JP2004068877A - Rolling bearing and bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide rolling bearing capable of generating smooth application of the load to its rolling elements in the load area by suppressing the shape error (waviness) of the inner raceway and the outer raceway, thereby suppressing generation of vibrations and noises, and suppressing a drop in the lifetime of the rolling elements originating from steep application of the load. <P>SOLUTION: The rolling bearing equipped with an even number of rolling elements (Z pieces) can suppress vibrations effectively by configuring so that about at least one of its raceway rings, the single side amplitude of the waviness having the number of apices (Z(2n-1)/2) per circumference of the raceway, where n is a positive integer being at least one, is made smaller than the maximum value of the single side amplitude of the waviness having the number of apices no less than (Z(2n-1)/2+1) per circumference of the raceway and no more than (Z(2n+1)/2). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is directed to a motor having a large rotor, a rotating machine having a rotating shaft driven by a belt, a pulley rotatably supporting a timing belt of an automobile engine, a belt for driving auxiliary equipment, and the like, and a radial motor. The present invention relates to a rolling bearing and a bearing device to which a load is applied.
[0002]
[Prior art]
When the rolling bearing is operated while a radial load is applied, vibration called so-called rolling element passing vibration is generated. The rolling element passing vibration is generated when the load distribution changes according to the position of each rolling element in the load area, and the displacement amount and the direction of the displacement of the rotating shaft slightly change. Normally, the amplitude of the rolling element passing vibration is small, so it is rarely a problem.In the event that a problem occurs, it is thought that it can be dealt with by reducing the radial clearance of the rolling bearing or applying a preload. I was
[0003]
[Problems to be solved by the invention]
However, according to the study of the present inventors, it has been found that the rolling element passing vibration becomes a problem, and that sufficient measures cannot be taken by merely reducing the radial clearance of the rolling bearing or applying a preload. This phenomenon will be described.
[0004]
A minute undulation is often formed on the raceway surfaces of the inner and outer races of the rolling bearing due to the characteristics of the processing machine. When the race is regarded as a rigid body and the contact between the race and the rolling element is regarded as a linear spring, a predetermined vibration is generated due to the undulation of the raceway surface. Vibration caused by such undulation can be reduced by the technique disclosed in, for example, Japanese Patent No. 3046764.
[0005]
However, according to the research of the present inventors, it has been found that the rolling element passing vibration is amplified by the undulation of the raceway surface. FIG. 1 is a diagram illustrating a relationship between a raceway ring and a rolling element according to the presence or absence of undulation, and FIG. 2 is a diagram illustrating a load state of the rolling element. In FIG. 1, if there is no undulation on the raceway surface, there is a uniform gap between the rolling element 1 and the raceway surface of the outer race 2 as shown by a dotted line, but the undulation with the smallest inner diameter at the lowest point is shown. If so, assuming that the rolling element 1 is pressed against the inner ring 3, the gap between the rolling element 1 and the raceway surface of the outer ring 2 becomes uneven according to the undulation as shown by the solid line. In an extreme case, even if a radial load is applied to the inner ring 3, a gap Δ of zero or more may be generated in the rolling element 1 at a position shifted from the lowest point by an angle θ (a position where the inner diameter is maximized). It is possible.
[0006]
As shown in FIG. 2, when a downward radial load Fr is applied to the inner race 3, if there is no undulation, a load indicated by a dotted line in the figure is applied to the rolling element 1. That is, a load is gradually applied to the rolling element 1 passing below the horizontal line as the distance from the horizontal line increases, and a maximum load is applied at the lowest point (also referred to as a rolling element maximum load position). It is decreasing. The load region in this case is a range below the horizontal line, and the no-load region is a range above the horizontal line. On the other hand, when there is a swell as shown in FIG. 1, for example, the rolling element 1 has no load up to a position shifted by an angle θ from the lowest point, and the load rapidly increases from that point to the lowest point. It will be. For this reason, the rolling element passing vibration is amplified, and in some cases, a problem such as separation of the raceway surface may be caused. In this case, the load region is a narrow range with an angle 2θ across the lowest point, and the no-load region is another range.
