JPS641537Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a double-sealed shell-shaped needle roller bearing in which seal bodies are attached to both ends of the inner peripheral side of the outer ring.

BACKGROUND ART A shell-shaped needle roller bearing with double seals is known, for example, as described in US Pat. No. 3,409,337. As shown in FIG. 4, this bearing has a structure in which a shaft C1 is inserted into the inner circumferential side of a shell-shaped outer ring A1 press-fitted into a housing H1 via needle rollers B1, and the shaft C1 is inserted into the housing H1. A seal body G1 consisting of a core metal E1 having a substantially square cross section and an elastic member F1 is mounted on the inner side of the bearing of a radially inwardly extending collar D1 formed at both ends of the outer ring A1. This structure is such that the end surface of the axial cylindrical portion of the gold E1 is attached to the inner surface of the collar D1 of the outer ring A1.

A similar bearing is also known as described in US Pat. No. 3,549,221. As shown in Fig. 5, the structure of this bearing is such that needle rollers B2 held by a cage J2 are arranged on the inner circumferential side of a shell-shaped outer ring A2 press-fitted into a housing H2. The shaft C2 is supported in the housing H2, and the seal body G2 is made up of a mandrel E2 and an elastic member F2.The seal body G2 is made of a mandrel E2 and an elastic member F2. Only F2 is attached so as to be in contact with the inner surface of the collar D2 and the inner peripheral surface of the outer ring.

Problems to be solved by the invention However, the above two conventional techniques have the following problems.

First, in the former case, if an axial force is applied to the shaft due to some influence, or if B1 is skewed, roller B1 and seal body G1 will come into contact and an axial force will be applied to the contact area. At this time, the collar D1 of the outer ring A1 and the core E1 of the seal body G1
Since they are in direct contact with each other, the seal body G1 acts on the roller B1 as a rigid body, and the force in the axial direction acts on the roller B1 and the seal body G1 as an excessive impact force. Therefore, noise and vibration are generated, and the roller B1 and the seal body G1 are damaged, which causes the life of the bearing to be shortened.

In the latter case, even if the axial force acts on the bearing, the elastic member F2 of the seal body G2 acts as a cushion against the force and can absorb the excessive impact force. Since the body G2 itself is attached to the outer ring A2 by simply fitting the elastic member F2 onto the outer ring A2, the seal body may be installed at an angle due to the deformation of the elastic member F2 itself, or the amount of deformation of the elastic member F2 may change. There is a drawback that the seal contact pressure between the seal body G2 and the shaft C2 changes due to variations in the pressure, and the seal body cannot be assembled with high precision.

In view of the above-mentioned problems of the prior art, this invention aims to provide a shell-type needle roller bearing in which the seal body itself has a function as a cushion to absorb the impact force, and the accuracy of assembling the seal body is improved. It is something to do.

Means for Solving the Problems The problems of the prior art described above will be explained with reference to the embodiment shown in FIG. and a plurality of needle rollers 3 arranged on the inner peripheral side of the outer ring 2.
and a seal body 7 fixed to the inner side of the flanges 5 and 6 at both ends of the outer ring 2, wherein the seal body 7 is slightly smaller than the inner diameter of the outer ring 2. It consists of a mandrel 8 having an outer diameter and an annular elastic member 9 that is integrally fixed to the radially inward side of the mandrel 8, and the tips of the flanges 5 and 6 of the outer ring 2 are bent inward at approximately right angles. The bent portion 5 formed by
Only a portion of the elastic member 9 of the seal body 7 is held between the inner peripheral surface of the outer ring 2 and the inner peripheral surface of the outer ring 2, and the core metal 8 is connected to a flange portion 82 that covers the end surface of the elastic member 9 on the roller side. A sealed needle roller bearing is formed in a cylindrical portion 81 that covers a part of the outer circumferential surface of the elastic member 9, and at least a portion of the outer circumferential surface of the cylindrical portion 81 is brought into contact with the inner circumferential surface of the outer ring 2. This can be solved by

Effect The above means works as follows.

