Abstract: Provided are at least two bearings; an outer shaft having a tubular shape and supporting the bearings at an outer circumferential surface; and an inner shaft housed in the outer shaft with one end extending out from one opening part of the outer shaft. The inner shaft includes a male thread part at least at a portion extending out from the outer shaft.

Abstract: A disk device includes one or more disks, a base shaft, a bearing shaft, first and second bearing units, first and second actuator assemblies, and a damping member. The bearing shaft has a tubular portion fixed around the base shaft. The first and second bearing units are attached around the bearing shaft and aligned in an axial direction of the bearing shaft. The first and second actuator assemblies are coupled to the first and second bearing units, respectively. The damping member is provided between an outer circumferential surface of the base shaft and an inner circumferential surface of the tubular portion of the bearing shaft.

Abstract: A split-shaft pivot assembly for a dual-actuator data storage device may include a first pivot shaft around which a first bearing assembly is affixed, a second pivot shaft around which a second bearing assembly is affixed, and whereby the two pivot shafts are coupled together by way of an interface spacer between the shafts. The interface spacer may include a receiving structure at each end of a housing, for receiving an end of a respective shaft, and an annular slot circumscribing the housing between the receiving structures, where an elastomeric damper is positioned within the slot. The interface spacer housing may be composed of a material having a lower elastic modulus than the material of which the shafts are composed, thereby making the interface spacer relatively compliant. Such features may serve to inhibit and/or damp transmission of vibrational energy among the actuators through the shared split-shaft.

Abstract: A split-shaft pivot assembly for a dual-actuator data storage device may include a first pivot shaft having a threaded stud extending from one end and an attachment flange at the other end, and a second pivot shaft having a threaded bore at one end a structurally equivalent attachment flange at the other end, where the two pivot shafts are attached to each other by threading the stud into the bore. A first bearing assembly may be affixed with a first preload around the first pivot shaft, and a second bearing assembly may be affixed with a second different preload around the second pivot shaft. The pivot assembly may further include an elastomeric damper positioned within an annular groove formed in, and around the threaded stud of, the first pivot shaft. Such features may serve to inhibit and/or damp transmission of vibrational energy among the actuators through the shared split-shaft.

Abstract: Hard disk drives of the invention are wrapped in laminate for enhanced sealing of the hard disk drive. Laminate-wrapped hard disk drives of the invention comprise: an enclosed hard disk drive housing comprising a base and a cover enclosed around internal components for facilitating reading and recording of data at a desired location on at least one disk contained within the housing; and a laminate wrapped around the enclosed housing in an at least partially overlapping manner to form the laminate-wrapped hard disk drive and prevent undesired migration therethrough such that a sealed environment exists within the laminate-wrapped hard disk drive, wherein the laminate comprises a barrier layer and an adhesive layer for adherence of the laminate to the enclosed housing.

Abstract: A hard disk drive according to an embodiment of the present invention includes a pivot assembly bearing device with a shaft, rolling bearings and a sleeve, a cylindrical convex portion formed in a cover member at the upper side, protruding inward, and fixed to an upper end surface of the shaft, a convex portion formed on a base member at the lower side, protruding inward, and fixed to a lower end surface of the shaft, and a labyrinth gap formed by opposing an outer peripheral surface of the convex portion to an inner peripheral surface of a sleeve in a radial direction and/or by opposing an outer peripheral surface of the convex portion to the inner peripheral surface of the sleeve in a radial direction.

Abstract: A printer includes a print head fastening facing a medium support surface; a scanning print carriage being movable along a guide in a scanning direction (Y); and a transporter for transporting the medium in a transport direction (X). The printer includes a suspension structure connecting the print head fastening to the scanning print carriage while allowing movement of the print head fastening with respect to the scanning print carriage in a direction (X) parallel to the transport direction. The suspension structure is elastically deformable to allow for the movement in said direction (X).

Abstract: Various aspects of the present disclosure are directed toward a disc drive actuator assembly including an e-block, a plurality of bearings, and one or more heat transfer components. The heat transfer component(s) operates to conductively draw heat from the plurality of bearings through the e-block, and convectively dissipate the heat into an atmosphere in contact therewith. The heat transfer component(s) mitigates temperature rise of the bearings during operation of a disc drive, thereby mitigating bearing lubricant outgassing from within the bearings.

