WO2022092062A1

WO2022092062A1 - Bearing device

Info

Publication number: WO2022092062A1
Application number: PCT/JP2021/039429
Authority: WO
Inventors: 隼人川口; 俊樹増田
Original assignee: Ntn株式会社
Priority date: 2020-10-29
Filing date: 2021-10-26
Publication date: 2022-05-05
Also published as: KR20230115985A; JP2022072100A; CN116457586A; JP7557340B2

Abstract

In a bearing device where an outer race (6) and a housing (2) have cylindrical mating surfaces (15, 16) that mate with each other, the outer race (6) has, formed in the mating surface (16) thereof, two or more flank surfaces (17) that are disposed at intervals in the circumferential direction and that extend over the entire axial width of the mating surface (16) so as to divide the mating surface (16) in the circumferential direction.

Description

Bearing equipment

The present invention relates to a bearing device incorporating a rolling bearing that supports a radial load between a shaft and a housing.

Generally, the shaft of an automobile transmission is supported by a rolling bearing fitted in a housing. This rolling bearing has an inner ring fitted on the outer periphery of the shaft, an outer ring coaxially arranged on the radial outer side of the inner ring, and a plurality of rolling elements incorporated between the inner ring and the outer ring.

Here, in the rolling bearing that supports the shaft of the transmission, the outer ring is usually squeezed with respect to the housing in order to facilitate the assembly work of the rolling bearing with respect to the housing. That is, the dimensional tolerance is set so that the outer diameter dimension of the cylindrical fitting surface on the outer circumference of the outer ring is always smaller than the inner diameter dimension of the cylindrical fitting surface on the inner circumference of the housing.

On the other hand, when the outer ring is squeezed into the housing, if the shaft is rotated with a radial load applied from the shaft to the inner ring, the outer ring may gradually rotate with respect to the housing (creep phenomenon).

The following is known as one of the mechanisms of this creep phenomenon. That is, when a radial load is applied from the shaft to the inner ring, the radial load is transmitted to the outer ring via the rolling element, and the outer ring is deformed into a corrugated shape. When the inner ring rotates in this state, the rolling element moves in the circumferential direction while rolling, so that the deformation of the waveform of the outer ring also moves in the circumferential direction, and the deformation of the outer ring forms a progressive wave. Then, the traveling wave causes a minute slip between the fitting surface on the outer circumference of the outer ring and the fitting surface on the inner circumference of the housing, and the creep phenomenon occurs by accumulating the minute slip.

Similarly, when the shaft is squeezed into the inner ring, a creep phenomenon may occur between the inner ring and the shaft.

In order to suppress this creep phenomenon, the inventor of the present application has already proposed the bearing device shown in FIG. 1 of Patent Document 1. This bearing device has a shaft, a housing that surrounds the outer circumference of the shaft, and a rolling bearing that supports a radial load between the shaft and the housing. The outer ring of the rolling bearing is squeezed into the housing. Then, in order to suppress the creep phenomenon from occurring between the outer ring and the housing, a flank that divides the cylindrical fitting surface of the outer circumference of the outer ring in the circumferential direction is formed at one place on the outer circumference of the outer ring.

In this bearing device, a flank that divides the cylindrical fitting surface in the circumferential direction is formed on the outer circumference of the outer ring, and the flank blocks the deformation of the waveform of the outer ring from being transmitted to the housing as a traveling wave. And the creep phenomenon can be suppressed.

For example, when a horizontally arranged shaft is supported by a rolling bearing and the shaft rotates while a vertically downward radial load is applied from the shaft to the inner ring, the shaft is vertical among the cylindrical fitting surfaces of the housing and the outer ring. The range corresponding to the predetermined central angle of less than 180 ° on the lower side is the load load range.

