JP2875229B2 - Center differential for power transmission of four-wheel drive vehicles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a center differential for power transmission of a four-wheel drive vehicle used for switching power transmission to front and rear wheels of a four-wheel drive vehicle. It is. 2. Description of the Related Art In a full-time four-wheel drive vehicle, usually, even when there is a difference between external forces applied to front and rear wheels, a predetermined distribution of torque from an engine to front and rear wheels is transmitted. A center differential is provided between the front wheel and the rear wheel. In such a center differential, a drive pinion and a ring gear that mesh with each other, and a differential pinion and a differential side gear are provided. [0003] In the above-mentioned prior art, the driving force of the engine is transmitted to the front wheels and the rear wheels with the same torque distribution. Therefore, this torque distribution is arbitrarily selected. Therefore, the degree of freedom in designing the power transmission system is small. The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to increase the degree of freedom in designing the torque distribution to the front and rear wheels and to reduce the outer shape. An object of the present invention is to provide a center differential for power transmission of a four-wheel drive vehicle that can be made compact. In order to achieve the above object, a power transmission center differential of a four-wheel drive vehicle according to the present invention includes a first sun gear and a first sun gear meshed with the first sun gear.
A planetary gear, integrally formed with the first planetary gear;
Formed second planetary gears, and the first and second planetary gears.
A carrier for supporting a planetary gear, and the first sun gear;
And coaxial with the second planetary gear.
A second sun gear that engages with the second sun gear and the carrier
Deflector that connects the front and rear wheels directly
A planetary gear mechanism comprising:
The first shaft part integrally formed with one sun gear is placed on the engine side.
A second sun gear integrally formed with the second sun gear;
The shaft is connected to one of the front wheels or the rear wheels via the second output shaft.
And the carrier is connected to the first planetary gear and the first planetary gear.
And a support shaft for supporting the second planetary gear and the support shaft.
Fixed to the ends and arranged adjacent to the first planetary gear
First carrier body and second planetary gear
And a second carrier body disposed adjacent to the
One carrier body is connected to the other of the front wheel or the rear wheel by the first output shaft.
And the differential lock means is connected to the second key.
The center differential of a four-wheel drive vehicle located adjacent to the carrier
In the above, the first carrier main body is attached to the first shaft portion,
The second carrier body is freely rotatably supported on the second shaft portion.
And smaller than the outermost rotation locus of the second planetary gear.
An outer diameter drive gear is formed integrally with the first carrier body.
And a driven gear formed integrally with the first output shaft
The first carrier main body is engaged with the driving gear to
Or if it is linked to the other of the rear wheels via the first output shaft
In each case, the gears and output shafts are connected to the front and rear wheels of the vehicle.
So that their axes of rotation are along the longitudinal direction of the vehicle.
It is characterized by being arranged in . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described based on an embodiment shown in the drawings. In FIG. 2, reference numeral 1 denotes a straddle-type four-wheeled motor vehicle. A vehicle body frame 2 supports a drive device 3 and a front wheel device 4 and a rear wheel device 5 driven by the drive device 3. A bar handle 7 and a fuel tank (not shown) are provided at an upper portion of the body frame 2, and a seat 9 is provided behind the fuel tank. Further, a pair of steps 10, 10 on which the rider on the seat 9 can put their feet are provided at the lower part of the body frame 2. [0007] The driving device 3 has an engine 12 and a first power transmission device 13 linked to the engine 12. The front wheel device 4 includes a pair of left and right front wheels 14,1.
A front axle 15 is connected to each of the front wheels 14. A well-known front wheel differential 17 is provided between the two axles 15. The rear wheel device 5 includes a pair of right and left rear wheels 20 and 2.
The two rear wheels 20, 20 are connected to each other by a rear axle 21. Further, a rear wheel gear device 23 is provided that enables power transmission from the drive device 3 to the rear axle 21. The first power transmission device 13 and the front wheel differential device 17 and the rear wheel gear device 23 are connected to the second power transmission device 2.
4 are interlocked and connected. The second power transmission device 2
Reference numeral 4 indicates that the driving force transmitted from the engine 12 via the first power transmission device 13 can be transmitted only to the rear wheels 20, 20, or in addition to the front wheels 14, 14. The second power transmission device 24 transmits the driving force to the rear wheel 2.
