Abstract:
An escalator or moving walkway includes, divided roller bearings to improve the efficiency of replacement thereof. The roller bearings may be located in the region of the drive axle or deflecting axle of the step chain. The divided roller bearing components can be mounted on the roller bearing axle, and removed therefrom, in radial direction.

Description:
[0001]    The invention relates to an escalator or a moving walkway comprising at least one roller bearing which is mounted between an axle or a shaft and at least one further constructional element.  
           [0002]    In the further description the term ‘escalator’ also includes ‘moving walkway’ and the term ‘step’ also includes ‘moving walkway pallets’.  
         BACKGROUND OF THE INVENTION  
         [0003]    The steps of a conventional escalator are fastened to two transport chains and form together therewith an endless, circulating step belt which runs over a respective pair of transport chainwheels at each of the two ends of the escalator, wherein one transport chainwheel pair belongs to the drive station and drives and deflects the step belt, and the other chainwheel pair is part of a step belt return station. The individual steps of the step belt are each equipped with two respective front and two respective rear guide rollers, at which the steps are guided in a location, which is defined in dependence on position by guide runners and deflecting runners primarily fastened to the support construction of the escalator.  
           [0004]    Roller bearings are used at various places in escalators, for example for mounting the transport chain drive wheels or the transport chain deflecting wheels.  
           [0005]    There is known from JP 06144762 a use of roller bearings in guide equipment which defines the path of the rear guide rollers of escalator steps in the region of the step belt return station. The U-shaped deflecting runners are not, in that case, fixedly secured to the support construction of the escalator, but arranged to be horizontally displaceable thereat between the transport chain deflecting wheels and coupled by way of roller bearings with the axle of the transport chain deflecting wheels. This axle is displaceable transversely to the axial direction for tensioning the transport chains. Relative movement between the deflecting wheels and deflecting runners during tensioning of the transport runners is avoided by the mentioned coupling between the axle of the transport chain deflecting wheels and the U-shaped deflecting runners. An always constant movement path of the steps in the region of the step belt return is thereby guaranteed without the deflecting runners having to be manually readjusted in the case of retensioning necessitated by operationally-caused chain elongation.  
           [0006]    The described construction has the disadvantage that in the case of a roller bearing defect extensive demounting and mounting operations are required, since the roller bearings can be removed and refitted only by longitudinal displacement to the axle end. The demand for short interruption times for rectification of every form of possible defect cannot be fulfilled with this construction.  
           [0007]    The present invention has the object of avoiding the stated disadvantage in an escalator or a moving walkway, i.e. of enabling the exchange of a defective roller bearing in substantially reduced time.  
         BRIEF DESCRIPTION OF THE INVENTION  
         [0008]    The object of the invention is met by a construction having a divided roller bearing mounted between an axle or shaft of an escalator or moving walkway and a further constructional element, whereby the roller bearing elements are mountable and demountable in a radial direction.  
           [0009]    Significant advantages are achieved in an escalator according to the invention if step guide equipment, which is present in the region of the step belt return station for guidance of the guide rollers mounted at the steps of the step belt, is coupled with the deflecting axle of the transport chain deflecting wheels by way of at least one divided roller bearing, whereby the correct relative position between step guide equipment and transport chain deflecting wheels is ensured at all times.  
           [0010]    The solution according to the invention has proved particularly advantageous in the case of an escalator in which the step guide equipment is coupled by way of roller bearings with a deflecting axle, which is displaceable transversely to the axial direction thereof for tensioning of the transport chains, of the transport chain deflecting wheels, whereby readjustment of the step guide equipment after retensioning of the transport chains has been carried out is superfluous.  
           [0011]    According to an advantageous embodiment of the escalator according to the invention each bearing housing of the roller bearing connecting the step guide equipment with the said deflecting axle consists of two differently shaped flanges which are flanged to one another at end faces oriented at right angles to the bearing axis and are connected together by screws. In that case a respective first flange is directly connected with the step guide equipment and a respective second flange is formed to be of hollow cylindrical shape and receives the entire roller bearing. After release of the screw connection between the two flanges of a bearing housing the flange of hollow cylindrical shape can be pulled off the roller bearing in axial direction so that the roller bearing is exposed for demounting.  
