The present disclosure relates to a sag compensation apparatus of a machine tool and a machine tool including the same, in which in case of sag of a cross-rail occurring due to transfer of a saddle and a ram spindle unit, hydraulic pressure compensates for the sag in real time, thereby improving machining precision and maximizing responsiveness and reliability.

A counterforce mechanism is arranged to exert a force on an object to maintain the object at a desired position. The mechanism comprises a driven body, a drive for moving the driven body, and a resilient coupling arrangement for coupling the driven body to a portion of an object. A control arrangement is arranged to output a drive signal to the driven body drive to move the driven body to a location where it exerts a force on the object via the coupling arrangement, such that the force counteracts an opposing force acting on the object and the mechanism holds the portion of the object at the desired position. A machine axis and a machine tool incorporating such a counterforce mechanism are also described, together with methods of operation thereof.

A holder in a non-limiting aspect of the present disclosure may include a base having a bar shape extended from a first end to a second end along a central axis, and a first weight having a column shape and a second weight having a column shape. The base may include a cavity extended along a central axis. The first weight may be located in the cavity. The second weight may be located in the cavity and located closer to the second end than the first weight.

A linear motion mechanism includes: a shaft; a base member having a through hole through which the shaft can be inserted; a static pressure bearing provided between the shaft disposed in the through hole and the base member to slidably support the shaft relative to the base member by introducing a pressurized fluid to the shaft; and an annular member provided between the static pressure bearing and the base member to elastically support the static pressure bearing.

A machine tool (1, 100) comprises a support structure (4, 104) and a machining head (8) bearing a mandrel (12). The machine further comprises at least one action device (20) contained on the support structure (4,104) and applied to it, which generates pushing or pulling actions on said support structure (4, 104) acting against the action of the weight of the head (8) thereon.

A linear motion mechanism includes: a shaft; a base member having a through hole through which the shaft can be inserted; a static pressure bearing provided between the shaft disposed in the through hole and the base member to slidably support the shaft relative to the base member by introducing a pressurized fluid to the shaft; and an annular member provided between the static pressure bearing and the base member to elastically support the static pressure bearing.

A mechanism for machining a workpiece includes a fixing base, a driving member, a connecting member, a cutter, a first guiding sleeve, and a spring. The driving member is positioned above the fixing base. The connecting member is coupled to the driving member. One end of the cutter is fixed to the connecting member, and the cutter is passed through the fixing base to machine the workpiece positioned under the fixing base. The spring is positioned between the connecting member and the fixing base. The spring is compressed when the driving member drives the cutter away from the fixing base to machine the workpiece, and the spring restores to bring the cutter back toward the fixing base after the machining.

An air balance mechanism includes a plate part, fixed shafts, and movable cylinders. A flange is provided at one end of each of the fixed shafts. The movable cylinders are movable relative to the fixed shafts. A space is formed below a lower surface of the flange. Further, the air balance mechanism includes fixing bolts and adjusting bolts. The fixing bolts fix the flange and a plate part at positions different from the space. The adjusting bolts are inserted into the plate part through the space for allowing the postures of the fixed shafts to be adjustable.

A mechanism for machining a workpiece includes a fixing base, a driving member, a connecting member, a cutter, a first guiding sleeve, and a spring. The driving member is positioned above the fixing base. The connecting member is coupled to the driving member. One end of the cutter is fixed to the connecting member, and the cutter is passed through the fixing base to machine the workpiece positioned under the fixing base. The spring is positioned between the connecting member and the fixing base. The spring is compressed when the driving member drives the cutter away from the fixing base to machine the workpiece, and the spring restores to bring the cutter back toward the fixing base after the machining.

Described is a laser processing machine with a height-adjustable laser component, a height-adjustable machine component, and a weight compensation system. The weight compensation system has at least one roller unit that includes at least two rollers fastened on a common axle and rotatably fixed with respect to one another. The axle is configured to rotate freely and slide in a machine frame guide of the laser processing machine. The laser component is held suspended by a first traction member wound onto the first roller. The machine component is held suspended by a second traction member wound onto the second roller. The first traction member and the second traction member are wound in reverse (opposite) directions onto the rollers. A counterweight device acts on the axle by exerting a counterforce, which compensates, at least partially, for the forces exerted by the laser component and the machine component.