JP5417777B2 - Bi-splitting rolling bearing and bearing structure provided with the same - Google Patents

Description

  The present invention relates to a split roller bearing and a bearing structure including the same.

  In engines such as automobiles and ships, the bearing that supports the crankshaft that converts the reciprocating motion of the pistons into rotational motion is arranged between the counterweights or between the counterweight and the connecting rod large end, A split bearing divided into two is used.

  Conventionally, a sliding bearing has been used as the support bearing. However, in recent years, since the demand for an engine with a lower fuel consumption is increasing, in order to reduce the rotation loss, the sliding bearing is replaced with the supporting bearing. It has been proposed to use rolling bearings divided in the circumferential direction.

  The split type rolling bearing includes, for example, a set of two split outer rings, a plurality of rollers that are arranged so as to be able to roll on each inner surface of the two split outer rings, and each roller. And a cage for holding the plates so as to be arranged at substantially equal intervals in the circumferential direction. The crankshaft is fitted into the rolling bearing as an inner ring member.

  By the way, in the split type rolling bearing, the circumferential end surfaces of the two pairs of split outer rings are brought into contact with each other to form a mating surface. However, the split rolling bearing has a support hole that accommodates the rolling bearing. Due to the assembly error and the processing state of the housing fitting surface, a radial shift may occur at both ends of the facing outer ring on the mating surface. As a result, a step that protrudes inward in the radial direction may be formed on the mating surface.

  Then, as shown in FIG. 6, when a step 75 is generated in the radial direction (vertical direction in FIG. 6) on the mating surface C of the split outer rings 72a and 72b, the vicinity of the mating surface C of the outer ring where the step 75 is generated. When the roller 73 rolls, the peripheral surface of the roller 73 may collide with the corner 75a of the step 75, and noise and vibration may be generated.

Therefore, in order to suppress the noise and vibration generated when the rollers pass through the steps, the raceway surface of the outer ring in the vicinity of the mating surface is allowed to escape radially outward to form “escape” or “escape surface”. Has been proposed (see, for example, Patent Document 1).
In the bearing described in Patent Document 1, a V-shaped convex portion is provided at a circumferential end portion of one outer ring forming a mating surface, and a V-shaped concave portion is provided at a circumferential end portion of the other outer ring. . Then, an inclined surface (flank) inclined in the direction of gradually decreasing the radial thickness dimension toward the tip edge on the inner peripheral surface side constituting the outer ring raceway surface in the circumferential end portions of both outer rings. Forming. According to the bearing described in Patent Document 1, even if a radial misalignment occurs on the mating surfaces of the outer rings, it is possible to prevent the formation of a step due to the formation of the inclined surface, resulting in noise and vibration. It is said that the occurrence of is suppressed.

  Further, in the bearing described in Patent Document 1, the “flank” is configured by an inclined surface linearly decreasing or increasing in diameter linearly, but instead of the outer ring raceway surface and an arcuate curved surface having a reverse curvature. Can be formed on the inner diameter side edge of the mating surface.

JP 2006-125606 A

  However, in the above-mentioned “flank” composed of an inclined surface and an arcuate curved surface, the speed vector of the roller changes abruptly at the junction that is the boundary between the inclined surface or arcuate curved surface and the outer ring raceway surface. And generation of vibrations cannot be sufficiently suppressed.

  The present invention has been made in view of the above circumstances, and provides a bifurcated rolling bearing capable of significantly suppressing the generation of noise and vibration associated with the rolling element passing through the mating surface, and a bearing structure including the same. The purpose is to do.

The split rolling bearing of the present invention includes a pair of split outer rings divided into two in the circumferential direction, and a plurality of rolling elements arranged so as to be able to roll on each inner surface of both split outer rings. A rolling bearing having a retainer for holding the rolling elements so as to be arranged at substantially equal intervals in the circumferential direction, and having a shaft fitted therein,
In the flank formed on the inner diameter side edge portion in the circumferential end surface of the split outer ring, at least the cross-sectional shape in a range where the rolling elements contact is configured by a relaxation curve,
The range of contact extends from the mating surface formed by the circumferential end surfaces of the pair of split outer rings facing each other to the junction that is the boundary between the raceway surface of the split outer ring and the flank surface. What range der, it is characterized that you suppress the generation of vibration and noise caused by the abrupt change of the velocity vector of the rolling element by causing gradual change the velocity vector of the rolling element in the junction.

  In the split bearing according to the present invention, at least a cross-sectional shape in a range in which the rolling elements come into contact with the clearance surface formed at the inner edge on the circumferential end surface of the split outer ring (a cross section perpendicular to the axial direction of the split roller bearing). Therefore, the velocity vector of the rolling element in the vicinity of the boundary (junction point) between the curved surface formed by the relaxation curve and the outer ring raceway surface gradually changes. For this reason, it is possible to suppress the generation of vibration and noise due to a rapid change in the velocity vector of the rolling element, and to significantly suppress the generation of vibration and noise associated with the rolling element passing through the mating surface.

