Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining causal models for controlling environments. One of the methods includes repeatedly selecting, by a control system for the environment, control settings for the environment based on internal parameters of the control system, wherein: at least some of the control settings for the environment are selected based on a causal model, and the internal parameters include a first set of internal parameters that define a number of previously received performance metric values that are used to generate the causal model for a particular controllable element; obtaining, for each selected control setting, a performance metric value; determining that generating the causal model for the particular controllable element would result in higher system performance; and adjusting, based on the determining, the first set of internal parameters.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining causal models for controlling environments. One of the methods includes identifying a procedural instance; determining a temporal extent for the procedural instance based on temporal extent parameters for the one or more entities in the procedural instance; selecting control settings for the procedural instance; monitoring environment responses to the control settings that are received for the one or more entities; determining which of the environment responses to attribute to the procedural instance in a causal model; and adjusting, based at least in part on the environment responses that are attributed to the procedural instance, the temporal extent parameters for the one or more entities.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining causal models for controlling environments. One of the methods includes repeatedly selecting control settings for the environment based on (i) a causal model that identifies causal relationships between possible settings for controllable elements in the environment and environment responses that reflect a performance of the control system in controlling the environment and (ii) current values of a set of internal parameters; and during the repeatedly selecting: monitoring environment responses to the selected control settings; determining, based on the environment responses, an indication that one or more properties of the environment have changed; and in response, modifying the current values of one or more of the internal parameters.

Abstract: The subject invention includes a coupling device for coupling a tooling arm to a robotic arm assembly. The coupling device includes a sensing mechanism which monitors relative distances within the coupling device in order to detect displacement in the coupling device. The coupling device also includes an adjustment method for setting the level of force required to execute a breakaway between the items being coupled, while providing a minimum magnetic holding force great enough to assure that robotic arm accelerations and de-accelerations can not cause the inertia or momentum to dislodge the tooling arm from the robotic arm assembly.

Abstract: The subject invention includes a coupling device for coupling a tooling arm to a robotic arm assembly. The coupling device includes a sensing mechanism which monitors relative distances within the coupling device in order to detect displacement in the coupling device. The coupling device also includes an adjustment method for setting the level of force required to execute a breakaway between the items being coupled, while providing a minimum magnetic holding force great enough to assure that robotic arm accelerations and de-accelerations can not cause the inertia or momentum to dislodge the tooling arm from the robotic arm assembly.

Abstract: A disk drive is usable in a chassis having first and second guide channels mounted on side surfaces of the chassis. The disk drive includes a head disk assembly that includes first and second side walls. The disk drive further includes first and second side rails and a securing system for securing the side rails to the side walls. The first and second side rails engage the first and second guide channels, respectively, for supporting the disk drive within the chassis. The securing system includes an engagement mechanism and a double-sided adhesive resilient mechanism. The engagement mechanism projects between the first and second side rails and the first and second side walls, respectively, of the head disk assembly.

Abstract: A spindle motor for a disk drive includes a shaft, a stator, a hub, an upper bearing, a lower bearing, means for defining a gap and an ionization source. The stator is concentrically positioned about the shaft. The upper and lower bearings rotatably maintain the hub relative to the shaft and each include a plurality of balls, each ball made from a high resistivity material. The ionization source ionizes air in the gap for allowing static electric charge to dissipate through a conductive path provided by the ionized air in the gap.

Abstract: A system for balancing devices having motors and rotating masses to be coupled to the motors utilizes a momentum transfer mechanism to shift the rotating mass based on sensed imbalance. In this manner the mass is shifted to a position which accounts for the inherent imbalance in both the motor and the mass. A controller receives imbalance information from a velocity sensor and controls a solenoid to strike a base coupled to the motor to shift a lightly clamped mass relative to the motor. In one embodiment, a disk drive has disks initially biased by the system against a hub, and then shifted during rotation to create a disk drive having concentrically aligned disks offsetting imbalance inherent in a motor used to rotate the disks. In one embodiment, the disks are held to the hub by a clamp having screws. The screws are driven simultaneously through the same angle of rotation to ensure that the axial clamping force of each one is substantially equal.

Abstract: A direct access storage device includes a base, a spindle and a hub supporting at least one data storage disk. The hub is mounted for rotation about the spindle by a motor having a bearing assembly. The device also preferably comprises an enclosure which contains the spindle and the hub. An annular member is secured to the hub and surrounds the spindle. The annular member has an upper and lower portion defined by a radial cavity which is open to the spindle. The lower portion is closer to the bearing assembly than the upper portion. The upper portion is exposed to ambient gas within the enclosure. Each of the upper and lower portions have an inside diameter surface facing the spindle with a gap therebetween. The upper portion has a vent hole in fluid communication with the radial cavity. The vent hole is positioned away from the end to the radial cavity to define a containment volume.

