JPH0743524Y2 - Lubricating oil supply device for four-wheel drive vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is provided in a hydraulic multiple disc clutch for differential limitation in a power distribution control device for a four-wheel drive vehicle equipped with a compound planetary gear type center differential device. The present invention relates to a lubricating oil supply device for a release bearing.

[Conventional technology]

As a four-wheel drive vehicle with a center differential,
A hydraulic multi-plate clutch for differential limiting is provided between two output elements of the center differential device, and torque is bypassed during differential limiting to variably control the torque distribution of the front and rear wheels. In this case, the hydraulic chamber and piston of the hydraulic multi-plate clutch are installed on the fixed side of the transfer case, and the fixed side piston is connected to the pressing plate of the clutch plate via the release bearing to absorb the rotational speed difference with the bearing. However, a method of pressing and engaging the clutch plate has already been proposed by the applicant of the present application.

According to the structure of the piston portion of the clutch, when the clutch is operated, a very large rotational speed difference occurs between the fixed side inner race and the rotating side outer race of the release bearing, and a large load is applied. For this reason, it is necessary to constantly and reliably supply lubricating oil to the rolling contact portions of the inner race, the outer race and the balls, and the sliding contact portions of the balls and their cages to ensure good lubrication.

Therefore, conventionally, for the supply of lubricating oil for this type of release bearing, there is a prior art disclosed in, for example, JP-A-59-164229. Here, a release bearing is attached inside the piston via a retainer, and a dog clutch sleeve is provided inside the bearing. The bearing and the sleeve are moved by the operation of the hydraulic piston to synchronously mesh with the spline of the intermediate shaft, and the intermediate shaft and the output shaft are integrally connected. Further, the lubricating oil flows down from the passage of the intermediate shaft and the lubricating port of the output shaft to the inside of the housing, is stored inside the housing by the cover, and is guided to the ball bearing of the output shaft. Then, the oil that has passed through the ball bearing is guided to the release bearing of the sleeve.

[Problems to be solved by the device]

However, in the above-mentioned prior art, the release bearing is installed in the dog clutch part,
Since it is provided between the stationary side piston and the rotating side sleeve, a large rotational speed difference occurs and a large lateral load is applied during synchronization. However, since all the oil in the housing is supplied to the ball bearings and guided to the release bearings after passing through the ball bearings, the release bearings cannot be lubricated positively and sufficiently.

Therefore, if such a lubrication method is applied to the release bearing of the hydraulic multi-plate clutch for differential limitation as in the present invention,
There is a problem that the oil flow rate is insufficient and the bearing is damaged or seized.

The present invention has been made in view of the above point, and an object of the present invention is to roll a release bearing provided on a piston of a hydraulic multi-disc clutch for differential limitation.
It is an object of the present invention to provide a lubricating oil supply device for a four-wheel drive vehicle capable of positively lubricating the sliding contact portion to sufficiently lubricate it and improve durability and reliability.

[Means for Solving the Problems]

As a means for achieving the above object, a lubricating oil supply device for a four-wheel drive vehicle according to the present invention is a four-wheel drive vehicle in which a center differential device and a hydraulic multi-plate clutch for limiting operation are adjacently arranged coaxially. The hydraulic multi-plate clutch is installed on the outer peripheral side of the boss portion of the case, which is a stationary member, and has a piston movable along the axial direction of the boss by control hydraulic pressure and a pressing plate for pressing each clutch plate. A release bearing that is rotatably supported and coupled to the piston, and a retainer that is attached to the tip of the piston in the vicinity of the release bearing and that supports one end of the return spring of the piston. An oil groove, which guides the oil introduced on the inner peripheral side to the outer peripheral side, is formed in the lower portion in the vicinity of the retainer, and The Na, characterized in that the oil flowing down from the oil groove is formed integrally with the oil guide for guiding between the inner race and the outer race of the release bearing.

[Action]

Based on the above configuration, the hydraulic multi-plate clutch absorbs the rotational speed difference with the movement of the piston on the fixed side of the case boss by the release bearing, so that the pressing plate presses while rotating with the clutch plate to limit the differential. Torque is generated. At this time, the oil inside the case is guided from the inside of the boss to the outside by the oil groove, and is positively supplied between the inner race and the outer race of the release bearing by the oil guide of the retainer, so that the rolling contact part and the sliding contact part. Will always be well lubricated with a lot of oil.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, a vertical transaxle type drive system to which the present invention is applied will be described. The transmission case 3 is joined to the rear portion of the torque converter case 1 and the differential case 2, and the transfer case 4 is attached to the rear portion of the transmission case 3. Are joined together, and an oil pan 5 is attached to the lower portion of the transmission case 3. Reference numeral 10 is an engine. A crankshaft 11 of the engine 10 is connected to a torque converter 13 provided with a lockup clutch 12 inside the torque converter case 1, and an input shaft 14 from the torque converter 13 is automatically connected inside the transmission case 3. Input to the transmission 30. Automatic transmission 30
The output shaft 15 outputs the output shaft 15 coaxially with the input shaft 14, and the output shaft 15 is coaxially connected to the center differential device 50 inside the transfer case 4. The front drive shaft 16 is arranged in parallel to the input and output shafts 14 and 15 inside the transmission case 3, and the rear end of the front drive shaft 16 is connected to the center differential device 50 via a pair of reduction gears 17 and 18. The front end of the front drive shaft 16 is configured to be transmitted to the front wheels via a front differential device 19 inside the differential case 2.

