JPH0834254A - Transfer device - Google Patents

Abstract

PURPOSE:To improve a degree of freedom on design which relates to an output position to an axle in a transfer device provided with a differential mechanism. CONSTITUTION:A transfer device is provided with a differential mechanism 12 in which power is input from a transmission through a high and low speed change-over mechanism 11, intermediate shafts 13, 14 which are provided in parallel below an output section of the differential mechanism 12 and connected by gears 40, 41, 42, 43, and output shafts 15, 16 which have gears 46, 47 which mesh with the gears 41, 43 of the intermediate shafts 13, 14 and transmit rotary drive force to front or rear wheels.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device provided in a full-time all-wheel drive system.

[0002]

2. Description of the Related Art As shown in FIG. 4, a power transmission system of an all-wheel drive vehicle inputs an output of an engine 2 via a transmission 1 to a transfer device (auxiliary transmission) 3 to front and rear axles 4. 5 is transmitted. The transfer device 3 has three shafts (an input shaft, an intermediate shaft, and an output shaft) that are arranged side by side in a substantially vertical direction, and has a structure in which gears attached to the respective shafts mesh with each other. In recent years, in addition to adding a high / low speed switching function to the input shaft, the output shaft is equipped with a differential mechanism such as a planetary gear type to reduce the difference in rotation caused by the difference in the turning radii of the front and rear wheels 6, 7 during turning. In addition to absorbing, proper torque distribution is performed (JP-A-4-3270).
58).

[0003]

By the way, in an all-wheel drive vehicle such as a truck, the ground height h of the transfer device 3 and the crossing angles θ ₁ , θ of the propeller shafts 8, 10 are set.
₂ is an important factor in securing driving performance and rotation transmission performance. That is, the higher the ground height h, the better the running performance on a bad road, and the smaller the crossing angles θ ₁ and θ _{2, the} smoother the rotation transmission, and the less the load on the universal joint 9. However, in the conventional transfer device including the differential mechanism, the propeller shafts 8 and 10 are connected to the output portion of the differential mechanism, and therefore the base end position thereof is substantially determined by the mounting structure with the transmission 1. , It was not possible to select the optimum ground height h and the intersection angles θ ₁ and θ ₂ for the vehicle.

Therefore, the present invention was devised to provide a transfer device provided with a differential mechanism capable of improving the degree of freedom of output position to the axle.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a differential mechanism which is rotationally input from a transmission through a high / low speed switching mechanism, and a differential gear mechanism are provided in parallel below an output portion of the differential mechanism and are connected by gears. And an output shaft that has a gear that meshes with the gear of the intermediate shaft and that transmits the rotational driving force to the front wheel or the rear wheel.

[0006]

With the above-described structure, the rotational driving force input from the transmission is transmitted from the output portion of the differential mechanism to the intermediate shaft and from the intermediate shaft to the output shaft by respective gears, and from the position of the output shaft to the front wheels or the rear wheels. Output to wheel axle.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show an embodiment of the transfer device according to the present invention. This transfer device includes a transmission (not shown) to a high / low speed switching mechanism 11
The differential mechanism 12 and the differential mechanism 1 which are rotationally input via
Two intermediate shafts 13 and 14 connected to the two output parts, and output shafts 15 and 16 connected to the intermediate shafts 13 and 14, respectively.
It is mainly composed of and.

The high / low speed switching mechanism 11 comprises an input shaft 17 coaxially connected to the output shaft of the transmission, and an idle shaft 18 arranged below the input shaft 17 and provided on the input shaft 17. A small gear 21 and a large gear 22 attached to the idle shaft 18 are meshed with the high speed gear 19 and the low speed gear 20, respectively. Input shaft 17 and idle shaft 1
The bearing 8 is supported on both sides by bearings 23 and 24 in the upper portion of the case 25. The high speed gear 19 and the low speed gear 20 are rotatably supported by a needle bearing 26, and selectively fastened by a switching fastening means (not shown) so that one of them rotates at the same speed as the input shaft 17 to reach its number of teeth. The speed is converted accordingly and transmitted to the idle shaft 18.

The differential mechanism 12 is composed of a well-known planetary gear and has a sun gear 28 having a first shaft 27 as one output portion, a carrier 30 supporting a pinion 29 meshing with the sun gear 28, and a pinion 29. And a ring gear 32 having a second shaft 31 that meshes with the other shaft and serves as the other output portion. The first shaft 27 and the second shaft 31 are held on the same axis by bearings 33 and 34, respectively. The shaft portion 35 of the carrier 30 extends so as to surround the first shaft 27 and is coaxially held by a bearing 36, and a gear 37 that meshes with the small gear 21 of the idle shaft 18 is attached. That is, the shafts 27 and 31 are rotated at a predetermined angular velocity and torque with a differential function and a driving force distribution ratio determined by the pitch circle radius of the sun gear 28 and the ring gear 32.

