JPH0648204Y2 - Lubrication structure of differential device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is a differential device in which rotation is transmitted to and cut off from a pair of output shafts via a reduction gear mechanism, a main shaft, and a multiple disc clutch from an input shaft. In regard to the above, the present invention relates to the arrangement of the oil pump and the structure of the lubricating oil passage for supplying the lubricating oil to the respective lubricating portions such as the speed reducing mechanism and the multiple disc clutch through the housing and the main shaft.

[Prior Art] In a differential (hereinafter referred to as differential) device,
Attempts have been made to transmit and block rotation from the input shaft to the pair of output shafts via the speed reduction mechanism (planetary gear mechanism), the main shaft, and the multiple disc clutch (see Japanese Patent Application No. 1-4228 proposed by the applicant). ).

[Problems to be Solved by the Invention] In such a diff device, the reduction gear mechanism is located on the outer peripheral side of the main shaft, and the multiple disc clutches are located on both ends of the main spindle. It is conceivable to pass the lubricating oil through the main shaft in order to simplify the supply of the lubricating oil. In that case, since the main shaft is the rotating member, the lubricating oil cannot be supplied into the main shaft unless the oil pressure by the oil pump is higher than the centrifugal force due to the rotation of the main shaft.

Further, it is desirable to make the housing compact in order to include the oil pump, and it is necessary to efficiently cool the lubricating oil.

Therefore, an object of the present invention is to generate a high hydraulic pressure by an oil pump in a differential device in which a rotary input shaft, a reduction mechanism, a main shaft, a multi-plate clutch, and an output shaft as described above are provided in a housing, and pass lubricating oil through the main shaft. To provide a lubricating structure that can supply lubricating oil including a reduction mechanism and each multi-plate clutch to simplify the supply of lubricating oil and efficiently cool the lubricating oil while keeping the housing compact. It is in.

[Means for Solving the Problems] In order to achieve the above objects, the present invention provides a rotary input shaft, a main shaft to which rotation is transmitted from the input shaft through a speed reduction mechanism, and a multi-axis shaft from both ends of the main shaft. A differential device that supports a pair of output shafts that transmit and block rotation via a plate clutch in a housing, wherein an oil pump is arranged on the input shaft and built in the housing, and A lubricating oil passage extending from the pump to the shaft is formed in the housing, and a lubricating oil passage opening from the lubricating oil passage to each lubrication portion including the reduction mechanism and the multi-plate clutch is formed in the main shaft. And

[Operation] Since the oil pump is arranged on the input shaft with a high rotational speed, a high hydraulic pressure can be generated when the lubricating oil is supplied to the main shaft to which the rotation is transmitted through the reduction mechanism, and the lubricating oil passage formed in the main shaft can be used. Lubricating oil can be supplied to each lubrication part including the outer peripheral speed reduction mechanism and both end side multi-plate clutches with a simple circuit.

Since the lubricating oil passage extending from the oil pump built into the housing to the main shaft is formed in the housing, the housing can be made compact and the lubricating oil is efficiently cooled while passing through the housing-side lubricating oil passage.

[Example] An example will be described below with reference to the accompanying drawings.

1 and 2 show the internal structure of a differential device to which the present invention is applied, and FIG. 5 shows the drive system of a four-wheel drive vehicle equipped with this differential device.

In FIG. 5, 1 is an engine, 2 is a transmission, 4 is a front diff device, 5 _L and 5 _R are left and right front wheels, 7 is a propulsion shaft, 9 _L and 9 _R are left and right rear wheels, and 10 is a rear diff device. is there. As shown in the figure, the rotational driving force is transmitted from the engine 1 to the left and right front wheels 5 _L and 5 _R via the transmission 2, the gear train 3 and the front differential device 4. Further, from the front differential device 4 to the rear differential device 10 via the gear train 6 and the propulsion shaft 7.
Rotational driving force is transmitted, is further rear differential device drive shaft 8 from 10 _L, 8 right and left rear wheels via the _R 9 _L, 9 _R to the rotational driving force is transmitted to the.

In FIG. 1 showing the rear differential device 10, 11 is a diff housing main body, 12 _L and 12 _R are left and right clutch housings, 13 is an input shaft, 15 is a diff case, and 17 is a side cover thereof. Rotation is transmitted from the input shaft 13 connected to the propulsion shaft 7 to the differential case 15 via bevel gears 14 and 16, and inside the differential case 15, two sets of planetary gear mechanisms 21 _L and 21 _R constituting a reduction mechanism are formed. Is provided.

