Component

Abstract

[Problem] To provide a component capable of suppressing separation of a snap ring. [Solution] This component comprises: a first member in which an accommodation groove, which extends in a circumferential direction, is formed in a peripheral wall surface; and a snap ring which is formed in a ring shape having a cut section in which a portion of the periphery thereof is cut, and in which an inner edge thereof is accommodated in the accommodation groove. The component is provided with a second member which is disposed on an outer peripheral section of the first member and which has a first wall section facing a side surface located in the thickness direction of the snap ring and a second wall section facing an outer peripheral surface of the snap ring. The second wall section is inclined so as to approach the first member in a direction moving away from the first wall section.

Description

parts

[0001] The present invention relates to a component.

[0002] Patent Document 1 discloses a spline joint as a component. The spline joint uses a circlip as a snap ring having a gap formed by cutting a portion of the circumference. The circlip is assembled with its inner edge housed in a housing groove.

[0003] Snap rings are also used in the components disclosed in Patent Documents 2 to 4.

[0004] Japanese Patent Laid-Open No. 08-145065 Japanese Patent Laid-Open No. 2000-074084 Japanese Patent Laid-Open No. 2004-340371 Japanese Patent Laid-Open No. 2016-125503

[0005] In such components, the snap ring may expand due to centrifugal force when rotating together with the rotating member, and the snap ring may fly out of the receiving groove when expanded by centrifugal force.

[0006] To prevent the snap ring from popping out, it is conceivable to provide a wall portion facing the outer peripheral surface of the snap ring. However, if the snap ring tilts in the axial direction, the outer peripheral surface may come off the wall portion and become detached.

[0007] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a component that can prevent a snap ring from coming off.

[0008] According to one aspect of the present invention, there is provided a part comprising: a first member having a circumferentially extending accommodating groove formed on its peripheral wall surface; a snap ring formed in a ring shape with a cut portion cut away from its periphery, the snap ring having its inner edge accommodated in the accommodating groove; and a second member disposed on the outer periphery of the first member and having a first wall portion facing a side surface located in the thickness direction of the snap ring, and a second wall portion facing the outer periphery of the snap ring, the second wall portion inclined so as to approach the first member as it moves away from the first wall portion.

[0009] According to one aspect of the present invention, the second wall portion of the second member facing the outer peripheral surface of the snap ring is inclined so as to approach the first member to which the snap ring is attached as it moves away from the first wall portion located in the thickness direction of the snap ring.

[0010] Therefore, when the snap ring tilts and its outer surface abuts against the second wall portion of the second member, the snap ring is pushed back toward the first wall portion by the tilted second wall portion, preventing it from protruding to the side opposite the first wall portion.

[0011] This makes it possible for the component to prevent the snap ring from coming off the accommodating groove of the first member.

[0012] FIG. 1 is a side view showing a main portion of a component according to this embodiment. FIG. 2 is an enlarged view of portion II of FIG. 1. FIG. 3 is a cross-sectional view showing a component according to a first modified example corresponding to portion II of FIG. 1. FIG. 4 is a cross-sectional view showing a component according to a second modified example corresponding to portion II of FIG. 1. FIG. 5 is a cross-sectional view showing a component according to a third modified example corresponding to portion II of FIG. 1. FIG. 6 is a cross-sectional view showing a component according to a fourth modified example corresponding to portion II of FIG. 1. FIG. 7 is a cross-sectional view showing a component according to a fifth modified example corresponding to portion II of FIG. 1. FIG. 8 is a cross-sectional view showing a component according to a comparative example. FIG. 9 is an explanatory view showing a state in which a snap ring in a component according to a comparative example is tilted.

[0013] <Embodiment> A component 10 according to an embodiment of the present invention will be described below with reference to the accompanying drawings. Fig. 1 is a side view showing a main part of the component 10 according to this embodiment. Fig. 2 is an enlarged view of part II in Fig. 1.

[0014] 1, the component 10 constitutes a planetary gear mechanism of a transmission in, for example, an electric drive unit of an electric vehicle. Note that, in this embodiment, an example is described in which the component 10 constitutes a planetary gear mechanism, but the component 10 is not limited to a planetary gear mechanism. The component 10 may also be another structure in which a snap ring 26 (described later) is attached to a rotating portion.

