JP2007292163A - Split type roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the vibration of a bearing during operation, resulting from unequal distribution of rollers along the circumferential direction of a cage. <P>SOLUTION: In a pocket portion 43 nearest an circumferential end face 42 of each split portion 41 of the cage 30, a roller 44a is rollably retained whose diameter is larger than that of a roller 44b rollably retained in the other pocket portion 45 of the cage 40. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a split roller bearing for rotatably supporting a crankshaft of an automobile engine, for example, in which a race and a cage are divided at least in the circumferential direction.

  Conventionally, as a bearing for supporting a crankshaft of an automobile engine, a split sliding bearing divided into two has been mainly used due to restrictions on assembly. However, the split type plain bearing has a high frictional resistance under high speed rotation. For this reason, in recent years, there has been a movement to improve fuel efficiency by adopting roller bearings with low frictional resistance.

  Here, when the bearing ring and the cage of the roller bearing are divided into two to form a split roller bearing, vibration during bearing operation becomes a problem. That is, in the split roller bearing, increasing the number of rollers can reduce vibration, so it is desirable to increase the number of rollers. However, on the other hand, when the number of rollers is increased, in the cage, the width of the column between the pocket portions that hold the rollers in a rollable manner is reduced.

Therefore, like the split roller bearing 100 shown in FIG. 3, the rollers 101 are unevenly distributed in the circumferential direction, and when the split portion 103 of the cage 102 passes through the load zone during the operation of the bearing 100, FIG. As shown in FIG. 4, there is a problem that the load distribution fluctuates and vibration due to the fluctuation occurs.
FIG. 3 is a cross-sectional view showing a conventional split roller bearing, and FIG. 4 is a graph showing changes in the displacement amount of the rotating shaft with respect to changes in the rotation angle of the cage of the split roller bearing of FIG.

  Therefore, referring to FIGS. 5 and 6, for example, as disclosed in Patent Document 1, in the plate material N forming the cage 111 of the roller bearing 110, the width of the column Na at both end portions (both sides of the divided portion). By making P / 2 narrower than the width P of the other pillar portion Nb, uneven distribution along the circumferential direction of the roller 112 is suppressed.

FIG. 5 is an exploded perspective view of a principal part showing the periphery of a cam shaft of a cylinder head to which the roller bearing disclosed in Patent Document 1 is applied, and FIG. 6 is a plate material forming a cage of the roller bearing of FIG. FIG.
Japanese Patent Laying-Open No. 2005-180459 (pages 5 to 7, FIGS. 2 and 7)

  However, in the conventional roller bearing 110 shown in FIG. 5 and FIG. 6 described in Patent Document 1 described above, the width P / 2 of the column part Na on both sides of the divided part in the cage 111 is made larger than the width P of the other column part Nb. Even if it is narrowed, there is a problem that the uneven distribution along the circumferential direction of the rollers 112 cannot be suppressed to a level that does not adversely affect the bearing performance. In addition, from the viewpoint of maintaining the strength of the cage 111, there is a limit in reducing the width of the column portion Na.

  An object of the present invention is to provide a split-type roller bearing capable of reducing vibration during bearing operation caused by uneven distribution of rollers along the circumferential direction of a cage.

The above object of the present invention is achieved by the following configurations.
(1) In the split roller bearing in which the raceway and the cage of the roller are divided at least in the circumferential direction,
The diameter of the roller that can be rolled in the pocket portion provided in the vicinity of each divided portion of the cage is larger than the diameter of the roller that can be rolled in the other pocket portion of the cage. Split roller bearing.

  (2) The maximum diameter of the rollers that are rollably held in pocket portions provided in the vicinity of the respective divided portions of the cage, and the rollers that are rollably held in other pocket portions of the cage. The split roller bearing according to (1), wherein the diameter gradually decreases as the distance from each split portion increases.

  In the split roller bearing described in the above (1), the diameter of the roller that is rollably held in the pocket portion provided in the vicinity of each split portion of the cage can be rolled in another pocket portion of the cage. Therefore, the displacement amount of the rotating shaft that is supported when each divided portion of the cage passes through the load zone is compensated by the roller having a larger diameter than the other portions in the vicinity of the divided portion.

Therefore, the amount of displacement of the rotating shaft that is supported when each divided portion of the cage passes through the load zone is approximately equal to the amount of displacement of the rotating shaft when a portion other than each divided portion of the cage passes through the load zone. To be suppressed. Thereby, the vibration during the bearing operation due to the uneven distribution of the rollers along the circumferential direction of the cage is reduced.
It is preferable that the difference between the diameter of the roller in the vicinity of the divided portion and the diameter of the other roller corresponds to the amount of displacement of the rotating shaft supported when each divided portion of the cage passes through the load zone.

