Valve timing control device

Abstract

To provide a valve opening / closing timing control device capable of early discharging lubrication oil lubricating a sliding portion in the device.SOLUTION: A valve opening / closing timing control device 100 includes a driving side rotating body A, a driven side rotating body and a phase adjusting mechanism for setting a relative rotation phase of the driving side rotating body A and the driven side rotating body B. The phase adjusting mechanism includes: an output gear 25 provided in the driven side rotating body coaxially with a rotation axis X; an input gear 30 coupled to the driving side rotating body A; and a cylindrical eccentric member 26 for rotating the input gear 30. The driving side rotating body A includes a front plate 12 on a side opposite to a cam shaft relative to the eccentric member 26 in a direction along the rotation axis X. The front plate 12 includes an opening 12b for discharging to outside, the lubrication oil supplied to the driven side rotating body at least at a portion opposing to a part of the input gear 30.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a valve timing control device. [Background technology]

[0002] Patent Document 1 describes a valve timing control device in an internal combustion engine that controls the timing of valve opening and closing by a cam portion of a camshaft using torque transmitted from the crankshaft. This valve timing control device includes a drive-side rotor, a driven-side rotor, and a phase adjustment mechanism that sets the relative rotational phase between the drive-side rotor and the driven-side rotor. The phase adjustment mechanism includes an output gear provided on the driven-side rotor coaxially with the rotational axis, an input gear that rotates about an eccentric axis parallel to the rotational axis and is connected to the drive-side rotor, a first bearing, a second bearing, and a cylindrical eccentric member that supports the input gear from its inner periphery via the second bearing and rotates the input gear.

[0003] In a valve timing control device, lubricating oil is typically supplied to the inside of the driven rotor while the engine is running. In the valve timing control device described in Patent Document 1, the driving rotor has a front plate on the opposite side of the camshaft with respect to the eccentric member in the direction along the rotation axis. This front plate is circular when viewed in the direction along the rotation axis and has a circular opening in its center. The opening is provided to discharge lubricating oil from the internal space of the eccentric member to the outside. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-17833 Summary of the Invention [Problem to be solved by the invention]

[0005] A valve timing control device has many sliding parts (hereinafter, sometimes referred to as "sliding parts") inside the device during operation, such as the meshing portion between an input gear and an output gear, and is configured to supply lubricating oil to these sliding parts. In the valve timing control device described in Patent Document 1, the front plate has a circular opening in the center and is formed to cover the entire input gear and output gear. This configuration makes it difficult for the lubricating oil that lubricates the sliding parts inside the device to be discharged to the outside from the front plate during engine operation. In particular, in cold environments where the viscosity of the lubricating oil increases, lubricating oil that accumulates inside the device experiences high shear resistance. If highly viscous lubricating oil accumulates in the sliding parts inside the device, the responsiveness of the valve timing control device will decrease. Furthermore, wear powder and foreign matter may be mixed into the lubricating oil at the sliding parts inside the device. In this case, the wear powder and foreign matter that accumulate together with the lubricating oil inside the device may accelerate wear of the sliding parts.

[0006] The present invention has been made in consideration of the above circumstances, and its object is to provide a valve timing control device that can quickly discharge lubricating oil that lubricates sliding parts inside the device to the outside. [Means for solving the problem]

[0007] A valve timing control device according to the present invention for achieving the above object has a characteristic configuration including a drive-side rotor that rotates synchronously with a crankshaft of an internal combustion engine about a rotational axis, a driven-side rotor that is coaxial with the rotational axis and is arranged inside the drive-side rotor and rotates integrally with a camshaft for opening and closing valves of the internal combustion engine, and a phase adjustment mechanism that sets the relative rotational phase between the drive-side rotor and the driven-side rotor, wherein the phase adjustment mechanism includes: an output gear that is coaxial with the rotational axis and is provided on the driven-side rotor; an input gear that rotates about an eccentric axis that is parallel to the rotational axis and is connected to the drive-side rotor; and a phase adjustment mechanism that supports the input gear from the inner peripheral side via a support bearing and rotates the input gear. the driven-side rotating body has a support wall portion connected to an end of the camshaft in an orientation perpendicular to the rotational axis, the support wall portion having an oil supply passage through which lubricating oil can be supplied from the outside to the inside of the driven-side rotating body; the driving-side rotating body has a front plate on the opposite side of the camshaft with respect to the eccentric member in a direction along the rotational axis, and the front plate has an opening at a portion facing at least a part of the input gear for discharging the lubricating oil supplied to the driven-side rotating body to the outside.

[0008] The valve timing control device has many sliding parts at and near the meshing portion of the input gear and output gear, and lubricating oil supplied from outside to the driven rotor is supplied to these sliding parts. In this configuration, the front plate has an opening in a portion facing at least a portion of the input gear for discharging lubricating oil supplied to the driven rotor to the outside. This allows the valve timing control device to quickly discharge the lubricating oil lubricating the sliding parts near the input gear through the opening in the front plate. Furthermore, even if wear debris or foreign matter becomes mixed in the lubricating oil lubricating the sliding parts or if wear debris or foreign matter is generated on the sliding parts due to sliding, the valve timing control device can discharge the wear debris and foreign matter along with the lubricating oil through the opening in the front plate. As a result, wear on the sliding parts and other parts of the device caused by wear debris or foreign matter mixed in the lubricating oil can be suppressed. Furthermore, since the lubricating oil that lubricates the sliding parts is easily discharged to the outside through the opening in the front plate and does not accumulate around the sliding parts, the responsiveness of the valve timing control device can be improved even in cold environments where the viscosity of the lubricating oil is high.

[0009] A further characteristic configuration of the valve timing control device according to the present invention is that the phase adjustment mechanism further includes an Oldham coupling, and the Oldham coupling has an internal engagement arm that protrudes radially outward about the rotation axis and an engagement recess formed on the inside of the internal engagement arm, the input gear has an engagement protrusion that engages with the engagement recess of the Oldham coupling, thereby being connected to the drive-side rotor, and the opening is formed to face the entire area where the engagement protrusion of the input gear slides radially relative to the engagement recess of the Oldham coupling.

