JP2013148030A - Valve timing adjusting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve timing adjusting device enhancing the life of a bearing.SOLUTION: A driving roller 11 has a first sun gear part 116 in the inside in a radial direction. A driven roller 12 has a second sun gear part 123 in the inside in the radial direction. A planetarium roller 13 has a first planetarium gear part 133, a second planetarium gear part 134, and a shaft hole 135. A cylinder shaft 14 is formed into a cylindrical shape. A center bolt 15 is rotatably arranged interlocking with a cam shaft 4. A first bearing 16 is arranged between the exterior wall of a center bolt 15 and the interior wall of the cylinder shaft 14. A second bearing 17 is arranged between the exterior wall of the cylinder shaft 14 and the interior wall of the shaft hole 135. The center BC1 of the first bearing and the center BC2 of the second bearing is positioned between the center GC1 of the first gear and the center GC2 of the second gear.

Description

  The present invention relates to a valve timing adjusting device.

  2. Description of the Related Art Conventionally, there is known a valve timing adjusting device that adjusts a valve timing by changing a relative rotational phase between two rotating bodies that rotate in conjunction with a crankshaft and a camshaft. For example, Patent Document 1 includes a planetary gear housed in a space composed of a driving side rotating body and a driven side rotating body, and a planetary frame that rotatably supports the planetary gear, and is driven by the planetary gear. A valve timing adjusting device that changes a relative rotational phase between a side rotating body and a driven side rotating body is disclosed.

JP 2007-71060 A

In the valve timing adjusting device described in Patent Document 1, the center in the axial direction of the bearing provided between the planetary frame and the driving side rotating body is the center in the axial direction of the first external gear portion of the planetary gear and the planet. The second outer gear portion of the gear is out of the center in the axial direction.
For this reason, when the planetary gear rotates while the first external gear portion and the second external gear portion of the planetary gear mesh with the first internal gear portion of the driven side rotating body and the second internal gear portion of the driving side rotating body, There is a risk that the rotating shaft may tilt due to the radial moment. When the rotating shaft is tilted, the bearing provided between the planetary frame and the driving side rotating body is unevenly worn.

  Further, in the valve timing adjusting device described in Patent Document 1, the bearings are arranged side by side in the axial direction, so that the oil path of the lubricating oil flowing through the bearings is elongated in the axial direction. For this reason, the foreign material contained in the lubricating oil tends to stay in the bearing.

Therefore, in the valve timing adjusting device described in Patent Document 1, the life of the bearing provided between the planetary frame and the driving side rotating body is reduced.
The present invention has been made in view of the above-described problems, and an object thereof is to provide a valve timing adjusting device that improves the life of a bearing.

  According to the first aspect of the present invention, the valve timing adjusting device is provided in a driving force transmission system that transmits the driving force of the internal combustion engine from the driving shaft to the driven shaft, and is configured to open and close the intake and exhaust valves driven by the driven shaft. At least one opening / closing timing is adjusted. The valve timing adjusting device includes a first rotating body, a second rotating body, a planetary rotating body, a cylindrical shaft, a support body, a first bearing, and a second bearing. The first rotating body is formed in a cylindrical shape, has a first sun gear portion inside, and rotates in conjunction with one of the drive shaft and the driven shaft. The second rotating body is formed in a cylindrical shape, has a second sun gear portion different from the inner diameter of the first sun gear portion on the inside, and rotates in conjunction with the other of the drive shaft and the driven shaft. The planetary rotator has a first planetary gear portion that meshes with the first sun gear portion, a second planetary gear portion that meshes with the second sun gear portion, and a shaft hole. And the relative rotational phase of the second rotating body are changed. The cylinder shaft is provided in the shaft hole so as to be rotatable relative to the planetary rotator, and has a cylindrical inner space therein and is formed in a cylindrical shape. The support is formed in a columnar shape, and is provided coaxially with the driven shaft so as to be rotatable in conjunction with the driven shaft. The first bearing has a cylindrical shape, is provided between the outer wall of the support and the inner wall of the cylindrical shaft, and rotatably supports the cylindrical shaft. The second bearing has a cylindrical shape and is provided between the outer wall of the cylindrical shaft and the inner wall of the shaft hole, and rotatably supports the planetary rotating body. The first bearing center that is the center in the axial direction of the first bearing and the second bearing center that is the center in the axial direction of the second bearing are the first gear center that is the center in the axial direction of the first planetary gear portion. The second planetary gear unit is located between the second gear center which is the center in the axial direction.

