KR102043284B1 - Ball bearing and processing method of contacting raceway - Google Patents

Abstract

에 기초하여 정의된다.A ball bearing is provided between an outer ring having a track surface formed on an inner circumferential surface, an inner ring having a track surface formed on an outer circumferential surface opposite to the track surface of the outer ring, and between the track surface of the outer ring and the track surface of the inner ring. A contact track surface which is a track surface in contact with at least two points of the raceway surface of the inner ring and at least one of the track surface of the inner ring, A first profile contacting the ball at one point; a second profile spaced apart from the first profile; and a second profile contacting at one point different from the ball; a first end and a second end of the first profile; And a central profile connecting the second end, which is the end of the profile, in a curved form, wherein the tangent of the first profile and the tangent of the central profile are at the first end thereof. Groups are the same, and the tangent of the tangent and the center of the profile and the second profile at the second ends and the inclination are equal to each other, the central profile with each other is, for expression, the center of the ball as the origin

Is defined on the basis of

Description

BALL BEARING AND PROCESSING METHOD OF CONTACTING RACEWAY}

The present invention relates to a method of machining a ball bearing and a contact raceway surface.

The bearing is a mechanical element that fixes the shaft of the rotating machine to a certain position and rotates the shaft while supporting the weight of the shaft and the load on the shaft. And a ball bearing is a bearing which supports the load on a shaft using the ball provided between the outer ring and the inner ring.

The bearing may be subjected to a thrust load applied in the axial direction of the ring and a radial load applied in a direction perpendicular to the axial direction. Recently, in order to support a load applied in a complex direction, a multi-point contact ball bearing which contacts with an outer ring or an inner ring at a plurality of points has been used.

1 is a cross-sectional view showing the shape of the outer ring, the inner ring and the ball of the conventional multi-point contact ball bearing. The ball is in contact with one point on the left track 1 and one point on the right track 2. However, if the bearing is subjected to an excessive load, the ball may contact the curved portion 5 formed while the left track and the right track meet.

By the way, since the curved part 5 is formed deeper compared with each track | orbit 1 and 2, there existed a problem that the finishing process for reducing the surface roughness is hard to implement.

That is, when the tool for finishing process, for example, the honing head 40 and the like to contact the curved portion 5, the honing head 40 and the tracks (1, 2) collide with each other, the honing head 40 is There was a problem of damage (see FIG. 5). In addition, when the finishing process is not performed on the curved portion 5 and the surface of the curved portion 5 becomes rough (see FIG. 6), there is a problem that the ball is damaged or peeled off when the ball contacts the curved portion 5.

One object of the present invention is to provide a ball bearing which is formed with a smooth curved portion, which enables finishing of the curved portion, and can prevent damage to the tool for finishing.

Another object of the present invention is to provide a ball bearing capable of preventing the damage or peeling of the ball and the track caused by finishing the surface of the curved portion and contacting the ball with the curved portion.

Still another object of the present invention is to provide a machining method for processing a raceway surface such that both raceways and curved portions in contact with the ball are connected smoothly.

여기서, x 축은 상기 링의 축 방향에 평행한 방향으로 상기 볼의 중심을 지나는 선에서 정의되고, y 축은 상기 링의 반경 방향으로 상기 볼의 중심을 지나는 선에서 정의된다.
조건1) 상기 중앙 프로파일의 양단이 각각 상기 제1 말단과 상기 제2 말단에 일치됨
조건2) 상기 제1 말단에서 상기 제1 프로파일의 접선의 기울기와 상기 중앙 프로파일의 접선의 기울기가 서로 동일함
조건3) 상기 제2 말단에서 상기 제2 프로파일의 접선의 기울기와 상기 중앙 프로파일의 접선의 기울기가 서로 동일함In one example, the ball bearing includes an outer ring having a raceway formed on an inner circumferential surface, an inner ring having a raceway formed on an outer circumferential surface opposite to the raceway surface of the outer ring, and between the raceway surface of the outer ring and the raceway surface of the inner ring. And a ball contacting at least two points with at least one of the raceway surface of the outer ring and the raceway surface of the inner ring, and the raceway surface contacting with the ball at two points in the raceway surface of the outer ring and the inner ring. The phosphorus contact raceway surface includes a first profile contacting the ball at one point, a second profile provided to be spaced apart from the first profile, and contacting at one point different from the ball, and a first end of the first profile. And a central profile connecting the distal end with the second distal end, the distal end of the second profile, wherein the central profile is based on the following formula, with the center of the ball as the origin. Constants A, B, and C in the following formula are set to satisfy all of the following conditions 1) to 3), and the center profile meets a reference line passing through the center of the ball in the radial direction of the ring. In this respect, assuming that the maximum separation distance farthest from the center of the ball, the maximum separation distance is equal to the absolute value of the sum of the constants A and C in the following equation, the sum of the constants A and C, In a state where all of the following conditions 1) to 3) are satisfied, various values can be set based on the load applied to the bearing.

