JPH04102767A - Oil seal - Google Patents

Abstract

PURPOSE:To make an oil seal adaptable to both normal and reverse rotary shaft and lengthen its seal lifetime by arranging the first lip on the dust lip side so that the second lip can cover the edge part of the first lip, and arranging notches around the edge parts of the first lip. CONSTITUTION:When a shaft rotation is in the downward arrow direction, the edge parts 6a of the first lip 6 bent in the rotating direction under the influence of the shaft rotation so that pumping action to pump oil out in the rotating direction is generated. Furthermore, similarly, when the rotation is in the upward arrow direction, it is bent in the rotating direction so that the pumping action to pump the oil out in the rotating direction is generated. Thereby, even if the shaft rotating direction is reciprocal, the pumping action is generated according to the rotating direction so that an excellent seal effect can be obtained. The occurrence of trouble such as protuberant, and overlapped edge parts 6a of the first lip 6 branched by means of notches 8 due to the shaft rotation, can be prevented, and the edge parts 6a of the first lip 6 can be also utilized until those are abraded completely.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an oil seal, and particularly to an oil seal that can be applied to a shaft portion whose rotational direction is not constant and that has an improved lifespan.

(Prior Art) Conventionally, for example, in order to prevent the oil in the bearing part of the crankshaft inside the crankcase from leaking outside, two parts were installed at the end of the crankcase as shown in FIG. An oil seal is used which is sandwiched between two metal rings 11 and 12 and has a lip 13 with a screw 14 at the tip.6 In the figure, 15 is a dust lip.

However, the shape of the tip of the lever lip 13 is shown in Fig. 6 (a>
As shown in (b), there are screw types with slits made with a cutter, and screw types with stamped molding, both of which have the function of preventing oil from leaking to the outside through the pumping action of this thread. are doing.

(Problem to be solved by the invention) However, once the lip made in this way is worn out due to sliding and the threaded part is worn out, it loses its function as a seal, and this oil seal can be used for a relatively short time. It becomes impossible.

In other words, the life of the seal is determined by the thread depths d and d' in Figures 6(a) and (b), and the thickness t of the beams d and d',
t'.

However, in order to ensure the eccentricity followability of the seal, the lip thicknesses t and t' cannot be made too thick, and therefore it has been impossible to extend the life of the oil seal.

In addition, since the screw is installed in a certain direction around the circumference (for example, clockwise), the rotation direction of the shaft to which it is attached is restricted. This type of oil seal could not be applied.

In view of this, it is an object of the present invention to provide an oil seal that can be applied to shafts rotating in either forward or reverse directions and that can extend the life of the seal, thereby eliminating the drawbacks of the prior art. It has been done.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides large and small metal rings that have an appropriate width on the outer circumferential surface serving as the large diameter portion, and have a substantially L-shaped cross section and are stacked concentrically. and an oil seal consisting of an oil lip and a dust lip, the base end of which is sandwiched between the axial clearance of the metal ring and the distal end thereof open, the oil lip is composed of two lips, and the first lip is the dust lip. The second lips are provided adjacent to each other so as to cover the tip of the first lip, and the first lips are provided adjacent to each other so as to cover the tip of the first lip.
A feature is that a large number of notches of a desired length are provided around the tip of the lip in the axial direction from the end surface.

(Function) According to the above configuration, when the oil seal is attached to the shaft, the first lip tip that is in direct contact with the shaft circumferential surface is bent in the shaft rotation direction as the shaft rotates, and the shaft circumferential surface is bent. A pumping action that pushes out oil in the direction of rotation can be performed.

(Example) The present invention will be described below with reference to the example shown in FIGS. 1 to 4.

The oil seal according to the present invention has an outer circumferential surface 1 that is a large diameter portion.
a, 2a, large and small metal rings 1°2 having an appropriate width and having a substantially I-shaped cross section and stacked concentrically, and the metal ring 1
, 2, the oil lip consists of an oil lip 4 and a dust lip 5, the base end of which is sandwiched between the axial gaps 3 of 2 and the distal end of which is open. 6 are provided adjacent to the dust lip 5 side, and the second lip 7 is provided adjacently so as to cover the tip 6a of the first lip 6, and the tip of the first lip 6 is in contact with the axial surface when installed. A large number of cuts 8 having a desired length are provided around the portion 6a in the axial direction from the end surface.

