A self-balancing line shaft of a machine tool includes a spindle device, a cutter tool holder and at least one balancing assembly. The spindle device includes a spindle extending along and rotatable about an axis, and at least one precision lock nut threadedly engaged with and rotated with the spindle. The cutter tool holder is coaxially connected and rotated with the spindle. The balancing assembly includes an annular groove formed in one of the precision lock nut and the cutter tool holder and extending along a circle path surrounding the axis, and a plurality of weight members disposed in the annular groove to be moved in a direction opposite to a rotation unbalance during rotation of the spindle such that the center of mass of the whole rotating system is close to the axis.

A main spindle device (10) for a machine tool that checks the seating of a tool holder (30) using compressed air, wherein the main spindle device (10) for a machine tool comprises: a main spindle (12) that has a distal end face (18) in close contact with a flange end of the tool holder (30); an annular recess (25) that is formed on the distal end face (18) of the main spindle so as to be covered by the flange end of the tool holder; an air supply flow channel (21) that is linked to the annular recess and that supplies compressed air to the annular recess; a compressed air source (23) that supplies air to the air supply flow channel; and a pressure detector (22) that detects the pressure of the compressed air in the air supply flow channel. The annular recess (25) has a first section (25a) and a second section (25b) that is deeper than the first section, and the air supply flow channel is opened to the second section (25b).

A machine tool includes a first machine element movable in a travel direction and having first and second side faces. The first and second side faces of the first machine element run parallel to the travel direction and are oriented at a right angle to each other. The first machine element is moved in the travel direction in a guideway of a second machine element by a drive unit in a positionally controlled manner. The machine tool further includes first and second vibration dampers which are oriented at a right angle to the travel direction and configured to dampen vibrations of the first machine element in respective vibration directions. At least one of the first and second vibration dampers is oriented to solely dampen a vibration in a vibration direction that is neither parallel to the first side face nor parallel to the second side face.

An object is to provide a machine-tool spindle cooling method and a machine tool capable of suppressing thermal deformation of a spindle while achieving energy saving. To achieve it, a machine-tool spindle cooling method is provided in which bearings (13) and a spindle rotation motor (14) that generate heat with rotation of a spindle (12) are cooled by causing a spindle cooling device (18) to supply and circulate cooled cooling oil inside a housing (11) rotatably supporting the spindle (12), the method comprising deactuating the spindle cooling device (18) to thereby stop supplying the cooling oil in a case where the number of revolutions of the spindle (12) is less than or equal to a predetermined number of revolutions and the temperatures of the bearings (13) and the spindle rotation motor (14) detected by temperature sensors (15, 16) are less than or equal to a predetermined temperature.

A tool holder used in a machine which supplies power via a spindle and deliveries coolant is provided with a connector in the spindle; a conductive ring on the connector and electrically connected to the spindle so as that power is configured to supply to the tool holder; a tool mounting member including an axial hole for fastening a portion of a tool; an actuator in the tool mounting member and electrically connected to the conductive ring so that power is transmitted to the tool via the axial hole; an axial passageway through both the connector and the tool mounting member; and a waterproof dividing member for dividing the axial passageway into a first channel for delivering coolant and a second channel for passing a wire. The first channel is spaced from the second channel so that electric power transmission and coolant delivery are made independently.

In a spindle device, a movable member is provided on a cover member, which is attached to a spindle housing and covers the outer peripheral surface of a chuck portion which is a disk-shaped rotating member. The movable member is moved by a gas flowing through a flow passage formed in the cover member and thereby brought into contact with the chuck portion. The movable member is electrically connected to a ground.

A three-axis tool head unit for a machine tool spindle, which comprises three components, which are rotatable or pivotable relative to each other about independent axes. A first head part is rotatably mounted on a support arm about a first axis with respect to the support arm. A second head part is rotatably mounted on the first head part about a second axis with respect to the first head part. A spindle device is rotatably mounted on the second head part about a third axis with respect to the second head part. The third rotary axis is oriented orthogonally to the first and the second rotary axes, while the first and the second rotary axes are inclined relative to each other. Each of the three rotary axes has an associated individual drive device for driving and controlling the rotation of the component about its respective axis.

A foreign matter detection device includes an ion sensor arranged in the interior of a feed axis motor. The ion sensor is formed so as to detect an ion contained in a cutting liquid. A machine controller judges whether an ion concentration is within a judgment range related to the cutting liquid based on output of the ion sensor, and judges that the cutting liquid has penetrated into the interior of the feed axis motor when the ion concentration is within the judgment range related to the cutting liquid.

The invention relates to a boring machine comprising a spindle (15) which is designed for rotationally driving a boring tool that is placed or can be placed on the spindle and which is paired together with rotational drive means that interact with a first drive motor (24) for rotational driving purposes and with adjustment drive means that interact with a second drive motor (26) for axially adjusting the spindle such that when the spindle is being rotated by the first drive motor, the spindle can be axially adjusted under the effect of the second drive motor. The rotational drive means have a rotational drive gear (38) which is connected to the spindle, and the adjustment drive means have an adjustment nut (58) which interacts with a threaded section (60) of the spindle (15) in the manner of a slide. Transmission means are integrated in the form of a transmission module for interacting with the rotational drive gear and the adjustment nut and are designed to connect to the first and the second drive motor. The transmission means have an adjustment gear (54) for meshing into a toothing of the adjustment nut (58), said adjustment gear being driven by a toothed gear assembly (46, 42) which engages onto an outer toothing (52) of the adjustment gear such that at least one first toothed gear (42a-c) of the toothed gear assembly receives a drive torque of the second drive motor, in particular the at least one first toothed gear interacts directly with a drive shaft (30) of the second drive motor (24, 24A), and at least one second toothed gear (46a-c, 46a-c) of the toothed gear assembly transmits a drive torque of the first toothed gear (26, 26k) to the outer toothing (52), in particular the at least one second toothed gear meshes directly with the first toothed gear and the outer toothing. The toothed gear assembly is held in a cage-like toothed gear support (44) such that at least the second toothed gear, preferably the first and the second toothed gear, can be released from the transmission module and replaced when disassembling the adjustment gear and/or a module which drives the rotational drive gear, in particular a toothed gear unit.

A machine tool with active damping is provided, having a ram with longitudinal walls wherein vibrations are produced during machining according to at least a main bending direction (D1, D2) of the ram, a head that is arranged at one free end of the ram, actuation means for actuating the head which are arranged on one of the longitudinal walls of the ram, and damping means configured to generate at least a force (F1, F2) in the main bending direction (D1, D2) of the ram, wherein the damping means are arranged in a partial cross section of the longitudinal wall of the ram wherein the actuation means are arranged, the partial cross section being located between the actuation means and the free end of the ram on which the head is arranged.