           [0012]    A particularly simple axial fixing of the roller bearing, which connects the step guide equipment with the said deflecting axle, on the deflecting axle of the transport chain deflecting wheels is achieved if the inner ring halves of the roller bearings are mounted in recesses in this deflecting axle.  
           [0013]    In advantageous manner the transport chain drive wheels are mounted by way of divided roller bearings on a stationary central axle in an escalator according to the invention. It is thereby achieved that, in installation situations where the escalator is not laterally accessible in the region of the transport chain drive wheels, the roller bearings can be drawn out of the bearing housings from the escalator inner side in direction towards the axle centre and can be remounted in reverse direction.  
           [0014]    A particularly stable construction of a transport chain drive wheel unit results if the two transport chain drive wheels are connected together by means of a hollow shaft. The large torsional stiffness of such a hollow shaft guarantees perfect synchronism of the transport chains, and problems with worn-out shaft/hub connections of customary kind are avoided by the screw connection between hollow shaft and transport chain drive wheels of large flange diameters.  
           [0015]    In order to be able to withdraw the roller bearings from their bearing seats in the direction of the axle centre and remove and reinstall their subsequently divided components for a roller bearing change in a transport chain drive wheel unit with a hollow shaft, a respective through-opening penetrating the cylinder wall of the hollow shaft is present in each of the two end regions of the hollow shaft.  
           [0016]    A particularly advantageous embodiment of the invention consists in that the hollow shaft connected with the transport chain drive wheels has in its cylinder wall at least two groups of radially arranged threads with setting screws, with the help of which the hollow shaft and the transport chain drive wheels are supported on the stationary drive wheel axle before removal of the roller bearings. A roller bearing change can thus be performed without the transport chains having to be removed from the transport chain drive wheels or the latter having to be fixed by involved measures.  
           [0017]    According to an advantageous development of the invention parallel bores are arranged in the component, which contains the bearing seat for the outer ring of a divided roller bearing, around this bearing seat, wherein a parallel, slot-shaped channel is present between each of these bores and the bearing seat. Inserted into each bore is a withdrawal device which fits therein and has at one end a form of nose which engages behind that end face of the outer ring of the roller bearing which lies more deeply in the bearing seat. The withdrawal device includes an axial thread and a withdrawal screw which co-operates therewith and which is supported by its end in the interior of the bearing seat component. Through rotation of this withdrawal screw there is effected an axial movement of the withdrawal device which in that case moves, by its nose, the outer ring out of the bearing seat. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    Illustrative embodiments of the invention are illustrated in FIGS.  1  to  10  and explained in more detail in the following description.  
         [0019]    [0019]FIG. 1 shows a general arrangement of an escalator;  
         [0020]    [0020]FIG. 2 shows, as a longitudinal section through the escalator, the region of the non-driven step belt return station with the step guide equipment and the displaceable deflecting axle;  
         [0021]    [0021]FIG. 3 shows, as a section through the escalator along the line III-III in FIG. 2, the region of the non-driven step belt return station with the step guide device, the displaceable return axle and the divided roller bearing which couples the step guide element with the deflecting axle;  
         [0022]    [0022]FIG. 4 shows, in detail, the roller bearing arrangement which forms the coupling between the guide equipment and deflecting axle of the transport chain deflecting wheels;  
         [0023]    [0023]FIG. 5 shows the transport chain drive wheel unit mounted on divided roller bearings; and  
         [0024]    FIGS.  6  to  10  show details with respect to the process of an exchange of a divided roller bearing in the transport chain drive wheel unit. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]    By “divided roller bearing” there is to be understood a roller bearing in which an inner ring, the roller body cage and an outer ring are each divided into two halves, so that all components of the roller bearing can be fitted in radial direction onto an axle or a shaft and removed again therefrom, wherein generally the inner ring halves and also the outer ring halves are connected together by screws.  
         [0026]    The most essential components of an escalator  1  are schematically illustrated in FIG. 1. Integrated in an escalator support construction  2  is a circulating, endless step belt  3  which is driven by a driven unit  5  by way of a transport chain drive wheel unit  4 . The region of a step belt return station is denoted by  6 .  
