JP4466473B2 - Rolling bearing - Google Patents

Description

  The present invention relates to a rolling bearing, and more particularly to a rolling bearing capable of preventing creep that occurs on a fitting surface between a bearing ring and a mating member.

  It is necessary to fix the rolling bearing around the inner ring and the outer ring to the housing with an appropriate fit, or to prevent rotation with an appropriate member such as a pin or resin, and this rotation prevention is insufficient. This creates a harmful slip called creep in the circumferential direction on the mating surface. When this creep occurs, various troubles such as abnormal heat generation, wear of the fitting surface, intrusion of wear powder into the bearing, vibration, etc. are caused.

  In particular, in a rolling bearing used under a high load condition, such as a shaft support bearing of an automobile transmission, creep occurs between the outer peripheral surface of the outer ring, which is a fixed ring, and the housing, and the outer ring and the housing are There is a problem of wear.

For such creep, conventionally, an annular member such as a resin ring is interposed between the outer peripheral surface of the outer ring and the housing (see, for example, Patent Document 1).
JP-A-6-159375

  However, as described above, in the case where an annular member such as a resin is interposed between the outer ring and the housing, the annular member may be compressed and broken by a large load. It is difficult to reliably prevent creep that occurs in rolling bearings used under high load conditions.

  An object of the present invention is to effectively suppress creep generated on a fitting surface between a fixed ring and its counterpart member even in a rolling bearing used under high load conditions.

  The inventors of the present invention have studied a mechanism in which creep occurs between a fixed ring, for example, an outer ring, and a housing that is a counterpart member thereof. It has been found that creep occurs due to relative slip due to elastic displacement of the contact area of the outer peripheral surface of the outer ring with the mating member (housing) when passing.

The rolling bearing according to the present invention was created based on the above knowledge, and in the fitting surface of the rolling bearing with the mating member of the fixed ring, the fixed ring or the mating surface of the mating member has a raceway width of the stationary ring. A clearance groove for preventing creep having a width not exceeding the width of the clearance groove is formed, and the depth of the clearance groove is the maximum amount of elastic deformation in the radial direction of the portion where the clearance groove is formed (maximum amount of deformation that can be elastically deformed). It is characterized by being set as follows .

  When the fixed ring is an outer ring, a clearance groove for preventing creep is formed on the outer peripheral surface of the outer ring or the inner peripheral surface of the mating member (housing). When the fixed ring is an inner ring, the inner peripheral surface or shaft of the inner ring An escape groove is formed on the outer peripheral surface of the.

  In the rolling bearing configured as described above, when the rolling element passes through the raceway surface of the fixed ring under a high load, the mating member and The maximum elastic displacement of the contact area occurs.

  In the present invention, there is a clearance groove on the fitting surface side of the raceway surface forming portion, and the clearance surface is spatially separated by this clearance groove so that the raceway surface formation portion and the counterpart member (housing or shaft) do not directly contact each other. Therefore, the elastic displacement of the raceway surface forming portion of the fixed ring is hardly transmitted to the counterpart member. For this reason, generation | occurrence | production of the creep by the fitting surface of a fixed ring and its mating member is suppressed.

  In the rolling bearing having the above-described configuration, it is desirable that the fixed ring is thick. More specifically, the thickness of a portion of the fixed ring excluding the relief groove and the formation portion of the raceway surface corresponds to that of the rotating ring. It is desirable that it is formed thicker than the thickness of the part.

  In this way, if the fixed ring on which the relief groove is formed is thick, the rigidity of the fixed ring increases due to the thick wall, so that the pulsation displacement of the fixed ring itself due to the pressure contact rolling of the rolling element can be suppressed. Combined with the above-described transmission blocking effect of the pulsation displacement of the escape groove, the creep between the fixed ring and its counterpart member is more effectively suppressed.

If the depth of the escape groove is limited as described above, if the escape groove forming portion of the fixed ring is greatly deformed to the side of the counterpart member such as the housing due to a high load, the deformed portion is received by the counterpart member. Therefore, excessive deformation of the clearance groove forming portion beyond that is suppressed, so that plastic deformation and breakage of the clearance groove forming portion due to high load can be prevented in advance, and therefore use of a bearing at high load is possible. Is possible.

