JP2011133081A - Split rolling bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a split rolling bearing device which can be in a raceway condition for suppressing peeling and wear at the bearing part of a rotary shaft, even when a rolling element of the split rolling bearing device supporting the rotary shaft rolls, using the cast iron rotary shaft to be manufactured at a low cost and material-molded by conventional casting. <P>SOLUTION: The split rolling bearing device supports a cast iron casting camshaft 10. The split rolling bearing device is composed of a partial inner ring 47 where the inside raceway surface of the split rolling bearing device is composed, which is made of a material harder than the camshaft 10, and which composes part in the circumferential direction; a split outer ring 42 where the outside raceway surface of the split rolling bearing device is composed, which is formed in a circular shape, and at least a circumferential part of which is split; a plurality of rollers 45 between the partial inner ring 47 and the split outer ring 42; and a split retainer 46 for retaining the rollers 45. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a split rolling bearing device. Specifically, the present invention relates to a split rolling bearing device that supports a rotating shaft made of cast iron formed by casting.

  2. Description of the Related Art Conventionally, cast iron rotary shafts formed by casting are cast iron cast camshafts (eg, spheroidal graphite cast iron) that are driven to rotate in synchronization with a vehicle engine. Some camshafts are machined after being formed into a material by casting and processed to harden the cam surface by heat treatment in order to improve the wear resistance of the cam. As a structure for supporting the camshaft, a structure in which the camshaft is rotatably assembled between a cylinder head and a cap member by a slide bearing is generally used. However, in recent years, in the camshaft device using the sliding bearing, when the camshaft rotates, sliding friction occurs between the camshaft and the sliding bearing, and torque loss due to the sliding frictional force occurs. Therefore, in order to reduce torque loss during rotation of the camshaft, a camshaft device configured to support the camshaft using a rolling bearing instead of a sliding bearing is known. As for the configuration of this rolling bearing, a split rolling bearing device is known in which an outer ring and a cage are divided in the circumferential direction in consideration of mounting the camshaft to a bearing portion. When this divided rolling bearing device is attached to a camshaft, it is necessary to perform heat treatment and polishing on the bearing portion of the camshaft. However, since this cast iron cast camshaft has insufficient hardness, there is a concern of peeling or wear.

JP 2009-167807 A

  Therefore, if the camshaft is manufactured from a material with a high surface hardness as a countermeasure, the concern about peeling and wear will be resolved. On the other hand, the polishing process of the camshaft with a high surface hardness increases the polishing resistance, so the processing time There is concern about an increase in work costs. It is also conceivable that sufficient hardness on the raceway surface of the rolling bearing can be obtained by processing the camshaft using chromium molybdenum steel (for example, JIS standard SCM415) and performing surface treatment such as carburizing and quenching. However, this chromium-molybdenum steel requires processing such as hot forging and is concerned about an increase in processing cost.

  Thus, the present invention was devised in view of the above points, and the problem to be solved by the present invention is that a cast iron rotating material formed by conventional casting that can be manufactured at low cost. Provided is a split rolling bearing device that uses a shaft and can be in a raceway state that suppresses peeling and wear of the bearing portion of the rotating shaft even if the rolling element of the split rolling bearing device that supports the rotating shaft rolls. It is in.

In order to solve the above problems, the divided rolling bearing device of the present invention takes the following means.
First, a split rolling bearing device according to a first aspect of the present invention is a split rolling bearing device that supports a rotating shaft made of cast iron formed by casting, and the split rolling bearing device is provided on an outer peripheral surface of the rotating shaft. An inner ring that constitutes the inner raceway surface of the divided rolling bearing device is disposed, and the outer race side of the inner raceway surface formed on the inner ring corresponds to the inner raceway surface and the split is divided into the inner circumference surface thereof. An outer raceway surface of the rolling bearing device is configured and formed in an annular shape, and a split outer ring configured by dividing at least a part in the circumferential direction is provided, and an inner raceway surface formed on the inner ring and the split outer ring A plurality of rolling elements are disposed between the outer raceway surface and the outer raceway surface formed on the inner ring, and at least part of the circumferential direction is divided on the outer circumference of the inner raceway surface formed on the inner ring. Around the outer periphery of the rotating shaft The inner ring is made of a material having a hardness higher than that of the rotating shaft and is a partial inner ring constituting a part in the circumferential direction. It is configured.

