JP2007205560A - Differential device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a differential device capable of reducing the dimension and the weight of a differential device and reducing its cost though a pair of clutch mechanisms are disposed. <P>SOLUTION: This differential device comprises a driving shaft 3 rotated by a driving force of a motor, an intermediate transmitting member 5, a gear transmitting mechanism 11 in which a driving gear 7 is connected with the driving shaft 3, and a driven gear 9 is connected with the intermediate transmitting member 5 for transmitting the rotation of the driving shaft 3 to the intermediate transmitting member 5, and a pair of clutch mechanisms 13, 13 for distributing the rotation of the intermediate transmitting member 5 to the side of a pair of wheels, and the clutch mechanisms 13, 13 are disposed at the radially inner side of the driven gear 9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a differential apparatus configured to distribute a driving force of a prime mover to a pair of wheels via a pair of clutch mechanisms.

The differential device described in Patent Document 1 includes a pair of left and right clutch devices, and drives the prime mover via a left clutch device on the left wheel and a right clutch device on the right wheel. It is configured to transmit force.
Japanese Patent Laid-Open No. 10-311404

  The differential device configured as described above has an advantage that an extremely large driving force distribution ratio adjustment function can be obtained by providing a pair of clutch devices, but it has a large size due to the use of two sets of clutch devices. (Especially in the axial direction), there is a tendency to increase the weight, and there is a demand for size reduction and weight reduction.

  Further, in general, a differential device is required to improve driving force transmission efficiency as a power transmission device. For this reason, for example, it is necessary to reduce drag torque due to oil viscosity. Therefore, cost reduction is required by reducing the number of parts and the number of assembly steps.

  Accordingly, an object of the present invention is to provide a differential device that can be reduced in size, weight, and cost while including a pair of clutch mechanisms.

  The differential apparatus according to claim 1 is configured such that a drive shaft that is rotated by a driving force of a prime mover, an intermediate transmission member, a drive gear is coupled to the drive shaft, a driven gear is coupled to the intermediate transmission member, A gear transmission mechanism that transmits the rotation to the intermediate transmission member and a pair of clutch mechanisms that distribute the rotation of the intermediate transmission member to the pair of wheels are provided.

  A differential apparatus according to a second aspect is the invention according to the first aspect, wherein a clutch mechanism is arranged radially inside the driven gear.

  A differential apparatus according to a third aspect is the invention according to the first aspect, wherein the differential transmission device includes a pair of bearings that support the intermediate transmission member on a stationary-side accommodation member, and the clutch mechanism has a diameter of both the bearings. It is arranged inside at least one of the direction and the axial direction.

  A differential apparatus according to a fourth aspect is the invention according to the first aspect, wherein the differential apparatus includes a pair of bearings that support the intermediate transmission member on a stationary housing member, and the rotation of the intermediate transmission member is controlled by the clutch mechanism. The connecting portion is arranged inside at least one of the radial direction of the driven gear, the radial direction of the both bearings, and the axial direction.

  A differential apparatus according to a fifth aspect is the invention according to any one of the first to fourth aspects, wherein the differential assembly is housed in a stationary-side housing member and includes the intermediate transmission member and a clutch mechanism. Thus, a seal is arranged between the members to form a sealing structure, and at least a space formed between the sealing structure portion and the stationary side accommodation member and not including the gear transmission mechanism is made oil-free. It is characterized by that.

  A differential device according to a sixth aspect is the invention according to the fifth aspect, wherein a portion corresponding to the range of the oil-less region is used for oil at a joint portion between the member constituting the stationary side accommodation member. It is characterized by not using a seal.

  The differential device according to claim 1 can obtain a very large driving force distribution ratio adjustment function by using a pair of clutch mechanisms, and can greatly improve the performance of the vehicle. , Weight reduction, and cost reduction are possible.

  In the differential device according to the second aspect, in this configuration in which the clutch mechanism is arranged on the radially inner side of the driven gear, the axial direction is significantly reduced, and the in-vehicle performance is improved accordingly.

  In the differential device according to claim 3, in this configuration in which the clutch mechanism is disposed on at least one of the radial direction and the axial direction with respect to the pair of bearings that support the intermediate transmission member, in one of the radial direction and the axial direction, Alternatively, both are significantly downsized, and the in-vehicle performance is greatly improved.

