JPH0747650Y2 - Combination seal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a seal device which is mounted between two mutually movable members to seal the inside and the outside of the two members, and more specifically, to a seal device. The present invention relates to a combined seal for improving airtightness.

[Prior Art] Conventionally, as a sealing structure formed by combining a plurality of sealing materials of this type, there is a combination seal of US Pat. No. 4,460,184. This is, as shown in FIG. 2, an L-shaped first sealing element 7 provided with one or more sealing lips 6,
The inverted L-shaped second sealing element 8 facing the first sealing element 7 is combined, and this structure prevents leakage of lubricant from the inside and intrusion of dust, muddy water, and the like.

[Problems to be Solved by the Invention] However, although this combination seal seals against muddy water which is trying to enter from the outside, the seal lip 6 is sealed by a sliding surface on which muddy water does not directly adhere Since a certain amount of muddy water is allowed to enter the seal lip 6, it is easy for the sealing lip 6 to bite dust and sand that have entered when the bearing is stopped and when the bearing is started from operation. It has a serious adverse effect on the sealing property, such as the occurrence of troubles such as rusting.

As a solution to this, the combination seal of EP Patent No. 65887A1 was considered.

As shown in FIG. 3, this is the first part with an L-shaped cross section that rotates relative to each other.
It has a sealing element 9 and an inverted L-shaped second sealing element 10, the sealing lips 11, 12, 13 being arranged on said first sealing element 9, said sealing lips 11, 12, 13 being directed to the outside world. It is a combination seal formed so as to be in the forward direction with the path.

However, although this combination seal is superior in sealing performance from the outside, the side lip is not tightened properly due to the axial displacement of both sealing elements 9 and 10 during assembly, and further grease from the bearing side There were drawbacks such as not exerting sufficient effect against runoff.

The present invention is a combination that eliminates these drawbacks and is effective in blocking foreign substances and muddy water that try to enter from the outside, and that also has protection measures against lubricants such as grease that try to leak from the inside. This is a developed seal.

[Means for Solving the Problems] The present invention is directed to a first sealing element 2 having a substantially L-shaped cross section fixed to a housing 1 on the outer peripheral side as shown in FIG. 1, and a shaft 3.
A plurality of lips 5 made of an elastic material such as synthetic rubber or synthetic resin are formed on the first sealing element 2 and the second sealing element 4 in combination with a second sealing element 4 having a substantially inverted L-shaped cross section. A double seal 5/5, which is a combination seal slidably brought into contact with a mating sealing element, the tips of the first sealing element 2 and the second sealing element 4 being directed backward in the inner direction of the housing 1 and the outer direction. To form a radial contact with each other, and the main lips 5a and 5'a of the double lips 5 and 5'which face the housing 1 toward the outside and the sub-lips 5b and 5b of which face the inner side of the housing 1.
It is characterized by having a larger tightening margin than 5'b.

[Operation] Since the combination seal of the present invention has such a structure, when the combination seal is installed, the double lip 5 of the second sealing element 4 located outside as shown in FIG. The lip 5a pushes out dust, muddy water, etc. from the outside, and presses in the muddy water, etc. that has entered into the space obtained by the auxiliary lip 5b. Furthermore, since the double lip 5'of the first sealing element 2 located inside serves as a sealing means, and its sub-lip 5'b is inwardly in radial contact, it holds and seals the lubricating oil inside. It is highly effective and has a sealed structure that is strong against fluctuations in internal / external pressure due to engine operation / stop.

[Embodiment] To carry out the present invention, the main lip 5a of the double lip 5, 5 '
The 5'a is configured to have a larger tightening margin than the sub-lips 5b and 5'b, but there are various means for implementing it, and the lip length and thickness shown in FIG. In addition, there is a method in which springs or rings are attached to the main lips 5a and 5'a or the hardness and characteristics of the elastic body are changed.

[Effect of the Invention] As described above, the combination seal of the present invention has a high sealing performance by providing the two main lips 5a and 5'a having a large interference allowance for making radial contact. Especially this main lip
With 5a and 5'a, the followability in the axial direction is greatly improved, and the fluctuation of the sealing force is extremely small. Also, the double lip 5
All of 5'are in radial contact with the mating element, which does not require axial assembly accuracy, and do not have side contact, which requires a large amount of radial space, so the difference between the outer and inner diameters of the combined seal can be designed to be highly versatile. Will have.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the combination seal of the present invention. 2 and 3 are sectional views of a conventional combination seal. 1 ... Housing, 2 ... First sealing element, 3 ... Shaft, 4
... Second sealing element, 5 ... Double lip, 5a ... Main lip, 5b ... Secondary lip

Claims (1)

[Scope of utility model registration request] 1. A first sealing element 2 having a substantially L-shaped cross section fixed to a housing 1, and a substantially inverted L cross section fixed to a shaft 3.
A combination seal formed by combining a letter-shaped second sealing element 4 and a plurality of lips 5 made of an elastic body formed on the first sealing element 2 and the second sealing element 4 and slidingly contacting with a mating sealing element; A double lip 5 whose front ends are directed toward the inner side of the housing 1 and the outer side of the first sealing element 2 and the second sealing element 4.
5'are formed in radial contact with the main lips 5a and 5'a of the double lips 5 and 5'outwardly facing the housing 1 from the width lips 5b and 5'b facing the back of the housing 1. A combination seal with a large tightening margin.