Abstract: A radial compression mechanism includes a plurality of die, each of the plurality of die have a wedge shaped tip. The dies are arranged around a common central axis so that the wedge shaped tips form an elongated central cavity and move between an expanded position and a contracted position. Each die includes a fluid duct extending lengthwise through the die proximate the wedge-shaped tip. Each fluid duct includes an inlet fluid port and an outlet fluid port. The fluid ducts are connected in parallel by a fluid supply manifold connected to each inlet fluid port of each die by an inlet conduit, and a fluid return manifold connected to each outlet fluid port of each die by an outlet conduit.

Abstract: Apparatus (20, 22) and a method for mechanically joining a steel sheet portion (28 or 32) of advanced high strength steel to a metallic sheet portion (30 or 34) is performed to a light-safe extent by a detector assembly (106) during the mechanical joining that may be clinching, clinch riveting, full-punch riveting or self-piercing riveting.

Abstract: An edge dam of a twin roll type strip caster is provided as a refractory material having a sealing member for sealing both end surfaces of a pair of casting rolls, and is pressed and raised according to wear of the sealing member. To uniformly maintain a contact area of the sealing member and the casting roll in a process in which the edge dam is moved while the edge dam is pressed and raised, both sides and a lower part of the sealing member are formed as an inclined surface inclined inwardly of the sealing member. An angle of inclination of the inclined surface is increased in a direction in which the sealing member is raised, and the angle of inclination ? of the inclined surface is obtained by a relationship between a moving distance l due to raising of the edge dam and a wear depth d.

Abstract: An injection assembly (2) of a hydraulic machine for diecasting is provided with a main shut-off valve (50) suitable to prevent the return of fluid from the main pressure chamber (30). The main valve (50) comprise a containment case (541), in which a return spring (540) is housed, suitable to retain any rupture fragments thereof.

Abstract: The invention relates to a refractory (fireproof) impact pad (also called impact pot).

Abstract: The invention relates to a refractory submerged entry nozzle (also called SEN or casting nozzle) especially but not limited for use in a continuous casting process for producing steel.

Abstract: A powder for molding is a mixture of first constituent particles, which are made up of first metal base particles, and second constituent particles, which are made up of second metal base particles. A first lubricant concentration that is a mass proportion of a first internal lubricant adhered to the surface of the first metal base particles with respect to the total of the first constituent particles, is greater than a second lubricant concentration that is a mass proportion of a second internal lubricant that is adhered to the surface of the second metal base particles with respect to the total of the second constituent particles.

Abstract: A finish heat treatment apparatus for an iron powder. Raw iron powder is placed on a continuous moving hearth and continuously charged into the apparatus. In a pretreatment zone, the raw iron powder is subjected to a pretreatment of heating the raw iron powder in an atmosphere of hydrogen gas and/or inert gas at 450 to 1100° C. In decarburization, deoxidation, and denitrification zones, the pretreated iron powder is subsequently subjected to at least two treatments of decarburization, deoxidation, and denitrification. In the pretreatment zone, a hydrogen gas and/or an inert gas serving as a pretreatment ambient gas is introduced separately from an ambient gas used in the at least two treatments is introduced from the upstream side of the pretreatment zone and released from the downstream side so as to flow in the same direction as a moving direction of the moving hearth.

Abstract: This method for producing porous sintered aluminum includes: mixing aluminum powder with a sintering aid powder containing titanium to obtain a raw aluminum mixed powder; mixing the raw aluminum mixed powder with a water-soluble resin binder, water, and a plasticizer containing at least one selected from polyhydric alcohols, ethers, and esters to obtain a viscous composition; drying the viscous composition in a state where air bubbles are mixed therein to obtain a formed object prior to sintering; and heating the formed object prior to sintering in a non-oxidizing atmosphere, wherein when a temperature at which the raw aluminum mixed powder starts to melt is expressed as Tm (° C.), a temperature T (° C.) of the heating fulfills Tm?10 (° C.)?T?685 (° C.).

Abstract: A forming die assembly includes an upper die including a first backup member and a first press member that is attached to the first backup member, has an L shape in a vertical sectional view, and is heat-resistant; and a lower die including a second backup member and a second press member that is attached to the second backup member, has an L shape in the vertical sectional view, and is heat-resistant. The first press member and the second press member press upper and lower surfaces of a workpiece accommodated in a press space that is formed between the first press member and the second press member, so as to produce a forged product.

