JP2018123727A - Valve timing adjustment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve timing adjustment device capable of suppressing occurrence of striking sound.SOLUTION: The valve timing adjustment device includes a rotary actuator and a phase adjustment part 12, and the phase adjustment part 12 has a speed reduction mechanism. The speed reduction mechanism has a driving side internal gear part of a driving rotation body, a driven side internal gear part 38 of a driven rotation body, and a planetary rotation body. The planetary rotation body has a driving side external gear part meshing with the driving side internal gear part, and a driven side external gear part 51 meshing with the driven side internal gear part. The linear expansion coefficient of the driving side external gear part is greater than the linear expansion coefficient of the driving side internal gear part, and the linear expansion coefficient of the driven side external gear part 51 is greater than a linear expansion coefficient 38 of the driven side internal gear part. Further, the linear expansion coefficient of the driving side external gear part and that of the driven side external gear part 51 have the same value, and the linear expansion coefficient of the driving side internal gear part and that of the driven side internal gear part 38 have the same value.SELECTED DRAWING: Figure 4

Description

  The disclosure herein relates to a valve timing adjustment device.

  Conventionally, a drive rotator that rotates in conjunction with a crankshaft of an internal combustion engine, a driven rotator that rotates in conjunction with a camshaft, and a speed reduction mechanism provided between the drive rotator and the driven rotator are provided. A known valve timing adjustment device is known. In this valve timing adjusting device, the valve timing of the valve that opens and closes the camshaft is adjusted by rotating the driven rotor relative to the drive rotor. As such a valve timing adjusting device, there are a device in which a speed reduction mechanism is configured including a cage that holds a plurality of rollers, and a device in which a speed reduction mechanism is configured including a planetary rotating body having a planetary gear unit. is there. For example, Patent Document 1 discloses a valve timing adjusting device in which a speed reduction mechanism is configured including a cage.

Japanese Patent No. 5538053

  However, while the valve timing adjustment device is in operation, the speed reduction mechanism collides with a member on the drive rotator side or a member on the driven rotator side, or when members of the speed reduction mechanism collide with each other, There is a concern that this will occur. Therefore, it is conceivable to reduce the striking sound by finely adjusting the dimensions of many members of the speed reduction mechanism one by one, but this increases the work burden when manufacturing the valve timing adjusting device. End up. In addition, it is conceivable to add or add special parts to reduce the hitting sound, but this method increases the number of parts of the valve timing adjustment device, so the valve timing adjustment device is large. There is a concern that

  The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide a valve timing adjusting device capable of suppressing the occurrence of a hitting sound.

In order to achieve the above object, the disclosed first aspect is:
A valve timing adjusting device (10) for adjusting a valve timing of a valve (81) that opens and closes a camshaft (91) by transmission of engine torque from a crankshaft (90) in an internal combustion engine (80),
A drive rotator (25) having a drive gear portion (37) and rotating in conjunction with the crankshaft;
A driven rotor (26) having a driven gear portion (38) and rotating in conjunction with the camshaft;
A first planetary gear portion (50) and a second planetary gear portion (51), and the first planetary gear portion and the second planetary gear portion are integrally engaged with each other while being eccentrically engaged with the drive gear portion and the driven gear portion, respectively. A planetary rotator (40) that changes the relative phase between the drive rotator and the driven rotator by planetary motion;
With
One of the first planetary gear portion and the second planetary gear portion is referred to as an external gear portion (50, 51) in which external teeth (50a, 51a) extend radially outward, and a drive gear portion and a driven gear portion. Of the outer gear portion is referred to as an internal gear portion (37, 38) in which the inner teeth (37a, 38a) extend radially inward, the linear expansion coefficient (αa1, This is a valve timing adjusting device in which αa2) is larger than the linear expansion coefficient (αb1, αb2) of the internal gear portion.

  According to the first aspect, the linear expansion coefficient of the external gear portion is larger than the linear expansion coefficient of the internal gear portion. For this reason, compared to the case where the temperature of the valve timing adjustment device is relatively low, such as when the internal combustion engine is started, the case where the temperature of the valve timing adjustment device rises, such as when the internal combustion engine is continuously operating, The distance in which the outer gear portion and the inner gear portion can move relatively is reduced. Here, when the temperature of the valve timing adjusting device is relatively low, the relative rotation between the external gear portion and the internal gear portion is not restricted due to the high viscosity of the lubricating oil. It is preferable that the distance that the gear portion and the internal gear portion are relatively movable is large to some extent. However, with the viscosity of the lubricating oil decreasing as the temperature rises, if the distance that the external gear part and the internal gear part can move relatively remains large, the external gear part and the internal gear part will There is a concern that the momentum at the time of collision tends to increase, and that the hitting sound associated with the collision increases.

  On the other hand, as described above, as the temperature of the valve timing adjusting device increases, the distance that the external gear portion and the internal gear portion can move relatively decreases, so that the external gear portion and the internal gear portion The momentum at the time of collision is unlikely to increase, and the hitting sound associated with the collision is unlikely to increase. In this case, for example, there is no need to newly install or add a dedicated component for reducing the hitting sound to the external gear portion or the internal gear portion, etc. And the hitting sound associated with the collision with the internal gear portion can be suppressed.

The second aspect is
A valve timing adjusting device for adjusting a valve timing of a valve that opens and closes a camshaft (102) by transmission of engine torque from a crankshaft in an internal combustion engine,
A drive rotor (101) that rotates in conjunction with the crankshaft;
A driven rotor (109) that rotates in conjunction with the camshaft;
An annular member (119) in which the inner teeth (119a) extend inward in the radial direction and rotates together with the drive rotating body, and an eccentric rotating body (provided on the inner peripheral side of the annular member and having an outer peripheral surface eccentric with respect to the axis) 130, 133), a plurality of rollers (134) provided between the annular member and the eccentric rotator, and a cage that rotates with the driven rotator and holds the rollers between the annular member and the eccentric rotator. (141), and a reduction mechanism (108) that changes the relative phase between the driving rotating body and the driven rotating body by rotating the cage relative to the annular member by the rotation of the eccentric rotating body,
With
In this valve timing adjustment device, the linear expansion coefficient (βb) of the eccentric rotating body is larger than the linear expansion coefficient (βc) of the annular member.

  According to the 2nd aspect, the linear expansion coefficient of an eccentric rotary body is large compared with the linear expansion coefficient of an annular member. For this reason, as the temperature of the valve timing adjusting device rises, the distance that the eccentric rotating body and the annular member can move relative to the roller decreases. Here, when the temperature of the valve timing adjusting device is relatively low, the relative rotation between the eccentric rotating body and the annular member via the roller is not restricted due to the large viscosity of the lubricating oil. In addition, it is preferable that the distance that the eccentric rotating body and the annular member can move relative to the roller is large to some extent. However, in the state where the viscosity of the lubricating oil becomes smaller as the temperature rises, if the distance that the eccentric rotating part and the annular member can move relative to the roller remains large, the eccentric rotating body and the annular member become the roller. There is a concern that the momentum at the time of collision is likely to increase, and that the hitting sound associated with the collision increases.

  As described above, since the distance that the eccentric rotator and the annular member can move relative to the roller becomes smaller as the temperature of the valve timing adjusting device increases, the eccentric rotator and the annular member collide with the roller. The momentum is difficult to increase, and the hitting sound associated with the collision is difficult to increase. In this case, for example, it is not necessary to finely adjust the outer diameter size in order to reduce the hitting sound for each of all the rollers, so reducing the work burden when manufacturing the valve timing adjustment device, The hitting sound associated with the collision between the eccentric rotating body or the annular member and the roller can be suppressed.

The third aspect is
A valve timing adjusting device for adjusting a valve timing of a valve that opens and closes a camshaft (102) by transmission of engine torque from a crankshaft in an internal combustion engine,
A drive rotor (101) that rotates in conjunction with the crankshaft;
A driven rotor (109) that rotates in conjunction with the camshaft;
An annular member (119) in which the inner teeth (119a) extend inward in the radial direction and rotates together with the drive rotating body, and an eccentric rotating body (provided on the inner peripheral side of the annular member and having an outer peripheral surface eccentric with respect to the axis) 130, 133), a plurality of rollers (134) provided between the annular member and the eccentric rotator, and a cage that rotates with the driven rotator and holds the rollers between the annular member and the eccentric rotator. (141), and a reduction mechanism (108) that changes the relative phase between the driving rotating body and the driven rotating body by rotating the cage relative to the annular member by the rotation of the eccentric rotating body,
With
The cage has roller holding portions (141a) arranged at predetermined intervals in the radial direction of the cage,
The roller is held by a cage by being arranged between adjacent roller holding portions,
This is a valve timing adjusting device in which the linear expansion coefficient (βa) of the roller is larger than the linear expansion coefficient (βd) of the cage.

  According to the third aspect, the linear expansion coefficient of the roller is larger than the linear expansion coefficient of the cage. For this reason, as the temperature of the valve timing adjusting device rises, the distance that the roller and the roller holding portion can relatively move in the direction in which the rollers are aligned decreases. Here, when the temperature of the valve timing adjusting device is relatively low, the relative displacement between the roller and the roller holding portion and the rotation of the roller are not restricted due to the large viscosity of the lubricating oil. It is preferable that the distance that the roller and the roller holding portion can move relatively is large to some extent. However, when the distance between the roller and the roller holder is relatively large with the viscosity of the lubricating oil decreasing as the temperature rises, the roller and the roller holder may collide with each other. There is a concern that the momentum is likely to increase, and that the hitting sound associated with the collision increases.

  On the other hand, as described above, since the distance that the roller and the roller holding portion can move relative to each other decreases as the temperature of the valve timing adjusting device increases, The momentum is unlikely to increase, and the hitting sound associated with a collision is unlikely to increase. In this case, similarly to the second aspect, for example, it is not necessary to perform an operation such as fine adjustment of the outer diameter in order to reduce the hitting sound for each of all the rollers. For this reason, it is possible to suppress the hitting sound associated with the collision between the roller and the roller holding portion while reducing the work burden when manufacturing the valve timing adjusting device.

  It should be noted that the reference numerals in parentheses described in the claims and in this section merely indicate correspondence with specific means described in the embodiments described later, and do not limit the technical scope of the invention. .