[0015] (Overall Description) The component 10 has a ring gear 20 as a first member, planetary gears (not shown) arranged on the inner periphery of the ring gear 20, and a sun gear (not shown) arranged on the inner periphery of the planetary gear. Fig. 1 shows a part of the ring gear 20, and the central axis of rotation of the ring gear 20 extends in the left-right direction on the page at the bottom of Fig. 1.

[0016] A guide member 22 serving as a second member is disposed on the outer periphery of the ring gear 20. The guide member 22 is spline-fitted to a peripheral wall surface 20A of the ring gear 20. Movement of the guide member 22 to one side 28 is restricted by a snap ring 26 provided on the ring gear 20. The guide member 22 is rotatable together with the ring gear 20 in a state in which movement of the ring gear 20 in the circumferential direction of the ring gear 20 is restricted by the spline-fitting.

[0017] A support guide member 34 is disposed on the other side 30 of the guide member 22. Movement of the support guide member 34 toward the other side 30, i.e., in a direction away from the guide member 22, is restricted by a support snap ring 36 provided on the ring gear 20.

[0018] A coil spring 40 is disposed in a compressed state between the support guide member 34 and the guide member 22. The coil spring 40 biases the guide member 22 toward one side 28, which is the snap ring 26 side.

[0019] A brake 44 fixed to, for example, a casing (not shown) is disposed on the outer periphery of the guide member 22. The brake 44 has an engaging claw (not shown) that can engage with the guide member 22. A transmission member 46 that transmits an operating force from an actuator (not shown) to the engaging claw is connected to the brake 44.

[0020] The brake 44 activates the engagement claw by the operating force transmitted from the transmission member 46, thereby creating a locked state that stops the rotation of the guide member 22 and the ring gear 20 that rotates together with the guide member 22. The brake 44 also activates the engagement claw by the operating force transmitted from the transmission member 46, thereby creating an unlocked state that allows the rotation of the guide member 22 and the ring gear 20.

[0021] The component 10 according to this embodiment will be described in detail.

[0022] 2, the component 10 includes a first member having a circumferentially extending accommodation groove 50 formed in a peripheral wall surface 20A. The first member is the ring gear 20 described above. The accommodation groove 50 formed in the peripheral wall surface 20A of the ring gear 20 has a rectangular cross section.

[0023] 1, a support accommodating groove 54 is formed in the peripheral wall surface 20A of the ring gear 20, extending circumferentially toward the other side 30 beyond the accommodating groove 50. The support accommodating groove 54 has a rectangular cross section.

[0024] A spline groove 58 extending in the axial direction 56 is formed on the peripheral wall surface 20A of the ring gear 20.

[0025] (Snap Ring) As shown in FIG. 2 , the component 10 is provided with the snap ring 26 described above, which is formed in a ring shape with a cutout portion (not shown) cut off from a portion of the circumference, and whose inner edge is received in the receiving groove 50.

[0026] The snap ring 26 can expand its inner diameter by elastically deforming the cut portion so as to widen it. The snap ring 26 can be assembled to the ring gear 20 with its inner diameter expanded. The snap ring 26 is positioned on the ring gear 20 with its inner edge accommodated in the accommodation groove 50.

[0027] The outer diameter of the snap ring 26 increases from one side surface 26A of the one side 28 to the other side surface 26B of the other side 30. As a result, the outer peripheral surface 26C of the snap ring 26 is inclined so as to approach the ring gear 20 as it moves in a direction away from a first wall portion 64 (described later).

[0028] 2, the component 10 includes a second member disposed on the outer periphery of the ring gear 20 serving as the first member. The second member is configured as the guide member 22 described above.

[0029] A guide step 60 is formed along the inner edge of the guide member 22 on the side surface of one side 28 of the guide member 22. A snap ring 26 is disposed on the guide step 60 of the guide member 22. Movement of the guide member 22 to the one side 28 is restricted by the snap ring 26.

[0030] The innermost surface of the guide step portion 60 forms a first wall portion 64 that faces the other side surface 26B, which is the side surface located in the thickness direction of the snap ring 26. The inner peripheral wall of the guide step portion 60 forms a second wall portion 66 that faces the outer peripheral surface 26C of the snap ring 26.

