JP2007032768A - Roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller bearing capable of maintaining good lubrication at a contact portion between a roller head and an inner ring large collar surface and preventing seizure.
A roller 4 is provided with a lubricating oil holding structure for holding a lubricating oil 14. The lubricating oil retaining structure is a plurality of circumferential concave grooves 41 or a plurality of holes 42 provided in through holes 40 that are open on both axial end surfaces of the roller 4. The lubricating oil retaining structure is a cylindrical deep countersunk hole 44, 45 provided so as to open on one end surface or both end surfaces of the roller 4, and the open end portion is formed by the deep countersunk hole. The cross-sectional area is smaller than the back side.
[Selection] Figure 1

Description

  TECHNICAL FIELD The present invention relates to a roller bearing that constitutes a rotation support portion of a mechanical device in general, such as a railway vehicle drive device, an axle, and a differential gear of an automobile. In particular, the amount of lubricating oil is small in the rotation support portion of these vehicle transmissions. The present invention relates to an improvement for preventing seizure and galling that occurs in a roller bearing when it is depleted in a short time, when it is depleted in a short time, or when a lubricating device fails.

  Conventionally, roller bearings are incorporated in the rotation support portions of various mechanical devices, but cylindrical rollers, tapered rollers, or spherical rollers are used as rolling elements of the roller bearings so that the rotation support portions can withstand a large load. It is used.

  As an example of such a roller bearing incorporated in a rotation support portion to which a large radial load and an axial load are applied, a tapered roller bearing is shown in FIGS. In FIG. 1, a tapered roller bearing 10 includes an outer ring 2 having a conical concave outer ring raceway 2a on an inner peripheral surface, an inner ring 3 having a conical convex inner ring raceway 3a on an outer peripheral surface, and the outer ring raceway 2a and the inner ring raceway. 3a, and a plurality of tapered rollers 4 provided so as to be freely rollable by a cage 7. The outer peripheral surface of each of these tapered rollers 4 is a conical convex rolling surface 4b that contacts the outer ring raceway 2a and the inner ring raceway 3a. The inner ring 3 is formed with a large-diameter side collar 3b at the large-diameter end and a small-diameter collar 3d at the small-diameter end of both ends of the outer peripheral surface.

Each of the tapered rollers 4 of the tapered roller bearing 10 as described above is rotated together with the cage 7 while rotating while being rotated toward the large diameter side of the outer ring raceway 2a and the inner ring raceway 3a as shown in FIG. Revolution allows the outer ring 2 and the inner ring 3 to freely rotate relative to each other. During the operation of the tapered roller bearing 10, the head 4 a that is the large-diameter side end surface of each tapered roller 4 and the inner surface 3 c of the large-diameter flange 3 b of the inner ring 3 (see also FIG. The surface 3c) is in contact with an elliptical contact portion 8 as shown by an oblique grid in FIG. .
This is also known as Hertz's elastic contact theory.

  However, in the conventional tapered roller bearing 10, the contact state at the contact portion 8 between the head 4 a of the tapered roller 4 and the inner ring large collar surface 3 c is a rolling contact with sliding, which is severe from the viewpoint of suppressing friction. Therefore, if the amount of lubricating oil supplied to the bearing 10 is too small or exhausted, damage such as seizure may be caused.

  Such damage such as seizure may occur not only in the tapered roller bearing 10 but also in other types of roller bearings, but the conditions are the most severe and damage is likely to occur as described above. It can be said that it is a contact portion 8 between the head 4a of the tapered roller 4 and the inner ring large collar surface 3c.

  Such seizure is likely to occur in railway vehicles and automobiles, particularly when starting at low temperatures in winter. During running of railway vehicles and automobiles, the lubricating oil splashes and lubricates the roller bearings due to the stirring effect of the oil accompanying the rotation of the shaft, etc. The lubricating oil remaining on the raceway surface can maintain the lubricating effect. However, if it stops once and restarts after a considerable amount of time, the lubricant will drop from the raceway due to gravity over time, and there will be no lubricant left for start-up. May occur.

