JP2020153493A - Differential device and its assembling method - Google Patents

Abstract

To eliminate the necessity for securing a wide side gear assembling space between a differential case inner face and a pinion gear even though an annular recess and a protrusion are specially formed for the prevention of the displacement of a side gear, in a differential device which can be engaged so that the annular recess is formed at one of mutually opposing faces between a differential case inner face and a side gear back face, the protrusion is formed at the other, and the annular recess and the protrusion permit the rotation of the side gear when the side gear is in a normal attachment position in the differential case, but prohibit a revolution around a pinion shaft.SOLUTION: In a differential device 10, one of opposing faces having an annular recess 50 out of mutually opposing faces of an inner face 8i of a differential case 8 and a side gear back face 23f has a passage groove 51 which communicates with the annular recess 50, and has a shape allowing a protrusion 61 to pass therethrough, and a groove width of an opening part e facing the annular recess 50, of the passage groove 51 is narrower than an outside diameter of the annular recess 50.SELECTED DRAWING: Figure 4

Description

The present invention includes a differential device, particularly an integrated differential case that can rotate around a predetermined axis, a pair of side gears whose back surface is rotatably supported around a predetermined axis on the inner surface of the differential case, and a pair that is housed in the differential case. A pair of pinion gears that mesh with the side gears, a pinion shaft that is mounted on the differential case and rotatably fits and supports the pinion gears, and a pinion shaft that extends in a direction orthogonal to a predetermined axis, and allows the pinion gears and side gears to be inserted into the differential case. The present invention relates to a differential device provided with a work window provided in the differential case.

In the above differential device, if the side gears are assembled during the period from when the pinion gear, the pinion shaft and the side gears are assembled in the differential case to the interlocking connection (for example, spline fitting) of the drive shafts to both side gears. If it revolves around the pinion shaft and shifts from the proper mounting position, the drive shaft cannot be interlocked and connected to both side gears. In this case, it is necessary to specially correct the position of the side gear, which makes the work troublesome.

Therefore, in order to prevent the side gear from shifting from the normal mounting position, an annular recess is provided on the inner surface of the differential case, and a cylindrical boss portion (that is, a convex portion) is provided on the back surface of the side gear corresponding to the annular recess. For example, a patent is provided in which an annular recess and a cylindrical boss are fitted (that is, engaged) so as to allow rotation of the side gear when the side gear is in the proper mounting position but prevent revolution around the pinion shaft. As shown in Document 1, it is conventionally known.

JP-A-2018-54043

In the above differential device, in order to avoid the pinion gear incorporated in the differential case prior to the side gear in the assembly process and the cylindrical boss portion protruding from the back surface of the side gear obstructing the incorporation of the side gear. In addition, it is necessary to secure a sufficiently large assembly space for the side gear between the inner surface of the differential case and the pinion gear so that the side gear can smoothly pass through, and there is a problem that design restrictions increase accordingly.

The present invention has been proposed in view of the above, and an object of the present invention is to provide a differential device capable of solving the above problems of a conventional device with a simple structure.

In order to achieve the above object, the present invention comprises an integrated differential case that can rotate around a predetermined axis, a pair of side gears whose back surface is rotatably supported on the inner surface of the differential case around the predetermined axis, and the differential case. A pair of pinion gears housed inside and meshing with the pair of side gears, a pinion shaft mounted on the differential case and rotatably fitting and supporting the pinion gears, and a pinion shaft extending in a direction orthogonal to the predetermined axis, and the pinion gears. A work window provided in the differential case is provided so as to allow the side gear to be inserted into the differential case, and the inner surface of the differential case and at least one of the facing surfaces of the back surface of the side gear are opposed to each other. An annular concave portion surrounding the predetermined axis is provided, and a convex portion is provided on one of the other portions corresponding to the annular concave portion. In the annular concave portion and the convex portion, one side gear is inside the differential case. In a differential device that allows the rotation of one of the side gears but prevents the revolution around the pinion shaft when it is in the normal mounting position, the annular recess of the facing surfaces. One of the facing surfaces having the above has a passage groove having a shape that communicates with the annular recess and allows the convex portion to pass through, and the groove width of at least the opening of the passage groove facing the annular recess is the annular shape. The first feature is that it is smaller than the outer diameter of the recess.

Further, in the present invention, in addition to the first feature, the annular recess and the passage groove are provided on the inner surface of the differential case, and the annular recess and the work window communicate with each other via the passage groove. The second feature is that the passage groove communicating with the one annular recess communicates with only one of the pair of work windows.

Further, in the present invention, in addition to the first or second feature, the one side gear in which the passage groove is inserted into the differential case through the work window is oriented around the pinion shaft toward the regular mounting position. A third feature is that at least a part of the passage groove has a specific groove portion extending in a direction intersecting the direction of revolution when revolving.

Further, the present invention includes an integrated differential case that can rotate around a predetermined axis, a pair of side gears whose back surface is rotatably supported around the predetermined axis on the inner surface of the differential case, and the pair that is housed in the differential case. A pair of pinion gears that mesh with the side gears, a pinion shaft that is mounted on the differential case and rotatably fits and supports the pinion gears and extends in a direction orthogonal to the predetermined axis, and inside the differential case of the pinion gear and the side gears. A work window provided in the differential case is provided so as to allow insertion into the differential case, and an annular shape surrounding the predetermined axis is provided on either one of the inner surface of the differential case and the opposite surface of at least one of the back surfaces of the side gears. A concave portion is provided, and a convex portion is provided on one of the other portions corresponding to the annular concave portion, and the annular concave portion and the convex portion have one side gear at a regular mounting position in the differential case. Occasionally, one of the side gears can be engaged so as to allow rotation but prevent revolution around the pinion shaft, and one of the facing surfaces having the annular recess is the annular recess. A differential device having a passage groove having a shape that allows the convex portion to pass through, and the groove width of at least the opening of the passage groove facing the annular recess is smaller than the outer diameter of the annular recess. Assembling method, a pre-assembly step of incorporating the pair of pinion gears and the pinion shaft into the differential case, and a side gear inserting step of inserting the pair of side gears into the differential case through the work window and engaging the pinion gears. A side gear revolving step of engaging the at least one side gear with the pinion gear and revolving the at least one side gear around the pinion shaft until the convex portion reaches the annular recess through the passage groove. A side gear rotation step in which at least one of the side gears of the opening and the convex portion of the passage groove is rotated so as to be out of phase with respect to the predetermined axis, and the convex portion and the annular concave portion are engaged with each other. Is sequentially executed in this order as a fourth feature.