  In the differential device according to a fourth aspect, in this configuration, the connecting portion that transmits the rotation of the intermediate transmission member to the clutch mechanism is disposed inside at least one of the radial direction of the driven gear, the radial direction of both bearings, and the axial direction. Therefore, it is miniaturized in the axial direction and the radial direction, and the in-vehicle performance is improved accordingly.

  In the differential device according to claim 5, a subassembly range including the intermediate transmission member and the clutch mechanism is provided with a seal between the members to form a sealing structure, and at least a space between the sealing structure portion and the stationary side accommodation member is provided. With this configuration in an oil-less state, the amount of enclosed oil and cost can be reduced.

  Further, in the oilless range, as described below, sealing means (for example, an O-ring) for preventing oil leakage is not required, and a drain hole, drain plug, seal washer, etc. for discharging oil are not required. At the same time, in the case of axial fueling, the components necessary for that are not necessary, and the cost and weight are reduced accordingly.

  In addition, an oil-less space can be provided inside the sealing structure portion, and the amount of oil and cost can be further reduced.

  Moreover, if low-viscosity oil is enclosed in the above-described subassembly range having a sealed structure, drag torque due to oil in the clutch mechanism is reduced, and performance is improved.

  Moreover, in this oil-less space, it is released from the rotational resistance due to oil, and the performance is improved.

  The differential device according to claim 6 is oil-free, so that a seal for oil is unnecessary at the joint between the members constituting the stationary housing member, the cost is reduced, and the reliability against oil leakage is improved. To do.

  Embodiments of the present invention will be described below.

<First Embodiment>
The rear differential 1 (differential device) of the first embodiment will be described with reference to FIGS. 1 and 4. FIG. 1 shows a rear differential 1 and FIG. 4 shows a power system of a four-wheel drive vehicle using the rear differential 1 and the like. The left and right directions are the left and right directions in FIGS. 1 and 4, and the upper side in FIG. 1 is the front of the four-wheel drive vehicle.

[Features of rear differential 1]
The rear differential 1 includes a drive pinion shaft 3 (drive shaft) that is rotated by a drive force of an engine (prime mover), a rotation case 5 (intermediate transmission member), and a drive pinion gear 7 (drive gear) that is integrated with the drive pinion shaft 3. A gear transmission mechanism 11 that is formed and a ring gear 9 (driven gear) is connected to the rotating case 5 and transmits the rotation of the drive pinion shaft 3 to the rotating case 5; A pair of multi-plate main clutches 13 and 13 (clutch mechanisms) are provided respectively to be distributed to the 427 (wheel) side.

  In the rear differential 1, the main clutches 13 and 13 are disposed on the radially inner side of the ring gear 9, and a pair of bearings 17 and 17 (bearings) for supporting the rotating case 5 on the differential carrier 15 (stationary accommodation member). And the main clutches 13 and 13 are disposed inside the bearings 17 and 17 in the radial and axial directions.

[Description of Power System of Four Wheel Drive Vehicle]
This power system includes a horizontal engine 401 (prime mover), a transmission 403, a transfer 407 having a 2-4 switching mechanism 405, a front differential 409 (a differential device that distributes the driving force of the engine to the left and right front wheels), The front axles 411 and 413, the left and right front wheels 415 and 417, the rear wheel propeller shaft 419, the rear differential 1 (a differential device that distributes the driving force of the engine to the left and right rear wheels), and the rear axles 421 and 423 And left and right rear wheels 425, 427 and the like.

  The driving force of the engine 401 is transmitted from the transmission 403 to the differential case 429 of the front differential 409, and is distributed from the front differential 409 to the left and right front wheels 415, 417 via the front axles 411, 413. When the 2-4 switching mechanism 405 is connected, the rotation of the differential case 429 is transmitted from the transfer 407 to the rear differential 1 via the propeller shaft 419 and the like, and the main clutches 13 and 13 of the rear differential 1 are connected. Then, the driving force of the engine 401 is distributed to the left and right rear wheels 425 and 427 via the rear axles 421 and 423, and the vehicle enters a four-wheel drive state.

  When the connection between the 2-4 switching mechanism 405 and each of the main clutches 13 and 13 is released, the vehicle enters the two-wheel drive state of the front wheel drive, and each power from the 2-4 switching mechanism 405 to the rotating case 5 is obtained. The rotation of the transmission member is stopped, the vibration is reduced, and the fuel consumption of the engine 401 is improved.