[0010] In some valve timing control devices, the phase adjustment mechanism includes an Oldham coupling. The Oldham coupling of the phase adjustment mechanism is displaced radially around the rotation axis due to the displacement of the input gear, causing the engaging recess of the Oldham coupling to slide against the engaging protrusion of the input gear, generating wear debris. Therefore, in this configuration, the opening in the front plate is formed to face the entire area where the engaging protrusion of the input gear slides radially against the engaging recess of the Oldham coupling. This allows the valve timing control device to quickly discharge lubricating oil that lubricates the sliding area between the engaging recess of the Oldham coupling and the engaging protrusion of the input gear through the opening in the front plate. Even if wear debris or foreign matter gets mixed into the lubricating oil that lubricates the sliding area between the engaging recess of the Oldham coupling and the engaging protrusion of the input gear, or if wear debris or foreign matter is generated at the sliding area due to sliding, the valve timing control device can discharge the wear debris and foreign matter together with the lubricating oil through the opening in the front plate.

[0011] A further characteristic feature of the valve timing control device according to the present invention is that the opening is formed to face the area extending from the bottom of the external teeth of the input gear to the bottom of the internal teeth of the output gear at the meshing portion between the input gear and the output gear.

[0012] The valve timing control device has an internal sliding portion, the meshing portion between the input gear and the output gear. Therefore, the valve timing control device is configured so that lubricating oil supplied from the outside to the inside of the driven rotor is also supplied to the meshing portion between the input gear and the output gear. Therefore, in this configuration, the opening in the front plate is formed to face the area at the meshing portion between the input gear and the output gear, which extends from the tooth bottom of the external teeth of the input gear to the tooth bottom of the internal teeth of the output gear. This allows the valve timing control device to quickly discharge wear debris and foreign matter, along with the lubricating oil, to the outside through the opening in the front plate. Even if wear debris or foreign matter gets mixed in with the lubricating oil that lubricates the meshing portion between the input gear and the output gear, the valve timing control device can discharge the wear debris and foreign matter, along with the lubricating oil, to the outside through the opening in the front plate.

[0013] A further characteristic feature of the valve timing control device according to the present invention is that the opening is formed to face an area larger than an operating area in which the engagement recess of the Oldham coupling and the engagement projection of the input gear move circumferentially while sliding radially.

[0014] The Oldham coupling of the phase adjustment mechanism is affected by the displacement of the input gear and displaces radially about the rotation axis. Therefore, in the valve timing control device, it is assumed that the engagement recess of the Oldham coupling and the engagement protrusion of the input gear have an operating region where they move circumferentially while sliding radially. Here, this operating region includes a portion where the engagement protrusion of the input gear slides radially relative to the engagement recess of the Oldham coupling. Furthermore, in the circumferential direction of this operating region, the input gear disposed inside the engagement recess and the output gear mesh together to form a meshed portion. In this case, the operating region of the engagement recess of the Oldham coupling and the engagement protrusion of the input gear includes at least the meshed portion of the input gear and the output gear.

[0015] Therefore, in this configuration, the opening in the front plate is formed to face an area larger than the operating area between the engagement recess of the Oldham coupling and the engagement protrusion of the input gear. This allows the valve timing control device to quickly discharge lubricating oil that lubricates the sliding portions near the engagement recess of the Oldham coupling and the engagement protrusion of the input gear to the outside through the opening in the front plate. Furthermore, if the opening is larger than the operating area between the engagement recess of the Oldham coupling and the engagement protrusion of the input gear, the opening in the front plate can face not only the sliding portion between the engagement recess of the Oldham coupling and the engagement protrusion of the input gear, but also the meshing portion between the input gear and the output gear. Therefore, with this configuration, the valve timing control device can discharge both the lubricating oil that lubricates the radial sliding portion and the lubricating oil that lubricates the circumferential sliding portion that are present near the operating area between the engagement recess of the Oldham coupling and the engagement protrusion of the input gear to the outside through the opening in the front plate.

[0016] A further characteristic feature of the valve timing control device according to the present invention is that a plurality of the openings are provided at equal intervals in the circumferential direction of the front plate.

[0017] With the above configuration, since the front plate has multiple openings, the valve timing control device can efficiently discharge lubricating oil that lubricates the sliding parts inside the device to the outside through the multiple openings in the front plate. Also, by distributing the multiple openings at equal intervals in appropriate locations around the circumferential direction of the front plate, the area of each opening in the front plate can be reduced. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a cross-sectional view of the valve timing control device. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 2 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is an enlarged front view of the main part of part K in FIG. 5. [Figure 7] FIG. 2 is an exploded perspective view of the valve timing control device. [Figure 8] FIG. 10 is a front view of a main part of a valve timing control device according to another embodiment. [Figure 9] FIG. 10 is a front view of a main part of a valve timing control device according to another embodiment. [Figure 10] FIG. 10 is a partial front view of a valve timing control device according to another embodiment. [Figure 11] FIG. 10 is a front view of a main part of a valve timing control device according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] [Basic configuration] As shown in FIG. 1, the valve timing control device 100 according to this embodiment includes a drive-side rotor A that rotates synchronously with a crankshaft 1 of an engine E as an internal combustion engine, an intake camshaft 2 (an example of a camshaft) that opens and closes an intake valve 2B (an example of a valve), a driven-side rotor B that rotates integrally with the intake camshaft 2 about a rotation axis X, and a phase adjustment mechanism C that sets the relative rotational phase between the drive-side rotor A and the driven-side rotor B using the driving force of a phase control motor M.

[0021] The engine E is a four-stroke engine in which pistons 4 are housed in multiple cylinders 3 formed in a cylinder block, and the pistons 4 are connected to a crankshaft 1 by connecting rods 5. A timing chain 6 (which may be a timing belt or the like) is wound around an output sprocket 1S of the crankshaft 1 of the engine E and a drive sprocket 11S of the drive-side rotor A.

[0022] As a result, when the engine E is running, the entire valve timing control device 100 rotates around the rotational axis X. In addition, the driving force of the phase control motor M operates the phase adjustment mechanism C, which makes it possible to displace the driven rotor B in the same direction as the rotational direction or in the opposite direction relative to the driving rotor A. This displacement by the phase adjustment mechanism C sets the relative rotational phase between the driving rotor A and the driven rotor B, thereby realizing control of the opening and closing timing of the intake valve 2B by the cam portion 2A of the intake camshaft 2.

