JP2507116B2 - Driving force transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a driving force transmission which is arranged between both inner and outer rotating members which are coaxially and relatively rotatably arranged and which transmits torque between these both members. Regarding the device.

(Prior Art) Such a driving force transmission device is disposed between a driving-side rotating member and a driven-side rotating member, and when both these members rotate relative to each other, the two members are coupled to each other so that torque can be transmitted to the driven-side rotating member. A member used as a connecting mechanism for driving members, a driving-side driven member, a driven-side rotating member, both driving-side rotating members, or both driven-side rotating members. Are connected to each other so that torque can be transmitted,
They are roughly classified into those used as a differential limiting mechanism for limiting the rotation difference between these two members. The former coupling mechanism is mainly arranged on one power transmission path of a real-time four-wheel drive vehicle, and the latter differential limiting mechanism is mainly arranged on each differential of the vehicle.

Thus, as a conventional driving force transmission device, Japanese Patent Laid-Open No. 63-
As disclosed in Japanese Patent No. 240429, it is arranged between both inner and outer rotating members that are coaxially and relatively rotatably positioned, and is operated by relative rotation of these both rotating members to connect both rotating members so that torque can be transmitted. Friction friction force that increases or decreases the frictional engagement force according to the axial pressing force that is applied, and an axial pressing force that corresponds to the relative rotation of both rotating members to generate the frictional force. The clutch is provided with a pressing force generating means, and the pressing force generating means is
An operating piston that is liquid-tightly slidable in the axial direction between the rotating members and integrally rotatably mounted on the outer rotating member to face the friction clutch, and is formed between the outer rotating member and the operating piston. And a rotor having a fluid chamber in which a viscous fluid is sealed at a predetermined interval in the axial direction and one or more vane portions extending in the radial direction, and the rotor being integrally assembled to the inner rotating member in the fluid chamber. There is a driving force transmission device configured by.

In this type of driving force transmission device, when a relative rotation occurs between both rotary members, an operating piston that is integrally rotatably mounted on the outer rotary member and a rotor that is integrally mounted on the inner rotary member. Relative rotation occurs between them, the viscous fluid in the fluid chamber is forced to flow in the vane portion of the rotor in the fluid chamber, and pressure is generated in the fluid chamber due to flow resistance or the like. That is, a pressure corresponding to the differential rotation speed is generated in the pressing force generating means. This pressure pushes the actuating piston in the axial direction to push the friction clutch, and the friction engagement force that connects both rotating members to the clutch so that torque can be transmitted is generated in the clutch. The frictional engagement force is proportional to the differential rotation speed, and torque proportional to the differential rotation speed is transmitted from one rotating member to the other rotating member. Therefore, the driving force transmission device functions as a connecting mechanism between the driving side rotation member and the driven side rotation member in one power transmission system path of the four-wheel drive vehicle, and also between the driving side and the driven side rotation member and both driving sides. It also functions as a differential limiting mechanism between rotating members or between both driven rotating members.

(Problems to be Solved by the Invention) In the driving force transmission device of the type described above, the working piston, the outer rotating member, or a part thereof may be formed of a metal that is lighter than iron such as aluminum alloy. It is advantageous in terms of weight reduction of the device, improvement of workability, reduction of cost, and the like. On the other hand, the rotor has a considerably small axial thickness in relation to the fluid chamber and is fitted to the inner rotating member so as to be movable in the axial direction. May tilt forward and backward or may be twisted left and right. When the vane portion of the rotor tilts, the corner of the tip of the vane portion interferes with the inner surface of the working piston, outer rotating member, etc., so that the iron rotor is made of aluminum alloy There is a risk that the side surface will be worn and further, a part of each inner side surface will be scraped and damaged, and the aluminum powder etc. generated by this will adhere to the seal member of the seal part of the fluid chamber and reduce the sealing performance, and The mixing of the aluminum powder into the viscous fluid may lower the viscosity of the viscous fluid and cause the torque transmission characteristics to change over time. Therefore, it is an object of the present invention to address such issues.

