JPH0266345A - Differential gear - Google Patents

Abstract

PURPOSE:To manufacture the title device at a low cost by connecting a first and a second side gears with a first and a second gear shafts rotatably supported at a movable casing by means of a planetary gear mechanism. CONSTITUTION:When the rotational resistance difference is generated to a first and a second output shafts 8, 9 for example at the turning time of a vehicle, a planetary gear mechanism is actuated, that is, if the rotational resistance of the output shaft 8 is smaller than that of the output shaft 9, the balance of the force worked on the engaging part between a first gear 22 and a second gear 23 is broken so that the gear 22 is rotated in the same direction as an input gear 25 and the gear 23 is rotated in the opposite direction. As a result, a first planetary gear 14 is automatically rotated in the same direction so as to highten the rotational speed of a first sun gear 11 and the output shaft 8. On the other hand, a second planetary gear 17 is automatically rotated in the opposite direction so as to lower the rotational speed of a second sun gear 12 and the output shaft 9. The output shafts 8, 9 are thus subjected to the differential action.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a differential gear device used in automobiles and the like.

(Prior art) In automobiles, when turning left and right, there is a difference in the rotational speed of the left and right drive wheels, which causes the wheels to slip and prevent smooth driving.Furthermore, in four-wheel drive, the front drive shaft and rear drive shaft If there is a difference in rotational speed between the drive wheels of the vehicle and the drive wheels, the vehicle will not be able to run smoothly.For this reason, automobiles are generally equipped with a differential gear system.

As a conventional general differential gear device, for example, the
There is one shown in Japanese Patent No. 6-32492.

As shown in FIG. 5, this differential gear device includes a pair of left and right side gears 02.0 rotatably provided in a case O1 that rotates by the driving torque of the engine.
It has 3. Bevel gears 04 and 05 are provided at mutually opposing ends of these side gears 02 and 03, respectively. Further, although not shown, left and right output shafts such as drive shafts are respectively connected to the other end of the side gear 02.03.

Between the bevel gears 04 and 05, the pinion bevel gear 0
6 is interposed so as to mesh with these gears 04.05. This binion bevel gear 06 is case 01
It is provided on a rotation shaft 07 that is rotatably supported by the side gear 02.03 and extends in a direction perpendicular to the axis of the side gear 02.03.

According to such a differential gear device, when the vehicle turns, it is possible to create a difference in rotational speed between the left and right drive wheels, or a difference in rotational speed between the front and rear drive shafts, so that the vehicle can turn smoothly. It becomes possible to run.

By the way, in such a differential gear device, if one of the drive shafts is idling due to muddy conditions, etc., the driving torque from the engine is transmitted to this idling drive shaft.
Almost no power is transmitted to the other drive shaft, so it is impossible to start (and engine torque is wasted unnecessarily).

To deal with this, as shown in Figure 5,
Conventionally, a differential gear device is provided with a differential limiting mechanism (differential lock mechanism) 08. This differential limiting mechanism 08 consists of a plurality of friction clutch plates 09.09 provided in the case 01.
．． ... and a plurality of friction clutch plates 010 provided on the side gears 02.03 are arranged alternately.

According to this differential limiting mechanism 08, when one drive shaft idles, both friction clutch plates 09.010 are pressed against each other, thereby locking the differential function of the differential gear device. There is.

(Problem to be Solved by the Invention) However, since such a differential limiting mechanism uses a friction clutch plate 09.010, if the friction clutch plate 09.010 wears out, it becomes impossible to obtain a stable locking force. Because of this, differential operation cannot be performed reliably.

In addition, the operating mechanism of these friction clutch plates 09.010 not only has a complicated structure, but also has a high manufacturing cost.Furthermore, since it uses a bevel gear, which is more expensive than a spur gear, the manufacturing cost is even higher. becomes expensive.

Therefore, it is conceivable to use a differential limiting mechanism with a structure other than the one that generates frictional resistance, but since a bevel gear is used in the differential gear, the differential limiting mechanism other than the differential limiting mechanism using friction clutch plates may be used. No restriction mechanism may be used.

The present invention has been made in view of these problems, and its purpose is to be able to use a differential limiting mechanism with a structure other than the differential limiting mechanism using friction clutch plates, and to be able to manufacture it at low cost. It is an object of the present invention to provide a differential gear device that can perform the following steps.

Furthermore, another object of the present invention is to provide a differential gearing device that can reliably limit the differential movement.

