JP2015052375A - Viscous coupling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a viscous coupling for preventing wear of an inner plate and an outer plate.SOLUTION: A viscous coupling 1 comprises an outer case 10, an inner shaft 20, a plurality of outer plates 30 showing a disk-like shape and having outer circumferential sides fixed to the outer case 10 and a plurality of inner plates 40 showing a disk-like shape, having inner circumferential sides fixed to the inner shaft 20 and alternatively arranged with the outer plates in an axial direction in which the outer plates 30 are formed with a plurality of first slits 31 having first inner ends 31a opened and first outer ends 31b closed, the inner plates 40 are formed with a plurality of second slits 41 having second inner ends 41a closed and second outer ends 41b opened and then silicone oil is encapsulated in a fluid chamber 71 between the outer case 10 and the inner shaft 20. The inner plates 40 are formed with outer through-pass holes 44 at more outside portions than the first outer ends 31b.

Description

  The present invention relates to a viscous joint.

  As a typical application example of the viscous coupling (viscous coupling), in a four-wheel drive vehicle based on FF (Front engine Front drive), it is in the middle of the propeller shaft and between the propeller shaft and the final reduction gear. Is provided. Such a viscous joint includes a bottomed cylindrical outer case (outer housing), an inner shaft (hub) that is coaxially and relatively rotatable with the outer case, and a disc-like shape that is spline-fitted to the outer case. An outer plate and a disc-like inner plate that is spline-fitted to the inner shaft and arranged alternately with the outer plate, and the fluid chamber between the outer case and the inner shaft has high viscosity silicone oil (viscous Fluid) is enclosed.

  Silicone oil is interposed in the gap between the outer plate and the inner plate in the axial direction. The outer case and the outer plate rotate integrally with the front wheel, and the inner shaft and the inner plate rotate integrally with the rear wheel.

  For example, when the front wheel idles, a rotational speed difference is generated between the rotational speed of the outer plate and the rotational speed of the inner plate. Then, a shearing force acts on the silicone oil, the inner plate rotates due to the viscosity of the silicone oil, and power is transmitted to the rear wheels.

  In addition, a slit extending radially about the rotation axis is formed in both or one of the outer plate and the inner plate, and the slit is also filled with silicone oil.

  Here, when the viscous joint rotates, a centrifugal force acts on the silicone oil, and the silicone oil moves radially outward (outside) through the gaps and slits. And the silicone oil moves corresponding to the magnitude of the centrifugal force, so that the power transmission characteristic of the viscous joint changes. That is, the shape and position of the slit affects the power transmission characteristics of the viscous joint. For example, in Patent Document 1, the slit is oriented in the radial direction (normal direction).

Japanese Utility Model Publication No. 47-203

  However, in Patent Document 1, since there is no slit in the outer plate 30 on the radially outer side of the inner plate 40A (see FIGS. 5 and 6) (the radially outer side of the virtual circle R31b in FIG. 6), the inner plate 40A and Silicone oil is insufficient between the outer plates 30, and the inner plate 40 </ b> A and the outer plate 30 may be in direct contact and wear. And when the abrasion powder by abrasion mixes in silicone oil, there exists a possibility that an original power transmission characteristic may not be acquired.

  That is, when the front wheel is idling or the like, the circumferential speed difference between the outer plate 30 and the inner plate 40A increases toward the outer side in the radial direction. Therefore, when not sufficiently lubricated, the outer end of the slit 31 of the outer plate 30 and the inner plate The inner plate 40A and the like are easily worn within the range of the outer peripheral edge of 40A.

  Then, this invention makes it a subject to provide the viscous coupling which prevents abrasion of an inner plate and an outer plate.

