JP4061470B2 - Rolling bearing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rolling bearing device, and more particularly to a rolling bearing device mainly composed of a shell needle roller bearing.
[0002]
[Prior art]
Needle roller bearings generally use a needle roller having a relatively small diameter and a length longer than the diameter as a rolling element. FIG. 3 shows a configuration example of the needle roller bearing in an axial parallel sectional view. In FIG. 3, only two needle rollers 52 appearing at both ends in the cross-sectional view are shown in order to avoid complication of the drawing, and the illustration of the needle rollers between them and the pockets of the cage 53 are omitted. is doing.
[0003]
The needle roller bearing shown in FIG. 3 is called a shell type, and is characterized by having an outer ring 51 formed by press-molding a steel plate, and has flanges 51a formed by bending at both ends in the axial direction. Inside the outer ring 51, a plurality of needle rollers 52 are accommodated in pockets 53a of a cage 53 and held at a constant pitch in the circumferential direction. Such shell-type needle roller bearings are being frequently used in place of conventional bushes for the purpose of improving the steering performance of, for example, an automobile handle device.
[0004]
By the way, in the needle roller bearing as described above, when the shaft inserted inside each needle roller is tilted, the original rotational performance is obtained, for example, a phenomenon called skew in which each needle roller tilts occurs. I can't. For this kind of shaft inclination, in general, there is a measure to add crowning that processes the generatrix of the rolling surface into a convex curve so that the diameter of the rolling surface of the needle roller increases toward the axial center. Thus, by performing crowning on the needle rollers, the rotational performance of the bearing can be maintained even if the shaft is slightly inclined.
[0005]
[Problems to be solved by the invention]
However, when shell-type needle roller bearings are used in a device that may be incorporated with the shaft tilted relatively greatly, such as the above-described automobile handle device, conventional measures for crowning the needle rollers are not possible. However, it is necessary to increase the crowning amount. However, increasing the crowning of the needle rollers not only makes it difficult to manufacture, but also tends to cause so-called roll-off in terms of assembly work. Therefore it is difficult. Although it is conceivable to perform the crowning process on the raceway surface of the outer ring, the shell-type needle roller bearing is extremely difficult to process because there are ridges formed at both ends of the raceway surface. Not practical.
[0006]
The present invention has been made in view of such circumstances, in a rolling bearing device mainly composed of needle roller bearings, without particularly difficult processing, and without the difficulty of assembly work, An object of the present invention is to provide a rolling bearing device capable of exhibiting the original rotational performance without causing skew or the like even when the shaft is incorporated with a relatively large inclination.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a rolling bearing device of the present invention is a rolling bearing device provided with a shell-type needle roller bearing having an outer ring made of steel plate, and the outer ring of the needle roller bearing is a collar. The outer peripheral surface of the outer ring is in a state in which the collar and the axial center substantially coincide with each other. This is characterized by being in close contact with the inner peripheral surface of the collar (claim 1).
[0008]
Here, in the present invention, a configuration (Claim 2) in which the axial dimension of the collar is substantially equal to the dimension of the raceway surface of the outer ring can be suitably employed.
[0009]
The present invention utilizes the fact that the outer ring of the shell-type needle roller bearing is relatively thin and easily deformed, and presses the outer ring into the inner side of the collar having a crowned shape on the inner peripheral surface. The outer ring raceway surface is deformed to conform to the shape of the inner peripheral surface of the collar, and the desired crowning is applied to the outer ring raceway surface. This eliminates the need for machining by machining the needle rollers and outer ring, achieving the intended purpose. It is something to try.
[0010]
That is, when the outer ring of the shell type needle roller bearing is press-fitted into the inner side of the collar formed of a convex curve with the inner peripheral surface generating line projecting inward toward the axial center, the outer peripheral surface is brought into close contact with the inner peripheral surface of the collar. The outer ring is deformed along the inner peripheral surface of the collar, and the generatrix shape of the raceway surface on the inner peripheral side becomes a convex curve that protrudes inward toward the center in the axial direction, and becomes a crowning shape. The convex curve shape of the generating line on the inner peripheral surface of the collar can be processed into an arbitrary shape relatively easily by grinding or the like because it has no wrinkles. Therefore, the outer ring is imitated on the inner peripheral surface of the collar. Thus, the crowning amount of the outer ring raceway surface obtained can be easily increased.
[0011]
And by imposing a relatively large crowning on the raceway surface of the outer ring by following the collar in this way, the outer ring and the needle roller are not subjected to any crowning by machining, so that the machining difficulty and assembly The needle roller bearing can exhibit its original rotational performance even if the shaft is assembled with a relatively large inclination without any difficulty.
[0012]
Here, in the present invention, the axial dimension of the collar is not particularly limited, but as in the invention according to claim 2, the axial dimension of the collar is the axial dimension of the outer ring raceway surface of the needle roller bearing. By making them substantially equal, it is possible to form a so-called full crowning shape on the outer ring raceway surface with a convexly curved generatrix from the center in the axial direction to both ends.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an axial parallel cross-sectional view of an embodiment of the present invention. In FIG. 1, only two needle rollers 2 appearing at both ends in the cross-sectional view are shown in order to avoid complication of the drawing. Is omitted. In FIG. 1, the shape of the inner peripheral surface 3 b of the collar 3 is exaggerated for easy understanding.
