Motor and assembly structure thereof

1 . A motor assembly structure comprising:

a stator,

a first end cap and a second end cap arranged on respective sides of the stator, and

at least one fastener fastening the stator, the first end cap, and the second end cap,

wherein:

the stator comprises:

a middle iron core,

a first side iron core disposed within the first end cap, and

a second side iron core disposed within the second end cap,

the first end cap has an inner edge with a first inner arc surface,

the first side iron core has an outer edge with a first outer arc surface in an interference fit with the first inner arc surface,

the second end cap has an inner edge with a second inner arc surface,

the second side iron core has an outer edge with a second outer arc surface in a clearance fit with the second inner arc surface, and

the fastener is disposed radially outward of the outer edges of the first and second side iron cores.

2 . The motor assembly structure according to claim 1 , wherein:

the first side iron core has a thickness h1,

the second side iron core has a thickness h3,

h1≥5 mm, and

h1≥h3.

3 . The motor assembly structure according to claim 2 , wherein:

the first inner arc surface has a depth L1 along an axial direction of the first inner arc surface, and

L1≥5 mm.

4 . The motor assembly structure according to claim 1 , wherein the middle iron core is polygonal.

5 . The motor assembly structure according to claim 4 , wherein:

a circle center of the first outer arc surface coincides with a center of the first side iron core, and

a circle center of the second outer arc surface coincides with a center of the second side iron core.

6 . The motor assembly structure according to claim 4 , wherein:

a distance between two sides of the first side iron core is a1,

the first outer arc surface has a diameter d1, and

(a1/cos 20°)≥d1>a1.

7 . The motor assembly structure according to claim 6 , wherein:

a distance between two sides of the second side iron core is a1, and

the second outer arc surface has a diameter d3.

8 . The motor assembly structure according to claim 6 , wherein a distance between two sides of the middle iron core is equal to a1.

9 . The motor assembly structure according to claim 1 , wherein:

the first end cap is provided with a plurality of first mounting holes,

the middle iron core is provided with a plurality of second mounting holes at respective corners of the middle iron core,

the second end cap is provided with a plurality of third mounting holes, and

the fastener comprises a plurality of fasteners extending through the first mounting holes, the second mounting holes, and the third mounting holes.

10 . The motor assembly structure according to claim 9 , wherein:

the first end cap is provided with a first flange abutting a surface of the middle iron core,

the first flange extends outward from an end portion of the first inner arc surface at an angle to the first inner arc surface,

the second end cap is provided with a second flange abutting a surface of the middle iron core,

the second flange extends outward from an end portion of the second inner arc surface at an angle to the second inner arc surface,

the first mounting holes are formed in the first flange, and

the second mounting holes are formed in the second flange.

11 . The motor assembly structure according to claim 9 , wherein:

a diameter of a circle connecting the second mounting holes is D3;

a distance from a center of the circle connecting the second mounting holes to a center of the middle iron core is 0.5D3,

the first outer arc surface has a diameter d1, and

(D3−d1)≥18 mm.

12 . The motor assembly structure according to claim 9 , wherein:

a diameter of a circle connecting the second mounting holes is D3;

the middle iron core has a third outer arc surface at each corner of the middle iron core,

a circle center of the third outer arc surface coincides with a center of the middle iron core,

the third outer arc surface has a diameter d2,

the second mounting holes have a diameter D2,

a distance from a circle center of the second mounting holes to the center of the middle iron core is 0.5D3, and

d2−(D2+D3)≥2.2 mm.

13 . The motor assembly structure according to claim 9 , wherein;

a diameter of a circle connecting the second mounting holes is D3;

the middle iron core is provided with a chamfer at each corner of the middle iron core,

a distance between tangent lines of two chamfers at opposite corners of the middle iron core is d2,

the second mounting holes have a diameter D2,

a distance from a circle center of the second mounting holes to the center of the middle iron core is 0.5D3, and

d2−(D2+D3)≥2.2 mm.

14 . The motor assembly structure according to claim 10 , wherein:

the first inner arc surface has a depth L1 along an axial direction of the first inner arc surface,

the first inner arc surface has a diameter D4,

the first outer arc surface has a diameter d1, the first side iron core has a thickness h1,

D4=d1, and

L1−h1≥10 mm.

15 . The motor assembly structure according to claim 14 , wherein a joint between the first flange and the first inner arc surface is provided with a rounded chamfer having a radius less than 2 mm.

16 . The motor assembly structure according to claim 10 , wherein:

the second inner arc surface has a depth L2 along an axial direction of the second inner arc surface,

the second inner arc surface has a diameter D5,

the second outer arc surface has a diameter d3,

the second side iron core has a thickness h3,

D5=d3, and

L2−h3≥10 mm.

17 . The motor assembly structure according to claim 16 , wherein a transition between the second flange and the second inner arc surface includes a chamfer having an axial depth less than or equal to 1 mm.

18 . The motor assembly structure according to claim 1 , wherein:

the first end cap is provided with a first bearing chamber at a side of the first end cap away from the stator,

the second end cap is provided with a second bearing chamber at a side of the second end cap away from the stator, and

the first bearing chamber, the second bearing chamber, and an inner circular surface of the stator are coaxially arranged.

19 . A motor comprising:

the motor assembly structure according to claim 1 ,

a rotor, and

a first bearing and a second bearing arranged at respective ends of the rotor,

wherein the first bearing is arranged in the first end cap and the second bearing is arranged in the second end cap.

20 . A motor assembly structure comprising:

a stator,

a first end cap and a second end cap arranged on respective sides of the stator, and

at least one fastener fastening the stator, the first end cap, and the second end cap,

wherein:

the stator comprises:

a middle iron core,

a first side iron core disposed within the first end cap, and

a second side iron core disposed within the second end cap,

the first end cap has an inner edge with a first inner arc surface and an end portion extending radially outward of the first inner arc surface to form a first flange,

the first side iron core has an outer edge with a first outer arc surface in an interference fit with the first inner arc surface,

the second end cap has an inner edge with a second inner arc surface and an end portion extending radially outward of the second inner arc surface to form a second flange,

the second side iron core has an outer edge with a second outer arc surface in a clearance fit with the second inner arc surface,

the fastener is disposed radially outward of the outer edges of the first and second side iron cores when fastening the stator, first end cap and second end cap, and

the fastener extends through the first and second flanges and the middle iron core.