Valve opening / closing timing control device

Abstract

To provide a valve opening / closing timing control device which does not become unable to operate even when a spring body for engaging the internal teeth and the external teeth of a speed reduction mechanism with each other is broken.SOLUTION: The valve opening / closing timing control device includes a driving side rotary body, a driven side rotary body, and a phase adjustment mechanism, the phase adjustment mechanism including an internal tooth type output gear 25, an external tooth type input gear 30, and an eccentric member 26 for engaging the output gear 25 with the input gear 30, the eccentric member 26 including a fixed ring 31 into which a spring member 71 is fitted for giving energizing force to a recessed part 70 formed in an eccentric support surface 26E to engage a tooth part of the input gear 30 with a tooth part 25A of the output gear 25, and which overlaps with the recessed part 70 in view from the radial direction, the fixed ring 31 having a specification part 31R to be fitted into the recessed part 70.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a valve opening / closing timing control device.

Background Art

[0002] For example, as a valve opening / closing timing control device for setting the opening / closing timing (valve timing) of an intake valve of an internal combustion engine, Patent Document 1 describes a configuration in which an internal gear type output gear is arranged around a rotation axis center, and an external gear type input gear having a smaller number of teeth than the number of teeth of this output gear is arranged around an eccentric shaft that is eccentric with respect to the aforementioned rotation axis center, and an eccentric member that meshes an external tooth portion of the input gear with an internal tooth portion of the output gear is provided, and a motor that drives and rotates the eccentric member is provided.

[0003] In the valve opening / closing timing control device of this Patent Document 1, the gear configuration described above is referred to as a hypoid type gear reduction mechanism. In this gear reduction mechanism, in order to maintain a state in which the external tooth portion of the input gear meshes with the internal tooth portion of the output gear, a spring member is fitted into a concave portion on the outer peripheral surface of the eccentric member, and the biasing force of this spring member is made to act on the inner peripheral side of the input gear.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the spring plate (spring member) having the configuration described in Patent Document 1 may break due to long-term use, and a part of the spring plate separated by the break may fall off from the eccentric member and enter between the external tooth portion of the input gear and the internal tooth portion of the output gear, or may come into contact with the operating parts in the device and disable the operation of the valve opening / closing timing control device, which has also been a concern.

[0006] For these reasons, there is a need for a valve opening / closing timing control device that does not become inoperable even when a spring body for engaging the internal tooth portion and the external tooth portion of the speed reduction mechanism breaks.

Means for Solving the Problems

[0007] The characteristic configuration of the valve opening / closing timing control device according to the present invention includes a drive-side rotating body that rotates synchronously with the crankshaft of the internal combustion engine about the rotation axis center, a driven-side rotating body that is coaxially arranged inside the drive-side rotating body with the same axis center as the rotation axis center and rotates integrally with the camshaft for opening and closing the valves of the internal combustion engine, and a phase adjustment mechanism that adjusts the relative rotation phase of the drive-side rotating body and the driven-side rotating body. The phase adjustment mechanism includes an internal gear type output gear that rotates integrally with the driven-side rotating body coaxially with the rotation axis center, an external gear type input gear that has fewer teeth than the output gear and is arranged inside the output gear and rotates about an eccentric axis center parallel to the rotation axis center, a joint member that links the input gear to the rotation of the drive-side rotating body, an eccentric member that meshes the external tooth portion of the input gear with the internal tooth portion of the output gear, and an electric actuator that drives and rotates the eccentric member about the rotation axis center. The eccentric member has a concave portion that is recessed in the radial direction with respect to an eccentric support surface centered on the eccentric axis center and is open in the direction of the end portion of the eccentric member along the eccentric axis center. A spring member that applies a biasing force for meshing the external tooth portion of the input gear with the internal tooth portion of the output gear is fitted into the concave portion, and a fixing ring is provided on the outer periphery of the eccentric support surface so as to overlap the concave portion in a radial view. The fixing ring has a regulating portion that fits into the concave portion to prevent the spring member from falling off.

[0008] According to this characteristic configuration, by fitting the spring member into the concave portion of the eccentric support surface of the eccentric member, it becomes possible to apply the biasing force of the spring member in the direction of meshing the tooth portion of the input gear with the tooth portion of the output gear. In addition, since the fixing ring has a regulating portion that fits into the concave portion, the spring member does not fall off from the concave portion even in a normal use state, and even when the spring member breaks due to long-term use or the like, the regulating portion prevents the broken pieces or the like separated by the breakage from falling off from the concave portion. Therefore, even when the spring member for meshing the internal tooth portion and the external tooth portion of the speed reduction mechanism breaks, a valve opening / closing timing control device that does not become inoperable is configured.

[0009] As a configuration added to the above configuration, the eccentric member has an annular groove on the outer periphery of the eccentric support surface of the eccentric member, and the fixed ring may be fitted into the annular groove.

[0010] According to this, since an annular groove is formed on the outer periphery of the eccentric support surface of the eccentric member and the fixed ring can be supported in a form of being fitted into this annular groove, it is not necessary to separately provide a support means for supporting the fixed ring.

[0011] As a configuration added to the above configuration, the spring member has a bent portion formed by bending a spring plate material, a support portion that extends one side of the spring plate material of the bent portion and contacts the bottom surface of the concave portion, a biasing portion that extends the other side of the spring plate material of the bent portion and applies a biasing force to the inner peripheral side of the input gear, and a bent portion that bends the tip side of the support portion in a posture of being separated from the bottom surface of the concave portion. In a view along the direction of the eccentric axis, the bent portion and the regulating portion may overlap.

[0012] According to this, since a bent portion that is separated from the bottom surface of the concave portion toward the tip side is formed at the end of the support portion that constitutes the spring member, in a view along the direction of the eccentric axis, the bent portion overlaps with the regulating portion, and by the bent portion contacting the regulating portion, the spring member can be prevented from falling off from the concave portion. Further, in this configuration, since the tip of the end of the spring plate material on the side that contacts the concave portion is separated from the bottom surface of the concave portion, wear of the bottom surface due to the tip contacting the bottom surface can also be suppressed.

[0013] As a configuration added to the above configuration, in a view along the direction of the eccentric axis, the gap between the protruding end of the regulating portion of the fixed ring and the bottom surface of the concave portion may be a value smaller than the plate thickness of the spring plate material.

