differential housing

Abstract

The differential carrier and differential holder of the differential case include a bearing mounting portion, a flange portion, and a mounting portion. The flange portion of the differential carrier and the flange portion of the differential holder are fastened together via multiple through-holes provided in at least one of the two. At least one of the differential carrier and the differential holder has multiple reinforcing ribs on its outer wall extending from the bearing mounting portion toward some or all of the multiple through-holes and the mounting portion.

Description

Technical Field

[0001] The present disclosure relates to a differential housing. Background Art

[0002] In recent years, automobiles have adopted differential gears to distribute a single engine's output between two different rotational speeds. These differential gears are housed in a differential case, where axle shafts (drive shafts) and propeller shafts are rotatably supported by bearings. The differential case can be divided into two parts: a differential carrier and a differential holder.

[0003] The differential device described in Japanese Patent Application Laid-Open No. 2001-146956 has a structure in which reinforcement ribs are provided radially from the bearing mounting portion in order to disperse the load applied to the bearing mounting portion. Summary of the Invention

[0004] However, the differential device described in Japanese Patent Application Laid-Open No. 2001-146956 has room for optimization in the structure of the reinforcement ribs, and it is desired to reduce the cross-sectional area of ​​the reinforcement ribs by optimizing the structure to achieve further weight reduction.

[0005] The present disclosure provides a differential case capable of reducing the cross-sectional area of ​​a reinforcement rib for distributing the load applied to a bearing mounting portion, thereby achieving weight reduction.

[0006] A differential case according to one embodiment of the present disclosure includes a differential carrier and a differential holder. Each of the differential carrier and the differential holder includes a bearing mounting portion for mounting a bearing that holds a shaft; a flange portion for fastening the differential carrier to the differential holder; and a mounting portion provided on the flange portion for mounting the differential case to a vehicle body. The flange portion of the differential carrier and the flange portion of the differential holder are fastened via a plurality of through-holes provided in at least one of the two flange portions. At least one of the differential carrier and the differential holder includes a plurality of reinforcing ribs on an outer wall extending from the position of the bearing mounting portion toward a portion or all of the plurality of through-holes and the mounting portion. With this configuration, the cross-sectional area of ​​the reinforcing ribs, which distribute the load applied to the bearing mounting portion, can be reduced, thereby achieving weight reduction.

[0007] Alternatively, the bearing mounting portions of the differential carrier and the differential holder may be locations where the bearings are mounted in a plurality of recessed portions provided on the inner walls of each of the differential carrier and the differential holder, and the plurality of reinforcing ribs may include a reinforcing rib extending from one of the plurality of recessed portions on the outer wall of at least one of the differential carrier and the differential holder. This allows the load to be distributed to the recessed portion where the load is greatest, further reducing the cross-sectional area.

[0008] Alternatively, the plurality of reinforcing ribs may include two or more reinforcing ribs extending from one of the plurality of recesses on the outer wall of at least one of the differential carrier and the differential holder. This allows the reinforcing ribs to be arranged in a triangular shape, further reducing the cross-sectional area.

[0009] Alternatively, the plurality of reinforcing ribs may include two or more reinforcing ribs extending from an outer wall of at least one of the differential carrier and the differential holder so as to merge at a position corresponding to one of the plurality of through-holes and the mounting portion. This allows the reinforcing ribs to be arranged in a triangular shape, further reducing the cross-sectional area.

[0010] The plurality of reinforcing ribs may be disposed on both the differential carrier and the differential holder. This allows for efficient reinforcement.

[0011] Alternatively, the plurality of reinforcing ribs may include a first reinforcing rib facing the assembly portion and a second reinforcing rib facing the through hole, wherein the first reinforcing rib has a larger cross-sectional area perpendicular to the extension direction than the second reinforcing rib. This allows for focused reinforcement of the assembly portion, which is subject to a greater load.

[0012] The differential carrier may also include: an additional bearing mounting portion for mounting an additional bearing that holds another shaft perpendicular to the shaft; and a U-shaped reinforcement rib extending from the flange portion of the differential carrier, around the additional bearing mounting portion, and toward the flange portion. This reduces the cross-sectional area of ​​the reinforcement rib that distributes the load applied to the additional bearing mounting portion, thereby achieving weight reduction.

[0013] According to the present disclosure, it is possible to provide a differential case that can reduce the weight by reducing the cross-sectional area of ​​the reinforcement rib portion that distributes the load applied to the bearing mounting portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Hereinafter, features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described with reference to the accompanying drawings, in which like reference numerals represent like elements, wherein:

[0015] Figure 1 It is a schematic perspective view showing a configuration example of a differential case according to the embodiment.