The vehicle has a center differential 25 capable of transmitting the torque to the front wheels 0, 20 and the front wheels 14, 14 with a predetermined torque distribution. Referring to FIG. 1 and FIGS. 3 to 5, the second power transmission device 24 will be specifically described. The second power transmission device 24 is connected to a rotary shaft (input shaft) 26 that receives the driving force of the engine 12 via the first power transmission device 13 and to a front wheel differential device 17 via a front wheel propulsion shaft 27. First
A front wheel output shaft 29 which is a two-output shaft, and a rear wheel propulsion shaft 30
The is coupled to the input side of the rear wheel gear unit 23 through a 1
It has an output shaft 31 for a rear wheel, which is an output shaft, and a rotating shaft (intermediate shaft) 33 disposed coaxially with the rotating shaft 26 and interposed between the rotating shaft 26 and the second output shaft 29. I have. The center differential 25 is interposed between the rotating shaft (input shaft) 26 and the rotating shaft (intermediate shaft) 33. The center differential 25 is configured as follows. That is, the first sun gear 3
5 are supported by spline fitting. The sun gear 3
5, a cylindrical first shaft portion 36 extending in the axial direction of the rotating shaft 26 is integrally formed. The rotation shaft 26
The carrier 37 is provided on the shaft of the. The carrier 37 includes a pair of first and second carrier bodies 37a, 37a 'having a substantially elliptical shape, and the carrier bodies 37a, 37a'.
It has a pair of support shafts 37b, 37b installed at the rotating end of a '. The carrier 3 is provided on the first shaft portion 36.
7, a first carrier body 37a is freely rotatably supported, and a pair of first planetary gears 38 meshing with the first sun gear 35 are freely rotatably supported on the support shafts 37b. Further, the carrier-side drive formic the said carrier 37
The lug 37c is welded. Further, second planetary gears 39, 39 of a planetary drive gear are welded to the first planetary gears 38 coaxially with the first planetary gears 38, respectively.
The planetary gear 39 rotates together with the first planetary gear 38. On the other hand, the rotation shaft (intermediate shaft) 33 has a second sun gear (first
The intermediate gear 41 is supported by spline fitting, and the second
The sun gear 41 has a cylindrical second shaft portion 42 extending in the axial direction of the rotation shaft 33. The second carrier body in the carrier 37 to the second shaft portion 42 37
a 'is freely rotatably supported. And as shown
In addition, both ends of the support shaft 37b are connected to the first carrier body 37a.
And the first shaft portion 36 via the second carrier body 37a '.
And it is supported by the second shaft portion 42 in a two-sided state. Ma
The carrier- side drive gear 37c is connected to the second planetary gear.
The diameter is smaller than the outermost rotation locus of the rear gear 39.
You. The first output shaft 31 supports a rear-wheel driven gear 46, which is a driven gear meshing with the carrier-side drive gear 37c, and the first output shaft 31 is connected to the carrier 37 in an interlocked manner. A differential lock means is provided for enabling the input side and the output side of the center differential 25 to be locked to each other (diff lock). That is, the rotating shaft (intermediate shaft) 33 has a differential lock engaging element 4
3 is supported by a spline fit so as to be slidable only in the axial direction of the rotary shaft 33, and the differential lock means 43 is detachably engageable with the carrier 37 in the form of a dog clutch by its axial movement. The engagement of the center differential 25
Is differential locked. A second intermediate gear 44 is supported on the rotating shaft (intermediate shaft) 33. On the other hand, the second output shaft 29 has a front wheel driven gear 47 meshing with the second intermediate gear 44.
Are freely rotatably supported. Further, the second output shaft 29 for the front wheels engaging member 48 is supported by slidably spline fitting only in the axial direction of the second output shaft 29, front wheel engaging element 48 in its axial movement The driven gear 47 for the front wheel can be freely engaged and disengaged in the form of a dog clutch. That is, the driven gear 47 for the front wheel and the engaging element 48 for the front wheel constitute a power connecting / disconnecting means. Then, as shown in FIG.
35, first planetary gear 38, second planetary gear 3
9, the second sun gear 41, the driving gear 37, the driven gear 46 and
And the second output shaft 29 and the first output shaft 31 are connected to the front wheels and the rear of the vehicle.
Between the wheels so that their axis of rotation lies in the longitudinal direction of the vehicle.