  According to the first aspect of the invention, the inner ring is made of a material having a hardness higher than that of the rotating shaft and is formed as a partial inner ring that constitutes a part in the circumferential direction. As a result, it is possible to arrange and configure only the part necessary for receiving the load on the inner ring, and use a rotating shaft made of cast iron formed by conventional casting that can be manufactured at low cost, and this rotating shaft is supported. Even if the rolling element of the divided rolling bearing device that rolls rolls, it can be in a raceway state that suppresses separation and wear of the bearing portion of the rotating shaft. In addition, the location where the partial inner ring is not disposed is a location where the load is less likely to be received, and the function of the bearing is not impaired.

  Next, in the divided rolling bearing device according to the second aspect of the present invention, in the first aspect described above, the rotating shaft is a camshaft formed with cams arranged on the shaft at intervals, The partial inner ring is provided as a separate component on the raceway of the rolling element at a bearing portion that supports the camshaft.

  According to the second aspect of the invention, the camshaft is preferably configured as the rotating shaft. The partial inner ring arranged at the bearing portion of the camshaft is provided as a separate component on the raceway of the rolling element. Thereby, a material with higher hardness can be selected for the partial inner ring than the camshaft made of cast iron. Therefore, even if the rolling element of the divided rolling bearing device that supports the camshaft rolls, it can be in a track state that suppresses separation and wear of the bearing portion of the rotating shaft.

  Next, the divided rolling bearing device according to a third aspect of the present invention is the above-described second aspect of the present invention, wherein the disposition position of the partial inner ring in the bearing portion of the camshaft is the cam shaft when viewed in the axial section of the camshaft. It is arranged and configured on the side opposite to the nose portion.

According to the third aspect of the invention, the disposition position of the partial inner ring at the bearing portion of the camshaft is disposed on the side opposite to the nose portion of the cam as viewed in the axial section of the camshaft.
Since the camshaft loads from the position of the nose portion of the cam toward the axial center of the camshaft when the valve is opened and closed, the load can be efficiently supported by adopting the arrangement configuration described above for the partial inner ring. Separation and wear of the bearing portion of the camshaft can be suppressed.

  Next, the divided rolling bearing device according to a fourth aspect of the present invention is the above-described third aspect, wherein the partial inner ring has a circumferential length of at least 180 degrees or more when viewed in the axial cross section, and the camshaft. The partial inner ring is mounted on the bearing portion of the camshaft by elastically expanding the partial inner ring in the radial direction.

  According to the fourth aspect of the present invention, the partial inner ring has a circumferential length of at least 180 degrees as viewed in the axial cross section and is formed smaller than the diameter of the bearing portion of the camshaft. The mounting of the camshaft on the bearing portion is a configuration in which the partial inner ring is mounted by elastically expanding in the radial direction. As a result, the partial inner ring can be prevented from falling off from the bearing portion of the camshaft, and the assemblability of the camshaft can be improved.

  According to the present invention, the rolling element of the divided rolling bearing device that supports the rotating shaft is used by using a cast iron rotating shaft that is formed by conventional casting, which can be manufactured at low cost, by taking the measures of the above inventions. Even if it moves, it can be in a raceway state that suppresses separation and wear of the bearing portion of the rotating shaft.

