JP3243335B2 - Driving force transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a driving force transmission device disposed between shafts and transmitting torque between these shafts.

[0002]

2. Description of the Related Art As one type of a driving force transmitting device, as shown in, for example, Japanese Patent Laid-Open No. 17233/1990, a clutch housing formed between inner and outer rotating members coaxially and relatively rotatably positioned. The two rotating members are housed in a room and operated by the relative rotation of the two rotating members to generate a frictional engaging force for connecting the two rotating members so as to be able to transmit the torque, and increase or decrease the frictional engaging force according to the applied axial pressing force. And a driving force transmitting mechanism having a pressing force generating means for generating an axial pressing force in accordance with the relative rotation of the two rotating members and applying the pressing force to the friction clutch. There is.

[0003] In the driving force transmitting device, a driving force transmitting mechanism for a four-wheel drive vehicle that is disposed between the drive shaft and the driven shaft of the vehicle and connects these two shafts to drive the vehicle four-wheels. It is used as a differential limiting mechanism disposed in a differential to limit the differential between the left and right wheels.

[0004]

The driving force transmitting device is disposed between two coaxially supported shafts, an outer rotating member is connected to one of the two shafts, and the two shafts are connected to each other. An inner rotating member is connected to the other and is generally exposed to the atmosphere. Normally, in the driving force transmission device, when the temperature is increased by operation, heat of the device is radiated to the atmosphere and cooled. However, when the temperature of the device becomes high, for example, 100 ° C. or more, when the traveling speed of the vehicle is low and the traveling wind is weak, or when the vehicle is stopped, heat radiation from the device is poor. As a result, in the driving force transmission device, the clutch oil in the clutch accommodating chamber thermally expands, and the viscosity of the viscous fluid constituting the pressing force generating means may decrease, so that the torque transmission characteristics may decrease. Accordingly, it is an object of the present invention to address such problems.

[0005]

SUMMARY OF THE INVENTION According to the present invention, both of these rotating members are housed in a clutch housing chamber formed between inner and outer rotating members which are coaxially and relatively rotatable and are operated by the relative rotation of the two rotating members. A friction clutch for generating a frictional engagement force for coupling the rotating members so as to transmit torque and increasing or decreasing the frictional engagement force in accordance with an applied axial pressing force; and an axial direction corresponding to a relative rotation of the two rotating members. A driving force transmitting mechanism having a pressing force generating means for generating the pressing force and applying the pressing force to the friction clutch, wherein the driving force transmitting mechanism is coaxially supported between two shafts. , The outer rotating member is connected to one of the two shafts, the inner rotating member is connected to the other of the two shafts, and the outer rotating member is connected to the outer rotating member. Department The outer periphery of the is characterized in that the entire surface or partially irregularities.

In the driving force transmitting device, it is preferable that the case is a differential case or a case integrated with the differential. Also,
In the driving force transmission device, it is preferable that the liquid is lubricating oil contained in a differential case.

[0007]

In the driving force transmitting device constructed as described above, since the driving force transmitting mechanism is arranged in the case containing the liquid, the heat of the mechanism is transferred from the outer peripheral surface of the outer rotating member to the case. It is transmitted to the liquid inside and radiated to the atmosphere. In this case, the heat transfer of the liquid to the liquid in the case and the heat transfer of the liquid to the outside of the case from the driving force transmission mechanism are particularly fast since the liquid has a very good heat transfer compared to the atmosphere, and the temperature of the device is high. The rise is suppressed. Therefore, in the driving force transmission device, it is possible to suppress a decrease in torque transmission characteristics due to a rise in temperature.

However, in the driving force transmitting device, the outer peripheral surface of the outer rotating member is formed entirely or partially in a concavo-convex shape, so that the surface area of the outer periphery is large, and the case from the driving force transmitting mechanism is not provided. The heat transfer to the liquid in the inside is large, and the heat is radiated and cooled more efficiently by cooperating with the liquid agitating action of the uneven portion of the outer rotating member. In addition,
Naturally, in the driving force transmission device, it is possible to prevent the friction clutch from burning due to the temperature rise of the driving force transmission mechanism.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a driving force transmission device 10 according to an embodiment of the present invention. As shown in FIG. 3, the driving force transmission device 10 is disposed on a driving force transmission path on the rear wheel side of a real-time four-wheel drive vehicle. In the vehicle,
The transaxle 21 includes a transmission and a transfer. The transaxle 21 outputs the driving force of the engine 22 to the axle shaft 23 to drive the front wheels 24 and outputs the driving force to the propeller shaft 25. The propeller shaft 25 is connected to the rear differential 26 via the driving force transmission device 10 according to the present embodiment. When the propeller shaft 25 and the differential 26 are connected to transmit torque, the driving force is Is output to the axle shaft 27 via the rear differential 26 to drive the rear wheel 28.

