JP2018091422A - Tapered roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress creeping which can occur in a fixed ring of a tapered roller bearing.SOLUTION: A tapered roller bearing 10 includes: an inner ring (fixed ring) 11 which has a conical inner ring raceway surface 21 and in which one side in an axial direction is thin; an outer ring 12 which has a conical outer ring raceway surface 31 and in which the other side in the axial direction is thin; a plurality of tapered rollers 13 interposed between the inner ring 11 and the outer ring 12; and a cage 14 for holding the plurality of tapered rollers 13. A fitting surface 40 with a shaft 2 on which the inner ring 11 is mounted has: a contact surface part 41 which comes into contact with the shaft 2; and a non-contact surface part 42 which does not come into contact with the shaft 2. The non-contact surface part 42 is shifted to the thin side of the inner ring 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tapered roller bearing.

  Tapered roller bearings have a high load capacity and are widely used in various fields. As shown in FIG. 5, the tapered roller bearing 90 includes an inner ring 91, an outer ring 92, a plurality of tapered rollers 93 interposed between the inner ring 91 and the outer ring 92, and a cage 94 that holds the tapered rollers 93. It has. For example, in a tapered roller bearing 90 for supporting the cylindrical member 98 on the outer side in the radial direction with respect to the shaft 99 so as to be rotatable, an inner ring 91 is attached to the shaft 99 so as to be fitted, and the outer ring 92 is It is attached to the inner peripheral surface 97 of the rotating cylindrical member 98.

  In the tapered roller bearing receiver 90 in which the outer ring 92 rotates, the outer ring 92 and the tubular member 98 are assembled in a “tight fit” state, whereas the inner ring 91 and the shaft 99 are assembled in a “clearance fit” state. May be. Therefore, creep (slip in the circumferential direction of the inner ring 91 with respect to the shaft 99) may occur between the inner ring 91 and the shaft 99 when the tubular member 98 is rotating together with the outer ring 92. When a large load is applied to the tapered roller bearing 90 and creep occurs, the outer peripheral surface of the shaft 99 is damaged, and maintenance for replacing the shaft 99 is required, which increases the cost.

  Therefore, as shown in Patent Document 1, a tapered roller bearing 90 in which a concave groove 96 (indicated by a two-dot chain line in FIG. 5) is formed on the inner peripheral surface 95 of the inner ring 91 is proposed. Trying to suppress.

JP 2007-78137 A

  In the tapered roller bearing 90 described in Patent Document 1, a concave groove 96 is formed in a region corresponding to the raceway surface position of the inner ring 91. That is, since the raceway surface 91 a is formed in the center in the axial direction on the outer peripheral surface of the inner ring 91, the concave groove 96 is provided in the center in the axial direction on the inner peripheral surface of the inner ring 91. In Patent Document 1, it is described that even if the inner ring 91 is deformed in a wave shape in a state where the tapered roller bearing 90 is rotating, the influence of the deformation hardly reaches the shaft 99.

  However, in the case of the tapered roller bearing 90, the thickness of the inner ring 91 is sufficiently large at the center in the axial direction of the inner ring 91 (for example, as compared with the deep groove ball bearing shown in FIGS. Even if it is not formed, the influence of the wave-like deformation in the inner ring 91 hardly affects the shaft 99. That is, even if the concave groove 96 is formed in the center of the inner ring 91 in the axial direction, the effect of suppressing creep is considered to be small. However, in the case of the tapered roller bearing 90 described in Patent Document 1, the contact area is reduced by restricting the contact between the inner ring 91 and the shaft 99 to the range on both sides of the central concave groove 96, and the contact surface pressure between them. To increase frictional resistance, which may prevent creep.

  Accordingly, an object of the present invention is to suppress creep that may occur in the fixed ring of the tapered roller bearing by technical means different from the conventional one.

  In the case of a tapered roller bearing, one side or the other side of the fixed ring in the axial direction is thin, and when a large load is applied from the tapered roller, it is likely to be distorted on the thin portion side, which is likely to cause creep. Is intended to reduce the distortion of the fixed ring that occurs on the mating member side by increasing the effective thickness on the thin part side of the fixed ring (even if the fixed ring is not thickened in the radial direction). Suppresses the generation of creep.

