Abstract: The present invention provides an appliance for chip removal applications comprising a vibration-damping material wherein the vibration-damping material is a material arranged by nano-dimensional cluster form. The present invention additionally provides a method for manufacturing said appliance. The present invention provides also an appliance obtainable by said method. Additionally the present invention provides an article or work piece for use in an appliance for chip removal applications. Also a computer program is provided for controlling the above method.

Abstract: A toolholder includes a body portion having an exterior surface and a dynamic absorber mounted on the exterior surface of the body portion. The dynamic absorber includes a rigid support member, a cover member, and an absorber mass disposed within a cavity formed by the rigid support member and the cover member. A first resilient support member is disposed between the rigid support member and the absorber mass, and a second resilient support member is disposed between the cover member and the absorber mass. The dynamic absorber is tuned by moving the cover member relative to the rigid support member. A method of suppressing vibrations of the toolholder includes externally mounting the dynamic absorber on the exterior surface of the toolholder.

Abstract: The invention relates to a machine tool, wherein the machine tool has a workpiece clamping device (10) for clamping a workpiece (9), wherein the workpiece clamping device (10) and in this way the workpiece (9) can be moved by means of a piezoactuator (11a, 11b, 11c, 11d). The invention furthermore relates to a corresponding method. The invention provides a machine tool in which vibrations occurring during a machining operation are reduced.

Abstract: The invention refers to a working machine with a machining tool which can be set in a spindle head of a working spindle. A monitoring unit is provided which monitors the shape of the spindle head.

Abstract: A method, system, and apparatus for an adaptive controller for controlling a machining operation on a workpiece by a machining tool are provided. The system includes a sensor for measuring a present value of a spindle load on a spindle drive, and an adaptive controller for comparing the present value of the spindle load to a present value of a target spindle load. The adaptive controller includes a computing element configured to determine a first feed rate value of a machining tool, and a number generator configured to generate a first feed rate dither adjustment value used for adding noise to the first feed rate value. The adaptive controller is configured to control the feed rate of the machining tool relative to the workpiece to maintain the present value of the spindle load approximately equal to the present value of the target spindle load using one or more of the first feed rate value, the first feed rate dither adjustment value, and the second feed rate dither adjustment value.

Abstract: The invention relates to a clamping device for clamping workpiece, which comprises a base in which a center holding fixture for the shank of a tool to be clamped and an annular damping cavity surrounding the fixture or a plurality of damping cavities arranged around the fixture and set off from each other are configured. Every damping cavity is open towards the front face of the chuck base facing the workpiece. The clamping device is characterized in that the open end of every damping cavity is at least partially closed by respective covers which are inserted into the respective damping cavity from the open front face and are fixed inside the damping cavity.

Abstract: A tool holder (1) in the form of a boring head, a chuck, a milling cutting arbor, or the like, is equipped with a damping element (2) in the form of an elongated body that is arranged in an end housing (3) of the tool holder (1), with corresponding shape and size. The tool holder that is characterized in that it includes a device (4) for preventing excessive heating of the damping element (2). The tool holder is more particularly applicable in the field of numerically-controlled machine tool accessories, machining centers, and flexible cells and workshops.

Abstract: A damping tool holder, such as a boring head, a chuck, or a milling cutting arbor, integrates a damping device (2), in the form of an elongated body. The damping device (2) is housed in a mounting body (3), connected by one end to the tool-holder body (1) and having at its other end an end fitting (4) for mounting a tool, whereby the mounting body (3) is equipped with at least one lubricant feed pipe (32), emptying at its front end into the end fitting (4) for mounting a tool and connected at its other end to a circular groove (102) for distributing lubricant that is provided on the front surface of the tool holder (1).

Abstract: A tool holder for a cutting and/or milling machine includes a shank portion configured to be attached to a spindle of the cutting and/or milling machine for mounting the tool holder, and a tool mounting portion for mounting a tool to the tool holder. The tool holder includes a cavity through the shank portion and/or the mounting portion, the cavity being aligned to the rotation axis of the tool holder. The tool holder includes a damping material disposed within the cavity for mitigating harmonic resonance during operation of the cutting and/or milling machine. The damping member may be used in all types and configurations of tool holders.