  In this configuration, the amount of the lubricating oil 14 may be lowered in order to reduce the amount of the lubricating oil 14 used and the stirring resistance of the lubricating oil 14. For this reason, even if the lubricating oil 14 can be supplied to the tapered roller bearing by splashing at the time of rotation, at low temperature start, the viscosity becomes high and the fluidity decreases, and the tapered roller cannot be sufficiently lubricated. Early breakage may occur.

  In particular, this phenomenon is likely to occur in a tapered roller bearing used in an automobile transmission. As shown in FIG. 13 (Patent Document 1), an outer ring 2 is fitted to an inner peripheral surface 11 a of a transmission housing 11, and an inner ring 3 is fitted to a counter shaft 12. 15 is externally fitted. Lubricating oil 14 is accumulated in the bottom 13 of the housing 11.

  Various proposals have been made to improve the above problems. For example, in Patent Document 2, the lack of lubrication at the contact portion is compensated by filling a large flange escape portion (corresponding to 3e in FIG. 11, roller head relief groove) of the inner ring with a solid oil lubricant.

  Further, in Patent Document 3, by providing a through hole with the central axis of the tapered roller as a center, the lubricating oil can easily flow through the through hole to the end surface side of the tapered roller by centrifugal force. Trying to improve the lack of lubrication at the contact area.

  Further, in Patent Document 4, by providing a recess in the corner portion of the tapered roller corresponding to the large collar escape portion of the inner ring to create an oil reservoir, insufficient lubrication at the contact portion between the roller head and the inner ring large collar surface is prevented. Trying to improve.

However, in these Patent Documents 3 and 4, when operation is stopped, the lubricating oil tends to flow out of the bearing due to gravity, and when operation is resumed, lubrication is likely to be insufficient at the contact portion between the tapered roller head and the inner ring large collar surface. There was a problem.
JP-A-8-1356666 JP2003-1556056A JP 2002-61655 A Japanese Utility Model Publication No. 5-38421

  Therefore, the present invention improves the above-mentioned conventional problems, and not only during operation, but also under conditions where the lubricating oil is difficult to reach each part at low temperatures in winter and at start-up, in particular, the roller head and inner ring collar It is an object of the present invention to provide a roller bearing having a simple configuration that can maintain good lubrication at a contact portion with a surface and prevent seizure.

In order to achieve the above object, according to the present invention, there is provided a cage between the inner ring and the outer ring, in which a plurality of rollers are rotatably held in pockets, and the contact portions of the inner and outer rings are lubricated with lubricating oil. In the roller bearing, the roller is provided with a lubricating oil holding structure for holding the lubricating oil.
The lubricating oil retaining structure is characterized by being a plurality of circumferential concave grooves or a plurality of holes provided in through holes formed so as to open at both axial end surfaces of the roller.

  Further, the lubricating oil retaining structure is a deep counterbore provided so as to open on one end surface or both end surfaces of the roller, and the opening end has a cross-sectional area larger than the back side of the deep counterbore. Is characterized by being smaller.

  Furthermore, the lubricating oil retaining structure is characterized by comprising a porous material filled in either or both of a relief portion provided in the roller head and a relief portion provided in the large collar portion of the inner ring. .

  The present invention is configured as described above, and the lubricating oil is easily held in the roller lubricating oil holding structure. Therefore, not only during the operation of the roller bearing, but also during the low temperature in winter and after the stop time has elapsed considerably Even under conditions where it is difficult for the lubricating oil to reach each part, the lubricating oil retained in the lubricating oil retaining structure is immediately supplied into the bearing, and the roller head and the inner ring large collar surface are seized. It can be prevented from occurring.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an axial sectional view of a tapered roller bearing showing a first embodiment of the present invention, and FIG. 2 is a partial sectional view showing a shape of a concave groove of the tapered roller.

  Although the present invention can be applied to all roller bearings, a tapered roller bearing 1 shown in FIG. 1 will be described as an embodiment.

