JPH0512534Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a sealing device used as a sealing means between a rotating shaft and a housing penetrated by the rotating shaft, and more specifically relates to a sealing device used as a sealing means between a rotating shaft and a housing penetrated by the rotating shaft. The present invention relates to the structure of a sealing device that can withstand use in the field.

(Prior art) For example, special consideration must be given to dust resistance for sealing devices for rotating shafts that are forced to operate in environments with dirt and sand, such as rotating shafts in construction machines such as shovel loaders. .

The one shown in FIG. 2 is an example of a conventional sealing device that takes into account dust resistance, and has a main lip 4 made of a rubber-like elastic material that slides on the circumferential surface of a rotating shaft 1, and a sub-lip 5 made of felt. An outer cylindrical fixed ring with a substantially L-shaped cross section is attached to the housing 2, and a sub lip 5 prevents external dust from entering, and a main lip 4 prevents internal lubricant from flowing out. It is configured as follows.

(Problems to be Solved by the Invention) The sealing device according to the above-mentioned conventional technology has a simple structure and is particularly equipped with only the felt sub-lip 5 as a means for blocking external dust. Products such as force transmission shafts, which are prone to eccentricity and axial wobbling during operation and are used under harsh environmental conditions, have low dust resistance and poor sealing performance against lubricants. There remained a problem.

The object of the present invention is to solve the above-mentioned problems and to present a structure of a sealing device having excellent dust resistance and a sealing function against lubricant.

(Means for Solving the Problems) The present invention has been made in consideration of the problems in the sealing devices according to the conventional technology described above. a first seal 3 having a main lip 4 made of a similar elastic material and mounted on the housing 2; a radial member 8 located on the atmosphere side of the seal 3 and fixed to the housing 2; a large diameter cylindrical portion 1 covering the radial member 8 on the outer end side;
2, and a slinger 9 comprising an end seal lip 10 made of a rubber-like elastic material located on the outer peripheral side of the cylindrical portion and sliding on the radial portion.

As an auxiliary means for the sealing function of the first seal and end seal lip described above, a felt sub-lip may be added to the first seal, or a labyrinth seal structure may be used between the radial member and the slinger fixed to the rotating shaft. Measures are taken to form a

(Function) In the sealing device having the above configuration, the main lip made of a rubber-like elastic material attached to the first seal and sliding on the circumferential surface of the rotating shaft prevents the lubricant from flowing out, and prevents the lubricant from flowing out. An end face seal lip made of a rubber-like elastic material that slides on the side surface of the shaft eliminates dust that enters from the outside with the shaking off action that occurs with rotation.

The felt sub-lip added as an auxiliary means for the first seal prevents fine dust that has passed through the seal formed by the flange, radial member, and end seal lip from entering the lubricant side. The added labyrinth seal structure superimposes the dust containment function provided by the end seal lip to facilitate external dust containment.

(Embodiment) In the embodiment shown in FIG. 1, the first seal 3, which has a main lip 4 made of a rubber-like elastic material and a sub lip 5 made of felt, which slides on the circumferential surface of the rotating shaft 1, has a stepped cylindrical shape. A radial member 8 , which is attached to the housing 2 via a retaining ring 6 having a shape and shaped as an annular body with a substantially Z-shaped cross-section, is fixed to the retaining ring 6 adjacent to the first seal 3 . The slinger 9 has a small diameter cylindrical part 11 and a large diameter part 12 facing the outer periphery of the retaining ring 6, and has an end seal lip 10 made of a rubber-like elastic material in the middle that slides on the side surface of the radial member 8. , the small diameter cylindrical portion 11 is fitted onto the rotating shaft 1, an end face seal is formed by the radial member 8 and the end face seal lip 10, and between the outer periphery of the small diameter cylindrical portion 11 and the inner end of the radial member 8, A labyrinth seal is formed between the large diameter portion 12 and the outer periphery of the retaining ring 6, respectively.

(Effects of the Invention) As described above, the sealing device of the present invention has a main lip made of a rubber-like elastic material that slides on the circumferential surface of the rotating shaft and is attached to the housing, and a radial member fixed to the housing and located on the atmosphere side of the first seal, the radial member having a cylindrical portion extending axially toward the atmosphere from an inner end of the radial portion; and an atmosphere side of the radial member. a large-diameter cylindrical portion located on the outer circumferential side of the cylindrical portion; By having a radial portion and a slinger comprising an end face seal lip made of a rubber-like elastic material that slides, the slinger can shake off dust and muddy water that try to enter from the outside as the rotating shaft rotates, and still Furthermore, even if muddy water etc. enters the inside of the slinger, the end face seal lip will prevent further intrusion. The muddy water or the like that is received by the rotary shaft 1 moves to the lower part of the rotating shaft 1 along the cylindrical portion and is discharged to the outside. Therefore, the sealing device of the present invention can maintain a good sealing function since the intrusion of external dust and muddy water into the interior is completely prevented and damage to the first seal 3 is prevented.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view of an example of a conventional sealing device. 1...Rotating shaft, 2...Housing, 3...First
Seal, 4...Main lip, 5...Secondary lip, 6
... Retaining ring, 7 ... Second seal, 8 ... Radial member, 9 ... Slinger, 10 ... End seal lip, 11 ... Small diameter cylindrical part, 12 ... Large diameter part.

Claims (1)

[Scope of utility model registration request] A first seal 3 is attached to the housing 2 and includes a main lip 4 made of a rubber-like elastic material that slides on the circumferential surface of the rotating shaft 1 passing through the housing 2, and a radial portion and an inner portion of the radial portion. The first seal 3 includes a cylindrical portion extending from the end toward the atmosphere in the axial direction.
a radial member 8 located on the atmospheric side and fixed to the housing 2; a radial member 8 located on the atmospheric side of the radial member 8 and having a radially inner end side fixed on the rotating shaft 1;
A large-diameter cylindrical portion 12 covering the radial member 8 is provided at the outer end in the radial direction, and an end seal lip 10 made of a rubber-like elastic material is provided on the outer periphery of the cylindrical portion and slides with the radial portion. A sealing device comprising a slinger 9.