JPH05187438A - Roller bearing - Google Patents

Abstract

PURPOSE:To reduce a frictionally contact part of each of rollers so as to reduce occurrence of damage by arranging the rollers so that their relative spaces are changeable, and by setting the total of gaps between the rollers arrayed in one row so as to be less than a predetermined value. CONSTITUTION:A roller bearing 1 has an inner race 2, an outer race 3 and several cylindrical rollers 4, and two annular flanges 5 are formed on the outer peripheral surface of the inner race 2, the several rollers 4 being held in one row between the annular flanges 5, 5 so that they are basically prevented from impacting upon one another. Further, an annular bead 7 is formed on each of the flanges 5, 5, being protruded toward the rollers 4, and makes contact with substantially centers of the surfaces of the rollers 4 facing the bead 7. In this arrangement, if the end faces of the rollers are flat, the rollers 4 make contact with the bead 7 in a substantially line-like contact condition under a static condition, but if the end faces of the rollers are formed in such a shape that their centers are protruded, they make contact with the bead 7 at their centers, thereby it is possible to reduce the friction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses rollers as rolling elements to support a rotating shaft and receives a load acting on the shaft,
The present invention relates to a roller bearing that smoothly rotates the shaft.

[0002]

2. Description of the Related Art A roller bearing which has been widely used in the prior art, as shown in FIGS. 13 to 15, is one of an outer ring 51 and an inner ring 52--in FIG. The collar 53 is formed, and the plurality of rollers 54 are accommodated in the collar 53 area and are sandwiched by the outer ring 51 and the inner ring 52 from both sides. With such a configuration, the inner ring or the outer ring provided with the collar is not displaced in the axial direction, and when the axis is used upright,
The roller 54 will not fall. The plurality of times 54
Are held at predetermined intervals in the circumferential direction of the inner ring by one retainer (retainer) 55 (FIG. 14).

[0003]

The retainer 55 is provided with a plurality of frames which are evenly distributed in the circumferential direction,
Each roller 54 is held in each of the frames. Therefore, when the roller 54 rolls, it is unavoidable that contact friction is generated between the roller 54 and the retainer 55 and between the retainer 55 and the outer ring 51 and the inner ring 52. Is being burned.

Further, since each roller 54 is held by the retainer 55, the presence of the retainer 55 reduces the free space between the inner ring 52 and the outer ring 51, and the design of the collar 53 that supports the roller 54 is reduced. Be restricted.

If the height of the collar 53 is low, the roller 5
4 comes into contact with the collar 53 near its outer periphery. When the roller 54 comes into contact with the collar 53 in the vicinity of the outer periphery thereof, a relatively large contact friction is inevitably generated between the roller 54 and the collar 53 due to the rotation of the roller and the revolution of the outer ring or the inner ring. In addition to the contact with the collar, the roller retainer 55
Since they also come into contact with each other, it is inevitable that the rollers, the retainer, and the outer ring or the inner ring are worn.

The present invention solves the above-mentioned conventional problems,
An object of the present invention is to provide a roller bearing having a small contact friction portion of the roller.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above problems in a roller bearing having an inner ring, an outer ring, and a plurality of rollers rolling on the inner ring raceway and the outer ring raceway. The problem was solved by arranging so that the relative spacing could be changed freely, and setting the total sum of the clearances of the rollers arranged in a row to a predetermined amount or less.

The predetermined amount is recursively obtained. For example, an inner ring outer diameter D _i = 43 mm, an outer ring inner diameter D _o = 55 mm, and a roller pitch circle diameter D _m = 49 mm of a raceway surface formed by a plurality of rolling rollers.
Then, when the diameter d of each roller is 6 mm, the number of rollers is about three, as will be seen from the test shown in FIG. 11 described below.
Obtaining this from roller bearings of various dimensions, the above-mentioned predetermined amount is

[0009]

[Equation 1]

Is defined by

[0011]

In the present invention, the conventional retainer is not used, and only a large number of rollers are arranged and housed between the inner ring and the outer ring so that the relative distance between the rollers can be varied. The shape of the roller is defined as required, but is generally cylindrical or conical. Of course, since there is no retainer, the roller is not damaged by friction between the roller and the retainer as in the conventional case. Despite the absence of the retainer, the rollers are distributed at equal intervals between the outer ring and the inner ring by the balance action according to the rotation of the outer ring or the inner ring of the roller bearing. That is, the relative spacing maintaining effect can be obtained as if the retainer was used. Since the retainer is not used, the number of rollers can be increased and the load capacity of the roller bearing as a whole can be increased as compared with the conventional roller bearing.