[0014] According to this, even when the spring member breaks, it is possible to eliminate the inconvenience that the broken pieces of the spring member or the like fall off from the gap between the protruding end of the restricting portion of the fixed ring and the bottom surface of the concave portion.

[0015] As a configuration added to the above configuration, the spring member includes a curved portion formed by bending a spring plate material, a support portion that extends one side of the spring plate material of the curved portion and contacts the bottom surface of the concave portion, and the other side of the spring plate material of the curved portion. An urging portion that extends and applies an urging force to the inner peripheral side of the input gear, and a bent portion that bends the tip side of the support portion so as to be separated from the bottom surface of the concave portion. The two spring members are respectively fitted into the concave portion so that their respective curved portions face the end faces at both ends in the circumferential direction of the concave portion. In a view along the direction of the eccentric axis, the curved portion of one of the spring members fitted into the concave portion is in contact with one of the end faces in the circumferential direction of the concave portion, and the restricting portion of the fixed ring is the other in the circumferential direction of the concave portion. When in the position closest to the end face, the circumferential restricting region length from the other end face in the circumferential direction of the concave portion to the edge on the far side from the other end face of the restricting portion of the fixed ring may be set larger than the circumferential spring region length from the other end face in the circumferential direction of the concave portion to the bent portion of the other spring member.

[0016] Assume a situation where two spring members are combined and fitted into a concave portion, one curved portion of the two spring members contacts one end face of the concave portion, and the restricting portion of the fixed ring is closest to the other end face of the concave portion. In this assumption, the circumferential restricting region length from the other end face in the circumferential direction of the concave portion to the edge on the far side from the other end face of the restricting portion of the fixed ring is set larger than the circumferential spring region length from the other end face in the circumferential direction of the concave portion to the bent portion of the other spring member. That is, in this assumption, in the state where the two spring members and the regulating portion are moved to the movement limits in opposite directions in the concave portion, the length of the regulating region with respect to the length of the spring region is determined so that the regulating portion is disposed at a position that sufficiently overlaps one of the spring members in the direction along the eccentric axis. This prevents the inconvenience of the spring member falling off and also enables prevention of the inconvenience of the broken pieces falling off when the spring member breaks.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described with reference to the drawings. 〔Basic Configuration〕 As shown in FIG. 1, a valve opening / closing timing control device 100 according to this embodiment includes a driving-side rotating body A that rotates synchronously with a crankshaft 1 of an engine E as an internal combustion engine, a driven-side rotating body B that rotates integrally with an intake camshaft 2 that opens and closes an intake valve 2B (an example of a valve), and a phase adjustment mechanism C that sets a relative rotational phase between the driving-side rotating body A and the driven-side rotating body B by the driving force of a phase control motor M.

[0019] In this valve opening / closing timing control device 100, the driving-side rotating body A and the driven-side rotating body B are provided so as to be relatively rotatable within a set range around a rotation axis core X.

[0020] The engine E is configured in a four-cycle type in which pistons 4 are accommodated in a plurality of cylinders 3 formed in a cylinder block, and the pistons 4 are connected to the crankshaft 1 by connecting rods 5. A timing chain 6 (a timing belt or the like may also be used) is wound around an output sprocket 1S of the crankshaft 1 of the engine E and a drive sprocket 11S of the driving-side rotating body A.

[0021] Thereby, when the engine E is operating, the entire valve opening / closing timing control device 100 rotates around the rotation axis core X. The phase adjustment mechanism C sets a relative rotational phase between the driving-side rotating body A and the driven-side rotating body B by the driving force of the phase control motor M, and realizes control of the opening / closing timing (opening / closing timing) of the intake valve 2B by the cam portion 2A of the intake camshaft 2.

[0022] That is, the operation in which the driven-side rotating body B is displaced relatively in the same direction as the rotation direction of the driving-side rotating body A is referred to as an advancing operation, and the intake compression ratio increases due to this advancing operation. Further, the operation in which the driven-side rotating body B is displaced relatively in the opposite direction to the driving-side rotating body A (an operation in the direction opposite to the advancing operation) is referred to as a retarding operation, and the intake compression ratio is reduced due to this retarding operation.

[0023] 〔Valve Opening / Closing Timing Control Device〕 As shown in Fig. 1, the driving-side rotating body A is composed of an outer case 11 with a driving sprocket 11S formed on its outer periphery, and a front plate 12, which are fastened together by a plurality of fastening bolts 13. The outer case 11 is a bottomed cylindrical type with an opening at the bottom.

[0024] As shown in Figs. 1 to 5, an intermediate member 20 as the driven-side rotating body B and a phase adjustment mechanism C (see Fig. 3 etc.) having a hypoid gear reduction mechanism are accommodated in the internal space of the outer case 11. The phase adjustment mechanism C includes an Oldham coupling Cx (see Figs. 4 and 5) that reflects the phase change to the driving-side rotating body A and the driven-side rotating body B.

[0025] The intermediate member 20 constituting the driven-side rotating body B is integrally formed with a support wall portion 21 that is connected to the intake camshaft 2 in a posture orthogonal to the rotation axis core X, and a cylindrical wall portion 22 that is cylindrical about the rotation axis core X and protrudes in a direction away from the intake camshaft 2.

[0026] This intermediate member 20 is fitted into the outer case 11 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 portion of the intake camshaft 2 by a connecting bolt 23 inserted through the central through hole of the support wall portion 21. In the state fixed in this way, the end portion on the outer side (the side far from the intake camshaft 2) of the cylindrical wall portion 22 is located inside the front plate 12.

[0027] As shown in Figs. 1 and 5, a groove portion 22a is formed over the entire circumference on the outer peripheral side of the cylindrical wall portion 22. The groove portion 22a improves the oil retention between the outer surface of the cylindrical wall portion 22 and the inner surface of the outer case 11. Thereby, the frictional force between the cylindrical wall portion 22 and the outer case 11 is reduced, enabling the intermediate member 20 to rotate smoothly with respect to the outer case 11.

[0028] As shown in FIG. 1, the phase control motor M is supported by the engine E by a support frame 7 so that its output shaft Ma is disposed coaxially with the rotation axis X. A pair of engagement pins 8 in a posture orthogonal to the rotation axis X are formed on the output shaft Ma of the phase control motor M (see also FIG. 4).

