JPH0633240Y2 - Transfer structure of four-wheel drive vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a structure of a transfer device of a four-wheel drive vehicle for distributing a driving force of an engine to a front wheel drive shaft and a rear wheel drive shaft.

(Prior Art) Generally, a transfer device for a four-wheel drive vehicle that distributes the driving force of an engine to a front-wheel drive shaft and a rear-wheel drive shaft is a transmission gear device and an output distribution device that are composed of gears, sprockets, and the like in a transfer case. Various devices such as
The gears and the like of each device are configured to be lubricated with oil.

By the way, in the conventional transfer device, the oil can freely flow in the transfer case. For this reason, the oil flow caused by each device in the transfer case interferes with each other, and the stirring resistance of the oil increases. There was a problem of not having. Therefore, in order to solve such a problem, as disclosed in Japanese Patent Laid-Open No. 61-2972, a transfer case is partitioned by a separation plate to regulate the flow of oil in the transfer case. Proposed.

On the other hand, in the transfer device, the inside of the transfer case is sealed so that oil does not leak outside. Therefore, the following problems occur. That is, when the transfer device operates, the gears of the transmission gear device and the like mesh with each other to generate frictional heat, the temperature inside the transfer case rises, and the air inside the transfer case expands. Then, as described above, since the inside of the transfer case is hermetically sealed, the pressure inside the transfer case becomes extremely high, and the oil seal inside the transfer case may come off, or the durability of the oil seal may deteriorate. The problem arises.

Therefore, in the conventional transfer device, a breather is provided to release the pressure in the transfer case. However, with such a structure, when the pressure inside the transfer case becomes high and the breather discharges air, if oil is splashed on the breather,
There was a problem that the oil splashed with the air was discharged outside. Because of this,
It has been desired to develop a transfer structure that can keep the pressure inside the transfer case constant without the oil being discharged outside.

On the other hand, recently, it has been strongly desired to simplify the structure of the transfer device and reduce the number of parts.

(Purpose of the Invention) In view of the above circumstances, the present invention has a simple structure, a small number of parts, and can reduce the stirring resistance of the oil and secure the oil level at a necessary place, and the It is an object of the present invention to provide a transfer structure for a four-wheel drive vehicle that can maintain a constant pressure in the transfer case without being discharged to the inside.

(Structure of the Invention) The present invention is an output composed of a drive-side transmission wheel provided on a drive-side shaft, a driven-side transmission wheel provided on a driven-side shaft, and a power transmission member connecting them. A four-wheeled vehicle that includes a distributor and is provided with a gear mechanism of a final reduction unit on a side of the drive-side transmission wheel on the drive-side shaft, and the output distributor and the gear mechanism are housed in a transfer case. A transfer structure of a drive vehicle, wherein a partition wall formed separately from the transfer case is provided between the drive-side transmission wheel and the gear mechanism, and the gear in the transfer case is provided by the partition wall. An oil reservoir is formed in the part where the mechanism is stored, and a breather for adjusting the pressure inside the transfer case to a constant level is provided. A baffle plate for preventing the baffle is formed integrally with the partition wall, and the baffle plate is composed of a bottom wall part and three side wall parts on the side of the output distributor and on the left and right sides, and an upper part where the breather is located and The gist is the transfer structure of a four-wheel drive vehicle, which is characterized in that the side portion on the gear mechanism side is open.

According to the above configuration, the partition wall reduces oil agitation resistance and secures an oil level required for the gear mechanism. Further, the pressure inside the transfer case is appropriately adjusted by the breather, and further, splashing of oil on the breather is prevented by the baffle plate. Moreover, since the baffle plate is formed integrally with the partition wall, the baffle plate mounting structure is simplified.