  First, a first embodiment of the present invention will be described with reference to FIG. In the figure, a tapered roller bearing 1 includes an outer ring 2 having a conical raceway surface 2a, an inner ring 3 having a conical raceway surface 3a, and a large flange 3b on the large diameter side of the raceway surface 3a. A plurality of tapered rollers 4 rotatably disposed between the raceway surface 2a of the outer ring 2 and the raceway surface 3a of the inner ring 3, and a retainer (not shown) that holds the tapered rollers 4 at a predetermined interval in the circumferential direction. It has. The inner ring 3 is externally fitted and fixed to the rotary shaft 5. When this tapered roller bearing 1 is used, lubricating oil is supplied between the inner ring 3 and the outer ring 2.

  The tapered roller 4 is provided with a through hole 40 that penetrates both axial end surfaces thereof. The through hole 40 has a cylindrical shape, and a plurality of (three in this embodiment) inner circumferential concave grooves 41 are annularly formed in the circumferential direction on the inner circumferential surface thereof at substantially equal intervals in the axial direction. . The inner circumferential groove 41 is a donut shape centered on the axis of the tapered roller 4 and has a semicircular cross-sectional shape. The tapered roller 4 having such an inner circumferential groove 41 must always hold the lubricating oil 14 regardless of its position.

  The configuration of the inner circumferential groove 41 for holding the lubricating oil 14 will be described with reference to the cross-sectional shape shown in FIG. When the bearing 1 is installed so that the direction of the rotating shaft 5 is horizontal, the direction of the rotating shaft 5 of the bearing 1 and the rotational axis P of the tapered roller 4 are shown in a vertical section passing through the rotating shaft P of the tapered roller 4 in FIG. And θ through the edge 41a of the inner circumferential groove 41, the straight line L1 forming an angle θ with the rotation axis P of the tapered roller 4, and the edge 41b of the inner circumferential groove 41. A triangle T (shown by diagonal lines) is formed by a straight line L2 forming an angle θ with the rotation axis P of the tapered roller 4 and a broken line L3 connecting the edge 41a and the edge 41b. In order for the tapered roller 4 to always hold the lubricating oil 14 regardless of its position as described above, the cross-sectional shape of the inner circumferential groove 41 is a shape that is partially larger than this triangle T, that is, It is necessary to be molded so as to have the arc portion 41c in FIG.

  With the above configuration, the lubricating oil 14 is held in the inner circumferential groove 41 of the tapered roller 4 during operation. Even if the lubricating oil 14 is temporarily stopped and restarted after a lapse of time in this state, the conventional gravity is used. As a result, the lubricating oil easily flows out from the side without the flange surface. However, since the lubricating oil 14 remains held in the inner circumferential groove 41, the tapered roller 4 rotates upon restart. Accordingly, the retained lubricating oil 14 is supplied to the inside of the bearing, and lubrication at the start can be performed.

  For this reason, the contact between the head 4a of the tapered roller 4 and the inner ring large collar surface 3c during the low temperature in winter or at the start after a considerable amount of stoppage time until the lubricating oil is supplied into the bearing. It is possible to prevent such a problem that seizure occurs in the part.

  FIG. 3 is an axial sectional view of a tapered roller bearing which is a first modification of the first embodiment of the present invention, and FIG. 4 is an axial sectional view of a tapered roller bearing which is a second modification of the first embodiment. It is.

  In the first embodiment, the annular inner circumferential groove 41 is provided as a lubricating oil retaining structure in the through hole 40 of the tapered roller 4. However, the present invention is not limited to this, and the first modification of the first embodiment shown in FIG. As an example, a hole 42 with a circular cross-section can be provided. The holes 42 may be disposed at a predetermined interval in the circumferential direction of the inner peripheral surface of the tapered roller 4, and are not limited to this, and may be in other arrangement forms.

  As a second modification of the first embodiment, as shown in FIG. 4, two small-diameter inward protruding portions 43 a in which the hole diameters near the opening portions at both ends are reduced in the through hole 40 of the tapered roller 4. , 43b, a reservoir 43 can be provided.

  The cross-sectional shapes of the hole 42 and the reservoir 43 described above are shapes such that the lubricating oil 14 is always held regardless of the position of the tapered roller 4 (see FIG. 2, overlapping), as in the first embodiment. Need to be omitted).

