JP4762576B2 - Mud-water resistant rolling bearing - Google Patents

Description

The present invention relates to a muddy water-resistant rolling bearing in which a bearing space between an inner ring and an outer ring is sealed with a contact seal.

  Rolling bearings used in an environment where dust, water, etc. are scattered have a sealed type rolling bearing in which the bearing space is sealed with a contact seal in order to prevent them from entering the bearing space between the inner ring and the outer ring. It is used. The contact seal seals the bearing space by bringing a seal lip formed of an elastic member such as rubber into contact with the seal sliding surface of the inner ring or the outer ring.

  This type of sealed-type rolling bearing has one contact seal mounted on each side of the bearing space (see, for example, Patent Document 1), and further outside the contact seal mounted one by one. Some have a contact shield (see, for example, Patent Documents 2 and 3). In what is described in Patent Document 2, a shield (shielding plate) is divided into one attached to an inner ring and one attached to an outer ring, and a labyrinth gap is formed between these divided shields. Moreover, in what was described in patent document 3, the labyrinth clearance gap was formed between the shield (cover) and the inner contact seal.

  On the other hand, since the rolling bearing used for the center shaft support part of the propeller shaft of the automobile and the joint shaft support part of the drive shaft is disposed under the floor of the vehicle, it receives muddy water splashes, Receives flying.

Japanese Utility Model Publication No. 7-10555 (Fig. 1) Japanese Utility Model Publication No. 8-3710 (Figs. 1 and 2) JP 2001-50288 A (Figs. 1, 3 to 10)

  When a sealed rolling bearing such as that described in Patent Document 1 is used at a site that receives muddy water scattering as described above, the muddy water that scatters adheres to the seal lip and the seal sliding surface of the contact seal, There is a problem that the seal lip and the seal sliding contact surface are worn by mud, and the sealing performance is remarkably lowered.

  The sealed rolling bearings described in Patent Document 2 and Patent Document 3 can prevent muddy water from directly adhering to the seal lip or seal sliding surface of the contact seal by the shield, but the shield has a non-contact gap. Therefore, muddy water enters between the shield and the contact seal through the labyrinth gap from this gap. The muddy water that has entered between the shield and the contact seal in this way increases in the concentration of the mud due to the evaporation of moisture, so that the muddy water with the increased concentration of mud adheres to the seal lip and seal sliding surface of the contact seal. Then, these wears are promoted. For this reason, it is not possible to sufficiently prevent a decrease in sealing performance.

Therefore, an object of the present invention is to provide a mud-water- resistant rolling bearing capable of sufficiently ensuring sealing performance even when used in an environment where mud is scattered.

In order to solve the above problems, the present invention is used in a center shaft support portion of a propeller shaft of an automobile or a joint shaft support portion of a drive shaft, and a bearing space between an inner ring and an outer ring is formed by an elastic member. In a muddy water-resistant rolling bearing sealed with a contact seal that makes the lip contact the seal sliding surface, the bearing space is sealed with two inner and outer contact seals, and the outer contact seal forms the seal lip And a cored bar whose outer surface is covered with the elastic member. The cored bar is fitted and fixed to the outer peripheral surface of the inner ring, and two inner and outer contact seals are provided on each of the inner and outer contact seals. provided the seal lip so that the tip faces outwardly, the leading edge portion of the seal lips of the inner contact seal is in line contact with the sealing sliding surface, contact of the outer sheet Each seal lip Le, due Rukoto contacting surface and a side surface portion on the inner peripheral surface formed tapered seal sliding surface so as to spread outward from axially inside of the outer ring, the outer Adopts a structure that shuts off the muddy water by the surface contact of each seal lip of the contact seal and blocks the moisture entering from the interface of the surface contact by the line contact of each seal lip of the inner contact seal. did.

That is, the bearing space is sealed with two inner and outer contact seals, and two inner and outer contact lips are provided on each of the inner and outer contact seals so that the tip faces outward. the sealing lip is in line contact with the seal sliding surface, by surface contact with each sealing lip of the outer contact seal sealing sliding surface, the mud inside and outside two sealing lips that contact the surface of the outer contact seal mud In order to prevent the mud from adhering to the seal lip and seal sliding contact surface of the inner contact seal, the moisture that penetrates from the interface of these surface contacts It was shut off and out of two sealing lips which line contact, be used in an environment where muddy water is scattered, and so the sealing performance can be sufficiently ensured.

  Nitrile rubber or fluororubber having excellent wear resistance is suitable for the elastic member forming each seal lip of the outer contact seal.

  The outer contact seal is provided with a metal core, the metal core is fitted to the inner ring or the outer ring, and the outer contact seal is firmly fixed, so that the outer contact when receiving a flying stone, etc. It is possible to prevent the sealing performance from being deteriorated due to damage or deviation of the seal.

The muddy water-resistant rolling bearing of the present invention seals the bearing space with two inner and outer contact seals, and the inner and outer contact seals are respectively provided with two inner and outer seal lips with the tips facing outward. The inner and outer contact seals are in line contact with the seal slidable contact surface, and the outer contact seals are brought into surface contact with the seal slidable contact surface to contact the inner and outer surfaces of the outer contact seal. completely blocked the mud content of the mud by two sealing lips, with mud fraction of mud is prevented from adhering to the seal lip and seal sliding surface of the inner contact seal, the sealing lip of the outer contact seal enough moisture but it penetrates from the interface of surface contact. Thus to shut off inside and outside two sealing lips in contact line of the inner contact seal, even when used in an environment where muddy water is scattered, the sealability It can be ensured.

