JP2010117008A - Structure and method of mounting rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mounting structure enabling even inner rings of a halved structure to be rigidly mounted to a shaft part of a crankshaft. <P>SOLUTION: This rolling bearing 1 has halved inner rings 5a and 5b, halved outer rings 2a and 2b, cages 4a and 4b and a roller 3. The halved inner rings 5a and 5b of the rolling bearing 1 are clamped and held in the axial direction by crank arms 14 arranged on both sides in the axial direction of a journal part 12 of a crankshaft 11, and are firmly installed in the journal part 12. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a rolling bearing mounting structure and method.

  In engines such as automobiles and ships, the bearing that supports the crankshaft that converts the reciprocating motion of the piston into a rotational motion is arranged between the crank arms, so a split bearing divided into two in the circumferential direction is used. Yes.

  Conventionally, a sliding bearing has been used as the split bearing. However, in recent years, the demand for an engine with lower fuel consumption has been increasing. Therefore, in order to reduce the rotation loss, a sliding bearing is used instead. It has been proposed to use rolling bearings divided in directions (see, for example, Patent Document 1).

  This split type rolling bearing is composed of a pair of split outer rings, a plurality of rolling elements arranged so as to be able to roll on each inner peripheral surface of both split outer rings, It is provided with a set of two split cages that are held so as to be arranged at substantially equal intervals in the circumferential direction. The journal portion of the crankshaft is fitted into the rolling bearing as an inner ring member.

JP 2007-247818 A

  The journal portion of the crankshaft usually does not have the performance such as wear resistance required for the inner ring of the rolling bearing, and there is a problem that peeling or wear occurs at an early stage. For this reason, it is conceivable to separately attach an inner ring to the journal part, but since there are crank arms on both sides in the axial direction of the journal part, the inner ring needs to be divided into two parts in the same manner as the outer ring. It is required that the inner ring be firmly attached to the journal portion so as not to occur. However, if the inner ring has a split structure, it cannot be strongly pressed against the journal part, so it is difficult to attach it firmly to the journal part.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a rolling bearing mounting structure and method that can be firmly attached to a shaft portion of a crankshaft even if the inner ring has a split structure.

The present invention is a rolling bearing mounting structure for the shaft portion of the crankshaft,
The rolling bearing is mounted on the outer peripheral surface of the shaft portion and arranged in two sets of split inner rings divided into two in the circumferential direction, and is arranged radially outside the split inner ring, and in the circumferential direction. A pair of two split outer rings divided between the two split outer rings and the two split inner rings so that the inner peripheral surface of the two split outer rings and the outer peripheral surface of the two split inner rings can roll. A plurality of rolling elements disposed on the crankshaft, and a cage for holding the rolling elements at substantially equal intervals in the circumferential direction, wherein the two split inner rings are disposed on both axial sides of the shaft portion. It is characterized by being clamped and held in the axial direction by an arm.

  According to the above configuration, the split inner ring is clamped and held in the axial direction by the crank arms arranged on both sides in the axial direction of the shaft part, so that the split inner ring can be firmly attached to the shaft part. The occurrence of creep of the split inner ring with respect to the portion can be suppressed.

  In the above configuration, the circumferential direction in which the circumferential end of one split inner ring and the circumferential end of the other split inner ring are axially pressed against each other by the clamping force of the two split inner rings by the crank arm It is preferable that a surface extending along is formed. In this case, since the two split inner rings are pressed against each other in the axial direction on the surface extending along the circumferential direction, the relative positions of the two split inner rings are firmly fixed. Therefore, the split inner ring can be more firmly attached to the shaft portion.

  The present invention is a method of attaching the above-described rolling bearing to a shaft portion of a crankshaft, wherein the axial dimensions of the two split inner rings, and the axial distance between the crank arms arranged on both sides of the shaft portion in the axial direction are provided. An axial interference margin is set between the two split inner rings, and the two split inner rings are inserted between the crank arms and attached to the shaft part by cooling fit of the two split inner rings or shrink fitting of the shaft part. It is said.

  With such an attachment method, the split inner ring can be firmly attached to the shaft portion of the crankshaft.

  In the present invention, even an inner ring having a split structure can be firmly attached to the shaft portion of the crankshaft.

  FIG. 1 is a front sectional view of a rolling bearing according to an embodiment of the present invention. The rolling bearing 1 of the present embodiment is attached to the outer peripheral surface of the journal portion 12 of the crankshaft 11 and is fitted in a support hole 13A of a housing 13 provided in the crankcase. The housing 13 includes an upper block 13B and a lower block 13C, and a support hole 13A is formed between the lower block 13B and the lower block 13B by bolting the lower block 13C to the lower surface of the upper block 13B.

  The crankshaft 11 includes a journal portion 12, a crank arm 14, a crankpin 15, a balance weight 16, and the like. The journal portion 12 is disposed at the rotation center position of the crankshaft 11 and is rotatably supported by the housing 13 via the rolling bearing 1. A plurality of crank arms 14 are arranged side by side in the axial direction and are connected to each other by a journal portion 12 and a crank pin 15. The crank pin 15 is provided at the front end portion of the crank arm 14, and the balance weight 16 is provided at the rear end portion of the crank arm 14. The balance weight 16 may be formed integrally with the crank arm 14 or may be formed separately from the crank arm 14.