According to the first feature of the present invention, the rotation of the side gear is allowed but around the pinion shaft by the engagement between the annular concave portion and the convex portion provided on the facing surface between the inner surface of the differential case and the back surface of at least one side gear. In the differential device capable of preventing the revolution of the above, one facing surface having an annular recess has a passage groove having a shape that communicates with the annular recess and allows the convex portion to pass through, and the annular recess of the passage groove has a passage groove. The groove width of the facing opening is set smaller than the outer diameter of the annular recess. As a result, even when the pinion gear and the side gear are installed after the pinion shaft in the differential case, when the side gear passes through the gap between the pinion gear and the inner surface of the differential case, the convex portion can reach the annular recess without difficulty by passing through the through groove. After reaching that point, the annular concave portion and the convex portion can be engaged with each other simply by rotating the side gear, and the side gear can be prevented from shifting. Therefore, even if there is an annular concave portion and a convex portion to prevent the deviation, it is not necessary to secure a wide assembly space for the side gear between the differential case and the pinion gear when assembling the side gear into the differential case. The degree of freedom can be increased.

Further, according to the second feature, the annular recess and the passage groove are provided on the inner surface of the differential case, and the annular recess and the work window communicate with each other via the passage groove, and the passage groove communicates with one annular recess. Communicates with only one of the pair of work windows. As a result, when the convex portion of the side gear is incorporated into the differential case so as to pass from one work window to the annular concave portion side through the communication groove, the side gear passes through the annular concave portion and goes too far toward the other work window. There is no risk of (that is, coming out of the other work window), and the side gear can be easily and accurately positioned at the regular mounting position.

Further, according to the third feature, when the side gear inserted into the differential case through the work window revolves around the pinion shaft toward the regular mounting position, a specific groove portion extending in a direction intersecting the direction of the revolution is formed. Since the passage groove has, the side gear inevitably rotates when the convex portion passes through the specific groove portion of the passage groove as the side gear revolves. Therefore, in order for the convex portion that has reached the inside of the annular recess to reverse the passage groove, it is necessary to rotate in addition to the revolution of the side gear, so that the possibility that the convex portion reverses the passage groove and falls off can be reduced. , The effect of preventing the side gear from slipping can be maintained more reliably.

Further, according to the fourth feature, even when the pinion gear and the pinion shaft are first incorporated in the differential case, the side gear can be subsequently inserted into the differential case through the work window. Further, after inserting the side gear, the side gear is revolved around the pinion shaft until the convex portion passes through the passage groove and reaches the annular concave portion, and after the revolution, the phase between the opening of the passage groove and the convex portion is shifted. By rotating the side gear in this way, the convex portion and the annular concave portion can be engaged with each other. As a result, even if the side gear is installed after the pinion gear in the differential case, the convex portion and the annular concave portion can be easily engaged to achieve the side gear displacement prevention function, and additional parts and jigs can be used to prevent the displacement. It does not require a jig and can contribute to the structural simplification of the differential device.

Overall vertical sectional view showing the differential device according to the first embodiment of the present invention. A single differential case is shown, where (a) is a vertical sectional view (corresponding to FIG. 1), (b) is a sectional view taken along line bb of FIG. 2 (a), and (c) is a sectional view of FIG. 2 (a). cc line cross section A single side gear is shown, where FIG. 3A is a vertical sectional view, FIG. 3B is a sectional view taken along line b of FIG. 3A, and FIG. 3C is a sectional view taken along line cc of FIG. 3B. Assembly process diagram for explaining an example of the procedure for assembling the side gear in the differential case in which the pinion gear is pre-assembled (corresponding diagram in FIG. 2B). A schematic assembly drawing (corresponding to FIG. 2C) that simply shows how the convex portion moves through the passage groove to the annular concave portion in the process of assembling the side gear. FIG. 5 correspondence diagram showing the second embodiment FIG. 5 correspondence diagram showing a third embodiment FIG. 5 correspondence diagram showing a fourth embodiment FIG. 5 correspondence diagram showing a fifth embodiment A first modification of the fifth embodiment is shown, in which FIG. 3A is a corresponding diagram of FIG. 3A, FIG. 10B is a view taken along the line b of FIG. 10A, and FIG. c) Correspondence diagram A second modification of the fifth embodiment is shown, in which (a) corresponds to FIG. 10 (a), (b) corresponds to FIG. 10 (b), and (c) corresponds to FIG. 10 (c). Figure FIG. 5 correspondence diagram showing the sixth embodiment The seventh embodiment is shown, in which (a) is a correspondence diagram of FIG. 2 (c), (b) is a correspondence diagram of FIG. 2 (b), and (c) is a correspondence diagram of FIG. 3 (a), (d). 3 (b) correspondence diagram, (e) is FIG. 3 (c) correspondence diagram FIG. 5 correspondence diagram showing the seventh embodiment

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 5 show the first embodiment. In FIG. 1, a differential device 10 for distributing and transmitting power from a power source (for example, an in-vehicle engine) (not shown) to left and right drive shafts 11 and 12 is housed in a vehicle, for example, a transmission case MC of an automobile. To. The differential device 10 includes an integrated differential case 8 and a differential gear mechanism 20 built in the differential case 8. The drive shafts 11 and 12 may be axles, or shaft members different from the axles that rotate in conjunction with the axles.

The differential case 8 has a hollow case body 8c that is formed in a substantially spherical shape and houses the differential gear mechanism 20 inside, and is integrally connected to the right side portion and the left side portion of the case body 8c and is arranged on the first axis X1. The first and second bearing bosses 8b1 and 8b2 are provided with an annular flange portion 8f integrally formed on the outer peripheral portion of the case body 8c in the radial direction outward.

The first axis X1 corresponds to the predetermined axis of the present invention and passes through the center O of the case body 8c. The inner surface 8i of the case body 8c is formed in a spherical shape whose center coincides with the center O of the case body 8c. Further, the first and second bearing bosses 8b1 and 8b2 are rotatably supported by the mission case MC around the first axis X1 via the bearings 13 and 14 on the outer peripheral side of the bosses 8b1 and 8b2.

The left and right drive shafts 11 and 12 are rotatably fitted to the inner peripheral surfaces of the central holes 8bh of the first and second bearing bosses 8b1 and 8b2, and the spiral grooves 15 and 16 for drawing in lubricating oil. (See FIGS. 1 and 2) is provided. The spiral grooves 15 and 16 can exert a screw pumping action of feeding the lubricating oil in the transmission case MC into the differential case 8 as the bearing bosses 8b1 and 8b2 rotate relative to the drive shafts 11 and 12.