Abstract: A tool holder (1) has a shaft (2) intended to be arranged in a tool holder in a manufacturing machine, a head (3) on which a cutter is intended to be arranged and a viscoelastic materials (4) arranged so that the cutter is in contact with the manufacturing machine solely via the viscoelastic material (4), in which at least those parts on the surface (5) of the shaft (2) that are intended to be in contact with the manufacturing machine are provided with the viscoelastic material (4). The viscoelastic material (4) is attached on a bearer material that is attached to the surface (5) of the shaft (2).

Abstract: A module for on-line vibration detection and adjustment and machining center using the same are provided in the present invention, wherein the module is disposed at the machining center having an interface of feedrate override and an interface of spindle override and the inverter. The module comprises at least one vibration sensor for detecting the vibrating status of the machining center, thereby generating corresponding at least one sensing signal and a processor for processing the at least one sensing signal so as to generate a spindle adjusting signal for the interface of spindle override and the inverter and a feedrate adjusting signal for the interface of the federate override. The computer numerical controller receives the spindle adjusting signal and the feedrate adjusting signal from the interface of the spindle override and federate override respectively and accordingly controls the feedrate and spindle rate of the machining center.

Abstract: Systems and methods are provided for use in assessing the stability of simultaneous machining (SM) dynamics (which is also known as parallel machining). In SM, multiple cutters, which are generally driven by multiple spindles at different speeds, operate on the same work-piece. In an alternative implementation of SM, single milling cutters with non-uniformly distributed cutter flutes operate on a work-piece. When SM is optimized in the sense of maximizing the rate of metal removal constrained with or by the machined surface quality, “chatter instability” phenomenon appears. The present disclosure declares the complete stability picture of SM chatter within a mathematical framework of multiple time-delay systems (MTDS). A cluster treatment of characteristic roots (CTCR) procedure determines the regions of stability completely in the domain of the spindle speeds for varying chip thickness, thereby replicating the well-known “stability lobes” concept of STM for simultaneous machining.

Abstract: The invention proposes a tool holder (1), in particular of the shrink-fit chuck type, the receiving section (5) of which comprises clamping means (9) which are provided centrally with respect to an axis of rotation (7) of the tool holder (1) for holding a shank (15) of a rotary tool, and which define a receiving opening (13) for the shank (15). The clamping means (9) can be displaced in the radial direction between a radially widened release position for insertion or removal of the shank (15) and a clamping position, in which the clamping means (9) exert radial press-fit forces, which hold the shank (15) in a frictional lock on its cylindrical outer circumferential surface (19), on the shank (15). The clamping means (9) are assigned a clamping surface (17) with a cylindrical contour which, in the clamping position, bears against the outer circumferential surface (19) of the shank (15) with surface-to-surface contact.

Abstract: The damping property of a rear rolling bearing (133) is adjusted by controlling a damping force that is applied by damping application means (5, 134) based on, for example, the type of a tool (T). Thus, it is possible to provide the optimum damping properties for various tools that differ in natural vibration, and to suppress the generation of chattering of the various tools. As a result, it is possible to increase the cut amount per unit time to increase the productivity.

Abstract: A dampened spindle cartridge and a dampened spindle adaptor are provided for damping tool vibrations during operation of a machine tool. Damping media is arranged inside a cavity formed within the spindle adaptor or the spindle cartridge. The damping media may be a solid aggregate, such as steel shot or sand, or a viscous fluid, such as oil. The damping media attenuates and/or converts tool vibrations into friction and heat, thereby dissipating vibration energy generated during cutting operations performed by the machine tool and prevents reinforcement of the forced vibration.

Abstract: The invention relates to a tool head for machine-tools comprising a base body (10) rotatable around an axis of rotation (13), a slider (14) which bears a cutting tool and is adjustable with respect to the base body (10) along an axis of displacement (16) oriented radially with respect to the rotation axis (13) with the aid of a drive mechanism and at least one balancing body (20) for damping the unbalance caused by the slider (14). The aim of said invention is to damp the unbalance and to reduce operating forces. For this purpose, at least two balancing body (20) whose center of gravity (28?, 28?) is offset on the side of the axis of displacement (16) are guidable and/or pivotable with respect to the slider and the base body at points remote from each other.

Abstract: The invention relates to a milling machine (1) for milling at least one surface (2) of a slab (3), wherein the milling machine (1) is preferably a component of a device for producing a metal strip by continuous casting, wherein the milling machine (1) comprises a machine base (4) on which a spindle holder (5) is disposed and from which a spindle holder (5) is formed, in which at least one bearing (7) holding at least one milling cutter (6) is disposed. In order to achieve improved vibration damping during the milling of hot slabs, the invention makes provision such that the machine base (4) is formed at least in sections, preferably completely, from a number of metal walls (8) which enclose a volume, the volume being filled with concrete (9).

