JP3373251B2 - Differential 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 vehicle differential device.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 3-248919 discloses a "power transmission device" for a vehicle as shown in FIG. This is a transfer 201 of a four-wheel drive (4WD) vehicle, and the driving force of the engine is distributed from a high / low switching mechanism 203 to a front wheel output shaft 207 and a rear wheel output shaft 209 via a differential mechanism 205. The differential of the differential mechanism 205 is limited by the clutch mechanism 211. The clutch mechanism 211 includes a multi-plate type main clutch 217 that connects the front wheel-side rotating body 213 and the rear wheel-side rotating body 215, an electromagnetic multi-plate type pilot clutch 219, and a cam 221. When engaged, the differential torque of the differential mechanism 205 is applied to the ball cam 221, and the cam thrust force engages the main clutch 217 to limit the differential.

[0003]

PROBLEM TO BE SOLVED BY THE INVENTION Pilot clutch 2
The clutch part 223 and the armature 225 of 19 are the rotating body 2
13, the electromagnet 227 is disposed inside the casing 22.
The air gaps 231 and 231 through which magnetism passes are formed between the rotating body 213 and the electromagnet 227. However, the electromagnet 227 is directly supported by the casing 229, while the rotating body 213 includes the bearing 233, the rotating body 215, the shaft 209, and the bearing 2.
35, the sprocket 237, etc.
Since it is supported by No. 9, it is difficult to adjust the air gap 231 to a predetermined interval. Since the air gap 231 has a large magnetic resistance, the differential limiting characteristic fluctuates significantly even with a slight change in the distance, and the differential limiting force cannot be properly controlled.

Therefore, an object of the present invention is to provide a differential device in which the air gap of an electromagnet of an electromagnetic friction clutch can be easily adjusted and the fluctuation of the air gap is small.

[0005]

The invention according to claim 1 is
A differential mechanism arranged in the casing for distributing the driving force from the engine to the wheel side, a friction clutch for connecting and disconnecting the rotating case and the hub receiving the differential torque, and an electromagnet arranged outside the rotating case. , In the magnetic path with the electromagnet
The rear wall of the rotating case while sandwiching it inside the rotating case.
The friction clutch is placed by moving with the attraction force of the electromagnet.
An armature to be fastened, the electromagnet is fixed to the casing, supports the rotating case via a bearing , and is formed between the electromagnet and the rear wall of the rotating case.
And an air gap through which the magnetism of the electromagnet passes is formed . According to a second aspect of the present invention, there is provided a differential mechanism arranged in the casing for distributing the driving force from the engine to the wheels, a friction clutch for connecting and disconnecting the rotating case and the hub receiving the differential torque, and a rotating case. Outside
The electromagnet to be arranged and the above-mentioned circuit in the magnetic path path of the electromagnet.
It is placed inside the rotating case while sandwiching the rear wall of the rotating case.
It moves by the attractive force of the electromagnet to engage the friction clutch.
And a armature, the electromagnet is fixed to the casing, with one side of the rotating case is supported through a bearing on the electromagnet and the other side is supported via bearings to a drive force transmitting shaft, the electromagnet and the Rotating case
An air gap formed between the rear wall and the magnets of the electromagnets
It is characterized in that it is formed . The invention according to claim 3 is the differential apparatus according to claim 2, wherein the electromagnet is fixed to the casing with a bolt. The invention according to claim 4 is the differential device according to claim 3, wherein cam means arranged between the electromagnet and the friction clutch for converting the attraction force of the electromagnet into a thrust force is interposed between the cam and the rotating case. , And a bearing for receiving a cam reaction force. The invention according to claim 5 is the differential device according to any one of claims 1 to 4, wherein the hub and the rotating case are arranged in a casing, and the driving force of the engine is provided in the casing on the wheel side. The differential mechanism and the friction clutch are arranged in series in the axial direction of the rotating case.