Except when the rollers are arranged without a gap, the rollers do not constantly come into contact with each other, and even if they come into contact with each other, only a linear contact state is established, so that the conventional surface contact between the roller and the retainer is not achieved. In comparison, the effect of friction is small.

[0013]

The details of the present invention will be explained based on the embodiments shown in the drawings.

1 and 2, the roller bearing 1 has an inner ring 2, an outer ring 3 and a large number of cylindrical rollers 4. Figure 1
As seen in FIG. 2, two rows of annular collars 5 are formed on the outer peripheral surface of the inner ring 2, and the annular groove 6 sandwiched between the annular collars 5 forms the inner ring 2.
Formed in. A large number of rollers 4 are accommodated in the annular groove 6 in a state that they are basically arranged in a line so as not to slide. The annular collar may be formed in three or more rows to form a plurality of annular grooves.

An annular protrusion 7 is formed on each of the collars 5 so as to project toward the roller 4. The annular protrusion 7 is in contact with substantially the center of the surface of each roller 4 facing the protrusion. The contact area of the contact portion between the collar 5 and the protrusion 7 is not particularly limited. Roller 4 protrusion 7
When the end face in contact with is flat, the roller 4 makes almost line contact with the annular protrusion 7 in a stationary state, but if it is formed as a face having a center, the roller 4 makes almost point contact at the center of the face. Will be done. In this case, the wear of the contact portion with the annular projection 7 due to the revolution of the inner ring of the roller,
The wear of the rollers due to their own rotation is also significantly reduced.

In FIG. 1, the inner surface of the outer ring 3 that contacts the rollers 4 is formed as a linear smooth circumferential surface. When the outer race is formed with the annular groove, the inner race is similarly formed and contacts the rollers.

When the collar 5 is constructed higher than the conventional one because there is no retainer, the rotation peripheral speed of the collar and
The revolution peripheral speed of the contact part with the roller is both higher than the conventional configuration, but by making point contact with the protrusion,
The rotation peripheral speed at the contact part with the collar of the roller becomes almost zero,
The contact area at the time of revolution also becomes small, and contact friction can be reduced.

3 and 4 show an example in which the annular groove 6 sandwiched by the collar 5 is formed in the outer ring 3 and the roller 4 is accommodated in the annular groove 6.

The collar 5 is formed at a height corresponding to almost the entire height of the roller 4. An annular protrusion 7 that protrudes toward the roller 4 is provided substantially at the center of the collar 5 so as to contact the surface center of the roller 4.

Both end surfaces of the roller 4 in contact with the projection 7 are formed as surfaces having a slightly projecting center, as in the example of FIG. 1, and the projection 7 and the surface center are substantially in point contact to reduce contact friction. It has become so.

The end surface of the roller, which is in contact with the annular projection, may be a flat surface, but in consideration of friction with the projection, it is preferable that the central portion has a shape projecting toward the annular projection as described above. A conical shape can be mentioned as an example. As a modification, a convex spherical surface is shown in FIG.

Further, the end face includes a concave spherical surface as shown in FIG. 6 and can be formed in any geometric shape. For example, the end face is basically formed as a flat surface,
As can be seen from FIG. 7, the flat surface may be provided with an annular projection 4a centered on the rotation center of the roller.
The closer the radius of the protrusion 4a is to 0, the closer it is to the convex spherical surface shown in FIG. 5, and the closer the radius is to the diameter of the roller 4, the more it is approximated to the concave spherical surface shown in FIG. When selecting the end face shape, it is necessary to consider both rolling stability and contact wear of the rollers at high speed rotation.

When the roller 4 of FIG. 7 having the annular projections 4a formed on both end surfaces is used, as shown in FIG. 8, when the outer ring 3 has an annular groove, the collar 5 of the outer ring is Protrusion 4a
Two concentric annular protrusions 7a arranged so as to abut
7b is formed.

For a roller having an end surface formed of a simple curved surface such as the convex spherical surface shown in FIG. 5 and the concave spherical surface shown in FIG. 6, the annular projection 7 of the collar 5 abuts at its center. Is most preferable, but is not essential. It is also possible to make contact with an arbitrary one deviated from the center.

For example, when the outer ring 3 is mounted stationary and the inner ring 2 is mounted on the rotating shaft, as shown in FIGS. 9 and 10, the annular projection 7 is located at the collar provided on the outer ring 3. It can be set at a position closest to the inner circumference of the roller 5 so as to contact the vicinity of the outer circumference of the roller 4. In this case, roller 4 is
Although it is in contact with the annular protrusion 7 in the vicinity of its outer periphery, the relevant portion is the position where the relative speed of the roller 4 with respect to the outer ring 3 is the smallest,
By configuring the rotation peripheral speed of the roller 4 and the revolution peripheral speed to be synchronized, the influence of contact friction can be minimized,
The twist of the roller can be avoided.