[0023] The operation in which the driven-side rotor B is displaced relatively in the same direction as the rotational direction of the driving-side rotor A is called advance operation, and this advance operation increases the intake compression ratio. On the other hand, the operation in which the driven-side rotor B is displaced relatively in the opposite direction to the driving-side rotor A (operation in the opposite direction to advance operation) is called retard operation, and this retard operation reduces the intake compression ratio.

[0024] [Valve timing control device] As shown in Fig. 1, the drive-side rotating body A is configured by fastening an outer case 11, which has a drive sprocket 11S formed on its outer periphery, to a front plate 12 with a plurality of fastening bolts 13. The outer case 11 is a cylindrical type with a bottom and an opening at the bottom.

[0025] 1 to 5, an intermediate member 20 (see FIG. 2, etc.) serving as a driven rotor B and a phase adjustment mechanism C (see FIG. 3, etc.) having a hypotrochoid gear reduction mechanism are housed in the internal space of the outer case 11. The phase adjustment mechanism C also includes an Oldham coupling Cx (see FIG. 4, etc.) that reflects a phase change in the drive rotor A and the driven rotor B.

[0026] The intermediate member 20 constituting the driven-side rotor B is integrally formed with a support wall portion 21 that is connected to the intake camshaft 2 in an orientation perpendicular to the rotation axis X, and a cylindrical wall portion 22 that is cylindrical and centered on the rotation axis X and protrudes from the outer peripheral edge of the support wall portion 21 in a direction away from the intake camshaft 2.

[0027] The intermediate member 20 is fitted so as to be relatively rotatable with the outer surface of the cylindrical wall portion 22 in contact with the inner surface of the outer case 11, and is fixed to the end of the intake camshaft 2 by a connecting bolt 23 inserted into a through-hole in the center of the support wall portion 21. In this fixed state, the outer end of the cylindrical wall portion 22 (the side farther from the intake camshaft 2) is configured to be located inside the front plate 12.

[0028] 1 and 7, a groove 22a is formed around the entire outer periphery of the cylindrical wall portion 22. The groove 22a improves the oil retention between the outer surface of the cylindrical wall portion 22 and the inner surface of the outer case 11. This reduces the friction between the cylindrical wall portion 22 and the outer case 11, allowing the intermediate member 20 to rotate smoothly relative to the outer case 11.

[0029] As shown in Fig. 1, the phase control motor M is supported on the engine E by a support frame 7 so that its output shaft Ma is arranged coaxially with the rotation axis X. A pair of engagement pins 8 are formed on the output shaft Ma of the phase control motor M and oriented perpendicular to the rotation axis X (see also Figs. 3 to 5).

[0030] [Phase adjustment mechanism] 1 and 7, the phase adjustment mechanism C includes an intermediate member 20, an output gear 25 formed on the inner circumferential surface of the cylindrical wall portion 22 of the intermediate member 20, an eccentric member 26, an elastic member S, a first bearing 28, a second bearing 29 (an example of a "support bearing"), an input gear 30, a fixed ring 31, a ring-shaped spacer 32, and an Oldham coupling Cx. While rolling bearings are used for the first bearing 28 and the second bearing 29, plain bearings can also be used. In this embodiment, the second bearing 29 is a ball bearing having an inner ring 29a attached to the eccentric member 26 and an outer ring 29b attached to the input gear 30.

[0031] As shown in FIG. 1, a support surface 22S centered on the rotation axis X is formed on the inner periphery of the cylindrical wall portion 22 of the intermediate member 20 on the inside (at a position adjacent to the support wall portion 21) in a direction along the rotation axis X (hereinafter referred to as the axial direction), and an output gear 25 centered on the rotation axis X is integrally formed outside the support surface 22S (on the side farther from the intake camshaft 2).

[0032] As shown in Figures 1, 2, and 7, the eccentric member 26 is cylindrical. A circumferential support surface 26S is formed on the axially inner side of the eccentric member 26 (the side closer to the intake camshaft 2) and is the outer peripheral surface of the eccentric member 26, the circumferential support surface 26E is formed on the axially outer side of the eccentric member 26 (the side farther from the intake camshaft 2) and is the outer peripheral surface of the eccentric member 26, the eccentric support surface 26E is formed on the axially outer side of the eccentric member 26, the outer peripheral surface of the eccentric member 26 being centered on an eccentric axis Y that is eccentric and parallel to the rotation axis X. Because the direction along the eccentric axis Y is the same as the axial direction, hereinafter, the direction along the eccentric axis Y will also be simply referred to as the axial direction.

[0033] As shown in Figures 4, 5 and 7, a first recess 70 recessed inward along the radial direction of the eccentric member 26 is formed in the eccentric support surface 26E. A pair of second recesses 79, 79 recessed toward the radial axis of the eccentric member 26 are formed in the bottom surface of the first recess 70 at both ends in the circumferential direction of the eccentric member 26. In this embodiment, the first recess 70 is symmetrical in the circumferential direction (left-right symmetry in Figures 4 and 5).

[0034] The second recesses 79, 79 are respectively formed at the ends of the first recess 70 in the circumferential direction of the eccentric member 26. The maximum depth of the bottom surface of the second recesses 79, 79 in the radial direction of the eccentric member 26 is deeper than the depth of the bottom surface of the first recess 70 near the center in the circumferential direction of the eccentric member 26. The surfaces from the bottom surface to the ends of each of the second recesses 79, 79 in the circumferential direction of the eccentric member 26 are formed in a shape that follows the curved shape of a spring member 71, which will be described later.

[0035] An elastic member S is fitted into the first recess 70. The elastic member S includes a pair of spring members 71, 71. In this embodiment, the pair of spring members 71, 71 have the same shape and size. The elastic member S applies a biasing force to the input gear 30 via the second bearing 29 so that a portion of the external teeth portion 30A of the input gear 30 meshes with a portion of the internal teeth portion 25A of the output gear 25. This prevents the backlash between the input gear 30 and the output gear 25 from increasing, thereby preventing abnormal noise. This also improves the durability of the input gear 30 and the output gear 25.

