JP2006250268A - Rolling bearing and cam shaft device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cam shaft device provided with a rolling bearing enabling effective oil supply to a raceway surface. <P>SOLUTION: This device is provided with a shaft 1 and a rolling bearing 3 rotatably supporting the shaft 1, and a cam 2 externally fitted and attached to the shaft 1. A circumference direction groove and an axial direction groove opening on a side surface of an outer ring 5 from an inside of the circumference direction groove are formed on an outer circumference surface of an outer ring 5 of the rolling bearing 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rolling bearing and a camshaft device using the same.

For example, in order to rotatably support the camshaft in the cylinder head, there are a case where a sliding bearing is used (see Patent Document 1) and a case where a rolling bearing is used (see Patent Document 2). In the case of a slide bearing, the lubricating oil is supplied from the oil supply hole formed in the cylinder head to the outer peripheral surface side of the slide bearing, and the lubricating oil passes through the radial through hole formed in the slide bearing. And the inner peripheral surface (journal surface) of the slide bearing. However, even if the sliding bearing is supplied with such oil, the frictional resistance with the shaft becomes larger than that of the rolling bearing.
Therefore, in order to further reduce the frictional resistance, it is preferable to use a rolling bearing.

JP-A-8-218817 Japanese Utility Model Publication No. 5-6104

However, when a rolling bearing is employed to reduce the frictional resistance between the bearing and the camshaft, it is difficult to supply oil from the cylinder head side to the raceway surface of the rolling bearing. In other words, in the case of a sliding bearing, there is no problem in terms of performance even if an oil supply hole is open on the inner peripheral surface of the slide bearing, but in the case of a rolling bearing, if the oil supply hole is open on the raceway surface, the rolling element There is a problem that vibrations and noises are generated due to passing through the holes and the life is shortened.
Accordingly, an object of the present invention is to provide a rolling bearing capable of supplying oil to the raceway surface without affecting the rolling of the rolling element, and a camshaft device using the rolling bearing.

In order to achieve the above object, the rolling bearing according to the present invention has a groove formed on the outer peripheral surface of the outer ring, and has an oil supply hole penetrating from the groove to a surface of the inner peripheral surface of the outer ring that does not contact the rolling element. It is characterized by being formed.
According to this, the lubricating oil supplied in the groove formed on the outer peripheral surface of the outer ring can be supplied to the inner peripheral surface of the outer ring through the oil supply hole penetrating the outer ring. Since the oil supply hole is opened on a surface that does not come into contact with the rolling element, it does not affect the rolling of the rolling element. The lubricating oil is supplied to a surface that does not come into contact with the rolling elements, that is, a portion other than the raceway surface. However, the lubricant oil flows toward the raceway surface along the inner peripheral surface of the outer ring and can be supplied to the raceway surface.

The rolling bearing according to the present invention is characterized in that a circumferential groove and an axial groove that opens from the circumferential groove to the side surface of the outer ring are formed on the outer circumferential surface of the outer ring. .
According to this, the lubricating oil supplied in the circumferential groove on the outer peripheral surface of the outer ring can be supplied to the side surface of the outer ring through the axial groove. The lubricating oil supplied to the side surface of the outer ring flows so as to wrap around the side surface of the outer ring and the inner peripheral surface of the outer ring, and oil supply to the raceway surface becomes possible.

Further, the circumferential groove is formed at an axial center portion on the outer peripheral surface of the outer ring, and the axial groove is a circumferential groove so as to linearly penetrate both side surfaces of the outer ring. It is preferable to be formed on both sides in the axial direction. As a result, the lubricating oil can be evenly supplied to both axial sides of the rolling bearing. This is effective when the environments on the left and right sides of the rolling bearing (for example, the shape of the peripheral members) are the same.
Alternatively, the circumferential groove is formed at an axial center portion on the outer circumferential surface of the outer ring, and the axial groove is displaced in the circumferential direction on both sides in the axial direction of the circumferential groove. Each of them is preferably formed. According to this, it becomes effective when the ease of flow of the lubricating oil differs between the left and right due to the difference in environment between the left and right sides of the rolling bearing.

  The axial groove is preferably formed to be inclined with respect to a straight line parallel to the central axis on the outer peripheral surface of the outer ring. According to this, it is possible to make it easy for the lubricating oil supplied into the circumferential groove to wrap around the side surface of the outer ring.

