JPH0322581Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a power transmission device that transmits power by the viscous resistance of a viscous fluid that is applied to a resistance plate in an operating chamber.

[Prior art]

This type of power transmission device is installed on the propeller shaft of a four-wheel drive vehicle.
-There is one described in Publication No. 188731. The details of this power transmission device are described in, for example, Japanese Utility Model Application Publication No. 60-99333, and this is a so-called viscous coupling device. In this viscous coupling device, for example, a working chamber in which a viscous fluid is sealed is formed between an inner shaft and an outer shaft concentric with the inner shaft. Resistance plates are respectively engaged with the inner periphery of the outer shaft. The torque input from the outer shaft connected to the propeller shaft is then output to the rear wheel differential device due to the viscous resistance of the viscous fluid that corresponds to the differential rotation between the inner shaft and the outer shaft. ing.

[Problem that the invention attempts to solve]

By the way, high-speed stability and maneuverability are among the performances required of automobiles. To satisfy the former, the capacity of the viscous cut spring in the rear wheel drive system described above can be increased, but on the other hand, the torsional torque generated between the front and rear wheels when parking, etc., also increases, causing the so-called tight corner braking phenomenon. In addition, since torque is transmitted from the engine to the front wheels without causing slippage, maneuverability is reduced, such as increased steering force.

On the other hand, in order to improve maneuverability, it is possible to install a low-capacity viscous cut spring in the front wheel drive system, but on the other hand, the slip of the viscous cut spring on the front wheel side is large when driving at high speeds or on rough roads. There was a risk that running stability as a wheel drive vehicle would be impaired.

On the other hand, if a viscous cup spring with a small capacity is installed in the front wheel drive system and a viscous cup spring with a large capacity is installed in the rear wheel drive system, and a lock-up mechanism is provided for each to selectively operate them, the above problem can be solved. can. However, the viscous cut springs must be provided at two locations, which complicates the support structure and requires the rear wheel drive system to be larger, which is extremely disadvantageous in terms of space.

Therefore, the object of this invention is to provide a power transmission device that simultaneously improves running stability and maneuverability as a four-wheel drive vehicle, has a simple support structure, and is advantageous in terms of space.

[Means for solving problems]

In order to achieve the above object, this invention provides a first shaft, a second shaft, which are arranged concentrically and are relatively rotatable.
first shafts having different effective radii, each of which is formed between the opposing peripheral surfaces of the first shaft and the second shaft and between the opposing peripheral surfaces of the second shaft and the third shaft, each of which is filled with a viscous fluid; a working chamber, a second working chamber, and a plurality of resistance plates located in the first working chamber and the second working chamber, alternately arranged in the respective working chambers, and respectively engaged with opposing circumferential surfaces of each shaft; An engaging means for selectively engaging and disengaging the first shaft, second shaft, and third shaft is provided.

[Effect]

According to the configuration of this invention, by selectively engaging and disengaging the engaging means, torque can be transmitted from the first working chamber with a large torque or the second working chamber with a small torque via each separate shaft.

〔Example〕

An embodiment of this invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is an overall sectional view of the power transmission device, and FIG. 2 is a list diagram showing the position of the coupling sleeve and the power transmission to the second and third shafts corresponding to FIG. 1.

In FIG. 1, a first shaft 1, a second shaft 3, and a third shaft 5, which are relatively rotatable, are sequentially fitted concentrically from the outside. That is, the first shaft 1 is formed into a cylindrical shape with a large diameter, and constitutes an input shaft that receives rotational input from a prime mover side (not shown). 2nd axis 3
is formed into a medium-diameter cylindrical shape having an appropriate distance from the inner peripheral surface of the first shaft 1, and the third shaft 5 is formed by a small-diameter hollow shaft having an appropriate distance from the inner peripheral surface of the second shaft 3. The first output shaft and the second output shaft are respectively connected to either one of a front wheel drive system and a rear wheel drive system (not shown).

A sealed first working chamber 7 is formed between the inner peripheral surface of the first shaft 1 and the outer peripheral surface of the second shaft 3.
A sealed second working chamber 9 is formed between the inner peripheral surface of the third shaft 5 and the outer peripheral surface of the third shaft 5. Therefore, the first working chamber 7 has a large effective radius, and the second working chamber 9 has a small effective radius. And each working chamber 7, 9
Each is filled with a viscous fluid such as silicone oil.

The first working chamber 7 is connected to the inner circumferential surface of the first shaft 1 by side walls 11a and 11b, which are fitted onto the inner circumference of both ends of the first shaft 1 and whose outer circumferential ends are integrated by means such as welding. The outer peripheral surface of the two shafts 3 is closed, and this side wall 11
A seal member 13 is provided at a portion of a, 11b that is in contact with the second shaft 3. The second working chamber 9 also includes a side wall 5a that is fitted onto the inner periphery of one end of the second shaft 3 and whose outer periphery end is integrated by means such as welding, and a side wall 15b that is fixed to the inner periphery of the other end. closes the inner circumferential surface of the second shaft 3 and the outer circumferential surface of the third shaft 5,
Seal members 17 and 19 are provided at portions of the side walls 15a and 15b that contact the second and third shafts 3 and 5, respectively.

