| 摘要 |
PURPOSE:To avoid the resonance of a rotor by construction to satisfy the prescribed relation in the inner to outer diameter ratio and the thickness of the rotor, thereby suppressing the excessive vibration at the time of starting with the full voltage. CONSTITUTION:A rotor 2 made of a hysteresis magnetic material, a stator 3 made of a coil 3a and a core 3b is oppositely disposed via an ultrafine interval in the rotary axial direction. The inner to outer diameter ratio and the thickness of the rotor 3 are provided to satisfy the relation of 2f1<lambda<2>t/4pia<2>.[Eg/3 (1-nu<2>)r]<1/2>, lambda=-0.373+25(b/a)-63.6(b/a)<2>+59.5(b/a), where (a) represents the outer radius of the rotor, (b) inner radius of the rotor, (t) the thickness of the rotor, E the elastic modulus of the rotor material, nu poison ratio, (r) specific weight, (g) gravity acceleration, f1 power source frequency, lambda indefinite figure coefficient determined by the inner to outer radius ratio b/a and the boundary condition of the vibration mode. |
