Abstract: A machine tool including a bed; a work table horizontally movable on the bed; a column extending from the bed; a spindle head movable on the column; an outer cylinder attached inside the spindle head; a stator of a built-in motor; and a spindle sub-cartridge. The spindle sub-cartridge includes a vertical rotating shaft; a front side bearing having an inner ring fitted to a front end of the rotating shaft and an outer ring fitted to a front housing; a rotor of the built-in motor; a rear side bearing having an inner ring fitted to a rear end of the rotating shaft and an outer ring fitted to a bearing sleeve. The movable range of the spindle head in the vertical direction is longer than a length necessary for inserting the spindle sub-cartridge into the spindle head. The spindle sub-cartridge is can be disassembled and assembled integrally with respect to the spindle head.

Abstract: A bearing unit capable of withstanding a large axial force based on a simple structure including: a bearing 10 having an internal ring 13 fitted to an inside member 2, an outer ring 14 fitted to an outside member 6, lots of rolling elements 15 disposed between the outer ring 14 and the inner ring 13; and a transmitting direction shifting means A transmitting an axial force F from the inner ring 13 to the outside member 6 when the axial force F transmitted from the inside member 2 to the internal ring 13 exceeds a predetermined value or above, and a main spindle device of a machine tool, which is provided with the bearing unit, are provided.

Abstract: A main spindle device includes: a housing having an air supply passage; a spindle that is inserted into the housing and supported by a bearing so as to be able to rotate relative to the housing; and an air sealing member that is positioned between an outer circumferential surface of the spindle and the housing on a front side with respect to the bearing along a rotation axis of the spindle, has a substantially annular shape, and is detachably fixed to the housing with an inner circumferential surface of the air sealing member facing the outer circumferential surface of the spindle, wherein air supplied from the air supply source through the air supply passage is discharged into a gap between the outer circumferential surface of the spindle and the housing, thereby effecting non-contact air sealing at least between the inner circumferential surface of the air sealing member and the outer circumferential surface of the spindle.

Abstract: The present invention is to provide a machine tool in which appropriate warm-up operation can be performed. Unnecessary warm-up operation before machining is not carried out and damage of bearings caused by the warm-up operation is prevented. A controlling unit stores data of a supply amount of lubricant to bearings and a rotation speed of a main spindle in a memory unit as time-series data. When rotation of the main spindle is started, the time-series data stored in the memory unit is used to calculate an amount of remaining lubricant in the bearings and determination of necessity of warm-up operation is made based upon the stored data. A rotation speed at a start-up time of the main spindle is controlled according to the determination result.

Abstract: This invention is related to a rigid tapping feedback assembly that is adapted to being retrofit on a milling machine having a spindle with a spindle end extending beyond a bearing cap and an automated drive. In embodiments, the assembly comprising a housing, spindle-pulley adapter that is drivably engaged with the spindle end, pulley assembly, shaft assembly, housing cover plate, and rotary encoder. The housing mounts to the bearing cap and holds the shaft assembly in substantially parallel-spaced alignment with the spindle-pulley adapter. The pulley assembly mechanically links the spindle-pulley adapter and the shaft assembly, typically utilizing pulleys and a timing belt. The housing cover plate mounts to the housing enclosing the assembly components above and supporting the rotary encoder in substantial axial alignment with the shaft assembly. In operation, the rotary encoder senses spindle rotational speed spindle and provides feedback to the automated drive to control downward movement of the spindle.

Abstract: The invention relates to a machining center for work piece machining. The machining center comprises a machine frame, a machine spindle driven by a motor and rotatably arranged on the machine frame, and a group of machine tools that can be exchanged on the machine spindle. The machine tools comprise a coupling shaft that is compatible with a holder of the machine spindle. Furthermore, a rotary transmitter for electric energy is provided, having a stator fixed to the machine in a stationary manner and a rotor rotating along with the machine spindle. It is claimed as novel that the rotary transmitter comprises at least two transmission paths for electric energy which can be selected according to the electric power to be transmitted and the rotational speed of the spindle to be set and which can be activated in the coupled state of the machine tool.