Abstract: Systems methods and/or apparatus for the conversion of various types of energy into thermal energy that may be stored and/or then converted into electrical energy. The electrical energy may be available on demand and/or at a user's desired power requirements (e.g., power level and/or type). For example, the energy may be available at a particular voltage and either as direct current (DC) energy or alternating current (AC) energy. The electrical energy may be easily transported and therefore available at a user's desired location. For example, the systems, methods and/or devices may eliminate or reduce the need for electricity transmission, at least for certain applications. In exemplary embodiments, the system may include an organic phase change material for storing the thermal energy.

Abstract: A system for monitoring activity of at least one subject in an environment, comprising at least one sensing assembly, detecting parameters in the environment; and a server communicating with at least one of: i) the subject and ii) the sensing assembly; the at least one sensing assembly comprising at least a first sensor connected to the region of the back of the neck of the subject, the first sensor unit comprising at least one accelerometer.

Abstract: Various aspects of the present disclosure are directed toward a disc drive actuator assembly including an e-block, a bearing, and a sleeve. The bearing includes an inner race, an outer race and a plurality of balls between the inner and outer races. The inner race being coupled to a pivot shaft of a disc drive, and the bearing being configured and arranged to facilitate rotation of the e-block around the pivot shaft. The sleeve coupling the outer race of the bearing to the e-block, and includes a groove along an inner diameter of the sleeve adjacent the outer race. The groove and outer race mitigate rotational torque changes due to thermal effects upon the disc drive actuator assembly by allowing the outer race of the bearing to deform into or away from the groove and therein mitigate or prevent the generation of certain forces in bearings.

Abstract: A tolerance ring includes: a base formed of a strip-like member substantially wound around into a shape; a plurality of projections provided along a winding direction of the base so as to protrude from an outer peripheral surface of the base in a radial direction of the base orthogonal to the outer peripheral surface; at least one extended portion extending from at least one of edge end portions in a width direction of the base, the width direction extending orthogonally to the winding direction and the radial direction. The extended portion extends from a region that includes at least one of a plurality of straight lines passing through respective contact points disposed between a section of the base and a circumscribed circle that circumscribes the section and extend in parallel with the width direction.

Abstract: A head stack assembly (HSA) having an actuator comb with a stepped inner bore may have an upper portion of the inner bore with a first diameter that is greater than the diameter of a lower portion of the inner bore. Therefore, little friction and resistance is encountered when force fitting a pivot-bearing assembly into the upper portion of the stepped inner bore, thereby avoiding surface damage and the generation of unwanted debris particles. The HSA may further comprise a plurality of tolerance rings to couple the actuator comb with the pivot-bearing assembly, such as one tolerance ring positioned below the step feature and one tolerance ring positioned above and seated on the step feature of the comb inner bore.

Abstract: A contamination mitigation cap for a hard disk drive actuator pivot assembly is affixed to the rotatable carriage of an actuator assembly and, in conjunction with a bearing hub cap, forms a labyrinth seal for retaining pivot bearing contamination. Consequently, the risk of such contamination migrating to the head-disk interface and causing read/write problems is mitigated, especially in the context of sleeveless pivot bearing assemblies. Various shapes of the contamination mitigation cap may be utilized, such as a flat ring, an S-section ring, and an L-section ring.

Abstract: A head stack assembly (HSA) for a disk drive includes an actuator body having a cylindrical bore therethrough and an actuator arm extending therefrom. A head is attached to a distal end of the actuator arm. A pivot bearing cartridge is disposed within the cylindrical bore. A tolerance band is radially preloaded between an outer surface of the pivot bearing cartridge and an inner surface of the cylindrical bore. The cylindrical bore has a first diameter in a first region adjacent a first axial end, and a second diameter in a second region adjacent a second axial end. There is a radial step between the first and second regions. The first diameter is greater than the second diameter by at least 20 microns but no more than 100 microns.

Abstract: A tolerance ring is formed of a plate member, in a ring shape that is substantially circular along a predetermined direction, and provided with a plurality of protrusions projected radially in a circumferential direction, wherein an even number of the protrusions are arranged along the circumferential direction, and a plurality of straight lines that pass through a central portion of the plurality of protrusions and a center of a circle that circumscribes the tolerance ring cross one another.