[0029] 〔Phase adjustment mechanism〕 As shown in FIGS. 1 and 5, the phase adjustment mechanism C includes an intermediate member 20, an output gear 25 formed on the inner peripheral surface of the cylindrical wall portion 22 of the intermediate member 20, an eccentric member 26, a biasing mechanism S, a first bearing 28, a second bearing 29, an input gear 30, a fixed ring 31, a ring-shaped spacer 32, and an Oldham coupling Cx. Note that rolling bearings are used for the first bearing 28 and the second bearing 29, but sliding bearings can also be used.

[0030] As shown in FIG. 1, a support surface 22S centered on the rotation axis X is formed on the inner side (at a position adjacent to the support wall portion 21) in the direction along the rotation axis X (hereinafter referred to as the axial direction) of the inner circumference of the cylindrical wall portion 22 of the intermediate member 20. An output gear 25 centered on the rotation axis X is integrally formed outside the support surface 22S (on the side far from the intake camshaft 2).

[0031] As shown in FIGS. 1, 2, and 5, the eccentric member 26 is cylindrical. The eccentric member 26 has a circumferential support surface 26S on the outer peripheral surface centered on the rotation axis X on the inner side in the axial direction (on the side close to the intake camshaft 2). As shown in FIGS. 1, 3, and 5, the eccentric member 26 has an eccentric support surface 26E on the outer peripheral surface centered on an eccentric axis Y that is eccentric in a posture parallel to the rotation axis X on the outer side (on the side far from the intake camshaft 2). Since 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.

[0032] As shown in FIGS. 5 and 6, the eccentric support surface 26E has a concave portion on the radially inner side of the eccentric member 26 and a concave portion 70 that opens in the end direction in the axial direction (outer end direction: the direction toward the front plate 12). This concave portion 70 has a bottom surface 70a and end surfaces 70b at both ends in the circumferential direction.

[0033] As shown in FIGS. 6 and 9, the bottom surface 70a is formed in a shape in which the central portion in the circumferential direction bulges outward in the radial direction as compared with the arc surface centered on the eccentric axis Y. Further, as shown in FIGS. 6 and 8 to 10, the pair of end surfaces 70b are flat when viewed in the direction along the eccentric axis Y and are formed symmetrically in the circumferential direction.

[0034] As will be described later, two spring members 71 constituting the biasing mechanism S are fitted into the concave portion 70. The relationship among the concave portion 70, the bottom surface 70a, and the pair of end surfaces 70b will be described later together with the fixed ring 31 to be described later.

[0035] As shown in FIGS. 1 and 5, on the inner circumference of the eccentric member 26, a pair of engagement grooves 26T into which each of the pair of engagement pins 8 of the phase control motor M (see FIG. 1) can engage are formed in a posture parallel to the rotation axis X. Further, on the inner side (the side of the support wall portion 21) of the eccentric member 26, a plurality of first lubricating oil grooves 26a (see FIG. 1) are formed in a posture along the radial direction, and on the outer side (the side far from the intake camshaft 2), a plurality of second lubricating oil grooves 26b are formed in a posture along the radial direction. Note that only one of the first lubricating oil grooves 26a and the second lubricating oil grooves 26b may be formed in the eccentric member 26. The number of these first lubricating oil grooves 26a and second lubricating oil grooves 26b may be arbitrarily set.

[0036] As shown in FIG. 5, on the inner peripheral side of the open end on the outer side (the side far from the intake camshaft 2) of the eccentric member 26, tapered portions 26c (inclined portions) whose diameters become smaller toward the inner side (the side close to the intake camshaft 2) are formed on both side portions of the engagement groove 26T. When engaging the pair of engagement pins 8 of the phase control motor M with the engagement groove 26T of the eccentric member 26, the engagement pins 8 are guided by the tapered portions 26c into the engagement groove 26T, so that the engagement operation between the phase control motor M and the eccentric member 26 becomes easy.

[0037] As shown in FIGS. 1 and 2, the first bearing 28 is externally fitted to the circumferential support surface 26S, and the first bearing 28 is fitted into the support surface 22S of the cylindrical wall portion 22. Thus, the eccentric member 26 is rotatably supported with respect to the intermediate member 20 about the rotation axis X. Further, as shown in FIGS. 1 and 3, the input gear 30 is rotatably supported about the eccentric axis Y with respect to the eccentric support surface 26E of the eccentric member 26 via the second bearing 29.

[0038] In this phase adjustment mechanism C, the number of teeth of the external tooth portion 30A of the input gear 30 is set to be one less than the number of teeth of the internal tooth portion 25A of the output gear 25. And a part of the external tooth portion 30A of the input gear 30 meshes with a part of the internal tooth portion 25A of the output gear 25.

[0039] The biasing mechanism S applies a biasing force to the input gear 30 via the second bearing 29 so that a part of the external tooth portion 30A of the input gear 30 meshes with a part of the internal tooth portion 25A of the output gear 25. Note that by externally fitting the inner race 29a of the second bearing 29 to the eccentric support surface 26E of the eccentric member 26 and fitting the outer race 29b of the second bearing 29 into the inner periphery of the input gear 30, the biasing force of the biasing mechanism S acts on the input gear 30 in the radial direction.

[0040] Thereby, a part of the external tooth portion 30A of the input gear 30 is stably meshed with the internal tooth portion 25A of the output gear 25, preventing the expansion of their backlash and preventing abnormal noise.

[0041] The biasing mechanism S is configured by combining two spring members 71 having the same shape and the same size as shown in FIG. 7.

[0042] As shown in FIGS. 7 and 8, the spring member 71 integrally forms a bent portion 72 formed by bending a spring plate material, a support portion 73 that extends one side of the spring plate material of the bent portion 72 and contacts the bottom surface 70a of the concave portion 70, and a biasing portion 74 that extends the other side of the spring plate material of the bent portion 72 and applies a biasing force to the inner peripheral side of the input gear 30. The spring member 71 also includes a bent portion 75 that bends the tip side of the support portion 73 in a posture of being separated from the bottom surface 70a of the concave portion 70.

[0043] That is, the bent portion 72 is bent by bending the spring plate material so as to have a U-shaped cross-section when viewed in the direction along the eccentric axis Y while being fitted into the concave portion 70, and is formed into a shape in which the support portion 73 and the biasing portion 74 are arranged in a substantially parallel posture.