The metal ring 1.2 has an outer peripheral surface 1a that becomes a large diameter portion.

It is an annular body having an appropriate width at 2a, and its cross section is approximately L-shaped, so the left and right inner diameters are different. Further, the metal ring 2 is concentrically overlapped inside the metal ring 1, so that there is no gap between the metal rings 1 and 2.

Furthermore, a gap 3 is provided in the axial direction between the metal rings 1.2 so that the oil lip 6.7 and the dust lip 5 can be sandwiched therebetween.

In the embodiment, Teflon is used as the sill material for the oil lip.

Fig. 2 shows an enlarged view of the tip 6a of the first lip 6 of the oil lip 4, excluding the second lip 7. A second lip 7 (not shown) is provided with a large number of notches 8.
covers the tip portion 6a of the first lip 6 to prevent it from being biased in the radial direction and expanding locally due to shaft rotation.

Next, the effect will be explained.

As shown in Fig. 3, when the shaft rotates in the direction of the arrow (downward), the tip 6a of the first lip 6 bends in the direction of rotation (downward) due to the influence of the rotation of the shaft, and pumps out oil in the direction of rotation. action occurs. Similarly, when the shaft rotates in the direction of the arrow (upward) as shown in FIG. 4, the tip 6a of the first lip 6 bends upward in the direction of rotation due to the influence of the shaft rotation, and drains the oil. A pumping effect occurs in the direction of rotation.

As a result, regardless of whether the shaft is rotated in the forward or reverse direction, the bong pink action is applied depending on the direction of rotation, so that a good sealing effect can be obtained.

In this case, the second lip 7 prevents the occurrence of problems such as the tips 6a of the first lip 6 branched by the notch 8 swelling and overlapping due to shaft rotation.

Furthermore, the tip end 6a of the first lip 6 can be used until it is completely worn out.

(Effects of the Invention) As explained above, the present invention provides large and small metal rings which have an appropriate width on the outer circumferential surface serving as a large diameter portion and are stacked concentrically with a substantially L-shaped cross section, and the metal rings. In an oil sill consisting of an oil lip and a dust lip, the base end of which is sandwiched between the axial clearances and the distal end thereof is open, the oil lip is composed of two lips, and the first lip is adjacent to the dust lip side. The second lip is provided adjacently so as to cover the tip of the first lip, and when installed, around the tip of the first lip that contacts the axial surface, there are a number of holes having a desired length in the axial direction from the end surface. Since the notch is provided, it is possible to follow the rotation of the shaft and produce a bomb pink effect in the rotational direction, and therefore it can be used without specifying the rotational direction.

Also, since there is no lip on the lip like in the past,
Compared to the conventional type, which ends its life due to wear of the screws, it is possible to significantly extend the life.

[Brief explanation of the drawing]

FIG. 1 is a side view of an embodiment of the oil seal according to the present invention, FIG. 2 is an enlarged view of the oil lip in FIG. 1, and FIG. FIG. 4 is a plan view showing the deformed state of the tip of the oil lip when it rotates in a downward direction, and FIG. 5 is a side view of a conventional oil seal, and FIG. 6 is an enlarged view of the tip of the oil lip of the oil seal shown in FIG. 5. (a) is a cutter screw type, (b) is a embossed molded type. 1.2...Metal ring, 1a, 2a...Outer peripheral surface, 3...
- Gap, 4... Oil lip, 5... Dust lip, 6... First lip, 6a... Tip, 7... Second lip, 8... Notch.

Claims (1)

[Claims] The outer peripheral surface, which is the large diameter part, has an appropriate width and the cross section is approximately L.
In an oil seal consisting of large and small metal rings stacked concentrically in a letter shape, and an oil lip and a dust lip whose base end is sandwiched between the axial gaps of the metal rings and whose tips are open, the oil lip is Consisting of two lips, the first lip is provided adjacent to the dust lip side, the second lip is provided adjacently so as to cover the tip of the first lip, and the tip of the first lip is in contact with the axial surface. An oil seal characterized in that a number of notches of a desired length are provided around the periphery in the axial direction from the end face.