Machine tool

A machine tool (M) comprising a kinematic structure (100) that moves an electric spindle (300) carrying a cutting tool (O), the cutting tool (O) rotating about an axis of the electric spindle (300),

• the kinematic structure (100) moving the electric spindle (300) in a positioning plane perpendicular to the axis of the electric spindle (300), the machine tool (M) further comprising a workpiece support module (200),
• wherein said kinematic structure (100) positions the electric spindle in said positioning plane and is an articulated structure comprising two articulated arms (110, 120), including:
• a first arm (110) having two ends (111, 112), a first end (111) of the two ends (111, 112) of the first arm (110) being mounted to pivot in relation to a plate (130) about a first axis of rotation that extends parallel to the axis of the electric spindle (300), and wherein a first means for driving in rotation (140) comprises a rotating shaft motor that ensures movement of the first arm (110) about the first axis of rotation, and
• a second arm (120) having two ends (121, 122), a first end (121) of the two ends (121, 122) of the second arm (120) being mounted to pivot in relation to a second end (112) of the two ends (111, 112) of the first arm (110) about a second axis of rotation that extends parallel to the axis of the electric spindle (300), and wherein a second means for driving in rotation (150) comprises a rotating shaft motor that ensures movement of the second arm (120) about the second axis of rotation,
• the second end (122) of the second arm (120) receiving the electric spindle (300),
• the machine tool configured to perform a machining by a relative translation movement of the workpiece (P) in relation to the tool (O) of the electric spindle (300) positioned and held fixed by the kinematic structure in said positioning plane,
• the relative translation movement of the workpiece (P) in relation to the tool (O) of the electric spindle (300) in a linear movement parallel to the axis of the electric spindle (300) being brought about by the workpiece support module (200) or by a plate support module;
• wherein two encoders are associated with each of the first and second axis of rotation of said articulated structure (100), and wherein the two encoders do not have the same functions, a first encoder of the two encoders being used to measure speed, while a second encoder of the two encoders measures position for the associated axis of rotation, and
• where each rotating shaft motor comprises a respective reducer, wherein the first encoder for each of the first and the second axis of rotation is associated with the motor upstream from the corresponding reducer and provides for measuring the speed and the second encoder is associated with a bearing and provides for measuring the position, and the second encoder for measuring the position comprises, for at least one arm, a rod sliding in a sheath and able to measure an angular position of the other end of the at least one arm.