[0006]

In the invention of claim 1, since the rotating case is directly supported by the electromagnet through the bearing and the electromagnet is fixed to the casing, for example, the rotating case is supported by the casing through the bearing, and the electromagnet is casing. Unlike the configuration supported by, the assembly error (play) between the electromagnet and the rotating case is small. Therefore, when adjusting the air gap formed between the electromagnet and the rotating case and through which the magnetism of the electromagnet passes, for example, by inserting a gap adjusting shim or the like between the casing and the electromagnet, the air gap can be easily adjusted. Adjustments (in the axial direction) can be made. In addition, since the error (play) between the electromagnet and the rotating case is small in the assembled state, the variation in the air gap after adjustment and assembly is small. In the invention of claim 2, one side of the rotating case is directly supported by the electromagnet through the bearing, and the other side is supported by the drive transmission shaft through the bearing and is fixed to the casing. As described above, the assembly error (play) between the electromagnet and the rotating case is small, and the air gap can be easily adjusted by inserting a shim or the like for adjusting the gap, and the fluctuation of the air gap after the adjustment is small. . According to the invention of claim 3, since the electromagnet is fixed to the casing with the bolt, the electromagnetic
The stone is stopped. According to the invention of claim 4, since the bearing is provided between the cam means and the rotating case, the rotating case can receive the cam reaction force without resistance even if the rotating case is rotating, and a reliable cam action is obtained. Is obtained. In the invention of claim 5, since the differential mechanism and the friction clutch are arranged in series in the axial direction of the rotating case, the radial dimension of the differential device is not increased.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIGS. FIG. 1 shows a transfer using the differential device of this embodiment for a center differential, and FIG. 2 shows a power system of a 4WD vehicle using this transfer. The left side of FIG. 1 is the front of this vehicle. In addition, members and the like without reference numerals are not shown.

As shown in FIG. 2, this power system includes an engine 1,
Transmission 3, transfer 5 of FIG. 1, propeller shaft 7, front differential 9 (front wheel side differential device), left and right front wheels 11, 13, propeller shaft 15, rear differential 17 (rear wheel side differential device), left and right rear wheels It is composed of 19, 21 and the like.

The driving force of the engine 1 is distributed from the transmission 3 to a front differential 9 and a rear differential 17 through a center differential 23 (a differential device of the embodiment arranged between the front and rear wheels) in the transfer 5, and each differential 9 , 17 from left and right front wheels 11, 13 and rear wheel 1 respectively
9 and 21.

As shown in FIG. 1, the transfer case 25
Rotating case 2 whose front and rear ends are open in the (casing)
7 is arranged, the output shaft 2 of the transmission 3
9 penetrates the rotating case 27. Rotating case 2
A differential mechanism 31 is arranged inside the device 7. The differential mechanism 31 includes a pinion gear 35 rotatably supported on a pinion shaft 33, and front and rear side gears 37 and 39 meshing with the pinion gear 35. The boss portion 41 of the pinion shaft 33 is spline-connected to the output shaft 29. The front side gear 37 is formed on the rotating case 27, and the rear side gear 39 is formed on the hub 43.

The sprocket 4 is attached to the outer periphery of the rotating case 27.
5 is formed and is connected to the sprocket on the propeller shaft 7 side via a chain 47. The hub 43 is spline-connected to the output shaft 49, and the output shaft 49 is connected to the transfer case 25 via a bearing 51.
And is connected to the propeller shaft 15 side via a flange 53. A seal 55 is arranged between the flange 53 and the transfer case 25. The output shaft 29 of the transfer 3 is supported by the transfer case 25 via a bearing 57, supports the rotary case 27 and the hub 43 via bearings 59 and 61, respectively, and also via the bearings 63 and 65, It is supported on the output shaft 49.

The driving force of the engine 1 input from the output shaft 29 of the transmission 3 to the differential mechanism 31 via the pinion shaft 33 is distributed to the front wheel side and the rear wheel side from the side gears 37 and 39 via the pinion gear 35, respectively. In addition, when a driving resistance difference occurs between the front and rear wheels, the pinion gear 35 is differentially distributed to the front and rear sides by the rotation and the revolution of the pinion gear 35.

A multi-plate type main clutch 67 is arranged between the rotating case 27 and the hub 43. On the rear side, the pressing member 69 is spline-connected to the hub 43 so as to be movable in the axial direction. A cam ring 71 is arranged on the outer circumference of the hub 43. A ball cam 73 is formed between the cam ring 71 and the pressing member 69,
A bearing 75 and a washer 77 that receive a cam reaction force are disposed between the cam ring 71 and the rotating case 27.