  According to the present invention, it is possible to suppress creep that occurs between the fixed ring and its counterpart member even under high load conditions.

  Hereinafter, the best mode of the present invention will be described with reference to FIG. In the best embodiment, the present invention is applied to a deep groove ball bearing, and FIG. 1 is a half sectional view of the deep groove ball bearing according to the best embodiment.

  In FIG. 1, reference numeral 1 denotes the entire deep groove ball bearing. The deep groove ball bearing 1 includes an outer ring 2, an inner ring 3, a ball 4, a cage 5, and a seal 6. In the present embodiment, the outer ring 2 is a fixed ring and is fitted to the inner periphery of the fitting hole of the housing 7. The inner ring 3 is fitted on the outer peripheral surface of a shaft 8 that is rotationally driven as a rotating wheel.

  The outer ring 2 has a raceway surface 2 a on which the balls 4 roll on the inner periphery, and a clearance groove 9 is formed on the entire outer periphery which is a fitting surface with the housing 7. The escape groove 9 is for preventing creep generated between the outer ring 2 and the housing 7, and is provided at a position corresponding to the radial direction of the raceway surface 2a. A value smaller than the width Wa of 2a is set (Wa> Wb).

  Further, the depth D of the escape groove 9 is set so that the escape groove 9 is deformed by the pressure contact of the balls 4 with the outer ring raceway surface 2a (the part where the escape groove 9 is formed among the respective parts in the width direction of the outer ring 2). More specifically, the depth is set to be equal to or less than the maximum elastic deformation amount in the radial direction of the portion where the relief groove 9 is formed. In short, when the part where the escape groove 9 is formed is deformed in the radial direction by the rolling contact of the balls 4 to the outer ring raceway surface 2a, if the deformation amount exceeds a predetermined amount (the amount corresponding to the depth D of the escape groove 9), A part of the portion where the escape groove 9 is formed contacts the housing 7 and can be received. Specifically, in the deep groove ball bearing, the depth D of the escape groove 9 is set within a range of 0.01 mm at the minimum and 1.0 mm at the maximum.

  Furthermore, in the present embodiment, the outer ring 2 is formed thick, and the thickness To of the portion of the outer ring 2 excluding the formation portions of the clearance groove 9 and the raceway surface 2a is a corresponding portion of the inner ring 3 (track). It is formed thicker than the thickness Ti of the portion excluding the formation portion of the surface 3a (To> Ti). In this case, the outer ring 2 may be increased on the outer diameter side without changing the pitch circle diameter (PCD) of the balls 4, or the outer ring 2 may be increased on the inner diameter side while reducing the PCD.

  In the deep groove ball bearing 1 having the above-described configuration, when the inner ring 3 rotates under a large rotational load, the outer ring 2, particularly, the formation portion of the raceway surface 2 a pulsates and displaces as the ball 4 rolls. There is a clearance groove 9 on the outer peripheral side of the raceway surface 2a formation site, and the raceway 2a formation site and the housing 7 are spatially separated by this escape groove 9, so that the pulsation displacement of the raceway surface 2a formation site Is hardly transmitted to the housing 7 and the occurrence of creep between the outer ring 2 and the housing 7 is suppressed.

  Further, since the outer ring 2 is formed to be thick, the rigidity is large, and the pulsation displacement of the entire outer ring 2 due to the press-contact rolling of the ball 4 is suppressed. Also from this point, the creep between the outer ring 2 and the housing 7 is more effectively suppressed.

  Further, when a high load is applied, the portion of the outer ring 2 where the escape groove 9 is formed tends to be greatly deformed to the housing 7 side. However, since the depth D of the escape groove 9 is limited, the deformed portion is inside the escape groove 9. And is received by the inner peripheral surface of the housing 7, and further deformation of the portion where the escape groove 9 is formed is suppressed. This prevents plastic deformation and breakage of the portion where the relief groove 9 is formed, and allows the use of the bearing with a high load.