[Configuration of rear differential 1]
The rear differential 1 is accommodated in a differential carrier 15 (stationary side accommodating member). The differential carrier 15 includes a carrier main body 25 (a member constituting a stationary side accommodating member), a front cover 27 (a member constituting a stationary side accommodating member), and left and right covers 29 and 31 (members constituting a stationary side accommodating member). ) And left and right support walls 33 and 35 (members constituting the stationary housing member) and the like, as shown in FIG. 4, the cover 27 is a bolt 431 (FIG. 4), and the covers 29 and 31 are bolts. At 433, the support walls 33 and 35 are fixed to the carrier body 25 by bolts 435, respectively.

  The front end of the drive pinion shaft 3 is splined to the intermediate shaft 37, and the intermediate shaft 37 is supported by the cover 27 and the carrier body 25 by ball bearings 39 and 41 at the front and rear ends, and is a flange that is splined to the front end of the intermediate shaft 37. 43 is connected to the propeller shaft 419 side. The drive pinion shaft 3 is supported on the carrier body 25 by bearings 45 and 47 that receive thrust force, the drive pinion gear 7 is formed at the rear end of the drive pinion shaft 3, and the ring gear 9 is attached to the rotating case 5 by bolts 49. It is fixed.

  Each main clutch 13 is a component of left and right clutch devices 19, 21. Each clutch device 19, 21 is composed of main clutch 13, multi-plate pilot clutch 51, ball cam 53, cam ring 55, and pressure ring 57. And an armature 59, a rotor 61, an electromagnetic coil 63, a return spring 65, a controller, and the like.

  Each main clutch 13 is disposed between a pair of hollow members 67 splined to the inner periphery of the rotating case 5 and the transmission shaft 69, respectively, radially inward of the rotating case 5, It is arranged on the inner side in the axial direction. The axially inner end of each transmission shaft 69 is supported on the inner periphery of the hollow member 67 by a bearing 71. In addition, left and right drive shafts 73, 73 are spline-connected to the axially outer end portions of the transmission shafts 69, and each drive shaft 73 is connected to the rear axle 421, 423 side by a respective flange 75 portion. The bearings 77 support the covers 29 and 31.

  The ball cam 53 is provided between the cam ring 55 and the pressure ring 57, and both the cam ring 55 and the pressure ring 57 are supported on the outer peripheral side of the transmission shaft 69 so as to be movable in the axial direction. Are splined to be axially movable. The rotor 61 is splined to the outer periphery of the transmission shaft 69, and the electromagnetic coil 63 is supported by the rotor 61 by a ball bearing 79 via an appropriate air gap. A needle bearing 80 that absorbs relative rotation is disposed between the pressure ring 57 and the return spring 65.

  A seal 81 is disposed between each drive shaft 73 and the left and right covers 29, 31, and a seal 83 is disposed between the left and right support walls 33, 35 and the rotary case 5, and the carrier body 25 and the cover 29 are disposed. , 31, an O-ring 85 is disposed between the carrier body 25 and the support walls 33, 35, and a seal 89 is disposed between the intermediate shaft 37 and the cover 27. The seal 91 is disposed between the intermediate shaft 37 and the carrier body 25. Each of the covers 29 and 31 is provided with a drain hole 93, and each drain hole 93 is sealed by a seal washer 95 and a drain plug 97.

  Low-viscosity oil is forcibly supplied from an oil passage 99 provided in the differential carrier 15 and an oil passage 101 provided through the drive shaft 73 and the transmission shaft 69 and communicating with the oil passage 99. The bearings 77, 79, The main clutch 13, the pilot clutch 51, the ball cam 53, and the like are lubricated and cooled. This low viscosity oil effectively lubricates and cools the sliding portions of the clutch plates in the main clutch 13 and the pilot clutch 51 in particular.

  Also, differential oil is sealed in the space 103 defined by the seal 91, the seal 83, and the O-rings 85, 87 inside the carrier body 25, and the meshing portion and the bearing of the gear transmission mechanism 11 (gears 7, 9). 17 and 17 are lubricated and cooled, and the seals 83 and 91 and the O-rings 85 and 87 prevent mixing of the differential oil and the low-viscosity oil on the clutch devices 19 and 21 side.

