Abstract:
The invention refers to a mounting and dismounting device ( 10 ) for an annular machine element ( 40 ) being mountable on an axle ( 20 ), which device ( 10 ) comprises pressing means ( 12 ), counteracting means ( 14 ) and tightening means ( 16, 42 ), where the tightening means ( 16, 42 ) is connectable to the counteracting means ( 14 ) for transfer of axial force to the machine element ( 40 ). The invention is characterized in that the counteracting means ( 14 ) comprises two parts and is provided to exert a radial force locking the counteracting means ( 14 ) against the axle ( 20 ), at exertion of axial force via the tightening means ( 16, 42 ).

Description:
[0001]    The present invention refers to a mounting and dismounting device for an annular machine element being mountable on an axle, which device comprises pressing means, counteracting moans and tightening means, where the tightening means is connectable to the counteracting mean for transfer of axial force to the machine element.  
         THE BACKGROUND OF THE INVENTION AND THE PROBLEM  
         [0002]    The device according to the invention is a tool used during mounting of machine elements such as for example rolling bearings on axles in e.g. gear boxes and electric motors. Similarly, the device according to the invention can be used during dismounting of the same. Further, the device can be used for mounting and dismounting of other machine elements such as for example bushings, sliding bearings and transmission wheels.  
           [0003]    Above all, when mounting bearings on axles in electric motors and gear boxes it is very important to try to eliminate arise of uncontrollable axial forces in the axle, as such forces can give rise to longitudinal displacements of the axle which can damage the function or components connected to the actual axle, for example drive gear in gear boxes, which are sensitive to axial displacements. The mounting and dismounting device according to the invention is designed so that only very small axial loads arise in the axle, which do not have a negative effect on the other components arranged on the axle.  
           [0004]    The invention is also provided to reduce misalignment loads on the bearing during the mounting procedure. Usually, the bearing is knocked onto the axle by a hammer and a sleeve and this method give rise to misalignment loads both on the be and the axle, which misalignment loads in turn can lead to a shortened endurance time of the bearing and also damages to other components mounted on said axle.  
           [0005]    In industry it is desired that a mounting and dismounting device according to the above-described type is also easy and quick to use, so that it is possible to gain time. It is also an advantage if it can be arranged on the axle at an optional position so that it can be used in many other types of applications and that the number of parts in the tool is low.  
           [0006]    From for stance the document EP 0 424 584 it is prior known a mounting device for e.g. bearings, which comprises a jig arrangement for mounting and fixing a bearing on an axle. The device firstly used in connection with conical bearings and comprises a conical part, which is threaded in one end, and provided to the axle end with the threads extending outwards. The bearing is pressed onto this part and a housing is surrounding the bearing. To mount and fix the bearing, an outer plate is screwed onto the conical part. The plate keeps the jig arrangement together and with screws, provided in the plate, the bearing can be positioned in the axial direction. The disadvantage with this jig arrangement, except for comprising many parts, is that it can not be removed tom the axle as long as the bearing shall be mounted to the axle and that it implies that the bearing shall be positioned in the vicinity of the axle end.  
           [0007]    From DE 412 595 it is prior known a device for mounting of bearings in which the tightening means such as screws are used to press a pressing washer against the bearing. The device comprises a fixed part, counteracting means, and a movable part, pressing washer. In a first embodiment the counteracting means is provided with pins which fit in corresponding recesses in the axle, so that the countering means is prevented from sliding away along the axle when the bearing is to be pushed on. In a second embodiment the counteracting means is in two parts so that it can be arranged in a slot radially provided around the axle. Only the friction between the screws and the pressing washer prevent the counteracting means from falling off the axle. Thus, these types of bearing mounting tools cast only be used in applications with special designed axles with suitable recesses. Further, the distribution of and the number of screws, and the fact that the counteracting means in the last mentioned embodiment is in two parts, lead to a large risk of existing misalignment loads to the bearing during mounting.  
           [0008]    Thus, with reference to at least the above mentioned disadvantages, it can be said that these tools for mounting of bearings is not suitable for easy mounting and dismounting of machine elements such as for example rolling bearings on axles in gear boxes and electric motors, and other types of machine elements such as bushings, sliding bearings and transmission wheels.  
