Differential device

Abstract

To provide a differential gear capable of achieving both weight reduction and lubrication performance of a differential case without complicating a structure.SOLUTION: The first case side CD1 is provided with the extended part 25 pivotally supporting one end of each pinion gear GP, and the cutout part 26 formed by cutting out, in a substantially U-shape, a part of the extended part 25 located between a part pivotally supporting one pinion gear GP and a part pivotally supporting another adjacent pinion gear GP, and the second case side CD2 is provided with the shielding part 35 protruding toward the cutout part 26 from the mating surface F between the first case side CD1 and the second case side CD2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a differential for a vehicle. [Background technology]

[0002] The differential is primarily incorporated into the housing of the final drive unit that drives the rear wheels of the vehicle. The differential device also includes a pair of side gears, pinion gears that mesh with the side gears, and a differential case that houses the side gears and pinion gears therein. The side gears have washers on their back surfaces and rotate relative to the differential case, which rotates coaxially. The pinion gears have through holes and are in sliding contact with the pinion shafts that are inserted through the through holes. The pinion gears also come in sliding contact with the washers arranged on their back surfaces. It is necessary to supply a sufficient amount of lubricating oil to each of these meshing portions and sliding contact portions. The differential case has a spherical shell shape and is equipped with cylindrical bosses at both ends in the direction of the rotation axis. The differential case is supported within a housing by bearings fitted onto the bosses. Lubricating oil is stored within the housing, and the lubricating oil is scooped up by a ring gear fitted onto the differential case and supplied to parts of the reduction gear that require lubrication. Some of the lubricating oil that is scooped up adheres to the inner walls of the top and sides of the housing and drips down the walls, but it is guided to the outside of the bearings that support the differential case through guide grooves etc. provided in the housing. The guided lubricating oil is then supplied into the differential case through guide grooves provided on the inner periphery of the boss of the differential case, and is used to lubricate the meshing portions and sliding portions of the side gears and pinion gears inside the differential case.

[0003] Most differential cases are formed by casting or forging. To accommodate side gears and pinion gears and to reduce weight, the differential case has openings on the circumferential surface of the spherical shell. In some cases, openings are also provided in the same locations, as in Patent Document 1. However, if such an opening is provided, the lubricating oil guided into the differential case will be subjected to centrifugal force and will be discharged from the opening to the outside of the differential case, which may result in a shortage of lubricating oil inside. For this reason, as in Patent Document 2, there is an example in which a lubricant oil retaining lip is added to the differential case to prevent the lubricant oil in the differential case from discharging from the opening. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2022 / 054135 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-128265 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the configuration described in Patent Document 2 is adopted, there are problems in that the number of parts increases and the number of steps required to assemble the lubricant oil retaining lip increases. The present invention has been devised to solve the above problems, and aims to provide a differential device that can achieve both weight reduction and lubrication performance of the differential case without complicating the structure. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the differential device of the present invention has a differential case that forms a hollow shape with a first case and a second case, a first side gear supported within the first case, a second side gear that faces the first side gear and is supported within the second case, and a plurality of pinion gears that are journaled on the differential case and mesh with each of the first side gear and the second side gear, wherein the first case has an extension that journals one end of each pinion gear, and a notch that cuts out a portion of the extension that is located between a portion that journals one of the pinion gears and a portion that journals another adjacent pinion gear in an approximately U-shaped manner, and the second case has a shielding portion that protrudes from the mating surface between the first case and the second case toward the notch. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a differential device that can achieve both weight reduction of the differential case and lubrication performance without complicating the structure. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a power transmission device for a vehicle equipped with a differential gear according to a first embodiment of the present invention. [Figure 2] 1 is a cross-sectional view showing a differential gear according to a first embodiment of the present invention. [Figure 3] 1 is a perspective view showing a differential gear according to a first embodiment of the present invention. [Figure 4] 1 is a perspective view showing a main case according to a first embodiment of the present invention. FIG. [Figure 5] FIG. 2 is a perspective view showing a sub-case according to the first embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view showing a differential gear according to a second embodiment of the present invention. [Figure 7] FIG. 6 is a perspective view showing a differential gear according to a second embodiment of the present invention. [Figure 8] FIG. 10 is a perspective view showing a sub-case according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a cross-sectional view showing a differential gear according to a third embodiment of the present invention. [Figure 10] FIG. 10 is an exploded perspective view showing a differential gear according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment A vehicle power transmission device S having a differential gear DF1 according to a first embodiment of the present invention will be described in detail with reference to FIGS. In the description, the same elements are given the same reference numerals and redundant description will be omitted. The vehicle power transmission device S of this embodiment is mounted on a four-wheel drive vehicle (not shown) based on front-wheel drive.

