Patent Publication Number: US-9850095-B2

Title: Elevator generating electric energy using displacement thereof

Description:
TECHNICAL FIELD 
     The present invention relates to an electricity generating elevator and, more particularly, to an electricity generating elevator capable of producing electric energy using displacement of a cage for carrying passengers or loads while the elevator is operated. 
     BACKGROUND ART 
     With the recent Manhattanization of buildings, various elevators capable of rapidly and efficiently carrying a lot of passengers are developed and installed. As well known, the elevator is a transporting means for safely carrying passengers or loads while vertically linearly moving along a shaft (called an enclosed space) that is vertical formed in a building. 
     Conventional elevators generally include guide rails that is firmly vertically installed in a shaft in a building, a cage that moves up and down along the guide rails, a wire rope that is connected to the cage at one end thereof, a counterweight that is connected to the other end of the wire rope and moves along the guide rails installed vertically at one side of the shaft without overlapping a movement path of the cage in the opposite direction of the moving direction of the cage, and a driving motor that is installed at the uppermost portion of the shaft, is in frictional contact with the wire rope, and raises/lowers the cage and the counterweight by means of forward/backward rotation. 
     In the case of the conventional elevator systems, only a single driving motor is used, and thus the driving motor has a large size. To operate the large driving motor, a machine room in which the driving motor and related components are installed on the rooftop of the building should be provided, and thus there is a problem in that the space is inefficiently used. Further, a driving motor having high torque and output is used, which increases manufacturing and maintenance costs. 
     To solve these problems, an elevator system is disclosed in Korean Unexamined Patent Application Publication No. 10-2010-0110555. 
     Such an elevator system includes a plurality of driving motors, a cage that is raised/lowered by the driving motors, a counterweight that is operated opposite to the raising/lowering operation of the cage, a wire rope that is connected to the driving motors, the cage, and the counterweight at the same time, a sensing unit that measures weight of passengers and loads mounted in the cage, and a controller that controls the plurality of driving motors so as to be selectively operated. 
     However, this elevator system is operated by the plurality of driving motors, and thus requires much power for driving the plurality of driving motors. 
     DISCLOSURE 
     Technical Problem 
     The present invention is intended to resolve such problems, and is directed to providing an electricity generating elevator capable of producing electric energy using a change in a position of a cage according to upward/downward movement of the cage while the elevator is operated, and of storing or using the produced electric energy for a driving motor that raises/lowers the cage. 
     Technical Solution 
     To accomplish the above object, an electricity generating elevator according to the present invention includes a cage installed in a shaft formed in a building in order to carry passengers or loads, a drive unit vertically moving the cage along the shaft, and an electricity generation unit including a coil section installed on the cage and a magnetic force generator that is installed in the shaft so as to face the coil section and provides a magnetic force to the coil section so as to generate an induced electromotive force according to a change in a position of the coil section while the cage moves up and down. 
     Here, the drive unit may include main guide rails that are vertically installed in the shaft so as to guide a movement path of the cage and support the cage so as to be vertically movable along the shaft, a wire rope whose one end is connected to the cage, a counterweight that is connected to the other end of the wire rope so as to move in the opposite direction of a moving direction of the cage, sub-guide rails that are vertically installed in the shaft in parallel to the main guide rails at a given interval and support the counterweight so as to be vertically movable along the shaft, and a winding machine that winds up and off the wire rope so as to vertically move the cage. The winding machine may include a wheel that is supported on a rotary axle rotatably installed on a frame above the cage and the counterweight and causes rolling friction against the wire rope, and a driving motor that drives the wheel. 
     Advantageous Effects 
     The electricity generating elevator according to the present invention includes the electricity generation unit having the coil section attached to the cage and the magnetic force generator arranged in the shaft at a position facing the coil section, so that electric energy can be produced by the coil section according to a change in a position of the cage while the cage vertically reciprocates in the shaft, and the produced electric energy can be used as a power source for vertically moving the cage. Thus, maintenance expenses of the elevator can be reduced. 
     Further, the electricity generating elevator according to the present invention has the electricity generation unit installed on the case and in the shaft as well as on the counterweight and in the shaft, and thus can increase electricity generation efficiency. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of an electricity generating elevator according to a first embodiment of the present invention. 