  The controller connects and disconnects the clutch devices 19 and 21 by exciting the electromagnetic coil 63, controlling the exciting current, stopping excitation, and the like, and intermittently operates the clutch devices 19 and 21 simultaneously with the 2-4 switching mechanism 405. When the electromagnetic coil 63 is excited, the armature 59 is attracted, the pilot clutch 51 is pressed and engaged, and the main clutch 13 is pressed and engaged via the pressure ring 57 by the cam thrust force of the activated ball cam 53, as described above. In addition, the driving force is transmitted to the left and right rear wheels 425, 427, and the vehicle enters a four-wheel drive state.

  At this time, by controlling the excitation current of the left and right electromagnetic coils 63 and adjusting the driving force (differential limiting force) transmitted to the rear wheels 425 and 427 between the clutch devices 19 and 21, the turning ability of the vehicle is achieved. And rough road running ability can be greatly improved.

  Further, when the excitation of the electromagnetic coil 63 is stopped, the connection of the main clutch 13 is released by the return spring 65, and the vehicle enters the two-wheel drive state of the front wheel drive as described above.

[Effect of rear differential 1]
Since the rear differential 1 uses the pair of main clutches 13 (clutch devices 19 and 21), an extremely large driving force distribution ratio adjustment function can be obtained as described above, and the performance of the vehicle can be greatly improved. .

  Further, the main clutch 13 is arranged on the inner side in the radial direction of the ring gear 9, so that the size is significantly reduced in the axial direction, and the onboard performance is improved.

  Further, by disposing the main clutch 13 on the inner side in the radial direction and the axial direction with respect to the bearings 17 and 17 of the rotating case 5, the size can be further reduced in both the radial direction and the axial direction, and the onboard performance is further improved. Yes.

Second Embodiment
The rear differential 201 (differential device) of the second embodiment will be described with reference to FIGS. The left and right directions are the left and right directions in FIGS. 2 and 4.

[Features of rear differential 201]
The rear differential 201 has a drive pinion shaft 3 (drive shaft) that is rotated by the drive force of the engine (prime mover), a rotation case 5 (intermediate transmission member), and a drive pinion gear 7 (drive gear) integrated with the drive pinion shaft 3. A gear transmission mechanism 11 that is formed and a ring gear 9 (driven gear) is connected to the rotating case 5 and transmits the rotation of the drive pinion shaft 3 to the rotating case 5; A pair of multi-plate main clutches 13 and 13 (clutch mechanisms) are provided respectively to be distributed to the 427 (wheel) side.

  In the rear differential 201, the main clutches 13 and 13 are disposed radially inward of the ring gear 9, and a pair of bearings 17 and 17 (bearings) for supporting the rotating case 5 on the differential carrier 15 (stationary housing member). The main clutches 13 and 13 are disposed inside the bearings 17 and 17 in the radial direction and the axial direction.

  Further, the rear differential 201 is accommodated in the differential carrier 15 (stationary accommodation member), and the subassembly range including the rotating case 5 and the main clutch 13 is divided into O-rings 203 and 203 (seal), X-ring 205, 205 (seal) and X-rings 207 and 207 (seal) form a sealing structure, and a space 209 between the X-ring 207 and the X-ring 207 and between the sealing structure and the differential carrier 15 are formed. The spaces 211 not including the transmission mechanism 11 are in an oilless state.

  Oil seals (O-rings 85 at the rear differential 1) are removed from the joints between the carrier body 25 and the left and right covers 29, 31 at portions corresponding to this oil-less range.

[Configuration of rear differential 201]
Hereinafter, differences from the rear differential 1 of the first embodiment will be described.

  Since the rear differential 201 has a sealed structure as described above, an oilless space 209 can be provided inside, and the O-ring 85 that is no longer necessary is omitted.

  In addition, forced oiling is abolished along with the sealing structure. As a result, the oil flow path 99 of the differential carrier 15, the drive shaft 73 and the oil flow path 101 of the transmission shaft 69 are abolished, and the drain holes of the covers 29 and 31 are also removed. 93, seal washer 95, and drain plug 97 are also abolished.

  The rotor 61 is splined to the hollow member 67 and positioned by the double nut function of the nut 213, and the O-ring 203 prevents oil leakage between the rotor 61 and the hollow member 67.

  Further, the pressure ring 57 is splined to the transmission shaft 69 so as to be axially movable. As a result, the needle bearing 80 used in the rear differential 1 becomes unnecessary and is omitted.