[0036] As shown in FIGS. 1 and 7, a pair of engagement grooves 26T, each engageable with a pair of engagement pins 8 of the phase control motor M (see FIG. 1), are formed on the inner periphery of the eccentric member 26 in a position parallel to the rotation axis X. Furthermore, a plurality of first lubricating oil grooves 26a (see FIG. 1) are formed on the inner side (the side of the support wall 21) of the eccentric member 26 and are oriented along the radial direction, and a plurality of second lubricating oil grooves 26b are formed on the outer side (the side farther from the intake camshaft 2) and are oriented along the radial direction. Note that the eccentric member 26 may be formed with only one of the first lubricating oil grooves 26a and the second lubricating oil grooves 26b. The number of the first lubricating oil grooves 26a and the second lubricating oil grooves 26b may be set arbitrarily.

[0037] 7, tapered portions 26c (inclined portions) whose diameter decreases toward the inside (side closer to the intake camshaft 2) are formed on both sides of the engagement groove 26T on the inner circumferential side of the open end on the outside (side farther from the intake camshaft 2) of the eccentric member 26. When the pair of engagement pins 8 of the phase control motor M are engaged with the engagement grooves 26T of the eccentric member 26, the engagement pins 8 are guided into the engagement grooves 26T by the tapered portions 26c, which makes it easier to engage the phase control motor M with the eccentric member 26.

[0038] 1 and 2, a first bearing 28 is fitted onto the circumferential support surface 26S of the eccentric member 26, and the first bearing 28 is fitted into the support surface 22S of the cylindrical wall portion 22, so that the eccentric member 26 is rotatably supported about the rotation axis X with respect to the intermediate member 20. Also, as shown in FIGS. 1 and 3, the input gear 30 is supported on the eccentric support surface 26E of the eccentric member 26 via a second bearing 29 so as to be rotatable about the eccentric axis Y.

[0039] In this phase adjustment mechanism C, the number of teeth of the external teeth portion 30A of the input gear 30 is set to be one tooth less than the number of teeth of the internal teeth portion 25A of the output gear 25. A portion of the external teeth portion 30A of the input gear 30 meshes with a portion of the internal teeth portion 25A of the output gear 25.

[0040] As shown in FIGS. 1 and 7, the fixing ring 31 is supported in a fitted state on the outer periphery of the eccentric member 26, thereby preventing the second bearing 29 from coming off.

[0041] [Phase adjustment mechanism: Oldham coupling] 1, 4, and 7, the Oldham coupling Cx is composed of a plate-shaped coupling member 40 that is integrally formed with a central annular portion 41, a pair of external engagement arms 42 that protrude radially outward from the annular portion 41 in a first direction (the left-right direction in FIG. 4), and an internal engagement arm 43 that protrudes radially outward from the annular portion 41 in a direction perpendicular to the first direction (the up-down direction in FIG. 4). Each of the pair of internal engagement arms 43 is formed with an engagement recess 43a that communicates with the opening of the annular portion 41.

[0042] A pair of guide grooves 11a are formed in the outer case 11 at the opening edge against which the front plate 12 abuts, as through-grooves, extending from the interior space of the outer case 11 to the exterior space, radially from the rotation axis X. The groove width of the guide grooves 11a is set slightly wider than the width of the external engagement arm 42, and a pair of discharge flow paths 11b are cut out and formed in each guide groove 11a. Note that the discharge flow paths 11b may be formed to allow lubricating oil to flow radially relative to the front plate 12.

[0043] One or more pockets 11c are formed by cutting out the inner periphery along the circumferential direction at the opening edge of the outer case 11 in a portion other than the guide groove 11a. Foreign matter that moves to the outer periphery due to the centrifugal force caused by the rotation of the drive-side rotor A is collected in the pockets 11c. FIG. 7 shows a case where four pockets 11c are formed.

[0044] Furthermore, a pair of engagement protrusions 30T are integrally formed on the end surface of the input gear 30 that faces the front plate 12. The engagement width of these engagement protrusions 30T is set slightly narrower than the engagement width of the engagement recess 43a of the internal engagement arm 43.

[0045] With this configuration, the Oldham coupling Cx can be made to function by engaging the pair of outer engaging arms 42 of the coupling part 40 with the pair of guide grooves 11a of the outer case 11 and by engaging the pair of engaging projections 30T of the input gear 30 with the engaging recesses 43a of the pair of inner engaging arms 43 of the coupling part 40.

[0046] The coupling member 40 is displaceable relative to the outer case 11 in a first direction (left-right direction in FIG. 4) in which the external engagement arm 42 extends, and the input gear 30 is displaceable relative to this coupling member 40 in a second direction (up-down direction in FIG. 4) along the formation direction of the engagement recess 43a of the internal engagement arm 43.

[0047] 1 and 7, the spacer 32 limits the distance of the gap through which the second bearing 29 can move in the axial direction to a predetermined set value or less. By providing the spacer 32 between the Oldham coupling Cx (coupling member 40) and the second bearing 29, the movement of the second bearing 29 in the axial direction is limited to a distance that is equal to or less than the predetermined set value. This makes it possible to prevent contact between the engaging protrusion 30T of the input gear 30 and the front plate 12.

[0048] [Layout of each part of the valve timing control device] 1, in the assembled valve timing control device 100, the support wall portion 21 of the intermediate member 20 is connected to the end of the intake camshaft 2 by a connecting bolt 23, and they rotate together. The eccentric member 26 is supported by a first bearing 28 so as to be rotatable relative to the intermediate member 20 about the rotation axis X. As shown in FIGS. 1 and 3, the input gear 30 is supported by an eccentric support surface 26E of the eccentric member 26 via a second bearing 29, and a portion of the external teeth portion 30A of the input gear 30 meshes with a portion of the internal teeth portion 25A of the output gear 25.

[0049] Furthermore, as shown in Figure 4, the outer engagement arms 42 of the Oldham coupling Cx engage with a pair of guide groove portions 11a of the outer case 11, and the engagement projections 30T of the input gear 30 engage with the engagement recesses 43a of the inner engagement arms 43 of the Oldham coupling Cx. Because the front plate 12 is disposed on the outer side of the coupling member 40 of the Oldham coupling Cx as shown in Figure 1, the coupling member 40 can move in a direction perpendicular to the rotation axis X while contacting the inner surface of the front plate 12. With this arrangement, the Oldham coupling Cx is disposed outward from both the first bearing 28 and the second bearing 29 (on the side farther from the intake camshaft 2) and inward from the front plate 12 (on the side closer to the intake camshaft 2).

[0050] As shown in FIGS. 1 to 3, a pair of engagement pins 8 formed on the output shaft Ma of the phase control motor M engage with the engagement grooves 26T of the eccentric member 26.