[0016] Figure 2 It shows Figure 1 Schematic diagram of the outer wall side of the differential holder.

[0017] Figure 3 It shows Figure 1 Schematic diagram of the outer wall side of the differential carrier.

[0018] Figure 4 yes Figure 3 Schematic side view of the differential carrier.

[0019] Figure 5 yes Figure 3 VV cross-sectional view of the differential carrier.

[0020] Figure 6 yes Figure 4 This is a cross-sectional view of the differential carrier taken along the VI-VI direction.

[0021] Figure 7 It shows Figure 2 A schematic diagram showing the load distribution of the differential cage.

[0022] Figure 8 It shows Figure 3 Schematic diagram of the load distribution of the differential carrier.

[0023] Figure 9 It shows Figure 4 Schematic diagram of the load distribution of the differential carrier.

[0024] Figure 10 Is shown separately Figure 2 A schematic diagram showing the load distribution of the differential cage.

[0025] Figure 11 Is shown separately Figure 2 A schematic diagram showing the load distribution of the differential cage.

[0026] Figure 12 Is shown separately Figure 3 Schematic diagram of the load distribution of the differential carrier.

[0027] Figure 13 Is shown separately Figure 3Schematic diagram of the load distribution of the differential carrier.

[0028] Figure 14 Is shown separately Figure 3 Schematic diagram of the load distribution of the differential carrier. DETAILED DESCRIPTION

[0029] Hereinafter, the present invention will be described by way of the embodiments of the invention, but the inventions according to the claims are not limited to the following embodiments. In addition, all the configurations described in the embodiments are not necessarily required as means for solving the problems.

[0030] (Implementation Method)

[0031] Hereinafter, embodiments will be described with reference to the drawings. Figure 1 1 is a schematic perspective view showing a configuration example of a differential case according to an embodiment. Figure 1 As illustrated, the differential case (hereinafter referred to as differential case) 1 according to the present embodiment is configured to include a differential carrier (hereinafter referred to as differential carrier) 20 and a differential holder (hereinafter referred to as differential holder) 10 .

[0032] The differential case 1 serves as a housing for a differential device and can be formed of aluminum casting made of, for example, aluminum alloy, but is not limited thereto. The differential case 1 can be used for both a front differential device and a rear differential device.

[0033] The differential case 1 is provided with bearings that rotatably support the shafts from the vehicle body side, and can be equipped with the differential case and other internal components of the differential system as components of the differential device. Examples of these shafts include propeller shafts and half shafts (sometimes also called drive shafts). Figure 1 In the example, the X direction refers to the front-rear direction of the vehicle body (the length direction of the propeller shaft), and the Y direction refers to the left-right direction of the vehicle body (the length direction of the drive shaft or half shaft).

[0034] Although not shown, this differential device can include the aforementioned internal components, a differential mechanism and a ring gear. For example, the differential mechanism can include two side gears connected to the axle shafts, one on each side, two pinions meshing with the side gears. A shaft serving as a rotational axis is attached to each gear, and the gears are retained within the differential case via bearings. The ring gear can be secured to the outer periphery of the differential case by welding.

[0035] The differential carrier 20 houses the main components of the differential mechanism, while the differential holder 10 serves as the cover for the differential case 1. This allows the differential case 1 to be divided into two parts, the differential carrier 20 and the differential holder 10, and can also be referred to as a differential case assembly. This split structure facilitates assembly of the differential mechanism and the like.

[0036] The differential holder 10 has an opening 11 in its main body for gradually inserting a shaft (not shown) on the vehicle body side (hereinafter referred to as the first shaft). The differential carrier 20 has an opening 21 in its main body for gradually inserting the first shaft or a shaft coaxial with the first shaft. For simplicity, the following assumes a single first shaft, but it can also be two (i.e., a pair) as described for coaxial shafts.

[0037] exist Figure 1 In the example of , the first shaft may be a half shaft (drive shaft). In addition, any type of shaft is applicable as the first shaft, and the configuration and structure of the differential device on the vehicle body are different.

[0038] The differential carrier 20 also has an opening 22 in its main body for slowly inserting a separate shaft (not shown) on the vehicle body side that extends perpendicularly to the first axis of the slowly inserting opening 21. This separate shaft (hereinafter referred to as the second shaft) is perpendicular to the first shaft and may be, for example, a propeller shaft. However, other types of shafts may be used depending on the type of the first shaft and the placement and structure of the differential device on the vehicle body.

[0039] The differential carrier 20 includes a bearing mounting portion 23, a flange portion 24, a mounting portion 25, and reinforcement ribs 27 and 28. The differential holder 10 includes a bearing mounting portion 13, a flange portion 14, a mounting portion 15, and reinforcement ribs 17 and 18. These will be described in detail below.