  In the split roller bearing described in (2) above, the diameter of the roller held in a rollable manner in a pocket provided in the vicinity of each divided portion of the cage is maximized, and the roller is rolled into another pocket portion of the cage. Since the diameter of the roller held so as to move is gradually reduced as the distance from each divided portion increases, the displacement of the rotating shaft when each divided portion of the cage passes through the load zone. The amount is made more uniform. Thereby, the vibration during the bearing operation due to the uneven distribution of the rollers along the circumferential direction of the cage is reduced.

  According to the split roller bearing of the present invention, the amount of displacement of the rotating shaft that is supported when each divided portion of the cage passes through the load zone, and when the portion other than each divided portion of the cage passes through the load zone. The amount of rotation of the rotating shaft can be suppressed to be substantially the same, and the vibration during the bearing operation due to the uneven distribution of the rollers along the circumferential direction of the cage can be reduced.

  The split roller bearing obtained by the present invention is suitably used for supporting a crankshaft of an automobile engine when low vibration, high load resistance, and high durability are required.

Hereinafter, the present invention will be described with reference to illustrated embodiments.
FIG. 1 is a sectional view showing a split roller bearing according to a first embodiment of the present invention.

  Referring to FIG. 1, the split roller bearing 30 includes a plurality of rollers 44 a and 44 b arranged in the circumferential direction, and an annular outer ring (track ring) 12 having a raceway surface 12 a of each roller 44 a and 44 b on the inner circumference. And a retainer 40 that is disposed on the inner peripheral side of the outer ring 12 and holds the rollers 44a and 44b in a rollable manner, and is used as a bearing that supports a crankshaft (not shown) of an automobile engine. It is done.

  The split roller bearing 30 has the outer ring 12 and the cage 40 equally divided into two in the circumferential direction, and can be rolled to the pocket portion 43 closest to the circumferential end face 42 in each divided portion 41 of the cage 40. The diameter of the roller 44a held by the roller 44a is larger than the diameter of the roller 44b held by the other pocket portion 45 of the cage 40 so as to be able to roll. The roller is made of a material such as bearing steel or ceramic.

  Here, in the conventional split roller bearing 100 shown in FIG. 3, the calculated amount of displacement of the rotating shaft (not shown) supported when each divided portion 103 of the cage 102 passes through the load zone is shown in FIG. As shown, it is about 1 μm.

  The calculation conditions of the amount of displacement of the rotating shaft (FIG. 4) when each divided portion 103 of the cage 102 of the conventional split roller bearing 100 shown in FIG. 3 passes through the load zone are as follows. FIG. 4 shows the relationship between the rotation angle of the cage 102 and the amount of vertical displacement of the rotation shaft when the rotation angle of the cage 102 in the state shown in FIG. Indicates.

Specifications of split roller bearings:
Roller diameter 4mm, Roller length 21mm, Number of rollers 26 (28 equally spaced), PCD 54mm, Radial clearance 30μm
Operating conditions for split roller bearings:
Radial load 5000N, rotation speed 2000rpm

  When the diameters of the rollers are all the same as in the prior art, as shown in FIG. 4, the displacement of the shaft when the divided portion of the cage passes through the load zone, the portion other than the cage divided portion passes through the load zone. It is derived from calculations based on Hertz's contact theory that it is about 1 μm larger than the case. Therefore, in the first embodiment, the diameter of the rollers 44a arranged in the pockets 43 on both sides of the dividing portion 41 shown in FIG. 1 is set to be 1 μm larger than the diameter of the rollers 44b arranged in the other pockets 45. And when the division | segmentation part 41 of the holder | retainer 40 passes a load zone, the part which the displacement of an axis | shaft increases is canceled and it was made equivalent to the case where parts other than the division | segmentation part 41 of the holder | retainer 40 pass a load zone. Thereby, the effect of reducing the vibration of the bearing 30 is obtained.

  According to 1st Embodiment, the diameter of the roller 44a hold | maintained so that rolling to the pocket part 43 nearest to the circumferential direction end surface 42 in each division part 41 of the holder | retainer 40 is the other pocket part of the holder | retainer 40. By forming the roller 44b so as to be able to roll on 45 by 1 μm larger than the diameter of the roller 44b, the displacement amount of the rotating shaft to be supported when each divided portion 41 of the cage 40 passes through the load zone is compensated. Therefore, the amount of displacement of the rotating shaft that is supported when each divided portion 41 of the cage 40 passes through the load zone is the displacement of the rotary shaft when a portion other than each divided portion 41 of the cage 40 passes through the load zone. Suppressed approximately equivalent to the amount.

  Similarly, when the bearing specifications and operating conditions are different, calculate the amount by which the shaft displacement increases when the cage divider passes through the load zone based on the bearing specifications and operating conditions. It is only necessary to increase the diameter of the rollers arranged on both sides of the divided portion.