  As means for solving the above-mentioned problems, the present invention provides a cylindrical outer case that is integral with the first rotating shaft, and a second rotating shaft that is integral with the first rotating shaft and is relatively rotatable on the axis of the outer case. The arranged inner shaft, a plurality of outer plates having a disk shape and having an outer peripheral side fixed to the outer case, and a disk shape having an inner peripheral side fixed to the inner shaft and alternating with the outer plate in the axial direction A plurality of inner plates disposed on the outer plate, wherein the outer plate has a plurality of first slits open at a first inner end and closed at a first outer end, and the inner plate has a second inner end. A plurality of second slits that are closed and the second outer end is opened, and a viscous fluid is sealed in a fluid chamber between the outer case and the inner shaft. A is, in the inner plate, a viscous coupling, characterized in that the outer through holes are formed in the outside portion of the first outer end.

  According to such a configuration, in the inner plate, the viscous fluid flows through the outer through hole formed in a portion outside the first outer end of the first slit formed in the outer plate. That is, the viscous fluid flows axially through the outer through hole. The viscous fluid flows into and accumulates in the outer through hole by centrifugal force.

  Thereby, in the range between the first outer end of the first slit in the radial direction and the outer peripheral edge of the inner plate, the viscous fluid flows in the axial direction through the outer through hole, and the viscous fluid flows between the inner plate and the outer plate. The fluid is interposed, and the inner plate and the outer plate are easily lubricated.

  Therefore, in the range between the first outer end and the outer peripheral edge of the inner plate, the inner plate and the outer plate are hardly brought into contact with each other, the inner plate and the outer plate are hardly worn, and the temperature of the viscous fluid is hardly increased. .

  Moreover, in the inner plate of the viscous joint, it is preferable that an inner through hole is formed in a portion inside the second inner end and outside the first inner end.

  According to such a configuration, in the inner plate, the inner through-hole formed in a portion inside the second inner end of the second slit and outside the first inner end of the first slit formed in the outer plate. Viscous fluid will flow through the holes. That is, the viscous fluid flows axially through the inner through hole.

  Thereby, in the range between the second inner end of the second slit and the first inner end of the first slit in the radial direction, the viscous fluid flows in the axial direction through the inner through hole, and the inner plate and the outer plate are lubricated. It becomes easy to be done.

  Therefore, in the range between the second outer end and the first inner end, the inner plate and the outer plate are difficult to contact, the inner plate and the outer plate are hardly worn, and the temperature of the viscous fluid is hardly increased.

  In the viscous joint, it is preferable that the first slit is inclined with respect to the radial direction, and the second slit is inclined with respect to the radial direction in a direction opposite to the first slit.

  The operation and effect of such a configuration will be described in the case where the viscous joint is applied between the propulsion shaft of the FF-based four-wheel drive vehicle and the final reduction gear. The outer case and the outer plate rotate integrally with the propulsion shaft (first rotation shaft), and the inner shaft and the inner plate rotate integrally with the drive pinion shaft (second rotation shaft) of the final reduction gear. . Similarly to the embodiment described later, the first outer end of the first slit (first outer end 31b in FIG. 4) and the second inner end of the second slit (second inner end 41a in FIG. 4) A description will be given with a configuration inclined to the reverse rotation side (reverse direction side).

For example, when the front wheel slips and idles during forward movement, the outer plate rotates at a higher speed than the inner plate, and the outer plate rotates relative to the inner plate on the positive rotation side (plus side).
Then, since the first outer end of the first slit of the outer plate is inclined to the reverse rotation side, the viscous fluid flows radially outward along the first slit of the outer plate rotating at high speed. Accordingly, the viscous fluid stays on the outer peripheral side (outside in the radial direction) in the fluid chamber, and the radius of the viscous fluid that transmits torque between the outer plate and the inner plate increases. Accordingly, the shearing force generated in the viscous fluid increases, and the torque transmitted from the outer plate to the inner plate increases.