  The hollow member 67 is positioned on the inner side in the axial direction with respect to the transmission shaft 69 by the snap ring 215, and the cam ring 55 is positioned on the outer side in the axial direction by a step portion 217 provided on the transmission shaft 69. The cam reaction force is canceled between the snap ring 215 and the step 217.

  With the configuration described above, the rear differential 201 is sub-assembled in a range excluding the drive pinion shaft 3, the drive pinion gear 7, and the ring gear 9.

[Effect of rear differential 201]
The rear differential 201 can obtain the same effect as the rear differential 1.

  Further, the subassembly range including the rotating case 5 and the main clutch 13 (clutch devices 19 and 21) is arranged in a sealed structure by arranging the seals 203, 205, and 207, and the internal space 209 is in an oilless state. In addition, since the external space 211 is in an oil-less state, the amount of enclosed oil and the cost are reduced accordingly.

  Further, along with the sealing structure, the O-ring 85, the oil flow paths 99 and 101, the drain hole 93, the seal washer 95, and the drain plug 97 can be omitted, and the components necessary for the axial center lubrication are also provided. It is no longer needed and costs and weight are greatly reduced.

  Further, the cover 29, 31 is shortened in the axial direction as the oil flow path 101 of the differential carrier 15 (covers 29, 31) necessary for the axial center lubrication is abolished. A flange portion 75 indicated by a two-point difference line indicates a position of the flange portion 75 that is not shortened, and the in-vehicle performance is improved by this shortening.

  In addition, since low-viscosity oil is enclosed in the subassembly range having a sealed structure, drag torque due to oil in the main clutch 13 and the pilot clutch 51 is reduced, and performance is improved.

  Further, in the oilless space 211, the rear differential 201 is released from the rotational resistance due to the differential oil, and the performance is improved.

  Further, since the oilless operation is used, the O-ring 85 can be eliminated at each joint portion between the carrier main body 25 and the left and right covers 29 and 31 constituting the differential carrier 15, and the cost is reduced accordingly. In the range, it is freed from oil leakage and reliability is improved.

  In addition to these effects, the pressure ring 57 is splined to the transmission shaft 69, so that the needle bearing 80 becomes unnecessary and the cost is reduced accordingly.

  Further, since the cam thrust force and the cam reaction force of the ball cam 53 are canceled by the snap ring 215 and the step portion 217, the balance of strength is improved accordingly.

  Further, the rear differential 201 is easily assembled within the sub-assembled range, and the assembly cost is reduced.

<Third Embodiment>
The rear differential 301 (differential device) of the third embodiment will be described with reference to FIGS. 3 and 4. The left and right directions are the left and right directions in FIGS. 3 and 4.

  Differences between the rear differential 1 of the first embodiment and the rear differential 201 of the second embodiment will be described below.

[Features and configuration of rear differential 301]
The rear differential 301 is obtained by eliminating the seal 83 between the left and right support walls 33 and 35 of the differential carrier 15 and the rotating case 5 in the rear differential 201. Therefore, the space 211 is not oilless.

  Similarly to the rear differential 1, an O-ring 85 is used between the carrier body 25 and the covers 29, 31. The covers 29, 31 are provided with a drain hole 93, and a seal washer 95 and a drain plug 97 are provided. It is installed.

[Effect of rear differential 301]
The rear differential 301 can obtain the same effects as the rear differential 201 except for the effect that the space 211 is oilless and the effect that the O-ring 85, the drain hole 93, the seal washer 95, and the drain plug 97 are eliminated.

  Further, the rear differential 301 is shortened in the axial direction along with the elimination of the seal 83. The flange portion 75 indicated by a two-point difference line is the position of the solid-line flange portion 75 at the rear differential 201, and is thus further shortened in the axial direction than the rear differential 201, and the in-vehicle performance is further improved by this shortening. .

<Fourth embodiment>
The rear differential 501 (differential device) of the fourth embodiment will be described with reference to FIG. The left and right directions are the left and right directions in FIG.

[Features of rear differential 501]
The rear differential 501 includes a drive pinion shaft 3 (drive shaft) that is rotated by a driving force of an engine (prime mover), a rotation case 5 (intermediate transmission member), and a drive pinion gear 7 (drive gear) that is integrated with the drive pinion shaft 3. A gear transmission mechanism 11 that is formed and a ring gear 9 (driven gear) is connected to the rotating case 5 and transmits the rotation of the drive pinion shaft 3 to the rotating case 5; A pair of multi-plate main clutches 13 and 13 (clutch mechanisms) are provided respectively to be distributed to the 427 (wheel) side.

