JPS6316929Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to the improvement of a combination seal that seals two mutually rotating members by combining annular bodies, and more specifically to a combination seal that uses a plurality of radial seal lips to achieve sealing. Regarding improvements.

Conventionally, this type of combination seal consists of a ring body having a plurality of non-contact seal lips and a ring body combined with the ring body, which are integrated by caulking to form a sealing device, or an axial lip. There has been a sealing device that is expected to achieve a seal by combining a ring body having a ring body and a ring body that contacts the axial lip.

However, since the former combination seal with a non-contact seal lip is non-contact, each ring body tends to separate and separate, easily damaging the seal lip, so they have no choice but to be integrated. It is necessary to caulk the end to combine it with the other ring. Furthermore, the dimensions of the non-contact seal lip greatly affect the sealing performance, requiring high precision, which has the drawback of extremely disadvantageous processing costs.

On the other hand, in the case of the latter combination seal with an axial lip, the axial lip contacts in the radial direction, which tends to cause installation errors when installing the combination seal, making it impossible to ensure uniformity of axial lip contact pressure, etc. There was a serious drawback in that a reliable sealing force could not be achieved.

The present invention eliminates these drawbacks and provides a combination seal that is easily assembled and integrated and has both good installation and sealing performance.

A detailed description will be given below with reference to the drawings.

As shown in Fig. 1, the present invention consists of an outer ring A having a plurality of radial lips 1 made of an elastic material such as synthetic rubber or synthetic resin, and an inner ring B made of metal that contacts the radial lips 1. The main seal lip 1a of the outer ring A is provided on the small diameter side and the auxiliary seal lip 1b is provided on the large diameter side so as to protrude outward, and the inner ring B facing this is provided with a main seal lip 1a projecting outward from the outer ring A. The main part of the outer ring A has a small diameter and is bent with a plurality of axial parts 2 and 3, for example, has a U-shape in cross section with an outward radial part, or a Z-shape as shown in FIG. This is a combination seal having a structure in which the seal lip 1a and the auxiliary seal lip 1b are brought into contact with the outer peripheral surfaces of the axial portions 2 and 3 of the inner ring B, respectively.

At this time, the main seal lip 1a located on the small diameter side with respect to the inner ring B has a large tightening force,
It is preferable to provide the auxiliary seal lip 1b located on the large diameter side with a small interference because this will effectively bring about the effects described below.

That is, since the inner circumferential side of the rotating member has a lower circumferential speed and a smaller contact circumferential area than the outer circumferential side, the main seal lip 1a that contacts this minimum inner circumferential axial direction portion 2 can be tightened even if the tension force is increased to strengthen the sealing force. Does not significantly affect frictional force. On the other hand, the auxiliary seal lip 1b that contacts the outer circumferential radial portion 3 of the inner ring B has an increased contact area and circumferential speed, increasing the frictional resistance, so the tension force is weakened to cope with this problem.

Such a configuration has a favorable effect on sealing performance since the contact peripheral surface of each seal lip with respect to the sealed space has a smaller diameter than the sealed space, reducing the contact peripheral area.

Furthermore, when assembling the seal lip 1 that makes pressure contact in the radial direction with another annular body, conventionally the seal lip 1 gets caught on the end of the annular body, causing damage to the seal lip 1 or turning it over, so that the seal lip 1 does not function at all. However, in the present invention, as shown in Fig. 3, the outer circumferential surface 4 of the inner end of the metal inner ring B is chamfered, and in addition, the shape of the seal lip 1 has a lip thickness h. The ratio of the lip length 1 to the lip length 1 is 5 times or less, and the shape is designed so that it contacts the inner ring B at an angle α of 45° or less with respect to the axial direction, resulting in extremely safe and easy assembly and strong sealing. Realized sex.

In addition, the static friction force caused by the contact between the plurality of radial lips 1 made of an elastic body is
In the case of a combination seal, the normal design weighs approximately 2 to 4 kg.
During normal handling such as transportation and storage, the combined sealing materials A and B remain integrated without separating, eliminating the need for processing steps such as metal caulking.

Further, in this structure, as shown in FIG. 2, a concave annular groove 6 is formed between the outer end 5 of the outer diameter fitting part of the outer ring A having the seal lip 1 and the auxiliary seal lip 1b.
Since it is a structure that can be easily formed, a part C of another member that rotates relative to the outer ring A is placed in this concave annular groove 6.
This structure has many advantages, such as the ability to bring the two parts close together to create a labyrinth seal effect.

As explained above, the present invention is an ideal combination seal that has a simple structure, is integrated, and achieves strong sealing force with low rotational torque.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the combination seal of the present invention. FIG. 2 is a sectional view showing an embodiment of the combination seal of the present invention. FIG. 3 is an enlarged partial sectional view of FIG. 1. A: Outer ring, B: Inner ring, 1: Seal lip, 2: Inner axial portion, 3: Outer axial portion, 4: Chamfered portion.

Claims (1)

[Claims for Utility Model Registration] (1) An outer ring having a plurality of radial contact lips formed of metal and an elastic material such as synthetic rubber or synthetic resin, and a seal formed of metal that contacts the sealing lip of the outer ring. In a combination seal configured with an inner ring; the main seal lip of the outer ring is provided on the small diameter side, and the auxiliary seal lip is provided on the large diameter side, respectively, protruding outward, and the opposing inner ring has a smaller diameter than the outer ring. 1. A combination seal, characterized in that it has a bent shape with a plurality of axial parts, and that the main seal lip and the auxiliary seal lip of the outer ring are brought into contact with each other at their respective axial outer circumferential surfaces of the inner ring. (2) The combination seal according to claim 1, wherein the inner ring has a chamfered portion on the outer peripheral surface of the inner end. (3) The plurality of protruding radial seal lips have a ratio of lip length to lip thickness of 5 times or less, and are in contact with the inner ring at an angle of 45° or less with respect to the axial direction. A combination seal according to claim 1 of the utility model registration claim.