[0040] First, refer to Figure 2 The differential holder 10 will be described. Figure 2 It shows Figure 1 FIG. 10 is a diagram showing the outer wall side of the differential retainer 10. Figure 2 As shown, the differential holder 10 has a bearing mounting portion 13 on its outer wall. The first shaft is rotatably held by a bearing (not shown) mounted on the bearing mounting portion 13 while being slowly inserted through the opening 11. While the bearing mounting portion 13 is described as being located on the outer wall of the differential holder 10, it may also be located on the inner wall of the differential holder 10.

[0041] The bearing mounting portion 13 is a portion for mounting a bearing for holding the first shaft, and may include a recess 13a. Figure 2 In the example, four large recesses 13a and two small recesses 13a are provided. The multiple recesses 13a can all be holes with bottoms, but some or all can also be through-holes. Furthermore, a circle is shown as an example of the shape of the surface perpendicular to the depth direction of the recesses 13a, but this is not limiting. Any shape can correspond to the shape of the convex portion on the bearing side.

[0042] The differential holder 10 has a flange portion 14 around it (around the surface perpendicular to the first axis of the slow insertion opening 11) for fastening to the differential carrier 20. Two assembly portions 15 are provided on the flange portion 14. The number of assembly portions 15 can be one or more, but preferably two or more. In addition, the configuration of the assembly portion 15 is not limited to the illustrated case. In addition, a plurality of through holes 16 are provided on the flange portion 14 for fastening the differential carrier 20 and the differential holder 10. The flange portion 14 is a portion that is fastened to the flange portion 24 on the side of the differential carrier 20 by the through holes 16 and the protrusions 26 described later. The through holes 16 can also be called fastening holes. The flange portions 14 and 24 become the portions that connect the differential holder 10 to the differential carrier 20 via the fastening holes. Furthermore, it is preferable that the fastening surface between the flange portion 14 and the flange portion 24 , that is, the fastening surface between the differential holder 10 and the differential carrier 20 , is formed perpendicular to the axis of the first shaft.

[0043] Mounting portion 15 is provided on flange portion 14 and serves as a location for mounting differential case 1, which houses the differential gear, on the vehicle body. Mounting to the vehicle body is achieved by aligning mounting portion 25 (described later) with mounting portion 15. While the example herein illustrates a case where mounting portion 25 includes a protrusion (not shown) for mounting to the vehicle body, and the differential case 1 is mounted to the vehicle body with the protrusion inserted into mounting portion 15, which serves as a through-hole, this is not limiting.

[0044] In addition, if Figure 2 As shown, the differential holder 10 has a plurality of reinforcing ribs on its outer wall, extending from the bearing mounting portion 13 toward some or all of the plurality of through-holes 16 and the mounting portion 15 (formed so as to extend outward). Reinforcing rib 17 is an example of a reinforcing rib extending from the bearing mounting portion 13 toward the mounting portion 15, and reinforcing rib 18 is an example of a reinforcing rib extending from the bearing mounting portion 13 toward each of the plurality of through-holes 16. The number of reinforcing ribs 17 and their cross-sectional shapes in the direction in which they extend are not limited, and the number of reinforcing ribs 18 and their cross-sectional shapes in the direction in which they extend are also not limited.

[0045] The bearing mounting portion 13 of the differential holder 10 is where additional bearings are mounted, located within multiple recesses 13a formed on the outer wall near the opening 11. In this case, the multiple reinforcing ribs provided on the differential case 1 can include a reinforcing rib (such as reinforcing rib 18) extending from one of the recesses 13a on the outer wall of the differential holder 10. Alternatively, the reinforcing rib extending from this one location can be reinforcing rib 17 extending toward the mounting portion 15. This allows the load to be distributed across the recesses 13a, where the greatest load is applied, allowing the load applied to the bearing mounting portion 13 to be more efficiently released, resulting in a reduction in the cross-sectional area of ​​the reinforcing ribs.

[0046] Reference Figures 3 to 6 The differential carrier 20 will be described. Figure 3 It shows Figure 1 A schematic diagram of the outer wall side of the differential carrier 20, Figure 4 yes Figure 3 A schematic side view of the differential carrier 20. Figure 5 yes Figure 3 A VV-direction cross-sectional view of the differential carrier 20, Figure 6 yes Figure 4 A cross-sectional view of the differential carrier 20 taken along the VI-VI direction.