  In the present invention, the first bearing and the second bearing are provided such that the first bearing center and the second bearing center are located between the first gear center and the second gear center. Thereby, the acting force generated when the first planetary gear portion and the first sun gear portion mesh with each other, and the acting force generated when the second planetary gear portion and the second sun gear portion mesh with each other, It acts on both sides in the axial direction of the bearing center and the second bearing center. For this reason, it is possible to prevent the radial moments received by the first bearing and the second bearing from canceling each other and tilting the rotating shaft. Therefore, the first bearing and the second bearing can be prevented from tilting in the radial direction, and uneven wear of the first bearing and the second bearing can be suppressed. Therefore, the lifetime of the first bearing and the second bearing can be improved.

  In the present invention, the first bearing is provided on the radially inner side of the second bearing, and the first bearing and the second bearing are provided to overlap each other. Such a configuration can shorten the flow path length through which the lubricating oil flows. For this reason, it can suppress that the foreign material contained in lubricating oil retains in a 1st bearing and a 2nd bearing. Therefore, wear of the sliding surfaces of the first bearing and the second bearing due to foreign matters can be suppressed. Therefore, the lifetime of the first bearing and the second bearing can be improved.

1 is a cross-sectional view of a valve timing adjusting device according to an embodiment of the present invention. 1 is a schematic diagram of a driving force transmission system according to an embodiment of the present invention. III-III sectional view taken on the line of FIG. IV-IV sectional view taken on the line of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(One embodiment)
A valve timing adjusting device according to an embodiment of the present invention is shown in FIGS.
The valve timing adjusting device 10 of this embodiment is a motor-driven valve timing adjusting device driven by a motor 21. In the driving force transmission system provided with the valve timing adjusting device 10 of the present embodiment, as shown in FIG. 2, it is fixed to a crankshaft 2 as a driving shaft of an internal combustion engine (hereinafter referred to as “engine”) 1. The timing chain 7 is wound around the gear 3 and the sprocket gears 118 and 6 fixed to the camshafts 4 and 5 as driven shafts, and the driving force is transmitted from the crankshaft 2 to the camshafts 4 and 5. . The camshaft 4 drives the intake valve 8 to open / close via the cam mechanism, and the camshaft 5 drives the exhaust valve 9 to open / close via the cam mechanism. The valve timing adjusting device 10 according to the present embodiment adjusts the rotational phase between the driving rotating body 11 that rotates in conjunction with the crankshaft 2 and the driven rotating body 12 that rotates in conjunction with the camshaft 4. Then, the opening / closing timing of the intake valve 8 is adjusted.

  The valve timing adjusting device 10 includes a drive rotator 11 as a first rotator, a driven rotator 12 as a second rotator, a planetary rotator 13, a cylindrical shaft 14, a center bolt 15 as a support, and a first bearing 16. , And the second bearing 17, and is driven and controlled by the control unit 20.

  As shown in FIG. 1, the drive rotator 11 has a cylindrical shape as a whole, and is configured by coaxially combining a bottomed cylindrical drive gear member 111, a cylindrical connection member 112, and a plate-like sprocket member 113. Has been. Hereinafter, in the valve timing adjusting device 10, the drive gear member 111 side is referred to as “one end side” and the sprocket member 113 side is referred to as “other end side”. In the cylindrical member, a radially inner wall surface is referred to as an “inner wall”, and a radially outer wall surface is referred to as an “outer wall”. The drive gear member 111, the connection member 112, and the sprocket member 113 are fastened by screws 119. The drive rotator 11 has an internal space 110 that accommodates the driven rotator 12, the planetary rotator 13, the cylindrical shaft 14, the center bolt 15, the first bearing 16, and the second bearing 17. Lubricating oil supplied from the supply passage 41 is supplied to the internal space 110.