When the rolling bearing is assembled so that the flank of the outer circumference of the outer ring is located in this load-bearing area, the outer circumference of the outer ring and the inner circumference of the housing are not in contact with each other in the load-bearing area. It is possible to block the deformation from being transmitted to the housing as a traveling wave, and the creep phenomenon is suppressed. On the other hand, when the rolling bearing is assembled so that the clearance surface on the outer circumference of the outer ring is located in the area outside the load-bearing area (for example, the range on the vertical upper side of the shaft in the cylindrical fitting surface of the housing and the outer ring). Immediately after assembly, in the load-bearing area on the vertical lower side of the shaft, the outer circumference of the outer ring and the inner circumference of the housing come into contact with each other, and the deformation of the waveform of the outer ring is transmitted to the housing as a traveling wave, so that the creep phenomenon occurs once. Although it occurs, the outer ring gradually rotates due to the creep phenomenon, and after the flank of the outer circumference of the outer ring reaches the load-bearing area, the outer circumference of the outer ring and the inner circumference of the housing become non-contact in the load-bearing area. The deformation of the waveform of the outer ring is blocked from being transmitted to the housing as a traveling wave, the outer ring does not rotate any more, and the creep phenomenon is suppressed.

Japanese Unexamined Patent Publication No. 2020-45987

When the inventor of the present application provides only one flank on the outer periphery of the outer ring of the rolling bearing as shown in FIG. 1 of Patent Document 1, as described above, the roll bearing is loaded with the flank on the outer ring of the outer ring. Even if it is assembled so that it is located in the area, or if it is assembled so that the flank of the outer circumference of the outer ring is located in the area outside the load-bearing area, the creep phenomenon can be suppressed regardless of the direction of the assembly. However, in reality, it turned out that there are cases where the creep phenomenon is not suppressed. Then, as a result of investigating the cause, it was found that the creep phenomenon was not suppressed when the load-bearing range of the rolling bearing fluctuated.

That is, the direction of the radial load applied to the rolling bearing is not constant and may always fluctuate. Typically, the load applied to the rolling bearing is a rotational load (when the direction of the radial load applied to the rolling bearing rotates). In this case, the load-bearing range of the rolling bearing always moves. Therefore, if a rolling bearing having only one flank on the outer periphery of the outer ring is used as shown in FIG. 1 of Patent Document 1, the load-bearing range moves with the movement of the rolling bearing. When the load-bearing area overlaps the position of the flank, it is possible to block the deformation of the outer ring waveform from being transmitted to the housing as a progressive wave, but while the load-bearing range is out of the flank position. , The deformation of the waveform of the outer ring is transmitted to the housing as a traveling wave, and a creep phenomenon occurs. Then, no matter where the flank of the outer ring of the outer ring moves due to this creep phenomenon, the load-bearing area always moves, so that the creep phenomenon does not subside after all. That is, when the load load range of the rolling bearing constantly moves, as in the case where the rotational load is applied to the rolling bearing, one flank surface is provided on the outer periphery of the outer ring of the rolling bearing as shown in FIG. 1 of Patent Document 1. It was found that the creep phenomenon could not be suppressed by providing the above.

The problem to be solved by the present invention is to provide a bearing device capable of effectively suppressing the creep phenomenon even when the direction of the radial load applied to the rolling bearing fluctuates.

In order to solve the above problems, the present invention provides a bearing device having the following configuration.
Axis and
A housing that surrounds the outer circumference of the shaft and
A rolling bearing, which supports a radial load between the shaft and the housing, is provided.
The rolling bearing has a raceway ring that is squeezed with a mating member that is one of the shaft and the housing.
In a bearing device having a cylindrical fitting surface in which the raceway ring and the mating member are fitted to each other.
On one of the raceway ring and the mating member, flanks extending in the entire axial direction of the fitting surface are spaced apart in the circumferential direction so as to divide the fitting surface of the member in the circumferential direction. A bearing device characterized in that two or more are formed.

In this way, two or more flanks are formed at one of the bearing ring and the mating member to which the bearing ring is squeezed at intervals in the circumferential direction, so that the rotational load is formed. Even when the direction of the radial load applied to the rolling bearing fluctuates, as in the case where is loaded on the rolling bearing, the deformation of the waveform of the raceway ring is difficult to be transmitted to the mating member as a traveling wave, and the creep phenomenon is effective. It is possible to suppress.

The flank can be formed on the raceway ring. That is, two or more flanks extending in the axial direction of the fitting surface can be formed on the raceway ring so as to divide the fitting surface of the raceway ring in the circumferential direction. ..

