JP2008045597A - Tapered roller bearing and pilot portion shaft supporting structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tapered roller bearing applicable to a pilot portion of a transmission, reducing sliding resistance when there is a self-rotating speed difference between the small diameter side and the large diameter side of a roller, and reducing torque loss due to the flowing resistance of lubricating oil while utilizing the skew preventing property of the roller-split tapered roller bearing. <P>SOLUTION: In pockets 4a provided at a plurality of circumferential positions on a cage 4, the plurality of rollers 3A, 3B are arranged side by side in the axial direction. The plurality of rollers 3A, 3B arranged side by side in the axial direction have outer peripheral faces which are tapered faces different in diameter to approximately form a common virtual tapered face. A small end face 3Ab of the roller 3A on the large diameter side or a large end face 3Ba of the roller 3B on the small diameter side is spherical, and it is made at its self-rotation axial center in point contact with the large end face 3Ba of the roller 3B on the small diameter side or the small diameter face 3Ab of the roller 3A on the large diameter side. A molybdenum-disulfide coating film is formed on the surface of each of the rollers 3A, 3B. In each of the pockets 4a of the cage 4, a cutout is provided at a columnar portion 4d on the narrow side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tapered roller bearing that is used in various devices and that is particularly suitable for use in a region where lubricating oil flows from the outside, and a pilot part shaft support structure for an automobile transmission equipped with the bearing.

  Tapered roller bearings for supporting the transmission pilot section of automobiles have elongated rollers due to structural limitations of the transmission, and as a condition of use, misalignment is large and there is a portion corresponding to the outer ring raceway surface. It is the inner diameter surface of the gear. For this reason, durability deterioration due to roller skew, for example, so-called large collar surface seizure or seizure due to contact between the large end surface of the roller and the large collar surface of the inner ring may occur. Patent Document 1 discloses a tapered roller bearing capable of solving such problems.

  In the tapered roller bearing disclosed in Patent Document 1, each tapered roller is divided into a plurality of divided tapered rollers arranged in the length direction, and these divided tapered rollers are formed at a plurality of locations in the circumferential direction of the cage. Hold it in your pocket. The raceway surfaces of the inner ring and the outer ring are formed as one conical surface that is continuous between the axial portions corresponding to the divided rollers. With such a configuration, while maintaining the rated load without increasing the cross-sectional height, the occurrence of skew is suppressed, and even when the contact position between the roller and the raceway surface approaches the small diameter side due to misalignment, etc. Therefore, the bearing life can be improved. When this tapered roller bearing is applied to a bearing for supporting a transmission pilot part shaft, the bearing life of the pilot part bearing is improved.

  Tapered roller bearings that support power transmission shafts such as automobile differentials and transmissions are used with the lower part immersed in an oil bath, and the oil in the oil bath flows into the bearing as lubricating oil as it rotates. . In tapered roller bearings used for such applications, the lubricating oil flows into the bearing from the small diameter side of the tapered roller, and the lubricating oil flowing from the outer diameter side of the cage flows along the raceway surface of the outer ring. The lubricating oil that passes to the larger diameter side and flows from the inner diameter side to the cage passes along the raceway surface of the inner ring to the larger diameter side of the tapered roller.

In such a tapered roller bearing used for a portion where the lubricating oil flows from the outside, a notch is provided in the pocket of the cage, and the lubricating oil that flows into the outer diameter side and the inner diameter side of the cage is separated. There are some which pass through this notch and improve the flow of lubricating oil inside the bearing (Patent Documents 2 and 3). 22A, a notch 31 is provided in the central portion of the column portion 34d between the pockets 34a of the retainer 34, and foreign matter mixed into the lubricating oil is generated inside the bearing as shown in FIG. So that it does not stay. Moreover, in what was described in patent document 3, as shown in FIG.22 (B), the notch 32 is provided in the small annular part 34b and the large annular part 34c of the axial direction both ends of the pocket 34a of the holder | retainer 34, and hold | maintained. The lubricating oil flowing in from the outer diameter side of the vessel 34 is made easier to flow to the inner ring side.
JP 2003-184885 A JP-A-9-32858 (FIG. 3) No. 11-2011149 (FIG. 2)

  In the tapered roller bearing of Patent Document 1, a plurality of divided tapered rollers are in the same pocket of the cage, and the small end surface of the roller adjacent to the large end surface of the roller on the small diameter side is in surface contact. Since the rollers are in surface contact with each other in this way, when a roller skew occurs, when a difference in rotation speed occurs between the small-diameter side roller and the large-diameter side roller, slip resistance at the contact portion increases. A new problem arises that torque is likely to increase.

  Further, as described above, in the tapered roller bearing in which the lubricating oil is divided into the outer diameter side and the inner diameter side of the cage and flows into the bearing, the ratio of the lubricating oil flowing from the inner diameter side of the cage to the inner ring side increases. It was found that the torque loss increased. The reason is considered as follows.

  That is, the lubricating oil flowing from the outer diameter side of the cage to the outer ring side has no obstacles on the inner diameter surface of the outer ring, so it smoothly passes along the raceway surface to the large diameter side of the tapered roller from the inside of the bearing. The lubricating oil that flows out from the inner diameter side of the cage to the inner ring side has a large flaw on the outer diameter surface of the inner ring, so it is large when it passes along the raceway surface to the larger diameter side of the tapered roller. It will be dammed up with a lance and will be easily retained inside the bearing. For this reason, when the ratio of the lubricating oil flowing from the inner diameter side to the inner ring side of the cage increases, the amount of the lubricating oil staying inside the bearing increases, and this staying lubricating oil becomes a flow resistance against the bearing rotation and generates torque. Loss is considered to increase.

