JPS6410689B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a cylindrical roller bearing and a method for manufacturing the same, and in particular, in a cylindrical roller bearing that rotates at high speed, the relative sliding contact portion between the guide surface of the guide collar of the outer ring or the inner ring and the end surface of the cylindrical roller. By forming a tapered part and a curved part on the guide surface of the guide collar, it is possible to reduce variations due to processing errors in the intersection line between the tapered part and the curved part, which are the contact points between the guide collar and the cylindrical roller, and to improve the relative By reducing the sliding speed and regulating the minimum width in the axial direction between the guide surfaces of the guide collars, the amount of axial movement of the cylindrical rollers is kept as small as possible, thereby reducing the skew of the cylindrical rollers. The force generated by the skew moment at the contact point between the guide collar and the cylindrical roller is reduced, and at the same time, the effect of lubricant infiltration into the guide surface is increased, and the formation of an oil film is improved to reduce wear on the cylindrical roller. It is intended to prevent

Generally, it is widely known that when a cylindrical roller bearing rotates under a radial load, a so-called skew phenomenon occurs. To explain this phenomenon with respect to a conventional cylindrical roller bearing with reference to FIGS. 1 to 3, an outer ring 1 having an inner ring 2 and a guide collar 3.
Let β be the skew angle when skew occurs in the cylindrical roller 4 rolling between Therefore, the point of contact between the end surface 9 of the cylindrical roller and the guide surface 7 of the guide collar is the radial edge A of the guide surface 7 of the collar. Now, if the rotational speed of the inner ring 2 is ωi, the rotation speed and revolution speed of the cylindrical roller 4 are ωr and ωc, respectively, and the skew moment of the cylindrical roller 4 is M, then due to these relative relationships, the contact point A has a relative Since a force P is generated due to the sliding speed V and the skew moment M, when the cylindrical roller bearing rotates at high speed under such conditions and the oil film at the contact point A breaks, the end face 9 of the cylindrical roller and the guide surface 7 of the collar This will cause wear during the process. The wear associated with the skew phenomenon described above is particularly noticeable in bearings that support rotating shafts that require high-speed rotation, for example, as high as 30,000 rpm, causing the problem that the bearing life reaches its limit early. The dot was hot.

In order to prevent such wear on cylindrical roller bearings, as is clear from the causes of its occurrence, (1) reduce the relative sliding speed V at the contact point, and (2) reduce the force P due to the skew moment M at the contact point. (3) Three conditions must be met at the same time to ensure good oil film formation at the contact point. Therefore, considering these conditions, first for condition (1), as shown in Fig. 3, the contact point is moved from the radial edge A of the guide surface 7 of the collar to B, which is closer to the raceway surface. The radius of rotation of the cylindrical roller 4 may be made smaller than the radius of rotation S at the contact point A, and for the condition (2), the contact point should be set at B.
to a position close to the radial edge of the guide surface 7 of the collar as shown in A, or the end surface 9 of the cylindrical roller.
By keeping the amount of axial movement of the roller ΔL (hereinafter simply referred to as the amount of axial movement of the roller) due to the axial clearance between the guide surface 7 of the rib and the guide surface 7 of the rib to a value that does not become too small, the skew angle β can be reduced. For condition (3), set the contact point to A.
From there, move to a position close to the raceway side as shown in B,
It turns out that it is sufficient to create a wedge effect in the vicinity.

It is known that the above-mentioned oil film formation can be effectively prevented by crowning the rib guide surface so that the end surface of the cylindrical roller does not come into contact with the radial edge of the rib guide surface.
This technique is disclosed in No. 1520060. However, crowning the guide surface of the brim has the disadvantage that it is extremely difficult to manufacture.
Furthermore, even if it were possible to manufacture it, it is virtually impossible to accurately finish the radius of curvature of the guide surface of the collar and the amount of axial movement of the rollers to the predetermined design values, and for this reason. Due to machining errors that occur, the contact point between the end face of the cylindrical roller and the guide surface of the collar is not at a constant position, making it difficult not only to control the contact point but also to control the skew angle. occurs. That is, in this cylindrical roller bearing, since the amount of movement of the rollers in the axial direction is indeterminate, when the contact point is located close to the radial edge of the guide surface of the collar, the relative sliding speed V increases, On the other hand, when the contact point is located close to the raceway surface or when the amount of axial movement of the roller increases, the skew angle β increases, so the force P due to the skew moment M increases, and the contact point further increases. Located close to the radial edge of the guide surface,
Moreover, when the amount of movement in the axial direction of the rollers is large, both the relative sliding predicate V and the force P due to the skew moment M become large. The force caused by this method is not necessarily small, and therefore, there is a drawback that the above three conditions cannot be satisfied at the same time.