That is, as shown in FIG. 2 in an enlarged manner, the two sets of planetary gear mechanisms 21 _L and 21 _R include ring gears 22 _L and 2 _{L on the} inner circumference of the differential case 15.
2 _R , a plurality of planetary gears 23 _L …, 23 _R …, and a sun gear
It consists of 24 _L and 24 _R. And left and right planetary gears 2
A common pinion shaft 26, which supports 3 _L and 23 _R by interposing roller bearings 25 _L and 25 _R , respectively, is supported by an integral case-shaped carrier 31.

The carrier 31 has the planetary gears 23 on the left and right of the drum portion 32.
_L ..., 23 window 33 to _R ... respectively facing _L ..., which has a 33 _R ..., shaft holes 35 _L ... for the pinion shaft 26 inward wall portion 34 _L, 34 _R of the drum portion 32 left and right, 35 _R ... Further, an inner flange 36 is integrally provided at the center of the drum portion 32.
The inner diameter of the inner flange 36 is smaller than the inner diameters of the wall portions 34 _L and 34 _R , a spline 37 is formed on the inner peripheral surface thereof, and the inner flange 36 is formed for the pinion shaft 26. A shaft hole 38 is formed.

The main shaft 41 arranged inside the differential case 15 is integrally provided with an outer flange 42 at the center, and a spline 43 is formed on the outer peripheral surface of the outer flange 42. This spline 43 matches the spline 37 of the inner flange 36.

Wherein upon assembly of the two sets of planetary gear mechanisms 21 _L, 21 _R, each window 33 _L of the carrier 31 ..., 33 _R ... planetary gears 23 in the _L ..., 23 _R ... causes the respective faces, and planetary gears 23
Apply thrust plates 27 _L ..., 27 _R ... to the end faces of _L ..., 23 _R ... respectively. Then, the pinion shaft 26 is fitted in the shaft holes 35 _L , 38, 35 _R , and the planetary gears 23 _L , 23 _R are fitted with the roller bearings 25 _L , 25 _R, ... Then, the pinion shaft 26 is fixed to the carrier 31. Further, thrust plates 28 _L and 28 _R are respectively applied to both end surfaces of the pinion shaft 26.

On the other hand, the sun gear 24 _L for the left and right of the spindle 41, 24 _R and integral cylindrical member 29 _L, 29 _R of the roller bearing 44 _L ..., 44 _R ... and interposed with mating, the sun gear 24 _L, Thrust bearings 45 _L and 45 _R are interposed between 24 _R and the outer flange 42,
The sun gear 24 _L, 24 the thrust plate 46 on the outer surface of the _{R L,} 46 _R
Guess

Then, the inner flange 36 of the carrier 31 and the outer flange 42 of the main shaft 41 are fitted and coupled by both splines 37, 43,
Two sets of planetary gear mechanisms 21 _L and 2 assembled in the differential case 15
1 The phases meshed with the gears of the _R, bind with each tubular member 29 _L, 29 _R of the roller bearings 47 _L, 47 bevel gear 16 the differential case 15 and the side cover 17 to support at _R by bolts 48 ....

In the above, by making the gear ratios of the left and right planetary gear mechanisms 21 _L and 21 _R different, the left planetary gear mechanism 21 _L is for speed-up (Hi) and the right planetary gear mechanism 21 _R is for constant speed ( Low)
Has become.

The flange member 49 _L, 49 _R is serration-fitted to the left and right of the tubular member 29 _L, 29 _R of the outer end portion on both flange members 49
One-way clutches 51 _L and 51 _{R, which} are schematically shown in _L and 49 _R , are provided. Further the one-way clutch 51 _L, via a flange member 49 _L and the cylinder member 29 _L and the rotation locking clutch 52 _L is provided to allow fixing the sun gear 24 _L on the left, also the flange members 49 _R and the cylinder member 29 _R There is provided a rotation fixing clutch 52 _R which can fix the right sun gear 24 _R via the.