(Means for solving the problem) In order to solve the above-mentioned problem, the invention of claim (1)
a first side gear that is rotatably supported by the fixed casing, has a first ring gear formed at its negative end, and has a first output shaft connected to its other end; a second side gear supported coaxially with the side gear, having a second ring gear formed at one end and connected to a second output shaft at the other end; a movable casing disposed within the fixed casing; a first sun gear, one end of which is rotatably supported by the first side gear and coaxially supported by the first side gear, and the other end of which is supported by the movable casing; a second sun gear that is coaxially supported by two side gears and whose other end is supported by the movable casing; and a first planetary gear that is rotatably supported by the movable casing and meshes with the first ring gear and the first sun gear. a second planetary gear rotatably supported by the movable casing and meshing with the second ring gear and the second sun gear; a second planetary gear rotatably supported by the movable casing and connected at one end to the first planetary gear; a first gear shaft rotatably attached to the movable casing;
a second gear shaft supported parallel to the gear shaft and connected at one end to the second planetary gear; a first gear housed in the movable casing and fixed to the first gear shaft; and a first gear in the movable casing. a second gear housed in the movable casing and fixed to the second gear shaft so as to mesh with the first gear shaft; and an input gear fixed to the movable casing and into which a driving torque is input. It is a feature.

Further, the invention of claim (2), in addition to the invention of claim +11, provides that the accommodation portion of the first and second gears in the movable casing is a sealed chamber, and this sealed chamber is used as the first and second gears. It is characterized in that it is divided into two small chambers by a gear, and these two small chambers are connected by a passage provided with an orifice, and a liquid is sealed in this passage and the sealed chamber.

Furthermore, the invention of claim (3), in addition to the invention of claim (1), provides a sealed chamber for housing the first and second gears in the movable casing; A feature is that a gap of a predetermined size is formed between the tip of the tooth and the inner wall surface of the sealed chamber facing the tip.

(Function) In the differential gear device according to the invention of claim (1) having such a configuration, the first and second side gears and the first and second gear shafts rotatably supported by the movable casing are , respectively, are connected by a planetary gear mechanism including 1j5 and second ring gears, first and second planetary gears, and first and second sun gears.

For example, when the vehicle is traveling straight, the first and second side gears are connected to the first and third side gears, respectively.
When no rotational resistance difference occurs in the output shaft, this planetary gear mechanism does not operate at all, that is, the first and second planetary gears do not rotate and remain fixed. Therefore, the torque input to the input gear is transmitted to the movable casing, the fixed first and second planetary gears, the first and second ring gears, and the first:! 3rd and 2nd
It is transmitted to the first and second output shafts via the side gears. Therefore, both output shafts rotate at the same speed and in the same direction.

For example, when a rotational resistance difference occurs between the first and second output shafts, such as when the vehicle turns, the planetary gear mechanism operates. In other words, for example, if the rotational resistance of the first output shaft is lower than that of the second output shaft, the balance of the forces acting on the meshing portion of the first gear and the second gear will be disrupted, and the first gear will become the same as the input gear. The second gear rotates in the opposite direction. Therefore, the first planetary gear rotates in the same direction, and the first planetary gear rotates in the same direction.
Increase the rotational speed of the sun gear and first output shaft. on the other hand,
The second planetary gear rotates in the opposite direction to reduce the rotational speed of the second sun gear and the second output shaft. In this way, the first and second output shafts operate differentially.

Further, in the differential gear device according to the invention of claim (2), as described above, when the first and second output shafts perform differential movement, the first and second gears rotate, so these gears are used as a gear pump. It comes to work. Therefore, the action of this gear pump causes the liquid to flow from the discharge side chamber through the orifice toward the suction side chamber.

In that case, since the rotation of the first and second gears is relatively small, the flow rate of the liquid is small, and the resistance due to the orifice is small. Therefore, the first and second gears can rotate smoothly, and the first and second gears The output shaft can be reliably operated differentially.

For example, assume that one wheel of a vehicle gets into mud or the like and its rotational resistance becomes almost zero compared to the other wheel, that is, the case where the rotational resistance of the first output shaft disappears. In this case, the first planetary gear rotates in the same direction as the input gear, so the first side gear and the first output shaft try to rotate at twice the speed of the human gear, while the second planetary gear rotates in the opposite direction. As a result, the second sun gear and the second output shaft tend to stop rotating. However, since the first and second gears rotate at high speed, the discharge amount of the gear pump increases, and the flow rate is restricted by the orifice. Therefore, the pressure inside the small chamber on the discharge side increases. This high pressure causes resistance to the rotation of the gear pump, and the rotation of the first and second gears is restricted to a predetermined number of rotations or more. As a result,
The rotation of the first and second planetary gears is also restricted. In this way, the planetary gear mechanism is in the locked state, so the input torque is also transmitted to the second side gear and the second output shaft via the movable casing and the second planetary gear, and the second output shaft also rotates.

