JPH068658B2 - Transmission torque biaxial variable distributor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention is best suited for an automobile capable of variably distributing and transmitting a rotational torque from a driving shaft to two driven shafts separated at the center. Transmission torque biaxial variable distributor.

(Prior Art) The load on each drive wheel of an automobile instantaneously changes depending on the running conditions. Therefore, in recent years, four-wheel drive vehicles having excellent running performance have been provided. This four-wheel drive vehicle adjusts the rotation difference between the inner and outer wheels even when traveling on a curve where the resistance of each wheel becomes unbalanced only with the conventional differential gear device, so that the vehicle can travel sufficiently stably. It is equipped with a device such as a viscous coupling that can suppress and reduce the rotational difference between the drive wheels.

(Problems to be solved by the invention) However, when the viscous coupling is used in a half-clutch state due to excessive torque for a long time, there is a problem that the fluid in the viscous coupling generates heat due to friction, and Could not be acted on.

Further, although the viscous coupling can buffer the rapid torque fluctuation, the degree of the buffer is determined by the characteristics of the liquid and cannot be controlled.

The present invention has been made in view of the above points, and provides a transmission torque biaxial variable distribution device capable of transmitting an appropriate driving force to both left and right wheels so that stable traveling can be performed even when traveling on a curve. The purpose is to

(Means for Solving the Problems) A transmission torque biaxial variable distribution device according to the present invention is interposed between a driving shaft side and a driven shaft side, and is capable of transmitting rotational torque by freely changing it. A torque biaxial variable distribution device, wherein a bevel gear is attached to the end of the driving shaft, a bevel gear that meshes with the bevel gear is attached to a cylindrical body, and a partition wall is formed in the center of the cylindrical body. A spline groove is formed in the circumferential surface of the cylindrical body in the axial direction, and two driven shafts that can be slightly eccentric to the cylindrical body can be independently moved in parallel in a direction perpendicular to the shafts. The spline groove is formed in the axial direction on the outer peripheral surface of the driven shaft and meshes with the cylindrical pair of spline grooves on the outer periphery in each space partitioned by the partition wall in the center of the cylindrical body. Multiple thin-walled discs with spline teeth and front A plurality of thin disk bodies formed with spline teeth that mesh with the spline grooves of the driven shaft, and are arranged alternately on the cylindrical body side and the driven shaft side so as to be movable in their respective axial directions, and the thin circles. A disk body having tapered surfaces on both sides of the plate body, the side surfaces of which are a flat surface and a curve having an extremely large radius of curvature R ₁ in the cross-sectional shape and which is slightly thin on the inner peripheral side;
The side surface has a flat surface and the radius of curvature R ₁ in its sectional shape.
A disk body having a taper surface slightly curved on the outer peripheral side with a curve having a radius of curvature R ₂ which is slightly different from each other, and the cylindrical body and the driven shaft are provided so that these taper surfaces can come into contact with each other. Are arranged so as to be spline-engaged with each other, and the cylindrical body is rotatably supported by the frame body, and support portions movable in a direction perpendicular to the axis of each driven shaft by pressure contact means are provided on both sides of the frame body. The driven shafts are rotatably supported by the respective support portions, and the pressure contact means are operated to appropriately move the driven shafts in a direction perpendicular to the axis, thereby tapering the cylindrical body side and the driven shaft side. By changing the pressure contact degree of the disc body having the surface, frictional contact according to the degree of pressure contact is made between the alternately arranged cylindrical body side and the plurality of thin disk bodies on the driven shaft side, and from the driving shaft. Arbitrary rotational torque is transmitted to each driven shaft side Characterized in that it is earthenware pots configuration.

(Operation) In the transmission torque biaxial variable distribution device configured as described above, the driven shaft is moved in the direction perpendicular to the axis, and the disc body having the tapered surface on the cylindrical body side and the tapered surface on the driven shaft side are brought into pressure contact with each other. The plurality of thin disk bodies on the cylindrical body side and the driven shaft side are in contact with each other, and the rotational torque can be transmitted from the driving shaft to the driven shaft. The degree of transmission of the rotational torque can be arbitrarily changed by changing the amount of movement to change the degree of contact.