The drive gear member 111 has a drive cylinder portion 114 and a drive bottom portion 115. On the inner wall of the drive cylinder portion 114, an inner tooth-shaped first sun gear portion 116 having a tooth tip circular surface on the inner peripheral side of the root circle is formed. A through hole 117 is formed at the center of the driving bottom 115.
The connection member 112 is formed in a cylindrical shape, and is provided between the drive cylinder portion 114 of the drive gear member 111 and the sprocket member 113.

  The sprocket member 113 is provided on the opposite side of the drive gear member 111 with respect to the connection member 112. The sprocket member 113 has a sprocket gear 118 that protrudes outward in the radial direction of the outer wall. Here, the sprocket member 113 is connected to the crankshaft 2 by the timing chain 7 spanned over the sprocket gear 118. Therefore, the drive rotator 11 rotates in conjunction with the crankshaft 2.

  The driven rotator 12 is provided on the radially inner side of the connection member 112, and is positioned closer to the sprocket member 113 than the end on the other end side of the drive cylinder portion 114. The driven rotor 12 has a bottomed cylindrical shape, and has a driven cylinder portion 121 and a driven bottom portion 122. On the inner wall of the driven cylinder portion 121, a second sun gear portion 123 having a tooth tip circular surface on the inner peripheral side of the root circle is formed. Here, the root circle of the second sun gear portion 123 is formed to have a smaller diameter than the root circle of the first sun gear portion 116. The driven rotator 12 is fixed to the camshaft 4 by a fixing pin 124 so as not to rotate relative to the camshaft 4. Therefore, the driven rotating body 12 rotates integrally with the camshaft 4 around the central axis O1 of the camshaft 4.

  The planetary rotator 13 is formed in a two-stage cylindrical shape, and includes a first cylinder part 131, a second cylinder part 132, and a shaft hole 135. The outer diameter of the first tube portion 131 is formed larger than the outer diameter of the second tube portion 132. The planetary rotator 13 is provided such that the first cylinder portion 131 is positioned inside the drive cylinder portion 114 and the second cylinder portion 132 is positioned inside the driven cylinder portion 121.

  On the outer wall of the first cylindrical portion 131, an outer-tooth-shaped first planetary gear portion 133 having a tooth tip circular surface on the outer peripheral side of the root circle is formed. The number of teeth of the first planetary gear portion 133 is set to be a predetermined number less than the number of teeth of the first sun gear portion 116. A part of the first planetary gear part 133 meshes with a part of the first sun gear part 116.

  On the outer wall of the second cylindrical portion 132, an externally toothed second planetary gear portion 134 having a tooth tip circular surface on the outer peripheral side of the root circle is formed. The root circle of the second planetary gear part 134 has a smaller diameter than the root circle of the first planetary gear part 133. Further, the number of teeth of the second planetary gear portion 134 is set to be a predetermined number less than the number of teeth of the second sun gear portion 123. A part of the second planetary gear part 134 meshes with a part of the second sun gear part 123.

  The shaft hole 135 is formed in the center of the second cylinder part 132 and penetrates the second cylinder part 132 in the axial direction. The shaft hole 135 accommodates the cylinder shaft 14 rotatably.

  The cylindrical shaft 14 is accommodated in the shaft hole 135 coaxially with the camshaft 4 and rotatably supports the planetary rotating body 13 (see FIGS. 3 and 4). The cylindrical shaft 14 has an input part 141, a transmission part 142, and a cylindrical internal space 143. The cylindrical shaft 14 is formed such that the central axis is eccentric with respect to the central axis O2 of the internal space 143. Therefore, the cylindrical shaft 14 is formed so that the radial thickness of the peripheral wall is different in the circumferential direction. Here, a portion where the radial thickness is formed thicker than the average thickness is referred to as a thick portion 144, and a portion where the radial thickness is formed thinner than the average thickness is referred to as a thin portion 145.

The input part 141 is formed on one end side of the cylindrical shaft 14 and has a joint part 146 in the center. By this joint portion 146, the cylindrical shaft 14 and the motor shaft 212 are fixed coaxially so as not to be relatively rotatable. Therefore, the cylindrical shaft 14 can rotate around the central axis O <b> 1 of the camshaft 4 together with the motor shaft 212.
Here, when the cylindrical shaft 14 rotates around the central axis O1, the planetary rotating body 13 rotates around the central axis O2 while revolving around the central axis O1. Further, the meshing locations of the first planetary gear portion 133 and the second planetary gear portion 134 and the first sun gear portion 116 and the second sun gear portion 123 move with the rotation of the planetary rotor 13.