[0007]
Even if the load of the rolling element 1 does not gradually decrease or increase smoothly as shown by a dotted line in FIG. 2, even if it is not an extreme swell as shown in FIG. Will be repeatedly received. That is, since the rolling bearing actually undergoes elastic deformation, when this is taken into consideration, as shown in FIG. 3, which shows the deformation in an exaggerated manner, there are large and small contact portions between the raceway surface and the rolling element. Specifically, a ₂ > a ₁ , a ₃ (a ₂ : the radius of the lowest rolling element at the time of Hertz elastic contact, a ₁ , a ₃ : the rolling element at a position shifted from the lowest point by an angle θ. , Δ ₂ > δ ₁ , δ ₃ (δ ₂ : the amount of elastic deformation of the Hertz in the rolling element at the lowest point, δ ₁ , δ ₃ : shifted from the lowest point by an angle θ (The amount of Hertz elastic deformation of the rolling element at the position), and the larger the undulation, the larger the rolling element load of the rolling element having a large hit and the smaller the rolling element load of the rolling element having a small hit. The torque in this case is proportional to the rolling element load in which the rolling element and the raceway contact each other, and may cause torque fluctuation. The center position in the radial direction of the rolling element with respect to the center position when waviness is zero, for the rolling elements of the position shifted by an angle θ from the lowest point, delta _1, outward by delta _3, the lowermost the rolling elements of the point moved inward by delta _2. That is, it rotates while moving in the radial direction by this amount.
[0008]
As described above, when the load of the rolling element 1 changes, the life is shortened due to the increase in the maximum rolling element load, and the torque changes due to the fluctuation of the rolling element load during one revolution, and further, while the rolling element rotates one revolution. When the center moves away from or approaches the center of the rolling bearing, vibration or noise may be generated.
[0009]
The present invention has been made in view of such a problem, and provides a rolling bearing and a bearing device that can suppress the generation of vibration and noise of a rolling element due to a sudden rise of a load and can achieve a long life. The purpose is to:
[0010]
[Means for Solving the Problems]
A rolling bearing according to a first aspect of the present invention includes a first race having a first race, a second race having a second race, and a first race between the first race and the second race. An even number (Z) of rolling elements provided so as to be freely rotatable in the rolling bearing, wherein each track has a minute undulation.
With respect to at least one of the first and second races, when n, which is a positive integer, is at least 1, per circumference of the raceway (Z (2n-1) / 2) The one-sided amplitude of the undulation having the number of peaks is not less than ((Z (2n-1) / 2) +1) and not more than (Z (2n + 1) / 2) per circumference of the orbit. It is characterized in that it is smaller than the maximum value of the one-sided amplitude of the undulation.
[0011]
According to a second aspect of the present invention, there is provided a rolling bearing having a first raceway having a first raceway, a second raceway having a second raceway, and the first raceway and the second raceway. An odd number (Z) of rolling elements provided rotatably on the rolling bearing, wherein each track has a minute undulation.
Regarding at least one of the first and second races, when n, which is a positive integer, is at least 1, per circumference of the raceway ((Z (2n-1)- Both the one-sided amplitude of the undulation having the number of peaks of 1) / 2) and the one-sided amplitude of the undulation having the number of peaks of ((Z (2n-1) +1) / 2) are:
The maximum value of the one-sided amplitude of the undulation having the number of peaks not less than ((Z (2n-1) +1) / 2 + 1) and not more than ((Z (2n + 1) -1) / 2-1) per circumference of the orbit. It is characterized by being smaller than.
[0012]
[Action]
The present inventors have further conducted intensive research and found that the rolling element passing vibration is amplified due to the undulation because of the shape error due to the undulation and the relationship between the number of rolling elements and the raceway surface of the inner and outer rings and the rolling element. It was found that the main factor was that the gap between the two changed periodically. That is, it has been found that the vibration can be suppressed by adjusting the number of rolling elements and the number of undulations. More specifically, the present inventors have further studied that, in a rolling bearing provided with an even number (Z) of rolling elements, when at least one of the races has a positive integer n of at least 1, , The one-sided amplitude of the waviness having the number of peaks of (Z (2n-1) / 2) per circumference of the track is ((Z (2n-1) / 2) +1) per circumference of the track. As described above, it has been found that the vibration can be effectively suppressed by making the value smaller than the maximum value of the one-sided amplitude of the undulation having the number of peaks equal to or less than (Z (2n + 1) / 2).
