An apparatus for energy assisted magnetic recording of a storage disk include a plurality of dielectric waveguide cores configured to direct received incident light energy to a target, and a near field transducer (NFT) configured to focus light energy received from the plurality of waveguide cores and to transmit the focused light energy onto the storage disk surface to generate a heating spot on the storage disk. The NFT includes a plurality of propagating surface plasmon polariton (PSPP) elements that are energized by the light energy from the waveguide cores. Each of the PSPP elements has a plasmonic metal bar disposed above a single waveguide core in a longitudinal alignment. Each metal bar has a width at least twice the width of the heating spot generated on the storage disk.

An optical head device (11) provided with: an optical element (36) for transmissively diffracting a light beam emitted from a semiconductor laser (34), generating a zero-order diffracted light beam and ±1-order diffracted light beams; and a photodetector (40) for receiving the zero-order diffracted light beam and the +1-order diffracted light beam after reflection from an optical disc (2). The photodetector (40) includes a primary light receiving section (400) for receiving the zero-order diffracted light beam, and a first secondary light receiving section (401) disposed outward from the primary light receiving section (400). The first secondary light receiving section (401) is positioned to detect an outer portion of the received light spot of the +1-order diffracted light beam, performs photoelectric conversion of this portion, and outputs a secondary detected signal.

Technologies are described herein for utilizing a head heater to test temperature stability of a head of a storage device and to prevent the head from operating in an unstable temperature condition. A first power level may be applied to a head heater of a head in a storage device, the first power level configured to simulate a temperature condition in the head. An instability of the head is determined and the temperature condition and the instability of the head are recorded in a memory. The process may be repeated to develop a range of temperature conditions in which the head exhibits instability. The range of temperature conditions and the head heater may then be utilized to prevent the head from operating in an unstable temperature condition during normal operation.

An optical recording medium includes a recording and reading layer that is previously staked or formed afterword and has no concavo-convex pattern for tracking control, and a servo layer in which a concavo-convex pattern or a groove for tracking control is formed. Information can be recorded in the recording and reading layer while tracking is performed using the servo layer.

A return path section includes first and second yoke portions and first, second and third columnar portions. The first and second yoke portions and the first columnar portion are located on the same side in the direction of travel of the recording medium relative to a wave guide core. The second and third columnar portions are located on opposite sides of a plasmon generator and connected to a shield. The first yoke portion connects a main pole to the first columnar portion. The second yoke portion connects the first columnar portion to the second and third columnar portions. A coil is wound around the first columnar portion.

A recording head for recording information on a rotating recording medium of a storage device includes a main magnetic pole which generates a recording magnetic field in a direction perpendicular to a recording medium facing surface of the magnetic recording head, and a light generating element which is provided on a leading side of the main magnetic pole, and generates light for heating the recording layer of the recording medium. The main magnetic pole includes an end surface facing the light generating element that is inclined with respect to the direction perpendicular to the recording medium facing surface toward the light generating element.

In a heat-assisted magnetic recording (HAMR) hard disk drive, a heat-dissipating head slider assembly is described in which the slider is stepped on the disk-opposing side and a HAMR laser module is mounted on the lower surface to assist with dissipation of heat from the laser. The lower surface is a surface of the main body of the slider and is composed primarily of a first material, and the slider may include a heat-dissipating plate that forms the higher stepped surface, where the plate is composed of a second material that has a higher thermal conductivity than the first material, such as silicon.

An apparatus includes a write element configured to apply a magnetic field to write data on a portion of a heat-assisted magnetic recording media in response to an energizing current. An energy source is configured to heat the portion of the media being magnetized by the write element. A preheat energizing current is applied to the write element during an interval before writing the data to the portion of the media. The preheat energizing current does not cause data to be written to the media and brings at least one of the write element and driver circuitry into thermal equilibrium prior to writing the data on the portion.

This invention is provides a means of playing LP records with minimal distortion. Low distortion is achieved by eliminating tracking error normally associated with pickup cartridges mounted to pivoting tone arms. This invention discloses a tone arm that constrains the motion of the stylus to straight radial path, mimicking the cutting path of the record lathe, supported on parallel rails by free rolling spherical bearings. Unlike many previous linear tracking tone arms, this invention does not rely on air pressure or servo motor mechanisms. The use of free rolling bearings or axles between parallel tracks fashioned from rails, rods or tubes, eliminates all sources of lateral friction other than pure static and rolling friction of the balls on the rails, rods or tubes. In the preferred embodiment, the fixed rods or tubes are driven synchronously, thereby eliminating static friction of the supporting rolling balls. Friction is further reduced using magnetic or buoyant support of the tone arm to reduce bearing load to that amount minimally sufficient to maintain full contact between the rolling balls and the upper and lower rods.