Abstract: Techniques are disclosed for fabricating multi-part assemblies. In particular, by forming release layers between features such as bearings or gear teeth, complex mechanical assemblies can be fabricated in a single additive manufacturing process.

Abstract: Described is a wear-resistant roller component for handling abrasive materials where the component comprises a metal body with at least one surface. It is characterized in that a metal template having a pattern of through-going holes is arranged on the at least one surface of the metal body and in that a cover arranged to cover at least a part of the metal template is located at a distance from the metal template to form a gap between the cover and the metal template and in that a powder material suitable for sintering is introduced into the through-going holes in the metal template through the gap and in that the metal body, the metal template, the cover and the material powder are bonded together by means of a sintering process.

Abstract: A cutting method in which, in cutting a circumferential face of a work, control is enabled to make a cutting velocity constant accurately by using a cutting tool projecting from a main shaft which turns around a predetermined position serving as a center and for which a turning radius is adjustable, wherein, in the case that a turning angular velocity of the main shaft is represented as ?, a distance from a turning center to a tip of the cutting tool is represented as R, and a cutting velocity of the tip of the cutting tool is set to a constant value C, making the cutting velocity of the cutting tool constant by performing control such that ?0 changes in association with a change in the distance R so that ?=(C2?{dot over (R)}2)1/2/R is formulated (where {dot over (R)} denotes a time differential of the distance R), thus providing an even cut face.

Abstract: A machining head is provided with a turret on which multiple rotating tools are mounted, and this head is configured such that rotation of each of the multiple rotating tools during machining and rotation of the turret are performed by a single motor. A switchable turret rotation transmission mechanism is disposed to be capable of transmitting the rotation of the motor shaft to the turret as the rotation of the turret and releasing the transmission. The rotation of each of the multiple rotating tools during the machining and the rotation of the turret can be performed by the single motor.

Abstract: A tool arrangement with a screw-in tool and a tool receiver, the screw-in tool having a thread for engagement in a counter thread on the tool receiver. The counter thread and the thread have different thread contours and therefore, in the screwed condition, these adapt to one another by elastic deformation.

Abstract: A bottom cutting step up reamer incorporates a shaft having a first end with attachment features adapted to be received in a chuck. A plurality of bottom cutting edges substantially perpendicular to the shaft are located at a second end distal from the first end. At least one step up land is provided proximate the plurality of bottom cutting edges and spaced toward the first end with a plurality of parallel cutting edges substantially parallel to the shaft.

Abstract: The hole saw with threadably removable portion is an improved hole saw that includes a removable portion that is able to slide back and forth with respect to an outer drill bit. The outer drill bit includes internal threadings along an inner surface, which correspond with external threadings provided on an outer surface of the removable portion. When the hole saw has bored a hole into an object, a core remains inside of the outer drill bit. The rotation of the drill rotates the removable portion with respect to the outer drill bit in order to push the core out of the outer drill bit. The outer drill bit includes a shoulder, which works in concert with the removable portion so as to lock the components together when in use as a hole saw.

Abstract: A machine tool includes a linear movement axis for moving a main spindle, at least two linear movement axes for moving a table, and a rotation table including at least one rotation axis, the rotation table being placed on the table. A numerical controller performs machining by executing a machining program for tool center point control where the tool orientation is fixed to a certain axis or a certain surface, and by changing the tool orientation by controlling each axis of the machine tool based on set tool use range and tool orientation change waveform pattern.

Abstract: Apparatus, methods, and other embodiments associated with a key duplication machine are described. In one embodiment, an assembly for duplicating a master key includes an optical imaging device, a logic, a clamping assembly, and a cutting member. The optical imaging device is capable of capturing an optical image of at least a portion of the master key. The logic is capable of determining a key pattern of the master key from the optical image of the master key. The clamping assembly is capable of clamping a key blank and the cutting member is capable of cutting a key pattern into said key blank.

Abstract: A ball end mill comprises a gash provided at a front end portion of a main end mill body rotated about an axis; and at least one cutting edge which has a rotational trajectory around the axis that forms a convex hemispherical shape having a center on the axis. The cutting edge is formed at a peripheral edge portion of a wall surface of the gash. A difference between a first and second included angles is within ±7°, where the first included angle is formed between the axis and a straight line connecting the center with a cutting edge position at which a depth of the gash is maximal in a cross-section orthogonal to the cutting edge, and the second included angle is formed between the axis and a straight line connecting the center with a cutting edge position at which a rake angle of the cutting edge is maximal.