[0013]
Further, with respect to at least one of the first and second races in the rolling bearing, when at least the integer n is 1, per one circumference of the raceway (Z (2n− The one-sided amplitude of the undulation having the number of peaks of 1) / 2 ± 1) is equal to or more than (Z (2n−3) / 2) per circumference of the orbit (however, in the case of n = 1, it is equal to or more than 2). , (Z (2n-1) / 2), it was found that the vibration can be more effectively suppressed by making it smaller than the maximum value of the one-sided amplitude of the undulation having the number of peaks equal to or less than (Z (2n-1) / 2). The degree of contribution is lower than the swell of (Z (2n-1) / 2) peaks per circumference of the track, but (Z (2n-1) / 2 ± 1) peaks per circumference of the track. This is because the swell of numbers also contributes to vibration.
[0014]
On the other hand, in the case of a rolling bearing provided with an odd number (Z) of rolling elements, at least one of the first or second races has a positive integer n of at least one. When 1, the one-sided amplitude of the undulation having ((Z (2n-1) -1) / 2) peaks per circumference of the orbit, and ((Z (2n-1) +1) / 2) Is one or more ((Z (2n-1) +1) / 2 + 1) or more than ((Z (2n + 1) -1) / 2) per circumference of the trajectory. -1) It has been found that vibration can be effectively suppressed by making the amplitude smaller than the maximum value of the one-sided amplitude of the undulation having the following number of peaks. When the number of rolling elements is an odd number, the number of peaks specified in the first invention does not become an integer. In this case, it is considered that the undulation of the number of peaks close to the specified number of peaks contributes to the vibration. Therefore, it was decided to handle as described above.
[0015]
Further, it is preferable that the number of peaks of the undulation is 20 or less per circumference of the track.
[0016]
In addition, it is preferable that at least one of the first race and the second race is attached to a housing that accommodates the rolling bearing or a shaft that supports the rolling bearing by interference fit.
[0017]
Further, at least one of the first race and the second race is a bearing steel or a carbon steel having a linear expansion coefficient of 10.1 × 10 ^{−6 to} 13.5 × 10 ⁻⁶ (m / ° C.). Alternatively, it is preferable that the housing or the shaft is made of structural steel, and the housing or the shaft is made of bearing steel having a linear expansion coefficient of 10.1 × 10 ^{−6 to} 13.5 × 10 ⁻⁶ (m / ° C.).
[0018]
If the temperature rises during the operation of the rolling bearing and the coefficient of linear expansion between the bearing and the shaft or between the bearing and the housing is different, the fitting stress changes. For this reason, even if the influence of the shape error is kept small in the assembling state, the shape error may change due to the temperature rise, but at least one of the first orbital ring and the second orbital ring has a linear expansion coefficient. 10.1 × 10 ^{−6 to} 13.5 × 10 ⁻⁶ (m / ° C.) is formed from bearing steel, and the housing or the shaft has a linear expansion coefficient of 10.1 × 10 ^{−6 to} 13.5 × 10. ^If the bearing is made of ^-6 (m / ° C) bearing steel, the linear expansion coefficient of the rolling bearing race and the shaft or the rolling bearing race and the housing is the same. It can be said that it is desirable because it is held as it is. However, in general, the shaft and the housing are often made of a material different from that of the bearing race, but in such a case, it is desirable that the shaft and the housing be made of a material as close to the race as possible.
[0019]
Specifically, as a material having a linear expansion coefficient of 10.1 × 10 ^{−6 to} 13.5 × 10 ⁻⁶ (m / ° C.), a linear expansion coefficient of 10.1 × 10 ⁻⁶ (m / ° C.) ) Martensitic stainless steel, 12.5 × 10 ⁻⁶ (m / ° C.) bearing steel SUJ2, and 13.5 × 10 ⁻⁶ (m / ° C.) austenitic stainless steel. Further, a case hardening steel such as SCr40 which is usually used can be applied as long as it has a linear expansion coefficient. The amount of elastic deformation at the maximum rolling element load position when approximately 25% of the dynamic rated load is applied to 5000N of a deep groove ball bearing having a nominal number of 6206 (inner diameter: 30 mm, outer diameter: 62 mm, width: 16 mm) (see FIG. Δ ₂ ) is about 36 μm. On the other hand, assuming that the temperature difference between the outer ring and the housing due to the temperature rise is 10 ° C., the dimensional change in the linear expansion coefficient range of 10.1 × 10 ^{−6 to} 13.5 × 10 ⁻⁶ (m / ° C.) is ( 13.5-10.1) × 10 ⁻⁶ × 0.062 × 10 ≒ 2.1 × 10 ⁻⁶ (2.1 μm), which is a sufficiently small value compared to the elastic deformation amount. It is not expected to affect change. As the material of the housing and the shaft, it is possible to use the bearing steel, structural steel such as S20C, and other carbon steel.