[0044] Also, in a plan view (a radial view orthogonal to the support portion 73 and the biasing portion 74), the width (axial dimension) of the support portion 73 is set to half (1 / 2) of the width (axial dimension) of the bent portion 72, and is arranged at a position biased in one direction in the width direction. The width (axial dimension) of the support portion 73 is set to half (1 / 2) of the width of the bent portion 72, and is arranged at a position biased in the other direction in the width direction.

[0045] As a result, as shown in FIG. 7, a support-side notch portion 73a in a posture along the width direction is formed at the boundary portion between the bent portion 72 and the support portion 73, and a biasing-side notch portion 74a in a posture along the width direction is formed at the boundary portion between the bent portion 72 and the biasing portion 74.

[0046] The two spring members 71 are configured as a biasing mechanism S arranged in opposite postures such that the respective bent portions 72 are arranged at the circumferential ends of the concave portion 70 in the direction of view shown in FIGS. 6 and 8, and are fitted into one concave portion 70. By being fitted in this way, the two spring members 71 have their respective bent portions 72 separated, and the two biasing portions 74 are arranged in parallel along the axial direction. As a result, a compact biasing mechanism S is configured.

[0047] As shown in FIGS. 7 and 8, in the region of the spring member 71 extending from the curved portion 72 to the support portion 73, the region is curved along the bottom surface 70a of the concave portion 70. A proximal-side contact position Q is formed at a position of the curved portion 72 facing the bottom surface 70a, and a distal-side contact position R is formed at the boundary between the support portion 73 and the bent portion 75. Further, the biasing portion 74 has a biasing top portion 74b protruding outward in the radial direction of the eccentric member 26 so as to intensively apply a biasing force in a direction in which the outer tooth portion 30A of the input gear 30 meshes most deeply with the inner tooth portion 25A of the output gear 25 on the inner surface of the inner race 29a of the second bearing 29.

[0048] The curved portion 72 is a main portion that generates the biasing force of the spring member 71 by elastic deformation. By combining two spring members 71 and fitting them into the concave portion 70, as shown in FIGS. 6 and 7, in a view along the direction of the eccentric axis core Y, the biasing top portions 74b of the respective biasing portions 74 of the two spring members 71 are arranged at overlapping positions. In this way, while having a structure in which two spring members 71 are fitted into one concave portion 70, it is possible to maintain the balance of the biasing force applied to the input gear 30.

[0049] Thereby, with the proximal-side contact position Q at the boundary between the support portion 73 and the curved portion 72 of the two spring members 71 as a fulcrum and in a state of being in contact with the bottom surface 70a of the concave portion 70, it becomes possible to apply a biasing force from the biasing top portions 74b of the two biasing portions 74 to the inner race 29a of the second bearing 29. Further, when applying the biasing force in this way, the distal-side contact position R, which is the boundary between the bent portion 75 and the support portion 73, is maintained in a state of being in contact with the bottom surface 70a of the concave portion 70.

[0050] Here, for example, assuming a step of externally fitting the second bearing 29 to the eccentric support surface 26E of the eccentric member 26 and inserting two spring members 71 between the inner periphery of the inner race 29a of this second bearing 29 and the concave portion 70, it is possible to insert the spring member 71 by bringing a jig or the like for insertion into contact with the bent portion 75 and the curved portion 72.

[0051] That is, for example, in the process of inserting the spring member 71 by applying pressure only to one location of the bent portion 72 (for example, near the proximal contact position Q), since pressure acts only on the end portion of the spring member 71, the posture of the spring member 71 deviates from the proper posture, and a part of the spring member 71 strongly contacts the end surface 70b of the concave portion 70, which may lead to a situation where insertion is difficult. On the other hand, by using a jig or the like and applying pressure to two locations (for example, near the proximal contact position Q and near the distal contact position R) spaced apart in the circumferential direction of the concave portion 70 with respect to the spring member 71, the pressure acting on the spring member 71 is not uneven, and it becomes possible to insert the spring member 71 along the axial direction while maintaining an appropriate posture with respect to the concave portion 70.

[0052] Further, the spring member 71 may move along the circumferential direction of the eccentric member 26 in a state of being fitted into the concave portion 70. The bent portion 75 has a posture in which the distal end side is separated from the bottom surface 70a of the concave portion 70, and since the corner portion (edge) of the distal end of the bent portion 75 is separated from the bottom surface 70a, even if the spring member 71 moves inside the concave portion 70, it is possible to suppress the inconvenience that the bottom surface 70a of the concave portion 70 wears.

[0053] 〔Fixed Ring - Spring Member〕 As shown in FIGS. 1 and 5, the fixed ring 31 is disposed at a position overlapping the concave portion 70 in a radial view by being fitted into an annular groove 26d formed annularly on the outer periphery of the eccentric support surface 26E of the eccentric member 26. The valve opening / closing timing control device 100 is provided with a spacer 32 at a position in contact with the fixed ring 31, thereby preventing the second bearing 29 from coming off.

[0054] As shown in FIGS. 4 and 5, the fixed ring 31 is a C-shaped annular member that fits into the annular groove 26d of the eccentric member 26 and is supported by the eccentric member 26. Further, the fixed ring 31 has a regulating portion 31R that is fitted into the concave portion 70 on the inner diameter side thereof, and a joint 31g having a gap is disposed on the side opposite to the regulating portion 31R in a view along the axial direction. The tip of this regulating portion 31R is arc-shaped and is gently connected to the fixed ring 31 (via an arc) on both sides in the circumferential direction.

[0055] For example, the fixed ring 31 without the restricting portion 31R has a small width in the radial direction over the entire circumference of the fixed ring 31, making it difficult to visually confirm whether it is worn. On the other hand, the fixed ring 31 with the restricting portion 31R has a large width in the radial direction of the restricting portion 31R (the protruding amount in the radial direction), facilitating visual confirmation of wearing.

[0056] Also, in the valve opening / closing timing control device 100, since the restricting portion 31R is fitted into the concave portion 70, the fixed ring 31 does not rotate along the annular groove 26d, preventing the situation where the gap of the mating opening 31g disturbs the posture of the spring member 71 when the mating opening 31g reaches the concave portion 70. Furthermore, by using the fixed ring 31 provided with the restricting portion 31R, the inconvenience of the spring member 71 falling off from the concave portion 70 even in the normal use state is eliminated.

