JPH0554453B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a four-wheel drive device for a part-time four-wheel drive vehicle with a transverse engine.

(Prior art) This type of 4-wheel drive vehicle is a transversely mounted front engine front wheel drive vehicle (FF vehicle) or a transversely mounted rear engine rear wheel drive vehicle (RR vehicle) that has been converted to 4 wheel drive. After shifting, the power from the engine is transmitted to the two differential output shafts via the differential gear, and is transmitted to the front two wheels (for FF vehicles).
Alternatively, a four-wheel drive system is usually created by adding a power distribution unit that distributes and transmits power to the other two wheels to the transaxle that drives the two rear wheels (in the case of RR vehicles).

As this type of four-wheel drive device, for example, Japanese Patent Application Publication No. 57
There has been a conventional four-wheel drive device as described in Japanese Patent No. 126727, and this four-wheel drive device is drive-coupled coaxially to the case of the differential gear, and has a power distribution driven gear juxtaposed to the transverse engine; The power distribution unit is composed of a power distribution driven gear that meshes with the power distribution driven gear, a direction change driven gear that is appropriately driven by this gear via a dog clutch, and a direction change live gear that meshes with this gear and is connected to the distribution power output shaft. It is housed within a power distribution case attached to the transaxle case.

(Problem to be Solved by the Invention) However, in this conventional four-wheel drive system, the power distribution driven gear and the direction change driven gear, which are arranged coaxially, are arranged so that the former is located on the transaxle case side, so the power The power distribution driven gear that meshes with the distribution driven gear is located in the immediate vicinity of the transaxle case, and in order to secure storage space for it, the power distribution case is shaped to protrude significantly in the radial direction near the transaxle case attachment part.

By the way, there is a mounting part of the transverse engine to the transaxle case in this part, and this and the above-mentioned protruding part of the power distribution case interfere with each other.
In order to avoid this interference, it is necessary to increase the distance between the shafts of the transverse engine and the power distribution driven gear, resulting in the problem that the four-wheel drive device becomes larger in the radial direction despite the constraints of installation space.

Furthermore, since the dog clutch is coaxially disposed on the side of the power distribution driven gear that is far from the direction change driven gear, a problem arises in that the dog clutch increases the length of the power distribution unit in the axial direction.

Therefore, the conventional four-wheel drive device described above is large in size both in the radial direction and the axial direction, making it difficult to install it in a small car where vehicle mounting space is severely restricted.

(Means for Solving the Problems) The present invention is based on the viewpoint that there is no need to worry about interference with the transverse engine even if the power distribution case protrudes in the radial direction at a location distant from the transaxle case. In the drive device, of the power distribution driven gear and the direction change driven gear, the direction change driven gear is arranged on the transaxle case side.

On the other hand, it is preferable to have bearings on both sides of the power distribution driven gear in order to increase bearing rigidity, but in this case, the bearing part on the transaxle case side may be located near the transaxle case.
The bearing part connects the power distribution case at this location,
This causes the bearing to protrude in the radial direction to the extent that it interferes with the attachment part of the transverse engine to the transaxle case, causing the above-mentioned problem again. It becomes necessary to increase the distance between the shafts of the conversion driven gears, which not only leads to an increase in the size of the four-wheel drive device in the radial direction, but also makes it impossible to set an appropriate gear ratio due to the accompanying change in gear ratio of the power distribution gear set.

Therefore, in the present invention, there is a wasted space between the power distribution driven gear and the direction change driven gear, and if the above-mentioned bearing part is housed in this space,
From the viewpoint of preventing the above-mentioned problem from occurring due to the bearing housing radial extension of the power distribution case being displaced from the mounting area of the transverse engine to the transaxle case and the bearing being displaced from the direction change driven gear, In addition to the above, the power distribution driven gear is bearing on both sides thereof, and the axial position of the bearing portion on the transaxle case side is between the power distribution driven gear and the direction change driven gear.

In addition, in view of the fact that there is wasted space between the power distribution driven gear and the direction change driven gear as described above, the present invention provides the aforementioned dog clutch between these gears, and this dog clutch increases the length of the power distribution unit in the axial direction. This was done so that it would not happen.

(Operation) The transaxle transmits the power from the transverse engine to two differential output shafts via a differential gear after shifting, and drives the front or rear two wheels.
When the dog clutch is connected here, the engine power is transmitted to the other two wheels via the differential gear case, power distribution driven gear, power distribution driven gear, dog clutch, direction change driven gear, direction change driven gear, and distribution power output shaft, These can be driven.

By the way, since the power distribution driven gear and the direction change driven gear are arranged so that the latter is located on the transaxle case side, the power distribution driven gear that meshes with the power distribution driven gear is located away from the transaxle case.
The radial projecting part of the power distribution case for securing the storage space can be shifted from the mounting part of the transverse engine to the transaxle case, and no interference therewith will occur. Therefore, there is no need to increase the distance between the shafts of the transverse engine and the power distribution driven gear, and the four-wheel drive device can be made compact in the radial direction.