[0020]
Further, in the rolling bearing, the first race is an inner race, the second race is an outer race, the inner race is configured to rotate, the coefficient of linear expansion of each race is: Preferably, the coefficient of linear expansion of the housing is equal to or less than the coefficient of linear expansion. In such a case, the inner ring rotates and the inner ring and the shaft are tightly fitted, and the other outer ring and the housing increase in temperature, and in the case of the tight fit, the interference is small, and the dimension changes in a direction to increase the gap. This is a combination in which at least the interference is tight and does not affect the shape change of the outer ring.
[0021]
Further, in the rolling bearing, the first race is an inner race, the second race is an outer race, the outer race is configured to rotate, the coefficient of linear expansion of each race is: It is preferable that the linear expansion coefficient be equal to or greater than the linear expansion coefficient of the shaft. In such a case, since the outer ring rotates and the outer ring and the housing are tightly fitted, and the other inner ring and the shaft increase in temperature, in the case of the tight fit, the interference is small, and the dimension changes in a direction to increase the gap. This is a combination in which at least the interference is tight and does not affect the shape change of the inner ring.
[0022]
Further, in the rolling bearing in which a load is mainly applied in the radial direction, it is preferable that a load region in which a load is applied to the rolling element and a non-load region in which a load is not applied to the rolling element exist. In particular, the present invention is effective when the number of rolling elements is small with respect to the dynamic load rating of the bearing. That is, when the diameter of the rolling element is small, the rolling bearing having many rolling elements and the diameter of the rolling element are large, and the rolling bearings having a small number of rolling elements have the same dynamic load rating, the present invention is more effective than the latter. is there.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 4 is a cross-sectional view of the rolling bearing according to the embodiment of the present invention.
[0024]
In the example shown in FIG. 4 (a), an idler pulley 5 used for an automobile engine or the like has a plurality of rolling rollers rotatably arranged between an outer wheel 2, an inner wheel 3 and both wheels 2, 3 in a center hole 5a thereof. The rolling bearing 4 having the moving body 1 is fitted. Further, the inner ring 3 of the rolling bearing 4 is fitted on the fixed shaft 6. The idler pulley 5 applies tension by wrapping an endless belt (not shown) around the outer peripheral surface 5b, and rotationally drives a rotation shaft and a camshaft of the auxiliary machine. The rolling bearing 4 is an example in which the inner ring is fixed and the outer ring rotates, mainly receiving a radial load. The coefficient of linear expansion of the two wheels 2 and 3 of the rolling bearing 4 is preferably 10.1 × 10 ^{−6 to} 13.5 × 10 ⁻⁶ (m / ° C.), and the coefficient of linear expansion of the idler pulley 5 and the fixed shaft 6 is Although it is preferably 10.1 × 10 ^{−6 to} 13.5 × 10 ⁻⁶ (m / ° C.), it is desirable that at least the linear expansion coefficients of the two wheels 2 and 3 be equal to or higher than the linear expansion coefficient of the fixed shaft 6.
[0025]
In another example shown in FIG. 4B, both ends of a rotating shaft 6 'having a rotor 6a' mounted at the center thereof are rotatably supported by a pair of rolling bearings 4 'with respect to a housing 5'. The rolling bearing 4 'has an outer ring 2', an inner ring 3 ', and a plurality of rolling elements 1' rotatably arranged between the two wheels 2 ', 3'. The rolling bearing 4 ′ is an example of inner ring rotation and outer ring fixing mainly receiving a radial load. It is preferable that the linear expansion coefficient of the two wheels 2 ', 3' of the rolling bearing 4 'is 10.1 × 10 ^{-6 to} 13.5 × 10 ^-6 (m / ° C.). The coefficient of linear expansion is preferably 10.1 × 10 ^{−6 to} 13.5 × 10 ⁻⁶ (m / ° C.), but the coefficient of linear expansion of at least both wheels 2 ′ and 3 ′ is not more than the coefficient of linear expansion of the housing 5 ′. Desirably.
