Differential device

Abstract

The differential device (1) is provided with a differential device housing (2), a first pinion pair (41), a second pinion pair (51), a side gear pair (31), and a pinion support member (53). The differential device housing (2) rotates around a first rotation axis (3) and has a spherical shell shape along the first rotation axis (3). A first pinion pair (41) that rotates about a second rotation axis line (4) orthogonal to the first rotation axis line (3) and is disposed inside the differential housing (2); a second pinion pair (51) that rotates about a third rotation axis line (5) orthogonal to the first rotation axis line (3) and the second rotation axis line (4), and that is disposed inside the differential housing (2); the side gear pair (31) is meshed with the first pinion pair (41) and the second pinion pair (51) at a right angle, rotates around a first rotation axis (3), and is arranged in a manner of being capable of rotating relative to the differential device housing (2); the pinion support member (53) is disposed on the rear surface of the second pinion pair (51), and is provided in an opening (2b) of the differential housing (2) at a position closer to the first rotation axis (3) than an end surface (5c) of a pinion support shaft (5b) that supports the second pinion pair (51) of the third rotation axis (5).

Description

Technical Field

[0001] The invention relates to a differential device. Background Art

[0002] A differential device for performing a differential between the left and right wheels of a vehicle or between the front and rear wheels generally uses a double pinion type differential device, which uses two pinions. In the case where the input torque is high, in order to reduce the load applied to the pinions and ensure durability, a four-pinion type differential device is used, which uses four pinions (for example, refer to Patent Document 1).

[0003] The differential device is assembled in the transmission (transaxle, variable speed drive axle) for driving the front wheels and the final reduction gear for driving the rear wheels. The differential device has a spherical shell-shaped differential case, a ring gear (ring gear) externally fitted in the differential case, a pair of pinion gears housed in the differential case, a pair of side gears (side gears) housed in the differential case, and a pinion shaft (pinion shaft) fitted in the differential case.

[0004] The pinion gear is arranged to be rotatable about a rotation axis arranged perpendicular to the rotation axis of the differential case. A pair of side gears mesh with the pinion gear, are arranged coaxially with the differential case, and are housed in the differential case so as to be relatively rotatable with the differential case. The pinion gear is supported by a pinion shaft.

[0005] Here, the differential case for the double pinion type differential device has an opening at a position offset 90 degrees from the arrangement position of the pinion gear in the direction of the rotation axis of the differential case in order to assemble the pinion gear and the side gear inside. Therefore, the differential case for the double pinion type differential device cannot be directly used for the four-pinion type differential device. Generally speaking, as described in Patent Document 1, the four-pinion type differential device does not have an opening for obtaining the pinion receiving surface of the differential case, but is configured to be able to split the differential case in the direction of the rotation axis and fastened together with bolts that fix the ring gear. [Prior art literature] [Patent Document]

[0006] Patent Document 1: Japanese Patent Publication No. 2007-270947 Summary of the invention Technical problem to be solved by the invention

[0007] However, in the four-pinion differential described in Patent Document 1, when one pinion shaft and two pinion shafts on the other side are assembled in a cross shape inside the differential case, the differential case has a two-point structure. Therefore, the four-pinion differential has a problem of increased cost due to an increase in the number of parts, processing man-hours, and assembly man-hours.

[0008] In addition, the ring gear fixing hole for inserting the ring gear fastening bolt requires high precision in hole diameter and position, so it is necessary to process the two-point differential case at the same time, that is, to perform coordinated processing. In addition, for the four-pinion differential, it is necessary to screw in small screws for temporarily fixing the two-point differential case in the process until the ring gear is installed, which reduces production efficiency.

[0009] In order to solve this problem, a four-pinion differential device is required in which the differential case is configured as a one-point type and the components of the differential case of a double pinion differential device are standardized while suppressing an increase in cost and a decrease in production efficiency.