Sectional drawing which shows the valve timing adjustment apparatus in 1st Embodiment. It is the II-II sectional view taken on the line of FIG. 1, Comprising: The figure which looked at the phase adjustment part from the chain cover side. III-III sectional view taken on the line of FIG. FIG. 4 is a sectional view taken along line IV-IV in FIG. 1. The VV sectional view taken on the line of FIG. The figure for demonstrating the outer diameter difference of a driven side. The figure for demonstrating the increase rate of a pitch circle outer diameter and a pitch circle inner diameter. The figure for demonstrating the change aspect of the outer diameter difference of an internal gear part and an external gear part. The figure for demonstrating the assumed distance before temperature rises. The figure for demonstrating the assumed distance after temperature rises. Sectional drawing which shows the valve timing adjustment apparatus in 2nd Embodiment. XII-XII sectional view taken on the line of FIG. XIII-XIII sectional view taken on the line of FIG. It is a disassembled perspective view of a cover member and a 1st oil seal. XV-XV sectional view taken on the line of FIG. The figure for demonstrating each dimension of an annular member, a 1st ball bearing, a roller, and a holder | retainer. The figure for demonstrating the increase rate of each dimension of a cyclic | annular member, a 1st ball bearing, and a holder | retainer. The figure for demonstrating the change aspect of the diameter difference of an annular member and a 1st ball bearing. The figure for demonstrating each dimension of the protrusion part and roller which are adjacent to a holder | retainer. The figure for demonstrating the increase rate of each dimension of the protrusion part and roller which adjoin a holder | retainer. The figure for demonstrating the change aspect of the dimensional difference which is a difference with the holding distance of an adjacent protrusion part, and the diameter of a roller. The figure for demonstrating the positional relationship of an annular member, a 1st ball bearing, a roller, and a holder | retainer before temperature rises. The figure for demonstrating the positional relationship of an annular member, a 1st ball bearing, a roller, and a holder | retainer after temperature rises.

  Hereinafter, a plurality of embodiments of the present disclosure will be described based on the drawings. In addition, the overlapping description may be abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment. When only a part of the configuration is described in each embodiment, the configuration of the other examples described above can be applied to other portions of the configuration. Moreover, not only the combination of the configurations explicitly described in the description of each embodiment, but also the configuration of a plurality of embodiments can be partially combined even if they are not explicitly described, as long as there is no problem in the combination. And the combination where the structure described in several embodiment and the modification is not specified shall also be disclosed by the following description.

(First embodiment)
The valve timing adjusting device 10 shown in FIG. 1 changes the rotational phase of the cam shaft 91 with respect to the crankshaft 90 of the internal combustion engine 80 of the vehicle to change the intake air of the intake valve 81 or the exhaust valve 82 that the cam shaft 91 is driven to open and close. The valve timing of the valve 81 is adjusted. The valve timing adjusting device 10 is provided in a path for transmitting power from the crankshaft 90 to the camshaft 91. In this case, the crankshaft 90 corresponds to the drive shaft, the camshaft 91 corresponds to the driven shaft, and the intake valve 81 hits the valve.

  The configuration of the valve timing adjusting device 10 will be described with reference to FIGS. The valve timing adjustment device 10 includes a rotary actuator 11 and a phase adjustment unit 12.

  As shown in FIG. 1, the rotary actuator 11 is an electric motor such as a brushless motor, for example, and is provided on the extension of the cam shaft 91 in the axial direction. The rotary actuator 11 is connected to the casing 20 fixed to the chain cover 92 of the internal combustion engine 80, a stator and a rotor (not shown) provided in the casing 20, and the rotor, and can be rotated forward and backward by the casing 20. And a supported rotating shaft 21. The chain cover 92 corresponds to a cover member. The casing 20 has an exposed portion 22 provided outside the chain cover 92 and an insertion portion 23 that is inserted into the through hole 93 of the chain cover 92. The rotary shaft 21 is provided so as to protrude from the insertion portion 23 toward the cam shaft 91 side.

  The rotary actuator 11 further includes an energization control unit (not shown) provided in the casing 20, for example. The exposed part 22 has a connector 24 for electrically connecting the energization control part to an external electronic control unit. The energization control unit includes a drive driver and a control microcomputer, and the like, and rotationally drives the rotary shaft 21 by controlling energization to the stator.

  As shown in FIGS. 1 to 5, the phase adjustment unit 12 includes a drive rotator 25, a driven rotator 26, and a speed reduction mechanism 27.

  The drive rotating body 25 is formed by fastening a bottomed cylindrical first housing 28, a second housing 29, and a signal plate 30 provided on the rotation axis AX1 of the cam shaft 91 with bolts 31. The first housing 28 has a sprocket 32 formed integrally with the outer wall. The first housing 28 is connected to the crankshaft 90 by looping an annular timing chain 95 between the sprocket 32 and the sprocket 94 of the crankshaft 90. With this connection, when the engine torque of the crankshaft 90 is transmitted to the sprocket 32 through the timing chain 95, the drive rotator 25 rotates in conjunction with the crankshaft 90. The rotation direction of the drive rotor 25 is set in the clockwise direction in FIGS.

  The signal plate 30 is a disk-shaped member for causing a cam angle sensor (not shown) to detect the rotation angle of the cam shaft 91. As shown in FIG. 2, when the phase adjustment unit 12 is viewed from the chain cover 92 side, the signal plate 30 covers the entire second housing 29.

  As shown in FIGS. 1 and 5, the driven rotator 26 is formed in a bottomed cylindrical shape, and is fitted inside the peripheral wall portion of the first housing 28 so as to be rotatable relative to the drive rotator 25. doing. The bottom wall portion of the driven rotor 26 is directly fixed to the end portion of the cam shaft 91 by screwing using a center bolt 34. By this fixing, the driven rotating body 26 rotates in conjunction with the cam shaft 91. The rotational direction of the driven rotator 26 is set in the clockwise direction of FIG.

  As shown in FIGS. 1 and 4, the drive rotator 25 and the driven rotator 26 are provided with a drive side stopper portion 35 and a driven side stopper portion 36, respectively. The drive side stopper portion 35 protrudes radially inward from four locations on the peripheral wall portion of the first housing 28. The driven side stopper portion 36 protrudes radially outward from four locations on the peripheral wall portion of the driven rotating body 26.

  As shown in FIG. 4, when the specific driven side stopper portion 36 abuts on the driving side stopper portion 35 in the retarding direction, the relative rotation of the driven rotating body 26 in the retarding direction with respect to the driving rotating body 25 is stopped, and driving is performed. The phase between the rotator 25 and the driven rotator 26 is regulated to the endmost phase on the retard side. Hereinafter, the phase between the drive rotator and the driven rotator will be referred to as “phase between rotators”. In the present embodiment, the retarded phase endmost phase is set to an initial phase for allowing the internal combustion engine 80 to start. On the other hand, when the specific driven-side stopper portion 36 abuts on the drive-side stopper portion 35 in the advance angle direction, the relative rotation in the advance angle direction of the driven rotation body 26 with respect to the drive rotation body 25 is stopped, and the phase between the rotation bodies is stopped. Is regulated to the most advanced phase on the advance side.

  As shown in FIGS. 1 to 4, the speed reduction mechanism 27 is a planetary gear mechanism including a driving side internal gear portion 37, a driven side internal gear portion 38, an input rotating body 39, and a planetary rotating body 40. .

  The drive-side internal gear portion 37 is integrally provided on the inner wall of the peripheral wall portion of the second housing 29. The axis of the drive side internal gear portion 37 coincides with the rotation axis AX1. The drive-side internal gear portion 37 has a plurality of internal teeth 37a extending radially inward. The bolt 31 is provided at the same circumferential position as the tooth tip portion of the drive-side internal gear portion 37. In the present embodiment, four bolts 31 are provided at unequal intervals in the circumferential direction.

  The driven side internal gear portion 38 is integrally provided on the inner wall of the peripheral wall portion of the driven rotating body 26. The axis of the driven side internal gear portion 38 coincides with the rotation axis AX1. The driven side internal gear portion 38 has a plurality of internal teeth 38a extending radially inward, and the diameter of the driven side internal gear portion 38 is set smaller than the diameter of the drive side internal gear portion 37, The number of teeth of the driven side internal gear portion 38 is set to be smaller than the number of teeth of the drive side internal gear portion 37. In this case, the pitch circle inner diameter Db1 that is the pitch circle diameter of the drive side internal gear portion 37 is larger than the pitch circle inner diameter Db2 that is the pitch circle diameter of the driven side internal gear portion 38.

  The driving side internal gear portion 37 corresponds to a driving gear portion, and the driven side internal gear portion 38 corresponds to a driven gear portion. One of the driving side internal gear portion 37 and the driven side internal gear portion 38 corresponds to an internal gear portion.

  The input rotating body 39 has a cylindrical shape as a whole, and is supported by the second housing 29 via a bearing 41 so as to be rotatable around the rotation axis AX1. The bearing 41 is provided on the bottom wall portion of the second housing 29. A pair of fitting grooves 42 extending in the axial direction and opening inward in the radial direction are formed in the inner wall of the input rotating body 39. The fitting groove 42 extends from one end surface of the input rotating body 39 to the other end surface. The input rotating body 39 is connected to the rotating shaft 21 by fitting the joint portion 43 of the rotating shaft 21 into the fitting groove 42. By this connection, the input rotator 39 can be driven to rotate together with the rotating shaft 21.

  The input rotating body 39 further includes an eccentric portion 44 that is eccentric with respect to the rotation axis AX1. The eccentric portion 44 is provided with a pair of concave portions 46 that are open toward the outer side in the radial direction so as to be offset toward the eccentric side of the eccentric portion 44. An elastic member 47 that generates a restoring force is accommodated in the recesses 46. In the present embodiment, the elastic member 47 is a metal leaf spring having a substantially U-shaped cross section.

  The planetary rotator 40 is formed by combining a planetary bearing 48 and a planetary gear 49. The inner ring of the planetary bearing 48 is disposed outside the eccentric portion 44 of the input rotor 39 with a predetermined clearance. The planetary bearing 48 is configured to transmit the restoring force received from each elastic member 47 to the planetary gear 49 while being supported from the inside by the eccentric portion 44 via each elastic member 47.

  The planetary gear 49 is formed in a stepped cylindrical shape, and is supported by the eccentric portion 44 via the planetary bearing 48 so as to be rotatable around the eccentric axis AX2. The large-diameter portion of the planetary gear 49 is a drive-side external gear portion 50 that meshes with the drive-side internal gear portion 37. The small diameter portion of the planetary gear 49 is a driven side external gear portion 51 that meshes with the driven side internal gear portion 38. The drive-side external gear portion 50 and the driven-side external gear portion 51 have a plurality of external teeth 50a and 51a extending outward in the radial direction. The number of teeth of the driving side external gear part 50 and the driven side external gear part 51 is set to be smaller by the same number than the number of teeth of the driving side internal gear part 37 and the driven side internal gear part 38, respectively. In this case, the pitch circle outer diameter Da1 that is the pitch circle diameter of the drive side external gear portion 50 is larger than the pitch circle outer shape Da2 that is the pitch circle diameter of the driven side internal gear portion 37.

