Patent ID: 9581247
Date: 2017-02-28
CPC Classifications: F16J

Claim:
1. A shaft seal apparatus comprising: a stationary ring secured to a seal cover of a casing; and a rotary ring secured to a rotational shaft that rotates with respect to said casing to rotate together with said rotational shaft, and having a rotational sliding surface that slides on a stationary sliding surface of said stationary ring, wherein said seal cover covers over said rotational shaft so that a sealed space of sealed fluid sealed by sliding of said stationary sliding surface and said rotational sliding surface is formed over said rotary ring, and a rotational pumping ring having a spiral projection on its outer circumferential surface and producing an axial flow of said sealed fluid and placed in said sealed space is fixed for rotation with said rotational shaft at an axial position different from said rotary ring and different from an impeller in the casing so that said sealed fluid positioned in said sealed space flows along the axial direction of said rotational shaft when said rotational shaft is rotated, a discharge hole is formed on an inner circumferential surface of said seal cover positioned in a downstream side of the axial flow of said sealed fluid resulting from a rotation of said rotational pumping ring, a flow guide having a side that is provided on the inner circumferential surface of said seal cover so that it protrudes radially inward in order to block a rotational flow of said sealed fluid along the rotating direction of said rotational shaft changed from the axial flow and orient the sealed fluid toward said discharge hole; and said discharge hole is formed on the inner circumferential surface of said seal cover positioned over said rotary ring, and said discharge hole is inclined to the inner circumferential surface of said seal cover in a direction accepting the flow of said sealed fluid along the rotating direction of said rotational shaft.