Abstract: Extraction tongs with replaceable jaw tips include jaw tips with mating gripping projections. Each extraction tong includes a plurality of inward extending teeth. A thickness of the extraction tong is reduced at a bottom to form a jaw tip extension. A substantially triangular projection extends outward from opposing sides of the jaw tip extension. A plurality of holes are formed through the jaw tip extension. Each jaw tip includes a tong slot, which is sized to receive the thickness of the jaw tip extension. A substantially triangular slot is formed in opposing walls of the tong slot to receive the two substantially triangular projections. A plurality of counterbore holes are formed in opposing sides of the jaw tip. A first lengthwise projection is formed on a gripping surface of the first jaw tip. A pair of second lengthwise projections are formed on a gripping surface of the second jaw tip.

Abstract: A saw bench having a first pair of legs and a second pair of legs. Between the first pair of legs and the second pair of legs are two cross members for material to be cut. A sawing kerf is formed between cross members. A first guide rail and/or a second guide rail for a sawing member is mounted on the saw bench in such a way that, during sawing of the material to be cut, the sawing member engages through the sawing kerf below a level of the material to be cut, which is held by the two cross members.

Abstract: A cylindrical calibration head for the drilling of a shaft, includes three flutes arranged evenly around the circumference so that they are spaced one from the next by an angle of 120° with respect to a rotation with respect to the axis of the calibration head, the flutes allowing for the removal of chips and the passage of lubricant during drilling, each of the flutes including a machining insert of which the position in the flute can be adjusted using an adjusting cartridge.

Abstract: A reamer or similar tool comprising a cutting device having a cutting edge, a clamping device, whereby the cutting device can be clamped to the main body of the tool, an adjusting device that interacts with the cutting device, for adjusting the machining diameter of the tool, and a guiding device comprising an elongated guiding element, which interacts with an elongated guiding receptacle such that the cutting device can be guided in a sliding manner perpendicularly to the center axis during a displacement when the adjusting device is activated. The guiding element and the guiding receptacle extend perpendicularly to the center axis of the main body of the tool. The guiding device of the tool has a single guiding element and/or a single guiding receptacle, and the guiding element has an elongated elevation and the guiding receptacle has an elongated recess.

Abstract: In a wire electric discharge machine, a control unit is configured to deposit constituents of a wire electrode between a workpiece and a portion to be cut off from the workpiece to bond the workpiece and the portion to be cut off by outputting a signal for making an output voltage of a variable DC power supply lower than during normal machining and the on-time of a second switching element longer than during the normal machining, at least in a part of a machining path.

Abstract: A method includes applying solder pastes separately to first and second portions of the first member; bringing the solder paste applied to the first portion of the first member and a first portion of the second member into contact with each other, and bringing the solder paste applied to the second portion of the first member and a second portion of the second member into contact with other; and causing the solder paste brought into contact with the first portion of the second member and the solder paste brought into contact with the second portion of the second member to melt. In the melting, molten solder formed by melting the solder paste brought into contact with the first portion of the second member and molten solder formed by melting the solder paste brought into contact with the second portion of the second member are joined to each other.

Abstract: The present invention relates to an impeller manufacturing method in which a thermal cycle is performed on an assembly body with a brazing material formed of a Ni-containing Au alloy being placed at a bond portion of at least two impeller constituent members. The thermal cycle includes a temperature increasing process with a temperature increasing rate of 20° C./hr. to 100° C./hr., the process including a first intermediate retention and a second intermediate retention each keeping the temperature, the first intermediate retention performed in a temperature range of 500° C. to 850° C. and the second intermediate retention performed in a temperature range of 850° C. to 950° C. (but not including 850° C.). In the thermal cycle, the temperature is increased in a temperature range exceeding 950° C. after the second intermediate retention at a rate lower than that before the second intermediate retention.

Abstract: A system and method to correct for height error during a robotic welding additive manufacturing process. One or both of a welding output current and a wire feed speed are sampled during a robotic welding additive manufacturing process when creating a current weld layer. A plurality of instantaneous contact tip-to-work distances (CTWD's) are determined based on at least one or both of the welding output current and the wire feed speed. An average CTWD is determined based on the plurality of instantaneous CTWD's. A correction factor is generated, based on at least the average CTWD, which is used to compensate for any error in height of the current weld layer.

