JP2018135957A - Conical roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce torque of a conical roller bearing.SOLUTION: A conical roller 4 includes a concave part 6 at a center part of both axial end surfaces. A holder 5 includes guide parts 5e projecting in opposite directions, on a pair of end surfaces of a pockets 5c storing the conical roller 4 opposite to the conical roller 4 in an axial direction. The guide part 5e is fitted to the concave part 6, and the conical roller 4 is held in a rollable manner by the guide part 5e. In this state, between a rolling surface of the conical roller 4 and a peripheral side edge of the pocket 5c, a first peripheral interval 7 allowing passage of lubricant exists.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a tapered roller bearing.

  As a prior art of the oil lubricated tapered roller bearing mentioned above, for example, there is one disclosed in Patent Document 1 below.

  The tapered roller bearing described in Patent Document 1 is provided with a concave oil convection notch for promoting oil convection between the inner and outer rings at the column portion between the roller pockets of the cage. .

  Due to the function of the oil convection notch, the lubricating oil flowing into the bearing from between the cage and the inner ring not only passes along the rolling surface of the inner ring, but also from the rolling surface of the inner ring to the outer ring side. Passes along the rolling surface of the outer ring.

JP-A-9-32858

  In order to meet the recent demand for lower torque for the bearing, it is necessary to further smooth the movement of the lubricating oil flowing between the cage and the inner ring toward the outer ring.

  An object of the present invention is to further reduce the torque of a tapered roller bearing.

  In order to solve the above problems, in the present invention, the tapered roller bearing is configured as follows.

That is, an inner ring, an outer ring, a tapered roller provided between the inner ring and the outer ring, and a cage that holds the tapered roller in a rollable manner,
The tapered roller has a recess in the center of both axial end faces,
The retainer has a pocket that accommodates the tapered roller, and a guide portion that is provided on each of a pair of end surfaces facing the tapered roller in the axial direction of the pocket and protrudes in opposite directions.
The guide part is held in the cage so that the tapered roller can roll by being fitted into the recess,
A first circumferential clearance is formed between the rolling surface of the tapered roller and one circumferential edge of the pocket of the retainer through which lubricating oil flowing from between the inner ring and the retainer passes. And
A second circumferential gap is formed between the rolling surface of the tapered roller and the other circumferential edge of the pocket of the cage,
The first circumferential clearance and the second circumferential clearance have a maximum value larger than the circumferentially movable amount of the tapered roller in the pocket,
The first circumferential gap is a tapered roller bearing larger than the second circumferential gap.

  In addition, the first circumferential clearance is the second circumferential clearance within a range where the tapered roller is allowed by a circumferential clearance (play) between the concave portion and the guide portion fitted in the concave portion. This is the maximum gap that can be achieved when it is biased to the maximum in the circumferential direction. Further, the second circumferential clearance is a maximum clearance that can be generated when the tapered roller is maximally biased toward the side having the first circumferential clearance.

  Further, the comparison of the sizes of the first circumferential gap and the second circumferential gap is a comparison in a state where the tapered rollers are maximally biased toward the side having the second circumferential gap.

  In addition, it is good for the said guide part to make its axial direction length larger than the axial direction allowable maximum motion allowance of the tapered roller in the said pocket.

  Further, the cage is preferably made of an elastically deformable resin and the guide portion is integrally formed.

  In the tapered roller bearing according to the present invention, since the tapered portion is held in a rollable manner by fitting a guide portion provided in the cage in a concave portion provided in the center portion of both end surfaces in the axial direction of the tapered roller, A first circumferential clearance having a sufficient width to allow passage of the lubricating oil can be provided between the rolling surface and one circumferential edge of the pocket of the cage.

  Lubricating oil flowing into the bearing from between the cage and the inner ring through the first circumferential gap can be sent to the outer ring side, and the fluidity of the lubricating oil fed to the outer ring side is improved, and the inside of the bearing is improved. Torque loss due to the stirring resistance of the lubricating oil is reduced.

  Note that the axial length of the guide portion is larger than the allowable axial maximum movement allowance of the tapered roller in the pocket (the distance that can move maximum in the axial direction in the pocket) from the tapered roller cage. Is surely prevented from falling off.

  In addition, when the cage is made of an elastically deformable resin, the guide portion can be fitted into the concave portions on both end surfaces of the tapered roller by utilizing the elastic deformation of the material resin.

