JPS626355Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an oil seal. If the oil or water to be sealed contains foreign matter such as fixed particles, the foreign matter will get stuck between the lip of the oil seal and the rotating shaft that are in sliding contact, causing damage to the lip of the oil seal and the rotating shaft. Surface wear may be accelerated, the sealing performance of the oil seal may be reduced, and the life of the oil seal may be shortened. For this reason, improved oil seals have been devised in which an auxiliary lip is provided on the side of the sealed liquid from the main lip to prevent foreign matter from directly acting on the main lip, but the auxiliary lip has the drawback of unstable sealing performance. There is.

The purpose of the present invention is to provide an oil seal for a rotating shaft that is particularly suitable for sealing out oil and water containing foreign matter such as fixed particles.

Embodiments of the present invention will be described with reference to the drawings. The oil seal 1 of the present invention is interposed in the gap between the rotating shaft 2 protruding from the device and the housing 8, and prevents oil, water, etc. from leaking from the inside of the device (the left side of the oil seal in Figure 1). are doing.

The oil seal 1 of the present invention has main lips 3 that are in sliding contact with the rotating shaft 2, as shown in FIG.
It has a first auxiliary lip 4 and a second auxiliary lip 5, forming sealing lip portions in sequence toward the liquid to be sealed. As mentioned above, an oil seal has been devised in the past in which a seal lip portion is formed by a main lip and an auxiliary lip 4 provided on the side of the sealed liquid from the main lip. 5 is a feature of the present invention. As shown in the drawing, the second auxiliary lip 5 extends toward the liquid to be sealed so as to surround the first auxiliary lip 4 almost parallel to the first auxiliary lip 4, and is formed on the inner peripheral surface of the tip thereof toward the center line of the rotating shaft 2. It is provided with a plurality of thin protrusions, that is, ribs 6. Further, the second auxiliary lip 5 is provided with a large number of through holes 7 in its midsection. Further, the rib 6 has a substantially trapezoidal cross section as shown in FIG. As shown in FIG. 3, the ribs 6 are desirably formed so that the thickness becomes thinner toward the liquid to be sealed.

With the above structure, when the rotating shaft 2 in sliding contact with the oil seal 1 of the present invention rotates in the direction of arrow A, the rib 6 provided on the second auxiliary lip 5 rotates.
is easily deformed as shown in FIG. 3, and performs a pumping action to discharge the liquid to be sealed, such as oil or water, that has entered through the through hole 7 in the direction of arrow B. This pump action causes the oil and water to circulate as shown by arrow B in FIG. That is, the oil or water discharged from the rib 6 by the pumping action flows clockwise in FIG. 1, passes through a number of through holes 7 provided in the midsection of the second auxiliary lip 5, and enters the rib 6 again. This circulating flow continues throughout the rotation of the rotating shaft 9. Therefore, foreign matter such as solid particles contained in this oil or water can cause damage to the first auxiliary lip 4, main lip 3, and rotating shaft 2.
It can prevent it from digging into the contact surface. Therefore, damage to these lips due to the influence of foreign matter such as fixed fine particles, and even damage to the rotating shaft, can be reduced, making it particularly suitable for use as oil seals for washing machines and diesel engines, where foreign matter is likely to be contained in the sealed liquid. Are suitable.

In the embodiment, the ribs were deformed by the rotation of the rotating shaft to perform the pumping action, but if the rotating direction of the shaft is constant, the ribs may be formed by deforming from the beginning in a direction that matches the rotating direction. You can leave it there.

[Brief explanation of the drawing]

FIG. 1 is a partial axial cross-sectional view of the oil seal of the present invention, FIG. 2 is a partial front view of the second auxiliary lip, and FIG. 3 is a developed view of the second auxiliary lip. 1... Oil seal, 2... Rotating shaft, 3... Main lip, 4... First auxiliary lip, 5... Second auxiliary lip,
6...Ribs, 7...Through holes.

Claims (1)

[Scope of utility model registration request] A main lip 3, a first auxiliary lip 4 provided on the side of the sealed liquid from the main lip, and a rotating lip 4 provided on the side of the sealed liquid so as to surround the first auxiliary lip 4. An oil seal characterized in that it includes a second auxiliary lip 5 having a plurality of ribs 6 in sliding contact with a shaft 9 and a plurality of through holes 7 in its midsection.