[0047] like Figure 3 、 Figure 5 and Figure 6 As shown, the differential carrier 20 has a bearing mounting portion 23 on its inner wall. When the first shaft is slowly inserted through the opening 21, it is rotatably held by a bearing (not shown) mounted on the bearing mounting portion 23. While the description uses an example in which the bearing mounting portion 23 is provided on the inner wall of the differential carrier 20, the bearing mounting portion 23 may also be provided on the outer wall of the differential carrier 20.

[0048] The bearing mounting portion 23 is a portion for mounting a bearing for holding the first shaft, and may include: Figure 6 The recess 23a shown in the example. Figure 6 In the example, two recesses 23a are provided in the direction of the surface perpendicular to the axis of the first axis. Figure 6 For convenience, the cross-section of the bearing is shown with the bearing mounted. The portion shown by bearing mounting portion 23 represents the cross-section of the bearing. The multiple recesses 23a provided can be holes with bottoms, and their shape is not limited, as long as they correspond to the convex portion on the bearing side. Alternatively, recesses 23a similar to recess 13a can be used, extending in a direction parallel to the axis of the first shaft.

[0049] The differential carrier 20 has a flange portion 24 around its periphery (around the surface perpendicular to the first axis of the slow insertion opening 21) for fastening to the differential holder 10. One or more mounting portions 25 are provided on the flange portion 24 at positions corresponding to the mounting portions 15. Furthermore, a plurality of protrusions 26 may be provided on the flange portion 24, each of which is inserted into a plurality of through-holes 16 to fasten the differential carrier 20 to the differential holder 10. Furthermore, although the protrusions 26 are not formed into a convex shape in the drawings, a protrusion is formed on the through-hole 16 side. The flange portion 24 is a portion fastened to the flange portion 14 on the differential holder 10 side via the through-holes 16 and the protrusions 26. However, the flange portion 24 of the differential carrier 20 and the flange portion 14 of the differential retainer 10 only need to be fastened via a plurality of through holes provided in at least one of the flange portion 24 of the differential carrier 20 and the flange portion 14 of the differential retainer 10. For example, a protrusion may be provided instead of a part or all of the through holes 16 and a through hole may be provided instead of the corresponding protrusion 26.

[0050] The mounting portion 25 is provided on the flange portion 24 and is a portion for mounting the differential case 1 housing the differential device on the vehicle body. As described above, mounting to the vehicle body is performed by aligning the mounting portion 25 with the mounting portion 15 .

[0051] In addition, if Figure 3 As shown, the differential carrier 20 has a plurality of reinforcing ribs on its outer wall, extending from the bearing mounting portion 23 toward some or all of the plurality of protrusions 26 and the mounting portion 25 (formed so as to extend outward). Reinforcing rib 27 is an example of a reinforcing rib extending from the bearing mounting portion 23 toward the mounting portion 25, while reinforcing rib 28 is an example of a reinforcing rib extending from the bearing mounting portion 23 toward the plurality of protrusions 26 (i.e., the plurality of through-holes 16). The number of reinforcing ribs 27 and their cross-sectional shapes in the direction of their extension are not limited, and the number of reinforcing ribs 28 and their cross-sectional shapes in the direction of their extension are also not limited.

[0052] Furthermore, the bearing mounting portion 23 of the differential carrier 20 is a portion where bearings are mounted in multiple recesses 23a formed on the inner wall near the opening 21. In this case, the multiple reinforcing ribs provided on the differential case 1 may include a reinforcing rib (e.g., reinforcing rib 28) extending from one of the multiple recesses 23a on the outer wall of the differential carrier 20. Alternatively, the reinforcing rib extending from the aforementioned one location may be the reinforcing rib 27 extending toward the mounting portion 25. This allows the load to be distributed across the recesses 23a, where the greatest load is applied, allowing the load applied to the bearing mounting portion 23 to be more efficiently relieved, resulting in a reduction in the cross-sectional area of ​​the reinforcing ribs.

[0053] In addition, if Figure 1 、 Figure 3 and Figure 4 As shown, the differential carrier 20 may further include reinforcing ribs 30 on the outer wall side, along the reinforcing ribs 28 facing the through-hole 16, to further reinforce the reinforcing ribs 28. In particular, it is preferable to provide the reinforcing ribs 30 at locations where the spacing between the reinforcing ribs 27 and 28 at the mounting portion 25 is wide when viewed from above the outer wall. In this example, the reinforcing ribs 30 are three parallel, plate-shaped ribs, but their shape and number are not limited; any ribs can be used as long as they further reinforce the reinforcing ribs 28. This allows the reinforcing ribs 28 to be made thinner. Furthermore, although not shown, the differential carrier 20 may further include reinforcing ribs 27 on the outer wall side, along the reinforcing ribs 27 facing the mounting portion 25, to further reinforce the reinforcing ribs 27. The same concept can also be applied to the differential holder 10.