Therefore, the applicant first formed a tapered surface inclined in two steps at a constant angle on the guide surface of the guide collar of the outer ring or the inner ring, and also suppressed the amount of axial movement of the cylindrical rollers as small as possible. Therefore, we applied for a utility model registration for the invention of a cylindrical roller bearing that eliminates the above-mentioned drawbacks (Utility Model Application No. 1987-
(See No. 99266).

However, in the cylindrical roller bearing of this invention, when forming a tapered surface on the guide surface of the guide collar, for example, if the tapered surface of the edge of the guide surface on the raceway surface side is formed first, the guide Due to a processing error when forming the tapered surface on the radial edge side of the surface, the raceway surface may extend beyond the position of the intersection line with the first stage tapered surface, which should be the contact point between the guide collar and the cylindrical roller. It is easy to machine to a position that is too close to the side, and on the other hand, if the tapered surface on the radial edge side of the guide surface is formed first, the tapered surface on the raceway side edge will be formed. When doing so, it is easy to machine the guide surface to a position that is too close to the radial edge side, and in any case, it is difficult to accurately set the position that should be the contact point between the guide collar and the cylindrical roller. However, there still remains a problem to be solved in terms of minimizing variations in the set positions of contact points caused by processing.

In addition, if a two-step tapered surface is formed on the guide surface, the skew angle when skew occurs on the cylindrical roller will be smaller on the radial edge side of the guide surface than on the raceway surface side with the contact point as the boundary, so the raceway surface There has been a problem in that the wedging effect between the side tapered surface and the radially edge side tapered surface is non-uniform, and a sufficient effect cannot necessarily be obtained regarding the formation of an oil film at the contact point.

This invention was made to solve the above-mentioned problems in cylindrical roller bearings, and both the position of the contact point between the guide surface of the guide collar and the end surface of the cylindrical roller and the amount of axial movement of the cylindrical roller This allows for accurate management with higher precision. Therefore, an object of the present invention is to reduce the relative sliding speed and the force due to the skew moment at the contact point between the guide collar and the cylindrical roller, and to improve the formation of an oil film at the contact point. The purpose of this invention is to prevent wear on the end face of the cylindrical rollers and extend the life of the bearing.It is also an object of this invention to prevent the position of the contact point between the guide collar and the cylindrical rollers due to molding errors. It is an object of the present invention to provide a method for manufacturing a cylindrical roller bearing that can reduce variations in the cylindrical roller bearing.A further object of the present invention is to provide a cylindrical roller bearing that can be effectively applied to a shaft rotating at high speed.

That is, in the present invention, as in the illustrated embodiment, the guide collar 3 is provided on either or both of the outer ring 1 and the inner ring, and the guide surface 7 of the guide collar 3 is provided.
In the cylindrical roller bearing that supports the end face of the cylindrical roller 4, in order to suppress the skew of the cylindrical roller 4,
In order to set the difference between the minimum width in the axial direction between the guide surfaces 7 of the guide collars 7 and the length L of the cylindrical roller 4 to a minute amount and to facilitate the entry of lubricating oil, the guide surface of the guide collar 3 is A tapered portion 7a whose cross-sectional shape is inclined at a constant angle with respect to the radial direction from the edge on the raceway surface side toward the outside in the axial direction, and a convex shape with a constant radius of curvature relative to the end surface 9 of the cylindrical roller 4. A first invention provides a cylindrical roller bearing characterized in that it is formed by a curved portion 7b that is curved in a curved direction and connected to the tapered portion 7a, and further includes a guide collar on either or both of the outer ring 1 or the inner ring. When forming the guide surface 7 of the guide collar 3 of the cylindrical roller bearing having a cylindrical roller bearing, the guide surface 7 is formed so that the entire surface of the guide surface 7 has a constant radius of curvature so as to be convex with respect to the end surface 9 of the cylindrical roller 4. The curved surface 7b is formed, and then the raceway surface side of the curved surface 7b is formed into a tapered surface 7a that slopes outward in the axial direction at a constant angle with respect to the radial direction. A second invention provides a method for manufacturing a cylindrical roller bearing, characterized in that the distance h in the radial direction between the intersection line 10 with the curved surface 7b and the raceway surface 5 is set to a predetermined length.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a partial longitudinal sectional view showing an example of the cylindrical roller bearing according to the present invention, in which cylindrical rollers 4 are assembled between an outer ring 1 and an inner ring 2 so as to be freely rolling, and the rolling The surfaces contact raceway surfaces 5 and 6 of outer ring 1 and inner ring 2, respectively, and roll. Outer ring 1
A guide collar 3 is provided at both ends of the cylindrical roller 4 to protrude in the radial direction, and a guide surface 7 facing the cylindrical roller 4
supports the end face 9 of. The guide collar may be provided on the inner ring 2, or may be provided on both the outer ring 1 and the inner ring 2. Further, the guide collar may be a fixed collar integrally molded as in the embodiment, or a collar ring formed separately from the raceway side. In the figure,
8 is a retainer.