(Means for Solving the Problem) In the driving force transmission device of the above-described type, the present invention provides a vane portion of the rotor with a shape that extends linearly in a radial direction with a predetermined width in the rotational direction of the vane portion. In addition to the above, the tip portion of the vane portion is characterized in that each tip corner portion on the rotational direction side of the vane portion is formed in a tapered shape having an arc shape.

(Operation and Effect of the Invention) According to this configuration, the shape of the tip of the vane portion of the rotor is such that each tip corner on the rotational direction side of the vane has a tapered shape with an arcuate shape, and each tip corner has a corner. Therefore, even if the rotor is tilted back and forth with respect to the axis or twisted left and right, the tip corners do not interfere with the side surfaces of the working piston and the outer rotating member that form the fluid chamber. Therefore, according to the driving force transmission device, each side surface is not damaged, and the sealing performance of the seal portion of the fluid chamber is not deteriorated due to the generation of aluminum powder, and the torque transmission characteristic may change over time. Nor.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a driving force transmission device according to the present invention. As shown in FIG. 4, the driving force transmission device 10 is arranged in a rear wheel side power transmission system path of a real-time four-wheel drive vehicle.

The front wheel side of the vehicle is always driven and the rear wheel side is driven when necessary. The transaxle 22 assembled to one side of the engine 21 is equipped with a transmission and a transfer, and the power from the engine 21 is transmitted to the axle shaft 23.
To drive the front wheels 24 and output to the first propeller shaft 25. The first propeller shaft 25 is connected to the second propeller shaft 26 via the driving force transmission device 10, and when both the shafts 25, 26 can transmit torque, power is output to the axle shaft 28 via the rear differential 27. Then, the rear wheel 29 is driven.

Thus, the driving force transmission device 10 includes a pressing force generating means 10a and a friction clutch in an annular working chamber composed of an outer case 11 and an end cover 15 which will be described later that form an outer rotating member, and an inner shaft 12 that forms an inner rotating member. Equipped with 10b.

The outer case 11 is provided with an inward flange portion 11b at one end of a tubular portion 11a having a predetermined length, the other end of the tubular portion 11a is open, and a threaded portion 11c is formed on the inner circumference of the other end. An end cover 15 that constitutes an outer rotating member together with the outer case 11 is screwed to the screw portion 11c. Inner shaft
12 is provided with an outward flange portion 12b on the outer periphery of the intermediate portion of a stepped cylindrical portion 12a, an outer spline portion 12c extending in the axial direction is formed on the outer periphery of the flange portion 12b, and the cylindrical portion 1
An inner spline portion 12d extending in the axial direction is provided on the inner periphery of one end of 2a.
Are formed. In the inner shaft 12, one end of the tubular portion 12a is fitted in the inner hole of the inward flange portion 12b of the outer case 11 and the other end is fitted in the inner hole of the end cover 15 in a liquid-tight and rotatable manner. Supported. The inner shaft 12 is fitted and fixed to the spline portion 26a at the tip of the second propeller shaft 26 at the inner spline portion 12d, and the outer case 11 is fixed to the rear end of the first propeller shaft 25.

The pressing force generating means 10a includes an operating piston 13 and a rotor 14.
The friction clutch 10b is of a wet multi-plate clutch type and is composed of a large number of clutch plates 16 and clutch discs 17. Each clutch plate 16 has a spline portion on the outer periphery thereof fitted to a spline portion 11d provided on the inner periphery of the outer case 11, and is assembled to the case 11 so as to be integrally rotatable and movable in the axial direction. Each clutch disc 17 has its inner peripheral spline portion fitted to the outer spline portion 12c of the inner shaft 12 so that each clutch plate 16
It is located between them and is attached to the shaft 12 so as to be integrally rotatable and movable in the axial direction. A predetermined amount of clutch oil and gas is sealed in the storage chamber R1 of the clutch plate 16 and the clutch disc 17.