[0051] [Operational form of phase adjustment mechanism] Although not shown in the drawings, the phase control motor M is controlled by a control device configured as an ECU. The engine E is equipped with sensors that can detect the rotational speeds (number of rotations per unit time) of the crankshaft 1 and the intake camshaft 2 and their respective rotational phases, and the detection signals of these sensors are input to the control device.

[0052] When the engine E is running, the control device maintains the relative rotational phase by driving the phase control motor M at a speed equal to the rotational speed of the intake camshaft 2. On the other hand, an advance operation is performed by reducing the rotational speed of the phase control motor M below the rotational speed of the intake camshaft 2, and conversely, a retard operation is performed by increasing the rotational speed. As described above, an advance operation increases the intake compression ratio, and a retard operation decreases the intake compression ratio.

[0053] When the phase control motor M rotates at the same speed as the outer case 11 (same speed as the intake camshaft 2), the position of the meshing portion of the external tooth portion 30A of the input gear 30 with the internal tooth portion 25A of the output gear 25 does not change, so the relative rotational phase of the driven side rotating body B with respect to the driving side rotating body A is maintained.

[0054] On the other hand, by driving and rotating the output shaft Ma of the phase control motor M at a speed higher or lower than the rotational speed of the outer case 11, the eccentric shaft Y in the phase adjustment mechanism C revolves around the rotational shaft X. Due to this revolution, the position of the meshing portion between the internal teeth portion 25A of the output gear 25 and the external teeth portion 30A of the input gear 30 is displaced along the inner circumference of the output gear 25, and a rotational force acts between the input gear 30 and the output gear 25. In other words, a rotational force about the rotational shaft X acts on the output gear 25, and a rotational force that rotates the input gear 30 about the eccentric shaft Y acts on the input gear 30.

[0055] As described above, the input gear 30 does not rotate relative to the outer case 11 because its engagement projection 30T engages with the engagement recess 43a of the internal engagement arm 43 of the coupling member 40, and a rotational force acts on the output gear 25. The action of this rotational force causes the intermediate member 20, together with the output gear 25, to rotate about the rotation axis X relative to the outer case 11. As a result, the relative rotational phase between the drive-side rotor A and the driven-side rotor B is set, and the opening and closing timing of the intake camshaft 2 is set.

[0056] Furthermore, when the eccentric axis Y of the input gear 30 revolves around the rotation axis X, the input gear 30 is displaced, and therefore the coupling member 40 of the Oldham coupling Cx is displaced in the direction in which the external engagement arm 42 extends relative to the outer case 11 (first direction), and the input gear 30 is displaced in the direction in which the internal engagement arm 43 extends (second direction).

[0057] As described above, the number of teeth on the external toothed portion 30A of the input gear 30 is set to be one tooth less than the number of teeth on the internal toothed portion 25A of the output gear 25. Therefore, when the eccentric axis Y of the input gear 30 revolves around the rotation axis X by one revolution, the output gear 25 rotates by one tooth, thereby achieving a large reduction in speed.

[0058] [Lubrication of Phase Adjustment Mechanism] 1, the intake camshaft 2 is formed with a lubricating oil passage 15 through which lubricating oil is supplied from an external oil pump P via an oil passage forming member 9. A supply oil passage 21a is formed in a portion of the surface of the support wall portion 21 of the intermediate member 20 that abuts against the intake camshaft 2, and that guides oil circulating through the lubricating oil passage 15 inside the eccentric member 26. In other words, the support wall portion 21 has the supply oil passage 21a that can supply lubricating oil from the outside to the inside of the driven-side rotor B.

[0059] As described above, the eccentric member 26 is formed with a plurality of first lubricating oil grooves 26a and a plurality of second lubricating oil grooves 26b (see FIGS. 1 and 7).

[0060] With this configuration, lubricating oil supplied from oil pump P is supplied from lubricating oil passage 15 of intake camshaft 2 through supply oil passage 21a of support wall portion 21 of intermediate member 20 to the internal space of eccentric member 26. The lubricating oil supplied in this manner is supplied by centrifugal force from first lubricating oil groove 26a of eccentric member 26 to first bearing 28, causing first bearing 28 to operate (slide) smoothly. The lubricating oil supplied to first bearing 28 is then supplied to adjacent second bearing 29, and is also supplied to between internal teeth portion 25A of output gear 25, which is arranged on the outer periphery of second bearing 29 and biased by elastic member S, and external teeth portion 30A of input gear 30, causing these portions (particularly the meshing portions) to operate (slide) smoothly.

[0061] At the same time, a portion of the lubricating oil in the internal space of the eccentric member 26 is supplied by centrifugal force from the second lubricating oil groove 26b to the coupling member 40, and is also supplied to the second bearing 29, and is supplied between the internal tooth portion 25A of the output gear 25 and the external tooth portion 30A of the input gear 30.

[0062] 1, the lubricating oil from the second lubricating oil groove 26b is supplied between the front plate 12 and the coupling member 40, and also to the gap between the outer engagement arm 42 of the coupling member 40 and the guide groove portion 11a of the outer case 11. This allows the coupling member 40 to operate smoothly.

[0063] As described above, a pair of discharge passages 11b are formed in the guide groove portion 11a (see FIGS. 4 and 7). Therefore, the lubricating oil supplied to the coupling member 40 is discharged to the outside through the gap between the external engagement arm 42 of the coupling member 40 and the guide groove portion 11a of the outer case 11. Furthermore, because the discharge passages 11b are formed in the guide groove portion 11a, the lubricating oil inside can be discharged from the discharge passages 11b by centrifugal force when the engine E is started.

[0064] 1, 5, and 7, the front plate 12 has a circular first opening 12a at its center, the first opening 12a being centered on the rotation axis X. By making the opening diameter of the first opening 12a larger than the inner diameter of the eccentric member 26, a step G is formed between the opening edge of the first opening 12a of the front plate 12 and the inner periphery of the eccentric member 26.

[0065] When the engine E is stopped, the step G allows the lubricating oil in the internal space of the eccentric member 26 to be discharged through the first opening 12a of the front plate 12, thereby reducing the amount of lubricating oil remaining inside.

