JP2012154428A - Split type rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the split type rolling bearing, which can control the fall of a bearing life while regulating the radial direction position at the cylindrical roller and preventing the noise and the vibration, at low cost.SOLUTION: This split type rolling bearing 10 includes the retainer 13 in which a plurality of pockets 16 that hold a plurality of rollers 12 are formed for retaining a plurality of rollers. A plurality of pockets 16 each have a pair of retaining faces 17 that are formed by facing each other with each of the rollers 12 in between to hold each of the rollers 12 A pair of retaining faces 17 are formed so that the mutual gap may become narrow gradually toward the outside radial direction of the retainer 13 to enable the regulation of the moving of each of the rollers 12.

Description

  The present invention relates to a split type rolling bearing used to rotatably support, for example, an engine crankshaft and a connecting rod large end.

  A crankshaft of an engine such as an automobile is integrally formed with a crank arm and a crankpin that constitute the crank. For this reason, split bearings that are divided in the circumferential direction are used as the bearings that are arranged in the crank journal formed between the crank arms and support the crankshaft with respect to the engine block.

  As the split bearing, a slide bearing has been used. On the other hand, in order to satisfy the recent high demands on economy and environment, the split bearing has a relatively low rotational torque instead of the slide bearing. Rolling bearings may be used.

  The split type rolling bearing is fixed to the housing on the engine block side and is divided into two and divided into an outer ring made up of a pair of half outer ring members, and a plurality of rolling elements arranged on the inner peripheral surface of the outer ring. Cylindrical rollers and a cage for holding these cylindrical rollers are provided, and the crankshaft of the crankshaft is used as an inner ring member so that the crankshaft is rotatably supported with respect to the engine block.

Since the outer ring of the split type rolling bearing is used as an outer ring by abutting the half outer ring members to each other, a minute step may occur on the inner peripheral surface of the outer ring at the abutting portion between the two half outer ring members.
If the above steps are present on the inner peripheral surface of the outer ring, vibration and sound are generated when the cylindrical roller passes through the step, and the cylindrical roller and outer ring are damaged, such as cracks and surface peeling. May be reduced.

  For this reason, in order to prevent the cylindrical roller from coming into contact with the step generated on the inner peripheral surface of the outer ring, a protrusion for restricting the cylindrical roller accommodated in the cage pocket from moving radially outward is provided on the cage. Attempts have been made to provide it at the pocket periphery (see, for example, Patent Document 1).

JP 2006-234074 A

  However, the cage rotates eccentrically while following the roller revolution when the inner ring of the rolling bearing is rotating. Therefore, the protrusion provided in the pocket for regulating the position of the cylindrical roller is relatively accurate. If not formed, the position of the cylindrical roller could not be limited as a result, and there was a risk of contact with the step. Further, if the protrusions are to be formed with high accuracy, a fine and highly accurate formation process is required, which increases the manufacturing cost, which is not preferable.

  The present invention has been made in view of such circumstances, and is a split-type rolling that can control the radial position of the cylindrical roller at a low cost and suppress a decrease in bearing life while preventing noise and vibration. An object is to provide a bearing.

  The present invention is a combination of a pair of halved outer ring members, an outer ring having an inner circumferential surface formed with a relief portion in which the inner circumferential surface escapes radially outward at a boundary portion of the pair of halved outer ring members, and an inner circumference of the outer ring. In a split-type rolling bearing comprising a plurality of rollers disposed on a surface so as to be freely rollable and a cage formed with a plurality of pockets for holding the plurality of rollers, each of the plurality of pockets includes the A pair of holding surfaces that are formed to face each other across the roller and slide in contact with the outer peripheral surface of the roller from both sides in the radial direction of the roller to hold the roller, and the pair of holding surfaces at the escape portion It is characterized in that the gaps are formed so as to gradually narrow toward the radially outer side of the cage so that the movement of the cage can be regulated radially outward.

According to the split type rolling bearing having the above-described configuration, the pair of holding surfaces whose gaps are gradually narrowed toward the radially outer side of the cage so that the rollers can be restricted from moving radially outward at the escape portion. However, since it is formed in the pocket of the cage, when the roller is positioned in the relief portion, the roller is moved radially outward when no radial load is applied to the roller. Thus, it is possible to prevent contact between the pair of halved outer ring members generated on the inner peripheral side of the escape portion. As a result, it is possible to suppress a decrease in bearing life while preventing noise and vibration.
Furthermore, according to the present invention, the position of the roller can be regulated by a simple configuration in which the pair of holding surfaces are formed as described above, so that a fine and highly accurate forming process as in the conventional example is not required. Cost reduction is possible.