Here, the x axis is defined in the line passing through the center of the ball in the direction parallel to the axial direction of the ring, the y axis is defined in the line passing through the center of the ball in the radial direction of the ring.
Condition 1) Both ends of the central profile coincide with the first end and the second end, respectively.
Condition 2) The slope of the tangent of the first profile and the slope of the tangent of the central profile are equal to each other at the first end
Condition 3) The slope of the tangent of the second profile and the slope of the tangent of the central profile are equal to each other at the second end

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In another example, the first and second ends may be spaced apart by an equal distance from each other on a line parallel to the axial direction of the ring with respect to the reference line.

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In another example, the maximum separation distance may be Dw / 2 + 0.25 * P to Dw / 2 + 0.75 * P. Where Dw is the diameter of the ball and P is the gap distance between the ball and the bend where the raceways on both sides meet when the central profile is not applied.

In another example, the distance spaced from the first end to the second end in a direction parallel to the axial direction of the ring may be 5% of the diameter of the ball to 25% of the diameter of the ball.

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In another example, the average roughness Ra of the surface corresponding to the center profile in the contact raceway surface may be 0.2 μm or less.

In another example, a ball bearing is provided between an outer ring having a raceway formed on an inner circumferential surface, an inner ring having a raceway formed on an outer circumferential surface, and a raceway between the raceway surface of the outer ring and the raceway surface of the inner ring. And a ball contacting at least two points with at least one of the raceway surfaces of the inner ring, and the contact raceway surface being a raceway contacting the ball at two points in the raceway surface of the outer ring and the inner ring, the ball A first profile contacting at one point with the second profile, a second profile contacting at one point different from the ball, and a center connecting a first end that is the end of the first profile and a second end that is the end of the second profile A tangent of the first profile and a tangent of the central profile at the first end, the slopes of which are equal to each other, and at the second end of the tangent of the second profile; The tangents of the center profile are equal in inclination to each other, and the center profile is defined based on the following formula, with the center of the ball as the origin, and the center profile is the most from the center of the ball at the point where it meets the reference line. It has a maximum separation distance which is far apart, and the said maximum separation distance is set based on the load added to the said bearing.

Wherein the x axis is defined in a line passing the center of the ball in a direction parallel to the axial direction of the ring, and the y axis is defined in a line passing the center of the ball in the radial direction of the ring.

In another example, the first and second ends may be spaced equally apart from each other in a direction parallel to the axial direction of the ring, with reference to the reference line passing through the center of the ball in the radial direction of the ring.

In another example, the constants A, B, and C of the above formula, wherein the central profile connects the first end and the second end, the tangent slope and the central profile of the first profile at the first end The inclination of the tangent of the same may be set to be equal to each other, and the inclination of the tangent of the second profile and the inclination of the tangent of the central profile at the second end may be equal to each other.