The cross-sectional shape of the guide surface 7 of the guide collar 3 of the cylindrical roller bearing is such that the raceway surface side is a tapered portion 7a that is inclined toward the outside in the axial direction, and the radial end edge side of the guide surface 7 is a cylindrical roller. It is formed as a curved portion 7b that is curved convexly toward the end surface 9 of 4.

FIG. 5 shows an enlarged example of the cross-sectional shape of the guide surface 7 of the guide collar 3, and FIG.
FIG. A tapered portion 7a is formed by slanting outward in the axial direction at a constant angle θ ₁ with respect to the radial direction from the radial edge of the relief 1a provided between the raceway surface 5 of the outer ring 1 and the guide surface 7 of the guide collar 3. A curved portion 7b having a constant radius of curvature R centered on the outside in the axial direction is intersected by an intersection line 10 in the tapered portion 7a. The angle θ ₂ between the tangent of the curved portion 7b at the intersection line 10 and the radial direction is set to be larger than the angle θ ₁ . These angles θ ₁ and θ ₂ are appropriately selected depending on the size of the bearing, usage conditions, etc., but in the above embodiment, the angle θ ₁ is between 5′ and θ 2 .
60', and the angle θ ₂ is preferably within the range of 10' to 120'.

Further, the position of the intersection line 10 is appropriately selected so as to be radially inward by a certain distance h from the raceway surface 5, but the length (height) of the guide surface 7 in the radial direction is
However, it is preferable that h=(0.4 to 0.8)H.

The end surface 9 of the cylindrical roller 4 forms a plane perpendicular to the axis, and the length in the axial direction between the guide surfaces on both sides of the outer ring 1 is equal to the minimum width in the axial direction between the guide surfaces on both sides and the cylindrical roller. The difference from the axial length L of No. 4 to a minute amount (for example, 0.3 to 0.01% of the axial length L of the cylindrical roller)
is set so that the amount of movement ΔL of the cylindrical roller 4 in the axial direction is kept as small as possible.

When forming the tapered portion 7a and the curved portion 7b as described above on the guide surface 7 of the guide collar 3, it is most preferable to perform the molding process as shown in FIG.

A curved surface having a predetermined radius of curvature R of the curved portion 7b is previously formed on the entire surface of the guide surface 7 from the radial edge 7c to the raceway surface 5 side.

Next, the cylindrical rollers 4 are arranged so that the raceway surface side of this curved surface becomes a tapered surface inclined at a predetermined angle θ ₁ .
The tapered portion 7a is formed by cutting to a predetermined contact point C with the metal.

Now, when forming the tapered part 7a, if the forming process is mistakenly performed past the predetermined contact point C, and the tapered part becomes 7d, the contact point becomes _C1 .
On the other hand, if the guide surface 7 is formed by a two-step tapered surface of the tapered part 7a and the tapered part 7e, the contact point will be _C2 if there is the above-mentioned processing error. In this way, the error in the radial distance h of the contact point C from the raceway surface 5 is △h ₁ when the contact point is C ₁ , and △h ₂ when the contact point is C ₂ , but the error is the same. As is clear from the figure, since Δh ₁ <Δh ₂ , variations in the position of the contact point C due to processing errors can be made smaller than in the case of a two-step tapered surface.

As a method of forming the guide surface, contrary to the above order, the tapered part may be formed on the entire surface of the guide surface, and then the curved part may be formed, or the tapered part and the curved part may be formed. The parts may be molded at the same time.

In the above embodiment, the case where the guide collar is provided on the outer ring is explained, but even when the guide collar is provided on the inner ring, the tapered part and the curved part can be formed on the guide surface in the same manner as described above. .

In the cylindrical roller bearing with the above configuration, the cylindrical roller 4
If skew occurs during rotation of cylindrical roller 4,
The end surface 9 of the guide surface 7 comes into contact with an intersection line 10 between the tapered portion 7a and the curved portion 7b of the guide surface 7. Since the contact point C on this intersection line 10 is located close to the raceway surface 5 side, the rotation radius of the cylindrical roller 4 becomes short, and therefore the relative sliding speed at the contact point C becomes small.