         [0027]    [0027]FIG. 2 shows a longitudinal section through the escalator in the region of the non-driven step belt return station  6  having the step guide equipment  17 , and FIG. 3 shows the same region as a section through the escalator along the line III-III in FIG. 2. The steps of the step belt, which each have two respective front guide rollers  8  and two respective rear guide rollers  9 , are denoted by  7 . The steps  7  are coupled to two circulating transport chains  11  by way of extensions of the roller axles  10  of the front guide rollers  8 . One of the two transport chain deflecting wheels  12 , which are fixed on a common deflecting axle  13 , is seen in FIG. 2 and FIG. 3. The deflecting axle  13  is displaceable in the direction of the arrow  14  in FIG. 2 so that the transport chains  11  can be tensioned after assembly of the escalator has been carried out and compensation can be later provided for chain elongation caused by operation. An adjusting spindle of a tensioning device is schematically indicated by  15  and serves for displacing the displaceable axial bearing  16  of said deflecting axle  13 . In addition, there is illustrated the step guide equipment  17  which essentially consists of two plate-shaped side panels  18  with first roller guide elements  19 , which are mounted thereon, for the front guide rollers  8  and second roller guide elements  20 , which are laterally displaced relative thereto, for the rear guide rollers  9 . The two side panels  18  are arranged between the two transport chain deflecting wheels  12  and are supported on a cross-member  22 , which is rigidly connected with the support construction  2 , to be displaceable in the direction of the arrow  14 , wherein two vertical guides  23  guarantee the vertical position thereof. Each of the side panels  18  has a semicircular plate cut-out  24  and is coupled in this region with the deflecting axle  13  of the two transport chain deflecting wheels  12  by way of a first flange  26  of a bearing housing  25  and by way of a roller bearing  28 . A relative displacement between the transport chain deflecting wheels  12  and the roller guide elements  19 ,  20  fastened to the side panels  18  is thereby avoided when the deflecting axle  13  is displaced for tensioning the transport chain  11 .  
         [0028]    [0028]FIG. 4 shows details of the roller bearing connection between each side panel  18  and the deflecting axle  13  of the transport chain deflecting wheels. This roller bearing connection comprises a bearing housing  25  having a first flange  26  and a second flange  27  of hollow cylindrical shape, the flanges being flanged to one another in the mounted state at end faces by means of connecting screws  34 , and a divided roller bearing  28  consisting of two respective half-shell-shaped halves of an inner ring  29 , an outer ring  30  and a roller body cage  31  with roller bodies  32  retained in the roller body cage. Constructional details of this divided roller bearing  28  are not illustrated here, since it is a usual commercial constructional element. The half-shell-shaped halves of such a roller bearing are mountable on the deflecting axle  13 , and demountable therefrom, in a radial direction. In the case of a bearing defect this bearing can therefore be replaced without the deflecting axle  13  having to be demounted for that purpose. In order to carry out such a bearing change, the second flange  27  is detached from the first flange  26  and axially pulled off the inner ring of the roller bearing  28  so that the bearing is freely accessible. The halves of the roller bearing components, which are held together in each case by means of screw connections, are separated and radially removed from the deflecting axle  13 . The installation of a replacement bearing takes place in reverse sequence.  
         [0029]    The respective two halves of the inner rings  29  of the two roller bearings  28  are seated in a recess  33  of the deflecting axle  13  and thus axially fixed in ideal manner.  
         [0030]    [0030]FIG. 5 shows a second example of use of divided roller bearings in an escalator. Divided roller bearings here serve as the mounting of a transport chain drive wheel unit  4 , comprising two transport chain drive wheels  42  which are connected together in a torsionally stiff manner by way of a hollow shaft  41 , and drive the transport chains  11 , which together with the steps  7  form the step belt  3 . The transport chain drive wheel unit  4  is supported by way of two divided roller bearings  43  on a non-rotating central axle  44  fastened at the ends thereof in the support construction  2  of the escalator  1 . The roller bearings are, according to FIG. 5, installed in bearing seats  45  of the hubs  46  of the transport chain drive wheels  42 . Instead of in the hubs  46  of the transport chain drive wheels  42 , these bearing seats could, however, also be integrated in the end flanges  47  of the hollow shaft  41 .  