[0066] As described above, in the valve timing control device 100, lubricating oil supplied to the driven rotor B can be discharged through the guide groove 11a of the outer case 11 and the first opening 12a of the front plate 12. However, lubricating oil supplied to sliding parts inside the device, such as the meshing portion between the input gear 30 and the output gear 25, is difficult to discharge to the outside through the guide groove 11a of the outer case 11 and the first opening 12a of the front plate 12. Particularly in cold environments where the viscosity of lubricating oil increases, lubricating oil remaining inside the device experiences high shear resistance. Furthermore, in the valve timing control device 100, wear debris and foreign matter may become mixed into the lubricating oil at the sliding parts. In this case, the wear debris and foreign matter remaining inside the device along with the lubricating oil may accelerate wear of the gears and other components. For this reason, it is desirable to quickly discharge the lubricating oil supplied to the sliding parts inside the device without allowing it to remain.

[0067] 5 to 7, second openings 12b (an example of "openings" in the present application) that are connected to the first openings 12a and extend radially outward are formed in the front plate 12. In the present embodiment, two (a pair) of second openings 12b are formed so as to face the pair of internal engagement arms 43 of the coupling part 40, respectively.

[0068] The second opening 12b is formed in a portion facing at least a portion of the input gear 30 to discharge lubricating oil supplied to the sliding portion to the outside. Here, the portion facing at least a portion of the input gear 30 refers to a portion where a circumferential portion of the external teeth 30A formed on the outer edge of the input gear 30 is exposed. The sliding portion refers to a portion of a member disposed inside the driven rotor B where sliding occurs during operation of the valve timing control device 100. Examples of such a portion include a portion where an engaging recess 43a of the Oldham coupling Cx and an engaging protrusion 30T of the input gear 30 slide radially, as well as a meshing portion between the input gear 30 and the output gear 25, which will be described later. The Oldham coupling Cx included in the phase adjustment mechanism C is displaced radially about the rotation axis X due to the displacement of the input gear 30. In this case, the engaging recess 43a of the internal engaging arm 43 slides against the engaging protrusion 30T of the input gear 30, generating wear debris. Therefore, in this embodiment, the second opening 12b of the front plate 12 is formed to face the entire region R1 where the engagement projection 30T of the input gear 30 slides radially relative to the engagement recess 43a of the Oldham coupling Cx. The region R1 is, for example, the region between a first position 43a1 on the radially outer side of the engagement recess 43a and a second position 43a2 on the radially inner side, as shown in Figure 6.

[0069] Furthermore, the second opening 12b of the front plate 12 is formed inside the engaging recess 43a of the Oldham coupling Cx and also faces the meshing portion, which is the sliding portion, of the input gear 30 and the output gear 25. Specifically, as shown in Fig. 6, the second opening 12b is formed to face a region R2 that extends from the tooth bottom 30Aa of the external tooth portion 30A of the input gear 30 to the tooth bottom 25Aa of the internal tooth portion 25A of the output gear 25.

[0070] In this way, the front plate 12 has the second opening 12b, which discharges lubricating oil supplied to the driven-side rotor B, at a portion facing a part of the input gear 30. Therefore, the valve timing control device 100 can quickly discharge the lubricating oil that lubricates the sliding parts near the input gear 30 to the outside through the second opening 12b. Even if wear debris or foreign matter gets mixed in the lubricating oil that lubricates the sliding parts, or if wear debris or foreign matter is generated at the sliding parts due to sliding, the valve timing control device 100 can discharge the wear debris and foreign matter together with the lubricating oil through the second opening 12b because the second opening 12b of the front plate 12 is located close to the sliding parts. As a result, wear on the sliding parts and other parts of the device due to wear debris or foreign matter mixed in the lubricating oil can be suppressed. Furthermore, the lubricating oil that lubricates the sliding parts is easily discharged to the outside through the second opening 12b of the front plate 12, and the lubricating oil does not accumulate around the sliding parts, so the responsiveness of the valve timing control device 100 can be improved even in cold environments where the viscosity of the lubricating oil is high.

[0071] Furthermore, the second opening 12b of the front plate 12 is formed to face the entire region R1 where the engaging recess 43a of the Oldham coupling Cx and the engaging projection 30T of the input gear 30 slide radially. This allows the valve timing control device 100 to quickly discharge the lubricating oil that lubricates the sliding portion between the engaging recess 43a of the Oldham coupling Cx and the engaging projection 30T of the input gear 30 to the outside through the second opening 12b of the front plate 12.

[0072] Furthermore, the second opening 12b of the front plate 12 is formed inside the engaging recess 43a of the Oldham coupling Cx so as to face a region R2 that extends from the tooth bottom 30Aa of the external tooth portion 30A of the input gear 30 to the tooth bottom 25Aa of the internal tooth portion 25A of the output gear 25 at the meshing portion between the input gear 30 and the output gear 25. As a result, even if wear debris or foreign matter is generated at the meshing portion between the input gear 30 and the output gear 25 due to sliding, the valve timing control device 100 can quickly discharge it, together with lubricating oil, to the outside from the second opening 12b of the front plate 12.

[0073] In this embodiment, as shown in Fig. 5, a pair of second openings 12b of the front plate 12 are formed to face the pair of internal engagement arms 43 of the coupling member 40, respectively. The external toothed portion 30A and the internal toothed portion 25A, which are arranged inside the pair of engagement recesses 43a and face the pair of second openings 12b of the front plate 12, are in a state where one side (e.g., the upper side in Fig. 5) of the external toothed portion 30A and the internal toothed portion 25A are engaged with each other, while the other side (e.g., the lower side in Fig. 5) of the external toothed portion 30A and the internal toothed portion 25A are spaced apart. At this time, the gap between the spaced external toothed portion 30A and the internal toothed portion 25A on the other side (lower side) becomes negative pressure compared to the outside, and the gap between the meshed external toothed portion 30A and the internal toothed portion 25A on the one side (upper side) becomes positive pressure compared to the outside. That is, by providing a pair of second openings 12b corresponding to a pair of engagement recesses 43a, the lubricating oil can be sucked from the gap between the external toothed portion 30A and the internal toothed portion 25A on the other side (lower side) where they are spaced apart, and the lubricating oil can be discharged to the outside from the gap between the external toothed portion 30A and the internal toothed portion 25A on one side (upper side) where they mesh, allowing the internal space of the driven-side rotating body B to function as a kind of pump. This allows the lubricating oil supplied to the meshing portion between the input gear 30 and the output gear 25 inside the engagement recesses 43a of the Oldham coupling Cx to be quickly discharged to the outside. Furthermore, instead of forming a pair of second openings 12b, they may be formed only on one side (upper side) where the external toothed portion 30A and the internal toothed portion 25A mesh, where positive pressure is generated and the lubricating oil can be discharged to the outside.

