A bearing design for a rotatable assembly includes two freely rotating balls mounted on the axis of rotation of the assembly and axially separated, one near each axial end of the assembly. Each ball is confined by a moving concave (preferably conical or frustro-conical) bearing surface of the rotatable assembly and a corresponding fixed concave bearing surface of a mounting attached to a frame, housing, or similar non-rotating structure. One of the fixed mountings is preferably attached to a compressible spring to provide a controlled axial pre-load to the assembly. The balls are substantially enclosed and lubricant provided in the enclosed cavity. In the preferred embodiment, the rotatable assembly is a rotary actuator assembly of a disk drive. Compared to conventional ball bearing designs, the present design reduces the number of parts and volume of space occupied by the bearings, reduces hysteresis, and improves shock resistance.
In the motor assembly of a pump in which a magnetic rotor is balanced on a spherical bearing projecting into an axial cavity of said rotor assembly, the bearing surface inside the cavity is shaped and dimensioned to stabilize the rotor assembly in the presence of diverging magnetic forces generated by the permanent magnets forming the core of the rotor.
A small electric motor has a rotor with a permanent magnet and a shaft having a first end provided with a depression. Axial and radial bearings support the shaft. A bushing receives the first end of the shaft. The axial bearing has a non-magnetic ball positioned in the depression. A side of the ball remote from the shaft runs against a running surface of the bushing. The shaft is magnetically loaded toward the running surface so that the ball is forced against the running surface. The shaft is ferromagnetic and part of a magnetic circuit of the permanent magnet. The ball forms an air gap at the first shaft end. An end face of the shaft facing the air gap forms a magnetic pole that attracts magnetic particles in the area of the axial bearing and keeps them away from the running surface to counteract destruction of running surface and ball.
Disclosed is a brushless vibration motor having a driving circuit therein, which is capable of operating like a typical DC motor. The brushless vibration motor having an eccentric rotor R having an eccentric weight 5b, a rotor case 5 and a magnet 6 which has a plurality of magnetic poles arranged in the rotor case; a shaft 2 for supporting the eccentric rotor, a housing H for supporting the shaft, a stator S which is disposed around the shaft on a stator base 1 constructing a part of the housing and which consists of armature coils to drive the rotor, and a driving circuit member lC which is mounted in a space K corresponding to an area of at least one armature coil.
A device for rotating inside of a disk player and/or recorder a disk shaped data carrier which takes into account that the rotating disk may be eccentered from an imposed rotation axis. A side moving apparatus allows the rotating disk and a fixing device to which the disk is removably fixed, to move inside the player and/or recorder in a rotation plane substantially perpendicular to an axis of rotation of the fixing device. The rotating disk and the fixing device go into a gyroscopic movement inside the player. A plurality of examples to realize the invention are described.