Further, the mating member may be the housing, and the raceway ring may be an outer ring. That is, the rolling bearing has an outer ring fitted with the housing, the outer ring and the housing have a cylindrical fitting surface that fits each other, and the outer ring has the fitting that the outer ring has. It is possible to adopt a configuration in which two or more flanks extending in the axial direction of the fitting surface are formed at intervals in the circumferential direction so as to divide the surface in the circumferential direction.

It is preferable that the flanks are provided on the outer periphery of the outer ring in a range of 3 or more and 6 or less at equal intervals in the circumferential direction.

When three or more flanks are provided on the outer periphery of the outer ring at equal intervals in the circumferential direction, the direction of the radial load applied to the rolling bearing changes, and even when the load load range constantly moves, the load is always present. It is possible to maintain a state in which one of the flanks enters the load range, and it is possible to effectively suppress the creep phenomenon. Further, by setting the number of flanks provided on the outer periphery of the outer ring at equal intervals in the circumferential direction to be 6 or less, it is possible to secure the circumferential length of each flank, so that the waveform of the outer ring is deformed. It is possible to effectively block the traveling wave from being transmitted to the housing.

The flank may be a flat surface or a concave arc shape, but a convex circle formed so as to pass radially inside the fitting surface of the outer ring. It is preferable to adopt an arc-shaped curved surface.

In this way, the radial thickness of the outer ring due to the formation of the flank is larger than the case where a flat flank or a concave arc shape is adopted as the flank formed on the outer periphery of the outer ring. It is possible to suppress the decrease in thickness, and it is possible to suppress the deflection of the outer ring when a radial load is applied.

It is preferable to adopt a configuration in which both ends of the flank in the circumferential direction are smoothly connected to the fitting surface of the outer ring.

In this way, the flank of the outer ring is smoothly connected to the fitting surface, so that the connection between the flank of the outer ring and the fitting surface attacks the fitting surface of the housing, causing excessive surface pressure. Can be prevented.

The flank is provided so that even when a maximum radial load is applied to the rolling bearing, the flank and the fitting surface of the housing do not come into contact with each other and a radial gap is secured between the flanks. It is preferable to form it.

By doing so, it is possible to reliably suppress the creep phenomenon even when the radial load applied to the rolling bearing is large.

In the bearing device of the present invention, two or more flanks are formed at one of the raceway ring and the mating member to which the raceway ring is squeezed at intervals in the circumferential direction. Even when the direction of the radial load applied to the rolling bearing fluctuates, such as when the rotational load is applied to the rolling bearing, the deformation of the waveform of the raceway ring is less likely to be transmitted to the housing as a traveling wave, effectively creeping. It is possible to suppress the phenomenon.

A partial cross-sectional view showing a bearing device according to an embodiment of the present invention. Sectional view taken along line II-II of FIG. Partial cross-sectional view showing an outer ring taken out from the bearing device shown in FIG. Enlarged view of the vicinity of the flank in FIG. The figure which shows the state which the vertical upward radial load is applied to the rolling bearing shown in FIG. The figure which shows the state which the direction of the radial load applied to the rolling bearing is rotated from the direction shown in FIG. Sectional drawing which shows the bearing apparatus which concerns on other embodiment of this invention.

1 and 2 show a bearing device according to an embodiment of the present invention. This bearing device has a shaft 1, a housing 2 that surrounds the outer periphery of the shaft 1, and a rolling bearing 3 that supports a radial load between the shaft 1 and the housing 2.

The shaft 1 is a rotation shaft in which rotation is input from a rotation drive source (automobile engine, etc.) (not shown). On the other hand, the housing 2 is a non-rotating fixing member. A cylindrical housing hole 4 is formed in the housing 2, and a rolling bearing 3 is incorporated in the housing hole 4.

The rolling bearing 3 includes an inner ring (inner raceway ring) 5 fitted to the outer periphery of the shaft 1, an outer ring (outer raceway ring) 6 coaxially arranged on the radial outer side of the inner ring 5, and an inner ring 5 and an outer ring 6. It has a plurality of rolling elements 7 incorporated at intervals in the circumferential direction, and a cage 8 for holding the circumferential spacing of the plurality of rolling elements 7. The rolling element 7 is a ball.