[0010] In this four-wheel drive vehicle, in addition to a drive unit (not shown) for driving the front wheels, a rear wheel drive unit RWD (final reduction gear) for driving the rear wheels is provided. The vehicle power transmission device S of this embodiment, together with the motor M serving as a drive source, constitutes rear wheel drive means RWD (see FIG. 1). That is, the vehicle power transmission device S of this embodiment is configured to transmit the driving force generated by the motor M to the rear wheels. The rear wheel drive means RWD is installed on the vehicle so that the rotation shaft of the motor M is oriented in the vehicle width direction and the motor M is positioned on the right side of the vehicle power transmission device S.

[0011] The vehicle power transmission device S is housed in a housing H and is configured as a single unit together with a motor M (see FIGS. 1 to 5). The housing H is made up of a first housing H1 and a second housing H2. The first housing H1 and the second housing H2 form a box-like shape and define a space in which the vehicle power transmission device S is housed.

[0012] The vehicle power transmission device S includes a housing H, a reduction gear RD, and a differential gear DF1. The reducer RD is configured to reduce the rotation speed of the motor M at a set reduction ratio while increasing the torque and transmitting it to the differential device DF1. The reducer RD is configured with a two-stage gear mechanism consisting of a first gear mechanism RD1 and a second gear mechanism RD2. The first gear mechanism RD1 and the second gear mechanism RD2 are configured with spur gears whose respective rotation axes (first rotation axis AX1, second rotation axis AX2) are arranged in parallel.

[0013] When the vehicle travels straight, the differential device DF1 transmits driving force equally to the left and right drive shafts SD at the same rotation speed (see FIGS. 1 to 5). Furthermore, when the vehicle turns, the differential device DF1 transmits driving force to the left and right drive shafts SD with a rotation difference corresponding to the inner wheel difference that occurs between the left and right drive shafts SD. The drive shaft SD serves as the output portion of the differential device DF1 and is connected to the rear wheels of the vehicle to transmit driving force to the rear wheels. The drive shaft SD is made up of a right drive shaft SDR and a left drive shaft SDL, with the right drive shaft SDR driving the right rear wheel (not shown) and the left drive shaft SDL driving the left rear wheel (not shown).

[0014] The differential device DF1 includes a differential case CD, a pinion gear GP, a right side gear GSR (first side gear), and a left side gear GSL (second side gear). The differential case CD is supported within the housing H via bearings BR so as to be rotatable about a third rotation axis AX3 (the rotation axis of the differential case). The third rotation axis AX3 is set as the rotation center of the differential case CD, ring gear GR, right side gear GSR, and left side gear GSL. The third rotation shaft AX3 is located behind the reducer RD (the first gear mechanism RD1 and the second gear mechanism RD2) and is oriented in the vehicle width direction.

[0015] The differential case CD has a generally cylindrical shape with the third rotation shaft AX3 as its central axis, and accommodates the pinion gear GP, the right side gear GSR, and the left side gear GSL inside the cylinder. The detailed structure of the differential case CD will be described later.

[0016] The pinion gear GP is configured to transmit the rotational force of the differential case CD to the left and right side gears GSR and GSL by meshing with the left and right side gears GSR and GSL and rotating together with the differential case CD (see Figures 1 to 5).

[0017] The right side gear GSR is disposed in the differential case CD so as to be rotatable relative to the differential case CD about a third rotation axis AX3. The right side gear GSR is composed of a bevel gear that can mesh with the pinion gear GP and is located at the right end of the differential case CD. The right side gear GSR is spline-fitted to the inner end of the right drive shaft SDR in the vehicle width direction, and rotates integrally with the right drive shaft SDR.

[0018] The left side gear GSL is journaled to the differential case CD so as to be rotatable relative to the differential case CD about a third rotation axis AX3, while facing the right side gear GSR. The left side gear GSL is composed of the same bevel gear as the right side gear GSR, and is rotatably arranged at the left end of the differential case CD while meshing with the pinion gear GP. The left side gear GSL is spline-fitted to the inner end of the left drive shaft SDL in the vehicle width direction, and rotates integrally with the left drive shaft SDL. In this embodiment, the left and right side gears GSR, GSL and the pinion gear GP are configured as bevel gears, but the present invention is not limited to this configuration. For example, a helical gear or a worm gear can be used, and the same effects can be obtained.