The left rotation fixing clutch 52 _L is a one-way clutch 51 _L
It is configured between a cylindrical member 53 _L provided on the outer peripheral side and a clutch case 18 interposed and fixed between the differential housing main body 11 and the clutch housing 12 _L , and the right rotation fixing clutch.
52 _R is formed between the flange member 49 _R and the differential housing body 11.

That is, it has a friction plate composed of an inner plate 54 _L ... Serrated with the tubular member 53 _L and an outer plate 56 _L ... Serrated with the clutch outer part 55 _L of the clutch case 18, and has a cylinder 57 of the clutch case 18. _A piston 58 _L is provided on _L to form a left rotation fixing clutch 52 _L. A cylinder of the diff housing body 11 has a friction plate composed of an inner plate 54 _R serratedly fitted to the flange member 49 _R and an outer plate 56 _R ... Serrated and fitted to the clutch outer portion 55 _R of the diff housing body 11. 57 _R is provided with a piston 58 _R to form a right rotation fixing clutch 52 _R.

In addition, the clutch case 18 is attached to the side cover 17 of the differential case 15.
Are supported through ball bearings 19 _L. The tubular member 53 _R of the right of the one-way clutch 51 _R outer peripheral side are serration-fitted to the differential housing body 11, the differential case 15 to the tubular member 53 _R is supported by interposing the ball bearings 19 _R.

Furthermore the flange member 59 _L, 59 _R has been fitted serrations on the right and left ends of the main shaft 41, both flange members 59 _L, 59 _R
And the output shaft provided in each of the clutch housings 12 _L and 12 _R
Variable torque transmission capacity clutch 6 between 71 _L and 71 _R
1 _L and 61 _R are provided. Both torque transmission capacity variable type clutches 61 _L and 61 _R have the same structure.

That is, as shown in FIG. 3 and FIG. 4 in an enlarged manner, the outer plates 63 _L , 63 _R, and both output shafts serrated and fitted to the clutch outer portions 62 _L , 62 _R of the flange members 59 _L , 59 _R , respectively. Flange members that are serrated with 71 _L and 71 _R
64 _L , 64 _R clutch inner parts 65 _L , has a friction plate consisting of inner plates 66 _L , 66 _R , which are serration-fitted to 65 _R , and each clutch housing 12 _L , 12 _R cylinder 67 _L, 67 _R to the piston 68 _L, 68 torque transmission right provided _R variable capacity clutch 61 _L, 61 _R is formed.
In addition, pressing members 69 _L and 69 _R are placed between the pistons 68 _L and 68 _R and the friction plate.
Is installed.

Both output shafts 71 _L and 71 _R are the left and right clutch housings 12
Ball bearings 72 _L and 72 _R are respectively supported by _L and 12 _R , and the output shafts 71 _L and 71 _R are the left and right rear wheel drive shafts 8 _L and 8 _{R, respectively.}
Are connected to each other.

Next, the lubrication structure for each part will be described.

As shown in FIG. 1, the input shaft 13 is the main body of the differential housing.
Tapered roller bearing 11 on front boss 111 of 11
It is supported by interposing a 2 _f, 112 _r, the pump housing 114 is coupled by bolts 115 ... to interposed a pump guide plate 113 to the front boss portion 111. And pump housing 1
The oil pump 116 is built in 14 and its inner hub 1
Reference numeral 17 is serration-fitted to the input shaft 13, 118 is an intake port, and 119 is a discharge port.

The lubricating oil from the discharge port 119 of the oil pump 116 passes through the oil passage 73 of the boss portion 111 as shown by the arrow, and is expanded from the oil passage 74 on the rear right side of the differential housing body 11 as shown in FIG. the tubular member 53 the one-way clutch 51 _R and each flange member 49 from the oil passage 75 and 76 of _{R R,} 59 oil passages _R 77 and 78
2 and flows into the axial oil passage 81 from the radial oil passage 79 on the right side of the main shaft 41 as shown by the arrow in FIG.