[0026]
Next, as shown in FIGS. 1 and 2, consider a case where a certain rolling element comes to the center of the load area. At that time, in the rolling elements on both sides, the number of peaks of the undulation with the largest gap with the raceway surface is Z (2n-1) / 2. Here, Z is the number of rolling elements orbiting, and n is a natural number. For example, when the number of rolling elements is six, the number of undulation peaks at which the gap between the rolling elements and the raceway surface is the largest is three. , 9 mountains, 15 mountains, ...
[0027]
If the number of peaks is large, the rolling element is likely to receive no load even at a position that is a load area, and a sudden load may be applied to the rolling element.
[0028]
The number of undulations Z (2n-1) / 2 described above does not exist when the number Z of rolling elements is an odd number. In this case, it is considered that the undulation of the number of peaks close to the value of the number Z of the rolling elements affects the rolling elements and the like. That is, it is considered that the undulation of the number of peaks represented by (Z (2n-1) -1) / 2 and (Z (2n-1) +1) / 2 influences.
[0029]
More specifically, the relationship between the number of undulations and the one-sided amplitude will be described with reference to FIG. FIG. 5 is a diagram showing an example of a curve indicating a general relationship between the number of peaks of undulation on the track surface and the one-sided amplitude. In this embodiment, when an even number (Z) of rolling elements are used, the one-sided amplitude of (Z (2n-1) / 2) undulations per circumference of the rolling element trajectory is (Z (2n-1). ) / 2 + 1) or more and (Z (2n + 1) / 2) or less, so as to be smaller than the maximum value of the undulation piece amplitude of the number of peaks.
[0030]
As shown by the curve C in FIG. 5, generally, the undulation piece amplitude tends to decrease as the number of peaks increases. According to this tendency, the half amplitude A of Z (2n-1) / 2 peaks per circumference of the rolling element trajectory should be the largest half amplitude among the number of peaks larger than that. On the other hand, in the present embodiment, contrary to the above tendency, the one-sided amplitude A is set to be equal to or larger than (Z (2n-1) / 2 + 1) and equal to or smaller than (Z (2n + 1) / 2). The vibration is effectively suppressed by managing the swell so that the maximum does not occur within the range (within the range indicated by X) (that is, A <B (maximum half amplitude)). Such management can be achieved by measuring components and combining them based on the measurement results.
[0031]
Next, with reference to FIG. 6, the relationship between the number of undulations and the half amplitude will be described for another example. FIG. 6 is a diagram illustrating another example of a curve indicating a general relationship between the number of undulations on the track surface and the one-sided amplitude. In this embodiment, when an odd number (Z) of rolling elements are used, ((Z (2n-1) -1) / 2) peaks and ((Z (2n-1)) per circumference of the rolling element orbit. ) +1) / 2) At least one of the peak amplitudes is not less than ((Z (2n-1) +1) / 2 + 1) and not more than ((Z (2n + 1) -1) / 2-1). It is set to be smaller than the maximum value of the undulation piece amplitude of a certain number of peaks.
[0032]
As shown by the curve C in FIG. 6, generally, the undulation piece amplitude tends to decrease as the number of peaks increases. According to this tendency, ((Z (2n-1) -1) / 2) peak amplitude A1 and ((Z (2n-1) +1) / 2) peak amplitude per circumference of the rolling element orbit. The amplitude A2 should be the largest one-sided amplitude in the number of peaks higher than that. On the other hand, in the present embodiment, contrary to the above tendency, the one-sided amplitude (here, A2) is set to be equal to or more than ((Z (2n-1) +1) / 2 + 1) peaks and ((Z (2n + 1) -1) ) / 2-1) By managing the swell so that it does not become the maximum among the swells of the number of hills below the peak (within the range indicated by X) (ie, so that A2 <B (maximum half amplitude)). , Which effectively suppresses vibration.