An object of the present invention is to make use of the anti-skew characteristic of a roller-separated tapered roller bearing and to reduce slip resistance when a difference in rotation speed occurs between a small-diameter side roller and a large-diameter side roller. Further, it is possible to reduce torque loss due to flow resistance of the lubricating oil in the tapered roller bearing in which the lubricating oil flows into the bearing.
Another object of the present invention is to reduce the rolling viscous resistance of a roller and to suppress an increase in torque.
Still another object of the present invention is to make it difficult for the pilot portion bearing skew to occur, to prevent the effect of skew even when misalignment occurs, and to improve the fluidity of the lubricating oil and to reduce the torque of the pilot portion. It is an object of the present invention to provide a pilot shaft support structure for a transmission that can perform transmission.

The tapered roller bearing according to the present invention includes an inner ring having small and large flanges on both sides of a raceway surface of an outer diameter surface, an outer ring having a raceway surface on an inner diameter surface, and a raceway surface between the inner ring and the outer ring. A plurality of tapered rollers arranged and a retainer that stores and retains these tapered rollers in respective pockets provided at a plurality of positions in the circumferential direction, and the retainer is disposed on the small collar side of the inner ring. A small annular portion that is continuous at the large collar side of the inner ring, and a plurality of pillars that connect these annular portions, and the pocket has a narrow circular side on the small annular portion side, a large circle The present invention is applied to a tapered roller bearing formed in a trapezoid shape where the ring side is the wide side.
In the tapered roller bearing of this precondition, a plurality of the tapered rollers are provided in the respective pockets along the axial direction, and the plurality of the rollers arranged in the axial direction substantially constitute a virtual tapered surface whose outer peripheral surface is common to each other. As described above, the rollers are conical surfaces having a difference in diameter from each other, and the rollers adjacent to each other in the axial direction have a spherical shape on the small end surface of the roller on the large diameter side and the large end surface of the roller on the small diameter side. A point contact is made on the center of the axis of rotation, and a molybdenum disulfide-based coating film is formed on at least the contact surface portion of the surface of each roller with the raceway surface, and the narrow side portion is formed in the pocket of the cage. It is characterized in that a notch is provided in the column part.

According to this configuration, each tapered roller is divided in the length direction, so that the rated load is ensured without increasing the cross-sectional height, the occurrence of skew is suppressed, and the contact between the roller and the raceway surface occurs due to misalignment. The effect of skew when the position approaches the small diameter side hardly occurs, and the bearing life can be improved. Since the small end face of the large diameter roller has a spherical shape and is in point contact with the large end face of the small diameter roller on the center of the rotation axis, there is a difference in the rotation speed of the roller. The sliding resistance at the contact portion between the rollers can be reduced, and the torque of the bearing can be reduced. Since a molybdenum disulfide-based coating film is formed on at least the contact surface portion of the surface of each roller with the raceway surface, it is possible to further reduce sliding frictional resistance, and further reduce torque, and Long life is obtained.
In addition, because the notch was provided in the narrow side column of the cage-shaped pocket of the cage, the lubricating oil flowing from the inner diameter side of the cage to the inner ring side can be used to store the small diameter side of the tapered roller. Because of the flow resistance of the lubricating oil, the amount of lubricating oil that quickly escapes from the notch to the outer ring side, decreases the amount of lubricating oil that reaches the main ring along the inner ring raceway surface, and reduces the amount of lubricating oil that stays inside the bearing. Torque loss can be reduced.

In the second tapered roller bearing of the present invention, the large end surface of the small-diameter side roller has a spherical shape, and is in point contact with the small end surface of the large-diameter side roller on the center of the rotation axis. It is different from the roller bearing, and other configurations are the same as those of the first tapered roller bearing.
Even in this configuration, by dividing the tapered roller in the length direction, while maintaining the rated load without increasing the cross-sectional height, the occurrence of skew is suppressed and the occurrence of misalignment causes the roller and raceway surface to be separated. The effect of skew is less likely to occur when the contact position approaches the small diameter side, and the bearing life can be improved. Also, the large end surface of the roller on the small diameter side has a spherical shape, and contact between the rollers when there is a difference in the rotation speed of the roller by making point contact with the small end surface of the large diameter roller on the center of the rotation axis. It is possible to reduce the slip resistance at the portion, and to reduce the torque of the bearing. Since a molybdenum disulfide-based coating film is formed on at least the contact surface portion of the surface of each roller with the raceway surface, it is possible to further reduce sliding frictional resistance, and further reduce torque, and Long life is obtained.
In addition, because the notch was provided in the narrow side column of the cage-shaped pocket of the cage, the lubricating oil flowing from the inner diameter side of the cage to the inner ring side can be used to store the small diameter side of the tapered roller. Because of the flow resistance of the lubricating oil, the amount of lubricating oil that quickly escapes from the notch to the outer ring side, decreases the amount of lubricating oil that reaches the main ring along the inner ring raceway surface, and reduces the amount of lubricating oil that stays inside the bearing. Torque loss can be reduced.

  In the present invention, a chevron-shaped crowning may be applied to the outer peripheral surface of the roller. When angled crowning is applied to the outer peripheral surface of the roller, torque increase due to skew is prevented, the rolling viscous resistance of the roller is lowered, and torque is further reduced.

  In the present invention, a mountain-shaped crowning may be applied to the raceway surface of the inner ring. Even when the inner ring raceway surface is chevron-shaped crowned, torque increase due to skew is prevented, the rolling viscous resistance of the roller is lowered, and torque is further reduced.

  The pocket may be provided with a notch in the small annular portion on the narrow side. By providing a notch in this part, the lubricating oil flowing from the inner diameter side of the cage to the inner ring side is released from the notch of this small annular part to the outer ring side, and the lubricating oil reaches the main shaft along the raceway surface of the inner ring. The amount of oil can be further reduced to further reduce torque loss due to the flow resistance of the lubricating oil.