[0010] The present invention is made to solve such a technical problem, and the technical problem to be solved is to provide a four-pinion differential device that can reduce the number of parts and achieve cost reduction. Technical solutions adopted to solve technical problems

[0011] In order to solve the above technical problems, the differential device involved in the present invention has a differential device case, a first pinion gear pair, a second pinion gear pair, a side gear pair and at least one pinion gear supporting member, wherein the differential device case rotates around a first rotation axis and is spherical along the direction of the first rotation axis; the first pinion gear pair rotates around a second rotation axis orthogonal to the first rotation axis and is arranged inside the differential device case; the second pinion gear pair rotates around a third rotation axis orthogonal to the first rotation axis and the second rotation axis and is arranged inside the differential device case; the side gear pair meshes with the first pinion gear pair and the second pinion gear pair at right angles, rotates around the first rotation axis, and is arranged in a manner that can rotate relative to the differential device case; at least one of the pinion gear supporting members is arranged on the back side of the second pinion gear pair, and is provided in an opening formed in the differential device case at a position on the third rotation axis that is closer to the first rotation axis side than the end face of the pinion gear supporting shaft supporting the second pinion gear pair. [Effects of the invention]

[0012] According to the differential device of the present invention, it is possible to provide a four-pinion differential device capable of reducing the number of parts and achieving cost reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a transverse cross-sectional view showing a main part of a differential device according to a first embodiment of the present invention. Figure 2 It is a longitudinal sectional view showing a main part of a differential device according to a first embodiment of the present invention. Figure 3 It is a side view showing a differential device according to the first embodiment of the present invention. Figure 4 It is an exploded perspective view of main parts showing a differential device according to a first embodiment of the present invention. Figure 5 It is a perspective view showing a main part of a differential device according to a first embodiment of the present invention. Figure 6 It is a diagram showing a differential device according to a first embodiment of the present invention, and is a perspective view of main parts showing a state in which a pinion gear support member is removed. Figure 7 It is an enlarged perspective view of the main parts showing the installation state of the snap ring. Figure 8 It is an enlarged perspective view showing a pair of snap rings. Fig. 9 It is a transverse cross-sectional view showing a main part of a differential device according to a second embodiment of the present invention. Fig.10 1 is a diagram showing a differential device according to a second embodiment of the present invention, and is a transverse cross-sectional view of a main part showing a state in which a side gear pair is assembled to a differential device case. Fig.11 It is an exploded perspective view of main parts showing a differential device according to a second embodiment of the present invention. Fig.12 It is a transverse cross-sectional view showing a main part of a differential device according to a third embodiment of the present invention. Fig.13 1 is a diagram showing a differential device according to a third embodiment of the present invention, and is a transverse cross-sectional view of a main part showing a state in which a side gear pair is assembled to a differential device case. Fig.14 It is an exploded perspective view of main parts showing a differential device according to a third embodiment of the present invention. Fig.15 The diagram showing a modified example of the snap ring of the differential device according to the first embodiment of the present invention is a schematic diagram showing the shape of the snap ring. DETAILED DESCRIPTION

[0014] [First embodiment] Reference Figures 1 to 8 A differential device 1 according to a first embodiment of the present invention will be described. In the following description, the same reference numerals are used for the same components, and repeated descriptions are omitted. In addition, in the differential device 1, the parts having substantially symmetrical shapes are described together as appropriate. Figure 1 and Figure 2 In the differential device 1 shown, the description will be given assuming that the direction in which the first rotation axis line 3 extends is the left-right direction of the vehicle.

[0015] Differential Figure 1 and Figure 2 The differential device 1 shown is assembled in a final reduction gear (not shown) for reducing the speed of the power generated by a prime mover (not shown) arranged in front of the vehicle and after the power is changed by a speed change device (not shown). The differential device 1 is a device for causing the left rear wheel and the right rear wheel to rotate at a differential speed by the power transmitted through the propeller shaft. Figure 1 or Figure 2 As shown, the differential device 1 includes a differential device case 2 , a first pinion shaft 40 , a second pinion shaft 50 , a side gear pair 31 , a first pinion pair 41 , a second pinion pair 51 , a thrust washer 52 , a pinion support member 53 , and a snap ring 54 .