Further, in the differential gear device according to the invention of claim (3), as in the invention of claim (2), when the first and second output shafts perform differential movement, the first and second gears rotate. , these gears come to act as a gear pump. Therefore, the action of this gear pump causes the liquid to be fed from the suction side to the discharge side. However, since the rotation of the first and second gears is relatively small and the flow rate of the liquid is small, the pressure on the discharge side does not become so high. Therefore, the resistance that the liquid acts on the gears is small. , the second gear can rotate smoothly, and the first gear can rotate smoothly. The second output shaft can reliably perform differential operation.

For example, if one of the wheels of the vehicle gets into mud or the like, the first and second gears will rotate at a high speed, increasing the discharge amount of the gear pump. Therefore, the pressure of the liquid on the discharge side increases, and the liquid tends to flow back from the discharge side to the suction side. As a result, the rotation of the gear pump is subjected to large resistance, and the rotation of the first and second gears is restricted to a predetermined number of rotations or more. That is, the rotation of the first and second planetary gears is restricted. In this way, the planetary gear mechanism is in a locked state, so that the input torque is transmitted to the second side gear and the second side gear through the movable casing and the second planetary gear. It is also transmitted to the second output shaft, and the second output shaft also begins to rotate.

(Example) Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the differential gear device according to the present invention, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line III-II in FIG. FIG.

As shown in FIG. 1, the differential gear device 1 includes a fixed casing 2, and a first side gear 3 and a second side gear 4 are coaxially arranged at both left and right ends of the fixed casing 2, and a bearing 5. It is rotatably supported by 5. 1st
, first and second ring gears 6.7 are formed at opposing ends of the second side gear 3.4, respectively, and the other ends of the first and second side gears 3, 4 are indicated by dashed double-dashed lines, respectively. The first and second output shafts 8.9 are spline-coupled as shown in FIG.

Further, a movable casing 10 is disposed between the first and second side gears 3.4, and one ends of the first and second sun gears 11.12 are supported on both left and right sides of the movable casing 10, respectively. The other ends of the first and second sun gears 11.12 are coaxially supported by the first and second side gears 3.4, respectively, and rotatably supported by bearings 13.13. That is, the movable casing 10 is connected to the first and second side gears 3.
．． It is supported so that it can rotate relative to 4.

Three first planetary gears 14 (two of which are not shown) are disposed between the first ring gear 6 and the first sun gear 11 so as to mesh with these gears 6.11. These three first planetary gears 14 are connected by a first carrier 15 at equal intervals in the circumferential direction.

Similarly, three second planetary gears 17 connected by a second carrier 16 are arranged between the second ring gear 7 and the second sun gear 12.

One of the first and second planetary gears 14.17 is provided with a first and second gear shaft 18.19, respectively, extending in parallel and toward the movable casing 10. These first and second gear shafts 18, 19 are rotatably supported by bearings 20, 20: 21, 21, respectively, in the movable casing lO. That is, the first and second side gears 3.4 and the first and second gear shafts 18.19 are connected by a planetary gear mechanism. First and second gear shafts 18.
First and second gears 22 and 23 are fixed to 19,
As shown in FIG. 2, these first and second gears 2
2 and 23 are meshed with each other and housed in the closed chamber 24 of the movable casing 10.

A ring-shaped input gear 2 is provided on the outer periphery of the movable casing 10.
5 is fixed. All gears are made up of spur gears.

As is clear from FIG. 2, the sealed chamber 24 is divided into two small chambers 24a and 24b by first and second gears 22,23. These two small chambers 24a, 24b are connected to a pair of passages 26a, 26b formed in the movable casing 10.
The movable casing 10 and the input gear 25 communicate with each other through a ring-shaped passage 26c formed between the movable casing 10 and the input gear 25. Third
As shown in the figure, the pair of passages 26a and 26b are provided with orifices 27a and 27b, respectively.
The flow rate of liquid flowing through 26b is restricted. Additionally, pressure responsive shutoff valves 28 are provided in the passages 26a and 26b.
a and 28b are provided. The pressure responsive shutoff valve 28a has a piston portion 28a at one end and a valve portion 28a at the other end.
2, and a spring 28a4 that always biases the piston valve 28a in the direction in which the passage 26a is opened. Similarly, the pressure responsive cutoff valve 28b also includes a piston valve 28b3 and a spring 28b4.

