JP3456887B2 - Driving force transmission device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force transmission device which is disposed between rotary members such as a drive shaft and a driven shaft of a vehicle to transmit torque between the rotary members.

[0002]

2. Description of the Related Art As one type of driving force transmission device, as proposed in Japanese Utility Model Registration No. 2525611 under the name of "multi-disc clutch", both inner and outer rotations are positioned coaxially and relatively rotatable with each other. A multi-plate friction clutch disposed between the members and an electromagnetic control unit that is activated by energization to frictionally engage the friction clutch are provided inside the outer rotary member. An armature that faces the friction clutch and an electromagnet that faces the friction clutch with the side wall of the outer rotation member located outside the outer rotation member are sandwiched between the armature and the armature by energizing the electromagnet. There is a drive force transmission device of a type that is sucked to frictionally engage the friction clutch, and the friction engagement force of the friction clutch causes the rotating members to be in a coupled state capable of transmitting torque.

However, in the driving force transmission device described in the above publication, the differential case is used as the outer rotating member and the hub of the planet carrier is used as the inner rotating member, and the electromagnetic control means is It is composed of an armature (pressing ring) located on one side of the friction clutch and an electromagnet located across a portion (magnetic material wall portion) of the differential case located on the other side of the friction clutch.

In the driving force transmission device, by energizing the electromagnetic coil of the electromagnet, a magnetic path for circulating the yoke, the magnetic wall of the differential case, the friction clutch, the armature, the friction clutch, the magnetic wall and the yoke is formed. Then, the armature is attracted to the friction clutch side by the magnetic induction action. As a result, the armature presses the friction clutch into frictional engagement, and the frictional engagement force directly actuates the main clutch mechanism to couple the rotating members so that torque can be transmitted.

[0005]

By the way, in the driving force transmission device of the above-mentioned type, the magnetic wall portion of the differential case and the clutch plate of the friction clutch facing the magnetic wall portion,
Also, since the armature and the clutch plate of the friction clutch that faces the armature are configured so as not to rotate relative to each other, an oil film may be formed in the gap between the magnetic wall and the clutch plate and the gap between the armature and the clutch plate. However, if an oil film is formed in these gaps, there is a problem in that the responsiveness of the operation of the friction clutch is reduced and an operation delay occurs. Therefore, it is an object of the present invention to address such issues.

[0006]

The present invention relates to a driving force transmission device, and in particular, one end side opening is closed by a side wall.
The cylindrical outer rotating member and the side wall
Is rotatably supported in the state of being coaxial with the outer rotating member.
Inner rotating member, a multi-plate friction clutch disposed between these rotating members, and between these rotating members
It is arranged to operate by energizing a control means of an electromagnetic frictional engagement with said friction clutch, a driving force transmission apparatus the two rotating members rotate together even when energization is stopped to the control means , The control means, the outer rotating member
An armature that is located inside the side wall and that faces the friction clutch ;
And configured to include an electromagnet that faces the friction clutch across the side walls located outside the side wall, the friction clutch frictionally engage by suction the armature by energizing the same electromagnet, the same friction clutch The present invention is applied to a driving force transmission device of a type in which both rotary members are in a connected state capable of transmitting torque by a frictional engagement force.

Therefore, in the first driving force transmitting device according to the present invention, in the driving force transmitting device of the above-mentioned type, the clutch plate of the friction clutch facing the armature can rotate integrally with the armature, and the electromagnet can rotate.
Even when the power supply to the
It is configured to rotate integrally with the armature, and an oil film breakage promoting means is provided on at least one of the facing surfaces of the clutch plate and the armature.

[0008] The second driving force transmission apparatus according to the present invention, in the driving force transmission apparatus of the type described above, the clutch plate opposite to the side wall of the outer rotating member in the friction clutch is rotatable integrally with the side wall , To the electromagnet
Even when the energization of the
When it is configured to rotate integrally, and is characterized in that the oil film promoting means on at least one of the opposing surfaces of the clutch plate and the side wall is provided.