[0016] <Differential gear case> like Figure 1 , Figure 2 or Figure 4 As shown, the differential housing 2 is a housing that rotates around the first rotation axis 3 and is spherical in shape along the direction of the first rotation axis 3. The differential housing 2 is a gear box that accommodates four pinions consisting of a pair of first pinion pairs 41 and a pair of second pinion pairs 51 and can cope with the so-called four-pinion type. The differential housing 2 is composed of components of a one-point structure formed by one component. The differential housing 2 has a spherical shell portion 2a, an opening portion 2b, a flange portion 2c, a gear storage chamber 2e, a snap ring engagement groove 2f, a fixing hole 2g, a boss portion 2h, a shaft support hole 2i and a shaft insertion hole 2j.

[0017] like Figure 1 , Figure 2 and Figure 4 As shown, the spherical shell 2a is a substantially cylindrical member and constitutes a gear storage chamber 2e for rotatably housing the side gear pair 31, the first pinion gear pair 41, and the second pinion gear pair 51. A plurality of openings 2b are formed in the spherical shell 2a.

[0018] The opening 2b is a window for assembling the side gear pair 31, the first pinion gear pair 41 and the second pinion gear pair 51 in the spherical shell 2a and is closed by the pinion gear support member 53. The opening 2b is formed in the outer peripheral portion of the spherical shell 2a by a substantially circular through hole formed at a position where the third rotation axis 5 is arranged. A snap ring engaging groove 2f is formed on the inner peripheral surface of the opening 2b.

[0019] The snap ring engagement groove 2f is a groove engaged with the toothed portion 54b formed on the outer periphery of the snap ring 54. The snap ring 54 is attached to the differential case 2 by the toothed portion 54b engaging with the snap ring engagement groove 2f. The snap ring engagement groove 2f is formed of a substantially annular (C-shaped) groove.

[0020] The flange portion 2c is a portion for fixing a ring gear (not shown) that rotates integrally with the differential case 2 to the outer periphery of the differential case 2. The flange portion 2c is formed in a circular ring shape and protrudes at a position close to the left end of the outer periphery of the spherical shell portion 2a. The flange portion 2c is formed with a plurality of fixing holes 2g at appropriate intervals, and the fixing holes 2g are used to insert a fixing member (not shown) that fixes the ring gear (not shown) to the differential case 2.

[0021] The ring gear (not shown) is an annular bevel gear that meshes with a drive pinion of a drive pinion shaft (not shown). The drive pinion gear (not shown) transmits the output from the transmission (not shown) to the ring gear (not shown). The drive pinion gear shaft having the teeth of the drive pinion gear integrally formed therewith is arranged along a direction perpendicular to the axis of the ring gear.

[0022] like Figure 1 or Figure 2 As shown, the gear storage chamber 2e is a storage portion for storing the side gear pair 31, the first pinion gear pair 41, and the second pinion gear pair 51. The gear storage chamber 2e is composed of a hollow storage space formed in the spherical shell portion 2a.

[0023] like Figure 1 to Figure 4 As shown, the boss portion 2h is a portion on which a bearing (not shown) for axially supporting (supporting in a freely rotatable manner) the differential housing 2 is mounted. The boss portion 2h is composed of a pair of left and right cylindrical portions formed by protruding from the left and right end sides of the spherical shell portion 2a. The pair of boss portions 2h is mounted on the axial support portion of the bracket through a pair of left and right bearings. Therefore, the differential housing 2 is supported by a pair of left and right bearings at both ends, and is axially supported in the bracket so as to be freely rotatable around the first rotation axis 3. An axial support hole 2i is formed in the boss portion 2h.

[0024] like Figure 1 and Figure 2As shown, the shaft support hole 2i is a hole for inserting a drive shaft (not shown). The side gear pair 31 is spline-fitted with the drive shaft and is disposed in a floating state inside the differential case 2. Furthermore, a shaft insertion hole 2j is formed in the spherical shell portion 2a, and the shaft insertion hole 2j axially supports (rotatably supports) a second rotation axis 4 that is arranged orthogonally to the shaft support hole 2i (first rotation axis 3).

