A rotor for a permanent magnet motor, including a rotor body having a cylindrical surface having a circumference. A plurality of magnets are disposed on the cylindrical surface at spaced intervals at the circumference, each of the magnets having a base disposed on the cylindrical surface and a top oriented radially away from the base, a sloping front side and a sloping rear side defining with the base and top an isosceles trapezoid shape in a cross sectional plane normal to an axis of rotation of the rotor, the isosceles trapezoid shape being broader at the base. A plurality of magnet retainers, each magnet retainer disposed between a neighboring pair of the plurality of magnets, include angled faces that engage respective front and rear sides of adjacent pairs of the plurality of magnets.