  In the first embodiment, one roller 44a is formed for each end face 42 in the vicinity of each divided portion 41. However, a plurality of rollers 44a may be set for each end face 42. For example, the roller 44b adjacent to the roller 44a in the vicinity of the dividing portion 41 may have a diameter 1 μm larger than the other rollers 44b.

FIG. 2 is a sectional view showing a split roller bearing according to a second embodiment of the present invention.
As shown in FIG. 2, the diameter of the roller 64a that is rotatably held in the pocket portion 63 provided in the vicinity of each divided portion 61 of the cage 60 is maximized, and the other pocket portion 65 of the cage 60 is provided. You may comprise so that the diameter of the roller 64b hold | maintained so that rolling is possible may become small gradually as it leaves | separates from each division part 61. FIG. In other words, the diameter of the rollers may gradually increase as approaching each divided portion 61.

  For example, when the number of rollers that receive a load when the divided portion comes into the load zone is four (two on one side) and the displacement amount at this time is 1 μm, the diameter of the roller 64a in the vicinity of the divided portion is The diameter of the other roller 64b is increased by 1 μm, and the diameter of the roller 64b adjacent to the roller 64a in the vicinity of the divided portion is increased by 0.5 μm than the diameter of the other roller 64b. In other words, depending on the amount of displacement when the split section comes into the load zone and the number of large diameter rollers in the load zone, a gradually decreasing value of the diameter of the large diameter roller is set, and the diameter of the roller near the split section is set to other rollers. The other rollers in the load range are linearly changed in diameter. In the above case, the diameter of the roller 64b adjacent to the roller 64a in the vicinity of the divided portion is 0.5 μm obtained by dividing the displacement amount of 1 μm by the number of 2 rollers in the load range, and is larger than the other rollers 64b. According to such a configuration, the amount of displacement of the rotating shaft is made more uniform.

  As described above, according to the first embodiment, the diameter of the roller 44 a that is rotatably held in the pocket portion 43 provided in the vicinity of each divided portion 41 of the cage 40 of the split roller bearing 30 is as follows. It is larger than the diameter of the roller 44b held in the other pocket part 45 of the holder | retainer 40 so that rolling is possible.

  Further, according to the second embodiment, the diameter of the roller 64a that is rotatably held in the pocket portion 63 provided in the vicinity of each divided portion 61 of the cage 60 of the split roller bearing 50 is maximized, The diameter of the roller 64b held so as to be able to roll in the other pocket portion 65 of the cage 60 gradually decreases as the distance from each divided portion 61 increases.

  Accordingly, the amount of displacement of the rotating shaft that is supported when each of the divided portions 41 and 61 of the cages 40 and 60 passes through the load zone, and the portion other than each of the divided portions 41 and 61 of the cage 40 and 60 has the load zone. The amount of displacement of the rotating shaft when passing can be suppressed to be approximately the same. As a result, vibration during operation of the bearings 30 and 50 due to uneven distribution of the rollers 44a and 64a along the circumferential direction of the cages 40 and 60 can be reduced.

It is sectional drawing which shows the split-type roller bearing which is 1st Embodiment of this invention. It is sectional drawing which shows the split roller bearing which is 2nd Embodiment of this invention. It is sectional drawing which shows the conventional split roller bearing. It is a graph which shows the displacement amount change of a rotating shaft with respect to the rotation angle change of the holder | retainer of the split-type roller bearing of FIG. It is a principal part disassembled perspective view which shows the surroundings of the cam shaft of the cylinder head to which the roller bearing currently disclosed by patent document 1 is applied. It is a top view which shows the board | plate material which forms the holder | retainer of the roller bearing of FIG.

Explanation of symbols

30, 50, 100 Split-type roller bearings 44a, 64a Rollers 44b, 64b Rollably held in pockets closest to the circumferential end face Rollers 12, 72 raceways held in other pockets Ring (outer ring)
12a, 72a Track surface 40, 60, 102 Cage 41, 61, 103 Dividing part 42, 62 Circumferential end face 43, 63 Pocket part in the vicinity of the circumferential end face (the pocket part closest to the circumferential end face)
45,65 Other pockets

Claims (2)

In the split roller bearing in which the raceway and the cage of the roller are divided into at least two parts in the circumferential direction,
The diameter of the roller that can be rolled in the pocket portion provided in the vicinity of each divided portion of the cage is larger than the diameter of the roller that can be rolled in the other pocket portion of the cage. Split roller bearing.   The diameter of the roller that can be rolled in the other pocket portion of the cage is maximized with the diameter of the roller that is rollably held in the pocket portion provided in the vicinity of each divided portion of the cage, 2. The split roller bearing according to claim 1, wherein the roller type gradually decreases as the distance from each split portion increases.

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