Abstract: In a machine tool or a processing method, a column base (12) is supported on a bed (11) movably in a horizontal direction, and a column (13) is installed vertically on the column base (12). A saddle (14) is supported on a side of the column (13) movably in a vertical direction, and a ram stock (15) is supported on the saddle (14) movably in a horizontal direction. A spindle (16) is rotatably supported by the ram stock (15), a damper (21) is provided on the ram stock (15), and an O-ring (22) is provided between the ram stock (15) and the damper (21), so that the O-ring (22) can be deformed by a pressing member (23). An NC device (24) can adjust a deformation degree of the O-ring (22) by the pressing member (23) depending on a mass of an attachment (17). Therefore, vibration of a tool can be effectively damped by changing a natural frequency according to replacement or movement of the attachment.

Abstract: Device and method for milling of materials including a milling cutter body including a first end portion and an opposite second end portion. The first end portion is connected to a rotatable spindle and the second end portion is provided with at least one cutting edge. The milling cutter body defines a longitudinal axis and is provided with an axial recess, wherein at least one mass element is arranged in the recess. The axial position of the mass element in relation to the milling cutter body is tuned by use of tuning members included in the device for the tuning of the natural frequency of the device. The mass element is axially locked in relation to the milling cutter body by use of lock members included in the device, in order to optimize the natural frequency of the device for the milling operation in question.

Abstract: An exemplary embodiment of a material removal tool has a housing at a mating end, an extension longitudinally extending from the housing to a distal end, a plurality of spacers arranged along the extension, and a nut at the distal end of the extension, wherein the plurality of spacers are formed from a material having a Young's modulus of greater than about 1.5 times that of steel. The spacers along the extension of the tool place the stiffer material of the spacer at a location of greatest resistance to bending moments (i.e. highest sectional modulus). Optionally preloading and “built-in” relief points contribute to improved performance of the material removal tool. A method of manufacturing a material removal tool and a method of machining a workpiece are also disclosed.

Abstract: The invention relates to a method of reducing vibrations, occurring during a machining operation, of a machine element (7,8) and/or of a workpiece (5) in a machine tool, production machine and/or in a machine (1) designed as a robot, wherein an additional mass (9a, 9b, 9c) is attached to the machine element (7,8) and/or to the workpiece (5) in an automated manner, wherein the mass of the additional mass (9a, 9b, 9c) is adapted to the machining operation. Furthermore, the invention relates to a machine (1) in this respect. The invention enables vibrations, occurring during a machining operation, of a machine element (7,8) of a machine (1) and/or of a workpiece (5) to be reduced.

Abstract: The invention relates to a machine tool, wherein the machine tool (1) has a spindle (4), wherein the spindle (4) is rotatably arranged in a spindle housing (8), and wherein a body (3) which surrounds the spindle rotary axis (9) is coupled to the spindle housing (8) via spring elements and/or active actuator elements. The invention also relates to a machine tool, wherein the machine tool (1) has a spindle (4) which is rotatably arranged in a spindle housing (8), and wherein at least two mass bodies are coupled to the spindle housing (8) via spring elements and/or active actuator elements. The invention creates a machine tool (1) for which vibrations occurring during a machining process are reduced.

Abstract: A representative machine comprises a non-rigid robotic device having a tool head; and a rigid inertial stiffening system that is part of a tool head and includes a mass to provide precise position of the tool head. The rigid inertial stiffening system achieves high positional precision of the tool head, in the face of large disturbing forces by locally accelerating the mass to counter the disturbing forces.

Abstract: Techniques and apparatuses to provide vibration reduction of a workpiece when performing machining operations are disclosed. In various embodiments, a machine tool includes a shank having at least one end configured for engagement with a machine operable to rotate the shank. A cutting portion has a diameter defined by features used to remove material from a workpiece. The cutting portion is coupled to the shank. A vibration reduction dampener may be located between the shank and the workpiece.

Abstract: A method for machining particularly spectacle lenses by means of a machine which comprises at least one cutting unit and at least one turning unit in a common working space, wherein at least two spectacle lenses are machined at the same time in the working space, one of said spectacle lenses being cut while the other is turned. The machine frames of the cutting unit and of the turning unit are essentially decoupled from one another in terms of vibration and/or at least two machining units of the machine comprise workpiece spindle units for generating a transverse movement of the spectacle lens to be machined with respect to the respective tool, the workpiece spindle units being arranged essentially perpendicular to one another. As a result, it is possible for spectacle lenses to be machined in an extremely short time with high machining performance and with high surface precision and quality.