  That is, the present invention provides an inner ring having a conical raceway surface whose diameter increases from one side in the axial direction toward the other side on the outer peripheral side, and a thin wall on one side in the axial direction, and from one side in the axial direction toward the other side. An outer ring having a conical raceway surface having an enlarged diameter on the inner peripheral side and a thin wall on the other side in the axial direction, a plurality of tapered rollers interposed between the inner ring and the outer ring, and the plurality of tapered rollers A tapered roller bearing in which one of the inner ring and the outer ring is a rotating ring and the other is a fixed ring, and a mating surface with a mating member to which the fixed ring is attached Has a contact surface portion that comes into contact with the counterpart member and a non-contact surface portion that makes no contact with the counterpart member, and the non-contact surface portion is provided to be biased toward the thin side of the fixed ring. .

  According to this tapered roller bearing, the effective thickness from the raceway surface to the mating member can be increased on the thin side of the fixed ring. For this reason, the distortion generated in the thin portion of the fixed ring is not easily transmitted to the counterpart member, and the occurrence of creep can be suppressed.

The non-contact surface portion is formed on the counterpart member side of the thinnest portion including the thinnest contact end portion in the contact range between the tapered roller and the raceway surface of the fixed ring. Preferably, this makes it possible to effectively increase the effective thickness on the thin side of the fixed ring.

Moreover, it is preferable that the intersection part with the virtual surface defined below among the said fitting surfaces is contained in the said non-contact surface part.
Virtual surface: a surface that passes through the contact end portion on the thinnest side in the contact range between the tapered roller and the raceway surface of the fixed ring and is orthogonal to the raceway surface. The distance to the position at which the strain generated in the stationary ring causing creep is transmitted to the mating member (that is, the effective thickness at the contact end) can be increased.

  Further, the non-contact surface portion is preferably a surface formed by a change in the radial dimension from the axial end surface on the thin-walled side of the fixed ring toward the axial center side. For example, if the peripheral surface on one side or the other side in the axial direction of the fixed ring is scraped (polished) from the axial end portion, a non-contact surface portion can be formed, and the fitting surface can be easily formed.

  Moreover, it is preferable that the non-contact surface portion is constituted by a tapered surface, which makes it easier to form the non-contact surface portion.

  According to the tapered roller bearing of the present invention, the effective thickness on the thin side of the fixed ring is increased, so that the distortion generated in the thin part of the fixed ring is not easily transmitted to the mating member, and the occurrence of creep can be suppressed. It becomes.

It is sectional drawing which shows an example of the tapered roller bearing of this invention. It is an expanded sectional view showing a non-contact surface part and its circumference. It is sectional drawing which shows the other example of a tapered roller bearing. It is an expanded sectional view showing a non-contact surface part and its circumference. It is sectional drawing of the conventional tapered roller bearing.

[Configuration of tapered roller bearing]
FIG. 1 is a cross-sectional view showing an example of a tapered roller bearing of the present invention. The tapered roller bearing 10 is provided in a rotating device having a shaft 2 and a cylindrical member 3 on the outer side in the radial direction, and supports the cylindrical member 3 so as to be rotatable with respect to the shaft 2. The tapered roller bearing 10 includes an inner ring 11 that is externally fitted to the shaft 2, an outer ring 12 that is attached to the tubular member 3, and a plurality of rollers that are interposed between the inner ring 11 and the outer ring 12. A tapered roller 13 and an annular cage 14 that holds the tapered roller 13 are provided. In the tapered roller bearing 10 shown in FIG. 1, the outer ring 12 is a rotating wheel that rotates together with the cylindrical member 3, and the inner ring 11 is a fixed ring that is stationary with the shaft 2. The cross section shown in FIG. 1 is a cross section including the center line C of the tapered roller bearing 10.

  In the present embodiment, the outer ring 12 and the tubular member 3 are assembled in an “tight fit” state, and the outer ring 12 is fitted in close contact with the tubular member 3 and can rotate integrally with the tubular member 3. . On the other hand, the inner ring 11 is attached to the shaft 2 in a fixed state, but is assembled to the outer peripheral surface 4 of the shaft 2 in a “clearance fit” state. For this reason, creep (slip in the circumferential direction of the inner ring 11 with respect to the shaft 2) may occur between the inner ring 11 and the shaft 2 when the cylindrical member 3 is rotated together with the outer ring 12. The creep will be described later.