It is arranged as follows. As shown by the solid line in FIG. 1, the differential lock means 43 is operated (arrow A in FIG. 1), which is engaged with the carrier 37 to differential lock the center differential 25, and the front wheel engaging element 48 is provided. Is operated (arrow B in FIG. 1) to release the engagement of the engaging element 48 with the front wheel driven gear 47, the driving force of the engine 12 is changed from the rotating shaft (input shaft) 26 to the first sun gear 35 to the first planetary gear. 38 → Carrier 3
7 → the carrier side drive gear 37c → the driven gear 46 → the first output shaft 31 → the rear wheel propulsion shaft 30 → the rear wheel gear device 23 → the power is transmitted only to the rear wheels 20, 20 via the rear axle 21. That is, the rear two-wheel drive state of the forward movement is obtained by this operation. Next, the differential lock means 43 is operated from the above state (arrow C in FIG. 1) to release the engagement with the carrier 37, and the front wheel engaging element 48 is operated (arrow in FIG. 1). D), this is engaged with the front wheel driven gear 47 to bring it into the state shown by the dashed line in FIG. Then, the center differential 2
5 functions and enters the full-time four-wheel drive state, and the front wheels 14,
The driving force from the engine 12 is distributed to the front wheel device 4 and the rear wheel device 5 at a predetermined ratio even when there is a difference between the external forces applied to the rear wheel device 14 and the rear wheels 20. Further, from the above state, the differential lock means 43
Is operated (arrow A in FIG. 1), and this is engaged with the carrier 37 so that the center differential 25 is differentially locked .
The output shaft 29 and the first output shaft 31 are directly connected to each other, and the driving force transmitted from the engine 12 to the carrier 37 as described above is changed from the differential lock means 43 to the rotating shaft (intermediate shaft) 33 to the second.
Intermediate gear 44 → front wheel driven gear 47 → front wheel engaging element 48
→ the second output shaft 29 → the front wheel propulsion shaft 27 → the front wheel differential 17 → the front wheel 14 and also transmitted to the front wheels 14 via the front axles 15. That is, by this operation, the front wheel device 4 and the rear wheel device 5 are directly connected, and the driving force of the engine 12 is equally distributed to the front wheel device 4 and the rear wheel device 5 to obtain a forward directly connected four-wheel drive state. Next, a description will be given of a switching operation device 50 for enabling selection of any one of the three driving states. Housing 5 of the second power transmission device 24
1 is a cylindrical body 52 whose axis is parallel to the rotating shaft (input shaft) 26.
Is rotatably supported around its axis.
An operation lever 53 is attached to one end of the control lever. On the other hand, a support shaft 54 is provided in parallel with the columnar body 52, and the first and second shift forks 5
6 and 57 are movably supported only in the axial direction of the support shaft 54. The first shift fork 56 is engaged with the differential lock engagement element 43, and the second shift fork 57 is engaged with the front wheel engagement element 48. In addition, the cylindrical body 5
The first and second shift forks 56, 57 are formed with first and second cam grooves 58, 59 on the outer peripheral surface of the second shift fork 56, 57.
Are engaged with cam projections 56a and 57a protruding therefrom. 60 is a positioning means. When the operating lever 53 is rotated to the right as shown by the solid line in FIG. 4 and is positioned by the positioning means 60, the differential lock means 43 is moved to the carrier as shown by the solid line in FIGS. 37 and the center differential 2
5 is in a differential locked state. Further, in this state, the engagement between the front wheel driven gear 47 and the front wheel engagement element 48 is released, that is, according to the operation of the operation lever 53, the rear two-wheel drive as described above is performed. The state is obtained. Next, as shown by an arrow E in FIG. 4, if the operation lever 53 is rotated leftward to rotate the columnar body 52, the first and second cam grooves 58, 59 moves as shown by the arrow F and the dashed line in FIG. 5, and in this state, the cylindrical body 52 is positioned by the positioning means 60. Then, the first and second cam grooves 58, 5 which move as described above.
The first and second shift forks 5 are guided along the axis of the support shaft 54 as shown by arrows G and H and a dashed line in FIG.
6, 57 move to the left. Then, the engagement of the differential lock means 43 with the carrier 37 is released, and the differential lock of the center differential 25 is released. Also, with this,
The front wheel engaging element 48 engages with the front wheel driven gear 47. That is, by operating the operation lever 53, the full-time four-wheel drive state as described above is obtained. Further, as shown by an arrow I in FIG. 4, if the operation lever 53 is rotated leftward to rotate the columnar body 52, the first and second cam grooves 58, 59 are accordingly caused. Move as shown by the arrow J and the two-dot chain line in FIG. 5, and in this state, the cylindrical body 52 is positioned by the positioning means 60. In this case, the position of the second shift fork 57 is unchanged, but is guided by the first cam groove 58 which moves as described above, and the first shift fork 56 is moved rightward as shown by the arrow K in FIG. Move and return to the original position. Then, the differential lock means 43 is engaged with the carrier 37 again, and the center differential 25 is differentially locked. That is, by operating the operation lever 53, the forward directly-connected four-wheel drive state as described above is obtained. The center differential for power transmission of a four-wheel drive vehicle according to the present invention is not only easy to manufacture and assemble since it is composed of planetary gears, but also integrally formed with the first sun gear.
