BACKGROUND

Technical Field

The present disclosure relates to a sealing apparatus to realize sealing between a shaft and a hole into which this shaft is to be inserted.

Background

In a vehicle, general-purpose machine, or the like, in order to prevent leakage of a target to be sealed such as, for example, a lubricant, and in order to seal a gap between a shaft and a hole into which this shaft is to be inserted, a sealing apparatus has been conventionally used. In such a sealing apparatus, sealing between the shaft and the sealing apparatus is realized by a seal lip being brought into contact with the shaft or an annular member attached to the shaft. Among such sealing apparatuses, there is a so-called end-face contact-type sealing apparatus. The end-face contact-type sealing apparatus prevents leakage of a target to be sealed by bringing a seal lip extending along a shaft into contact with a slinger attached to the shaft.

Among conventional end-face contact-type sealing apparatuses, there is an apparatus in which sealing properties are improved by providing grooves at a slinger that a seal lip contacts and sending a target to be sealed such as oil to a side of the target to be sealed along with air on an atmosphere side by pumping action of the grooves while the slinger is rotating. In such a conventional end-face contact-type sealing apparatus, while a target to be sealed which has oozed can be returned to the side of the target to be sealed by the pumping action while the slinger is rotating as described above, when the slinger is stopped, there is a case where so-called static leakage which is leakage of the target to be sealed from a gap formed between the groove of the slinger and an end-face lip, may occur.

To prevent this static leakage, among conventional end-face contact-type sealing apparatuses, there is an apparatus in which a seal lip which contacts a slinger is further provided on an inner periphery side of a seal lip to prevent a target to be sealed which has oozed by static leakage occurring at the seal lip on an outer periphery side from further leaking to outside (see, for example, Japanese Utility Model Laid Open No. 4-88773).

SUMMARY

In such a conventional end-face contact-type sealing apparatus, while static leakage is prevented by the seal lip on the inner periphery side as described above, two seal lips contact the slinger, which increases sliding resistance with respect to a shaft while the slinger is rotating. In recent years, in a sealing apparatus, it is required to reduce sliding resistance with respect to the shaft to meet a demand for reducing fuel consumption of a vehicle, or the like, and in an end-face contact-type sealing apparatus, a structure is required which can reduce sliding resistance with respect to the shaft while preventing static leakage.

The present disclosure is related to providing a sealing apparatus which can prevent static leakage of a target to be sealed without increasing sliding resistance with respect to a shaft.

In accordance with one aspect of the present disclosure, there is provided a sealing apparatus for sealing an annular gap between a shaft and a hole into which the shaft is to be inserted. The sealing apparatus includes a sealing apparatus body fitted into the hole, and a slinger attached to the shaft. The sealing apparatus body includes a reinforcing ring annular around an axis line, and an elastic body portion which is formed with an elastic body attached to the reinforcing ring and which is annular around the axis line. The slinger including a flange portion which is a portion extending toward an outer periphery side and annular around the axis line. The elastic body portion includes an end-face lip. The end face lip is a lip extending toward one side in an axis line direction and contacts a surface of the flange portion on another side in the axis line direction. The end face lip is annular around the axis line. At least one shallow groove is formed on the surface of the flange portion of the slinger on the other side.

In a sealing apparatus according to one aspect of the present disclosure, the slinger has a plurality of shallow grooves.

In a sealing apparatus according to one aspect of the present disclosure, a depth of each of the grooves is equal to or less than 15 μm.

In a sealing apparatus according to one aspect of the present disclosure, a depth of each of the grooves is equal to or less than 10 μm.

In a sealing apparatus according to one aspect of the present disclosure, the groove intersects with a portion where the seal lip contacts.

According to a sealing apparatus according to the present disclosure, it is possible to prevent static leakage of a target to be sealed without increasing sliding resistance with respect to a shaft.