[0019] The differential case CD, which houses the pinion gear GP, right side gear GSR, and left side gear GSL, includes a main case CD1 (first differential case) and a sub-case CD2 (second differential case). The main case CD1 and the sub-case CD2 form a hollow spherical shell shape. The differential case CD is configured so as to be divided into a main case CD1 and a sub-case CD2 on the left and right sides in the vehicle width direction along a plane perpendicular to the third rotation axis AX3.

[0020] The mating surface F that divides the main case CD1 and the sub case CD2 is set to be located at the maximum diameter portion MX of the bevel gear of the left side gear GSL in the axial direction of the third rotation axis AX3 (hereinafter referred to as the axial direction). In other words, the mating surface F is set closer to the left side gear GSL than the pinion shaft SHP1. The mating surface F may be set to be located near the maximum diameter portion of the bevel gear of the right side gear GSR, or may be located on the central axis of the pinion shaft SHP1.

[0021] The main case CD1 (first differential case) has a cylindrical shape with the third rotation axis AX3 as its central axis. The main case CD1 includes a small main cylinder portion 21 and a large main cylinder portion 22. The main small cylinder portion 21 has a cylindrical shape with a hole diameter that allows the right drive shaft SDR to be inserted therethrough. The outer end of the main small cylinder portion 21 in the vehicle width direction is rotatably supported by a boss portion provided inside the housing H via a bearing BR. The main small cylinder portion 21 is provided with a spiral groove (guide groove 21a) on its inner cylindrical surface. When the differential case CD and the right drive shaft SDR rotate relative to each other, the lubricating oil flows through the guide groove 21a and is supplied into the differential case CD.

[0022] The main large cylinder portion 22 has a generally cylindrical shape with a larger diameter than the main small cylinder portion 21 . The outer end of the main large cylinder portion 22 in the vehicle width direction is formed integrally with the inner end of the main small cylinder portion 21 in the vehicle width direction via a main partition wall 23 having an annular shape. A washer (side washer 51) is disposed between the main partition wall 23 and the right side gear GSR. The main partition wall 23 also has a gear flange 24 on its outer periphery, and a ring gear GR is mounted on the gear flange 24. The ring gear GR is composed of a spur gear that rotates together with the differential case CD around the third rotation axis AX3. The ring gear GR meshes with the reducer RD and transmits the rotational force of the motor M to the differential case CD.

[0023] The main large cylindrical portion 22 accommodates three pinion gears GP meshing with the right side gear GSR inside the cylindrical portion. A washer (pinion washer 52) is disposed between each pinion gear GP and the inner surface of the main large cylinder portion 22. The main large cylinder portion 22 includes an extension portion 25 , a notch portion 26 , and a main fitting portion 27 .

[0024] The extension portion 25 extends from the main partition wall 23 toward the sub-case CD2, centered on the third rotation axis AX3, and forms a cylindrical wall portion of the main large cylinder portion 22. The end face of the extension 25 on the sub-case CD2 side is set at a mating surface F on the main case side that divides the differential case CD into the main case CD1 and the sub-case CD2. The extension 25 has a pinion support hole 25a and a bolt insertion hole 25b.

[0025] The pinion support hole 25a is configured to support the radially outer end of the shaft portion 11 that constitutes the pinion shaft SHP1. The pinion support hole 25a is configured as a hole that penetrates the extension portion 25 in the radial direction. In other words, the pinion support holes 25a are provided to support the outer ends of the three shaft portions 11, and three of them open at equal angular intervals in the circumferential direction (hereinafter referred to as the circumferential direction) centered on the third rotation axis AX3.

[0026] The bolt insertion holes 25b are configured to receive fastening bolts 53 for fastening the main case CD1 and the sub-case CD2 together. A pair of bolt insertion holes 25b are arranged for each pinion support hole 25a, with the pinion support hole 25a sandwiched therebetween. In this embodiment, the fastening bolts 53 are used as means for fastening the main case CD1 and the sub-case CD2 together, but the present invention is not limited to this. For example, it is possible to employ a technique of forming the main case CD1 and the sub-case CD2 integrally by welding, and similar effects can be obtained.

[0027] The notch 26 is formed by cutting out a substantially U-shape on the mating surface F side of the cylindrical wall of the main large cylindrical portion 22 located between adjacent pinion support holes 25a. In this embodiment, three pinion support holes 25a are provided, and therefore three notches 26 are provided. That is, in the main large cylinder portion 22, three notched portions 26 and three extended portions 25 are arranged alternately in the circumferential direction.