  Even in the configuration of the first modification of the first embodiment or the second modification of the first embodiment, the lubricating oil 14 is always held in the hole 42 or the reservoir 43 during the operation of the tapered roller bearing 1. Therefore, as in the first embodiment, seizure can be prevented from occurring at the contact portion between the tapered roller 4 head 4a and the inner ring large collar surface 3c even when restarted after being stopped for a long time. . In particular, in the configuration of the second modification of the first embodiment (reservoir 43), an efficient processing method such as forging is used as compared with the configuration of the first embodiment and the first modification. There is an advantage that you can.

  In addition, the said embodiment and its 1st and 2nd modification are each only one Embodiment of this invention, and are not necessarily limited to this. The roller bearing of the present invention is composed of at least an outer ring, an inner ring, and a plurality of rollers incorporated between the outer ring and the inner ring, and has through holes that are open at both end faces of the roller, and grooves are formed in the through holes. Or the shape of the through hole, the shape and number of the grooves, and the shape and number of the holes are the same as those of the above embodiment and the first and second modifications thereof. The configuration is not limited.

  In the above embodiment and the first and second modifications thereof, the single-row tapered roller bearing 1 has been described. However, a double-row roller bearing may be used, and both a metric system and an inch system may be used. There is no limitation on the size.

  Next, a second embodiment will be described with reference to FIGS.

  FIG. 5 is an axial sectional view of a tapered roller bearing showing a second embodiment of the present invention, FIG. 6 is an axial sectional view of a tapered roller bearing showing a first modification of the second embodiment, and FIG. It is an axial sectional view of a tapered roller bearing showing a second modification of the second embodiment.

  The second embodiment is substantially the same as the first embodiment, and the same reference numerals are given to the same members, and duplicate descriptions are omitted. The difference from the first embodiment is that, as shown in FIG. 5, the tapered roller 4 is provided with a deep counterbore 44 that opens to the large-diameter end 4c.

  In this configuration, in the splashing type lubrication, the lubricating oil falls due to gravity, but as shown in FIG. 5 (a), as indicated by an arrow A at the upper part of the bearing (↑) above the shaft center g. As shown, the falling lubricating oil 14 can be stored in the deep counterbore 44 of the tapered roller 4 at the top of the bearing. For this reason, when the shaft rotates and the tapered roller 4 moves to the lower (↓) bearing lower part in the figure, the lubricating oil flows out from the vicinity of the roller head and the inner ring large collar surface at the upper part of the bearing. The contact portion 8 between the roller head 4a and the inner ring large collar surface 3c can be lubricated, and the lubricating oil in the deep counterbore 44 flows out as shown by the arrow B even at the lower portion of the bearing, so that the roller head is wetted. By rotating in this state, the contact portion 8 between the roller head 4a of the tapered roller 4 and the inner ring large collar surface 3c can be lubricated. Therefore, the same effect as in the first embodiment can be expected.

  In the second embodiment, the deep counterbore 44 of the tapered roller 4 is provided as one that opens at the large-diameter side end 4c of the roller 4, but the present invention is not limited thereto, and the second counterbore shown in FIG. As a first modification of the embodiment, two deep counterbores 44 opened at the large-diameter end 4c of the tapered roller 4 and two deep counterbores 45 opened at the small-diameter end 4d may be provided back to back. good.

In this configuration, in the splashing type lubrication, the lubricating oil falls due to gravity, but as shown in FIG. 6 (a), it falls on the upper bearing (↑) in the figure above the axis g. The coming lubricating oil 14 accumulates in the deep counterbore 44 of the tapered roller 4 at the upper part of the bearing as indicated by an arrow A, and the shaft rotates to move the tapered roller 4 to the lower bearing (↓) in the figure. Sometimes, in the upper part of the bearing, lubricating oil flows out from the vicinity of the roller head and the inner ring large collar surface, so that the contact portion 8 between the roller head 4a of the tapered roller 4 and the inner ring large collar surface 3c can be lubricated, and the bearing lower part However, the lubricating oil in the deep counterbore 44 flows out as indicated by arrow B and rotates with the roller head wet, so that the contact portion between the roller head 4a of the tapered roller 4 and the inner ring large collar surface 3c. 8 can be lubricated. On the other hand, the lubricating oil 14 that falls as indicated by the arrow C at the lower part (↓) of the bearing below the shaft center g accumulates in the counterbore 45 of the tapered roller 4 at the lower part of the bearing, and the shaft When the tapered roller 4 rotates and moves to the upper side (↑) in the figure, the lubricating oil in the deep counterbore 45 flows out as shown by the arrow D, so that the inner ring surface can be lubricated. The deep countersunk holes 44 and 45 may have any shape as long as lubricating oil can be stored, but a cylindrical shape is preferable in consideration of workability.
For this reason, compared with the said 2nd Embodiment, there exists an effect that it can lubricate uniformly over the bearing 1 whole.