[0014]
The needle roller bearing 1 is equivalent to the conventional shell-type needle roller bearing shown in FIG. 3, and is provided with a steel plate outer ring 11 having flanges 11a formed at both ends in the axial direction, and an inner side thereof. A plurality of needle rollers 2 that can roll with respect to the raceway surface 11b formed on the inner peripheral side of the outer ring 1 and each needle roller 2 are accommodated in a pocket 3a so that they are constant in the circumferential direction. A cage 3 that holds the pitch is provided. The raceway surface 11b of the outer ring 11 of the needle roller bearing 1 and the rolling surface of each needle roller 12 are not subjected to crowning.
[0015]
The needle roller bearing 1 is fitted and fixed inside the housing 2 with the collar 3 interposed outside the outer ring 11. Then, the shaft S is inserted inside each needle roller 2 of the needle roller bearing 1, and each needle roller 2 comes into contact with both the surface of the shaft S and the inner raceway surface 11b of the outer ring 11 to roll. As a result, the shaft S is rotatably supported.
[0016]
The outer peripheral surface 3a of the collar 3 is a cylindrical surface, and the inner peripheral surface 3b is a convex curve with its generatrix protruding inward at the center in the axial direction. As schematically shown in FIG. 2, the needle roller bearing 1 is press-fitted inside the collar 3 before being assembled into the housing 2. At this time, it is press-fitted into the collar 3 so that the outer peripheral surface 11c of the outer ring 11 of the needle roller bearing 1 is in close contact with the inner peripheral surface 3b of the collar 3 and the axial centers of both are coincident with each other. ing.
[0017]
The axial dimension of the collar 3 is substantially equal to the axial dimension of the raceway surface 11b of the outer ring 11 of the needle roller bearing 1, and the inner diameter dimension of the inner peripheral surface 3b of the collar 3 is the natural diameter of the outer ring 11 at both ends. It is approximately equal to the outer diameter in the state. Therefore, when the collar 3 is press-fitted, the entire outer ring 11 made of a steel sheet follows the inner peripheral surface 3b of the collar 3, so that the raceway surface 11b is equivalent to the inner peripheral surface 3b of the collar 3. The shape has a convex curve generating line with the center in the direction projecting inward, and is substantially a full crowning shape.
[0018]
The protrusion amount at the center of the convex curve of the generatrix shape of the inner peripheral surface 3b of the collar 3 is set to, for example, about several tens of μm according to the expected inclination of the axis S, whereby the track surface 11b of the outer ring 11 is The amount of crowning is the same, and even if the shaft S is assembled with a slight inclination with respect to the housing 2, the needle rollers 12 are inclined corresponding to the inclination of the shaft S, and the track of the shaft S and the outer ring 11. It rolls while being in rolling contact with both of the surfaces 11b, demonstrates the original rotational performance of the needle roller bearing 1, and at the same time can achieve the original life.
[0019]
The material of the collar 3 is not particularly limited, but it is preferable to use a steel material or the like from the viewpoints of workability, function, cost, and the like.
[0020]
In the above-described embodiment, the point to be particularly noted is that the needle roller bearing 1 itself is entirely crowned on both the raceway surface 11b of the outer ring 11 and the outer peripheral surface (rolling surface) of each needle roller 2. Even without processing, a crowning shape corresponding to the shape of the inner peripheral surface 3b of the collar 3 is formed on the raceway surface 11b of the outer ring 11, and protrusions such as ridges are formed on the inner peripheral surface 3b of the collar 3. Since there is no object, it is possible to easily process the generatrix into a convex curve by grinding, etc., so there is no difficulty in processing or assembly work, so the total cost is much lower. Without raising, even if the shaft to be supported is inclined relatively largely, the original rotation performance can be exhibited without causing the skew of the needle rollers.
[0021]
【The invention's effect】
As described above, according to the present invention, a shell-type needle roller bearing is press-fitted into a collar having a convex curve in which the generatrix of the inner peripheral surface protrudes inward at the center in the axial direction. The outer ring raceway is made to follow the inner peripheral surface of the collar, and this gives crowning to the outer ring raceway surface. Rolling bearings that can exhibit their original rotational performance without causing any skew even with respect to the inclination of the shaft, without giving any crowning to needle rollers or needles, thus increasing the total cost. Further, it is possible to prevent the life of the rolling bearing from being shortened due to the inclination of the shaft.
[Brief description of the drawings]
FIG. 1 is an axially parallel sectional view of an embodiment of the present invention, in which a part of a needle roller is not shown, and an inner peripheral surface shape of a collar is exaggerated.
FIG. 2 is a schematic explanatory view of a process before assembling into the housing according to the embodiment of the present invention.
FIG. 3 is an axial parallel cross-sectional view showing a configuration example of a conventional shell-type needle roller bearing.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shell type needle roller bearing 11 Outer ring 11a 鍔 11b Track surface 11c Outer peripheral surface 12 Needle roller 13 Cage 2 Housing 3 Collar 3b Inner peripheral surface S Axis

Claims (2)

A rolling bearing device provided with a shell-type needle roller bearing having a steel plate outer ring,
The outer ring of the needle roller bearing is press-fitted into the inside of the collar, and the generatrix of the inner peripheral surface of the collar is a convex curve that protrudes inward toward the center in the axial direction. A rolling bearing device, wherein the outer peripheral surface is in close contact with the inner peripheral surface of the collar in a matched state. The rolling bearing device according to claim 1, wherein an axial dimension of the collar is substantially equal to a dimension of a raceway surface of the outer ring.

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