Abstract:
A motor rotor and outer shell mounting structure for ceiling fan in which the outer shell has inner mounting blocks and outer recessed portions and through holes through the mounting blocks and the recessed portions, and the rotor has flanged top mounting posts and flanged bottom mounting posts respectively positioned on the mounting blocks and fixedly secured thereto by screws.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to ceiling fans, and more specifically, to a motor rotor and outer shell mounting structure for ceiling fan, which enables the rotor to be quickly and accurately positioned in the outer shell. 
     A regular ceiling fan motor, as shown in FIG. 1, is generally comprised of an outer shell C, a stator B, and a rotor A. The outer shell C is comprised of a top cover shell and a bottom cover shell. The top cover shell and bottom cover shell of the outer shell C are respectively formed of a metal sheet by stamping. The rotor A is mounted in the outer shell C and fixedly fastened to respective mounting holes C 3  of the outer shell C by tie screws D. The stator B is mounted in the stator A inside the outer shell C with its center shaft extended out of the top and bottom center axle hole C 1  of the outer shell C. The matching precision of the rotor A and the stator B is subject to the distance between the central axis of the center axle holes C 1  and the periphery C 2  of the outer shell C. In order to achieve high precision, the outer diameter A 1  and inner diameter A 2  of the rotor A must be properly trimmed by means of the application of a CNC (computer numerical control). This processing process takes much time, and greatly increases the manufacturing cost of the ceiling fan motor. Further, because the mounting holes C 3  are flat holes directly; cut in the outer shell C, the formation of the mounting holes C 3  weakens the structural strength of the outer shell C. When tightening up the tie screws D, the outer shell C may be forced to deform, affecting the precision of the positioning of the rotor A and stator B in the outer shell C. A impact may also causes the outer shell C to deform. 
     SUMMARY OF THE INVENTION 
     It is one object of the present invention to provide a motor rotor and outer shell mounting structure for ceiling fan, which eliminates the aforesaid drawbacks. According to one aspect of the present invention, the motor rotor and outer shell mounting structure for ceiling fan comprises an outer shell, a stator mounted in the outer shell, and a rotor mounted in the outer shell around the stator for synchronous rotation with the outer shell. The outer shell has inner mounting blocks and outer recessed portions and through holes through the mounting blocks and the recessed portions. The stator has a center shaft extended out of top center axle hole and bottom center axle hole of the outer shell. The rotor has flanged top mounting posts and flanged bottom mounting posts respectively positioned on the mounting blocks and fixedly secured thereto by screws. According to another aspect of the present invention, the flanged top mounting posts and flanged bottom mounting posts each have an axially extended positioning protrusion (flange), and the outer shell has positioning slots adapted to receive the positioning protrusion of each of the flanged top mounting posts and flanged bottom mounting posts for quick positioning of the rotor in the outer shell. According to another aspect of the present invention, the mounting blocks are formed with the recessed portions on the outer shell by stamping, and the formation of the mounting blocks and the recessed portions greatly reinforce the structural strength of the outer shell against deformation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded view of a motor rotor and outer shell mounting structure for ceiling fan according to the prior art. 
     FIG. 2 is an exploded view of a motor rotor and outer shell mounting structure for ceiling fan according to the present invention. 
     FIG. 3 is a sectional assembly view of the motor rotor and outer shell mounting structure for ceiling fan according to the present invention. 
     FIG. 4 is an elevational view of a motor rotor and outer shell mounting structure for ceiling fan according to a second embodiment of the present invention. 
     FIG. 5 is an elevational view of a motor rotor and outer shell mounting structure for ceiling fan according to a third embodiment of the present invention. 