[0025] <First rotation axis> like Figure 1 and Figure 2 As shown, the first rotation axis 3 is the rotation axis of the differential case 2 and is also the rotation axis of the side gear pair 31 spline-connected to the drive shaft.

[0026] <Side gear pair> The side gear pair 31 is a pair of gears meshing at right angles with the first pinion pair 41 and the second pinion pair 51. The side gear pair 31 is configured to be rotatable about the first rotation axis 3 and to be rotatable relative to the differential case 2. A thrust washer 32 that applies force to the side gear pair 31 in the direction of the center O1 is interposed between the side gear pair 31 and the gear storage chamber 2e.

[0027] <Second rotation axis> like Figure 2 As shown, the second rotation axis 4 is the rotation axis of the first pinion gear pair 41. The first pinion shaft 40 supporting the first pinion gear pair 41 is a shaft member arranged orthogonally to the first rotation axis 3 and extending in the radial direction of the differential case 2. Shaft insertion holes 2j are fitted at both ends of the first pinion shaft 40.

[0028] <First pinion pair> like Figure 2 As shown, the first pinion gear pair 41 is a pair of bevel gears that rotate around the second rotation axis 4. A through hole 41a for inserting the first pinion shaft 40 is formed in the first pinion gear pair 41. The first pinion gear pair 41 is arranged inside the gear storage chamber 2e in a freely rotatable manner. A thrust washer 42 that applies force to the first pinion gear pair 41 in the direction of the center O1 is interposed between the first pinion gear pair 41 and the gear storage chamber 2e.

[0029] <Third rotation axis> like Figure 1 and Figure 2 As shown, the third rotation axis 5 is the rotation axis of the second pinion gear pair 51. The second pinion gear shaft 50 supporting the second pinion gear pair 51 is a shaft member arranged orthogonally to the first rotation axis 3 and the second rotation axis 4. Figure 4 As shown, the second pinion shaft 50 has a shaft support hole 50a, a pinion support shaft 50b, and an end surface 50c.

[0030] The shaft support hole 50 a is a through hole for inserting and arranging the first pinion shaft 40 . The second pinion shaft 50 supports the second pinion gear pair 51 and the thrust washer 52 in a relatively rotatable manner, and is supported by the differential case 2 via a pinion gear support member 53 to be described later.

[0031] <Second pinion pair> like Figure 1 and Figure 4 As shown, the second pinion gear pair 51 is a pair of left and right bevel gears that rotate around the third rotation axis 5. The second pinion gear pair 51 is formed with a through hole 51a for inserting the second pinion shaft 50. The second pinion gear pair 51 is arranged inside the gear storage chamber 2e to be freely rotatable around the third rotation axis 5.

[0032] <Thrust washer> like Figure 1 and Figure 4 As shown, the front and rear thrust washers 52 are arranged between the back surface of the second pinion gear pair 51 and the inner surface of the pinion gear support member 53 to improve the lubrication performance between the two surfaces that rotate relatively.

[0033] <Pinion gear support parts> like Figure 1 and Figure 4 As shown, a pair of left and right pinion support members 53 are bearing members that support the second pinion shaft 50. The pinion support member 53 is composed of a thick cover-shaped member, and has a shaft insertion hole 53a for axially supporting (rotatably supporting) the pinion support shaft 50b. A snap ring mounting groove 53b for mounting a snap ring 54 is formed on the outer periphery of the pinion support member 53. The pinion support member 53 is arranged on the back side (the side opposite to the first rotation axis 3) of the second pinion pair 51 via a thrust washer 52, and functions as a support member that supports the second pinion pair 51 from the back side at the opening 2b of the differential case 2.

[0034] The pinion gear support member 53 is a cover-shaped member that is detachably fixed to the opening 2b of the differential case 2 by engaging the snap ring 54 with the snap ring engagement groove 2f. Figure 1 As shown, the pinion gear support member 53 is locked to the opening portion 2 b of the differential case 2 by a snap ring 54 within the range of the fitting portion in the direction of the third rotation axis 5 .