When an axial force is applied to the bearing, the rollers 3 move in the axial direction, bringing the retainer 4 into contact with the radial flange portion 82 of the mandrel 8 of the seal body 7. At this time, since the outer diameter of the cylindrical portion 81 of the mandrel 8 is slightly smaller than the inner diameter of the outer ring 2, the seal body 7 tends to move in the axial direction due to the axial force acting from the rollers, but the elastic member 9 becomes a cushion and absorbs this power.

Furthermore, since the seal body 7 is mounted on both ends of the inner circumferential side of the outer ring 2 such that only the elastic member 9 of the seal body 7 is held between the outer ring 2 and the flange tips 51 and 61, the elastic member 9 Although the seal member 9 is deformed, the seal member 7 itself is prevented from deforming due to the contact between the cylindrical portion 81 of the mandrel 8 and the outer ring 2, and is no longer deformed in the radial direction.

Embodiment FIGS. 1 and 2 show a first embodiment of the present invention. Note that FIG. 2 is a longitudinal sectional view of the main part of FIG. 1.
1 is a housing; 2 is a shell-shaped outer ring that is attached to the housing and has flanges 5 and 6 extending radially inward at both ends on the inner circumferential side; 3 is a plurality of rings arranged on the inner circumferential side of the outer ring 2; (In the case of the embodiment, the needle rollers 3 are used in double rows, but they may be in a single row or in a multi-row format with three or more rows). The needle rollers 3 are held in a cage 4, and the shaft 10 is supported within the housing 1 via the outer ring 2 and the needle rollers 3.

Reference numeral 7 denotes a sealing body, which is formed of a core metal 8 and an elastic member 9. The mandrel 8 includes a conical cylindrical portion 81 that is slightly inclined radially inward toward the flange side of the outer ring 2, and an elastic member that extends radially inward from the end of the cylindrical portion 81 on the roller 3 side. 9, and a flange portion 82 that covers the end surface of the roller 3 side of the elastic member 9.
The elastic member main body 91 is integrally fixed to the core metal 8 by baking or the like, and the seal lip 92 extends radially inward from the inner peripheral surface of the elastic member main body 91.
and extension portions 93 extending from the distal end side of the cylindrical portion 81 of the elastic member main body 91 toward the flange portions 5 and 6 of the outer ring 2, respectively.

Further, the mandrel 8 covers a part of the outer circumferential surface of the elastic member 9 with its cylindrical portion 81 and the radial flange 82 as well as the end surface on the 3 side, and the outer circumferential surface of the cylindrical portion 81 of the mandrel 8 The maximum diameter portion is formed as a contact portion 83 with the inner circumferential surface of the outer ring 2 to position the seal body 7 in the radial direction when the outer ring 2 is attached.

The seal body 7 is positioned in the axial direction by bending the extension portion 93 of the elastic member 9 at a substantially right angle to the tips of the flanges 5 and 6 at both ends of the outer ring 2, and aligning the bent portion 51 with the inner circumferential surface of the outer ring 2. This is done by holding only the extension portion 93 between the two. Therefore, the seal body 7 is axially displaceable within the elastic deformation region of the extension 93 of the elastic member 9, and the elastic deformation of the extension 93 applies an axial force to the seal body 7. In order to assemble the bearing itself, first, one seal body 7 is inserted into the flange 5 of the outer ring 2, which has a flange 5 formed on one end side. The extension part 93 of the elastic member 9 of the passage seal body 7 is held between the bent part 51 at the tip of the collar 5 and the inner peripheral surface of the outer ring 2. Next, the roller 3 held in the cage 4
After inserting into the outer ring 2 and inserting the other seal body 7, a flange 6 is formed on the other end side of the outer ring 2, the tip of the flange 6 is bent, and the other seal body 7 is held in the same manner as above. It is done by.

The wall thickness of the outer ring on the side where the flange 6 is formed is made thin so that the flange 6 and the bent portion formed at the tip of the flange 6 can be easily formed.

FIG. 3 is a view corresponding to FIG. 2 showing another embodiment of this invention, in which the cylindrical portion 181 of the mandrel 18 of the seal body 17 is formed into a cylindrical shape parallel to the axis. In the case of this embodiment, the entire outer circumferential surface of the cylindrical portion 181 contacts the inner circumferential surface of the outer ring 2, so that the accuracy of positioning the seal body 17 and the outer ring 2 in the radial direction is improved.

