Abstract:
The invention concerns a lift having a drive unit. The invention further concerns a wind power installation having a lift. To reduce the costs of the lift and thus make the lift economically more attractive the lift of the kind set forth in this specification is characterized by a cupboard used as the lift car. In that respect the invention is based on the realization that a cupboard in its basic structure with bottom, side walls and a door does not differ from a lift car produced specifically for a lift. Naturally there are differences, for example in suspension and operation of the door, but those differences can be removed insofar as they are an obstacle to use of a cupboard as a lift car so that the complication and expenditure overall is always still less than the complication and expenditure for a lift car constructed specifically for the lift.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention concerns a lift having a drive unit. The invention further concerns a wind power installation having a lift. 
         [0003]    2. Description of the Related Art 
         [0004]    Nowadays lifts, also called elevators, are usual in particular in large wind power installations for transporting people and material. That makes it unnecessary for example for maintenance engineers who have to perform operations in the pod of the wind power installation to make a strenuous and time-consuming climb by way of the ladders which generally lead perpendicularly upwardly in the pylon. In the case of wind power installations with hub heights of about 140 m which are not unusual nowadays, that would more specifically involve a vertical climb up (and naturally also a subsequent climb down) over precisely that distance of 140 m. If it is further considered that a maintenance team may be active in a number of wind power installations in the course of a working day, it will quickly be clear that using the ladders can involve an extreme physical stress. 
         [0005]    To the extent to which the size of the wind power installations is increasing and the importance of wind power is growing, more and more installations are being erected of a size in which a lift is at least desirable, and in many cases, a necessity. As a result the lifts are becoming more and more a cost factor because they no longer occur occasionally in wind power installations. 
         [0006]    At this point as state of the art attention is directed generally to the following publications: DE 10 2005 009 500 A1, WO 97/11020 A1, DE 101 04 351 A1 and DE 10 2006 034 299 A1. 
       BRIEF SUMMARY 
       [0007]    Therefore one object of the present invention is to reduce the costs of the lift and thus make the lift economically more attractive. 
         [0008]    For that purpose, the lift of the kind set forth in the opening part of this specification is characterized by a cupboard which is used as a lift car. 
         [0009]    In that respect the invention is based on the adaptive use of a cupboard or electric switch cabinet in its basic structure with a bottom, side walls and a door as a lift car produced specifically for a lift. There are differences, for example in the suspension and operation of the door between a cupboard and a lift car, but the cupboard can be modified sufficient to provide safe operation of the lift, so that the complication and expenditure overall is always still less than the complication and expenditure on a lift car constructed specifically for a lift. 
         [0010]    To permit the lift to be transported to its location of use in a space-saving fashion, provided at the top side of the lift car at opposite sides are substantially horizontally arranged holders and carriers arranged extending substantially vertically thereon for the drive unit, wherein the carriers are releasably connected to the holders and are vertically displaceable. In that way the drive unit can be pushed into the lift car for transport so that, for transport purposes, only the outside dimensions of the lift car are relevant and the drive unit does not require any additional space for transport thereof. 
         [0011]    For that purpose in the first position the connection is made between the drive unit and the lift car in the operating position so that all of the internal space in the lift car is available for transporting freight and/or people while in the second vertically displaced position the drive unit is held in a lowered position in the lift car, which saves on transport space. 
         [0012]    The change between the transport position and the operating position only involves releasing the connection between the drive unit and the lift car, moving the drive unit into the desired position and restoring or tightening the connection in the correspondingly different position. There is no need for further interventions. In that way the change between the transport position and the operating position can be effected very easily and with a time saving. 
         [0013]    In a preferred development of the invention the lift system is characterized by a drive unit having a capstan winch. That means that there is no need for a complicated and expensive rail arrangement within the pylon but it is only necessary to provide two appropriately sized cables. One for normal operation and one as a catch cable to be able to stop the lift in the event of a technical failure. 
         [0014]    Particularly preferably the entire control is arranged in the drive unit and an operating element connected to the control extends down into the lift car so that a change in the drive unit between the transport position and the operating position is possible without any intervention into the control and/or the operating element connected thereto. 
         [0015]    A further possible way of cost savings is afforded if, instead of a particular lift car, a cupboard which is usually employed as a switch cabinet is used as the car for a lift. Switch cabinets can be produced in large numbers at lower cost, they can be used as cars for lifts and they can be easily adapted to the particular demands involved as a car for a lift so that the cost advantage is also not lost as a result of that. 
         [0016]    Particularly advantageously the lift according to the invention is used in a wind power installation as there, apart from erection, the lift is only used occasionally and therefore has to meet the fundamental demands made on a lift, but particular comfort is not required. 