[0057] As shown in FIG. 8, when the thickness of the spring member 71 is the plate thickness T and the height due to bending with reference to the tip-side contact position R of the bent portion 75 of the spring member 71 is the bending amount H, the relationship is set such that the bending amount H is larger than the plate thickness T (H>T). Note that the bending amount H is, as shown in FIG. 8, in the direction along the virtual line connecting the eccentric axis core Y and the tip-side contact position R in a straight line along the radial direction when viewed in the direction along the eccentric axis core Y, and is the distance between the tip-side contact position R and the highest position among the bent portions 75.

[0058] Thus, by making the bending amount H larger than the plate thickness T, for example, when the spring member 71 moves in the direction (axial direction) in which it contacts the fixed ring 31, the bent portion 75 also contacts the region along the protruding direction of the restricting portion 31R.

[0059] The restricting portion 31R can contact the side surfaces of the curved portion 72, the supporting portion 73, and the biasing portion 74 of the spring member 71 over a wide area. Therefore, when the side surfaces of the curved portion 72, the supporting portion 73, and the biasing portion 74 of the spring member 71 contact the restricting portion 31R and the bent portion 75 contacts, it suppresses the spring member 71 from changing to an improper posture, enabling the stabilization of the acting direction of the biasing force of the biasing mechanism S.

[0060] As shown in Fig. 9, the distance between the protruding end of the regulating portion 31R of the fixed ring 31 and the bottom surface 70a of the concave portion 70 is defined as a gap G. The dimensional relationship is set such that this gap G is smaller than the plate thickness T of the spring member 71 (G < T).

[0061] In the same figure, the inner peripheral edge of the protruding end of the regulating portion 31R is arc-shaped centered on the eccentric axis Y, and the bottom surface 70a of the concave portion 70 has a shape that does not center on the eccentric axis Y by smoothly protruding a part of the arc outward. Therefore, the gap G is shown at the narrowest part between these. However, the distance between the inner peripheral edge of the regulating portion 31R and the bottom surface 70a of the concave portion 70 may be made uniform, and all of the inner peripheral edge of the regulating portion 31R may have the same gap G. Note that as the shape of the bottom surface 70a, a non-circular shape such as an ellipse can be assumed. For example, a shape formed in an arc shape centered on a position deviated from the eccentric axis Y is also conceivable.

[0062] By making the gap G smaller than the plate thickness T in this way, even when the spring member 71 breaks, it becomes impossible for the broken object or the like to pass through the gap G. For example, the broken object or the like drops in the direction toward the front plate 12, and the inconvenience of contacting the inner tooth portion 25A of the output gear 25, the outer tooth portion 30A of the input gear 30, etc. can be eliminated. As a result, the valve opening / closing timing control device 100 does not become inoperable.

[0063] As shown in Fig. 10, in the view along the direction of the eccentric axis Y, the length (arc length) along the circumferential direction of the eccentric support surface 26E of the eccentric member 26 from the end surface 70b of the concave portion 70 to the end edge on the farther side in the circumferential direction among the two end edges of the regulating portion 31R is defined as the regulation region length D. Note that the length (arc length) along the circumferential direction of the concave portion 70 is hereinafter referred to as the "circumferential direction length".

[0064] Further, as shown in Fig. 10, with two spring members 71 combined and fitted into the concave portion 70, for example, by integrally moving the two spring members 71 to one side (the right side in the figure) of the concave portion 70, the outer surface of the curved portion 72 of one spring member 71 is brought into contact with the end surface 70b, and by moving the regulating portion 31R of the fixing ring 31 fitted into the annular groove 26d to the other side (the left side in the figure), the regulating portion 31R is brought closest to the end surface 70b.

[0065] That is, in a situation where the two spring members 71 and the regulating portion 31R have moved to their respective movement limits in opposite directions in the concave portion 70, the circumferential length of the gap between the curved portion 72 of the other spring member 71 and the other end surface 70b is defined as the separation distance U. Also, in this situation, the circumferential length from the curved portion 72 to the tip of the bent portion 75 of the other spring member 71 is defined as the spring region length F. Furthermore, the dimensional relationship is set such that the circumferential regulating region length D is larger (D > U + F) than the value obtained by adding the separation distance U and the spring region length F.

[0066] This dimensional relationship always holds when the regulating region length D, which is the circumferential length from the other end surface 70b to the edge on the far side of the other end surface of the regulating portion 31R of the fixing ring 31, is set larger (D > F) than the spring region length F, which is the circumferential length from the curved portion 72 of the spring member 71 on the other side (the left side in Fig. 10) in the circumferential direction of the concave portion 70 to the tip of the bent portion 75 of the other spring member 71.

[0067] The spring region length F from the curved portion 72 to the tip of the bent portion 75 of the spring member 71 is the circumferential length along the circumferential direction of the concave portion 70 connecting the outer end position 72t of the curved portion 72 and the tip in the extending direction of the bent portion 75. The separation distance U is the circumferential length of the concave portion 70 connecting the outer end position 72t of the curved portion 72 of the spring member 71 and the position where the arc centered on the eccentric axis Y passing through this outer end position 72t intersects the end surface 70b.

[0068] By setting the relationship between the separation distance U between the curved portion 72 and the end face 70b of the concave portion 70, the spring region length F from the curved portion 72 to the tip of the bent portion 75, and the regulation region length D of the regulation portion 31R as described above, regardless of the position of the spring member 71 inside the concave portion 70, the side surfaces of the curved portion 72, the support portion 73, and the biasing portion 74 are surely brought into contact with the regulation portion 31R, not only to stabilize the posture of the spring member 71, but also to prevent the breakage product or the like from dropping from the concave portion 70 toward the front plate 12 even when the spring member 71 breaks.

[0069] [Phase adjustment mechanism: Oldham coupling] As shown in FIGS. 1, 4, and 5, the Oldham coupling Cx is composed of a plate-shaped joint member 40 integrally formed with a central annular portion 41, a pair of external engagement arms 42 protruding radially outward along the first direction (the left-right direction in FIG. 4) from the annular portion 41, and internal engagement arms 43 protruding radially outward along the direction orthogonal to the first direction (the up-down direction in FIG. 4) from the annular portion 41. Engagement recesses 43a connected to the opening of the annular portion 41 are formed in each of the pair of internal engagement arms 43.