Lubricating oil is supplied from the axial oil passage 81 to a large number of radial oil passages 82 ...
The lubricating oil flows from the radial oil passages 83 of the outer flange 42 at the center to the radial oil passages 84 of the inner flange 36 at the center of the carrier 31 via the joints formed by the splines 37 and 43. Further, from each of the radial oil passages 84 ... From each of the pinion shafts
26. Lubricating oil flows into the axial oil passages 86 through the central radial oil passages 85, and the lubricating oil is supplied to the bearing portions from the other radial oil passages 87 with the thrust plates at both ends. . Further, as shown in FIGS. 3 and 4 in an enlarged manner, both ends of the axial oil passage 81 of the main shaft 41 have respective sleeve-shaped pipes 91.
Axial oil passage 9 of each output shaft 71 _L , 71 _R via _L , 91 _R
Connected to 2 _L and 92 _R respectively. Further radial oil passages 93 _L , 93
Wherein the _R each flange member 64 _L, 64 _R radial oil passage 94 _L of 94
Each torque transmitting capacity located respectively radially outward with each bearing portion than _R variable clutch 61 _L, 61 lubricating oil _R is supplied.

Here, in the embodiment, the left and right sleeve-shaped pipes 91 _L , 91 _R
Are press-fitted and fixed to both open ends of the axial oil passage 81 of the main shaft 41, while the axial oil passages of the left and right output shafts 71 _L and 71 _R are respectively fixed.
The open ends of 92 _L and 92 _R are respectively loosely fitted, and this loose fitting structure allows relative rotation between the main shaft 41 and the output shafts 71 _L and 71 _R. Further, the inner diameter of the right pipe 91 _R is set smaller than the inner diameter of the left pipe 91 _L , that is, the right pipe 91 _R close to the radial oil passage 79 for feeding the lubricating oil into the axial oil passage 81 of the main shaft 41. by the diaphragm action of the inner diameter, the supply of lubricating oil to the axial oil passage 92 _L, 92 _R of the left and right both output shafts 71 _L, 71 _R is adapted to be evenly distributed.

Contrary to the embodiment, the pipes 91 _L and 91 _R are connected to the output shafts 71 _L and 71 _R.
Of the main shaft 41 by press-fitting into the axial oil passages 92 _L and 92 _R of
Of course, the one that fits in 81 may be used.

And for the wet multi-plate both torque transmission capacity of the left and right a clutch variable clutch 61 _L, 61 _R, 65 the clutch inner portion _L, 65 radial oil passage 95 guides the lubricating oil to the _{R L,} 95 _R are formed and which is further clutches outer portions 62 _L, 62 _R is the radial oil passage 96 for discharging the lubricating oil _L ..., 96 _R ... is formed.

Further, in the figure, 97 _L and 97 _R are coil springs for return for urging the pistons 68 _L and 68 _R toward the fastening force releasing side, and 98 _L and 98 _R are pistons 68 _L and 68 _R and pressing members 69 _L and 69 _R , respectively. thrust bearing between _R, a detent pin 99 _L, 99 _R is a piston 68 _L, 68 _R. Regarding the rotation fixing clutches 52 _L and 52 _R ,
101 _L and 101 _R are disc springs for return that urge the pistons 58 _L and 58 _R to the fastening force releasing side respectively, 102 _L and 102 _R are set plates for preventing their rotation, and 103 _L is the left cylinder. a roller bearing between the member 53 _L and the flange member 59 _L.

According to four-wheel drive vehicle shown in FIG. 5 equipped with rear differential device 10 described above, at the time of straight running, the rotation fixing clutch 52 _R of the right to OFF (free). In addition, the left rotation fixing clutch 52 _L is also turned off (free).

Therefore, when traveling straight ahead, the one-way clutch 51 _R holds the sun gear 24 _R of the planetary gear mechanism 21 _R for constant speed (Low) in a fixed state when the rotation speed of the front wheel side> the rotation speed of the rear wheel side, and the rear wheel The driving force is transmitted to the side.

When the rotation speed of the front wheels <the rotation speed of the rear wheels, the one-way clutch 51 _R holds the sun gear 24 _R in a free state to cut off the transmission of the driving force to the rear wheels.

Specifically, when excessive braking force acts on the front wheel side during braking, the excessive braking force is transmitted to the rear wheel side to prevent the rear wheel side from locking. As a result, the engine brakes and the rear wheels are free when the vehicle is backing.

If you want to apply braking force to the rear wheels by engine braking, or if you want to transmit the driving force to the rear wheels when you are backing, turn on the right rotation fixing clutch 52 _R (fix), that is, in the cylinder 57 _R. Oil is supplied to move the piston 58 _R forward, the friction plates 54 _R and 56 _R are fastened to each other, and the constant speed (Low) planetary gears are irrespective of the one-way clutch 51 _R through the flange member 49 _R and the tubular member 29 _R. holding the sun gear 24 _R mechanisms 21 _R in a fixed state, transmitting the braking force and driving force to the rear wheel side.