As shown in FIG. 2, on the outer periphery of the inner ring 5, an inner ring raceway groove 9 with which the rolling element 7 rolls and contacts, and an inner ring shoulder portion 10 located on both sides of the inner ring raceway groove 9 in the axial direction are formed. Also on the inner circumference of the outer ring 6, an outer ring raceway groove 11 with which the rolling element 7 rolls and contacts, and an outer ring shoulder portion 12 located on both sides of the outer ring raceway groove 11 in the axial direction are formed. The inner ring raceway groove 9 and the outer ring raceway groove 11 are both grooves having an arcuate cross section.

The inner ring 5 is squeezed around the outer circumference of the shaft 1. That is, the inner ring 5 has a cylindrical fitting surface 13 formed on the inner circumference of the inner ring 5, and the shaft 1 has a cylindrical fitting surface 14 formed on the outer periphery of the shaft 1, and the inner ring 5 has a cylindrical fitting surface 14. The fitting surface 13 and the fitting surface 14 of the shaft 1 are fitted with a tightening margin. Here, in the state before the inner ring 5 is attached to the outer circumference of the shaft 1, the inner diameter of the fitting surface 13 on the inner circumference of the inner ring 5 is smaller than the outer diameter of the fitting surface 14 on the outer circumference of the shaft 1.

The outer ring 6 is fitted in the housing hole 4 of the housing 2. That is, the housing 2 has a cylindrical fitting surface 15 formed on the inner circumference of the housing hole 4, and the outer ring 6 has a cylindrical fitting surface 16 formed on the outer circumference of the outer ring 6. The fitting surface 15 of the housing and the fitting surface 16 of the outer ring 6 are fitted with a gap (a small annular gap). Here, in the state before fitting the outer ring 6 into the housing hole 4, the outer diameter of the fitting surface 16 on the outer circumference of the outer ring 6 is smaller than the inner diameter of the fitting surface 15 on the inner circumference of the housing hole 4.

As shown in FIG. 3, on the outer periphery of the outer ring 6, two or more flanks 17 extending in the circumferential direction are spaced apart from each other so as to divide the fitting surface 16 in the circumferential direction. In the figure, three are formed at 120 ° intervals. It is preferable that the flanks 17 are provided on the outer periphery of the outer ring 6 at equal intervals in the circumferential direction in a range of 3 or more and 6 or less.

As shown in FIG. 2, a radial gap 18 is formed between the flank 17 of the outer ring 6 and the fitting surface 15 of the housing 2. The radial gap 18 has a thin crescent shape. The radial dimension of the radial gap 18 gradually decreases from the circumferential center of the radial gap 18 toward both ends in the circumferential direction, and the radial dimension of the circumferential center of the radial gap 18 is the fitting surface of the outer ring 6. It is larger than the radial dimension of the gap (annular microgap) set between the fitting surface 15 of the housing 2 and the housing 2. The radial gap 18 is a space in which no member exists.

As shown in FIG. 4, the flank 17 is a convex arcuate curved surface formed so as to pass radially inside the fitting surface 16 of the outer ring 6 (the position of the alternate long and short dash line in the figure). .. Both ends of the flank 17 in the circumferential direction are smoothly connected to the fitting surface 16. That is, both end portions of the flank surface 17 in the circumferential direction have a shape having the contour of a curve (for example, an arc curve, a logarithmic curve, etc.) having a curvature larger than the central portion in the circumferential direction of the flank surface 17, and the flank surface 17 is formed. Both ends of the flank 17 in the circumferential direction are smoothly connected to the fitting surface 16 so that an edge does not occur at the boundary of the fitting surface 16.

