Shaft-sealing device

Abstract

The purpose of the invention is to provide a shaft-sealing device, which does not leak at rest, operates with fluid lubrication during rotation including the initial period of rotation while preventing leakage, and is able to establish sealing and lubrication simultaneously. As a means for achieving the purpose, the invention is characterized in: multiple pumping sections being formed on the outer circumferential surface of a rotating member that are separated from each other in the circumferential direction, the pumping sections generating a pumping effect as a result of the relative rotational sliding of the lip seal and the rotating member; the multiple pumping sections being provided with in-drawing pumping sections that act in a direction that draws in the fluid that is being sealed and discharging pumping sections that act in a direction that expels the fluid that is being sealed; and the lip of the lip seal running toward the air side leaving a portion of the pumping sections, in the axial direction, on the side of the fluid that is being sealed.

Description

Technical field [0001] The present invention relates to a shaft sealing device of a lip type seal for sealing between a housing and a rotating shaft. Background technique [0002] In the past, in lip seals that are mounted on a fixed housing and slide the surface of a rotating shaft, in order to cope with environmental issues, the lip shape and size and the lip material are optimized, the sliding surface of the lip or the surface of the target shaft The coating and the surface roughness of the target shaft are optimized to achieve low friction. [0003] In the lip seal that coats the sliding surface of the lip or the surface of the target shaft, and the lip seal that optimizes the surface roughness of the target shaft, there are some that are effective only at the initial stage and have low friction due to wear over time. Unsustainable problems. [0004] On the other hand, as a shaft sealing device that improves lubrication characteristics, known Picture 12 The illustrated sealing ...

AI Technical Summary

Problems solved by technology

[0009] However, in Figure 12 In the shaft sealing device of prior art 1 shown, the sealing edge 53 of the lip seal body 51 is in contact with the arrow-shaped groove 55, and the arrow-shaped groove 55 is formed of a high-hardness material. The contact portion area 54 provided on the surface of the rotating shaft, therefore, the wear of the sealing edge portion 53 is fast, and each groove 56 of the arrow-shaped groove portion 55 is formed to directly communicate with the atmosphere side and the sealed fluid side in the axial direction. "く-shaped" shape, and the end portion of the sealing edge 53 is not in contact with the "く-shaped" groove 56, therefore, the sealed fluid side and the atmospheric side are always in a state of communication, therefore, in the static state of the device There is a possibility that the sealed fluid leaks to the atmosphere side

It is known that when the surface roughness of the shaft reaches 2.5 μm or more in general oil seals, it becomes the cause of leakage at rest. serious spill

[0010] Furthermore, even in a shaft seal device in which a spiral groove is provided instead of the arrow-shaped groove of prior art 1, since the atmosphere side and the sealed fluid side are directly connected via the spiral groove, there is a difference from prior art 1. same question

[0011] In addition, in Figure 13 In the shaft sealing device of the prior art 2 shown, the pressing force of the sealing lip 60 is lowered to reduce the torque of the sealing lip 60 , so the sealing performance of the sealing lip 60 is lowered and air is mixed in. to the side of the fluid being sealed

Images