JP2011196460A - Split type rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a split type rolling bearing, easier in incorporation of a shaft, and capable of further restraining vibration, an abnormal sound and damage to a rolling element.SOLUTION: An outer ring member is constituted of a first outer ring split body 21 and a second outer ring split body 31 divided into two parts in the circumferential direction, and a flank Mn is formed in the vicinity of a split surface MB. The first outer ring split body 21 is a substantially C shape, and the length in the circumferential direction of the first outer ring split body 21 is longer than the length in the circumferential direction of the second outer ring split body 31. When supporting the shaft 1 by the first outer ring split body 21, the second outer ring split body 31 and the rolling element 15, the split surface MB is formed so that a plane including a shaft rotary shaft ZS and a plane MV passing through the center in the circumferential direction of the second outer ring split body 31 and the split surface MB become parallel. An interval between the split surface and the split surface in the first outer ring split body 21 is set at an interval by which the shaft 1 or the shaft 1 of arranging the rolling element 15 on the periphery, can pass in the radial direction.

Description

  The present invention relates to a split type rolling bearing in which an outer ring member is constituted by two outer ring divided bodies divided into two in the circumferential direction.

Two examples of conventional split-type rolling bearings are shown in FIGS. 4 (A) and 4 (B).
As shown in FIG. 4A, in a split rolling bearing for rotatably supporting a crankshaft (shaft 1) of an internal combustion engine such as an automobile or a ship on two split housing bodies 310 and 320 of a housing 300. A structure in which the outer ring member 200 is constituted by two outer ring divided bodies 210 and 310 that are divided into two in the circumferential direction, and is assembled to the two divided housing bodies 310 and 320 constituting the housing, respectively.
In such a split type rolling bearing, two outer rings as shown in FIG. 4 (A) together with the split housing bodies 310 and 320 due to an assembly error due to fastening of the bolts 4 of the two split housing bodies 310 and 320 and the like. In the divided bodies 210 and 220, a slight displacement ΔL may occur.
In this case, since a step is generated at the joining portion of the divided raceway surfaces of the two outer ring divided bodies 210 and 220, the rolling element 15 may collide with the edge portion of the step, which may cause vibration, abnormal noise, damage, and the like. . Further, when the step is large, there is a possibility of causing rotation failure.

Therefore, in the prior art described in Patent Document 1, as shown in FIG. 4B, an arc-shaped relief is provided in the vicinity of the division position SP on the raceway surfaces 231 and 241 of the two outer ring divided bodies 230 and 240. A split-type rolling bearing having a surface Mn is disclosed. In this case, the raceway surfaces 231 and 241 which are positions away from the division position SP on the inner circumferential surfaces of the outer ring divided bodies 230 and 240 are set to arcs having a radius r ₀ (constant) with the rotation axis ZS of the shaft 1 as the center. Has been. The flank Mn in the vicinity of the split position SP is set to an arc having a radius r ₁ (constant) centered on a position On offset from the rotation axis ZS of the shaft 1 by a distance ε, and the flank Mn is deepest. If the depth of the position is δ, the distance from the shaft rotation axis ZS to the farthest position (distance from the shaft rotation axis ZS to the division position SP) is the distance r ₀ + δ.
The two outer ring divided bodies 230 and 240 have the same circumferential length, and the divided surfaces at both ends of the two outer ring divided bodies 230 and 240 are the same plane including the shaft rotation axis ZS. Located on the top.

  In the prior art described in Patent Document 2, a plurality of pockets are radially provided in a cage made of an annular plate in which an opening narrower than the diameter of a supporting shaft is formed, and rolling elements are provided in the pockets. A thrust bearing is disclosed in which the inner circumference of the cage is 180 degrees or more.