여기서, x 축은 상기 링의 축 방향에 평행한 방향으로 상기 볼의 중심을 지나는 선에서 정의되고, y 축은 상기 링의 반경 방향으로 상기 볼의 중심을 지나는 선에서 정의된다.
조건1) 상기 중앙 프로파일의 양단이 각각 상기 제1 말단과 상기 제2 말단에 일치됨
조건2) 상기 제1 말단에서 상기 제1 프로파일의 접선의 기울기와 상기 중앙 프로파일의 접선의 기울기가 서로 동일함
조건3) 상기 제2 말단에서 상기 제2 프로파일의 접선의 기울기와 상기 중앙 프로파일의 접선의 기울기가 서로 동일함In another example, one of an outer ring having a raceway formed on an inner circumferential surface and an inner ring having a raceway formed on an outer circumferential surface thereof, and a contact raceway surface which is a raceway surface of a ring contacting at two points with a ball provided between the rings. The processing method of the contact track surface for processing the, based on the first profile in contact with the ball at one point, and the second profile provided to be spaced apart from the first profile and in contact with the ball at one point, the A first step of preparing a body of a ring having a contact track surface machined, and a center between a surface processed based on the first profile and a surface processed based on the second profile among the contact track surfaces of the body. And a second step of processing based on the profile, wherein the central profile connects a first end that is the end of the first profile and a second end that is the end of the second profile, wherein The constants A, B, and C of the following formula are defined to satisfy all of the following conditions 1) to 3), and the center profile is the radius of the ring. The maximum separation distance is the same as the absolute value of the sum of the constants A and C in the following equation, provided that it has a maximum separation distance farthest from the center of the ball at the point of meeting the reference line passing through the center of the ball in the direction. The sum of the constants A and C can be set to various values based on the load applied to the bearing in a state where the following conditions 1) to 3) are all satisfied.

Here, the x axis is defined in the line passing through the center of the ball in the direction parallel to the axial direction of the ring, the y axis is defined in the line passing through the center of the ball in the radial direction of the ring.
Condition 1) Both ends of the central profile coincide with the first end and the second end, respectively.
Condition 2) The slope of the tangent of the first profile and the slope of the tangent of the central profile are equal to each other at the first end
Condition 3) The slope of the tangent of the second profile and the slope of the tangent of the central profile are equal to each other at the second end

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In another example, the second step may be performed while polishing at least a portion of the contact raceway surface after the first step.

In another example, the method of processing the contact raceway surface may further include a third step of finishing the contact raceway surface to reduce the roughness of the contact raceway surface after the second step.

According to the present invention, the central profile of the ball bearing is smoothly connected to the first and second profiles, and the depth of the groove formed in the central profile is shallow, so that finishing can be easily performed even for the central profile.

In addition, according to the present invention, the roughness of the surface corresponding to the center profile is finished to the same level as the first and second profiles, so that even if the ball contacts the center profile, damage or peeling may not occur on the profile and the ball.

In addition, according to the present invention, in defining the central profile, by using a specific cosine equation, the central profile smoothly connected to the first and second profiles can be adjusted to various shapes according to the purpose of use.

1 is a cross-sectional view showing the shape of the outer ring, the inner ring and the ball of the conventional multi-point contact ball bearing.
2 is a perspective view schematically showing a ball bearing according to an embodiment of the present invention.
3 is a cross-sectional view illustrating a cross section taken along line AA of FIG. 1.
4 is an enlarged cross-sectional view of portion A of FIG. 3.
5 is a cross-sectional view showing a process in which honing is performed for a conventional ball bearing.
6 is a cross-sectional view showing a process in which honing is performed for a conventional ball bearing.
7 is a cross-sectional view showing a process in which honing is performed for a ball bearing according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the embodiments of the present invention, if it is determined that the detailed description of the related well-known configuration or function disturbs the understanding of the embodiments of the present invention, the detailed description thereof will be omitted.

Ball bearing

2 is a perspective view schematically showing a ball bearing according to an embodiment of the present invention. 3 is a cross-sectional view illustrating a cross section taken along line A-A of FIG. 2. 4 is an enlarged cross-sectional view of portion A of FIG. 3. Hereinafter, a ball bearing according to an exemplary embodiment of the present invention will be described with reference to FIGS. 2 to 4.

Ball bearing according to an embodiment of the present invention includes an outer ring 10, the inner ring 20 and a plurality of balls (30).

The raceway surface 100 is formed on the inner circumferential surface of the outer ring 10. The track surface refers to a surface for guiding a path in which the ball 30 to be described later moves. The outer circumferential surface of the inner ring 20 is formed with a raceway surface 200 facing the raceway surface 100 of the outer ring.

The ball 30 is provided between the raceway surface 100 of the outer ring and the raceway surface 200 of the inner ring. When the ball 30 is located in the middle between the raceway surface 100 of the outer ring and the raceway surface 200 of the inner ring, the ball 30 and the raceway surfaces 100, 200 may be spaced apart by a predetermined interval. (See Figure 4). Lubricating oil may be interposed at this interval to minimize friction between the ball 30 and the raceways 100, 200.