Further, the flange portion 8f is offset from the center O of the case body 8c on one side (in the embodiment, the side of the first bearing boss 8b1) in the direction along the first axis X1. A ring gear 9 serving as a torque input portion of the differential case 8 is concentrically fixed to the flange portion 8f.

The ring gear 9 includes a cylindrical rim 9a having a helical gear-shaped tooth portion 9ag on the outer periphery, and ring plate-shaped spokes 9b that integrally project inward in the radial direction from the inner peripheral surface of the rim 9a. The inner peripheral end of the spoke 9b is concentrically fitted to the outer peripheral end of the flange portion 8f, and the fitting portion is fixed by welding (for example, laser welding, electron beam welding, etc.). As the coupling means for connecting the flange portion 8f and the ring gear 9, various fixing means other than welding (for example, bolt coupling, caulking, etc.) can be performed.

The tooth portion 9ag of the ring gear 9 meshes with the drive gear 31 which is the output portion of the transmission connected to the engine, whereby the rotational driving force is input to the differential case 8 from the drive gear 31 via the ring gear 9. In FIG. 1, the tooth portion 9ag is displayed in cross section along the tooth muscle in order to simplify the display.

The differential gear mechanism 20 is arranged on a second axis X2 orthogonal to the first axis X1 at the center O of the case body 8c and is supported by the case body 8c and a straight rod-shaped pinion shaft 21 and is rotatable on the pinion shaft 21. It is provided with a pair of pinion gears 22 and 22 supported by the pinion gears 22 and left and right side gears 23 and 23 that mesh with each pinion gear 22 and can rotate around the first axis X1. The both side gears 23 and 23 function as output gears of the differential gear mechanism 20, and the left and right side gears 23 and 23 are fitted into the first and second bearing bosses 8b1 and 8b2 in the center holes 23h of the side gears 23 and 23. The inner ends of the drive shafts 11 and 12 are interlocked and connected (spline fitting in the illustrated example). The pinion gear 22 and the side gear 23 are composed of bevel gears in this embodiment.

The back surfaces 22f and 23f of the pinion gear 22 and the side gear 23 are formed in a spherical shape, and are rotatably and slidably supported on the inner surface 8i of the case body 8c. A washer (not shown) may be interposed between the back surfaces 22f and 23f and the inner surface 8i of the case body 8c, if necessary.

Further, the pinion shaft 21 for fitting and supporting the pinion gear 22 is inserted and held in a pair of support holes 8h1 provided on the outer peripheral wall portion of the case body 8c and extending on the second axis X2. A retaining pin 17 penetrating across one end of the pinion shaft 21 in the support hole 8h1 is inserted (for example, press-fitted) into the pin hole 8h2 provided on the outer peripheral wall of the case body 8c, and the retaining pin 17 is inserted. As a result, the pinion shaft 21 is prevented from being separated from the support hole 8h1. The fixing means of the pinion shaft 21 to the case body 8c is not limited to the retaining pin 17, and other suitable fixing means (for example, bolts, caulking, welding, etc.) may be used.

Thus, the rotational driving force transmitted from the drive gear 31 to the differential case 8 via the ring gear 9 is distributed and transmitted to the left and right drive shafts 11 and 12 via the differential gear mechanism 20 while allowing differential rotation. Since the power distribution function of the differential gear mechanism 20 is well known in the past, further description thereof will be omitted.

Further, the case body 8c of the differential case 8 is in a direction along the third axis X3 orthogonal to the first and second axis X1 and X2 (direction orthogonal to the paper surface in FIG. 1) with the peripheral wall portion on one side of the pinion shaft 21. The peripheral wall portion on the other side has a pair of work windows 8w that allow the pinion gear 22 and the side gear 23 to be inserted into the differential case 8. Each work window 8w is from a front insertion posture (see FIG. 4A) in which the side gear 23 places its rotation axis (that is, a rotation axis) in a direction along the third axis X3, or from its front insertion posture. The work window 8w is inserted in a slightly inclined insertion posture, and is formed into a shape that allows passage.

For example, as shown in FIG. 2A, the work window 8w of the present embodiment is formed into a circular hole having an outer diameter slightly larger than the maximum diameter of the side gear 23 so that it can be inserted in the front insertion posture. To. The work window 8w does not necessarily have to be formed in a circular shape, and may be formed in, for example, an oval hole close to a perfect circle.

By the way, as is clear from FIG. 2, a pair of left and right annular recesses 50 surrounding the first axis X1 are formed on the inner surface 8i of the differential case 8 facing the back surface 23f of each side gear 23, and the first and second bearing bosses. It is provided at the inner peripheral edge of the central hole 8bh of 8b1 and 8b2, respectively.

On the other hand, on the back surface 23f of the left and right side gears 23, as is clear from FIG. 3, a pair of convex portions 61 arranged in the direction of one diameter line (and therefore at equal intervals in the circumferential direction) with the rotation axis of the side gears 23 in between. Be thrust. In the illustrated example, these convex portions 61 are each formed in an arc shape extending along the circumferential direction of the side gear 23, and the form thereof corresponds to the form after the cylindrical boss is cut out at two points in the circumferential direction.

The annular concave portion 50 and the convex portion 61 are shown in the set position 23S (for example, FIGS. 1, 4 (c), 5 (c), (d)) in which the side gear 23 is a regular mounting position in the differential case 8. In the state of position), the side gears 23 can be engaged with each other so as to allow rotation but prevent revolution around the pinion shaft 21. According to the engagement, the side gear 23 set at the regular mounting position in the differential case 8, that is, the set position 23S, is surely prevented from shifting around the pinion shaft 21 even when the drive shafts 11 and 12 are not inserted. it can.

Further, on the inner surface 8i of the differential case 8 facing the back surface 23f of each side gear 23, a passage groove 51 having one end opened in the annular recess 50 and the other end opening in the work window 8w is formed. The passage groove 51 follows a shape through which the convex portion 61 can pass in the process of assembling the side gear 23 into the differential case 8 described later (that is, along the movement path of the convex portion 61 that follows the revolution around the pinion shaft 21 of the side gear 23). Shape) is formed.

Further, the passage groove 51 communicating with one annular recess 50 is formed so as to communicate with only one (that is, one) work window 8w of the pair of work windows 8w. In this case, it is possible to carry out a modified example in which a plurality of passing grooves 51 communicating with each other from any one work window 8w to the plurality of annular recesses 50 are provided, but in the modified example, any of the passing grooves 51 is provided. Is formed so as to communicate only with one work window 8w and not to communicate with the other work window 8w. Further, in this modification, of the pair of side gears 23, the convex portion 61 is provided only on one of the side gears 23, that is, when the side gear 23 provided with the convex portion 61 is incorporated in the differential case 8, it passes through. The side gear 23 can be inserted only from one work window 8w leading to the groove 51, and the side gear 23 can be revolved around the pinion shaft 21 in either forward or reverse direction in the side gear revolving process described later.