     FIG. 6 is elevational view of a rotor for the motor rotor and outer shell mounting structure for ceiling fan according to the second embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 2, the invention comprises a rotor  1 , a stator  2 , and an outer shell  3 . The outer shell  3  is comprised of a top cover shell  31  and a bottom cover shell  32 . The top cover shell  31  and the bottom cover shell  32  are symmetrical, each comprising a center axle hole  30 , a plurality of recessed portions  33  formed in the outside wall at the border area and equiangularly spaced around the center axle hole  30 , a plurality of mounting blocks  34  protruded from the inside wall at the border area corresponding to the recessed portions  33 , a plurality of through holes  332  respectively disposed in the recessed portions  33  and extended through the mounting blocks  34 , and a plurality of positioning slots  331  extended through the outside and inside walls and respectively disposed adjacent to the mounting blocks  34  at an outer side. The stator  2  has a center shaft  21  protruding from the top and bottom sides thereof. The rotor  1  comprises symmetrical top mounting posts  11  and bottom mounting posts  11 ′ corresponding to the mounting blocks  34  of the shells  31 ; 32 . The mounting posts  11 ; 11 ′ each having an axially extended screw hole  12  and an axially extended positioning protrusion  13 . The mounting posts  11 ; 11 ′ can be made having a circular cross section (see FIG. 2) or arched cross section (see FIG.  6 ). 
     Referring to FIG.  3  and FIG. 2 again, during assembly, the rotor  1  is put in the top cover shell  31  (or bottom cover shell  32 ) to force the positioning protrusion  13  of each of the top mounting posts  11  (or bottom mounting posts  11 ′) into the positioning slots  331  of the top cover shell  31  (or bottom cover shell  32 ), keeping the top mounting posts  11  (or bottom mounting posts  11 ′) respectively stopped against the mounting blocks  34 , and then screws  333  are respectively inserted into the through holes  332  in the recessed portions  33  of the top cover shell  31  (or bottom cover shell  32 ) and threaded into the screw holes  12  of the top mounting posts  11  (or bottom mounting pots  11 ′) of the rotor  1  to fixedly secure the top cover shell  31  (or bottom cover shell  32 ) and the rotor  1  together, and then the stator  2  is put the rotor  1 , enabling one end of the center shaft  21  of the stator  2  to be extended out of the top cover shell  31  (or bottom cover shell  32 ) through the center axle hole  30  of top cover shell  31  (or bottom cover shell  32 ), and then the bottom cover shell  32  (or top cover shell  31 ) is closed on the top cover shell  31  (or bottom cover shell  32 ) to force the positioning protrusion  13  of each of the bottom mounting posts  11  (or top mounting posts  11 ) into the positioning slots  331  of the bottom cover shell  32  (or top cover shell  31 ), keeping the bottom mounting posts  11 ′ (or top mounting posts  1 ) respectively stopped against the respective mounting blocks  34 , and then screws  333  are respectively inserted into the through holes  332  in the recessed portions  33  of the bottom cover shell  32  (or bottom cover shell  31 ) and threaded into the screw holes  12  of the bottom mounting posts  11 ′ (or top mounting pots  11 ) of the rotor  1  to fixedly secure the bottom cover shell  32  (or top cover shell  31 ) and the rotor  1  together. The mounting blocks  34  are formed integral with the cover shell  31  or  32  upon formation of the recessed portions  33  by stamping. The formation of the mounting blocks  34  greatly reinforces the structural strength of the cover shell  31  or  32  against deformation. 
     FIG. 4 shows an alternate form of the present invention. According to this alternate form, the recessed portions  33  are elongated, smoothly arched grooves, and at least one through hole  332  is respectively formed in each of the recessed portions  33 . The formation of the elongated, smoothly arched recessed portions  33  reinforces the structural strength of the outer shell  3  against deformation. 
     FIG. 5 shows another alternate form of the present invention. According to this alternate form, the recessed portions  33  form an annular groove, the through holes  332  are equiangularly spaced in the annular groove formed of the recessed portions  33 , and the positioning slots  331  are disposed at an outer side in the annular groove formed of the recessed portions  33  adjacent to the through holes  332 . 
     A prototype of motor rotor and outer shell mounting structure for ceiling fan has been constructed with the features of FIGS.  2 ˜ 6 . The motor rotor and outer shell mounting structure functions smoothly to provide all of the features discussed earlier. 
     Although particular embodiments of the invention have been described in detail for purposes: of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.