JP2016161118A - Conical roller bearing and holder used in the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve strength and workability of a holder, enable a pitch circle diameter of a pillar part of the holder to be made small, and thereby prevent abrasion due to contact of the holder and an outer ring, in a conical roller bearing having high roller filling rate.SOLUTION: A conical roller bearing 1 has a roller coefficient γ of over 0.94. A holder 5 of the conical roller bearing 1 has a metal part 51 provided at least in a plurality of pillar parts 5c, and a resin part 52 provided with a guide surface 5d of the holder 5 with the metal part 51 molded as an insert component.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a tapered roller bearing and a cage used therefor.

  Tapered roller bearings support both radial and axial loads by interposing a plurality of tapered rollers between tapered raceway surfaces provided on the inner ring and outer ring. For example, transmissions and differentials of automobiles It is incorporated in the power transmission system.

  In recent years, in power transmission systems such as automobile transmissions, low-viscosity oil tends to be used to reduce fuel consumption. When low-viscosity oil is used, surface-origin separation due to poor lubrication occurs on the raceway surface of the inner ring with particularly high surface pressure when adverse conditions such as oil temperature increase, oil volume decrease, or preload loss overlap. Sometimes.

  For example, Patent Document 1 discloses a technique for reducing the maximum surface pressure of the raceway surface of the inner ring by increasing the roller filling rate of the tapered roller bearing and avoiding the short life due to the surface origin separation as described above. .

JP 2005-188738 A

  Tapered roller bearings are usually provided with cages that hold the rollers at a predetermined interval. When the roller filling rate of the tapered roller bearing is increased as in Patent Document 1 above, the circumferential interval between the rollers is narrowed, so that the pillar portion of the cage disposed between the rollers is narrowed. When such a cage is made of resin, for example, the strength of the pillar portion may be insufficient. Therefore, the pitch circle diameter of the pillar portion of the cage is increased, and the pillar is placed in a place where the gap between the rollers is relatively large. It is necessary to secure the strength by arranging the parts and thickening the pillars. However, when the pitch circle diameter of the pillar portion of the cage is increased, the cage is likely to come into contact with the outer ring, and wear of the cage becomes a problem.

  On the other hand, when the cage is made of metal, the strength can be increased compared to the resin. However, when the roller filling rate is increased and the column portion of the cage becomes thin, it becomes difficult to press the cage. In particular, the guide surface that guides the tapered roller is required to have high accuracy, but if the column portion becomes thin, it becomes difficult to press-mold the guide surface with high accuracy. For this reason, in the same way as described above, it is necessary to increase the pitch circle diameter of the pillar portion of the cage to increase the thickness of the pillar portion and improve the workability of the cage (especially the guide surface). Contact with is a problem.

  As described above, when the roller filling rate of the tapered roller bearing is increased, whether the cage is made of resin or metal, the pitch circle diameter of the pillar portion of the cage is increased to thicken the column portion. There is no choice but to wear due to contact with the outer ring.

  From the above circumstances, the technical problem to be solved by the present invention is to improve the strength and workability of the cage in the tapered roller bearing having a high roller filling rate, thereby reducing the pitch circle diameter of the column portion of the cage. Therefore, it is possible to suppress wear and prevent wear due to contact between the cage and the outer ring.

  In order to solve the above problems, the present invention provides an inner ring having a tapered raceway surface on an outer peripheral surface, an outer ring having a tapered raceway surface on an inner peripheral surface, a raceway surface of the inner ring, and a raceway surface of the outer ring. A plurality of tapered rollers that are arranged so as to be able to roll, a small-diameter-side annular portion, a large-diameter-side annular portion, and these are connected in the axial direction, and are arranged between the circumferential directions of the plurality of tapered rollers. A tapered roller bearing having a plurality of column portions, each column portion including a cage on which a guide surface for guiding the plurality of tapered rollers is formed, and having a roller coefficient γ exceeding 0.94, Provided is a tapered roller bearing in which a cage includes at least a metal part provided on the plurality of column parts and a resin part formed using the metal part as an insert part and provided with the guide surface.