         [0017]    A conventional wind power installation which can be equipped with a lift according to the invention includes at any event a foundation or another base on which a pylon, in particular a tubular steel or concrete pylon, is set up, at the upper end of which is arranged a wind power installation pod. Fixed to the pod is an aerodynamic rotor which is to be caused to rotate by means of wind and which for that purpose has at least one and usually three rotor blades. The pod further includes some elements for operation of the wind power installation, which can usually include the generator coupled to the aerodynamic rotor, as well as various other elements such as a drive unit for rotating the pod to change the azimuth position thereof, or for example aviation lights to make the pod better visible to air traffic, to give just some examples. The lift according to the invention is to be provided in particular in the pylon in order to convey one or more people and/or articles from the base of the pylon to the pod, and/or vice versa. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0018]    The invention is described in greater detail hereinafter with reference to the Figures in which: 
           [0019]      FIG. 1  shows an overall perspective view of a lift according to the invention, 
           [0020]      FIG. 2  shows a switch cabinet body, 
           [0021]      FIG. 3  shows the switch cabinet body with door and side portions, 
           [0022]      FIG. 4  shows a switch cabinet body as shown in  FIG. 3  and in addition a drive unit, 
           [0023]      FIG. 5  shows a switch cabinet body as shown in  FIG. 4  but with the drive unit lowered into the lift car, 
           [0024]      FIG. 6  shows a simplified view of the operating portion in the interior of the lift car, 
           [0025]      FIG. 7  shows a simplified view of the operating portion on the outside on the lift car, 
           [0026]      FIG. 8  shows a view of the control cabinet from the side towards the interior of the lift car, 
           [0027]      FIG. 9  is an isometric view of the drive unit above the lift car, being made ready for use, and 
           [0028]      FIG. 10  is an isometric cut away view of the drive unit inside the lift car, when being shipped. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]      FIG. 1  shows the complete lift with the lift car  10  and the drive unit  11 . The lift car  10  substantially includes a switch cabinet body  12  as a load-bearing structure. Fitted into that switch cabinet body  12  is a sliding door  14  in which a window  16  is in turn provided. Side portions and naturally a rear wall (not shown in this Figure) are also installed. The side portion  18  having a window  20  can be clearly seen in this Figure. 
         [0030]    In addition, shown at the left-hand side which is visible in this Figure are guide cable rollers  22  for the guide cable  74  and a carrier cable guide  24  through which the carrier cable  70  is guided. Corresponding guide cable rollers are disposed on the opposite side of the lift car  10  according to the invention, that side however is not shown in this Figure. There, there is also a catch cable guide (also not shown in this Figure) for the catch cable  72  which holds the lift car for example upon failure of the normal lift drive. 
         [0031]    Holders  30  are mounted at the top side of the switch cabinet body  12  and carriers  32  which extend perpendicularly upwardly are in turn attached to the holders  30 . Disposed on the carriers  32  is a roof plate  34  which protects the lift from articles which drop down. Also mounted to the holders  32  is a capstan winch  36 , by means of which the lift can travel upwards or downwards in the desired direction on the carrier cable  70 . There is also a control cabinet  38  in which the entire control system is disposed. This Figure also shows a catch device  50  which as a safety device holds the lift on a catch cable  72  if the drive consisting of the capstan winch  36  and the carrier cable  70  should fail. In addition to the carrier cable  70  and the catch cable  72  there are also guide cables  74  which guide the lift so as to avoid swinging movement of the lift. 
         [0032]    Provided for the power supply is a cable  92  which is passed into the drive unit by way of a cable guide  90 . Finally the Figure shows a bottom or floor switch  80  which detects when the lift encounters the floor (or another obstacle) and which can stop the lift. 
         [0033]      FIG. 2  shows a perspective view of a switch cabinet body  12  which according to the invention forms the load-bearing structure of the lift car  10 . The switch cabinet body  12  is often used to hold large banks of electrical equipment, such as computers, switches, power supplies, and the like. Such a switch cabinet body  12  is nowadays a component which is produced in large numbers and which therefore is relatively inexpensive but which enjoys sufficient strength and load-bearing capability to be able to provide for transporting people and material. 
         [0034]    The structure of a standard electrical switch cabinet body is built to hold at least one or two hundred kilograms of heavy industrial and electrical equipment. Thus, the frame and support structure have more than enough strength and integrity to hold a person while being used as an elevator car, also called a lift car here. When being used as a lift car, the door and sides may have windows and the roof has a specific structure attached, as will now be explained. 
         [0035]      FIG. 3  shows that switch cabinet body  12  with an installed sliding door  14  in which there is a window  16 . This Figure further shows a side portion  18  having a further window  20  while illustrated in the lower region of the side portion  18  are guide cable rollers  22  and a carrier cable guide  24 . 