[0009]

[0010]

The oil film breakage promoting means in these driving force transmission devices according to the present invention is preferably the clutch plate, the armature, or a plurality of oil drain grooves formed on the opposing surfaces of the side walls.

Further, in these driving force transmission devices according to the present invention, the main clutch mechanism for transmitting torque between the rotary members by frictional engagement between the rotary members, and the friction mechanism activated by energization. An electromagnetic pilot clutch mechanism that engages, and a cam mechanism that is located between the main clutch mechanism and the pilot clutch mechanism and that converts the frictional engagement force of the pilot clutch mechanism into a pressing force for the main clutch mechanism, It is preferable that the clutch mechanism includes the friction clutch and the control means.

[0013]

In the driving force transmission device according to the present invention, by energizing the electromagnetic coil forming the electromagnet,
A magnetic path that circulates through the yoke that supports the electromagnet, the side wall of the outer rotating member, the friction clutch, the armature, the friction clutch, the side wall, and the yoke is formed, and the armature is attracted to the friction clutch side by the magnetic induction action. As a result, the armature presses the friction clutch for frictional engagement, and the frictional engagement force brings both rotary members into a coupled state capable of transmitting torque, and torque transmission according to the frictional engagement force is performed between both rotary members. It

Therefore, in the first driving force transmission device according to the present invention, the clutch plate facing the armature in the friction clutch is configured so as to be rotatable integrally with the armature, and between the facing surfaces of the clutch plate and the armature. An oil film is formed in the gap, but the oil film breakage promoting means formed on at least one of the opposing surfaces of the clutch plate and the armature accelerates the oil film breakage, so that the responsiveness of the friction clutch operation due to the formation of the oil film is reduced. It does not decrease and cause an operation delay.

Further, in the second driving force transmitting apparatus of the present invention, the clutch plate facing the side wall of the outer rotating member of the friction clutch is constructed so as to be rotatable integrally with the side wall, and the facing surface of the clutch plate and the side wall. Although an oil film is formed in the gap between them, the oil film breakage promoting means formed on at least one of the facing surfaces of the clutch plate and the side wall promotes the oil film breakage, so that the response of the friction clutch operation caused by the oil film formation There is no possibility that operation delay will occur due to deterioration of the property.

In the drive force transmission device according to the present invention, the clutch plate facing the armature in the friction clutch is configured to be rotatable integrally with the armature, and faces the side wall of the outer rotating member in the friction clutch. When the clutch plate is integrally rotatable with the side wall, the oil film breakage promoting means is provided on at least one of the facing surfaces of the clutch plate and the armature and at least one of the facing surface of the clutch plate and the side wall. As a result, it is possible to promote the oil film breakage between the clutch plate and the armature and between the clutch plate and the side wall, and it is possible to more effectively prevent the decrease in the responsiveness of the operation of the friction clutch due to the formation of the oil film.

[0017]

[0018]

[0019]

[0020]

[0021]

[0022]

Further, in each of the above-mentioned driving force transmission devices according to the present invention, a main clutch mechanism for transmitting torque between the rotating members by frictional engagement between the rotating members, and a friction mechanism activated by energization. An electromagnetic pilot clutch mechanism that engages, and a cam mechanism that is located between the main clutch mechanism and the pilot clutch mechanism and that converts the frictional engagement force of the pilot clutch mechanism into a pressing force for the main clutch mechanism. With the structure formed by the friction clutch and the control means, the friction engagement force of the pilot clutch mechanism can be smoothly and increased transmitted to the main clutch mechanism via the cam mechanism.

As a result, the main clutch mechanism is strongly frictionally engaged to increase the transmission torque between both rotary members, and the drive force transmission characteristic of the drive force transmission device can be improved.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows an example of a driving force transmission device according to the present invention. As shown in FIG. 6, the driving force transmission device 10 is arranged in the driving force transmission path to the rear wheels of the four-wheel drive vehicle.