The working piston 13 forming the pressing force generating means 10a is liquid-tightly integrally rotatable with the inner circumference of the other end side of the tubular portion 11a of the outer case 11 and slidable in the axial direction. Liquid-tightly rotatable and axially slidable assemblies are respectively attached to the outer circumference thereof, and one side surface 13a thereof abuts the clutch plate 16 at the rightmost end in the drawing. As shown in FIGS. 1 and 2, the rotor 14 has an annular boss portion 14
Radially extending at positions 180 ° apart from each other on the outer circumference of a 2
The vane portion 14b is provided, and the annular boss portion 14a is fitted to the outer periphery of the tubular portion 12a of the inner shaft 12.
It is assembled so that it can rotate together. The rotor 14 is formed to have substantially the same thickness as the depth of the annular recess 13b provided on the other side of the working piston 13, and is fitted in the annular recess 13b. After the working piston 13 and the rotor 14 are assembled, the end cover 15 is screwed to the outer case 11 by the threaded portion 15a, and the position of the end cover 15 is adjusted in the axial direction, and the end cover 15 is fixed to the outer case 11 by the caulking means. Case
11 and inner shaft 12 are liquid-tight. The end cover 15 is in contact with the annular outer edge surface 13c on the other side of the working piston 13 at its one side surface 15b, and the one side surface 15b and the other side surface 13d of the working piston 13 form a fluid chamber in which the rotor 14 is located. ing. A predetermined amount of highly viscous fluid such as silicone oil is enclosed in this fluid chamber.
The outer peripheral surface of the vane portion 14b is liquid-tightly contacted with the inner peripheral surface of the annular recess 13b, and the fluid chamber 14 is divided into two retention chambers R2.

Therefore, the working piston 13 and the end plate 15 are formed of an aluminum alloy to reduce the weight of the device, improve the workability, and reduce the cost. On the other hand, the rotor 14 is made of iron, and each vane portion 14b of the rotor 14 has a second
As shown in FIG. 3 and FIG. 3, the vane portion 14b is formed in a shape having a predetermined width in the rotation direction and a constant width and extending linearly in the radial direction, and the tip end portion of the vane portion 14b is in the rotation direction of the vane portion 14b. Is formed in a tapered shape in the shape of an arc. That is, in the vane portion 14b of the rotor 14,
Left and right rotational direction side portions 14b ₂ from the tip apex 14b ₁ are formed in a tapered shape without an angle, and the cross section of the vane portion 14b is formed in an elliptical shape in the left and right rotational directions. It has a wedge shape.

In the driving force transmission device 10 having such a configuration, torque is transmitted between the first and second propeller shafts 25 and 26 when the relative rotation occurs. That is, these both shafts 25,
When a relative rotation occurs between the two 26, the outer case 11, the working piston 13, and the end cover 15 that are integrally rotatably assembled to the first propeller shaft 25, and the second propeller shaft 26 are integrally rotatably assembled. Relative rotation occurs between the inner shaft 12 and the rotor 14, which are rotating. Therefore, in the fluid chamber of the pressing force generating means 10a, the retention chamber R
The viscous fluid in 2 is forcibly flown at a speed proportional to the relative rotation speed, and in the retention chamber R2 that sequentially makes relative movement in the circumferential direction, due to flow resistance, the following flow from the downstream end of the vane portion 14b A pressure distribution in which the pressure is gradually increased toward the upstream end of the vane portion 14b is generated. The pressure increasing portion of this pressure distribution increases in proportion to the differential rotation speed, and presses the working piston 13 in the axial direction. As a result, the working piston 13 becomes a friction clutch.
By pressing 10b, each clutch plate 16 constituting the friction clutch 10b and the clutch disc 17 are frictionally engaged with each other via the clutch oil. As a result, in the friction clutch 10b, a torque proportional to the differential rotation speed is applied to the outer case 11
Is transmitted to the inner shaft 12, and the vehicle is in the four-wheel drive state. Further, in this four-wheel drive state, differential rotation of the front and rear wheels is allowed, and the occurrence of the tight corner braking phenomenon is prevented.