Thus, the strength of the cage can be increased by reinforcing the pillar portion of the cage with the metal portion. Further, by providing the guide surface on the resin portion, the processing of the guide surface is facilitated as compared with the case where the guide surface is press-molded on the metal column portion. As described above, the tapered roller bearing of the present invention has a high strength of the retainer column portion and easy molding of the guide surface, so that the roller filling rate is increased (specifically, the roller coefficient γ Even when the column portion becomes thinner (by increasing the value from 0.94), the strength of the column portion and the workability of the guide surface can be ensured. Thereby, since it becomes unnecessary to make the pitch circle diameter of the pillar part of the cage excessively large, contact between the cage and the outer ring can be prevented. The roller coefficient γ is defined by the following equation.
γ = (Z · DA) / (π · PCD)
However, Z: Number of rollers, DA: Roller average diameter, PCD: Roller pitch circle diameter, π: Circumference ratio

  By the way, in order to increase the load capacity of the tapered roller bearing, it is conceivable to increase the roller length in addition to increasing the roller filling rate. However, when the roller length is increased, the pocket for accommodating the roller needs to be enlarged, so that the axial width of the annular portion of the cage is reduced and the strength of the cage is reduced. Increasing the axial width of the annular portion (especially the small-diameter side annular portion) to ensure strength increases the amount of axial projection of the cage from the end face of the outer ring, and the cage and other members (for example, other conical shapes) Interference with roller bearing cages, housings, etc.) is a problem.

  In view of this point, in the above tapered roller bearing, the metal portion is provided in a plurality of columnar metal portions provided in each column portion and the small diameter side annular portion, and the small diameter side ends of the plurality of columnar metal portions. It can be set as the structure provided integrally with the cyclic | annular metal part which connects a part. In this way, the strength of the small-diameter-side annular portion is enhanced by reinforcing the small-diameter-side annular portion of the cage with the annular metal portion, so that the axial width of the small-diameter-side annular portion is suppressed while ensuring the required strength. be able to. Thereby, the axial protrusion amount of the cage from the end surface of the outer ring can be suppressed, and interference between the cage and other members can be avoided. In addition, since the annular metal portion and the columnar metal portion are integrally provided, the boundary between the small-diameter-side annular portion and the column portion of the cage where stress tends to concentrate can be reinforced, so that the strength of the cage can be further increased.

  Further, in the tapered roller bearing, the metal portion is provided in a plurality of columnar metal portions provided in each column portion and the large-diameter side annular portion, and a large-diameter side end portion of the plurality of columnar metal portions. It is good also as a structure provided with the cyclic | annular metal part which connects these. Further, in the tapered roller bearing described above, the metal portion is provided in the plurality of columnar metal portions provided in each column portion and the small diameter side annular portion, and connects the small diameter side end portions of the plurality of columnar metal portions. A small-diameter annular metal portion and a large-diameter-side annular metal portion that is provided in the large-diameter-side annular portion and that connects the large-diameter-side end portions of the plurality of columnar metal portions. Good.

  In the above tapered roller bearing, when the resin part is injection molded using the metal part as an insert part, it is necessary to position the metal part at a predetermined position in the cavity of the injection molding die. At this time, if the metal part is exposed on the surface of the cage, the metal part can be positioned at a predetermined position in the cavity by holding the exposed part with a mold. However, in order to form the guide surface with the resin portion, it is preferable that the metal portion is exposed to a region excluding the guide surface on the surface of the cage.

  As described above, according to the present invention, in the tapered roller bearing having a high roller filling rate, the strength and workability of the cage can be improved, so that the pitch circle diameter of the pillar portion of the cage can be suppressed, Thereby, wear due to contact between the cage and the outer ring can be prevented.

It is an axial sectional view of a tapered roller bearing according to an embodiment of the present invention. It is a cross-sectional view in the direction perpendicular to the axis of the tapered roller bearing. (A) A figure is a front view of the retainer of the said tapered roller bearing, (b) A figure is sectional drawing in the XX line of (a) figure. (A) The figure is the top view and sectional drawing of a metal part original form, (b) The figure is the top view and sectional drawing of a metal part. (A) A figure is a front view of a cage concerning other embodiments, and (b) figure is the same sectional view. (A) A figure is a front view of the holder concerning other embodiments, and (b) figure is the same sectional view. (A) A figure is a sectional view of a maintenance machine concerning other embodiments, and (b) figure is a sectional view in the YY line of (a) figure. It is sectional drawing of the metal mold | die which carries out the injection molding of the resin part of the holder | retainer of FIG. It is sectional drawing of the holder | retainer which concerns on other embodiment.

  Hereinafter, the tapered roller bearing which concerns on one Embodiment of this invention is demonstrated based on FIGS.