In the present invention, the radius of curvature R ₁ of the taper surface of the disk body mounted on the driving shaft side cylindrical body which is the rotational torque transmitting surface.
Is the radius of curvature R ₂ of the taper surface of the disk body mounted on the driven shaft.
Since it is a little different from the above, as disclosed in Japanese Patent Application No. 62-161700 (variable transmission torque clutch device), the contact area between the two is very high according to the following Hertzian theoretical formula expressing the contact area (a). growing.

In the above equation, K ₁ and K ₂ are constants determined by the materials of the objects constituting the cylindrical body and the disc body mounted on the driven shaft, respectively, and P is the pressure contact force that presses both disc bodies. .

Since a very wide contact area can be obtained for the whole volume, the force per unit contact area can be made extremely small. However, in the Japanese Patent Application No. 62-161700, since a plurality of disk-shaped bodies having inclined surfaces at the peripheral edge portion are in pressure contact with a plurality of substantially V-shaped grooves, respectively, variations in pressure contact force may occur. Excessive operating force is inevitable. However, in the present invention, since the rotational torque is transmitted by pressing the disk body having the tapered surface at one location on each of the left and right sides of the thin disk body, there is no variation in the pressure contact force and the effect of the wedge action is obtained. The operating force is relatively small.

Further, in the present invention, the rotational center of the driven shaft can be slightly eccentric with respect to the rotational center of the cylindrical body, but the amount of transmission torque can be changed by changing the amount of eccentricity. . That is, the center of rotation of the driven shaft is slightly eccentric to the center of rotation of the cylindrical body (for example, 0.2 m).
m)), the transmission torque amount can be reduced by making the positions and sizes of the oil supply holes pre-drilled in the cylindrical body and the plurality of thin disk bodies arranged on the driven shaft substantially the same. Can be large. That is, since there is a relatively large amount of lubricating oil in the lubrication hole as compared with the flat portion, the resistance due to the viscosity of the lubricating oil when the two thin disk pairs make sliding contact is equal to the resistance at the flat portion. , It becomes large because resistance is added at the portion where the holes for oil supply substantially match. As a result, the coefficient of friction between the two thin circular plates increases, and the amount of transmitted torque increases. In the above case, when the eccentric amount of the rotation center of the driven shaft with respect to the rotation center of the cylindrical body is made larger than the eccentric amount (for example, about several mm), the refueling holes are displaced, so both thin circular plates Since the resistance due to the viscosity of the lubricating oil when making sliding contact with the body is mainly in the flat part, as a result, the friction coefficient between both thin plate bodies becomes relatively small, and the amount of transmitted torque is also slightly smaller than the above. Become. However, in this case, the so-called disengagement of the clutch is improved.

Further, in the present invention, since the support structure for the driven shaft is a double-supported structure, the support by the bearing can be made relatively compact.

(Embodiment) An embodiment in which the transmission torque biaxial variable distribution device according to the present invention is used for a rear wheel drive shaft of a four-wheel drive vehicle will be described below with reference to the drawings. FIG. 1 is a sectional view of this device. FIGS. 2 (a) and 2 (b) are side views of the cylindrical body and the thin disk bodies arranged on the driven shaft, and FIG. 3 is a side view showing a state in which the two thin plate bodies are overlapped with each other. FIG. 4 is a side view of the present apparatus, and FIGS. 5 (a) and 5 (b) are enlarged views of a portion indicated by P surrounded by a one-dot chain line in FIG.

In FIG. 1, reference numeral 1 is a driving shaft, a helical bevel gear 2 is mounted on an end of the driving shaft 1, and a helical bevel gear 3 meshing with the helical bevel gear 2 is a cylindrical body. 4 is integrally screwed with a flange portion formed on one side surface side. Cylindrical body 4
A partition wall 5 is formed on both side surfaces of the, and a partition wall 6 is formed in the center. The cylindrical body 4 is supported by the frame body 8 via a tapered roller bearing 7 provided outside the partition wall 5.

