JPH0610205Y2 - Sealed needle roller bearing - Google Patents

Description

[Detailed Description of the Invention] <Industrial field of application> The present invention relates to a sealed needle roller bearing which is used after being mounted inside and outside of a casing or a housing so that their ends face each other. .

<Prior Art> A conventional example of this type of closed needle roller bearing will be described with reference to FIG. Reference numeral 10 in this figure is a cylindrical shell-shaped outer ring, and is formed by being bent inward in the axial direction after being extended in the radial direction at the opening ends located on both sides along the axial direction. Collar portions 11 and 12 are provided respectively. On the inner peripheral surface side of the outer ring 10, a cage 20 having a substantially cylindrical shape is coaxially mounted with the outer ring 10. Further, this retainer 20 has a plurality of elongated holes 21 formed on its circumferential surface with a predetermined interval, and depending on each elongated hole 21, a plurality of needle rollers 30 having a cylindrical shape are respectively formed. It is rotatably held. In addition, these needle rollers 30 are shafts installed in a closed needle roller bearing.
The shaft 60 is rotatably supported by rolling on the outer peripheral surface of the shaft 60.

Further, annular first and second sealing members 40 and 50 which are in sliding contact with the outer peripheral surface of the shaft 60 are fitted inside the collar portions 11 and 12 provided at the open end of the outer ring 10. Cage,
These seal members 40, 50 are formed by integrally forming seal rings 42, 52 on the inner circumferences of annular seal cores 41, 51 having a substantially L-shaped cross section. And these seal rings 4
Lip portions 421, 422 and 521, 522, which project in opposite directions along the axial direction and have a V-shaped cross section, are formed on the inner peripheral surfaces of 2, 52, respectively. The seal rings 42, 52 are not limited to those having the above-mentioned cross-sectional shape, but in the sealed needle roller bearing, the lip portions 421, 422 and 5 having the same cross-sectional shape as described above are used.
It is general to use seal members 40 and 50 composed of seal rings 42 and 52 having 21,522 formed in combination.

Furthermore, the assembly of such a sealed needle roller bearing is
The procedure is as follows. First,
The collar portion 11 provided at the opening end on one side of the outer ring 10 is expanded outward along the axial direction, and the collar portion 12 provided at the opening end on the other side has the same shape as described above. It is bent and formed in advance. Then, from the opening end on one side of the outer ring 10 with the collar portion 11 being expanded, the second
The seal member 50, the cage 20 loaded with the needle rollers 30 and the first seal member 40 are housed in the order described, and then the collar 11 is bent to form various parts inside the outer ring 10. The procedure is to store. Since it is necessary to perform such a final bending operation, the wall thickness of the collar portion 11 is usually made thinner than the wall thickness of the collar portion 12 in advance.

Furthermore, the sealed needle roller bearing assembled in this manner is to be mounted after being press-fitted into the shaft 60 indicated by the alternate long and short dash line in the figure from one direction, but with a thin walled collar portion. If pressing force is applied to the opening end side where 11 is provided, this part may deform, so when press fitting,
It is a convention that the opening end side where the collar portion 11 is provided is pressed against the shaft 60, and then the other opening end 12 side where the thicker collar portion 12 is provided is pressed.

<Problems to be Solved by the Invention> By the way, in the above-mentioned conventional sealed needle roller bearing, the second seal member 50 is provided inside the thick collar portion 12 at the initial stage of the assembling work. In contrast to being fixed, the first seal member 40 is fixed to the inside of the flange portion 11 only by bending and forming the thin flange portion 11 at the final stage of the assembling work. And in this case, the bent collar part 11
The storage space of the first seal member 40 formed by the above tends to be larger than the storage space of the second seal member 50 by the thick walled flange portion 12, so that the elasticity of the first seal member 40 is reduced. The compressive force of the collar portion 11 on the seal ring 42, which is a member, is smaller than the compressive force of the collar portion 12 on the seal ring 52 of the second seal member 50.

Therefore, the seal ring 42 on which a smaller compression force acts
The protrusion of the lip portions 421,422 formed on the shaft 60 with respect to the shaft 60 tends to be smaller than the protrusion of the lip portions 521,522 of the seal ring 52.
The pressing force acting on the shaft 60 via 2 and 521,522 is smaller in the first seal member 40 than in the second seal member 50.

Therefore, for example, as shown in FIG. 3, when grease is injected from the nipple 80 to supply the grease to the needle roller 30 through the passage 81, if the filled grease leaks, the shaft 60 is pushed. The first seal member 40 having a low pressure leaks from the opening end side into which the first seal member 40 is fitted.

Then, like a circular frame shown by the one-dot chain line in FIG. 4, a shaft 3 for supporting the fork 2 of the clutch release 1 with such a closed needle roller bearing, and an operating member for operating the shaft 3 (illustration) Attached to the connection part with (omitted),
In the case where the open ends of the closed needle roller bearing face the inside and the outside of the clutch housing 4, respectively, the open end having the thin collar portion 11 is located inside the clutch housing 4. Because of this, the grease leakage direction is directed to the inside of the clutch housing 4, and the grease leaked to the inside of the clutch housing 4 may cause inconvenience such as clutch slippage.