  You may provide a notch also in the pillar part at least on the wide side of a pocket. By providing a notch in the column part on the wide side of the pocket, the tapered roller can be brought into sliding contact with the column part in a balanced manner.

  The total area of the notches provided on the narrow side of the pocket may be larger than the total area of the notches provided on the wide side of the pocket. This also makes it possible to further reduce the torque loss due to the flow resistance of the lubricating oil by reducing the amount of the lubricating oil reaching the surface along the raceway surface of the inner ring.

  The tapered roller bearing having the above-described configuration of the present invention may be used as a bearing for supporting a transmission pilot portion of an automobile. In the transmission pilot portion, the arrangement space of the bearing rolling elements is narrow due to the structural restrictions, and if it is a single roller, it is elongated and easily skewed. Therefore, by using the tapered roller bearing of the present invention as a bearing for supporting the pilot part, the advantages are effectively exhibited, and the torque in the transmission part of the automobile can be reduced and the life can be extended.

In the transmission pilot shaft support structure of the present invention, the input side shaft is rotatably supported by the housing via the bearing, the lower stage side shaft is disposed on the same axis as the input side shaft, and both shafts rotate relative to each other. In the pilot part shaft support structure of the transmission in which the pilot part bearing that is freely supported is provided between the outer periphery of the lower stage side shaft and the inner periphery of the input side shaft, the pilot part bearing is any one of the above-described configurations in the present invention This is a tapered roller bearing.
According to this configuration, in addition to the effect of preventing the skew of the tapered roller bearing in the present invention and the effect of reducing the influence of the skew when misalignment occurs, the slip at the contact portion between the rollers when a difference occurs in the rotation speed of the roller occurs. The effect of reducing the resistance, further preventing the torque increase due to skew, and suppressing the torque loss due to the flow resistance of the lubricating oil, the effect of further reducing the torque is effective, the bearing life of the pilot part bearing Will improve.

The tapered roller bearing according to the present invention has a plurality of rollers arranged in the axial direction in each pocket provided in a plurality of locations in the circumferential direction of the cage. It is a conical surface having a difference in diameter so that a common virtual conical surface is substantially configured, and the rollers adjacent to each other in the axial direction have a spherical shape on the large end surface of the roller on the small diameter side. Point contact with the small end surface of the roller on the side on the center of the rotation axis, or the large end surface of the roller on the small diameter side has a spherical shape, and the point on the small end surface of the roller on the large diameter side and the center of the rotation axis Because it is in contact, skew is maintained when the contact position between the roller and the raceway surface is closer to the smaller diameter due to misalignment, etc. The bearing life is improved. Door can be. Further, it is possible to reduce the slip resistance between the rollers when there is a difference in the rotation speed of the rollers, and it is possible to reduce the torque of the bearing. Since the surface of each roller has a molybdenum disulfide-based coating film at least on the contact surface with the raceway surface, it is possible to further reduce sliding friction resistance, further reducing torque, and extending the service life Is obtained. In addition, since the notch is provided in the narrow column of the trapezoidal pocket of the cage, the amount of lubricating oil staying in the bearing is reduced and torque loss due to the flow resistance of the lubricating oil is reduced. can do.
If the roller or inner ring raceway surface is provided with a chevron crowning, the rolling viscous resistance of the roller is lowered, and the torque can be further reduced.

  Since the pilot portion shaft support structure of the transmission of the present invention uses the pilot portion bearing as the tapered roller bearing of the present invention, the effect of preventing skew of the tapered roller bearing according to the present invention and the effect of skew when misalignment occurs are mitigated. In addition to the effect of the above, the effect of reducing the slip resistance at the contact portion between the rollers when there is a difference in the rotation speed of the rollers and the effect of reducing the torque loss due to the flow resistance of the lubricating oil are effective. Thus, the bearing life of the pilot part bearing is improved.

  An embodiment of a tapered roller bearing according to the first invention will be described with reference to FIGS. The tapered roller bearing includes an inner ring 1, an outer ring 2, a plurality of tapered rollers 3 arranged in a circumferential direction so as to be freely rollable between raceway surfaces 1a and 2a of the inner and outer rings 1 and 2, a cage 4. The inner ring 1 has a raceway surface 1a formed in a conical shape, and has large ridges 5 and small ridges 6 on the large diameter side and the small diameter side of the track surface 1a, respectively. The inner side surface of the large bowl 5 is the large bowl surface 5a. The outer ring 2 has a raceway surface 2a formed in a conical shape and has no wrinkles. The outer ring 2 may be an independent bearing part, or may also be used as another mechanical part such as a gear or a shaft. For example, when this tapered roller bearing is used as a bearing for a pilot portion of a transmission, the outer ring 2 is a component that also serves as a gear.

  This tapered roller bearing is obtained by dividing each tapered roller 3 into a plurality of divided rollers 3A and 3B arranged in the axial direction, that is, in the length direction. The number of divisions of the tapered roller 3 is two in this embodiment, but it may be divided into three divided rollers 3A, 3B, 3C as shown in FIG. 7, or may be divided into four or more. . Increasing the number of divisions is effective when the bearing width is wide. The raceway surfaces 1a and 2a of the inner ring 1 and the outer ring 2 are formed as a single conical surface extending between the axial portions corresponding to the divided rollers 3A and 3B.

In this embodiment, the end face shapes of the split rollers 3A and 3B are the large end face 3Aa of the large diameter side split roller 3A that contacts the large collar surface 5a of the inner ring 1, the large end face 3Ba and the small end face of the small diameter side split roller 3B. 3Bb has a flat surface shape.
The small end surface 3Ab of the large diameter side split roller 3A has a spherical shape, and is in point contact with the large end surface 3Ba of the small diameter side split roller 3B on the center of the rotation axis.