[0054] In addition, as mentioned above, Figure 1 、 Figure 4 and Figure 6 As shown, the differential carrier 20 may have an opening 22 for slowly inserting a second shaft perpendicular to the first shaft. The second shaft slowly inserted into the opening 22 is rotatably held by another bearing (not shown) provided on the differential carrier 20. Figure 6 As shown, two additional bearings can be mounted on additional bearing mounting portions 31 and 32 provided on the differential carrier 20. The number of additional bearings can be two or more. A cylindrical slow insertion portion 33 is provided between the additional bearing mounting portion 31 and the additional bearing mounting portion 32, into which the second shaft is slowly inserted.

[0055] Furthermore, in addition to the aforementioned reinforcing ribs 17, 18, 27, and 28, the differential carrier 20 preferably includes a U-shaped reinforcing rib 29 extending from the flange portion 24 of the differential carrier 20, around the additional bearing mounting portions 31 and 32, and toward the flange portion 24. In this example, since there are two additional bearing portions, two reinforcing ribs 29 are provided, one corresponding to each. This reduces the cross-sectional area of ​​the reinforcing ribs 29, which distribute the load applied to the additional bearing mounting portions 31 and 32, thereby achieving weight reduction.

[0056] Furthermore, the U-shaped reinforcement rib 29 described here can also be applied to a differential case that does not include the above-mentioned reinforcement ribs 17 , 18 , 27 , and 28 .

[0057] Below, refer to Figures 7 to 14The effects of the reinforcing ribs 17 and 18 , the reinforcing ribs 27 and 28 , and the reinforcing rib 29 , which are the main features of this embodiment, will be described together.

[0058] First, refer to Figures 7 to 9 Schematic diagram illustrating the transfer of loads from the first and second axes. Figure 7 It shows Figure 2 Schematic diagram of the load distribution of the differential holder 10. Figure 8 It shows Figure 3 A schematic diagram showing the load distribution of the differential carrier 20 is shown. Figure 9 It shows Figure 4 Schematic diagram of the load distribution of the differential carrier 20.

[0059] First, if Figure 7 As shown by the hollow arrow in FIG, on the differential holder 10 side, the force from the first shaft is applied to the bearing mounting portion 13. Figure 7 As shown by the thick arrows, the reinforcing ribs 17 and 18 are formed. Figure 7 As shown by the dotted line, it is transferred to the flange portion 14 and passes through the flange portion 14 toward Figure 7 The force is also transmitted to the mounting portion 15 in the direction of the arrow i. In addition, the force is also transmitted directly from the reinforcing rib 18 to the mounting portion 15. It can be said that the reinforcing ribs 17 and 18 are configured so that the loaded force can be efficiently dispersed through such a transmission path.

[0060] Likewise, Figure 8 As shown by the hollow arrow in FIG, on the differential carrier 20 side, the force from the first shaft is applied to the bearing mounting portion 23. Figure 8 As shown by the thick arrows, the reinforcing ribs 27 and 28 are formed. Figure 8 As shown by the dotted line, it is transferred to the flange portion 24 and passes through the flange portion 24 toward Figure 8 The force is transmitted to the mounting portion 25 in the direction of the arrow ii. In addition, the force is also transmitted directly from the reinforcing rib 28 to the mounting portion 25. It can be said that the reinforcing ribs 27 and 28 are configured so that the applied force can be efficiently dispersed through such a transmission path.

[0061] In addition, the second axis is as follows. Figure 9 As shown by the hollow arrows in FIG, the force from the second shaft is applied to the bearing mounting portions 31, 32 on the side of the opening portion 22 at the differential carrier 20 (see FIG. Figure 6 ). This force is mainly applied to the recessed portion (not shown) of the bearing mounting portion 31, 32. Figure 9 As shown by the thick arrows, these forces are transmitted through the reinforcing ribs 29, as shown in FIG. Figure 9As shown by the dot-dash line, the force is transmitted to the flange portion 24, and is transmitted to the fitting portion 25 through the flange portion 24. It can be said that the reinforcing rib 29 is configured so that the applied force can be efficiently dispersed through such a transmission path.

[0062] Next, refer to Figure 10 and Figure 11 , the distribution of the force (load) applied to the differential holder 10 will be described in detail. Figure 10 and Figure 11 Are shown separately Figure 2 Schematic diagram of the load distribution of the differential holder 10.

