JP2605745Y2 - Viscous coupling - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscous coupling for transmitting torque through a viscous fluid.

[0002]

2. Description of the Related Art Generally, for example, a viscous coupling used as a differential device in a power transmission system between front and rear axles of a four-wheel drive vehicle includes first and second transmission members arranged to be relatively rotatable, The first transmission member includes two sets of plates and an operating chamber filled with a viscous fluid, wherein the first set of plates is slidable in the rotation axis direction of the first transmission member. A second plate set is slidable in the rotation axis direction of the second transmission member, and is rotatably disposed together with the second transmission member;
The plates of the first and second plate sets are alternately arranged in the working chamber, and the plates of at least one of the plate sets are spaced from one another.

[0003] The torque transmission characteristic of such a viscous coupling is such that the transmission torque changes substantially in proportion to the rotational speed difference caused by the relative movement of the first and second plate sets, and therefore, in a high rotational speed difference region. If the viscous coupling is set so that a sufficient transmission torque can be obtained, the driving torque in the low rotational speed difference region also increases, and a problem such as occurrence of a tight corner braking phenomenon occurs. Therefore, if the viscous coupling is set so as to reduce the transmission torque in the low rotation speed difference region, sufficient driving torque cannot be obtained in the high rotation speed difference region, and the poor road running performance will be reduced.

In such a viscous coupling, a transmission torque is generated due to a difference in the number of rotations caused by the relative movement of the first and second plate sets regardless of the rotation direction. Therefore, for example, when the front wheel is locked by braking the vehicle, the rear wheel rotates faster than the front wheel, and in this state, a rotation speed difference is generated between the first and second plate sets due to relative motion. The viscous coupling acts to drive the front wheels and generates rotational torque that induces rear wheel lock.

For example, Japanese Patent Application Laid-Open No. H4-221 discloses a first and second transmission members arranged rotatably relative to each other, a working chamber filled with a viscous fluid, a first transmission member and a rotating member. A first plate set engaged in the first direction and a clutch plate set alternately arranged in the working chamber and the first plate set and engaged with the second transmission member in the rotation direction. A viscous coupling comprising: a second plate set; and an operating member that presses the clutch plate set in the rotation axis direction and frictionally clamps the second plate set to the clutch plate set, wherein a biasing member preliminarily sets the clutch plate. The operating member urged in the direction opposite to the pressing direction with respect to the set has a torque transmitting means whose transmission torque changes in proportion to the rotational speed difference between the first operating member and the first transmitting member. Wherein the work member is a cam mechanism second
The invention discloses a viscous coupling characterized in that it is configured to be driven in a pressing direction of a clutch plate set against a biasing force of the biasing member when a rotational speed difference occurs between the transmission member and the transmission member. Have been.

That is, according to the above-mentioned viscous coupling, the torque transmitting characteristic of the torque transmitting means, the urging force of the urging member, and the cam profile of the cam mechanism are appropriately adjusted to thereby improve the torque transmitting characteristic of the viscous coupling. It can be changed according to the level of the rotational speed difference.

[0007]

However, in the case of the viscous coupling disclosed in the above-mentioned Japanese Patent Laid-Open Publication No. Hei 4-21, the second plate set is entirely rotated with the second transmission member via the clutch plate set. Due to the structure in which the operation member engages in the direction, a large thrust force in the clutch pressing direction by the operation member acts on the clutch plate group, and if the clutch is not connected, the shear force of the viscous fluid is not generated. If the relative rotation speed difference between the first transmission member and the operation member does not become significantly large, the first transmission member does not operate, and thus the rise of the transmission torque is slow.

When the relative rotation speed difference between the first transmission member and the second transmission member is small, the operating member is moved in the clutch pressing direction so as to release the clutch and reduce the transmission torque. A biasing member for biasing in the opposite direction is required, and a seal for keeping the working chamber liquid-tight between the operating member and the second transmitting member is required, increasing the number of parts and complicating the structure. become. Further, the first and second transmission members each have a dedicated shape,
Since the transmission member of the general viscous coupling cannot be diverted, there is a problem that the manufacturing cost is increased.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a good viscous coupling having a simple structure while having a function of adjusting a torque transmission characteristic.

