Non-contact shaft sealing device.

摘要

A non-contacting shaft sealing device in which an even-number of dynamic pressure generating groove groups (7) are arranged in the peripheral direction thereof on a sealing end face (5a) of the seal case side or a sealing end face (5a) of the rotary shaft side (2). Each dynamic pressure generating groove group (7) is composed of one or plural shallow L-shaped grooves of a specific groove width comprising a fluid lead-in part extending in the radial direction from a peripheral edge of high pressure side (H) of said sealing end face and a dynamic pressure generating part extending in the peripheral direction from the end portion thereof. When the dynamic pressure generating groove group (7) is composed of plural L-shaped grooves, those L-shaped grooves are arranged close to each other at an equal pitch without crossing each other such that the end portion of each dynamic pressure generating part is positioned on a fourth sealing end face diametral line. Each dynamic pressure generating groove group (7) is symmetrical with respect to each of the adjacent dynamic pressure generating groove groups (7) on both sides thereof around a first sealing end face diametral line passing between those fluid lead-in parts (between the fluid lead-in parts of the outermost side when the dynamic pressure generating groove group is composed of a plurality of the L-shaped grooves) or a second sealing end face diametral line passing between those dynamic pressure generating groove groups. The groove land ratio theta 1/ theta 2 in the peripheral direction is 0.5 to 0.9 wherein the angle of intersection theta 1 is formed between the third sealing end face diametral line running along the fluid lead-in part of the dynamic pressure generating groove group (7) (the fluid lead-in part of the outermost side when the dynamic pressure generating groove group is composed of a plurality of L-shaped grooves) and the fourth sealing end face diametral line on which the end portion of the dynamic pressure generating part is positioned, while the angle of intersection theta 2 is formed between the fourth sealing end face diametral line of the adjacent dynamic pressure generating groove group which is adjacent to the dynamic pressure generating parts of the aforementined dynamic pressure generating groove group (7) and the aforemention third sealing end face diametral line. <IMAGE>