The main clutches 13 and 13 are arranged on the inner side in the radial direction of the ring gear 9,
It has a pair of bearings 17 and 17 (bearings) for supporting the rotating case 5 on the differential carrier 15 (stationary housing member), and the main clutches 13 and 13 are arranged inside the bearings 17 and 17 in the radial direction and the axial direction. Has been.

  The rear differential 501 is used in place of the rear differential 1, 201, 301 in the four-wheel drive vehicle of FIG.

[Configuration of rear differential 501]
Hereinafter, differences from the rear differential 1 of the first embodiment will be described.

  Each main clutch 13 is a component of left and right clutch devices 503 and 505. Each clutch device 503 and 505 includes a main clutch 13, a ball cam 507, cam rings 509 and 511, a pressure ring 513, and a two-stage clutch. The reduction gear sets 515 and 517, the electric motor 519, the return spring 521, and a controller are included.

  The inner end of the transmission shaft 69 in the axial direction is supported by the bearing 71 on the inner periphery of the hollow member 67, and the outer end in the axial direction is supported by the left and right covers 29, 31 by the ball bearing 523. A bearing 525 that receives the cam thrust force of the ball cam 507 is disposed at the end.

  The ball cam 507 is provided between the cam rings 509 and 511, the cam ring 509 on the outer side in the axial direction is positioned on the bearing 523 side via a bearing 527 receiving thrust force, and the cam ring 511 on the outer side in the axial direction is thrust force The main clutch 13 can be pressed via a bearing 529 for receiving the pressure and a pressure ring 513.

  The reduction gear set 515 includes a small diameter gear 533 formed on the output shaft 531 of the electric motor 517 and a large diameter gear 537 rotatably supported on the support shaft 535. The reduction gear set 517 includes the large diameter gear 537. And a large-diameter gear 541 formed integrally with the cam ring 509. Each reduction gear set 515, 517 decelerates the rotation of the electric motor 517, and a ball cam via the cam ring 509. 507.

  The electric motor 517 is attached to the bracket 543, and the bracket 543 is attached to the left and right covers 29 and 31. An O-ring 545 is disposed between the bracket 543 and the covers 29 and 31.

  The controller connects and disconnects the clutch devices 503 and 505 by operating, reversing, and stopping the electric motor 517, and intermittently operates the clutch devices 503 and 505 simultaneously with the 2-4 switching mechanism 405. When the electric motor 517 is actuated, the ball cam 507 is actuated by receiving the torque, and the main clutch 13 is pressed and fastened by the cam thrust force via the cam ring 511, the bearing 529, and the pressure ring 513, and the vehicle is driven by four wheels. It becomes a state. When the electric motor 517 is reversed, the connection of the main clutch 13 is released by the return spring 521, and the vehicle enters a two-wheel drive state of front wheel drive.

[Effect of rear differential 501]
Since the rear differential 501 uses the pair of main clutches 13 (clutch devices 503 and 505), an extremely large driving force distribution ratio adjustment function can be obtained, and the performance of the vehicle can be greatly improved.

  Further, the main clutch 13 is arranged on the inner side in the radial direction of the ring gear 9, so that the size is significantly reduced in the axial direction, and the onboard performance is improved.

  Further, by disposing the main clutch 13 on the radially inner side and the axially inner side with respect to the bearings 17, 17 of the rotating case 5, the size of the main clutch 13 is further reduced in both the radial direction and the axial direction, thereby further improving the onboard performance. .

<Fifth Embodiment>
The rear differential 601 (differential device) of the fifth embodiment will be described with reference to FIGS. 6 and 7. FIG. 6 shows a rear differential 601, and FIG. 7 shows a power system of a four-wheel drive vehicle using the rear differential 601. The left and right directions are the left and right directions in FIGS. 6 and 7, and the upper side in FIG. 6 is the front of the four-wheel drive vehicle.