  Also, (1) When the ABS is activated and the front wheel is temporarily locked during forward movement, (2) When the front wheel is idle during reverse movement, the inner plate rotates at a higher speed than the outer plate, and the inner plate is moved to the outer plate. On the other hand, it rotates relative to the positive rotation side (plus side). In other words, the outer plate rotates relative to the inner plate on the reverse rotation side (minus side).

  Then, since the second inner end of the second slit of the inner plate is inclined in the reverse rotation side, the viscous fluid flows inward in the radial direction along the second slit of the inner plate that rotates at high speed. As a result, the viscous fluid stays on the inner circumferential side (inward in the radial direction) in the fluid chamber, and the radius of the viscous fluid that transmits torque between the outer plate and the inner plate is reduced. Therefore, the shearing force generated in the viscous fluid is reduced, and the torque transmitted from the outer plate to the inner plate is reduced.

  ADVANTAGE OF THE INVENTION According to this invention, the viscous coupling which prevents abrasion of an inner plate and an outer plate can be provided.

It is a top view of the viscous coupling which concerns on this embodiment. It is a front view of the outer plate which concerns on this embodiment. It is a front view of the inner plate which concerns on this embodiment. It is a front view of what overlapped the inner plate and outer plate which concern on this embodiment. It is a front view of the inner plate which concerns on a comparative example. It is a front view of what overlapped the inner plate and outer plate which concern on a comparative example.

  An embodiment of the present invention will be described with reference to FIGS.

  The viscous coupling 1 in this embodiment shown in FIG. 1 is mounted on an FF-based four-wheel drive vehicle, and rotates around a rotation axis O, and a propulsion shaft (first rotation shaft) and a final reduction gear (not shown). It is a joint that transmits power by connecting 100 drive pinion shafts 101 (second rotating shaft).

  The propulsion shaft extends in the front-rear direction below the vehicle body, and engine power is input via a transmission and a transfer device.

  The final reduction gear 100 is a device that transmits power to the left and right rear wheels after reducing the power, and meshes with the drive pinion shaft 101, the drive pinion gear 102 formed at the rear end of the drive pinion shaft 101, and the drive pinion gear 102. A ring gear 103, a differential case 104 that rotates integrally with the ring gear 103, a pinion gear 105 and a side gear 106 that are accommodated in the differential case 104, and a housing 107 that rotatably accommodates the differential case 104.

  The pinion gear 105 is rotatable about a pinion shaft 108 fixed to the differential case 104, and the side gear 106 meshes with the pinion gear 105 and rotates integrally with a drive shaft (not shown).

≪Configuration of viscous joint≫
The viscous joint 1 includes an outer case 10, an inner shaft 20, a plurality of outer plates 30, a plurality of inner plates 40, and an end plate 50. Each of the outer plate 30 and the inner plate 40 has a disk shape, and is a fluid chamber 71 formed between the outer case 10 and the inner shaft 20 while leaving a minimal gap in the axial direction (front-rear direction). They are stacked alternately.

<Outer case>
The outer case 10 has a bottomed cylindrical shape with the front side closed, and includes a disk-shaped front wall portion 11 and a peripheral wall portion 12 (cylindrical portion) extending rearward from the outer peripheral edge of the front wall portion 11. ing. The outer case 10 is made of, for example, an aluminum alloy or a steel material.

  The rear end of the propulsion shaft is fastened to the front surface of the front wall portion 11 by a bolt. That is, the front wall portion 11 is connected to and integrated with the propulsion shaft. Thus, the propulsion shaft, the outer case 10 and the outer plate 30 that is spline-fitted to the outer case 10 are rotated together.

<Inner shaft>
The inner shaft 20 is a cylindrical member disposed on the rotation axis O (on the axis of the outer case 10), and is splined to the outside of the drive pinion shaft 101, and is integrated with the drive pinion shaft 101. ing. As a result, the drive pinion shaft 101, the inner shaft 20, and the inner plate 40 that is spline-fitted to the inner shaft 20 rotate integrally. The inner shaft 20 is made of, for example, a steel material.