  When the input rotating body 39 rotates around the rotation axis AX1, the planetary gear 49 performs a planetary motion that revolves around the rotation axis AX1 while rotating around the eccentric axis AX2. At this time, the rotation speed of the planetary gear 49 is reduced with respect to the rotation speed of the input rotor 39. The driven side internal gear portion 38 and the driven side external gear portion 51 correspond to transmission means for transmitting the rotation of the planetary gear 49 to the driven rotating body 26.

  The planetary gear 49 corresponds to a planetary rotating body, the driving side external gear portion 50 corresponds to a first planetary gear portion, and the driven side external gear portion 51 corresponds to a second planetary gear portion. One of the driving side external gear part 50 and the driven side external gear part 51 corresponds to an external gear part.

  The phase adjusting unit 12 having the configuration described so far decelerates the relative rotation of the rotary actuator 11 with respect to the drive rotator 25 and converts it into relative rotation of the driven rotator 26 with respect to the drive rotator 25, thereby rotating these rotators. The phase between the rotating bodies, which is the phase between 25 and 26, is adjusted. Specifically, when the rotation shaft 21 rotates at the same speed as the drive rotator 25 and the input rotator 39 does not rotate relative to the drive rotator 25, the planetary gear 49 does not perform planetary motion and the rotator 25. , 26. Therefore, the phase between the rotating bodies is maintained.

  Further, when the rotary shaft 21 rotates at a low speed or reversely with respect to the drive rotator 25 and the input rotator 39 rotates relative to the drive rotator 25 in the retarding direction, the planetary gear 49 performs a planetary motion. Thus, the driven rotator 26 rotates relative to the drive rotator 25 in the retard direction. Therefore, the phase between the rotating bodies is retarded.

  In addition, when the rotary shaft 21 rotates at a high speed with respect to the drive rotator 25, the planetary gear 49 rotates in a planetary motion when the input rotator 39 rotates relative to the drive rotator 25 in the advance direction. The body 26 rotates relative to the drive rotator 25 in the advance direction. Therefore, the phase between the rotating bodies is advanced.

  The pitch circle outer diameter Da1 of the drive side external gear portion 50 is smaller than the pitch circle inner diameter Db1 of the drive side internal gear portion 37, and the pitch circle outer diameter Da2 of the driven side external gear portion 51 is set to the driven side internal gear portion 38. Is larger than the pitch circle inner diameter Db2. On the driving side, the difference between the pitch circle outer diameter Da1 and the pitch circle inner diameter Db1 is the outer diameter difference ΔD1, and on the driven side, as shown in FIG. 6, the pitch circle inner diameter Da2 and the pitch circle outer diameter Db2 are different. The difference is the outer diameter difference ΔD2.

  In the valve timing adjusting device 10, it is conceivable that each component is thermally expanded. For example, when the gear portions 37, 38, 50, 51 are thermally expanded, the outer diameter differences ΔD1, ΔD2 are considered to change. In the present embodiment, the linear expansion coefficients αb1, αb2, and the like of the gear portions 37, 38, 50, and 51 are reduced so that the outer diameter differences ΔD1 and ΔD2 become smaller as the temperature of the gear portions 37, 38, 50, and 51 increases. αa1 and αa2 are set.

  On the drive side, the linear expansion coefficient αa1 of the drive side external gear portion 50 is such that the increase rate of the pitch circle outer diameter Da1 is larger than the increase rate of the pitch circle inner diameter Db1. It is larger than the coefficient αb1. In this case, the outer diameter difference ΔD1 becomes smaller as the temperature rises. On the driven side, the linear expansion coefficient αa2 of the driven side external gear portion 51 is such that the increase rate of the pitch circle inner diameter Da2 is larger than the increase rate of the pitch circle outer diameter Db2. It is larger than the coefficient αb2. Thereby, the outer diameter difference ΔD2 becomes smaller as the temperature rises.

  In the present embodiment, the linear expansion coefficient αa1 of the driving side external gear portion 50 and the linear expansion coefficient αa2 of the driven side external gear portion 51 have the same value. The driving side external gear portion 50 and the driven side external gear portion 51 are formed of the same steel material such as S45C. Further, the linear expansion coefficient αb1 of the driving side internal gear portion 37 and the linear expansion coefficient αb2 of the driven side internal gear portion 38 have the same value. The driving side internal gear portion 37 and the driven side internal gear portion 38 are formed of the same steel material such as SUS440C. In the present embodiment, the heating and cooling of the gear portions 37, 38, 50, and 51 proceed in the same manner, and the temperatures of the gear portions 37, 38, 50, and 51 are assumed to be the same.

  When the increase rate of the pitch circle outer diameters Da1 and Da2 is larger than the increase rate of the pitch circle inner diameters Db1 and Db2, when the temperature in the valve timing adjusting device 10 rises excessively, the pitch circle outer diameters Da1 and Da2 become pitch circles. There is a concern that it may be larger than the inner diameters Db1 and Db2. Therefore, in the present embodiment, during the operation of the internal combustion engine 80, the linear expansion coefficients αb1, αb2, αa1, and αa2 are set so that the planetary motion of the planetary gear 49 is not inhibited by thermal expansion.

  For example, the thermal expansion on the driven side will be described. As shown in FIG. 7, the temperature Tx1 is caused by the increase rate of the pitch circle outer diameter Da2 of the driven side outer gear portion 51 being larger than the increase rate of the pitch circle inner diameter Db2 of the driven side inner gear portion 38. The pitch circle outer diameter Da2 may catch up with the pitch circle inner diameter Db2. In other words, as shown in FIG. 8, the outer diameter difference ΔD2 decreases as the temperature of the driven-side outer gear portion 51 and the driven-side inner gear portion 38 increases, and this outer diameter difference ΔD2 becomes the temperature Tx2. May become zero.

  Here, even if the pitch circle outer diameter Da2 does not increase to the pitch circle inner diameter Db2, if the outer diameter difference ΔD2 is smaller than a predetermined value, the driven-side outer gear portion 51 is not engaged with the driven-side inner gear portion 38. It is assumed that the outer teeth 51a and the inner teeth 38a come into contact unintentionally. In the present embodiment, as shown in FIGS. 7 and 8, the smallest possible value of the outer diameter difference ΔD2 within a range where the outer teeth 51a do not contact the inner teeth 38a unintentionally is referred to as a limit diameter difference ΔDy2, and the outer diameter difference The temperature at which ΔD2 decreases to the limit diameter difference ΔDy2 is referred to as limit temperature Ty. In the valve timing adjusting device 10, the gear portion is set so that the limit temperature Ty is higher than the temperature (for example, 130 ° C.) that the gear portions 37, 38, 50, 51 can reach in the normal operation of the internal combustion engine 80. Steel materials and materials of 37, 38, 50, and 51 are selected.

  On the drive side as well as the driven side, the outer diameter difference ΔD1 decreases as the temperature of the drive side external gear portion 50 and the drive side internal gear portion 37 increases. However, as shown in FIG. 8, the drive-side outer diameter difference ΔD1 becomes zero at a temperature Tx2 higher than the temperature Tx1. On the drive side, when the outer diameter difference ΔD1 at the limit temperature Ty is referred to as the limit diameter difference ΔDy1, the driven-side limit diameter difference ΔDy2 is smaller than the drive-side limit diameter difference ΔDy1. For this reason, if the gear portions 37, 38, 50, 51 reach the limit temperature Ty, the collision between the driven side external gear portion 51 and the driven side internal gear portion 38 is caused by the driving side external gear portion 50 and the driving side. It is more likely to occur than a collision with the internal gear portion 37. In this way, if the driven side is set to have a relationship in which a collision is more likely to occur, in order to suppress the hitting sound caused by the collision between the external gear portions 50 and 51 and the internal gear portions 37 and 38, driving is performed. It is only necessary to manage the thermal expansion of the gear portions 51 and 38 on the driven side of the side and the driven side. For this reason, the design burden of the valve timing adjusting device 10 can be reduced.

In the present embodiment, as shown in FIG. 7, a temperature lower than the limit temperature Ty is set as a reference temperature Tp, and for this reference temperature Tp, the pitch circle outer diameter Da2 of the driven side external gear portion 51 is set as the reference diameter Da2p. A pitch circle inner diameter Db2 of the side internal gear portion 38 is set as a reference diameter Db2p. In this case, for the dependent side, if the linear expansion coefficient αa2 of the driven side external gear part 51 and the linear expansion coefficient αb2 of the driven side internal gear part 38 are used,
Da2p × αa2> Db2p × αb2 (1)
This relationship holds. That is, the product of the reference diameter Da2p and the linear expansion coefficient αa2 is larger than the product of the reference diameter Db2p and the linear expansion coefficient αb2.

As with the subordinate side, on the drive side, with respect to the reference temperature Tp, the pitch circle outer diameter Da1 of the drive side outer gear portion 50 is set as the reference diameter Da1p, and the pitch circle inner diameter Db1 of the drive side inner gear portion 37 is set as the reference diameter Db1p. Yes. In this case, when the linear expansion coefficient αa1 of the driving side external gear part 50 and the linear expansion coefficient αb1 of the driving side internal gear part 37 are used,
Da1p × αa1> Db1p × αb1 (2)
This relationship holds. That is, the product of the reference diameter Da1p and the linear expansion coefficient αa1 is larger than the product of the reference diameter Db1p and the linear expansion coefficient αb1. The reference temperature Tp is a room temperature such as 20 ° C., for example.

  According to the present embodiment described so far, the linear expansion coefficients αa1 and αa2 of the external gear portions 50 and 51 are larger than the linear expansion coefficients αb1 and αb2 of the internal gear portions 37 and 38. For this reason, as the temperature rises in the valve timing adjustment device 10, the outer diameter differences ΔD1, ΔD2 become smaller. That is, the assumed distances CL1 and CL2 at which the outer gear portions 50 and 51 and the inner gear portions 37 and 38 can move relatively become smaller. The assumed distances CL1 and CL2 are obtained by virtually moving the outer gear portions 50 and 51 and the inner gear portions 37 and 38 in the radial direction so that the meshed external teeth 50a and 51a and the internal teeth 37a and 38a are separated from each other. In this case, the distance between the external teeth 50a and 51a and the internal teeth 37a and 38a engaged with each other. The assumed distance CL1 is a movable distance on the driving side, and the assumed distance CL2 is a movable distance on the driven side.