[0035] <Snap ring> As described above, the snap ring 54 is a fixing member for detachably mounting the pinion support member 53 in the opening 2b. The snap ring 54 is composed of a disc spring snap ring having an arc portion 54a, a toothed portion 54b, and a tool locking portion 54c.

[0036] like Figure 4 or Figure 8 As shown, the arc portion 54a is a portion that engages with the snap ring mounting groove 53b of the pinion gear support member 53. The arc portion 54a is composed of a flat plate portion formed in an arc shape.

[0037] The toothed portion 54b is a portion that has a function of generating a load force in the direction of the third rotation axis 5, thereby engaging with the snap ring engagement groove 2f on the differential case 2 side and the snap ring mounting groove 53b on the pinion support member 53 side, thereby applying a force to the second pinion pair 51 toward the center O1 side, thereby suppressing the clearance of the meshing portion with the side gear pair 31 to be small. The toothed portion 54b is composed of a plurality of toothed protrusions formed at appropriate intervals on the outer periphery of the flat arc portion 54a. The toothed portion 54b extends obliquely outward from the outer periphery of the arc portion 54a.

[0038] The tool locking portion 54 c is a portion for inserting a tool (not shown) to attach or detach the snap ring 54 when attaching or detaching the snap ring 54 to or from the snap ring mounting groove 53 b of the pinion gear support member 53 .

[0039] 《Effects of Differential Devices》 The differential device 1 according to the first embodiment of the present invention is basically configured as described above. Figures 1 to 8 The effect of the action is described.

[0040] like Figure 1 and Figure 2 As shown, the side gear pair 31, the first pinion pair 41, and the second pinion pair 51 are housed in the gear storage chamber 2e of the differential housing 2 formed by a single component. Therefore, the differential housing 2 can reduce the number of components and assembly man-hours of the differential 1 to achieve cost reduction. In addition, the four-pinion differential housing 2 can be shared with the double-pinion differential housing, so the four-pinion differential 1 can be produced without increasing costs or reducing production efficiency.

[0041] In addition, if Figure 1 and Figure 4 As shown, a pinion support member 53 supporting the second pinion gear pair 51 is disposed in the opening 2b of the differential case 2. The pinion support member 53 is mounted in the opening 2b by engaging a snap ring 54 mounted in a snap ring mounting groove 53b of the pinion support member 53 with the snap ring engaging groove 2f.

[0042] like Figure 1 As shown, the locking position of the snap ring 54 is located within the range of the thickness of the pinion support member 53 (opening 2b), wherein the pinion support member 53 axially supported (rotatably supported) around the third rotation axis 5 is engaged with the opening 2b. Therefore, for the differential case 2, compared with the case where the snap ring 54 is arranged on the end surface (outer surface) of the pinion support member 53, the structure around the opening 2b can be made thinner, so that the differential case 2 can be miniaturized and lightweight.

[0043] In addition, the pinion gear support member 53 is mounted on the opening 2b of the differential case 2 at a position closer to the first rotation axis 3 than the end surface 50c of the pinion gear support shaft 50b. Therefore, the pinion gear support member 53 and the wall portion of the differential case 2 around the opening 2b can be formed thinner, so that the differential case 2 can be miniaturized and lightened.

[0044] In addition, the opening 2b of the differential case 2 is closed by the pinion support member 53, thereby making it possible to make the dedicated area of ​​the opening portion formed in the differential case 2 smaller than that of the differential case of the prior art. Therefore, the opening portion from the inside of the differential case 2 to the outside of the differential device 1 can be reduced, so that the lubricating oil stored in the inside of the differential case 2 can be suppressed from being discharged to the outside. As a result, the lubricity of the meshing portions and sliding contact portions of the first pinion pair 41, the second pinion pair 51, the side gear pair 31, and the pinion shaft of the differential device 1 can be improved.