When the shaft of the machine in which the bearing is coupled rotates so that the ball 30 is subjected to centrifugal force or the bearing is loaded, the ball 30 may contact the raceways 100, 200. The rotating axis may be loaded in the axial direction (t) or in the direction perpendicular to the axis (r). In order to withstand the load in the complex direction, the ball 30 is in the outer ring raceway 100 and the inner At least two points of contact with at least one of the raceway surfaces 200 of the ring.

The track surface which contacts the ball 30 at two points is called a contact track surface. The raceway surface 200 of the inner ring may be the contact raceway surface, or both the raceway surface 100 of the outer ring and the raceway surface 200 of the inner ring may be the contact raceway surface and may be a four-point contact bearing. For convenience of understanding, hereinafter, the contact track surface will be described on the assumption that the raceway surface 100 of the outer ring is the contact raceway surface with reference to FIG. 4.

The raceway surface 100 of the outer ring includes a first profile 110, a second profile 120, and a central profile 150.

The first profile 110 and the second profile 120 are provided to be spaced apart from each other. The first profile 110 and the second profile 120 may be part of circles drawn with the same radius at different centers. The ball 30 contacting at two points when in contact with the contact track surface is in contact with the first profile 110 at one point and at one point different from the second profile 120.

The central profile 150 connects the first profile 110 and the second profile 120. More specifically, the central profile 150 connects the first end 111, which is the end of the first profile 110, and the second end 121, which is the end of the second profile 120, in a curved shape. The first end 111 refers to the radial (r) side end of the ring of the first profile 110, and the second end 121 refers to the radial (r) side end of the ring of the second profile 120. Say.

The first end 111 and the second end 121 may be spaced apart by the same distance from each other on a line parallel to the axial direction t of the ring with respect to the reference line g. The reference line g refers to a line passing through the center of the ball 30 in the radial direction r of the ring. That is, the first end 111 and the second end 121 may be formed symmetrically with respect to the reference line g. In this case, the distance spaced from the first end 111 to the second end 121 in a direction parallel to the axial direction t of the ring may be 5% to 25% of the diameter of the ball 30.

If the distance between the first end 111 and the second end 121 is less than 5%, the length of the center profile 150 may be too short, and the ball may not be easily supported by the center profile 150. In addition, when the distance between the first end 111 and the second end 121 is greater than 25%, the length of the center profile 150 becomes too long and is set based on the load added to the bearing. Problems may occur in contact between the first profile 110 and the second profile 120.

The tangent of the first profile 110 and the tangent of the central profile 150 at the first end 111 have the same slope. In addition, the tangent of the second profile 120 and the tangent of the central profile 150 at the second end 121 have the same slope.

The ball 30 comes into contact with the contact raceway at two points, and when the ball bearing is loaded, the position where the ball 30 comes into contact may change. However, the inclination of the tangent of the first profile 110 and the tangent of the central profile 150 is the same at the first end 111, and the tangent and the central profile 150 of the second profile 120 at the second end 121. Since the inclination of the tangent of () is the same, even if the ball 30 is in contact with the first end 111 or the second end 121, or pass through the first end 111 or the second end 121, the contact trajectory Since the surface or the ball 30 is not impacted, damage or peeling of the ball bearing can be prevented.

In addition, when the ball bearing is subjected to an excessive load, the ball 30 may also contact the center profile 150. The surface of the center profile 150 may have an average roughness Ra of 0.2 μm or less through finishing, or the like. have. This may be at a level similar to the average roughness Ra level of the surfaces of the first profile 110 and the second profile 120. The face of the center profile 150 is finished to the level of the face of the first and second profiles 110 and 120 so that the center profile 150 and the ball 30 may be contacted even when the ball 30 contacts the center profile 150. This can be prevented from being damaged.

The central profile 150 may have a maximum separation distance D that is farthest from the center of the ball 30 at the point of meeting the reference line g. The maximum separation distance D can be set based on the load added to the bearing.

If the load applied to the bearing is large and the contact between the central profile 150 and the ball 30 is excessive, the maximum separation distance D can be narrowed. And in order to minimize the friction between the ball 30 and the central profile 150, it is necessary to process the dimensions of the central profile 150 precisely according to the designed value, that is, to have a small tolerance compared to the designed value. In addition, the roughness of the surface of the central profile 150 also needs to be precisely machined.

