Magnetic liquid sealing device with controllable sealing clearance

Abstract

A liquid sealing device with a controllable sealing gap belongs to the field of mechanical engineering sealing. It solves the problem that the existing magnetic liquid sealing device has a large diameter and a large temperature difference, and the sealing gap changes due to the thermal expansion and contraction characteristics of the material, which seriously affects the performance of the sealing device. The device is composed of a magnetic liquid sealing assembly, a spring (3), a spring base (2) and the like. The inner surface of the pole piece is parallel to the outer surface of the truncated portion of the shaft sleeve (11) and intersects with the axis of the rotary shaft (13). There is an axial clearance H between the end cover (9) and the housing (1): tighten the screws on the end cover (9), the axial clearance H becomes smaller, and the pole piece and the permanent magnet (6) are aligned axially as a whole. Move to the left, the sealing gap becomes smaller; when the screw on the end cover (9) is loosened, the axial distance H becomes larger, and the pole piece and the permanent magnet (6) move along the axial direction as a whole under the elastic force of the spring (3). Moving to the right, the seal gap becomes larger. Adjust the screw on the end cover (9) to adjust the size of the sealing gap.

Description

technical field [0001] The invention belongs to the field of mechanical engineering seals, and is especially suitable for magnetic liquid seals under the working conditions of large diameter and large temperature difference. Background technique [0002] Magnetic liquid seals are widely used due to their advantages of zero leakage, long life, and low friction. However, in practical applications, under the condition of large diameter and large temperature difference, the sealing gap of the magnetic liquid seal will increase or decrease due to the thermal expansion and contraction characteristics of the material. If the sealing gap is too large, the pressure resistance of the sealing device will be reduced. If it is too small, it is easy to cause friction and even "stuck" the shaft, which seriously affects the performance of the sealing device. For example, the linear expansion coefficient of steel in engineering is generally taken as 1.2×10 -5 mm / mm·℃, if the diameter of th...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is that under the conditions of large diameter and large temperature difference in the existing magnetic liquid rotary sealing device, the sealing gap increases or decreases due to the thermal expansion and contraction characteristics of the material, and if the sealing gap is too large, the sealing device will be reduced. If the sealing gap is too small, it is easy to cause friction and even "stuck" the shaft, which seriously affects the performance of the sealing device

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