Incidentally, tentatively, the collar portions 11, 1 at the respective open ends of the outer ring 10 are
Even when using a sealed needle roller bearing configured so that the wall thicknesses of 2 are the same and the pressing forces of the first and second seal members 40 and 50 against the shaft 60 are equal, Will only leak from both sides of the outer ring 10,
After all, it is unavoidable that grease gets inside the clutch housing 4.

The present invention was devised in view of such inconvenience, and an object thereof is to provide a sealed needle roller bearing in which grease cannot leak into the inside of a casing or the like.

<Means for Solving Problems> In the present invention, in order to achieve such an object,
A plurality of needle rollers that roll on the outer peripheral surface of the shaft to be installed,
A cage that rotatably holds the needle rollers, and a cylindrical shell-shaped outer ring that internally houses the cage and the needle rollers and that has flanges that extend in the radial direction at both ends. When,
The outer ring is provided with annular first and second seal members that are fixed to the inside of each of the flange portions and that are in sliding contact with the shaft. Further, the collar that fixes the first seal member is provided. In a closed needle roller bearing, the thickness of which is smaller than the thickness of the flange that secures the second seal member, in the lip portion of the second seal member which is arranged axially outside. To reduce the pressing force against the shaft to be smaller than the pressing force against the shaft of the first seal member arranged on the inner side in the axial direction, and direct these lip portions outward along the axial direction. It is characterized by being inclined.

<Operation> According to the above configuration, the pressing force of the second seal member against the shaft is smaller than the pressing force of the first seal member, and moreover, the lip portion of the second seal member moves in the axial direction. Since it is inclined outward along the axis, the grease supplied and filled in the needle rollers leaks outward from the second seal member in the axial direction, and is discharged inside the casing or housing. The grease will not leak.

<Embodiment> An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an exploded perspective view of a closed needle roller bearing according to this embodiment, and FIG. 2 is a cross-sectional view showing a state in which the closed needle roller bearing is mounted on a shaft. In these drawings, FIG. The same reference numerals are given to parts and portions that are the same as or corresponding to those of the conventional example.

That is, as shown in FIGS. 1 and 2, this closed needle roller bearing has a plurality of needle rollers 30 rolling on the outer peripheral surface of the shaft 60 to be internally mounted, and the needle rollers 30. A retainer 20 that holds it rotatably, and a retainer 20 and a needle roller 30 that are internally mounted, and a flange portion that extends in the radial direction at both ends.
A tubular shell-shaped outer ring 10 having 11, 12 and first and second annular seal members 40 fixed to the inner sides of the collar portions 11, 12 of the outer ring 10 and slidingly contacting the shaft 60. , 70
The wall thickness of the collar portion 11 to which the first seal member 40 is fixed is smaller than the wall thickness of the collar portion 12 to which the second seal member 70 is fixed. The present embodiment is different from the conventional example in that the second seal member in FIG. 3 is used.
A second 50 having a structure as shown in FIG. 1 and FIG.
By changing to the seal member 70 of No. 2, the pressing force of the second seal member 70 arranged axially outside of the outer ring 10 on the shaft 60 is made smaller than the pressing force of the first seal member 40 on the shaft 60, and This is at the point where the lip portion of the second seal member 70 is inclined outward along the axial direction.

Specifically, the second seal member 70 is arranged on the outer side in the axial direction after the seal ring 72 is integrally formed on the inner circumference of the annular seal core metal 71 having a substantially L-shaped cross section. The inner peripheral surface of the seal ring 72 is provided with bifurcated lip portions 721 and 722 that are inclined in parallel with each other toward the outside (right side in the drawing) along the axial direction. . Then, the pair of lip portions 721,722
One of the two, for example, the lip located on the inner side in the axial direction
The 722 is shorter than the lip portion 721 located on the outer side in the axial direction and has a smaller wall thickness. Further, at this time, the lip portions 421, 422 of the first seal member 40, which are to be arranged on the inner side in the outer ring 10 in the axial direction, are arranged on the outer side and the inner side, which are opposite to each other along the axial direction, as in the conventional example. By projecting toward each other, the cross section has a V-shape, and the thickness and length of both lip portions 421 and 422 are substantially the same.

Then, this closed needle roller bearing is assembled according to the same procedure as in the conventional example, and the storage space of the first seal member 40 formed by the collar portion 11 is formed by the thicker collar portion 12. The seal ring 42 of the first seal member 40 becomes wider than the storage space of the second seal member 70.
The compressive force from the collar portion 11 against the second seal member 70
The second seal ring 72 has a seal ring 72 provided with a lip portion 722 that is short and thin, although the compression force of the collar portion 12 against the seal ring 72 tends to be smaller.
Therefore, the pressing force of the seal member 70 on the shaft 60 is smaller than the pressing force of the first seal member 40 on the shaft 60.