Alternatively, when the load applied to the bearing is small or the high-speed rotation condition does not cause severe contact between the central profile 150 and the ball 30, the maximum separation distance D may be widened. And more lubricant can be interposed between the central profile 150 and the ball 30.

More specifically, the maximum separation distance D may be Dw / 2 + 0.25 * P to Dw / 2 + 0.75 * P. Where Dw is the diameter of the ball 30, P is the gap distance between the ball 30 and the curved portion formed when the raceway surfaces of both sides meet when the central profile is not applied (see Fig. 4).

The gap distance between the curved portion formed by the raceway of the outer ring and the ball 30 may be defined as P _o , and the gap distance between the curved portion formed by the raceway of the inner ring and the ball 30 is formed by P _i . .

That is, the maximum separation distance D of the center profile 150 of the contact raceway surface formed on the outer ring may be Dw / 2 + 0.25 * P _o to Dw / 2 + 0.75 * P _o . In addition, the maximum separation distance D of the central profile of the contact raceway surface formed in the inner ring may be Dw / 2 + 0.25 * P _i to Dw / 2 + 0.75 * P _i .

In this case, the raceway surface forming the outer ring and the raceway surface forming the inner ring may have different radii of curvature, and in general, the radius of curvature of the outer ring may be larger than the radius of curvature of the inner ring.

Definition of the central profile

Hereinafter, the principle that the central profile 150 is defined in the ball bearing according to an embodiment of the present invention will be described. The central profile 150 may be defined based on the following formula, which is based on the center of the ball 30.

Here, the x axis is defined in the line passing through the center of the ball 30 in a direction parallel to the axial direction t of the ring. The y axis is defined in the line passing through the center of the ball 30 in the radial direction r of the ring.

Constants A, B, and C of the equation may be set such that the central profile 150 runs smoothly with the first profile 110 and the second profile 120. As can be seen in the graph of the trigonometric function, as the constant C increases, the base position of the central profile 150 moves to the radial (r) side of the ring (eg, + y axis direction).

As the constant A increases, the central profile 150 moves the maximum value of the function toward the radial r side of the ring with respect to the base position defined according to the value of the constant C. Therefore, the maximum separation distance D of the central profile 150 may be equal to the absolute value of the sum of A and C. The maximum separation distance D is the distance defined at the point where the center of the ball 30 and the central profile 150 meet the baseline g, and x for the baseline g is 0, so x of the above formula It is clear that if we substitute 0 in the value, y becomes A + C.

The constant B is a value that determines the degree of smoothness of the central profile 150. As the value of the constant B increases, the degree of bending of the central profile 150 becomes greater.

In this way, by adjusting the values of the constants A, B, and C, both ends of the central profile 150 may be set to coincide with the first end 111 and the second end 121, respectively. In addition, the inclination of the tangent of the first profile 110 and the inclination of the tangent of the central profile 150 may be set to be the same at the first end 111. In addition, the inclination of the tangent of the second profile 120 and the inclination of the tangent of the central profile 150 may be set to be the same at the second end 121. The values of the constants A, B, and C are mutually organic, and may be adjusted in consideration of the maximum separation distance D and the degree of smoothness of the central profile 150 depending on the purpose of use.

For example, the process of obtaining A, B, and C values under the following conditions will be described.

The coordinates of the second end 121 of the second profile 120: (0.800, 4.306)

Slope of the second profile 120 at the second end 121: -0.205

When the central profile 150 is not applied

  Height of the bend where both raceways of the outer ring meet: 4.399mm

-Diameter of the ball 30 (Dw): 8.731 mm

First, the process of determining the A value will be described. In the case of the above conditions, the clearance distance P _o between the curved portion and the ball 30 is 4.399-8.731 / 2 = 0.0335 mm. A value may be set such that the sum of A and C satisfies Dw / 2 + 0.25 * P _o to Dw / 2 + 0.75 * P _o . That is, the sum of A and C may be set to have a value of 4.373875 mm or more and 4.390625 mm or less. For example, the A value may be determined as 0.3.