Each of the intermediate shafts 13 and 14 has a first shaft 27.
And a pair of bearings 38 and 39 that are coaxially supported on both sides of the bearings 38 and 39, respectively.
A gear 41 meshing with a gear 40 mounted on the first shaft 27 causes the front intermediate shaft 13 to mesh with a gear 42 mounted on the second shaft 31 and a gear 4 meshing with the gear 42.
The rear intermediate shafts 14 are rotated by 3 respectively. The output shafts 15 and 16 are provided in parallel below the intermediate shafts 13 and 14, respectively, and are coaxially supported by a pair of bearings 44 and 45.
Gears 46, 47 meshing with 1, 43 are attached, respectively. The output shaft 15 to which the rotational driving force from the first shaft 27 is transmitted is a front output, and the output shaft 16 to which the rotational driving force from the second shaft 31 is transmitted is a rear output.
It has been extended out. Gears 46, 4 of the output shafts 15, 16
7 has a relatively small diameter and has the same number of teeth as the number of teeth of the gears 40 and 42 of the shafts 27 and 31.

With this configuration, the rotational driving force distributed by the differential mechanism 12 is output at the positions of the front and rear output shafts 15 and 16 which are independent of each other, and the position of the differential mechanism 12 is Regardless of the final drive (final reducer) input position can be determined to the optimum position. That is, as shown by the chain double-dashed line in FIG.
6, 47 and the gears 41, 43 of the intermediate shafts 13, 14 mesh with each other, and the gears 37, 40, 42 of the differential mechanism 12
Can be arbitrarily selected on the arcuate trajectory A in the range that does not interfere with, reducing the propeller shaft intersection angle in the mounted vehicle,
Also, the degree of freedom in design for maintaining the ground height of the transfer device can be increased. Further, the rotation directions of the output shafts 15 and 16 are the same as the rotation directions of the shafts 27 and 31 of the differential mechanism 12, and there is no need to change the design on the axle side. Then, as shown in FIG. 2, each shaft 13 ... 18 and the shaft 2
In the staggered arrangement of 7 and 31, by maximizing the radial distance (horizontal offset amount) and reducing the diameters of the gears 41, 43, 46 and 47 of the intermediate shafts 13 and 14 and the output shafts 15 and 16. The total height inside the case 25 does not become excessively large, and the clearance S with the lower surface of the case can be set appropriately. If the clearance S is smaller, the lower surface of the case 25 can be kept higher, and the ground height of the transfer device can be increased. However, if the clearance S is too small, the pump action of the gears 46, 47 causes the lubricating oil to operate in the high speed rotation range. Care must be taken as it may increase the oil temperature. In this embodiment, small diameter gears 46 and 47 are used for the output shafts 15 and 16 to reduce the stirring resistance as much as possible and reduce the clearance.

Although the intermediate shafts 13 and 14 and the output shafts 15 and 16 are coaxial with each other in this embodiment, they are not necessarily coaxial. Also, two independent output shafts 15 and 16
The torque is distributed to the front and rear axles with the differential mechanism 12 as shown in FIG.
The rear output may be provided only on the side of the second shaft 53, and the driving force may be transmitted to the front axle by the first shaft 54 as in the conventional case. This configuration can be applied to a vehicle in which there is no problem even if the position of the front output is the position of the differential mechanism 12, and the overall size (case 55) is slightly smaller than that of the above embodiment. The other structure, function and effect are similar to those of the above embodiment. On the other hand, a structure in which the intermediate shaft and the output shaft are provided only on the first shaft 54 side and is directly connected to the rear axle is also conceivable. Further, the differential mechanism is not limited to the planetary gear type of this embodiment, but may be a bevel gear type.

[0014]

In summary, according to the present invention, the output position to the front and rear axles can be arbitrarily selected along the circumferential direction of the intermediate shaft, and the excellent degree of design freedom can be achieved.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of a transfer device according to the present invention.

FIG. 2 is a front view of FIG.

FIG. 3 is a side view showing another embodiment of the present invention.

FIG. 4 is a side view of a power transmission system including a conventional transfer device.

[Explanation of symbols]

 11 High / low speed switching mechanism 12 Differential mechanism 13,14 Intermediate shaft 15,16 Output shaft 27 First shaft (output part of differential mechanism) 31 Second shaft (output part of differential mechanism) 40 Gear (of first shaft) ) 42 gear (second shaft) 41,43 gear (intermediate shaft) 46,47 gear (output shaft)

Claims (1)

[Claims] 1. A differential mechanism rotationally input from a transmission through a high / low speed switching mechanism, an intermediate shaft arranged below an output portion of the differential mechanism and connected by a gear, and the intermediate shaft. A transfer device comprising: a gear that meshes with a gear of a shaft; and an output shaft that transmits a rotational driving force to a front wheel or a rear wheel.