In addition, by bearing the power distribution driven gear on both sides, the bearing rigidity can be increased, and since the axial position of the bearing part on the transaxle case side is between the power distribution driven gear and the direction change driven gear, the power distribution case The radial extension for storing the bearing part of the transaxle case is displaced from the attachment point of the transverse engine to the transaxle case, and the bearing part is also displaced from the direction change driven gear. It is possible to prevent the distance between the axes from increasing, and the four-wheel drive device can have a compact configuration in the radial direction.

Furthermore, since the dog clutch is interposed in the wasted space between the power distribution driven gear and the direction change driven gear, the dog clutch does not increase the length of the power distribution unit in the axial direction.

Therefore, the four-wheel drive device of the present invention can be made compact in both the radial and axial directions, and is fully practical even for small vehicles with extremely limited mounting space.

(Example) Hereinafter, the present invention will be described in detail based on the illustrated example.

The drawing shows one embodiment of the four-wheel drive system of the present invention, in which 1 shows a transverse engine, 2 shows a transaxle, and 3 shows a power distribution unit. The transaxle 2 is a conventional one that houses a clutch or torque converter, a transmission gear mechanism (all not shown), and a differential gear 5 in a case 4, and is used to shift the power from the transverse engine 1. The signal is transmitted to the ring gear 6, and the case 7 of the differential gear 5 is rotationally driven via the ring gear. The differential gear 5 transmits the shifting power to the differential output shafts 8 and 9 on both sides via a differential gear set in the case 7, and drives two front wheels or two rear wheels (not shown) connected thereto. drive

The power distribution unit 3 distributes and transmits the engine power to the other two wheels, and drives these to enable four-wheel drive. The following transmission train is assembled into the attached power distribution case 10.

That is, the differential output shaft 9 passing through the power distribution case
A power distribution driven gear 11 is rotatably provided above, and this gear is rotatably supported within the power distribution case 10 by ball bearings 12 and 13 on both sides thereof. A spline penetrates the boss portion of the power distribution driven gear 11 into the differential gear case 7 at the outer periphery of the left end in the figure (indicated by 11a).
By doing so, the drive is coupled coaxially to this. A power distribution driven gear 14 is meshed with the power distribution driven gear 11, and is rotatably supported on a subshaft 15 parallel to the differential output shaft 9. The subshaft 15 has
A direction change driven gear 16 arranged closer to the transaxle case 4 than the power distribution driven gear 14 is spline-fitted (indicated by 16a), and this gear 1
6 and the end of the subshaft 15 remote from this are rotatably supported in the power distribution case 10 by thrust roller bearings 17 and 18, respectively.

The subshaft 15 further includes a power distribution driven gear 14.
A clutch gear 15a is integrally molded to be disposed between the direction change driven gear 16, and a clutch gear 14a having the same diameter is formed on the outer periphery of the boss portion of the adjacent power distribution driven gear 14. Clutch gear 14a
The dog clutch 19 is slidably fitted in the axial direction, and the dog clutch is appropriately connected to the clutch gear 15.
When in the position shown, which also meshes with a, the power distribution driven gear 14 can be drivingly connected to the countershaft 15 and thus to the diversion driven gear 16.

The direction change driven gear 16 is a bevel gear, and the direction change driven gear 2 of the bevel gear type meshes with this.
0 is integrally molded on the distributed power output shaft 21. The distributed power output shaft 21 is connected to the power distribution case 10 by a pair of thrust roller bearings 22 and 23.
The shaft 21 is rotatably supported within the power distribution case 10, and the shaft 21 protrudes from the power distribution case 10 at the lower end in the figure, so that it can be driven and connected to differential gears of two corresponding wheels.

Of the ball bearings 12 and 13, the ball bearing 1 closest to the transaxle case 4
The axial position of 2 is between the power distribution driven gear and the direction change driven gear 16, and the part 24 of the power distribution case 10 that supports this ball bearing 12 overlaps with the direction change driven gear 16.
Remove at.

Also, regarding lubrication, transaxle case 4
Lubrication inside the power distribution case 10 and lubrication inside the power distribution case 10 are performed separately, and for this purpose, the boss portion of the power distribution driven gear 11 and the transaxle case are designed to prevent the flow of lubricating oil between the two cases 4 and 10. 4 and the power distribution case 10, and a seal 27 is provided in the middle of the fitting portion between the power distribution driven gear 11 and the differential output shaft 9. Power distribution driven gear 11 on the left side of the figure with the seal 27 in between
The sliding contact portions of the differential output shaft 9 and the differential output shaft 9 are lubricated by lubricating oil inside the transaxle case, and the seal 27
The mutual sliding contact portion of the power distribution driven gear 11 and the differential output shaft 9 on the right side of the figure in the figure is lubricated by lubricating oil in the power distribution case 10 that is supplied through an oil hole 28 provided in the boss portion of the gear 11. .

