A damper assembly for use with a non-rotating tool holder includes a hollow ram for supporting a non-rotating tool and a damper assembly mounted in the hollow ram for absorbing vibrations of the ram. The damper assembly includes a front plate and a rear plate, an upper tie rod and a lower tie rod extending between the front plate and the rear plate, and a damper mass mounted between the front plate and the rear plate. Ring dampers are mounted between the damper mass and the front and rear plates, and suspension springs are mounted between the upper tie rod and the lower tie rod. The suspension springs carry the weight of the damper mass so that the ring dampers do not have to carry the weight of the damper mass, and the damper mass is free to respond to vibrations in the ram.

An apparatus or system comprises: a damper side linear motor; a drive side linear motor; a first detection unit that detects a first position that is a position of a movable portion of the drive side linear motor in relation to a machine base; a second detection unit that detects a second position that is a position of a movable portion of the damper side linear motor in relation to the machine base; a third detection unit that detects a third position that is a position of the movable portion of the drive side linear motor in relation to the movable portion of the damper side linear motor; a drive side control unit that controls the drive side linear motor, based on the first position and the third position; and a damper side control unit that controls the damper side linear motor, based on the second position.

Provided is a vibration-proof structure capable of more effectively reducing rotational vibration of a rotating body during a cutting operation. According to a configuration of the structure, inside a main body of the rotating body, there are provided a plurality of shaft members arranged along a longitudinal direction of a rotation axis of the rotating body and at least one layer of multiple tubular members fitted over the shaft members and arranged coaxially with the rotation axis along the longitudinal direction of this rotation axis; and a boundary position between the shaft members adjacent each other in the longitudinal direction and a boundary position between the tubular members adjacent each other in the longitudinal direction are set as different positions along the longitudinal direction.

The invention relates to a method for reducing regenerative chatter in that a workpiece (1) rotates in relation to a tool head (2) having at least one chip-removal tool (3, 3a, 3b, 3c) arranged at one end of the tool head (2), the tool head (2) machines walls of the workpiece (1) by means of the at least one chip-removal tool (3, 3a, 3b, 3c), the tool head (2) is vibrationally excited during the machining, a loose additional mass (m.sub.z) is moved by the vibration, which additional mass randomly touches the tool head (2) in first positions or randomly has no connection to the tool head (2) in second positions, and thus the total mass of the tool head (2) is randomly changed by the amount of the additional mass (m.sub.z).

A main spindle device for a machine tool includes a main spindle, a cushioning member, and an arithmetic unit. The cushioning member is disposed on a position where a vibration displacement of a rotator exists. The arithmetic unit uses data of a tool to be used to analyze a vibration mode in a free vibration of the rotator based on a support rigidity of a bearing, masses of respective parts of the rotator including the tool, an attenuation coefficient, and an equation of motion derived from rigidity and inertia by a rotation. An outer diameter of a sleeve positioned outside the bearing is changed such that a position of an antinode of the vibration or a position on which a vibration displacement exists in the vibration mode matches a position of the cushioning member inside the main spindle to change a preload on the bearing.

A spindle arrangement for a machine tool, comprising a spindle for driving a tool and at least one actuator for exciting vibration of the tool, characterized in that the spindle arrangement is provided with a compensation device for at least partly compensating the inertia forces produced by the vibration excitation in the spindle region.

Provided is a vibration-proof structure capable of more effectively reducing rotational vibration of a rotating body during a cutting operation. According to a configuration of the structure, inside a main body of the rotating body, there are provided a plurality of shaft members arranged along a longitudinal direction of a rotation axis of the rotating body and at least one layer of multiple tubular members fitted over the shaft members and arranged coaxially with the rotation axis along the longitudinal direction of this rotation axis; and a boundary position between the shaft members adjacent each other in the longitudinal direction and a boundary position between the tubular members adjacent each other in the longitudinal direction are set as different positions along the longitudinal direction.

A system, method, and computer-readable medium for providing a user interface. The system includes circuitry configured to generate chatter information based on sensor data collected from a machining operation of a machine performed at a previously selected tool speed setting. The chatter information includes a chatter level value and a chatter frequency value. A plurality of different candidate tool speed settings is determined based on the generated chatter frequency value from the machining operation. The circuitry generates the user interface that includes a plurality of different tool speed settings, including the previously selected tool speed setting and the plurality of different candidate tool speed settings for selection by a user. The user interface is configured to indicate the chatter level value for the previously selected.

An apparatus includes a machining executing part causing a machine tool to execute an operation of, while changing a spindle rotation speed of the machine tool in a stepwise manner, machining a workpiece by a predetermined distance or for a predetermined period of time at each spindle rotation speed, a displacement detector detecting a position displacement of a tool during the machining, a cutting force detector detecting a cutting force applied to the tool, a frequency analysis part performing frequency analysis on displacement data and cutting force data for each rotation speed to calculate a displacement spectrum and a cutting force spectrum, and a natural frequency deriving part calculating a compliance spectrum for each spindle rotation speed by deriving the displacement spectrum by the cutting force spectrum, calculating an integrated compliance spectrum by superimposing the compliance spectra, and deriving, as a natural frequency, a frequency showing the largest compliance value.

The present invention proposes a macro-micro integrated compound platform with adjustable dynamic characteristics. When a macro platform mover and a micro platform mover are driven at the same time, the whole large-scale high-speed motion can be realized; when a motion deviation occurs, a micro motion platform can be driven separately to realize the high-frequency motion deviation compensation, because the micro motion platform has small inertia and zero friction and achieves precision displacement output through elastic deformation. The macro-micro integrated compound platform can realize high-speed precision motion through compound motion control, is mounted and used in a manner consistent with the traditional platform, and is convenient to be popularized and applied; a stiffness and frequency adjustment mechanism and a variable damper are arranged, so that the micro motion platform can transfer the motion of a macro motion platform and isolate the vibration at any frequency, and realize high-precision displacement compensation; meanwhile, damping of the variable damper is matched with the stiffness and frequency parameters to ensure the high-precision displacement compensation at any frequency and increase the range of working frequency.