  For example, the assumed distance CL2 will be described with reference to FIGS. FIG. 9 after the virtual movement of the external teeth 51a and the internal teeth 38a of the portion where the driven-side external gear portion 51 and the driven-side internal gear portion 38 mesh with each other in the state before being virtually moved; In FIG. 10, the shortest distance is assumed as an assumed distance CL2. FIG. 9 shows an assumed distance CL2 when the temperature of the lubricating oil or the like of the valve timing adjusting device 10 is sufficiently lowered, such as when the internal combustion engine 80 is cold started. In this case, because the viscosity of the lubricating oil is large, the relative movement between the driven side external gear portion 51 and the driven side internal gear portion 38 is easily restricted by the lubricating oil, so even if the assumed distance CL2 is somewhat large, the driven side The momentum when the outer gear portion 51 and the driven-side inner gear portion 38 collide is unlikely to increase.

  On the other hand, FIG. 10 shows an assumed distance CL2 when the internal combustion engine 80 is in operation and the temperature of the lubricating oil or the like of the valve timing adjusting device 10 becomes high. The assumed distance CL2 in this case is equal to the assumed distance CL2 at the time of cold start because the linear expansion coefficient αa2 of the driven side external gear part 51 is larger than the linear expansion coefficient αb2 of the driven side internal gear part 38. It is smaller than that. For this reason, even if the viscosity of the lubricating oil decreases as the temperature rises, the collision distance of the driven-side external gear portion 51 and the driven-side internal gear portion 38 is small due to the small moving distance. The momentum is difficult to increase. Therefore, even when the temperature of the valve timing adjusting device 10 is high or low, it is possible to reduce the hitting sound when the driven-side external gear portion 51 and the driven-side internal gear portion 38 collide.

  According to the present embodiment, the rate of increase of the pitch circle outer diameters Da1 and Da2 accompanying the temperature increase of the external gear portions 50 and 51 is the rate of increase of the pitch circle inner diameters Db1 and Db2 due to the temperature rise of the internal gear portions 37 and 38. Bigger than Further, the relationship (1) and the relationship (2) are established. In these cases, in addition to the linear expansion coefficients αb1, αb2, αa1, and αa2, the pitch circle outer diameters Da1 and Da2 and the pitch circle inner diameters Db1 and Db2 are taken into consideration, and therefore the assumed distance CL1 is increased as the temperature rises. , CL2 can be reliably reduced.

  According to this embodiment, the linear expansion coefficient αa1 of the drive side external gear portion 50 and the linear expansion coefficient αb1 of the drive side internal gear portion 37 are set to the same value, and the linear expansion of the driven side external gear portion 51 is set. The coefficient αa2 and the linear expansion coefficient αb2 of the driven side internal gear portion 38 are set to the same value. In this case, the thermal expansion on the driving side and the thermal expansion on the driven side can be managed together at the design stage. For this reason, it is possible to easily suppress the occurrence of an unintentional hitting sound due to the collision between the outer gear parts 50 and 51 and the inner gear parts 37 and 38 and to suppress the unexpectedly high hitting sound.

  According to this embodiment, if the ratio between the linear expansion coefficients αa1 and αa2 of the external gear portions 50 and 51 and the linear expansion coefficients αb1 and αb2 of the internal gear portions 37 and 38 is set appropriately, the gear portions 37, 38, Even if the dimensions of 50 and 51 are not set to dedicated values, the above relationships (1) and (2) are established. For this reason, in the design stage of the valve timing adjusting device 10, it is not necessary to change the dimensions, thereby suppressing an increase in cost burden for the design work.

(Second Embodiment)
In the first embodiment, the speed reduction mechanism 27 of the valve timing adjusting device 10 has the planetary gear 49, but in the second embodiment, the speed reduction mechanism has a plurality of rollers instead of the planetary gear 49. .

  A valve timing adjusting device 100 shown in FIGS. 11 to 15 includes a sprocket 101, a camshaft 102, a cover member 103, and a phase changing unit 104. The sprocket 101 is a drive rotator that is rotationally driven by a crankshaft of an internal combustion engine. The camshaft 102 is rotatably supported on a cylinder head (not shown) via a bearing 144, is rotated by the rotational force transmitted from the sprocket 101, and corresponds to a camshaft. The cover member 103 is a fixing member that is disposed at the front position of the sprocket 101 and is fixed to the chain cover 140 by bolts. The phase changing unit 104 is arranged between the sprocket 101 and the camshaft 102 and changes the relative rotational phase between the sprocket 101 and the camshaft 102 according to the engine operating state. The chain cover 140 is fixedly attached to the cylinder head with bolts.

  The sprocket 101 has an annular base portion 101a and a gear portion 101b. The entire base portion 101a is integrally formed of an iron-based metal, and the inner peripheral surface is formed in a stepped diameter shape. The gear portion 101b is integrally provided on the outer periphery of the base portion 101a, and receives the rotational force from the crankshaft via the wound timing chain 142. A second ball bearing is provided between the circular base groove 101c formed on the inner peripheral side of the base portion 101a and the outer periphery of the thick flange portion 102a provided integrally with the front end portion of the camshaft 102. 143 is provided. The sprocket 101 is rotatably supported on the camshaft 102 by the second ball bearing 143.

  An annular base protrusion 101e is integrally provided on the outer periphery of the front end portion of the base portion 101a. An annular member 119 coaxially positioned on the inner peripheral side of the base protrusion 101e is disposed at the front end portion of the base portion 101a, and a large-diameter annular plate 106 is disposed on the front end surface of the annular member 119. The bolts 107 are fastened together from the axial direction. Further, as shown in FIG. 23, a stopper protrusion 101d, which is an arcuate engagement portion, is formed on a part of the inner peripheral surface of the base portion 101a up to a predetermined length range along the circumferential direction. A cylindrical housing 105 constituting a part of an electric motor 112 (to be described later) of the phase changing unit 104 is fixed to the outer periphery on the front end side of the plate 106 by bolts 111.

  On the inner periphery of the annular member 119, an internal tooth 119a that is a wavy engagement portion is formed. A cylindrical housing 105 constituting a part of an electric motor 112 described later of the phase changing unit 104 is fixed to the outer periphery of the front end side of the plate 106. A cylindrical housing 105 constituting a part of an electric motor 112 (to be described later) of the phase changing unit 104 is fixed to the outer periphery on the front end side of the plate 106 by bolts 111.

  The housing 105 has a U-shaped cross section made of iron-based metal and functions as a yoke. The housing 105 has an annular plate-shaped holding portion 105a integrally on the bottom side as the front end side. In addition, in the housing 105, the entire outer peripheral side including the holding portion 105 a is covered with a cover member 103 with a predetermined gap.

  The camshaft 102 has two drive cams per cylinder for opening two intake valves per cylinder on the outer periphery, and a driven member 109 that is a driven rotating body at the front end portion is axially driven by a cam bolt 110. Are combined. Each intake valve is urged in a closing direction by a valve spring (not shown). Therefore, positive and negative alternating torque is generated in the camshaft 102 due to the spring force of the valve spring and the like.

  Further, as shown in FIG. 13, a stopper groove 102b into which the stopper protrusion 101d of the base portion 101a is engaged is formed in the flange portion 102a of the camshaft 102 along the circumferential direction. The stopper groove 102b is formed in an arc shape having a predetermined length in the circumferential direction, and the camshaft 102 rotates in this length range so that the edges 101f and 101g of the stopper projection 101d are opposed to each other in the circumferential direction. 102c and 102d contact each other. Accordingly, the stopper groove 102b regulates the relative rotational position of the camshaft 102 on the maximum advance angle side or the maximum retard angle side with respect to the sprocket 101.

  Here, in the state where the camshaft 102 rotates and the one opposed edge 102d on the camshaft 102 side is in contact with the one end edge 101g on the sprocket 101 side as shown in FIG. Side relative rotation phase. In this case, on the contrary, the relative rotation phase on the maximum advance angle side is obtained in a state where the other facing edge 102c is in contact with the other end edge 101f. The stopper mechanism is constituted by the stopper protrusions 101d and the stopper groove 102b.

  The cam bolt 110 includes a head portion 110a and a shaft portion 110b that is integrally formed with the head portion 110a, and a flange-shaped seating surface portion 110c is integrally formed at an end edge of the head portion 110a on the shaft portion 110b side. In addition, a male screw portion 110d is formed on the outer periphery of the shaft portion 110b.

  The driven member 109 is integrally formed of a ferrous metal material, and as shown in FIG. 11, a disc portion 109a formed on the rear end side and a cylinder formed integrally on the front end surface of the disc portion 109a. And a cylindrical portion 109b.

  The disc portion 109a is integrally provided with an annular step projection 109c having substantially the same outer diameter as the flange portion 102a of the camshaft 102 at a substantially central position in the radial direction of the rear end surface. Further, the disc portion 109a is inserted into the inner periphery of the inner ring 143a of the second ball bearing 143 while the outer peripheral surface of the step projection 109c and the outer peripheral surface of the flange portion 102a face each other. This facilitates the shaft core operation between the camshaft 102 and the driven member 109 during assembly. The outer ring 143b of the second ball bearing 143 is press-fitted and fixed to the inner peripheral surface of the base groove 101c of the base portion 101a.

  Further, as shown in FIGS. 11 and 12, a retainer 141 that is a holding member that holds a roller 134 that is a rolling element, which will be described later, is integrally provided on the outer peripheral portion of the disc portion 109 a. The retainer 141 has a plurality of protrusions 141a formed so as to protrude from the annular base integrally formed on the outer periphery of the disc part 109a in the same direction as the cylindrical part 109b, that is, in the axial direction of the cylindrical part 109b. doing. Each of the protrusions 141a is formed in a substantially comb-like shape and has a substantially rectangular cross section, and is formed with a predetermined gap at substantially equal intervals in the circumferential direction of the annular base. . The protruding portion 141a corresponds to a roller holding portion that holds the roller 134.

  As shown in FIG. 11, the cylindrical portion 109 b has a through hole 109 d through which the shaft portion 110 b of the cam bolt 110 is inserted, and a needle bearing 128 described later on the outer peripheral side.

