The ornamental design for a rotary screwcompressor.
FIG. 1 is a perspective view of the embodiment thereof;
FIG. 2 is a back view of the embodiment thereof;
FIG. 3 is a front view of the embodiment thereof,
FIG. 4 is a right side view of the embodiment thereof,
FIG. 5 is a left side view of the embodiment thereof,
FIG. 6 is a top view of the embodiment thereof; and,
FIG. 7 is a bottom view of the embodiment thereof.
The broken line showing of elements shown throughout the drawings is included for the purpose of illustrating non-claimed environmental matter and forms no part of the claimed design.