Abstract: A vibration suppressing method and a vibration suppressing device are disclosed. After a tool is attached to a main spindle, a modal parameter of the tool or a workpiece is computed. Thereafter, a relation between chatter frequency and phase difference is calculated as an approximation formula based on the obtained modal parameter and machining conditions. If chatter vibration occurs after initiation of the machining, a chatter frequency corresponding to a target phase difference is obtained using the approximation formula, and based on the obtained chatter frequency, the number of tool flutes and the main spindle rotation speed, the optimum rotation speed is calculated. The rotation speed of the main spindle is then changed in accordance with the obtained optimum rotation speed.

Abstract: A chattering vibration inhibiting mechanism capable of inhibiting chattering vibration of a machine tool without increasing weight nor requiring a time-consuming adjustment work is provided. A box-shaped package body 21 attached to a spindle head 6, a supporting member 22 disposed to bridge between front and rear walls 21a, 21b in the box-shaped package body 21, and a damper 23 composed of an elastic member 27 and a weight 26 supported by the supporting member 22 are provided.

Abstract: A method of forming integrally bladed rotors for gas turbines is described. The method includes drilling in a workpiece material recesses defining flow passages and rotor blades, performing a coarse milling step to refine surfaces of the rotor blades, and filling the recesses between the rotor blades with a damping material, thus encasing the rotor blades in the damping material. The method further includes performing a finishing milling step to remove the damping material and the workpiece material on surfaces of the rotor blades, while maximizing a damping effect of the damping material on the rotor blades. To maximize the damping effect, the finishing milling tool moves along a path that preferentially mills one surface of a blade while the other surface is in contact with the damping material.

Abstract: For balancing a tool coupling, the compensating measures (removal of material, use of other material) are carried out in two planes an axial distance apart. Tool couplings are provided with recesses for imbalance compensation in two planes an axial distance apart.

Abstract: Disclosed herein is the structure of a damper that is capable of improving the degree of freedom in design to optimize the damping characteristics of the damper and is capable of allowing the damper to be easily optimized and manufactured for a wide variety of dynamic stiffness characteristics of a tool body, and a manufacturing method using the same. A plurality of ring-shaped elastic members are disposed at opposite ends of a weight part. The weight part is connected to the tool body via the elastic members. Consequently, the weight part is moved relative to the tool body. The plurality of elastic members are mounted while spacers are disposed between the elastic members, and the spacers are moved with respect to the weight part in the axial direction thereof. A viscous fluid is filled in the region surrounded by the outer circumferential surfaces of the spacers, the elastic members, and the inner surface of a hollow part of the tool body.

Abstract: Feed back vibrations of a metallic tool generated during the machining of metallic workpieces are damped by detecting an oscillatory motion of the tool, identifying a frequency of the oscillatory motion and generating a mechanical camping force having the same frequency as the oscillatory motion and applied to the tool in counter-direction to a velocity of the oscillatory motion. The damping force can be of constant amplitude or gradually decreasing amplitude.

Abstract: A tool holder and rotating spindle of a milling machine is provided. A dampening member may be disposed on an outer surface of the tool holder or spindle or between the tool and tool holder or tool holder and spindle to mitigate harmonic resonance attributable to the use of the tool holder with the cutting tool.

Abstract: A computer assisted detecting and restraining system for cutting tool chatter. The system comprises a network monitor system, a signal extraction system, a chatter detection system, and a chatter restraint system. The network monitor system monitors a machine tool and receives audio caused during a cutting process. The signal extraction system extracts vibration displacement signals generated during the cutting process converts the vibration displacement signals to digital signals and transfers the digitalized signals. The chatter detection system receives the digitalized vibration displacement signals and sends a control command when the signals are high frequency signals. The chatter restraint system receives the control command and adjusts rotation rates of a spindle of the machine tool accordingly.

Abstract: A spindle structure in which a noise occurrence due to a tap hole and a screw is effectively prevented. A nut for adjusting a preload of a bearing is threadedly engaged with an outer circumference of a spindle. On an edge of the nut, a plurality of tap holes for balance adjustment are provided at even intervals on a circumference centered around the axis of the spindle and to be parallel to the axial direction of the spindle. These tap holes are countersunk, and a plate screw is threadedly engaged so that an edge of each plate screw is flush with a surface of the nut. In addition, the plate screw is used as a balance weight by changing the length thereof.