The radial depth δ of the flank 17 with respect to the radial position of the fitting surface 16 of the outer ring 6 (the position of the alternate long and short dash line in the figure) is the flank 17 even when the rolling bearing 3 is loaded with the maximum radial load. The housing 2 is formed in such a size that a radial gap 18 (see FIG. 2) is secured between the flank surface 17 and the fitting surface 15 without contacting the fitting surface 15. The maximum radial load is, for example, a basic static radial rated load. The basic static radial rated load is that when the rolling element 7 is a ball, the contact stress at the center of the contact portion between the rolling element 7 and the outer ring raceway groove 11 that receives the maximum load when the rolling bearing 3 is loaded with the static radial load is 4. It is a static radial load such that it becomes .2 GPa.

As shown in FIG. 3, the circumferential length of the flank 17 can be defined by the angle α around the center of the outer ring 6. As shown in FIG. 1, the angle α corresponding to the circumferential length of the flank 17 is the rolling element 7 when the pitch angle of the rolling elements 7 corresponding to the arrangement intervals of the adjacent rolling elements 7 is θ. It is preferable to set the pitch angle θ to 0.5 times or more. This makes it possible to effectively block the deformation of the waveform of the outer ring 6 from being transmitted to the housing 2 as a traveling wave. Further, the angle α corresponding to the circumferential length of the flank 17 is preferably set to 2.0 times or less (preferably 1.0 times or less) the pitch angle θ of the rolling element 7. As a result, it is possible to suppress the deflection of the outer ring 6 when a radial load is applied.

In this bearing device, since two or more flanks 17 are formed on the outer ring 6 at intervals in the circumferential direction, a load is applied to the rolling bearing 3 as in the case where a rotational load is applied to the rolling bearing 3. Even when the direction of the radial load is changed, the deformation of the waveform of the outer ring 6 is difficult to be transmitted to the housing 2 as a traveling wave, and the creep phenomenon can be effectively suppressed.

That is, as shown in FIG. 5, when the radial load F is loaded from the shaft 1 to the inner ring 5, a load load region W is generated in the direction in which the radial load F is loaded. In this load-bearing region W, the radial load F loaded from the shaft 1 to the inner ring 5 is transmitted to the outer ring 6 via the rolling element 7 (see FIG. 1), and the outer ring 6 is deformed into a waveform. Then, as shown in FIGS. 5 and 6, when the direction of the radial load F loaded on the inner ring 5 from the shaft 1 rotates, the load load region W generated in the direction in which the radial load F is loaded is also the radial load F. It moves in the circumferential direction according to the rotation of. Here, in the bearing device of this embodiment, since two or more flanks 17 are formed on the outer ring 6 at intervals in the circumferential direction, the load load region W may move to any position. The load-bearing region W tends to overlap the position of the flank 17, and the deformation of the waveform of the outer ring 6 is difficult to be transmitted to the housing 2 as a traveling wave. Therefore, it is possible to effectively suppress the creep phenomenon.

It is preferable that three or more flanks 17 are provided on the outer periphery of the outer ring 6 at equal intervals in the circumferential direction. In this way, even when the direction of the radial load F loaded on the rolling bearing 3 fluctuates and the load load region W constantly moves, one of the flanks 17 always enters the load load region W. It can be maintained and the creep phenomenon can be effectively suppressed. It is also possible to provide three or more flanks 17 unevenly on the outer circumference of the outer ring 6. In this case, regardless of the direction in which the radial load F is loaded, the flank surface 17 may be arranged so that at least one flank surface 17 is included in the load load region W due to the radial load F.

Further, it is preferable that the number of flanks 17 provided on the outer periphery of the outer ring 6 at equal intervals in the circumferential direction is 6 or less. By doing so, it is possible to secure the circumferential length of each flank 17, so that it is possible to effectively block the deformation of the waveform of the outer ring 6 from being transmitted to the housing 2 as a traveling wave. Become.

As shown in FIG. 4, this bearing device adopts a convex arcuate curved surface formed so as to pass radially inside the fitting surface 16 of the outer ring 6, so that the outer ring 6 has a curved surface. The radial wall thickness of the outer ring 6 is reduced by forming the flank 17 as compared with the case where a flat flank or a concave arc shape is adopted as the flank 17 formed on the outer periphery. It can be suppressed. Therefore, it is possible to suppress the deflection of the outer ring 6 when the radial load F is applied.

