Abstract:
Disclosed herein is means for directly coupling a main motor shaft to a working machine with a coupling head as an intermediate component. The machine unit assembled according to the present invention does not require rechecking of dimensional deviations after completion of assembly. The present invention is applicable to both upright type and lateral type machine units.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the invention 
     The present invention relates to means for directly coupling a main motor shaft to a working machine, and more particularly, means for directly coupling the shaft of a main driving motor to that of a working machine on the same machine base. 
     2. Description of the Prior Art 
     FIG. 1 is a schematic view showing a conventional scheme of a main motor shaft directly coupled to a working machine wherein a main motor  91  drives a direct coupling shaft  93  by a shaft coupling  92 . As it is shown in FIG. 1, the main motor  91  is fixedly mounted on the headstock  95  of a working machine  94 . With such a layout, the geometrical accuracy of positional relation among the main motor  91 , direct coupling shaft  93 , and the headstock  95  of the working machine  94  has to rely on a worker&#39;s precision aligning skill. However, it requires a much labor and high production costs to attain the necessary assembly accuracy for the machine to work without too loud of a noise or severe vibration. Besides, there are other problems such as strenuous regular maintenance and expensive repair work. In order to palliate the above described existing shortcomings, the present inventor has delved into this matter for a long time, and after repeated efforts of research, simulations and experiments, finally has come to a realization of the present invention. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide means for directly coupling a main motor shaft to a working machine so that the previous shortcomings, such as relying on skilled workers for precision alignment, high production costs, and wasted labor time for assembly can be eliminated, therefore improving marketability. 
     It is another object of the present invention to provide means for directly coupling a main motor shaft to a working machine so that too loud machine noise and severe machine vibration can be alleviated. 
     To achieve the above mentioned objects, means for directly coupling a main motor shaft to a working machine according to the present invention comprises: employing a machine headstock having an installation cavity; a coupling head formed of a hollow body which can be sleeved into the installation cavity of the headstock along the outer edges of the hollow body; a spindle housing inserted into the coupling head along the head&#39;s inner edges; a main motor for supplying driving power; and a shaft coupling for coupling the main motor with a rotating shaft of the spindle housing such that the driving power of the main motor can be transmitted to the rotating shaft via the shaft coupling. For assembling the aforementioned components, such as the coupling head to the headstock, the spindle housing to the coupling head, the main motor to an main motor interconnecting plate, and the interconnecting plate to the coupling head, screw engagement is employed in all cases. Meanwhile, the above mentioned interconnecting plate is interposed between the coupling head and the main motor. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above objects and other advantages of the present invention will become more apparent by describing in detail the preferred embodiment of the present invention with reference to the attached drawings in which: 
     FIG. 1 is a schematic view showing a conventional scheme of a main motor shaft directly coupled to a working machine; 
     FIG. 2 is a longitudinal cross sectional view for illustrating means for directly coupling a main motor shaft to a working machine according to the present invention; 
     FIGS.  3 (A) and  3 (B) are view illustrating how the main motor shaft is coupled with the working machine according to the present invention; and 
     FIG. 4 is a cross sectional view of an assembled direct coupling main motor and working machine according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 2, a working machine  1 , a coupling head  2 , a spindle housing  3 , a main motor  4 , a shaft coupling  5 (see FIG. 4 for detail) and a main motor interconnecting plate  6  are assembled to form a directly coupled motor and working machine unit. Further to this, the working machine  1  includes a machine headstock  11  with an installation cavity  12 . The coupling head  2  is formed of a hollow body which can be sleeved into the installation cavity  12  of the headstock  11  along the outer edges  21  of the hollow body. The spindle housing  3  is inserted into the coupling head  2  along the inner edges of the coupling head  2 . The main motor  4  supplies driving power to the working machine  1 . The shaft coupling  5  is employed to couple a rotatable shaft  31  of the spindle housing  3  with a rotating shaft  41  of the main motor  4  such that the main motor  4  may drive the shaft  31  to rotate. The interconnecting plate  6  is interposed between the coupling head  2  and the main motor  4  and interconnects the above two components with screws  72  and  71  respectively. 
     Referring to FIGS. 2,  3 (A),  3 (B) and  4  simultaneously, the direct coupling motor and working machine unit is assembled by means of the present invention in the way that first, the shaft coupling  5  is provided as two parts, a main motor shaft side  51 , and a machine shaft side  52 . Then, the shaft coupling  5  is fixed appropriately in the accurate position after the main motor shaft side  51  has been mated to the rotating shaft  41  of the main motor  4 . On the other hand, the machine shaft side  52  is sleeved into the rotating shaft  31  of the spindle housing  3  and appropriately fixed thereat. Then, the bottom portion  23  of the coupling head  2  is sleeved into the machine shaft side  52  of the shaft coupling  5  to which the spindle housing  3  is attached. Then a gauge  8  is set on the rotating shaft  31  of the spindle housing  3  so as to check if the positional deviation of the coupling head  2  in its inner cavity  24  is allowable. When it is considered to be allowable, the spindle housing  3  is directly coupled to the coupling head  2  with screws  73 . After that, the coupling head  2  together with its screw engaged spindle housing  3  is inserted into the installation cavity  12  from the bottom portion  13  of the machine headstock  11  of the working machine  1  and engaged with the headstock  11  with screws  74 . Then, by applying a precision machining technique, the accuracy of parallelism is adjusted between two contact surface planes  61  (contacting the coupling head  2 ) and  62  (contacting the main motor  4 ) of the interconnecting plate  6  in a range within 2 um, and the clearance between the coupling head  2  and the main motor  4  is controlled, and the positional deviation of the inner cavity  24  of the coupling head  2  is controlled to a minor possible value. After that, the main motor  4  can be screwed onto the interconnecting plate  6  with screws  71 , and the interconnecting plate  6  can be screwed onto the coupling head  2  with screws  72 . The assembly quality of the main motor  4 , the interconnecting plate  6  and the coupling head  2  does not need to be rechecked before operation of the working machine  1 . Finally, the assembly work for the whole unit is completed by connecting the main motor shaft side  51  and the machine shaft side  52  of the shaft coupling  5 . Incidently, the present invention is applicable to both upright and lateral machines. 
     It is understood from the description of the above embodiment that the invention has several note worthy advantages, in particular: 
     1. The present invention provides means for directly coupling main motor shaft to a working machine without a need for skillful workers for precision alignment, requirement for high production cost, and wasting long time labor of assembly so as to improve marketability. 
     2. According to the present invention, excessive machine noise and severe machine vibration can be alleviated. 
     Although the invention has been described in terms of a preferred embodiment, it is apparent that numerous variations and modifications may be made without departing from the true spirit and scope thereof as set forth in the following claims.