PURPOSE: To extend the applicable range of a welded pipe and to transmit the stable motor driving force even in a high-temperature atmosphere by constituting a pressing mechanism of a pressing ring, a cover member and a wave washer inserted between those to simplify the pressing mechanism to energize a gear to the bearing side.

CONSTITUTION: The titled automatic circumferential welding equipment is provided with a opening part 32 and an arcuate recessed groove 35a is provided to the inside of the cover member 35 so that the gear 4 does not fall off from a housing 1 and the arcuate pressing ring 36 is inserted freely slidably therein. At the same time, the single arcuate wave washer 37 is stored in the space surrounded by the ring 36 and the recessed groove 35a and when the cover member 35 is assembled in the housing 1, the washer 37 is regenerated and by its energization force, the pressing ring 36 is abutted on the gear 4 which can be always energized to the bearing 2 side by the uniform pressing force. Accordingly, the number of parts is reduced and the dimensions in the pipe axial direction of the welding equipment is reduced. In addition, since a driving part to fix a motor 9 directly is constituted on an extension part 2b of a bearing 2, the stable motor driving force is transmitted.