JPH0547410B2 - - 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).

For example, as this type of four-wheel drive device,
There has been something like the one described in Publication No. 126727,
This four-wheel drive device includes, as one element of a power distribution unit, a power distribution drive gear coaxially drive-coupled to the case of the differential gear and rotatably fitted to one of the differential output shafts, This unit is housed in a power distribution case attached to the transaxle case.

(Problem to be solved by the invention) However, in such a conventional four-wheel drive device,
The inside of the transaxle case and the inside of the power distribution case are connected through the penetration part between the power distribution drive gear, the transaxle case and the power distribution case, and the fitting part between the power distribution drive gear and one of the above differential output shafts. Because lubricating oil can freely flow between
This causes the following problems.

In other words, when the vehicle tilts or lateral acceleration occurs, a large amount of oil moves from the transaxle case to the power distribution case, or from the power distribution case to the transaxle case, causing malfunction in the case where oil is low. This may result in poor lubrication. In this state, if there is a lack of oil in the transaxle case, the transmission (especially automatic transmission) will malfunction, causing serious trouble.

Furthermore, when it is necessary to vary the oil levels in both cases, or when oils with different characteristics are used in both cases, the conventional four-wheel drive system cannot handle the situation due to the above-mentioned oil movement.

(Means for Solving the Invention) In view of the above-mentioned circumstances, the present invention is based on the above-mentioned type 4, from the viewpoint that it is preferable to prevent oil from flowing back and forth between the transaxle case and the power distribution case. In a wheel drive device, a seal is provided between the power distribution drive gear and at least one of the transaxle case and the power distribution case, and between the power distribution drive gear and the differential output shaft fitted with the power distribution drive gear. .

(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.
At this time, the engine power reaching the differential gear case is transmitted to the other two wheels via a power distribution unit including a power distribution drive gear, and can drive these wheels.

By the way, the above seal prevents oil from flowing back and forth between the transaxle case and the power distribution case. Therefore, even when the vehicle is tilted or lateral acceleration occurs, oil does not come and go between the transaxle case and the power distribution case, and the amount of oil in these cases is always maintained at a predetermined level. . Therefore, no malfunction or poor lubrication occurs within these cases. or,
Even if the oil levels in both cases are different or oils with different characteristics are used in both cases, this requirement can be fully met by not mixing the oils between the two cases.

(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 drive 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 drive 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 drive gear 11 and is rotatably supported on a subshaft 15 parallel to the differential output shaft 9. The subshaft 15 has
A direction change drive 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 drive 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 coupled to the countershaft 15 and thus to the redirection drive gear 16.

The direction change drive gear 16 is a bevel gear, and the direction change driven gear 2 of the bevel gear type meshes with the direction change drive gear 16.
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 portion of the power distribution case 10 that supports this ball bearing 12 is removed at a point 24 where it overlaps with the direction change drive gear 16.

Also, regarding lubrication, transaxle case 4
Lubrication within the power distribution case 10 and lubrication within the power distribution case 10 are performed separately, and for this purpose, the boss portion of the power distribution drive gear 11 and the transaxle are designed to prevent the flow of lubricating oil between the two cases 4 and 10. In addition to providing seals 25 and 26 between the case 4 and the power distribution case 10, respectively,
A seal 27 is provided in the middle of the fitting portion between the power distribution drive gear 11 and the differential output shaft 9. Power distribution drive gear 1 on the left side in the figure across the seal 27
1 and the differential output shaft 9 are lubricated by lubricating oil inside the transaxle case, and the seal 2
The mutually sliding portion of the power distribution drive gear 11 and the differential output shaft 9 on the right side in the figure across 7 is the gear 11.
The power distribution case 10 is lubricated with lubricating oil supplied through an oil hole 28 provided in the boss portion of the power distribution case 10.

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 drive gear 11. Now move the dog clutch 19 to the right in the diagram and shift it to clutch gear 1.
5a, 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 passes through the dog clutch 19 to the subshaft 15 and the direction change drive gear 1.
6, and is then supplied to the other two wheels by the direction change driven gear 20 and the distributed power output shaft 21,
A four-wheel drive state is obtained.

(Effects of the Invention) Thus, as described above, the four-wheel drive system of the present invention provides a connection between the power distribution drive gear 11 and at least one of the transaxle case 4 and the power distribution case 10 (both in the illustrated example), and the power distribution drive. Since the seals 25 to 27 are provided between the gear 11 and the differential output shaft 9 fitted with the gear 11, oil is prevented from flowing between the cases 4 and 10, and therefore the vehicle Even when the vehicle is tilted or when lateral acceleration occurs, the amount of oil in these cases 4 and 10 can always be maintained at a predetermined amount, and there will be no malfunction or poor lubrication within these cases. Also, even if the oil levels in both cases 4 and 10 are different, or oils with different characteristics are used in both cases 4 and 10, this requirement can be sufficiently met by not mixing oil between both cases. I can respond.

[Brief explanation of the drawing]

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 drive gear, 12, 13...Ball bearing, 14...Power distribution driven gear, 15...Subshaft, 16...Direction change drive 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 four-wheel drive system comprising: a power distribution unit including a power distribution drive gear drive-coupled to the transaxle and rotatably fitted to one of the differential output shafts; housed in a power distribution case attached to the case of the transaxle; The apparatus is characterized in that a seal is provided between the power distribution drive gear and at least one of the transaxle case and the power distribution case, and between the power distribution drive gear and the one differential output shaft. 4-wheel drive system.