  The transmission portion 142 is formed on one end side of the cylindrical shaft 14. The cylindrical shaft 14 is provided such that the transmission portion 142 is located between the inner wall of the second cylindrical portion 132 and the outer wall of the center bolt 15. On the outer wall of the thick portion 144 of the transmission portion 142, housing recesses 147 are formed at two locations in the circumferential direction. The two accommodating recesses 147 accommodate the elastic members 148 individually. The elastic member 148 is elastically deformed, so that the first planetary gear part 133 and the second planetary gear part 134, the first sun gear part 116 and the second sun gear part 123 are connected via a first bearing 16 described later. The planetary rotator 13 is urged toward the meshing side.

  The center bolt 15 is formed in a cylindrical shape. The center bolt 15 is screwed into one end of the camshaft 4 so as not to rotate relative to the camshaft 4, and is positioned in the internal space 143 of the cylindrical shaft 14.

  The first bearing 16 is provided between the outer wall of the center bolt 15 and the inner wall of the transmission portion 142. The first bearing 16 is a needle bearing having a plurality of cylindrical needle rollers 161 in the circumferential direction. The needle roller 161 reduces the frictional resistance between the center bolt 15 and the cylindrical shaft 14 while rotating between the outer wall of the center bolt 15 and the inner wall of the transmission portion 142. In the present embodiment, the center of the first bearing 16 in the axial direction coincides with the center of the needle roller 161 in the axial direction. Here, the center of the first bearing 16 in the axial direction is defined as a first bearing center BC1. The first bearing 16 includes a first bearing center BC1, a first gear center GC1 that is the center of the first planetary gear portion 133 in the axial direction, and a second gear that is the center of the second planetary gear portion 134 in the axial direction. A gear center GC0 that is the center in the axial direction between the center GC2 and the center GC2 is provided to coincide.

  Here, if the distance in the axial direction between the first gear center GC1 and the second gear center GC1 is d, the axial direction between the first bearing center BC1 and the first gear center GC1 or the second gear center GC1. The distance at is d / 2.

  The second bearing 17 is provided between the outer wall of the transmission part 142 and the inner wall of the second cylinder part 132. The second bearing 17 is a ball bearing having a plurality of spherical balls 171 provided in the circumferential direction. The ball 171 reduces the frictional resistance between the cylindrical shaft 14 and the planetary rotating body 13 while rotating between the outer wall of the transmission portion 142 and the inner wall of the second cylindrical portion 132. In the present embodiment, the center in the axial direction of the second bearing 17 and the center between the two balls 171 in the axial direction coincide. Here, the center of the second bearing 17 in the axial direction is defined as a second bearing center BC2. The second bearing 17 is provided so that the second bearing center BC2 and the gear center GC0 coincide.

  The control unit 20 includes a motor 21 and a control unit 22. The motor 21 is disposed on the opposite side of the camshaft 4 with the valve timing adjusting device 10 interposed therebetween. The motor 21 is, for example, a brushless motor, and includes a motor case 211 fixed to the engine 1 and a motor shaft 212 that is supported by the motor case 211 so as to be rotatable forward and backward. The control unit 22 is an electric circuit such as a microcomputer, and is disposed outside the motor case 211 and is electrically connected to the motor 21. The control unit 22 controls energization of the motor 21 according to the operating state of the engine 1 and the like. By this energization control, the motor 21 forms a rotating magnetic field around the motor shaft 212, and outputs rotational torque in directions X and Y (see FIGS. 3 and 4) according to the direction of the rotating magnetic field from the motor shaft 212.

Here, the operation of the valve timing adjusting device 10 of the present embodiment will be described.
In the present embodiment, the drive rotator 11 and the driven rotator 12 are engaged with the first sun gear portion 116 and the first planetary gear portion 133, and between the second sun gear portion 123 and the second planetary gear portion 134. It is linked via the planetary rotating body 13 by meshing.