  As shown in FIGS. 11 and 15, the cover member 103 is integrally formed of a non-magnetic synthetic resin material, and is integrally formed with a cover body 103a swelled in a cup shape and an outer periphery of a rear end portion of the cover body 103a. Bracket 103b.

  The cover main body 103 a covers the front end side of the phase changing unit 104. In this case, the cover main body 103a is arranged so as to cover almost the entire rear end side from the holding portion 105a on the front end side of the housing 105 with a predetermined gap, and at a substantially central position of the substantially flat front end wall. Has a working hole 103c formed therethrough. The working hole 103c is for aligning the coaxiality of the oil seal 150 and the phase changing portion 104. After the assembly is completed, the first plug portion 129 having a substantially U-shaped cross section is fitted and fixed. It is designed to block the inside. On the other hand, in the bracket 103b, bolt insertion holes 103f are formed through six boss portions formed in a substantially annular shape.

  Further, as shown in FIG. 11, the cover member 103 is fixed to the chain cover 140 by a plurality of bolts 147 inserted through the bolt insertion holes 103f of the bracket 103b. Further, double slip rings 148a and 148b, which are double inside and outside, are embedded and fixed integrally on the inner peripheral surface of the front end wall of the cover main body 103a with the inner end surfaces exposed. Each of the slip rings 148a and 148b is formed in a substantially thin annular shape and is arranged inside and outside with a predetermined gap, and the outer end portion in the axial direction is fixed in an embedded state on the inner surface side of the front end wall. .

  Further, a connector portion 149 is provided at the upper end portion of the cover member 103. The connector portion 149 has a long plate-like connector terminal 149 a with a base end portion embedded and fixed inside the cover member 103, and is embedded and fixed inside the cover member 103. The connector portion 149 includes a crank-shaped conductive member 149b having one end connected to the base end of the connector terminal 149a and the other end connected to the slip rings 148a and 148b. The connector terminal 149a is energized or de-energized from a battery power source (not shown) via the controller 121.

  As shown in FIGS. 11 and 14, a large-diameter first oil seal 150 as a seal member is interposed between the inner peripheral surface on the rear end side of the cover main body 103a and the outer peripheral surface of the housing 105. ing. The first oil seal 150 is formed in a substantially U-shaped cross section, a core metal is embedded in the synthetic rubber base material, and an annular base portion 150a on the outer peripheral side is a rear end portion of the cover member 103. It is fitted and fixed in a circular groove 103d formed on the inner peripheral surface of this. In addition, a seal surface 150b that contacts the outer peripheral surface of the housing 105 is integrally formed on the inner peripheral side of the annular base portion 150a.

  The phase changing unit 104 includes an electric motor 112 that is an actuator disposed on the substantially coaxial front end side of the camshaft 102, and a speed reduction mechanism 108 that reduces the rotational speed of the electric motor 112 and transmits it to the camshaft 102. It is configured.

  As shown in FIG. 11, the electric motor 112 is a brushed DC motor, a housing 105 that is a yoke that rotates integrally with the sprocket 101, and a motor output shaft that is rotatably provided inside the housing 105. 113, a pair of semicircular permanent magnets 114 and 115 fixed to the inner peripheral surface of the housing 105, and a stator 116 which is a stator provided on the inner bottom surface side of the housing holding portion 105a. .

  The motor output shaft 113 is formed in a cylindrical shape and functions as an armature. An iron core rotor 117 having a plurality of poles is fixed to the outer periphery at a substantially central position in the axial direction, and an electromagnetic wave is provided on the outer periphery of the iron core rotor 117. A coil 118 is wound. A commutator 120 is press-fitted and fixed to the outer periphery of the front end portion of the motor output shaft 113. An electromagnetic coil 118 is connected to each segment divided into the same number as the number of poles of the iron core rotor 117 of the commutator 120 by a harness. Further, a second plug portion 131 having a substantially U-shaped cross section that closes the interior of the motor output shaft 113 after the cam bolt 110 is fastened is press-fitted and fixed. This prevents free draining of oil.

  As shown in FIG. 15, the stator 116 includes an annular plate-shaped resin holder 122 fixed to the inner bottom wall of the holding portion 105a by four screws 122a, and the resin holder 122 and the holding portion 105a from the axial direction. First brushes 123a and 123b, which are two feeding brushes inside and outside in the circumferential direction, which are arranged in a penetrating manner so that each tip surface is slidably contacted with a pair of slip rings 148a and 148b, and on the inner peripheral side of the resin holder 122. The second brushes 124a and 124b, which are energization switching brushes that are held so as to be movable back and forth, and whose arcuate tip end is in sliding contact with the outer peripheral surface of the commutator 120, are mainly configured.

  The first brushes 123a, 123b and the second brushes 124a, 124b are connected by pigtail harnesses 25a, 25b, and the slip rings 148a, 148b side and the commutator 120 by the spring force of the torsion springs 126a, 127a that are elastically contacted respectively. Each side is energized.

  As shown in FIG. 11, the motor output shaft 113 is provided on the outer peripheral side of the needle bearing 128 provided on the outer peripheral side of the cylindrical portion 109 b of the driven member 109 and the shaft portion 110 b on the seating surface portion 110 c side of the cam bolt 110. The third ball bearing 135 is rotatably supported on the cam bolt 110. Further, an eccentric shaft portion 130 which is a cylindrical eccentric rotating body constituting a part of the speed reduction mechanism 108 is integrally provided at the rear end portion of the motor output shaft 113 on the camshaft 102 side.

  As shown in FIG. 12, the needle bearing 128 includes a cylindrical retainer 128a press-fitted into the inner peripheral surface of the eccentric shaft portion 130, and a plurality of needle rollers 128b rotatably held in the retainer 128a. It is configured. The needle roller 128 b rolls on the outer peripheral surface of the cylindrical portion 109 b of the driven member 109.

  In the third ball bearing 135, the inner ring 135 a is fixed between the front end edge of the cylindrical portion 109 b of the driven member 109 and the seat surface portion 110 c of the cam bolt 110. On the other hand, the outer ring 135b is positioned and supported while being sandwiched from the axial direction between a stepped portion formed on the inner periphery of the motor output shaft 113 and a snap ring 136 which is a retaining ring.

  A second oil seal 132 is provided between the outer peripheral surface of the motor output shaft 113 and the inner peripheral surface of the plate 106 to prevent leakage of lubricating oil from the inside of the speed reduction mechanism 108 into the electric motor 112. Yes. In addition to the sealing function, the second oil seal 132 has an inner peripheral portion that is in elastic contact with the outer peripheral surface of the motor output shaft 113 so as to give a frictional resistance to the rotation of the motor output shaft 113. It has become.

  The controller 121 detects the current engine operating state based on information signals from various sensors such as a crank angle sensor, a cam angle sensor, an air flow meter, a water temperature sensor, an accelerator opening sensor, and the like, and the ignition timing, fuel injection amount, etc. Is controlling. The crank angle sensor detects the rotational position of the crankshaft, the cam angle sensor detects the rotational position of the camshaft 102, and the air flow meter detects intake air.

  Further, the controller 121 detects a relative rotation angle phase between the crankshaft and the camshaft 102 based on detection signals output from the crank angle sensor and the cam angle sensor. Based on these detection signals, the electromagnetic coil 118 of the electric motor 112 is energized to control forward / reverse rotation of the motor output shaft 113, and the relative rotation phase of the camshaft 102 with respect to the sprocket 101 is controlled via the speed reduction mechanism 108. To do.

  As illustrated in FIGS. 11 and 12, the speed reduction mechanism 108 includes an eccentric shaft portion 130, a first ball bearing 133, a roller 134, a cage 141, and a driven member 109. The eccentric shaft portion 130 is a member that performs eccentric rotational motion, and the first ball bearing 133 is a rotating member that is provided on the outer periphery of the eccentric shaft portion 130. The roller 134 is a plurality of rolling elements provided on the outer periphery of the first ball bearing 133, and the cage 141 is a member that allows movement in the radial direction while holding the roller 134 in the rolling direction. The driven member 109 is provided integrally with the cage 141.

  The eccentric shaft portion 130 is formed in a cylindrical shape, and the shaft center Y of the cam surface formed on the outer peripheral surface is slightly eccentric from the shaft center X of the motor output shaft 113 in the radial direction.

  The first ball bearing 133 is formed in a large diameter and is disposed so as to substantially overlap the needle bearing 128 at the radial position. In the first ball bearing 133, a plurality of balls 33c are supported between the inner ring 133a and the outer ring 133b so as to be able to roll, the inner ring 133a is press-fitted and fixed to the outer peripheral surface of the eccentric shaft portion 130, and the outer ring The roller 134 is always in contact with the outer peripheral surface of 133b. Further, as shown in FIG. 12, a crescent-shaped annular gap C is formed on the outer peripheral side of the outer ring 133 b, and the entire first ball bearing 133 is rotated eccentrically through the gap C. Accordingly, it can move in the radial direction, that is, it can move eccentrically. The first ball bearing 133 and the eccentric shaft portion 130 are configured as an eccentric rotating body.

  Each roller 134 is formed in a solid cylindrical shape made of a metal material, and is selected from a plurality of rollers having different outer diameters which will be described later. In addition, each roller 134 has an inner peripheral surface that abuts a predetermined region with the outer peripheral surface of the outer ring 133b of the first ball bearing 133 as a result of eccentric movement, and a part of the outer peripheral side contacts the inner teeth 119a of the annular member 119. Is inserted. The first ball bearing 133 moves in the radial direction along with the eccentric movement, and swings in the radial direction while being guided in the circumferential direction by the protrusions 141a of the cage 141.

  As described above, the retainer 141 has a plurality of protrusions 141a provided at regular intervals in the circumferential direction, and one end side in the axial direction of each protrusion 141a, that is, the driven member 109 side is closed. . The cage 141 is open on the side opposite to the driven member 109, and is closed by the plate 106 when the opening 141 b is fastened together with the bolt 107.

  As shown in the lower part of FIG. 12, a part of each roller 134 is not fitted to each inner tooth 119 a of the annular member 119 depending on the eccentric position of the first ball bearing 133. In this case, each roller 134 is disengaged from each internal tooth 119a and is located at the top of the mountain between each internal tooth 119a, or is in an incompletely fitted state. In addition, as shown in the upper part of FIG. 12, even in a region where the inner teeth 119a are completely fitted, there is a small clearance between the inner surface 19b of the inner teeth 119a and the outer peripheral surface of the roller 134. Is formed. Thereby, the rolling property of each roller 134, the reduction of the noise of VTC, control responsiveness, etc. are ensured.