An involute spline 9 is formed between the partition wall 5 and the partition wall 6 of the cylindrical body 4, and a plurality of thin disk bodies 10 having spline teeth formed on the outer periphery thereof are mounted on the involute spline 9. In addition, the spline teeth are formed on the outer periphery and the side surface is composed of a flat surface and a tapered surface in its cross-sectional shape, and the tapered surface has an extremely large radius of curvature R.
_A disc body that is a curve consisting of ₁ and is slightly thin on the inner peripheral side
11 is also attached to the involute spline 9 in each of the left and right spaces between the plurality of thin disk bodies 10 and the partition wall 5.

A driven shaft 12 is disposed in a space formed by penetrating the cylindrical body 4 at the center of rotation of the cylindrical body 4, and the driven shaft 12 is separated at the center and a minor axis is provided via a needle bearing 14.
It is connected with 13.

An involute spline 15 is formed on the shaft end side separated at the center of the driven shaft 12, and on the involute spline 15, a plurality of thin-walled disc bodies 16 with spline teeth formed on the inner circumference are formed. The thin disk bodies 10 are mounted so as to be inserted into each other and movable in the axial direction of the driven shaft. Further, each of the separated shafts of the driven shaft 12 is formed with spline teeth on the inner periphery thereof so as to be able to come into contact with the tapered surface of the disk body 11 mounted on the cylindrical body. In its cross-sectional shape, its side surface is composed of a flat surface and a taper surface, and the taper surface is a curve having a radius of curvature R ₂ slightly smaller than the radius of curvature R ₁ and also a disc body 17 having a slightly thin outer peripheral side. It is attached to the involute spline 15. The tapered surface of the disk body 11 and the tapered surface of the disk body 17 are in pressure contact with each other to transmit torque.

Regarding the state in which the plurality of thin-walled discs 10 and 16 and the discs 11 and 17 are intruded into each other, P surrounded by a one-dot chain line in FIG.
It is shown in FIGS. 5 (a) and 5 (b) which is an enlarged view of the portion indicated by. As is clear from FIG. 5 (a), by making the thickness of the contact portion of the plurality of thin disk bodies 10 and 16 half the thickness of the mounting side, the overall thickness of the disk body can be reduced. . FIG. 5 (b) shows the engagement between the disk bodies 11 and 17 having the tapered surface.
Is shown in.

In FIG. 1, each of the driven shafts 12 separated at the center is
It is supported by a support member 19 via a bearing 18, and this support member
The bolt 19 can be moved in the axial direction of the port 20 by a bolt 20. The bolt 20 is screwed with a screw 22, and a disc spring 23 and a thrust bearing 24 are interposed between the frame body 21 and the screw 22.
The bolt 20 is rotatably connected to the frame body 21. The screw 22 is connected to a link lever described later. A flange is attached to the output end of the driven shaft 12 opposite to the shaft end.
25 is provided, and the flange 25 is connected to the wheels by a constant velocity universal joint and a propeller shaft (not shown).

Reference numeral 26 is a bearing unit with a seal, 27 is a seal cover, and these members 26 and 27 close the frame body 8, the frame body 21, and the output end.

FIGS. 2 (a) and 2 (b) are side views of the thin-walled disc bodies 10 and 16, and a large number of small holes are punched in both thin-walled disc bodies.

FIG. 3 is a side view showing a state where the thin disk bodies 10 and 16 overlap each other. In this case, the rotation center of the cylindrical phase and the driven shaft is several mm.
An example of eccentricity is shown. Therefore, a thin disk body
Since the positions of the oil supply holes drilled in 10 and 16 do not match, as described above, the resistance due to the viscosity of the lubricating oil when both thin disk bodies make sliding contact is mainly limited to the flat part, and the friction The coefficient is relatively small.

FIG. 4 is a side view of the device, which includes the link lever 28 and screws.
22 are combined. The link lever 28, the screw 22, the bolt 20, the bearing 18, the support member 19, the disc spring 23,
A series of members consisting of the thrust bearing 24 is provided on the left and right sides of the device, and the screw is operated by operating the link lever 28.
The driven shaft is moved in the direction perpendicular to the axis by rotating the bolt 22 and moving the bolt 20. The link lever 28 is operated by an actuator (not shown).

