JP2004231070A - Power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize the common use of parts without remodeling a front differential when changing the specification to the four-wheel drive vehicle by consecutively installing a transfer unit to the front differential of a two-wheel drive vehicle. <P>SOLUTION: A spline internal tooth 32 is formed on the inner peripheral of a boss 24b formed at the right side of a differential case 22 supporting a right side gear 29b provided in the front differential 3, and a spline external tooth 36 meshed with the internal tooth 32 is formed on the shaft end part of a transfer input shaft 34 provided in the transfer unit 6. When changing the specification of the two-wheel drive vehicle to the four-wheel drive vehicle, the transfer unit 6 is fixed to the front differential 3, and the spline external tooth 36 formed on the shaft end of the transfer input shaft 34 is meshed with the spline internal tooth 32 formed on the boss 24b to distribute the driving force of the engine transmitted to the differential case 22 to the rear wheel-side through the transfer input shaft 34. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power transmission device that realizes sharing of parts between a two-wheel drive vehicle and a four-wheel drive vehicle.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, when changing the specification of a two-wheel (front wheel) drive vehicle of a horizontally mounted engine to a four-wheel drive vehicle, a transfer is provided to a differential case provided in a front differential that transmits a driving force to a pair of left and right front wheel drive shafts in an operating state. There is known a technique of connecting input shafts and distributing a driving force to a rear wheel drive shaft via the transfer input shaft.
[0003]
For example, "Wagon R + (Plus) Service Manual Overview", May 1999 Issued by Suzuki Motor Co., Ltd., Differential 2E-2 In the front differential column, the front differential (two-wheel drive) front differential case has 4 There is disclosed a technology for changing the specification of a two-wheel (front wheel) drive vehicle to a four-wheel drive vehicle by replacing the differential case with a wheel drive specification differential case.
[0004]
That is, in a four-wheel drive differential case, a spline shaft portion is formed in a boss portion through which a front axle shaft extending from one of a pair of differential side gears provided to be rotatable relative to each other is inserted. A transfer input shaft is connected to the drive shaft, and the driving force is distributed to the rear axle shaft via the transfer input shaft.
[0005]
According to this prior document, when changing the specification of a front wheel (two-wheel) drive vehicle to a four-wheel drive vehicle, it is only necessary to replace the front wheel (two-wheel) drive differential case with a four-wheel drive specification differential case. It is possible to realize sharing of other components.
[0006]
[Non-patent document 1]
Wagon R + (Plus) Service Manual Overview, May 1999 Issued by Suzuki Motor Co., Ltd. [0007]
[Problems to be solved by the invention]
However, according to the technology disclosed in the above-mentioned prior art document, when changing the specifications of the front wheel (two-wheel) drive vehicle to the four-wheel drive vehicle, at least the differential case must be changed, so that the parts cannot be shared. In addition, since it is necessary to separately manufacture the front case (two-wheel drive) differential case and the four-wheel drive specification differential case, there is a limit in sharing the production equipment.
[0008]
In addition, since the transfer input shaft is structured so as to be external to the spline shaft, the diameter of the transfer input shaft is increased, which is an obstacle to realizing compactness.
[0009]
Further, as the diameter of the transfer input shaft increases, it becomes difficult to secure a sufficient gap between the transfer input shaft and the outer case. Since the structure is restricted, there is an inconvenience that the degree of freedom of design is limited.
[0010]
In view of the above circumstances, the present invention makes it possible to change the specifications of a four-wheel drive vehicle by using a differential adopted in a two-wheel drive vehicle, realizes simplification of parts management by sharing the differential, and reduction of production equipment. In addition to reducing the product cost, the size of the outer diameter of the transfer input shaft to be connected when changing the specifications of a two-wheel drive vehicle to a four-wheel drive vehicle has been reduced, and the transfer input shaft and outer case It is an object of the present invention to provide a power transmission device capable of ensuring a sufficient space between the gaps and increasing the degree of freedom in designing an inclusion such as an oil seal interposed in the space.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, a first power transmission device according to the present invention includes a differential case rotatably driven by the driving force of an engine, a boss rotatably supporting the differential case protruding from the differential case, and a differential case. A differential having a pair of side gears which are housed and transmit the rotation of the differential case to the driving wheels so as to be rotatable in a differential manner, and which are rotatably supported coaxially with the rotation axis of the boss; and connected to the differential. A transfer unit capable of distributing the driving force of the engine transmitted to the differential case to the other drive wheel side, wherein a transfer input shaft provided on the transfer unit is provided on an inner periphery of the boss. Forming a shaft engaging portion that engages with the outer periphery of the shaft end to regulate the relative rotation between the boss and the transfer input shaft. Characterized in that was.