JP 2007-2914 A JP 2009-162299 A

In the prior art described in Patent Document 1 shown in FIG. 4B, as shown in FIG. 2B, the direction in which the largest load is received from the crankshaft (the crankshaft receiving the rotational driving force from the piston is shown in FIG. The flank Mn and the split surface MB of the outer ring split body are located at the maximum load Fmax in the direction shown in FIG. Since the rolling element 15 revolves on the outer circumferential surface of the shaft 1 while rotating, the rolling element 15 that has moved in the direction of the maximum load Fmax is not in contact with both the flank Mn and the shaft 1 at the same time. At this position, the vibration of the rolling element 15 tends to increase. For this reason, when a greatly vibrating rolling element enters the raceway surface from the flank, it is likely to be caught at the boundary between the flank and the raceway, which may increase the noise and vibration of the crankshaft and reduce the bearing life. is there.
In addition, the conventional thrust bearing described in Patent Document 2 supports the shaft in the thrust direction and does not support the shaft in the radial direction, but is disposed on the outer peripheral portion of the shaft and extends in the circumferential direction. Has an opening. Although it is arranged on the outer periphery of the shaft, the width of the opening of the cage is smaller than the diameter of the shaft, so the shaft cannot be inserted in the radial direction from the opening of the cage, and the shaft rotation axis direction A shaft must be inserted along the cage. For this reason, workability at the time of attaching a bearing to the shaft is not good, and in the case of a crankshaft, there is a possibility that it cannot be inserted to a desired position depending on the position of the crank.
The present invention was devised in view of the above points, and is a split type rolling bearing that is easier to incorporate a shaft and that can further suppress vibration, noise, damage, etc. of rolling elements. The issue is to provide.

In order to solve the above problems, the split rolling bearing according to the present invention takes the following means.
First, according to a first aspect of the present invention, there is provided a first outer ring divided body in which an annular outer ring member that rotatably supports a shaft around a shaft rotation axis via a plurality of rolling elements is divided into two in the circumferential direction. In the split type rolling bearing constituted by two outer ring divided bodies, the first outer ring divided is provided at both end portions of each raceway surface which is an inner peripheral surface of each of the first outer ring divided body and the second outer ring divided body. When the shaft is supported by the body, the second outer ring divided body, and the rolling element, a flank is formed which gradually increases the distance from the shaft rotation axis.
The first outer ring divided body has a substantially C-shape, and the circumferential length of the first outer ring divided body is longer than the circumferential length of the second outer ring divided body. ing.
Furthermore, when the shaft is supported by the first outer ring divided body, the second outer ring divided body, and the rolling element, the plane includes a shaft rotation axis, and the center in the circumferential direction of the second outer ring divided body. The dividing surface is formed so that a plane passing therethrough and a dividing surface at a dividing portion of the first outer ring divided body and the second outer ring divided body are parallel to each other, and the dividing surface in the first outer ring divided body And the dividing surface are set such that the shaft or the shaft around which the rolling elements are arranged can pass in the radial direction.

According to the first aspect of the present invention, the positions of the dividing surface and the flank can be moved to a position shifted from the position where the maximum load is applied from the crankshaft (see FIG. 2A).
As a result, at the position where the maximum load is applied from the crankshaft, the rolling elements are in contact with both the outer peripheral surface of the crankshaft and the raceway surface of the outer ring member at the same time. Noise, damage, and the like can be further suppressed, and the life of the split rolling bearing can be extended.
Further, the shaft is inserted into the first outer ring divided body from the shaft rotation axis direction by setting the interval between the divided surfaces of the first outer ring divided body (that is, the width of the opening) to be an interval through which the shaft can pass in the radial direction. The shaft (or the shaft around which the rolling elements are arranged) can be assembled in the radial direction from the opening of the first outer ring divided body, so that the workability during assembly is good.

They are sectional drawing (A) which shows the state which assembled | attached the division | segmentation type rolling bearing 10 of this invention to the housing 5, and an exploded view (B) which shows an assembly order. It is a figure explaining the difference between the outer ring division body (the 1st outer ring division body 21 and the 2nd outer ring division body 31) in this Embodiment, and the conventional outer ring division bodies 240 and 230. FIG. It is a figure explaining the maximum width WSmax and the minimum width WSmin of the shaft 1 in which the rolling elements 15 are arrange | positioned in an outer peripheral surface in each of the case where the number of the rolling elements 15 is an even number, and an odd number. It is a figure explaining the example of the conventional division | segmentation rolling bearing.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing. FIG. 1A is a cross-sectional view showing a state in which the split rolling bearing 10 of the present invention is assembled to the housing 5, and FIG. 1B is an exploded view showing the assembly order.

