Adjustable pitch rotor for milling applications

An adjustable pitch rotor for a milling machine, comprising:

• an inner drum having a hollow cylindrical shape and an inner drum outer surface;
• an outer shell comprising:
• a first outer shell portion disposed on the inner drum outer surface and having a first set of drum cutting assemblies having first cutting bits extending outward from a first shell portion outer surface, wherein each of the first cutting bits is longitudinally spaced from longitudinally adjacent first cutting bits by a pitch distance, and
• a second outer shell portion disposed on the inner drum outer surface and having a second set of drum cutting assemblies having second cutting bits extending outward from a second shell portion outer surface, wherein each of the second cutting bits is longitudinally spaced from longitudinally adjacent second cutting bits by the pitch distance;
• and
• a shell adjustment mechanism engaging the first outer shell portion and the second outer shell portion, wherein the shell adjustment mechanism is operable to move the first outer shell portion and the second outer shell portion longitudinally relative to each other,
• wherein, when the shell adjustment mechanism moves the first outer shell portion and the second outer shell portion to a first pitch configuration, each of the first cutting bits is longitudinally aligned with a corresponding one of the second cutting bits such that first grooves milled in a work surface by the adjustable pitch rotor are spaced by the pitch distance, and
• wherein, when the shell adjustment mechanism moves the first outer shell portion and the second outer shell portion to a second pitch configuration, each of the first cutting bits is longitudinally spaced from longitudinally adjacent second cutting bits by one-half of the pitch distance such that second grooves milled in the work surface by the adjustable pitch rotor are spaced by one-half of the pitch distance.

An adjustable pitch rotor for a milling machine, the adjustable pitch rotor having a longitudinal axis, the adjustable pitch rotor comprising:

• an inner drum having a hollow cylindrical shape and an inner drum outer surface;
• a first drum flange having an annular shape and extending radially outward from the inner drum outer surface at a first drum end;
• a second drum flange having the annular shape and extending radially outward from the inner drum outer surface at a second drum end;
• an outer shell comprising:
• a first outer shell portion disposed on the inner drum outer surface and having a first set of drum cutting assemblies having first cutting bits extending outward from a first shell portion outer surface, wherein each of the first cutting bits is longitudinally spaced from longitudinally adjacent first cutting bits by a pitch distance, and
• a second outer shell portion disposed on the inner drum outer surface and having a second set of drum cutting assemblies having second cutting bits extending outward from a second shell portion outer surface, wherein each of the second cutting bits is longitudinally spaced from longitudinally adjacent second cutting bits by the pitch distance;
• a first end ring mounted on the first drum flange and extending axially inward past the first drum flange and overlaying first outer edges of the first outer shell portion and the second outer shell portion;
• and
• a second end ring mounted on the second drum flange and extending axially inward past the first drum flange and overlaying second outer edges of the first outer shell portion and the second outer shell portion,
• wherein the first drum flange and the second drum flange extend radially outward from the inner drum outer surface by a flange radial length that is at least equal to an outer shell radial thickness so that the first drum flange and the second drum flange engage lateral edges of the first outer shell portion and the second outer shell portion to limit longitudinal movement of the first outer shell portion and the second outer shell portion along the inner drum outer surface,
• wherein, when the first outer shell portion and the second outer shell portion are mounted to the inner drum outer surface in a first pitch configuration, each of the first cutting bits is longitudinally aligned with a corresponding one of the second cutting bits such that first grooves milled in a work surface by the adjustable pitch rotor are spaced by the pitch distance, and
• wherein, when the first outer shell portion and the second outer shell portion are mounted to the inner drum outer surface in a second pitch configuration, each of the first cutting bits is longitudinally spaced from longitudinally adjacent second cutting bits by one-half of the pitch distance such that second grooves milled in the work surface by the adjustable pitch rotor are spaced by one-half of the pitch distance.