[0070] In the outer case 11, a pair of guide groove portions 11a extending radially around the rotation axis X are formed in a through-groove shape across the internal space and the external space at the opening edge portion where the front plate 12 abuts. The groove width of the guide groove portion 11a is set slightly wider than the width of the external engagement arm 42, and a pair of discharge channels 11b are formed as notches in each of the guide groove portions 11a. Note that the discharge channels 11b may be formed so as to flow lubricating oil radially with respect to the front plate 12.

[0071] At the opening edge portion of the outer case 11, one or more pocket portions 11c having the inner peripheral side notched along the circumferential direction are formed at portions other than the guide groove portions 11a. Foreign matter that moves to the outer peripheral side by the centrifugal force generated by the rotation of the drive-side rotating body A is collected in the pocket portions 11c. FIG. 5 shows a case where four pocket portions 11c are formed.

[0072] Further, a pair of engaging protrusions 30T are integrally formed on the end surface of the input gear 30 facing the front plate 12. The engaging width of the engaging protrusion 30T is set slightly narrower than the engaging width of the engaging recess 43a of the internal engaging arm 43.

[0073] With such a configuration, by engaging the pair of external engaging arms 42 of the joint member 40 with the pair of guide groove portions 11a of the outer case 11 and engaging the pair of engaging protrusions 30T of the input gear 30 with the engaging recesses 43a of the pair of internal engaging arms 43 of the joint member 40, the Oldham joint Cx can be made to function.

[0074] Note that the joint member 40 can be displaced in a first direction (the left - right direction in FIG. 4) in which the external engaging arm 42 extends with respect to the outer case 11, and the input gear 30 can be displaced in a second direction (the up - down direction in FIG. 4) along the forming direction of the engaging recess 43a of the internal engaging arm 43 with respect to the joint member 40.

[0075] 〔Lubrication of the Phase Adjustment Mechanism〕 As shown in FIG. 1, the intake camshaft 2 forms a lubrication oil passage 15 through which lubricating oil from an external oil pump P is supplied via an oil passage forming member 9. The support wall portion 21 of the intermediate member 20 forms an opening 21a for guiding oil inside the eccentric member 26 with respect to a part of the surface that abuts against the intake camshaft 2.

[0076] As described above, a plurality of first lubricating oil grooves 26a and a plurality of second lubricating oil grooves 26b are formed in the eccentric member 26 (see FIGS. 1 and 5). Also, on the surface of the front plate 12 facing the joint member 40, a lubricating recess 12a is formed that provides a slight gap in the radial direction with the surface of the joint member 40. Note that this lubricating recess 12a is formed on the inner peripheral side of the front plate 12, but it may be formed in a region reaching the outer periphery of the front plate 12, or the lubricating recess 12a may be omitted and the lubricating oil may be supplied to the gap between the front plate 12 and the joint member 40.

[0077] As described above, a pair of discharge channels 11b are formed in the guide groove portion 11a (see FIGS. 4 and 5). Further, by making the opening diameter of the opening 12b of the front plate 12 sufficiently larger than the inner diameter of the eccentric member 26, a difference in the opening diameter is set between the opening edge of the front plate 12 and the inner periphery of the eccentric member 26.

[0078] From this configuration, the lubricating oil supplied from the oil pump P is supplied from the lubricating oil passage 15 of the intake camshaft 2 to the internal space of the eccentric member 26 through the opening 21a of the support wall portion 21 of the intermediate member 20. The lubricating oil supplied in this way is supplied from the first lubricating oil groove 26a of the eccentric member 26 to the first bearing 28 by centrifugal force, and the first bearing 28 is smoothly operated.

[0079] At the same time, the lubricating oil in the internal space of the eccentric member 26 is supplied from the second lubricating oil groove 26b to the joint member 40 by centrifugal force, and is also supplied to the second bearing 29 and supplied between the internal tooth portion 25A of the output gear 25 and the external tooth portion 30A of the input gear 30.

[0080] Also, as shown in FIG. 1, the lubricating oil from the second lubricating oil groove 26b is supplied between the front plate 12 and the joint member 40 by the lubricating recess 12a, and is also supplied to the gap between the external engagement arm 42 of the joint member 40 and the guide groove portion 11a of the outer case 11. Thereby, the joint member 40 is smoothly operated. Then, the lubricating oil supplied to the joint member 40 is discharged to the outside from the gap between the external engagement arm 42 of the joint member 40 and the guide groove portion 11a of the outer case 11.

[0081] In particular, as shown in FIG. 1, since a step is formed between the inner diameter of the opening edge of the front plate 12 and the inner diameter of the eccentric member 26 by making the inner diameter of the eccentric member 26 smaller than that of the front plate 12, when the engine E stops, the lubricating oil in the internal space of the eccentric member 26 can be discharged from the opening 12b of the front plate 12, and the amount of lubricating oil remaining inside can be reduced. When a large amount of lubricating oil remains inside the valve opening / closing timing control device 100, after starting the engine E in a cold environment, the operation of the phase adjustment mechanism C will be suppressed due to the influence of the viscosity of the lubricating oil. However, by discharging the lubricating oil when the engine E stops, such inconvenience can be eliminated.

[0082] Furthermore, since the discharge passage 11b is formed in the guide groove portion 11a, when starting the engine E in a stopped state in a cold environment, the internal lubricating oil can be quickly discharged through the discharge passage 11b by centrifugal force. Therefore, the highly viscous lubricating oil can be discharged in a short time, eliminating the influence of the viscosity of the lubricating oil and enabling the rapid operation of the phase adjustment mechanism C.

[0083] As shown in FIG. 5, on the inner side (the side closer to the intake camshaft 2) of the front plate 12, a convex portion 12c protruding inward is formed. The convex portion 12c is lightly abutted to such an extent that it can be in sliding contact with the intermediate member 20. The intermediate member 20 is restricted from moving toward the side closer to the front plate 12 by abutting against the convex portion 12c. Thereby, the Oldham joint Cx (joint member 40) can operate smoothly between the front plate 12 and the intermediate member 20 while maintaining a predetermined interval.

