A method for reducing regenerative chatter in chip-removal machines wherein a tool head (2) machines walls of a workpiece (1) by means of at least one chip-removal tool and during this machining, the tool head is vibrationally excited and a loose additional mass (m.sub.z) is moved by the vibration. The additional mass randomly touches the tool head (2) in first position or randomly has no connection to the tool head (2) in second position, and thus the total mass of the tool head (2) is randomly changed by the amount of the additional mass (m.sub.z). This change in mass of the tool head in turn changes the frequency of vibration.

This observation device includes a command output unit that rotates a rotation part and stops a moving body; a first acquisition unit that acquires the rotation angle of the rotation part; a second acquisition unit that acquires the positional deviation of the moving body; a correction unit that corrects the rotation angle on the basis of an angle difference; a second storage control unit that establishes a correspondence between the rotation angle and the positional deviation; and a display control unit that displays, on a display unit, a graph indicating the correspondence between the rotation angle and the positional deviation.

The invention relates to a machine tool system (1) comprising a machine tool (2) comprising a spindle (3) that can be rotatably driven for machining workpieces, with a plurality of tools each clamped in chucks (5), in the form of so-called tool heads (4), that can be coupled to the spindle (3), and a balancing device (8) for balancing the tool heads (4), the machine tool system (1) comprising a data memory (11) in which the balancing protocol associated with each system-associated tool head (4) is stored, and a controller (12) that reads balancing data from the balancing protocol, for a tool head (4) coupled to the spindle (3), and compares it with at least one parameter of the machining for which said tool head (4) is provided, or with at least one general balancing parameter, the machine tool system (1) preferably being designed such that it rejects a tool head (4) when there is no available balancing data for said tool head (4).

A movable element for a damping system includes an absorbent mass arranged to be positioned in a housing. At least two adapted portions are arranged on a periphery of the absorbent mass. A plurality of elastic elements are arranged in the adapted portions and are designed to bear against an internal wall of the housing. The elastic elements have optimum damping properties in different variation ranges of at least one parameter. The present invention further relates to a damping system.

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.

A balance and runout amount adjustment system for a rotary tool includes a rotary tool constituted of a tool holder mounted on a spindle, a balance determining device configured to obtain outer circumference position data of the rotary tool and to determine a mass balance of the rotary tool based on the outer circumference position data obtained, in the course of rotation of the rotary tool and a runout determining device configured to obtain shape data of the rotary tool and to determine a runout amount of the rotary tool based on the shape data obtained, in the course of rotation of the rotary tool. The rotary tool is configured to be capable of adjustment of the mass balance based on the result of the determination made by the balance determining device and capable also of adjustment of the runout amount based on the result of the determination made by the runout determining device.

A balance and runout amount adjustment system for a rotary tool includes a rotary tool constituted of a tool holder mounted on a spindle, a balance determining device configured to obtain outer circumference position data of the rotary tool and to determine a mass balance of the rotary tool based on the outer circumference position data obtained, in the course of rotation of the rotary tool and a runout determining device configured to obtain shape data of the rotary tool and to determine a runout amount of the rotary tool based on the shape data obtained, in the course of rotation of the rotary tool. The rotary tool is configured to be capable of adjustment of the mass balance based on the result of the determination made by the balance determining device and capable also of adjustment of the runout amount based on the result of the determination made by the runout determining device.

A device for damping vibrations of a machine, in particular for damping vibrations of a machine tool, wherein the device includes a first linear motor primary part, a pendulum mass, mounted via at least one supporting sheet-metal assembly provide a relative motion of the pendulum mass along the first linear motor primary part, a first linear motor secondary part fastened to the pendulum mass such that the pendulum mass is actuated via the first linear motor primary part to dampen vibrations of the machine, a second linear motor primary part, and a second linear motor secondary part fastened to the pendulum mass such that the pendulum mass is additionally actuated via the second linear motor primary part to dampen vibrations of the machine so as to achieve an especially compact device that makes it possible to dampen vibrations of machines, in particular machine tools, effectively and without maintenance.

A balance and runout amount adjustment system for a rotary tool includes a rotary tool constituted of a tool holder mounted on a spindle, a balance determining device configured to obtain outer circumference position data of the rotary tool and to determine a mass balance of the rotary tool based on the outer circumference position data obtained, in the course of rotation of the rotary tool and a runout determining device configured to obtain shape data of the rotary tool and to determine a runout amount of the rotary tool based on the shape data obtained, in the course of rotation of the rotary tool. The rotary tool is configured to be capable of adjustment of the mass balance based on the result of the determination made by the balance determining device and capable also of adjustment of the runout amount based on the result of the determination made by the runout determining device.

The invention relates to a dynamically dampened centerless grinding machine tool comprising wheels between which there is arranged a part to be ground, heads for carrying the wheels, at least one translation means for translating one of the heads to cause a movement according to a separation and approach direction of the wheels, detection means for detecting a vibration of at least one of the heads, and at least one damper configured for causing a vibration damping movement.