         [0036]    It can be clearly seen in this Figure that by relatively simple measures, the switch cabinet body  12  can be made into a car for a lift, which meets all requirements, but which overall is markedly less expensive than a standard lift car. 
         [0037]    Such a lift car will usually be of a size to hold one person. Many standard electrical cabinets come in a size of about 200 cm high by 40-80 cm wide and 30-60 cm deep for holding racks of power supplies, computers, and switches. A lift car in a wind turbine may be used a few times a day when the turbine is first being brought online, and during routine maintenance over the life of the wind turbine a few times a month or once every few months. Thus, the electrical switch cabinet used as the lift car is sufficient to provide the basic starting structure. 
         [0038]    In  FIG. 4  the view in  FIG. 3  has been supplemented by holders  30  which are fixed at the top on the switch cabinet body  12 . Carriers  32  are in turn mounted perpendicularly to the holders  30 . A roof plate  34  is fitted on the carriers  32 . The roof plate  34  prevents articles being able to drop from above into the lift car or the drive. Arranged on the carriers is a capstan winch  36 , a control cabinet  38  and a catch device  50 , by means of which the essential functions of the lift can be performed. There are also guide cable rollers  22  which guide the lift during operation along guide cables which are provided, and which thus prevent the lift from swinging. Shown at the underside of the lift car  10  is a floor switch  80  which detects when the lift encounters the floor or meets an obstacle and can immediately stop the lift. 
         [0039]    The carriers  32  are releasably connected to the holders  30  and can be displaced in the direction of the vertical axis of the lift. In that way the drive unit carried by the carriers  32  can be lowered into the lift car  10  so that the lift requires less room for transport, namely essentially the space in the lift car  10 . 
         [0040]    That is shown in  FIG. 5 . The roof plate  34  can be seen in  FIG. 5  above the holders  30  while the remainder of the drive unit is lowered with the carriers  32  (not shown in this Figure) into the lift car  10 . 
         [0041]    In addition this perspective view shows the right-hand side of the lift with a right-hand side wall  19  and a right-hand side wall window  21 , as well as an external operating portion  60  shown on the right-hand side wall  19  and guide cable rollers  26  and a catch cable guide  28 . 
         [0042]    The structure for this lift car is very different from the standard life car in a number of ways. In this lift car, the drive unit is removably attached to the car itself. All that is needed is to attach the support cables at a secure location in the top region of the wind turbine. Further, the drive unit is removably attached, again a significant difference in the prior art in which drive units are not made to be easily placed on and removed from the lift car. In addition, the drive unit can move vertically with respect to the lift car for ease of transportation. The entire drive unit can be lowered into the lift car for storage and transportation, then, when ready for use, the drive unit is vertically raised upward to be coupled above the lift car  10  so a person may enter. 
         [0043]      FIG. 9  shows the lift car with the drive unit in position for use and  FIG. 10  shows the lift car with the drive unit inside the lift car for shipment, as will now be explained. The drive unit  11  can be raised from a transportation position according to  FIG. 10  to a position ready for use as shown in  FIG. 9 . Accordingly,  FIGS. 9 and 10  show an embodiment to illustrate these two different positions of the drive unit  11 . In the transportation position according to  FIG. 10 , the drive unit  11  is fixed with first fasteners  102  to a support rail  104 . The support rail  104  is one component in the holders  30  and is shown in more detail in  FIGS. 9 and 10 . The fasteners  102  may be bolts, screws, pins or any acceptable fastener to properly and securely couple the carriers  32  to the holders  104 . 
         [0044]    In the condition shown in  FIG. 10 , the lift takes up much less space since the drive unit is inside the electrical switch cabinet frame that forms the lift car. It can be easily transported in this condition, but of course is not ready for use. After delivery of the lift, the lift is placed, to give one example, inside the tower of a wind power installation. A lift cable fixed in the tower head is introduced into the drive unit  11  through an opening slot  106  in a roof plate  108 . This lift cable, which is not shown in  FIGS. 9 and 10 , is then installed in the drive unit  11  and connected to the capstan winch  36 , which includes a power drive member  110 . The drive unit  11  is also electrically connected to a power supply and prepared for use. 
         [0045]    The drive unit  11  is then operated in manual mode such that the drive unit  11  will be lifted by means of the lift cable and the capstan winch  36 . Since the first screws  102  have been detached, only the drive unit  11  is lifted in this manual mode, i.e., it is lifted with respect to the lift car  10 , until it has reached the position shown in  FIG. 9 . In the next step the drive unit  11  is then fixed to the same support rail  104  by a plurality of second fasteners  112 . 
