A ptfe multi-group oil return line oil seal

Abstract

The invention discloses a PTFE (polytetrafluoroethylene) oil seal arranged with multi-group oil return lines and made of a PTFE material; a contact face between a sealing lip slice PTFE of the PTFE oil seal and a shaft piece is provided with multiple groups of oil return lines; meanwhile, parameter of oil return line grooves and a rotating space between the oil return lines are improved. By comparing with a traditional PTFE oil seal, the thickness of the PTFE sealing lip is reduced by about 1 / 3, and the magnitude of interference between an inner hole of the PTFE sealing lip and the rotating shaft is also correspondingly reduced; therefore, the radial force is reduced by about a half, and the requirements on saving energy and reducing emission are realized. Width, space and depth of spiral oil return grooves are reduced by about 1 / 3; for adopting a combined structure of multi-group spiral oil return grooves, it is guaranteed that the oil return grooves and the surface of the rotating shaft have enough contact length and enough helix angles; therefore, the oil seal has enough oil returning ability. The oil seal is longer in service life, and able to greatly reduce the risk of failure of an oil seal piece.

Description

Technical field [0001] The invention relates to a shaft oil seal, in particular to a PTFE oil seal made of PTFE material with multiple sets of oil return lines. Background technique [0002] At present, the premature aging of the seal lip is a relatively common failure mode under the conditions of ultra-high speed (lip line speed exceeding 30m / s) and high temperature (ambient temperature exceeding 130°C) at home and abroad. The pressure diesel engine is more obvious. The resistance of PTFE materials to high and low temperatures and various corrosive substances are better than special rubbers such as fluoroelastomers, and can adapt to more severe working conditions, so PTFE oil seals came into being. However, PTFE oil seals are not ideal in practical applications, especially automobile engines and transmissions. Therefore, rubber oil seals are still widely used in China. The reason is that the current domestic PTFE oil seals (hereinafter referred to as traditional PTFE oil seals)...

AI Technical Summary

Problems solved by technology

However, PTFE oil seals are not ideal in practical applications, especially in automobile engines and transmissions. Therefore, rubber oil seals are still widely used in China. The reason is that there are some defects in the performance of domestic PTFE oil seals (hereinafter referred to as traditional PTFE oil seals): PTFE seals The radial force of the lip is too large, the friction between the sealing lip and the rotating shaft is too large during operation, and the temperature rise of the lip contact area is too high, which will cause premature deterioration of the lubricating oil and affect the lubrication of the system. The wear of the shaft is serious, resulting in the leakage of the sealing medium; because the traditional PTFE oil seal has a large friction torque, which does not meet the requirements of modern automobiles for energy saving and emission reduction, so pure rubber low friction oil seals (ESS oil seals) have begun to be used

[0009] Scientific structural parameter design and precise manufacturing can achieve the sealing function of the oil seal; however, the structural parameters of the PTFE oil seal designed in the prior art often fail to meet the requirements for use, affect product quality, and even cause seal failure

[0010] The PTFE oil seal in the prior art has the following problems: 1. The oil return line of the PTFE sheet is a single oil return line, and the oil return performance is poor; 2. The thickness of the PTFE sheet is large, and the formed sealing lip exerts a large radial force on the rotating shaft , so the friction torque is large, the friction heat is large, and the wear on the shaft is also large; 3. The width, spacing, and depth of the spiral oil return groove are large, and it is difficult to ensure sufficient contact length and sufficient helical lift between the oil return groove and the surface of the rotating shaft. angle, therefore, poor sealing performance

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