In a heat-assisted magnetic recording hard disk drive, one or more thermally conductive features are incorporated to assist with dissipation of heat from a laser module that comprises a laser and a submount. The submount may be coupled to the slider with solder covering a wider adhesive area for enhanced conduction of heat away from the laser module and to the slider, one or both of the submount and the laser may include a surface coating that increases the thermal radiation of the corresponding component, and/or one or both of the submount and the laser may include fins configured to transfer heat from the corresponding component. Further, a HAMR HGA may be configured such that the submount is coupled directly to the suspension flexure using a thermally conductive material, for conduction of heat away from the laser module and to the flexure.

Techniques are provided for increasing spectral efficiency over data channels in a storage or communication system. In some embodiments, data may be encoded and transmitted over multiple channels. The transmitted data from the multiple channels may be considered together as a channel bundle, thereby increasing the edge transitions of the group of signals to improve clock recovery and reduce coding constraints. In some embodiments, the channel bit size is reduced to maximize data rates based on the reduced coding constraints. Furthermore, the channel bundle has only one channel with timing markers, so that a receiver may receive information from the channel bundle and recover clocking based on the timing markers in the one channel.

An near-field light device (100) is provided with: a first electrode layer (123) having a protruding portion (123a); a second electrode layer (121); and a light emitting layer (122), the protruding portion protrudes along a predetermined direction (Y axis direction) to be capable of extracting energy which is caused by emission of light at the light emitting layer, the predetermined direction intersects with a laminated direction (X axis direction) of the near-field light device, an edge surface of at least one portion of the projection portion is located at more outward side in the optical device than an edge surface of the second electrode layer is.

The relative health of data storage drives may be determined based, at least in some aspects, on data access information and/or other drive operation information. In some examples, upon receiving the operation information from a computing device, a health level of a drive may be determined. The health level determination may be based at least in part on operating information received from a client entity. Additionally, a storage space allocation instruction or operation may be determined for execution. The allocation instruction or operation determined to be performed may be based at least in part on the determined health level.

In a heat-assisted magnetic recording head for use in a hard disk drive, a thermal shunt is positioned between an E-antenna near field transducer (NFT) and a return pole, to draw excess heat away from the NFT region. The thermal shunt comprises two portions separated by a gap that has a trapezoidal cross-section, where the NFT-side of the gap is wider than the return pole-side of the gap.

An apparatus includes a writer, an arrangement comprising a plasmonic near-field transducer (NFT) adjacent the writer and comprising a material having a temperature coefficient of resistance (TCR), and a lead arrangement connected to the NFT arrangement. In some configurations, the NFT arrangement includes a heat sink, and the lead arrangement is connected to the heat sink. In other configurations, the lead arrangement is connected directly to the NFT.

A device and method for using the device arranged to maintain anatomical alignment between a joint by creating a dynamic load around the joint to restore and maintain the anatomical alignment. The orthotic device uses a hinge to create a directed force on a tibia by maintaining misalignment of an instant center of rotation (ICoR) of the hinge at a position relative to an anatomical knee joint.

A sleep apnea prevention sleep-aid mask is described. The sleep-aid mask is configured to secure the lips of a user together in a natural state, in order to encourage the respiratory system of the user to employ the nasal passages rather than the mouth for respiration. A pad equipped with a perforated mesh or channel is positioned over the lips and mouth of the user, and secured in position on the user via an adhesive, which temporarily affixes the pad to the face of the user. The sleep-aid mask is preferably shaped and sized according to the specific size of the user's face, and is configured to limit the effective diameter of the mouth of the user, in order to cause continued use of respiration via the nasal passages.

A kit of parts for forming an orthotic head support. The kit includes at least one frame having a plurality of arms extending from a central region. Examples of such frames are W-frames, Y-frames and H-frames. The kit further includes at least one extension connectable to a frame. Such extension members include straight extensions, L-shaped extensions, and extension with two elements at an acute angle to one another. The kit has elements for attaching the extensions to the frames. The frames and extensions may have lines of reduced stiffness formed therein about which they are preferentially bendable to conform the support to the shape of a wearer's head and/or neck. The kit further includes padding members connected, or connectable, to the frames and/or extensions on the surfaces thereof which in use are to be adjacent the wearer.