It is the disassembled perspective view which showed each component of the division | segmentation rolling bearing apparatus assembled | attached to the camshaft which concerns on Example 1. FIG. It is the elements on larger scale which showed the assembly structure of the division | segmentation rolling bearing apparatus corresponding to the 2nd journal part of the camshaft apparatus assembly which concerns on Example 1. FIG. It is the fragmentary sectional view shown from the side of the division | segmentation rolling bearing apparatus assembled | attached to the cam shaft which concerns on Example 1. FIG. It is the IV-IV sectional view taken on the line of FIG. It is a whole perspective view of the partial inner ring | wheel of the division | segmentation rolling bearing apparatus assembled | attached to the cam shaft which concerns on Example 1. FIG. FIG. 6 is a sectional view taken along line VI-VI in FIG. 5. (A) The figure is sectional drawing of the whole partial inner ring | wheel. (B) The figure is an expanded sectional view of the peripheral direction edge part of a partial inner ring. It is a whole perspective view of the modification 1 of the partial inner ring | wheel of the division | segmentation rolling bearing apparatus assembled | attached to the cam shaft which concerns on Example 1. FIG. It is a whole perspective view of the modification 2 of the partial inner ring | wheel of the division | segmentation rolling bearing apparatus assembled | attached to the cam shaft which concerns on Example 1. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a description will be given of a camshaft in which cams disposed at intervals on the shaft are formed as a rotating shaft made of cast iron formed by casting.

First, a camshaft device assembly according to Embodiment 1 of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 and 3, the camshaft device assembly according to the first embodiment generally includes a camshaft 10, an adapter member 20, and a rolling bearing 31 corresponding to the first journal portion 30. And a split rolling bearing device 41 corresponding to the journal portion 40 after the second journal portion.

First, the camshaft 10 will be described.
As shown in FIGS. 1 and 3, the camshaft 10 is configured to be driven to rotate in synchronization with the engine of the vehicle, and is on a shaft as a rotating shaft made of cast iron formed by casting. This is a cast iron cast camshaft in which cams 60 arranged at intervals are formed.
The material of the camshaft 10 is not particularly limited, and examples thereof include murine cast iron, spheroidal graphite cast iron, or alloy cast iron containing about 0.05 to 10% by weight of Cr, Mo, or the like.
Moreover, the casting method of the camshaft 10 can employ | adopt the methods used normally, such as sand casting and die casting. As shown in FIG. 2, the camshaft coarse material obtained by casting has a desired bearing diameter for the journal portion 40 (bearing portion), a nose portion 60a of the cam 60 for the cam 60, and a base circle. A desired cam surface 65 (cam profile) to be the part 60b is subjected to machining such as cutting and polishing to form a required shape. In addition, the cam surface 65 is hardened by applying heat treatment to the surface of the cam surface in order to improve wear resistance.

Next, the adapter member 20 will be described.
As shown in FIG. 3, the adapter member 20 is press-fitted and fixed to one end portion of the camshaft 10. A bearing assembly portion 21 for assembling a rolling bearing 31 corresponding to the first journal portion 30 is formed on the outer peripheral surface of the adapter member 20. A flange 22 is formed on one end side of the bearing assembly 21 on the outer peripheral surface of the adapter member 20, and an annular groove 23 in which a retaining ring 24 such as a C ring is fitted is formed on the other end side. Yes.
In addition, a knock pin 25 for positioning and attaching a drive member 27 such as a variable valve timing unit, a timing sprocket, a timing gear, and a pulley is driven into one end side of the adapter member 20.

Next, the rolling bearing 31 will be described.
As shown in FIG. 3, the rolling bearing 31 corresponding to the first journal portion 30 is an angular ball bearing, and can roll between the inner ring 32, the outer ring 33, and the inner ring 32 and the outer ring 33. Are provided with a plurality of rolling elements 35 (balls) and a cage 36.
In the rolling bearing 31, the inner ring 32 is press-fitted to the bearing assembly portion 21 of the adapter member 20, and a retaining ring 24 such as a C ring is fitted into the annular groove 23. It is fitted and fixed so that it cannot move in the axial direction.

Next, the divided rolling bearing device 41 will be described.
As shown in FIGS. 1 and 2, the split rolling bearing device 41 corresponding to the journal portion 40 after the second journal portion is configured as a shell needle roller bearing, and includes a split outer ring 42, a roller 45, and the like. A split cage 46 and a partial inner ring 47 are provided.
The divided outer ring 42 has an inner peripheral surface configured as an outer raceway surface of the roller 45. The split outer ring 42 has a cylindrical shape made of carbon steel (preferably bearing steel, for example, SUJ2) divided in the circumferential direction, and is formed in a semicircular shape when viewed in the axial cross section.