In the four-wheel drive vehicle, the transaxle 21 integrally includes a transmission, a transfer, and a front differential, and outputs the driving force of the engine 22 to both axle shafts 23a via the transaxle 21. The left and right front wheels 23b are driven and output to the propeller shaft 24 side. The propeller shaft 24 is connected to the rear differential 25 via the driving force transmission device 10, and the propeller shaft 24 and the rear differential 2 are connected to each other.
When 5 is connected so that torque can be transmitted, the driving force is transmitted to the rear differential 25, and is output from the differential 25 to both axle shafts 26a to drive the left and right rear wheels 26b.

The driving force transmission device 10 is housed in a differential carrier 27 together with the rear differential 25 and supported by the carrier 27, and is supported by the vehicle body via the carrier 27. Note that FIG.
Shows a half part of the driving force transmission device 10 cut around the axis, and the half part (not shown) is omitted because it is formed substantially symmetrically around the axis.

Therefore, as shown in FIG. 1, the driving force transmission device 10 includes an outer case 10a which is an outer rotating member,
An inner shaft 10b, which is an inner rotating member, a main clutch mechanism 10c, a pilot clutch mechanism 10d, and a cam mechanism 10e are provided.

The outer case 10a comprises a bottomed cylindrical front housing 11a and a rear housing 11b screwed into a rear end opening of the front housing 11a to cover the opening.
Is formed of an aluminum alloy which is a non-magnetic material, and the rear housing 11b is formed of iron which is a magnetic material. A cylindrical body 11b1 made of stainless steel, which is a non-magnetic material, is embedded in an intermediate portion in the radial direction of the rear housing 11b, and the cylindrical body 11b1 forms an annular non-magnetic portion.

A nut member 11c is screwed so as to be able to move forward and backward to a screw portion formed on the outer peripheral portion of the rear end of the rear housing 11b. The nut member 11c tightens the front housing 11a from the rear end side and presses the screw portion of the front housing 11a against the screw portion of the rear housing 11b to eliminate the looseness between these screw portions.

The outer case 10a is rotatably supported by the differential carrier 27 on the outer periphery of the front end of the front housing 11a, and is supported by the differential carrier 27 on the outer periphery of the rear end of the rear housing 11b. . A rear end portion of the propeller shaft 24 is coupled to the front end portion of the front housing 11a so that torque can be transmitted.

The inner shaft 10b is inserted into the front housing 11a by liquid-tightly penetrating the central portion of the rear housing 11b, and the front housing 11a and the rear housing 11 are restrained from moving in the axial direction.
It is rotatably supported by b. Inner shaft 10b
The tip portion of the drive pinion shaft 28 is inserted into the shaft and is connected so that torque can be transmitted.

The main clutch mechanism 10c is a wet multi-plate friction clutch, which is provided with a large number of clutch plates (inner clutch plate 12a, outer clutch plate 12b), and is arranged on the inner wall side of the front housing 11a. ing. Each inner clutch plate 12a constituting the friction clutch is spline-fitted to the outer circumference of the inner shaft 10b and is movably assembled in the axial direction, and each outer clutch plate 12b is splined to the inner circumference of the front housing 11a. It is fitted and assembled so as to be movable in the axial direction. The inner clutch plates 12a and the outer clutch plates 12b are alternately located, abutting against each other for frictional engagement, and separated from each other to be in a free state.

The pilot clutch mechanism 10d includes an electromagnet 13, a friction clutch 14, and an armature 15. The electromagnet 13 has an annular shape, and is fitted in the yoke 16 and fitted in the annular recess 11b2 of the rear housing 11b. The yoke 16 is supported in a state of being axially supported by the differential carrier 27 via a conical spring 16a, and is rotatably supported on the outer periphery of the rear end portion of the rear housing 11b. As a result, the rear housing 11b and the yoke 1
A predetermined air gap is formed between the first and second electrodes.