[0045] In this way, Figure 1 to Figure 4 As shown, the differential device 1 involved in the first embodiment of the present invention comprises a differential device case 2, a first pinion pair 41, a second pinion pair 51, a side gear pair 31 and at least one pinion support component 53, wherein the differential device case 2 rotates around the first rotation axis 3 and is in the shape of a spherical shell along the direction of the first rotation axis 3; the first pinion pair 41 rotates around the second rotation axis 4 orthogonal to the first rotation axis 3 and is arranged inside the differential device case 2; the second pinion pair 51 rotates around the second rotation axis 4 orthogonal to the first rotation axis 3 and the second rotation axis 4. The side gear pair 31 is arranged inside the differential case 2 so as to rotate around the first rotation axis 3 as the center and is arranged at a right angle with the first pinion gear pair 41 and the second pinion gear pair 51, and is arranged in a manner that it can rotate relative to the differential case 2; at least one pinion gear supporting member 53 is arranged on the back side of the second pinion gear pair 51, and is provided in an opening portion 2b formed in the differential case 2 at a position on the third rotation axis 5 that is closer to the first rotation axis 3 than the end surface 50c of the pinion gear supporting shaft 50b supporting the second pinion gear pair 51.

[0046] According to this structure, the differential case 2 accommodates the first pinion pair 41, the second pinion pair 51, and the side gear pair 31, rotates around the first rotation axis 3, and has a spherical shell shape along the direction of the first rotation axis 3. Therefore, the differential case 2 can be composed of a case of a one-point structure that can cope with a four-pinion type, so the number of parts and assembly man-hours can be reduced to achieve cost reduction. In addition, the pinion gear support member 53 is arranged on the back side of the second pinion gear pair 51, and is provided in the opening portion 2b at a position closer to the first rotation axis 3 than the end face 50c of the pinion gear support shaft 50b supporting the second pinion gear pair 51. Therefore, the pinion gear support member 53 and the periphery of the opening portion 2b of the differential case 2 can be formed thinner, so that the differential case 2 can be miniaturized and lightweight. Furthermore, the pinion gear support member 53 can support the second pinion gear pair 51 axially supported (rotatably supported) about the third rotation axis line 5 from the rear side, and thus can support the second pinion gear pair 51 so as to rotate in a stable state.

[0047] In addition, if Figure 1 and Figure 4 As shown, the pinion support shaft 50b is a pinion shaft, and the pinion support component 53 receives the back surface of the second pinion pair 51 and is locked in the opening portion 2b of the differential case 2 by a snap ring 54 within the range of the fitting portion in the direction of the third rotation axis 5. Here, "within the range of the fitting portion in the direction of the third rotation axis 5" means within the range of the thickness of the pinion support component 53 (opening 2b) where the pinion support component 53 axially supported (rotatably supported) around the third rotation axis 5 fits with the opening 2b.

[0048] According to this configuration, the pinion gear support member 53 is locked to the opening portion 2 b of the differential case 2 by the snap ring 54 . Therefore, the pinion gear support member 53 can be firmly fixed in the opening portion 2 b without rattling. Furthermore, since the fixing tool for fixing the pinion gear support member 53 to the opening portion 2 b of the differential case 2 is constituted by the snap ring 54 , the snap ring 54 can be firmly fixed to the middle of the outer peripheral portion of the pinion gear support member 53 in the thickness direction.

[0049] In addition, as a modification of the first embodiment, it is also possible to Fig.15 As shown, the snap ring 54C has a tool locking portion 54Cc extending radially from the third rotation axis 5, and the differential case 2C has a tool locking portion accommodating portion 2Cd formed continuously with the opening 2Cb and communicating with the inside and outside of the differential case 2C.

[0050] According to this structure, the snap ring 54C has a tool locking portion 54Cc, and the tool locking portion 54Cc is composed of a protrusion 54Cd extending radially from the third rotation axis 5, thereby expanding the tool locking portion 54Cc of the snap ring 54, and the snap ring 54C can be easily removed. The lightening portion 2Cn is formed by cutting off a part of the opening 2Cd to form a notch, thereby making it easy to form the tool locking portion accommodating portion 2Cd.