● [Overall structure of split type rolling bearing 10 (Fig. 1)]
As shown in FIG. 1A, a split type rolling bearing 10 for rotatably supporting a shaft 1 (for example, a crankshaft of a vehicle, a ship, etc.) on two split housing bodies 6 and 8 of a housing 5 is a shaft. The outer ring member 20 is disposed on the outer periphery of the inner ring raceway surface 2 with an annular space therebetween, and a plurality of rolling elements (steel balls, rollers, etc.) 15 accommodated in the annular space, And a cage 16 that holds the interval between the adjacent rolling elements 15.
That is, the inner peripheral surfaces of the two divided housing bodies 6 and 8 constituting the housing 5 are respectively formed with semicircular arc bearing recessed portions 7 and 9 that are divided into two in the circumferential direction. The other divided housing body 8 is fastened to 6 by bolts 4.

The outer ring member 20 includes a first outer ring divided body 21 and a second outer ring divided body 31 that are divided into two in the circumferential direction, and is assembled to the bearing assembling recesses 7 and 9 of the two divided housing bodies 6 and 8, respectively. ing.
As shown in FIG. 1B, the first outer ring divided body 21 has a substantially C-shaped shape with an open top, and the length of the first outer ring divided body 21 in the circumferential direction is second. The outer ring divided body 31 is formed to be longer than the circumferential length.
Divided raceway surfaces 22 and 32 (corresponding to raceway surfaces) are formed on the inner peripheral surfaces of the first outer ring segment 21 and the second outer ring segment 31, respectively.

Note that the two divided housing bodies 6 and 8 together with the two divided housing bodies 6 and 8 are caused by an assembly error due to fastening of the bolts 4 of the two divided housing bodies 6 and 8 or the shape errors of the first outer ring divided body 21 and the second outer ring divided body 31. There is a possibility that a slight displacement (see FIG. 4A) may occur on the dividing surfaces MB of the first outer ring divided body 21 and the second outer ring divided body 31.
In consideration of this positional shift, the first outer ring divided body 21 and the second outer ring divided body 31 have both ends (circumferential ends) at both ends (circumferential ends) of the first race. When the shaft 1 is supported by the outer ring divided body 21, the second outer ring divided body 31, and the rolling element 15, a flank Mn is formed such that the distance from the shaft rotation axis ZS gradually increases. The flank Mn is formed to be deeper than the divided raceway surfaces 22 and 32 on the inner peripheral surface of the first outer ring divided body 21 and the second outer ring divided body 31 around the divided surface MB.

  When the shaft 1 is incorporated, as shown in FIG. 1 (B), the first outer ring divided body 21 is fitted into the bearing assembly recessed portion 7 of the divided housing body 6 and a part of the cage 16 is separated. After rolling the rolling element 15 (and the cage 16) around the outer peripheral surface, the shaft 1, which has been reconnected to the disconnected portion of the cage 16, is moved in the radial direction of the shaft 1 to Install from the opening. Then, the dividing surface MB of the second outer ring divided body 31 and the divided surface MB of the first outer ring divided body 21 are matched, and a part of the first outer ring divided body 21 and the second outer ring divided body 31 are divided into the divided housing bodies 8. The divided housing body 6 and the divided housing body 8 are fastened with the bolts 4.

● [The position of the flank Mn and the dividing surface MB and the direction of the dividing surface MB (FIGS. 2 and 3)]
FIG. 2A shows a state in which the shaft 1 is supported via the rolling elements 15 by the first outer ring divided body 21 and the second outer ring divided body 31 in the present embodiment, and FIG. Shows a state in which the shaft 1 is supported by the conventional outer ring divided bodies 230 and 240 via the rolling elements 15.
3A includes the rolling elements when the rolling elements 15 are arranged at equal intervals around the shaft 1 when the number of the rolling elements 15 is an even number (in this case, six). An example of the maximum width WSmax and the minimum width WSmin of the shaft 1 is shown. 3B shows a shaft including rolling elements when the rolling elements 15 are arranged at equal intervals around the shaft 1 when the number of rolling elements 15 is an odd number (in this case, five). An example of a maximum width WSmax of 1 and a minimum width WSmin is shown.