Effects This invention has the above-mentioned configuration, and in particular, the outer diameter of the core of the seal body is formed slightly smaller than the inner diameter of the outer ring, and an extension is formed in the main body of the elastic member of the seal, and the extension is By sandwiching the chisel between the tips of the flanges formed at both ends of the outer ring, even if an axial force acts on the bearing and the rollers or cage come into contact with the seal body, the seal body will not move in the axial direction. The extension part formed on the seal body elastically deforms and absorbs the movement of the seal body, and also prevents the cylindrical part of the mandrel from directly hitting the flange of the outer ring. No impact is caused by contact between the cage and the seal body. Therefore, even if an axial force is applied to the bearing, the rollers, retainer, and seal body will not be damaged.

The radial movement of the seal body is regulated by bringing at least a portion of the cylindrical portion of the mandrel into contact with the inner circumferential surface of the outer ring, so that the extension of the seal body is held between the tip of the flange of the outer ring. Even when the seal body is attached to the outer ring, the deformation of the seal body is limited to only the extension portion, and the seal body itself is not deformed and tilted, and the contact pressure between the seal lip and the shaft does not change. Therefore, the seal body can be mounted and positioned with high accuracy.

Since the mandrel of the seal body and the outer ring are loosely fitted, it is easy to attach the seal body to the outer ring.

In the case of the first embodiment, since the cylindrical portion of the mandrel of the seal body is formed into a conical shape, when the seal body is attached to the outer ring, the tip of the cylindrical portion bites the inner circumferential surface of the outer ring, causing damage to the outer ring and the outer ring. Damage to the mandrel can be prevented.

Further, in the case of the second embodiment, by forming the cylindrical portion of the seal body into a cylindrical shape, deformation of the seal body can be more reliably prevented and movement of the seal body in the radial direction can be more reliably restricted. Moreover, since the mandrel can be easily processed, the seal body itself can also be processed easily.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view showing a first embodiment of this invention, Fig. 2 is an enlarged view of the main part of Fig. 1, and Fig. 3 is a view equivalent to Fig. 2 showing a second embodiment of this invention. , FIG. 4, and FIG. 5 are longitudinal sectional views showing the prior art, respectively. 2... Outer ring, 3... Roller, 5, 6... Tsuba, 7
... Seal body, 8 ... Mandrel, 9 ... Elastic member, 1
0...Shaft, 81...Cylinder part, 82...Flange part,
83... Contact portion, 91... Elastic member main body, 92...
...Seal lip, 93...Extension part.

Claims (1)

[Claims for Utility Model Registration] (1) A shell-shaped outer ring having flanges extending radially inward at both ends, a plurality of needle rollers arranged on the inner circumferential side of the outer ring, and both ends of the outer ring. In a shell-type needle roller bearing comprising a seal body fixed to the inner side of the flange of the part, the seal body has a core metal having an outer diameter slightly smaller than the inner diameter of the outer ring and a radially inner surface of the core metal. an annular elastic member integrally fixed to the outer ring, and an elastic member of the seal body is formed between the bent part formed by bending the flange tip of the outer ring inward at a substantially right angle and the inner circumferential surface of the outer ring. Only a portion of the member is held, and the mandrel is formed into a radial flange portion that covers the roller-side end surface of the elastic member and a cylindrical portion that subsequently covers a portion of the outer circumferential surface of the elastic member, and the cylindrical portion A sealed needle roller bearing characterized in that at least a portion of the outer peripheral surface of the bearing is in contact with an inner peripheral surface of an outer ring. (2) The cylindrical portion of the mandrel of the seal body is formed into a conical shape that is slightly inclined radially inward toward the flange of the outer ring, and the maximum diameter portion of the outer circumferential surface of the cylindrical portion is formed on the inner circumferential surface of the outer ring. A shell-shaped needle roller bearing according to claim 1 of the claimed utility model registration. (3) The shell-shaped needle according to claim 1, wherein the cylindrical portion of the mandrel of the seal body is formed into a cylindrical shape, and the entire outer circumferential surface of the cylindrical portion is brought into contact with the inner circumferential surface of the outer ring. shaped roller bearings.