3 ) to slightly and momentarily attenuate the angular speed of the flywheel  14 . This is in effect the damping force. 
         [0020]    For a semi-active system, the EF damper  10  dissipates energy. For an active system, the EF damper  10  can create an active vertical force to the vehicle body for a certain time. As part of an active system, the EF damper  10  includes a clutch to vary the rotating resistance of the flywheel  14 . More particularly, in an active mode, a controller (or inverter)  32  ( FIG. 1 ) associated with the electric motor  12  may regulate the speed of the flywheel  14  to the preselected speed. Higher forces can be generated by the electric motor  12  by varying the load line or resistance. Specifically, the load is varied by engaging the clutch  19  between the flywheel  14  and the chassis  28  of the vehicle. The controller  32  is controlling the torque demands of the electric motor  12  and speed regulation of the flywheel  14 . The clutch is controllable by an electrical signal either from the controller  32  or from a different controller. 
         [0021]      FIG. 4  illustrates the properties of the EF damper  10  when it is implemented as an active system. As an active system, the resistance level as seen by the rotor  20 , relative to the stator  22 , is moved (varied) by engaging the clutch  19 . Thus, a certain (controlled) amount of force can be created which acts on the suspension link  24 . 
         [0022]    At high frequencies, the rotor  20  and flywheel  14  absorb the energy by rotating freely without being controlled by the controller  32 . The controller  32  actively controls the rotor  20 , and thus the angular speed of the flywheel  14 , at low frequency bands, which is manageable by the controller. The disturbance experienced by the EF damper  10  at high frequencies is absorbed by the inertia of the rotor  20 . 
         [0023]    The EF damper  10  comprises at least one damper element for damping the relative movement of a first mass located at the wheel suspension side against the inertia of a fast spinning flywheel connected to supported from the vehicle body. The electric motor  12  of the EF damper  10  produces an electromagnetic resistance force that opposes the relative rotational movement of the flywheel. Due to the inertia of the flywheel  14 , harsh movements of the suspension system do not translate into high peak currents. In summary, the EF damper  10  of the present disclosure is a suspension rotary damper, comprising an electromagnetic motor combined with a flywheel system for harshness compliance. The EF damper  10  dampens the peak currents during the operation of an electromagnetic damper system by use of the flywheel. 
         [0024]    The foregoing description of the various embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.