[0010]

SUMMARY OF THE INVENTION The above object of the present invention includes a working chamber which is composed of the viscous fluid by the first and second transmission member is sealed relatively rotatably disposed, the first及
And the second transmission member are rotatably disposed in the working chamber.
And the working chamber is divided into a main working chamber and a sub-working chamber in the direction of the rotation axis.
A third transmission member having a dividing partition, and the main working chamber
Second play rotationally engaged with a second transmission member within the second play
And the second plate set and the second plate set are alternately arranged.
Clutch plate engaged in rotation direction with first transmission member
A first plate set sandwiched by the set, and the sub-actuation
A fourth press rotatably engaged with the second transmission member indoors
And the fourth plate set are alternately arranged.
, A third plate rotationally engaged with the third transmission member
Set and the said viscous coupling and a pressing member of the first plate assembly frictionally clamped to the clutch plate assembly of the clutch plate assembly is pressed against the rotary shaft direction together to engage the first transmission member and the rotating direction Wherein a part of the plates of the first plate set is rotationally engaged with the first transmission member, and the pressing member is moved relative to the third transmission member by a cam mechanism. The clutch plate set is configured to be driven in the clutch pressing direction in proportion to the displacement amount , and a part of the first plate set that is rotationally engaged with the first transmission member. This is achieved by viscous coupling in which the number of plates is greater than the number of plates in the third plate set.

[0011]

According to the above construction, the phase between the first transmission member and the first transmission member is set.
The third transmission member, which causes the pressing member to follow the clutch pressing direction with respect to the clutch plate set by the cam mechanism when the amount of displacement becomes large, is disposed in the working chamber, so that the sealing member for keeping the working chamber liquid-tight. Need not be provided between the third transmission member and the first and second transmission members,
As the first and second transmission members, transmission members of a general viscous coupling can be used.

[0012] Further, even when the rotational speed difference between the first transmission member and the second transmission member is small, and a large thrust force in the clutch pressing direction by the pressing member is not acting on the clutch plate assembly, Some of the plates of the first plate set are rotationally engaged with the first transmission member, and a torque between the first transmission member and the second transmission member due to the shear resistance of the viscous fluid. Since the transmission is enabled, the viscous coupling can quickly generate a rising torque.

Further, the temperature in the main working chamber including the first plate set is always higher than the temperature in the sub working chamber including the third plate set, and the pressure in the main working chamber is higher than the pressure in the sub working chamber. Therefore, a thrust force is generated between the plates in the main working chamber so as to move away from each other, and when the urging force in the clutch pressing direction by the pressing member is weak, the pressing member is applied in a direction opposite to the clutch pressing direction. Can be energetic.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. First, the configuration of the viscous coupling 1 will be described with reference to FIGS. The housing 2 (first transmission member) and the hub 3 (second transmission member) are arranged so as to be relatively rotatable. For example, the housing 2 is connected to a transfer shaft (not shown) by an integral spline 35 and is driven to rotate. The hub 3 is connected to a transmission member (not shown) on the propeller shaft side.

A working chamber 11 is provided between the housing 2 and the hub 3.
Is formed, and high-viscosity silicone oil (viscous fluid) is enclosed. X-rings 17 and 19 (X-shaped cross-section seals) and backup rings 18 and 20 are arranged at the sliding contact between the housing 2 and the hub 3 to keep the working chamber 11 liquid-tight. Further, a built-in housing 21 as a third transmission member is provided in the working chamber 11 on the right side in FIG.
The hub 3 is rotatably disposed relative to the housing 3. An annular pressing member 31 is engaged with an outer peripheral portion of the built-in housing 21 on the left side in FIG. 1 via a cam mechanism. The built-in housing 21 has a spline 1 formed on the inner peripheral surface of the housing 2.
2 and a partition wall 24 extending radially inward from one opening edge of the cylindrical portion.
Separates the working chamber 11 into a main working chamber 25 and a sub-working chamber 2.
6. A spline 33 that engages with the spline 12 of the housing 2 is formed on the outer peripheral surface of the cylindrical portion of the pressing member 31, and an opening 22 through which the hub 3 passes is formed at the center of the partition wall 24. Is engaged with the housing 2 in the rotation direction and is movable in the rotation axis direction.