[0051] [Second embodiment] Next, refer to Figures 9 to 11 The differential device 1A according to the second embodiment of the present invention will be described mainly with respect to the differences from the differential device 1 according to the first embodiment. The same reference numerals are given to the components that have already been described, and description thereof will be omitted.

[0052] Fig. 9 It is a transverse cross-sectional view of a main part showing a differential device 1A according to a second embodiment of the present invention. Fig.10 1A is a diagram showing a differential device 1A according to a second embodiment of the present invention, and is a transverse cross-sectional view of a main part showing a state in which a side gear pair 31 is assembled to a differential device case 2A. Fig.11 It is an exploded perspective view of main parts showing a differential device 1A according to a second embodiment of the present invention.

[0053] like Figures 9 to 11 As shown, the difference between the differential device 1A involved in the second embodiment of the present invention and the first embodiment is that: the pinion support component 53A receives the back side of the second pinion pair 51 and is screwed into the opening portion 2Ab of the differential device case 2A; and the annular protrusion 53Ad is riveted and fixed to the outer end portion of the internal thread portion 2Am.

[0054] In this case, an internal thread portion 2Am is formed on the inner wall of the opening portion 2Ab of the differential case 2A. Fig. 9 and Fig.11 As shown, the pinion gear support member 53A is a cover-shaped member that closes the opening 2Ab. On the outer peripheral surface of the pinion gear support member 53A mounted on the opening 2Ab, there are formed an external threaded portion 53Ab that is screwed with the internal threaded portion 2Am, and an annular protrusion 53Ad formed at the outer end of the external threaded portion 53Ab. The pinion gear support member 53A is configured to clamp the thrust washer 52 and the second pinion gear pair 51 with the side gear pair 31 by screwing the external threaded portion 53Ab into the internal threaded portion 2Am.

[0055] The annular protrusion 53Ad is a locking protrusion for locking the pinion support member 53A inserted into the opening 2Ab to the outer end of the internal thread portion 2Am in a non-rotatable manner. After the pinion support member 53A is screwed into the opening 2Ab, it is riveted and fixed to the outer end of the internal thread portion 2Am, thereby the annular protrusion 53Ad functions as a rotation stopper for the pinion support member 53A.

[0056] A tool engagement hole 53Ac and a shaft insertion hole 53Aa for inserting the second pinion shaft 50 are formed on the side surface of the pinion support member 53A.

[0057] According to this structure, the pinion support component 53A of the differential device 1A of the second embodiment needs to be screwed together while adjusting the tooth clearance between the second pinion pair 51 and the side gear pair 31, but in this case, by locking the tool with a protruding pin in the tool engagement hole 53Ac, the screwing amount of the pinion support component 53A can be easily and appropriately obtained.

[0058] Furthermore, the pinion gear support member 53A may be provided with uniform concavities and convexities in the circumferential direction, and a lock plate may be provided to be engaged with the concavities and convexities. The opening 2Ab of the differential case 2A may be reduced in diameter to an inner diameter through which the side gear pair 31 and the first pinion gear pair 41 assembled therein can be inserted. In this case, the opening 2Ab of the differential case 2A may be provided with a notch larger than the inner diameter of the internal thread portion 2Am.

[0059] [Third embodiment] Fig.12 It is a transverse cross-sectional view of a main part showing a differential device 1B according to a third embodiment of the present invention. Fig.13 1B is a diagram showing a differential device 1B according to a third embodiment of the present invention, and is a transverse cross-sectional view of a main part showing a state in which a side gear pair 31 is assembled to a differential device case 2B. Fig.14 It is an exploded perspective view of main parts showing a differential device 1B according to a third embodiment of the present invention.

[0060] like Figure 12 to Figure 14 As shown, the difference between the differential device 1B involved in the third embodiment of the present invention and the first embodiment is that a shaft portion 51Bb is provided on the back side of the second pinion pair 51B, and the shaft portion 51Bb is inserted into the shaft support hole 53Ba of the pinion support component 53B for shaft support (supported in a rotatable manner); the pinion support component 53B is a ball bearing.