Further, passages 26a and 26b are provided with hydraulic pressure adjusting devices 29a and 29b, respectively. Hydraulic pressure adjustment device 29a
is a pair of pistons 29 a + , 2 in a hole with a circular cross section.
9a1 are slidably fitted together. The pair of pistons 29a+, 29a slide so as to increase the volume of the fluid pressure regulator 29a when the liquid expands due to a rise in temperature, and to decrease the volume of the fluid pressure regulator 29a when the liquid contracts due to a drop in temperature. By moving the ring-shaped passage 26c, the pressure inside the ring-shaped passage 26c is adjusted to be approximately atmospheric pressure at all times. Similarly, the hydraulic pressure adjustment device 2
9b is also configured in the same manner as the hydraulic pressure adjustment device 29a.

Next, the operation of this embodiment configured as described above will be explained.

For example, when the vehicle is traveling straight, the first. Second output shaft 8
．． When there is no difference in rotational resistance between the input gears 9 and 9, this planetary gear mechanism does not operate at all, that is, the first and second planetary gears 14 and 17 do not rotate (but are in a fixed state). The driving torque input to
A movable casing lO, first and second planetary gears 14.17 in a fixed state, and first and second ring gears 6.7,
It is transmitted to the first and second output shafts 8.9 via the first and second side gears 3.4. In that case, since three first and second planetary gears 14.17 are provided,
The input torque is distributed and transmitted to the first and second ring gears 6.7 in a well-balanced manner. Therefore, both output shafts 8.9 rotate at the same speed and in the same direction.

For example, when the vehicle turns, the first and second output shafts 8 and 9
When a difference in rotational resistance occurs, the planetary gear mechanism operates. That is, for example, the first output shaft 8 is higher than the second output shaft 9.
If the rotational resistance is smaller than that of the first gear 22 and the second
The balance of the forces acting on the meshing portion with the gear 23 is disrupted, causing the first gear 22 to rotate in the same direction as the input gear 25 and the second gear 23 to rotate in the opposite direction. Therefore, the first planetary gear 14 rotates in the same direction, and the first Zang gear 11 and the first
Increase the rotation speed of the output shaft 8. On the other hand, the second planetary gear 17 rotates in the opposite direction to reduce the rotational speed of the second sun gear 12 and the second output shaft 9. In this way, the first
, the second output shaft 8.9 operates differentially. and,
In this manner, when the first and second output shafts 8.9 perform differential movement, the first and second gears 22.23 rotate, so that these gears 22.23 function as a gear pump. That is, the liquid flows from the small chamber 24a on the discharge side to the orifice 27a, the ring-shaped passage 26c, and the orifice 27.
b and then flows toward the small chamber 24b on the suction side. In that case, since the rotational speed of the first and second gears 22 and 23 is relatively low, the amount of liquid discharged is small, and the resistance due to the orifices 27a and 27b is small.
The pressure of 4a and the discharge amount of the gear pump have a relationship along line a, as shown in FIG. therefore,
The first and second gears 22 and 23 can rotate smoothly, and the first and second output shafts 8.9 can reliably perform differential movement.

For example, when one wheel of the vehicle gets into mud or the like and its rotational resistance becomes extremely small compared to the other wheel, that is, when the rotational resistance of the first output shaft 8 becomes extremely small, the first planetary gear 14 rotates in the same direction as the input gear 25, the first side gear 3 and the first output shaft 8 try to rotate at twice the speed of the input gear 25, while the second planetary gear 17 rotates in the opposite direction. Therefore, the second sun gear 12 and the second output shaft 9 tend to stop rotating. However, at this time, the first and second gears 22, 23 begin to rotate at high speed, so the discharge amount of the gear pump increases, the flow rate is restricted by the orifices 27a and 27b, and an orifice effect appears. Therefore, the pressure inside the small chamber 24a on the discharge side increases.