Abstract: A disk drive includes a disk, a magnetic transducer, and a rotary actuator arrangement for positioning the magnetic transducer over a selected area of the disk. The rotary actuator arrangement includes a head stack assembly including a body portion and a plastic arm having an arm surface, a first end and a distal end, with the first end being attached to the body portion. The head stack assembly further includes a load beam for supporting the transducer. The load beam has a plurality of mounting sites, an arm-facing surface, and a retention surface. The head stack assembly further includes a plurality of plastic binding structures that secure the load beam to the arm. Each plastic binding structure has a shaft portion projecting through a respective one of the mounting sites, has a bonding portion forming a homogeneous plastic bond with the arm surface, and has a retention portion abutting the retention surface; whereby the load beam is securely attached to the plastic arm.

Abstract: A spindle motor shaft having variable geometrical features for adjusting the torsion mode frequency of the shaft/stator assembly. The variable geometric features allow the torsion mode frequency to be tuned away from the driving force frequency of the motor. Variable geometrical features for the shaft may include circumferential grooves, radial slots cut through the shaft, or transverse holes disposed along the axis of the shaft. The radial slots have a longitudinal axis that is parallel to the axis of the shaft. Where circumferential grooves are used, the circumferential grooves may be designed to form a locator region along the shaft axis to promote axial alignment of the shaft and stator. Thermal track-misregistration (TMR) or screw torque problems are not introduced in the process of reducing or eliminating the acoustic problem thereby establishing a torsion mode frequency which is not subject to change due to temperature or time.

Abstract: A clamp ring for clamping disks to a rotating hub includes a inner diameter leg portion, a cross member portion and a disk contacting portion. A cross sectional view of the clamp ring is N-shaped. The clamp ring is heated so that it thermally expands to a diameter that is larger than the outer diameter of the hub. A thermally expanded clamp ring is placed on the top of the disk stack which has at least one disk. An axial load is placed on the inner diameter leg portion as the clamp ring cools. The inner diameter grips the hub as it cools. The cross member is compressed as the clamp ring cools. The disk contacting portion moves slightly as the clamp ring cools. This movement counteracts the outward movement of the disk contacting portion of the clamp during loading resulting in little tendency to cone the disk. The result is a disk stack clamped without a resulting radial load on the disks.

Abstract: A technique for joining a hub and a spindle of a disk drive is disclosed wherein the hub and spindle are joined by an interference fit. The interface between the hub and the spindle is provided with a surface contact pattern having a zone of contact extending about the spindle of the disk drive motor in the form of a circle or a very narrow height cylinder. Extending either unidirectionally or bidirectionally from the continuous zone of contact are zones of surface contact alternating with zones of relief which eliminate contact between the hub and the spindle. The continuous contact zone circumscribing the spindle of the drive motor insures that the hub is anchored relative to the spindle and anchors the hub to prevent tilting or cocking of the hub with respect to the spindle and spin axis of the spindle.

Abstract: A disk drive includes a cast base upon which is mounted the disk stack-spindle assembly and the actuator assembly and a cover that is loosely received by the cast base to form the head-disk enclosure. The cover is secured and sealed to the cast base by a malleable metal foil tape that surrounds the enclosure and continuously overlies the interface between cover and base. The tape complies with the surface irregularities and does not creep, to provide permanent shielding and sealing between base and cover. Further, cables exiting the enclosure may be sealed using a piece of double sided adhesive which is interposed between cable and casting followed by application of the malleable foil tape thereover. Thus in a compact device, no significant thickness is added to the enclosure wherein a maximum available height is used to house the stack of disks while providing noise and EMC shielding in addition to securing and sealing the cover.

Abstract: Disclosed is a method and apparatus for attaching a bearing cartridge to an actuator arm assembly in a disk drive. The bearing cartridge includes the actuator shaft, an outer sleeve and a set of bearings. The actuator arm assembly has a bore therein which receives the bearing cartridge. The bearing cartridge is anchored to the actuator arm assembly at a single location.

Abstract: A recirculating filter system is provided for a sealed magnetic disk drive by providing a cartridge housing that mounts a filter medium closely adjoining the disk stack and substantially concentric therewith. The frame that mounts the filter medium also serves as a baffle or diverter to deflect air impelled by rotation of the disks to the rear of the filter medium. The remaining sides of the housing contact the cover or enclosure to define a dead box behind the filter medium wherein the velocity head of the air flow is converted to a potential head. Air impelled along the surface of the medium, at the side confronting the disk stack, provides some aspiration. A plenum formed at the radial outward side of the filter medium enables effective use of the entire medium surface. The recirculating air filter cartridge is not only compact within a corner of the cover or enclosure, but also is easily manufactured as a result of the simple filter medium configuration.

Abstract: A system for clamping and retaining a stack of rigid magnetic disks is shown using disk spacer rings with an annular groove in the outer cylindrical surface. A concentrated axial load is applied to the stack by support surfaces which overlie the grooved portions of the spacers. The concentrated load is only partially distributed over the radial extent of the spacers with respect to the disks at the axial ends of the stack to resist coning or cupping of such end disks, while the force distribution approaches a uniform loading with respect to inner disks of the stack to retain the undistorted, planar orientation of such inner disks. The grooved spacers also provide a surface which can be used to engage and manipulate the disk assembly during manufacture of the drive.