Abstract:
A method is proposed for forming a toothing ( 7 ) and/or a profile ( 5 ) onto a shaft ( 3 ). This is distinguished by the following step:  
     forming the toothing ( 7 ) and/or the profile ( 5 ) onto the shaft ( 3 ) mounted in a unit ( 1 ).

Description:
FIELD OF THE INVENTION  
         [0001]    The invention relates to a method for forming toothings and profiles according to the preamble of claim 1 and also to a unit according to the preamble of claim 54.  
         BACKGROUND OF THE INVENTION  
         [0002]    Methods and units of the kind mentioned here are known. It is conceivable to use prepared shafts which are already provided with toothings and/or profiles. These are then directly mounted in the unit, particularly electric motors and gearboxes. A certain logistic expense in production is necessary for this purpose, and once manufactured, motors are only usable for a given range of use, according to the processed shaft. Also, such shafts are often expensive, particularly when manufactured in small numbers. In order to use scale effects of mass production suppliers, attempts were also made to supply these with shafts made cost-efficiently by mass production. It has been found that here also there is a certain logistic expense, particularly when the mass production suppliers are established in far distant production locations. Thus this manner of proceeding is only rational with large numbers of items. It is also conceivable to dismantle cost-favorable units, particularly electric motors, to provide them with a correspondingly prepared shaft, and then assemble them again. Here it is a problem that just those units produced by mass production are often poorly suitable for dismantling and subsequent reassembly. Thus the retrofitting cost can easily exceed the price of the unit itself, which means a high total cost. In order to further reduce this total cost, formed parts and/or profiles as separate parts are pressed or shrunk onto shafts of units. This of course means an increase in weight and an increase of the constructional space and also leads to bad tolerances, which can lead to running errors.  
         BRIEF SUMMARY OF THE INVENTION  
         [0003]    The object of the invention is therefore to provide a method and a unit of the kind mentioned at the beginning, which avoids these disadvantages.  
           [0004]    A method having the features given in claim 1 is proposed in order to attain this object. It is distinguished in that toothings and/or a profile are formed onto a shaft mounted in a unit, particularly a motor and/or gearbox. The mounting of the shaft in the unit can be used for fixing this in the forming process. It is also possible to form profiles and/or toothings of the highest accuracy onto the shaft. Furthermore, this makes it possible, at a low total cost, to provide the shafts with profiles and/or toothings of smaller dimensions and lower weight.  
           [0005]    In a particularly preferred embodiment of the method, the profile and/or toothings are formed on commercial units, particularly units manufactured by mass production. Thus with high requirements on the running accuracy with small constructional space of the formed profiles and/or toothings, a particularly low total expense can be attained.  
           [0006]    Further advantages will become apparent from the remaining dependent claims.  
           [0007]    In order to attain the basic object of the invention, a unit, particularly an electric motor or a gearbox, is proposed which has the features stated in claim 54. This is distinguished by a shaft onto which a profile and/or a toothing was applied in the mounted state. This makes it possible to implement very good running on the profile and/or the toothings with a small constructional space. Also, high gear ratios and good efficiencies can hereby be attained. Furthermore, the production of the unit can take place very cost-effectively. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    Details are given hereinbelow of the method of forming toothings and profiles on shafts. Reference is made to the Figure for this purpose. 
     
    
       [0009]    The toothing  7  and/or the profile  5  are directly formed on the shaft  3  mounted in the unit  1 .  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0010]    The invention is explained in detail hereinafter with reference to the accompanying drawing. The single Figure shows a portion of a unit  1  with a shaft  3 .  
         [0011]    The shaft  3  has a profile  5 , in the form of a conical region, and a toothing  7  in the form of a two-start screw. This corresponds to an extreme oblique toothing. The toothing  7  thus intersects all the generatrices of the shaft  3  at the same angle, the toothing angle. The shaft  3  is continued in a housing  9 , which is only partially shown here. The profile  5  and the toothing  7  were fixed to the shaft  3  in the mounted state.  
         [0012]    The toothing  7  can mesh with other gear wheels, particularly skew toothed gearwheels, and drive these or be driven by these.  
