| 摘要 |
Provided is a mechanical seal which can have a balance ratio of 1 or less regardless of the configuration of a rotary shaft. This mechanical seal is characterized in that: the mechanical seal is equipped with a sleeve (130) affixed to a rotary shaft (200); the sleeve (130) has a first annular part (131) having a step the inner diameter and outer diameter of which is larger on the sealed fluid (F) side than on the opposite side therefrom; the inner circumferential surface of a small diameter part (131a) of the first annular part (131) is fitted against the outer circumferential surface of the rotary shaft (200), and a stationary ring (110) is arranged on the outer circumferential surface side of the small diameter part (131a); a rotating ring (120) is arranged such that the annular gap between the outer circumferential surface of a large diameter part (131b) of the first annular part (131) and the inner circumferential surface of the rotating ring (120) is sealed; and when S1 is defined as the sliding surface area between the stationary ring (110) and the rotating ring (120) and S2 is defined as the pressure-receiving surface area where the stationary ring (110) receives pressure from the rotating ring (120) due to the pressure of the sealed fluid (F), the relationship S2÷S1≤1 is satisfied. |