The operation of the above embodiment will be explained next.

Power from the transverse engine 1 is changed in speed by a transaxle 2 and transmitted to a differential gear 5 of the transaxle via a ring gear 6 and a differential gear case 7. The differential gear 5 outputs this engine power to the differential output shafts 8 and 9, and drives the corresponding two wheels via these.

The engine power that has reached the differential gear case 7 also reaches the power distribution driven gear 14 via the power distribution driven gear 11. Now move the dog clutch 19 to the right in the diagram and shift it to clutch gear 1.
When the mesh with 5a is released, the engine power that has reached the power distribution driven gear 14 comes to a dead end and is not transmitted to the other two wheels. Therefore, a two-wheel drive condition is obtained in this case.

When the dog clutch 19 is placed in the illustrated position and also engaged with the clutch gear 15a, the engine power that has reached the power distribution driven gear 14 is transferred to the subshaft 15 and the direction change driven gear 1 via the dog clutch 19.
6, after which it is supplied to the other two wheels from the direction change driven gear 20 and the distribution power output shaft 21, and
Wheel drive condition is obtained.

(Effects of the Invention) Thus, as described above, in the four-wheel drive system of the present invention, the power distribution driven gear 14 and the direction change driven gear 16 are arranged so that the latter is located closer to the transaxle case 4 than the former, so that the four-wheel drive device of the present invention meshes with the power distribution driven gear 14. Power distribution driven gear 1
1 is located away from the transaxle case 4, and the radial projecting portion of the power distribution case 10 to secure storage space for the power distribution case 10 can be moved from the attachment portion 1a of the transverse engine 1 to the transaxle case 4. and there will be no interference with this. Therefore, there is no need to increase the distance between the shafts of the horizontal engine 1 and the power distribution driven gear 11, and the four-wheel drive system can be made compact in the radial direction, making it possible to install the four-wheel drive system even in a restricted space. can be installed.

In addition, the power distribution driven gear 11 is mounted on both sides with bearings (in the illustrated example, ball bearings 12, 1
3), the bearing rigidity can be increased, and since the axial position of the bearing part 12 on the transaxle case 4 side is between the power distribution driven gear 14 and the direction change driven gear 16, this bearing part 12 can be stored. The radial protrusion of the power distribution case 10 is also offset from the engine portion 1a, and the radially compact configuration of the four-wheel drive device is not hindered in any way. Moreover, such an arrangement of the bearing portion 12 can avoid interference with the direction change driven gear 16, and therefore the power distribution driven gear 11 can avoid interference with the direction change driven gear 16.
The distance between the shafts and the direction change driven gear 16 is not large, and the four-wheel drive device can be made compact in the radial direction.
The gear ratio between 14 and 14 can be set appropriately.

In addition, since the dog clutch 19 is arranged in the wasted space existing between the power distribution driven gear 14 and the direction change driven gear 16, the dog clutch 19 does not make the power distribution unit 3 any longer in the axial direction, so that four-wheel drive is possible. The device can also be made compact in the axial direction.

Therefore, the four-wheel drive device of the present invention has a compact configuration in both the radial and axial directions, and can be put to practical use even in small vehicles with limited mounting space.

[Brief explanation of drawings]

The drawing is an exploded sectional view of essential parts of the four-wheel drive device of the present invention. 1... Horizontal engine, 2... Transaxle, 3... Power distribution unit, 4... Transaxle case, 5... Differential gear case, 8, 9... Differential output shaft, 10... Power Distribution case, 11...Power distribution driven gear, 12,
13... Ball bearing (bearing part), 14...
Power distribution driven gear, 15... subshaft, 16...
Direction change driven gear, 19...Dog clutch, 20...Direction change driven gear, 21...Distribution power output shaft, 25-27...Seal, 28...
oil hole.

Claims (1)

[Scope of Claims] 1. A transaxle capable of transmitting power from a transverse engine to two differential output shafts via a differential gear after shifting, the transaxle being coaxial with the case of the differential gear. a power distribution driven gear drivingly coupled to the transverse engine and disposed in parallel with the transverse engine; a power distribution driven gear meshing with the power distribution driven gear; a direction change driven gear suitably driven by the power distribution driven gear via a dog clutch; A four-wheel drive device in which a direction change driven gear meshed with a distribution power output shaft is housed in a power distribution case attached to a case of the transaxle, wherein the direction change driven gear is connected to the power distribution driven gear and the direction change driven gear. A conversion driven gear is disposed on the transaxle case side, the power distribution driven gear is bearing on both sides thereof, and the axial position of the bearing portion on the transaxle case side is between the power distribution driven gear and the direction change driven gear, and the dog clutch is A four-wheel drive device characterized in that the power distribution driven gear and the direction change driven gear are interposed between the power distribution driven gear and the direction change driven gear.