In this case, the direction of the revolution of the side gear 23 corresponds to the direction along the virtual plane Z including the first axis X1 and the third axis X3. Therefore, as clearly shown in FIGS. 2 (c) and 5 (a), the passage groove 51 has a groove shape extending in the direction of the revolution of the side gear 23, in other words, a groove shape extending in the direction along the virtual plane Z. Is.

Moreover, the groove width of the opening e of the passage groove 51 facing at least the annular recess 50 is formed to be smaller than the outer diameter of the annular recess 50. In the illustrated example, the passage groove 51 is set to have the same groove width as the opening e not only in the opening e but also in the other groove portions, but the groove width of the other groove portions is set to be larger than that of the opening e. It may be set wide.

Further, only one passage groove 51 of the present embodiment is provided for each pair of convex portions 61, and both convex portions 61 of the passage groove 51 are provided as shown in FIGS. 5A to 5C. The groove width is formed so that the passage grooves 51 can be sequentially passed in a state of being arranged in the extending direction (that is, the direction along the virtual plane Z). As a result, when the side gear 23 revolves so as to pass between the pinion gear 22 and the inner surface 8i of the differential case 8 with the pinion shaft 21 and the pinion gear 22 pre-assembled in the differential case 8, the pair of convex portions 61 are formed. As will be described later, it is possible to reach the inside of the annular recess 50 by sequentially passing through the passage grooves 51.

Next, the operation of the first embodiment will be described. The entire differential case 8 is integrally molded (for example, by casting) with a metal material (for example, aluminum, aluminum alloy, iron-based alloy, etc.), and after the integral molding, each part of the differential case 8 is appropriately machined.

Next, after assembling the differential gear mechanism 20 in the differential case 8, the hub 9b of the ring gear 9 is fixed to the flange portion 8f of the differential case 8. Depending on the relative positional relationship between the ring gear 9 and the pinion shaft 21 (that is, if the ring gear 9 does not interfere with the insertion of the pinion shaft 21 into the differential case 8), the differential case before assembling the differential gear mechanism 20 in the differential case 8 The hub 9b of the ring gear 9 may be fixed to the flange portion 8f of 8.

Next, an example of the procedure for assembling the differential gear mechanism 20 in the differential case 8 will be described mainly with reference to FIGS. 4 and 5. That is, in the present embodiment, the differential gear mechanism 20 is assembled by sequentially executing the following steps. Simply put, the pinion gear 22 and the pinion shaft 21 are assembled in advance in the differential case 8, and then the side gears are assembled. 23 is to be assembled.
[First assembly process]
First, a pair of pinion gears 22 are inserted into the differential case 8 through the work window 8w and arranged along the second axis X2, and then the pinion shaft 21 is inserted into the support hole 8h1 of the differential case 8 and fitted into the center hole of each pinion gear 22. Let me. Then, the pinion shaft 21 is fixed to the differential case 8 by the retaining pin 17. In this way, the pinion gear 22 and the pinion shaft 21 are pre-assembled in the differential case 8.
[Side gear insertion process]
Next, as shown in FIG. 4A, the pair of side gears 23 were inserted into the differential case 8 through the work window 8w in a front insertion posture so that the rotation axis of the side gears 23 was along the third axis X3, and were pre-assembled. Both pinion gears 22 are engaged.
[Side gear revolution process]
As shown in FIG. 4B, the side gear 23 inserted into the differential case 8 from the work window 8w is changed in posture so as to gradually revolve around the pinion shaft 21 while being meshed with the pinion gear 22. Then, due to this revolution, the side gear 23 passes through the gap between the pinion gear 22 and the inner surface 8i of the differential case 8 and is aligned with the first and second bearing bosses 8b1 and 8b2 on the same axis as the set position 23S (that is, regular mounting). The position) is reached, and the back surface 23f of the side gear 23 is in sliding contact with the inner surface 8i of the differential case 8 in the process of passing through the position).

In this case, as shown in FIG. 5A, the side gear 23 has a phase (revolution posture) such that the pair of convex portions 61 are aligned on the extension line of the passage groove 51, so that the side gear 23 has both convex portions with respect to the passage groove 51. 61 can reach the inside of the annular recess 51 by sequentially entering and passing through (see, for example, FIGS. 5B and 5C), and the reached position is the set position 23S.

It should be noted that FIG. 5 is a schematic process diagram simply showing how the convex portion 61 moves through the passage groove 51 and the annular concave portion 50 in the revolution process of the side gear 23, and the side gear 23 is not shown. For the sake of simplification, the side gears 23 are drawn in the same posture, ignoring the actual tilted posture. For example, in FIG. 5, (b) shows a state immediately after the revolution of the side gear 23 starts and the first convex portion 61 enters the passage groove 51, and (c) shows the convex portion 61 together with the revolution. Both of them pass through the passage groove 51 and reach the annular recess 50, indicating that the side gear 23 is in the set position 23S.
[Side gear rotation process]
Next, the side gear 23 at the set position 23S is rotated by a predetermined amount around the first axis X1 to shift the phase between the opening e of the passage groove 51 and the convex portion 61 as shown in FIG. 5 (d). .. The amount of rotation at that time is set to such an amount that the convex portion 61 does not return to the side of the passage groove 51, and can be arbitrarily set. When the convex portion 61 and the annular concave portion 50 are engaged with each other, the side gear 23 is prevented from shifting from the set position 23S (that is, rotating around the pinion shaft 21), so that the side gear 23 is moved to the set position 23S. Be retained. After that, the frictional resistance acting between each part of the differential gear mechanism 20 and the differential case 8 suppresses the rotation of the side gear 23 (thus, the natural release of the engaged state due to the rotation).

Thus, the assembly process of the differential device 10 is completed. After that, the differential device 10 is transported to an automobile assembly factory, and the first and second bearing bosses 8b1 and 8b2 of the differential case 8 are rotatably attached to the mission case MC via the bearings 13 and 14 on the assembly line there. .. Further, the inner ends of the left and right drive shafts 11 and 12 are inserted into the center holes 23h of the left and right side gears 23 and 23 through the first and second bearing bosses 8b1 and 8b2, that is, they are spline-fitted to fit the differential device 10. Assembling to the car is completed.