  As shown in FIGS. 1 and 2, the tapered roller bearing 1 of the present embodiment includes an inner ring 2 having a tapered raceway surface 2a on the outer peripheral surface, and an outer ring 3 having a tapered raceway surface 3a on the inner peripheral surface. A plurality of tapered rollers 4 having a tapered rolling surface 4a on the outer peripheral surface, and a tapered roller 4 in the circumferential direction, etc., are arranged so as to roll freely between the raceway surface 2a of the inner ring 2 and the raceway surface 3a of the outer ring 3. It is comprised with the holder | retainer 5 hold | maintained at a space | interval. In this tapered roller bearing 1, tapered rollers 4 are filled with high density, and specifically, a roller coefficient γ is γ> 0.94. The tapered roller bearing 1 is incorporated in a power transmission system such as an automobile transmission or a differential.

  The inner ring 2, the outer ring 3, and the tapered roller 4 are made of steel, for example, bearing steel, carburized steel, stainless steel, or the like. The inner ring 2 has a small flange portion 2b provided on the small diameter side (left side in FIG. 1) of the raceway surface 2a and a large collar portion 2c provided on the large diameter side (right side in FIG. 1) of the raceway surface 2a. .

  The cage 5 includes a small-diameter-side annular portion 5a, a large-diameter-side annular portion 5b, and a plurality of column portions 5c that connect the small-diameter-side annular portion 5a and the large-diameter-side annular portion 5b in the axial direction. One tapered roller 4 is accommodated in each of the pockets surrounded by the small-diameter-side annular portion 5a, the large-diameter-side annular portion 5b, and the pair of column portions 5c, and each column portion of the cage 5 is interposed between the circumferential directions of the tapered rollers 4. 5c is arranged. The cage 5 is arranged on the outer diameter side of the center of the tapered roller 4 and at a position not in contact with the outer ring 3 (see FIG. 2).

  5 d of guide surfaces which contact the tapered roller 4 are provided in the side surface of the circumferential direction both sides of each pillar part 5c. The guide surfaces 5d on both sides in the circumferential direction of each pocket (that is, the pair of guide surfaces 5d facing each other in the circumferential direction) are gradually widened as the circumferential interval increases toward the inner diameter side. In the illustrated example, the guide surface 5d is a flat surface inclined with respect to the radial direction.

  As shown in FIGS. 3A and 3B, the cage 5 includes a metal part 51 and a resin part 52. The metal part 51 includes a plurality of columnar metal parts 51a provided in each pillar part 5c and an annular metal part 51b provided in the small diameter side annular part 5a and connecting the small diameter side ends of the plurality of columnar metal parts 51a. Have one. In the illustrated example, the entire metal part 51 is embedded in the resin part 52. The columnar metal portion 51a does not reach the large-diameter-side annular portion 5b, and a large-diameter-side end portion is provided at an axially intermediate portion (in the illustrated example, near the central portion in the axial direction) of the column portion 5c. The ratio between the axial width W1 of the annular metal portion 51b and the axial width W2 of the small-diameter-side annular portion 5a is set in a range of 0.2 ≦ W1 / W2 ≦ 0.8, for example. The ratio of the circumferential width W3 of the columnar metal part 51a and the circumferential width W4 of the columnar part 5c is set in the range of 0.2 ≦ W3 / W4 ≦ 0.8, for example. In addition, the structure of the metal part 51 is not restricted above, For example, you may extend the large diameter side edge part of the pillar part 5c until it reaches the large diameter side annular part 5b.

  The metal part 51 is formed by press work, for example. Specifically, first, a metal plate is punched to form a metal part original 51 'having a shape as shown in FIG. The metal part original shape 51 ′ is integrally provided with a plurality of columnar metal parts 51 a ′ extending radially and an annular metal part 51 b ′ connecting the inner diameter ends of the columnar metal parts 51 a ′. The metal part original 51 ′ is pressed, and the boundary between the annular metal part 51b ′ and the columnar metal part 51a ′ is bent, so that the columnar metal part 51a and the annular metal part 51b shown in FIG. The metal part 51 which has is formed. In this case, the axial width W2 of the annular metal portion 51b and the thickness W5 of the columnar metal portion 51a (specifically, the thickness in the direction perpendicular to the outer diameter surface or inner diameter surface of the columnar metal portion 51a, see FIG. 3). Is almost equal. Moreover, both the axial orthogonal cross section (refer FIG. 2) of the columnar metal part 51a and the axial cross section {refer FIG.3 (b)} of the cyclic | annular metal part 51b have comprised the rectangle. The metal part 51 is formed of a material excellent in press workability and strength, and is formed of, for example, a steel material, specifically SPCC, SPHC, spring steel, or the like.