[0061] In this way, the second pinion pair 51B of the differential device 1B of the third embodiment can also be that the shaft portion 51Bb is protrudingly provided on the back side, the pinion support component 53B has an shaft support hole 53Ba for axially supporting (rotatably supporting) the shaft portion 51Bb, and the pinion support component 53B is inserted into the opening portion 2Bb of the differential device case 2B and is supported in the opening portion 2Bb by a retaining ring 54B provided in the opening portion 2Bb.

[0062] In this case, if Figure 12 to Figure 14 As shown, the second pinion gear pair 51B has a shaft portion 51Bb on the back side of the helical tooth portion 51Bc. The shaft portion 51Bb is composed of a cylindrical protrusion fitted into the shaft support hole 53Ba of the pinion gear support member 53B, and is supported by the opening portion 2Bb through the pinion gear support member 53B.

[0063] The pinion gear support member 53B is constituted by a bearing member such as a bearing, for example. The outer side surface (back side) of the pinion gear support member 53B whose outer peripheral portion is fitted into the opening portion 2Bb is held in the opening portion 2Bb by a snap ring 54B.

[0064] In the case of a double pinion type differential, the differential case 2 can be used as is. It is also possible to omit processing of the opening 2Bb of the differential case 2B where the pinion support member 53B is to be mounted, and keep the cast rough surface as it is.

[0065] According to this configuration, the pinion gear support member 53B is formed of a ball bearing, and rotatably supports the shaft portion 51Bb of the second pinion gear pair 51B, thereby functioning as a bearing member of the second pinion gear pair 51B.

[0066] 1, 1A, 1B: differential device; 2, 2A, 2B, 2C: differential device housing; 2b, 2Ab, 2Bb: opening portion; 2d: tool locking portion accommodating portion; 3: first rotation axis; 4: second rotation axis; 5: third rotation axis; 31: side gear pair; 41: first pinion pair; 50b: pinion support shaft; 50c: end face; 51, 51B: second pinion pair; 51Bb: shaft portion; 53, 53A, 53B: pinion support component; 53Ba: shaft support hole; 54, 54B, 54C: retaining ring; 54c, 54Ba, 54Cc: tool locking portion.

Claims

1. A differential device, characterized in that: A differential housing, a first pinion gear pair, a second pinion gear pair, a side gear pair and at least one pinion gear support member are provided, wherein: The differential housing rotates around a first rotation axis and is spherical along the direction of the first rotation axis. The first pinion gear pair rotates around a second rotation axis orthogonal to the first rotation axis, and is arranged inside the differential device case; The second pinion gear pair rotates around a third rotation axis orthogonal to the first rotation axis and the second rotation axis, and is arranged inside the differential device case; The side gear pair is meshed with the first pinion gear pair and the second pinion gear pair at right angles, rotates around the first rotation axis, and is arranged to be relatively rotatable with the differential case; At least one of the pinion gear support members is arranged on the back side of the second pinion gear pair, and is provided in an opening portion formed in the differential device case at a position on the third rotation axis that is closer to the first rotation axis side than the end surface of the pinion gear support shaft supporting the second pinion gear pair.

2. The differential device according to claim 1, characterized in that: The pinion support shaft is a pinion shaft, The pinion gear support member receives the back surface of the second pinion gear pair and is locked to the opening of the differential case via a snap ring within the range of the fitting portion in the direction of the third rotation axis.

3. The differential device according to claim 1, characterized in that: The pinion support shaft is a pinion shaft, The pinion gear support member receives the back surface of the second pinion gear pair and is screwed into the opening of the differential case.

4. The differential device according to claim 1, characterized in that: A shaft portion is protrudingly provided on the back side of the second pinion gear pair. The pinion gear support member has a shaft support hole for shaft-supporting the shaft portion, and the pinion gear support member is inserted into an opening of the differential case and supported in the opening via a snap ring provided in the opening.

5. The differential device according to claim 2 or 4, characterized in that: The retaining ring has a tool retaining portion extending radially from the third rotation axis. The differential case includes a tool locking portion accommodating portion that is continuous with the opening and communicates with the inside and outside of the differential case.

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