Patent Publication Number: US-2022227194-A1

Title: Suspension system

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
     This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2021-0006793, filed on Jan. 18, 2021 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The disclosure relates to a suspension system, and more particularly, to a suspension system including a damper that generates a damping force and an actuator that may control the damping force of the damper as well as generate electricity. 
     BACKGROUND 
     In general, a suspension system for a vehicle serves to support the weight of a vehicle body and suppress and damp vibrations transmitted from a road surface to the vehicle body thereof. 
     A conventional suspension system for a vehicle includes a carrier for rotatably supporting a wheel to which a road wheel is coupled, an upper arm for connecting an upper portion of the carrier to a vehicle body, a lower arm, assist arm and trailing arm for connecting a lower portion of the carrier to the vehicle body, a damper (shock absorber) connecting the upper portion of the carrier with the vehicle body, an elastic spring arranged between the lower arm and the vehicle body, a stabilizer bar fixed to the vehicle body, and a connecting links for connecting the stabilizer bar with the lower arm. 
     Recently, in a suspension system for a vehicle, a regenerative system for charging a storage battery by generating electricity using an impact transmitted from a road surface while the vehicle is traveling is proposed. 
     Such a conventional regenerative system is disclosed in Korean Patent Laid-Open No. 10-2012-0064846. In the above document, the regenerative device is installed on a suspension link arm of a vehicle and uses the shock transmitted to an axle of the vehicle, in other words, uses a method of recovering kinetic energy generated during rebounding as electrical energy. 
     However, because the conventional regenerative system has a complicated structure that is mechanically connected to the suspension link arm of the vehicle, the size of the device increases, so that securing an installation space is difficult. Furthermore, because an impact is transmitted through the mechanical connection, damage of the device due to the impact is occurred when a force is repeatedly applied to driving parts of the regenerative systems. 
     SUMMARY 
     An aspect of the disclosure is to provide a suspension system capable of securing easily an installation space by coupling directly an actuator capable of generating electricity to a damper. 
     Another aspect of the disclosure is to provide a suspension system capable of adjusting a damping force of the damper by varying an area of a flow path hole through which a working fluid passes, such that the damping force required in damping sections of a low speed, a medium speed, and a high speed is generated. 
     Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure. 
     In accordance with an aspect of the disclosure, a suspension system includes a damper in which a piston valve is movably provided in a chamber inside a cylinder; and an actuator coupled to a side portion of the cylinder to communicate with the chamber inside the cylinder; wherein the actuator comprises a rotating body in which a rotational drive shaft coupled to a center thereof, the rotating body configured to be rotated by working fluid transmitted from the chamber during a stroke of the piston valve; a centrifugal valve coupled to the rotational drive shaft in front of the rotating body, the centrifugal valve rotating together with the rotating body and varying an area of a flow path hole through which the working fluid passes according to a rotational speed of the rotating body; and a generator combined motor in which the rotational drive shaft is rotatably arranged at a rear of the rotating body, the generator combined motor configured to charge by generating electric energy through the rotation of the rotational drive shaft. 
     The suspension system may further include a housing whose one side is opened so that the generator combined motor, the rotating body, and the centrifugal valve are sequentially accommodated therein; and a cover coupled to close the opened side of the housing and provided with a connection port communicating with the chamber inside the cylinder. 
     A bypass flow path may be provided between an inner side of the cover and the centrifugal valve so that the working fluid introduced through the connection port flows into the rotating body. 
     The rotating body may be provided with a propeller having a plurality of blades arranged at regular intervals along a circumferential direction of the rotational drive shaft. 
     The centrifugal valve may include a valve body in which the rotational drive shaft is coupled to a center thereof, the valve body having at least one flow path hole formed therethrough in a radial direction about the rotational drive shaft; a valve cover installed on the valve body and moving in a radial direction according to the rotation of the valve body to open and close the flow path hole; and an elastic member coupled to the valve cover to elastically support the valve cover in a direction in which the flow path hole is opened. 
     The valve body may include a base plate including a pair of guide rods formed on one side thereof to support opposite sides of the valve cover so that the valve cover is slidable, and a fixing portion provided between the pair of guide rods so that one end of the elastic member is fixed, and a cover plate coupled to the one side of the base plate to prevent separation of the valve cover and the elastic member provided in the base plate; and wherein the base plate and the cover plate are provided with the flow path hole corresponding to positions at which the valve cover is moved in a radial direction, respectively. 
     The rotational drive shaft may include a first rotary shaft connected to the center of the rotating body and the centrifugal valve, and a second rotary shaft connected to the center of the rotating body and the generator combined motor, and the first and second rotary shafts are provided to be coaxially connected by a coupling provided at the center of the rotating body. 