In the split type rolling bearing, it is preferable that the pair of holding surfaces are formed as tapered surfaces in which a gap between the pair of holding surfaces gradually decreases toward the radially outer side of the cage.
In this case, the pair of holding surfaces can be easily formed, and the cost can be further reduced.

Furthermore, the pair of holding surfaces may be formed in a concave curved surface so that a gap between the pair of holding surfaces gradually decreases toward the outside in the radial direction of the cage.
In this case, since the holding surface is formed as a concave curved surface, it is possible to restrict the roller from moving radially outward while enhancing the holding property of the roller by the pocket.

  According to the split type rolling bearing of the present invention, the radial position of the cylindrical roller can be regulated at a low cost, and a decrease in bearing life can be suppressed while preventing noise and vibration.

It is sectional drawing of the crankshaft support part which applied the split type rolling bearing which concerns on one Embodiment of this invention as a bearing for crank journals. It is the expanded sectional view which showed the pocket part of the holder | retainer in FIG. 1, and the boundary part of a half outer ring member. It is the expanded sectional view which showed the pocket part of the holder | retainer in the split-type rolling bearing which concerns on other embodiment of this invention.

Next, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a crankshaft support portion in which a split rolling bearing according to an embodiment of the present invention is applied as a crank journal bearing.
In FIG. 1, the crankshaft support portion 1 includes an upper block 2 provided on a cylinder block (not shown) and a bearing cap 4 constituting the housing 3 by being fixed to the upper block 2.
The bearing cap 4 is fixed to the upper block 2 by fixing bolts 6. The housing 3 constituted by the upper block 2 and the bearing cap 4 is formed in a cylindrical hole shape. A split type rolling bearing 10 is press-fitted on the inner peripheral surface side of the housing 3.

The split type rolling bearing 10 is disposed between the housing 3 and the crankshaft 5 and rotatably supports the crankshaft 5 with respect to the cylinder block.
The split-type rolling bearing 10 includes an outer ring 11 disposed in close contact with the inner peripheral surface of the housing 3, a plurality of rollers 12 disposed on the inner peripheral surface 11 a of the outer ring 11, and rollers 12. And a retainer 13 for holding them so as to be arranged at substantially equal intervals in the circumferential direction. The plurality of rollers 12 are in contact with the crank journal 5a of the crankshaft 5, and roll on the outer peripheral surface of the crank journal 5a. That is, the split type rolling bearing 10 uses the crank journal 5a as a member on the inner ring side.

  The outer ring 11 is configured by combining a set of half-split outer ring members 14 divided into two in the circumferential direction. The retainer 13 is also configured by combining a pair of half members 15 that are also divided in the circumferential direction, and the split type rolling bearing 10 is installed in the circumferential direction to be attached to the crank journal 5a. Can be divided into two.

The cage 13 is an annular member formed using a resin, and a plurality of pockets 16 for holding the rollers 12 are formed at substantially equal intervals in the circumferential direction.
FIG. 2 is an enlarged cross-sectional view showing the pocket 16 portion of the cage 13 and the boundary portion of the half outer ring member 14 in FIG.
Each of the pockets 16 is formed in a rectangular hole so as to hold a cylindrical roller, and has a pair of holding surfaces 17 formed facing each other across the roller 12 as shown in the figure. ing. The pair of holding surfaces 17 are in sliding contact with the outer peripheral surface 12 a of the roller 12 from both sides in the radial direction of the roller 12 to hold the roller 12.

  In addition, the pair of holding surfaces 17 are formed in tapered surfaces in which the gap between each other gradually decreases toward the outside in the radial direction of the rolling bearing.

Here, as shown in FIG. 2, the inner peripheral surface 11a of the outer ring 11 expands radially outward to escape at the boundary part of the pair of half-split outer ring members constituting the outer ring 11. A portion 30 is formed.
Therefore, when the roller 12 passes through the escape portion 30, no radial load is applied to the roller 12.
On the other hand, the pair of holding surfaces 17 are formed as tapered surfaces capable of restricting the rollers 12 from moving outward in the radial direction to the extent that the rollers 12 do not contact the inner peripheral surface 11a in the escape portion 30. ing.

That is, the holding surface 17 of the present embodiment is formed in a tapered surface such that the movement of the roller 12 outward in the radial direction is restricted to the position indicated by the broken line in FIG. Further, when the roller 12 rotates due to the relative rotation of the inner and outer rings, the roller 12 rotates while being in sliding contact with the holding surface 17. At this time, the holding surface 17 with which the roller 12 is slidably contacted is a tapered surface as described above. Therefore, the roller 12 tries to move in a direction in which it is pressed radially inward.
For the above reason, the roller 12 is restricted from moving radially outward by the pair of holding surfaces 17.