         THE OBJECT OF THE INVENTION AND THE SOLUTION TO THE PROBLEM  
         [0009]    Thus, the object of the invention is to provide a mounting and dismounting device for machine element such as for example bearings, which device:  
           [0010]    does not give rise to any misalignment loads on the machine element during mounting/dismounting,  
           [0011]    eliminates the arise of uncontrollable axial forces in the axle which can damage other machine elements mounted on the axle,  
           [0012]    gives an even pressure on the machine element during mounting/dismounting,  
           [0013]    is easy to mount and demount on to axle,  
           [0014]    can be arranged at an optional position on the axle,  
           [0015]    is prevented form sliding away along the axle during mounting/dismounting of the machine element,  
           [0016]    only has to be arranged on the axle during mounting/dismounting procedure,  
           [0017]    is easy to manufacture, and  
           [0018]    comprises few parts.  
           [0019]    These objects have been solved in that the counteracting means comprises two parts and is provided to exert a radial force locking the counteracting against the axle, at exertion of axial force via the tightening means. 
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0020]    In the following, the invention will be more closely described with reference to the attached drawings, in which:  
         [0021]    [0021]FIG. 1 shows a top view and a section taken along the line A-A of an embodiment of the invention in which a bearing is to be mounted,  
         [0022]    [0022]FIG. 2 shows a top view and a section taken along the line B-B of the embodiment of FIG. 1 during dismounting of a bearing, and  
         [0023]    [0023]FIG. 3 shows a top view and a section taken along the line C-C where hydraulics is used during dismounting of a bearing.  
     
    
     DESCRIPTION OF EMBODIMENTS  
       [0024]    In the following, the mounting and dismounting device will be described with help of a number of embodiments and with reference to the attached drawings. The device as a whole is denoted with the numeral  10 .  
         [0025]    The mounting and dismounting device  10  according to the invention comprises pressing means  12 , counteracting means  14  and tightening means  16 . In an embodiment of the invention, where a bearing is to be mounted on an axle, which is shown in FIG. 1, the pressing means  12  is forced as a having an axial hole  18  with a diameter which is preferably the same as the one of the axle  20  on which the bearing is to be mounted. The counteracting means  14  comprises partly an outer element  22  with a through hole with a conical inner envelope surface  24  and partly an element  26  in the form of a sleeve with a conical outer envelope surface  28  and a longitudinal slot  27 . The conicity of both said surfaces  24 ,  28  corresponds to each other. Further, the inner element  26  has a through hole  30  with a diameter is corresponding to the diameter of the axle  20 . In the outer element  22  there are two recesses  32  in the outer surface and three axial, threaded, through screw holes  34  which are symmetrically distributed around the axle  20 . Moreover, the device  10  comprises tightening screws  16  which fit in the three through screw holes  34 . Eventually, these three screws  16  can be provided with a steel ball  36  in the end which will reduce the friction between pressing washer  12  and the screw  16 . Further, the device  10  comprises biasing means  38  in the form of a bushing that can be fixedly threaded into the outer element  22  of the counteracting means  14  at the edge of the conical hole.  
         [0026]    Below, and with reference to FIG. 1, mounting of a bearing  40  on an axle  20  will be described where the device according to the invention is used. Naturally, even other machine elements than bearings can be mounted with the tool according to the present invention.  
         [0027]    The bearing  40  is pushed up on the axle  20  on which it is to be mounted. Thereafter, the pressing means  12 , the washer, is arranged onto the axle  20  adjacent the bearing  40 . Preferably, the washer  12  is chosen so that it has at least as large outer diameter as the outer diameter of the bearing  20 , and further so that its through hole  18  has a relevant clearance against the axle  20 , so that the washer  12  can easily be displaced along the axle  20 . Thereafter, a suitably dimensioned counteracting means  14  is arranged on the axle  20  by placing the outer element  22  over axle  20  and the inner element  26  is pushed up on the axle  20  and is pushed into the conical hole of the outer element  22 . The inner element  26  is then biased with help of the bushing  38  so that the inner element  26  is prevented from falling out off the outer element  22  in the initial phase of the mounting. Thereafter, the three tightening screws  16  are screwed into the through threaded holes  34  in the outer element  22  and by alternately turn the screws  16  one round at a time, the pressing washer  12  is evenly pushed up along the axle  20  and presses the bearing  40  up along the axle  20 . When the tightening screws  16  are screwed into the through holes  34  and are starting to press on the pressing washer  12 , i.e. at exertion of a evenly distributed axial force via the tightening means  16 , a radially directed locking force arises between the counteracting means  14  and the axle  20 . This is caused by the displacement movement between the envelope surfaces  24  and  28 . The counteracting means  14  is therefore very by arranged on the axle  20  and thus there is not any risk that the counteracting means  14  slides away along the axle  20  during the bearing mounting procedure. The harmful axial and misalignment loads that arise in the bearing are very small, which provides a mounting that does not damage the bearing nor the components that are connected to the axle.  