  The inner ring 11 is referred to as a conical track surface 21 (hereinafter referred to as an inner ring track surface 21) whose diameter increases from the one axial side (left side in FIG. 1) toward the other axial side (right side in FIG. 1). )have. The inner ring 11 has a small flange 22 that protrudes radially outward on one axial side of the inner ring raceway surface 21, and projects radially outward on the other axial side of the inner ring raceway surface 21. A large collar 23 is provided. The small collar portion 22 is smaller in the radial direction than the large collar portion 23. The inner peripheral surface of the inner ring 11 (the fitting surface 40 with the shaft 2) is configured by a cylindrical surface centered on the bearing center line C, except for a non-contact surface portion 42 described later. From the above, the inner ring 11 is thinner on one axial side than the other axial side. That is, the inner ring 11 is thin on one side in the axial direction except for the small flange portion 22.

  On both sides in the axial direction of the inner ring raceway surface 21, concave relief portions 29 a and 29 b that are not in contact with the tapered roller 13 are formed. For this reason, the contact range of the inner ring raceway surface 21 with the outer peripheral surface of the tapered roller 13 is a range excluding the escape portions 29a and 29b. In FIG.

  The outer ring 12 has a conical raceway surface 31 (hereinafter referred to as an outer ring raceway surface 31) whose diameter increases from one axial side to the other axial side on the inner peripheral side. The outer peripheral surface of the outer ring 12 (the fitting surface 49 with the tubular member 3) is a cylindrical surface centered on the bearing center line C. The outer ring 12 is thinner on the other axial side than the one axial side. That is, the outer ring 12 is thin on the other axial side.

  The tapered roller 13 is interposed between the inner ring 11 and the outer ring 12, and when the tapered roller bearing 10 (outer ring 12) rotates, the inner ring raceway surface 21 and the outer ring raceway surface 31 are brought into rolling contact. The tapered roller 13 has a small end surface 35 having a small diameter on one side in the axial direction, and a large end surface 36 having a large diameter on the other side in the axial direction. The tapered roller bearing 10 is in a state where a pressure is applied in the axial direction, and the large end surface 36 is in contact with a flange surface (side surface) 24 of the large flange portion 23 of the inner ring 11. When the tapered roller bearing 10 rotates, the large end surface 36 and the flange surface 24 come into sliding contact.

  The cage 14 has an annular portion 32 on one axial side, an annular portion 33 on the other axial side, and a plurality of column portions 34 connecting the annular portions 32 and 33. A pocket for accommodating the tapered roller 13 is formed between the annular portions 32 and 33 on both sides in the axial direction and between the column portions 34 and 34 adjacent in the circumferential direction.

  In the tapered roller bearing 10 shown in FIG. 1, an inner ring 11 that is a fixed ring is attached to a shaft 2 (a mating member), and an inner peripheral surface of the inner ring 11 is fitted with a fitting surface 40 with an outer peripheral surface 4 of the shaft 2. It has become. The fitting surface 40 includes a contact surface portion 41 that contacts the outer peripheral surface 4 of the shaft 2 and a non-contact surface portion 42 that does not contact the outer peripheral surface 4 of the shaft 2. The contact surface portion 41 is formed of a cylindrical surface centered on the bearing center line C. The non-contact surface portion 42 is configured by scraping off the inner peripheral portion on one side in the axial direction of the inner ring 11, and the non-contact surface portion 42 is provided so as to be biased toward the thin side that is one side in the axial direction of the inner ring 11. ing. The shape of the fitting surface 40 is the same without changing along the circumferential direction.

  FIG. 2 is an enlarged cross-sectional view showing the non-contact surface portion 42 and its periphery, and is a cross-sectional view including the bearing center line C shown in FIG. The non-contact surface portion 42 is formed by scraping (polishing) the inner circumference of one side in the axial direction of the inner ring 11 from the end portion, and the non-contact surface portion 42 is axially extended from the axial end surface 44 on the thin side of the inner ring 11. It is a surface where the radial dimension gradually changes toward the center side (the right side in FIG. 2) (a surface where the inner diameter gradually decreases). In particular, the non-contact surface portion 42 of the present embodiment is configured by a tapered surface centered on the bearing center line C. By forming the non-contact surface portion 42 into a tapered shape, it can be easily formed.