[Features of rear differential 601]
The rear differential 601 includes a drive pinion shaft 3 (drive shaft) that is rotated by a driving force of an engine (prime mover), a rotation case 5 (intermediate transmission member), and a drive pinion gear 7 (drive gear) that is integrated with the drive pinion shaft 3. A gear transmission mechanism 11 that is formed and a ring gear 9 (driven gear) is connected to the rotating case 5 and transmits the rotation of the drive pinion shaft 3 to the rotating case 5; A pair of multi-plate main clutches 13 and 13 (clutch mechanisms) are provided respectively to be distributed to the 427 (wheel) side.

  The rear differential 601 also has a pair of bearings 17 and 17 (bearings) that support the rotating case 5 on the differential carrier 15 (stationary housing member), and a ball spline 603 that transmits the rotation of the rotating case 5 to the main clutch 13 ( The ball spline 603 is disposed on the radially inner side of the ring gear 9, on the radially inner side and on the axially inner side of the bearings 17, 17.

[Description of Power System of Four Wheel Drive Vehicle]
This power system includes a horizontal engine 401 (prime mover), a transmission 403, a transfer 407, a front differential 409 (a differential device that distributes the driving force of the engine to the left and right front wheels), front axles 411, 413, Left and right front wheels 415, 417, a rear wheel side propeller shaft 419, a rear differential 601 (a differential device that distributes the driving force of the engine to the left and right rear wheels), rear axles 421, 423, left and right rear wheels 425, 427 and the like.

  The driving force of the engine 401 is transmitted from the transmission 403 to the differential case 429 of the front differential 409 and distributed from the front differential 409 to the left and right front wheels 415 and 417 via the front axles 411 and 413, and the rotation of the differential case 429 is transmitted from the transfer 407 It is transmitted to the rear differential 601 side through the propeller shaft 419 and the like. Further, when the coupling 605 incorporated in the rear differential 601 and the main clutches 13 and 13 of the rear differential 601 are respectively connected, the driving force of the engine 401 is applied to the left and right rear wheels 425 and 427 via the rear axles 421 and 423. The vehicle is in a four-wheel drive state.

  When the coupling 605 and the main clutches 13 and 13 are disconnected, the vehicle enters a two-wheel drive state of front wheel drive.

[Configuration of rear differential 601]
Hereinafter, differences from the rear differential 1 of the first embodiment will be described.

  Each main clutch 13 is a component of left and right clutch devices 607 and 609. Each clutch device 607 and 609 includes a rear differential 601 having the ball spline 603 and the coupling 605, the main clutch 13, and a pilot clutch. 51, a ball cam 53, a cam ring 55, a pressure ring 57, an armature 59, a rotor 61, an electromagnetic coil 63, a return spring 65, a controller, and the like.

  The coupling 605 includes a multi-plate clutch 611 disposed between the intermediate shaft 37 and the drive pinion shaft 3, an electromagnetic coil 613, and the like. Functions as a 2-4 switching mechanism.

  The ball spline 603 connects the hollow member 67 and the transmission shaft 69 in the rotational direction, and allows the transmission shaft 69 to move left and right. The pressure ring 57 is fixed to the transmission shaft 69. The return spring 65 is disposed between the hollow member 67 and the transmission shaft 69 and urges the transmission shaft 69 and the pressure ring 57 in the direction of releasing the connection of the main clutch 13 (axially outward). The main clutch 13 is disposed between the clutch housing 615 and the pressure ring 57, and the rotor 61 is spline-connected to the clutch housing 615 and the drive shaft 73 to connect them in the rotational direction. The transmission shaft 69 and the drive shaft 73 are centered so as to be relatively rotatable via a bearing 617.

  Further, the electromagnetic coil 63, the pilot clutch 51, and the armature 59 are disposed on the radially inner side of the main clutch 13, and the ball cam 53 is disposed on the radially inner side of the pilot clutch 51 and the armature 59.

  The controller performs coupling and decoupling of the clutch devices 607 and 609 by exciting the electromagnetic coil 63, controlling the exciting current, stopping the excitation, and the like, and intermittently operates the clutch devices 607 and 609 simultaneously with the coupling 605. When the electromagnetic coil 63 is excited, the armature 59 is attracted and the pilot clutch 51 is pressed and engaged, and the main clutch 13 is pressed and engaged via the pressure ring 57 by the cam thrust force of the activated ball cam 53, as described above. The driving force is transmitted to the left and right rear wheels 425 and 427, and the vehicle enters a four-wheel drive state.

