Motor

1 . A motor comprising:

a stator; and

a rotor surrounded in a circumferential direction of the rotor by the stator, wherein the rotor includes:

a sleeve including an axial hole extending in a first direction,

a plurality of rotor cores spaced apart from each other around the sleeve in the circumferential direction of the rotor,

a plurality of permanent magnets respectively arranged, between each two adjacent rotor cores of the plurality of rotor cores,

a plurality of bridges respectively corresponding to the plurality of rotor cores, wherein each bridge of the plurality of bridges is between the sleeve and a corresponding rotor core of the plurality of rotor cores,

each hole of a plurality of holes respectively corresponding to each bridge of the plurality of bridges, wherein each hole of the plurality of holes extends through a corresponding bridge of the plurality of bridges such that a connection between a first end portion and a second end portion of the corresponding bridge is blocked by each hole, and

a molding unit disposed between the sleeve and the plurality of rotor cores, wherein the molding unit connects the sleeve to the plurality of permanent magnets and the plurality of rotor cores.

2 . The motor of claim 1 , wherein

the plurality of rotor cores, the sleeve, and the plurality of bridges extend to have a certain thickness in the first direction, and

each hole of the plurality of holes extends in the first direction through the corresponding bridge of the plurality of bridges.

3 . The motor of claim 2 , further comprising one or more balance members extending in the first direction and disposed in one or more holes of the plurality of holes.

4 . The motor of claim 3 , wherein the one or more balance members includes at least two balance members and each balance member of the at least two balance members has a length extended in the first direction which is equal or different from each other.

5 . The motor of claim 3 , wherein each balance member of the one or more balance members includes an insulating material.

6 . The motor of claim 1 , wherein

the plurality of rotor cores extend to have a certain thickness in the first direction,

a first sleeve is arranged at upper end portions of the plurality of rotor cores and a second sleeve is arranged at lower end portions of the plurality of rotor cores,

a plurality of first bridges are arranged between the upper end portions of the plurality of rotor cores and the first sleeve,

a plurality of second bridges are arranged between the lower end portions of the plurality of rotor cores and the second sleeve,

a plurality of first holes respectively corresponding to the plurality of first bridges, wherein each hole of the plurality of first holes extends through the corresponding bridge of the plurality of first bridges, and

a plurality of second holes corresponding to the plurality of second bridges, wherein each hole of the plurality of second holes extends through the corresponding bridge of the plurality of second bridges.

7 . The motor of claim 6 , wherein

the molding unit is between the plurality of first bridges and the plurality of second bridges arranged to be spaced apart from each other in the first direction,

each first hole of the plurality of first holes extends through a corresponding first bridge of the plurality of first bridges to the molding unit so as to have a first depth in the first direction, and

each second hole of the plurality of second holes extends through a corresponding second bridge of the plurality of second bridges to the molding unit so as to have a second depth in the first direction.

8 . The motor of claim 7 , wherein

depths of two or more first holes of the plurality of first holes are equal or different from each other, and

depths of two or more second holes of the plurality of second holes are equal or different from each other.

9 . The motor of claim 6 , wherein the molding unit includes an insulating material.

10 . A motor comprising:

a stator; and

a rotor surrounded in a circumferential direction of the rotor by the stator, wherein the rotor includes:

a sleeve including an axial hole extending in a first direction,

a plurality of rotor cores spaced apart in the circumferential direction of the rotor,

a plurality of permanent magnets respectively arranged, between each two adjacent rotor cores of the plurality of rotor cores,

a plurality of first bridges respectively corresponding to the plurality of rotor cores, wherein each first bridge of the plurality of first bridges is between the sleeve and a corresponding rotor core of the plurality of rotor cores,

each hole of a plurality of first holes respectively corresponding to each first bridge of the plurality of first bridges, wherein each first hole of the plurality of first holes extends through a corresponding first bridge of the plurality of first bridges such that a connection between a first end portion and a second end portion of the corresponding first bridge is blocked by each first hole,

a plurality of second bridges between each two adjacent rotor cores of the plurality of rotor cores,

each hole of a plurality of second holes respectively corresponding to each second bridge the plurality of second bridges, wherein each second hole of the plurality of second holes extends through a corresponding second bridge of the plurality of second bridges such that a connection between the first end portion and the second end portion of the corresponding second bridge is blocked by each second hole.

11 . The motor of claim 10 , wherein

the plurality of rotor cores and the plurality of second bridges extend to have a certain thickness in the first direction, and

each second hole of the plurality of second holes extends in the first direction through the corresponding second bridge of the plurality of second bridges.

12 . The motor of claim 11 , further comprising one or more balance members extending in the first direction and in one or more second holes of the plurality of second holes.

13 . The motor of claim 12 , wherein the one or more balance members includes at least two balance members and each balance member of the at least two balance members have a length extended in the first direction which is equal or different from each other.

14 . The motor of claim 10 , wherein

the plurality of rotor cores extend to have a certain thickness in the first direction,

a plurality of upper bridges is among the plurality of first bridges and the plurality of upper bridges are arranged between upper end portions of the plurality of rotor cores in the first direction,

a plurality of lower bridges is among the plurality of first bridges and the plurality of lower bridges are arranged between lower end portions of the plurality of rotor cores in the first direction,

a plurality of upper holes is among the plurality of first holes and each upper hole of the plurality of upper holes respectively corresponds to each upper bridge of the plurality of upper bridges, wherein each upper hole of the plurality of upper holes extends through a corresponding upper bridge of the plurality of upper bridges, and

a plurality of lower holes is among the plurality of first holes and each lower hole of the plurality of lower holes respectively corresponds to each lower bridge of the plurality of lower bridges, wherein each lower hole of the plurality of lower holes extends through a corresponding lower bridge of the plurality of lower bridges.

15 . The motor of claim 14 , further comprising:

a molding unit,

wherein the plurality of upper bridges and the plurality of lower bridges are spaced apart from each other in the first direction,

the molding unit is between the plurality of upper bridges and the plurality of lower bridges,

each upper hole of the plurality of upper holes extends through each corresponding upper bridge of the plurality of upper bridges to the molding unit so as to have a first depth in the first direction, and

each lower hole of the plurality of lower holes extends through each corresponding lower bridge of the plurality of lower bridges to the molding unit so as to have a second depth in the first direction.