[0028] The bottom of the substantially U-shaped notch 26 is set as a notch bottom 26a (main-side shielding portion). The notch portion 26 is cut out so that the notch bottom portion 26a radially overlaps with the maximum diameter portion MX of the right side gear GSR. That is, when the main case CD1 is viewed from the radially outer side, the notch bottom 26a overlaps the right side gear GSR, and the notch 26 is cut out so as to hide the right side gear GSR. Further, the notch bottom 26a is set so that its radial dimension (wall thickness dimension) is smaller (thinner) than the wall thickness dimension of the extension portion 25. This allows for further weight reduction, and since one end is open rather than having a hole, productivity is improved when forming the member by casting or forging.

[0029] The main fitting portion 27 is formed on the end surface of the extension portion 25 on the sub-case CD2 side (the inner end surface in the vehicle width direction). The main fitting portion 27 is configured as an arc-shaped recess into which a sub-fitting portion 34 (described later) can be inserted. The main fitting portion 27 fits into the sub-fitting portion 34, thereby positioning the main case CD1 and the sub-case CD2.

[0030] The sub-case CD2 (second differential case) has a cylindrical shape with the third rotation axis AX3 as its central axis. The sub-case CD2 includes a sub-small cylinder portion 31 and a sub-large cylinder portion 32. The sub-small cylinder portion 31 has a cylindrical shape with a hole diameter that allows the left drive shaft SDL to be inserted therethrough. The outer end of the sub-small cylinder portion 31 in the vehicle width direction is rotatably supported by a boss portion provided inside the housing H via a bearing BR.

[0031] The left drive shaft SDL has its inner end in the vehicle width direction inserted into the left side gear GSL and its outer end in the vehicle width direction connected to the left rear wheel, thereby transmitting the rotational force of the differential case CD to the left rear wheel (not shown). Similarly to the main small cylinder portion 21, the sub small cylinder portion 31 has a guide groove 21a formed on its inner cylindrical surface. When the differential case CD and the left drive shaft SDL rotate relative to each other, the lubricating oil flows through the guide groove 21a and is supplied into the differential case CD.

[0032] The sub-large cylindrical portion 32 has a funnel-like cylindrical shape in which the diameter of the cylindrical hole gradually increases toward the inside in the vehicle width direction. The outer end of the sub-large cylinder portion 32 in the vehicle width direction is formed integrally with the inner end of the sub-small cylinder portion 31 in the vehicle width direction, and the inner end in the vehicle width direction is fitted into the main large cylinder portion 22. That is, the end face of the sub-large cylindrical portion 32 on the main case CD1 side (the inner end face in the vehicle width direction) forms the mating surface F on the sub-case CD2 side. The sub-large cylindrical portion 32 includes a sub-flange 33, a sub-fitting portion 34, and a shielding portion 35.

[0033] The sub-flange 33 is configured as an arc-shaped segment that extends radially outward from the end face of the large cylindrical sub-portion 32 on the main case CD1 side so as to overlap the end face of the extension portion 25. The fastening bolts 53 are inserted through the sub-flanges 33 and screwed into the bolt insertion holes 25b, thereby fastening the main case CD1 and the sub-case CD2 together. The sub-fitting portion 34 is formed on the mating surface F on the sub-case CD2 side, and is configured as a protrusion curved in an arc shape that can be fitted into the main fitting portion 27. The portion of the sub-fitting portion 34 that faces the notch portion 26 on the same axis as the sub-fitting portion 34 is set as the shielding portion 35 . The shielding portion 35 is formed coaxially with the sub-fitting portion 34 and at the same height in the direction of the rotation axis AX3. The shielding portion 35 has a slightly smaller diameter than the sub-fitting portion 34 to reduce machining, but may have the same diameter as the sub-fitting portion 34 and have a machined surface.

[0034] That is, the shielding portion 35 is formed at a portion of the sub-fitting portion 34 facing the notch portion 26 so as to protrude toward the notch portion 26. In this way, the opening area of ​​the notch portion 26 is partially reduced by the shielding portion 35. The shielding portion 35 and the sub-fitting portion 34 are set so that the dimensions of their projections from the mating surface F overlap the maximum diameter portion MX of the left side gear GSL in the radial direction. That is, when the subcase CD2 is viewed from the radially outer side, the shielding portion 35 overlaps the left side gear GSL and is formed so as to hide the maximum diameter portion MX of the left side gear GSL.