  When the cylindrical shaft 14 does not rotate relative to the drive rotator 11, the planetary rotator 13 is engaged with the first planetary gear portion 133 and the first sun gear portion 116, and the second planetary gear portion 134 2 Rotates around the central axis O1 together with the drive rotator 11 and the driven rotator 12 while maintaining the meshing position with the sun gear portion 123. Thereby, since the relative rotational phase between the drive rotator 11 and the driven rotator 12 is maintained, the valve timing is also maintained.

  On the other hand, when the cylindrical shaft 14 rotates relative to the drive rotator 11 in the advance angle direction X as the rotational torque increases in the direction X, the planetary rotator 13 is connected to the first planetary gear 133 and the first sun gear. The driven rotor 12 is advanced with respect to the drive rotor 11 by performing planetary movement while changing the meshing position with the part 116 and the meshing position between the second planetary gear part 134 and the second sun gear part 123. Relative rotation in direction X Therefore, the valve timing changes to the advance side, and the valve timing of the most advanced angle phase can be realized.

  Further, when the cylindrical shaft 14 rotates relative to the drive rotating body 11 in the retarding direction Y as the rotational torque increases in the direction Y, the motor 21 suddenly stops, etc., the planetary rotating body 13 becomes the first planetary gear section. The driven rotator 12 is driven by a planetary motion while changing the meshing position of 133 and the first sun gear part 116 and the meshing position of the second planetary gear part 134 and the second sun gear part 123. 11 relative to the retarding direction Y. Therefore, when the valve timing changes to the retard side, and particularly when the motor 21 is suddenly stopped, the valve timing of the most retarded phase at which the engine 1 can be started can be realized.

Hereinafter, effects derived from the configuration of the present embodiment will be described.
(1) In the present embodiment, the first bearing 16 and the second bearing 17 are provided such that the first bearing center BC1 and the second bearing center BC2 are located between the first gear center GC1 and the second gear center GC2. It has been. Thereby, the action force generated when the first planetary gear part 133 and the first sun gear part 116 mesh with each other, and the action force generated when the second planetary gear part 134 and the second sun gear part 123 mesh with each other. Acts on both sides of the first bearing center BC1 and the second bearing center BC2 in the axial direction. For this reason, it is possible to prevent the radial moments received by the first bearing 16 and the second bearing 17 from canceling each other and tilting the rotating shaft. Therefore, the first bearing 16 and the second bearing 17 can be prevented from tilting in the radial direction, and uneven wear of the first bearing 16 and the second bearing 17 can be suppressed. Therefore, the lifetimes of the first bearing 16 and the second bearing 17 can be improved.

The first bearing 16 is provided inside the second bearing 17 in the radial direction, and the first bearing 16 and the second bearing 17 are provided to overlap each other. Such a configuration can shorten the flow path length through which the lubricating oil flows. For this reason, it can suppress that the foreign material contained in lubricating oil retains in the 1st bearing 16 and the 2nd bearing 17. FIG. Therefore, abrasion of the sliding surfaces of the first bearing 16 and the second bearing 17 due to foreign matters can be suppressed. Therefore, the lifetimes of the first bearing 16 and the second bearing 17 can be improved.
Further, since the first bearing 16 and the second bearing 17 are arranged in the radial direction, the physique in the axial direction of the valve timing adjusting device 10 can be reduced.

  (2) In the present embodiment, the first bearing 16 and the second bearing 17 are provided such that the first bearing center BC1 and the second bearing center BC2 coincide. Thereby, the effect which suppresses the partial wear of the 1st bearing 16 and the 2nd bearing 17 can be heightened.

  (3) In the present embodiment, the first bearing 16 and the second bearing 17 are provided such that the first bearing center BC1 and the second bearing center BC2 coincide with the gear center GC0. Thereby, the effect which suppresses the partial wear of the 1st bearing 16 and the 2nd bearing 17 can be heightened more.

  (4) In the present embodiment, the first bearing 16 is a needle bearing. Thereby, the physique of the radial direction of the valve timing adjustment apparatus 10 can be reduced.

(Other embodiments)
In the above-described embodiment, the example in which the valve timing adjusting device adjusts the valve timing of the intake valve has been described. On the other hand, in another embodiment, the valve timing adjusting device may adjust the valve timing of the exhaust valve.

  In the above embodiment, an example has been described in which the driving rotating body rotates in conjunction with the crankshaft and the driven rotating body rotates in conjunction with the camshaft. On the other hand, in another embodiment, the driven rotator may rotate in conjunction with the crankshaft, and the drive rotator may rotate in conjunction with the camshaft.

