JP2009019702A - Split type needle roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a needle roller bearing which can reliably come in close contact with a mounted part and contribute to yield improvement. <P>SOLUTION: The needle roller bearing whose outer ring 14 is circumferentially divided into at least two parts is characterized in that the outer diameter D1 of the divided outer rings 14a, 14b is 1% to 3% greater than the inner diameter D of housings 10a, 10b and that the total of circumferential lengths L1, L2 of the divided outer rings 14a, 14b is equal to or greater than the circumferential length 2L of the inner diameter faces 12a, 12b or the housings 10a, 10b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a needle roller bearing in which a bearing ring and a cage are divided at least in the circumferential direction. For example, a split needle used in a rotating portion of a crankshaft or a connecting rod of an automotive engine or industrial machine. The present invention relates to a tapered roller bearing.

Conventionally, as a bearing for supporting a crankshaft of an automobile engine, a split sliding bearing divided into two parts has been mainly used because of assembly restrictions. However, the split type plain bearing has a high frictional resistance under high speed rotation. For this reason, in recent years, there has been a movement to improve fuel efficiency by adopting needle roller bearings with low frictional resistance.
As shown in FIG. 4, the split needle roller bearing 100 includes a plurality of needle rollers 106 arranged in at least two outer rings 104 a and 104 b attached to a housing 102, and functions as an inner ring (see FIG. 4). (Not shown).

Here, when the bearing ring and the cage of the needle roller bearing 100 are divided into two to form a split roller bearing, for example, an integral bearing ring as described in Patent Document 1 is centered by a method of “natural splitting”. The method of cutting with is taken.
JP-A-6-81846

  As a method for bringing the outer ring housing into close contact with each other, there is a method called a crash method. In this method, as shown in FIG. 5 (a), the circumferential length of the bearing outer rings 104a and 104b is slightly longer than the circumferential length of the housing, and as shown in FIG. The outer rings 104a and 104b are brought into close contact with each other by a force for crushing the end faces. In this case, an appropriate amount of crash is set according to the use conditions and size. However, the above-mentioned natural cracking method, etc. has a fractured surface at the split end face, and the direction of fracture is not constant. Is not suitable.

  Therefore, in the method described in Patent Document 1, it is not possible to apply an adhesion force due to a crash or the like to the fitting surface of the attached member (housing) with the inner diameters 104a and 104b. Further, in the case of the housings 102a and 102b using a light alloy, a gap is formed on the mating surface between the outer rings 104a and 104b and the housings 102a and 102b due to the difference in linear expansion coefficient between the outer rings 104a and 104b and the housings 102a and 102b at high temperatures. Occurs, and there is a problem that the mating surface relatively shifts (creep). Then, when the outer rings 104a and 104b creep in the circumferential direction and the split end faces 104c of the outer rings 104a and 104b are displaced to the load zone as shown in FIG. 6, problems such as flaking and abnormal noise occur. There is.

  In addition, when split bearings are mounted on parts that receive variable loads such as crankshafts, noise is generated because the outer ring is displaced in the radial direction by the load due to the gap generated on the mating surface, causing the housing to strike the housing. There is a problem.

  Moreover, in order to prevent creep, it is necessary to attach rotation prevention members, such as a pin, and there exists a problem of an increase in an assembly man-hour and a cost increase.

  Further, when the outer rings 104a and 104b are not divided by natural cracking but by machining, as shown in FIG. 7, one outer ring 104b is divided at a central angle of 180 ° or more in order to add a crash portion. There is a need. Then, the remaining outer ring 104a having a central angle of less than 180 ° indicated by the imaginary line cannot be a product, and only one usable divided outer ring 104b can be made from one integrated outer ring, resulting in poor yield. There's a problem.

  An object of the present invention is to provide a split-type needle roller bearing that can be securely brought into close contact with a mounted portion and that can improve the yield.

The above object of the present invention can be achieved by the following constitution.
(1) In the needle roller bearing in which the outer ring is divided at least in the circumferential direction,
The outer diameter of the divided outer ring is 1% to 3% larger than the inner diameter of the attached member, and the total circumferential length of the divided outer ring is the circumferential length of the inner diameter surface of the attached member. A needle roller bearing characterized by having a height greater than that.

(2) The needle roller bearing according to (1), wherein the divided outer ring is formed by dividing an integrated outer ring by machining.

  According to the configuration of (1), the outer ring is divided into outer rings having an outer diameter larger than the inner diameter of the mounted member, and the total circumferential length is the circumferential length of the inner diameter surface of the mounted member. Since the outer ring as described above is attached to the attached member, when the divided outer rings are combined, the outer ring comes into close contact with the inner diameter surface of the attached member due to a crash action.

  Further, by dividing the outer ring having an outer diameter that is 1% to 3% larger than the inner diameter of the member to be attached, all the divided outer rings divided from the integrated outer ring can be used as bearings. No waste is generated from the outer ring, and the yield is improved.

  Here, if the outer diameter of the divided outer ring is less than 101% of the inner diameter of the mounted member, there is a risk that the cutting allowance will not be sufficiently obtained when the outer ring is cut. There is a possibility that it cannot be firmly fixed. Further, if the outer diameter of the divided outer ring is larger than 103% of the inner diameter of the member to be attached, the amount of deformation when attached to the member to be attached increases, so the outer ring is properly attached to the attachment surface of the member to be attached. There is also a concern that the outer ring may break in some cases.

  According to the configuration of (2), since the integrated outer ring before the division is divided by machining, the division surface of the outer ring becomes a flat surface, and the division surface of the outer ring is aligned when mounted on the mounted portion, so that the bearing is accurately Can be attached to.