Abstract: A tolerance ring has a band with outwardly extending corrugated protrusions forming waves that engage an outer surface of a shaft. At one end of the tolerance ring is an inwardly flared guide surface extending axially and radially from the band. The guide surface acts as a tapered entrance to a bore of a housing to assist during assembly.

Abstract: A lightweight radio/CD player for vehicular application includes a case and frontal interface formed of polymer based material molded to provide details to accept audio devices and radio receivers, as well as the circuit boards required for electrical control and display. The case and frontal interface are of composite structure, including an insert molded electrically conductive wire mesh screen that has been pre-formed to contour with the molding operation. The wire mesh provides shielding and grounding of the circuit boards via exposed wire mesh pads and adjacent ground clips.

Abstract: A bearing device includes 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 therein and having a first screw on a part of an outer surface thereof, a second cylindrical member having a second screw engaging with the first screw on an inner surface thereof and mounted to the outer surface of the first cylindrical member by engaging the first screw with the second screw, a restricting member provided on the outer surface of the second 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 member contacts the restricting member.

Abstract: The present invention generally relates to a head comb for use in a hard disk drive. In one embodiment, the head comb comprises a core body having a bore formed therethrough. The bore is bound by walls having a top extension extending into the opening and a bottom extension extending into the opening. The top extension has a first height, and the bottom extension has a second height that is different than the first height.

Abstract: Disclosed is a head stack assembly, which comprises a pivot bearing assembly having a main body which comprising a first end surface and a second end surface, and a flange extended from the main body and located between the first and second end surfaces, the flange having a first interface adjacent the first end surface of the main body and a second interface opposite to the first interface; a drive arm mounted on the main body and secured on the first interface of the flange; and a fantail spacer mounted on the main body and secured on the second interface of the flange.

Abstract: According to one embodiment, a head stack assembly cartridge is provided. The head stack assembly cartridge includes a base plate having a pivot shaft for pivotally mounting a head stack assembly and a base voice coil motor magnet attached to an inner surface of the base plate. The base voice coil motor magnet is arranged on the inner surface of the base plate to be adjacent to a coil of the head stack assembly pivotally mounted on the pivot shaft. The head stack assembly cartridge further includes a cover removably attached to the base plate and a pivot clamp removably attached to the cover and configured to secure the head stack assembly pivotally mounted on the pivot shaft.

Abstract: A tolerance ring is disclosed and can include a strip of material having a length, a first end, a second end opposite the first end, and a plurality of radially extending projections between the first and second ends. The strip of material can be curved into a ring having a gap. The radially extending projections are configured to be compressible between a bore and a shaft. A width and/or a height of a radially extending projection closest to the first end is different from a width and/or a height of a radially extending projection closest to a line extending perpendicular to the length and bisecting the strip of material within a circumferential row of the radially extending projections.

Abstract: A tolerance ring is disclosed and can include a strip of material having a length, a first end, a second end opposite the first end, and a plurality of radially extending projections between the first and second ends. The strip of material can be curved into a ring having a gap. The radially extending projections are configured to be compressible between a bore and a shaft. A width and/or a height of a radially extending projection closest to the first end is different from a width and/or a height of a radially extending projection closest to a line extending perpendicular to the length and bisecting the strip of material within a circumferential row of the radially extending projections.

Abstract: Described herein is a tolerance ring for a disk drive that includes a substantially cylindrical body having outer surface. The tolerance ring can be positioned between a rotational bearing and an actuator for providing rotational movement of the actuator. The tolerance ring can also include a contact member, positioned along the outer surface, that protrudes outward from the outer surface. The contact member can be connected to the outer surface by first and second angulated arms that extend from the outer surface to the contact member at different angles relative to the outer surface.

Abstract: A novel tolerance ring includes a hollow cylindrical body defining a longitudinal axis that passes axially through its center. A circumferential gap divides the hollow cylindrical body so that the hollow cylindrical body includes first and second longitudinal edges that define the circumferential gap. A plurality of bumps protrude radially from the hollow cylindrical body, and consists of a plurality of gap-adjacent bumps and a plurality of non-gap-adjacent bumps. At least one of the plurality of bumps is circumferentially between the gap and each of the non-gap-adjacent bumps. None of the plurality of bumps is circumferentially between the gap and each of the gap-adjacent bumps. The tolerance ring includes a means for increasing an otherwise lower average radial compressive stiffness of the gap-adjacent bumps to become substantially equal to an average radial stiffness of the non-gap-adjacent bumps.