Inner plates 5 and 10, which are second and fourth sets of plates, are spline-engaged with the splines 13 formed on the outer peripheral surface of the hub 3 so as to be movable in the direction of the rotation axis. In the chamber 25, the first outer plate set, the engaged outer plate 4a and the disengaged outer plate
The sub- plates 4 b are alternately arranged with the inner plates 5, and the outer plate 9, which is a third plate set, is alternately arranged with the inner plates 10 in the sub-operation chamber 26. The engaging outer plate 4a, which is a part of the first plate set, is
The inner spline 12 formed on the peripheral surface spline engaged is rotatable integrally with the housing 2, the engagement A <br/> Songs chromatography plates 4a and alternately arranged the disengaged Au <br of The housing plate 4b is loosely fitted inside the housing 2 and is rotatable relative to the housing 2.

Further, the outer edge side of the non-engagement outer plate 4b is arranged such that the clutch plates 8 sandwich the outer peripheral portion of each disengaged outer plate 4b, the clutch plate 8 the inner periphery of the housing 2 The spline 12 is spline-engaged with the spline 12 formed on the surface and engages with the housing 2 in the rotation direction and is movable in the rotation axis direction. Therefore, the pressing member 31 is moved in the main working chamber 25 side, the engaging outer plate 4a, when the disengaged outer plates 4b and the clutch plates 8 for pressing the clutch pressing direction, disengaged outer plates 4b clutch plate 8 so as to be rotatable integrally with the hub 2.

Further, the outer plate 9 spline-engaged with the spline 16 formed on the inner peripheral surface of the built-in housing 21 is connected to the inner plate 10 spline-engaged with the spline 13 formed on the outer peripheral surface of the hub 3.
Are alternately arranged, and are kept at a predetermined interval by the spacer ring 14. Therefore, a rotational torque is transmitted between the built-in housing 21 and the hub 3 almost in proportion to a rotational speed difference caused by the relative motion.

As shown in FIG. 3, a spiral cam surface provided at the axial end of the pressing member 31 facing the sub-operation chamber 26 is provided on the outer peripheral portion of the built-in housing 21 on the side of the main operation chamber 25. A meshing tooth 23 corresponding to the meshing tooth 32 is formed, and a predetermined range between the built-in housing 21 and the pressing member 31 is provided between the built-in housing 21 and the pressing member 31.
(Relative displacement within the range that does not cross each other's meshing teeth)
The pressing member 31 is pushed in the clutch pressing direction (FIG.
A cam mechanism that is driven to follow ( middle, left direction) is configured.
That is, when the built-in housing 21 is displaced relative to the pressing member 31 and the housing 2 in the direction of the arrow Y in FIG. 3, the pressing member 31 is disengaged when the clutch plate 8 is disengaged. The slider is slid in the clutch pressing direction to clamp the tar plate 4b.

The spiral cam surfaces of the meshing teeth 23 and the meshing teeth 32 are formed so as to be inclined in the same direction along the rotation direction of the built-in housing 21.
Relative rotation varying internal housing 21 in the arrow Y direction in FIG. 3
The pressing member 31 is slid in the clutch pressing direction only when the pressing member 31 is positioned. The viscous coupling 1 rotates integrally with the housing 2.
The number of plates of the engagement outer plate 4a is set to be larger than the number of plates of the outer plate 9, and the temperature in the main working chamber 25 is initially set during the rotation operation.
There is configured to be higher than the temperature of the work Doshitsu 26. Therefore, the pressure in the main working chamber 25 is higher than the pressure in the sub-working chamber 26 during the initial stage of the rotation operation, and the thrust force is increased in the direction in which the gap between the plates in the main working chamber 25 is widened. appear. Therefore, the built housing 21 and not relative rotational displacement, the pressing member 31 the biasing force of the clutch pressing direction by the cam mechanism provided in engagement with the inner built housing 21 does not act, a direction opposite to the clutch pressing direction It is urged to.