Abstract: A multi-spindle machining machine comprises a base including a working room to move a tool and a workpiece; a working head including a driving spindle disposed on a lower end thereof to clamp the tool; a carrier including a seat fixed on one side of the working room, a rotary shaft mounted on the seat laterally to drive the seat to rotate in an axial direction, a fixing holder connected to the rotary shaft to fix the workpiece to the fixing holder; a lateral driving device disposed on the base and located on one side of the working room in a horizontal direction to drive the working head to move in X and Y axes; a vertical driving device disposed on the base and located on another side of the working room in a lateral direction to drive the seat to move in Z axis direction.

Abstract: A multi-spindle machining machine with a tool changing mechanism comprising a base; a carrier including a seat to move in Z axis, a rotary shaft fixed on the seat laterally to drive the seat to rotate in A axis, and a fixing holder coupled to an end portion of the rotary shaft to fix a workpiece; a tool changing mechanism including a mount mounted to the rotary shaft to rotate with the rotary shaft and a monitor fixed on the seat to measure a length of the tool clamped on the driving spindle, and including a plurality of slots to receive the tools respectively; a working head moving above the carrier and the tool changing mechanism in X and Y axes and including a driving spindle mounted on a lower end thereof to rotate axially, and the lower end of the driving spindle allowing to engage and disengage the tool.

Abstract: When an attachment surface of. a device body is attached to or detached from an end face of a spindle head, the device body is rotated in a stable posture.

Abstract: To provide a spindle device and a machining center, in which spindle replacement can be carried out in an extremely short time, downtime during maintenance is short, and productivity is high. In a spindle device 20, there are provided wirings 41, 42 extended from a spindle 30 and wired to support arms via a bracket 21, and joint components 74, each provided at a position a predetermined length extended from extended parts for the wirings 41, 42, are accommodated within the bracket 21.

Abstract: The invention relates to an apparatus for cutting an oval hole in the wall of a pipe. The pipe secured to a baseplate (1) of the apparatus is cut for an oval hole by means of a tool (20) having its cutter head (24) rotated about its axis while it is driven along a circular path in relation to a carriage (2) of the apparatus. The carriage (2) is mounted on the baseplate (1) by way of linear runners (3). Adapted for rotation along with a drive pulley (4) of the tool (20) is a cogged wheel (10), which through the transmission of a cam lever (11) is adapted to drive a shaft (12) having its rotational motion transmitted on the one hand to drive a gear (22) and on the other hand to work the carriage (2) back and forth in relation to the baseplate (1), a round-trip displacement (2xa) being equal to a difference between the major axis and the minor axis of a desired ellipse.

Abstract: By controlling an amount of preload applied to a rolling bearing that supports a spindle in accordance with the change of state of the spindle in actual machining, the rotation of the spindle is controlled in an optimal state, and the service life of the bearing is extended while the required stiffness of the spindle is ensured. When a corrected preload amount falls outside a range of a preload as a controllable region, the corrected preload amount is corrected so as to fall within the range of the preload. That is, an actually controlled preload is regulated to fall within the preset range of preload. Therefore, it is possible to ensure the stiffness of the rolling bearing or prevent heating and excessive increase in contact pressure of the rolling bearing.

Abstract: The invention provides an improved seal structure of cutting fluid supplied to a spindle of a milling spindle. The milling spindle 100 comprises a spindle 20 supported within a housing via a bearing 16, and a drawbar 24 having a through coolant passage 22. The cutting fluid C1 passing through the rotary joint 40 and 50 is sent to the through coolant passage 22, but a portion thereof is collected in a drain chamber 105. A rotation member 110 is attached to a rear end portion of the spindle 20, which is equipped with a labyrinth device 150 having a lip seal member 152. An air supply member 120 has two air seal members 142 and 144, and air A1 is sent toward the labyrinth device 150, by which an air seal is formed.