As shown in FIGS. 1 and 2, the roller 45 is a cylindrical needle roller made of carbon steel (preferably bearing steel, for example, SUJ2) as a shell needle roller bearing.
The split cage 46 is formed in an annular shape so that a metal strip-like member can be wound around the outer periphery of the camshaft 10, and the outer peripheral surface of the roller 45 is formed on the outer peripheral surface of the strip plate. Substantially the same number of through-holes are formed in the circumferential direction by a certain number of rollers 45 at regular intervals. Further, the split cage 46 is divided into two in the circumferential direction and formed as a semi-circular shape when viewed in the axial cross section.

The partial inner ring 47 will be described.
As shown in FIG. 5, the partial inner ring 47 has an outer peripheral surface configured as an inner raceway surface 47 a of the roller 45.
First, the material of the partial inner ring 47 will be described. As shown in FIG. 2, the partial inner ring 47 is made of a material harder than the camshaft 10 in order to obtain a track state that suppresses peeling and wear of the journal portion 40 of the cast shaft 10 made of cast iron. Yes.
Specifically, the material of the partial inner ring 47 is determined based on the relationship between the hardness of the material used for the camshaft 10 configured on the inner peripheral side of the partial inner ring 47 and the roller 45 configured on the outer peripheral side. That is, the camshaft 10 is formed as a cast iron cast camshaft. For example, in the case of spheroidal graphite cast iron, the Rockwell hardness has a hardness of HRC8 to HRC30. On the other hand, the roller 45 is made of carbon steel. When bearing steel (SUJ2) is selected, the Rockwell hardness has HRC58 to HRC65. Accordingly, the partial inner ring 47 is preferably made of a material having a Rockwell hardness of 58 HRC or higher. For example, it is preferable to select carbon steel (preferably bearing steel such as SUJ2) in the same manner as the roller 45.
Next, the shape of the partial inner ring 47 will be described. As shown in FIG. 5, the partial inner ring 47 is formed in a semicircular shape when viewed in the axial section by machining a cylindrical member made of carbon steel and dividing it in the circumferential direction. Further, as shown in FIG. 6A, the partial inner ring 47 has a circumferential length 47c of at least 180 degrees when viewed in the axial cross section. The partial inner ring inner diameter 47d of the partial inner ring 47 is formed smaller than the journal part diameter 40a of the journal part 40 (bearing part) of the camshaft 10 shown in FIG. As shown in FIG. 2, the partial inner ring 47 is mounted on the journal portion 40 (bearing part) of the camshaft 10 by elastically expanding the partial inner ring 47 in the radial direction.
Further, as shown in FIG. 6B, both ends in the circumferential direction of the partial inner ring 47 are thinned at the tip end when viewed in the axial cross section so that the rollers 45 roll smoothly on the inner raceway surface 47a. It is preferably formed on an inclined surface 47b that is gradually inclined.
Further, as illustrated in FIG. 5, the partial inner ring both ends 47 e, which are both ends in the circumferential direction of the partial inner ring 47, are formed in a mountain shape that gradually inclines from both axial ends toward the axial center. It is comprised so that it may roll smoothly to the inner track surface 47a sequentially from the center part. It should be noted that various shapes can be applied to the shapes of the both ends 47e of the partial inner ring as long as the rollers 45 are configured to smoothly roll on the inner raceway surface 47a sequentially. For example, the shape of the partial inner ring both ends 47e may be formed in an arc shape.

A method for assembling the divided rolling bearing device 41 to the camshaft 10 will be described.
As shown in FIG. 3, the camshaft 10, the adapter member 20 having the rolling bearing 31 corresponding to the first journal portion 30, and the divided rolling bearing device 41 corresponding to the second journal portion 40 are prepared. . First, the adapter member 20 having the rolling bearing 31 corresponding to the first journal portion 30 is press-fitted and fixed to one end portion of the camshaft 10.

