JPS6446068A - Shaft seal device - Google Patents

Abstract

PURPOSE:To obtain a shaft seal device with high reliability and a long life by providing spiral grooves in a direction in which a high-pressure sealed fluid is entrained and increases its pressure on one side of an intermediate ring and spiral grooves in a direction in which the fluid is moved on the low pressure side on the other side thereof. CONSTITUTION:Due to the pumping action caused by the rotation of a rotary shaft 3, spiral grooves 9b entrain liquid from an open end on a center side and are directed to the outer periphery and, as a result, a dynamic pressure is generated and increased, generating a higher pressure than the pressure of a sealed fluid in a space L at the final end part of the spiral grooves 9b. Also, a very thin liquid film is formed between sealed faces 11 and 21 and the part between both sealed faces is fluid lubricated. On the other hand, although a ring 2 tends to be rotated together with the rotation of the rotary shaft 3, since spiral grooves 23b formed on the back face 22 are directed opposite to the twisting direction of the grooves 9b and as the outer peripheral part side is opened to the space L on the low pressure side, the liquid in the groove part tends to be discharged to the outer periphery side of the ring 2 without generating a dynamic pressure, and an adsorbing force acts on the part between the back face 22 and a retainer part 16 causing the ring 2 to be attached completely closely to the retainer 2 and to rest.