Abstract: The invention provides an improved drain structure of a cutting fluid supplied to a spindle of a milling spindle. The milling spindle 100 comprises a spindle 20 supported within a housing via a bearing 16, and a drawbar 24 having a through coolant passage 22. The cutting fluid C1 passing through the rotary joint 40 and 50 is sent to the through coolant passage 22, but a portion thereof is collected in a drain chamber 110. When the pressure within the drain chamber rises, the drain device 150 pushes open the ball 160 resisting against the spring 170, and the cutting fluid C1 is discharged to the exterior.

Abstract: The invention relates to an auxiliary device for a portable tool, comprising a receptacle (2) for a motor-operated portable tool (22) having an output shaft (26), and comprising a drive train (9) which has a tool receptacle (8), to be opened and closed by rotation, and which can be connected to the output shaft (26) of the motor-operated portable tool (22) via a coupling device. Provision is made for the auxiliary device (1) for the portable tool to have an anti-rotation locking means (13) acting on the drive train (9).

Abstract: An angular indexing apparatus for a machine tool includes a rotating shaft to which a rotationally driven member is secured; a housing, surrounding the outer periphery of the rotating shaft and mounted to and removed from the body of the machine tool; bearings disposed between the housing and the rotating shaft, and driving means disposed between the housing and the rotating shaft and rotating the rotating shaft to index an angular position. The driving means includes drive motors, each including a motor rotor and a motor stator concentrically disposed around the rotating shaft in the housing. The housing has wiring holes in a thick-walled internal portion of an outer cylinder surrounding the outer periphery of the rotating shaft. The wiring holes are provided along an axial direction of the rotating shaft. The wiring holes receive at least upstream portions in entire lengths in a drawing-out direction of cables connected to the driving motors.

Abstract: A support shaft of a spindle unit having a through hole in which wires are laid has a structure that can obtain much spatial room so as to prevent a break in cables and to be compatible with a high-output spindle motor. A machine-tool spindle head 1 includes a support head 6 that drives a spindle unit 4 for indexing around a turn axis (A-axis) of the spindle unit 4 by rotatably supporting a pair of support shafts 9 coupled to the spindle unit 4 on the A-axis by a pair of fork arms 7 and bearings 13. The pair of support shafts 9 have through holes 12 in which a plurality of wires 22 extending from the spindle unit 4 are laid, the plurality of wires 22 are divided into two wire groups, and the wire groups are separately laid in the pair of support shafts 9.

Abstract: A machining head for a machine tool includes a spindle unit having a spindle to which a tool is attachable and a support head component. The support head component includes an index mechanism that rotates the spindle unit in order to index an angular position of the spindle unit. The support head component further includes first and second support segments containing respective support shafts disposed opposite to each other across the spindle unit such that shaft centers of the support shafts are aligned with the axis line. Each of the first and second support segments has a housing having a bearing member fixed thereto, the bearing member rotatably supporting the corresponding support shaft through a bearing.

Abstract: A machining head has a support head component, which includes first and second support segments and a base segment supporting both the first and second support segments, the support segments being disposed opposite to each other across the spindle unit to hold the spindle unit therebetween such that a center of axle thereof is aligned with a rotary axis line thereof, the first and second support segments respectively including support shafts whose opposing end surfaces have the spindle unit secured thereto. The support segments respectively include housings as main bodies that are independent of the base segment. The housings accommodate the support shafts. Each housing is attached to the base segment by means of a plurality of first screw members that are screwed to the base segment and are manipulatable from the outside. The spindle unit is attached to the support shafts by means of a plurality of second screw members that are screwed to the support shafts and are manipulatable from the outside.