[0035] In the differential device DF1 configured as above, rotation of the ring gear GR causes the differential case CD and the pinion gear GP to rotate (revolve) around the third rotation axis AX3. As the pinion gear GP revolves, it transmits the rotation of the differential case CD (ring gear GR) to the meshing right side gear GSR and left side gear GSL. When the right side gear GSR rotates, the right drive shaft SDR rotates, and when the left side gear GSL rotates, the right drive shaft SDR rotates. Additionally, when the differential case CD rotates, the pinion gear GP rotates (spins) around the pinion shaft SHP1, transmitting rotation while creating a rotational difference between the left and right drive shafts SD.

[0036] When the differential case CD rotates, the lubricating oil stored in the housing H is scooped up by the ring gear GR and supplied to each part of the reducer RD. In addition, part of the lubricating oil that is scooped up adheres to the inner wall of the housing H and drips down the wall surface. A portion of the dripping lubricating oil is guided to the outside of the bearing BR that supports the differential case CD.

[0037] When the differential case CD and the left and right drive shafts SD rotate relative to each other, the lubricating oil guided to the bearings BR is supplied into the differential case CD through the guide groove 21a provided on the inner circumference of the boss of the differential case CD and via the inner and outer surfaces of the left and right side gears GSR and GSL. This lubricates and cools the meshing portions between the left and right side gears GSR and GSL and the pinion gear GP, as well as other sliding contact portions. Furthermore, the centrifugal force generated by the rotation of the side gears GSR and GSL causes the lubricating oil adhering to the side gears GSR and GSL to move to the maximum diameter portion MX of the side gears GSR and GSL, and then the lubricating oil is scattered radially outward from the maximum diameter portion MX. The scattered lubricating oil hits the shielding portion 35 and is collected in the differential case CD, where it is reused for lubricating and cooling the meshing portions between the left and right side gears GSR and GSL and the pinion gear GP, as well as other sliding contact portions.

[0038] Next, the effects of the differential device DF1 of this embodiment will be described. The differential device DF1 of this embodiment has a sub-fitting portion 34 (shielding portion 35) that protrudes toward the notch portion 26 from the mating surface F on the sub-case CD2 (second case) side. That is, the sub-fitting portion 34 protrudes toward the notch portion 26 beyond the mating surface F between the main case CD1 (first case) and the sub-case CD2 (second case). With this configuration, the lubricating oil that splashes when the side gears GS rotate can be efficiently collected in the differential case CD. This ensures that lubricating oil is supplied sufficiently to the parts of the differential device DF that require lubrication, improving the lubrication and durability of the sliding contact parts of the side gear GS, pinion gear GP, and pinion shaft SHP1. Furthermore, even if the cutout portion 26 is provided to reduce the weight of the differential case, it is possible to store the minimum amount of lubricating oil required within the differential device DF1, thereby achieving both weight reduction and strength and durability.

[0039] Furthermore, in the differential device DF1 of this embodiment, the shielding portion 35 is provided so as to overlap in the radial direction with the maximum diameter portion MX of the left side gear GSL (second side gear). With this configuration, the lubricating oil discharged from the differential case CD can be returned to the inside of the differential case. This further improves the lubrication of the meshing portions and sliding contact portions of the left side gear GSL in particular.

[0040] In addition, in the differential device DF1 of this embodiment, the shielding portion 35 is formed on the mating surface F and is composed of a sub-fitting portion 34 (fitting portion) that protrudes from the sub-case CD2 (second case) toward the main case CD1 (first case). As a result, even if the cutout portion 26 is in a form that is open to the mating surface F, the shielding portion 35 protrudes into the cutout portion 26, thereby reducing the cutout area and suppressing the discharge of lubricating oil.

[0041] Second Embodiment Next, a differential device DF2 according to a second embodiment of the present invention will be described with reference to FIGS. In the description, the same elements as those in the first embodiment are denoted by the same reference numerals, and duplicated descriptions will be omitted. The differential device DF2 of this embodiment differs from the first embodiment in that the shielding portion 35 is configured with a shielding tongue piece 36, but other configurations are the same as those of the first embodiment.

[0042] The shielding tongue piece 36 has a dimension that projects from the mating surface F toward the main case CD1 that is set to be larger than that of the sub-fitting portion 34. The dimension of the projection toward the main case CD1 is set so that the shielding tongue piece 36 overlaps the inner end face of the left side gear GSL in the vehicle width direction when the main case CD1 is viewed from the outside in the radial direction.