(Embodiment) FIGS. 1 to 3 show a transfer device having an embodiment of a transfer structure for a four-wheel drive vehicle according to the present invention. This transfer device includes a transfer case 2 connected to a transmission case 1. The transfer case 2 is divided into a front case 21 and a rear case 22. Then, in the transfer case 2, an input shaft (only the end portion is shown) 3 to which the driving force of the engine is transmitted via a transmission and the like, and an input shaft 3
Rear wheel side output shaft (drive side shaft) 4 arranged on the same axis line as the input shaft 3 behind (on the right side in FIG. 1), and rear wheel side output shaft 4 on the side of the rear wheel side output shaft 4. A front wheel side output shaft (driven shaft) 5 arranged in parallel with 4 is provided.

At the front end position of the rear wheel side output shaft 4, as a gear mechanism of the final reduction unit, a reduction mechanism (transmission gear unit) 6 for switching the transmission ratio of the power transmitted from the engine to the wheels to a low speed state and a high speed state. And a differential device 7 that performs a differential action between the rear wheel output shaft 4 and the front wheel output shaft 5. The reduction mechanism 6 includes a sun gear 61 rotatably supported on the rear wheel output shaft 4, a pinion gear 62 meshing with the sun gear 61, and a ring gear 63 meshing with the pinion gear 62.
Etc., and is configured in a known manner. The differential device 7 also includes a sun gear 71 spline-coupled to the rear wheel output shaft 4, a pinion gear 72 meshing with the sun gear 71, a ring gear 73 meshing with the pinion gear 72, a pinion carrier 74 carrying the pinion gear 72, and the like. It is constructed in a known manner. At the rear end position of the rear wheel side output shaft 4, a switching mechanism that switches the differential state of the differential device 7 and the drive mode between the two-wheel drive state and the four-wheel drive state (illustration). (Omitted) is provided.

Behind the differential gear 7, a drive side sprocket rotatably supported by the rear wheel output shaft 4 (a drive side) via a connecting member 81 connecting the pinion carrier 74 of the differential gear 7 and the switching mechanism. A transmission vehicle 82 is provided. A driven sprocket (driven gear) 83 is integrally formed on the front wheel output shaft 5. A chain 84 as a power transmission member is wound between the driven-side sprocket 83 and the driving-side sprocket 82. The driving-side sprocket 82, the driven-side sprocket 83, and the chain 84 connect the input shaft 3 to the front-wheel-side output shaft. An output distribution device 8 for transmitting power to the motor 5 is configured.

A partition wall 9 for partitioning the inside of the transfer case 2 is arranged between the drive side sprocket 82 and a gear mechanism of a final reduction unit located on the side (front side) thereof.
Specifically, the partition wall 9 is arranged between the drive side sprocket 82 and the differential device 7. This partition wall 9
As shown in FIGS. 1 and 4, the wall plate portion located between the drive-side sprocket 82 and the differential gear 7 and a substantially cylindrical portion 9b connected to the wall plate portion and surrounding the differential gear 7 are connected.
And a flange portion 9a connected to the transfer case 2, which is formed separately from the transfer case 2 in advance and is mounted inside the transfer case 2. An oil sump chamber 23 is formed inside the substantially cylindrical portion 9b of the partition wall 9 in the portion accommodating the speed reduction mechanism 6 and the differential gear 7. With this oil reservoir chamber 23, the oil level is maintained at a predetermined level in the portion where the speed reduction mechanism 6 and the differential device 7 are housed. Moreover, the partition wall 9
Since the oil flow caused by the operation of the reduction gear mechanism 6 and the differential device 7 and the oil flow caused by the operation of the output distribution device 8 are not interfered with each other, the oil agitation is provided. The resistance can be reduced.

A breather 24 is attached to the front case 21 so as to be close to the partition wall 9. This breather 24
The air escape port 24a of the above is exposed to the inside of the transfer case 2, and the air discharge port 24b is exposed to the outside of the transfer case 2. This breather 24 is a transfer case 2
When the internal pressure becomes high, the air is discharged through the air escape port 24a and the air discharge port 24b, and when it becomes low, the air is sucked through the air escape port 24a and the air discharge port 24b. .
Therefore, even if the pressure inside the transfer case 2 rises or falls, the breather 24 keeps the pressure inside the transfer case 2 constant.