As shown in FIG. 1, the driving force transmission device 10
The driving force transmission mechanism 10a is housed in a case 10b. The driving force transmission mechanism 10a includes a housing 11, an inner shaft 12, and an end cover 13, and is formed by these three members 11, 12, and 13. A friction clutch 10c and a pressing force generating means 10d disposed in the storage chamber. The driving force transmission mechanism 10
In a, the housing 11, the end cover 13, and the inner shaft 12 correspond to the outer rotating member and the inner rotating member of the present invention, and the end cover 13 is screwed into a rear opening of the housing 11. The inner shaft 12 is supported by the housing 11 and the end cover 13 so as to be liquid-tight and rotatable while being inserted into the housing 11, and forms an annular accommodation chamber having a predetermined width in the axial direction within the housing 11. are doing. On the other hand, the friction clutch 10c is composed of a large number of separate plates 14a and friction plates 14b, and the pressing force generating means 10d includes an operating piston 15 and a rotor 16
And a viscous fluid.

Each of the separate plates 14a constituting the friction clutch 10c is slidably mounted in an axial direction on an inner spline provided on the inner periphery of the housing 11, and each friction plate 14b is connected to an outer flange It is assembled to the outer spline provided in the portion so as to be slidable in the axial direction, and is arranged alternately with each of the separate plates 14a. The working piston 15 constituting the pressing force generating means 10d is mounted on the inner shaft 12 so as to be liquid-tight and slidable, and the tip end thereof is engaged with an inner spline of the housing 11, and And can rotate together. The end cover 13 is in contact with the working piston 15, and the working piston 15 is in contact with the friction clutch 10c. An annular recess is formed in the end cover 13 to form a fluid chamber between the end cover 13 and the working piston 15.

As shown in FIGS. 1 and 2, the rotor 16 has two blades 16a and 16b extending in a radial direction, and is mounted on the inner shaft 12 so as to be integrally rotatable therewith. It is located between the covers 13. The rotor 16 is fitted in the annular recess of the end cover 13 in this state, and the blades 16a, 16a,
16b form two retaining chambers R1. Each retention chamber R1 contains a highly viscous fluid such as silicone oil. Further, clutch oil is stored in the clutch storage chamber R2.

The rear differential 26 itself is a known one, and includes a differential case 26a, a pinion shaft 26b, a ring gear 26c, and a pair of pinion gears 26.
d, a pair of side gears 26e and a pair of side gear shafts 26f. In the differential 26, each of the components 26b to 26f is housed in a differential case 26a, and the pinion shaft 26b
Are connected to the inner shaft 12 of the driving force transmission mechanism 10a so as to be able to transmit torque, and the both side gear shafts 26
f is connected to the axle shaft 27 so that torque can be transmitted. As a result, the driving force from the driving force transmission mechanism 10a is distributed to each side gear 26e via the pinion shaft 26b, the ring gear 26c, and both pinion gears 26d,
The power is transmitted to each side gear shaft 26f.

Thus, the driving force transmission mechanism 10a is housed in the case 10b. The case 10b has a propeller shaft 25 connected to the housing 11 at one end.
It is liquid-tightly and rotatably supported on the upper side, and is liquid-tightly mounted and supported on a differential case 26a at the other end side, and is rotatably supported on the pinion shaft 26b. The inside of the case 10a communicates with the inside of the differential case 26a through a plurality of communication passages 26g and 26h provided in the differential case 26a.
A predetermined amount of the differential oil accommodated therein is accommodated. Further, in the driving force transmission mechanism 10a, a large number of convex groups formed of a plurality of straight ridges 11a extending in the longitudinal direction are formed on the outer periphery of the housing 11. The propeller shaft 25 has a plurality of communication passages 25a for communicating the inside of the case 10b and the inside of the housing 11 with each other.
25b are formed.

In the driving force transmission device 10 configured as described above, torque is transmitted when relative rotation occurs between the propeller shaft 25 and the pinion shaft 26b of the differential 26 during running of the vehicle. That is, when the shafts 25 and 26b rotate relative to each other, the housing 11, the end cover 13, and the working piston 15 are integrally rotatably mounted on the propeller shaft 25.
Then, relative rotation occurs between the inner shaft 12 and the rotor 16 which are integrally rotatably mounted on the pinion shaft 26b.

Accordingly, in the fluid chamber of the pressing force generating means 10d, the viscous fluid in the stagnation chamber R1 is forcibly made to flow by the blades 16a and 16b of the rotor 16 at a speed corresponding to the relative rotation speed, and the circumference is changed. In the stagnation chamber R1 which sequentially moves in the direction, the blades 16a,
A pressure distribution is generated in which the pressure is gradually increased from the downstream end of the blade 16b to the upstream end of the next blade 16b, 16a. The pressure increasing portion of this pressure distribution increases according to the relative rotation speed (differential rotation speed) and presses the working piston 15 in the axial direction. As a result, the working piston 15 is
c, and each of the separate plates 14a and the friction plates 14b are frictionally engaged with a pressing force corresponding to the differential rotation speed. As a result, in the friction clutch 10c, a torque corresponding to the differential rotation speed is transmitted from the housing 11 to the inner shaft 12, and the vehicle enters a four-wheel drive state. In addition, even in this four-wheel drive state, the driving force transmission mechanism 10a allows differential rotation of the front and rear wheels and also prevents the occurrence of a tight corner braking phenomenon.