Abstract: A gyration balancing calibration fee high-speed boring tool, allowing fast replacement for boring bar bodies of different bore sizes, includes an adapter and a boring bar body; a micro-eccentric bore on the adapter to accommodates a pivoting shaft; a V-shaped ring groove being disposed on the pivoting shaft; both a securing hole and a positioning threaded hole being provided on the adapter, each provided with an eccentric positioning recess; a securing screw being disposed to a positioning pin and an elastic positioning screw for foolproof assembly; the boring bar body being tightly engaged with the adapter.

Abstract: A tool holder for use in a rotating spindle of a milling machine. The tool holder comprises a conically tapered shank portion for insertion into the spindle and a cutting tool mounting portion. Disposed between the shank and mounting portions is a flange portion. The flange portion includes a continuous channel formed therein which circumvents the shank portion and is adapted to accommodate a dampening member. The dampening member is compressable between the flange portion and the spindle when the tool holder is inserted into the spindle, and is adapted to eliminate harmonic resonance attributable to the use of the tool holder with a cutting tool.

Abstract: Products and processes for forming assemblies are disclosed. One product described comprises a first element having a structured surface adapted to be coupled with a second element.

Abstract: For a spring sliding on the drawbar, the coil spring is used; the removal work for keeping the inner diameters of the coil springs aligned is performed such that the clearance between the outer diameter of the drawbar and the inner diameter of the coil spring becomes a minimum; and the coil springs are caused to be guided integrally with the drawbar. By doing so, the movement of the center of gravity of the spring that is caused by repeated rotational operation of the main spindle or repeated tool clamping operation will be reduced and the amplitude by vibration will be made smaller.

Abstract: The present invention provides a dynamic balancing ring for a cutter holder for balancing the cutter holder. The dynamic balancing ring includes a circle, plural fixing elements and an adjusting element. The plural fixing elements are used for fixing the circle on the cutter holder, and after the center-of-gravity position of the cutter holder is obtained by dynamic balance corrector, the adjusting element can be installed at a position on the circle corresponding to the center-of-gravity position, and through adjusting the adjusting element, the dynamic balance of the cutter holder can be corrected. For using the dynamic balancing ring for the cutter holder according to the present invention, it is convenient that the dynamic balancing ring can be directly installed on the cutter holder, which is needed to be corrected, without additional processing.

Abstract: A spindle structure in which a noise occurrence due to a tap hole and a screw 2007 is effectively prevented. A nut 8 for adjusting a preload of a bearing 5 is threadedly engaged with an outer circumference of a spindle 2. On an edge of the nut 8, a plurality of tap holes for balance adjustment are provided at even intervals on a circumference centered around the axis of the spindle 2 and to be parallel to the axial direction of the spindle 2. These tap holes are countersinked, and a plate screw 11 is threadedly engaged so that an edge of each plate screw 11 is flush with a surface of the nut 8. In addition, the plate screw 11 is used as a balance weight by changing the length thereof.

Abstract: A machine tool and a tool include an automatic balancing device, with a first balancing mass located such that it is movable relative to the shaft of the machine tool in all radial directions and in the circumferential direction, that may be started rotating via the rotation of the shaft, and that, during rotation, exerts a force on the shaft in the radial direction.

Abstract: The present invention provides a dynamic balancing ring for a cutter holder for balancing the cutter holder. The dynamic balancing ring includes a circle, plural fixing elements and an adjusting element. The plural fixing elements are used for fixing the circle on the cutter holder, and after the center-of-gravity position of the cutter holder is obtained by dynamic balance corrector, the adjusting element can be installed at a position on the circle corresponding to the center-of-gravity position, and through adjusting the adjusting element, the dynamic balance of the cutter holder can be corrected. For using the dynamic balancing ring for the cutter holder according to the present invention, it is convenient that the dynamic balancing ring can be directly installed on the cutter holder, which is needed to be corrected, without additional processing.

Abstract: A device and method for vibration control in a machine for cutting, said machine comprising a cutting tool supported by a tool holder. The device comprises a control unit and converting means which are connectible to the control unit and comprise a vibration sensor and an actuator. The actuator comprises an active element which converts an A.C. voltage supplied by the control unit to the actuator into dimensional changes. Said active element is adapted to be embedded in the body of the tool holder and in such manner that said dimensional changes impart bending to the body of the tool holder.