By the way, in the differential device 10 for which the assembly process has been completed, the side gear 23 is correct as described above due to the engagement between the convex portion 61 and the annular concave portion 50 even until the differential device 10 is assembled to the automobile (for example, during the transportation). Since it is held at the set position 23S, the left and right drive shafts 11 and 12 can be accurately fitted and connected to the side gear 23. After the drive shafts 11 and 12 are once fitted and inserted into the side gear 23 of the differential device 10, the side gear 23 continues to be held at the set position 23S by the fitting, so that the side gear 23 rotates and the convex portion 61 However, even if the position faces the opening e of the passage groove 51, there is no possibility that the convex portion 61 moves backward toward the passage groove 51 and the engagement is released.

In the differential device 10 of the first embodiment described above, the side gear 23 rotates due to the engagement between the annular recess 50 and the convex portion 61 provided on the opposite surfaces of the inner surface 8i of the differential case 8 and the back surface 23f of the side gear 23. The structure is such that the rotation around the pinion shaft 21 can be prevented, but in particular, the inner surface 8i of the differential case 8 having the annular recess 50 has a passage groove 51 that communicates with the annular recess 50 and allows the protrusion 61 to pass through. The groove width of the opening e of the passage groove 51 facing the annular recess 50 is set to be smaller than the outer diameter of the annular recess 50.

Therefore, even when the pinion gear 22 and the pinion shaft 21 are pre-assembled in the differential case 8, the side gear 23 can be subsequently inserted into the differential case 8 through the work window 8w, and after the insertion, the side gear 23 can be inserted into the pinion shaft 21. When passing through the gap between the pinion gear 22 and the inner surface 8i of the differential case 8 so as to revolve around, the convex portion 61 can reasonably reach the inside of the annular recess 50 by passing through the passing groove 51, and with the arrival thereof. The side gear 23 is at the correct set position 23S on the first axis X1. Moreover, after reaching the position, the annular recess 50 and the convex portion 61 can be easily engaged by simply rotating the side gear 23 slightly, and the engagement causes the side gear 23 to move away from the set position 23S (that is, around the pinion shaft 21). Revolution) is blocked.

Therefore, the differential device 10 is provided with an annular recess 50 and a convex portion 61 on the opposite surfaces of the inner surface 8i of the differential case 8 and the back surface 23f of the side gear 23 in order to prevent the side gear 23 from shifting from the set position 23S. Even if it has a structure, it is for a wide side gear for engaging the annular recess 50 and the convex portion 61 between the inner surface 8i of the differential case 8 and the pinion gear 22 when the side gear 23 is assembled in the differential case 8 as in the conventional device. There is no need to secure assembly space, and the degree of freedom in design is increased accordingly.

Moreover, the above-mentioned passage groove 51 is specially provided on the inner surface 8i of the differential case 8, and the convex portion 61 is made into the annular concave portion 50 by a simple structure and assembly procedure in which the convex portion 61 is passed through the convex portion 61 and the side gear 23 is slightly rotated after the passage. Since the engaged state can be quickly and accurately placed, the structure of the differential device 10 can be simplified without the need for additional parts or jigs to prevent the side gear 23 from shifting.

Further, in the present embodiment, the passage groove 51 communicating with one annular recess 50 is formed so as to communicate with only one of the pair of work windows 8w. As a result, when the convex portion 61 of the side gear 23 is incorporated in the differential case 8 from one work window 8w through the communication groove 51 toward the annular recess 50 side (in other words, one work window 8w). When the side gear 23 inserted into the differential case 8 is revolved in a specific direction so that the convex portion 61 passes through the passage groove 51 and moves to the annular recess 50), the side gear 23 reaches the annular recess 50. However, there is no risk of passing through the annular recess 50 and going too far in the direction of the other work window 8w (that is, coming out of the other work window 8w). As a result, the side gear 23 can be easily and accurately positioned at the set position 23S (that is, the regular mounting position).

Further, in the present embodiment, particularly on the back surface 23f of the side gear 23, a plurality of convex portions 61 are provided at intervals in the circumferential direction (as if the cylindrical boss portions were notched at several points in the circumferential direction). The notch-shaped space formed between the convex portions 61 adjacent to each other in the circumferential direction can function as a lubricating oil supply oil passage to the sliding gap between the back surface 23f of the side gear 23 and the inner surface 8i of the differential case 8. .. That is, when the lubricating oil reaches the back surface 23f side of the side gear 23 from the spiral grooves 15 and 16 of the central holes 8bh of the first and second bearing bosses 8b1 and 8b2, this is due to the action of centrifugal force from the notch-like space. Since it can efficiently flow into the sliding gap, the amount of oil supplied to the sliding gap can be effectively increased, which is effective in preventing seizure of the back surface 23f of the side gear 23.

On the other hand, if the convex portion 61 on the back surface 23f of the side gear 23 is a cylindrical boss portion (that is, an annular convex portion) as in the conventional device, the notch-shaped space is not formed, and the sliding gap is increased accordingly. The amount of oil supplied to is reduced.

Further, in the above embodiment, the shape and position of the convex portion 61 and the passing groove 51 are set so that the pair of convex portions 61 can sequentially pass through one common passing groove 51, so that the number of passing grooves 51 is reduced accordingly. Therefore, the processing cost can be reduced.

In the first embodiment, the pair of convex portions 61 are formed in an arc shape in a cross section, but the shape of the convex portions 61 is not limited to the illustrated example, and may be at least a form capable of passing through the passage groove 51. For example, it may be formed in a hemispherical shape as in the second, third, and fifth embodiments (see FIGS. 6, 7, and 9) described later, or may be formed in a rectangular or columnar cross section. Good.

Further, FIGS. 6 and 7 show the second and third embodiments, respectively. In the second and third embodiments, the convex portion 62 provided on the back surface 23f of the side gear 23 is formed in a hemispherical shape having a relatively small diameter.

Further, the passage groove 51 of the first embodiment has a straight groove shape extending in the direction in which the side gear 23 revolves around the pinion shaft 21, that is, in the direction along the virtual plane Z (thus, when the convex portion 61 passes through the passage groove 51). The side gear 23 is formed in a shape that does not rotate). On the other hand, the passage groove 52 of the second and third embodiments has a convex portion 62 as the side gear 23 inserted into the differential case 8 through the work window 8w revolves around the pinion shaft 21 toward the set position 23S. Has a specific groove portion 52a, 52b having a shape in which the side gear 23 inevitably rotates while sliding and passing through the passage groove 52, in at least a part of the passage groove 52.

The specific groove portions 52a and 52b are directed in the direction of the revolution of the side gear 23 (that is, the direction along the virtual plane Z, in other words, the direction in which the back surface 23f of the side gear 23 moves relative to the inner surface 8i of the differential case 8 during the revolution. ) Extends in the direction of intersection. Therefore, the side gear 23 rotates in conjunction with the convex portion 62 sliding and passing through the specific groove portions 52a and 52b while the convex portion 62 slides and passes through the passage groove 52 with the above-mentioned revolution of the side gear 23. To do.