  The resin part 52 is formed of resin using the metal part 51 as an insert part. In the present embodiment, the resin portion 52 is formed by resin injection molding using the metal portion 51 as an insert part. Specifically, in a state where the metal part 51 is disposed at a predetermined position in the cavity of the mold, the molten resin is injected into the cavity and the resin is solidified so that the metal part 51 and the resin part 52 are integrated. It is formed. The resin portion 52 is provided in a region of the cage 5 where at least the guide surface 5d is formed. In the illustrated example, the entire surface of the cage 5 is formed of the resin portion 52. The resin portion 52 is formed of engineering plastic, for example, PA46, PA66, PPS, or the like.

  When the inner ring 2 and the outer ring 3 of the tapered roller bearing 1 rotate relative to each other, each tapered roller 4 revolves along the circumferential direction of the inner ring 2 and the outer ring 3 while rotating in the pocket of the cage 5. At this time, the large diameter side end surface 4b of each tapered roller 4 and the large flange portion 2c of the inner ring 2 slide, and the rolling surface 4a of each tapered roller 4 and the guide surface 5d of the cage 5 slide. .

  In this embodiment, since the metal part 51 is provided in the retainer 5, it has sufficient strength. In particular, since the columnar metal part 51a is provided in the column part 5c, the circumferential width of the column part 5c can be reduced while ensuring the required strength. Thereby, it becomes possible to reduce the pitch circle diameter of the column part 5c of the cage 5 (the entire column part 5c is brought closer to the inner diameter side, or the outer diameter surface of the column part 5c is brought closer to the inner diameter side). Since the outer ring 3 and the outer ring 3 can be sufficiently separated in the radial direction, wear due to contact between the cage 5 and the outer ring 3 can be avoided.

  In the present embodiment, since the guide surface 5d of the cage 5 is provided on the resin portion 52, the guide surface 5d can be molded simultaneously with the injection molding of the resin portion 52. Accordingly, the guide surface 5d can be easily formed even when the pitch circle diameter of the column portion 5c is reduced and the column portion 5c is narrowed as described above.

  In the present embodiment, since the annular metal portion 51b is provided in the small-diameter side annular portion 5a of the cage 5, the axial width of the small-diameter side annular portion 5a is reduced while ensuring the required strength. Can do. Thereby, the axial protrusion amount of the cage 5 from the small diameter side end surface 3b of the outer ring 3 is reduced, or the small diameter side end portion of the cage 5 is retracted to the larger diameter side than the small diameter side end surface 3b of the outer ring 3. Therefore, the interference between the cage 5 and other parts can be prevented.

  The present invention is not limited to the above embodiment. Hereinafter, although other embodiment of this invention is described, the same code | symbol is attached | subjected to the location which has the same function as said embodiment, and duplication description is abbreviate | omitted.

  In the embodiment shown in FIG. 5, the metal part 51 of the cage 5 is provided in the plurality of columnar metal parts 51 a provided in each column part 5 c and the large-diameter side annular part 5 b, and the plurality of columnar metal parts 51 a are arranged. An annular metal portion 51c that connects the large-diameter end is integrally provided. In this case, since the large-diameter side annular portion 5b of the cage 5 is reinforced by the annular metal portion 51c, the axial width of the large-diameter side annular portion 5b can be reduced.

  In the embodiment shown in FIG. 6, the metal part 51 of the cage 5 is provided in the plurality of columnar metal parts 51 a provided in each column part 5 c and the small diameter side annular part 5 a, and the small diameter of the plurality of columnar metal parts 51 a. An annular metal portion 51b on the small diameter side that connects the side ends, and an annular metal portion 51c on the large diameter side that is provided on the large diameter side annular portion 5b and connects the large diameter side ends of the plurality of columnar metal portions 51a. Prepare for one. In this case, the small-diameter-side annular portion 5 a, the large-diameter-side annular portion 5 b, the plurality of column portions 5 c, and their boundaries are all reinforced with the metal portion 51.

  In the above embodiment, the case where the metal part 51 of the cage 5 is embedded in the resin part 52 and the metal part 51 is not exposed on the surface of the cage 5 is shown. 51 may be exposed on the surface of the cage 5. In this case, in order to form the guide surface 5d of the column portion 5c of the cage 5 with the resin portion 52, it is preferable that the metal portion 51 is exposed in a region of the surface of the cage 5 excluding the guide surface 5d. Specifically, for example, in the embodiment shown in FIGS. 7A and 7B, the inner diameter surface 51 a 1 of the columnar metal portion 51 a is exposed to the inner diameter surface of the column portion 5 c of the cage 5. In this case, when the resin part 52 is injection-molded, as shown in FIG. 8, when the metal part 51 is disposed in the cavity 13 formed by the molds 11 and 12, the outer peripheral surface 11 a of one mold 11 is columnar. By fitting the inner diameter surface 51a1 of the metal portion 51a, the metal portion 51 can be positioned at a predetermined position in the cavity 13. In the illustrated example, the end surface 51b1 on the large diameter side of the annular metal portion 51b is further exposed on the end surface on the large diameter side of the small diameter side annular portion 5a of the cage 5. Accordingly, as shown in FIG. 8, the end surface 51b1 of the annular metal portion 51b can be brought into contact with the end surface 11b of the mold 11, so that the metal portion 51 can be positioned more stably in the cavity 13. be able to.