Further, as shown in FIG. 4, in this bearing device, both ends of the flank surface 17 in the circumferential direction are smoothly connected to the fitting surface 16, so that the connection portion between the flank surface 17 and the fitting surface 16 of the outer ring 6 is formed. It is possible to prevent excessive surface pressure from being generated by attacking the fitting surface 15 of the housing 2.

Further, even when the maximum radial load is applied to the rolling bearing 3, this bearing device escapes so that the flank 17 and the fitting surface 15 do not come into contact with each other and a radial gap 18 is secured between them. Since the surface 17 is formed, it is possible to reliably suppress the creep phenomenon even when the radial load F applied to the rolling bearing 3 is large.

In the above embodiment, of the outer ring 6 and the housing 2 that are fitted to each other due to the clearance fit, the flank 17 is formed on the outer ring 6, but the flank 17 may be formed on the housing 2 instead of the outer ring 6. good. That is, in the housing 2, two or more flanks 17 extending in the axial direction of the fitting surface 15 are formed at intervals in the circumferential direction so as to divide the fitting surface 15 of the housing 2 in the circumferential direction. May be adopted.

Further, in the above embodiment, the rolling bearing 3 in which the outer ring 6 and the housing 2 are fitted in a crevice fit is taken as an example, but the present invention is based on the crevice fit between the inner ring 5 and the shaft 1. It can also be applied to a rolling bearing 3 that fits. In this case, a flank 17 is formed on one of the inner ring 5 and the shaft 1 which are fitted to each other due to the clearance fit.

Specifically, as shown in FIG. 7, the inner ring 5 is spaced in the circumferential direction from the flanks 17 extending over the entire axial width of the fitting surface 13 so as to divide the fitting surface 13 of the inner ring 5 in the circumferential direction. It is possible to adopt a configuration in which two or more (three in the figure) are formed. In this way, even when the direction of the radial load F loaded on the rolling bearing 3 fluctuates, as in the case where the rotational load is loaded on the rolling bearing 3, the deformation of the waveform of the inner ring 5 is the axis as a traveling wave. It is difficult to transmit to 1, and it is possible to effectively suppress the creep phenomenon. Further, a configuration is adopted in which two or more flanks 17 extending over the entire axial width of the fitting surface 14 are formed on the shaft 1 at intervals in the circumferential direction so as to divide the fitting surface 14 of the shaft 1 in the circumferential direction. You can also do it.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Shaft 2 Housing 3 Rolling bearing 5 Inner ring (track ring)
6 Outer ring (orbital ring)
13, 14, 15, 16 Fitting surface 17 Escape surface 18 Radial gap

Claims

Axis (1) and
The housing (2) surrounding the outer circumference of the shaft (1) and
A rolling bearing (3) that supports a radial load between the shaft (1) and the housing (2) is provided.
The rolling bearing (3) has a raceway ring fitted with a mating member which is one of the shaft (1) and the housing (2).
In a bearing device having a cylindrical fitting surface in which the raceway ring and the mating member are fitted to each other.
On one of the raceway ring and the mating member, flanks (17) extending in the axial direction of the fitting surface so as to divide the fitting surface of the member in the circumferential direction are spaced apart from each other in the circumferential direction. A bearing device characterized in that two or more bearing devices are formed.
The bearing device according to claim 1, wherein the flank (17) is formed on the raceway ring.
The mating member is the housing (2).
The bearing device according to claim 2, wherein the raceway ring is an outer ring (6).
The bearing device according to claim 3, wherein the flank (17) is provided on the outer periphery of the outer ring (6) at equal intervals in the circumferential direction in a range of 3 or more and 6 or less.
According to claim 3 or 4, the flank surface (17) is a convex arcuate curved surface formed so as to pass radially inside the fitting surface (16) of the outer ring (6). The described bearing device.
The bearing device according to any one of claims 3 to 5, wherein both ends of the flank surface (17) in the circumferential direction are smoothly connected to the fitting surface (16) of the outer ring (6).
The flank surface (17) is in contact with the clearance surface (17) and the fitting surface (15) of the housing (2) even when the maximum radial load is applied to the rolling bearing (3). The bearing device according to any one of claims 3 to 6, which is formed so as to secure a radial gap (18) between the two.