In particular, the passage groove 52 of the second embodiment is bent in a crank shape at an intermediate portion. That is, the passage groove 52 includes an intermediate groove portion 52a extending in a direction orthogonal to the direction of revolution of the side gear 23, and a first connection groove portion extending in the direction of revolution from one end of the intermediate groove portion 52a toward the work window 8w. It has 52s1 and a second connecting groove portion 52s2 extending from the other end of the intermediate groove portion 52a toward the annular recess 50 in the direction of revolution. Then, the intermediate groove portion 52a constitutes the specific groove portion.

Since the other structures of the second embodiment are the same as those of the first embodiment, each component is only given the same reference code as the corresponding component of the first embodiment, and further structural explanations are given. Omit. Thus, even in the second embodiment, basically the same action and effect as in the first embodiment can be achieved.

Further, according to the second embodiment, since the passing groove 52 has the intermediate groove portion 52a as the specific groove portion, the convex portion 62 passes through the intermediate groove portion 52a of the passing groove 52 with the revolution of the side gear 23. (For example, see the partially enlarged view of FIG. 6B), the side gear 23 inevitably rotates on its axis. Therefore, as shown in FIGS. 6 (e) and 6 (f), in order for the convex portion 62 that has reached the inside of the annular concave portion 50 to reverse the passage groove 52, it is necessary to rotate the side gear 23 in addition to the revolution of the side gear 23. It is possible to reduce the possibility that the 62 moves backward in the passage groove 52 and falls off, and the effect of preventing the side gear 23 from slipping can be maintained more reliably.

On the other hand, substantially all of the passage groove 52 of the third embodiment shown in FIG. 7 is curved and extends in a direction diagonally intersecting the direction of revolution of the side gear 23, and the curved groove portion is a specific groove. It constitutes a portion 52b. As a modification of the third embodiment, substantially all of the passage grooves 52 may be extended straight in a direction diagonally intersecting the direction of revolution of the side gear 23 to form the specific groove portion 52b.

Since the other structures of the third embodiment are the same as those of the second embodiment, each component is only given the same reference code as the corresponding component of the second embodiment, and further structural explanations are given. Omit. Then, even in the third embodiment, basically the same action and effect as in the second embodiment can be achieved. For example, when the convex portion 62 passes through the specific groove portion 52b over substantially the entire area of the passage groove 52 (see, for example, the partially enlarged view of FIG. 7B) as the side gear 23 revolves, the side gear 23 inevitably moves. Rotate. Therefore, as shown in FIGS. 7 (e) and 7 (f), in order for the convex portion 62 that has reached the inside of the annular recess 50 to reverse the passage groove 52 (that is, the specific groove portion 52b), the side gear 23 rotates in addition to the revolution. Therefore, the same action and effect as those of the second embodiment can be expected.

In the second and third embodiments described above, the shape of the convex portion 62 is not limited to a hemisphere, and may be at least a shape capable of passing through the passage groove 52. For example, it may be formed in a rectangular or columnar cross section.

Next, a fourth embodiment will be described with reference to FIG. In the fourth embodiment, the convex portion 63 provided on the back surface 23f of the side gear 23 is formed in an annular shape having substantially the same diameter as the annular concave portion 50, and the outer peripheral surface of the convex portion 63 has a pair of parallel planar shapes. The cut surface 63c is chamfered. On the other hand, the passage groove 53 formed on the inner surface 8i of the differential case 8 is formed to have a groove width smaller than the outer diameter of the annular recess 50 so that the convex portion 63 can pass through the cut surface 63c. It is also possible to carry out a modification in which the cut surface 63c is only one, and in that case, the groove width of the passage groove 53 is set wider by the amount that the cut surface 63c is reduced.

Since the other structures of the fourth embodiment are the same as those of the first embodiment, each component is only given the same reference code as the corresponding component of the first embodiment, and the structure is more than that. The description is omitted. Thus, even in the fourth embodiment, basically the same action and effect as in the first embodiment can be achieved.

Next, a fifth embodiment will be described with reference to FIG. In the fifth embodiment, three hemispherical convex portions 64 are projected from the back surface 23f of the side gear 23 at equal intervals in the circumferential direction, while the inner surface 8i of the differential case 8 has two rows connected to the annular recess 50. The passage grooves 54 are formed so as to extend parallel to each other and in the revolution direction of the side gear 23 (that is, in the direction along the virtual plane Z).

Since the other structures of the fifth embodiment are the same as those of the first embodiment, each component is only given the same reference code as the corresponding component of the first embodiment, and the structure is more than that. The description is omitted. Thus, even in the fifth embodiment, basically the same action and effect as in the first embodiment can be achieved.

Further, in the fifth embodiment, since only two passing grooves 54 are provided for the three convex portions 64, when the convex portion 64 passes through the passing grooves 54, for example, it is shown in FIG. 9A. As described above, the side gear 23 is arranged in a phase (revolution posture) in which two convex portions 64 are arranged in the direction in which one passage groove 54 extends and the remaining one convex portion 64 is located in the direction in which the other passage groove 54 extends. Revolves around the pinion shaft 21. Due to this revolution, two convex portions 64 sequentially pass through one passing groove 54, and the remaining one convex portion 64 passes through the other passing groove 54. That is, the passing grooves 54 are set in the shape and position of the grooves so that all the convex portions 64 can pass through even if the number of the passing grooves 54 is smaller than the number of the convex portions 64, and the processing cost is reduced by the reduction in the number of the passing grooves 54. Can be reduced.

Further, in the case where a plurality of convex portions 64 are arranged at equal intervals in the circumferential direction on the back surface 23f of the side gear 23 as in the fifth embodiment, a snap ring (for example, not shown) temporarily locked to the drive shafts 11 and 12 (for example). When the drive shafts 11 and 12 are removed from the side gears 23 by the circlip), there are the following advantages. That is, when the drive shafts 11 and 12 are fitted and inserted into the side gears 23 through the bearing bosses 8b1 and 8b2 with the snap ring temporarily fixed to the outer periphery of the inner end thereof, a plurality of convex portions existing at equal intervals in the circumferential direction. Since the snap ring abuts 64 in a well-balanced and even manner, the snap ring can be smoothly overcome.