Splines 2 are provided on the inner periphery of the first shaft 1 and the outer periphery of the second shaft 3 constituting the first working chamber 7, respectively.
1, 23 are formed, and the splines 21,
A plurality of resistance plates 25a and 25b are engaged with the resistor plate 23 so as to alternately face each other with small gaps between them. That is,
Among the plurality of resistance plates 25a and 25b, the resistance plate 25a
is fitted on the first shaft 1 side and rotates together with the first shaft 1, and is also fitted on the resistance plate 25b and the second shaft 3 side so as to rotate together with the second shaft 3. A viscous fluid such as the silicone oil is acting on each of these resistance plates 25a and 25b.

A spline 2 is formed between the inner periphery of the second shaft 3 and the outer periphery of the third shaft 5 constituting the second working chamber 9.
7, 29 are formed, and the splines 27,
A plurality of resistance plates 31a and 31b are fitted to 29 so as to alternately face each other with small gaps. That is, among the plurality of resistance plates 31a and 31b, resistance plate 3
1a is fitted on the second shaft 3 side and rotates together with the second shaft 3, and resistance plate 31b is fitted on the third shaft 5 side and rotates together with the third shaft 5. A viscous fluid such as the silicone oil is acting on each of these resistance plates 31a and 31b.

Between the first shaft 1, the second shaft 3, and the third shaft 5, there is an engaging means for selectively and detachably engaging the first shaft 1 with the second shaft 3 and the third shaft 5. Coupling sleeves 33a, 33b are provided.

The coupling sleeve 33a, which serves as an engaging means for engaging the first shaft 1 and the third shaft 5 side, is connected to the third shaft 5 side.
The splines 37a and 37b are fitted to the outer periphery of a flange 35 connected to one end of the flange 35. The flange 35 is connected to one end of the third shaft 5 by fitting splines 39a and 39b, and is rotatably supported by a case (not shown) and a side wall 15a of the second shaft 3 via bearings 41 and 43. is,
It is supported by the bearing 41, and the side wall 15a of the second shaft 3 is supported by the bearing 43. A groove 45a is formed on the outer periphery of the coupling sleeve 33a, and a groove 45a is formed on the outer circumference of the coupling sleeve 33a.
Clutch teeth 49a are formed to removably engage with clutch teeth 47a formed on the side wall 11a. Then, the spline 37 is moved back and forth by the shift fork 50a engaged with the groove 45a.
a slides on the spline 37b of the flange 35, so that the clutch 49a is removably engaged with the clutch 47a.

The coupling sleeve 33b, which serves as an engaging means for engaging the first shaft 1 and the second shaft 3 side, is connected to the second shaft 3 side.
is fitted to the outer periphery of by splines 51a and 51b. The spline 51a of this coupling sleeve 33b also fits into the spline 53b formed on the outer periphery of the flange portion 53a of the shaft 53 disposed on one end side of the second shaft 3, so that the second shaft 3 and the shaft 5
3 are connected. The shaft 53 has bearings 55 and 57 attached to the inner periphery of one end of the second shaft 3 and to a case (not shown).
It is rotatably mounted through the The coupling sleeve 33b has a groove 45b on the outer periphery.
is formed, and a clutch 49b is formed which detachably engages with a clutch 47b formed on the side wall 11b of the first shaft 1. Then, due to the reciprocating movement of the shift fork 50b engaged with the groove 45b, the spline 51a slides on the splines 51b and 53b of the second shaft 3 and the shaft 53,
Clutch 49b is adapted to removably engage clutch 47b.

The shift forks 50a and 50b are interlocked and connected by a link mechanism 59. Therefore, the shift forks 50a, 50b are simultaneously reciprocated via the link mechanism 59, so that when either one of the coupling sleeves 33a, 33b is engaged with the first shaft 1, the other is disengaged. It's summery. In addition, shift fork 50a, 5
The reciprocating movement of 0b can be performed either automatically or manually.

Next, the operation of the above embodiment will be described.

When the shift fork 50a, 50b is moved according to the road surface condition and the driving condition while driving,
The coupling sleeves 33a, 33b are connected to the splines 37b of the flange 35 and the second shaft 3 and the shaft 53.
is moved left and right in the axial direction on the splines 51b and 53b, so that one of the coupling sleeves 33a and 33b selectively connects the second shaft 3 and the third shaft 5.
is engaged with.