  The front end portion 21 of the inner shaft 20 passes through the front wall portion 11 of the outer case 10, and a bearing 61 is provided between the front end portion 21 and the front wall portion 11. The bearing 61 is composed of, for example, a radial ball bearing. Thereby, the inner shaft 20 is disposed so as to be rotatable relative to the outer case 10.

  A lock nut 62 is screwed into the front end portion of the drive pinion shaft 101 protruding from the inner shaft 20. As a result, the inner shaft 20 is prevented from being detached from the drive pinion shaft 101.

  A ring-shaped fluid chamber 71 (working chamber) is formed between the outer case 10 and the inner shaft 20. A disc-shaped end plate 50 is provided behind the fluid chamber 71, and the end plate 50 closes a ring-shaped gap formed between the outer case 10 and the inner shaft 20. The fluid chamber 71 is filled with silicone oil (viscous fluid).

  A seal member 63 such as an X ring and a seal member 64 are provided between the front wall portion 11 and the inner shaft 20 and between the end plate 50 and the inner shaft 20. Further, a seal member 65 such as an O-ring is provided between the outer case 10 and the end plate 50. The seal member 63, the seal member 64, and the seal member 65 prevent silicone oil from leaking from the fluid chamber 71 to the outside, and prevents external muddy water or the like from entering the fluid chamber 71. Furthermore, a bearing 66 that allows the inner shaft 20 and the end plate 50 to rotate relative to each other is provided outside the seal member 64 in the axial direction.

<Outer plate>
The outer plate 30 is a disk-shaped component (see FIG. 2), and its outer peripheral side is fixed by spline fitting to the inner peripheral surface of the peripheral wall portion 12 (outer case 10). However, the fixing method of the outer plate 30 and the outer case 10 may be other fixing methods.

  A plurality of first slits 31 are formed in the outer plate 30 in the circumferential direction. The first inner end 31a on the radially inner side of the first slit 31 opens into the hollow portion on the center side, and the first outer end 31b on the radially outer side is closed.

  In other words, the outer plate 30 has an outer peripheral portion 32 having a ring shape on the outer peripheral side, and a substantially triangular first tongue piece extending inward in the radial direction from the inner peripheral edge of the outer peripheral portion 32 and arranged at predetermined intervals in the circumferential direction. 33. And the 1st slit 31 is formed between the 1st tongue pieces 33 adjacent in the circumferential direction.

  The first slit 31 is directed at a predetermined angle with respect to the radial direction (normal direction). Specifically, the first outer end 31b of the first slit 31 is inclined in the opposite direction side (retreat direction side) with respect to the radial direction.

  As a result, when the vehicle moves forward, the front wheel is idled and the outer plate 30 is rotated at a higher rotational speed than the inner plate 40, that is, the outer plate 30 is relative to the inner plate 40 in the positive direction. When rotated, the silicone oil interposed at the intersection of the first slit 31 and the second slit 41 in the axial direction is sent radially outward by centrifugal force (see arrow A1 in FIG. 4). . That is, when the outer plate 30 rotates relative to the inner plate 40 on the forward rotation side, the first outer end 31b of the first slit 31 is inclined in the reverse direction side, so that the silicone in the first slit 31 is The oil moves radially outward.

  Then, in the fluid chamber 71, the silicone oil gathers on the outer peripheral side (radially outer side), and the radial position of the silicone oil that transmits torque (power) between the outer plate 30 and the inner plate 40 increases. ing. As a result, even if the pressing force (contact force) of the outer plate 30 and the inner plate 40 against the silicone oil is the same, the torque transmitted between the outer plate 30 and the inner plate 40 increases, and the power is good for the rear wheels. To communicate.

<Inner plate>
The inner plate 40 is a disk-shaped component (see FIG. 3), and its inner peripheral side is fixed by spline fitting to the outer peripheral surface of the inner shaft 20. However, the fixing method of the inner plate 40 and the inner shaft 20 may be other fixing methods.