         FIG. 2  is a detailed perspective view illustrating main components of the electricity generating elevator illustrated in  FIG. 1 . 
         FIG. 3  is a schematic side view illustrating an electricity generating elevator according to a second embodiment of the present invention. 
         FIG. 4  is a detailed perspective view of an electricity generating elevator according to a third embodiment of the present invention. 
         FIG. 5  is a detailed perspective view of an electricity generating elevator according to a fourth embodiment of the present invention. 
     
    
    
     MODES OF THE INVENTION 
     Hereinafter, electricity generating elevators according to exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The electricity generating elevator according to the present invention is illustrated in  FIGS. 1 and 2 . 
     Referring to  FIGS. 1 and 2 , the electricity generating elevator of the present invention includes a cage  100 , a drive unit, an electricity generation unit, and a control unit  500 . 
     The cage  100  is provided therein with a boarding space for carrying passengers or loads, and closable elevator doors that allow the passengers or the loads to enter the boarding space through a doorway. The cage  100  is installed in a shaft  2  formed vertically in a building so as to be movable up and down. 
     The cage  100  has the same structure as a typical elevator cage. A buffer  150  for cushioning any impact of the cage  100  when the cage  100  falls due to a failure is installed at the bottom of the shaft  2 . 
     The drive unit is provided to vertically move the cage  100  along the shaft  2 , and includes main guide rails  210  that are vertically installed in the shaft  2  so as to guide a movement path of the cage  100  and support the cage  100  so as to be vertically movable along the shaft  2 , a wire rope  220  whose one end is connected to the cage  100 , a counterweight  230  that is connected to the other end of the wire rope  220  so as to move in the opposite direction of a moving direction of the cage  100 , sub-guide rails  240  that are vertically installed in the shaft  2  in parallel to the main guide rails  210  at a given interval so as to guide a movement path of the counterweight  230  and support the counterweight  230  so as to be vertically movable along the shaft  2 , and a winding machine  300  that winds up and off the wire rope  220  so as to vertically move the cage  100 . 
     The main guide rails  210 , the sub-guide rails  240 , the wire rope  220 , and the counterweight  230  are typically used in an elevator system, and thus detailed description thereof will be omitted. 
     The winding machine  300  is installed in a machine room  310  that is provided separately from the shaft  2  at an upper portion of the shaft  2 , i.e. at an upper portion of the building. The winding machine  300  includes a frame  320  installed in the machine room  310 , a rotary axle that is rotatably installed on the frame  320 , a wheel  330  that is supported on the rotary axle, is located above the main guide and sub-guide rails  210  and  240 , and causes rolling friction against the wire rope  220  for raising/lowering the cage  100 , a driving motor  340  that drives the wheel  330 , and a brake unit (not shown) that is installed on a driving axle of the wheel  330  or a driving axle of the driving motor  340 . 
     The electricity generation unit generates electricity using electromagnetic induction, and includes a coil section  410  that is fixed to the cage  100 , and a magnetic force generator  450  that is installed in the shaft  2  and provides a magnetic force to the coil section  410  so as to generate an induced electromotive force according to a change in a position of the coil section  410  while the cage  100  moves up and down. 
     The coil section  410  is formed by winding a conducting wire having electric conductivity such that magnetic flux generated from the magnetic force generator  450  can pass. 
     The coil section  410  includes numerous unit coils  411 , and the unit coils  411  are installed on an outer circumferential surface of the cage  100  at intervals. The unit coils  411  are mutually connected in series or parallel. Electric energy induced from each unit coil  411  is stored in a storage battery of the control unit  500  to be described below. 
     The magnetic force generator  450  is installed on an inner wall of the shaft  2 , is disposed at a position facing the coil section  410  installed on the cage  100 , and is arranged in line in a direction in which the shaft  2  extends, i.e. in a vertical direction. The magnetic force generator  450  employs permanent magnets  451 . 
     A process of generating the induced electromotive force using the coil section  410  and the magnetic force generator  450  will be described. First, when the cage  100  moves upward or downward in a state in which it is stopped at an arbitrary position, the coil section  410  also moves along with the cage  100 . Here, the magnetic force generator  450  disposed on the opposite side of the coil section  410  continues to provide a magnetic force toward the coil section  410 . 