Further, as a second modification of the second embodiment, as shown in FIG. 7, in addition to the configuration of the first modification of the second embodiment, deep seats of both end portions 4c and 4d of the tapered roller 4 are provided. Ring-shaped lids 9a and 9b each having an inner diameter slightly smaller than the diameter of the deep counterbore hole may be concentrically attached to the opening ends of the counterbore holes 44 and 45, respectively.
In this configuration, the action of the lubricating oil 14 accumulating and flowing out in each of the counterbore holes 44 and 45 is the same as that of the first modification of the second embodiment, and redundant description is omitted. However, lids 9a and 9b are disposed at both ends of the tapered roller 4, and as shown in FIG. 5B, the lids 9a and 9b serve as weirs having a height h. As shown in FIG. 4A, the lubricating oil 14 entering the deep countersunk holes 44 and 45 is blocked by the lids 9a and 9b, and more lubricating oil 14 is accumulated than when the lids 9a and 9b are not provided. be able to. For this reason, the effect of being lubricated evenly over the entire bearing 1 can be further enhanced.
It should be noted that the structure that functions as a weir at the openings of the deep countersunk holes 44 and 45 functions as long as the cross-sectional area of the openings of the deep counterbore 44 and 45 is smaller than the cross-sectional area at the back of the deep counterbore. However, it is preferable that a ring-shaped lid slightly smaller than the deep counterbore diameter is attached in view of workability and assembly.

  In the second embodiment and the first and second modified examples, the single-row tapered roller bearing 1 has been described. However, a double-row roller bearing may be used. Can also be targeted, and the size is not limited.

  Next, a third embodiment will be described with reference to FIGS.

  FIG. 8 is an axial sectional view of a tapered roller bearing showing a third embodiment of the present invention, and FIG. 9 is an axial sectional view of a tapered roller showing a modification of the third embodiment.

  The third embodiment is substantially the same as the first embodiment, and the same members are denoted by the same reference numerals, and redundant description is omitted. The difference from the first embodiment is that, as shown in FIG. 8, a porous material 15 is filled in the escape portion 3e of the inner ring large collar portion 3b.

  In this configuration, the lubricating oil oozes out from the porous material 15 of the escape portion 3e due to the centrifugal force accompanying the rotation of the inner ring 3, and the contact portion 8 between the head 4a of the tapered roller 4 and the inner ring large collar surface 3c described above. Lubricating oil can be supplied, and the same effect as in the first embodiment can be expected.

  In the third embodiment, the porous material 15 is filled only with the escape portion 3e of the inner ring large collar portion 3b. However, when the escape portion is also provided in the inner ring small collar portion 3d (not shown). The escape portion can also be filled.

  In the third embodiment, the porous material 15 is filled in the escape portion 3e of the inner ring large collar portion 3b (or the inner ring small collar portion 3d). However, the present invention is not limited to this configuration, and the third embodiment shown in FIG. As a modification of the form, the porous material 16 may be filled in the escape portion 4 e provided on the head 4 a side of the tapered roller 4. The opening width W of the escape portion 4e is preferably set so as to cover the inner ring large collar surface 3c (see FIG. 8). Either or both of these third embodiments and their modifications can be employed.

  The configurations of the third embodiment and its modification are the same as those of the inner ring 2 and the tapered roller 4 disclosed in FIGS. 1 and 2 of Patent Document 1, but porous instead of the solid oil lubricant 7. The difference is that the material 16 is filled.