Due to this high pressure, rotation of the gear pump is subjected to large resistance, and the first and second gears 22 and 23 hardly rotate. That is, as shown by the line in FIG. 4, only the pressure inside the small chamber 24a increases,
The discharge amount hardly increases, and as a result, the first and second planetary gears 14°17 hardly rotate. In this way, the planetary gear mechanism is almost in a locked state, and the input torque is also transmitted to the second side gear 4 and the second output shaft 9, so that the second output shaft 9 also rotates. In this way, the first and second gears 22, 23, the small chamber 24a
, 24b, orifices 27a, 27b, passages 26a, 2
6b, 26c, and the liquid constitute a differential limiting mechanism that fixes the differential. When the pressure inside the small chamber 24a reaches a certain level, the piston valve 28a releases the spring 28.
It moves against the urging force of a4 and blocks the passage 26a.

Therefore, the liquid stops flowing completely, and the first and second gears 22, 23 stop rotating completely. That is, the planetary gear mechanism is completely locked. As a result, all of the input torque is transmitted to the second output shaft 9.

In addition, in the above-mentioned embodiment, the orifices 27a, 2
It is assumed that two 7b are provided.

The present invention is not limited to this, and the number of orifices may be one.

Additionally, in the embodiments described above, the pressure-responsive shutoff valves 28a, 28
b is provided, but this pressure-responsive shutoff valve is not necessarily necessary and can be omitted.

5 and 6 show different embodiments of the invention, FIG. 5 being a sectional view similar to FIG. 1, partially showing a cross section of this embodiment, and FIG. It is a sectional view along the -Vl line. Although FIG. 5 only shows a part of this embodiment, for the parts not shown, this embodiment has completely the same components as the previous embodiment. Furthermore, the constituent elements shown in FIG. 5 that correspond to those in the above-described embodiment are given the same reference numerals, and their explanation will be omitted.

As is clear from FIG. 5, the input gear 25 is provided on one side member of the movable casing 10. Also the 6th
As is clear from the figure, a gap α of a predetermined size is formed between the inner wall surface 24c of the sealed chamber 24 and the tooth tip 22a of the first gear 22. Similarly, the inner wall surface 24 of the sealed chamber 24
A gap α is also formed between the tooth tip 23a of the second gear 23 and the tooth tip 23a of the second gear 23.

The movable casing 10 is provided with a pair of hydraulic pressure adjusting devices 29a and 29b each having a pair of pistons (not shown in FIGS. 5 and 6), as in the previous embodiment. These hydraulic pressure regulators 29a, 29b communicate with the closed chamber 24 through a passage 26' formed in the movable casing IO.

Next, the operation of this embodiment will be explained.

When the vehicle turns, the first and second output shafts 8.9 operate differentially in this embodiment as in the previous embodiment. When differential gearing is performed, the first and second gears 22 and 23 rotate to perform the action of a gear pump. therefore,
Liquid is supplied from the suction side to the discharge side within the sealed chamber 24. The liquid also flows through the passage 26' to the hydraulic pressure regulators 29a, 29b. However, since the rotational speeds of the first and second gears 22 and 23 are extremely low, the amount of liquid fed is small and the pressure on the discharge side does not increase. Second gear 22
．． 23 can rotate smoothly with almost no resistance. As a result, the first and second output shafts 8.9
operates reliably.

When one wheel of the vehicle gets into mud or the like and its rotational resistance becomes extremely small compared to the other wheel, the first and second gears 22 and 23 are rotated at a high speed as in the previous embodiment. become. Therefore, a large amount of liquid is fed from the suction side toward the discharge side, and the pressure on the discharge side increases. When the pressure on the discharge side becomes considerably high, the liquid tends to flow back through the gap α from the discharge side toward the suction side. As a result, the first and second gears 22.2
3 will receive a lot of resistance and will hardly rotate. In other words, the planetary gear mechanism is in a locked state,
Differential is limited. In this way, the first and second gears 22.2
3. A differential limiting mechanism for fixing the differential is configured by the sealed chamber 24, the gap α of a predetermined size, and the liquid.

In this embodiment, the orifices 27a, 27b and passages 26a, 26b, 26 used in the previous embodiment are
Since c is not required, the structure is not only simplified, but also
The number of parts is small, and manufacturing costs can be reduced.

(Effects of the Invention) As is clear from the above description, the differential gear device according to the invention of claim (1) connects the first side gear to the movable casing via the first ring gear, the first planetary gear, and the first sun gear. At the same time, the second side gear is connected to the second gear disposed on the movable casing via the second ring gear, the second planetary gear, and the second sun gear. Since the two gears are made to mesh with each other and the axes of all the gears are arranged coaxially or in parallel, each gear can be constructed from a spur gear. therefore,
If the first and second gears are used as a gear pump, it becomes possible to utilize a differential limiting mechanism based on fluid resistance other than frictional resistance.

