Internal milling machine

An internal milling machine for machining rotating work pieces with an internal milling cutter, the internal milling machine comprising:

• (a) a first spindle stock (2) rotatably supporting a work piece spindle that is rotatable in a controlled manner about a rotation axis (10) that extends in a Z-direction,
• (b) a bed (1) comprising:
• (i) a mounting surface (1a) for the first spindle stock (2), which mounting surface (1a) extends in the Z-direction and in an X-direction that is perpendicular to the Z-direction, and
• (ii) a lower support surface (1b),
• wherein the mounting surface (1a) is sloped downward relative to the support surface (1b) by a bed angle (8) from a backside of the bed towards a front side of the bed,
• (c) a tool support (3a), including:
• (i) a Z-slide (4a) in the form of a portal slide that is movable in the Z-direction along the bed (1) on first Z-supports (6a, b), the portal slide including two arms interconnected by a yoke, wherein each of the arms is movable in the Z-direction along a respective one of the first Z-supports,
• (ii) a transversal slide (7) that is movable along the Z-slide (4a) in a movement direction X′ along transversal supports (9a, b), wherein the X′ movement direction extends transversal to the Z-direction,
• (iii) an annular internal milling cutter (5) that is rotatably supported for rotation about a cutter axis (11) that extends in the Z direction, which milling cutter and that is drivable by a cutter drive,
• wherein:
• a Z pass-through that is open in the Z direction is configured through the Z-slide (4a) between the arms,
• the movement direction X′ of the transversal slide (7) is inclined along the portal slide (4a) relative to the X-direction by an angle that is from 0° to 45° , and
• wherein the first spindle stock is receivable within the Z pass-through.