  A plurality of second slits 41 are formed in the inner plate 40 in the circumferential direction. The second inner end 41a on the radially inner side of the second slit 41 is closed, and the second outer end 41b on the radially outer side is open to the outside.

  In other words, the inner plate 40 has a ring-shaped inner peripheral portion 42 and a substantially trapezoidal shape extending radially outward from the outer peripheral edge of the inner peripheral portion 42 and arranged at predetermined intervals in the circumferential direction. 2 tongue pieces 43. And the 2nd slit 41 is formed between the 2nd tongue pieces 43 adjacent in the circumferential direction.

  The second slit 41 is directed in the direction opposite to the first slit 31 and inclined at a predetermined angle with respect to the radial direction. Specifically, the second inner end 41a of the second slit 41 is inclined in the opposite direction side (retreat direction side) with respect to the radial direction.

  Thus, for example, (1) when the ABS is activated and the front wheels are locked momentarily when the vehicle is moving forward, the outer plate 30 integrated with the front wheels and the propulsion shaft is locked, and the rotational speed of the outer plate 30 is low. Thus, the outer plate 30 rotates relative to the inner plate 40 at a low speed. That is, the outer plate 30 rotates relative to the inner plate 40 in the opposite direction (minus direction), in other words, the inner plate 40 rotates relative to the outer plate 30 at a high speed. It has become.

  Then, when viewed in the axial direction, the silicone oil interposed at the intersection of the first slit 31 and the second slit 41 is sent inward in the radial direction along the second slit 41 (FIG. 4, arrow). A2). That is, when the inner plate 40 rotates relative to the outer plate 30 on the forward rotation side, the second inner end 41a of the second slit 41 is inclined in the reverse direction side, so that the silicone in the second slit 41 is The oil moves radially inward.

  Then, in the fluid chamber 71, the silicone oil gathers on the inner peripheral side (in the radial direction), and the radial position of the silicone oil that transmits torque (power) between the outer plate 30 and the inner plate 40 is reduced. Has been. As a result, even if the pressing force (contact force) of the outer plate 30 and the inner plate 40 against the silicone oil is the same, the torque transmitted between the outer plate 30 and the inner plate 40 is reduced, and the power is transmitted to the rear wheels. It is difficult to do.

  The same applies when (2) the front wheels are idled when the vehicle is moving backward. That is, in this case, when the outer plate 30 and the inner plate 40 are rotating in the opposite directions, the rotational speed of the outer plate 30 is increased due to idling of the front wheels, so that the silicone oil causes the first slit 31 to pass through the first inner end 31a. The silicone oil tends to gather on the inner peripheral side (in the radial direction).

<Inner plate-outer through hole>
In the inner plate 40, an outer through hole 44 is formed in a portion outside the first outer end 31b of the first slit 31 (see FIG. 4). Specifically, in each of the second tongue pieces 43, one outer through hole 44 is formed in a radially outer portion than a virtual circle R31b passing through the first outer end 31b. However, two or more outer through holes 44 may be formed.

  As a result, silicone oil is likely to be interposed in the gap between the outer plate 30 and the inner plate 40 in a range radially outside the virtual circle R31b. As a result, the outer plate 30 and the inner plate 40 are well lubricated and worn. It has become difficult.

<Inner plate-inner through hole>
In the inner plate 40, an inner through hole 45 is formed in a portion radially inward from the second inner end 41 a of the second slit 41 and radially outer than the first inner end 31 a of the first slit 31. . Specifically, an inner through hole 45 is formed in a portion radially inward of the virtual circle R41a passing through the second inner end 41a and radially outer than the virtual circle R31a passing through the first inner end 31a. Yes. That is, one inner through hole 45 is formed on the base side of each second tongue piece 43. However, two or more inner through holes 45 may be formed for each second tongue piece 43.