By the way, in the case where a plurality of convex portions 64 are arranged on the back surface 23f of the side gear 23 so that the convex portions 64 pass through the plurality of passing grooves 54 as in the fifth embodiment, the convex portions 64 are arranged and passed. Depending on the number of grooves 54, even if the arrangement of the convex portions 64 in the side gear 23 is the same, there is a difference in the phase pattern around the rotation axis of the side gear 23 that allows the convex portions 64 to match the passing grooves 54 and pass through the grooves. Occurs.

For example, when the number of passing grooves 54 is the same as the number of the convex portions 64 and the convex portions 64 are arranged at equal intervals as in the first modification of the fifth embodiment shown in FIG. The phase of the side gear 23 that can pass through the groove is as many as 6 patterns. On the other hand, if the same number of convex portions 64 are not arranged at equal intervals (not shown), the phase pattern of the side gear 23 that allows the groove to pass through can be reduced. Further, in a structure in which the number of passage grooves 54 is less than that of the convex portions 64 as in the fifth embodiment, the two convex portions 64 that pass through one of the three convex portions 64 are selected from the three convex portions 64. There are 3 patterns equal to the number of combinations when selecting.

Therefore, the smaller the phase pattern of the side gear 23 that allows the groove to pass through, the less frequently the convex portion 64 of the side gear 23 at the set position 23S moves backward and falls off the passing groove 54. It is desirable that the number and positions of the convex portions 64, the number of passing grooves 54, and the like are selected so that the phase pattern that allows the passage is minimized. That is, the arrangement of the convex portions 64 is arranged at unequal intervals (not shown), or even if the convex portions 64 are arranged at equal intervals, the number of passing grooves 54 is convex as in the fifth embodiment. If the number is reduced from the number of the portions 64, the phase pattern of the side gear 23 that can pass through the groove can be reduced and the frequency can be reduced, which is advantageous in preventing the side gear 23 at the set position 23S from shifting. ..

Further, FIG. 11 shows a second modification of the fifth embodiment. In the fifth embodiment and the first modification thereof, the three convex portions 64 are formed at the same height (that is, the amount of protrusion from the back surface 23f of the side gear 23), but in the second modification, one The convex portion 64 of the above is formed higher than the other two convex portions 64. Then, one passage groove 54 is formed in a groove deeper than the other passage grooves 54 in response to such a difference in height of the convex portion 64.

Therefore, according to the second modification, only one convex portion 64 having a high height can pass through only one deep passage groove 54, so that the number and arrangement of the convex portion 64 and the passage groove 54 are different. Despite being the same as in the fifth embodiment, there is only one phase pattern of the side gear 23 through which the convex portion 64 can pass through the passage groove 54. As a result, the convex portion 64 of the side gear 23 at the set position 23S can reduce the frequency of reversing and falling off the passage groove 54, which is advantageous in preventing the side gear 23 at the set position 23S from slipping.

Thus, the above-mentioned first and second modifications can basically achieve the same effects as those of the fifth embodiment.

Next, a sixth embodiment will be described with reference to FIG. In the first embodiment, the cross-sectional shape of the pair of convex portions 61 arranged on one diameter line of the back surface 23f of the side gear 23 is a short arc shape, but in the sixth embodiment, the cross-sectional shape of the pair of convex portions 65 is A pair of passing grooves 55, which are formed in a long (close to a semi-circular) arc shape and through which the pair of convex portions 65 can individually pass, are provided parallel to the inner surface 8i of the differential case 8.

Since the other structures of the sixth embodiment are the same as those of the first embodiment, each component is only given the same reference code as the corresponding component of the first embodiment, and the structure is more than that. The description is omitted. Thus, even in the sixth embodiment, basically the same action and effect as in the first embodiment can be achieved.

Next, a seventh embodiment will be described with reference to FIGS. 13 and 14. In the first to sixth embodiments, the convex portions 61 to 65 are provided on the side gear 23 side (that is, the back surface 23f), and the annular recess 50 and the passage grooves 51 to 55 are provided on the differential case 8 side (that is, the inner surface 8i). Although shown, contrary to the arrangement, in the seventh embodiment, a pair of convex portions 61'are provided on the inner surface 8i of the differential case 8, and an annular recess 50'and a pair of passage grooves 51'are provided at least one of them. It is provided on the back surface 23f of the side gear 23.

Since the other structures of the seventh embodiment are the same as those of the first embodiment, each component is only given the same reference code as the corresponding component of the first embodiment, and the structure is more than that. The description is omitted. Thus, even in the seventh embodiment, basically the same action and effect as in the first embodiment can be achieved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments, and various design changes can be made without departing from the gist thereof.

For example, in each of the above embodiments, the differential device 10 is mounted on a differential device for a vehicle, for example, an automobile, but in the present invention, the differential device 10 is mounted on various mechanical devices other than the vehicle. You may.

Further, in each of the above-described embodiments, the tooth portion 9ag of the ring gear 9 is shown in the shape of a helical gear, but the ring gear is not limited to the embodiment, and may be, for example, a bevel gear, a hypoid gear, a spur gear, or the like. The torque input portion coupled to the differential case 8 is not limited to the ring gear 9, and may be another suitable transmission wheel (for example, V pulley, sprocket, etc.).

Further, in each of the above-described embodiments, convex portions 61 to 65, or annular recesses 50'and passage grooves 51'are provided on the back surfaces 23f of both the left and right side gears 23, but in the present invention, either the left or right side gear 23 is provided. Convex portions 61 to 65, or annular recesses 50'and passage grooves 51' may be provided only on the back surface 23f of the side gear 23. In this case, even if the back surface 23f of the other side gear 23 does not have the protrusions 61 to 65, or the annular recess 50'and the passage groove 51', both the left and right side gears 23 are in mesh with the pinion gear 22. If the side gear 23 and the differential case 8 are engaged with each other via the convex portions 61 to 65, 61'and the annular recesses 50, 50', the effect of preventing not only one side gear 23 but also the other side gear 23 from slipping. Can also be expected.

Further, in the assembly procedure of the differential device 10 of each of the above-described embodiments, the side gear 23 is passed through the work window 8w in a front insertion posture so that the rotation axis of the side gear 23 is along the third axis X3, and the pinion gear 22 in the differential case 8 is passed. However, if the side gear 23 can mesh with the pinion gear 22 even in the tilted insertion posture slightly tilted from the front insertion posture when passing through the work window 8w, the side gear 23 is engaged with the work window 8w in the tilted insertion posture. It may be inserted into the differential case 8 through.

Further, in each of the above-described embodiments, the inner surface 8i of the differential case 8 is formed in a spherical shape, but the shape of the inner surface 8i of the differential case 8 is not limited to the embodiment, and for example, a part of the inner surface 8i (for example, the pinion gear 22) is shown. The support surface, etc.) may be formed on a curved surface, a tapered surface, or a flat surface other than a spherical surface.