Abstract: A tool holder plate (51) is fixed to a shaft end part (413) of a hollow motor shaft (41) of a brushless DC servo motor (1), and a cutting tool is mounted in a tool mounting hole (51a) formed in the tool holder plate (51) and a work is cut-processed by this cutting tool. In order to prevent intrusion of a cutting processing oil containing cutting powder into the inside of the motor from between the shaft end part (411) of the hollow motor shaft (41) and an end plate portion (22) of a motor housing (2), a labyrinth seal (55) including a double circular groove (553, 555) having a fine width extended in the axis direction (1a) is formed between a metal plate (53), the tool holder plate (51), and the shaft end part (411). The other shaft end part (414) is also formed with a labyrinth seal (56) of the same structure.

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: In a spindle head for a machine tool in which a spindle (10) to which a tool is mounted is rotated around an axial line of a support shaft (58, 59), two rotating members (9, 58) that form a rotation transmission mechanism for rotating the spindle (10) and that transmit drive force of the rotation driving device (56) are fastened to each other at respective connection sections thereof by a bolt group (301) and are connected to each other so as to be prevented from rotating relative to each other by friction force resulting from the fastening. Rotation prevention torque based on the friction force is a value greater than torque applied to the connection sections during processing and smaller than torque applied to the connection sections when external force that causes the spindle (10) to deform beyond a permissible range is applied to the spindle (10).

Abstract: The present invention provides a milling machine drive mechanism. The milling machine drive mechanism includes a main shaft, a gear assembly, and a machine shaft. The gear assembly includes a first gear and a second gear. The first gear is pin-jointed to the main shaft, so as to rotate with the main shaft. The second gear is operatively connected to the first gear. Wherein, the main shaft drives the second gear to rotate through the first gear. The main shaft is pin-jointed to the main shaft, so as to rotate with the second gear.

Abstract: A motorized precision spindle apparatus (10) including an outer cartridge spindle (12) supported on a motor cartridge spindle (14) and a motor-driven outer cartridge spindle shaft (16) supported for rotation on bearings (22) disposed between the shaft (16) and an outer spindle shaft housing (20). A tool holder (26) releasably holds a tool in position for rotation with the shaft (16). A draw-bar (30) is supported through the shaft (16) and the motor cartridge spindle (14) for reciprocal axial motion, is connected to the tool holder (26), and is biased in an axial direction that causes the tool holder (26) to grip a tool (28). An actuator (32) is connected to the draw-bar (30) and moves the draw-bar (30) in a direction opposite the bias, thereby releasing any tool the holder may be holding. An isolation tube (36) is supported within the motor cartridge spindle (14), is connected to the shaft (16), and supports the shaft (16) against transmitting axial forces to the bearings (22).

Abstract: A spindle apparatus which facilitates assembling and removing operations at the time of maintenance and which is low cost. In the invention, the diameter becomes smaller in the order of an inner peripheral diameter of an outer cylinder (3), an inside diameter of a stator (4), and an outside diameter of a bearing sleeve (11); a sub-assembly (2) made up of a front housing (8), a rotating shaft (6), and the bearing sleeve (11) is withdrawable from the outer cylinder (3); and the diameter of a rotating part in an arbitrary section located rearwardly of the bearing sleeve (11) is made smaller than a minimum diameter of a non-rotating part between a rear end of the bearing sleeve (11) and the section.

Abstract: A spindle apparatus includes a housing for rotatable support of a spindle. The spindle is sealed by a brush seal in order to prevent fluid, contained in the housing, from escaping and/or to prevent ingress of a medium from outside into the housing.

Abstract: To provide a spindle device and a machining center, in which spindle replacement can be carried out in an extremely short time, downtime during maintenance is short, and productivity is high. In a spindle device 20, there are provided wirings 41, 42 extended from a spindle 30 and wired to support arms via a bracket 21, and joint components 74, each provided at a position a predetermined length extended from extended parts for the wirings 41, 42, are accommodated within the bracket 21.