     With the movement of the cage  100 , the magnetic flux passing through the unit coils  411  is repetitively increased and reduced. In this process, an induced current is generated from each unit coil  411  by the electromagnetic induction. 
     The aforementioned electromagnetic induction means that, when magnetic flux passing through a closed circuit is changed over time, an electromotive force proportional to a rate of change is generated in the closed circuit in a direction in which it obstructs a change in the magnetic flux. In other words, the present invention is realized by applying the unit coils  411  to a closed circuit and moving the unit coils  411  relative to the magnetic force generator  450  in order to change the magnetic flux. 
     In the present embodiment, the coil section  410  is installed on the cage  100 , and the magnetic force generator  450  is installed on the inner wall of the shaft  2 . 
     However, the opposite example may be applied. That is, any structure may be applied if relative movement between the coil section  410  and the magnetic force generator  450  is possible. 
     Unlike the illustrated example, the magnetic force generator  450  may be installed on the main guide rails  210  including or excluding the inner wall of the shaft  2 . In this case, a separate bracket for installing the magnetic force generator  450  so as to be supported on the main guide rails  210  and to face the coil section  410  is preferably provided. 
     In addition, as illustrated in  FIG. 3 , the coils  411  of the coil section  410  may also be installed on the counterweight  230  in addition to the cage  100 . In this case, the permanent magnets  451  providing the magnetic force to the coils  411  installed on the counterweight  230  are installed on the shaft  2  or the sub-guide rails  240  located opposite to the coils  411  installed on the counterweight  230 . In this structure, electricity can be generated by the coils and the permanent magnets, both of which are respectively installed on the cage and the shaft or on the cage and the main guide rails. Further, secondary power can be produced by the coils  411  and the permanent magnets  451 , both of which are respectively installed on the counterweight  230  moving in the opposite direction of the cage  100  and on the sub-guide rails  240  supporting the counterweight  230 . 
     Meanwhile, in the electricity generating elevator according to the present invention, as illustrated in  FIG. 4 , the coil sections  410  may be coupled to the wire rope  220  connected to the top of the cage  100  so as to be able to increase electricity generation output. A separate bracket  470  may be installed on the wire rope  220  so as to be adjacent to the magnetic force generator  450  installed in the shaft  2 , and the coil sections  410  coupled to the wire rope  220  may be fixed to ends of support bars  480  extending from the bracket  470  at a given length. 
     The control unit  500  is installed inside the machine room  310 , and controls an operation of the drive unit, particularly the winding machine  300 . The control unit  500  includes a drive controller that controls an operation of the driving motor  340  for moving the cage  100  and controls an opening/closing operation of the doors of the cage  100 , and an auxiliary power supply controller that stores the electric energy produced by the electricity generation unit and supplies the electric energy to the driving motor  340 . 
     The auxiliary power supply controller is configured to collect the induced electromotive force generated from each coil section  410 , store the induced electromotive force in the storage battery (not shown) as the electric energy, and supply the stored electric energy to the driving motor  340  as needed. 
     The control unit  500  may further include an inverter, and is configured to convert the electric energy produced by the electricity generation unit into a direct current through the inverter and store the direct current in the storage battery. The electric energy stored in the storage battery may be used as the power for raising/lowering the elevator as described above, or be supplied to electric fittings having relatively low power consumption such as lighting lamps installed in the building in which the elevator is installed. 
     Further, as illustrated in  FIG. 5 , the electricity generating elevator according to the present invention may further include a display unit  600  capable of displaying an amount of electricity that is currently generated by the electricity generation unit. The display unit  600  is installed in the cage and around a boarding standby platform of the elevator so as to enable the passengers getting in the cage as well as waiting passengers to recognize the electricity generation output. 
     Although the electricity generating elevator according to the present invention has been described with reference to the examples illustrated in the drawings, it will be understood to those skilled in the art that a variety of equivalents and modifications can be made at the time of filing the present invention. 
     Therefore, the genuine technical scope of the present invention should be defined from the accompanying claims.