  The relaxation curve can be a clothoid curve or a cubic parabola. In this case, the speed vector of the rolling elements in the vicinity of the junction can be gradually changed, and the generation of vibration and noise due to a sudden change in the speed vector of the rolling elements can be suppressed.

The bearing structure of the present invention is characterized by comprising the above-described split roller bearing and a housing having a support hole for closely supporting the split roller bearing.
In the bearing structure of the present invention, since the above-described split rolling bearing is used, the speed vector of the rolling elements in the vicinity of the joint can be gradually changed, and noise and noise caused by the rolling elements passing through the mating surface Generation of vibration can be greatly suppressed.

  According to the two-rolling bearing of the present invention and the bearing structure including the same, it is possible to significantly suppress the generation of noise and vibration associated with the rolling element passing through the mating surface.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a split rolling bearing of the present invention (hereinafter also simply referred to as “rolling bearing”) and a bearing structure using the same will be described in detail below with reference to the accompanying drawings.
FIG. 1 is an explanatory cross-sectional view of a rolling bearing 1 according to an embodiment of the present invention, and FIG. 2 is an enlarged explanatory view of the vicinity of a mating surface of the rolling bearing 1 shown in FIG. The rolling bearing 1 includes a pair of two split outer rings 2a and 2b that are divided in two in the circumferential direction, and a plurality of rolling bearings 1 that can roll on inner surfaces of the two split outer rings 2a and 2b. And a retainer 4 that holds the rollers 3 at substantially equal intervals in the circumferential direction. The cage 4 is provided with a split portion at one place in the circumferential direction, and the cage 4 can be assembled by expanding the diameter of the split portion when the cage 4 is assembled into the shaft 5. However, it is good also as a division type which provided the split part in the circumferential direction two places. The shaft 5 is fitted into the rolling bearing 1 by being supported by the plurality of rollers 3. This shaft 5 also functions as an inner ring.

A mating surface C is constituted by the circumferential end face of the split outer ring 2a and the circumferential end face of the split outer ring 2b facing the end face. In the present embodiment, as shown in FIG. 2, a curved surface B as a flank is formed on the inner diameter side edge of each end surface of the split outer ring 2a, 2b constituting the mating surface C. Among them, the cross-sectional shape of the range where the roller 3 rolls and contacts is constituted by a relaxation curve. More specifically, as shown in FIG. 3 (a), in the circumferential direction, the joining surface C is a boundary between the raceway surfaces 2a1, 2b1 of the split outer rings 2a, 2b and the curved surface B from the mating surface C. This is a range L that reaches point J, and in the radial direction, the cross-sectional shape of the curved surface in the range h from the raceway surfaces 2a1 and 2b1 to the radial direction is constituted by a relaxation curve. The size of L can be appropriately selected according to the inner diameters of the raceway surfaces 2a1 and 2b1 of the split outer rings 2a and 2b and the diameter of the rollers 3, but usually when the diameter of the rollers 3 is D, it is more than 2D. Selected within a small range. The size of h differs depending on the radial displacement (step) in the outer ring mating surface C and the diameter of the roller 3, but usually a value larger than the size of the step is selected. If the size of h is set to a value larger than the size of the step, at least a range where the rollers 3 are in contact can be a relaxation curve.
Of the curved surface B, the curved surface other than the contact range of the roller 3 may be an arcuate curved surface, or may be a curved surface whose cross-sectional shape is a relaxation curve. Further, as the flank, a surface composed of a curved surface in which the cross-sectional shape of the present invention is a relaxation curve and an inclined plane following the outer diameter side (housing side) of the curved surface may be employed.

  By making at least the range in which the roller 3 is in contact with a relaxation curve, the change in the speed vector of the roller 3 at the junction J can be reduced, and the occurrence of vibration and noise due to the rapid change in the speed vector is suppressed. be able to. As such a relaxation curve, a typical clothoid curve (Cornu spiral) can be preferably used, but a cubic parabola that approximates the clothoid curve can also be used.