Incidentally, it is known that variations in the position of the contact point C have a large effect on the relative sliding speed.

However, as mentioned above, when the tapered part 7a and the curved part 7b are formed by the forming process shown in FIG. Since the contact point C is smaller than that of the two-step tapered surface, the position of the contact point C can be controlled more accurately than in the case of a two-step tapered surface, and the influence on the relative sliding speed can be suppressed to a minimum.

Furthermore, when skew occurs during the rotation of the cylindrical roller 4, the direction of infiltration of the lubricant at the contact point between the both end surfaces and the guide surface is as shown by the arrow in FIG.
At the contact point C on the left end surface, the guide surface 7 is moved from the raceway surface 5 side to the guide surface 7.
On the other hand, at the contact point D on the right end surface, the radial edge side of the guide surface 7 becomes the raceway surface 5 side, but the guide surface 7 is separated from the tapered part 7a and the curved part 7b. As shown in FIG. 9, the skew angle when formed is a curve E that is symmetrical about the contact points C and D.
The wedge shape of the tapered portion 7a and the curved portion 7b with D as the boundary is the same shape at the contact point C on the left end surface and the contact point D on the right end surface. Therefore, the wedge effect between the tapered portion 7a and the curved portion 7b is the same on both the left and right sides of the guide surface 7, making it easier for lubricant to penetrate into the contact points C and D, preventing the formation of an oil film due to the wedge effect. , will be achieved very effectively.

On the other hand, when a two-step tapered surface is formed on the guide surface, the skew angle becomes a left-right asymmetrical curve F with the contact point as the center, so the wedge shapes of both tapered surfaces with the contact point as the boundary become unequal. , the lubricant infiltration and wedging effect at the tapered surface of the second stage will be reduced.

Furthermore, even if skew occurs during the rotation of the cylindrical rollers 4, the axial movement amount ΔL of the cylindrical rollers 4 is kept as small as possible, so the skew angle can be kept to a minimum. The force due to skew moment can be kept small.

10 and 11 show other embodiments of the present invention, in which the cross-sectional shape of the guide surface 7 of the guide collar is the same as that shown in FIG. 5, but the end surface 9 of the cylindrical roller is The shape is such that the peripheral edge on the rolling surface side of the end face is a spherical surface 9a that bulges outward in the axial direction with a constant radius of curvature r, and the central portion that smoothly extends to the spherical surface 9a is a flat surface 9b perpendicular to the axis. It has been formed. The center O of the radius of curvature r is selected at an appropriate position between the transfer surface and an axial line passing through the radial edge of the guide surface of the collar. In this way, the end surface of the cylindrical roller is partially crowned on the rolling surface side. Also in this embodiment, the axial length between the guide surfaces on both sides of the outer ring 1 is selected so that the amount of axial movement ΔL of the cylindrical rollers 4 is as small as possible.

Even in the cylindrical roller bearing with the above configuration, when skew occurs during rotation of the cylindrical rollers 4, the guide surface 7
Since the contact position with the tapered part 7a and the curved part 7b is the intersection line 10, the contact point is a position C close to the raceway surface 5 side of the outer ring 1, as shown in FIG. The relative sliding speed is small at the radius, and furthermore, at the contact point C, a strong wedge is created due to the synergistic effect of the tapered portion 7a and curved portion 7b formed on the guide surface 7 and the crowning applied to the end surface 9 of the cylindrical roller 4. Due to this effect, the formation of an oil film on the guide surface 7 on both the right and left sides becomes even more excellent. Further, since the amount of axial movement ΔL of the cylindrical roller 4 is suppressed as small as possible, the skew angle does not become excessive, and the force due to the skew moment can be reduced.

In each of the above embodiments, the tapered portion 7a and the curved portion 7b formed on the guide surface of the guide collar of the outer ring are as follows:
Although they are intersected at the contact point C, they do not necessarily have to be intersected in this manner, and may be intersected by a curved surface 12 having a constant radius R ₁ as shown in FIG. This radius _R1 may be appropriately selected so that the curved surface 12 smoothly connects with the tapered portion 7a and the curved portion 7b. Even in this case, the contact position between the end face of the cylindrical roller and the guide surface of the guide collar is between the tapered part 7a and the curved part 7.
Since this is the closest point to the position C where C intersects B, the same effect as described above can be achieved.

Further, in each of the above embodiments, the tapered portion 7a is formed from the radial edge of the relief portion 1a, but the tapered portion 7a is formed from the edge on the raceway surface 5 side without providing the relief portion 1a. Good too.