The friction clutch 14 is a multi-plate friction clutch consisting of a plurality of clutch plates (inner clutch plate 14a, outer clutch plate 14b), and each inner clutch plate 14a constitutes a first cam mechanism 10e which will be described later. The cam member 17 is assembled by spline fitting so as to be movable in the axial direction, and each outer clutch plate 14b is assembled by spline fitting on the inner circumference of the front housing 11a so as to be movable in the axial direction. Has been. The inner clutch plates 14a and the outer clutch plates 14b are alternately located,
They come into contact with each other and frictionally engage with each other, and are separated from each other to be in a free state.

The armature 15 has an annular shape, is spline-fitted to the inner circumference of the front housing 11a, and is assembled so as to be movable in the axial direction.
Located on one side and facing each other.

In the above construction of the pilot clutch mechanism 10d, the outer case 10a corresponds to the outer rotating member of the present invention, and the rear housing 11b corresponds to the side wall of the outer rotating member. To the yoke 16, the rear housing 11b, and
Friction clutch 14, armature 15, friction clutch 1
4, a magnetic path is formed between the rear housing 11b and the yoke 16. It should be noted that the energization of the electromagnetic coil of the electromagnet 13 is interrupted by switching the switch, and will be described later.
It is possible to select one drive mode. The switch is arranged near the driver's seat in the vehicle compartment so that the driver can easily operate it. However, this switch is not always necessary.

The cam mechanism 10e comprises a first cam member 17, a second cam member 18, and a cam follower 19. The first cam member 17 and the second cam member 18 are provided with a plurality of cam grooves facing each other on their facing surfaces at predetermined intervals in the circumferential direction. The first cam member 17 is
It is rotatably fitted to the outer periphery of the inner shaft 10b,
The rear housing 11b is rotatably supported, and each inner clutch plate 14a of the friction clutch 14 is spline-fitted to the outer periphery thereof.

The second cam member 18 serves as the inner shaft 10.
It is spline-fitted to the outer periphery of b and is integrally rotatably assembled, and is located to face the inner clutch plate 12a of the main clutch mechanism 10c. A ball-shaped cam follower 19 is interposed in the cam grooves of the second cam member 18 and the first cam member 17 which face each other.

In the driving force transmission device 10, however, the friction clutch 14 constituting the pilot clutch mechanism 10d has three inner clutch plates 14a and four outer clutch plates 1 as shown in FIG.
4b, the inner outer clutch plate 14b faces the armature 15, and the outer outer clutch plate 14b faces the rear housing 11b.

The armature 15 and the outer clutch plate 14b facing the armature 15 are spline-fitted to the inner spline 11a1 of the front housing 11a in the same manner as the armature 15, so that the armature 15 and the armature 15 can be integrally rotated with the front housing 11a. Has been. The outer clutch plate 14b facing the rear housing 11b is spline-fitted to the inner spline 11a1 of the front housing 11a so as to be integrally rotatable with the front housing 11a, and is integrally rotatable with the rear housing 11b. It is possible.

A facing surface 14b1 of the inner outer clutch plate 14b facing the armature 15 and a rear housing 11b of the outer outer clutch plate 14b.
As shown in FIG. 3, an infinite number of oil drain grooves 14b3 extending in a curved line are formed on the entire surface of the facing surface 14b2 facing each other.

In the driving force transmission device 10 having such a structure, the electromagnet 1 which constitutes the pilot clutch mechanism 10d.
When the electromagnetic coil 3 is not energized, the magnetic path is not formed and the friction clutch 14 is in the non-engaged state.
Therefore, the pilot clutch mechanism 10d is in the non-actuated state, and the first cam member 1 that constitutes the cam mechanism 10e.
7 is integrally rotatable with the second cam member 18 via the cam follower 19, and the main clutch mechanism 10c is in the inoperative state. Therefore, the vehicle constitutes a two-wheel drive mode.

On the other hand, when the electromagnetic coil of the electromagnet 13 is energized, a magnetic path is formed in the pilot clutch mechanism 10d, and the electromagnet 13 attracts the armature 15. Therefore, the armature 15 presses the friction clutch 14 into frictional engagement, connects the first cam member 17 of the cam mechanism 10e to the front housing 11a side, and then connects the second cam member 18 to the second cam member 18.
Causes relative rotation between and. As a result, the cam mechanism 1
In 0e, the cam follower 19 has both cam members 17, 18
Are pressed in directions away from each other.