Furthermore, the camshaft device of the present invention includes the rolling bearing, a shaft rotatably supported by the rolling bearing, a separate body from the shaft, and having a through-hole so as to be fitted on the shaft. The rolling bearing has a bearing ring made of a ring-shaped integral member and is attached to the shaft as an outer fitting shape.
According to such a configuration, by supporting the shaft by the rolling bearing, the frictional resistance in the bearing can be reduced and the friction loss during rotation can be reduced. In particular, the frictional resistance at the time of starting rotation and during low-speed rotation can be reduced. Further, since the cam is separated from the shaft, before the cam is attached to the shaft, the rolling bearing can be attached by moving the shaft from the end of the shaft to a predetermined position. Therefore, it is not necessary to make the bearing ring of the rolling bearing have a divided structure, and no joint is formed on the raceway surface. In addition, if the raceway has a split structure and a joint exists on the raceway surface, vibration and noise are generated when the rolling element passes through, and the life of the bearing is reduced. Furthermore, the cam can be moved from the end of the shaft as an insertion shape of the shaft, and attached to a predetermined position.

  According to the present invention, the lubricating oil can be effectively supplied to the raceway surface of the rolling bearing without affecting the rolling of the rolling elements.

  The present invention will be described in a camshaft device in which a shaft 1 having a cam 2 is rotatable as shown in FIG. This camshaft device operates a supply / exhaust valve of an automobile engine.

  The entire camshaft device will be described. This camshaft device is accommodated in a housing H (cylinder head) made of an aluminum block. The camshaft device is separate from the linear shaft 1 and the shaft 1. Are provided with a plurality of substantially oval cams 2 that are externally fitted to each other and a plurality of rolling bearings 3 that rotatably support the shaft 1. A cam 2 and a rolling bearing 3 are disposed on the shaft 1 at predetermined positions in the axial direction of the shaft 1. In addition, one rolling bearing 3 is provided between the cams 2 that form a pair.

The rolling bearing 3 is attached to the shaft 1 as an outer fitting shape, and rotatably supports the shaft 1 and is a deep groove ball bearing. As shown in FIG. 2, the rolling bearing 3 has an inner ring 4 and an outer ring 5 provided radially outward of the inner ring 4, and a raceway surface (track groove) 6 of the inner ring 4 and an outer ring. A rolling element composed of a plurality of balls 7 is interposed between the five raceway surfaces (orbital grooves) 12. These balls 7 are held by a cage 13.
In the rolling bearing 3, the inner ring 4 is fixed by being fitted to the outer peripheral surface 1 a of the shaft 1, and the outer ring 5 is fixed by being fitted to the inner surface of the housing H of the housing H.

  FIG. 8 is a partially sectional side view showing another embodiment of the camshaft device. The rolling bearing 3 provided in the device is an inner ring of the rolling bearing 3 on the outer peripheral surface 1 a of the camshaft 1. A raceway surface 6 is formed. That is, the inner ring 4 in the camshaft device of FIG. 1 is omitted, and the camshaft 1 is an inner ring. Thereby, the number of parts can be reduced and the load capacity can be increased.

FIG. 2 is a cross-sectional view showing a first embodiment of the rolling bearing 3. In the rolling bearing 3, a circumferential groove 31 (hereinafter referred to as a circumferential groove 31) is formed on the outer circumferential surface 5 a of the outer ring 5. An oil supply hole 33 penetrating from the inside of the circumferential groove 31 to the inner peripheral surface 5b of the outer ring 5 is formed. The circumferential groove 31 is a concave groove that does not penetrate the outer ring 5 in the radial direction, and is formed continuously in the circumferential direction.
And the oil supply hole 33 is formed so that it may open in the surface which does not contact the ball | bowl 7 as a rolling element among the internal peripheral surfaces 5b of the outer ring | wheel 5. FIG. Specifically, the oil supply hole 33 is a surface other than the raceway surface 12 formed with a predetermined radius of curvature on the inner peripheral surface 5b of the outer ring 5, that is, on the side of the raceway surface 12 in the axial direction, and the central axis C Is open in the linear non-orbital surface 34 in a direction parallel to. Thereby, the oil supply hole 33 does not affect the rolling of the ball 7.