Next, the grease flow when the grease is supplied to the closed needle roller bearing according to the present embodiment will be described.

As shown in FIG. 2, when grease is injected from the nipple 80 attached to the end face of the shaft 60, the injected grease advances along the direction of arrow A in the passage 81 formed inside the shaft 60. It flows toward the needle rollers 30. Then, the grease that has reached the needle roller 30 flows toward the first and second seal members 40 and 70 after being branched substantially evenly as shown by arrows B ₁ and B ₂ in the figure. Furthermore, the grease that has reached and filled the first and second seal members 40, 70 is along a direction that is determined based on the magnitude of the pressing force of the first and second seal members 40, 70 on the shaft 60. It will be leaked. That is, as described above, the second seal member 40 is larger than the first seal member 40.
Since the pressing force of the 70 against the shaft 60 is smaller, the grease is the second sealing member with a smaller pressing force against the shaft 60.
Only the 70 side will leak.

At this time, since all the lip portions 721, 722 of the seal ring 72 of the second seal member 70 are inclined outward along the axial direction, the first seal member 40 side is also provided. Therefore, it is easier for grease to leak from the second seal member 70 side. It should be noted that the shafts 6 are formed by the lip portions 721 and 722 of the second seal member 70.
The pressing force applied to 0 is the lip portion 42 of the first seal member 40.
Although it is supposed to be smaller than the pressing force applied to the shaft 60 by 1,422, the pressing forces when the lip portions 721 and 421 are compared with each other are almost the same, and the second sealing member 70 side It is considered that a significantly large amount of grease cannot be leaked from the equipment.

Therefore, such a closed needle roller bearing as described above is supported by the fork 2 of the clutch release 1 and a shaft 3 for supporting the fork 2 of the clutch release 1 and an operating member for operating the shaft 3 (shown in the figure). Attached to the connection part with (omitted),
When the open ends of the closed needle roller bearing face the inner side and the outer side of the clutch housing 4, the open ends having the thin collar portion 11 are located inside the clutch housing 4. However, it is possible to limit the direction of grease leakage from the closed needle roller bearing to the outside of the clutch housing 4, which causes inconvenience such as clutch slippage due to the grease leaking to the inside of the clutch housing 4. Disappears.

In this embodiment, the pressing force is smaller than the pressing force of the first seal member 40 by reducing the thickness of the lip portion 722 of the second seal member 70. The present invention is not limited to this, and, for example, by increasing the thickness of the lip portions 421 and 422 of the first seal member 40, the thickness of the lip portion 722 of the second seal member 70 is made relatively thin. Of course, it is okay.

<Effects of the Invention> As described above, according to the present invention, the thickness of the lip portion of the second seal member arranged on the outer side in the axial direction of the sealed needle roller bearing is reduced to push it against the shaft. When the grease leaks because the pressure is made smaller than the pressing force of the first seal member arranged on the inner side in the axial direction against the shaft, and these lip portions are inclined outward along the axial direction. The leak direction of the grease in is limited to the second seal member side. When this bearing is incorporated in various devices, it is common to arrange the first seal member facing the inside of the casing and the second seal member facing the outside of the casing. Therefore, the grease leaks inevitably face the outside of the casing or the like, and as a result, it is possible to reliably prevent the grease from leaking toward the inside of the casing or the like.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a closed needle roller bearing according to an embodiment of the present invention, and FIG. 2 is a sectional view of the closed needle roller bearing mounted on a shaft. Further, FIG. 3 is a cross-sectional view showing a state in which a closed needle roller bearing according to a conventional example is mounted on a shaft, and FIG. 4 is an explanatory view showing a use place of the closed needle roller bearing. 10 …… Outer ring 11 …… One open end 12 …… The other open end 20 …… Cage 30 …… Needle roller 40 …… First seal member 60 …… Shaft 70 …… Second seal member

Claims (1)

[Scope of utility model registration request] 1. A plurality of needle rollers that roll on the outer peripheral surface of a shaft to be mounted, a cage that rotatably holds the needle rollers, and the cage and the needle rollers that are internally mounted, and , A cylindrical shell-shaped outer ring having a flange portion extending in the radial direction at both ends, and an annular first ring fixed to the inner side of each of the flange portions of the outer ring and slidingly contacting the shaft. 1 and a second seal member, and the wall thickness of the flange portion to which the first seal member is fixed is thinner than the wall thickness of the flange portion to which the second seal member is fixed. In the closed needle roller bearing, the thickness of the lip portion of the second seal member arranged outside in the axial direction is reduced so that the pressing force against the shaft is arranged inside in the axial direction. The pressure of the seal member against the shaft should be less than A sealed needle roller bearing characterized in that the portion is inclined outward along the axial direction.