As a result, the second cam member 18 is pressed toward the main clutch mechanism 10c, and the main clutch mechanism 1
0c is frictionally engaged according to the frictional engagement force of the friction clutch 14 to transmit torque between the outer case 10a and the inner shaft 10b. Therefore, the vehicle constitutes a four-wheel drive mode in which the propeller shaft 24 and the drive pinion shaft 28 are not directly connected. In this drive mode,
The driving force distribution ratio between the front and rear wheels is 100:
0 (two-wheel drive state) to 50:50 (direct drive four-wheel drive state)
Can be controlled.

When the current applied to the electromagnetic coil of the electromagnet 13 is increased to a predetermined value, the armature 15 of the electromagnet 13 is increased.
, The armature 15 is strongly attracted to increase the friction engagement force of the friction clutch 14 and increase the relative rotation between the cam members 17 and 18. As a result,
The cam follower 19 increases the pressing force on the second cam member 18 to bring the main clutch mechanism 10c into the engaged state. Therefore, the vehicle constitutes a four-wheel drive mode in which the propeller shaft 24 and the drive pinion shaft 28 are directly connected.

As described above, in the driving force transmission device 10, by energizing the electromagnetic coil forming the electromagnet 13, the yoke 16 supporting the electromagnet 13, the rear housing 11b, the friction clutch 14, the armature 15, the friction clutch 14 are provided. A magnetic path that circulates between the rear housing 11b and the yoke 16 is formed, and the armature 15 is attracted to the friction clutch 14 side by the magnetic induction action. As a result, the armature 15 presses the friction clutch 14 into frictional engagement, and by this frictional engagement, the outer case 10a and the inner shaft 10b are brought into a coupled state capable of transmitting torque, and the outer case 10a and the inner shaft 10b are connected. Then, torque is transmitted according to the frictional engagement force.

Thus, in the driving force transmission device 10, the outer clutch plate 14b of the friction clutch 14 facing the armature 15 is constructed so as to be rotatable integrally with the armature 15 and the rear housing 11b.
The outer clutch plate 14b opposed to the rear housing 11b is configured to be rotatable integrally with the rear housing 11b. Are formed.

Therefore, the outer clutch plate 14b
Between the armature 15 and the armature 15, and between the outer clutch plate 14b and the rear housing 11b is promoted to prevent the oil film from running out, which prevents the response of the friction clutch 14 from being lowered due to the formation of the oil film.

Incidentally, in the driving force transmission device 10, the facing surface 14b of each outer clutch plate 14b.
1, 14b2 have oil drain grooves 14b3 formed therein, but the facing surface 15a of the armature 15 and the facing surface 11b3 of the rear housing 11b facing the respective outer clutch plates 14b.
Alternatively, the oil drain groove 14b3 may be formed.

Further, in the driving force transmission device 10, between the outer case 10a and the inner shaft 10b,
Outer case 10a and inner shaft 1 due to frictional engagement
Main clutch mechanism 10c for transmitting torque between 0b
And an electromagnetic pilot clutch mechanism 10d which is activated by electric conduction and frictionally engages, and a frictional engagement force of the pilot clutch mechanism 10d located between the main clutch mechanism 10c and the pilot clutch mechanism 10d.
Since the cam mechanism 10e for converting the pressing force against 0c is provided, the frictional engagement force of the pilot clutch mechanism 10d can be smoothly transmitted to the main clutch mechanism 10c via the cam mechanism 10e.

As a result, the main clutch mechanism 10c is strongly friction-engaged with each other, so that the transmission torque between the outer case 10a and the inner shaft 10b can be increased, and the driving force transmission characteristic of the driving force transmission device 10 is improved. be able to.

FIG. 4 shows an example of a pilot clutch mechanism 10f which is a modification of the pilot clutch mechanism 10d in the driving force transmission device 10.