  The non-contact surface portion 42 has an inclination angle Q 1 with respect to the contact surface portion 41, and an annular minute space G is formed between the non-contact surface portion 42 and the outer peripheral surface 4 of the shaft 2. In FIG. 1 and FIG. 2 and the like showing the non-contact surface portion 42, the inclination angle Q1 (the minute space G) is greatly described in order to facilitate the description of the shape of the fitting surface 40. The inclination angle Q1 for constituting the contact surface portion 42 is small. The difference in radius between the end portion 43 on the one side in the axial direction of the non-contact surface portion 42 and the contact surface portion 41 that is cylindrical, that is, the maximum radial direction dimension of the minute space G is, for example, less than 1 mm. Although not shown, the non-contact surface portion 42 may be constituted by a concave groove. In this case as well, the non-contact surface portion 42 (concave groove) is provided to be biased toward the thin side of the inner ring 11. As will be described later, the non-contact surface portion 42 is provided to suppress slippage in the circumferential direction of the inner ring 11 with respect to the shaft 2, that is, creep.

[About creep]
The creep that occurs between the shaft 2 and the inner ring (fixed ring) 11 will be described with reference to FIG. Here, description will be made assuming that the non-contact surface portion 42 is not formed on the fitting surface 40. The following three are considered as possible creeps in the tapered roller bearing 10. In the present embodiment, the bearing rotation direction described below is the rotation direction of the outer ring 12 that is a rotating wheel.
-First creep: creep in which the inner ring 11 slips slowly in the same direction as the bearing rotation direction-Second creep: creep in which the inner ring 11 slides in the same direction as the bearing rotation direction-Third creep: reverse to the bearing rotation direction Creep that inner ring 11 slides in the direction

  The first creep is likely to occur when a large load (particularly a large radial load component) is applied to the tapered roller bearing 10, and is considered to be generated by the following mechanism. That is, when a large load is applied to the rotating tapered roller bearing 10, the tapered roller 13 comes into contact with the inner ring raceway surface 21 with a high load, so that the inner ring 11 is elastically deformed. The tapered roller 13 and the inner ring raceway surface 21 are in a line contact state, and an approximately equally distributed load acts on both. When the tapered roller bearing 10 is rotated, the tapered roller 13 is in rolling contact with the inner ring raceway surface 21 in a state where a large load is applied, so that the inner ring 11 undergoes pulsation deformation (pulsation displacement). In the case of the tapered roller bearing 10, since the inner ring 11 is thin on one side in the axial direction, distortion tends to increase on the thin portion 25 side, and pulsation deformation occurs on the inner peripheral side of the thin portion 25. Thus, if pulsating deformation has occurred on the inner peripheral side of the thin-walled portion 25, it is considered that relative slip occurs with the shaft 2 due to this, and the first creep occurs due to this relative slip. The axial center and the other axial side of the inner ring 11 (which are referred to as the thick part 26) have a sufficient thickness. Therefore, in the thick part 26, distortion due to the pulsation deformation is caused by the inner circumference of the inner ring 11. Relative slip to the shaft 2 does not occur. That is, the thick portion 26 has a large thickness (effective thickness) that is effective for the first creep suppression. From the above, in the case of the tapered roller bearing 10, it is considered that the pulsation deformation in the thin portion 25 on one axial side causes the first creep.

  The second creep is the same in the moving direction (sliding direction) of the first creep and the inner ring 11, but is likely to occur when the tapered roller bearing 10 is unloaded. That is, when there is no load, it is considered that the inner ring 11 is rotated by the rotation of the outer ring 12, thereby generating a second creep.

  In the third creep, the moving direction (sliding direction) of the inner ring 11 is opposite to that of the first and second creeps. This is because, for example, an eccentric load acts on the tapered roller bearing 10 so that the inner ring 11 has the shaft 2. It is considered that the vibration occurs due to swinging along the outer peripheral surface 4.