Abstract: An apparatus includes an inner component, an outer component; and a tolerance ring located between the inner and outer components to provide an interference fit there between. The tolerance ring includes a strip of material having a plurality of radially extending projections. The strip of material is curved into a ring having a gap. The radially extending projections are compressible between the inner and outer components, and the stiffness of the radially extending projections varies around the circumference of the tolerance ring.

Abstract: A disk drive includes a head for accessing a disk, a suspension for supporting the head, a carriage coupled to the suspension, a pivot-bearing assembly, an adhesive, and an adhesion inhibitor. The pivot-bearing assembly is housed in a hole of the carriage that is configured to rotate in such a way that the carriage is configured to oscillate. The adhesive is disposed between the pivot-bearing assembly and an inner circumferential surface of the hole for bonding the pivot-bearing assembly with the carriage. The adhesion inhibitor is disposed on the same surface as the adhesive for controlling a region of adhesion.

Abstract: A bearing device has a sleeve that encircles a shaft, and two side-by-side roller bearings rotatably support the sleeve coaxially on the shaft. A spacer portion protrudes radially inwardly from the sleeve and extends between the two roller bearings. The sleeve axially overlaps a minor portion of one roller bearing but does not overlap a race surface thereof, and the sleeve axially overlaps a major portion of the other roller bearing including a race surface thereof.

Abstract: Various methods and apparatus relating to disk drive actuators and methods of manufacturing them are disclosed and claimed. In certain embodiments, a disk drive actuator assembly comprises a pivot bearing defining a pivot bearing rotational axis; an actuator arm including a bore, the pivot bearing disposed at least partially within the bore; a first tapered shim, interposed in the bore between the pivot bearing and the actuator arm, the first tapered shim having a thickness at a first end greater than a thickness at a second end; and a second tapered shim, interposed in the bore between the pivot bearing and the actuator arm, the second tapered shim having a thickness at a third end greater than a thickness at a fourth end; wherein the second tapered shim frictionally engages the first tapered shim to hold the pivot bearing substantially in place relative to the actuator arm.

Abstract: A tolerance ring (10) for providing an interference fit between inner and outer components (36, 50) is disclosed. The tolerance ring (10) comprises a deformable band wound to form a first layer (111) having a plurality of radially extending projections (12, 13, 15) around its circumference and an unformed second layer (110) which overlaps with the first layer. The second layer acts as a force diffuser to spread the forces transferred through the projections on to the inner or outer component.

Abstract: A tolerance ring has a band (16) with outwardly extending corrugated protrusions forming waves (2) which engage a surface (8) of the bore (4) in a housing (5). At one end of the tolerance ring is an outwardly flared guide surface (15) extending axially from the band (16). The guide surface (15) acts as an enlarged entrance to the band (16) for a shaft (3) to be mounted in the bore (4) by insertion into the tolerance ring. The use of the guide surface (15) assists assembly and reduces or eliminates particle production. It is also possible for the corrugated portions to extend inwardly, for the guide surface to be inwardly flared, and for the tolerance ring to be mounted on the shaft prior to insertion in the bore.

Abstract: A post-assembly head/disk offset adjuster is disclosed. One embodiment provides a housing and at least one disk coupled with the housing. In addition, an adjustable pivot plate is coupled with the housing such that access to at least one adjustment point of the adjustable pivot plate is provided regardless of a state of assembly of the hard disk drive. Furthermore, an actuator is coupled with the adjustable pivot plate. In so doing, an adjustment to the at least one adjustment point of the adjustable pivot plate results in an adjustment to the actuator regardless of the state of assembly of the hard disk drive.

Abstract: A novel tolerance ring includes a hollow cylindrical body defining a longitudinal axis that passes axially through its center. A circumferential gap divides the hollow cylindrical body so that the hollow cylindrical body includes first and second longitudinal edges that define the circumferential gap. A plurality of bumps protrude radially from the hollow cylindrical body, and consists of a plurality of gap-adjacent bumps and a plurality of non-gap-adjacent bumps. At least one of the plurality of bumps is circumferentially between the gap and each of the non-gap-adjacent bumps. None of the plurality of bumps is circumferentially between the gap and each of the gap-adjacent bumps. The tolerance ring includes a means for increasing an otherwise lower average radial compressive stiffness of the gap-adjacent bumps to become substantially equal to an average radial stiffness of the non-gap-adjacent bumps.