     The generator combined motor may be electrically connected to an inverter configured to convert the generated electrical energy; a controller configured to control the current of the inverter; and a storage battery configured to store the electric energy converted by the inverter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  is a cross-sectional view illustrating a suspension system according to an embodiment of the disclosure. 
         FIG. 2  is an exploded perspective view illustrating a suspension system according to an embodiment of the disclosure. 
         FIG. 3  is an exploded perspective view illustrating a centrifugal valve provided in a suspension system according to an embodiment of the disclosure. 
         FIGS. 4 to 6  are views illustrating an operating state of a centrifugal valve provided in a suspension system according to an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, the embodiments of the disclosure will be described in detail with reference to accompanying drawings. It should be understood that the terms used in the specification and the appended claims should not be construed as limited to general and dictionary meanings, but interpreted based on the meanings and concepts corresponding to technical aspects of the disclosure on the basis of the principle that the inventor is allowed to define terms appropriately for the best explanation. Therefore, the description proposed herein is just a preferable example for the purpose of illustrations only, not intended to limit the scope of the disclosure, so it should be understood that other equivalents and modifications could be made thereto without departing from the spirit and scope of the disclosure. 
       FIG. 1  is a cross-sectional view illustrating a suspension system according to an embodiment of the disclosure,  FIG. 2  is an exploded perspective view illustrating a suspension system according to an embodiment of the disclosure,  FIG. 3  is an exploded perspective view illustrating a centrifugal valve provided in a suspension system according to an embodiment of the disclosure, and  FIGS. 4 to 6  are views illustrating an operating state of a centrifugal valve provided in a suspension system according to an embodiment of the disclosure. 
     Referring to  FIGS. 1 to 6 , a suspension system according to an embodiment of the disclosure includes a damper  1  and an actuator  10 . 
     The damper  1  is a device for damping shock or vibration during a vehicle operation, and may include a cylinder  2  (e.g., two or more) having a cylindrical shape forming a chamber  3  therein, a piston valve (not shown) provided to be reciprocally movable within the chamber  3  of the cylinder q, and a piston rod (not shown) connected to the piston valve. A working fluid is filled in the chamber  3  of the cylinder  2 , and the chamber  3  is divided into a lower compression chamber and an upper rebound chamber by the piston valve. The piston valve performs compression or rebound strokes while being coupled to one end of the piston rod, and the other end of the piston rod extends to an outside of the cylinder  2  to be connected to an axle of the vehicle. The damper  1  is well-known technologies, so detailed description thereof is omitted, and only a cylinder (an outermost cylinder in case of a plurality of) is shown in  FIG. 1 . 
     The actuator  10  includes a generator combined motor  200 , a rotating body  300 , and a centrifugal valve  400 . Furthermore, the actuator  10  further includes a housing  110  with one side open so that the motor  200 , the rotating body  300 , and the centrifugal valve  400  are sequentially accommodated, and cover a cover  120  coupled to close the one open side of the housing  110  and provided with connection ports  121  and  122  communicating with the chamber  3  inside the cylinder  2 . The actuator  10  may adjust a damping force of the damper  1  by adjusting a flow amount of the working fluid according to the rebound or compression stroke of the damper  1 . Furthermore, electricity may be generated using the flow of the working fluid. In other words, as will be described later, the rotating body  300  is rotated by the pressure of the working fluid flowing in from the damper  1 , and a rotational drive shaft  220  connected to the generator combined motor  200  is rotated by the rotation of the rotating body  300 . As a result, the generator combined motor  200  may be operated as a generator. 
     The generator combined motor  200  may be rotated by receiving electricity from an external power source, and the rotational direction or speed thereof may be controlled by an electronic control unit (ECU) of a vehicle equipped with a suspension system. For example, when the damper  1  is to be maintained hard, the generator combined motor  200  may be operated to control the flow of the working fluid by operating the centrifugal valve  400  to be described later. Furthermore, when the generator combined motor  200  is used as a generator, an electrical wire may be connected so that the generator combined motor  200  stores electric energy in a storage battery. 