  When the metal cage is designed such that the axial gap between the bottom of the recess provided in the tapered roller and the guide portion of the cage is smaller than the axial length of the guide portion, Since it is necessary to separately process and attach at least one of the guide portions provided on the large-diameter side ring portion, the assembly work and the structure of the guide portion attachment portion are complicated, but it is possible to fit into the concave portion due to elastic deformation. Such a problem does not occur if the cage is made of a resin having a guide portion.

It is sectional drawing which shows an example of the tapered roller bearing of this invention. It is an expanded sectional view which shows a part of tapered roller bearing of FIG. FIG. 3 is a view as viewed in the direction of the arrow Z in FIG. 2, showing the positional relationship between the retainer and the tapered roller of the tapered roller bearing in FIG. 1. It is a perspective view which shows a part of cage | basket employ | adopted as the tapered roller bearing of FIG.

  Embodiments of the tapered roller bearing according to the present invention will be described below with reference to FIGS. In the following description, the direction along the central axis of the tapered roller bearing is referred to as “axial direction”, the direction orthogonal to the central axis is referred to as “radial direction”, and the direction along the arc centered on the central axis is referred to as “circumferential direction”. Call.

  As shown in FIGS. 1 and 2, the tapered roller bearing 1 includes an inner ring 2, an outer ring 3, a tapered roller 4 disposed between the inner and outer rings 2 and 3 at a predetermined interval in the circumferential direction, and the tapered roller. And a cage 5 that holds the roller in a rollable manner.

  Concave portions 6 having a predetermined depth are formed in both end surfaces of the tapered roller 4 in the axial direction, that is, in the central portion of the end surface on the small diameter side and the central portion of the end surface on the large diameter side.

  The cage 5 is formed of an elastically deformable resin, for example, a polyamide resin (66 nylon or 46 nylon) reinforced with 20 to 30% by mass of glass fiber. The cage 5 is entirely tapered.

  As shown in FIG. 4, the cage 5 has a small-diameter side ring portion 5a, a large-diameter side ring portion 5b, and a predetermined interval in the circumferential direction between the small-diameter side and the large-diameter side ring portions 5a and 5b. And a plurality of pockets 5c and a column portion 5d that connects the small-diameter side ring portion 5a and the large-diameter side ring portion 5b between the pockets.

  In addition, a guide portion 5e is provided on each of the pair of end faces facing the tapered roller 4 in the axial direction of each pocket 5c. The guide portion 5 e protrudes toward the tapered roller 4. In other words, the cage 5 is provided with a plurality of (a pair of) guide portions 5e protruding in opposite directions. The guide 5e is a cantilevered round shaft. One guide portion 5e is integrally formed with the small-diameter side ring portion 5a, and the other guide portion 5e is integrally formed with the large-diameter side ring portion 5b.

  When the tapered roller bearing 1 is assembled, the guide portion 5e is elastically deformed so as to be fitted into the recesses 6 at both ends in the axial direction of the tapered roller 4, so that the tapered roller 4 is opposed to the oppositely arranged pair. It is supported by the guide part 5e so that it can roll.

  As shown in FIG. 3, a first circumferential gap 7 is provided between the rolling surface (outer circumferential surface) of the tapered roller 4 and one circumferential edge of the pocket 5 c of the cage 5. Further, the first circumferential gap 7 provided with the second circumferential gap 8 between the rolling surface of the tapered roller 4 and the other circumferential edge of the pocket 5c of the cage 5 is a tapered shape. The maximum dimension B is obtained when the roller 4 is maximally biased toward the second circumferential gap 8 side. Here, when the tapered roller 4 is maximally biased toward the second circumferential gap 8, the circumferential side surface of the recess 6 (the side opposite to the second circumferential gap 8) is the guide portion. This is when it is in contact with 5e.

  The maximum dimension B of the first circumferential gap 7 and the dimension of the second circumferential gap 8 when the tapered roller 4 is biased to the maximum in the first circumferential gap 7 side are the recess 6 and the guide part. It is larger than the circumferential gap (play) A that occurs between 5e. The maximum value of the first circumferential gap 7 and the second circumferential gap 8 is larger than the circumferentially movable amount of the tapered roller 4 in the pocket 5c. Here, when the tapered roller 4 is maximally biased toward the first circumferential gap 7 side, the other circumferential side surface of the concave portion 6 of the tapered roller 4 (the surface on the side opposite to the first circumferential gap 7). ) Is in contact with the guide portion 5e.

  The dimension B is larger than the dimension of the second circumferential gap 8. The comparison between the sizes of the first circumferential gap 7 and the second circumferential gap 8 is a comparison when the tapered roller 4 is in a state of being biased to the maximum on the side where the second circumferential gap 8 is present. is there.