[0033]
With reference to FIG. 7, the relationship between the number of undulations and the one-sided amplitude will be described for still another example. FIG. 7 is a diagram showing still another example of a curve indicating a general relationship between the number of peaks of the undulations on the track surface and the one-sided amplitude. In the present embodiment, when an even number (Z) of rolling elements are used, the half amplitudes A3 and (Z (2n−2) of (Z (2n−1) / 2-1) peaks per circumference of the rolling element orbit. 1) / 2 + 1) One-sided undulation amplitude A4 of the ridges is equal to or more than ((Z (2n-3) / 2) peaks and equal to or less than (Z (2n-1) / 2-1) peaks). Is made smaller than the maximum value.
[0034]
As shown by a curve C in FIG. 7, generally, the undulation piece amplitude tends to decrease as the number of peaks increases. In the examples shown in FIGS. 5 and 6, the one-sided amplitude of the undulation is determined to counter this tendency. On the other hand, the inventors have found that the vibration suppression effect can be further enhanced by following this tendency. I found it. More specifically, the above-mentioned half-amplitudes A3 and A4 are undulated with the number of peaks equal to or more than Z (2n-3) / 2 and less than Z (2n-1) / 2-1 (within the range indicated by X). This effect is achieved by managing the swell so as not to be the maximum in (i.e., A3, A3 <B (maximum half amplitude)).
[0035]
When the number of rolling elements is large (for example, 10 pieces), as shown in FIG. 8, the rolling elements (1) in the radial load direction support the load, and the rolling elements (2) and (10) on both sides share the load. Otherwise, the distance between the rolling elements (3) and (9) on both sides thereof and the raceway surface is further reduced, so that the collision between the rolling elements and the raceway surface is less likely to occur. Become. Therefore, when the number of rolling elements is 10 or more, the strict management described above is not necessary, and as shown in the example in FIG. 7, when an even number (Z) of rolling elements are used, per one circumference of the rolling element trajectory is used. (Z (2n-1) / 2-1) peak half amplitude A3 and (Z (2n-1) / 2 + 1) peak undulation half amplitude A4 are equal to or more than ((Z (2n-3) / 2) peak) , (Z (2n-1) / 2-1) peaks or less should be smaller than the maximum value of the undulation piece amplitude, and it is desirable to reduce the residual gap of the bearing portion after fitting. For this purpose, the radial clearance of the rolling bearing may be reduced.
[0036]
Further, since swells of 20 or more hills rarely cause a problem, swells of 20 or less hills may be considered. For example, assuming that Z = 6, the number of undulations in question is three, nine, and fifteen. The amplitude of the undulation of three ridges is the amplitude of undulations in which the number of ridges is four or more and nine or less. If the peak of the swell of 9 peaks is not set to the maximum among the undulations of 10 peaks or more and 15 peaks or less, and the same applies to the undulation of 15 peaks, the above-mentioned problem is solved. A remarkable effect can be expected.
[0037]
Further, since the amplitude of the undulation usually decreases as the number of peaks increases, the number n of peaks, which is the most problematic, is 1, and it is effective to take a countermeasure when n = 1.
[0038]
In addition, as a method of managing the magnitude of the undulation, it is conceivable to set the undulation to a value smaller than the maximum value among all the undulations. It is considered effective if the size range is about half of the maximum value.
[0039]
Further, if the amplitude of the undulation is controlled and the gap inside the bearing is reduced, further effects can be expected.
[0040]
As described above, the present invention has been described with the embodiments, but the present invention is not limited to these, and various modifications can be made within the technical idea of the present invention. For example, the rolling bearing may be incorporated in a bearing device.
[0041]
【The invention's effect】
According to the rolling bearing of the present invention, the shape error (undulation) of the inner ring raceway surface and the outer ring raceway surface is suppressed, so that the load applied to the rolling element in the load region becomes smooth, and the generation of vibration and noise is suppressed. In addition, it is possible to suppress a reduction in the life of the rolling element due to a sudden load.
[Brief description of the drawings]
FIG. 1 is a diagram showing a relationship between a raceway and rolling elements according to the presence or absence of undulation.
FIG. 2 is a diagram showing a load state of a rolling element.
FIG. 3 is a diagram showing a relationship between undulation of a raceway surface and deformation of a rolling element subjected to a radial load.