         [0031]    The exchange of a divided roller bearing  43  can be carried out without the escalator  1  having to be laterally accessible in the region of the transport chain drive wheel unit  4  and without the latter having to be demounted or the transport chains  11  having to be removed from the transport chain drive wheels  42 . Merely two or three steps  7  are demounted from the transport chains  11  in order to make the region of the bearing locations accessible from the inner side of the escalator.  
         [0032]    Radially arranged setting screws  49  are located in the transition region between the centre part of the hollow shaft  41  and the bell-shaped end enlargements thereof. The hollow shaft  41  together with the transport chain drive wheels  42  is supported relative to the central axle  44  by these setting screws  49  before a roller bearing exchange, so that during the roller bearing exchange a perfect centring of the transport chain drive wheel unit  4  is maintained.  
         [0033]    In the region of its two end flanges  47  the hollow shaft  41  is enlarged in bell shape and provided with three through-openings  48 , through which the actions necessary for demounting and installing the divided roller bearing  43  are carried out and the components of the roller bearing  43  removed or reintroduced to the installation location. Detail A shows a withdrawal device  52  for withdrawing the outer ring  53  of the divided roller bearing  43 . This detail is described more specifically in connection with FIG. 7.  
         [0034]    FIGS.  6  to  10  show details of demounting a divided roller bearing  43  from the above-described transport chain drive wheel unit  4 . The reinstallation takes place in reverse sequence.  
         [0035]    [0035]FIG. 6 shows how the bearing cover  50  is detached by removal of the bearing cover screws  51  so that it can be displaced on the central axle or, if the bearing cover  50  is constructed to be divided in two, can be removed via the through-openings  48 .  
         [0036]    [0036]FIG. 7 and detail A in FIG. 5 show how the outer ring  53  of the divided roller bearing  43  is withdrawn from its bearing seat  45  by means of the withdrawal device  52 . Bores  54  are arranged in the hub  46  of the transport chain drive wheel  42  (not illustrated here) around the bearing seat  45 , which is present therein, to be parallel to the axis of this bearing seat  45 . The peripheries of these bores  54  intersect the peripheries of the bearing seat  45 , so that a slot parallel to the axis of the bearing seat  45  exists between each bore  54  and the bearing seat  45 . A substantially cylindrical withdrawal device  52 , which has an axial internal thread into which a withdrawal screw  55  is introduced if needed, is inserted into each bore  54  before mounting of the roller bearing  43 . The withdrawal device  52  has a flat  56  which extends parallel to its axis and which prevents the per se cylindrical body from protruding into the region of the bearing seat  45 , wherein the flat extends in longitudinal direction only to such an extent that the full cylinder diameter is maintained, in the form of a kind of nose  57 , at one end of the withdrawal device  52 . This nose  57  engages behind that end face of the outer ring  53  of the roller bearing  43  which lies more deeply in the bearing seat  45 . For withdrawal of the roller bearing  43  initially all withdrawal screws  55  are screwed in until their forward ends hit the bases of the bores  54 , so that on further rotation the withdrawal device  52  is urged out of the bores  55  and draws, by the nose  57  thereof, the outer ring  53  and thus the entire roller bearing  43  out of the bearing seat  45 .  
         [0037]    In FIG. 8 it is illustrated how, with the roller bearing  43  withdrawn from the bearing seat  45 , the outer ring  53  is divided into two half shells  53 . 1  and  53 . 2  by demounting the outer ring screws  60 , the half shells being subsequently removed from the region of the hollow shaft  51  via the through-openings  48 .  
         [0038]    [0038]FIG. 9 shows how, after demounting the outer ring  53 , the roller body cage  61  divided into two roller body cage halves  61 . 1  and  61 . 2  is removed, together with its roller bodies  62 , via the through-openings  48 .  
         [0039]    In FIG. 10 it is seen how, as last components of the divided roller bearing  43  to be demounted, the inner ring  63  thereof seated on the central axle  44  is divided into two half shells  63 . 1  and  63 . 2  by undoing the inner ring screws  64  and is removed from the region of the hollow shaft  41  via the through-openings  48 .