Abstract: In an operating head, a tool assembly is provided with an inlet shaft engaged on an electrospindle and pivotally engaged through a corresponding containing casing, which is oriented about a longitudinal axis of the electrospindle by means of an electric motor coaxially mounted to the axis and provided with a rotor coupled in an angularly fixed manner to the casing itself.

Abstract: A machine includes a spindle for rotating about a rotating axis, a fixture having a central axis coaxial with the rotating axis, a connecting bar and a vacuum pump. The spindle has a first end surface, an opposite second end surface and a plurality of through holes extending through the first and second end surfaces. The connecting bar is detachably interconnected between the fixture and the spindle. The fixture is configured for rotating jointly with the spindle. The vacuum pump is in communication with the through holes.

Abstract: A main spindle device includes: a housing having an air supply passage; a spindle that is inserted into the housing and supported by a bearing so as to be able to rotate relative to the housing; and an air sealing member that is positioned between an outer circumferential surface of the spindle and the housing on a front side with respect to the bearing along a rotation axis of the spindle, has a substantially annular shape, and is detachably fixed to the housing with an inner circumferential surface of the air sealing member facing the outer circumferential surface of the spindle, wherein air supplied from the air supply source through the air supply passage is discharged into a gap between the outer circumferential surface of the spindle and the housing, thereby effecting non-contact air sealing at least between the inner circumferential surface of the air sealing member and the outer circumferential surface of the spindle.

Abstract: In a main spindle device provided with a housing and a main spindle, a labyrinth-forming annular groove is formed, in the circumferential direction of the main spindle, on the outer circumferential surface of a protruding portion of the spindle that protrudes from the housing on the front side. A housing lid member having a protruding portion that is inserted into the labyrinth-forming annular groove so as not to contact an inside surface of the labyrinth-forming annular groove all around the periphery is fixed to the housing on the front side thereof and forms a labyrinth seal portion between the protruding portion and the labyrinth-forming annular groove. The housing lid member is constructed so that the housing lid member can be divided into at least two pieces with respect to the circumference of the labyrinth-forming annular groove.

Abstract: Provided is a machine tool spindle balancer that stably pulls and biases the spindle unit upward and thus reduces the load of the lift means for moving the spindle unit vertically, is easily applicable to existing machine tools, highly durable, downsizable, and has a simple structure advantageous in production cost. A spindle balancer 30 comprises a gas spring 31 having a cylinder body 32, a rod 33, and a compressed gas. The gas spring 31 is provided above the spindle unit 10. The bottom end of the rod 33 is coupled to the spindle unit 10 so that the spindle unit is pulled and biased upward by the biasing force of the gas spring 31 that is applied on the rod 33, whereby the biasing force of the gas spring 31 serves to reduce the load of the lift mechanism 20.

Abstract: A manufacturing method includes shearing or cutting an elongated rod blank from bar stock, forge-forming a through hole in the rod blank that extends longitudinally through opposing ends of the rod blank, forge-forming a radially-extending collar on the rod blank between the opposing ends, forming attachment holes in the radially-extending collar, and extruding bearing bores in each of the recesses to form a main spindle housing. Bearings are supported in forged recesses at each end, and a shaft is rotatably supported on the bearings. The spindle housing includes a rod portion and collar both forged from the rod blank for work-hardened strength of material, and includes attachment holes and the through hole formed by pressing out slugs of material, thus facilitating recycling of scrap.

Abstract: An air driven tool for use in a machining center, the air driven tool including an adjustable speed regulator and a turbine. The turbine is driven by pressurized air directed thereto. The turbine is rotatable about an axis. A flow of the air is regulated by the adjustable speed regulator. The adjustable speed regulator includes a biasing member, an inclined annular surface, a regulator plate and a plurality of moveable bearings. The inclined annular surface has an angle relative to the axis. The plurality of movable bearings are positioned between the inclined annular surface and the regulator plate. The biasing member biases the inclined annular surface and/or the regulator plate toward each other.

