Abstract: A motor for driving a magnetic disk in which the rotational center of the magnetic disk is a fixed shaft. The motor has a frame, a shaft formed integral with the frame, an armature, a bearing provided on the shaft, a hub to which a magnetic disk is securable, a magnetic sealing material arranged in the vicinity of the bearing and a magnetic material opposed to the sealing material. A magnetic seal is arranged between the magnetic sealing mateial and the magnetic material. The frame, the shaft, the hub and the magnetic disk are formed of aluminum, so that changes in temperature will not adversely affect motor performance due to the differences in thermal expansion of these motor parts. The magnetic material is in the form of a sleeve which enables the motor to be magnetically sealed and prevents foreign matter in the motor from reaching the magnetic disk.

Abstract: A brushless motor is disclosed, in which an armature core is secured to a frame through vibration isolating members by a clamping member having an interval regulator regulating so that the vibration isolating members are held within a regulated thickness determined by the interval regulator.