  FIG. 2 is a side view of the rolling bearing 1. The rolling bearing 1 includes a set 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 are arranged so as to roll on the inner peripheral surfaces of the two split outer rings 2a and 2b. A roller 3 that is a rolling element and a pair of split cages 4a and 4b that hold the rollers 3 so as to be arranged at substantially equal intervals in the circumferential direction are provided. Furthermore, the rolling bearing 1 according to the present embodiment includes a pair of split inner rings 5 a and 5 b that are divided into two in the circumferential direction, and the inner peripheral surfaces of the two split inner rings 5 a and 5 b are the outer peripheral surfaces of the journal portion 12. The rollers 3 are disposed so as to be fitted and roll on the outer peripheral surfaces of the two split inner rings 5a and 5b. The cage is not limited to the split structure, but may be a ring structure that is divided at one place in the circumferential direction, and this divided place may be widened and attached to the outer peripheral side of the split inner rings 5a and 5b. Good.

  FIG. 3 is an exploded perspective view of the split inner ring 5a, 5b. The split inner rings 5a, 5b are made of bearing steel such as SUJ2, and have desired performance such as hardness (for example, HRC58 or higher), mechanical strength, wear resistance, etc. as the raceway of the rolling bearing 1. The two split inner rings 5a and 5b are each formed in a semicircular arc shape, and both circumferential end surfaces are divided surfaces 5a2 and 5b2 that extend straight along the axial direction. The two split inner rings 5a and 5b are abutted with each other on the split surfaces 5a2 and 5b2 at both ends in the circumferential direction, or face each other with a slight gap in the circumferential direction.

  As shown in FIG. 1, the inner peripheral diameters of the two split inner rings 5a and 5b are set to be substantially the same as the outer diameter of the journal part 12, and the inner peripheral surfaces of the two split inner rings 5a and 5b are formed on the outer peripheral surface of the journal part 12. Are configured to be in close contact with each other. Further, the axial length of the split inner rings 5a, 5b is set slightly larger than the axial interval W between the crank arms 14 arranged on both sides in the axial direction of the journal portion 12, and a predetermined distance between both dimensions is set. Tightness is set.

And the split inner ring | wheel 5a, 5b is attached to the outer peripheral surface of the journal part 12 by cold fitting or shrink fitting. That is, the split inner rings 5a and 5b are fitted to the outer peripheral surface of the journal portion 12 in a state where the axial dimension is reduced by being cooled, or the interval between the crank arms 14 is heated by heating the journal portion 12. It is fitted to the outer peripheral surface of the journal portion 12 with W widened.
When the split inner ring 5a, 5b or the journal portion 12 returns to normal temperature, the opposed end surfaces T of the crank arm 14 are pressed against the axially opposite end faces 5a1, 5b1 of the split inner ring 5a, 5b, and the split inner ring 5a is caused by the frictional force therebetween. , 5b is held by the crank arm 14.

Therefore, the rolling bearing 1 of this embodiment can be firmly attached and fixed to the journal portion 12 even though the inner rings 5a and 5b have a split structure, and the creep of the split inner rings 5a and 5b with respect to the journal portion 12 is prevented. It is possible to do.
As shown in FIG. 2, a plurality of narrow grooves 18 extending along the axial direction are formed on the inner peripheral surfaces of the split inner rings 5a and 5b at intervals in the circumferential direction. 12, the resistance in the circumferential direction of both split inner rings 5a and 5b is increased, and creeping of the split inner rings 5a and 5b is prevented.

  Further, by using the rolling bearing 1 having the split inner rings 5a and 5b as in this embodiment, the roller 3 does not roll on the outer peripheral surface of the journal part 12, and the journal part 12 is worn or damaged. Can be prevented. Further, even when the rolling bearing 1 itself has reached the end of its life, the journal portion 12 is hardly worn and can be dealt with by replacing the rolling bearing 1.

  Further, as in the present embodiment, the split inner rings 5a, 5b are held by the crank arm 14 so that there is no need to attach a fastener such as a bolt to the split inner rings 5a, 5b. Therefore, the structure of the split inner ring 5a, 5b itself can be simplified, and the wall thickness of the split inner ring 5a, 5b can be reduced. 1 lifespan can be improved.

  FIG. 4 is an exploded perspective view showing another embodiment of the split inner ring. In the present embodiment, one end in the circumferential direction of the split inner ring 5a, 5b projects in the circumferential direction on one axial side, and the other end in the circumferential direction projects in the circumferential direction on the opposite side in the axial direction. ing. Therefore, the split surfaces at both ends in the circumferential direction of the split inner rings 5a, 5b are divided surfaces 5a2, 5b2 extending along the axial direction, and split surfaces 5a3 extending along the circumferential direction (direction perpendicular to the axial direction). 5b3, and these are arranged in a substantially Z shape (crank shape).