Next, the operation of the viscous coupling 1 will be described. Initially during the rotation operation of the housing 2 and the hub 3 rotated in the direction of the arrow X in FIG.
The pressing member 31 is urged in a direction opposite to the clutch pressing direction by a thrust force in a direction in which a gap between the respective plates in the main working chamber 25 having a higher internal pressure than the sub-working chamber 26 is expanded . The built-in housing 21 rotates integrally with the pressing member 31 and does not undergo relative rotational displacement . So, housing 2
A rotational speed difference between the hub 3 small shear resistance of silicon oil for little, without acting clamping force of the clutch plates 8 with respect to the non-engagement outer plate 4b, the disengaged <br/> Since slippage occurs between the outer plate 4b and the clutch plate 8 and the rotation torque cannot be transmitted,
The housing 2 and the hub 3 are substantially separated from each other, and the transmission of torque is cut off.

Next, when the housing 2 rotates faster than the hub 3 and a predetermined rotation speed difference starts to occur between the two transmission members,
First, the housing 2
The torque transmission is performed between the engagement outer plate 4a engaged with the hub 3 and the inner plate 5 engaged with the hub 3, and the viscous coupling 1 quickly generates a rising torque. At the same time, internal housing 21 which rotates integrally with the pressing member 31, torque between the outer plate 9 engaged with the internal housing 21 and the inner plate 10 engaged with the hub 3 of the sub-operating chamber 26 Communication takes place. Then, the built-in housing 21 tends to rotate in the same rotation direction as the hub 3, and is therefore relatively rotated and displaced with respect to the pressing member 31 in the arrow Y direction in the drawing. Then, the relative rotational force is converted into meshing by meshing teeth 23 of the teeth 32 and the internal housing 21, the pressing force sliding the pressing member 31 to the clutches pressing direction of the pressing member 31 constituting the cam mechanism. Therefore, as the relative displacement between the built-in housing 21 and the hub 3 increases, the pressing force of the pressing member 31 against the thrust force due to the pressure in the main working chamber 25 increases.

Therefore, the clutch plate 8 is connected to the pressing member 3.
Is pressed in 1, disengaged outer plate 4b is Ru is connected to the housing 2 in strength corresponding to the strength of the gripping force of the clutch plates 8, as shown in FIG.

That is, the rotation of the housing 2 due to the driving force of the engine or the like is controlled by the engagement outer plate 4a and the non- engagement arm.
While being transmitted from the outer plate 4b to the inner plate 5 by the shear resistance of the silicon oil, the pressing member 3
1 and the outer plate 9 via the built-in housing 21.
Transmitted by shear resistance of the silicon oil to the inner plate 10 from.

When the rotational speed difference between the rotation of the housing 2 and the rotation of the hub 3 becomes small, the built-in housing 2
Rotation torque transmitted from the outer plate 9 to the inner plate 10 which engages the 1 becomes small, the pressing force of the built housing 21 also becomes small. So, housing 2
And because the shear resistance of silicon oil is less little torque transmission is not performed because there is almost no difference in number of revolutions between the hub 3, disengaged
Since the combined outer plate 4b is released from the clamping force of the clutch plate 8, the housing 2 and the hub 3 are substantially separated, and the transmission of torque is cut off.

As described above, in the viscous coupling 1 of the present invention, the number of the engagement outer plates 4a rotatable integrally with the housing 2 and the meshing teeth 31, 23 of the pressing member 31 and the built-in housing 21 are provided. By appropriately setting the cam surface shape, the transmission torque can be substantially cut off in the low rotation speed difference region, and the transmission torque can be largely automatically adjusted in the high rotation speed difference region. Further, when an excessive torque is input slip the clutch plates 8 and a disengaged outer plate 4b, acts as a torque limiter.