FIG. 4 is a sectional view of a rolling bearing incorporated in an idler pulley.
FIG. 5 is a diagram showing a general relationship between the number of peaks of undulations on a track surface and one-sided amplitude.
FIG. 6 is a diagram illustrating a general relationship between the number of peaks of undulations on a track surface and one-sided amplitude.
FIG. 7 is a diagram illustrating a general relationship between the number of peaks of undulations on a track surface and one-sided amplitude.
FIG. 8 is a diagram illustrating an example in which a radial load is applied to the outer ring from above from applied to the rolling bearing;
[Explanation of symbols]
1, 1 'ball (rolling element)
2, 2 'Outer ring 3, 3' Inner ring 4, 4 'Rolling bearing 5 Idler pulley 5' Housing 6 Fixed shaft 6 'Rotating shaft

Claims (10)

A first race having a first race, a second race having a second race, and an even number of rolling members provided between the first race and the second race. (Z) a rolling element, wherein each of the raceways has a minute undulation.
With respect to at least one of the first and second races, when n, which is a positive integer, is at least 1, per circumference of the raceway (Z (2n-1) / 2) The one-sided amplitude of the undulation having the number of peaks is not less than ((Z (2n-1) / 2) +1) and not more than (Z (2n + 1) / 2) per circumference of the orbit. A rolling bearing, wherein the rolling bearing has a smaller value than the maximum value of the one-sided amplitude. With respect to at least one of the first race and the second race in the rolling bearing, when at least the integer n is 1, per circumference of the race (Z (2n-1)) (1/2 (1)), the one-sided amplitude of the waviness having a peak number of (Z (2n-3) / 2) or more per circumference of the orbit (however, in the case of n = 1, 2 or more), ( The rolling bearing according to claim 1, wherein the rolling bearing has a peak number equal to or less than Z (2n−1) / 2) and is smaller than a maximum value of the one-sided amplitude of the undulation. A first raceway having a first raceway, a second raceway having a second raceway, and an odd number of rolling elements provided between the first raceway and the second raceway so as to be freely rotatable; (Z) a rolling element, wherein each of the raceways has a minute undulation.
Regarding at least one of the first and second races, when n, which is a positive integer, is at least 1, per circumference of the raceway ((Z (2n-1)- Both the one-sided amplitude of the undulation having the number of peaks of 1) / 2) and the one-sided amplitude of the undulation having the number of peaks of ((Z (2n-1) +1) / 2) are:
The maximum value of the one-sided amplitude of the undulation having the number of peaks not less than ((Z (2n-1) +1) / 2 + 1) and not more than ((Z (2n + 1) -1) / 2-1) per circumference of the orbit. A rolling bearing characterized in that it is smaller than the rolling bearing. The rolling bearing according to any one of claims 1 to 3, wherein the number of peaks of the waviness is 20 or less per circumference of the track. The at least one of the first bearing ring and the second bearing ring is attached to a housing that accommodates the rolling bearing or a shaft that supports the rolling bearing by an interference fit. 4. The rolling bearing according to any one of 4. At least one of the first race and the second race is formed of bearing steel having a linear expansion coefficient of 10.1 × 10 ^{−6 to} 13.5 × 10 ⁻⁶ (m / ° C.),
The housing or the shaft is made of bearing steel, carbon steel, or structural steel having a linear expansion coefficient of 10.1 × 10 ^{−6 to} 13.5 × 10 ⁻⁶ (m / ° C.). The rolling bearing according to any one of claims 1 to 5, wherein In the above-mentioned rolling bearing, the first race is an inner race, the second race is an outer race, and the inner race is rotated. 7. The rolling bearing according to claim 6, wherein the coefficient of linear expansion is not more than. In the rolling bearing, the first race is an inner race, the second race is an outer race, and the outer race is rotated. The linear expansion coefficient of each race is the same as that of the shaft. The rolling bearing according to claim 6, wherein the rolling bearing has a linear expansion coefficient of not less than. The rolling bearing according to any one of claims 1 to 8, wherein the rolling bearing that mainly applies a load in the radial direction includes a load area where a load is applied to the rolling element and a non-load area where a load is not applied to the rolling element. bearing. A bearing device using the rolling bearing according to claim 1.

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