At least one oil supply hole 33 may be formed, but it is preferable to provide a plurality of oil supply holes at equal intervals in the circumferential direction in order to supply oil to a plurality of locations simultaneously. The oil supply hole 33 is opened at a position including the bottom surface of the circumferential groove 31 having a rectangular cross section. In FIG. 2, the oil supply hole 33 is opened at a corner between the bottom surface and the side surface of the circumferential groove 31. As a result, the lubricating oil tends to stay in the corner, but such lubricating oil can be supplied to the oil supply hole 33, and the staying of the lubricating oil can be prevented.
Further, the circumferential groove 31 is formed in the axial center portion on the outer circumferential surface 5a of the outer ring 5, and the oil supply hole 33 is a straight line extending radially inward from the circumferential groove 31 toward the axial side. It is formed as a shape. Although not shown, the circumferential groove 31 is formed in the axial edge (side) on the outer peripheral surface 5 a, and the oil supply hole 33 extends from the circumferential groove 31 to the axial center (the axial center track). It may be formed as a straight line extending radially inward while facing the surface 12).

  According to the rolling bearing 3, the lubricating oil is supplied into the circumferential groove 31 of the outer ring 5 of the rolling bearing 3 through the lubricating oil hole 35 formed in the housing H. The lubricating oil passes through the oil supply hole 33. Of the inner peripheral surface 5 b of the outer ring 5, the non-track surface 34 is supplied. The lubricating oil supplied to the non-race surface 34 portion flows toward the race surface 12 along the inner peripheral surface 5b of the outer ring 5 and can be supplied to the race surface 12.

  FIG. 3 is a side view showing a second embodiment of the rolling bearing 3. The rolling bearing 3 has a circumferential groove 31 (hereinafter referred to as a circumferential groove 31) and an outer circumferential surface 5 a of the outer ring 5. An axial groove 32 (hereinafter referred to as an axial groove 32) that opens from the circumferential groove 31 to the side surface 5c of the outer ring 5 is formed. The circumferential groove 31 is a concave groove that does not penetrate the outer ring 5 in the radial direction, and is formed continuously in the circumferential direction. The circumferential groove 31 is formed in the central portion in the axial direction on the outer circumferential surface 5 a of the outer ring 5. That is, the circumferential groove 31 is formed on a virtual center line that is continuous in the circumferential direction that bisects the outer circumferential surface 5a of the outer ring 5 in the axial direction.

  The axial direction groove | channel 32 is formed so that the circumferential direction groove | channel 31 may be crossed and the both side surfaces 5c of the outer ring | wheel 5 may be penetrated linearly. That is, the axial grooves 32 are formed side by side on both axial sides (left and right sides) of the circumferential groove 31, and the axial grooves 32 on both sides are linear in the axial direction across the circumferential groove 31. A continuous groove is formed. Further, at least one axial groove 32 may be formed in the circumferential direction, but as shown in FIG. 3, it is preferable to form a plurality of strips at equal intervals in the circumferential direction. FIG. 4 is a view of a part of the outer peripheral edge of the outer ring 5 viewed from the axial direction, and the axial groove 32 and the circumferential groove 31 are formed at the same depth. According to this embodiment, since the axial grooves 32 are formed symmetrically about the circumferential groove 31, the lubricating oil can be supplied evenly from both axial sides.

FIG. 5 is a side view showing a third embodiment of the rolling bearing 3, and this rolling bearing 3 has a circumferential groove 31 on the outer circumferential surface 5 a of the outer ring 5, as in the second embodiment. An axial groove 32 is formed, and the circumferential groove 31 is formed in the axial center of the outer peripheral surface 5 a of the outer ring 5.
The axial grooves 32 are formed on both axial sides (left and right sides) of the circumferential groove 31, respectively. However, the left and right axial grooves 32 are displaced from each other in the circumferential direction (with different phases). Is formed. Therefore, unlike the second embodiment (FIG. 3), the axial groove 32 does not linearly penetrate both side surfaces 5c of the outer ring 5.
Further, at least one axial groove 32 may be formed in the circumferential direction on both sides of the circumferential groove 31, but it is preferable that a plurality of axial grooves 32 be formed at equal intervals in the circumferential direction as shown in FIG. Other configurations are the same as those of the second embodiment. According to this embodiment, it is effective when the flowability of the lubricating oil differs between the left and right due to the difference in the shape of the housing H on the left and right sides of the rolling bearing 3.

  FIG. 6 is a side view showing a fourth embodiment of the rolling bearing 3, and FIG. 7 is a side view showing a fifth embodiment of the rolling bearing 3. Similar to the second embodiment, these rolling bearings 3 are formed with a circumferential groove 31 and an axial groove 32 on the outer circumferential surface 5 a of the outer ring 5, and the circumferential groove 31 is an outer circumferential surface of the outer ring 5. In 5a, it forms in the axial direction center part. The axial groove 32 is formed on the outer peripheral surface 5a of the outer ring 5 so as to be inclined at a predetermined inclination angle θ with respect to a straight line parallel to the central axis C of the rolling bearing 3 (hereinafter referred to as a reference line e). .