  In the above embodiment, an example in which the first bearing center and the second bearing center coincide with the gear center has been described. On the other hand, in other embodiments, the first bearing center and the second bearing center may be positioned between the first gear center and the second gear center without matching the gear center.

  In the said embodiment, the example in which the center bolt is applied as a support body was shown. On the other hand, in another embodiment, another member integrated with the camshaft may be applied as the support.

  In the above embodiment, the first bearing is a needle bearing and the second bearing is a ball bearing. On the other hand, in other embodiments, the first bearing may be a ball bearing, and the second bearing may be a needle bearing. Further, both the first bearing and the second bearing may be needle bearings, or both may be ball bearings.

  The present invention described above is not limited to the above-described embodiment, and can be applied to various embodiments without departing from the gist thereof.

1 ... engine (internal combustion engine),
2 ... Crankshaft (drive shaft),
4 ... Camshaft (driven shaft),
5 ... Camshaft (driven shaft)
10 ... Valve timing adjusting device,
11 ... Drive rotator (first rotator),
12 ... driven rotor (second rotor),
13 ... Planetary rotating body,
14 ... Cylinder shaft,
15 ... Center bolt (support),
16 ... 1st bearing,
17 ... second bearing,
116 ... 1st sun gear part,
123 ... the second sun gear part,
133 ... 1st planetary gear part,
134 ... the second planetary gear section,
135 ... shaft hole,
143 ... internal space,
BC1 ... 1st bearing center,
BC2 ... the center of the second bearing,
GC1 ... center of the first gear,
GC2 is the center of the second gear.

Claims (4)

An intake valve (8) and an exhaust valve (8) provided in a driving force transmission system for transmitting the driving force of the internal combustion engine (1) from the driving shaft (2) to the driven shafts (4, 5) and driven to open and close by the driven shaft. 9) A valve timing adjusting device (10) for adjusting the opening / closing timing of at least one of 9),
A first rotating body (11) which is formed in a cylindrical shape, has a first sun gear portion (116) on the inside, and rotates in conjunction with one of the drive shaft and the driven shaft;
A second rotating body formed in a cylindrical shape, having a second sun gear portion (123) having an inner diameter different from that of the first sun gear portion on the inside, and rotating in conjunction with the other of the drive shaft and the driven shaft ( 12)
The first planetary gear portion (133) that meshes with the first sun gear portion, the second planetary gear portion (134) that meshes with the second sun gear portion, and the shaft hole (135) have a planetary motion. A planetary rotating body (13) for changing a relative rotational phase between the first rotating body and the second rotating body,
A cylindrical shaft (14) which is provided in the shaft hole so as to be rotatable relative to the planetary rotating body, has a cylindrical inner space (143) inside, and is formed in a cylindrical shape;
A support body (15) which is formed in a columnar shape and is provided coaxially with the driven shaft so as to be rotatable in conjunction with the driven shaft;
A cylindrical first bearing (16) provided between an outer wall of the support and an inner wall of the cylindrical shaft, and rotatably supporting the cylindrical shaft;
A cylindrical second bearing (17) provided between the outer wall of the cylindrical shaft and the inner wall of the shaft hole, and rotatably supporting the planetary rotating body,
The first bearing center (BC1) which is the center in the axial direction of the first bearing and the second bearing center (BC2) which is the center in the axial direction of the second bearing are in the axial direction of the first planetary gear unit. The valve timing adjusting device is located between the first gear center (GC1) which is the center of the second planetary gear portion and the second gear center (GC2) which is the center of the second planetary gear portion in the axial direction.   2. The valve timing adjusting device according to claim 1, wherein the first bearing and the second bearing are provided such that a center of the first bearing and a center of the second bearing coincide with each other.   The first bearing and the second bearing are gears in which at least one of the first bearing center and the second bearing center is an axial center between the first gear center and the second gear center. 3. The valve timing adjusting device according to claim 1, wherein the valve timing adjusting device is provided so as to coincide with the center (GC0).   The valve timing adjusting device according to any one of claims 1 to 3, wherein at least one of the first bearing and the second bearing is a needle bearing.

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