[0074] As shown in Figure 7, the front plate 12 has a protrusion 12c that protrudes inward on its inner surface (the side closer to the intake camshaft 2). The protrusion 12c lightly abuts the intermediate member 20 to the extent that it can slide against the intermediate member 20. The intermediate member 20 abuts against the protrusion 12c, thereby restricting movement of the intermediate member 20 toward the front plate 12. This allows the Oldham coupling Cx (coupling member 40) to operate smoothly, with a predetermined gap maintained between the front plate 12 and the intermediate member 20.

[0075] Furthermore, the eccentric member 26 is supported on the support surface 22S on the inner circumference of the intermediate member 20 by a first bearing 28, and the input gear 30 is supported on the eccentric support surface 26E of the eccentric member 26 via a second bearing 29. Therefore, even if the biasing force of the elastic member S acts in a direction that changes the attitude of the eccentric member 26, the entire circumference of the outer surface of the circumferential support surface 26S of the eccentric member 26 is held so as to be embraced by the inner circumference of the intermediate member 20 by the first bearing 28, and the positional relationship between the eccentric member 26 and the intermediate member 20 can be maintained.

[0076] In this configuration, the biasing force of the elastic member S acts only between the eccentric member 26 and the intermediate member 20, and does not act on external members. Therefore, for example, there is no need to consider deformation or displacement of external members due to the biasing force of the elastic member S, and the posture of the eccentric member 26 can be maintained with even greater precision.

[0077] Furthermore, by forming the first lubricating oil groove 26a and the second lubricating oil groove 26b for flowing lubricating oil at the end of the eccentric member 26, the Oldham coupling Cx operates smoothly, the first bearing 28 and the second bearing 29 operate smoothly, the internal teeth portion 25A of the output gear 25 meshes smoothly with the external teeth portion 30A of the input gear 30, and the load acting on the phase control motor M is reduced. By forming the first lubricating oil groove 26a and the second lubricating oil groove 26b in this way, lubricating oil is supplied to areas where it is needed, so it is not wasted and the amount of lubricating oil can be reduced.

[0078] In particular, by supplying lubricating oil between the coupling member 40 constituting the Oldham coupling Cx and the front plate 12, the operation of the coupling member 40 can be performed smoothly, and the load acting on the phase control motor M can be further reduced.

[0079] Second Embodiment In the second embodiment, as shown in Fig. 8, the second opening 12b of the front plate 12 is formed as an independent opening spaced apart from the first opening 12a. Specifically, in the front plate 12, the second opening 12b is not connected to the first opening 12a, and an intermediate region 12d exists between the first opening 12a and the second opening 12b. The second opening 12b has a pair of opening portions 12b1, 12b1 extending radially and an opening portion 12b2 extending circumferentially. The pair of opening portions 12b1, 12b1 extend radially from the engagement recess 43a in the front plate 12 and are formed to face the entire region R1 where the internal engagement arm 43 of the Oldham coupling Cx and the engagement protrusion 30T of the input gear 30 slide. The opening portion 12b2 connects the radially outer sides of the pair of opening portions 12b1, 12b1, and is formed to face an area ranging from the tooth bottom 30Aa of the external tooth portion 30A of the input gear 30 to the tooth bottom 25Aa of the internal tooth portion 25A of the output gear 25 at the meshing portion between the input gear 30 and the output gear 25. This makes the second opening 12b U-shaped as a whole, and although the area of the second opening 12b is smaller than in the first embodiment, it is possible to achieve the same effects as in the first embodiment.

[0080] Third Embodiment In the third embodiment, as shown in Fig. 9, the second opening 12b is formed in the front plate 12 so as to face the entire region R1 where the engagement recess 43a of the internal engagement arm 43 of the Oldham coupling Cx and the engagement projection 30T of the input gear 30 slide. Specifically, the second opening 12b is formed by a pair of openings 12b1, 12b1 that are connected to the first opening 12a and extend in the radial direction (the direction in which the region R1 extends). Therefore, in the third embodiment, the second opening 12b of the front plate 12 has a smaller area for discharging wear debris and foreign matter compared to the above-described embodiments, but can still achieve the same effects as the above-described embodiments. Specifically, it can mainly discharge lubricating oil supplied to the region where the engagement recess 43a of the Oldham coupling Cx and the engagement projection 30T of the input gear 30 slide.

[0081] [Fourth embodiment] 10 , in the front plate 12, the second opening 12b is formed in an area facing the circumferential outer side of the engagement recess 43a of the internal engagement arm 43 of the Oldham coupling Cx, so as to face the meshing portion between the external tooth portion 30A and the internal tooth portion 25A. Specifically, a plurality of rectangular second openings 12b (one on each side of the internal engagement arm 43 in this embodiment) are formed along the circumferential direction of the internal engagement arm 43 in the circumferential direction based on the rotation axis X. The second openings 12b are formed by opening portions 12b2 facing a region R2 that extends from the tooth bottom 30Aa of the external tooth portion 30A of the input gear 30 to the tooth bottom 25Aa of the internal tooth portion 25A of the output gear 25 in the meshing portion between the input gear 30 and the output gear 25. Therefore, in the fourth embodiment, the second opening 12b of the front plate 12 can mainly discharge the lubricating oil supplied to the area outside the internal engagement arm 43 of the Oldham coupling Cx, where the input gear 30 and the output gear 25 mesh.

[0082] Fifth Embodiment In the valve timing control device 100, the Oldham coupling Cx of the phase adjustment mechanism C is displaced in the radial direction around the rotation axis X due to the influence of the displacement of the input gear 30. Therefore, the engagement recess 43a of the Oldham coupling Cx and the engagement protrusion 30T of the input gear 30 have operating regions (regions R3 and R4 in FIG. 11 ) in which they move circumferentially while sliding radially. Here, region R3 is a region in which the engagement recess 43a and the engagement protrusion 30T move circumferentially as the Oldham coupling Cx displaces in the direction in which the external engagement arm 42 extends (first direction). Furthermore, region R4 is a region in which the engagement protrusion 30T moves radially relative to the engagement recess 43a. Therefore, the radial region R4 is the same as region R1 in which the engagement protrusion 30T of the input gear 30 slides radially relative to the engagement recess 43a of the Oldham coupling Cx. Moreover, the region R3 is a portion where the input gear 30 and the output gear 25 mesh with each other inside the engaging recess 43a.