In FIG. 6, both axial grooves 32 adjacent to each other with the circumferential groove 31 interposed therebetween are formed in directions in which the respective center lines intersect each other. On the other hand, in FIG. 7, both axial grooves 32 adjacent to each other with the circumferential groove 31 interposed therebetween are formed so that the center lines are parallel to each other. According to FIGS. 6 and 7, there is an axial groove 32 that is oriented so that the lubricating oil moves downward in the axial groove 32 due to its own weight, so that the lubricating oil can move toward the side surface 5 c of the outer ring. This makes it easy for the lubricating oil supplied into the circumferential groove 31 to enter the side surface 5c of the outer ring 5.
Furthermore, although not shown, in FIGS. 6 and 7, the left and right axial grooves 32 are arranged side by side with the circumferential groove 31 therebetween, but may be shifted in the circumferential direction on the left and right, Alternatively, a plurality of axial grooves 32 having different inclination angles θ may be formed in the circumferential direction.

  As described above, according to the rolling bearing 3 of the second to fifth embodiments, the lubricating oil is supplied into the circumferential groove 31 from the hole 35 formed in the housing H, and this lubricating oil passes through the axial groove 32. It is supplied to both axial side surfaces 5c, 5c of the outer ring 5. Then, the lubricating oil supplied to the side surface 5c of the outer ring 5 flows around the side surface 5c of the outer ring 5 and the inner peripheral surface 5b of the outer ring 5 and can supply oil to the track portion.

  Furthermore, the bearing ring of the rolling bearing 3 of each embodiment is not a divided structure, but is formed of an annular one-piece structure (one-piece structure). That is, in FIG. 1, the inner ring 4 and the outer ring 5 are each made of an annular integral member, and in FIG. 8, the outer ring 5 is made of an annular integral member. Thereby, a joint is not produced on the raceway surface. The rolling bearing 3 is attached to a predetermined position in the axial direction of the shaft 1 (rolling bearing mounting portion 15), with the shaft 1 inserted from the end of the shaft 1 and moved in the axial direction along the shaft 1.

  As shown in FIG. 1 or FIG. 8, this camshaft device has an assembly structure in which the shaft 1 and the cam 2 are assembled as separate bodies and then assembled into a camshaft. That is, the shaft 1 is a linear member, and the cam 2 is formed with a through-hole 10 for fitting to the shaft 1. Thus, the cam 2 is fitted from the end of the shaft 1 and can move in the axial direction along the shaft 1, and is attached to a predetermined position (cam mounting portion 14) in the axial direction of the shaft 1. The shaft 1, the cam 2, and the rolling bearing 3 can be configured as one camshaft unit, and what is configured in advance as this unit can be assembled to the housing H.

  A shaft member 26 is attached to one end (left side) of the shaft 1, and this shaft member 26 is fixed so as to be concentric with the shaft 1. A pulley 9 for rotating the shaft 1 and a cylindrical roller bearing 11 that supports the vicinity of the pulley 9 are attached to the shaft member 26. A large radial belt load acts on the pulley 9, but the shaft member 26 and the shaft 1 can be stably supported by using the cylindrical roller bearing 11 having a large load capacity. Although not shown, the oil supply hole 33, the circumferential groove 31, and the axial groove 32 are also formed in the outer ring of the cylindrical roller bearing 11.

  The cam 2 attached to the shaft 1 will be further described. The cam 2 may be configured to rotate integrally with the shaft 1 using a key member or the like (not shown). Are preferably fitted and fixed. Therefore, the cam 2 may be attached to the shaft 1 by shrink fitting, for example. As a result, the cam 2 can be easily and firmly attached, no separate fixing member is required, and the number of parts can be reduced.

  The shaft 1 will be further described. The shaft 1 is configured as a straight line that allows the cam 2 and the rolling bearing 3 to be attached to predetermined positions by moving the cam 2 and the rolling bearing 3 in the axial direction from the end side. That is, in order to move the cam 2 and the rolling bearing 3 axially from the end portion of the shaft 1 to predetermined positions, the cam mounting portion 14 and the rolling bearing mounting portion 15 have the same outer diameter, and these portions The shaft 1 is configured so as to have a circular cross section having a maximum outer diameter. In FIG. 8, the raceway surface 6 is formed on the rolling bearing mounting portion 15, and the outer diameter of the rolling bearing mounting portion 15 is the diameter at the shoulder. As a result, centerless machining (centerless polishing) can be performed on the cam mounting portion 14 and the rolling bearing mounting portion 15 of the shaft 1, and the highly accurate shaft 1 can be manufactured easily and at low cost.