  More specifically, as described above, the occurrence of creep is based on the relative mechanism by the elastic displacement of the contact area of the fitting surface, so that the counterpart member (the housing 7 in this embodiment) is deformed by the deformation of the escape groove 9. Escape in advance so that the surface pressure in contact with the outer surface of the outer ring 2 that is a fixed ring is equal to or less than the surface pressure of the shoulders of the outer surface of the outer ring 2 (the outer surface of the outer ring 2 on both sides of the escape groove 9). If the depth and width of the groove 9 are set, the relative slip amount between the deformed portion of the escape groove 9 and the groove shoulder portion of the outer peripheral surface of the outer ring 2 becomes almost the same, so that the load just below the ball 4 that is a rolling element Thus, a large surface pressure (elastic displacement) is not produced only at the portion where the raceway surface 2a is formed, and the deformation of the escape groove 9 can be received by the mating member, thereby preventing a decrease in strength of the escape groove 9 portion. Improve creep resistance performance Reluctant, so that can also ensure strength.

  Next, the results of experiments conducted to find the above configuration and the results of model analysis will be described with reference to the relationship diagrams of FIGS.

  In the experiment, three types of deep groove ball bearings 1 having different outer ring 2 thicknesses are prepared as A, B, and C3 series samples, and the outer ring 2 has no escape groove 9 for each of the various deep groove ball bearings 1. The outer ring 2 was made to have relief grooves 9 with different widths.

  That is, the A series sample is a deep groove ball bearing of a predetermined standard (model number 62122RS), and has an outer diameter of 110 mm and a PCD of 87 mm. The A-series samples include those in which the outer ring 2 does not have the escape grooves 9 and those in which the outer ring 2 has the respective relief grooves 9 having a width of 4 mm, 6 mm, 8 mm, 10 mm, and 12 mm.

  The B series sample is a deep groove ball bearing in which the wall thickness To of the outer ring 2 is increased by 1 mm to the outer diameter side from the A series sample, and the PCD is 87 mm and the outer diameter is 112 mm. The B-series samples include those in which the outer ring 2 does not have the escape grooves 9 and those in which the outer ring 2 has the relief grooves 9 having a width of 4 mm, 6 mm, and 8 mm.

  The C series sample is a deep groove ball bearing in which the wall thickness To of the outer ring 2 is increased by 1 mm (2 mm in total) both on the inner diameter side and the outer diameter side compared to the A series sample, and the PCD is reduced accordingly. The outer diameter is 112 mm and the PCD is 85 mm. The C-series samples include those in which the outer ring 2 does not have the escape grooves 9 and those in which the outer ring 2 has the relief grooves 9 having a width of 4 mm, 6 mm, and 8 mm.

  When the experiment was carried out using the samples of each of the A, B, and C series on a test apparatus, results as shown in FIG. 2 were obtained. FIG. 2 is a relationship diagram showing the relationship between the width Wb of the escape groove 9 and the amount of slip in the circumferential direction (creep amount). The horizontal axis indicates the groove width (mm), and the vertical axis indicates the circumference near the maximum load portion. The maximum amount of sliding in the direction (μm) is taken.

  From the results shown in FIG. 2, it can be seen that in any series of samples, the greater the width Wb of the relief groove 9, the smaller the slip amount in the circumferential direction, which is effective against creep. Further, when the results are seen for each series, it can be seen that the thicker the wall thickness To of the outer ring 2 is, the smaller the amount of slip in the circumferential direction is, which is effective against creep.

  Next, a sample of the A series was selected as a representative example from the samples of the A, B, and C series, and the stress generated in the outer ring 2 was determined by model analysis for each sample of the A series. The result as shown in FIG. FIG. 3 is a diagram showing the relationship between the width Wb of the relief groove 9 and the main stress inside the outer ring 2. The horizontal axis indicates the groove width (mm), and the vertical axis indicates the maximum main stress maximum value (MPa) near the maximum load portion. ).

