Abstract: An electric progressive cavity pump system includes a progressive cavity pump in operation connection with a six-pole, three-phase electric motor. A method of producing fluid from a wellbore includes the steps of positioning a progressive cavity pump below a fluid level in the wellbore, connecting a six-pole, three-phase electric motor that includes a stator having eighteen slots and a plurality of windings distributed among the eighteen slots, wherein the windings of different phases do not pass through the same slot and operating the progressive cavity pump via the electric motor to produce the fluid from the wellbore. The electric motor may be positioned below the fluid level in the wellbore or at the surface.

Abstract: An electric progressive cavity pump system includes a progressive cavity pump in operation connection with a six-pole, three-phase electric motor. A method of producing fluid from a wellbore includes the steps of positioning a progressive cavity pump below a fluid level in the wellbore, connecting a six-pole, three-phase electric motor that includes a stator having eighteen slots and a plurality of windings distributed among the eighteen slots, wherein the windings of different phases do not pass through the same slot and operating the progressive cavity pump via the electric motor to produce the fluid from the wellbore. The electric motor may be positioned below the fluid level in the wellbore or at the surface.

Abstract: A technique is provided for constructing a submersible motor. The submersible motor has a stator positioned within a housing. Windings are arranged through the stator with end coils on opposite ends of the stator. The winding end coils are supported by a support structure that prevents the end coils from collapsing inwardly.

Abstract: An electric progressive cavity pump system includes a progressive cavity pump in operation connection with a six-pole, three-phase electric motor. A method of producing fluid from a wellbore includes the steps of positioning a progressive cavity pump below a fluid level in the wellbore, connecting a six-pole, three-phase electric motor that includes a stator having eighteen slots and a plurality of windings distributed among the eighteen slots, wherein the windings of different phases do not pass through the same slot and operating the progressive cavity pump via the electric motor to produce the fluid from the wellbore. The electric motor may be positioned below the fluid level in the wellbore or at the surface.

Abstract: A method and apparatus are provided for generating an adaptive feedforward cancellation signal for a next sector of a disc in a disc drive. The cancellation signal includes at least one tap weight multiplied by at least one trigonometric function. To form the cancellation signal, the method and apparatus first determine a servo loop transfer function relative to a feedforward cancellation component in the disc drive. The transfer function is then inverted to form filter parameters. A position error value is then measured for a current signal and is passed through a filter formed from the filter parameters. This creates a filtered position error value that is used with the tap weights of a current sector to determine the tap weights for the cancellation signal of the next sector.

Abstract: A permanent magnet synchronous motor system. The system uses a permanent magnet AC synchronous motor having an elongated housing, of the type used in progressive cavity pumping applications. Within the stator, a multi-section rotor is rotatably mounted. The rotor includes a plurality of rotor sections that are angularly offset from each other. The rotor sections are mounted on a drive shaft, and the sum of the offsets is generally comparable to the angular displacement undergone by the drive shaft under a normal operating load.

Abstract: A system for pumping and heating viscous fluids in a wellbore includes electrical power supplies, a switchboard, conductors, and a submergible pumping system having a pump and a submergible electric motor. The electrical power supplies are coupled to the submergible pumping system through a switchboard and conductors that supply electrical power to the motor. The electrical power supplies provide direct or alternating current and include protective circuitry. The submergible pumping system may be supplied with electrical power to motor stator windings to generate heat to raise the temperature and lower the viscosity of adjacent viscous fluids.

Abstract: Embodiments of apparatus are directed to a rotational shock tester system comprising a disc drive support system, a drop mechanism and an impact apparatus. The disc drive support system includes a rotation plate, wherein a disc drive is coupled to the rotation plate. The drop mechanism is coupled to the disc drive support system and includes an elevating apparatus, wherein the elevating apparatus elevates and releases the rotation plate which is supporting the disc drive. The impact apparatus is releasably coupled to the drop mechanism and is aligned with the rotation plate such that upon release of the rotation plate, the rotation plate impacts the impact apparatus such that the impact apparatus imparts an angular acceleration to the rotation plate and imparts a rotational shock to the disc drive.

Abstract: A disc drive system includes a rotatable disc, an actuator arm, and a suspension load beam connected to the actuator arm. A head positioning mechanism includes a motor attached to the suspension load beam. A gimbal has a first end attached to the motor, and a slider carrying a transducing head is attached to a second end of the gimbal. Control Circuitry generates electrical control signals to operate the motor to selectively position the transducing head proximate a predetermined radial location on the rotatable disc.

Abstract: An apparatus for measuring magnetic recording head transducer to disc surface spacing and a method of fabricating the same are disclosed. A slider body of a read/write head has first and second rails forming portions of an air bearing surface of the slider body. First and second cavities are formed in the first and second rails of the slider body at the air bearing surface. First and second capacitance plates are positioned within the first and second cavities, respectively, such that a surface of each of the first and second capacitance plates is substantially coplanar with at least portions of the air bearing surface.