  Lubricating oil is supplied into the reduction mechanism 108 by lubricating oil supply means. As shown in FIG. 11, the lubricating oil supply means has an oil supply passage 145, an oil supply hole 146, an oil groove 146a, and an oil supply hole 146b. The oil supply passage 145 is an annular groove-like passage formed on the outer periphery of the journal of the camshaft 102 that is supported by the bearing 144 of the cylinder head. The oil supply hole 146 is formed in the inner axial direction of the camshaft 102 and communicates with the oil supply passage 145. The oil groove 146 a is formed on the distal end surface of the camshaft 102 and is connected to the downstream end of the oil supply hole 146. The oil supply hole 146b is a small-diameter hole that is formed so as to penetrate the driven member 109 in the inner axial direction, and that one end opens into the oil groove 146a and the other end opens near the needle bearing 128 and the first ball bearing 133. . The lubricating oil supply means has three oil discharge holes (not shown), and the oil discharge holes are large-diameter holes formed through the driven member 109.

  The oil supply passage 145 is always supplied with lubricating oil from an oil pump through a main oil gallery (not shown) formed inside the cylinder head. Accordingly, sufficient lubricating oil is always supplied to the needle bearing 128, the first ball bearing 133, the inner teeth 119a of the annular member 119, the rollers 134, the protrusions 141a of the retainer 141, and the like.

  Hereinafter, a basic operation of the valve timing adjusting device 100 in the present embodiment will be described. First, when the crankshaft of the engine is driven to rotate, the sprocket 101 rotates via the timing chain 142. Then, the rotational force is transmitted to the housing 105 of the electric motor 112 via the annular member 119 and the plate 106, and the permanent magnets 114 and 115 and the stator 116 rotate synchronously. On the other hand, the rotational force of the annular member 119 is transmitted from the roller 134 to the camshaft 102 via the retainer 141 and the driven member 109. As a result, the camshaft 102 rotates at a half rotational speed of the crankshaft, and the cam on the outer peripheral side opens the intake valve against the spring force of the valve spring.

  During normal operation after the engine is started, the electromagnetic coil 118 of the electric motor 112 is energized from the battery power source via the slip rings 148a and 148b by the control signal of the controller 121. As a result, the motor output shaft 113 is controlled to rotate forward and backward, and this rotational force is transmitted to the camshaft 102 via the speed reduction mechanism 108 so that the relative rotational phase with respect to the sprocket 101 is controlled.

  That is, when the eccentric shaft portion 130 rotates eccentrically with the rotation of the motor output shaft 113, each roller 134 is guided in the radial direction on the side surface of each protrusion 141 a of the retainer 141 for each rotation of the motor output shaft 113. While being guided, these rollers 134 move over one internal tooth 119a of the annular member 119 while rolling to another adjacent internal tooth 119a, and are successively contacted in the circumferential direction while repeating this. The rotation of the motor output shaft 113 is decelerated by the rolling contact of each roller 134, and the rotational force is transmitted to the camshaft 102 via the driven member 109. The reduction ratio at this time can be arbitrarily set according to the number of rollers 134, and the reduction ratio decreases as the number of rollers 134 increases, and increases as the number decreases.

  As a result, the camshaft 102 is rotated relative to the sprocket 101 in the forward and reverse directions to convert the relative rotation phase, and the opening / closing timing of the intake valve is converted to the advance side or the retard side.

  As described above, the maximum position regulation of the forward and reverse relative rotation of the camshaft 102 with respect to the sprocket 101 is such that each end edge 101f, 101g of the stopper projection 101d is in contact with one of the opposite edges 102c, 102d of the stopper groove 102b. It is done by touching.

  That is, the driven member 109 that rotates together with the camshaft 102 rotates in the same direction as the rotation direction of the sprocket 101 as indicated by the arrow in FIG. As a result, the opposite edge 102c on the other side of the stopper groove 102b comes into contact with the other edge 101f of the stopper projection 101d, and further rotation in the same direction is restricted. As a result, the relative rotation phase of the camshaft 102 with respect to the sprocket 101 is changed to the maximum on the advance side.

  On the other hand, when the driven member 109 rotates in the direction opposite to the rotation direction of the sprocket 101, the opposite edge 102d on one side of the stopper groove 102b comes into contact with one end edge 101g of the stopper protrusion 101d, and the same direction beyond that. Rotation is regulated. As a result, the relative rotation phase of the camshaft 102 with respect to the sprocket 101 is changed to the maximum on the retard side.

  As a result, the opening / closing timing of the intake valve is converted to the maximum on the advance side or the retard side, and the fuel efficiency and output of the engine can be improved.

  Thus, the relative rotational position of the camshaft 102 can be reliably regulated by the stopper mechanism of the stopper protrusion 101d and the stopper groove 102b.

  In the valve timing adjusting device 100, it is conceivable that each component thermally expands, similarly to the valve timing adjusting device 10 of the first embodiment. In the present embodiment, the linear expansion coefficient βa of the roller 134, the linear expansion coefficient βb of the first ball bearing 133, the linear expansion coefficient βc of the annular member 119, and the linear expansion coefficient βd of the cage 141 are used as the linear expansion coefficients of the respective components. Is set. For the first ball bearing 133, the linear expansion coefficient of the outer ring 133 b is the linear expansion coefficient βb of the first ball bearing 133. In the present embodiment, the magnitude of the linear expansion coefficient is set to a relationship of βb> βd> βc and a relationship of βa> βd. The annular member 119 and the cage 141 are formed of a steel material such as SUS440C, and the outer ring 133b and the roller 134 of the first ball bearing 133 are formed of a steel material such as SUJ2 that is different from the annular member 119 and the cage 141. Yes.

  As shown in FIG. 16, the roller 134 has an outer diameter Ba as a diameter, and the annular member 119 has a pitch circle inner diameter Bc that is a pitch circle diameter. The outer diameter Bb of the first ball bearing 133 is the outer diameter of the outer ring 133b, and is smaller than the pitch circle inner diameter Bc of the annular member 119. In the present embodiment, in the cage 141, the diameter of a virtual circle M (see FIG. 19) connecting the centers of the plurality of protrusions 141a is referred to as a holding diameter Bd. The holding diameter Bd is larger than the outer diameter Bb of the first ball bearing 133, but smaller than the pitch circle inner diameter Bc of the annular member 119. Here, the difference between the outer diameter Bb of the first ball bearing 133 and the pitch circle inner diameter Bc of the annular member 119 is defined as a diameter difference ΔB1. The virtual circle M may be a circle that connects the inner peripheral side ends of the protrusions 141a, or may be a circle that connects the outer peripheral side ends.

  Here, when the annular member 119 and the first ball bearing 133 are thermally expanded, it is considered that the diameter difference ΔB1 changes. In the present embodiment, the linear expansion coefficient βb of the first ball bearing 133 and the linear expansion coefficient βc of the annular member 119 are reduced so that the diameter difference ΔB1 decreases as the temperature of the annular member 119 and the first ball bearing 133 increases. And are set. As shown in FIG. 17, the increasing rate of the outer diameter Bb of the first ball bearing 133 is larger than the increasing rate of the pitch circle inner diameter Bc of the annular member 119, and the diameter difference ΔB1 becomes smaller as the temperature rises. .

  Further, the increasing rate of the holding diameter Bd of the cage 141 is larger than the increasing rate of the outer diameter Bb of the first ball bearing 133 and smaller than the increasing rate of the pitch circle inner diameter Bc of the annular member 119. For this reason, the cage 141 does not thermally expand as compared with the first ball bearing 133, the difference between the outer diameter Bb and the holding diameter Bd becomes too small, and the relative relationship between the cage 141 and the first ball bearing 133 is reduced. It is suppressed that rotation is inhibited. In addition, the cage 141 is excessively expanded as compared with the annular member 119, and the difference between the pitch circle inner diameter Bc and the retaining diameter Bd becomes too small, and the relative rotation between the cage 141 and the annular member 119 is hindered. Is suppressed.

  As shown in FIGS. 17 and 18, as the temperature rises, the diameter difference ΔB1 between the outer diameter Bb of the first ball bearing 133 and the pitch circle inner diameter Bc of the annular member 119 decreases, while the outer diameter of the roller 134 Ba becomes large. That is, as the temperature rises, the distance between the first ball bearing 133 and the annular member 119 and the roller 134 decreases between the first ball bearing 133 and the annular member 119. In this case, when the roller 134 is sandwiched between the first ball bearing 133 and the annular member 119 and the diameter difference ΔB1 becomes so small that the rotation of the roller 134 is hindered, the speed reduction mechanism 108 is properly operated. The possibility of not working increases.

  In the present embodiment, the smallest possible value of the diameter difference ΔB1 is referred to as a limit value ΔBz1 within a range where the diameter difference ΔB1 does not become too small to prevent the rotation of the roller 13, and the diameter difference ΔB1 is reduced to the limit value ΔBz1. This temperature is referred to as a limit temperature Tz1. In the valve timing adjusting device 100, the limit temperature Tz1 is set to be higher than the temperature (for example, 130 ° C.) that the annular member 119, the first ball bearing 133, and the roller 134 can reach in the normal operation of the internal combustion engine. Steel materials and materials are selected. That is, the steel members and materials of the annular member 119, the first ball bearing 133, the roller 134, and the cage 141 are selected so that the limit temperature Tz1 is higher than the temperature that the lubricating oil of the valve timing adjusting device 100 can reach. Yes.

In the present embodiment, a temperature lower than the limit temperature Tz1 is referred to as a reference temperature Tq, and for this reference temperature Tq, the outer diameter Bb of the first ball bearing 133 is referred to as a reference diameter Bbq. For this reference temperature Tq, the pitch circle inner diameter Bc of the annular member 119 is referred to as a reference diameter Bcq, the holding diameter Bd of the retainer 141 is referred to as a reference diameter Bdq, and the outer diameter Ba of the roller 134 is referred to as a reference diameter Baq. In this case, using the linear expansion coefficient βa of the roller 134, the linear expansion coefficient βb of the outer ring 133b of the first ball bearing 133, and the linear expansion coefficient βc of the annular member 119,
Baq × βa + Bbq × βb> Bcq × βc (3)
This relationship holds. That is, the sum of the product of the reference diameter Baq and the linear expansion coefficient βa and the product of the reference diameter Bbq and the linear expansion coefficient βb is larger than the product of the reference diameter Bcq and the linear expansion coefficient βc. It has become. The reference temperature Tq is a room temperature such as 20 ° C., for example.