     The generator combined motor  200  may include a stator  210  disposed on an inner surface of the housing  110 , a rotor including the rotational drive shaft  220  disposed to be rotated within the housing  110 . A part of the rotational drive shaft  220  protrudes toward an opening direction of the housing  110 , and the rotating body  300  and the centrifugal valve  400  are fixedly connected to the protruding part of the rotational drive shaft  220 . Herein, an embodiment of the disclosure is shown that the rotating body  300 , the centrifugal valve  400 , and the generator combined motor  200  are connected through one rotational drive shaft  220 , it is not limited thereto, and if it is connected coaxially, the rotational drive shaft  220  may be divided and combined with each component. For example, the rotational drive shaft  220  may include a first rotary shaft connected to a center of the rotating body  300  and the centrifugal valve  400 , and a second rotary shaft connected to a center of the rotating body  300  and the generator combined motor  200 . The first and second rotary shafts may be provided to be coaxially connected by a coupling provided at the center of the rotating body  300 . Accordingly, a the rotating body  300  rotates, the first and second rotary shafts rotate together, and the centrifugal valve  400  and the rotor connected to the first and second rotary shafts rotates. 
     An inverter for converting the generated electrical energy, a controller C for controlling current of the inverter and a storage battery for storing the electrical energy converted by the inverter may be electrically connected to the generator combined motor  200 . 
     On the other hand, an undescribed reference numeral  112  denotes a bearing that supports the rotational drive shaft  220  so that the rotational drive shaft  220  rotates stably within the housing  110 . 
     The cover  120  is coupled to close the one open side of the housing  110 , and may be coupled to a side portion of the cylinder  2 . The cover  120  may be provided with the connection ports  121  and  122  in fluidly communication with the chamber  3  inside the cylinder  2 . The connection ports  121  and  122  may be divided into a first port  121  and a second port  122  for fluidly communicating the chamber  3  and the inside of the actuator  10 . For example, the first port  121  may communicate with the rebound chamber of the chambers  3  of the cylinder  2 , and the second port  122  may communicate with the compression chamber. The connection ports  121  and  122  communicate with a flow path hole  402  formed in the centrifugal valve  400  to be described later. 
     Meanwhile, a bypass flow path  130  may be provided between an inner side of the cover  120  and the centrifugal valve  400  so that the working fluid introduced through the connection ports  121  and  122  flows into the rotating body  300 . The bypass flow path  130  may be formed in a groove shape inside the cover  120 , or may be formed by a gap spaced apart from the centrifugal valve  400 . The bypass flow path  130  serves to rotate the rotating body  300  by allowing hydraulic pressure generated during the stroke of the damper  1  to be directly transmitted to the rotating body  300 . 
     In other words, when the piston valve performs a stroke, the rotating body  130  rotates while the working fluid flows in through the bypass flow path  130 . In this process, the centrifugal valve  400  connected to the rotational drive shaft  220  rotates in one direction, as well as the rotor of the generator combined motor  200  rotates together. Accordingly, the generator combined motor  200  charges the storage battery with electrical energy generated through the rotation of the rotational drive shaft  220 . 
     The rotating body  300  is provided to be rotated by the working fluid transmitted from the chamber  3  during the stroke of the piston valve. Furthermore, the rotating body  300  may be provided as a propeller comprising a plurality of blades through which the rotational drive shaft  220  is coupled through the center thereof, and the plurality of blades is arranged at regular intervals along a circumferential direction of the rotational drive shaft  220 . The rotating body  300  is rotated by the working fluid introduced along the bypass flow path  130 , and rotates the rotational drive shaft  220  to rotate the centrifugal valve  400 , and at the same time, generates electricity to the generator combined motor  200 . Meanwhile, a rotational speed of the rotating body  300  may be determined by a hydraulic force generated in response to the stroke of the piston valve. For example, the rotating body  300  rotates rapidly in a high speed damping section to generate a high rotational force, and rotates slowly in a low speed damping section to generate a low rotational force. 
     The centrifugal valve  400  may be coupled to the rotational drive shaft  200  at the front of the rotating body  300  to rotate together with the rotational driveshaft  220  according to the rotation of the rotating body  300 . The centrifugal valve  400  may be provided to vary an area of the flow path hole  402  through which the working fluid passes according to the rotational speed of the rotating body  300 . At this time, the flow path hole  402  communicates with the connection ports  121  and  122  so that the working fluid in the chamber  3  flows into the actuator  10 . The centrifugal valve  400  may include a valve body  410 , a valve cover  420 , and an elastic member  430 . 
     In particular, the valve body  410  is coupled to a rotational drive shaft  220  at the center thereof, and at least one flow path hole  402  is formed through the rotational drive shaft  220  in a radial direction about the rotational drive shaft  220 . The valve body  410  includes a base plate  411  provided to support the valve cover  420  and the elastic member  430 , and a cover plate  415  coupled to the base plate  411 . 
     A pair of guide rods  412  for supporting opposite sides of the valve cover  420  may be provided on one side of the base plate  411  so that the valve cover  420  may be slidably. Two flow path holes  402  having a phase difference of 180 degrees with respect to the center thereof are formed passing through the base plate  411 . Accordingly, the pair of guide rods  412  are positioned on the both side surfaces of the two flow path holes  402  to guide the valve cover  420  to move stably. 