Further, since there is no need to use an expensive bevel gear as in the conventional case, the differential gear device can be manufactured at low cost.

Furthermore, in the invention of claim (2), the above-mentioned first and second gears are configured as a gear pump, and the discharge side and suction side thereof are communicated via the orifice, so that one output shaft When the gear pump idles, the amount of liquid discharged by the gear pump increases and the resistance due to the orifice increases. Since this resistance is added to the rotation of the first and second gears of the gear pump, the first and second gears no longer rotate.

As a result, the differential gear device is in a locked state, and the input torque is transmitted to the other output shaft that does not idle. In this case, since a conventional friction clutch plate is not used, the locking force does not become unstable due to wear, and the differential can be reliably limited.

Furthermore, since friction clutch plates and mechanisms for operating these friction clutch plates are not required, manufacturing costs can be significantly reduced.

Furthermore, the invention of claim (3) configures the first and second gears as a gear pump, and provides a predetermined gap between the tips of the first and second gears and the inner wall surface of the sealed chamber that accommodates these gears. Since only a gap of a certain size is provided, the number of parts is small, and manufacturing costs can be further reduced.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of a differential gear device according to the present invention, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is an explanatory diagram showing the relationship between the discharge amount and pressure of the gear pump used in the differential gear device, and FIG. 5 is a partial diagram showing another embodiment of the differential gear device according to the present invention. show,
A vertical cross-sectional view similar to Fig. 1, and Fig. 6 is the Vl in Fig. 5.
A sectional view taken along the line -Vl, and FIG. 7 is a longitudinal sectional view of a conventional differential gear device. l... Differential gear device, 2... Fixed casing, 3...
...First side gear, 4...Second side gear, 6...
・First ring gear, 7...Second ring gear, 8...
First output shaft, 9... Second output shaft, 10... Movable casing, 11... First sun gear, 12... Second sun gear, 14...-first planetary gear, 17-...-th 2
Planetary gear, 18... first gear shaft, 19... second gear shaft, 22... first gear, 22a... tooth tip, 2
3... Second gear, 23a... Tooth tip, 24... Sealed chamber, 24a, 24b... Small chamber, 24c... Inner wall surface,
25...Input gear, 26a, 26b, 26cm passage,
27a, 27b...orifice, α...gap Fig. 2

Claims (3)

[Claims] (1) a first side gear rotatably supported by the fixed casing, having a first ring gear formed at one end and connected to the first output shaft at the other end; a second side gear supported coaxially with the first side gear, having a second ring gear formed at one end and connected to a second output shaft at the other end; a movable casing disposed within the fixed casing; a first sun gear, one end of which is rotatably supported by the first side gear and coaxially supported by the first side gear, and the other end of which is supported by the movable casing; a second sun gear coaxially supported by the second side gear and whose other end is supported by the movable casing;
a first planetary gear rotatably supported by the movable casing and meshing with the first ring gear and the first sun gear; a first planetary gear rotatably supported by the movable casing;
a second planetary gear meshing with the second ring gear and the second sun gear; a first gear shaft rotatably supported by the movable casing and having one end connected to the first planetary gear; and a first gear shaft rotatably connected to the movable casing. a second gear shaft supported parallel to the first gear shaft and connected at one end to the second planetary gear; and a first gear housed in the movable casing and fixed to the first gear shaft. and a second gear shaft housed in the movable casing and fixed to the second gear shaft so as to mesh with the first gear shaft.
A differential gear device comprising a gear and an input gear fixed to the movable casing and into which driving torque is input. (2) The housing portion of the first and second gears in the movable casing is a sealed chamber, and this sealed chamber is divided into two small chambers by the first and second gears, and these two small chambers are separated by the first and second gears. 2. The differential gear device according to claim 1, wherein the channels are connected by a passage having an orifice, and a liquid is sealed in the passage and the sealed chamber. (3) The accommodation portion of the first and second gears in the movable casing is a sealed chamber, and the tooth tips of the first and second gears are connected to the inner wall surface of the sealed chamber opposite to these tooth tips. 2. The differential gear device according to claim 1, wherein a gap of a predetermined size is formed therebetween, and a liquid is sealed in the sealed chamber.