[0063] In the differential holder 10, the forces from the first shaft are mainly applied to the recessed portion 13a of the bearing mounting portion 13. And, these forces are applied in one direction, such as Figure 10 As shown by the thick arrow, the force is transmitted to the flange portion 14 through the reinforcing rib 18, and as described above, is transmitted to the mounting portion 15 through the flange portion 14. The same applies to forces in other directions.

[0064] However, if Figure 11 Specifically, the plurality of reinforcing ribs provided on the differential holder 10 may include two or more reinforcing ribs 18, and the two or more reinforcing ribs 18 are provided at positions corresponding to the plurality of through holes 16 and one of the mounting portions 15 (in the Figure 11 That is, the reinforcing ribs provided on the differential holder 10 may be provided in plurality toward one through hole 16 of the flange portion 14 or the mounting portion 15. Thus, as Figure 11 As shown by the bold arrows, the reinforcing ribs 18 can be arranged in a triangular shape (ie, the reinforcing ribs form a triangle), which can further ensure strength (in other words, the cross-sectional area of ​​the reinforcing ribs can be further reduced).

[0065] In addition, you can also Figure 11 Specifically, it is preferred that the plurality of reinforcing ribs provided on the differential holder 10 include two or more reinforcing ribs 17 and 18 that branch off and extend from one of the plurality of recesses 13a on the outer wall side of the differential holder 10. That is, it is preferred that the reinforcing ribs provided on the differential holder 10 be formed in plurality starting from one recess 13a of the bearing mounting portion 13. Thus, as Figure 11 As shown by the dotted arrows, the reinforcing ribs can be arranged in a triangular shape (ie, the reinforcing ribs form a triangle with each other), which can further ensure strength (in other words, the cross-sectional area of ​​the reinforcing ribs can be further reduced).

[0066] As described above, the differential holder 10 is provided with reinforcing ribs 17 and 18, which effectively disperses the load from the first shaft. In particular, since the flange 14 functions as the corresponding surface of the housing (differential carrier 20, differential holder 10) that is divided into two parts, by flexibly utilizing this function, it is possible to achieve a greater reinforcement effect while also achieving weight reduction, compared to a case where the flange 14 is not flexibly utilized and the reinforcing ribs are formed alone, or a case where no reinforcing ribs are provided and the housing is formed thicker. Specifically, in the differential holder 10, compared to a case where the flange 14 is not flexibly utilized and the reinforcing ribs are formed alone, not only is weight reduction achieved, but the quality degradation problem described below can also be reduced. Specifically, when manufacturing by casting, the reinforcing ribs need to be arranged in an intersecting manner or lengthened, resulting in the problem of deterioration in casting quality due to deterioration in the flow of molten metal. However, in the differential holder 10, such a problem can be reduced. Furthermore, in the differential holder 10 , compared with a case where the wall is simply formed thick, it is possible to reduce the problem of casting defects such as shrinkage cavities occurring during casting and causing a decrease in casting quality.

[0067] Next, refer to Figures 12 to 14 The following describes in detail how the force (load) applied to the differential carrier 20 is distributed. Figures 12 to 14 Are shown separately Figure 3 Schematic diagram of the load distribution of the differential carrier 20.

[0068] In the differential carrier 20, the force from the first shaft is mainly applied to the recessed portion 23a of the bearing mounting portion 23. Figure 12 As shown by the thick arrow, the force is transmitted to the flange portion 24 through the reinforcing rib 28, and is transmitted to the mounting portion 25 through the flange portion 24 as described above. The same applies to forces in other directions.

[0069] However, you can also Figure 13 Specifically, the plurality of reinforcing ribs provided on the differential carrier 20 may include two or more reinforcing ribs 28, the two or more reinforcing ribs 28 being provided at positions corresponding to the plurality of through holes 16 (corresponding to the positions of the plurality of protrusions 26) and at a position corresponding to one portion of the mounting portion 25 (corresponding to the positions of the plurality of protrusions 26). Figure 13 That is, the reinforcing ribs provided on the differential carrier 20 may be provided in plurality toward one convex portion 26 (the convex portion corresponding to the through hole 16) of the flange portion 24 or the mounting portion 25. Figure 13As shown by the bold arrows, the reinforcing ribs 28 can be arranged in a triangular shape (ie, the reinforcing ribs form a triangle), which can further ensure strength (in other words, the cross-sectional area of ​​the reinforcing ribs can be further reduced).

[0070] In addition, you can also Figure 13 Specifically, the plurality of reinforcing ribs provided on the differential carrier 20 preferably include two or more reinforcing ribs 28 extending in a divergent manner from one of the plurality of recesses 23a on the outer wall side of the differential carrier 20. In other words, the reinforcing ribs provided on the differential carrier 20 are preferably formed in a plurality starting from one recess 23a of the bearing mounting portion 23. Thus, as Figure 13 As shown by the dotted arrows, the reinforcing ribs can be arranged in a triangular shape (ie, the reinforcing ribs form a triangle with each other), which can further ensure strength (in other words, the cross-sectional area of ​​the reinforcing ribs can be further reduced).

