| 摘要 |
<p>A brushless motor comprises: a rotor (R) with 2n (n=1,2,3,...) uniformly spaced apart permanent magnets (M); a stator (ST) separated from the rotor (R) by an air gap (T) of width (w) having a plurality of slots (C) separated by intervals of uniform size (p); in which, in order to reduce the cogging torque, the permanent magnets (M) are spaced apart and shaped such that f(x) defines a function representing the density of magnetic energy stored in the air gap (T), x being a linear co-ordinate taken along the air gap and f(x), in correspondence with the magnets (M), having a substantially constant development with a value equal to 2f0, the function f(x) satisfying the following conditions: f(x) is substantially constant for at least one value of x in an interval between two magnets (M); (x1, x2) being two points in which f(x)=f0, substantially close to any two ends of the magnets (M) when one of the two points (x1, x2) is in correspondence with one of the slots (C) and also the other of the two points (x1, x2) is in correspondence with one of the slots (C). <IMAGE></p> |