  From the results shown in FIG. 3, it can be seen that the stress (maximum principal stress maximum value) at the center of the raceway surface 2a increases as the width Wb of the escape groove 9 increases. In this model, when the groove width exceeds 6 mm, the stress also exceeds 1000 MPa, and when the groove width Wb exceeds the width Wa of the raceway surface 2a, the stress is further increased, and plastic deformation and breakage are caused. The potential for this is great. In this way, when the width Wb of the escape groove 9 becomes wider and exceeds the width Wa of the raceway surface 2a, the stress increases further because the escape groove 9 and the raceway surface 2a overlap in the radial direction inside and outside. This is probably because a thin portion is formed between the groove 9 and the raceway surface 2a, and stress is concentrated on this portion. Therefore, generally, if the width Wb of the escape groove 9 is within the range of the width Wa of the outer ring raceway surface 2a so that the overlap between the escape groove 9 and the raceway surface 2a is reduced, the maximum of the outer ring 2 is achieved. It can be estimated that the maximum principal stress in the vicinity of the load portion does not become excessive, and the plastic deformation and breakage of the outer ring 2 can be prevented.

<Other embodiments>
In the above embodiment, the inner ring rotation type deep groove ball bearing 1 is provided with the escape groove 9 for preventing creep on the outer peripheral surface of the outer ring 2 which is a fixed ring, but the outer ring rotation type bearing is shown in FIG. In addition, a relief groove may be formed on the inner peripheral surface of the inner ring which is a fixed ring.

  FIG. 4 is a half sectional view of a deep groove ball bearing according to another embodiment. The deep groove ball bearing 1 of this embodiment is an outer ring rotating type, and the inner ring 3 is fitted on the outer periphery of the stationary shaft 8 as a fixed ring. On the inner peripheral surface that is the fitting surface of the inner ring 3, an escape groove 10 for preventing creep is formed over the entire periphery. The width Wd of the relief groove 10 is set to a width that does not exceed the width Wc of the raceway surface 3a of the inner ring 3 as in the embodiment of FIG. It is desirable that the depth D of the escape groove 10 is set to be equal to or less than the maximum elastic deformation amount in the radial direction of the portion where the escape groove 10 is formed.

  Furthermore, it is desirable that the inner ring 3 that is a fixed ring is thick. In the example shown in the drawing, the thickness Ti of the portion of the inner ring 3 excluding the formation portions of the escape groove 10 and the raceway surface 3a is equal to that of the outer ring 2. It is formed thicker than the corresponding part thickness To.

  According to the configuration of this embodiment, the creep generated between the inner peripheral surface of the inner ring 3 and the outer peripheral surface of the shaft 8 due to the presence of the escape groove 10 in the inner periphery of the inner ring 3 and the thick inner ring 3. Is suppressed.

  Further, in the above-described embodiment, the escape ring for preventing creep is provided in the fixed ring of the bearing, but the pulsation displacement is not transmitted between the outer peripheral side of the raceway surface 2a formation portion and the housing due to the rolling of the balls 4. Needless to say, the same creep preventing effect can be obtained even if the clearance groove which is the space to be provided is provided not on the fixed ring of the bearing but on a mating member such as a housing which is a fitting surface with the fixed ring.

  The present invention is applicable not only to deep groove ball bearings but also to other types of rolling bearings such as cylindrical roller bearings and tapered roller bearings.

1 is a half sectional view of a deep groove ball bearing according to the best mode of the present invention. The relationship figure which shows the relationship between the groove width of the escape groove in the said deep groove ball bearing, and the amount of circumferential slip. The relationship figure which shows the relationship between the width | variety of the escape groove in the said deep groove ball bearing, and the main stress inside an outer ring | wheel. The half sectional view of the deep groove ball bearing concerning other embodiments of the present invention.

Explanation of symbols

1 Deep groove ball bearing 2 Outer ring (fixed ring)
2a Raceway surface 3 Inner ring (Rotating wheel)
4 ball 7 housing (mating member)
9 Relief groove Wa Outer ring raceway width Wb Escape groove width To Outer ring thickness Ti Inner ring thickness D Escape groove depth

Claims (1)

In fitting surface with the mating member of the fixed ring of the rolling bearing, said the fitting surface of the stationary ring or the mating member, the anti-creep for clearance groove width of the range not exceeding the orbital plane width of the stationary ring is formed, the relief A rolling bearing characterized in that the depth of the groove is set to be equal to or less than the maximum elastic deformation amount in the radial direction of the clearance groove forming portion .

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