JPH0225974Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a lip seal having a spiral groove for sealing the rotating shaft of various types of equipment.

[Conventional technology]

2. Description of the Related Art Conventionally, lip seals have been widely known in which spiral grooves are formed on the inner diameter sliding surface of a lip member, and the sealing performance is improved by the screw pump action of the grooves.

FIG. 3 is a half-cut sectional view showing an example of this type of lip seal, in which the lip seal is airtightly fitted into a step 3 formed in the shaft hole 2 of the housing 1 of the device via an O-ring 4. An annular metal outer case 6 fixed to the outer case 6, a rubber gasket 7 fitted to the outer case 6, and an annular metal inner case with a substantially L-shaped cross section fixed to the inner surface of the outer case 6 by caulking. The outer diameter part is airtightly clamped by the case 8, and consists of a disc-shaped lip member 15 whose main material is tetrafluoroethylene resin, and the inner diameter part of the lip member 15 is rotatable in the shaft hole 2. By slidingly contacting the outer circumferential surface of the rotary shaft 9 loosely inserted into the space B with an appropriate surface pressure while being bent and deformed in the axial direction so as to protrude into the space A on the sealed fluid side, the sealed fluid flows into the space B on the atmospheric side. To prevent leakage, a required number of spiral grooves 17 are carved on the inner diameter sliding surface 16 of the lip member 15.
Due to the screw pump action of 7..., the fluid that is about to enter between the sliding surface 16 and the outer peripheral surface of the rotating shaft 9 is discharged to the sealed fluid side space A, so that it has excellent sealing performance.

[Problem that the invention attempts to solve]

However, the above-mentioned conventional lip seals require a lot of effort to manufacture; in other words, since the lip member 15 is mainly made of polytetrafluoroethylene resin, which has poor flexibility and elasticity, it is very difficult to form the spiral grooves 17. Therefore, the production of a lip member having such a configuration is as shown in Fig. 4.
First, a cylindrical lip material a having a hollow part b is formed, and as shown in FIG. The process is as shown in Figure 4 (b), then cut to a predetermined thickness (see Figure 4 (c)).
It requires a lot of man-hours and has problems in processing cost and mass productivity.

[Means for solving problems]

The present invention was devised in view of the above-mentioned problems, and provides a lip seal with a spiral groove that can be easily manufactured.
Of both disc-shaped sheets, the inner diameter portion of the disc-shaped sheet on the side that comes into sliding contact with the outer circumferential surface of the rotating shaft has a required number of spiral-shaped punching grooves punched in the thickness direction thereof, and the punching grooves are The overlap of both disc-shaped sheets forms a spiral groove on the inner diameter sliding surface.

[Effect]

According to the above structure, in manufacturing the lip member, both disc-shaped sheets constituting the lip member are manufactured by punching and forming the sheet material using a press machine, and at this time, the spiral notch is also punched and formed at the same time. It is very easy to manufacture.

〔Example〕

Next, a preferred embodiment of the present invention will be described based on the drawings.

In this embodiment, the same reference numerals are given to the parts having the same structure as those of the conventional example shown in FIG. 3, and the explanation thereof will be omitted.

That is, FIG. 1 is a half-cut sectional view of the lip seal of this embodiment, and the lip member 10, whose outer diameter portion is held by the packing 7 and the inner case 8, is made mainly of polytetrafluoroethylene resin. It has a structure in which two disc-shaped sheets 11 and 12 are stacked on each other, and a rotating shaft 9 is connected to the inner diameter of the sheets.
A required number of spiral shapes are punched in the thickness direction as shown in FIG. A punched groove 13... is formed, and the spiral punched groove 13...
forms a spiral groove 14 (as shown in FIG. 1) when it overlaps with the other disc-shaped sheet 11. Note that the spiral grooves 14... (spiral punched grooves 13...) seal the fluid and close the fluid side space A.
Of course, it is inclined in the direction of discharge.

According to the above structure, the lip member 10 first includes two types of disc-shaped sheets 1 as shown in FIG.
1 and 12 are manufactured by punching and forming using a press machine (not shown) (however, the sheet 11 may also be manufactured by cutting a cylindrical lip material in the conventional manner), and both discs are The shaped sheets 11 and 12 are adhered to each other by means such as baking, and the spiral punching grooves 13 can be formed at the same time during the punching process, so manufacturing is easy.
Man-hours are also reduced.

[Effect of idea]

As described above, according to the lip seal of the present invention, the lip member has a structure in which two disc-shaped sheets are stacked together, so that the spiral groove on the inner diameter sliding surface can be formed using a polytetrafluoroethylene resin material, etc. This makes it possible to easily manufacture a lip member with a spiral groove, which is made of a material that is difficult to form, contributing to a reduction in processing costs and an improvement in mass productivity.

[Brief explanation of the drawing]

FIG. 1 is a half-cut sectional view showing an embodiment of the lip seal of the present invention, FIG. 2 is an exploded perspective view of the same essential parts, and FIG. 3 is a half-cut sectional view showing a conventional lip seal.
FIG. 4 is an explanatory diagram of the same processing process. 1...Housing, 2...Shaft hole, 3...Step part, 4...O
Ring, 5...Snat spring, 6...Outer case, 7
...Packskin, 8...Inner case, 9...Rotating shaft, 10...
Lip member, 11, 12... Disc-shaped sheet, 1
3...Spiral punched groove, 14...Spiral groove, A...Sealed fluid side space, B...Atmospheric side space.

Claims (1)

[Scope of utility model registration request] It consists of an annular metal case that is hermetically fitted to the inner periphery of the shaft hole of the housing, and a disk-shaped lip member whose outer diameter is hermetically fixed to the case, and whose inner diameter is In a lip seal that prevents leakage of the sealed fluid by slidingly contacting the outer circumferential surface of the rotating shaft with an appropriate interference in a state of bending and protruding toward the sealed fluid side, the lip member is made of two disc-shaped sheets stacked on each other. Of the two disc-shaped sheets, the disc-shaped sheet on the side that comes into sliding contact with the outer circumferential surface of the rotating shaft has a required number of spiral punched grooves punched out in the thickness direction of the disc-shaped sheet. A lip seal characterized in that the punched groove forms a spiral groove on the inner diameter sliding surface due to the overlap of both disc-shaped sheets.