Abstract: Components and assemblies for a hard disk drive (HDD) with a recessed actuator joint are described. A rotary actuator hub assembly comprises a shaft having a flange, and a pivot seat on which the flange is seated when the shaft is fastened to an HDD chassis. According to an embodiment, the pivot seat has at least one “contact-reducing feature” recessed from the surface of the pivot seat at which the seat contacts the flange. A purpose of the contact-reducing feature(s) of the pivot seat is to weaken the joint between the actuator hub assembly and the chassis, thereby mechanically loosening the rotary actuator assembly from the chassis. Consequently, movements to and vibrations from the chassis are less likely to be transmitted to the rotary actuator assembly and, ultimately, to the HDD read/write head(s).

Abstract: A hard disk drive including an actuator arm to pivot across a disk and having a read/write head disposed at an end of the actuator arm to read data from the disk and to write data to the disk, and a crash stop to prevent the read/write head from being pivoted beyond a preset outermost position of the disk. The crash stop can include a housing coupled to a base of the disk drive and disposed adjacent to an outer circumference of the disk, and a buffer member forcibly coupled to the housing. A coupling groove can be provided on one of the housing and the buffer member and a coupling protrusion can be provided on the other one of the housing and the buffer member to precisely locate the read/write head at the preset outermost position of the disk when the actuator arm contacts the crash stop.

Abstract: An integrated pivot-carriage for a hard disk drive for improving a pivot bonding process. Embodiments include a pivot-bearing assembly comprising an upper bearing, a lower bearing and a pivot-bearing spacer there between; a carriage comprising: a center-bore within which a pivot-shaft coupled with the pivot-bearing assembly is disposed; and a plurality of pivot-bonding glue dispensers, each of the pivot-bonding glue dispensers comprising: a glue inlet; a glue outlet; and an enclosing wall defining an interior flow passage between the glue inlet and the glue outlet, the interior flow passage configured for conveying bonding glue there through; and a glue receiving region coupling the glue outlet with a bearing of the upper and the lower bearing, the glue receiving region configured for receiving bonding glue dispensed thereto, thereby bonding the pivot-bearing assembly with the carriage.

Abstract: An apparatus and associated method for reflecting elastic waves that propagate from an excitation source to an excitation-sensitive component in a device. The device has an enclosure with a base constructed of a first metal. An elastic wave reflector is constructed of a different second metal and is operably affixed to the base. The elastic wave reflector defines a support surface to which the excitation-sensitive component is operably affixed within the enclosure.

Abstract: A tolerance ring configured to improve mass eccentricity of an actuator arm assembly. The tolerance ring has a cylinder with a predetermined length between two ends, with a gap along the predetermined length of the cylinder, the gap having a first and a second edge, the cylinder having an aperture in the surface of the cylinder at the second edge.

Abstract: An internal support interface which provides vibration and acoustic isolation. A stationary shaft has a medial portion about which a rotatable member rotates. An end portion of the shaft has an annular base surface surrounding a stub shaft projection. A substantially planar housing member has a support post which extends from an annular interior surface in adjacent, non-contacting proximity to the stub shaft projection to form a gap therebetween. An annular damping member mutually contactingly surrounds the stub shaft projection and the support post while being compressed between the base surface of the shaft and the interior surface of the housing member.

Abstract: A tolerance ring configured to prevent interlocking during shipping and handling. The tolerance ring has a cylinder with a first radius about an axis of rotation and a gap in the cylinder surface having a first edge and second edge extending along the axis. The gap in the cylindrical base has a first tab on the first edge and a second tab on the second edge. The first tab is adapted for coupling to the second tab and thereby prevents the interlocking of one tolerance ring with another. The gap can be configured to be non-linear.

Abstract: A hard disk case for installation in a computer case includes a support frame for installation of a hard disk drive, a base mounted to the support frame, and a handle. The handle has a pivoting end pivotally connected with the base, a first protrusion insertable in an insertion portion of the computer case and pushable against a periphery wall of the insertion portion for enabling engagement of the hard disk drive with the computer case, and a second protrusion spaced from the first protrusion and pushable against a stopping portion of the computer case for enabling disengagement of the hard disk drive from the computer case. As a result, the hard disk case of the present invention is convenient in assembly and disassembly works.