[0084] 〔Operating Mode 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 control device is provided with sensors capable of detecting the rotational speeds (number of rotations per unit time) of the crankshaft 1 and the intake camshaft 2 of the engine E, and the rotational phases of each, and the detection signals of these sensors are input to the control device.

[0085] When the control device drives the phase control motor M at the same speed as the rotational speed of the intake camshaft 2 during the operation of the engine E, it maintains the relative rotational phase. On the other hand, by reducing the rotational speed of the phase control motor M below the rotational speed of the intake camshaft 2, the advance operation is performed. Conversely, by increasing the rotational speed, the retard operation is performed. As described above, the intake compression ratio increases during the advance operation and decreases during the retard operation.

[0086] When the phase control motor M rotates at the same speed as the outer case 11 (the same speed as the intake camshaft 2), the meshing position of the outer tooth portion 30A of the input gear 30 with respect to the inner tooth portion 25A of the output gear 25 does not change. Therefore, the relative rotational phase of the driven-side rotating body B with respect to the driving-side rotating body A is maintained.

[0087] On the contrary, 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, in the phase adjustment mechanism C, the eccentric shaft center Y revolves around the rotation shaft center X. Due to this revolution, the meshing position of the outer tooth portion 30A of the input gear 30 with respect to the inner tooth portion 25A of the output gear 25 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. That is, a rotational force centered on the rotation shaft center X acts on the output gear 25, and a rotational force that tries to rotate the input gear 30 around the eccentric shaft center Y acts on the input gear 30.

[0088] As described above, since the engaging projection 30T of the input gear 30 engages with the engaging recess 43a of the internal engaging arm 43 of the joint member 40, the input gear 30 does not rotate relative to the outer case 11, and the rotational force acts on the output gear 25. Due to the action of this rotational force, the intermediate member 20 rotates around the rotation shaft center X with respect to the outer case 11 together with the output gear 25. As a result, the relative rotational phase between the driving-side rotating body A and the driven-side rotating body B is set, and the setting of the opening and closing timing by the intake camshaft 2 is realized.

[0089] When the eccentric axis Y of the input gear 30 revolves around the rotation axis X, as the input gear 30 is displaced, the joint member 40 of the Oldham joint Cx is displaced in the direction (the first direction) in which the outer engagement arm 42 extends with respect to the outer case 11, and the input gear 30 is displaced in the direction (the second direction) in which the inner engagement arm 43 extends.

[0090] As described above, since the number of teeth of the external tooth portion 30A of the input gear 30 is set to be one tooth less than the number of teeth of the internal tooth portion 25A of the output gear 25, when the eccentric axis Y of the input gear 30 revolves around the rotation axis X only once, the output gear 25 rotates by one tooth, thereby achieving a large reduction ratio.

[0091] 〔Operation and Effect of Embodiment〕 The valve opening / closing timing control device 100 supports the eccentric member 26 on the support surface 22S of the inner periphery of the intermediate member 20 by the first bearing 28, and supports the input gear 30 on the eccentric support surface 26E of the eccentric member 26 via the second bearing 29. Further, a biasing mechanism S configured by combining two spring members 71 is fitted into the concave portion 70 formed on the eccentric support surface 26E of the eccentric member 26, and a biasing force is applied from the two spring members 71 to the inner periphery of the inner race 29a of the second bearing 29.

[0092] Thereby, it is possible to maintain a state in which the biasing force of the biasing mechanism S keeps a part of the external tooth portion 30A of the input gear 30 engaged with a part of the internal tooth portion 25A of the output gear 25.

[0093] The eccentric member 26 supports the fixing ring 31 in the annular groove 26d of the eccentric support surface 26E, and fits the regulating portion 31R formed on this fixing ring 31 into the concave portion 70. Further, the spring member 71 is formed by bending a spring plate material so that the curved portion 72, the support portion 73, and the biasing portion 74 are integrally formed, and is formed in a posture in which the bent portion 75 at the end of the support portion 73 is bent away from the bottom surface 70a of the concave portion 70.

[0094] By doing so, the insertion of the spring member 71 can be easily performed by bringing a jig for insertion into contact with the bent portion 75 and the curved portion 72 and applying pressure. Since the tip side of the bent portion 75 is in a posture separated from the bottom surface 70a of the concave portion 70, it is possible to suppress the inconvenience that the bottom surface 70a of the concave portion 70 is worn due to the contact of the end portion of the spring member 71.

[0095] Also, since the restricting portion 31R is formed on the fixing ring 31, it is possible to easily visually confirm the presence or absence of the mounting of the fixing ring 31. Since the restricting portion 31R is fitted into the concave portion 70, the fixing ring 31 cannot rotate, and it is possible to prevent the inconvenience that the posture of the spring member 71 is disturbed by the gap of the joint 31g. Since the restricting portion 31R of the fixing ring 31 contacts the side surfaces of the curved portion 72, the supporting portion 73, and the urging portion 74 of the spring member 71 over a wide area, the posture of the spring member 71 is properly maintained. In particular, since the amount of bending H of the bent portion 75 formed on the spring member 71 is larger than the plate thickness T of the spring member 71, the spring member 71 can maintain its posture more properly when the restricting portion 31R comes into contact.

[0096] As shown in FIG. 9, the distance between the protruding end of the restricting portion 31R of the fixing ring 31 and the bottom surface 70a of the concave portion 70 is defined as the gap G. Since this gap G is smaller than the plate thickness T, even when the spring member 71 breaks, the broken pieces or the like cannot pass through the portion of this gap G.

[0097] Also, as shown in FIG. 10, in the situation where the two spring members 71 and the restricting portion 31R in the concave portion 70 have moved to the movement end limits in the opposite directions, the distance between the curved portion 72 of the other spring member 71 and the other end surface 70b in the circumferential direction of the concave portion 70 is defined as the separation distance U, and the spring region length F from the curved portion 72 to the tip of the bent portion 75 of the other spring member 71 is defined. Further, the dimensional relationship is set such that the restricting region length D in the circumferential direction of the fixing ring 31 is larger than the value obtained by adding the separation distance U and the spring region length F (D>U + F).