         [0013]    The unit  1  can be a gearbox or a motor, particularly a commercial electric motor running at high speed and made by mass production.  
         [0014]    For this purpose, the unit  1 , particularly the motor and/or the gearbox, can be fixed. Provided that the shaft  3  projects sufficiently far from the unit  1 , it is also possible to fix the shaft  3  directly. The toothing  7  and/or the profile  5  are formed on the thus directly or indirectly fixed shaft  3  by deformation and/or electrochemical processing and/or cutting methods. Specifically, the deformation can take place by stamping, pressing, rolling, grinding, flat grinding, milling, flat milling, lasering, gear shaping, hob peeling, roll honing, gear shaving, gear hobbing, bevel gear cutting by reciprocating tools, gear grinding, profile slotting, profile grinding, eccentric grinding, end-milling, high speed milling, rasping, broaching, water jet cutting, water jet milling, slide drawing, die forming, longitudinal rolling with press rollers, transverse rolling with press rollers, transverse rolling with rolling rods, transverse rolling with outer rollers/end wheels, transverse rolling with inner-toothed front jaws, thread rolling, skew rolling with disk rollers, roll jaw rolling (also known as outer rolling), electro-erosion, electrochemical erosion pressing, electrochemical erosion, electrochemical removal, chemical removal, precise electrochemical machining (PEM), etching, laser beam removal, laser beam cutting, vortex methods, torsional broaching and/or rotary swaging (also known as form swaging).  
         [0015]    In a particularly preferred embodiment of the method, the toothing  7  is formed as skew toothing, particularly skew toothing with a large toothing angle, by rotary swaging and/or roll jaw rolling and/or end milling and/or high speed milling.  
         [0016]    In a particularly preferred embodiment of the method, in which the forming process takes place by rolling, the shaft  3  can be driven by a suitable device and/or by the roller used for the purpose. The formed profile  5  of the shaft  3  consists here of a conical region, and the toothing  7  consists of the double screw.  
         [0017]    After the forming process, which can take place in one or more steps, the fixation is released. For fixing the shaft  3  it is also conceivable to block the shaft  3  in the motor and/or gearbox. In this case, it is sufficient to fix the motor, and thus indirectly the shaft  3 .  
         [0018]    It is also possible for special methods of forming, to fix only the motor and/or the gearbox, so that the shaft  3  is rotatably mounted. In this embodiment of the method, the shaft  3  can thus be rotated during forming. Thereby even possible irregularities present on the shaft  3 , particularly irregularities of running, can be corrected. Thus existing profiles and toothings are particularly suitable for gear boxes which have to satisfy high requirements with respect to a high efficiency and a low noise development.  
         [0019]    Furthermore, the unit  1  can be fed toward a stationary device for forming the profile  5  and/or the toothing  7 . For this purpose, the part to be formed of the shaft  3  built into the unit  1  is fed past, and/or fed into, the device, whereby forming is performed.  
         [0020]    In a particularly preferred embodiment of the method, the unit  1  is a commercial component, particularly one which is mass-produced. Mass-produced units  1  can be produced favorably. Dismantling is often not provided for or can be performed only with difficulty. Thus by means of using the method, toothings  7  and profiles  5  of the highest accuracy can be formed on shafts of such units  1 , without expensive dismantling and subsequent assembly. The toothings  7  and profiles  5  can be used as the output shaft or drive shaft of the unit  1  for optional uses. Particularly advantageous is the use of the shaft  3  with formed-on toothing  7  as the output shaft of a motor, simultaneously serving as the drive shaft for a gearbox fitted to this.  
         [0021]    The method can be used in manufacture, in which like units  1  with differently toothed shafts  3  are required. Here it is particularly advantageous that the alternatives required because of the different shafts  3  are first produced shortly before building in of the unit  1 , reducing the logistics expense.  
         [0022]    It is also conceivable to form only a toothing  7 , and thus no profile  5 , onto the shaft  3 .  
         [0023]    It is also possible to form a single or multiple screw instead of the double screw.  
         [0024]    Finally a toothing  7  can also be formed on which runs in the axial direction, and thus parallel to the generatrices of the shaft  3 .