Abstract: A grease composition for a pivot assembly bearing is provided and includes a thickener of 5 to 25% by mass and a base oil of 95 to 75% by mass with respect to the total mass of the thickener and the base oil. Two or more ureas selected from: urea A: a urea comprising diurea compounds having an aliphatic (ALA)/alicyclic (ACA) substituent; urea B: a urea comprising diurea compounds having an alicyclic (ACA)/aromatic (ARA) substituent; and urea C: a urea comprising diurea compounds having an aromatic (ARA)/aliphatic (ALA) substituent are used as the thickener. A poly ?-olefin mixture having a kinematic viscosity at 40° C. of 40 to 70 mm2/s prepared by mixing poly ?-olefin (PAO HV) having a kinematic viscosity at 40° C. of 350 to 450 mm2/s with poly ?-olefin (PAO LV) having a kinematic viscosity at 40° C. of 25 to 40 mm2/s in a mass ratio of 15:85 to 30:70 is used as a base oil. A lead free additive may be used as an additive.

Abstract: An integrated pivot-carriage for a hard-disk drive. The integrated pivot-carriage includes a carriage having a center-bore with an integrated bearing-spacer portion. The integrated pivot-carriage also includes a pivot-shaft configured to provide support for rotation of the carriage. The pivot-shaft is disposed within the center-bore of the carriage. In addition, the integrated pivot-carriage includes at least one raceless ball-bearing that is configured to allow rotation of the carriage about the pivot-shaft. The raceless ball-bearing is disposed between the pivot-shaft and the carriage.

Abstract: A head support device of self-balancing type and a disk drive are disclosed. The head support device reduces manufacturing variation in a load and the number of components, and has stability and reliability, while being inexpensive. In this head support device, a flange and a nut cramp, via a collar, a head support arm having a reinforcing plate fixed thereto. The head support arm is supported rotatably about a line provided between contact points at which pivots contact the flange and in a direction perpendicular to a recording medium. A spring as an elastic member provides an urging force toward the recording medium, and is provided unitarily with the head support arm. Bent portions are provided on both sides of the arm composing the head support arm to a tab.

Abstract: A method of manufacturing a head suspension for a hard disk drive includes a rigid part chain product manufacturing step forming a rigid part chain product where rigid parts are provided continuously, a flexure manufacturing step forming the flexure integrated with the resilient part and the reinforcing parts, a base manufacturing step forming the base, a stacking and coupling step stacking and connecting the rigid part chain product, the resilient part chain product, the bases, and the flexures, to form the stacked set, and a cutting step cutting and separating respective head suspensions from a stacked set.

Abstract: A tolerance ring configured to improve mass eccentricity of an actuator arm assembly. The tolerance ring has a cylinder with a predetermined length between two ends, with a gap along the predetermined length of the cylinder, the gap having a first and a second edge, the cylinder having an aperture in the surface of the cylinder at the second edge.

Abstract: A lubricant is applied to swage contact surfaces in a disk drive of the type including a suspension arm connected to an actuator arm by a swaging process. A preferred thin film lubricant may be applied to the contact surfaces by immersion and draining, immersion and raising the part out of the solution, localized spraying, or various deposition processes. Application of the lubricant reduces chipping during de-swaging, particularly with nickel plated metal components. Application of the lubricant has also shown to improve gram load uniformity, reduce adverse distortion to the actuator assembly and reduces torque out retention values. Improved gram load uniformity enhances overall disk drive functioning, reduced distortion preserves intended attitude and flatness of the actions for assembly and reduced torque out retention values improves reworkability of the disk drive.

Abstract: A low cost method of attaching an actuator arm assembly to a single head hard disk drive that has a reduced part count The actuator arm assembly includes a suspension arm stamped from a metal and a pivot bearing cartridge contained by a reduced mass outer sleeve.

Abstract: A tolerance ring configured to improve mass eccentricity of an actuator arm assembly. The tolerance ring has a cylinder with a predetermined length between two ends, with a gap along the predetermined length of the cylinder, the gap having a first and a second edge, the cylinder having an aperture in the surface of the cylinder at the second edge.