That is, when the shift forks 50a, 50b are moved to the left in FIG. 1 and the clutch 49b of the coupling sleeve 33b is engaged with the clutch 47b of the side wall 11b of the first shaft 1,
As shown in FIG. They are connected by viscous fluid. Therefore, the power from the first shaft 1 side is transferred to the resistance plate 25 of the first working chamber 7.
There is no differential movement between a and 25b, and the viscous resistance of the viscous fluid is transmitted directly from the first shaft 1 to the second shaft 3 due to the differential movement of the resistance plates 31a and 31b in the second working chamber 9. is transmitted to the third shaft 5 by.

Furthermore, by moving the shift forks 50a and 50b to the right in FIG.
When the clutch 47a of the clutch 47a is engaged, the first shaft 1 and the third shaft 5 are in an integrated state, that is, a locked state, as shown in FIG.
Therefore, the power from the first shaft 1 side is transferred to the flange 3.
5 to the third shaft 5, and the resistance plate 25a of the first working chamber 7 is transmitted to the second shaft 3.
It is transmitted to the second shaft 3 by the viscous resistance of the viscous fluid due to the differential movement of the shafts 25b.

The first working chamber 7 and the second working chamber 9 have different effective radii, with the first working chamber 7 having a larger effective radius and the second working chamber 9 having a smaller effective radius. Therefore, the transmission torque capacity is large in the first working chamber 7 and small in the second working chamber 9. Therefore, with the rear wheel drive system connected to the second shaft 3 and the front wheel drive system connected to the third shaft 5 as a transfer of a four-wheel drive vehicle, the coupling sleeves 33a, 3
3b in the state shown in FIG. 2, the rear wheel drive system is directly connected to the first shaft 1 via the second shaft 3, and the front wheel drive system is connected to the second shaft 3 and the second working chamber 9
Since it is connected to the third shaft 5 via the front wheel, torque transmission to the front wheels is reduced, reducing steering force when parking the vehicle at low speeds and improving maneuverability. Moreover, the coupling sleeve 33a,
33b in the state shown in FIG. 2, the rear wheel drive system side is connected to the first shaft 1 via the first working chamber 7 and the second shaft 3, and the front wheel drive system side is connected to the third shaft 5. Since it is directly connected to the first axle 1 via the engine, the engine torque is evenly distributed to the four wheels while absorbing the differential between the front and rear wheels during cornering, improving running stability when driving straight at high speed.

In addition, since the weight distribution between the front wheels and the rear wheels differs depending on the vehicle, such as torque, it is necessary to vary the capacity of the viscous coupling spring device that transmits power to each wheel. By using this, the capacity of the viscous coupling device can be obtained in accordance with the weight distribution between the front and rear wheels. That is, when the weight distribution on the front wheel side is large, the second shaft 3 on the first working chamber 7 side with a large transmission torque capacity is connected to the front wheel side, and when the weight distribution on the rear wheel side is large, By connecting the second shaft 3 to the rear wheel side, appropriate torque transmission can be performed, and maneuverability and running stability can be improved.

[Explanation of the idea]

As is clear from the above explanation, according to the configuration of this invention, it is possible to selectively connect the front wheel and rear wheel drive systems to the transmission path via the working chambers with different transmission torque capacities. It is suitable for improving the driving stability and maneuverability of a vehicle at the same time. Moreover, since the working chambers with different effective radii are coaxially arranged inside and outside, it is possible to significantly reduce the size compared to a case where the chambers are provided separately, and the supporting structure can also be simplified.

[Brief explanation of drawings]

Fig. 1 is an overall sectional view of a power transmission device according to an embodiment of this invention, and Fig. 2 shows the position of the coupling sleeve and power transmission to the second and third shafts corresponding to Fig. 1. The list diagram and FIG. 3 are characteristic diagrams showing the relationship between the differential rotation ΔN between the resistance plates and the transmission torque T generated by the differential rotation of the resistance plates in a conventional power transmission device. Explanation of symbols representing main parts of the drawings, 1...1st
Axis, 3...Second axis, 5...Third axis, 7...First working chamber, 9...Second working chamber, 25a, 25b, 31
a, 31b...resistance plate, 33a, 33b...coupling sleeve (engaging means).

Claims (1)

[Scope of utility model registration request] The first part is arranged concentrically and is relatively rotatable.
an effective radius formed between the shaft, the second shaft, and the third shaft, and between the opposing peripheral surfaces of the first shaft and the second shaft, and between the facing peripheral surfaces of the second shaft and the third shaft, each containing a viscous fluid; a first working chamber and a second working chamber that are different from each other;
a plurality of resistance plates located in the working chamber and the second working chamber, arranged alternately in the respective working chambers and individually engaged with opposing circumferential surfaces of the respective shafts; and the first shaft, the second shaft, and the third shaft. and an engagement means for selectively engaging and disengaging the power transmission device.