At this time, the left and right variable torque transmission capacity clutches 61 _L , 6
Equal hydraulic pressure is applied to each of the 1 _R cylinders 67 _L and 67 _R , and the friction plates 63 _L and 66 _L by the forward movement of the pistons 68 _L and 68 _R ,
Evenly hold the fastening force of 63 _R and 66 _R , and evenly distribute the left and right driving forces.

Therefore, the rotation input from the propulsion shaft 7 to the differential case 15 via the input shaft 13 and the bevel gears 14 and 16 is transmitted to the ring gear 22 _R.
As a result, the planetary gear 23 _{R of} the right-side planetary gear mechanism 21 _R for constant speed ( _R ) with the sun gear 24 _R fixed is transmitted as a revolution to the main shaft 41 integrated with the carrier 31. Driving force is applied to both output shafts 71 _L and 71 _R from the left and right of the main shaft 41 via the flange members 59 _L and 59 _R , the torque transmission capacity variable type clutches 61 _L and 61 _R, and the flange members 64 _L and 64 _R , respectively. Evenly distributed, the left and right rear wheels 9 _L , 9 _R rotate at a constant speed via the drive shafts 8 _L , 8 _R. As a result, straight running stability, especially high speed stability, is enhanced.

Also, when turning, the left rotation fixing clutch
52 _L is turned ON (fixed), that is, oil is supplied into the cylinder 57 _L to advance the piston 58 _L and the friction plates 54 _L and 56 _L are engaged to connect the one-way clutch 51 _L , the flange member 49 _L and the cylinder. Sun gear 24 of speed increasing (Hi) planetary gear mechanism 21 _L via member 29 _L
Hold _L in a fixed state and rotate right side clutch 5
2 _{Turn R} off (free). At this time, for example, in the case of a left turning state, a higher hydraulic pressure is applied to the right torque transmission capacity variable clutch 61 _R on the outer wheel side than the left torque transmission capacity variable clutch 61 _L on the inner wheel side to apply the driving force. It sets larger allocation to the right rear wheel 9 _R a.

Therefore, rotation from the differential case 15 is performed by increasing the speed of the left (Hi) planetary gear mechanism 2 with the sun gear 24 _L fixed relative to the ring gear 11 _L.
It is transmitted from the carrier 31 to the main shaft 41 as the revolution of the 1 _L planetary gear 23 _L. Then, the increased rotational speed is transmitted from the main shaft 41 to the right output shaft 71 _R by different driving force distributions by the left and right variable torque transmission capacity clutches 61 _L and 61 _R , and the left output shaft 71 _L receives this increased rotation. Since less rotation is transmitted, the right rear wheel 9 _R accelerates more than the left rear wheel 9 _L. This improves the turning performance.

Further, during high-speed turning, it is possible to increase the speed of the inner wheels and increase the distribution of driving force to improve stability.

As described above, it is possible to contribute to the improvement of the movement performance of the vehicle.

In the rear differential device 10 described above, the two sets of planetary gear mechanisms 21 _L and 21 _R are particularly compactly configured in the differential case 15 and are lightweight.

Regarding the lubrication oil supply from the oil pump 116 to the lubrication section including the two planetary gear mechanisms 21 _L and 21 _R , which are reduction mechanisms, and the variable torque transmission capacity type clutches 61 _L and 61 _R of the wet multi-plate, first, Since the oil pump 116 is arranged on the high input shaft 13, the high oil pressure is generated when the lubricating oil is supplied to the main shaft 41 to which the reduced rotation is transmitted via the planetary gear mechanisms 21 _L and 21 _R. You can

Further, the lubricating oil passages 73, 74 from the oil pump 116 to the main shaft 41
Since it is formed to the rear part of the diff housing main body 11,
The lubricating oil can be efficiently cooled while flowing through the housing side lubricating oil passages 73 and 74 extending to the rear.