[0012]
In this case, preferably, the shaft engaging portion formed on the inner periphery of the boss is a spline internal tooth, and the spline external tooth engaging with the spline internal tooth is formed on the outer periphery of the shaft end of the transfer input shaft. It is characterized by being formed.
[0013]
In such a configuration, in a two-wheel drive vehicle, an output shaft connected to the drive wheels is connected to a pair of side gears housed in a differential case. When the specification of the two-wheel drive vehicle is changed to a four-wheel drive vehicle, the transfer unit is provided on a shaft engaging portion such as a spline internal tooth formed on the inner periphery of a boss protruding from the differential case. By engaging a shaft engaging portion such as an external spline tooth formed on the outer periphery of the shaft end of the transfer input shaft, the driving force of the engine transmitted to the differential case is transmitted to the other drive wheel side via the transfer unit. Distribute to
[0014]
The second power transmission device includes a differential case rotatably driven by the driving force of the engine, a boss rotatably supporting the differential case protruding from the differential case, and a boss stored in the differential case and rotating the differential case. And a differential having a pair of side gears rotatably supported coaxially with the rotation axis of the boss and transmitted to the differential case in a manner connected to the differential. In a power transmission device including a transfer unit capable of distributing the driving force of the engine to the other drive wheel side, the transfer unit is configured to engage with a shaft end surface of a transfer input shaft provided in the transfer unit on an end surface of the boss. A shaft engaging portion for restricting relative rotation between the boss and the transfer input shaft is formed.
[0015]
In this case, preferably, the shaft engaging portion formed on the end face of the boss is a dog tooth, and another dog tooth engaging with the dog tooth is formed on the shaft end of the transfer input shaft. It is characterized by the following.
[0016]
In such a configuration, in a two-wheel drive vehicle, an output shaft connected to the drive wheels is connected to a pair of side gears housed in a differential case. When the specification of the two-wheel drive vehicle is changed to a four-wheel drive vehicle, a transfer input shaft provided on a transfer unit is provided on a shaft engaging portion such as a dog tooth formed on an end face of a boss protruding from a differential case. A shaft engaging portion such as another dog tooth formed at the shaft end is engaged to distribute the driving force of the engine transmitted to the differential case to the other driving wheel side via the transfer unit.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1A is a schematic diagram of a main part of a drive system of a front wheel drive vehicle, and FIG. 1B is a schematic diagram of a main part of a drive system of a four wheel drive vehicle.
[0018]
The drive system of the front-wheel drive vehicle shown in FIG. 1A includes a horizontal engine 1, a transmission 2 for inputting a driving force output from a crankshaft (not shown) of the horizontal engine 1, and a transmission 2. A front differential 3 for distributing the driving force from the transmission 2 to the left and right, front joint shafts 4a and 4b (see FIG. 3) for outputting the driving force from the front differential 3 to the left and right, and front joint shafts 4a and 4b. Front wheel drive shafts 5a and 5b are provided to drive the left and right front wheels 5 in series.
[0019]
When the front-wheel drive vehicle shown in FIG. 1A is changed to a four-wheel drive vehicle, as shown in FIG. 1B, a transfer unit 6 is connected to the front differential 3 and driven from the front differential 3. The power is distributed and the power transmission direction is changed by 90 °. A rear differential 8 is connected to the transfer unit 6 via a propeller shaft 7, and rear wheel drive shafts 10a and 10b for driving left and right rear wheels 10 via left and right joint shafts (not shown) are connected to the rear differential 8. It is installed continuously. Reference numeral 11 denotes a fluid coupling that automatically performs differential limitation between front and rear wheels and distribution of front and rear drive torque.
[0020]
The transmission case 12 of the transmission 2 is connected in series to the left side of the horizontal engine 1, that is, to the side of the crankshaft projecting. As shown in FIG. 2, the driving force of the engine 1 input into the transmission case 12 passes through a torque converter 13, and is supplied to an input shaft 14, a reduction drive shaft 15, a reduction drive gear 16, a reduction driven gear 17, and a drive pinion shaft 18. , A pinion gear 19 and a final gear 20 to be transmitted to the front differential 3. Note that the power that has been shifted is transmitted from the input shaft 14 to the reduction drive shaft 15 via a multi-stage transmission unit 21 using a planetary gear mechanism or the like.