  As shown in FIG. 19, the holding distance L <b> 1, which is a separation distance between adjacent protrusions 134 a in the holder 141, is larger than the outer diameter Ba of the roller 134. In the adjacent protrusions 134a, the linear distance between the points through which the virtual circle M passes on the opposing surfaces facing each other is set as the holding distance L1. Here, the difference between the holding distance L1 and the outer diameter Ba of the roller 134 is defined as a dimensional difference ΔB2 (see FIGS. 22 and 23).

  As shown in FIGS. 20 and 21, the linear expansion coefficient βa of the roller 134 and the linear expansion coefficient βd of the cage 141 are reduced so that the dimensional difference ΔB2 decreases as the temperature of the roller 134 and the cage 141 increases. Is set. The increasing rate of the outer diameter Ba of the roller 134 is larger than the increasing rate of the holding distance L1 of the cage 141, and the dimensional difference ΔB2 becomes smaller as the temperature rises. For this reason, it is suppressed that the roller 134 expands too much heat compared with the holder | retainer 141, and the roller 134 is inserted | pinched between the adjacent protrusion parts 134a, and rotation of the roller 134 is inhibited.

  In the present embodiment, a value in which the dimension difference ΔB2 is as small as possible is called a limit value ΔBz2 within a range where the rotation of the roller 134 is not hindered by being sandwiched between adjacent protrusions 134a, and is reduced to the dimension difference ΔB2. This temperature is referred to as a limit temperature Tz2. In the valve timing adjusting device 100, the steel materials and materials of the roller 134 and the cage 141 are selected so that the limit temperature Tz2 is higher than the temperature (for example, 130 ° C.) that the roller 134 and the cage 141 can reach. Yes.

The reference temperature Tq is lower than the limit temperature Tz1 as well as the limit temperature Tz2. For this reference temperature Tq, the outer diameter Ba of the roller 134 is referred to as a reference diameter Baq, and the holding distance L1 of the cage 141 is used as a reference. This is referred to as distance L1q. In this case, if the linear expansion coefficient βa of the roller 134 and the linear expansion coefficient βd of the cage 141 are used,
Baq × βa> L1q × βd (4)
This relationship holds. That is, the product of the reference diameter Baq and the linear expansion coefficient βa is larger than the product of the reference distance L1q and the linear expansion coefficient βd.

  At the reference temperature Tq, the width dimension of the protrusion 141a in the radial direction of the cage 141 is smaller than the outer diameter Ba of the roller 134. In this case, since the configuration in which the roller 134 reliably contacts the first ball bearing 133 and the annular member 119 is realized, the speed reduction mechanism 108 can be appropriately operated without the roller 134 contacting the first ball bearing 133 and the annular member 119. It can suppress that it does not operate.

  According to the present embodiment described so far, the linear expansion coefficient βb of the outer ring 133b of the first ball bearing 133 is larger than the linear expansion coefficient βc of the annular member 119. Along with the increase, the diameter difference ΔB1 decreases. That is, the assumed distance CL3 in which the roller 134 can move in the radial direction of the first ball bearing 133 is reduced between the first ball bearing 133 and the annular member 119. The assumed distances CL3 and CL2 are obtained when the first ball bearing 133 and the annular member 119 are virtually moved in the radial direction so that the inner teeth 119a of the annular member 119 and the roller 134 that are meshed with each other are separated from each other. , The distance between the engaged inner teeth 119a and the roller 134.

  The assumed distance CL3 will be described with reference to FIGS. In the state before the virtual movement, the inner teeth 119a and the roller 134 that has been in contact with the bottom of the internal teeth 119a are virtually moved, and the bottom of the inner teeth 119a and the rollers in FIGS. The shortest distance to 134 is assumed to be an assumed distance CL3. FIG. 22 shows an assumed distance CL3 when the temperature of the lubricating oil or the like of the valve timing adjusting device 100 is sufficiently lowered, such as when the internal combustion engine is cold started. In this case, the relative movement of the first ball bearing 133, the roller 134, and the annular member 119 is easily restricted by the lubricating oil due to the large viscosity of the lubricating oil. For this reason, even if the assumed distance CL3 is large to some extent, the momentum when the first ball bearing 133 or the annular member 119 collides with the roller 134 is unlikely to increase.

  On the other hand, FIG. 23 shows an assumed distance CL3 when the internal combustion engine is in operation and the temperature of the lubricating oil or the like of the valve timing adjusting device 100 becomes high. The assumed distance CL3 in this case is larger than the assumed distance CL3 at the time of cold start because the linear expansion coefficient βb of the outer ring 133b of the first ball bearing 133 is larger than the linear expansion coefficient βc of the annular member 119. It is getting smaller. For this reason, even if the viscosity of the lubricating oil decreases as the temperature rises, the moving distance when the roller 134 collides with the first ball bearing 133 or the annular member 119 is small, and the momentum of the collision is difficult to increase. Therefore, even when the temperature of the valve timing adjusting device 100 is low or high, it is possible to reduce the hitting sound when the roller 134 collides with the first ball bearing 133 or the annular member 119.

  According to this embodiment, the increasing rate of the outer diameter Bb accompanying the temperature rise of the first ball bearing 133 is larger than the increasing rate of the pitch circle inner diameter Bc accompanying the temperature rise of the annular member 119. As described above, since the outer diameter Bb and the pitch circle inner diameter Bc are taken into consideration in addition to the linear expansion coefficients βb and βc for the first ball bearing 133 and the annular member 119, the assumed distance CL3 decreases as the temperature rises. Can be realized.

  According to this embodiment, the increasing rate of the outer diameter Ba of the roller 134 is higher than the increasing rate of the diameter difference ΔB1 that is the difference between the pitch circle inner diameter Bc of the annular member 119 and the outer diameter Bb of the first ball bearing 133. large. Further, the relationship (3) is established. In these cases, since the movement mode of the roller 134 in the separation space between the first ball bearing 133 and the annular member 119 is considered including the degree of expansion of the roller 134, the assumed distance CL1 is increased as the temperature rises. A smaller configuration can be realized more reliably.

  According to the present embodiment, the dimensions of the first ball bearing 133 and the annular member 119 are conventionally set by appropriately setting the ratio of the linear expansion coefficient βb of the first ball bearing 133 and the linear expansion coefficient βc of the annular member 119. Even if it does not change from (1), the relationship (3) can be satisfied. For this reason, in the design stage of the valve timing adjusting device 100, it is not necessary to change the dimensions, and thus an increase in cost burden for the design change can be suppressed.

  According to the present embodiment, since the linear expansion coefficient βa of the roller 134 is larger than the linear expansion coefficient βd of the cage 141, the dimensional difference ΔB2 becomes smaller as the temperature of the valve timing adjusting device 100 increases. Become. Here, the dimension difference ΔB <b> 2 is a distance that the roller 134 can move in the circumferential direction of the virtual circle M between the adjacent protrusions 141 a of the cage 141.

  As shown in FIG. 22, in a state where the heat of the lubricating oil is sufficiently released, the relative movement between the protrusion 141a of the cage 141 and the roller 134 is restricted by the lubricating oil because the viscosity of the lubricating oil is large. Easy to be. For this reason, even if the dimensional difference ΔB2 is large to some extent, the momentum when the protrusion 141a and the roller 134 collide is unlikely to increase.

  On the other hand, as shown in FIG. 23, when the temperature of the lubricating oil becomes high, the dimensional difference ΔB2 is caused by the fact that the linear expansion coefficient βa of the roller 134 is larger than the linear expansion coefficient βd of the cage 141. This is smaller than the dimensional difference ΔB2 at the cold start. For this reason, even if the viscosity of the lubricating oil decreases as the temperature rises, the moving distance when the roller 134 collides with the protrusion 141a is small, and the momentum of the collision is difficult to increase. Therefore, even when the temperature of the valve timing adjusting device 100 is low or high, it is possible to reduce the hitting sound when the roller 134 collides with the protrusion 141a of the retainer 141.

  According to the present embodiment, the increasing rate of the outer diameter Ba accompanying the temperature rise of the roller 134 is larger than the increasing rate of the holding distance L1 accompanying the temperature rise of the cage 141. Further, the relationship (4) is established. In these cases, in addition to the linear expansion coefficients βa and βd, the outer diameter Ba and the holding distance L1 between the adjacent protrusions 141a are taken into consideration for the roller 134 and the cage 141. Therefore, the dimensional difference ΔB2 as the temperature rises. Can be realized.

  According to the present embodiment, by appropriately setting the ratio of the linear expansion coefficient βa of the roller 134 and the linear expansion coefficient βd of the cage 141, the dimensions of the roller 134 and the cage 141 do not have to be changed conventionally. Thus, the relationship (4) can be satisfied. For this reason, in the design stage of the valve timing adjusting device 100, it is not necessary to change the dimensions, and thus an increase in cost burden for the design change can be suppressed.

(Other embodiments)
Although a plurality of embodiments according to the present disclosure have been described above, the present disclosure is not construed as being limited to the above embodiments, and can be applied to various embodiments and combinations without departing from the gist of the present disclosure. can do.

  As a first modification, in the first embodiment, the linear expansion coefficients αb1 and αb2 of the internal gear portions 37 and 38 are not the same value, but the linear expansion coefficients αb1 and αb2 are different values. Also good. That is, the driving side internal gear portion 37 and the driven side internal gear portion 38 may be formed of different steel materials. Similarly, although the linear expansion coefficients αa1 and αab of the external gear portions 50 and 51 have the same value, these linear expansion coefficients αa1 and αab may have different values. That is, the drive side external gear part 50 and the driven side external gear part 51 may be formed of different steel materials. Even in these cases, the linear expansion coefficients αa1 and αa2 of the external gear portions 50 and 51 need only be larger than the linear expansion coefficients αb1 and αb2 of the internal gear portion 37 on the driving side and the driven side, respectively.

  As a second modification, in the first embodiment, the limit diameter difference ΔDy2 on the driven side may not be smaller than the limit diameter difference ΔDy1 on the drive side. For example, the limit diameter differences ΔDy1 and ΔDy2 have the same value. In this configuration, if the gear portions 37, 38, 50, 51 reach the limit temperature Ty, the collision between the driven-side external gear portion 51 and the driven-side internal gear portion 38, and the driving-side external gear portion 50 and the driven It is considered that the collision with the side internal gear portion 38 occurs with the same degree.