The groove-shaped groove 6 can be deepened to almost the entire height of the roller 4, and by deepening the groove and increasing the thickness of the collar 5 portion, a ring having an appropriate groove can be formed. It becomes easy to form the lubricating oil supply hole 8 and the discharge hole 9 in the. As a result, a roller bearing having significantly better lubricity can be obtained as compared with the conventional configuration in which the lubricating oil is ejected from a position slightly away from the roller. In the configuration of FIG. 9, the lubricating oil supply hole 8 is formed so that the lubricating oil can be directly supplied to the position where the roller contacts the inner ring 2, the position where the roller contacts the outer ring 3 and the position where the roller contacts the annular projection 7. It is convenient. And each hole can be formed in only one of the both collars 5, or both.

In FIG. 3 as well, the lubricating oil supply hole 8 and the discharge hole 9 are formed. However, as long as the positions and the number of the holes are within the range of the collar 5, the allowable strength is not exceeded. Can be changed to

In FIGS. 9 and 10, members and parts corresponding to those in FIGS. 3 and 4 are designated by the same reference numerals as those in FIGS. 3 and 4, and therefore description other than the above is omitted.

The above roller bearing can be formed by utilizing the inner ring, outer ring and roller of the conventional cylindrical roller bearing and tapered roller bearing, which are defined by JIS. It can be made. The ratio B / D of the width B to the diameter D of the roller is 1 or less.

In the roller bearing of the present invention, since the conventional retainer is not used, when the rollers are incorporated between the inner ring and the outer ring, the relationship between the rollers is not restricted by anything, and the relative The interval can be changed freely. In other words, the number of rollers and the distance between them can be arbitrarily selected, and while the conventional roller bearing limits the number of rollers and the distance between them by the retainer, it requires more rollers than before. It can be mounted and the load capacity can be increased.

For example, when the circumference of the circle passing through the center of each roller arranged between the inner ring and the outer ring is an integral multiple of the diameter of the roller, the rollers can be arranged without any interval.
In that case, the load capacity becomes maximum. On the other hand,
Even though they are in line contact, they are always in contact with each other, so
There is a problem in terms of life. In order to prevent the life from being shortened due to friction, it is preferable to reduce the number of rollers that can be properly accommodated by one or more.

As shown in FIG. 11, with the inner ring 2 fitted to the spindle 21 of the tester and the outer ring 3 fitted to the housing 22, the roller bearing 1 is mounted and the shaft 21 is rotated for testing. When the temperature of the outer ring 3 is measured by the measuring device 23 and the vibration is measured by the vibration measuring device 24, for example, the inner ring outer diameter D _i of the raceway surface is D _i = 43 mm, the outer ring inner diameter D _{o is} 55 mm, and the roller pitch circle diameter D _{m is} 49 mm. Diameter of each roller d = 6mm
In the case of, the results shown in FIG. 12 were obtained. In the figure, the horizontal axis represents the number of rollers and the rigidity (kg / mm). The number of rollers is shown as an increase with respect to the standard number based on the conventional standard number. The right vertical axis shows the temperature difference (° C.) of the roller bearing, and the left vertical axis shows the vibration acceleration (G). A curve A represents a change in vibration acceleration with respect to the number of accommodated objects, a curve B represents a change in temperature difference with respect to the accommodated number, and a straight line E represents change in rigidity with respect to the accommodated number.

In the illustrated example, the temperature measuring device 23 has a thermistor 25 as a temperature measuring section, and the vibration measuring device 24 is
It has an acceleration pickup 26 and a vibrometer 27.

The number of rotations of the spindle 21 is 20,000r
In the case of pm, the differential temperature, that is, the temperature rise value in the conventional standard cylindrical roller bearing having a retainer is 4.5 ° C. as shown at point C, and the vibration acceleration value is as shown at point D. On the other hand, while it was about 2.7, it was found that in the roller bearing according to the present invention, as the number of rollers increases, the temperature difference decreases as shown by the curve B. The vibration acceleration also decreases as the number of rollers increases.

Further, as compared with the conventional standard roller bearing, it is effective when the gap between the rollers corresponds to three rollers or less.

When this is obtained from roller bearings of various sizes,

[0037]

[Table 1]

(The unit of dimension is mm). Also in Examples 2 to 4, the relationship of the graph in FIG. 12 was derived. From this, further inductively, the predetermined amount, which is the maximum limit value of the total of the roller gaps, can be derived from the values of various dimensions as follows.