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 machining unit comprising a quill carrying a spindle, a tool clamping mechanism on a forward end of the spindle, a drive shaft for rotatably driving the spindle through the quill, a tool feed actuator for extending and retracting the quill to and from a home position in both axial directions, the clamping mechanism being arranged to grip a tool holder when the quill is at or forward of the home position and to release or accept a tool holder when it is rearward of the home position.

Abstract: An exemplary embodiment of a high speed spindle for rotating a tool at high rotational rates includes a hollow spindle body and a cylindrical spindle shaft configured for rotation within the spindle body and having a front end and a rear end. The spindle shaft includes a front hollow region and a rear hollow region. A motor is configured to impart rotational drive forces to the spindle shaft during operation. The spindle shaft includes a thrust bearing flange disposed intermediate the front end and the back end of the spindle shaft. A front air bearing and a rear air bearing are configured to radially support the spindle shaft for high speed rotational movement. A thrust air bearing is disposed between the front air bearing and the rear air bearing within the spindle housing and configured to act on the thrust bearing flange of the spindle shaft to constrain axial movement of the spindle shaft within the spindle housing. A collet is disposed within the front hollow region of the spindle shaft.

Abstract: A system and technique wherein an ultra high-pressure (UHP) stream of water passing through a calibrated orifice achieves high water velocity. The orifice would be made from an extremely hard material such as sapphire or diamond. This high velocity stream impacts on a driving fluid turbine impeller attached to a shaft forming an opposed high-speed tool, which results in very high rotational speed with very high available power to do work. Off/On Control of the system would be accomplished through an integrated ultra high-pressure valve system.

Abstract: A spindle head device (10) includes a spindle (12) and a tool retaining mechanism (16) detachably retaining a tool holder (14) on the spindle. The tool retaining mechanism includes a tool support member (52) having a receiving recess (50) detachably receiving the shank (46) of the tool holder, a tool clamp member (54) disposed to be displaceable with respect to the tool support member between an operative position and an inoperative position, and a mounting member (56) detachably mounting the tool support member and the tool clamp member to the spindle. The tool clamp member grips the shank of the tool holder and fixedly holds the shank to the receiving recess of the tool support member at an operative position, and, at an inoperative position, releases the shank to allow the tool holder to be attached or detached to or from the receiving recess.

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: The present invention provides a cartridge-type spindle device having an easily separable structure despite the fact that it comprises a rotary joint for a through spindle coolant device. In the cartridge replacement type spindle device (11), front bearings of the spindle are built in a front housing (23) and rear bearings of the spindle (15) are supported on a rear housing (25) so that, when the front housing (23) is separated from the rear housing (25), the front bearings (17a, 17b), the spindle (15), and the rear bearings (19a, 19b) can be separated from the rear housing (25) integrally with the front housing (23). The rotary joint is disposed in a piston (63) of an unclamp means for unclamping a tool (21, T) mounted to the forward end of the spindle (15), so that a draw bar (51) accompanied by a seal ring can be separated from the rear housing (25) and the rotary joint together with the spindle (15) and the front housing (23).

Abstract: An exemplary machining apparatus (30) includes a tool spindle (40) for mounting a tool (42) and a workpiece spindle (44). The tool spindle is rotatable relative to a vertical direction. The workpiece spindle is rotatable in an axis thereof. A rotational axis of the workpiece spindle is oblique relative to a rotational axis of the tool spindle.

Abstract: The spindle device 1 is provided with: a housing 10 formed with a support hole 10a; a spindle 12 which is supported to rotate freely about an axis within the support hole 10a of the housing 10 and of which distal end is attached with a tool T; a drive motor 20 for rotating the spindle 12 about the axis, the drive motor 20 being configured by a rotor 22 arranged to rotate freely on an outer circumferential surface of the spindle 12 and a stator 23 fixedly provided on an inner circumferential surface of the support hole 10a of the housing 10; an electromagnetic clutch 30 for transmitting intermittently a drive force of the drive motor 20 to the spindle 12; and a controlling device 40 for controlling an operation of the drive motor 20 and that of the electromagnetic clutch 30.

