A workpiece lifting and lowering device is provided with: a workpiece base supported as to be capable of being lifted and lowered, and mounting a workpiece; a link mechanism connected to the workpiece base, and lifting and lowering the workpiece base by converting a rotation motion to a lifting and lowering motion; and a driving mechanism rotationally driving the link mechanism through a transmission member.

A machine tool includes: a plurality of machining units, each including: a first saddle movable in a right-left direction; a second saddle supported by the first saddle and movable in an up-down direction; and a spindle device supported by the second saddle and movable in a front-rear direction. The plurality of machining units are arranged in the right-left direction such that spindles provided in the respective spindle devices are parallel to each other. The machining tool further includes an X-axis moving mechanism that moves the first saddle in the right-left direction; and a control device that controls an operation of the X-axis moving mechanism during machining of a workpiece and during correction of a spindle spacing between the machining units. A plurality of the X-axis moving mechanisms are provided corresponding to the respective machining units.

A machine tool includes: a plurality of machining units, each including: a first saddle movable in a right-left direction; a second saddle supported by the first saddle and movable in an up-down direction; and a spindle device supported by the second saddle and movable in a front-rear direction. The plurality of machining units are arranged in the right-left direction such that spindles provided in the respective spindle devices are parallel to each other. The machining tool further includes an X-axis moving mechanism that moves the first saddle in the right-left direction; and a control device that controls an operation of the X-axis moving mechanism during machining of a workpiece and during correction of a spindle spacing between the machining units. A plurality of the X-axis moving mechanisms are provided corresponding to the respective machining units.

A linear drive and its use for machining an optical workpiece are proposed, the linear drive having a linear movable rotor, a linearly movable compensating body and an electrical compensating drive for movement of the compensating body opposite to the rotor and the rotor extending into the compensating drive and/or a first bearing arrangement mounting the rotor in a torsionally stiff manner and a second bearing arrangement pivotally mounting the rotor.

A linear drive and its use for machining an optical workpiece are proposed, the linear drive having a linear movable rotor, a linearly movable compensating body and an electrical compensating drive for movement of the compensating body opposite to the rotor and the rotor extending into the compensating drive and/or a first bearing arrangement mounting the rotor in a torsionally stiff manner and a second bearing arrangement pivotally mounting the rotor.

A method for controlling the motor of a tool magazine that rotates around a horizontal rotation axis is configured so that: at least two indexing positions for the tool magazine are determined; the load torque acting on the tool magazine when stopped at said indexing positions is measured; an unbalance torque, which is the load torque when stopped at the indexing position at which the load torque when stopped is maximal, is calculated from multiple load torques when stopped; and the servo motor for the tool magazine is controlled on the basis of the unbalance torque.

A method for controlling the motor of a tool magazine that rotates around a horizontal rotation axis is configured so that: at least two indexing positions for the tool magazine are determined; the load torque acting on the tool magazine when stopped at said indexing positions is measured; an unbalance torque, which is the load torque when stopped at the indexing position at which the load torque when stopped is maximal, is calculated from multiple load torques when stopped; and the servo motor for the tool magazine is controlled on the basis of the unbalance torque.

A machine tool which causes a tool mounted on a main spindle and workpiece attached to a table to move relative to each other so as to machine the workpiece, said machine tool being equipped with: a column that has guides for guiding movements in the vertical direction, that is, the direction of gravity; and a moving body that supports a spindle head at the front and moves in the vertical direction along the guides. The guides comprise a pair of right and left first guides and at least one second guide that is provided on the inner side of and posterior to the pair of first guides.

A machine tool which causes a tool mounted on a main spindle and workpiece attached to a table to move relative to each other so as to machine the workpiece, said machine tool being equipped with: a column that has guides for guiding movements in the vertical direction, that is, the direction of gravity; and a moving body that supports a spindle head at the front and moves in the vertical direction along the guides. The guides comprise a pair of right and left first guides and at least one second guide that is provided on the inner side of and posterior to the pair of first guides.

A drive unit for driving a carriage which can be displaced along a transporting path comprises a barrel cam, which can be driven to rotate and has a drive groove for engagement of a driver arranged on the carriage, and also comprises a control device for controlling the drive of the carriage. The barrel cam has a first barrel portion and a second barrel portion, which is separate from the first, wherein the barrel portions can be driven independently of one another, and wherein the control device is designed so that, once the carriage has been received from a separate drive unit, it can accelerate the carriage with the first barrel portion and can supply the accelerated carriage to the second barrel portion.