         [0028]    When the bearing  40  is in place, the tightening screws  16  are screwed out off the counteracting means  14  which afterwards can be disassembled and removed with a suitable tool. Finally, the pressing washer  12  is removed from the axle  20 .  
         [0029]    In a variant of the described embodiment, which is not shown, the inner element  26  of the counteracting means  14  is instead divided into two cone halves. These are biased with biasing means  38  just like above, which in tins case also prevents the sleeve parts from being locked in an inclined position in relation to each outer.  
         [0030]    With reference to FIG. 2, dismounting of a bearing  40  from an axle  20  by means of the mounting and dismounting device according to the invention will be described. Dismounting with the device  10  according to the invention is not made exactly in the same way as mounting. The largest differences are that the pressing washer is not at all needed and that the tightening means  16  in the case of dismounting are any sort of withdrawal tool, for instance hook-equipped screws  42 . Which type of hook-equipped screws  42  that is needed depends on the position of the bearing  40 . In the following a case will be described in which it is free space behind the bearing  40  so that conventional hook-equipped screws can be used, but there are also cases who the bearing is situated in for example a bearing housing and where such hooks can not be used. In such cases, dismounting can be made with for example internal hook tools, which grip the bearing at the race track.  
         [0031]    During dismounting, the counteracting means  14  is placed on the axle  20  in a direction opposite that of mounting, i.e. fist the biasing means  38  is placed adjacent the bearing  40 , afterwards the inner element  26  of the counteracting means  14  is aged on the axle, and finally the axle is provided with the outer element  22  which is screwed into the biasing means  38 . In the recesses  32  of the outer element  22  of the counteracting means  14  the hook-equipped screws  42  are positioned with the hooks  46  positioned against the bottom surface  44  of the bearing  40 , and the nuts  48  are screwed onto the upper portions of the screws  42  adjacent the outer element  22  of the counteracting means  14 . When the nuts  48  are alternately tightened one round at a time, the forces that arise will lock the counteracting means  14  against the axle  20  and the hooks  46  will displace the bearing  40  out along the axle  20 .  
         [0032]    The dismounting of a bearing according to the above does not have to be made manually, instead it is possible to use hydraulics. In an embodiment, which is shown FIG. 3, the tightening means  42  is affected by hydraulic tensioning means  50 . Schematically, the tensioning mean  50  works in the same way as the earlier described nuts  48  and can thus lock the counteracting means  14  against the axle  20 , simultaneously as the be  40  is pulled out from the axle  20 . The advantage of using hydraulics is that it is possible to control the force that is being exerted on the bearing in a reliable way.  
         [0033]    It is to be understood that the invention is not limited to the described embodiments, but can be modified within the scope of the attached claims.  
       LIST OF REFERENCE NUMERALS  
       [0034]    [0034] 10  mounting and dismounting device  
         [0035]    [0035] 12  pressing means (washer)  
         [0036]    [0036] 14  counteracting means  
         [0037]    [0037] 16  tightening means (screw)  
         [0038]    [0038] 18  hole  
         [0039]    [0039] 20  axle  
         [0040]    [0040] 22  outer element  
         [0041]    [0041] 24  conical inner envelope surface  
         [0042]    [0042] 26  inner element  
         [0043]    [0043] 27  slot  
         [0044]    [0044] 28  conical outer envelope surface  
         [0045]    [0045] 30  hole (inner element)  
         [0046]    [0046] 32  recess/hole (outer element)  
         [0047]    [0047] 34  screw hole (outer element)  
         [0048]    [0048] 36  steel ball  
         [0049]    [0049] 38  biasing means (bushing)  
         [0050]    [0050] 40  bearing  
         [0051]    [0051] 42  tightening means (hook-equipped screw)  
         [0052]    [0052] 44  bottom side (bearing)  
         [0053]    [0053] 46  hook  
         [0054]    [0054] 48  nut  
         [0055]    [0055] 50  hydraulic tensioning means