[0021]
The drive pinion shaft 18 is disposed in parallel with the input shaft 14 and the reduction drive shaft 15, and the driving force output from the reduction drive shaft 15 is applied by the drive pinion shaft 18 to the central portion of the vehicle width. And transmitted to the front differential 3.
[0022]
As shown in FIG. 3, the front differential 3 is housed in a differential housing 23 formed integrally with the transmission case 12. The transmission case 12 is formed by connecting a main case 23a and a converter case 23b which are divided into left and right in the vehicle width direction. When the main case 23a and the converter case 23b are connected, the front differential 3 is attached to the differential housing portion 23. Assembled.
[0023]
Bosses 24a, 24b are protruded from the left and right sides of the differential case 22 of the front differential 3, and the outer periphery of each of the bosses 24a, 24b is rotatably supported by a differential housing portion 23 through a bearing 25. I have.
[0024]
A pinion shaft 26 is inserted through the differential case 22. The pinion shaft 26 is integrally fixed to the differential case 22 via a pin 27. Further, a final gear 20 is fixed to a large diameter portion of the differential case 22 via a bolt (not shown).
[0025]
A pair of pinion gears 28 are rotatably supported on both shaft end sides of the pinion shaft 26, and the left and right side gears 29 a and 29 b rotate in a direction orthogonal to the axis of the pinion shaft 26 with the pinion shaft 26 interposed therebetween. The side gears 29a and 29b and the pinion gear 28 are meshed with each other to form a differential mechanism of the differential 3.
[0026]
The side gears 29a and 29b are rotatably supported on the inner periphery of bosses 24a and 24b protruding from the left and right sides of the differential case 22, and the inner periphery of a hole formed on the inner side thereof has left and right sides. Spline internal teeth 31a and 31b are formed to engage with spline external teeth 30 formed at opposite ends of the front joint shafts 4a and 4b (see FIG. 4). In FIG. 4, only the spline external teeth 30 formed on the right front joint shaft 4b are shown, and the spline external teeth 30 formed on the left front joint shaft 4a are omitted.
[0027]
When the driving force of the engine 1 is transmitted to the final gear 20 fixed to the differential case 22 via the transmission 2 and the differential case 22 rotates, the driving force is transmitted from the pinion shaft 26 via the pinion gear 28 to the left and right side gears 29a. , 29b and transmitted to the left and right front wheel drive shafts 5a, 5b via the front joint shafts 4a, 4b. At this time, when a driving resistance difference is generated between the left and right front wheels 5 due to a curve running or the like, the two side gears 29a and 29b rotate differentially due to the rotation of the pinion gear 28, and the driving force of the engine 1 is applied to the left and right front wheels 5. Distributed differentially.
[0028]
In FIG. 4, spline external teeth 36 as a shaft engaging portion formed at a shaft end of a transfer input shaft 34, which will be described later, are engaged with the inner periphery of a boss 24 b protruding from the right side of the differential case 22. A spline inner tooth 32 is formed as another shaft engaging portion. The inner diameter of the spline internal teeth 32 is formed to be larger than the inner diameter of the spline internal teeth 31b formed on the side gear 29b.
[0029]
The front differential 3 employed in the present embodiment can be used in common for a front wheel (two-wheel) drive vehicle and a four-wheel drive vehicle. In the case of a front wheel drive vehicle, the left and right front joint shafts 4a are used. , 4b are spline-engaged with spline internal teeth 31a, 31b formed on the left and right side gears 29a, 29b of the front differential 3, and the front joint shafts 4a, 4b By connecting the front wheel drive shafts 5a and 5b to each other, the driving force of the engine 1 is distributed to the left and right front wheel drive shafts 5a and 5b via the front differential 3.
[0030]
In the front differential 3 adopted in the present embodiment, the pinion gear 28 and the side gears 29a and 29b are formed by bevel gears, but may be formed by planetary gears.
[0031]
On the other hand, in the case of a four-wheel drive vehicle, as shown in FIG. 1B, a transfer unit 6 is connected to the front differential 3 so that the driving force input to the front differential 3 is applied to the rear wheel drive shafts 10a and 10b. Distribute to
[0032]
As shown in FIG. 4, a transfer input shaft 34 is rotatably supported in a transfer case 33 of the transfer unit 6 via a bearing 35. One end of the transfer input shaft 34 protrudes from the transfer case 33, and spline external teeth 36 are formed at the shaft end. The transfer input shaft 34 is formed in a hollow shape, and the right front joint shaft 4b penetrates the hollow shaft portion 34a.