Further, even when the rotational speed difference between the housing 2 and the hub 3 is small and a large thrust force in the clutch pressing direction by the pressing member 31 is not acting on the clutch plate 8, the engagement outer plate 4a is engaged with the housing 2 in the rotational direction.
Torque can be transmitted between the hub and the hub 3 by the shear resistance of the silicone oil, so that the viscous coupling 1 can quickly generate a rising torque.

Further, since the built-in housing 21 is disposed in the working chamber 11 formed by the housing 2 and the hub 3, only the X-rings 17 and 19 need to seal the working chamber 11 in a liquid-tight manner. It is not necessary to provide another sealing member between the built-in housing 21 and the housing 2 and the hub 3, and the housing 2 and the hub 3 according to the present invention have a conventional viscous coupling housing without a clutch plate assembly and a conventional housing. Hubs can be diverted. In addition, the viscous coupling causes the pressure in the main working chamber 25 to be higher than the pressure in the sub-working chamber 26 during the rotation operation.
Oite is high, the inter-plate plow in the main working chamber 25
Since the thrust force is generated in the direction in which the space is widened , when the urging force of the pressing member 31 in the clutch pressing direction is weak, the pressing member 31 can be urged in the direction opposite to the clutch pressing direction, and the conventional disc spring has Omit urging member
You can also. That is, the viscous coupling of the present invention can reduce the number of parts, simplify the structure, and facilitate the assembling, so that the manufacturing cost can be reduced.

In the above embodiment, the pressing member 31
Although the cam mechanism provided between the housing and the built-in housing 21 is constituted by the meshing teeth 32 and 21 having a spiral cam surface, it is needless to say that other forms can be adopted. FIG. 5 shows another embodiment of the present invention, in which a pressing member 4 is provided.
1 and a built-in housing 43, and a cam mechanism for driving the pressing member 41 in the clutch pressing direction in proportion to the relative displacement between the housing and the built-in housing 43 by other means. Is the same as that of the above embodiment, and the description is omitted.

The outer peripheral portion of the built-in housing 43 on the side of the main working chamber 25 is replaced with a ball 4 instead of the meshing teeth 23 of the above embodiment.
5 are formed, and a plurality of rectangular concave portions 44 are formed.
It corresponds to a meshing tooth 42 having a spiral cam surface provided at an axial end of a pressing member 41 facing the sub-operation chamber 26. That is, when the built-in housing 43 is displaced relative to the pressing member 41 and the housing 2 in the direction of the arrow Y in FIG. 5, the pressing member 41 is disengaged from the clutch plate 8 as in the above embodiment.
(b) is slid in the clutch pressing direction. Further, the spiral cam surfaces of the meshing teeth 42 are in contact with the spheres 45 held in the rectangular recesses 44 of the built-in housing 43, respectively. The operation of the pressing member 41 can be made smooth.

Further, in the above embodiment, the first transmission member and the second transmission member are the housing and the hub, respectively. However, the present invention is not limited to this. For example, the first transmission member may be a hub. The second transmission member may be a housing. Further, each transmitting member, pressing member, and the like are not limited to the shape of the above-described embodiment, but may take various forms based on the gist of the present invention.

[0032]

According to the viscous coupling of the present invention, when the relative displacement between the first transmission member and the first transmission member increases, the cam mechanism causes the pressing member to follow the clutch pressing direction against the clutch plate set. Since the third transmission member is disposed in the working chamber, there is no need to provide a seal member for keeping the working chamber liquid-tight between the third transmission member and the first and second transmission members. And the transmission member of a general viscous coupling can be used as the second transmission member. Further, the pressure in the main working chamber is higher than the pressure in the sub-working chamber in the initial stage during the rotation operation, and a thrust force is generated in a direction in which a gap between the respective plates in the main working chamber is widened. When the urging force is weak, the pressing member can be urged in the direction opposite to the clutch pressing direction, and the urging member can be omitted.
it can. That is, the viscous coupling of the present invention can reduce the number of parts, simplify the structure, and facilitate the assembling, so that the manufacturing cost can be reduced.