     Furthermore, a fixing portion  413  may be provided on one side of the base plate  411  between the pair of guide rods  412  so that one end of the elastic member  430  is fixed. In other words, one end of the elastic member  430  is fixed to the fixing portion  413  and the other end thereof is coupled to the valve cover  420 . 
     The rotational drive shaft  220  is coupled to the center of the other side of the base plate  411 , so that the base plate  411  rotates with the rotation of the rotational drive shaft  220 . 
     The cover plate  415  is coupled to one side of the base plate  411  and rotates together with the base plate  411 , as well as serves to prevent separation of the valve cover  420  and the elastic member  430  provided in the base plate  411 . The flow path hole  402  is formed in the cover plate  415  at a position corresponding to the flow path hole  402  formed in the base plate  411 . 
     As the centrifugal valve  400  rotates, the valve cover  420  moves in a radial direction relative to the center of the centrifugal valve  400  by a centrifugal force. At this time, a moving distance of the valve cover  420  may be changed according to the rotational speed of the centrifugal valve  400 . For example, as shown in  FIG. 4 , when the centrifugal valve  400  is rotated at a low speed, the valve cover  420  may be slid to close a part of the flow path hole  402 . Furthermore, as shown in  FIG. 5 , when the centrifugal valve  400  rotates at a medium speed the valve cover  420  may be slid to close about half of the flow path hole  402 . Furthermore, as shown in  FIG. 6 , when the centrifugal valve  400  rotates at high speed the valve cover  420  may be slid to completely close the flow path hole  402 . As such, the damping force may be controlled by adjusting the flow amount of the working fluid according to the degree of opening and closing of the flow path hole  402 . The valve cover  420  moved in the radial direction may be returned to its original position by elastic restoring force of the elastic member  430 . 
     On the other hand, in the centrifugal valve  400  of the embodiment, because the two flow path holes  402  having a phase difference of 180 degrees from each other are formed passing through the centrifugal valve  400 , the valve cover  420  and the elastic member  430  are provided as a pair, respectively, but it is not limited thereto. The flow path holes  402 , the valve cover  420  and the elastic member  430  may be selectively increased or decreased by having a corresponding number to each other. 
     Furthermore, although the suspension system according to an embodiment of the disclosure has been illustrated and described as being coupled to the side portion of the cylinder  2 , it is not limited thereto, and may be coupled to a lower portion of the cylinder  2 . 
     In the suspension system as described above, the rotating body  300  rotates by the working fluid flowing in from the chamber  3  of the cylinder  2  during the stroke of the damper  1  to operate the centrifugal valve  400  and generate electric energy. In other words, in response to the rotational speed of the rotating body  300 , the flow amount of the working fluid through the centrifugal valve  400  may be controlled, as well as electric energy may be obtained by rotating the rotational drive shaft  220  connected to the generator combined motor  200 . 
     Such a suspension system may be operated in a regenerative mode during a general road driving. In other words, the working fluid of the damper  1  is pressurized by the stroke of the piston valve and flows, and the rotating body  300  is rotated by as the working fluid. Accordingly, the rotational drive shaft  220  is rotated together with the rotating body  300 , so that the generator combined motor  200  connected thereto may be generate electricity. Furthermore, the centrifugal valve  400  rotates together with the rotating body  300  and controls the degree of opening and closing of the flow path hole  402  in response to the rotational speed thereof, so that the damping force required may be provided. 
     On the other hand, the suspension system may be operated in an active mode when the vehicle is traveling on a rough road or when it is necessary to maximize handling performance. In this case, electricity is supplied to the generator combined motor  200  to rotate the rotational drive shaft  220 , and the flow of the working fluid is controlled through the centrifugal valve  400 , so that the damping force of the damper  1  may be made much harder or softer. 
     As a result, the suspension system according to the embodiment of the disclosure actively adjusts the damping force of the damper according to driving conditions of the vehicle to reduce a roll, a pitch, a heave motion, etc., thereby improving adjustment stability, as well as generating electric energy. 
     As is apparent from the above, the embodiments of the disclosure may provide the suspension system having the effect of securing easily the installation space by directly coupling the actuator capable of generating electricity using hydraulic pressure according to the stroke of the damper. 
     In addition, by using the centrifugal valve to vary the area of the flow path holes through which the working fluid passes in response the rotational speed, the damping force required in damping sections of low speed, medium speed, and high speed may be adjusted, thereby improving riding comfort. 
     As described above, although a few embodiments of the disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.