The circumferential length S _d per roller in the maximum number that can be accommodated in the circumferential length S _m = πD _m of the roller pitch circle diameter D _m is

[0040]

[Equation 2]

Therefore, the theoretical roller storage number Z _t of the roller bearing is

[0042]

[Equation 3]

It becomes When Z _t becomes an integer, the rollers are in close contact with each other. In the case of Examples 1 to 4 above, the actual maximum number of accommodated rollers Z is smaller than Z _t , and therefore,

[0044]

[Equation 4]

It becomes Then, by using the above formula to derive the limit roller reduction number that can maintain a more advantageous state than the conventional standard bearing in terms of temperature difference and vibration acceleration even if the number of stored rollers is reduced from the maximum number of rollers, the above predetermined amount is obtained. ,

[0046]

[Equation 5]

It is defined by

In the roller bearing of the present invention, a large number of rollers are accommodated without a retainer, and the distance between the rollers can be changed.
At the time of relative rotation between the inner ring and the outer ring, they act so as to be balanced as a whole, so that the rollers are dispersed so that the intervals are even. Therefore, unless they are housed in a close state, contact between the rollers is prevented, and the relative distance between the rollers is maintained as if a retainer was used.

In the case where the total number of storable parts is completely closed, it is most preferable to store a smaller number than the maximum storable number in terms of temperature and vibration.
It has a long life.

[0050]

According to the roller bearing of the present invention, the interval between the rollers can be freely changed without providing a retainer, and therefore, more rollers can be mounted than the conventional one, and the load capacity is large. became.

Further, in the roller bearing of the present invention, the height of the collar provided on the inner ring or the outer ring can be increased, and the lubricating oil can be reliably and easily supplied to the raceways of the inner ring and the outer ring.
It is also possible to avoid sudden seizure of the bearing due to oil film shortage, and to suppress heat generation during operation.

[Brief description of drawings]

1 is a cross-sectional view of the roller bearing according to the present invention taken along the line AA of FIG.

FIG. 2 is a right side view of FIG.

3 is a cross-sectional view of another example corresponding to FIG. 1 taken along the line BB of FIG.

FIG. 4 is a right side view of FIG.

FIG. 5 is a diagram showing a modified example of a roller.

FIG. 6 is a view showing another modification of the rollers.

FIG. 7 is a view showing still another modification of the rollers.

8 is a partial cross-sectional view of a roller bearing using the roller of FIG.

9 is a sectional view of another example of the roller bearing according to the present invention taken along the line CC of FIG.

FIG. 10 is a right side view of FIG.

FIG. 11 is a schematic view of a part of the testing machine.

FIG. 12 is a graph showing test results.

13 is a sectional view of the conventional roller bearing taken along the line DD of FIG.

FIG. 14 is a right side view of FIG.

FIG. 15 is a sectional view of another known roller bearing corresponding to FIG.

[Explanation of symbols]

 1 Roller bearing 2 Inner ring 3 Outer ring 4 Roller 5 Collar 6 Annular groove 7 Annular protrusion 8 Lubricating oil supply hole 9 Discharge hole

Claims (10)

[Claims] 1. A roller bearing having an inner ring, an outer ring, and a plurality of rollers rolling on a raceway of the inner ring and a raceway of the outer ring, wherein the rollers are arranged such that a relative distance between them is freely variable, and the rollers are arranged in a line. A roller bearing characterized in that the total of the gaps between the arranged rollers is not more than a predetermined amount. 2. An annular groove sandwiched by a collar is formed on one of the inner ring and the outer ring, the roller is housed in the annular groove, and an annular projection is formed on the collar that contacts the centers of both ends of the roller. The roller bearing according to claim 1, wherein: 3. The height of the collar is substantially equal to the height of the roller, and the collar is provided with a supply hole for supplying lubricating oil toward a contact portion between the roller and the inner and outer races. The roller bearing according to claim 2. 4. A stationary outer ring is formed with an annular groove sandwiched by a collar, the roller is housed in the annular groove, and the annular projection is located at a position closest to the outer circumference of the roller in a region closest to the inner circumference of the flange. 2. The structure according to claim 1, wherein
Roller bearing described in. 5. The roller bearing according to claim 4, wherein the collar is provided with a supply hole for supplying lubricating oil toward a contact portion between the roller and the inner and outer races. 6. The roller bearing according to claim 1, wherein both end faces of the roller are formed in a conical surface shape. 7. The roller bearing according to claim 1, wherein both end faces of the roller are formed in a convex spherical shape. 8. The roller bearing according to claim 1, wherein both end faces of the roller are formed in a concave spherical shape. 9. The roller bearing according to claim 1, wherein both end surfaces of the roller are formed in a three-dimensional curved surface shape. 10. An annular projection centering on the center of rotation of the roller is formed on both end faces of the roller, and an annular projection that abuts the annular projection is formed on each of the collars. Item 6. A roller bearing according to any one of items 2 to 5.