[Configuration for suppressing first creep]
Similarly to the thick portion 26 of the inner ring 11, the thin portion 25 may be increased in thickness (effective thickness Te) effective for the first creep suppression. Therefore, in the present embodiment, the inner ring 11 itself is not thickened, but the non-contact surface portion 42 is provided to be biased toward the thin side of the inner ring 11, and the boundary N between the non-contact surface portion 42 and the contact surface portion 41 is It is set at a predetermined position. Accordingly, in the cross section shown in FIG. 2, when the end portion on the thinnest side (hereinafter referred to as a contact end portion) in the contact range B between the tapered roller 13 and the inner ring raceway surface 21 is denoted by “M”, The distance between the contact end M and the boundary N is the (minimum) effective thickness Te in the thin portion 25. By bringing the position of the boundary N closer to the thick wall side, the effective wall thickness Te in the thin wall portion 25 can be made equal to the wall thickness Tc in the central portion 27 in the axial direction of the inner ring 11. In the case of the wall thickness Tc in the central portion 27, even if the inner ring 11 is pulsated and deformed, the inner portion of the central portion 27 is not distorted and relative slip with respect to the shaft 2 does not occur. As described above, the non-contact surface portion 42 is provided so as to be biased toward the thin side of the inner ring 11, and the boundary N is set at a predetermined position, so that the effective thickness effective in suppressing creep in the thin portion 25. Te can be increased.

  Here, in the case of the conventional example shown in FIG. 5, the distortion caused by the pulsating deformation of the inner ring 91 in the thin portion 91b is the thinnest contact end in the contact range B between the tapered roller 93 and the inner ring raceway surface 91a. It affects the position P that is linearly directed radially inward from the portion M. For this reason, the distance from the contact end portion M to the point P immediately below it is the thickness (effective thickness Ta) of the thin portion 91b in the conventional example. When comparing the inner ring 11 of the present embodiment shown in FIGS. 1 and 2 with the inner ring 91 (without the concave groove 96) of the conventional example shown in FIG. 5, the shape is the same except for the presence or absence of the non-contact surface portion 42. The effective thickness Te of this embodiment is larger than the effective thickness Ta of the conventional example. As described above, according to the present embodiment, the effective thickness Te can be increased without increasing the minimum thickness t (in the contact range B) of the inner ring 11.

  In the present embodiment (see FIG. 1), the non-contact surface portion 42 is formed in a region including the point P (see FIG. 5) as described above. That is, a region where the distortion due to the pulsating deformation that may cause the first creep does not reach the inner peripheral side of the inner ring 11 (the inner peripheral region of the thick portion 26) is defined as the contact surface portion 41 that contacts the shaft 2. In addition, a region of the thin portion 25 in which distortion due to the pulsation deformation may occur on the inner peripheral side is a non-contact surface portion 42 that is not in contact with the shaft 2.

  In order to increase the effective thickness Te, the contact surface portion 41 and the non-contact surface portion 42 are located closer to the thicker side than the intersection line X2 between the virtual surface K indicated by a two-dot chain line in FIG. What is necessary is just to set the range (axial direction range) of the non-contact surface part 42 so that the boundary N may be located. The virtual surface K is a surface that passes through the contact end M on the thinnest side in the contact range B between the tapered roller 13 and the inner ring raceway surface 21 and is orthogonal to the inner ring raceway surface 21. That is, in order to make the effective thickness Te larger than that of the conventional example, the boundary N may be positioned on the thicker side than the intersecting line X2, and thereby, the virtual surface K of the fitting surface 40 can be obtained. The crossing portion (intersection line) X1 is included in the non-contact surface portion 42.

  Thus, in this embodiment, the non-contact surface part 42 which is non-contacting with the axis | shaft 2 among the fitting surfaces 40 with respect to the axis | shaft 2 of the inner ring | wheel 11 is provided in the thin-walled side of the inner ring | wheel 11. And the non-contact surface part 42 is formed in the inner peripheral side (shaft 2 side) of the thinnest part 25a where the inner ring | wheel 11 is the thinnest. The thinnest portion 25 a is a portion included in the thin portion 25. More specifically, the thinnest wall portion 25a is a portion including the contact end portion M, and more specifically, a portion on a virtual plane that passes through the contact end portion M and is orthogonal to the bearing center line C. .

  When a large load is applied to the tapered roller bearing 10, the region on the inner peripheral side of the thin portion 25 of the inner ring 11 is further elastically deformed (reduced in diameter) in the radial direction, but this region is the non-contact surface portion 42. Accordingly, this elastic deformation (diameter reduction) occurs in the range of the non-contact surface portion 42. For this reason, the elastic deformation in the thin portion 25 of the inner ring 11 is not transmitted to the shaft 2 (almost), and the occurrence of the first creep between the inner ring 11 and the shaft 2 is suppressed.