The outer peripheral edges of the end faces on both sides of each of the divided rollers 3A and 3B are chamfered. For the final finishing of the small end surface 3Ab of the large diameter side split roller 3A and the both end surfaces 3Ba, 3Bb of the small diameter side split roller 3B, any processing method such as header, turning or grinding may be adopted. The large end surface 3Aa of the split roller 3A on the large diameter side is ground or superfinished. The large end surface 3Aa of the large-diameter roller 3A that contacts the large flange surface 5a may be spherical, so that the oil film forming ability of the sliding portion with the large flange surface 5a is the same as that of the conventional tapered roller bearing. Can be secured.

  In FIG. 1, it is a ratio of the total length L of the tapered rollers 3, that is, the total length L of the plurality of split rollers 3A and 3B arranged in the length direction, and the maximum diameter d of the plurality of split rollers 3A and 3B. The value of (roller total length L) / (maximum diameter d) is, for example, twice or more. Since each of the divided rollers 3A and 3B is obtained by dividing the tapered roller 3 in the length direction, the divided roller 3A on the large diameter side of the inner ring raceway surface 1a has an outer diameter than the divided roller 3B on the small diameter side. Is a big one.

  The lengths L1 and L2 of the divided rollers 3A and 3B in the tapered roller 3 may be the same length or may be different from each other. The same applies to the case where the tapered roller 3 is divided into three or more. When the tapered roller 3 is divided into two, the lengths L1 and L2 of the divided rollers 3A and 3B are preferably L1 ≦ L2, and more preferably L1 <L2. That is, it is preferable that the length L2 of the split roller 3B on the small diameter side of the inner ring 1 is longer than the length L1 of the split roller 3A on the large diameter side. When the tapered roller 3 is divided into three or more, among the divided rollers 3A, 3B, 3C,... (FIG. 7), the length of the divided roller 3A arranged on the largest diameter side of the inner ring 1 is the shortest. It is preferable to do.

  Each of the split rollers 3A and 3B has a molybdenum disulfide (MoS2) -based coating film 8 formed on the surface (FIG. 4). As the molybdenum disulfide-based coating film 8, it is preferable to use sol best (trade name). In this embodiment, the coating film 8 is formed on the entire surface of the split rollers 3A and 3B, but it may be formed only on a portion where sliding contact is likely to occur. For example, it may be formed only on the end surfaces of the split rollers 3A and 3B, particularly on the large end surface of the large-diameter side split roller 3A, and on the end surfaces of the split rollers 3A and 3B that are in contact with each other. On the end surfaces of the split rollers 3A and 3B that are in contact with each other, the coating film 8 may be formed only in the vicinity of the central portion that is the contact point of the roller end surfaces.

  As shown in FIGS. 2 and 3, the cage 4 has pockets 4a for holding the tapered rollers 3 at a plurality of locations in the circumferential direction, and a plurality of divided rollers 3A and 3B arranged at the same length direction position. Are held in the same pocket 4 a of the cage 4.

  The cage 4 is connected to the small annular portion 4b that is continuous on the small diameter end side of the tapered roller 3 (that is, the small flange 6 side of the inner ring 1) and the large diameter end side of the tapered roller 3 (that is, the large flange 5 side of the inner ring 1). It consists of a large annular portion 4c and a plurality of column portions 4d that connect these small annular portion 4b and the large annular portion 4c. As a result, a trapezoidal pocket 4a is formed in which the portion storing the small diameter side of the tapered roller 3 is the narrow side and the portion storing the large diameter side is the wide side. On the narrow side and the wide side of the pocket 4a, two notches 21 and 22 are provided in the column portions 8 on both sides, respectively. The widths of the notches 21 and 22 are preferably less than or equal to half the length of the corresponding divided rollers 3A and 3B.

  As shown in FIG. 1, a radially inward flange 4ba facing the outer diameter surface of the small collar 6 of the inner ring 1 is provided outside the small annular portion 4b of the cage 4 in the axial direction. A gap a between the inner diameter surface of the flange 4ba of the small annular portion 4b and the outer diameter surface of the small flange 6 of the inner ring 1 is set narrowly to 2.0% or less of the outer diameter of the small flange 6. .

  The retainer 4 can be the same as the non-separated retainer. For example, a conventional iron plate retainer can be provided with notches 21 and 22. The method of assembling the tapered roller 3 with respect to the cage 4 also differs in that two split rollers 3A and 3B are arranged, and the tapered roller 3 can be assembled to the inner ring 1 by spreading the cage 4 and crimping. Yes. In this example, the cage 4 is made of iron plate, but may be made of resin.

In addition to the above, the cage 4 may be modified as shown in FIGS. 5 and 6, for example. In the modification shown in FIG. 5, the notch 23 is also provided in the small annular portion 4b on the narrow side of the pocket 4a, and the total area of the three notches 21, 21, 23 on the narrow side is equal to that on the wide side. The area is larger than the total area of the two notches 22 and 22.
In the modification shown in FIG. 6, the depth of each notch 21 of the narrow-side column part 4d is formed deeper than each notch 22 of the wide-side column part 4d, and each notch on the narrow side is formed. The total area of 21 and 21 is wider than the total area of the notches 22 and 22 on the wide side.