  As shown in FIG. 2, the partial inner ring 47 is elastically expanded from the radial direction of the journal portion 40 of the camshaft 10 and attached. At this time, the arrangement position of the partial inner ring 47 is arranged and configured on the side opposite to the nose portion 60 a of the cam 60 when viewed in the axial section of the camshaft 10. A split cage 46 with rollers 45 fitted on the outer periphery of the camshaft 10 is mounted and disposed. Further, the outer ring 42 is attached and the divided rolling bearing device 41 is assembled. As shown in FIG. 4, the cylinder head 70 is fitted between the camshaft metal cap 72 and the cylinder head 70. With this, the split rolling bearing device 41 can be assembled to the camshaft 10.

The divided rolling bearing device 41 according to the first embodiment is configured by the above-described assembly.
As described above, according to the divided rolling bearing device 41 of the first embodiment, the partial inner ring 47 is made of a material harder than the camshaft 10 and has a part in the circumferential direction. As a result, the partial inner ring 47 can be arranged and configured only in a required portion, and the camshaft 10 made of cast iron that is formed by a conventional casting that can be manufactured at low cost is used to support the camshaft 10. Even if the roller 45 of the divided rolling bearing device 41 rolls, it can be in a raceway state that suppresses peeling and wear of the journal portion 40 of the camshaft 10.

  Further, the partial inner ring 47 configured in the journal portion 40 of the camshaft 10 is provided as a separate structure on the track of the roller 45. Thereby, the partial inner ring 47 can select a material having higher hardness than the cast iron cast camshaft 10. Therefore, even if the roller 45 of the divided rolling bearing device 41 that supports the camshaft 10 rolls, it can be in a track state that suppresses the peeling and wear of the journal portion 40 of the camshaft 10.

  Further, the disposition position of the partial inner ring 47 in the journal portion 40 of the camshaft 10 is arranged on the side opposite to the nose portion 60a of the cam as viewed in the axial section of the camshaft 10. Since the camshaft 10 is subjected to a load from the position of the nose portion 60a of the cam toward the axial center of the camshaft 10 when the valve is opened and closed, the above-described load can be efficiently applied by arranging the partial inner ring 47 as described above. It can support and can prevent peeling and abrasion of the journal portion 40 of the camshaft 10.

  The partial inner ring 47 has a circumferential length of at least 180 degrees as viewed in the axial cross section and is formed smaller than the diameter of the journal portion 40 of the camshaft 10. The mounting to the journal portion 40 is a configuration in which the partial inner ring 47 is mounted by elastically expanding in the radial direction. As a result, the partial inner ring 47 can be prevented from falling off from the journal portion 40 of the camshaft 10, and the assembling property of the camshaft 10 can be improved. The circumferential positioning of the partial inner ring 47 in the journal portion 40 can be performed by the elastic force and frictional force of the configuration in which the partial inner ring 47 is elastically expanded in the radial direction. It can also be performed by means for making the relative rotation impossibility positive by appropriate means.

As mentioned above, although embodiment of this invention was described in Example 1, the rolling bearing device for wheels of this invention is not limited to this Embodiment, In the range which does not deviate from the summary of this invention, it is with various forms. It can also be implemented.
For example, in the first embodiment, the split rolling bearing device 41 that supports the camshaft 10 on which the cams 60 are disposed as spaced apart on the shaft as a rotating shaft made of cast iron formed by casting is formed. Indicated. However, the present invention is not limited to this, and the divided rolling bearing device according to the present invention can also be applied to a divided rolling bearing device that supports a balancer shaft or the like by applying a partial inner ring to a portion where inertia due to a weight acts. is there.

Further, in the first embodiment, the configuration of the half-divided split cage that is split in half is shown. However, the present invention is not limited to this, and the divided rolling bearing device according to the present invention may have any configuration as long as at least a part of the divided cage is divided. It may be of one configuration.
In the first embodiment, the split holder 46 is made of metal. However, the present invention is not limited to this, and the split cage in the split rolling bearing device according to the present invention may be made of synthetic resin.