A wound treatment device comprises a wound surface contacting plug and a cover for covering the wound surface and the plug, wherein said plug consists of a flat textile isolating material comprising at least one first surface layer, one second surface layer and one intermediate space arranged between said surface layers. At least the first surface layer is provided with a biocompatible surface and a structure which enables a liquid to pass and prevents a wound tissue from growing in said structure. The intermediate space is provided with isolating threads elastically holding the first surface layer and the second surface layer at a certain distance from each other.

A bandage includes a reservoir filled with a perfluorochemical fluid, saturated with oxygen. Oxygen passes through a permeable membrane to the skin or wound to promote healing, and carbon dioxide travels from the skin or wound to the reservoir.

A system and method for long-term monitoring of cardiac conditions such as arrhythmias is disclosed. The invention includes a pulse generator including means for sensing an arrhythmia. The pulse generator is coupled to at least one subcutaneous electrode or electrode array for providing electrical stimulation such as cardioversion/defibrillation shocks and/or pacing pulses. The electrical stimulation may be provided between multiple subcutaneous electrodes, or between one or more such electrodes and the housing of the pulse generator. In one embodiment, the pulse generator includes one or more electrodes that are isolated from the can. These electrodes may be used to sense cardiac signals.

A patch permitting division of only its release sheet by simply pulling right and left, wherein detachment of the release sheet is easy. There is provided a patch comprising a stretchable support, a plaster applied substantially all over one major surface of the support and a release sheet attached to the whole surface of the plaster wherein only the release sheet is divided at a division zone by simply pulling right and left, and wherein one or two or more precut parts that open when the patch is pulled right and left are disposed in the neighborhood on the division zone.

The present invention provides a metal passivator/trap comprising a rare earth oxide dispersed on a matrix containing a calcined hydrous kaolin.

The present invention relates to a vehicular air cleaner. A DOR (Direct Ozone Reduction) system for suppressing deterioration of a purifying function of an ozone purifying material is provided. Active oxygen is produced by an ozone purifying function of activated carbon. The probability that the active oxygen contacts with a fin of a radiator on a rear surface side is higher than that on a front surface side of the radiator. Accordingly, the activated carbon on the rear surface side of the radiator is easily oxidized as compared with the activated carbon on the front surface side. Therefore, in the fin, a coating amount of the activated carbon on the front surface side of the radiator is adjusted to be larger than a coating amount of the activated carbon on the rear surface side. Thus, the probability that the active oxygen contacts with the activated carbon can be reduced.

This disclosure relates to a catalyst system adapted for transalkylation a C9+ aromatic feedstock with a C6-C7 aromatic feedstock, comprising: (a) a first catalyst comprising a first molecular sieve having a Constraint Index in the range of 3-12 and 0.01 to 5 wt. % of at least one source of a first metal element of Groups 6-10; and (b) a second catalyst comprising a second molecular sieve having a Constraint Index less than 3 and 0 to 5 wt. % of at least one source of a second metal element of Groups 6-10, wherein the weight ratio of the first catalyst over the second catalyst is in the range of 5:95 to 75:25 and wherein the first catalyst is located in front of the second catalyst when they are brought into contacting with the C9+ aromatic feedstock and the C6-C7 aromatic feedstock in the present of hydrogen.

A catalyst comprising of nano nickel-silica catalyst for dewaxing of heavy petroleum feed at a temperature 200-350° C. at 8 bar and 30 bar hydrogen pressure and in the presence of hydrogen is designed for petrochemical industries. According to a specific aspect of the invention, the nano catalyst is designed and employed to convert heavy hydrocarbon feeds of high viscosity index to low pour point and good stability in a single step.

The present invention provides stable aqueous thermosetting binder compositions having a total solids content of 15 wt. % or higher, preferably, 20 wt. % or higher, and having extended shelf life comprising one or more reducing sugar, one or more primary amine compound, and one or more stabilizer acid or salt having a pKa of 8.5 or less. The total amount of stabilizer used may range from 5 to 200 mole %, based on the total moles of primary amine present in the binder. The stabilizer may be an organic stabilizer chosen from a monocarboxylic acid, a dicarboxylic acid, a fatty acid, an acid functional fatty acid ester, an acid functional fatty acid ether, or an inorganic stabilizer chosen from a mineral acid, a mineral acid amine or ammonia salt, and a Lewis acid, and mixtures thereof. The compositions can be used to provide binders for substrate materials including, for example, glass fiber.