  According to the tapered roller bearing of this configuration, since each tapered roller 3 is divided in the length direction, the ratio of the roller length to the roller diameter of each of the divided rollers 3A and 3B becomes small, and the divided rollers 3A divided from each other. , 3B behave independently of each other with respect to skew. For this reason, it becomes difficult to generate the skew of the divided rollers 3A and 3B. Further, since the length L1 of the large-diameter split roller 3A in contact with the large collar surface 5a of the inner ring 1 is short, even if the contact position between the raceway surface 1a and the split roller 3A approaches the small-diameter side due to misalignment or the like, The distance between the contact position and the large flange surface 5a serving as the resistance generating portion is short, and the influence of the skew of the split rollers 3A is not easily transmitted to the large flange surface 5a. Since the split roller 3B on the small diameter side does not contact the large collar surface 5a, even if the contact position between the raceway surface 1a and the split roller 3B moves to the small diameter side, there is no influence on the large collar surface 5a. These also make it difficult for skew to occur. The small-diameter split roller 3B that does not contact the large collar surface 5a has no effect on the large collar surface 5a even if the contact position between the raceway surface 1a and the split roller 3B approaches the small-diameter side. By making the length of the split roller 3B not in contact with 5a longer than the split roller 3A on the large diameter side in contact with the large flange surface 5a, the length of the split roller 3A in contact with the length can be reduced. This is preferable for the occurrence of misalignment.

  As described above, the division of the tapered roller 3 improves the skew resistance characteristic of the roller 3 itself (characteristic that the roller tries to roll straight without generating skew), and the influence of skew due to misalignment hardly occurs. Become. In particular, when the ratio L / d between the total length L of the plurality of split rollers 3A and 3B arranged in the length direction and the maximum diameter d of the plurality of split rollers 3A and 3B is set to be twice or more, The roller non-divided bearing generates a large amount of skew. Therefore, the above-described effect of reducing the skew by dividing the tapered roller 3 is large. Although each tapered roller 3 is divided, the total length L of the divided rollers 3A and 3B aligned in the length direction is maintained to be equal as compared with the non-divided bearing, so that an equivalent load rating can be ensured. In this way, the roller length can be shortened while keeping the rated load equivalent to that of the conventional product, skew can be suppressed, and the bearing life can be improved.

  The small end surface 3Ab of the large-diameter split roller 3A has a spherical shape and is in point contact with the large end surface 3Aa of the split roller 3B on the center of the rotation axis. Even if there is a difference in the rotation speed, the sliding resistance at the contact portion between the small end surface 3Ab of the split roller 3A and the large end surface 3Ba of the split roller 3B is small, and the torque of the bearing can be reduced.

  As described above, the sliding resistance between the split rollers 3A and 3B is reduced, the effect of suppressing the occurrence of skew due to the division of the tapered rollers and the effect of making the skew less likely to be caused by misalignment, and the like. Improvement is achieved and, for example, the suitability for use as a bearing for supporting a transmission pilot portion of an automobile increases.

  Further, since the tapered roller bearing of this embodiment does not need to change the mounting shape with respect to the bearing-using device, it can be directly replaced with a conventional roller non-divided bearing with respect to the bearing-using device. Also for the components of this tapered roller bearing, the inner ring 1 and the outer ring 2 are one tapered surface in which the raceway surfaces 1a, 2a are continuous between the axial portions corresponding to the divided rollers 3A, 3B, The same as the non-divided bearing, and the same retainer 4 as the non-divided bearing can be used.

  Furthermore, in the tapered roller bearing of this embodiment, since the molybdenum disulfide-based coating film 8 is formed on the surfaces of the split rollers 3A and 3B, it is possible to further reduce the sliding friction resistance, and to further reduce the torque, and Long life is obtained. For example, the slip resistance at the contact portion between the large end surface of the large diameter side split roller 3A and the inner surface of the inner ring collar 5 or the small end surface 3Ab of the large diameter side split roller 3A and the large end surface of the small diameter side split roller 3B Slip resistance at the contact portion with 3Ba is reduced, and torque reduction and wear relaxation are obtained. Further, a minute slip between the circumferential surfaces of the split rollers 3A and 3B and the raceway surfaces 1a and 2a, which occurs when the inner and outer rings 1 and 2 are synchronously rotated and relatively stopped, and vibration or the like repeatedly acts from the outside. Slip resistance is reduced and fretting wear is reduced.

  The lubricating oil flow will be described. When this tapered roller bearing rotates at high speed and its lower part is immersed in an oil bath, as shown by the arrow in FIG. 1, the lubricating oil in the oil bath starts from the small diameter side of the tapered roller 3 to the outer diameter side and inner diameter of the cage 4. The lubricating oil that flows into the bearing and flows into the outer ring 2 from the outer diameter side of the retainer 4 passes along the raceway surface 2a of the outer ring 2 to the larger diameter side of the tapered roller 3 and is bearing. Escape from inside. On the other hand, the lubricating oil that flows from the inner diameter side of the cage 4 to the inner ring 1 side has a narrow gap a between the flange 4ba of the small annular portion 4b of the cage 4 and the small flange 6 of the inner ring 1, It is far less than the lubricating oil flowing in from the outer diameter side of the cage 4, and most of the lubricating oil flowing in from the gap a passes through the notch 21 provided in the narrow column portion 4d of the pocket 4a. Then, the cage 4 moves to the outer diameter side. Therefore, the amount of the lubricating oil that reaches the main shaft 6 along the raceway surface 1a of the inner ring 1 becomes very small, and the amount of the lubricating oil staying inside the bearing can be reduced.

  FIG. 7 shows an embodiment in which the tapered roller 3 includes three divided rollers 3A, 3B, 3C. The outer peripheral surfaces of the three divided rollers 3A, 3B, 3C are conical surfaces having a difference in diameter so as to substantially constitute a common virtual conical surface. The large end surface 3Aa of the large diameter split roller 3A that contacts the large collar surface 5a of the inner ring 1, the large end surface 3Ba of the intermediate split roller 3B that does not contact the large collar surface 5a, and the large end surface of the split roller 3C on the small collar 6 side. 3Ca and the small end surface 3Cb are flat surfaces. Further, the small end surface 3Ab of the split roller 3A on the large diameter side and the small end surface 3Bb of the intermediate split roller 3B are spherical, and rotate with the large end surface 3Ba of the split roller 3B and the large end surface 3Ca of the split roller 3C, respectively. Point contact is made on the axis center. Even when the tapered roller is divided into four or more pieces, the small end surface on the large diameter side of the adjacent divided roller is formed into a spherical shape.

