JPH0520931Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a sealing device disposed between a rotating shaft and a housing that are arranged concentrically with each other, and in particular to a mechanical device that rotates at high speed using grease as a lubricant. This invention relates to an effective sealing device used in

(Prior Art) As illustrated in FIG. 2, the sealing means between the rotating shaft and the housing which are arranged concentrically with each other is made of a rubber-like elastic material.
Sealing devices are widely used which have a sliding lip 7 which comes into elastic contact with the circumferential surface of the pipe to prevent the leakage of internal lubricant and the ingress of external dust.

(Problems to be Solved by the Invention) In the conventional sealing device described above, the sealing effect is achieved by the elastic contact of the sliding lip 7 with the circumferential surface of the rotating shaft 1. Problems caused by sliding friction cannot be avoided.

That is, not only is there a loss of torque due to friction, but also an increase in leakage due to a decrease in the viscosity of the lubricant due to frictional heat, or a decrease in the sealing function due to wear of the circumferential surface of the rotating shaft 1 or the inner circumference of the sliding lip 7. is brought about.

It is an object of the present invention to provide a structure of a sealing device that eliminates the above-mentioned problems and prevents loss of torque and deterioration of sealing function due to friction.

(Means for Solving the Problems) In consideration of the problems in the conventional sealing devices described above, the present invention provides a sealing device for sealing between a housing and a rotating shaft that rotate relative to each other, a base fixed to the housing; and a grease lip made of a rubber-like elastic material, which is formed into a conical shape and extends toward the lubricant side while maintaining a small gap from the base to the circumferential surface of the rotating shaft; A dust strip made of a rubber-like elastic material is formed into a conical shape and extends toward the atmosphere while maintaining a small gap between the base and the circumferential surface of the rotating shaft, and the rotating shaft is provided between the grease lip and the dust lip. It has a structure having a plurality of intermediate lips made of a rubber strip elastic material, which exist with a small gap between them and the circumferential surface of the tube.

It is best to set the small gap between the internal lip, grease lip, dust lip and the circumferential surface of the rotating shaft to 0.5 mm or less, and to set the small gap between the intermediate lip and the circumferential surface of the rotating shaft to 0.8 mm or less. It was confirmed to be effective.

(Function) In a sealing device with the above configuration, an internal lip made of felt material placed on the lubricant side with a small gap between it and the circumferential surface of the rotating shaft prevents the lubricant inside the bearing from flowing out. However, as shown in Figure 1, the lubricant adhering to the upper part of the grease lip made of rubber-like elastic material is placed next to the inner lip with a small gap between it and the circumferential surface of the rotating shaft. When it falls to the rotating shaft circumferential surface along the outer circumferential conical surface, it has a velocity component toward the lubricant side. Since the lubricant and the like are shaken off by the rotation of the sealing device, it is possible to completely prevent the lubricant and the like from returning to the sealing device and leaking to the atmosphere. Also,
A plurality of intermediate lips made of rubber-like elastic material are arranged next to the grease lip with a small gap between them and the circumferential surface of the rotating shaft, which prevents internal grease from leaking due to the labyrinth effect. A dust strip made of a rubber-like elastic material placed on the atmosphere side with a small gap between it and the surrounding surface acts in the same way as the grease lip, as shown in Figure 1, and dust returns to the sealing device for lubrication. It is possible to completely prevent the agent from entering the drug side.

Therefore, the sealing device of the present invention has the ability to completely seal on both the lubricant side and the atmosphere side.

(Embodiment) In the embodiment shown in Fig. 1, the inner lip 2 is made of felt material and has a substantially snake-like shape, and forms a minute gap with the circumferential surface of the rotating shaft 1. located on the lubricant side of the
A grease lip 3 made of a rubber-like elastic material is disposed, which is made into a conical shape that tapers toward the inner lip 2 side, and forms a minute gap with the circumferential surface of the rotating shaft 1.
Next to the grease lip 3, protruding inwardly,
Two intermediate lips 4 made of a rubber-like elastic material are arranged to form a small gap with the circumferential surface of the rotating shaft 1, and are tapered outward on the right side of the figure toward the atmosphere. A dust strip 5 made of a rubber-like elastic material is arranged to form a small gap between the dust strip 5 and the circumferential surface of the rotating shaft 1.

(Advantages of the Invention) As described above, the sealing device of the present invention is a sealing device that seals between a housing and a rotating shaft that rotate relative to each other, and comprises a base portion fixed to the housing, a grease slip made of a rubber-like elastic material that extends from the base portion to the circumferential surface of the rotating shaft with a minute gap between the base portion and the circumferential surface of the rotating shaft and is formed into a cone shape toward the lubricant,
The device has a rubber-like elastic dust lip that extends from the base toward the atmosphere with a small gap between it and the circumferential surface of the rotating shaft and is formed into a cone shape, and a plurality of rubber-like elastic intermediate lips that exist between the grease lip and the dust lip and the circumferential surface of the rotating shaft with a small gap between them, thereby preventing leakage of the lubricant through the labyrinth action of the intermediate lip, preventing the lubricant, etc. from returning to the sealing device and leaking to the atmosphere with the grease lip, and preventing the intrusion of external dust with the dust lip, thereby providing a perfect seal on both the lubricant and atmosphere sides. Moreover, since the inner peripheral end of each lip does not contact the circumferential surface of the rotating shaft, there is no loss of torque due to friction and no wear of the lip tip and the circumferential surface of the rotating shaft, and the normal sealing function is maintained for a long period of time.

[Brief explanation of drawings]

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... Internal lip, 3... Grease lip, 4... Intermediate lip, 5... Dust lip, 7... Sliding lip.

Claims (1)

[Scope of utility model registration request] This is a sealing device that seals between a housing 10 and a rotating shaft that rotate relative to each other, and has a small gap between a base 6 fixed to the housing 10 and the circumferential surface of the rotating shaft 1 from the base 6. A grease lip 3 made of a rubber-like elastic material is formed into a conical shape and extends toward the lubricant side while maintaining a slight gap between the base and the circumferential surface of the rotating shaft 1 and extends toward the atmosphere side. A dust lip 5 made of a rubber-like elastic material is made into a conical shape, and a plurality of rubber-like strips are present between the grease lip 3 and the dust lip 5 with a slight gap between them and the circumferential surface of the rotating shaft 1. A sealing device having an intermediate lip 4 made of elastic material.