[0033]
Further, external spline teeth 36 formed at the shaft end of the transfer input shaft 34 protruding from the transfer case 33 are formed in the spline formed on the inner periphery of the boss 24 b protruding from the right side of the differential case 22. The teeth 32 are splined. Reference numerals 40a, 40b, and 40c denote the outer peripheries of the front joint shafts 4a and 4b (34 for a four-wheel drive vehicle) and the openings of the differential housing portion 23 (and the transfer case 33 for a four-wheel drive vehicle). This is an oil seal that seals between the two.
[0034]
Further, a transfer gear 37 is provided in the middle of the transfer input shaft 34, and the transfer gear 37 is meshed with an idler gear 39 provided on an idler shaft 38. Although not shown, a drive-side orthogonal gear is provided at the shaft end of the idler shaft 38, and a driven shaft having a driven-side orthogonal gear that meshes with the drive-side orthogonal gear is extended rearward of the vehicle body, and It is connected to the propeller shaft 7 via a shaft.
[0035]
Next, the operation of the present embodiment having such a configuration will be described.
In a front-wheel (two-wheel) drive vehicle as shown in FIG. 1A, spline internal teeth 31a and 31b formed on side gears 29a and 29b provided on a front differential 3, as shown in FIGS. , The spline external teeth 30 formed at the opposite ends of the front joint shafts 4a and 4b are spline-engaged. By connecting front wheel drive shafts 5a and 5b to the front joint shafts 4a and 4b, the driving force of the engine 1 is distributed to the left and right front wheel drive shafts 5a and 5b via the transmission 2 and the front differential 3. .
[0036]
On the other hand, in the case of a four-wheel drive vehicle, the transfer unit 6 is connected to the front differential 3 as shown in FIG. That is, the stepped portion 33a formed on the inner periphery of the opening protruding from the shaft end of the transfer input shaft 34, which is opened in the transfer case 33 of the transfer unit 6, is attached to the differential housing portion 23 of the front differential 3. It is mounted on the outer periphery of the opening from which the opened front joint shaft 4b projects.
[0037]
Then, the spline external teeth 36 formed at the shaft end of the transfer input shaft 34 protruding from the opening of the transfer case 33 are formed on the inner periphery of the boss 24 b protruding left and right of the differential case 22. The spline internal teeth 32 are spline-engaged, and the front joint shaft 4 b passes through the hollow shaft portion 34 a of the transfer input shaft 34.
[0038]
As a result, the transfer input shaft 34 rotates integrally with the differential case 22, and the driving force of the engine 1 transmitted to the differential case 22 is distributed to the transfer input shaft 34 side. The driving force distributed to the transfer input shaft 34 is transmitted through an idler shaft 38, and the power transmission direction is changed by 90 ° by a driven shaft having a driven-side orthogonal gear meshing with a driving-side orthogonal gear provided on the idler shaft 38. After that, it is output in the direction of the rear differential 8 via a propeller shaft 7 (see FIG. 1B) connected to a joint shaft (neither is shown).
[0039]
As described above, in the present embodiment, the spline internal teeth 32 are formed on the inner periphery of the boss 24b projecting from the right side of the differential case 22 of the front differential 3 and projecting the front joint shaft 4b. The spline external teeth 36 formed at the shaft end of the transfer input shaft 34 are spline-engaged with the front wheel 32 to change the specification of the front-wheel (two-wheel) drive vehicle to a four-wheel drive vehicle. Can be shared by the front-wheel (two-wheel) drive vehicle and the four-wheel drive vehicle, so that parts management can be simplified and production equipment can be shared.
[0040]
Spline external teeth 36 are formed at the shaft end of the transfer input shaft 34, and the spline external teeth 36 are spline-engaged with spline internal teeth 32 formed on the inner periphery of the boss 24 b protruding from the gear case 22. As a result, the size of the transfer input shaft 34 in the outer diameter direction can be reduced.
[0041]
Further, by making the size of the transfer input shaft 34 in the outer diameter direction compact, it is possible to secure a sufficient gap between the transfer input shaft 34 and the transfer case 33, and to make the transfer input shaft 34 and the transfer case 33 The degree of freedom in the design of the oil seals 40b and 40c for sealing between the oil seals 33 and 33 can be increased, and high reliability can be obtained.
[0042]
FIGS. 5 and 6 show a power transmission device according to a second embodiment of the present invention.