[0031] As a result, the guide member 22 as the second member has a first wall portion 64 facing the other side surface 26B as the side surface located in the thickness direction of the snap ring 26, and a second wall portion 66 facing the outer peripheral surface 26C of the snap ring 26.

[0032] The guide member 22 is formed in the shape of a circular ring plate. The guide member 22 has an inner edge formed with a ridge 68 that is inserted into the spline groove 58 of the ring gear 20.

[0033] The second wall portion 66 is configured with an inclined surface that is inclined so as to approach the inner edge of the guide member 22 as it moves toward the one side 28, which is the direction away from the first wall portion 64. As a result, when the guide member 22 is assembled to the ring gear 20, the second wall portion 66 is inclined so as to approach the ring gear 20 as it moves in the direction away from the first wall portion 64.

[0034] The end portion 22A located on one side 28 of the second wall portion 66 opposite the first wall portion 64 is positioned so as to overlap with the edge 50A of one side 28 of the accommodating groove 50 in the axial direction 56 when viewed radially.

[0035] However, the end 22A of the second wall portion 66 located on the opposite side from the first wall portion 64 may be positioned so as to overlap with the accommodating groove 50 in the axial direction 56 when viewed from the radial direction, as shown by the dotted line in Figure 2.

[0036] 2 , the end 22A of the second wall portion 66 located on the opposite side from the first wall portion 64 may be disposed at a position away from the accommodation groove 50 in the axial direction 56 toward one side 28 when viewed from the radial direction. In this case, the distance 70 from the corresponding position 20T of the ring gear 20 corresponding to the end 22A in the axial direction 56 to the edge 50A of the accommodation groove 50 is set to be smaller than the thickness dimension T of the snap ring 26.

[0037] 1, the component 10 includes the aforementioned support snap ring 36. The support snap ring 36 is formed in a ring shape with a cut portion (not shown) where part of the circumference has been cut off.

[0038] The inner diameter of the support snap ring 36 can be expanded by elastically deforming the cut portion so as to widen it. The support snap ring 36 can be assembled to the ring gear 20 with its inner diameter expanded. The support snap ring 36 is positioned on the ring gear 20 with its inner edge accommodated in the support accommodation groove 54.

[0039] The outer peripheral surface 36A of the supporting snap ring 36 extends substantially perpendicular to the side surface 36B.

[0040] (Support Guide Member) The component 10 includes the above-described support guide member 34. The support guide member 34 is formed in the shape of a circular ring plate.

[0041] A support step 80 is formed along the inner edge of the support guide member 34 on the side surface of the other side 30 of the support guide member 34. A support snap ring 36 is disposed on the support step 80 of the support guide member 34. Movement of the support guide member 34 toward the other side 30 is restricted by the support snap ring 36.

[0042] The inner surface of the support step portion 80 constitutes a first support wall portion 84 that faces a side surface located in the thickness direction of the support snap ring 36. The inner peripheral wall of the support step portion 80 constitutes a second support wall portion 86 that faces the outer peripheral support surface 36A of the support snap ring 36.

[0043] The second supporting wall portion 86 extends perpendicular to the first supporting wall portion 84. However, similar to the second wall portion 66 of the guide member 22 described above, the second supporting wall portion 86 may be configured as an inclined surface that is inclined so as to approach the inner edge of the supporting guide member 34 as it extends toward the other side 30, which is the direction away from the first supporting wall portion 84.

[0044] In this embodiment, the second wall portion 66 of the guide member 22 is configured as an inclined surface that approaches the inner edge of the guide member 22 as it moves away from the first wall portion 64, but the second wall portion 66 is not limited to this shape. The second wall portion 66 of the guide member 22 may be configured, for example, as in the following modified example.

[0045] Next, each of the modifications will be described with reference to the drawings.

[0046] (First Modification) FIG. 3 is a cross-sectional view showing a component 10 of a first modification, which corresponds to part II in FIG.