  As described above, in the case of the tapered roller bearing 10, one side in the axial direction of the inner ring 11 serving as a fixed ring is thin, and when a large load is applied from the tapered roller 13 to the inner ring 11, the thin portion 25 side tends to be distorted. According to the configuration of the embodiment, the effective thickness Te on the thin portion 25 side of the inner ring 11 is increased without increasing the inner ring 11 in the radial direction (without increasing the minimum thickness t in the contact range B). be able to. Thereby, the distortion of the inner ring 11 generated on the side of the shaft 2 becomes difficult to be transmitted to the shaft 2, and the occurrence of the first creep can be suppressed. As a result, it is possible to prevent wear caused by the inner ring 11 sliding on the shaft 2.

[Other types of tapered roller bearings]
In the above-described embodiment, the case where the inner ring 11 is a fixed ring and the outer ring 12 is a rotating ring has been described. However, the configuration in which the non-contact surface portion 42 is included in the fitting surface 40 is as described above. Can be applied to tapered roller bearings in which one of them is a rotating wheel and the other is a fixed ring. That is, FIG. 3 is a cross-sectional view showing another example of the tapered roller bearing 10. In this tapered roller bearing 10, the inner ring 11 is a rotating ring and the outer ring 12 is a fixed ring. In this case, the inner ring 11 and the shaft 2 are assembled in a “tight fit” state, and the inner ring 11 can rotate integrally with the shaft 2. On the other hand, the outer ring 12 is attached to the cylindrical member 3 in a fixed state, but is assembled to the inner peripheral surface 5 of the cylindrical member 3 in a “clear fit” state. Therefore, creep (slip in the circumferential direction of the outer ring 12 with respect to the tubular member 3) may occur between the outer ring 12 and the tubular member 3 when the shaft 2 is rotated together with the inner ring 11.

  This creep is the same type as the first creep, and is generated by pulsation deformation in the thin portion 55 on the other axial side of the outer ring 12. In addition, since the axial center and the other axial side of the outer ring 12 (which are referred to as the thick part 56) have a sufficient thickness, distortion due to pulsation deformation of the outer ring 12 occurs in the thick part 56. It does not extend to the outer peripheral side. That is, the thick portion 56 has a large thickness (effective thickness) effective for the first creep suppression.

  The tapered roller bearing 10 shown in FIG. 3 has the same configuration as that of the above-described embodiment (see FIG. 1) in order to suppress the first creep. That is, the outer peripheral surface of the outer ring 12 is a fitting surface 49 with the inner peripheral surface 5 of the tubular member 3, and the fitting surface 49 is formed of a contact surface portion 61 that comes into contact with the tubular member 3 and a tubular shape. It has the non-contact surface part 62 used as the member 3 and non-contact. The non-contact surface portion 62 is configured by a tapered surface as in the above-described embodiment. The non-contact surface portion 62 has an inclination angle Q <b> 2 with respect to the contact surface portion 61, and an annular minute space G is formed between the non-contact surface portion 62 and the inner peripheral surface 5 of the tubular member 3. Yes.

  In the thin portion 55 on the other axial side of the outer ring 12, the non-contact surface portion 62 is biased toward the thin side of the outer ring 12 in order to increase the thickness (effective thickness Te) effective for the first creep suppression. The boundary N between the non-contact surface portion 62 and the contact surface portion 61 is set at a predetermined position. That is, in the cross section shown in FIG. 4, if the end (contact end) on the thinnest side in the contact range B between the tapered roller 13 and the outer ring raceway surface 31 is denoted by “M”, the contact end M and The distance from the boundary N is the (minimum) effective thickness Te in the thin portion 55. By setting the boundary N at a predetermined position, it is possible to increase the effective thickness Te that is effective for suppressing creep in the thin portion 55.

  In order to increase the effective wall thickness Te, the contact surface portion 61 and the non-contact surface portion 61 are arranged on the thicker side than the intersection line X2 between the virtual surface K indicated by a two-dot chain line and the inner peripheral surface 5 of the cylindrical member 3 in FIG. What is necessary is just to set the range (axial direction range) of the non-contact surface part 62 so that the boundary N with the contact surface part 62 may be located. The virtual surface K is a surface that passes through the contact end M on the thinnest side in the contact range B between the tapered roller 13 and the outer ring raceway surface 31 and is orthogonal to the inner ring raceway surface 21. That is, in order to increase the effective thickness Te, the boundary N may be positioned on the thicker side than the intersecting line X2, and thereby the intersection of the fitting surface 49 with the virtual surface K. (Intersection line) X <b> 1 is included in the non-contact surface portion 62.