Next, the process of determining the B value will be described. Since the slope of the second profile 120 at the second end 121 is -0.205, when the x value of the above equation is 0.8, the coefficient B having a slope value of -0.205 is obtained, whereby the second at the second end 121 is obtained. The central profile 150 with the same slope as the profile 120 can be determined. Through this process, the B value may be determined as 1.22633.

Finally, by substituting the A value and the B value, the C value at which the central profile 150 and the second profile 120 contact each other at the second end 121 may be determined to be 4.08728.

The A, B, and C values are not limited thereto, and may be variously determined according to values obtained in the same manner.

Processing method of contact track surface

Hereinafter, in the ball bearing according to an embodiment of the present invention, a contact track surface processing method for processing the contact track surface will be described.

First, based on the first profile 110 and the second profile 120, a body of a ring having a contact raceway machined is prepared (first step). The body may be prepared by turning the unprocessed ring on the first profile 110 and the second profile 120 using a lathe or the like. In this case, the spaced portion between the first profile 110 and the second profile 120 is processed to connect the first end 111 and the second end 121 in a direction parallel to the axial direction t of the ring. can do. Alternatively, a portion spaced between the first profile 110 and the second profile 120 in consideration of the processing of the center profile 150 to be described later, the first end 111 and the second end 121 is a center profile As 150, it can process rather than depth to be processed.

Next, among the contact raceways, the surface processed based on the first profile 110 and the surface processed based on the second profile 120 are processed based on the central profile 150 (second step). . At this time, the center profile 150 is defined based on the following formula which makes the center of the ball 30 the origin.

Here, the x axis is defined in a line passing through the center of the ball 30 in a direction parallel to the axial direction t of the ring, and the y axis is defined in a line passing through the center of the ball 30 in the radial direction r of the ring. do.

The central profile 150 may connect the first end 111 and the second end 121 based on the above formula. In addition, the constants A, B, and C of the formula are that the central profile 150 connects the first end 111 and the second end 121 and each profile at the first end 111 and the second end 121. The inclinations of the tangent lines may be set to be equal to each other.

The second step may be performed while polishing at least a portion of the contact raceway surface after the first step. In order to reduce the friction between the ball 30 and the contact raceway, it is preferable that a grinding process is performed on the contact raceway. The polishing process can be processed into the shape of the central profile 150 while scraping off the surface by using the abrasive grindstone.

Honing may be additionally performed to finish the surface more precisely (not roughly) with respect to the contact raceway surface where the surface is somewhat smoothed by the second step (third step).

5 and 6 are cross-sectional views showing a process in which honing is performed for a conventional ball bearing. 7 is a cross-sectional view showing a process in which honing is performed for a ball bearing according to an embodiment of the present invention.

More specifically, FIGS. 5 to 7 are views showing a process in which the honing head 40 equipped with the whetstone is rotating reciprocating relative to the raceway surface 100. Referring to FIGS. 5 and 6, a curved portion 5 in which both side tracks 1 and 2 meet each other is deeply formed. Therefore, the area where the honing head 40 and the two orbits 1 and 2 are in contact with each other is large (see FIG. 5), or the honing head 40 is not inserted into the bent portion 5 so that the bent portion 5 is honed. There was a problem that could not be achieved (see Figure 6).

However, when the second step is performed in the process of polishing the center profile 150, the center profile 150 may be formed smoothly, as shown in FIG. 7, the honing head 40 and the respective profiles 110 and 120. ) Can reduce the area of impact. Therefore, it is possible to prevent damage to each profile 110, 120 or the honing head 40. In addition, since the honing process may be easily performed on the surface of the central profile 150, the friction between the ball 30 and the central profile 150 may be minimized. Therefore, even if the ball bearing is subjected to an excessive load and the ball 30 contacts the central profile 150, damage or peeling of the ball bearing or the ball 30 can be prevented.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1: Track surface of conventional ball bearing
2: raceway surface of conventional ball bearing
5: bend of the conventional ball bearing
10: outer ring
20: inner ring
30: ball
40: honing head
100: raceway surface of the outer ring
110: first profile
111: first terminal
120: second profile
121: second terminal
150: center profile
200: raceway surface of the inner ring
D: Maximum separation distance
Dw: diameter of ball
P (P _o, P _i ): clearance
r: radial direction of the ring
t: axial direction of the ring

Claims (16)