The first shaft thus formed is linked to the engine side, and the second
A second shaft portion integrally formed with the gear is connected through a second output shaft.
And linked to one of the front wheel or rear wheel
The first planetary gear and the second planetary gear.
And a support shaft for supporting the support shaft, and fixed to both ends of the support shaft,
First carrier body disposed adjacent to first planetary gear
And a second key arranged adjacent to the second planetary gear.
And the first carrier body is a front wheel.
Or the other of the rear wheel because interlockingly connected through the first output shaft, of course it is of Ru can be arbitrarily set the torque distribution to the front and rear wheels in the selection of the gear ratios of the gears, support the planetary gears
The two ends of the supporting shaft are the first carrier body and the second carrier.
A first shaft integrally formed with the first sun gear via the main body
And a second shaft formed integrally with the second sun gear.
Because it is supported in a holding state, this support shaft and the first and
Not only the second carrier body but also the first planetary gear and
The second planetary gear can be downsized while maintaining the strength.
Things. Also, connect each gear and each output shaft in front of the vehicle.
Between the wheels and the rear wheels, their axis of rotation is
And a first key supported by the first shaft portion.
Is the drive gear with a small outer diameter formed integrally with the carrier body?
Power from the carrier.
Can be easily removed at a position adjacent to the planetary gear mechanism
In addition, a simple structure suitable for gear and shaft arrangement can be obtained , and the overall outer shape can be made compact.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial sectional view of a power transmission device to which the present invention is applied. FIG. 2 is an overall schematic plan view of the vehicle. FIG. 3 is a sectional view of a switching operation device. FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3; FIG. 5 is a developed view of the outer peripheral surface of a cylindrical body. [Description of Signs] 12 Engine 14 Front wheel 20 Rear wheel 25 Center differential 26, 33 Rotating shaft 29 Second output shaft 31 First output shaft 35 First sun gear 36 First shaft portion 37 Carrier 37a First carrier body 37a 'Second Carrier body 37b Support shaft 37c Drive gear 38 First planetary gear 39 Second planetary gear 41 Second sun gear 42 Second shaft 43 Differential lock means 46 Follower gear

Claims (1)

(57) [Claims] The first sun gear 35 meshes with the first sun gear 35
The first planetary gear 38 and the first planetary gear 3
A second planetary gear 39 integrally formed with
Carrier 3 for supporting these first and second planetary gears
7 and are arranged coaxially with the first sun gear 35;
Second sun gear 4 meshing with the second planetary gear 39
1, the second sun gear 41 and the carrier 37 are integrated.
Differential lock means for connecting the front and rear wheels directly to each other
43, a first shaft portion 36 integrally formed with the first sun gear 35.
And a second shaft portion 42 integrally formed with the second sun gear 41.
Of the front wheel 14 or the rear wheel 20 via the second output shaft 29.
The carrier 37 is connected to one of the first planetary gears 38 and
And a support shaft 37b supporting the second planetary gear 39 and the second planetary gear 39.
The first planetary is fixed to both ends of the support shaft 37b.
The first carrier main body 37a and the first carrier main body 37a
And a second key disposed adjacent to the second planetary gear 39.
Carrier body 37a ', and the first carrier body 37a is connected to the front wheel 14 or the rear wheel 2
0 through the first output shaft 31 and the differential lock means 43 is connected to the second carrier body 37.
In the center differential of a four-wheel drive vehicle disposed adjacent to a ′, the first carrier main body 37a is attached to the first shaft portion 36 in front.
The second carrier body 37a 'idles on the second shaft portion 42.
Freely supported, smaller than the outermost rotation locus of the second planetary gear 39
An outer diameter drive gear 37c is connected to the first carrier body 37a.
And a driven gear 46 formed integrally with the first output shaft 31.
The first carrier is engaged with the driving gear 37c.
The body 37a is connected to the other of the front wheel 14 or the rear wheel 20 by a first output shaft.
31 and the gears 35, 38, 39, 41, 37c, 46 and
And the output shafts 29 and 31 are connected to the front wheels 14 and the rear wheels 20 of the vehicle.
So that their axes of rotation are along the longitudinal direction of the vehicle
A center differential for power transmission of a four-wheel drive vehicle, which is arranged .