The device configured as described above operates as follows.

When the link lever 28 is rotated in the tightening direction, the bolt 20 moves in the axial direction by the screw pitch of the bolt 20 corresponding to the rotation angle, and the disc spring 23 is deformed. As a result, the driven shaft moves in the direction perpendicular to the axis. Therefore, in FIG. 1, the disk body 17 having a tapered surface is pressed by the deformation of the disc spring 23 and moves upward, and the circular surface having the tapered surface mounted on the cylindrical body 4 on the moved side. Plate
11 and a disk body 17 having a tapered surface attached to the driven shaft 12
Gap disappears and both tapered surfaces make sliding contact.
The thin-walled disc body 10 and the thin-walled disc body 16 are generated by the horizontal component of the force generated as a result of the pressure contact between the tapered surfaces of the disc bodies 11 and 17.
Is laterally pressed. As a result, the thin-walled disc bodies 10 are provided between the disc bodies 11 and 17 having the tapered surfaces and the partition wall 6.
16 makes full contact. In this way, the rotational torque is transmitted from the driving shaft 1 to the driven shaft 12. This contact pressure state is performed in proportion to the movement amount, and by rotating the link lever 28 in accordance with a desired rotation transmission torque, the sliding friction transmission corresponding to it is performed.

Further, in the present invention, since the driven shaft 12 is separated at the center, the amount of torque transmission to the left and right wheels can be arbitrarily changed by changing the amount of rotation of the left and right link levers 28 shown in FIG. You can

When applying this device to an actual vehicle, the actuator that operates the link lever is adjusted according to the running state of the vehicle, the state is detected by a sensor, and the link lever is automatically operated using the signal from the sensor. It may be configured such that it is operated to change the transmission ratio of the driving force to the left and right wheels.

(Effect of the invention) The transmission torque biaxial variable distributor according to the present invention separates the driven shaft into two shafts when transmitting the torque from the driving shaft to the driven shaft.
Since each of the separated driven shafts can be individually controlled to reduce the force per unit contact area, it is possible to appropriately transmit torque to the left and right wheels according to the running condition (road surface condition). There is no problem of fluid heat generation even when used in a half-clutch state due to excessive torque for a long time like conventional viscous coupling, and it is possible to provide a vehicle with extremely good running performance that always guarantees comfortable running. it can.

As described above, by changing the amount of eccentricity of the driven shaft with respect to the center of rotation of the cylindrical body on the driving shaft side, the viscous resistance of the lubricating oil between the cylindrical body and the thin disk bodies mounted on the driven shaft can be reduced. Since the action changes, the amount of transmitted torque can be changed. That is, when the center of rotation of the driven shaft is deviated slightly (about 0.2 mm) from the center of rotation of the cylindrical body, the viscous resistance of both thin-walled discs becomes large and the friction coefficient increases. As a result, the amount of transmitted torque can be made relatively large. When the eccentricity of one rotation center of the driven shaft with respect to the rotation center in the cylindrical state is made larger than the above (number
(about mm) The viscous resistance of both thin discs becomes small and the friction coefficient decreases, so the amount of transmitted torque becomes relatively small. When the transmission torque biaxial variable distribution device according to the present invention is applied to an actual vehicle, it may be used as a front / rear wheel torque variable distribution device (hereinafter referred to as the former) or an axle torque left / right variable distribution device (hereinafter referred to as the latter). But,
In the former case, the reduction gear ratio is comparatively small and it is often used at high rotation, so the amount of transmitted torque is smaller than in the latter case.
On the contrary, the latter has a relatively large reduction gear ratio and is often used at low rotations, and therefore the amount of transmitted torque is larger than that of the former. Therefore, when the present invention is used for the former, the rotation center of the driven shaft is several mm with respect to the rotation center of the cylindrical body on the driving shaft side.
When eccentric to some extent and when the present invention is used for the latter,
Optimum characteristics can be secured by making the center of rotation of the driven shaft slightly eccentric (about 0.2 mm) with respect to the center of rotation of the cylindrical body on the side of the former drive shaft.