Pilot clutch mechanism 10 according to a modification
f is the pilot clutch mechanism 10 in that it includes the electromagnet 13, the friction clutch 14, and the armature 15.
Similar to d, but the friction clutch 14 is composed of three inner clutch plates 14a and two outer clutch plates 14b, and the inner inner clutch plate 14a faces the armature 15 and The outer inner clutch plate 14a, which is assembled to the cam member 17 and faces the rear housing 11b, is a first
It is different from the pilot clutch mechanism 10d in that it is assembled to the cam member 17.

Therefore, the inner inner clutch plate 1
4a and the armature 15 rotate relative to each other, and the outer inner clutch plate 14a and the rear housing 11b rotate relative to each other.
As shown in FIG. 5, an oil drain groove 14a3 is formed on the entire surface of the facing surface 14a1 facing the armature 15 of a and the facing surface 14a2 of the outer inner clutch plate 14a facing the rear housing 11b. There is.

Also, the inner inner clutch plate 14
The facing surface 15a of the armature 15 facing a and the facing surface 11b3 of the rear housing 11b facing the outer inner clutch plate 14a are nitrided, and the facing surface 15a and the facing surface 11b3 are high. It has hardenability, wear resistance, and corrosion resistance.

Pilot clutch mechanism 10 having such a configuration
The driving force transmission device including the f operates in the same manner as the driving force transmission device including the pilot clutch mechanism 10d and has the same operational effects, but particularly exhibits the following operational effects. Is.

That is, the pilot clutch mechanism 10f
In, the armature 15 in the friction clutch 14
The inner clutch plate 14a facing to the rear housing 11b is rotatable relative to the armature 15 and the inner clutch plate 14a facing to the rear housing 11b is rotatable relative to the rear housing 11b. Housing 11b
Since the oil drain groove 14a3 is formed in the facing surfaces 14a1 and 14a2 facing each other, it is possible to promote the oil film breakage between the inner clutch plate 14a and the armature 15 and between the inner clutch plate 14a and the rear housing 11b, and thus the oil film As a matter of course, it is possible to prevent a decrease in the responsiveness of the operation of the friction clutch 14 due to the formation of the friction clutch 1.
The outer clutch plate 14b of No. 4 can be made to function similarly, and the friction clutch 14 can be made compact compared with the friction clutch 14 which comprises the pilot clutch mechanism 10d.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a driving force transmission device according to an example of the present invention.

FIG. 2 is a partial cross-sectional view showing a pilot clutch mechanism that constitutes the driving force transmission device.

FIG. 3 is a front view of an outer clutch plate that constitutes the pilot clutch mechanism.

FIG. 4 is a view showing a modified example of the pilot clutch mechanism.
It is a fragmentary sectional view corresponding to.

FIG. 5 is a front view of an inner clutch plate that constitutes the pilot clutch mechanism.

FIG. 6 is a skeleton diagram of a vehicle equipped with the driving force transmission device.

[Description of Reference Signs] 10 ... Driving force transmission device, 10a ... Outer case, 10b
… Inner shaft, 10c… Main clutch mechanism, 10
d, 10f ... Pilot clutch mechanism, 10e ... Cam mechanism, 11a ... Front housing, 11a1 ... Inner spline, 11b ... Rear housing, 11b1 ... Cylindrical body, 11
b2 ... annular recess, 11b3 ... facing surface, 11c ... nut member, 12a ... inner clutch plate, 12b ... outer clutch plate, 13 ... electromagnet, 14 ... friction clutch, 14a ... inner clutch plate, 14a1, 14
a2 ... facing surface, 14a3 ... oil drain groove, 14b ... outer clutch plate, 14b1, 14b2 ... facing surface, 14b3 ... oil drain groove, 15 ... armature, 15a ... facing surface, 16 ... yoke, 16a ... conical spring, 17 ... First cam member, 18 ... Second cam member, 19 ... Cam follower, 21
... transaxle, 22 ... engine, 23a ... axle shaft, 23b ... front wheel, 24 ... propeller shaft,
25 ... Rear differential, 26a ... Axle shaft, 26b ... Rear wheel, 27 ... Differential carrier, 28 ... Drive pinion shaft.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiko Ikeda 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (56) References JP-A-1-145434 (JP, A) JP-A-1-145438 (JP, A) JP-A-1-261525 (JP, A) JP-A-4-92126 (JP, A) JP-A-9-60660 (JP, A) JP-A-48-6136 (JP, A) Open 64-6525 (JP, A) Open flat 1-140028 (JP, U) Open flat 6-32763 (JP, U) Open 61-175630 (JP, U) US Patent 2989161 (US, A) ) U.S. Patent No. 3037601 (US, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16D 27/10-27/115 F16D 11/00-23/14

