JPH0712143A - Driving force transmission gear - Google Patents

Abstract

PURPOSE:To suppress temperature rise caused by the actuation of a driving force transmission gear so as to prevent a torque transmission characteristic from being lowered by the heating of this transmission gear. CONSTITUTION:Driving force transmission mechanism 10a forming a driving force transmission gear 10 is disposed in a case 10b stored with liquid, between two coaxially supported shafts. A housing 11 forming the driving force transmission mechanism 10a is connected to one shaft, and an inner shaft 12 is connected to the other shaft. The whole or partial outer peripherl surface of the housing 11 is formed into uneven shape, and the temperature up heat of the mechanism 10a is transmitted to the liquid in the case 10b for heat radiation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a coaxially supported 2
The present invention relates to a driving force transmission device that is disposed between shafts and that transmits torque between these shafts.

[0002]

2. Description of the Related Art As one type of driving force transmission device, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-17233, a clutch housing formed between both inner and outer rotating members coaxially and relatively rotatable with each other. The frictional engagement force that is housed in the chamber and operates by the relative rotation of the two rotation members generates a frictional engagement force that connects the two rotation members so that torque can be transmitted, and the frictional engagement force is increased or decreased according to the axial pressing force applied. And a driving force transmission mechanism having a frictional clutch and a driving force transmission mechanism that generates a pressing force in the axial direction according to the relative rotation of the two rotary members and applies the same pressing force to the friction clutch. There is.

However, the drive force transmission device is a drive force transmission mechanism for a four-wheel drive vehicle which is disposed between the drive shaft and the driven shaft of the vehicle and connects both shafts to drive the vehicle by four wheels. It is used as a differential limiting mechanism that is placed in the differential and limits the differential between the left and right wheels.

[0004]

By the way, in the driving force transmission device, the outer rotary member is arranged between two coaxially supported shafts, and the outer rotary member is connected to one of the two shafts. The inner rotating member is connected to the other side and is generally exposed to the atmosphere. Usually, in the driving force transmission device, when the temperature is raised by the operation, the heat of the device is radiated to the atmosphere and cooled. However, when the device has a high temperature of, 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 in a stopped state, heat radiation from the device is poor. As a result, in the driving force transmission device, the clutch oil in the clutch accommodating chamber may thermally expand, and the viscosity of the viscous fluid that constitutes the pressing force generating means may decrease, resulting in deterioration of torque transmission characteristics. Therefore, it is an object of the present invention to address such issues.

[0005]

SUMMARY OF THE INVENTION The present invention is accommodated in a clutch accommodating chamber formed between both inner and outer rotating members that are coaxially and relatively rotatable, and operates by relative rotation of the both rotating members. A friction clutch that generates a frictional engagement force that connects the rotating members so that torque can be transmitted, and that increases or decreases the frictional engagement force according to an axial pressing force that is applied, and an axial direction that corresponds to the relative rotation of the two rotating members. In a driving force transmission device having a driving force transmission mechanism having a pressing force generating means for generating the pressing force of the driving force and applying the pressing force to the friction clutch, the driving force transmission mechanism is provided between two axes coaxially supported. Is disposed in a case containing a liquid to connect the outer rotating member to one of the two shafts, the inner rotating member to the other shaft of the two shafts, and the outer rotating member. Department The outer periphery of the is characterized in that the entire surface or partially irregularities.

In the driving force transmission 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 having the above-described structure, the driving force transmitting mechanism is arranged in the case containing the liquid, so that the heat of the mechanism is transferred from the outer peripheral surface of the outer rotating member to the case. It is transferred to the liquid inside and released into the atmosphere. In this case, the liquid, in particular, has a very good heat transfer compared to the atmosphere, so the heat transfer from the driving force transfer mechanism to the liquid inside the case and the heat transfer of the liquid to the outside of the case are fast, and the temperature of the device The rise is suppressed. Therefore, in the driving force transmission device, it is possible to suppress the deterioration of the torque transmission characteristic due to the temperature rise.

In the driving force transmission device, however, since the outer periphery of the outer rotating member is formed in a wholly or partially uneven shape, the surface area of the outer periphery is large, and the case from the driving force transmission mechanism is large. The heat transfer to the liquid inside is large, and the heat is dissipated and cooled more efficiently in cooperation with the liquid stirring action of the uneven portion of the outer rotary member. In addition,
Naturally, in the driving force transmission device, it is possible to prevent the friction clutch from being burned out 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 arranged in the driving force transmission path on the rear wheel side in a real-time four-wheel drive vehicle. In the vehicle,
The transaxle 21 is equipped with a transmission and a transfer, and outputs the driving force of the engine 22 to the axle shaft 23 to drive the front wheels 24 and also 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 so that torque can be transmitted, the driving force is increased. Is output to the axle shaft 27 via the rear differential 26 to drive the rear wheels 28.

As shown in FIG. 1, the driving force transmission device 10 has
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 are provided 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 to the rear opening of the housing 11. Further, the inner shaft 12 is rotatably supported by the housing 11 and the end cover 13 in a liquid-tight manner while being inserted into the housing 11, and forms an annular accommodation chamber having a predetermined width in the axial direction in the housing 11. is 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 the working piston 15 and the rotor 16.
And a viscous fluid.

Each separate plate 14a constituting the friction clutch 10c is axially slidably mounted on an inner spline provided on the inner circumference of the housing 11, and each friction plate 14b is an outward flange of the inner shaft 12. The outer splines are axially slidably attached to the outer splines and are alternately arranged with 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 portion thereof is engaged with the inner spline of the housing 11, so that the housing 11 It is possible to rotate together with. 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 with the working piston 15.

