A motor driver circuit includes: an error detection amplifier configured to receive a current feedback signal indicating a drive current of a motor as an object to be driven and an analog command signal indicating a target amount of the drive current, and generate an analog error signal indicating an error between the drive current and the target amount of the drive current; an A/D converter configured to convert the analog error signal generated by the error detection amplifier into a digital error signal; a digital compensator configured to generate a digital control amount based on the digital error signal output by the A/D converter; a D/A converter configured to convert the digital control amount into an analog control signal; and an output stage configured to supply a drive signal according to the analog control signal to the motor.

A vector production system is provided. The system comprises recombinant cells designed to encode at least a first recombinase under the control of an inducible promoter and the cells include an expression vector encoding a nucleic acid of interest within the regulatory elements of the expression vector which are flanked on either side by a target sequence for at least the first recombinase. The vector production system provides an efficient one-step process for producing linear or circular covalently closed vectors that incorporate a nucleic acid sequence of interest.

A fluid-dynamic bearing system comprising a stationary bearing component (12, 16, 18) and a bearing component (14, 14a) rotatable about a rotation axis, wherein, during operation of the bearing, the stationary and rotary components are separated from each other by a bearing gap (20) filled with a bearing fluid, wherein at least one fluid-dynamic radial bearing (22, 24) and at least one fluid-dynamic thrust bearing (28) or, alternatively, at least one conical fluid-dynamic bearing are arranged along the bearing gap (20), and wherein the bearing gap (20) comprises first and second open ends sealed by a first sealing gap (34) and a second sealing gap (36). The second sealing gap (36) exclusively extends normal to the rotation axis (40).

A spindle motor has a base plate, a stator core fixed to the base plate, a rotor member rotatable with respect to the base plate, a rotor magnet facing the stator core in a radial direction and fixed to the rotor member and a ring-shaped magnetic attractive plate attached to the base plate bottom surface facing the rotor magnet in an axial direction to generate a magnetic attracting force between the rotor magnet and the magnetic attractive plate. A ring-shaped wall surface is on the base plate bottom surface. At least one of an outer and inner circumference of the ring-shaped magnetic attractive plate has a polygonal shape formed of linear parts and corner parts. In a state in which at least one of the outer and inner circumferences having the polygonal shape contacts the ring-shaped wall surface, the ring-shaped magnetic attractive plate is adhesively fixed to the base plate.

A cup portion of a base member includes a cylindrical portion and a bottom plate portion. The cylindrical portion is arranged to be coaxial or substantially coaxial with a central axis extending in a vertical direction. The bottom plate portion is defined integrally with the cylindrical portion, and is arranged to close a lower portion of the cylindrical portion. A bearing mechanism is arranged inside of the cup portion. An outer circumferential surface of the bearing mechanism and an inner circumferential surface of the cylindrical portion have an adhesive layer arranged therebetween. In one preferred embodiment of the present invention, a communicating hole passing through the cylindrical portion in a direction that crosses an axial direction is defined in the vicinity of a junction of the cylindrical portion and the bottom plate portion. In another preferred embodiment of the present invention, the base member includes a communicating hole passing through the bottom plate portion in the axial direction.

A sintered metal bearing is formed through sintering of a compact obtained through compression molding of raw-material powder. The sintered metal bearing includes chamfered portions that are respectively formed at least along outer rims of both end surfaces of the sintered metal bearing, and a dynamic pressure generating portion formed on an inner peripheral surface of the sintered metal bearing by sizing. An axial dimension of each of the chamfered portions is set larger than a radial dimension of the each of the chamfered portions, and a difference in axial dimension between the chamfered portions on one end side and another end side in an axial direction of the sintered metal bearing is set larger than a difference in radial dimension between the chamfered portions on the one end side and the another end side in the axial direction.

Embodiments disclosed herein generally relate to magnetic recording systems having a spindle motor and, more particularly, to an optimized lubricant for bearings within the spindle motor. A lubricant used in a fluid dynamic bearing motor has an antioxidant additive and a charge control agent dissolved in a diester base oil. The charge control agent is chemically attached to the same diacid reactant used in the diester lubricant base oil, and is prepared through an esterification reaction. The charge control agent is then dissolved in the lubricant base oil. The charge control agent is soluble in the lubricant, and is resistant to free radical oxidation. The charge control agent effectively controls the charge of the lubricant by creating electron donor/acceptor sites in the lubricant, facilitating an independent electronic pathway through the lubricant.

According to one embodiment, a disk device includes a magnetic disk and a rotary unit. The magnetic disk is rotatable about a first rotation axis extending in the first direction. The rotary unit includes a rotary member, a bearing, and a first filter. The bearing contains a lubricant and rotatably supports the rotary member about a second rotation axis. The first filter captures at least one component contained in the lubricant. The rotary member is provided with a hole and a first communication port. The hole extends along the second rotation axis to accommodate the bearing. The first communication port extends in a direction intersecting the second rotation axis to allow the hole to be in communication with an outside of the rotary member. The first filter is disposed in the first communication port or covers the first communication port.

A motor includes a shaft, a base portion, a stator, and a rotor. The shaft extends along a central axis extending in an axial direction. The base portion extends in a radial direction on one axial direction side of the shaft. The stator is located in another axial direction with respect to the base portion and surrounds the shaft. The rotor is rotatable around the central axis. The rotor includes a rotor tube portion, a magnet, and a rotor flange portion. The rotor tube portion surrounds the stator. The magnet is opposed to the stator in the radial direction. The rotor flange portion extends in a radially outer direction from one axial end portion of the rotor tube portion. The rotor tube portion includes a yoke tube portion and a hub tube portion. The yoke tube portion is located on a radially inside surface of the hub tube portion.

A vector production system is provided. The system comprises recombinant cells designed to encode at least a first recombinase under the control of an inducible promoter and the cells include an expression vector encoding a nucleic acid of interest within the regulatory elements of the expression vector which are flanked on either side by a target sequence for at least the first recombinase. The vector production system provides an efficient one-step process for producing linear or circular covalently closed vectors that incorporate a nucleic acid sequence of interest.