  According to the split-type needle roller bearing of the present invention, since the outer ring can be mounted in close contact with the mounted portion, flaking and abnormal noise can be prevented. Moreover, since all the outer rings divided from the integral outer ring can be used, the yield at the time of manufacturing the outer ring is improved.

  Note that the outer ring in the present invention is preferably used as an outer ring of the same bearing as it is as a set of divided outer rings as a result of dividing the outer ring that was integrated, but the set of outer rings that were integrated is not necessarily used for the same bearing. A part of the split outer ring may be used for other bearings. That is, the split surfaces of the split outer rings obtained by splitting different integral outer rings may be processed into appropriate contact surfaces, and the split outer rings may be appropriately combined and used for the same bearing.

  The split roller bearing obtained by the present invention is suitably used for supporting a crankshaft of an automobile engine when low vibration, high load resistance, and high durability are required.

  Hereinafter, the present invention will be described with reference to illustrated embodiments.

  FIG. 1A is a cross-sectional view of a housing as a mounted member to which the split needle roller bearing of the embodiment of the present invention is mounted, and FIG. 1B is a split needle roller bearing of the embodiment of the present invention. FIG. 2 is a front view of the divided outer ring.

  As shown in FIG. 1 (a), the housing 10 is composed of divided housings 10a and 10b that are divided into upper and lower parts, and the outer ring mounting surface 12 of the housing 10 is a curved surface having an inner diameter D and a circumferential length L. On the other hand, as shown in FIG. 1B, the outer ring 14 is formed such that the outer diameter D1 is 1.01 to 1.03 times the housing inner diameter D.

  The outer ring 14 may be divided by natural splitting, but is preferably divided by machining. When the outer ring 14 is divided into two parts by machining, as shown in FIG. 2, the outer ring 14 becomes divided outer rings 14a and 14b having circumferential lengths L1 and L2, and the divided surfaces are flat. Since the outer diameters D1, D2 of the split outer rings 14a, 14b are 1.01-1.03 times the housing inner diameter D, the circumferential lengths L1, L2 of the split outer rings 14a, 14b are also in the housing circumferential direction. It is approximately 1.01-1.03 times the length 2L. In the present embodiment, the circumferential lengths L1 and L2 of the two divided outer rings 14a and 14b are equal. The total length of the peripheral lengths of the split outer rings 14a and 14b is shorter than the peripheral length of the outer ring 14 before splitting by twice the cutting allowance t by machining.

  Since the circumferential lengths L1 and L2 of the split outer rings 14a and 14b are longer than the circumferential length L of the housing, if the split outer rings 14a and 14b are to be mounted in the housing, the split outer rings 14a and 14b As shown in FIG. 3, a gap s is generated between the split outer rings 14a and 14b and the housings 10a and 10b without being completely contained in the housing. When the split outer rings 14a and 14b are elastically deformed in the radial direction as shown by an arrow A to reduce the diameter and push into the housing to fill the gap s, the split outer rings 14a and 14b are mounted on the inner diameter surfaces 12a and 12b. The two ends protrude slightly from the housing. The total amount of protrusion is the amount of crash. When the outer diameters D1 and D2 of the split outer rings 14a and 14b are larger than 103% of the housing inner diameter D, the amount of elastic deformation increases and attachment becomes difficult. In addition, problems such as breaking of the outer rings 14a and 14b are likely to occur.

  When the split outer rings 14a and 14b formed in this way are attached to the housings 10a and 10b by the crash method shown in FIG. 5, the split outer rings 14a and 14b are pushed into the housing inner diameter surfaces 12a and 12b according to the amount of crash. The ends are fixed in pressure contact.

  According to the above-described embodiment, the split outer ring is divided by machining so that the outer diameter D1 is larger by 1% to 3% than the housing inner diameter D in consideration of the crush amount and the cutting allowance according to the necessary adhesion force. , Two equally sized split outer rings can be obtained from one integral outer ring. As a result, the two split outer rings can be used without waste, and the yield of the split outer rings is improved.

  The split outer ring is attached to the housing in a state where the end portions are in close contact with each other by an appropriate contact force according to the amount of crash, and is in close contact with the inner diameter surface of the housing. Therefore, there is no gap between the split outer ring and the housing inner surface, and it is possible to prevent abnormal noise and flaking caused by the gap.

  In addition, this invention is not limited to the said embodiment, All the deformation | transformation are possible according to the main point of this invention. For example, the number of divisions of the outer ring is not limited to two, and the outer ring may be divided into three or more.

(A) is sectional drawing which shows the housing with which the split-type roller bearing which is embodiment of this invention is mounted | worn, (b) is a front view of the outer ring | wheel of the split-type roller bearing which is embodiment of this invention. It is a front view of the divided | segmented outer ring | wheel of the split roller bearing which is embodiment of this invention. It is a schematic diagram when attaching the outer ring | wheel of the split-type roller bearing which is embodiment of this invention to a housing. It is sectional drawing of a split type roller bearing. It is a schematic diagram which mounts a split type roller bearing to a housing by the crush method. It is sectional drawing of the state to which the division surface moved at the time of mounting | wearing with the conventional division type roller bearing. It is a front view of the conventional divided outer ring.

Explanation of symbols

10, 10a, 10b Housing 12a, 12b Inner diameter surface 14, 14a, 14b Outer ring

Claims (2)

In the needle roller bearing in which the outer ring is divided at least in the circumferential direction,
The outer diameter of the divided outer ring is 1% to 3% larger than the inner diameter of the attached member, and the total circumferential length of the divided outer ring is the circumferential length of the inner diameter surface of the attached member. A needle roller bearing characterized by having a height greater than that.   The needle roller bearing according to claim 1, wherein the divided outer ring is formed by dividing an integrated outer ring by machining.

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