Further, as shown in FIG. 7, a configuration like a partial inner ring 147 can be considered as a first modification of the partial inner ring 47. That is, the partial inner ring 147 is an aspect in which an inner flange 147b is formed in which both ends in the axial direction extend toward the inner diameter direction. Corresponding to the inner flange 147b, the journal portion 40 (see FIG. 1) of the camshaft 10 forms a groove shape (not shown). Thereby, the partial inner ring 147 can be mounted in an engaged state with the journal portion 40, and the movement of the partial inner ring 147 in the axial direction can be suppressed.
Further, as shown in FIG. 8, a configuration like a partial inner ring 247 can be considered as a second modification of the partial inner ring 47. That is, the partial inner ring 247 is an aspect in which an outer flange 247b in which both ends in the axial direction extend in the outer diameter direction is formed. With the configuration of the outer casing 247b, the movement of the rollers 45 and the split cage 46 in the axial direction can be suppressed.
Moreover, the thing which comprised both the above-mentioned inner collar 147b and the outer collar 247b may be sufficient.
Further, in the journal portion 40, the inner raceway surface may be configured by disposing a partial inner ring made of synthetic resin corresponding to the partial inner ring 47 in a portion where the partial inner ring 47 is not arranged. In the journal portion 40, the roller 45 is supported by a high hardness partial inner ring 47 at a portion where the load is applied, and a synthetic resin partial inner ring is formed at a portion where the load is relatively small, so that the roller 45 can be smoothly rotated. Can move.

DESCRIPTION OF SYMBOLS 10 Camshaft 20 Adapter member 21 Bearing assembly part 22 Flange 23 Annular groove 24 Retaining ring 25 Knock pin 27 Drive member 30 1st journal part 31 Rolling bearing 32 Inner ring 33 Outer ring 35 Rolling body 36 Cage 40 2nd journal part 40a Journal part Diameter 41 Rolling bearing 42 Divided outer ring 45 Roller 46 Divided cage 47 Partial inner ring 47a Inner raceway surface 47b Inclined surface 47c Perimeter length 47d Partial inner ring inner diameter 47e
60 Cam 60a Nose part 60b Base circular part 65 Cam surface 70 Cylinder head 72 Camshaft metal cap 147 Partial inner ring 147b Inner flange 247 Partial inner ring 247b Outer flange

Claims (4)

A split rolling bearing device that supports a rotating shaft made of cast iron formed by casting,
The divided rolling bearing device is:
An inner ring that constitutes an inner raceway surface of the divided rolling bearing device is disposed on an outer peripheral surface of the rotating shaft,
On the outer peripheral side of the inner raceway surface formed on the inner ring, the outer raceway surface of the split rolling bearing device is formed on the inner peripheral surface corresponding to the inner raceway surface, and is formed in an annular shape so as to be at least a part in the circumferential direction. A split outer ring configured by being divided is disposed,
A plurality of rolling elements are disposed between an inner raceway surface formed on the inner ring and an outer raceway surface formed on the split outer ring,
On the outer periphery of the inner raceway surface formed on the inner ring, it is formed in an annular shape, and at least a part of the circumferential direction is divided so that it can be wound around the outer periphery of the rotating shaft to hold the rolling element. A split cage is provided,
Further, the inner ring is constituted by a material having a hardness higher than that of the rotating shaft and is constituted as a partial inner ring constituting a part in the circumferential direction. The split rolling bearing device according to claim 1,
The rotating shaft is a camshaft formed with cams arranged at intervals on the shaft,
The partial rolling bearing device according to claim 1, wherein the partial inner ring is provided as a separate component on the raceway of the rolling element at a bearing portion that supports the camshaft. The split rolling bearing device according to claim 2,
The split rolling bearing device according to claim 1, wherein the disposition position of the partial inner ring in the bearing portion of the camshaft is disposed on the side opposite to the nose portion of the cam as viewed in the axial section of the camshaft. The split rolling bearing device according to claim 3,
The partial inner ring has a circumferential length of at least 180 degrees as viewed in the axial cross section, and is formed smaller than the diameter of the bearing portion of the camshaft.
The partial rolling bearing device according to claim 1, wherein the mounting of the partial inner ring to the bearing portion of the camshaft is configured to elastically expand the partial inner ring in the radial direction.

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