As shown in FIGS. 1 and 2, the rotor 16 is provided with two blades 16a and 16b extending in the radial direction, and is mounted on the inner shaft 12 so as to be integrally rotatable therewith and the working piston 15 and the end. It is located between the covers 13. In this state, the rotor 16 is fitted into the annular recess of the end cover 13, and the plates 16a, 16b in the fluid chamber formed between the end cover 13 and the working piston 15 are connected to each other.
16b form two retention chambers R1. A high-viscosity viscous fluid such as silicone oil is contained in each of the retention chambers R1. 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 such a differential 26, the constituent members 26b to 26f are housed in the differential case 26a, and the pinion shaft 26b is provided.
Is coupled to the inner shaft 12 of the driving force transmission mechanism 10a so that torque can be transmitted, and 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 the side gears 26e via the pinion shaft 26b, the ring gear 26c, and the both pinion gears 26d,
It 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 thereof.
It is liquid-tightly and rotatably supported on the upper side, is liquid-tightly mounted and supported on the 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 via a plurality of communication passages 26g and 26h provided in the differential case 26a.
A predetermined amount of diff oil contained therein is contained. Further, in the driving force transmission mechanism 10a, a large number of convex groups formed of a plurality of straight-shaped convex strips 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 with the inside of the housing 11.
25b is formed.

In the driving force transmission device 10 thus constructed, torque is transmitted when relative rotation occurs between the propeller shaft 25 and the pinion shaft 26b of the differential 26 while the vehicle is running. That is, when the two shafts 25, 26b rotate relative to each other, the housing 11, the end cover 13, and the working piston 15 that are integrally rotatably assembled to the propeller shaft 25.
And relative rotation occurs between the inner shaft 12 and the rotor 16 that are integrally rotatably assembled to the pinion shaft 26b.

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

By the way, in the driving force transmission device 10, since the driving force transmission mechanism 10a is arranged in the case 10b containing the differential oil, the heat of the mechanism 10a is transferred from the outer peripheral surface of the housing 11 to the inside of the case 10b. It is transmitted to the differential oil, and from the differential oil to the case 10
It is radiated to the atmosphere through b. In this case, since the heat transfer of the differential oil is extremely good as compared with the atmosphere, the heat transfer from the driving force transfer mechanism 10a to the differential oil is quick and the temperature rise of the mechanism 10a is suppressed. In particular, in the driving force transmission mechanism 10a, a large number of convex stripes 11a are formed on the entire outer peripheral surface of the housing 11, and the entire outer peripheral surface is formed in a concavo-convex shape, so that the outer peripheral surface area is large and the convex stripes 11a form a diff oil. Because of the agitation effect of 1, the heat transfer from the housing 11 of the drive force transmission mechanism 10a to the differential oil in the case 10b and the heat transfer to the outside of the case 10b are large, so that the heat in the drive force transmission mechanism 10a is more efficiently atmospheric. Heat is radiated to and cooled.

Therefore, in the driving force transmission device 10, it is possible to suppress the deterioration of the torque transmission characteristic due to the thermal expansion of the clutch oil due to the temperature rise and the viscosity decrease of the viscous fluid. Further, it is naturally possible to prevent the friction clutch 10c from being burned out due to the temperature rise of the driving force transmission mechanism 10a.

However, in the differential 26 having the driving force transmission device 10 assembled therein, the differential oil is normally housed in the differential case 26a up to about half the level. Therefore, the differential oil scraped up by the ring gear 26c of the differential gear 26 flows into the case 10b through the upper communication passage 26g, and the case 1
The differential oil that has flowed into 0b is the ridge 1 of the housing 11.
The stirring action of 1a causes the lower communication passage 26h to flow back into the differential case 26a. That is, the differential oil in the case 10b and the differential case 26a are
26a, the cooling effect of the heated differential oil is enhanced by the circulation, and the circulation of the differential oil causes the differential oil to flow from the gaps between the communication passages 25a and 25b and the assembly parts of the respective constituent members to the drive transmission mechanism 10a. It is supplied to each bearing, sliding part, etc., and efficiently lubricates these parts.

Although the driving force transmission device 10 is an example in which a straight ridge 11a is provided on the outer circumference 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, a thrust force toward the differential case 26a side can be applied to the differential oil that is agitated by the ridges, and the inside of the differential oil case 10b and the differential case 26 can be provided.
The circulation between the insides of a can be performed more efficiently, and the cooling of the driving force transmission device 10 and the lubrication inside the device 10 can be further improved.

[Brief description of drawings]

FIG. 1 is a cross-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 same driving force transmission device taken along line 2-2 of FIG.

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

[Explanation of symbols]

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.

Claims (3)

[Claims] 1. A clutch accommodating chamber formed between both inner and outer rotating members that are coaxially and rotatable relative to each other, and is operated by relative rotation of the rotating members to connect the rotating members so that torque can be transmitted. And a friction clutch that increases or decreases the frictional engaging force according to the axial pressing force that is applied, and an axial pressing force that corresponds to the relative rotation of the rotating members. In a driving force transmission device including a driving force transmission mechanism having a pressing force generating means for applying pressure to the friction clutch, a case in which a liquid is accommodated between two shafts coaxially supporting the driving force transmission mechanism. And the outer rotating member is connected to one of the two shafts and the inner rotating member is connected to the outer shaft.
A driving force transmission device, characterized in that it is connected to the other of the shafts, and the outer circumference of the outer rotating member is formed in a concavo-convex shape in whole or in part. 2. The driving force transmission device according to claim 1, wherein the case is a differential case or a case integral with the differential. 3. The driving force transmission device according to claim 1, wherein the liquid is lubricating oil contained in a differential case.