A hydrogel tissue adhesive having decreased gelation time and decreased degradation time is described. The hydrogel tissue adhesive is formed by reacting an oxidized polysaccharide containing aldehyde groups with a water-dispersible, multi-arm amine in the presence of a thiol additive. The thiol additive accelerates the process to form the hydrogel and accelerates the degradation of the hydrogel formed. The hydrogel may be useful as a tissue adhesive or sealant for medical applications, such as a hemostat sealant or to prevent undesired tissue-to-tissue adhesions resulting from trauma or surgery.

Devices and methods for implantation at a native mitral valve. One embodiment of the device includes a valve support having a first region and a second region, and anchoring member having a longitudinal dimension with a first portion configured to contact tissue at the non-circular annulus, a second portion configured to be attached to the valve support, and a lateral portion transverse to the longitudinal dimension between the first portion and the second portion. The anchoring member and the valve support are configured to move from a low-profile configuration to an expanded configuration in which the first portion of the anchoring member at least partially adapts to the non-circular annulus of the native mitral valve and a shape of the first region of the valve support is at least partially independent of a shape of the first portion of the anchoring member.

A collapsible prosthetic heart valve includes a stent and a valve assembly. The stent has an annulus section with a relatively small cross-section, and an aortic section with a relatively large cross-section. The valve assembly, including a cuff and a plurality of leaflets, is secured to the stent in the annulus section such that the valve assembly can be entirely deployed in the native valve annulus and function as intended while at least a portion of the aortic section is held by the delivery device in a manner that allows for resheathing. The configuration of the prosthetic valve is such that the valve leaflets can fully coapt and the valve can function properly even when the stent and/or valve assembly become distorted upon deployment or use.

A method of forming an orthopedic implant, the method comprising the steps of providing a first implant component and a second implant component, the first implant component having a stem and a second implant component including a head defining a female taper sized to receive the stem; coupling the stem to the female taper of the head; forming a modular injunction between the stem and head; applying a seal to the modular injunction to limit bodily fluid from contacting the modular injunction; and forming the orthopedic implant.

The present disclosure relates to methods of facilitating bone growth. The method may include positioning a device around at least a portion of a bone exhibiting a defect, the device capable of retaining bone segments and micro-structured particles. The method may also include applying micro-structure particles within the device to the defect, wherein each of the micro-structure particles include at least one pore therein. In addition, the method may include aligning at least a portion of the micro-structure particles and applying a polymer to the particles and solidifying the polymer.

A device for improving the function of a heart valve comprises a first loop-shaped support, which is configured to abut a first side of the heart valve, and a second loop-shaped support, which is configured to abut a second side of the heart valve opposite to said first side, whereby a portion of the valve tissue is trapped between the first and second supports. An outer boundary of the second support is greater than an outer boundary of the first support.

Fluoroaryl Grignard reagents are produced from a hydrocarbyl Grignard reagent and fluoroaromatic compounds via separate additions of different fluoroaromatic compounds, such that the conversion of hydrocarbyl Grignard reagent to the desired fluoroaryl Grignard reagent is essentially complete, and thus the reaction product is free or essentially free of agents that may negatively affect subsequent reactions. The fluoroaryl Grignard reagents may be further reacted with boron trihalides in order to obtain tris(fluoroaryl)boranes or tetrakis(fluoroaryl)borates.

A universal linker structure is provided, in which a functional group and activating leaving group are placed on a tether, allowing the placement of an electrophile at the end of any nucleic acid sequence. The electrophile on the tether can react with a second nucleic acid carrying a nucleophile when the two nucleic acids are hybridized near one another, resulting in release of the leaving group, and creation of a functional change. The linker can be designed to destabilize the ligation product without slowing the rate of reaction. This lowers product inhibition, and the target DNA or RNA can become a catalyst for isothermally generating multiple signals for detection. This enhanced signal is demonstrated in solution experiments and in solid supported assays. The universal linkers of the present invention are simple and inexpensive to prepare, and can be appended to any polynucleotide in automated steps on a standard DNA synthesizer.