Abstract: A machining apparatus for conducting at least one of a cutting process and a grinding process, comprises a stationary base; and a working device mounted on the stationary base and having a degree of freedom of more than two axes to conduct at least one of a cutting process and a grinding process, the working device comprising a first working bench which is formed of a ceramic material and is movable linearly with a degree of freedom of not less than one axes or more while holding a work piece or a tool.

Abstract: A main shaft includes a plurality of elastic engagement pieces arrayed along an outer perimeter of an attachment hole. During and after assembly, the elastic engagement pieces elastically abut at least an outer surface of a tapered shank in a tool holder and deform slightly in a radial direction. The elastic engagement pieces provide uniform engagement force between the main shaft and the tool holder over a broad surface area. An elastic flange provides additional elastic engagement and easy separation from the main shaft. Together, the elastic engagement pieces and elastic flange reliably engage and securely attach the main shaft to the tool holder while aiding disengagement.

Abstract: A machine tool (1) for machining by chip removal, in which a machining head (2) operates while being positioned in a horizontal plane and is mounted on a vertical bed (3) to which it discharges the forces (F) by which it is axially stressed, this vertical bed (3) being connected to a supporting structure (4). The vertical bed (3) is pivoted on the supporting structure (4) and there are interposed between the vertical bed and the supporting structure one or more bars (5) whose axial length (L) can be varied by magnetostriction produced by electric currents whose characteristics are determined continuously by a control device (6) in such a way as to counteract the horizontal movements of the vertical bed (3), thus keeping the machining head (2) fixed with respect to the workpiece (7) which it is machining.

Abstract: An arrangement for reducing vibrations in a tool holder (4) with a cutting tool (3) and has a vibration sensor on the tool holder (4) that is connected to a guide unit (11). The tool holder (4) has further two piezo-electric actuators 14 and 15. Under the influence of the vibration sensor (9), the guide unit (11) provides an electric alternating current that is actively guided over time so that the actuators movably affect the tool holder (4) to reduce the vibrations in this. To also be able to dampen transients in the tool holder (4) this is movably connected with a passive dampening arrangement that is independent of the guide unit (11) and that is based on the principle of a springing (8) suspended mass (7). The invention also relates to a method for reducing vibrations. The vibrations in the tool holder are sensed and a corresponding signal is provided to a guide unit that over time provides actively guided signals to the actuators.

Abstract: A machine tool capable of reducing the lateral width of the upper part thereof by reducing the lateral width of a bed (1) while machining through the same lateral moving distance of a spindle (10) as before, comprising longitudinal guide rails (2) installed on the bed (1), a slide (3) installed through the guide rails (2) movably in a longitudinal direction, a column (6) movable in vertical direction, wherein first cover plates (25) are fixed at the right and left sides of a vertical moving route for the spindle (10), side cover plates (26) are installed continuously with the outer end edges of the first cover plates (25) so as to be turnable rearward, a second cover plate (32) is installed at the front sides of the first cover plates (25) and the side cover plates (26) integrally with the slide (3) so as to cover the front side of the moving range of the column (6), and a shielded machining space (SK) is formed at the front of the second cover plate (32).

Abstract: A support structure or sleeve for the spindle of a machine tool consists of a tubular casing, preferably made of sheet steel with a high modulus of elasticity, in contact with a layer of agglomerate obtained by casting inside the casing a mixture formed by a granulate of stone and/or ceramic and/or expanded clay material as well as a synthetic resin of the hardening type, which is subject to cross-linking. The structure thus obtained combines a high vibration damping factor with an excellent mechanical strength and a reduced weight. The structure may also comprise a second casing which is located inside the layer of agglomerate and in contact therewith. The mass of agglomerate may also have, embedded in it, pipes for circulation of a cooling fluid in order to dispose of the heat produced by the spindle during operation.

Abstract: A method for processing a screw rotor includes a step of rotating a blade holder 2 while shifting the blade holder 2 in X-axis, Y-axis, and Z-axis directions to form a groove on the outer surface of a rotating cylindrical workpiece 1 with a tool 3 using a processing apparatus having a bed 11; a C-axis shaft supporter 12 disposed on the bed 11; a C-axis shaft 14 held by the C-axis shaft supporter 12, the C-axis shaft 14 for rotating the cylindrical object 1; a column 13 disposed on the bed 11; the blade holder 2 rotatably held by the column 13; and the tool 3 attached to the blade holder 2.