Abstract: A method and apparatus for detecting and measuring head-disc interference, in a disc drive, for the purpose of taking preventative and corrective measures, to prevent disastrous head crashes and permanent data loss, is disclosed. The method and apparatus detect and measure the frequency modulation (FM) of a read back signal generated by longitudinal head oscillation, as a result of head-disc interference. The longitudinal head oscillation can be ascribed to the non-linear response of the air bearing supporting the head on the disk surface. The response exhibits a vibration frequency in the head in the 100 to 250 kHz range. The more severe the interference contact is, the higher the vibration amplitude which then leads to read signal frequency modulation (FM). A method and apparatus is described to detect the FM modulation and thereby to detect the severity of the head disk interference for proximity recording. A pre-written pattern on the disk can be read back to monitor for FM, and a modulation index, .beta.

Abstract: A device for reading and recording magnetic data includes an aerodynamically supported slider with an air bearing surface, and a transducer mounted to the slider for movement toward and away from the air bearing surface responsive to changes in the slider operating temperature. In one embodiment, the transducer movement is primarily due to a difference in thermal expansion coefficients between a transducing region of the slider incorporating the transducer, and the remainder of the slider body. In another embodiment, a strip of thermally expansive material is incorporated into the slider near the transducer to contribute to the displacement by its own expansion. A temperature control circuit, coupled to the strip of thermally expansive material or to a resistance heating element on the slider, employs a variable current source to control the slider temperature and transducer displacement.

Abstract: An swage plate bumper overlies the swage plate of a suspension arm and the end of an actuator arm in a computer disc drive. The swage plate bumper may be molded in two pieces which snap together onto the actuator arm through the swaged hole. Alternatively, the swage plate bumper may be provided with an adhesive attachment to the swage plate, or the swage plate may be coated with a compressible coating during manufacture. The swage plate bumper extends over four corners of the swage plate and prevents damage to the disc surface which might otherwise be caused when the corners of the swage plate contact the disc during a drop or other sudden acceleration.

Abstract: A method is provided for allocating digital processing activities of an embedded microcontroller within a disk drive between repetitive periodic digital servo loop service routines synchronized to rotation of a data storage disk of the drive and irregularly occurring host service routines supporting a high level, digital interface to a host computing environment. The new method comprises the steps of:prioritizing the host service routines into priority routines and non-priority routines,detecting calls to one of the priority routines, andbypassing execution of a predetermined number of the servo loop service routines to enable execution of the called priority routine without interruption.

Abstract: A formation process has a plurality of process steps performed according to a set of process parameters. The formation process is used to form substrates in magnetic discs. A displacement signal is obtained which is representative of surface displacement of the substrate after at least one of the process steps. A first spectral signature is determined based on the displacement signal. The first spectral signature has characteristics representative of the surface displacement of the substrate when processed according to a first set of process parameters. The first spectral signature is compared with a second spectral signature having characteristics indicative of surface displacement of a substrate when processed according to a second set of process parameters. Based on the comparison, the set of process parameters is identified which provides a spectral signature closest to a desired spectral signature.

Abstract: A submersible motor includes a stator section along the entire length of rotor sections attached to the motor shaft, with a rotor bearing and sleeve assembly between each rotor section, each bearing including a fixed key for positioning in longitudinal spacings formed as a part of the stator section, to prevent rotation of the bearing during use.

Abstract: A plug-in type pothead includes specially designed seal sleeves formed from a heat shrinkable polymer. One end of the sleeve has an annular collar about it which, when snugly fitted within the motor lead entry hole of the terminal block, forms a watertight seal between the terminal block and the sleeve. The other end of each of the sleeves is heat shrunk about its respective motor lead to form a watertight seal between the sleeve and the lead. In addition, a gasket between the connecting face of the terminal block and the connecting face of the pothead provides a watertight seal between the pothead and the terminal block. The result is a completely watertight connecting system, extending from the pothead through the terminal block to the motor leads.

Abstract: A submersible motor includes a stator section along the entire length of rotor sections attached to the motor shaft, and a non-magnetic rotor bearing and sleeve assembly between each rotor section, with the rotor bearing being releasable but normally interconnected with the stator to prevent its rotation relative to the sleeve which rotates with the motor shaft.

Abstract: A permanent magnet rotor configuration which produces four magnetic poles utilizing two sets of symmetrically-disposed permanent magnets. The slots carrying the magnets exhibit a truncated V-shaped configuration, extending from points on the periphery of the rotor to meet the ends of a straight, central portion which lies parallel to a tangent to the rotor shaft. A short magnetic bridge interrupts the center of each slot, the slots being disposed generally symmetrically upon opposite sides of the rotor shaft.

Abstract: A permanent magnet rotor configuration which produces two magnetic poles. Two pairs of axial slots are provided in which permanent magnets are arranged about the rotor shaft. A third, diametrically opposed pair of slots is provided which extend radially outwardly and in which permanent magnets are disposed. Off-axis magnetic bridges are formed on either side of the third slots, separating them from the first and second sets of slots.