Note that the crowning of the end face of the cylindrical roller in each embodiment is partial crowning in which the raceway surface side of the end face is made spherical, but it may also be carried out as full crowning in which the entire end face is made spherical.

As described above, this invention forms the cross-sectional shape of the guide surface of the guide collar with a tapered part on the raceway side and a curved part on the radial edge side, and minimizes the amount of axial movement of the cylindrical rollers. It is designed to suppress.

Therefore, according to the present invention, when skew occurs, it is possible not only to reduce the relative sliding speed at the contact point between the guide collar and the cylindrical roller and the force due to the skew moment, but also to reduce the lubrication at the contact point. Infiltration of the agent and formation of an oil film
This is significantly better than when the guide surface is a two-step tapered surface.

Further, in the present invention, when molding the guide surface of the guide collar, the curved portion is first molded, and then the tapered portion is molded to a predetermined position.

Therefore, if a cylindrical roller bearing is manufactured using this forming method, variations in the position of the contact point between the guide collar and the cylindrical roller due to processing errors when skew occurs can be avoided by making the guide surface a two-step tapered surface. This makes it extremely easy to manage the set position of the contact point, and it is possible to suppress an increase in the relative sliding speed due to an error in the position of the contact point.

As described above, according to the present invention, the wear on the end face of the cylindrical roller is significantly reduced compared to the case where a two-step tapered surface is formed on the guide surface, and its life is extended, making it particularly suitable for high-speed rotation bearings. You get the advantage of having one.

[Brief explanation of drawings]

1 to 3 are explanatory diagrams of the skew phenomenon, and FIG. 1 is a partial perspective view of a cylindrical roller bearing;
Figure 2 is the action diagram of skew moment M, and Figure 3 is
4 is a partial vertical sectional view showing an example of the cylindrical roller bearing of the present invention. FIG. 5 is a partially enlarged view showing an embodiment of the present invention. The figure is a side view, FIG. 7 is an explanatory diagram showing the error in the position of the contact point during molding of the guide surface of the guide collar, FIG. 8 is an explanatory diagram showing the direction of oil infiltration, and FIG. 9 10 is a partially enlarged view showing another embodiment of the present invention, and FIG. 11 is a side view thereof.
FIG. 12 is a cross-sectional view showing the joint portion of the guide surface of the guide collar. In the figure, 1... outer ring, 3... guide rib, 4... cylindrical roller, 5... raceway surface, 7... guide surface of guide rib, 7a... taper part, 7b... curved part, 9...
... End face of the cylindrical roller, 10... Intersection line between the tapered part and the curved part, C... Contact point between the guide surface of the guide collar and the end face of the cylindrical roller, h... Height of the contact point from the raceway surface , ΔL... is the amount of movement of the cylindrical roller in the axial direction.

Claims (1)

[Claims] 1. To suppress skew of the cylindrical rollers in a cylindrical roller bearing having a guide collar on either or both of the outer ring or the inner ring and supporting the end face of the cylindrical rollers on the guide surface of the guide collar. In order to set the difference between the minimum width in the axial direction between the guide surfaces of the guide collar and the length of the cylindrical roller to a minute value, and to facilitate the entry of lubricating oil, the cross-sectional shape of the guide surface of the guide collar is A tapered portion is inclined axially outward from the edge on the raceway side at a constant angle with respect to the radial direction, and the tapered portion is curved convexly with a constant radius of curvature relative to the end face of the cylindrical roller. A cylindrical roller bearing characterized by being formed by connected curved parts. 2. The cylindrical roller bearing according to claim 1, wherein the tapered portion and the curved portion formed on the guide surface of the guide collar smoothly intersect with each other via a curved surface. 3. The cylindrical roller bearing according to claim 1, wherein the end surface of the cylindrical roller in contact with the guide surface of the guide collar is a plane perpendicular to the axis. 4. The cylindrical roller bearing according to claim 1, wherein the end face of the cylindrical roller in contact with the guide surface of the guide collar is crowned. 5. When forming the guide surface of the guide collar of a cylindrical roller bearing having a guide collar, a curved portion with a constant radius of curvature is formed on the entire surface of the guide surface so as to be convex with respect to the end surface of the cylindrical roller. Then, the raceway surface side of the curved portion is molded to form a tapered portion that is inclined outward in the axial direction with respect to the radial direction, and the intersection between the tapered portion and the curved portion is formed. A method for manufacturing a cylindrical roller bearing, characterized in that the distance in the radial direction between a cutting line and a raceway surface is set to a predetermined length.