A baffle plate 91 is arranged below the air escape port 24a of the breather 24. As shown in FIG. 4, the baffle plate 91 includes a bottom wall portion 91a and three side wall portions 91b, 9 on both sides of the output distributor and the left and right sides.
The upper portion where the breather 24 is located and the side portion on the gear mechanism side are open, and the baffle plate 91 is formed integrally with the collar portion 9a of the partition wall 9. When the baffle plate 91 is formed as described above, the oil is splashed by the operation of the output distribution device 8, and even if the oil is splashed from below or sideways toward the air escape port 24a of the breather 24, The oil is applied to the bottom wall portion 91a of the baffle plate 91 and the side wall portions 91b, 91c, 91d and does not reach the air escape port 24a of the breather 24. Therefore, only the air is discharged from the breather 24 to the outside of the transfer case 2, and the oil is not discharged. The oil that has entered the baffle plate 91 from the open upper portion of the baffle plate 91 is collected in the oil sump chamber 23 from the open portion of the baffle plate 91 on the gear mechanism side.

In FIG. 2, reference numeral 25 is an inlet pipe of the lubrication pump for guiding the oil accumulated in the output distributor 8 into the oil reservoir chamber 23. Further, 92 is an oil path for receiving the oil splashed up in the oil sump chamber 23, guiding it to the output distribution device 8, and supplying the oil to the output distribution device 8, the switching mechanism, etc., and at the bottom thereof. Although not shown in the figure, a large number of holes are formed therethrough.

(Effect of the Invention) As described above, in the transfer structure of the four-wheel drive vehicle according to the present invention, the partition wall is provided between the drive side transmission wheel of the output distribution device and the gear mechanism in the transfer case. An oil sump chamber is formed in a portion of the transfer case in which the gear mechanism is housed, which is provided. Therefore, the stirring resistance of the oil can be reduced and the oil level can be secured where necessary. Also, since the breather is provided to adjust the pressure inside the transfer case to a constant level, the pressure inside the transfer case does not become extremely high, and the oil seal inside the transfer case may come off or the oil seal There is no problem that the durability of the becomes worse. Moreover, since the baffle plate that prevents the oil from splashing onto the breather is provided, the breather is not covered with the oil, and the oil is not discharged outside together with the air. Furthermore, since the baffle plate is formed integrally with the partition wall, compared to the case where the baffle plate is formed separately, the baffle plate attachment parts are not required and the number of parts can be reduced. Further, the mounting structure of the baffle plate is simplified, and as a result, it is possible to prevent the transfer structure from becoming complicated.

[Brief description of drawings]

FIG. 1 is a transfer device having an embodiment of a transfer structure for a four-wheel drive vehicle according to the present invention, which is a cross-sectional view taken along the line I--I of FIG. 2, and FIG. FIG. 3 is a right side view of the closed state, FIG. 3 is a sectional view taken along the line III-III of FIG. 2, and FIG. 4 is a perspective view showing a partition wall and a breather. 2 ... Transfer case, 9 ... Partition wall, 23 ... Oil reservoir, 24 ... Breather, 91 ... Baffle plate.

Claims (1)

[Scope of utility model registration request] 1. A drive-side transmission wheel provided on a drive-side shaft,
The driven-side transmission wheel is provided on the driven-side shaft, and an output distribution device including a power transmission member that connects the driven-side transmission wheel and the drive-side transmission wheel is provided on the drive-side shaft. A transfer mechanism of a four-wheel drive vehicle in which a gear mechanism of a reduction gear unit is provided, and the output distribution device and the gear mechanism are accommodated in a transfer case, and between the drive-side transmission vehicle and the gear mechanism, A partition wall formed separately from the transfer case is provided, and this partition wall forms an oil sump chamber in the portion of the transfer case where the gear mechanism is housed, while at the same time reducing the pressure inside the transfer case. A breather for constant adjustment is provided, and a baffle plate for preventing splashing of oil on the breather is formed integrally with the partition wall, The baffle plate is composed of a bottom wall portion and three side wall portions on the side of the output distributor and on the left and right sides, and the upper portion where the breather is located and the side portion on the gear mechanism side are open. Transfer structure for wheel drive vehicles.