Abstract: A method of single-sided resistance welding includes providing a first workpiece and a second workpiece. The first workpiece is positioned so that at least a portion of the first workpiece is in contact with at least a portion of the second workpiece. A weld electrode is positioned in contact with the first workpiece, and a ground electrode is positioned in contact with the second workpiece. A determination is made as to whether a gap or other high resistance condition is present between the first workpiece and the second workpiece. If a gap or other high resistance condition is determined to be present between the first workpiece and the second workpiece, the gap or other high resistance condition is reduced, and the first workpiece and the second workpiece are joined through welding.

Abstract: As a correction amount is acquired a deviation between a first rotational angle of a servo motor when a reference movable electrode is brought into contact with a reference opposite electrode and a second rotational angle of the motor when the reference movable electrodes pushes in the reference opposite electrode with a predetermined pressing force; and a third rotational angle of the servo motor when a movable electrode to be measured pushes in an opposite electrode to be measured with the same pressing force is corrected based on the correction amount.

Abstract: A wafer producing method for producing a hexagonal single crystal wafer from a hexagonal single crystal ingot including a separation start point forming step of setting the focal point of a laser beam inside the ingot at a predetermined depth from the ingot's upper surface, which depth corresponds to the thickness of the wafer to be produced, and next applying the laser beam to the upper surface of the ingot while relatively moving the focal point and the ingot to thereby form: (i) a modified layer parallel to the ingot's upper surface, and (ii) cracks extending from the modified layer, thus forming a separation start point. Preferably, the laser beam includes a plurality of laser beams to be simultaneously applied to form a plurality of linear modified layers. The focal points of the laser beams are arranged with predetermined spacing in the direction of formation of an off angle.

Abstract: A method for processing a part (10) with an energy beam A mask (70, 80) is arranged between a source of the energy beam and the part. The mask is configured with a beam-transmissive portion (71) in correspondence with mutually opposed portions (12, 14) of the part. Simultaneously heating the mutually opposed portions of the part is performed with energy beamlets passing through the beam-transmissive portions of the mask This simultaneous heating is configured to keep a thermally-induced distortion of the part within a predefined tolerance. Scanning of the mask with the energy beam may be performed without precisely tracking the mutually opposed portions of the part, thereby avoiding a need for complicated numerical programming for tracking a relatively complex geometry defined by the mutually opposed portions of the part.

Abstract: There is provided a power control method for a fiber laser processing machine including: a fiber laser oscillator having a plurality of fiber laser modules each of which generates a laser beam; a laser processing head for emitting the laser beam generated from the fiber laser oscillator; and a condenser lens with a prescribed focal length provided between a workpiece and the laser processing head, for irradiating the workpiece with the laser beam having a spot diameter output from the laser processing head, wherein the number of the plurality of fiber laser modules oscillated is adjusted so as to achieve the spot diameter corresponding to the workpiece, and thereby, a beam quality from the laser processing head is adjusted.

Abstract: The present embodiments providing methods, systems and apparatuses of protecting a surface during laser machining. In some embodiments, a method of protecting a surface during laser machining comprises: directing a fluid into a cavity of an object being laser machined, where the fluid does not have laser absorption properties; and directing a plurality of laser pulses at a wall of the object being laser machined, where the laser pulses are configured to form a hole through the wall such that at least one laser pulse passes through the hole and enters the cavity while the fluid is directed into the cavity such that the laser pulse is incident on the fluid and a surface together in order to inhibit backwall damage.

Abstract: A laser welding apparatus generates laser by a laser oscillator, converges the laser by a condenser lens, and applies the laser to an upper sheet and a lower sheet superposed together so as to weld the upper sheet and the lower sheet to each other. According to this apparatus, by laser irradiation, a melt pool Y is formed in the upper sheet and the lower sheet superposed together. Furthermore, by laser irradiation, the melt pool Y is caused to flow, and the upper sheet and the lower sheet are welded together.