  In the embodiment shown in FIG. 9, the end surface 51 b 2 on the small diameter side of the annular metal part 51 b is further exposed from the end surface on the small diameter side of the small diameter side annular part 5 a of the cage 5 in the configuration shown in FIG. 7. Thereby, when the resin part 52 is injection-molded, the annular metal part 51b can be sandwiched from both sides in the axial direction by a mold, so that the metal part 51 can be positioned more stably in the cavity (illustrated). (Omitted). Further, since the axial width of the small-diameter side annular portion 5a of the cage 5 is only the axial width of the annular metal portion 51b, the axial width of the small-diameter side annular portion 5a can be further reduced. And other members can be prevented more reliably.

  In addition, although not shown, the outer diameter surface of the columnar metal part 51 a may be exposed to the outer diameter surface of the column part 5 c of the cage 5. Alternatively, the inner diameter surface and the outer diameter surface of the columnar metal part 51a may be exposed to the inner diameter surface and the outer diameter surface of the column part 5c of the cage 5, respectively. Alternatively, only the guide surface 5d of the surface of the cage 5 may be formed by the resin portion 52, and the metal portion 51 may be exposed in the entire region other than the guide surface 5d.

  Further, in the embodiment shown in FIGS. 5 and 6, the metal part 51 may be exposed in a region excluding the guide surface 5 d on the surface of the cage 5.

DESCRIPTION OF SYMBOLS 1 Tapered roller bearing 2 Inner ring 3 Outer ring 4 Tapered roller 5 Cage 5a Small diameter side annular part 5b Large diameter side annular part 5c Column part 5d Guide surface 51 Metal part 51a Columnar metal part 51b Annular metal part 51c Annular metal part 52 Resin part

Claims (6)

An inner ring having a tapered raceway surface on the outer peripheral surface, an outer ring having a tapered raceway surface on the inner peripheral surface, and a plurality of rolls disposed between the raceway surface of the inner ring and the raceway surface of the outer ring. A tapered roller, a small-diameter-side annular portion, a large-diameter-side annular portion, and a plurality of column portions that are axially connected to each other, and are arranged between the circumferential directions of the plurality of tapered rollers. A tapered roller bearing having a guide surface for guiding the plurality of tapered rollers and having a roller coefficient γ exceeding 0.94,
A tapered roller bearing in which the cage includes at least a metal portion provided on the plurality of column portions, and a resin portion formed using the metal portion as an insert part and provided with the guide surface.   The metal part integrally includes a plurality of columnar metal parts provided in each column part, and an annular metal part provided in the small diameter side annular part and connecting the small diameter side ends of the plurality of columnar metal parts. The tapered roller bearing according to claim 1.   The metal part is integrated with a plurality of columnar metal parts provided in each column part and an annular metal part provided in the large-diameter side annular part and connecting the large-diameter side end parts of the plurality of columnar metal parts. The tapered roller bearing according to claim 1, wherein the tapered roller bearing is provided.   A plurality of columnar metal portions provided in each column portion; and a small-diameter-side annular metal portion that is provided in the small-diameter side annular portion and connects the small-diameter side end portions of the plurality of columnar metal portions; The tapered roller bearing according to claim 1, wherein the tapered roller bearing is integrally provided with a large-diameter annular metal portion that is provided in the large-diameter annular portion and connects large-diameter side ends of the plurality of columnar metal portions.   The tapered roller bearing according to any one of claims 1 to 4, wherein the metal portion is exposed in a region excluding the guide surface on a surface of the cage. A small-diameter-side annular portion, a large-diameter-side annular portion, and a plurality of column portions that are connected in the axial direction and are arranged between circumferential directions of the plurality of tapered rollers, and each column portion includes the plurality of cones. A cage formed with a guide surface for guiding rollers,
A tapered roller bearing retainer having at least a metal portion provided on the plurality of column portions and a resin portion formed with the metal portion as an insert part and provided with the guide surface.

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