  As described above, in the embodiment shown in FIGS. 3 and 4, the non-contact surface portion 62 that is not in contact with the shaft 2 out of the fitting surface 49 of the outer ring 12 with respect to the tubular member 3 is provided on the thin side of the outer ring 12. It has been. Moreover, the non-contact surface portion 62 is formed on the outer peripheral side (tubular member 3 side) of the thinnest wall portion 55a including the contact end portion M. The thinnest portion 55 a is a portion included in the thin portion 55. More specifically, the thinnest portion 55a is a portion including the contact end portion M, and more specifically, a portion on a virtual plane that passes through the contact end portion M and is orthogonal to the bearing center line C. .

  As described above, in the case of the tapered roller bearing 10 shown in FIG. 3, the other side in the axial direction of the outer ring 12 serving as a fixed ring becomes thin. Although it is easy, according to the said structure, the effective thickness Te in the thin part 55 side of the outer ring | wheel 12 can be enlarged, without thickening the outer ring | wheel 12 to radial direction. Thereby, the distortion of the outer ring 12 generated on the cylindrical member 3 side becomes difficult to be transmitted to the cylindrical member 3, and the occurrence of the first creep can be suppressed. As a result, it is possible to prevent wear due to sliding of the outer ring 12 with respect to the tubular member 3.

[Others]
The embodiments disclosed above are illustrative in all respects and not restrictive. That is, the tapered roller bearing of the present invention is not limited to the illustrated form, but may be of another form within the scope of the present invention. For example, the shape of the cage 14 may be different. Moreover, in the said embodiment, the case where the non-contact surface part 42 (62) was a shape (taper shape) from which the radial direction dimension changes gradually toward the axial direction center side from the axial direction end surface 44 (64) was demonstrated. However, it may be a shape whose radial dimension changes stepwise (not shown).

2: Shaft (mating member) 3: Cylindrical member (mating member) 10: Tapered roller bearing 11: Inner ring 12: Outer ring 13: Tapered roller 14: Cage 21: Inner ring raceway surface 25: Thin part 25a: Thinnest part 31 : Outer ring raceway surface 40: fitting surface 41: contact surface portion 42: non-contact surface portion 44: axial end surface 49: fitting surface 55: thin wall portion 55a: thinnest wall portion 61: contact surface portion 62: non-contact surface portion 64: axial direction End surface B: Contact range K: Virtual surface M: Contact end portion Te: Effective thickness X1: Intersection

Claims (5)

An inner ring having a conical raceway surface that expands from one side in the axial direction toward the other side on the outer peripheral side, and one side in the axial direction is thin;
An outer ring having a conical raceway surface that expands from one side in the axial direction toward the other side on the inner peripheral side, and the other side in the axial direction is thin;
A plurality of tapered rollers interposed between the inner ring and the outer ring;
A cage for holding the plurality of tapered rollers,
A tapered roller bearing in which one of the inner ring and the outer ring is a rotating ring and the other is a fixed ring,
The mating surface with the mating member to which the fixed ring is attached has a contact surface portion that comes into contact with the mating member, and a non-contact surface portion that is in non-contact with the mating member,
The non-contact surface portion is a tapered roller bearing provided so as to be biased toward the thin side of the fixed ring.   The said non-contact surface part is formed in the said other member side of the thinnest part including the contact end part of the thinnest side among the contact ranges of the said tapered roller and the said track surface of the said fixed ring. Tapered roller bearings described in 1. The tapered roller bearing according to claim 1, wherein an intersecting portion of the fitting surface with a virtual surface defined below is included in the non-contact surface portion.
Virtual plane: a plane that passes through the contact end on the thinnest side and is orthogonal to the raceway surface in the contact range between the tapered roller and the raceway surface of the fixed ring   The said non-contact surface part is a surface comprised when the radial direction dimension is changing toward the axial direction center side from the axial direction end surface by the side of the thin wall of the said fixed ring. Tapered roller bearings as described in the section.   The tapered roller bearing according to any one of claims 1 to 4, wherein the non-contact surface portion is configured by a tapered surface.

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