[0098] As a result, regardless of the position of the spring member 71 inside the concave portion 70, not only can the side surfaces of the curved portion 72, the support portion 73, and the biasing portion 74 be reliably brought into contact with the restricting portion 31R to stabilize the posture of the spring member 71, but also the restricting portion 31R can prevent the falling off of broken objects or the like, eliminating the inconvenience that the valve opening / closing timing control device 100 becomes inoperable. In particular, even when the restricting region length D is set larger than the spring region length F (D > F), the restricting portion 31R similarly prevents the spring member 71 from falling off, making it possible to suppress the falling off of judgment objects.

[0099] 〔Alternative Embodiment〕 In addition to the above-described embodiment, the present invention may be configured as follows (components having the same functions as those in the embodiment are given the same numbers and reference signs as in the embodiment).

[0100] (a) As the biasing mechanism S, it is also possible to use a single spring member 71. Also, it is conceivable to arrange and use three or more spring members 71 in parallel.

[0101] Even with the configuration of this alternative embodiment (a), the dimensional relationship in which the gap G between the bottom surface 70a of the concave portion 70 and the protruding end of the restricting portion 31R of the fixed ring 31 is smaller than the plate thickness T of the spring member 71 is effective.

[0102] (b) When the biasing mechanism S is configured using two spring members 71 with the same configuration as in the embodiment, it is also possible to configure it such that the outer surfaces of the curved portions 72 of the two spring members 71 are fitted into the concave portion 70 in a state of being in contact with the end surface 70b of the concave portion 70.

[0103] Even with the configuration of this alternative embodiment (b), the dimensional relationship in which the gap G between the bottom surface 70a of the concave portion 70 and the protruding end of the restricting portion 31R of the fixed ring 31 is smaller than the plate thickness T of the spring member 71 is effective. Also, it is effective to form a bent portion 75 in the spring member 71.

[0104] (c) By making the regulation area length D of the regulation part 31R of the fixed ring 31 substantially equal to the width of the concave part 70, the regulation part 31R closes the part of the concave part 70 that opens in the direction of the front plate 12. When the spring member 71 breaks, it becomes possible to effectively suppress the dropping of broken pieces or the like.

Industrial Applicability

[0105] The present invention can be used in a valve opening / closing timing control device.

Explanation of Reference Numerals

[0106] 1 Crankshaft 2 Intake camshaft (camshaft) 25 Output gear 26 Eccentric member 26E Eccentric support surface 26d Annular groove 30 Input gear 31 Fixed ring 31R Regulation part 40 Joint member 70 Concave part 70a End face 70b Bottom face 71 Spring member 72 Curved part 73 Support part 74 Biasing part 75 Regulation part 100 Valve opening / closing timing control device A Driving-side rotating body B Driven-side rotating body C Phase adjustment mechanism E Internal combustion engine (engine) G Gap M Phase control motor (electric actuator) T Plate thickness U Separation distance X Rotation axis center Y Eccentric axis center

Claims

1. A driving-side rotating body that rotates synchronously with the crankshaft of an internal combustion engine about a rotation axis; A driven-side rotating body that is coaxially arranged with the rotation axis inside the driving-side rotating body and rotates integrally with a camshaft for opening and closing valves of the internal combustion engine; A phase adjustment mechanism for adjusting the relative rotation phase between the driving-side rotating body and the driven-side rotating body, comprising: The phase adjustment mechanism includes an internally toothed output gear that rotates integrally with the driven-side rotating body coaxially with the rotation axis, an externally toothed input gear that is arranged inside the output gear with fewer teeth than the output gear and rotates about an eccentric axis parallel to the rotation axis, a joint member that links the input gear to the rotation of the driving-side rotating body, an eccentric member that meshes the external teeth of the input gear with the internal teeth of the output gear, and an electric actuator that drives and rotates the eccentric member about the rotation axis; The eccentric member has a concave portion that is recessed in the radial direction with respect to an eccentric support surface centered on the eccentric axis and is open in the direction of the end of the eccentric member along the eccentric axis; A spring member that applies a biasing force for meshing the external teeth of the input gear with the internal teeth of the output gear is fitted into the concave portion; A fixing ring is provided on the outer periphery of the eccentric support surface so as to overlap the concave portion in a radial view; A valve opening / closing timing control device in which the fixing ring has a restricting portion that fits into the concave portion to prevent the spring member from falling off.

2. The eccentric member has an annular groove on the outer periphery of the eccentric support surface of the eccentric member; The valve opening / closing timing control device according to claim 1, wherein the fixing ring is fitted into the annular groove.

3. The spring member has a curved portion formed by bending a spring plate material, a support portion that extends one side of the spring plate material of the curved portion and contacts the bottom surface of the concave portion, a biasing portion that extends the other side of the spring plate material of the curved portion and applies a biasing force to the inner peripheral side of the input gear, and a bent portion that bends the tip side of the support portion away from the bottom surface of the concave portion; The valve opening / closing timing control device according to claim 1 or 2, wherein the bent portion and the restricting portion overlap in a view along the direction of the eccentric axis.

4. The valve opening / closing timing control device according to claim 3, wherein the gap between the protruding end of the restricting portion of the fixing ring and the bottom surface of the concave portion is smaller than the thickness of the spring plate material in a view along the direction of the eccentric axis.

5. The spring member has a curved portion formed by bending a spring plate material, a support portion that extends one side of the spring plate material of the curved portion and contacts the bottom surface of the concave portion, a biasing portion that extends the other side of the spring plate material of the curved portion and applies a biasing force to the inner circumferential side of the input gear, and a bent portion that bends the tip side of the support portion in a posture of being separated from the bottom surface of the concave portion. The two spring members are fitted into the concave portion such that the respective curved portions face the end surfaces at both ends in the circumferential direction of the concave portion. When, in a view along the direction of the eccentric axis core, the curved portion of one of the spring members fitted into the concave portion is at a position in contact with one of the end surfaces in the circumferential direction of the concave portion, and the restricting portion of the fixed ring is at a position closest to the other end surface in the circumferential direction of the concave portion. The valve opening / closing timing control device according to any one of claims 1 to 4, wherein the length of the restriction region along the circumferential direction from the other end surface of the concave portion to the edge on the side farther from the other end surface of the restricting portion of the fixed ring is set to be larger than the length of the spring region along the circumferential direction from the other end surface of the concave portion to the bent portion of the other spring member.

Images