[0047] In the component 10 according to the first modification, the second wall portion 66 of the guide member 22 serving as the second member is formed in an arc-shaped cross section that is inclined so as to approach the inner edge of the guide member 22 as it moves in a direction away from the first wall portion 64. The second wall portion 66 of the first modification has a slope that becomes steeper toward the inner edge as it moves in a direction away from the first wall portion 64.

[0048] (Second Modification) FIG. 4 is a cross-sectional view showing a component 10 of a second modification, which corresponds to the part II in FIG.

[0049] In the component 10 according to the second modification, the second wall portion 66 of the guide member 22 serving as the second member is formed in an arc-shaped cross section that is inclined so as to approach the inner edge of the guide member 22 as it extends in a direction away from the first wall portion 64. The second wall portion 66 of the second modification has a gentler slope toward the inner edge as it extends in a direction away from the first wall portion 64.

[0050] (Third Modification) FIG. 5 is a cross-sectional view showing a component 10 of a third modification, which corresponds to part II in FIG.

[0051] In the part 10 relating to the third modified example, the second wall portion 66 of the guide member 22 as the second member has a first inclined surface 66A and a second inclined surface 66B that are inclined so as to approach the inner edge of the guide member 22 as they move away from the first wall portion 64.

[0052] When the rotation center axis is used as a reference, the first inclination angle α of the first inclined surface 66A located on the first wall portion 64 side is smaller than the second inclination angle β of the second inclined surface 66B located at a position away from the first wall portion 64.

[0053] (Fourth Modification) FIG. 6 is a cross-sectional view showing a component 10 of a fourth modification, which corresponds to part II in FIG.

[0054] In the part 10 relating to the fourth modified example, the second wall portion 66 of the guide member 22 as the second member has a first inclined surface 66A and a second inclined surface 66B that are inclined so as to approach the inner edge of the guide member 22 as they move away from the first wall portion 64.

[0055] When the rotation center axis is used as a reference, the first inclination angle α of the first inclined surface 66A located on the first wall portion 64 side is larger than the second inclination angle β of the second inclined surface 66B located at a position away from the first wall portion 64.

[0056] In the above-described embodiment and each modified example, the outer peripheral surface 26C of the snap ring 26 is inclined toward the ring gear 20 as it moves toward the one side 28, which is the direction away from the first wall portion 64 of the guide member 22. However, the snap ring 26 is not limited to this configuration. For example, the snap ring 26 may be configured as in the following fifth modified example.

[0057] (Fifth Modification) FIG. 7 is a cross-sectional view showing a component 10 of a fifth modification, which corresponds to part II in FIG.

[0058] The component 10 according to the fifth modification has a different configuration of the snap ring 26 compared to the above-described embodiment, and only the differences from the embodiment will be described.

[0059] That is, the snap ring 26 of the component 10 according to the fifth modification has the outer peripheral surface 26C extending substantially perpendicular to the one side surface 26A and the other side surface 26B. As a result, when the snap ring 26 expands, the corner 26D on one side 28 of the outer peripheral surface 26C abuts against the inclined second wall portion 66 of the guide member 22.

[0060] Furthermore, in the guide member 22 of this modified example, the end portion 22A of the second wall portion 66 located on one side 28 opposite the first wall portion 64 is positioned so as to overlap with the edge 50A of one side 28 of the accommodating groove 50 in the axial direction 56 when viewed radially.

[0061] 7 , the end 22A of the second wall portion 66 located opposite the first wall portion 64 may be located at a position away from the accommodation groove 50 toward one side 28 in the axial direction 56. In this case, the distance 70 from the corresponding position 20T of the ring gear 20 corresponding to the end 22A in the axial direction 56 to the edge 50A of the accommodation groove 50 is set to be smaller than the thickness dimension T of the snap ring 26.

[0062] (Functions and Effects) The main functions and effects of the component 10 configured as above will be summarized below.

[0063] (1) The component 10 includes a ring gear 20 as a first member having a circumferentially extending accommodation groove 50 formed in a peripheral wall surface 20A, and a snap ring 26 formed in a ring shape with a cut portion cut away from the periphery, with the inner edge accommodated in the accommodation groove 50. The component 10 includes a guide member 22 as a second member, which is disposed on the outer periphery of the ring gear 20 and has a first wall portion 64 facing a side surface (26B) positioned in the thickness direction of the snap ring 26, and a second wall portion 66 facing an outer circumferential surface 26C of the snap ring 26. The second wall portion 66 is inclined so as to approach the ring gear 20 as it moves away from the first wall portion 64.