[0083] 11, the second opening 12b of the front plate 12 is formed to face an area larger than the operating area (area R3 and area R4) between the engagement recess 43a of the Oldham coupling Cx and the engagement projection 30T of the input gear 30. This allows the valve timing control device 100 to quickly discharge lubricating oil that lubricates the sliding portions adjacent to the engagement recess 43a of the Oldham coupling Cx and the engagement projection 30T of the input gear 30 to the outside through the second opening 12b of the front plate 12.

[0084] Furthermore, if the second opening 12b of the front plate 12 is larger than the operating regions (regions R3 and R4), the second opening 12b of the front plate 12 can be made to face not only the sliding portion between the engaging recess 43a of the Oldham coupling Cx and the engaging projection 30T of the input gear 30, but also the meshing portion between the input gear 30 and the output gear 25. Therefore, the valve timing control device 100 can quickly discharge both the lubricating oil that lubricates the radial sliding portion and the lubricating oil that lubricates the circumferential sliding portion to the outside from the second opening 12b of the front plate 12 near the operating region between the engaging recess 43a of the Oldham coupling Cx and the engaging projection 30T of the input gear 30.

[0085] [Another embodiment] (1) The number of second openings 12b formed in the front plate 12 may be one or more. Providing multiple second openings 12b in the front plate 12 allows lubricating oil to be more efficiently discharged to the outside through the second openings 12b. Also, distributing multiple second openings 12b at appropriate locations on the front plate 12 allows the area of each second opening 12b in the front plate 12 to be reduced. In this case, the multiple second openings 12b may be arranged at equal intervals along the circumferential direction. Also, the multiple second openings 12b may be arranged in locations that achieve rotational balance of the Oldham coupling Cx, for example, near the outer engaging arm 42 or the inner engaging arm 43 of the Oldham coupling Cx, which have a larger mass than the annular portion 41. The second openings 12b may be provided in both the front plate 12 at a position facing the inner engaging arm 43 of the Oldham coupling Cx and at a position outside the inner engaging arm 43 that faces a region where the external teeth portion 30A and the internal teeth portion 25A mesh.

[0086] (2) In the second embodiment, the second opening 12b in the front plate 12, which is spaced apart from the first opening 12a, is formed in a U-shape. However, the second opening 12b may be formed in a rectangular shape.

[0087] (3) In the third embodiment, an example is shown in which the opening portion 12b1 of the second opening 12b in the front plate 12 is connected to the first opening 12a, but the opening portion 12b1 may be formed away from the first opening 12a. [Industrial Applicability]

[0088] The present invention can be used in a valve timing control device. [Explanation of symbols]

[0089] 1: Crankshaft 2: Intake camshaft (camshaft) 2B: Intake valve 11: Outer case 12: Front plate 12a: First opening 12b: Second opening (opening) 12b1,12b2,12b3: Opening part 20: Intermediate member 21: Support wall part 21a: Oil supply line 25: Output gear 25A: Internal tooth part 25Aa: Tooth bottom 26: Eccentric member 28:First bearing 29: Second bearing (support bearing) 30: Input gear 30A: External tooth part 30Aa: Tooth bottom 40: Joint member 41: Annular section 42: External engagement arm 43: Internal engagement arm 43a: Engagement recess 43a1 :1st position 43a2: 2nd position 100: Valve opening / closing timing control device A: Drive side rotor B: Driven rotating body C: Phase adjustment mechanism Cx: Oldham coupling E: Engine (internal combustion engine) R1,R2: area R3,R4: Working area S: Elastic material X: Rotation axis Y: Eccentric shaft center

Claims

1. a drive-side rotating body that rotates synchronously with the crankshaft of the internal combustion engine around a rotation axis; a driven-side rotor that is arranged coaxially with the rotation axis and inside the driving-side rotor, and that rotates integrally with a camshaft for opening and closing a valve of the internal combustion engine; and a phase adjustment mechanism that sets the relative rotational phase between the drive-side rotor and the driven-side rotor, The phase adjustment mechanism includes: an output gear provided on the driven rotor and coaxial with the rotation axis; an input gear that rotates about an eccentric axis parallel to the rotation axis and is connected to the drive-side rotor; a cylindrical eccentric member that supports the input gear from an inner peripheral side via a support bearing and rotates the input gear, The rotation of the eccentric member causes the eccentric shaft to revolve, thereby changing the position of the meshing portion between the output gear and the input gear, the driven-side rotor has a support wall portion connected to an end of the camshaft in an orientation perpendicular to the rotation axis, the support wall portion has an oil supply passage that can supply lubricating oil from the outside to the inside of the driven-side rotating body, the drive-side rotor has a front plate on the opposite side of the eccentric member from the camshaft in the direction along the rotation axis, the front plate has an opening at a portion facing at least a part of the input gear for discharging the lubricating oil supplied to the driven-side rotating body to the outside, the phase adjustment mechanism further includes an Oldham coupling; the Oldham coupling has an internal engagement arm that protrudes radially outward about the rotation axis, and an engagement recess formed inside the internal engagement arm, the input gear has an engaging protrusion, and is connected to the drive-side rotor by the engaging protrusion engaging with the engaging recess of the Oldham coupling, The opening is formed to face the entire area where the engaging projection of the input gear slides radially relative to the engaging recess of the Oldham coupling.

2. 2. The valve timing control device according to claim 1, wherein the opening is formed to face a region extending from the bottom of the external teeth of the input gear to the bottom of the internal teeth of the output gear at the meshing portion between the input gear and the output gear.

3. 3. The valve timing control device according to claim 1, wherein the opening is formed to face an area larger than an operating area in which the engagement recess of the Oldham coupling and the engagement protrusion of the input gear move circumferentially while sliding radially.

4. The valve timing control device according to any one of claims 1 to 3, wherein a plurality of the openings are provided at equal intervals in the circumferential direction of the front plate.

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