         [0046]    The second fasteners  112  can be any acceptable fasteners, such as bolts, screws, pins or the like. These fasteners  112  will hold the drive unit in place while the lift car  10  is being used by a person for riding from the bottom of the wind turbine to the top. Accordingly, a high quality set of fasteners, such as hardened steel bolts, may be used that have sufficient strength and safety margin for repeated use in carrying the weight of the elevator and cargo over its expected time of use. Thus, there may be a plurality of main fasteners  112  and also one or more additional backup fasteners on each side. The fasteners  112  will be stronger and have a higher safety factor than needed for the fasteners  102 , since the fasteners  102  need only hold the lift  11  in the car  10  while it is being transported, but the fasteners  112  must support the lift car  10  while it is in use and carrying a person. To save time and space, the same fasteners can be used for both, namely, a mechanic can simply remove the fasteners  102 , operate the winch  36  to lift the drive unit  11  into place, and then reinstall the same fasteners, this time as fasteners  112  into either the same or different holes in rail  104  to hold the carriers  32  on the holders  30 . This will be convenient and save having to ship fasteners  112  separately. Thus, while it is permitted to use different fasteners for 102 and 112, it is also permitted to use the same fasteners. 
         [0047]    The lift is then basically ready to be used. However, some further steps such as providing a covering of the drive unit  11  can be performed in addition. 
         [0048]    To be able to operate the lift at least one operating unit is naturally required.  FIG. 6  shows such an operating unit  62  which is provided in the interior of the lift car and which besides operating buttons for moving upwards or downwards includes a switch for switching on the control system, a reset button, an emergency stop switch and an operation/fault light. In that way the essential lift functions can be controlled and operational readiness or a fault can be signaled. 
         [0049]      FIG. 7  shows an external operating portion  60  by way of which the fundamental functions can be operated, for example when transporting material. That external operating portion  60  is used when people transport is not involved. Then the lift which is filled with material can be set in operation for example with the ‘up’ button in order to transport the material upwardly from the base of the installation. The ‘down’ button causes automatic travel in the opposite direction, that is to say downwardly. 
         [0050]      FIG. 8  shows the side  40  of the control cabinet  38  which is towards the interior of the lift car. Provided at that side of the control cabinet  38  is a multiplicity of lights and switches which signal different operating states or which make it possible to actuate given functions. In normal operation the lift is operated by way of the operating portion  60  or the operating portion  62 . As soon as a fault is displayed at one of those operating portions however, the operator can obtain further information about the nature of the fault, with a glance upwardly, namely to the underside  40  of the control cabinet  38 , which is shown in  FIG. 8 . 
         [0051]    The switch labeled ‘lighting’ serves for switching the lighting on and off. 
         [0052]    The light identified by ‘control voltage 24 V ok’ shows whether the 24 V voltage required for satisfactory operation of the control is available and the lift can be operated. 
         [0053]    The light ‘fault rotary field’ shows whether the rotary field at the motor for the desired operation is or is not in order. A light which is switched on indicates a fault. That can be for example a missing phase in the power supply or a wrong connection of the rotary field. 
         [0054]    The ‘door open’ light shows precisely that, namely that the door of the lift is not correctly closed. If the door is correctly closed that display can also indicate a defective door switch. More specifically, both mean that the lift cannot be set in operation. That ensures that the lift moves only when the door is securely and correctly closed. 
         [0055]    The ‘limit switch down’ light shows triggering of the lower limit switch (the so-called car floor switch), for example when the lowermost position is reached or the switch is actuated by an obstacle. Triggering of the upper limit switch or the emergency stop function is signaled by the ‘limit switch up/emergency stop’ light. Continuous lighting thereof shows that the lift has reached the upper operating position while flashing shows the uppermost emergency stop position. 
         [0056]    The ‘overload’ light indicates overloading of the lift and the ‘catch device triggered’ light indicates that the catch device has fixed the lift on the catch cable so that further movement of the lift is not possible without releasing the catch device. 
         [0057]    As human lives also depend on reliable functioning of the drive and the safety devices, a maintenance interval is prescribed, within which those components have to be repetitively checked. In the present example this involves a 200 hour interval. A display light is also provided for that purpose to indicate the expiry of that interval to the user. That light is labeled ‘200 h maintenance’. 
         [0058]    Finally there is a ‘bridging limit switch down’ switch which permits bridging of the limit switch and thus enables that switch to be taken out of operation, if that is required for example upon installation for re-starting the arrangement or also when changing the cables. 
         [0059]    The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent application, foreign patents, foreign patent application and non-patent publications referred to in this specification and/or listed in the Application Data Sheet are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, application and publications to provide yet further embodiments. 
         [0060]    These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.