The invention relates to a safety device (1) for detecting electrode breakage in an electric arc furnace, wherein an electrode (6) is secured on an electrode support arm (4), and wherein a conduit is filled with a medium under a constant pressure and a pressure drop is produced at an electrode breakage, which is detected as an alarm signal. Here, the conduit (7a-d,3) is integrated in a protective component that is arranged beneath the electrode support arm (4) thereon, wherein in case of an electrode breakage, the conduit (7a-d,3) is damaged by a produce electric arc and the pressure drop takes place.

Metallurgical reactors having cooling capability and electrode feed capability are disclosed. The reactors may include a shell having a sidewall and a bottom, where the shell is adapted to contain a molten material. The reactors may include at least one consumable electrode protruding through an opening of the shell and into the molten material. The reactors may include a current contact clamp configured to conduct operating current to the electrode, where the current clamp is in contact with the electrode, and where the current clamp comprises at least one internal channel, wherein the internal channel is configured to circulate a cooling medium. The reactors may include an electric isolation ring disposed between the electrode and the opening of the shell, wherein the electric isolation ring is configured to sealingly engage the electrode and the opening so as to restrict flow of the molten material out of the shell.

Apparatus and method are provided for electric induction heating and/or stirring of a molten electrically conductive composition in a containment vessel with the apparatus being removably insertable in the molten composition. An induction coil embedded in refractory or a coating is submerged in the composition and used to heat and/or stir the molten composition either externally or internally to the refractory or coating.

A method for treating spheroidal graphite iron includes the step: pouring molten spheroidal graphite iron into a pouring electrical furnace (1); covering the molten spheroidal graphite iron (5) with alkali slag (6) which is melted at high temperature and rich in alkali earth metal ion, rare earth metal ion, or mixture of them; connecting the molten spheroidal graphite iron (5) with the negative pole of the direct current source by one pole (7); connecting the alkali slag (6) with the positive pole of the direct current source by another pole (4), treating the molten spheroidal graphite iron (5) with the alkali slag (6) which is used as electrolyte. The method can prevent the spheroidized fading velocity of the spheroidal graphite iron. The pouring electrical furnace can be used for treating the molten spheroidal graphite iron.

A support arm for a water-cooled, current-conducting electrode includes wall elements, wherein each wall element is a flat conductive metal with a hollowed out recess on its outer surface extending over its length. The support arm further includes a cover extending over each recess to define a closed cooling channel within each wall element when the cover is welded to the wall element. The cover includes with an inlet port and an outlet port for cooling water.

A sealing device is arranged around a rod electrode extending vertically through an aperture made in the ceiling of an arc furnace and being vertically movable inside the furnace to prevent the access of gases from the furnace through the aperture to the atmosphere, and on the other hand to prevent air from flowing from the atmosphere into the furnace. The sealing device comprises a gas distribution chamber provided with an inlet channel for feeding essentially passive gas, such as nitrogen or air, into the gas distribution chamber. The sealing device also includes a slit nozzle encasing the electrode, through which nozzle a gas jet is arranged to be discharged from the gas distribution chamber towards the electrode in a direction that is at an angle with respect to the horizontal plane and has a slightly upwards inclined orientation, and that is, with respect to the furnace interior, pointed outwardly, so that the sealing is carried out owing to the effect of the created stagnation pressure.

A combustion tube mounting system releasably mounts a combustion tube to an aperture in the floor of a furnace housing. The combustion tube has a base assembly with a cam and can be manually or automatically unlocked by cam pins in the floor for selectively engaging the cam for lowering the combustion tube from the floor of the furnace. When a new combustion tube is placed on the lower seal assembly and raised, it automatically aligns and engages the upper furnace seal and engages cams on the floor of the furnace housing which lock the combustion tube in place as it is introduced into the furnace.

Apparatus and process for heating and melting a material in a susceptor vessel are provided wherein phase synchronized ac voltage is supplied from a separate power source to each one of at least two induction coils in separate zones around the vessel. Power magnitude from each source to an induction coil is controlled by pulse width control of the source's output voltage. Output frequency from each source is either fixed or variable based upon the electrically conductive state of the material. Optional electromagnetic stirring is achieved by establishing a phase shift between the voltage outputs of the power supplies after the material in the susceptor vessel has melted.

