| 摘要 |
PURPOSE:To smooth rotation of a rotor to a case. CONSTITUTION:A rotor 1 is installed on the opening surface of a case 2 whose one end surface is opened so as to be rotatable freely. A center shaft 5 arranged protrusively on the bottom surface of the case 2 is inserted in a recessed part 6 formed with the rotor 1 as its center, and an annular projecting part 4 formed on the outer periphery of the rotor 1 is inserted in an annular recessed part 3 formed on the inner periphery of the case 2. An inside diameter of the recessed part 6 is approximately equal to an outside diameter of the center shaft 5, and an outside diameter of the anuular projecting part 4 is slightly smaller than an inside diameter of the annular recessed part 3. Rotational friction between the rotor 1 and the case 2 due to fitting of the center shaft 5 and the recessed part 6 is caused small since the rotary shaft diameter is small, and since center deflection of the rotor 1 due to adjusted fitting of the center shaft 5 and the recessed part 6 is hardly caused, rotational friction between the outer peripheral surface of the annular projecting part 4 having a large rotary shaft diameter and the inner peripheral surface of the annular recessed part 3 is not caused substantially. |