Further, in the present invention, since torque transmission is performed by contacting the driving shaft side and the driven shaft side with two tapered surfaces, there is no variation in the contact force and the operating force is relatively small due to the effect of the wedge action. Can be small.

Further, since the thickness of the thin disk body can be suppressed, the entire volume can be kept relatively compact even when the capacity is increased.

Further, in the present invention, since the support structure for the driven shaft is a double-supported structure, the support by the bearing can be made relatively compact.

[Brief description of drawings]

FIG. 1 is a sectional view of this device. 2 (a) and 2 (b) are side views of the cylindrical body and the thin-walled discs arranged on the driven shaft, and FIG. 3 shows a state in which the thin-walled discs are overlapped with each other. FIG. 4 is a side view, FIG. 4 is a side view of the present apparatus, and FIGS. 5 (a) and 5 (b) are enlarged views of a portion indicated by P surrounded by a chain line in FIG. 1 ・ ・ Driving shaft, 2 ・ ・ Bevel bevel gear, 3 ・ ・ Bevel bevel gear, 4 ・ ・ Cylindrical body, 5 ・ ・ Partition wall, 6 ・ ・ Partition wall, 7 ・ ・
Tapered roller bearing, 8 ... Frame, 9 ... Involute spline, 10 ... Thin disc, 11 ... Disc, 12 ... Driven shaft, 13 ... Short shaft, 14 ... Needle bearing , ... Involute splines, 16 ... Thin discs, 17 ... Discs, 18 ... Bearings, 19 ... Supporting members,
20 ・ ・ Bolts, 21 ・ ・ Frames, 22 ・ ・ Screws, 23 ・ ・ Disc springs, 24 ・ ・ Thrust bearings, 25 ・ ・ Flanges, 26 ・ ・ Seal bearing units, 27 ・ ・ Seal covers, 28
..Link levers

Claims (1)

[Claims] 1. A transmission torque biaxial variable distribution device, which is interposed between a driving shaft side and a driven shaft side and is capable of freely changing and transmitting a rotational torque, wherein a bevel gear is provided at an end portion of the driving shaft. And a bevel gear that meshes with the bevel gear is mounted on a cylindrical body, a partition wall is formed in the center of the cylindrical body, and a spline groove is formed in the axial direction on the peripheral surface of the cylindrical body. Two driven shafts that can be slightly eccentric to the body are arranged so that the respective shafts can independently move slightly parallel to each other in the direction perpendicular to the shafts, and the outer peripheral surface of the driven shaft is splined in the axial direction. Forming grooves, in each space partitioned by the partition wall in the center of the cylindrical body, a plurality of thin-walled disc bodies on the outer periphery of which spline teeth that mesh with the spline grooves of the cylindrical body are formed, and on the inner periphery thereof A plurality of spline teeth that mesh with the spline groove of the driven shaft A thin disk body is alternately arranged on the cylindrical body side and the driven shaft side so as to be movable in the respective axial directions, and on both sides of the thin disk body, side surfaces are flat surfaces in its cross-sectional shape. A disc body having a tapered surface with a curve having an extremely large radius of curvature R ₁ and slightly thin on the inner peripheral side;
The side surface has a flat surface and the radius of curvature R ₁ in its sectional shape.
A disk body having a taper surface slightly curved on the outer peripheral side with a curve having a radius of curvature R ₂ which is slightly different from each other, and the cylindrical body and the driven shaft are provided so that these taper surfaces can come into contact with each other. Are arranged so as to be spline-engaged with each other, and the cylindrical body is rotatably supported by the frame body, and support portions movable in a direction perpendicular to the axis of each driven shaft by pressure contact means are provided on both sides of the frame body. The driven shafts are rotatably supported by the respective support portions, and the pressure contact means are operated to appropriately move the driven shafts in a direction perpendicular to the axis, thereby tapering the cylindrical body side and the driven shaft side. By changing the pressure contact degree of the disc body having the surface, frictional contact according to the degree of pressure contact is made between the alternately arranged cylindrical body side and the plurality of thin disk bodies on the driven shaft side, and from the driving shaft. Arbitrary rotational torque is transmitted to each driven shaft side Transmission torque twin variable distributor apparatus characterized by being earthenware pots configuration.