Abstract: An apparatus and method for machining a workpiece in a single-pass comprising a tool configured to produce a borehole when rotated and translated relative to the workpiece, a toolholder configured to fixedly secure and rotate the tool, and a bushing retractably coupled to the toolholder, so as to be shiftable between extended and fully retracted positions, and preferably biased towards the extended position, wherein said tool, toolholder, and bushing are cooperatively configured such that the bushing provides lateral support for the tool during the machining process.

Abstract: In through-feed grinding workpieces by grinding stones rotating around the axes of spindles, the spindles are tiltably held by elastic holding means around tilt axes substantially orthogonal to the direction of exit and entrance of the workpieces with respect to the grinding stones. When a grinding loads are imposed on the entrance sides of the grinding stones, the spindles are tilted by offset loads around the tilt axes against the force of urging means in such a manner that the axial displacement and the exit displacement of the grinding stone due to the offset load are substantially the same. The grinding stones are reset around the tilt axes by the elastic holding means immediately before the end of processing at which time the axial displacement is smaller. This makes it possible to reduce the number of defectively ground articles coming from the through-feed grinding and reduce the wear in the grinding stones.

Abstract: A carriage is moved in a direction including a Y axis component in order to move a turning process tool that is attached to a tool spindle along a horizontal line that is perpendicular to a Z axis, and thus, a turning process is carried out on a workpiece which is attached to a workpiece spindle.

Abstract: A mill head assembly apparatus utilizing centrifugal hydrodynamic force to circulate lubrication oil while retaining the lubricant without the need for a replaceable (contact-type) seal, the apparatus comprising a set of stationary components including a trunnion, an oil ring, a bearing-retainer, and a collector ring and rotating components including a housing, a pump ring, and a baffle-ring, front and rear bearing means. The oil ring receives and circulates the lubrication oil to the bearing means, the housing is disposed with a plurality of housing passages to re-circulate the lubrication oil, and the forward and rear rotating interfaces to retain the lubrication oil within the front and rear mill head assembly. Potential lubrication oil leakage is retained and re-circulated back to the collector ring by close-tolerance seal means.

Abstract: The present invention relates to dental machining apparatus (1) for blanks (3) comprising a tool spindle (2) having an axis of rotation (2.8) and mounted in a bearing housing (1.2) disposed on the machine housing side. A force sensor (5) is also provided, which is disposed between the tool spindle (2) and the bearing housing (1.2) for the purpose of detecting the machining force acting on the tool spindle (2), wherein the tool spindle (2) can be supported against the bearing housing (1.2) directly or indirectly via the force sensor (5).

Abstract: A portable multifunction machine tool (PMMT) for performing operations upon a work structure. The PMMT has a movable frame attached to and structured to provide support for a tool carriage that is movably connected to the frame and that comprises at least one machine tool assembly adapted to receive a tool. The PMMT also has a processor communicatively connected to the tool carriage and machine tool assembly and programmed to control the movement of the tool carriage.

Abstract: The spindle device 1 is provided with: a housing 10 formed with a support hole 10a; a spindle 12 which is supported to rotate freely about an axis within the support hole 10a of the housing 10 and of which distal end is attached with a tool T; a drive motor 20 for rotating the spindle 12 about the axis, the drive motor 20 being configured by a rotor 22 arranged to rotate freely on an outer circumferential surface of the spindle 12 and a stator 23 fixedly provided on an inner circumferential surface of the support hole 10a of the housing 10; an electromagnetic clutch 30 for transmitting intermittently a drive force of the drive motor 20 to the spindle 12; and a controlling device 40 for controlling an operation of the drive motor 20 and that of the electromagnetic clutch 30.