By the way, in the driving force transmission device 10, the rotor 14
14b ₂ of each vane portion 14b at the tip end in each rotational direction
(Each distal corners) are formed in an arc shape, because the corners to the rotation direction side portion 14b ₂ does not exist, it has been likened slope before and after the rotor 14 is relative to the inner shaft 12, or twisted to the left and right However, it does not interfere with the other side surface 13d of the working piston 13 or the one side surface 15b of the end cover 15. Therefore, according to the driving force transmission device 10, the side surfaces 13d, 1
5b will not be damaged or the aluminum powder generated by such damage will not reduce the sealing performance of the seal part of the working piston 13, the end plate 15 to the outer case 11 and the inner shaft 12, and the viscous fluid due to the mixing of the aluminum powder. The torque transmission characteristic does not deteriorate with time due to the decrease in viscosity.

Further, in the present embodiment, the vane portion 14b of the rotor 14 is
The cross section of the rotor 14 is formed in an elliptical shape in the left and right rotation directions and has a wedge shape.
14b and working piston 13 and end cover 15 on each side 13
A wedge action is generated on the viscous fluid between d and 15b, and the wedge action remarkably increases the pressure of the pressure-increased portion of the viscous fluid. As a result, the torque transmission efficiency is improved.

In the above embodiment, the rotor 14 is used as the working piston.
The example in which the rotor 14 is arranged between the end cover 15 and the end cover 15 has been shown.
And the friction clutch 10b may be arranged between the working piston 13 and the end cover 15.

[Brief description of drawings]

1 is a sectional view of a driving force transmission device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG.
FIG. 4 is a sectional view taken along the line III-III in FIG. 2, and FIG. 4 is a schematic view of a vehicle employing the same device. Explanation of reference numerals 10 ... Driving force transmitting device, 10a ... Pressing force generating means, 10b ...
Friction clutch, 11 outer case, 12 inner shaft, 13 working piston, 14 rotor, 14b
Vane part, 14b ₂ ... Left and right rotation direction side parts (tip corners), 15 ... End cover, 13d, 15b ... Inner side surface, 16 ...
… Clutch plate, 17 …… Clutch disc, 25,26
……Propeller shaft.

(72) Inventor Hiroaki Asano 1-1 Asahi-cho, Kariya city, Aichi Toyota Koki Co., Ltd. (72) Inventor Shigeo Tanooka 1-1-1 Asahi-cho, Kariya city Aichi Toyota Koki Co., Ltd. (56) References JP 63-240429 (JP, A) JP Hei 2-21038 (JP, A)

Claims (1)

(57) [Claims] 1. A frictional engagement force which is disposed between both inner and outer rotating members coaxially and relatively rotatably arranged and which is actuated by relative rotation of these both rotating members to couple the both rotating members so that torque can be transmitted. And a friction clutch that increases or decreases the friction engagement force according to the axial pressing force applied,
And a pressing force generating means for generating an axial pressing force according to the relative rotation of both rotating members and applying the pressing force to the friction clutch. Which is slidable in the direction of rotation and integrally rotatably mounted on the outer rotary member to face the friction clutch, and a viscous piston formed between the outer rotary member and the working piston with a predetermined gap in the axial direction. A driving force transmission device including a fluid chamber in which a fluid is enclosed, and a rotor including one or more vane portions extending in the radial direction and integrally rotatably assembled to the inner rotating member in the fluid chamber. In the above, the vane portion of the rotor is formed into a shape that has a predetermined width in the rotational direction of the vane portion and linearly extends in the radial direction, and the tip end portion of the vane portion is provided on each side of the vane portion in the rotational direction. tip Part driving force transmission device, characterized in that is formed in an arc-like tapered shape.