As shown in FIG. 2 (B), the outer ring divided bodies 230 and 240 in the conventional split type rolling bearing 110 have the same circumferential length, and both have a length of 180 degrees. MB is located on a plane MH including the shaft rotation axis ZS and parallel to the horizontal direction (XY plane in the case of FIG. 2B).
Since the flank Mn is formed in the vicinity of the dividing surface MB, the flank Mn is positioned in the horizontal direction with respect to the shaft 1.
Here, when the shaft 1 is, for example, a crankshaft of an internal combustion engine, the crankshaft converts the vertical motion of a connected piston (not shown) into a rotational motion, but the most when the piston moves from top to bottom. Upon receiving a large force, the maximum load Fmax applied to the split rolling bearing 10 by the shaft 1 is in the horizontal direction (see FIG. 2B).
However, in the outer ring divided bodies 230 and 240 in the conventional split type rolling bearing 110, the dividing surface MB and the flank Mn are located in the direction in which the maximum load Fmax from the shaft 1 is applied, and the outer peripheral surface of the shaft 1 is revolved. When the rolling element 15 that has reached the position of the flank Mn (position in the direction of the maximum load Fmax), the opposite side (outer peripheral side) of the rolling element 15 at this position is not supported by the outer ring divided body (flank Mn Therefore, it is easy to vibrate greatly (vibrates in the radial direction of the shaft 1). And since it enters from the flank Mn to the raceway surface with large vibration, it is easy to catch on the raceway surface gradually narrowing from the flank Mn, and noise and vibration increase. In addition, the life of the rolling elements 15, the cage 16, and the outer ring divided bodies 230 and 240 is likely to be affected.

Therefore, in the split type rolling bearing 10 of the present embodiment shown in FIG. 2A, the positions of the split surfaces MB and flank Mn of the first outer ring split body 21 and the second outer ring split body 31 are determined from the shaft 1. The position is changed to a position shifted from the direction in which the maximum load Fmax is applied.
Specifically, the first outer ring divided body 21 has a substantially C-shape, and the circumferential length of the first outer ring divided body 21 is greater than the circumferential length of the second outer ring divided body 31. (The circumferential length of the first outer ring segment 21 is longer than 180 degrees, and the circumferential length of the second outer ring segment 31 is shorter than 180 degrees). .
Thereby, even if the shaft 1 transmits force to the rolling element 15 in the direction of the maximum load Fmax, the rolling element 15 that has moved in the direction of the maximum load Fmax is the first outer ring divided body 21 from the opposite side (outer peripheral side). Therefore, the vibration of the rolling element 15 is suppressed.

Further, with respect to the dividing plane MB, not only the position but also the orientation of the dividing plane MB is changed. In the conventional outer ring divided bodies 230 and 240 shown in FIG. 2B, the dividing surface MB is positioned on the plane MH including the shaft rotation axis ZS. However, the dividing surface MB of the first outer ring divided body 21 (and the second outer ring divided body 31) of the present embodiment shown in FIG. 2A is a plane including the shaft rotation axis ZS and the second outer ring divided body. 31 (or first outer ring divided body 21) is formed to be parallel to a plane MV passing through the center in the circumferential direction. That is, the divided surfaces MB at both ends of the first outer ring divided body 21 are parallel to each other, and the divided surfaces MB at both ends of the second outer ring divided body 31 are also parallel to each other.
For this reason, the first outer ring divided body 21 and the second outer ring divided body 31 can be separated and molded by punching in a vertical direction from an outer ring member formed in an annular shape. Can be created at low cost.

Further, the split position width W (the interval between the division surfaces MB facing each other in the first outer ring divided body 21) which is the interval between the openings in the circumferential direction of the first outer ring divided body 21 is larger than the diameter of the shaft 1. Is set to an interval at which the shaft 1 can pass in the radial direction.
Thereby, it is not necessary to insert the first outer ring divided body 21 in the shaft rotation axis ZS direction from the end surface direction of the shaft 1, and the shaft 1 is inserted in the radial direction from the opening direction of the opening of the first outer ring divided body 21 ( Workability is good.

In addition, after partly separating the retainer 16 and winding the rolling element 15 and the retainer 16 around the shaft 1, the shaft 1 reconnected to the disengagement part of the retainer 16 is removed from the opening of the first outer ring divided body 21. When inserting, it is necessary to set the split position width W shown in FIG. 2A as follows.
In addition, in the state shown in FIG. 2A, the split position width W is the interval between the divided surfaces MB facing each other in the first outer ring divided body 21, or the divided surfaces at both ends in the circumferential direction in the second outer ring divided body 31. MB interval.
Further, as shown in FIG. 2A, the diameters of the raceway surfaces of the first outer ring divided body 21 and the second outer ring divided body 31 (that is, the outer ring member 20) are set to D ₁ , and the first outer ring divided body 21 and the second outer ring divided. When the diameter of the outer peripheral surface of the body 31 (that is, the outer ring member 20) is set to D ₀ , the diameter of the rolling elements 15 is set to dn, and the number of the rolling elements 15 is set to N, in each of cases where N is an even number and odd numbers, The split position width W is set as follows.