  FIGS. 3A and 3B are diagrams for explaining inclinations of various escape portions with respect to the outer ring raceway. FIG. 3A shows cross-sectional shapes of the various escape portions, and FIG. 3B shows inclinations of the various escape portions with respect to the outer ring raceway. . In FIG. 3, the diameter of the outer ring is 60 mm, the coordinate angle of the relief portion is 5 deg, and the relief depth is 1 mm. The solid line indicates a cubic parabola (relaxation curve), the broken line indicates an arc, and the alternate long and short dash line indicates a primary incremental line. In the primary incremental line, the clearance from the mating surface C to the junction point J (the movement from the bottom to the top in FIG. 3A and the movement from the right to the left in FIG. 3B) is the flank for the outer ring. Although the inclination of is constant 0.2 mm / deg, it becomes 0 at a stretch at the junction point J. That is, the speed vector of the roller rolling on the primary gradual increase line changes abruptly at the junction J. For this reason, a large vibration and noise are generated when passing through this junction. In the arc, the inclination is reduced at a constant rate from the mating surface C to the junction point J. However, the change in the inclination at the junction point J is large and not as large as the primary incremental line. Vibration and noise are generated. On the other hand, in the case of a cubic parabola, the rate of change in the slope decreases as the joint J is approached, so that the change in the speed vector of the roller when passing through the joint can be reduced. As a result, it is possible to suppress the generation of vibration and noise due to a rapid change in the velocity vector, and to significantly suppress the generation of vibration and noise associated with the roller passing through the mating surface.

  Next, an embodiment of the bearing structure of the present invention will be described. FIG. 4 is a cross-sectional explanatory view of a connecting rod (connecting rod) large end portion to which a bearing structure according to an embodiment of the present invention is applied. The connecting rod 40 has a large end 41 supported by the crankshaft 42, and a piston (not shown) is attached to the small end (not shown) via a pin.

  The large end portion 41 has a cap portion 44, which is a second housing portion, having a concave portion having a substantially semicircular cross section, and a bolt 45. In this structure, the support hole 46 having a substantially circular cross section is formed by fastening and fixing. A two-rolling bearing 51 is incorporated in a support hole 46 having a substantially circular cross section formed by the main body 43 and the cap 44.

  The rolling bearing 51 is arranged so that it can roll on each inner side surface of a pair of split outer rings 52a, 52b and two split outer rings 52a, 52b disposed in close contact with the support hole 46. A plurality of rolling elements 53 and a retainer 54 that holds the rollers 53 so as to be arranged at substantially equal intervals in the circumferential direction, and the crankshaft 42 constitutes an inner ring member of the rolling bearing 51. doing. And in the flank formed in the inner diameter side edge part in the circumferential direction end surface of the said split outer ring 52a, 52b, the cross-sectional shape of the range which the said roller 53 contacts is comprised by the clothoid curve which is a relaxation curve. .

  In the embodiment shown in FIG. 4, the bearing structure is applied to the large end of the connecting rod. However, as shown in FIG. 5, the housing constitutes a part of the crankshaft fixing portion 60. It can also be used as a bearing for supporting a crankshaft disposed in a support hole formed by an upper block 61 and a lower block 62 which is a housing integrally coupled to the upper block 61. In FIG. 5, 63 is a fixing bolt for integrally fixing the upper block 61 and the lower block 62, and 64 is a support shaft for the crankshaft.

In the above-described embodiment, the crankshaft is exemplified as the shaft fitted in the bearing. However, the bearing structure of the present invention can be applied to other shafts such as a camshaft.
Furthermore, although embodiment mentioned above is provided with the needle bearing which used the roller as a rolling element, the ball bearing which used the ball as a rolling element can also be employ | adopted.

It is a section explanatory view of one embodiment of a rolling bearing of the present invention. FIG. 2 is an enlarged explanatory view in the vicinity of a mating surface of the rolling bearing shown in FIG. 1. It is a figure explaining the inclination of the various escape parts with respect to an outer ring track. It is a section explanatory view of one embodiment of the bearing structure of the present invention. It is sectional explanatory drawing of other embodiment of the bearing structure of this invention. It is sectional explanatory drawing of the vicinity of the mating surface of the conventional split outer ring.

Explanation of symbols

1 Rolling bearing 2a, 2b Split outer ring 3 Roller (rolling element)
4 Cage 5 Shaft 51 Rolling bearings 52a, 52b Split outer ring 53 Roller 54 Cage B Curved surface C Matching surface J Joint point

Claims (3)

A pair of split outer rings divided into two in the circumferential direction, a plurality of rolling elements arranged so as to be able to roll on each inner surface of both split outer rings, and each rolling element in the circumferential direction A two-rolling bearing comprising a cage that is held so as to be arranged at substantially equal intervals, and in which a shaft is fitted,
In the flank formed on the inner diameter side edge portion in the circumferential end surface of the split outer ring, at least the cross-sectional shape in a range where the rolling elements contact is configured by a relaxation curve,
The range of contact extends from the mating surface formed by the circumferential end surfaces of the pair of split outer rings facing each other to the junction that is the boundary between the raceway surface of the split outer ring and the flank surface. What range der, halved characterized that you suppress the generation of vibration and noise caused by the abrupt change of the velocity vector of the rolling element by causing gradual change the velocity vector of the rolling element in said junction Rolling bearing.   The split bearing according to claim 1, wherein the relaxation curve is a clothoid curve or a cubic parabola. A bi-rolling bearing according to claim 1;
A bearing structure comprising: a housing having a support hole that closely supports the split bearing.

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