  Further, the limit diameter difference ΔDy1 on the driving side is configured to be smaller than the limit diameter difference ΔDy2 on the driven side. In this configuration, if the gear portions 37, 38, 50, 51 reach the limit temperature Ty, the collision between the drive side external gear portion 50 and the driven side internal gear portion 38 is driven by the driven side external gear portion 51 and the driven side. It is more likely to occur than a collision with the side internal gear portion 38. In order to suppress the hitting sound caused by the collision between the external gear portions 50 and 51 and the internal gear portions 37 and 38, it is only necessary to manage the thermal expansion of the gear portions 50 and 37 on the drive side of the drive side and the driven side. It will be.

  As a third modification, in the first embodiment, the linear expansion coefficients αa1 and αa2 of the external gear portions 50 and 51 are compared with the linear expansion coefficients αb1 and αb2 of the internal gear portion 37 for one of the driving side and the driven side. It does not have to be large. For example, on the driving side, the linear expansion coefficient αa1 of the driving side external gear portion 50 and the linear expansion coefficient αb1 of the driving side internal gear portion 37 are set to the same value.

  As a fourth modification, in the second embodiment, the linear expansion coefficient βc of the annular member 119 and the linear expansion coefficient βd of the cage 141 are not the same value, but the linear expansion coefficients βc and βd are different. It may be a value. That is, the annular member 119 and the cage 141 may be formed of different steel materials. Further, the linear expansion coefficient βa of the roller 134 and the linear expansion coefficient βb of the first ball bearing 133 may not be the same value. That is, the roller 134 and the outer ring 133b of the first ball bearing 133 may be formed of different steel materials. Even in these cases, it is sufficient that the linear expansion coefficient βb of the first ball bearing 133 is larger than the linear expansion coefficient βc of the annular member 119. It is only necessary that the linear expansion coefficient βa of the roller 134 is larger than the linear expansion coefficient βd of the cage 141.

  As a fifth modification, in the first and second embodiments, the valve timing adjusting device may adjust the valve timing of the exhaust valve instead of adjusting the valve timing of the intake valve.

  DESCRIPTION OF SYMBOLS 10 ... Valve timing adjustment apparatus, 25 ... Drive rotary body, 26 ... Driven rotary body, 37 ... Drive side internal gear part as drive gear part, 37a ... Internal tooth, 38 ... Drive side internal gear part as driven gear part, 38a ... internal teeth, 80 ... internal combustion engine, 49 ... planetary gear as a planetary rotor, 50 ... drive side external gear part as a first planetary gear part, 51 ... driven side external gear part as a second planetary gear part, 81 ... Intake valve, 90 ... Crankshaft, 91 ... Cam shaft, Da1 ... Pitch circle outer diameter of drive side external gear part, Da1p ... Reference diameter, Da2 ... Pitch circle outer diameter of driven side external gear part, Da2p ... Reference diameter , Db1... Pitch circle inner diameter of the driving side internal gear portion, Db1p... Reference diameter, Db2... Pitch circle inner diameter of the driven side internal gear portion, Db2p... Reference diameter, αa1. Linear expansion coefficient of side external gear part, αb1... Drive Linear expansion coefficient of the internal gear part, αb2 ... Linear expansion coefficient of the driven side internal gear part, Tp ... Reference temperature, 100 ... Valve timing adjusting device, 101 ... Sprocket as a moving rotor, 102 ... Cam shaft as a cam shaft, DESCRIPTION OF SYMBOLS 108 ... Deceleration mechanism, 109 ... Driven member as driven rotator, 119 ... Ring member, 119a ... Internal tooth, 130 ... Eccentric shaft part which constitutes eccentric rotator, 133 ... First ball bearing which constitutes eccentric rotator, 134: Roller, 141: Cage, 141a: Projection as a roller holding portion, Ba: Outer diameter of roller, Baq: Reference diameter, Bb: Outer diameter of first ball bearing, Bbq: Reference diameter, Bc: Annular member Pitch circle inner diameter, Bcq ... reference diameter, Bd ... retainer holding diameter, Bdq ... reference diameter, ΔB1 ... diameter difference between Bb and Bc, L1 ... separation distance between adjacent protrusions Lifting distance, L1Q ... reference distance, the linear expansion coefficient of .beta.a ... roller, .beta.b ... linear expansion coefficient of the first ball bearing, the linear expansion coefficient of .beta.c ... annular member, the linear expansion coefficient of the .beta.d ... retainer, Tq ... reference temperature.

Claims (11)

A valve timing adjusting device (10) for adjusting a valve timing of a valve (81) that opens and closes a camshaft (91) by transmission of engine torque from a crankshaft (90) in an internal combustion engine (80),
A drive rotator (25) having a drive gear portion (37) and rotating in conjunction with the crankshaft;
A driven rotating body (26) having a driven gear portion (38) and rotating in conjunction with the camshaft;
A first planetary gear portion (50) and a second planetary gear portion (51) are provided, and the first planetary gear portion and the second planetary gear portion are eccentrically engaged with the drive gear portion and the driven gear portion, respectively. A planetary rotator (40) that changes a relative phase between the driving rotator and the driven rotator by performing planetary motion integrally;
With
One of the first planetary gear part and the second planetary gear part is referred to as an external gear part (50, 51) in which external teeth (50a, 51a) extend radially outward, and the drive gear part and When the driven gear portion that meshes with the external gear portion is referred to as an internal gear portion (37, 38) in which internal teeth (37a, 38a) extend inward in the radial direction, The valve timing adjusting device, wherein the linear expansion coefficient (αa1, αa2) is larger than the linear expansion coefficient (αb1, αb2) of the internal gear portion.   The rate of increase in the pitch circle diameter (Da1, Da2) of the external gear portion accompanying the temperature increase of the external gear portion is the pitch circle diameter (Db1, Db2) of the internal gear portion accompanying the temperature rise of the internal gear portion. The valve timing adjusting device according to claim 1, wherein the valve timing adjusting device is larger than an increase rate.   The product of the linear expansion coefficient (αa1, αa2) of the external gear part and the pitch circle diameter (Da1p, Da2p) of the external gear part at a predetermined reference temperature (Tp) is the linear expansion coefficient of the internal gear part. The valve timing adjusting device according to claim 1 or 2, wherein the valve timing adjusting device is larger than a product of (αb1, αb2) and a pitch circle diameter (Db1p, Db2p) of the internal gear portion at the reference temperature.   Of the first planetary gear part and the second planetary gear part, not only the outer gear part but also the linear expansion coefficients (αa1, αa2) of both are only the inner gear part of the drive gear part and the driven gear part. The valve timing adjustment device according to any one of claims 1 to 3, wherein the valve timing adjustment device is larger than both of the linear expansion coefficients (αb1, αb2). A valve timing adjusting device for adjusting a valve timing of a valve that opens and closes a camshaft (102) by transmission of engine torque from a crankshaft in an internal combustion engine,
A drive rotator (101) that rotates in conjunction with the crankshaft;
A driven rotor (109) that rotates in conjunction with the camshaft;
An annular member (119) in which an inner tooth (119a) extends radially inward and rotates together with the drive rotating body, and an eccentric rotation provided on the inner peripheral side of the annular member and having an outer peripheral surface eccentric with respect to the axis. A body (130, 133), a plurality of rollers (134) provided between the annular member and the eccentric rotating body, and the driven rotating body rotating between the annular member and the eccentric rotating body. A retainer (141) for retaining the roller, and the rotation of the eccentric rotator causes the retainer to rotate relative to the annular member, thereby allowing the drive rotator and the driven rotator to move between each other. A speed reduction mechanism (108) for changing the relative phase of
With
The valve timing adjusting device, wherein a linear expansion coefficient (βb) of the eccentric rotating body is larger than a linear expansion coefficient (βc) of the annular member.   The increasing rate of the outer diameter (Bb) of the eccentric rotating body accompanying the temperature rise of the eccentric rotating body is larger than the increasing rate of the pitch circle diameter (Bc) of the annular member accompanying the temperature rise of the annular member, The valve timing adjusting device according to claim 5.   The increase rate of the diameter (Ba) of the roller is larger than the increase rate of the difference (ΔB1) between the pitch circle diameter (Bc) of the annular member and the outer diameter (Bb) of the eccentric rotating body. Or the valve timing adjustment apparatus of 6. The product of the linear expansion coefficient (βa) of the roller and the outer diameter (Baq) of the roller at a predetermined reference temperature (Tq);
The product and sum of the linear expansion coefficient (βb) of the eccentric rotator and the outer diameter (Bbq) of the eccentric rotator at the reference temperature are:
The valve timing according to any one of claims 5 to 7, which is larger than a product of a linear expansion coefficient (βc) of the annular member and a pitch circle diameter (Bcq) of the annular member at the reference temperature. Adjustment device. A valve timing adjusting device for adjusting a valve timing of a valve that opens and closes a camshaft (102) by transmission of engine torque from a crankshaft in an internal combustion engine,
A drive rotator (101) that rotates in conjunction with the crankshaft;
A driven rotor (109) that rotates in conjunction with the camshaft;
An annular member (119) in which an inner tooth (119a) extends radially inward and rotates together with the drive rotating body, and an eccentric rotation provided on the inner peripheral side of the annular member and having an outer peripheral surface eccentric with respect to the axis. A body (130, 133), a plurality of rollers (134) provided between the annular member and the eccentric rotating body, and the driven rotating body rotating between the annular member and the eccentric rotating body. A retainer (141) for retaining the roller, and the rotation of the eccentric rotator causes the retainer to rotate relative to the annular member, thereby allowing the drive rotator and the driven rotator to move. A speed reduction mechanism (108) for changing the relative phase of
With
The cage has roller holding portions (141a) arranged at a predetermined interval in the radial direction of the cage,
The roller is disposed between the roller holding portions adjacent to each other, and is held by the cage.
The valve timing adjusting device, wherein a linear expansion coefficient (βa) of the roller is larger than a linear expansion coefficient (βd) of the cage.   The increase rate of the outer diameter (Ba) of the roller accompanying the temperature rise of the roller is larger than the increase rate of the separation distance (L1) of the roller holding portions adjacent to each other due to the temperature rise of the cage. 9. The valve timing adjusting device according to 9.   The product of the linear expansion coefficient (βa) of the roller and the outer diameter (Baq) of the roller at a predetermined reference temperature (Tq) is adjacent to the linear expansion coefficient (βb) of the cage. The valve timing adjusting device according to claim 9 or 10, wherein the valve timing adjusting device is larger than a product of a separation distance (L1q) of the holding portion.

Images