  The outer contact seal is provided with a core, and the outer contact seal is fixed when the outer contact seal is firmly fixed by fitting the core to the inner ring or the outer ring. It is possible to prevent a decrease in sealing performance due to damage or displacement.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, this mud-water-resistant rolling bearing has a bearing space in which a ball 3 is held by a cage 4 between an inner ring 1 and an outer ring 2 with two inner and outer contact seals 5 and 6. It is a sealed ball bearing.

As shown in FIG. 2, each of the contact seals 5 and 6 is composed of cored bars 5a and 6a and elastic members 5b and 6b, respectively. The inner contact seal 5 is fixed to an engagement groove 2b provided on the inner peripheral surface of the outer ring 2 by an elastic member 5b, and two inner and outer seal lips 5c and 5d are provided. These seal lips 5c, The front edge portion of 5d is in line contact with the seal sliding contact surface 1a provided on the outer peripheral surface of the inner ring 1. Therefore, these sealing lips 5c, the line contact 5d, each seal lip 6c of the outer contact seal 6 to be described later, the water entering from the contact interface 6d are completely shield off.

The outer contact seal 6 is firmly fixed by fitting a cored bar 6a to a stepped portion 1b provided on the outer peripheral surface of the inner ring 1, and two inner and outer elastic members 6b made of nitrile rubber or fluororubber. The seal lips 6c and 6d are provided, and the side surfaces of the seal lips 6c and 6d are in surface contact with the seal sliding contact surface 2a provided on the inner peripheral surface of the outer ring 2. Therefore, mud mud content out two sealing lips 6c that scattered around, completely blocked by 6d surface contact, the seal lips 5c of the inner contact seal 5, the muddy water to 5d and the sealing sliding surface 1a Mud does not adhere.

As an example, a mud-water-resistant rolling bearing shown in FIG. 1, as a comparative example, a sealed rolling bearing (comparative example 1) with a contact seal on the inside and a non-contact seal on the outside, and an inner and outer seal A sealed type rolling bearing (Comparative Example 2) having a contact seal having one seal lip was prepared. The sealed rolling bearings of these examples and each comparative example were subjected to a muddy water infiltration test in which a rotation cycle in which high speed rotation and low speed rotation were alternately performed in muddy water, and the amount of muddy water entering the bearing space was investigated. The number of samples n in the examples and the comparative examples was 4 respectively, and the amount of muddy water entering the bearing space was determined by measuring the amount of mass increase W of the bearing before and after the test. The test conditions are as follows.
・ Rotation cycle: 1000rpm → 0rpm → 300rpm → 0rpm
(30 minutes / cycle)
・ Test time: 160 hours ・ Muddy water: Kanto loam powder JIS 8 types (mud concentration 5% by mass)

  The results of the muddy water penetration test are shown in Table 1. The comparative example 1 in which the inner side is a contact seal and the outer side is a non-contact seal has a very large mass increase amount W of the bearing, and is not very effective in preventing muddy water from entering. Further, in Comparative Example 2 in which the inner and outer seals are contact seals each having one seal lip, the bearing mass increase W is reduced to about half that of Comparative Example 1, Infiltration cannot be sufficiently prevented. On the other hand, the inner and outer seals are contact seals having two inner and outer seal lips, each seal lip of the inner seal is in line contact, and each seal lip of the outer seal is in surface contact. Thus, it can be seen that the mass increase amount W of the bearing is not remarkably recognized, and the muddy water permeation preventing effect is very excellent.

In the embodiment described above, the muddy water sealed rolling bearing was the ball bearing, muddy water sealed rolling bearing according to the present invention can be adopted to other types of rolling bearings such as roller bearings.

Longitudinal sectional view showing an embodiment of a muddy water sealed rolling bearing Sectional drawing which expands and shows the principal part of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner ring 1a Seal sliding contact surface 1b Step part 2 Outer ring 2a Seal sliding contact surface 2b Locking groove 3 Ball 4 Cage 5, 6 Contact seal 5a, 6a Core metal 5b, 6b Elastic member 5c, 5d, 6c, 6d Seal lip

Claims (2)

Used in the center shaft support part of automobile propeller shaft or joint shaft support part of drive shaft, the bearing space between the inner ring and outer ring is sealed with a contact seal that makes the seal lip formed of an elastic member contact the seal sliding contact surface In the muddy water- sealed rolling bearing, the bearing space is sealed with two inner and outer contact seals, and the outer contact seal is covered with an elastic member forming the seal lip and an outer surface of the elastic member. The inner metal ring is fitted and fixed to the outer peripheral surface of the inner ring, and two inner and outer seal lips are provided on the inner and outer contact seals so that the tip faces outward . the leading edge portion of the seal lips of the inner contact seal is in line contact with the sealing sliding surface, the sealing lips of the outer contact seals, before the side portions The axially inside to the inner peripheral surface of the outer ring by Rukoto brought into surface contact with the tapered seal sliding surface formed so as to spread toward the outside, the muddy water in surface contact each seal lip of said outer contact seal A mud- water-resistant rolling bearing characterized by blocking mud and blocking water entering from the interface of the surface contact by line contact of each seal lip of the inner contact seal . The muddy water- sealing type rolling bearing according to claim 1, wherein the elastic member forming each seal lip of the outer contact seal is nitrile rubber or fluorine rubber.

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