When the number N of rolling elements 15 is an even number, the split position width W is set as shown in (Formula 1).
W ≧ (D ₁ −dn) cos (π / N) + dn (Formula 1)
When the number N of rolling elements 15 is an odd number, the split position width W is set as shown in (Expression 2).
W ≧ {(D ₁ −dn) cos (π / N) + (D ₁ + dn)} * 1/2 (Formula 2)
By setting so as to satisfy the above-mentioned split position width W, a part of the retainer 16 is cut off, the rolling element 15 and the retainer 16 are wound around the shaft 1, and then the disconnected portion of the retainer 16 is reconnected. In the case where the shaft 1 is inserted in the radial direction from the opening of the first outer ring divided body 21, interference during assembly can be avoided.

As described above, the position of the flank Mn is shifted from the direction where the maximum load Fmax from the shaft 1 is applied as shown in FIG. 2A (in this case, the shaft rotation axis ZS between the flank faces Mn facing each other). 3) (or FIG. 3A) (or FIG. 3A) by setting the split position width W to satisfy (Equation 1) (or (Equation 2)). 3 (B)) can be set larger than the minimum width WSmin.
In the above description, the rolling element 15 and the retainer 16 are wound around the shaft 1 and then inserted from the opening of the first outer ring divided body 21. 16 (and rolling element 15) is inserted through the opening of the first outer ring divided body 21 and the cage 16 is held on the inner peripheral surface of the first outer ring divided body 21, and the shaft 1 of the first outer ring divided body 21 is held. You may make it insert from an opening part and reconnect the isolation | separation part of the holder | retainer 16. FIG. In this case, the width of the opening of the first outer ring divided body 21 may be set larger than the diameter of the shaft 1, and it is not necessary to consider the diameter of the rolling element 15. It is possible to make the split position width slightly smaller than the split position width W of 2).

As described above, the split type rolling bearing 10 described in the present embodiment has the PV value (the bearing operation given by the bearing pressure P and the sliding speed V) generated when the rolling element 15 enters the raceway surface from the flank Mn. The factor that gives the limit) can be reduced.
In addition, the vibration and noise of the rolling element 15 can be suppressed, and the life of the bearing can be further improved.
Further, by reducing vibration and noise, energy that generates vibration and noise is reduced, which can contribute to improvement of fuel consumption.

The split rolling bearing 10 of the present invention is not limited to the appearance, configuration, structure, and the like described in the present embodiment, and various modifications, additions, and deletions can be made without departing from the spirit of the present invention.
The divided type rolling bearing described in the present embodiment can be applied to various divided type rolling bearings such as a ball screw and a ball spline that have a shape change or a step on the raceway surface.

DESCRIPTION OF SYMBOLS 1 Shaft 5 Housing 6, 8 Split housing body 10 Split type rolling bearing 15 Rolling body 16 Cage 20 Outer ring member 21 1st outer ring split body 31 2nd outer ring split body 22, 32 Split track surface MB Split surface Mn Flank W Split Position width ZS Shaft rotation axis

Claims (1)

An annular outer ring member that rotatably supports a shaft about a shaft rotation axis via a plurality of rolling elements is divided into two parts, which are constituted by a first outer ring divided body and a second outer ring divided body that are divided into two in the circumferential direction. In the bearing
The first outer ring divided body, the second outer ring divided body, and the rolling element are attached to both end portions of the raceway surfaces that are the inner peripheral surfaces of the first outer ring divided body and the second outer ring divided body, respectively. When the shaft is supported, a flank is formed so that the distance from the shaft rotation axis gradually increases.
The first outer ring divided body has a substantially C-shape, and the circumferential length of the first outer ring divided body is longer than the circumferential length of the second outer ring divided body. ,
A plane that includes a shaft rotation axis when the shaft is supported by the first outer ring divided body, the second outer ring divided body, and the rolling element, and that passes through the center in the circumferential direction of the second outer ring divided body. And the split surface is formed so that the split surfaces of the split portions of the first outer ring split body and the second outer ring split body are parallel to each other. The distance between the surface and the shaft, or the shaft around which the rolling elements are arranged, is set to an interval that can pass in the radial direction.
Split type rolling bearing.

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