Further, from the rear oil passage 74, a one-way clutch is formed from oil passages 75 and 76 formed in the cylindrical member 53 _R fixed to the differential housing main body 11.
After 51 _R , during normal traveling, it passes through the oil passage 77 formed in the flange member 49 _R fixed to the one-way clutch 51 _R and the oil passage 78 formed in the flange member 59 _R rotating integrally with the main shaft 41,
The lubricating oil flows from the radial oil passage 79 of the main shaft 41 into the axial oil passage 81. Here, the main shaft 41 rotates at a low rotation speed that is decelerated from the input shaft 13, the rotation speed is 0 up to the oil passage 77, and the flange rotates at the same low rotation speed as the main shaft 41. Since the outer diameter of the opening of the oil passage 78 of the member 59 _R is also small and the hydraulic pressure due to the centrifugal force of the rotation of the opening of this oil passage 78 is small, the oil pump 116 provided on the input shaft 13 having a high rotational speed produces a high hydraulic pressure. The lubricating oil can be reliably fed into the opening of the passage 78.

Therefore, the lubricating oil can be supplied to each portion by the lubricating oil passage formed by the simple hydraulic circuit formed in the main shaft 41. That is, the spindle 41
Lubricating oil is supplied from both ends of the axial oil passage 81 to the left and right variable torque transmission capacity clutches 61 _L and 61 _R, and the planetary gear mechanisms 21 _L and 21 _L from the central radial oil passage 83 to the outer peripheral side. Lubricating oil can be supplied to _R , and lubricating oil can be supplied from the other radial oil passages 82 to many bearing parts.

Since the lubricating oil passages 73 and 74 extending from the oil pump 116 built in the front boss portion 111 of the diff housing body 11 to the main shaft 41 are formed in the diff housing body 11, the pump and hydraulic piping are exposed outside the housing. I haven't.

Therefore, the entire differential housing can be made compact.

The differential device of the embodiment can be used as a front differential or a center differential in addition to the rear differential. Further, in addition to the four-wheel drive vehicle of the front wheel drive base of the embodiment, it is also used in a four-wheel drive vehicle of the rear wheel drive base and a four-wheel drive vehicle in which the driving force is transmitted to the front and rear wheels via the center differential. .

[Advantages of the Invention] As described above, according to the present invention, in a diff device having a rotary input shaft, a reduction mechanism, a main shaft, a multi-plate clutch, and an output shaft provided in a housing, an oil pump is used for an input shaft with a high rotational speed. With this arrangement, it is possible to supply a high oil pressure to the lubricating oil passage formed in the main shaft to which rotation is transmitted via the reduction gear mechanism, and to reduce the speed reduction mechanism on the outer peripheral side from the lubricating oil passage in the main shaft and each of the both end sides. Lubricating oil can be supplied to each lubrication part including the multi-plate clutch with a simple circuit.
A lubricating oil passage extending from the oil pump built into the housing to the spindle is formed in the housing to connect to the lubricating oil passage inside the spindle, so while maintaining compactness of the housing, while passing through the lubricating oil passage on the housing side Lubricating oil can be cooled efficiently.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view showing the internal structure of a rear differential device to which the present invention is applied, FIG. 2 is an enlarged view of a planetary gear device portion, and FIGS. 3 and 4 are enlarged views of two multi-plate clutch portions. FIG. 5 is a configuration diagram of a drive system of a four-wheel drive vehicle as an example including a rear differential device. In the drawing, 11, 12, 111 and 114 are housings, 13 is a rotary input shaft, 21 is a reduction mechanism, 41 is a main shaft, 61 is a multi-disc clutch, 71
Is the output shaft, 73 and 74 are the lubricating oil passages on the housing side, and 75, 76, 77 and 78
Is a housing-main shaft lubricating oil passage, 79, 81, 82, 83 are main spindle lubricating oil passages, and 116 is an oil pump.

Claims (1)

[Scope of utility model registration request] 1. A rotation input shaft, a main shaft to which rotation is transmitted from the input shaft via a speed reduction mechanism, and a pair of transmission / cutoff rotations from both ends of the main shaft via respective multi-plate clutches. A differential device in which an output shaft is supported in a housing, wherein an oil pump is arranged on the input shaft and built in the housing, and a lubricating oil passage extending from the oil pump to the main shaft is formed in the housing. A lubricating structure for a differential device, wherein a lubricating oil passage opening from the lubricating oil passage to each lubrication portion including the speed reduction mechanism and the multi-disc clutch is formed in the main shaft.