| 摘要 |
PROBLEM TO BE SOLVED: To provide an easily manufacturable butterfly valve superior in durability, by maintaining superior operability and sealability by restraining an increase in operation torque, while preventing an inside structure from being complicated or the whole from being enlarged. SOLUTION: This butterfly valve is provided by rotatably arranging a circular plate-like disk 4 via stems 5 and 6 in a seat ring 3 installed on an inner peripheral surface 2a of a cylindrical body 2. In this butterfly valve, a step height part 10 composed of a large diameter part 8 and a small diameter part 9 is formed in the stem 5 installed in a shaft installing cylinder 7 of a body 2, and a bearing body 11 composed of a seal cylinder part 15 contacting in a seal via a seal ring 18 installed on the inner-outer periphery and a bearing cylinder part 16 integrally suspended and formed from an outer peripheral side under surface 15c of this seal cylinder part 15, is installed between the small diameter part outer periphery 9a and the shaft installing cylinder inner periphery 7a of this step height part 10, and an upper bearing 21 for supporting the stem 5 is interposed between the bearing cylinder part 16 and the large diameter part 8, and a lower bearing 22 is also installed in the large diameter part on the disk 4 side. COPYRIGHT: (C)2012,JPO&INPIT |
