Patent ID: 11881749
Assignee: MITSUBISHI ELECTRIC CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A synchronous reluctance motor comprising:
an annular stator core having S slots arranged at equal intervals along an inner circumferential surface thereof;
a winding stored in each of the slots; and
a cylindrical rotor core provided on an inner surface side of the stator core and having P magnetic poles, the rotor core having, for each magnetic pole, a plurality of slits formed by arc-shaped openings which are convex toward a cylinder center and whose apexes are positioned on a q axis, as seen in a center axis direction of the cylinder, wherein
an angle θ formed with respect to the cylinder center by circumferential-direction midpoints of short-side-direction arcs along an outer circumferential surface of the rotor core, of the openings of the adjacent slits, is the same among the respective adjacent slits,
an angle formed with respect to the cylinder center by a d axis and the midpoint of the slit closest to the d axis is θ/2,
where
a number of the plurality of slits provided in one pole of the rotor core is denoted by bmax,
of the plurality of slits, the slit closest to the outer circumferential surface of the rotor core is defined as a first slit,
with b and n defined as integers not less than 1, at a bth slit from the outer circumferential surface of the rotor core toward the cylinder center, an inner edge close to the cylinder center, of the opening forming the bth slit is defined as a (n=2b)th arc, and an outer edge opposed to the inner edge, of the opening forming the bth slit is defined as a (n=2b−1)th arc, and
an arc of an inner edge of a bmaxth slit closest to the cylinder center is defined as an nmaxth arc,

the nth arc has an arc center point on the q axis at a distance D(n) from the outer circumferential surface of the rotor core,
where a radius of the nth arc with respect to the arc center point is denoted by R(n),
a ratio k(n) between the distance D(n) and the radius R(n) is defined as k(n)=D(n)/R(n), and
the ratios k(1) to k(n) respectively corresponding to the first to nth arcs are determined such that
a ratio k(nmax) for the nmaxth arc is in a range of 0.20≤k(nmax)≤0.37,
the ratio k(n) for the nth arc satisfies a relationship of k(nmax)< . . . <k(n)< . . . <k(1)<1, and
in a graph with the integer n set on a horizontal axis and the ratio k(n) set on a vertical axis, a slope a when plotted points of values of the ratios k(1) to k(nmax) are linearly approximated is in a range of (−0.92/nmax)≤a≤(−0.71/nmax).