  At this time, by controlling the excitation current of the left and right electromagnetic coils 63 and adjusting the driving force (differential limiting force) transmitted to the rear wheels 425 and 427 between the clutch devices 607 and 609, the turning ability of the vehicle is achieved. And rough road running ability can be greatly improved.

  When the excitation of the electromagnetic coil 63 is stopped, the connection of the main clutch 13 is released by the return spring 65, and the vehicle enters a two-wheel drive state of front wheel drive.

  Note that the coupling 605 may be disposed at a position (inside the transfer 407) indicated by a broken arrow 619 in FIG.

[Effect of rear differential 601]
Since the rear differential 601 uses the pair of main clutches 13 (clutch devices 607 and 609), an extremely large driving force distribution ratio adjustment function can be obtained, and the performance of the vehicle can be greatly improved.

  In addition, the ball spline 603 that transmits the rotation of the rotating case 5 to the main clutch 13 is disposed radially inside the ring gear 9 and radially and axially inside the bearings 17 and 17, so The size has been reduced, and the in-vehicle performance has been improved accordingly.

[Other Embodiments Included within the Scope of the Present Invention]
In the differential device of the present invention, the clutch mechanism may be a meshing clutch in addition to a friction clutch such as a main clutch.

  In addition to the electromagnetic coil and the electric motor, the actuator for operating the clutch mechanism may be a fluid actuator such as a pneumatic actuator or a hydraulic actuator.

It is sectional drawing which shows the rear differential 1 of 1st Embodiment. It is sectional drawing which shows the rear differential 201 of 2nd Embodiment. It is sectional drawing which shows the rear differential 301 of 3rd Embodiment. It is a skeleton mechanism diagram showing a power system of a four-wheel drive vehicle using rear differentials 1, 201, 301. It is sectional drawing which shows the rear differential 501 of 4th Embodiment. It is sectional drawing which shows the rear differential 601 of 5th Embodiment. It is a skeleton mechanism diagram showing a power system of a four-wheel drive vehicle using a rear differential 601.

Explanation of symbols

1 Rear differential (differential device)
3 Drive pinion shaft (drive shaft)
5 Rotating case (intermediate transmission member)
7 Drive pinion gear (drive gear)
9 Ring gear (driven gear)
11 Gear transmission mechanism 13 Main clutch (clutch mechanism)
15 Differential carrier (stationary housing member)
17 Bearing (bearing)
25 Carrier body (member constituting stationary housing member)
27 Front cover (member constituting the stationary housing member)
29, 31 Left and right covers (members constituting stationary housing member)
201 Rear differential (differential device)
203 O-ring (seal)
205,207 X-ring (seal)
209, 211 Oil-free space 301 Rear differential (differential device)
501 Rear differential (differential device)
601 Rear differential (differential device)
603 Ball spline (connecting part)

Claims (6)

  A drive shaft that is rotated by the driving force of the prime mover, an intermediate transmission member, a drive gear is connected to the drive shaft, a driven gear is connected to the intermediate transmission member, and rotation of the drive shaft is transmitted to the intermediate transmission member And a pair of clutch mechanisms that distribute the rotation of the intermediate transmission member to the pair of wheels, respectively. A differential device according to claim 1, comprising:
The differential device according to claim 1, wherein the clutch mechanism is disposed radially inward of the driven gear. A differential device according to claim 1, comprising:
A pair of bearings for supporting the intermediate transmission member on a stationary-side accommodation member;
The differential device according to claim 1, wherein the clutch mechanism is disposed inside at least one of a radial direction and an axial direction of the both bearings. A differential device according to claim 1, comprising:
A pair of bearings for supporting the intermediate transmission member on a stationary-side accommodation member;
A connecting portion for transmitting the rotation of the intermediate transmission member to the clutch mechanism;
The differential device according to claim 1, wherein the connecting portion is disposed inside at least one of a radial direction of the driven gear, a radial direction of the both bearings, and an axial direction. A differential device according to any one of claims 1 to 4, wherein
A seal is disposed between the members in a subassembly range that is housed in the stationary housing member and includes the intermediate transmission member and the clutch mechanism, and at least the sealing structure portion and the stationary side housing A differential device characterized in that a space formed between the members and not including the gear transmission mechanism is in an oilless state. A differential device according to claim 5, comprising:
A differential apparatus characterized in that an oil seal is not used at a joint portion between a member constituting the stationary side accommodation member at a portion corresponding to the oilless range.

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