Abstract: A laser plotter, a device and a method for cutting of a graphic is disclosed. The method may comprise preparation or loading of a processing job with a graphic and identification features at a display; application of the recognition features and of the graphic to the workpiece; arrangement of the workpiece in a processing area of a laser plotter; acquisition or detection of identification features in order to determine the position and alignment of the applied graphic in the processing area; carrying out the processing after successful identification of the graphic; after the insertion of the workpiece, a laser-pointer is positioned on any selected identification feature, whereupon, a processing image represented on a display element, with the identification feature, is moved at the display element in such a way that a laser position displayed at the display element coincides with the identification feature.

Abstract: Methods of laser processing a transparent material are disclosed. The method may include positioning the transparent material on a carrier and transmitting a laser beam through the transparent material, where the laser beam may be incident on a side of the transparent material opposite the carrier. The transparent material may be substantially transparent to the laser beam and the carrier may include a support base and a laser disruption element. The laser disruption element may disrupt the laser beam transmitted through the transparent material such that the laser beam may not have sufficient intensity below the laser disruption element to damage the support base.

Abstract: A vehicle frame assembly has a first frame member defining a first frame member axis and a slot and having a first frame member connection portion adjacent the slot. A second frame member defining a second frame member axis has a projection and a second frame member connection portion adjacent thereto. The projection is received in the slot. The first frame member connection portion is connected to the second frame member connection portion to form a connection region in which the second frame member axis is disposed at a non-zero angle to the first frame member axis in the connection region. The method of assembling the frame includes inserting the projection into the slot, contacting the connection portions to each other to form the connection region with the members being positioned for connection with their axes disposed at a non-zero angle to each other, and connecting the connection portions.

Abstract: The invention relates to a paste, preferably for joining components of power electronics modules, the paste comprising a solder powder, a metal powder and a binder, wherein the binder binds solder powder and metal powder before a first heating. According to the invention, the binder is free of flux or is a flux having only low activation. In this way, a joining layer which exhibits only few included voids and good mechanical and electrical stability can be provided between a first and a second component.

Abstract: A welding filler metal or a welding filler metal product having, in weight percent: 17.0-23.0% chromium, 5.0-12.0% molybdenum, 3.0-11.0% tungsten, 3.0-5.0% niobium, 0-2.0% tantalum, 1.2-3.0% titanium, 0.005-1.50% aluminum, 0.0005-0.100% carbon, <2.0% iron, <5.0% cobalt, and balance nickel wherein the nickel is 56.0-65.0%. A weld deposit formed from the welding filler metal has a minimum yield strength in the as-welded condition of at least 72 ksi (496 MPa). Also, a weld deposit and a method of forming a weld deposit comprising, in weight percent: 17.0-23.0% chromium, 5.0-12.0% molybdenum, 3.0-11.0% tungsten, 3.0-5.0% niobium, 0-2.0% tantalum, 1.2-3.0% titanium, 0.005-1.50% aluminum, 0.0005-0.100% carbon, <8.0% iron, <5.0% cobalt, and balance nickel wherein the nickel is 56.0-65.0%. The weld deposit has a minimum yield strength in the as-welded condition of at least 72 ksi (496 MPa).

Abstract: Various embodiments of a metal cored wires and methods are disclosed. In one embodiment of the present invention, a metal cored wire comprises a metal sheath and a metal-powder core material comprising manganese particles. The manganese particles are coated with a coating material to reduce the manganese fumes and exposure during welding.

Abstract: The present invention is directed to flux compositions and uses thereof. One composition comprises an activator and a solvent being a glycerol ethoxylate with a molecular weight of 200-500. Another composition comprises an activator, a solvent being a glycerol ethoxylate with a molecular weight of 200-500 and an amine. A soldering method for joining objects is also provided, comprising the steps of applying a flux composition to at least a portion of one or more of the objects, and joining the objects.

Abstract: A pre-flux coating for the manufacturing of heat exchanger components of aluminum, wherein the coating comprises a combination of fluxes in the form of potassium aluminum fluoride K1-3AlF4-6, potassium trifluoro zincate, KZnF3, lithium aluminum fluoride Li3AlF6, a filler material in the form of metallic Si particles, Al—Si particles and/or potassium fluoro silicate K2SiF6, an additive in the form of aluminum oxide and at least one other oxide selected from the group consisting of zinc oxide, titanium oxide and cerium oxide forming a post braze ceramic layer, and a solvent and a binder containing at least 10% by weight of a synthetic resin which is based, as its main constituent, on a methacrylate homopolymer or a methacrylate copolymer.