[0043] With this configuration, the area cut out by the notch 26 can be further reduced without increasing the number of processing steps. Furthermore, even if the notch bottom 26a of the notch portion 26 is set at a position spaced apart from the mating surface F, the area of ​​the notch can be controlled.

[0044] <Third embodiment> Next, a differential device DF3 according to a third embodiment of the present invention will be described with reference to FIGS. In the description, the same elements as those in the first embodiment are denoted by the same reference numerals, and duplicated descriptions will be omitted. The differential device DF3 of this embodiment differs from the first embodiment in that a shielding member 41 is provided to close the notch 26, but other configurations are the same as those of the first embodiment.

[0045] The shielding member 41 has a generally cylindrical shape centered on the third rotation axis AX3, and is fitted onto the main large cylinder portion 22. The shielding member 41 includes a shielding body 42 and a fitting portion 43 . The shielding body 42 is fitted onto the main large cylinder portion 22 and the extension portion 25 . The fitting portion 43 is fitted into the substantially U-shaped notch portion 26 . The shielding member 41 is positioned in the circumferential direction by fitting the fitting portion 43 into the notch portion 26. In addition, the shielding member 41 is positioned in the axial direction by being fitted so that its inner end in the vehicle width direction abuts against the extended ends 33a and 33b of the sub-flange 33 and its outer end in the vehicle width direction abuts against the notch bottom 26a.

[0046] With this configuration, the portion cut out by the notch 26 can be shielded without impairing the ease of assembly of the differential device DF3. This reduces the amount of lubricating oil discharged. Furthermore, by fitting the fitting portion 43 into the notch portion 26, the spatial volume within the main large cylinder portion 22 is further reduced. This reduces the volume required to store the recovered lubricating oil, and as the pinion gear GP rotates, the amount of lubricating oil scooped up increases relatively, allowing the engine to achieve sufficient lubricating performance with less lubricating oil.

[0047] In this embodiment, the fitting portion 43 is configured to shield the entire portion cut out by the notch portion 26, but the present invention is not limited to this configuration. For example, the fitting portion 43 may be configured to have a plurality of small holes. This configuration makes it possible to control the amount of lubricating oil recovered. In addition, in this embodiment, the shielding member 41 is configured to be fitted onto the outside of the main large cylinder portion 22, but the present invention is not limited to this configuration. For example, it is possible to configure the shielding member to be fitted inside the main large cylinder portion 22, and then clamped and positioned between the main fitting portion 27 and the sub-fitting portion 34, thereby achieving the same effects as those of this embodiment. [Explanation of symbols]

[0048] DF1, DF2, DF3...Differential device CD...Differential case CD1...First case (main case) CD2...Second case (sub-case) AX3...Differential case rotating shaft (third rotating shaft) GSR...First side gear (right side gear) GSL...Second side gear (left side gear) GP...Pinion gear F...Mating surface 25...Extension portion 26...Notch portion 34...Fitting portion (sub-fitting portion) 35...Shielding portion 41...Shielding member

Claims

1. a differential case that forms a hollow shape with the first case and the second case and is supported rotatably around a rotation axis; a first side gear supported in the first case so as to be rotatable relative to the differential case about a rotation axis of the differential case; a second side gear supported in the second case so as to be rotatable relative to the differential case about a rotation axis of the differential case and to face the first side gear; a plurality of pinion gears journalled on the differential case and meshing with the first side gear and the second side gear, respectively; and The first case is an extension portion that pivotally supports one end of each of the pinion gears; a notch portion formed by cutting out a portion of the extension portion located between a portion supporting one of the pinion gears and a portion supporting another adjacent pinion gear in a substantially U-shape; and The second case is A shielding portion protrudes toward the notch portion beyond the mating surface between the first case and the second case. Differential device.

2. 2. The differential device according to claim 1, The shielding portion is The second side gear extends radially to overlap the maximum diameter portion of the second side gear. Differential device.

3. 2. The differential device according to claim 1, The shielding portion is a mating portion formed on a mating surface that divides the first case and the second case, the mating portion being coaxial with a mating portion that protrudes from the second case toward the first case; Differential device.

4. 4. The differential device according to claim 3, The shielding portion is Extending from the fitting portion along the rotation axis of the differential case Differential device.

5. 2. The differential device according to claim 1, a shielding member that is sandwiched between the first case and the second case and that closes at least a part of the notch; Differential device.

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