[0064] According to this embodiment, the second wall portion 66 of the guide member 22 facing the outer peripheral surface 26C of the snap ring 26 is inclined so as to approach the ring gear 20 to which the snap ring 26 is attached as it moves away from the first wall portion 64 located in the thickness direction of the snap ring 26.

[0065] Therefore, when the snap ring 26 tilts and the outer surface 26C abuts against the second wall portion 66 of the guide member 22, the snap ring 26 is pushed back toward the first wall portion 64 by the tilted second wall portion 66, preventing it from protruding to the side opposite the first wall portion 64.

[0066] This makes it possible for the component 10 to prevent the snap ring 26 from coming off the accommodating groove 50 of the guide member 22 .

[0067] Furthermore, the component 10 of this embodiment constitutes a planetary gear mechanism in an automatic transmission of an electric vehicle, and the ring gear 20 of the planetary gear mechanism, which is rotated by a motor, rotates at high speed. Therefore, the snap ring 26 attached to the ring gear 20 is subject to a large centrifugal force and is likely to expand.

[0068] The snap ring 26 expands due to this centrifugal force, and the outer peripheral surface 26C abuts against the second wall portion 66 of the guide member 22. As a result, the snap ring 26 is pushed back toward the first wall portion 64 by the inclined second wall portion 66, preventing it from protruding to the side opposite the first wall portion 64. In this way, the part 10 can prevent the snap ring 26 from coming off the accommodating groove 50, even when it forms a planetary gear mechanism in which the ring gear 20 rotates at high speed.

[0069] Furthermore, compared to cases where the snap ring 26 is prevented from coming off by increasing the plate thickness to prevent it from expanding due to centrifugal force or by increasing the rigidity of the snap ring 26, the part 10 of this embodiment makes it possible to increase the ease of assembly of the snap ring 26.

[0070] Furthermore, compared to when the length of the second wall portion 66 is increased to prevent the snap ring 26 from coming off, the component 10 of this embodiment can have a shorter length in the axial direction 56 .

[0071] Comparative Example Here, a comparative example component 100 will be described with reference to the drawings, in which the second wall portion 66 of the guide member 22 that faces the outer peripheral surface 26C of the snap ring 26 does not have an inclination. Note that parts that are the same as or equivalent to those in the above-described embodiment will be described with the same reference numerals.

[0072] Fig. 8 is a cross-sectional view showing a component 100 according to a comparative example. Fig. 9 is an explanatory diagram showing a state in which the snap ring 102 in the component 100 according to the comparative example is tilted.

[0073] 8 and 9 , the component 100 according to the comparative example differs from the component 10 according to the embodiment in that the second wall portion 66 of the guide member 22 that faces the outer peripheral surface 102C of the snap ring 102 extends so as to be approximately perpendicular to the first wall portion 64. The component 100 according to the comparative example also differs from the component 10 according to the embodiment in that the outer peripheral surface 102C of the snap ring 102 extends so as to be approximately perpendicular to the one side surface 102A or the other side surface 102B.

[0074] In the component 100 of the comparative example, separation due to expansion of the snap ring 102 can be suppressed by the second wall portion 66 of the guide member 22. However, in the component 100 of the comparative example, if the snap ring 102 tilts (see FIG. 9 ), the outer peripheral surface 102C may come off the second wall portion 66, which may cause the snap ring 102 to separate.

[0075] In contrast, in the part 10 according to the embodiment described above, the second wall portion 66 of the guide member 22 is inclined so as to approach the ring gear 20 as it moves away from the first wall portion 64, and therefore, as described above, it is possible to prevent the snap ring 102 from coming off the accommodating groove 50.

[0076] (2) The outer peripheral surface 26C of the snap ring 26 is inclined so as to approach the ring gear 20 as the first member as it moves away from the first wall portion 64 .

