Balancing plate for a motor

#1. Field of the Invention

#The present invention relates to a balancing plate for a motor. In particular, the present invention relates to a balancing plate having at least two induction edges, each induction edge having an arc length that mates with a length of one of plural poles of the annular permanent magnet on a rotor, thereby allowing stable rotation of the motor and allowing easy restarting of the motor by means of preventing the rotor from being locked by excessive magnetic attractive force between the respective induction edge and the permanent magnet.

#2. Description of the Related Art

#FIG. 1 is an exploded perspective view of a conventional motor with a conventional balancing plate.

#FIG. 2 is a plan view of the motor and the conventional balancing plate after assembly.

#FIG. 3 is an exploded perspective view of a motor with a balancing plate in accordance with the present invention.

#A preferred embodiment in accordance with the present invention will now be described with reference to the accompanying drawings.

#FIG. 3 is an exploded perspective view of a motor with a balancing plate in accordance with the present invention. FIG. 4 is a sectional view of the motor in FIG. 3. FIG. 5 is a sectional view taken along plane 5-5 in FIG. 4. The numerals in FIGS. 3 through 5 identical to those in FIGS. 1 and 2 denote identical elements in FIGS. 1 and 2, and detailed description of these elements is not given to avoid redundancy.

#Referring to FIG. 3, a balancing plate 50 in accordance with the present invention is generally assembled with a rotor 10, a stator 20, and a circuit board 40 along an axial direction to form a motor 1. The balancing plate 50 is made of magnetically conductive material and comprises an axial hole 51, a plurality of necks 52, two induction edges 53, and two grooves 54. The axial hole 51, the necks 52, the induction edges 53, and grooves 54 are located on a common plane. In particular, the induction edges 53 are located on a common plane such that the induction edges 53 have an identical distance to the annular permanent magnet 11 of the rotor 10. Thus, the force between the respective induction edge 53 and the annular permanent magnet 11 is the same. Each neck 52 extends from the axial hole 51 along a radial direction to the respective induction edge 53, leaving two grooves 54 for separating the induction edges 53. The induction edges 53 have identical arc length a′ that is preferably equal to a length b of one of plural poles of the annular permanent magnet 11 of the rotor 10, as illustrated in FIG. 5. Alternatively, the arc length a′ of the respective induction edge 53 is slightly smaller than length b of the respective pole of the annular permanent magnet 11.