  The dimension B of the first circumferential gap 7 is a dimension when the tapered roller 4 is maximally biased toward the side having the second circumferential gap 8 within the range allowed by the circumferential gap (play) A. Thus, the lubricating oil is allowed to pass smoothly.

  The axial length D of the guide portion 5e is larger than the allowable axial movement allowance C of the tapered roller 4 in the pocket 5c.

  As a result, the tapered roller 4 is prevented from falling off from the cage 5, and the tapered roller 4 is securely held in the pocket 5c.

  The guide portion 5e having an axial length D larger than the axially allowable maximum movement allowance C of the tapered roller 4 is elastically deformed and inserted into the recess 6.

  When the cage 5 is formed of a metal or hard resin that is not elastically deformed, at least one of the guide portions 5e provided on the small-diameter side ring portion 5a side and the large-diameter side ring portion 5b side is separated from the ring portion. It is made independent and attached to the ring part so as to allow adjustment of the axial length.

  In the example tapered roller bearing 1 configured as described above, the lubricating oil supplied between the cage 5 and the inner ring 2 is formed between the rolling surface of the tapered roller 4 and the cage 5. It also flows to the outer ring 3 side through the first circumferential gap 7.

  The notch for oil convection proposed in Patent Document 1 needs to prevent the tapered roller from being displaced in the circumferential direction in the pocket, and therefore it is allowed to be formed along the entire length of the tapered roller. Not.

  On the other hand, the first circumferential clearance 7 in the tapered roller bearing 1 of the present invention holds the circumferential positioning in the pocket of the tapered roller 4 inserted into the recessed portion 6 provided in the tapered roller 4 and the recessed portion 6. Since it is performed with the guide part 5e of the vessel 5, the first circumferential gap 7 can be formed along a region extending over the entire length of the tapered roller 4.

  As a result, the fluidity of the lubricating oil fed to the outer ring 3 side is improved, torque loss due to the stirring resistance of the lubricating oil inside the bearing is reduced, and the torque of the internal lubricated tapered roller bearing is further reduced.

DESCRIPTION OF SYMBOLS 1 Tapered roller bearing 2 Inner ring 3 Outer ring 3a Rolling surface 4 Tapered roller 5 Cage 5a Small diameter side ring part 5b Large diameter side ring part 5c Pocket 5d Pillar part 5e Guide part 6 Recessed part 7 Rolling surface of tapered roller and circumference of pocket First circumferential clearance 8 formed between one side edge in the second direction Second circumferential clearance A formed between the rolling surface of the tapered roller and the other circumferential edge of the pocket. Clearance B between the rolling roller and the cage The maximum circumferential dimension C of the clearance between the rolling surface of the tapered roller and the cage D The maximum allowable axial movement allowance of the tapered roller D The axial length Z of the guide section The direction of looking at the cage and tapered roller in Fig. 3

Claims (3)

Inner ring (2),
Outer ring (3),
A tapered roller (4) provided between the inner ring (2) and the outer ring (3);
A retainer (5) for holding the tapered roller (4) in a rollable manner,
The tapered roller (4) has a recess (6) at the center of both axial end faces,
The cage (5) is provided on each of a pocket (5c) for accommodating the tapered roller (4) and a pair of end faces facing the tapered roller (4) in the pocket (5c) in the axial direction. And a guide portion (5e) protruding in opposite directions,
The guide portion (5e) is fitted in the concave portion (6) so that the tapered roller (4) is held by the retainer (5) in a rollable manner.
Between the inner ring (2) and the cage (5) between the rolling surface of the tapered roller (4) and the circumferential side edge of the pocket (5c) of the cage (5). A first circumferential gap (7) is formed through which inflowing lubricating oil passes;
A second circumferential gap (8) is formed between the rolling surface of the tapered roller (4) and the other circumferential edge of the pocket (5c) of the cage (5),
The maximum value of the first circumferential gap (7) and the second circumferential gap (8) is larger than the circumferentially movable amount of the tapered roller (4) in the pocket (5c),
The first circumferential clearance (7) is greater than the second circumferential clearance (8) in a state where the tapered roller (4) is maximally biased to the side where the second circumferential clearance (8) is present. Large tapered roller bearing.   The tapered roller bearing according to claim 1, wherein an axial length (D) of the guide portion (5e) is larger than an axially allowable maximum movement allowance (C) of the tapered roller (4) in the pocket (5c). .   The tapered roller bearing according to claim 1 or 2, wherein the cage (5) is made of an elastically deformable resin.

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