As the cage 4, the example shown in FIG. 3 or FIG. 5 and FIG. 6 is used. In this case, it is preferable that the width of each of the notches 21 and 22 provided in the column portion 4d is equal to or less than half the length of the corresponding split rollers 3A and 3C.
Other configurations in this embodiment are the same as those in the first embodiment shown in FIGS.

  In this embodiment, the effect obtained when the tapered roller 3 includes the three divided rollers 3A, 3B, and 3C, and the effect obtained when the small end surface 3Ab of the divided roller 3A and the small end surface 3Bb of the divided roller 3B have a spherical shape. The effect of forming the molybdenum disulfide-based coating film 8 on each of the rollers 3A, 3B, 3C and the effect of providing the notches 21 to 23 on the cage 4 are the same as those of the first embodiment. Since it is the same as the effect mentioned, the description is abbreviate | omitted here. Further, the end face shapes of the divided rollers 3A, 3B, 3C can be changed in the same manner as described above, and it is also preferable that the outer peripheral edge of each end face is preferably chamfered.

8 to 10 show an embodiment of a tapered roller bearing according to the second invention. In this embodiment, as in the example of FIGS. 1 to 3, the tapered roller 3 is composed of two split rollers 3A and 3B, but the large end surface 3Ba of the small-diameter side split roller 3B has a spherical shape. This is different from the first embodiment shown in FIGS. 1 to 4 in that the small end surface 3Ab of the large-diameter split roller 3A is in point contact with the center of the rotation axis. Other configurations are the same as those of the first embodiment shown in FIGS.
Therefore, the effect obtained by dividing the tapered roller 3 is the same as described above. The point where the large end surface 3Ba of the small-diameter side split roller 3B has a spherical shape and is in point contact with the small end surface 3Ab of the large-diameter side split roller 3A on the center of the rotation axis is also a point contact portion of the spherical shape. The effects are the same, only the mutual relationship is different. The effect of forming the molybdenum disulfide-based coating film 8 and the effect of providing the retainers 4 with the notches 21 and 22 as described above are the same as in the first embodiment.

  Also in this embodiment, the tapered roller 3 can be divided into three as shown in the example of FIG. 11, or four or more. Also in this embodiment, the cage 4 shown in FIGS. 5 and 6 can be used.

  12 to 14 show still another embodiment of the present invention. In this embodiment, in the first embodiment shown in FIGS. 1 to 4, the shape of the rolling surfaces 3Ac and 3Bc which are the outer peripheral surfaces of the divided rollers 3A and 3B in the tapered roller 3 is a chevron crowning shape. Is. The crowning is preferably an arc-shaped crowning shape over the entire length, that is, a full crowning, and the drop amount δ is 10 μm or more. The drop amount δ is a difference in bus height caused by crowning. Other configurations in this embodiment are the same as those in the first embodiment shown in FIGS. As the cage 4, the same one as that shown in FIG. 3 is used, or one shown in FIGS. 5 and 6 is used.

In the case of this embodiment, since the shape of the rolling surfaces 3Ac, 3Bc of each of the split rollers 3A, 3B is a mountain-shaped crowning shape, the rolling viscous resistance on the raceway surfaces 1a, 2a of the split rollers 3A, 3B is reduced, and the rolling is reduced. It is possible to reduce the torque.
Other operations and effects in this embodiment are the same as those in the first embodiment.

FIG. 15 shows still another embodiment. In this embodiment, in the example in which the roller 3 shown in FIG. 7 is divided into three, the shapes of the rolling surfaces 3Ac, 3Bc, 3Cc of the divided rollers 3A, 3B, 3C are the same as those in the examples of FIGS. Yamagata crowning shape.
In the case of this embodiment, similarly to the examples of FIGS. 12 to 14, the effect of reducing the rolling viscous resistance due to the crowning shape is obtained. Other configurations and effects are the same as those of the embodiment shown in FIG.

FIG. 16 shows an embodiment in which the raceway surface is crowned. In this embodiment, the tapered roller 3 is composed of two split rollers 3A and 3B, and the large end surface 3Aa of the large-diameter side split roller 3A that contacts the large flange surface 5a of the inner ring 1 and the large split roller 3B on the small-diameter side. The end surface 3Ba and the small end surface 3Bb are flat surfaces, and the small end surface 3Ab of the split roller 3A on the large diameter side has a spherical shape so as to make point contact with the large end surface 3Ba of the split roller 3B on the center of the rotation axis. Has been made. This point is the same as the embodiment of FIG. 12, but in this embodiment, the shape of the rolling surfaces 3Ac, 3Bc of the split rollers 3A, 3B is not a chevron crowning shape, and the raceway surface 1a of the inner ring 1 is Corresponding to each of the divided rollers 3A and 3B, a chevron crowning shape composed of two rows of cross-sectional chevron-shaped annular protrusions 1aa and 1ab is formed.
Thus, when the raceway surface 1a of the inner ring 1 has a chevron crowning shape, the viscous resistance is small, as in the case where the rolling surfaces 3Ac and 3Bc of the split rollers 3A and 3B have a chevron crowning shape, It is possible to reduce the torque at the rolling part. The effect of dividing the tapered roller 3, the effect of the small end surface 3Ab of the divided roller 3A having a spherical shape, the effect of forming the molybdenum disulfide-based coating film 8, and the notch in the cage 4 The effect obtained by providing 21 and 22 is the same as that of the embodiment of FIGS.