Further, even when the rotational speed difference between the first transmission member and the second transmission member is small and a large thrust force in the clutch pressing direction by the pressing member is not acting on the clutch plate set, Some of the plates of the first plate set are rotationally engaged with the first transmission member, and a torque between the first transmission member and the second transmission member due to the shear resistance of the viscous fluid. Since the transmission is enabled, the viscous coupling can quickly generate a rising torque.

Therefore, it is possible to provide a good viscous coupling which has a simple structure while having a function of adjusting the torque transmission characteristic and has a good function.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a viscous coupling according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of the viscous coupling shown in FIG.

FIG. 3 is an exploded perspective view of a pressing member and a built-in housing according to an embodiment of the present invention.

FIG. 4 is a partially enlarged view for explaining an operation state of the viscous coupling shown in FIG. 1;

FIG. 5 is a partially enlarged view of a pressing member and a built-in housing according to another embodiment of the present invention.

[Explanation of symbols]

1 a viscous coupling 2 housing (first transmission member) 3 hub (second transmission member) 4a engages the outer plates (first plate set) 4b disengaged outer plates (first plate set one
Part 5) Inner plate (second plate set) 8 Clutch plate (clutch plate set) 9 Outer plate (third plate set) 10 Inner plate ( fourth plate set) 11 Working chamber 17 X ring 19 X Ring 21 built-in housing (third transmission member) 23 meshing teeth 24 partition wall 25 main working chamber 26 sub-working chamber 31 pressing member 32 meshing teeth

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-21 (JP, A) JP-A-3-51522 (JP, A) JP-A-4-64727 (JP, A) JP-A-2- 26328 (JP, A) JP-A-64-6527 (JP, A) JP-A-3-60624 (JP, U) JP-A-3-127834 (JP, U) JP-A 1-144534 (JP, U) Japanese Utility Model Application No. Sho 63-109039 (JP, U) Japanese Utility Model Application No. Sho 62-155233 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16D 35/00

Claims (1)

(57) [Scope of request for utility model registration] A first and a second rotatably arranged first and second rotatable members.
Is constituted by the transmission member (2,3) in working chamber viscous fluid is sealed (11), said first and second transmission member and (2,3)
It is disposed in the working chamber (11) so as to be rotatable relative to
The chamber (11) is divided into a main working chamber (25) and a sub-working chamber (26) in the direction of the rotation axis.
A third transmission member (21) having a partition (24) to be split,
Rotationally engages the second transmission member (3) in the working chamber (25);
A second plate set (5), and the second plate set (5)
Alternately arranged and rotating with the first transmission member (2)
Sandwiched by the clutch plate set (8)
A first plate set (4a, 4b) and a second plate
The fourth plate rotationally engaged with the second transmission member (3)
Sets (10) and the fourth plate set (10) are alternately arranged.
With the third transmission member (21) in the rotational direction.
The first plate set (4a, 4b) is engaged with the plate set (9) and the first transmission member (2) in the rotation direction and pressing the clutch plate set (8) in the rotation axis direction. A viscous coupling having a pressing member (31 ) for frictionally sandwiching the clutch plate set (8) , wherein a part of the first plate set (4a, 4b ) has the first transmission While being engaged with the member (2) in the rotational direction, the pressing member (31) is moved by the cam mechanism (23, 32) in proportion to the relative displacement between the third transmitting member (21) and the pressing member (31). It consists clutch plate assembly (8) so as to follow the clutch pressing direction, and one of said first transmission member (2) and the rotation direction engaged so was the first plate assembly (4a, 4b) The number of the plates (4a) is equal to the third plate set (9).
Viscous couplings larger than the number of plates in (1) .