Abstract: Apparatus for assisting in weld assembling a box column from a tack-welded pre-assembly of planar plate components. The apparatus features (1) an elongate frame defining a rotational-assembly axis, and (2) plural pre-assembly-receiving, rotational support structures mounted at spaced locations on the frame—each support structure including (a) an openable/closable yoke possessing a collar-reception zone, (b) an openable/closable collar rotatably receivable within this reception zone, and possessing a central throughpassage having a cross-sectional configuration which is larger than that of a box-column which is to be assembled, and (c) a pair of removably-collar-attachable, throughpassage clamping shoes for forming cooperatively, within the collar throughpassage, a window for complementarily, receiving extension therethrough of a box-column pre-assembly's cross section.

Abstract: A method for repairing a defect affecting a weld. A sheet of filler metal is placed on the surface of the welded part, next to the region of the defect. The sheet is locally welded to the welded part in the region of the defect using a friction stir welding tool having a retractable welding pin. The welded part and the sheet are separated such that the filler metal amalgamated with the metal of the welded part remains in position. The local welding operation includes successively performing the following: setting the welding tool into rotation and putting it under pressure; inserting the pin to a small distance from the anvil while maintaining or increasing the pressure on the shoulder of the welding tool; progressively retracting the pin while maintaining or increasing the pressure on the shoulder; and stopping the pressure on the shoulder when the retractable pin has been retracted.

Abstract: A process for producing a bearing seat or a drive journal having a large diameter on a rolled threaded spindle is disclosed. The blank of the threaded spindle is hot-upset in the longitudinal direction, such that it bulges radially with respect to the longitudinal direction, a first longitudinal region having an enlarged diameter being provided.

Abstract: A header box, a furnace and a blocked condensation protection system are disclosed herein. In one embodiment, the header box includes: (1) a first channel having a first channel supply port positioned to be in fluid communication with an inlet of a combustion air blower and a first pressure port couplable to a first input of a pressure sensing device, the combustion air blower and the pressure sensing device associated with the cold end header box and (2) a second channel having a second channel supply port positioned to be in fluid communication with the inlet of the combustion air blower, a second pressure port couplable to a second input of the pressure sensing device and a pressure reference inlet, the second channel in fluid communication with the first channel and configured to have about a same pressure as the first channel when the pressure reference inlet is blocked.

Abstract: A reconfigurable autonomous workstation includes a multi-faced superstructure including a horizontally-arranged frame section supported on a plurality of posts. The posts form a plurality of vertical faces arranged between adjacent pairs of the posts, the faces including first and second faces and a power distribution and position reference face. A controllable robotic arm suspends from the rectangular frame section, and a work table fixedly couples to the power distribution and position reference face. A plurality of conveyor tables are fixedly coupled to the work table including a first conveyor table through the first face and a second conveyor table through the second face. A vision system monitors the work table and each of the conveyor tables. A programmable controller monitors signal inputs from the vision system to identify and determine orientation of the component on the first conveyor table and control the robotic arm to execute an assembly task.

Abstract: A strut (6) of a circular plug projects upward from a main body (4) of a housing (3) and inserts into circular hole (9) of work (8). An opening (20) is formed laterally in a left portion of peripheral wall (18) of strut (6), a cam portion (28) projects leftward from a right portion of the peripheral wall (18). A positioning rod (22) inserts into insertion hole (14) in upper portion of housing (3) which is movable vertically and radially. A cam surface (32) is provided vertically on upper right portion of positioning rod (22), and pushing portion (33) is provided on upper left portion thereof. When a driving arrangement (D) drives positioning rod (22) downward for locking, cam portion (28) pushes the cam surface (32) leftward, and pushing portion (33) passes through opening (20) to press inner periphery of the circular hole (9) of work (8).

Abstract: A circumferential positioning device of automobile hub having rotary positioning seat, transition seat, bearing, positioning pin, positioning cylinder, bearing, base frame, main rotating shaft with sliding spline, coupling assembly, link snap-gauge assembly, lead screw, connecting bolt, nut, servo motor, lower bracket of main rotating shaft, small bracket of belt servo motor, belt pulley servo motor, small belt pulley axle, small belt pulley, belt, large belt pulley. The device in the present invention two radial grooves passing through the center that are formed in the bottom surface of the flange of the hub, correspond to the spoke direction on the facade of the hub and are just matched with the two radial bosses passing through the center on the top face of the positioning seat to achieve a positioning purpose.