[0077] In this embodiment, the outer peripheral surface 26C of the snap ring 26 that faces the second wall portion 66 of the guide member 22 is inclined so as to approach the ring gear 20 as it moves away from the first wall portion 64 (see FIG. 2). This enhances the effect of preventing the snap ring 26 from protruding away from the first wall portion 64 when the snap ring 26 is inclined in the axial direction 56. Furthermore, the effect of preventing the snap ring 26 from protruding away from the first wall portion 64 when the snap ring 26 expands is also enhanced.

[0078] This makes it possible for the component 10 to further prevent the snap ring 26 from coming off the accommodating groove 50 of the guide member 22 .

[0079] (3) The end 22A of the second wall portion 66, which is located opposite the first wall portion 64, is positioned so as to overlap the accommodation groove 50 in the axial direction 56 (see the dashed line in FIG. 2).

[0080] In this embodiment, the component 10 has an increased effect of suppressing the popping-out of the snap ring 26 due to the inclination of the second wall portion 66, so it is possible to shorten the length of the guide member 22 in the axial direction 56. As a result, by shortening the length of the component 10 in the axial direction 56, it is possible to make the component 10 more compact.

[0081] (4) The end 22A of the second wall portion 66 located opposite the first wall portion 64 is positioned away from the accommodating groove 50 in the axial direction 56 (see the two-dot chain lines in Figures 2 and 9).

[0082] According to this embodiment, the end 22A of the second wall portion 66 reaches a position away from the accommodation groove 50 toward the one side 28 in the axial direction 56. Therefore, even if the snap ring 26 is tilted in the axial direction 56 and the corner portion 26D on the second wall portion 66 side protrudes beyond the edge 50A of the accommodation groove 50 toward the one side 28, the corner portion 26D of the snap ring 26 can be positioned inside the second wall portion 66.

[0083] This allows the component 10 to further enhance the effect of preventing the snap ring 26 from coming off.

[0084] (5) The distance 70 from the corresponding position 20T of the ring gear 20 as the first member corresponding to the end portion 22A in the axial direction 56 to the edge 50A of the accommodation groove 50 is smaller than the thickness dimension T of the snap ring 26.

[0085] In the present embodiment, in component 100, end 22A of second wall portion 66 reaches a position away from accommodating groove 50 in axial direction 56, and therefore guide member 22 having second wall portion 66 has a long length in axial direction 56. However, since the configuration in which second wall portion 66 is tilted can prevent snap ring 26 from coming off, the length of guide member 22 in axial direction 56 can be reduced.

[0086] Therefore, the component 10 can be made more compact by increasing the effect of preventing the snap ring 26 from coming off and by reducing the length of the guide member 22 in the axial direction 56 .

[0087] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0088] REFERENCE SIGNS LIST 10 Component 20 Ring gear (first member) 20A Peripheral wall surface 20T Corresponding position 22 Guide member (second member) 22A End portion 26 Snap ring 26A One side surface 26B Other side surface 26C Outer circumferential surface 50 Storage groove 50A Edge 56 Axial direction 64 First wall portion 66 Second wall portion 66A First inclined surface 66B Second inclined surface 70 Separation dimension T Thickness dimension

Claims

1. A component comprising: a first member having a circumferentially extending accommodation groove formed on its peripheral wall surface; a snap ring formed in a ring shape with a cut portion cut away from its periphery, the inner edge of which is accommodated in the accommodation groove; and a second member disposed on the outer periphery of the first member and having a first wall portion facing a side surface of the snap ring positioned in the thickness direction, and a second wall portion facing the outer periphery of the snap ring, wherein the second wall portion is inclined so as to approach the first member as it moves away from the first wall portion.

2. A component according to claim 1, wherein the outer peripheral surface of the snap ring is inclined so as to approach the first member as it moves away from the first wall portion.

3. A component according to claim 2, wherein an end of the second wall portion located on the opposite side to the first wall portion is positioned so as to overlap with the accommodation groove in the axial direction.

4. A component according to claim 1, wherein an end of said second wall portion located on the opposite side to said first wall portion is positioned at a position axially spaced apart from said receiving groove.

5. A component according to claim 4, wherein the distance from a corresponding position of said first member corresponding to said end in the axial direction to the edge of said receiving groove is smaller than the thickness of said snap ring.

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