| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotor assembly and an inner-rotor motor which can be assembled accurately, easily and at a low cost, can prevent ferromagnetic particles produced from a permanent magnet and external contaminants from penetrating into air gaps in an assembly work and in an operation and can achieve the high rotation precision and the dimensional reduction. SOLUTION: A rotor 2 comprising a rotor shaft 10 supported by bearings 16 and 18 and rotating a rotary medium mechanically and a permanent magnet 14 formed coaxially on the rotor shaft 10 is provided in a protective cylinder unit 20 comprising receptacles 32 and 42 receiving the bearings 16 and 18 airtightly and a sleeve 30 formed between the receptacles 32 and 42 to form a rotor assembly 1. The rotor assembly 1 is inserted into the center hole of a laminated core 52 of a stator 51 without a circumferential play and fixed to construct an inner-rotor motor. |