According to the split type rolling bearing having the above-described configuration, a pair of gaps gradually narrowing toward the radially outer side of the cage 13 so that the roller 12 can be restricted from moving radially outward in the escape portion 30. Since the holding surface 17 is formed in the pocket 16 of the cage 13, when the roller 12 is positioned in the escape portion 30, when the radial load is not applied to the roller 12, It is possible to prevent the roller 12 from moving outward in the radial direction and coming into contact with the step 31 between the pair of half outer ring members 14 generated on the inner peripheral side of the escape portion 30. As a result, it is possible to suppress a decrease in bearing life while preventing noise and vibration.
Furthermore, according to the present embodiment, the position of the roller 12 can be regulated by a simple configuration in which the pair of holding surfaces 17 are formed so that the gap between the holding surfaces 17 gradually decreases toward the outside in the radial direction. Such a fine and highly accurate formation process is not required, and the cost can be reduced.

  Further, in the present embodiment, the pair of holding surfaces 17 are formed as tapered surfaces whose gaps gradually become narrower toward the radially outer side of the rolling bearing, so that the pair of holding surfaces 17 can be easily formed. Further cost reduction is possible.

  Further, in the above embodiment, protrusions 18 and 19 projecting inward of the pocket 16 are formed on the outer peripheral side edge and the inner peripheral side edge of the pair of holding surfaces 17 of the pocket 16, respectively. These protrusions 18 and 19 supplementarily restrict the movement of the roller 12 in the radial direction, and the protrusions 18 and 19 can more effectively restrict the movement of the roller 12 in the radial direction.

FIG. 3 is an enlarged cross-sectional view showing a pocket 16 portion of the cage 13 in a split-type rolling bearing according to another embodiment of the present invention.
The present embodiment is different from the above-described embodiment in that the pair of holding surfaces 17 are formed as concave curved surfaces.
That is, the pair of holding surfaces 17 in the pocket 16 of the cage 13 of the present embodiment is formed in a concave curved surface in which a gap between each pair gradually decreases toward the outside in the radial direction of the cage 13. It restricts that 12 moves to the diameter direction outside.
In the case of this embodiment, since the pair of holding surfaces 17 are formed in a concave curved surface, it is possible to restrict the rollers 12 from moving outward in the radial direction while improving the holding properties of the rollers 12 by the pockets 16. .

The present invention is not limited to the above embodiments. In each of the above-described embodiments, the case of the split type rolling bearing divided into two in the circumferential direction has been illustrated, but the present invention can also be applied to a split type rolling bearing having three or more parts.
Moreover, in the said embodiment, although the case where the holder | retainer 13 was formed using resin was illustrated, it can also be formed using metals, such as a steel plate, copper, aluminum, for example.
Moreover, in the said embodiment, although the case where this invention was applied to the bearing for crank journals was illustrated, it is applicable also to the bearing of the big end part of a connecting rod, for example.

DESCRIPTION OF SYMBOLS 10 Split type rolling bearing 11 Outer ring 11a Inner peripheral surface 12 Roller 13 Cage 14 Half outer ring member 16 Pocket 17 Holding surface 30 Escape part

Claims (3)

An outer ring formed by combining a set of half outer ring members, and forming an escape portion in which the inner peripheral surface escapes radially outward at the boundary of the set of half outer ring members;
A plurality of rollers disposed on the inner peripheral surface of the outer ring so as to be freely rollable;
In a split type rolling bearing provided with a cage formed with a plurality of pockets for holding the plurality of rollers,
Each of the plurality of pockets has a pair of holding surfaces that are formed to face each other with the roller interposed therebetween and that are in sliding contact with the outer peripheral surface of the roller from both radial sides of the roller and hold the roller.
The pair of holding surfaces are formed such that a gap between the pair of holding surfaces gradually narrows toward the radially outer side of the cage so that the rollers can be restricted from moving radially outward in the escape portion. Divided type rolling bearing characterized by   2. The split type rolling bearing according to claim 1, wherein the pair of holding surfaces are formed as tapered surfaces in which a gap between the pair of holding surfaces gradually decreases toward the outside in the radial direction of the cage.   2. The split type rolling bearing according to claim 1, wherein the pair of holding surfaces are formed as concave curved surfaces in which a gap between the pair of holding surfaces gradually decreases toward a radially outer side of the cage.

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