  The shaft 1 may have the same diameter over the entire length and may have a linear cross section that is uniform in the axial direction (that is, the outer circumferential surface 1a has no step over the entire length) but has the same outer diameter. All of the cam mounting portions 14 and all of the rolling bearing mounting portions 15 may have a maximum diameter, and the other portions may have a portion slightly smaller in diameter so as to be linear with a small step.

According to the above configuration, the lubricating oil can be effectively supplied to the bearing track portion, and a camshaft device including the rolling bearing 3 with excellent lubrication performance can be obtained. As a result, the camshaft unit including the shaft 1, the cam 2, and the rolling bearing 3 can prevent oil from running out and can function smoothly.
Further, since all of the bearings supporting the shaft 1 are the rolling bearings 3 (deep groove ball bearings and cylindrical roller bearings 11), the frictional resistance can be reduced particularly at the start of rotation and at the time of low speed rotation. Friction loss during rotation can be greatly reduced in the entire apparatus. Therefore, by using this shaft device for the camshaft device for operating the air supply / exhaust valve of the automobile engine, it is possible to contribute to improving the fuel efficiency of the engine.

Further, by using the rolling bearing 3 that supports the shaft 1 in the vicinity of the cam 2 as a deep groove ball bearing, the following effects can be obtained. A plurality of cams 2 are provided on the shaft 1, and a load is applied to the cams 2 during the operation of the supply / exhaust valve of the engine, causing periodic waviness (vibration) on the shaft 1. However, the displacement due to the undulation of the shaft 1 can be released by the curved track surface and the balls 7 in contact therewith.
Furthermore, an axial load acting on the shaft 1 can be received by the rolling bearing 3, and the axial displacement of the shaft 1 can be regulated.

  Further, the shaft device of the present invention is not limited to the illustrated form, and may be of other forms within the scope of the present invention. In FIGS. 1 and 8, eight cams 2 are provided, and the rolling bearing 3 is provided. Although the number is four, the arrangement and quantity thereof are not limited to this and can be changed.

It is a side view of the partial cross section which shows the camshaft apparatus which concerns on one Embodiment of this invention. It is sectional drawing which shows 1st Embodiment of a rolling bearing. It is a side view which shows 2nd Embodiment of a rolling bearing. It is the enlarged view which looked at a part of outer periphery part of the outer ring from the axial direction. It is a side view which shows 3rd Embodiment of a rolling bearing. It is a side view which shows 4th Embodiment of a rolling bearing. It is a side view which shows 5th Embodiment of a rolling bearing. It is a side view of the partial cross section which shows other embodiment of a camshaft apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft 2 Cam 3 Rolling bearing 5 Outer ring 5a Outer peripheral surface 5b Inner peripheral surface 5c Side surface 10 Through hole 31 Circumferential groove 32 Axial groove 33 Oil supply hole C Center line

Claims (6)

  A rolling bearing characterized in that a groove is formed on the outer peripheral surface of the outer ring, and an oil supply hole is formed through the surface of the inner peripheral surface of the outer ring that does not contact the rolling element.   A rolling bearing characterized in that a circumferential groove and an axial groove that opens from the circumferential groove to the side surface of the outer ring are formed on the outer circumferential surface of the outer ring.   The circumferential groove is formed at an axial center portion on the outer circumferential surface of the outer ring, and the axial groove is a shaft of the circumferential groove so as to linearly penetrate both side surfaces of the outer ring. The rolling bearing according to claim 2, wherein the rolling bearing is formed on both sides in the direction.   The circumferential groove is formed in an axial center portion on the outer peripheral surface of the outer ring, and the axial groove is shifted in the circumferential direction on both sides in the axial direction of the circumferential groove. The rolling bearing according to claim 2 formed respectively.   5. The rolling bearing according to claim 2, wherein the groove in the axial direction is formed to be inclined with respect to a straight line parallel to the central axis on the outer peripheral surface of the outer ring.   A rolling bearing according to any one of claims 1 to 5, a shaft rotatably supported by the rolling bearing, and a shaft that is separate from the shaft and has a through hole, and is fitted on the shaft. And a camshaft device, wherein the rolling bearing has a raceway ring formed of an annular integral member and is attached to the shaft as an outer fitting shape.

Images