An outer ring having a raceway formed on an inner circumferential surface thereof;
An inner ring having a raceway surface formed on an outer circumferential surface thereof so as to face the raceway surface of the outer ring; And
A ball provided between the raceway surface of the outer ring and the raceway surface of the inner ring, the ball contacting at least two points with at least one of the raceway surface of the outer ring and the raceway surface of the inner ring,
The contact raceway surface, which is a raceway surface contacting the ball at two points in the raceway surface of the outer ring and the inner ring, is provided with a first profile contacting the ball at one point and spaced apart from the first profile; A second profile contacting at another point and a central profile connecting the first end, which is the end of the first profile, and the second end, which is the end of the second profile, in a curved form;
The said central profile is defined based on the following formula which makes the center of the said ball the origin,
Constants A, B, and C of the following formula are set to satisfy all of the following conditions 1) to 3),
Given that the central profile has a maximum separation distance farthest from the center of the ball at the point where it meets a reference line passing through the center of the ball in the radial direction of the ring, the maximum separation distance is a constant of the formula Equal to the absolute value of the sum of A and C,
The sum of said constants A and C is a ball bearing which can be set to various values based on the load applied to a bearing, when the following conditions 1) thru | or 3) are all satisfied.

Wherein the x axis is defined in a line passing the center of the ball in a direction parallel to the axial direction of the ring, and the y axis is defined in a line passing the center of the ball in the radial direction of the ring.
Condition 1) Both ends of the central profile coincide with the first end and the second end, respectively.
Condition 2) The slope of the tangent of the first profile and the slope of the tangent of the central profile are equal to each other at the first end
Condition 3) The slope of the tangent of the second profile and the slope of the tangent of the central profile are equal to each other at the second end The method according to claim 1,
The first and second ends are ball bearings spaced apart from each other by an equal distance on a line parallel to the axial direction of the ring with respect to the reference line. delete The method according to claim 2,
The maximum separation distance is a ball bearing Dw / 2 + 0.25 * P to Dw / 2 + 0.75 * P.
Where Dw is the diameter of the ball and P is the clearance between the ball and the bend where the raceways on both sides meet when the central profile is not applied. The method according to claim 2,
The distance from the first end to the second end in a direction parallel to the axial direction of the ring is from 5% of the diameter of the ball to 25% of the diameter of the ball. delete delete The method according to claim 1,
The average roughness Ra of the surface corresponding to the said central profile in the said contact track surface is 0.2 micrometer or less. delete delete delete Any one of an outer ring having a raceway formed on the inner circumferential surface and an inner ring formed with a raceway formed on the outer circumferential surface, the contact track surface being a raceway surface of the ring contacting at two points with the ball provided between the rings, the contact In the processing method of the raceway surface,
Preparing the body of the ring with the contact raceway surface based on the first profile in contact with the ball at one point and the second profile provided to be spaced apart from the first profile and in contact with the ball at one point. First step; And
A second step of processing between the surface processed based on the first profile and the surface processed based on the second profile, based on the central profile, among the contact raceway surfaces of the body,
The central profile is defined on the basis of the following formula connecting the first end, which is the end of the first profile, and the second end, which is the end of the second profile, with the center of the ball as the origin,
Constants A, B, and C of the following formula are set to satisfy all of the following conditions 1) to 3),
Given that the central profile has a maximum separation distance farthest from the center of the ball at the point where it meets a reference line passing through the center of the ball in the radial direction of the ring, the maximum separation distance is a constant of the formula Equal to the absolute value of the sum of A and C,
The sum of said constants A and C can be set to various values based on the load applied to a bearing in the state in which the following conditions 1) thru | or 3) are satisfied, The processing method of the contact track surface.

Wherein the x axis is defined in a line passing the center of the ball in a direction parallel to the axial direction of the ring, and the y axis is defined in a line passing the center of the ball in the radial direction of the ring.
Condition 1) Both ends of the central profile coincide with the first end and the second end, respectively.
Condition 2) The slope of the tangent of the first profile and the slope of the tangent of the central profile are equal to each other at the first end
Condition 3) The slope of the tangent of the second profile and the slope of the tangent of the central profile are equal to each other at the second end delete delete The method according to claim 12,
And said second step is performed during polishing at least a portion of the contact track surface after said first step. The method according to claim 12,
And a third step of finishing the contact raceway surface to reduce the roughness of the contact raceway surface after the second step.

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