  As a result, silicone oil is likely to be interposed in the gap between the outer plate 30 and the inner plate 40 in the range between the virtual circle R31a and the virtual circle R41a. As a result, the outer plate 30 and the inner plate 40 are well lubricated. It is hard to wear.

≪Function and effect of viscous joint≫
According to such a viscous joint 1, the following effects are obtained.

  When the vehicle travels and the viscous joint 1 rotates, centrifugal force acts on the silicone oil, the silicone oil moves toward the radially outer side, and the pressure on the radially outer side increases in the fluid chamber 71. If it does so, the 2nd tongue piece 43 extended in the radial direction outward of the inner plate 40 will become easy to bend in an axial direction (front or back).

  In this case, the silicone oil is interposed in the outer through-hole 44 and enters the gap between the outer plate 30 and the inner plate 40 adjacent in the axial direction in a range radially outside the virtual circle R31b. And the inner plate 40 is lubricated well. Thereby, even if the 2nd tongue piece 43 contacts the outer plate 30 directly, the outer plate 30 and the inner plate 40 become difficult to wear. In addition, the temperature of the silicone oil is difficult to increase, and the seal member 63 and the like are not easily thermally degraded.

  Further, silicone oil is interposed in the inner through hole 45 and enters the gap between the outer plate 30 and the inner plate 40 adjacent in the axial direction in the range of the virtual circle R31a and the virtual circle R41a. Plate 40 is well lubricated. Thereby, even if the 1st tongue piece 33 bends in an axial direction, even if it contacts the inner plate 40 directly, the outer plate 30 and the inner plate 40 become difficult to wear. In addition, the temperature of the silicone oil is difficult to increase, and the seal member 63 and the like are not easily thermally degraded.

  Since the silicone oil is interposed between the outer plate 30 and the inner plate 40 in this way, for example, when the front wheel is idled and a rotational speed difference occurs between the outer plate 30 and the inner plate 40, this A shearing force is generated in the silicone oil corresponding to the rotational speed difference. Thereby, the viscous coupling 1 can exhibit ideal power transmission characteristics.

≪Modification≫
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, For example, you may change as follows.

  In the above-described embodiment, the configuration in which the first slit 31 and the second slit 41 are inclined with respect to the radial direction (normal direction) is exemplified. However, for example, at least one of the first slit 31 and the second slit 41 is used. May be configured so as not to be inclined but along the radial direction.

DESCRIPTION OF SYMBOLS 1 Viscous joint 10 Outer case 20 Inner shaft 30 Outer plate 31 1st slit 31a 1st inner end 31b 1st outer end 40 Inner plate 41 2nd slit 41a 2nd inner end 41b 2nd outer end 44 Outer through-hole 45 Inner through-hole Hole 71 Fluid chamber 101 Drive pinion shaft (second rotating shaft)

Claims (3)

A cylindrical outer case integral with the first rotating shaft;
An inner shaft that is integral with the second rotation shaft and that is relatively rotatable on the axis of the outer case;
A plurality of outer plates having a disc shape and having an outer peripheral side fixed to the outer case;
A plurality of inner plates that have a disk shape and the inner peripheral side is fixed to the inner shaft, and are arranged alternately with the outer plates in the axial direction;
With
The outer plate is formed with a plurality of first slits whose first inner end is open and whose first outer end is closed,
The inner plate is formed with a plurality of second slits whose second inner end is closed and whose second outer end is opened,
A viscous joint in which a viscous fluid is sealed in a fluid chamber between the outer case and the inner shaft,
In the inner plate, an outer through hole is formed in a portion outside the first outer end. 2. The viscous joint according to claim 1, wherein an inner through hole is formed in a portion inside the second inner end and outside the first inner end in the inner plate. The first slit is inclined with respect to the radial direction,
The viscous joint according to claim 1 or 2, wherein the second slit is inclined with respect to the radial direction in a direction opposite to the first slit.

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