Bearing device and swing arm assembly for magnetic disk

A bearing device comprising:

• a shaft having an axis;
• plural rolling bearings arranged at axially separated positions and rotatably supporting the shaft;
• a first cylindrical member for supporting the rolling bearings on an inner surface thereof and having a first screw formed on an outer surface thereof;
• a second cylindrical member having a second screw formed on an inner surface thereof and mounted to the outer surface of the first cylindrical member by engagement of the first screw with the second screw;
• and
• a restricting member provided on the outer surface of the first cylindrical member for preventing relative axial movement of the second cylindrical member with respect to the first cylindrical member when a portion of the second cylindrical member contacts the restricting member, wherein
• the first cylindrical member and the second cylindrical member form a sleeve assembly, and the sleeve assembly is supported by the plural rolling bearings and is relatively rotatable with respect to the shaft,
• the second cylindrical member is composed of one member,
• the restricting member of the first cylindrical member is a flange provided at one end side of the outer surface of the first cylindrical member,
• the first screw of the first cylindrical member is formed at another end side of the outer surface of the first cylindrical member,
• the portion of the second cylindrical member is an end surface of one end side of the second cylindrical member, and
• when a tightening torque is increased and the second cylindrical member is strongly tightened to the first cylindrical member, the end surface of one end side of the second cylindrical member presses the flange of the one end side of the first cylindrical member toward a direction directed from the another end side to the one end side of the first cylindrical member.

A bearing device comprising:

• a shaft having an axis;
• plural rolling bearings arranged at axially separated positions and rotatably supporting the shaft;
• a first cylindrical member for supporting the rolling bearings on an inner surface thereof and having a first screw formed on an outer surface thereof;
• a second cylindrical member having a second screw formed on an inner surface thereof and mounted to the outer surface of the first cylindrical member by engagement of the first screw with the second screw;
• a restricting member provided on the outer surface of the first cylindrical member for preventing relative axial movement of the second cylindrical member with respect to the first cylindrical member when an end surface of one end side of the second cylindrical member contacts the restricting member;
• and
• a slit provided at an end surface of another end side of the second cylindrical member, wherein
• the first cylindrical member and the second cylindrical member form a sleeve assembly, and the sleeve assembly is supported by the plural rolling bearings and is relatively rotatable with respect to the shaft, and
• the slit of the second cylindrical member is adapted to receive an end portion of a torque driver, such that a tightening torque of the second cylindrical member with respect to the first cylindrical member can be adjusted by the torque driver to thereby adjust a resonance frequency of the bearing device.