  Furthermore, both the configuration of the third embodiment and the configuration of the modified example of the third embodiment are adopted, and the porous materials 15 and 16 are attached to the escape portion 3d of the inner ring large collar portion 3b and the head portion 4a. If the relief portion 4e is filled, the lubrication state can be further improved.

As the porous material 15 used in the third embodiment and its modifications, for example, a sintered ceramic material, a general sponge, etc. can be considered, but in short, lubricating oil is used when the bearing is stopped. Any material may be used as long as it is a material that can be held inside and can satisfy the condition of oozing out the lubricating oil by centrifugal force during operation, and is not particularly limited.
In addition, said 3rd Embodiment and its modification are each only one Embodiment of this invention, and are not necessarily limited to this. The roller bearing of the present invention is composed of at least an outer ring, an inner ring, and a plurality of rollers incorporated between the outer ring and the inner ring, and any one of a relief part of a flange part of the inner ring and a relief part of a roller head On the other hand, it is characterized in that the porous material is filled in one or both of them, and the shape of the escape portion, the porous material, and the number of the escape portions filling the porous material in the bearing are the third embodiment, And it is not necessarily limited to the structure of the modification.

  Moreover, in the said 3rd Embodiment and its modification, it demonstrated using the single row tapered roller bearing 1, However, A double row roller bearing may be sufficient and both metric system and inch system are object. The size is not limited.

It is an axial sectional view of a tapered roller bearing showing a 1st embodiment of the present invention. It is a fragmentary sectional view which shows the shape of the concave groove of a tapered roller. It is an axial sectional view of a tapered roller bearing showing the 1st modification of a 1st embodiment. It is an axial sectional view of a tapered roller bearing showing a second modification of the first embodiment. It is an axial sectional view of a tapered roller bearing and a tapered roller showing a second embodiment of the present invention. It is an axial sectional view of a tapered roller bearing and a tapered roller showing a first modification of the second embodiment. It is an axial sectional view of a tapered roller bearing and a tapered roller showing a second modification of the second embodiment. It is an axial direction fragmentary sectional view of the tapered roller bearing which shows the 3rd Embodiment of this invention. It is an axial sectional view of a tapered roller showing a modification of the third embodiment. It is a perspective fragmentary sectional view which shows the conventional tapered roller bearing. It is an axial sectional view showing a positional relationship between a conventional tapered roller and inner and outer rings. FIG. 12 is a view on arrow E in FIG. It is an axial direction fragmentary sectional view of the transmission for motor vehicles provided with the conventional tapered roller bearing.

Explanation of symbols

1: Tapered roller bearing 2: Outer ring 2a: Outer ring raceway surface 3: Inner ring 3a: Inner ring raceway surface 3b: Large collar part 3c: Inner ring large collar surface 3d: Small collar part 3e, 4e: Escape part 4: Conical roller 4a: Roller Heads 9a and 9b: Lids 15 and 16: Porous material 40: Through hole 41: Inner peripheral concave groove 42: Hole 43: Reservoir 44, 45: Deep counterbore 8: Contact part 9: Lid 14: Lubricating oil 15: Porous material

Claims (6)

Between the inner ring and the outer ring, a roller bearing having a plurality of rollers rotatably held in pockets in a pocket, and lubricating the contact portion of the inner and outer rings with lubricating oil,
A roller bearing provided with a lubricating oil holding structure for holding the lubricating oil in the roller. The roller bearing according to claim 1, comprising a roller having the lubricating oil retaining structure, and used for a vehicle transmission. The lubricating oil retaining structure is a plurality of circumferential concave grooves or a plurality of holes provided in through holes formed so as to penetrate both end surfaces in the axial direction of the roller. Or the roller bearing described in 2. The roller bearing according to claim 1 or 2, wherein the lubricating oil retaining structure is a deep counterbore provided so as to open on one end surface or both end surfaces of the roller. The roller bearing according to claim 4, wherein an opening end portion of the deep spot bore has a smaller cross-sectional area than a depth side of the deep spot bore. The lubricating oil holding structure is made of a porous material filled in one or both of a relief portion provided in the roller head and a relief portion provided in a large collar portion of the inner ring. Item 3. A roller bearing according to item 1 or 2.

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