A heating electrode assembly for a crystal growth furnace includes: a heat insulation board unit that is disposed between a furnace wall and a heater, that includes a first surface facing the furnace wall and a second surface facing the heater, and that is formed with a hole extending through the first surface and the second surface; an electrode unit that includes an electricity input portion mounted to the furnace wall, a post portion disposed in the hole, and an abutment flange connecting the post portion and the heater; and an electrical insulating unit including a tubular sleeve that is disposed in the hole and that surrounds the post portion, and a pad that is clamped between the abutment flange and the second surface.

In a sealing device (1) for sealing the through hole of an electrode, the pressurizing medium that generates the pressure of mechanical sealings against a rod electrode structure is an inert gas, such as nitrogen. The means for pressing the created sealing ring (6) against the rod electrode structure (4) include a gas distribution chamber (8) surrounding the sealing ring (6); a first channel (9) that is arranged to provide a flow path for the inert gas in between the hose (14) and the gas distribution chamber (8); an annular groove (10) in the sealing surface (7) of the sealing ring (6); and a second channel (11), which is placed in the sealing ring (6) and is arranged to provide a flow path for the gas from the gas distribution chamber to the groove (10) for extruding the gas in between the sealing surface (7) and the rod electrode structure (4).

Disclosed herein are a graphite crucible for electromagnetic induction-based silicon melting and an apparatus for silicon melting/refining using the same, which performs a melting operation by a combination of indirect melting and direct melting. The crucible is formed of a graphite material and includes a cylindrical body having an open upper part through which a silicon raw material is charged into the crucible, and an outer wall surrounded by an induction coil, wherein a plurality of slits are vertically formed through the outer wall and an inner wall of the crucible such that an electromagnetic force created by an electric current flowing in the induction coil acts toward an inner center of the crucible to prevent a silicon melt from contacting the inner wall of the crucible.

Systems and methods are provided for a high performance heater. In an embodiment, the high performance heater comprises a first stackable tray comprising a first alignment pin that insulates a first heating element disposed in the first stackable tray; a second stackable tray comprising a second alignment pin that insulates a second heating element disposed in the second stackable tray, wherein a top of the first alignment pin fits into a cutout of a bottom of the second alignment pin when the first and second stackable trays are stacked, and wherein the first and second stackable trays comprise one or more materials, an outer diameter and an inner diameter, and wherein an area between the outer diameter and the inner diameter of the stackable trays comprises at least one cutout portion that allows expansion of the material(s) when the high performance heater is at high temperatures.

An electrode for a resistance analytical furnace has a crucible-engaging surface and an end spaced from the crucible-engaging surface having a plurality of grooves formed therein. A manifold mounted on the end of the electrode defines a dust recovery plenum and includes an outlet communicating with the plenum for coupling to a vacuum source to remove debris from the electrode. The improved electrode and electrode cleaning manifold positioned on the electrode provides a turbulent airflow for removal of dust and debris from an analytical furnace.

A coupling means (10) provided with a first member (20) suitable for being fastened to a first rotary part (2) and with a second member (30) suitable for being fastened to a second rotary part (3), the first member (20) being provided with a first diaphragm (22) and the second member (30) being provided with a second diaphragm (32) that is secured to the first diaphragm (22). An emergency torque transmission device comprises at least one bayonet system including a protuberance (50) secured to one member (30) and co-operating with an angled groove (60) secured to the other member (20) by being inserted in the angled groove (60) by a thrust-and-rotation movement, in the absence of said breakage said coupling means (10) including both axial clearances in compression (70') and in translation (70″) and also circumferential clearance between each protuberance (50) and walls defining the corresponding angled groove (60).

A shaft portion of a joint outer ring where projections extending in an axial direction are provided is press-fitted into a hole portion of a hub wheel to thereby form recesses by the projections in an inner diameter surface of a shaft fitting hole of the hub wheel, by which a recess-projection fitting structure is constructed. An entire area of fitting sites of the projections and the recesses are brought into close contact. Moreover, a bolt member is fastened in a bolt hole provided in the shaft portion of the joint outer ring after the construction of the recess-projection fitting structure, which restricts separation between the hub wheel and the joint outer ring. As the bolt member, if an outer diameter of a seating surface thereof is d1 and a shaft diameter is d2, a bolt member satisfying a relational expression of 2.3≦(d1/d2)2≦4.9 is used.