FIG. 17 shows an embodiment in which the roller 3 is divided into three and the raceway is crowned. In this embodiment, the tapered roller 3 includes three divided rollers 3A, 3B, and 3C, and the shapes of the rolling surfaces 3Ac, 3Bc, and 3Cc of the divided rollers 3A, 3B, and 3C are not the crowning shape, and the inner ring 1 The raceway surface 1a has a crowning shape composed of three rows of annular chevron projections 1aa, 1ab, 1ac corresponding to the divided rollers 3A, 3B, 3C. The small end surface 3Ab of the split roller 3A on the large diameter side and the small end surface 3Bb of the split roller 3B have a spherical shape, and the spherical end surfaces 3Ab and 3Bb each have a large end surface 3Ba on the small diameter side 3B. Further, the point that is in point contact with the large end surface 3Ca of the split roller 3C on the center of the rotation axis is the same as the example of FIG.
Also in this embodiment, the viscous resistance is small and the torque at the rolling portion is reduced as in the case where the shape of the rolling surfaces 3Ac, 3Bc, 3Cc of the split rollers 3A, 3B, 3C is a chevron crowning shape. Is possible. Other effects are the same as in the example of FIG.

18 to 20 show still another embodiment of the present invention. This embodiment is an example in which the rolling surfaces of the divided rollers 3A and 3B are crowned in the embodiment shown in FIGS. That is, the tapered roller 3 is composed of two split rollers 3A and 3B, the large end surface 3Ba of the small diameter side split roller 3B is spherical, and the small end surface 3Ab of the large diameter side split roller 3A and the center of the rotation axis In the tapered roller bearing in point contact above, the rolling surfaces of the split rollers 3A and 3B are formed in a crowning shape. Other configurations are the same as those of the embodiment shown in FIGS.
As described above, even when the large end surface 3Ba of the small-diameter split roller 3B has a spherical shape, by making the rolling surfaces of the split rollers 3A and 3B crowned, the viscous resistance is reduced, and the rolling portion Torque can be reduced. Other effects can also be obtained in the same manner as in the above embodiments.

  Even when the large end surface 3Ba of the small-diameter split roller 3B is spherical, the roller 3 may be divided into three or more, and the raceway surface of the inner ring 1 as in the embodiment of FIGS. 1a may be a crowning shape.

  FIG. 21 shows an example of a pilot part shaft support structure of a transmission equipped with a tapered roller bearing according to an embodiment of the present invention. This transmission is a manual transmission of an automobile. An input side shaft 13 serving as an input shaft is rotatably supported by the housing 11 via a bearing 12, and a lower stage shaft 14 serving as a main shaft is disposed on the same axis as the input side shaft 13. Both shafts 13 and 14 are supported by a pilot portion bearing 15 so as to be rotatable relative to each other. The pilot portion bearing 15 is provided between the outer periphery of the lower stage side shaft 14 and the inner periphery of the input side shaft 13.

  The pilot portion bearing 15 is a tapered roller bearing according to any one of the above-described embodiments of the present invention, and in the drawings, the tapered roller bearing according to the first embodiment shown in FIGS. The inner ring 1 of the pilot portion bearing 15 is fitted and attached to the outer diameter surface of the lower stage side shaft 14. The outer ring 2 of the pilot unit bearing 15 is constituted by a hollow shaft portion provided at the shaft end of the input side shaft 13, and a gear 16 is formed on the outer periphery. That is, the outer ring 2 is configured as a part that also serves as the gear 16, and is configured integrally with the input side shaft 13. The gear 16 meshes with a gear provided on a counter shaft (not shown) parallel to the lower stage side shaft 14. The dog teeth 18 of the dog clutch 17 are integrally provided in the adjacent portion of the gear 16 of the input side shaft 13, and the rotation of the input side shaft 13 is transferred to the lower stage side shaft 14 via the dog clutch 17 having a synchronizer. It can be transmitted. Further, the rotation of the input side shaft 13 can be transmitted to the lower side shaft 14 through a transmission path (not shown) different from the above through the counter shaft.

  In the pilot portion of the transmission having such a configuration, a large load capacity is required for the pilot portion bearing 15 and the sectional height of the bearing 15 cannot be increased. Therefore, the pilot portion bearing 15 is a tapered roller bearing having a long roller length. Moreover, the pilot portion bearing 15 is likely to be misaligned due to the bending between the shafts 13 and 14. However, since the tapered roller bearing of the above embodiment is used as the pilot portion bearing 15, there is a difference in the effect of preventing the skew, the effect of reducing the influence of the skew when misalignment occurs, and the rotation speed of the split rollers 3A and 3B. In addition to the effect of reducing the sliding resistance at the contact portion between the rollers 3A and 3B when the rolling occurs, in addition to the angled crowning shape formed on the rolling surfaces 3Ac and 3Bc of the split rollers 3A and 3B or the raceway surface 1a of the inner ring 1 Thus, the effect of reducing the viscous resistance becomes effective, and the bearing life of the pilot portion bearing 15 is improved.

  In the pilot portion of the transmission shown in FIG. 21, the input side shaft 13 is an Ipput shaft, and the lower stage side shaft 14 is the main shaft. Can be generally applied to pilot section bearings provided between the outer periphery of the lower stage side shaft disposed coaxially and the inner periphery of the input side shaft. For example, in the pilot portion of the transmission of FIG. 21, the lower shaft 14 is divided in the axial direction into a pilot shaft and a main shaft, which are upper and lower shafts, and a pilot portion bearing (see FIG. (Not shown), the tapered roller bearing of the present invention may be used for the pilot portion bearing.