  In the present embodiment, the circumferential end of one split inner ring 5a and the circumferential end of the other split inner ring 5b extend in the circumferential direction by engaging each other in the circumferential direction. The divided surfaces 5a3 and 5b3 are in surface contact with each other. Accordingly, when the axially opposite end faces 5a1 and 5b1 of the split inner rings 5a and 5b are clamped by the crank arm 14, the split surfaces 5a3 and 5b3 extending along the circumferential direction of the split inner rings 5a and 5b are pressed in the axial direction. The relative positions of the two split inner rings 5a and 5b are firmly fixed by the frictional force. Therefore, in this embodiment, the split inner rings 5a and 5b can be attached to the journal portion 12 more firmly than in the first embodiment.

  FIG. 5 is an exploded perspective view showing still another embodiment of the split inner ring. In the present embodiment, one end portion in the circumferential direction of the split inner rings 5a, 5b protrudes in the circumferential direction at the central portion in the axial direction, and the other end portion in the circumferential direction recedes in the circumferential direction at the central portion in the axial direction. It has become. Therefore, the split surfaces at both ends in the circumferential direction of the split inner rings 5a and 5b include split surfaces 5a2 and 5b2 extending along the axial direction and split surfaces 5a3 and 5b3 extending along the circumferential direction. It is arranged in a convex shape and a substantially concave shape.

  Also in the present embodiment, the circumferential end of one split inner ring 5a and the circumferential end of the other split inner ring 5b are fitted to each other in the circumferential direction so that the circumferential direction extends along the circumferential direction. The extending divided surfaces 5a3 and 5b3 are in surface contact with each other in the axial direction. When the axially opposite end faces 5a1 and 5b1 of the split inner rings 5a and 5b are clamped by the crank arm 14, the split surfaces 5a3 and 5b3 extending along the circumferential direction of the split inner rings 5a and 5b are pressed in the axial direction. The relative positions of the two split inner rings 5a and 5b are firmly fixed by the frictional force, and the split inner rings 5a and 5b can be attached to the journal portion 12 more firmly.

The present invention is not limited to the above-described embodiment, and the design can be changed as appropriate. For example, the present invention can be applied to the case where the rolling bearing 1 is attached to the crankpin 15 of the crankshaft 11. In this case, the split inner rings 5a and 5b of the rolling bearing 1 are fitted to the outer peripheral surface of the crankpin 15, and the split inner rings 5a and 5b are held by the crank arms 14 on both sides in the axial direction of the crankpin 15 to be held. What is necessary is just to fit the outer peripheral surface of 1 split outer ring 2a, 2b to the support hole of the big end part of a connecting rod (not shown).
Moreover, although the bearing apparatus of 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 front sectional drawing of the rolling bearing 1 which concerns on embodiment of this invention. It is a side view which shows the rolling bearing shown by FIG. It is a disassembled perspective view which shows the split inner ring of the rolling bearing shown by FIG. It is a disassembled perspective view which shows other embodiment of a split inner ring. It is a disassembled perspective view which shows other embodiment of a split inner ring.

Explanation of symbols

1 Rolling bearing 2a Split outer ring 2b Split outer ring 3 Roller (rolling element)
4a Cage 4b Cage 5a Split inner ring 5b Split inner ring 5a3 Split surface 5b3 Split surface 10 Bearing device 11 Crankshaft 12 Journal part (shaft part)
14 Crank arm

Claims (3)

A structure for mounting a rolling bearing on a shaft portion of a crankshaft,
The rolling bearing is
A set of two split inner rings attached to the outer peripheral surface of the shaft portion and split into two in the circumferential direction;
A set of two split outer rings arranged on the radially outer side of the split split inner ring and split in two in the circumferential direction;
A plurality of rolling elements disposed between the two split outer rings and the two split inner rings so as to roll the inner peripheral surface of the two split outer rings and the outer peripheral surface of the two split inner rings;
A holder that holds the rolling elements at substantially equal intervals in the circumferential direction,
2. A rolling bearing mounting structure, wherein the split inner ring is held by being clamped in the axial direction by crank arms disposed on both axial sides of the shaft portion.   Surfaces along the circumferential direction that are pressed against each other by the clamping pressure of the two split inner rings by the crank arm to the circumferential end of one of the split inner rings and the circumferential end of the other split inner ring. The rolling bearing mounting structure according to claim 1, which is formed. A method of mounting a rolling bearing on a crankshaft shaft,
The rolling bearing is
A set of two split inner rings attached to the outer peripheral surface of the shaft portion and split into two in the circumferential direction;
A set of two split outer rings arranged on the radially outer side of the split split inner ring and split in two in the circumferential direction;
A plurality of rolling elements disposed between the two split outer rings and the two split inner rings so as to roll the inner peripheral surface of the two split outer rings and the outer peripheral surface of the two split inner rings;
A holder that holds the rolling elements at substantially equal intervals in the circumferential direction,
An axial interference margin is set between the axial dimension of the two split inner rings and the axial interval between the crank arms arranged on both axial sides of the shaft part, A method of mounting a rolling bearing, comprising: fitting the two split inner rings between the crank arms by fitting the shaft portion to the shaft portion.

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