To provide a rotary sleeve support device in a continuously water supplied pipe cutting device, cutting and facilitating cutting of an existing pipe having a large bore diameter.

This invention relates to the rotary sleeve support device in a continuously water supplied pipe cutting device in which the existing pipe 10 is cut with a cutting tool 40 rotated in a body with an rotary annular body 30 by rotation of the rotary annular body 30 water-tightly and rotatably mounted on a fixed annular body 20 fixed to the outer periphery of the existing pipe 10. Two sides 31 of the rotary annular body 30 are provided with a number of freely rotating rollers 32, and the fixed annular body 20 is provided with a substantially complete round guide part 23 coming into contact with the outer peripheral surfaces of the rollers 32 to guide the rollers 32 to move along the outer periphery of the existing pipe 10. Thus, the rollers 32 are brought into contact with the guide part 23, whereby the rotary annular body 30 is supported on the existing pipe 10 through the fixed annular body 20.