In the above-described first embodiment, the spline internal teeth 32 are formed on the inner periphery of the boss 24 b projecting from the differential case 22, and the spline engaging with the spline internal teeth 32 is formed at the shaft end of the transfer input shaft 34. Although the external teeth 36 are formed, in the present embodiment, the bosses 24b and the transfer input shaft 34 disposed coaxially with the bosses 24b are axially protruded from and opposed to each other so as to mesh with each other. A large number of dog teeth 41a and 41b are formed at regular intervals in the circumferential direction, and the dog teeth 41a and 41b are meshed with each other, so that the driving force transmitted to the differential case 22 is input to the transfer case. The distribution is made to the shaft 34.
[0043]
According to the present embodiment, the driving force is distributed by dog-engaging the boss 24b and the transfer input shaft 34 via the dog teeth 41a and 41b, so that as in the first embodiment. It is not necessary to make the end faces of the boss 24b and the transfer input shaft 34 overlap for power transmission, and the boss 24b can be reduced in diameter accordingly.
[0044]
【The invention's effect】
As described above, according to the present invention, the specification adopted for a two-wheel drive vehicle is changed to a four-wheel drive vehicle by using the same as it is. Therefore, the parts management is simplified by sharing the differential, and The production equipment can be reduced, and the product cost can be reduced.
[0045]
In addition, since spline external teeth are formed at the shaft end of the transfer input shaft, and spline internal teeth that engage with the spline are formed on the differential case side, the size of the transfer input shaft in the outer diameter direction can be downsized, It is possible to sufficiently secure a gap between the transfer input shaft and the outer case relatively, and it is possible to increase the degree of freedom in designing an oil seal and other inclusions interposed in the gap. Reliability can be improved.
[Brief description of the drawings]
FIG. 1A is a schematic view of a main part of a drive system of a front wheel drive vehicle according to a first embodiment; FIG. 1B is a schematic view of a main part of a drive system of a four-wheel drive vehicle; FIG. 3 is an enlarged cross-sectional view of the front differential. FIG. 4 is a schematic cross-sectional view of a state where a transfer unit is connected to the front differential. FIG. 5 is a front cross-sectional view of the front differential according to the second embodiment. FIG. 6 is a schematic sectional view showing a state in which a transfer unit is connected. FIG. 6 is a perspective view showing engagement between a differential case and a transfer input shaft.
1 engine 3 front differential 5 front wheel (drive wheel)
6 Transfer unit 10 Rear wheel (drive wheel)
22 Differential case 24a, 24b Boss 29a, 29b Side gear 32 Spline internal teeth (shaft engaging part)
34 Transfer input shaft 36 Spline external teeth (shaft engagement part)
41a, 41b dog teeth (shaft engagement part)

Claims (4)

A differential case rotatably driven by the driving force of the engine, a boss protrudingly provided on the differential case and rotatably supporting the differential case, and a differential case rotatably transmitted to drive wheels housed in the differential case and rotatably driven by the differential case. And a differential having a pair of side gears rotatably supported coaxially with the rotation axis of the boss,
A transfer unit connected to the differential and transmitted to the differential case to transmit the driving force of the engine to the other drive wheel side;
In a power transmission device comprising:
On the inner periphery of the boss, a shaft engaging portion that engages with the outer periphery of the shaft end of the transfer input shaft provided in the transfer unit and regulates the relative rotation between the boss and the transfer input shaft is formed. Power transmission device characterized. The shaft engaging portion formed on the inner periphery of the boss is a spline internal tooth, and spline external teeth engaging with the spline internal tooth are formed on the outer periphery of the shaft end of the transfer input shaft. The power transmission device according to claim 1, wherein: A differential case rotatably driven by the driving force of the engine, a boss protrudingly provided on the differential case and rotatably supporting the differential case, and a differential case rotatably transmitted to drive wheels housed in the differential case and rotatably driven by the differential case. And a differential having a pair of side gears rotatably supported coaxially with the rotation axis of the boss,
A transfer unit connected to the differential and transmitted to the differential case to transmit the driving force of the engine to the other drive wheel side;
In a power transmission device comprising:
An end surface of the boss is provided with a shaft engaging portion that engages with a shaft end surface of a transfer input shaft provided in the transfer unit and regulates relative rotation between the boss and the transfer input shaft. Power transmission device. The shaft engaging portion formed on the end face of the boss is a dog tooth, and another dog tooth engaging with the dog tooth is formed on the shaft end of the transfer input shaft. Item 6. The power transmission device according to Item 1.

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