Claims (4)

(57) [Claims] 1. A cylindrical outer rotating member whose one end side opening is closed by a side wall, and an inner side which is rotatably supported in a state of penetrating the side wall and is coaxially positioned inside the outer rotating member. A rotary member, a multi-plate friction clutch arranged between the rotary members, and an electromagnetic control unit arranged between the rotary members and operated by energization to frictionally engage the friction clutch. A driving force transmission device in which both the rotating members rotate together even when the energization to the control means is stopped, the control means being located inside the side wall of the outer rotation member and facing the friction clutch. And an electromagnet that is located outside the side wall of the outer rotating member and faces the friction clutch with the side wall interposed therebetween. The armature is attracted by energizing the electromagnet. In a drive force transmission device that frictionally engages the friction clutch and brings the rotating members into a coupled state capable of transmitting torque by the friction engagement force of the friction clutch, the clutch plate facing the armature in the friction clutch is the same. It is configured to rotate integrally with the armature, and to rotate integrally with the armature by the rotation of both rotating members even when the energization of the electromagnet is stopped, and promotes oil film breakage on at least one of the opposing surfaces of the clutch plate and the armature. A driving force transmission device, characterized in that means are provided. 2. A cylindrical outer rotating member whose one end side opening is closed by a side wall, and an inner side which is rotatably supported while penetrating the side wall and is coaxially positioned inside the outer rotating member. A rotary member, a multi-plate friction clutch arranged between the rotary members, and an electromagnetic control unit arranged between the rotary members and operated by energization to frictionally engage the friction clutch. A driving force transmission device in which both the rotating members rotate together even when the energization to the control means is stopped, the control means being located inside the side wall of the outer rotation member and facing the friction clutch. And an electromagnet that is located outside the side wall of the outer rotating member and faces the friction clutch with the side wall interposed therebetween. The armature is attracted by energizing the electromagnet. In a driving force transmission device that frictionally engages the friction clutch and brings the rotating members into a coupled state capable of transmitting torque by the friction engagement force of the friction clutch, the driving force transmitting device faces a side wall of the outer rotating member of the friction clutch. The clutch plate is rotatable integrally with the side wall, and is configured to rotate integrally with the side wall by the rotation of the rotating members even when the energization of the electromagnet is stopped, and at least one of the facing surfaces of the clutch plate and the side wall. A driving force transmission device characterized in that an oil film breakage promoting means is provided in the. 3. The driving force transmission device according to claim 1 or 2.
In the above, the oil film breakage promoting means is
On the opposing surface of the armor, armature, or sidewall.
A driving force transmission device having a plurality of oil drain grooves . 4. The driving force transmission according to claim 1, 2, or 3.
In the device, frictional engagement is applied between the rotating members.
Main clutch machine that transmits torque between these two rotating members
And an electromagnetic pyro that operates by energization and frictionally engages
Output clutch mechanism, the main clutch mechanism, and the clutch
The pilot clutch located between the ilot clutch mechanisms
The frictional engagement force of the mechanism is pushed against the main clutch mechanism.
The pilot clutch is equipped with a cam mechanism that converts pressure.
H mechanism is composed of the friction clutch and the control means.
A driving force transmission device characterized by being .