It is sectional drawing of the tapered roller bearing concerning one Embodiment of 1st invention. It is a partial expanded view which shows the relationship between the holder | retainer and a tapered roller. It is a partial expanded view of the cage. It is sectional drawing which shows the detail of the split roller in the embodiment. It is a partial expanded view of the modification of a holder | retainer. It is a partial expanded view of the other modification of a holder | retainer. It is sectional drawing which shows the detail of the split roller in other embodiment. It is sectional drawing of the tapered roller bearing concerning one Embodiment of 2nd invention. It is a partial expanded view which shows the relationship between the holder | retainer and the tapered roller in the embodiment. It is sectional drawing which shows the detail of the split roller in the embodiment. It is sectional drawing which shows the detail of the split roller in other embodiment. It is sectional drawing of the tapered roller bearing concerning other embodiment. It is a partial expanded view which shows the relationship between the holder | retainer and a tapered roller. It is sectional drawing which shows the detail of the split roller in the embodiment. It is sectional drawing which shows the detail of the split roller in other embodiment. It is sectional drawing which shows the detail of the split roller in other embodiment. It is sectional drawing which shows the detail of the split roller in other embodiment. It is sectional drawing of the tapered roller bearing concerning other embodiment. It is a partial expanded view which shows the relationship between the holder | retainer and a tapered roller. It is sectional drawing which shows the detail of the split roller in the embodiment. It is sectional drawing of the pilot part shaft support structure of the transmission which applied the tapered roller bearing concerning embodiment of this invention. It is a partial expanded view of each example of the conventional cage.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inner ring 1a ... Race surface 3 of inner ring ... Tapered roller 3A ... Split roller (cone roller on large diameter side)
3Aa: Large end face 3Ab of large diameter side tapered roller ... Small end face 3B of large diameter side tapered roller: Split roller (small diameter tapered roller)
3Ba: Large end face 3Bb of the small diameter side tapered roller 4 Small end face 4 of the small diameter side tapered roller 4 ... Cage 4a ... Pocket 4b ... Small annular portion 4c ... Large annular portion 4d ... Column 8 ... Coating film 11 ... Housing 12 ... Bearing 13 ... Input side shaft 14 ... Lower stage side receiver 15 ... Pilot part bearings 21 to 23 ... Notches

Claims (9)

An inner ring provided with small and large flanges on both sides of the raceway surface of the outer diameter surface, an outer ring provided with a raceway surface on the inner diameter surface, and a plurality of tapered rollers arranged between the raceway surfaces of the inner ring and the outer ring And a retainer that stores and holds these tapered rollers in respective pockets provided in a plurality of locations in the circumferential direction, and the retainer includes a small annular portion that is continuous on the small collar side of the inner ring, and an inner ring. And a plurality of pillars connecting the annular portions, and the pocket is a trapezoid in which the small annular portion side is a narrow side and the large annular portion side is a wide side. For tapered roller bearings
A plurality of the tapered rollers are provided side by side in the axial direction in each pocket, and the plurality of rollers arranged in the axial direction have a difference in diameter from each other so that the outer peripheral surfaces substantially constitute a common virtual tapered surface. Conical surfaces of rollers that are adjacent to each other in the axial direction. The small end surface of the large diameter roller has a spherical shape, and is in point contact with the large end surface of the small diameter side roller on the center of the rotation axis. A molybdenum disulfide-based coating film is formed on at least a contact surface portion with the raceway surface on the surface of each roller, and a notch is provided in the column portion at the narrow side portion in the pocket of the cage. Tapered roller bearings characterized by that. An inner ring provided with small and large flanges on both sides of the raceway surface of the outer diameter surface, an outer ring provided with a raceway surface on the inner diameter surface, and a plurality of tapered rollers arranged between the raceway surfaces of the inner ring and the outer ring And a retainer that stores and holds these tapered rollers in respective pockets provided in a plurality of locations in the circumferential direction, and the retainer includes a small annular portion that is continuous on the small collar side of the inner ring, and an inner ring. And a plurality of pillars connecting the annular portions, and the pocket is a trapezoid in which the small annular portion side is a narrow side and the large annular portion side is a wide side. For tapered roller bearings
A plurality of the tapered rollers are provided side by side in the axial direction in each pocket, and the plurality of rollers arranged in the axial direction have a difference in diameter from each other so that the outer peripheral surfaces substantially constitute a common virtual tapered surface. Conical surface of rollers that are adjacent to each other in the axial direction. The large end surface of the small-diameter roller has a spherical shape, and is in point contact with the small end surface of the large-diameter roller on the center of the rotation axis. A molybdenum disulfide-based coating film is formed on at least a contact surface portion with the raceway surface on the surface of each roller, and a notch is provided in the column portion at the narrow side portion in the pocket of the cage. Tapered roller bearings characterized by that.   The tapered roller bearing according to claim 1 or 2, wherein an outer peripheral surface of the roller is chevron-shaped crowned.   The tapered roller bearing according to any one of claims 1 to 3, wherein a raceway surface of the inner ring is provided with a chevron-shaped crowning.   The tapered roller bearing according to any one of claims 1 to 4, wherein a notch is provided in the small annular portion on the narrow side in the pocket.   The tapered roller bearing according to any one of claims 1 to 5, wherein a notch is provided at least in a column portion at a wide side portion in the pocket.   The tapered roller bearing according to claim 6, wherein the total area of the notches provided on the narrow side of the pocket is wider than the total area of the notches provided on the wide side of the pocket.   The tapered roller bearing according to any one of claims 1 to 7, wherein the tapered roller bearing is used as a bearing for supporting a transmission pilot portion of an automobile.   The input side shaft is rotatably supported via a bearing in the housing, the lower stage side shaft is disposed on the same axis as the input side axis, and the pilot section bearing that supports both shafts so as to be relatively rotatable is a lower stage side shaft. In the pilot portion shaft support structure of the transmission provided between the outer periphery of the transmission and the inner periphery of the input side shaft, the pilot portion bearing is the tapered roller bearing according to any one of claims 1 to 7. A pilot shaft support structure for the transmission.

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