A multi-plate pilot clutch 79 (friction clutch) is arranged between the rotating case 27 and the cam ring 71, and an armature 81 is arranged in front of it.
It is (freely fitted) and positioned by the retaining ring 83. Further, a ring-shaped electromagnet 87 is arranged behind the rear wall 85 provided at the rear end of the rotating case 27. An air gap 91 is formed between the yoke 89 of the electromagnet 87 and the rear wall 85, and a stainless steel ring 93 for preventing a short circuit of the magnetic force of the electromagnet 87 is arranged on the rear wall 85, as shown by a thick line. A magnetic circuit 95 including the air gap 91 is formed.

The electromagnet 87 is fixed to the transfer case 25 with bolts 97, and directly supports the rear end of the rotary case 27 via a bearing 99. Therefore, for example, the air gap formed when the rear end of the rotating case 27 is bearing-supported by the transfer case 25 and the electromagnet 87 is supported by the transfer case 25 is:
The error of the air gap (play) is large because it is affected by the accumulated error of the assembly of the rotating case 27 to the transfer case 25 and the assembly error of the electromagnet 87 to the transfer case 25. It is not easy to insert shims or adjust dimensions. Further, even if the air gap is adjusted to a predetermined gap, the electromagnet 87
Assembled with the transfer case and the rotating case 27
When the assembly state between the transfer case 25 and the transfer case 25 changes, the gap of the predetermined air gap also changes greatly, and it becomes difficult to maintain that value. However, the rear end of the rotating case 27 is directly supported by the electromagnet 87, the shim 101 is arranged between the electromagnet 87 and the transfer case 25, and the thickness of the shim 101 is adjusted to easily adjust the air gap 91 in the axial direction. Can be held at that value. In this way, the air gap 91 can be easily and accurately adjusted in terms of both spacing and width, and the adjusted values do not fluctuate, so the magnetic resistance between the air gap 91 and the magnetic circuit 95 is stabilized.

In this way, the center differential 23 is constructed.

When the electromagnet 87 attracts the armature 81, the pilot clutch 79 is pressed and engaged. In this state, the differential torque of the differential mechanism 31 is applied to the ball cam 73, and the cam thrust force causes the main clutch 67 to be pressed by the pressing member 69 to be engaged. Each clutch 67, 79
The differential force of the differential mechanism 31 is limited by the coupling force of the. If this differential limiting force is made large enough, the differential between the front and rear wheels will be locked to improve the straight running stability of the vehicle, and if it is loosened appropriately to allow the differential, smooth and stable cornering will be possible and tight corner braking will be possible. The ringing phenomenon is prevented. Further, when the pilot clutch 79 is released, the cam thrust force of the ball cam 73 disappears, the main clutch 67 is also released, and the differential becomes free.

As described above, since the magnetic resistance of the air gap 91 is stable, the differential limiting characteristic controlled by the electromagnet 87 is stable, and the differential limiting force is optimized according to the running condition of the vehicle and the road surface condition. The controllability of the vehicle improves the maneuverability and stability of the vehicle.

The differential device of the present invention may be used as a front differential or a rear differential, and is not a structure provided with a main clutch and a pilot clutch as in the embodiment, but a single friction clutch that is engaged by an electromagnet. May be configured to limit the differential.

[0020]

