Symmetrical multi-axis linear motor machine tool

A machine tool for advancing a tool, such as a rotary cutting took, along at least mutually transverse axes comprising:

• a spindle having a tool mounted thereon;
• a frame having a first set of top and bottom frame members and a second set of side frame members joined to define a central opening and to support the spindle and cutting tool while cutting and being advanced along the transverse axes;
• a vertical gantry connected to at least two frame members for slidable movement in a first axis relative to the frame;
• a saddle mounted on the gantry and carried therewith and mounted for slidable movement in a second axis perpendicular to the first axis along the vertical gantry between the top and bottom frame members;
• a ram carried by the saddle for movement along a third axis perpendicular to the second axis and carrying the spindle and rotary cutting tool along the third axis;
• a first linear drive having at least one linear motor for moving the gantry relative to the frame members along the first axis and supported by the gantry and first set of side frame members;
• a second linear drive having at least one linear motor for moving the saddle along the gantry and along the second axis and supported by the gantry and saddle;
• a third linear drive having at least one linear motor for moving the ram and spindle along the third axis and supported by the spindle and ram and saddle, the frame members defining an internal space with the gantry and saddle mounted relative to the frame in the internal space and the frame includes means for substantially sealing and pressurizing the internal space to allow the ram and spindle to extend beyond the internal space while limiting workpiece chips generated and coolant used at the tool and workpiece interface from entering the internal space during a machining operation.

A box assembly for driving a tool along a plurality of mutually transverse axes, the box assembly comprising:

• a spindle capable of receiving a tool;
• a box frame defining an internal space having a top and a bottom wall extending between laterally spaced sides defining a forwardly facing opening;
• a vertical gantry extending between the top and the bottom wall mounted for slidable movement relative to the frame along a horizontal X-axis extending between the laterally spaced sides adjacent to the opening, the gantry having a front face therebetween forming an elongate central vertical slot adjacent the frame opening;
• carriage means for mounting the spindle for sliding movement in two directions perpendicular to the X-axis, one direction being along a vertical Y-axis coincident with the vertical slot with the carriage means further defining the other direction along a horizontal of movement extending through the slot;
• and
• linear motor drive means associated with the vertical gantry and carriage means capable of causing a tool to be advanced at a speed of at least 1,500 inches/minute and at an acceleration or deceleration of at least 1 G along the X, Y and Z-axis with the frame, gantry and carriage means being formed from a material having with a high level of material stiffness.

A machine tool comprising:

• a rotary spindle having a cutting tool mounted thereon;
• a frame having side frame members defining a central opening;
• a vertical gantry extending parallel to the side frame members and mounted for slidable movement on the frame;
• a saddle mounted on the gantry and carried therewith and mounted for slidable movement along the gantry;
• a ram carried by a portion of the saddle and mounted for slidable movement through the central opening and carrying the spindle and rotary cutting tool through the opening;
• a first linear drive mounted on the frame and having an upper linear, magnetic motor extending in a first direction for propelling the gantry with magnetic force and applying an upwardly-directed force to the gantry;
• the first linear drive mounted on the frame and having a lower linear, magnetic motor extending in the first direction and parallel to the upper linear motor for propelling the gantry with magnetic force and applying a downwardly-directed force to gantry to oppose and offset the upwardly-directed force from the upper linear motor;
• a second linear drive having right and left linear, magnetic motors extending vertically on opposite sides of the saddle portion for exerting magnetic force attractions to propel the saddle;
• the right linear, magnetic motor exerting an attractive force on the right side of the saddle portion;
• the left linear, magnetic motor exerting an attractive force on the left side of the saddle portion to offset the rightwardly-directed attractive force of the right linear motor;
• and
• a third linear drive having one or more motors having a stator coil section and permanent magnet section for moving the ram and spindle.

A linear motor machine tool having a rotatable tool movable along at least three mutually transverse axes;

• a box-like frame having four metal frame members joined in a box shape including a lower frame member for resting on a floor support surface without being attached to a heavy foundation;
• vibration members between the lower frame member and a floor support surface to isolate the machine from vibrations to or from the floor support surface;
• a gantry mounted between a first pair of opposite frame members;
• a symmetrical, linear, gantry drive for the gantry having a first linear, gantry drive, magnetic motor mounted on a first frame member and a first side of the saddle for driving the gantry to travel along a first axis;
• a second linear, gantry drive, magnetic motor in the symmetrical linear gantry drive mounted on a second frame member parallel to and opposite of the first frame member and mounted on a second side of the saddle for driving the gantry to travel along the first axis;
• the magnetic forces of the first and second linear, magnetic motors being in opposite directions and offsetting against one another and providing substantial symmetry relative to the first axis;
• a spindle-carrying slide mounted on the gantry for travel along a second axis perpendicular to the first axis;
• a symmetrical linear slide motor drive for driving the spindle-carrying slide along the second axis;
• a first linear, magnetic motor in the symmetrical linear slide motor drive mounted on the gantry and on the slide located on a third side of the gantry for driving the gantry to travel along the second axis;
• a second linear, magnetic motor in the symmetrical linear, slide motor drive mounted on the gantry and on the slide on a fourth side of the gantry parallel to and opposite of the third side of the gantry to drive the slide to travel along the second axis;
• the magnetic forces of the first and second linear motors of the linear slide motor drive being in opposite directions and offsetting against one another and providing substantial symmetry relative to the second axis;
• carriage means mounted on the slide and supporting the spindle to travel along the slide along a third axis, which is perpendicular to the second axis;
• and
• a linear drive for the carriage means having at least one linear magnetic motor for moving the carriage means and the spindle thereon along the third axis.