[0071] In addition, you can also Figure 14 The applied force is divided as shown by the dotted arrows. Specifically, it is preferred that the plurality of reinforcing ribs provided on the differential carrier 20 include two or more reinforcing ribs 27 extending in parallel toward an assembly portion 25 on the outer wall side of the differential carrier 20. In addition, although not shown, the plurality of reinforcing ribs provided on the differential carrier 20 may include two or more reinforcing ribs 28 extending in parallel from the position of a through hole 16 (a position corresponding to a protrusion 26) on the outer wall side of the differential carrier 20. Thus, as Figure 14 As shown by the dotted arrows, each reinforcing rib can be made thinner (its cross-sectional shape can be reduced), thereby reducing the total cross-sectional area and efficiently ensuring rigidity.

[0072] As described above, the differential carrier 20 is provided with reinforcing ribs 27 and 28, which effectively distributes the load from the first shaft. In particular, since the flange 24 functions as the corresponding surface of the bisected housing (differential carrier 20, differential holder 10), by utilizing the flange 24, a greater reinforcing effect can be achieved while also reducing weight, compared to a case where the flange 24 is not utilized and reinforcing ribs are formed alone, or a case where no reinforcing ribs are provided and the housing is thickened. Specifically, the differential carrier 20 is not only reduced in weight, but also reduced in quality degradation, as described below, compared to a case where the flange 24 is not utilized and reinforcing ribs are formed alone. Specifically, when manufacturing the differential carrier 20 by casting, the reinforcing ribs need to be arranged in an intersecting manner or lengthened, resulting in deterioration in casting quality due to poor molten metal flow. However, this problem is reduced in the differential carrier 20. Furthermore, in the differential carrier 20 , compared to the case where the wall is simply formed thick, it is possible to reduce the problem of casting defects such as shrinkage cavities occurring during casting and causing a decrease in casting quality.

[0073] As described above, in the differential case 1 according to this embodiment, the load applied to the bearing mounting portion can be released to the assembly portion via the reinforcing ribs through the flange portion. In a particularly preferred embodiment, the reinforcing ribs connecting the bearing portion and the flange portion are configured as described below (1) to (3) in accordance with the load vector direction, thereby enabling more efficient force transmission.

[0074] (1) The fastening parts (exemplified by the through-hole 16 and the protrusion 26 ) are directly connected to each other.

[0075] (2) By designing the reinforcement ribs not as ribs with a large cross-sectional shape but as multiple ribs with a small cross-sectional shape extending in parallel, the total cross-sectional area is reduced, and the rigidity is efficiently ensured.

[0076] (3) Two reinforcing ribs are connected from one fastening portion, using a triangle to ensure strength.

[0077] Therefore, in this embodiment, the cross-sectional area of ​​the reinforcing ribs that distribute the load applied to the bearing mounting portion 13 and / or the bearing mounting portion 23 can be reduced, thereby achieving weight reduction. In addition, according to this embodiment, when such a differential case 1 is mounted on a vehicle, the vehicle can also be lightweight.

[0078] In addition, as described above, the cross-sectional shapes of the reinforcing ribs 17 and 18 and the cross-sectional shapes of the reinforcing ribs 27 and 28 are not limited, but it is preferable to set the following restrictions. The reinforcing rib 17 (first reinforcing rib) can have a larger cross-sectional area perpendicular to the extension direction than the reinforcing rib 18 (second reinforcing rib). As a result, the assembly portion 15, to which a greater load is applied, can be strengthened. Similarly, the reinforcing rib 27 (first reinforcing rib) can have a larger cross-sectional area perpendicular to the extension direction than the reinforcing rib 28 (second reinforcing rib). As a result, the assembly portion 25, to which a greater load is applied, can be strengthened.

[0079] The manufacturing methods of the differential case 1 and its components are not limited. Furthermore, the differential case 1, comprising the differential holder 10 and differential carrier 20, can be applied to various differential devices. For example, it can be used with various AT (Automatic Transmission), CVT (Continuously Variable Transmission), and MT (Manual Transmission) systems. Furthermore, in PHVs (Plug-in Hybrid Vehicles) and EVs (Electric Vehicles), its application to the differential assembly of the transaxle can reduce the size and weight of the unit, thereby reducing battery usage.