According to the invention of claim 1, the rotating case is directly supported by the electromagnet through the bearing, and the electromagnet is fixed to the casing .
Is formed between the rear wall, the magnetic electromagnet is easy to adjust the air gap Ru passing, moreover it is possible to prevent variation of the air gap, to accurately control the intermittence of the rotating casing and the hub it can. That is, when the rotating case is fixed to the casing and the electromagnet fixed to the casing is also positioned while ensuring the necessary air gap, there is no error in assembling or dimensional error when fixing the rotating case to the casing. In addition, assembling errors and dimensional errors when fixing the electromagnet to the casing are piled up.Therefore, if such assembling is performed, the positional deviation between the electromagnet and the rotating case becomes large, and the required air gap is increased. However, by mounting the rotating case directly on the electromagnet fixed to the casing via the bearing, the assembly error that occurs when fixing the rotating case to the casing is
Since it does not add to the assembling error when assembling the electromagnet to the casing, the assembling error (play) of the rotating case to the electromagnet can be reduced. Further, the fact that the assembly error (play) of the rotating case with respect to the electromagnet is reduced means that the air gap between the electromagnet and the rotating case is adjusted, that is, the shim or the like for adjusting the gap between the casing and the electromagnet. By inserting, the air gap can be easily adjusted. Also, assembly error (backlash)
Is small, the assembly of the rotating case with respect to the electromagnet changes only by a small amount of play, so that the variation after adjustment of the air gap is small and the differential limiting characteristic can be stabilized. According to the invention of claim 2, one side of the rotating case is directly supported by the electromagnet via the bearing, and the other side is supported by the drive transmission shaft via the bearing and is fixed to the casing. Therefore, between the electromagnet and the rotating case. The backlash is small and, therefore, is formed between the electromagnet and the rear wall of the rotating case.
Therefore, it is easy to adjust the air gap through which the magnetism of the electromagnet passes, and the fluctuation of the air gap after the adjustment is small. According to the invention of claim 3, by the electromagnet is secured by bolts to the casing, the electromagnet around the casing stop
To be According to the invention of claim 4, since the bearing is provided between the cam means and the rotating case, the rotating case can receive the cam reaction force without resistance even when the rotating case is rotating, and the rotating case can be securely operated. A cam action can be obtained. According to the invention of claim 5, since the differential mechanism and the friction clutch are arranged in series in the axial direction of the rotating case, the radial dimension of the differential device is not increased.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment.

FIG. 2 is a skeleton mechanism diagram showing a power system of a vehicle using this embodiment.

FIG. 3 is a sectional view of a conventional example.

[Explanation of symbols]

23 Center differential (differential device) 25 Transfer case (casing) 27 rotating cases 31 Differential mechanism 79 Pilot clutch (friction clutch) 87 Electromagnet 99 bearing

Continuation of front page (56) Reference JP-A-4-185917 (JP, A) JP-A-5-87210 (JP, A) Actually open 3-127838 (JP, U) Actually open 4-17523 (JP , U) Actual flat 4-122829 (JP, U) Actual flat 4-122830 (JP, U) Actual flat 5-27403 (JP, U) Actual flat 5-36158 (JP, U) Actual flat 5-38438 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16H 48/04 F16H 48/22

Claims (5)

(57) [Claims] 1. A differential mechanism arranged in a casing for distributing a driving force from an engine to a wheel side, a friction clutch for connecting and disconnecting a rotating case and a hub for receiving the differential torque, and a friction clutch outside the rotating case. Electromagnet to be arranged and the electromagnet
While sandwiching the rear wall of the rotating case in the magnetic path of
It is placed in the rolling case and moves by the attractive force of the electromagnet.
And a armature for fastening the friction clutch, the electromagnet bearing a rotating case via a bearing with being fixed to the casing, the electromagnet and the rotating Ke
Is formed between the rear wall of the base and the magnetic field of the electromagnet.
A differential device in which an gap is formed . 2. A differential mechanism arranged in the casing for distributing the driving force from the engine to the wheel side, a friction clutch for connecting and disconnecting the rotating case and the hub receiving the differential torque, and a friction clutch arranged outside the rotating case. Electromagnet and the electromagnet
While sandwiching the rear wall of the rotating case in the magnetic path of
It is placed in the rolling case and moves by the attractive force of the electromagnet.
An armature for fastening a friction clutch, the electromagnet is fixed to the casing, one side of the rotating case is supported by the electromagnet via a bearing, and the other side is supported by a driving force transmission shaft via a bearing. Formed between the electromagnet and the rear wall of the rotating case
The differential device is characterized in that an air gap through which the magnetism of the electromagnet passes is formed . 3. The differential device according to claim 2, wherein the electromagnet is fixed to the casing with a bolt. 4. The differential device according to claim 3, wherein a cam is arranged between the electromagnet and the friction clutch to convert a suction force of the electromagnet into a thrust force and a rotating case. A differential device having a bearing for receiving a reaction force. 5. The differential device according to claim 1, wherein the hub and the rotating case are arranged in a casing, and the driving force of the engine is distributed to the wheel side in the casing. A differential device comprising a differential mechanism, wherein the differential mechanism and the friction clutch are linearly arranged in an axial direction of the rotating case.