Further, in each of the above-described embodiments, the shapes and numbers of the convex portions 61 to 65, the annular recesses 50'and the passage grooves 51'provided to the pair of side gears 23 are the same in both side gears 23. In the present invention, the shape and / or number of the convex portions 61 to 65 provided on one side gear 23, or the annular concave portions 50'and the passing grooves 51'are combined, and the convex portions 61 to 61 provided on the other side gear 23. It may be different from the combination mode of the shape and / or the number of 65 or the annular recess 50'and the passage groove 51'.

Further, in the first embodiment, the pair of convex portions 61 are sequentially passed through a single passage groove 51, but as a modification of the first embodiment, the pair of convex portions 61 are parallel to each other. A structure (not shown) that allows the pair of passage grooves 51 to pass individually and simultaneously can be implemented, and the arrangement mode of the pair of passage grooves 51 in that case is, for example, the sixth embodiment (FIG. 12). It is the same as the arrangement of the passage grooves 55 of the above, and only the groove width is narrower than that of the sixth embodiment.

X1 ... First axis as a predetermined axis e, e'... Opening of a passage groove 8 ... Diff case 8i ... Diff case inner surface 8w ...・ ・ ・ Work window 10 ・ ・ ・ ・ ・ ・ Differential device 21 ・ ・ ・ ・ ・ ・ Pinion shaft 22 ・ ・ ・ ・ ・ ・ Pinion gear 23 ・ ・ ・ ・ ・ ・ Side gear 23S ・ ・ ・ ・ ・ Regular side gear Set position 50, 50'as a mounting position ... Annular recesses 51 to 55, 51' ... Passing grooves 52a, 52b ... Bent groove portion as a specific groove portion, curved groove portion 61 to 65, 61'.・ Convex part

Claims (4)

A pair of an integrated differential case (8) that can rotate around a predetermined axis (X1) and a back surface (23f) that is rotatably supported around the predetermined axis (X1) on an inner surface (8i) of the differential case (8). Side gear (23), a pair of pinion gears (22) housed in the differential case (8) and meshed with the pair of side gears (23), and the pinion gear (22) mounted on the differential case (8). Insertion of the pinion shaft (21), which rotatably fits and supports the pinion shaft (21) extending in a direction orthogonal to the predetermined axis (X1), and the pinion gear (22) and the side gear (23) into the differential case (8). It is provided with a pair of work windows (8w) provided in the differential case (8) so as to allow it.
An annular recess (50, 50') surrounding the predetermined axis (X1) on any one of the facing surfaces of the inner surface (8i) of the differential case (8) and the back surface (23f) of at least one side gear (23). ) Is provided, and a convex portion (61 to 65, 61') corresponding to the annular recess (50, 50') is provided on any one of the other, and the annular recess (50, 50') and the said. The convex portion (61 to 65, 61') means that when one of the side gears (23) is in the normal mounting position (23S) in the differential case (8), the rotation of the one side gear (23) is In a differential that is permissible but can be engaged to prevent revolution around the pinion shaft (21).
One of the facing surfaces having the annular recess (50, 50') communicates with the annular recess (50, 50') and the convex portion (61 to 65, 61') can pass through. Has a well-shaped passage groove (51-55, 51')
The groove width of the opening (e, e') facing at least the annular recess (50, 50') of the passage groove (51 to 55, 51') is the outer diameter of the annular recess (50, 50'). A differential that is characterized by being smaller than. The annular recess (50) and the passage groove (51 to 55) are provided on the inner surface (8i) of the differential case (8), and the annular recess (50) and the work window (8w) are formed in the passage groove (8w). They communicate with each other via 51-55)
The difference according to claim 1, wherein the passage groove (51 to 55) communicating with the one annular recess (50) communicates with only one of the pair of work windows (8w). Dynamic device. In the passage groove (52), the one side gear (23) inserted into the differential case (8) through the work window (8w) revolves around the pinion shaft toward the regular mounting position (23S). Claims 1 and 2 are characterized in that at least a part of the passage groove (52) has a specific groove portion (52a, 52b) extending in a direction intersecting the direction of revolution. The differential device according to any one of the above items. A pair of an integrated differential case (8) that can rotate around a predetermined axis (X1) and a back surface (23f) that is rotatably supported around the predetermined axis (X1) on an inner surface (8i) of the differential case (8). Side gear (23), a pair of pinion gears (22) housed in the differential case (8) and meshed with the pair of side gears (23), and the pinion gear (22) mounted on the differential case (8). Insertion of the pinion shaft (21) rotatably fitted and supported and extending in a direction orthogonal to the predetermined axis (X1) and the pinion gear (22) and the side gear (23) into the differential case (8). It is provided with a work window (8w) provided in the differential case (8) so as to allow it.
An annular recess (50, 50') surrounding the predetermined axis (X1) on any one of the facing surfaces of the inner surface (8i) of the differential case (8) and the back surface (23f) of at least one side gear (23). ) Is provided, and a convex portion (61 to 65, 61') corresponding to the annular recess (50, 50') is provided on any one of the other, and the annular recess (50, 50') and the said. The convex portion (61 to 65, 61') means that when one of the side gears (23) is in the normal mounting position (23S) in the differential case (8), the rotation of the one side gear (23) is Although it is permissible, it can be engaged so as to prevent the revolution around the pinion shaft (21), and one of the facing surfaces having the annular recess (50, 50') is the annular recess ( It has a passage groove (51 to 55, 51') that communicates with 50, 50') and has a shape that allows the convex portion (61 to 65, 61') to pass through, and the passage groove (51 to 55, 51'). ), At least in the method of assembling a differential device in which the groove width of the opening (e, e') facing the annular recess (50, 50') is smaller than the outer diameter of the annular recess (50, 50'). There,
A pre-assembly process for incorporating the pair of pinion gears (22) and the pinion shaft (21) into the differential case (8), and
A side gear insertion step of inserting the pair of side gears (23) into the differential case (8) through the work window (8w) and engaging the pinion gear (22).
While engaging the at least one side gear (23) with the pinion gear (22), the convex portion (61 to 65, 61') passes through the passage groove (51 to 55, 51') and the annular recess (50). , 50'), and a side gear revolution step in which at least one of the side gears (23) revolves around the pinion shaft (21).
The opening (e, e') of the passage groove (51 to 55, 51') and the convex portion (61 to 65, 61') are said to be out of phase with respect to the predetermined axis (X1). A side gear rotation step of rotating at least one side gear (23) to engage the convex portion (61 to 65, 61') with the annular concave portion (50, 50').
A method of assembling a differential device, which comprises sequentially executing in this order.