[0080] The present invention is not limited to the above-described embodiment, and can be modified appropriately without departing from the spirit of the present invention. For example, the shape of the differential case 1 including the shape of the reinforcement rib is not limited to the shape shown in the figure.

[0081] Furthermore, although the example in which multiple reinforcing ribs are provided on both the differential carrier 20 and the differential holder 10 is described, and the reinforcing ribs are provided at the same relative positions on both the differential carrier 20 and the differential holder 10, the reinforcing ribs may be provided in different positional relationships. Furthermore, reinforcing ribs may be provided on only one of the differential carrier 20 or the differential holder 10. However, providing reinforcing ribs on both can further ensure strength compared to providing reinforcing ribs on only one of the differential carrier 20 and the differential holder 10, thus achieving efficient reinforcement.

[0082] The differential holder 10 and the differential carrier 20 may be referred to as the first differential case member and the second differential case member, respectively. In practice, the ratio of the two components housed in the differential device is not limited. For example, a configuration may be employed in which a portion of the differential device is covered by the differential holder 10. Furthermore, while the differential case 1 is assumed to be divided into two sections on a flat surface, it may also be divided on a three-dimensional curved surface, or may be divided into three or more sections for purposes such as assembling a differential mechanism.

[0083] In any case, the differential cases can be joined together via flanges between adjacent components. Therefore, using the same concept, reinforcing ribs can be provided on at least one of the differential carrier and the differential holder. Furthermore, reinforcing ribs can also be provided on other corresponding components (components having bearing mounting portions) to distribute the load applied to the bearing mounting portions.

[0084] In addition, Figure 1 In the examples, the differential case 1 is shown in which the direction of division is the direction of the plane perpendicular to the Y axis, but the differential case 1 may be divided in the direction of the plane horizontal to the Y axis (in the direction of Figure 1 In this case, the differential case can be divided on a surface passing through the openings 11 and 21 or on a surface not passing through them. Even in this case, adjacent components of the differential case can be joined together via flanges. Based on the same concept, reinforcing ribs can be provided on at least one of the differential carrier and the differential holder to distribute the load applied to the bearing mounting portion.

Claims

1. A differential case comprising a differential carrier and a differential holder, In the differential housing, The differential carrier and the differential holder both include: a bearing mounting portion for mounting a bearing for holding a shaft extending in a first direction; a flange portion for fastening the differential carrier and the differential holder; and An assembly portion provided on the flange portion for mounting the differential case on the vehicle body along the first direction via the assembly portion of the differential carrier and the assembly portion of the differential holder, wherein: The mounting portion of the differential carrier and the mounting portion of the differential holder are aligned in the first direction, The flange portion of the differential carrier and the flange portion of the differential holder are fastened together via a plurality of through holes provided in at least one of the two flange portions. One of the differential carrier and the differential holder has a plurality of reinforcing ribs on an outer wall side, and the reinforcing ribs include a first reinforcing rib extending from a position of the bearing mounting portion toward a position of the assembly portion of one of the differential carrier and the differential holder.

2. The differential case according to claim 1, wherein: The bearing mounting portions of the differential carrier and the differential holder are locations where the bearings are mounted on a plurality of recessed portions provided on the inner walls of each of the differential carrier and the differential holder. The first reinforcing rib extends from a position of one of the plurality of recesses.

3. The differential case according to claim 2, wherein: The plurality of reinforcing ribs include two or more reinforcing ribs including the first reinforcing rib, which diverge and extend from a position of one of the plurality of recessed portions on an outer wall side of one of the differential carrier and the differential holder.

4. The differential case according to any one of claims 1 to 3, wherein: The plurality of reinforcing ribs include two or more reinforcing ribs extending on the outer wall side of one of the differential carrier and the differential holder so as to merge at a position corresponding to one of the plurality of through holes or the fitting portion.

5. The differential case according to any one of claims 1 to 3, wherein: The other of the differential carrier and the differential holder has a plurality of reinforcing ribs on the outer wall side, the plurality of reinforcing ribs including a first reinforcing rib extending from the position of the bearing mounting portion toward the position of the assembly portion of the other of the differential carrier and the differential holder.

6. The differential case according to any one of claims 1 to 3, wherein: The plurality of reinforcing ribs further include a second reinforcing rib facing the through hole, The first reinforcement rib has a larger cross-sectional area perpendicular to the extending direction than the second reinforcement rib.

7. The differential case according to any one of claims 1 to 3, wherein: The differential carrier includes: another bearing mounting portion, on which another bearing for holding another shaft perpendicular to the shaft is mounted; and a U-shaped reinforcement rib portion, which starts from the flange portion of the differential carrier, goes around the other bearing mounting portion and faces the flange portion.

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