In the driving force transmitting device 10, since the driving force transmitting mechanism 10a is disposed in the case 10b containing the differential oil, heat of the mechanism 10a is transferred from the outer peripheral surface of the housing 11 to the inside of the case 10b. While being transmitted to the differential oil, the case 10
Heat is released to the atmosphere via b. In this case, since the differential oil has a much better heat transfer than the atmosphere, the heat transfer from the driving force transmitting mechanism 10a to the differential oil is faster, and the temperature rise of the differential mechanism 10a is suppressed. In particular, in the driving force transmission mechanism 10a, a large number of ridges 11a are formed on the entire outer periphery of the housing 11, and since the entire outer periphery is formed in an uneven shape, the surface area of the outer periphery is large, and the ridge 11a is Therefore, heat transfer from the housing 11 of the driving force transmission mechanism 10a to the differential oil inside the case 10b and heat transmission outside the case 10b are large, and the heat inside the driving force transmission mechanism 10a can be more efficiently released to the atmosphere. The heat is dissipated and cooled.

Therefore, in the driving force transmission device 10, it is possible to suppress a decrease in torque transmission characteristics due to a thermal expansion of the clutch oil due to a rise in temperature and a decrease in viscosity of the viscous fluid. Further, it is natural that the burning of the friction clutch 10c due to the temperature rise of the driving force transmission mechanism 10a can be prevented.

Thus, in the differential 26 to which the driving force transmitting device 10 is assembled, the differential oil is normally stored in the differential case 26a to a level approximately half. Therefore, the differential oil scooped by the ring gear 26c of the differential 26 flows into the case 10b from the upper communication passage 26g, and the case 1
The differential oil that has flowed into the housing 11b is the ridge 1 of the housing 11.
Due to the stirring action of 1a, the gas flows back from the lower communication passage 26h into the differential case 26a. That is, the differential oil in the case 10b and the differential oil in the differential case 26a
26c, the cooling effect of the differential oil whose temperature has been raised is also enhanced by the circulation, and the differential oil allows the differential oil to pass through the communication passages 25a and 25b and the gaps between the assembly portions of the respective components, thereby causing the drive transmission mechanism 10a to rotate. It is supplied to each bearing part, sliding part, etc., and efficiently lubricates these parts.

Although the driving force transmitting device 10 is an example in which a straight ridge 11a is provided on the outer periphery of the housing 11, the ridge 11a can be formed in a twisted shape such as a spiral shape. . In this case, by selecting the twisted shape, it is possible to impart a thrust toward the differential case 26a to the differential oil agitated by the ridge, and the differential oil can be provided in the differential oil case 10b and the differential case 26a.
It is possible to more efficiently circulate through the inside of a, and to further improve the cooling of the driving force transmission device 10 and the lubrication inside the device 10.

[Brief description of the drawings]

FIG. 1 is a sectional view of a driving force transmission device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the driving force transmission device in a direction indicated by an arrow 2-2 in FIG. 1;

FIG. 3 is a schematic configuration diagram of a four-wheel drive vehicle employing the driving force transmission device.

[Explanation of symbols]

Reference numeral 10: driving force transmission device, 10a: driving force transmission mechanism, 10
b: case, 10c: friction clutch, 10d: pressing force generating means, 11: housing, 11a: ridge, 12: inner shaft, 15: working piston, 16: rotor, 25
... Propeller shaft, 26 ... Differential, 26
a: Differential case, 26b: Pinion shaft.

──────────────────────────────────────────────────続 き Continued from the front page (56) References JP-A-4-107328 (JP, A) JP-A-3-66931 (JP, A) JP-A-1-173533 (JP, U) JP-A-57-173 10535 (JP, U) JP-A 3-114637 (JP, U) JP-A 2-29331 (JP, U) JP-A 1-141934 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) F16D 43/284

Claims (3)

(57) [Claims] 1. A clutch housing chamber formed between inner and outer rotating members coaxially and relatively rotatably positioned, the two rotating members being actuated by the relative rotation of the two rotating members to connect the two rotating members so that torque can be transmitted. A friction clutch that generates a frictional engagement force and increases or decreases the frictional engagement force in accordance with the applied axial pressing force, and generates an axial pressing force in accordance with the relative rotation of the two rotating members to generate the same. In a driving force transmitting device including a driving force transmitting mechanism having a pressing force generating means for applying pressure to the friction clutch, a case in which a liquid is stored between two shafts coaxially supported by the driving force transmitting mechanism. And the outer rotating member is connected to one of the two shafts, and the inner rotating member is connected to the two shafts.
A driving force transmission device which is connected to the other one of the shafts, and wherein the outer periphery of the outer rotating member is entirely or partially made uneven. 2. The driving force transmission device according to claim 1, wherein the case is a differential case or a case integrated with the differential. 3. The driving force transmission device according to claim 1, wherein the liquid is lubricating oil contained in a differential case.