JPS6028841Y2 - Oil seal for low torque - Google Patents

Description

[Detailed description of the invention] The present invention relates to a low-torque oil seal, in which the lip portion of the oil seal is formed by integrally combining a lip made of a low-friction material and a lip made of a non-woven fabric. It's about stickers.

Conventionally, as a low-torque oil seal, there is an oil seal provided with a lip portion 3 in the form of a nonwoven fabric as shown in FIG.

Reference numeral 1 denotes a fixed portion which is fitted and fixed into a hole in the housing, and a lip portion 3 extends from one end of the fixed portion 1 in the axial direction toward the shaft, and has a sealing surface 3 that fits and seals with the shaft.

In this oil seal, when the shaft is rotating, the fibers in contact with the shaft circumferential surface are pulled in the direction of rotation and maintained in a twisted position with respect to the axial direction, creating a screw action on the airflow to be sealed. , can exhibit considerable sealing properties, but while the shaft is stationary, the fibers are kept in a direction approximately coincident with the axis,
Since the above-mentioned screw action is not generated, the airflow to be sealed passes between the nonwoven fibers, so that sealing performance cannot be expected.

The object of the present invention is to eliminate the drawbacks of the conventional low-torque oil seals described above and provide a low-torque oil seal that can exhibit good sealing performance not only during rotation but also when stopped. It is something to do.

The gist of the present invention is to include a fixed part that is fitted into either one of a shaft and a hole that are combined concentrically with each other, and a fixed part that extends obliquely from the fixed part to the other side of the shaft and hole, and A low-torque oil seal having a lip portion that slides sealingly with the lip portion, the lip portion being made of a low-friction rubber material and disposed on the atmosphere side; The second lip is attached to the oil side of the first lip, and during rotation, the non-woven fibers of the second lip are pulled in the direction of rotation by the sliding surface to provide a sealing action. At the same time, when the rotor is stopped, the first lip is in contact with the mating circumferential surface to provide a sealing effect, and the low friction of the first lip keeps the torque due to friction during rotation low.

The first lip is preferably made of fluororesin, polyamide resin, polyimide resin, polyester resin, or low-friction rubber.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a half-sectional view of the low torque oil seal of the present invention.

The annular fixing part 1 that is fitted into the hole of the housing includes an outer ring 15 made of metal with a substantially rectangular cross-section and an inner ring 16 made of metal with a rectangular cross-section.
It is composed of a combination of

The lip portion 2 is composed of a first lip 11 made of a fluororesin material and a second lip 12 made of non-woven fiber. 12 is combined with the first lip 11 on the side opposite to the atmosphere side.

The support portion 17 of the lip portion 2 is connected to the outer ring 15 of the fixed portion 1.
and the inner ring 16, and the side of the lip portion 2 opposite to the support portion 17 has a first portion that fits and seals the shaft.
It consists of a first sealing surface 13 of the lip and a second sealing surface 14 of the second lip.

By configuring the present invention as described above, the present invention has the following effects.

By arranging the first lip 11, which is made of a low-friction material, on the atmosphere side in the axial direction of the fixed part 1, and the second lip 12, which is made of nonwoven fabric, on the opposite side of the first lip 11 from the atmosphere, rotation of the shaft is prevented. Inside, the second lip surface 14 of the second lip provides a good seal to the shaft.

Further, while the shaft is at rest, the shaft can be well sealed by the first sealing surface 13 of the first lip.

That is, while the shaft is rotating, the fibers of the second sealing surface 14 are pulled against the shaft peripheral surface and maintained in an inclined position with respect to the axial direction, resulting in good sealing performance due to the screw action. Furthermore, during temporary fixing, the second lip 12 maintains the fiber direction approximately in the axial direction.
Although sealing performance cannot be expected due to the first sealing surface 13
Good sealing performance can be achieved by appropriately setting the tension force.

As described above, not only good sealing performance is provided during rotation and during stoppage, but also the first lip 11 is made of an elastic material exhibiting low friction, and the second lip 12 is made of non-woven fibers. Because of this, the torque due to sliding friction with the shaft circumferential surface is kept at a low value.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view of a conventional oil seal, and FIG. 2 is a half-sectional view of an oil seal showing an embodiment of the present invention. 1... Fixed part, 2... Lip part, 11
...First lip, 12...Second lip, 13...First sealing surface, 14...
・Second sealing surface, 15...Outer ring, 16...
...Inner ring, 17...Support part.

Claims (1)

[Scope of utility model registration request] a fixing part 1 fitted into either one of the shaft and the hole that are combined concentrically with each other; and a fixing part 1 extending obliquely from the fixing part 1 toward the other side of the shaft and the hole, and sealing with the circumferential surface of the other. a first lip 1 having a sliding lip part 2, the lip part 2 being made of a low-friction rubber material and disposed on the atmosphere side;
1 and a second lip 12 made of non-woven fibers and attached to the oil side of the first lip 11.