On the other hand, the rear drive shaft 20 outputs from the center differential device 50, and the rear drive shaft 20 is configured to be transmitted to the rear wheels via a propeller shaft 21, a rear differential device 22, and the like. The center differential device 50 is provided with a wet multi-plate hydraulic multi-plate clutch 60.

The automatic transmission 30 has a front planetary gear 31 and a rear planetary gear 32.
31, rear planetary gear 32, high clutch 33, reverse clutch 34, brake band 35, forward clutch
36, an overrunning clutch 37, a low-and-reverse clutch 38, and one-way clutches 39 and 40 are provided, and by selectively engaging these, a shift speed of four forward gears and one reverse gear is obtained. Further, in front of the automatic transmission 30, an oil pump 41 is connected to the impeller sleeve 13a of the torque converter and the drive shaft 4.
The control valve body 43 is accommodated in the oil pan 5 so that the oil pan 5 is connected to the drive valve 2 and is always driven. The control valve body 43 supplies and drains oil to each of the above-mentioned friction elements, and selectively engages them.

In FIG. 2, first, the part of the center differential device 50 will be described.

First, with the front end of the rear drive shaft 20 inserted in the rear end of the transmission output shaft 15, both are coaxially rotatably fitted together via the bush 23 and thrust washer 28, and the reduction gear 17 also outputs. Bush 23 and thrust bearing on shaft 15
24 and 24 are coaxially and rotatably fitted together, and a center differential device 50 is coaxially provided between these three members. The center differential device 50 is a compound planetary gear type and includes a first sun gear 51 formed on the transmission output shaft 15, a first pinion 52 meshing with the first sun gear 51, a second sun gear 53 formed on the rear drive shaft 20, and It has a mating second pinion 54. First and second pinion
52 and 54 are integrated, and are pivotally supported by a pinion shaft 56 of a carrier 55 integrally formed with the reduction gear 17 via a needle bearing 26. The front and rear of the carrier 55 having the reduction gear 17 are pivotally supported by the ball bearings 25.

In this way, the power of the transmission output shaft 15 is input to the first sun gear 51, and the carrier 55 is transmitted through the first and second pinions 52 and 54.
And torque is transmitted to the second sun gear 53 at a predetermined distribution ratio. When the torque is transmitted, the rotation difference between the carrier 55 and the second sun gear 53 is absorbed by the rotation and revolution of the first and second pinions 52 and 54.

Next, the connecting structure of the hydraulic multi-plate clutch 60 and the center differential device 50 will be described.

First, the carrier 55 of the center differential device 50
Are three arms 55a that are curved from the reduction gear 17
Are projected at equal intervals on the circumference, and an abutting surface 55b for positioning is formed in steps at the tip of the arm 55a. Further, in the plate 55c of the carrier 55, three pinion shaft holes 55d are arranged so as to alternately penetrate through the arms 55a at equal intervals on the substantially same circumference as the arms 55a.

On the other hand, in the hydraulic multi-plate clutch 60, the drum 61 has a bowl shape having a side wall 61b on one side of the outer peripheral portion 61a, and a boss portion 61c is formed inside the center of the side wall 61b. A plurality of driven plate fitting grooves 61d are provided at equal intervals inside the outer peripheral portion 61a, and three long holes 61e and three pinion shaft holes 61f are alternately arranged at equal intervals on the side wall 61b.

Therefore, in a state where the carrier 55 and the drum 61 of the hydraulic multi-plate clutch 60 are aligned with each other, each arm 55a of the carrier 55 is inserted into the slot 61e of the drum side wall 61b with the abutting surface 55b in contact with the arm 55a. The side wall 61b and the side wall 61b are welded together by, for example, electron beam welding. Also, the plate 55c of the carrier 55
And the pinion shaft holes 55d and 61f of the side wall 61b are inserted into the pinion shaft holes 55d and 61f with three pinion shafts 56 at equal positions.
At 1 g, the lock pin 57 is press-fitted into the pinion shaft 56 to prevent it from coming off. And the three first and one integrated with this pinion shaft 56
The second pinions 52, 54 are attached via the needle bearings 26, and washers 58, 58 are provided between the first and second pinions 52, 54 and the reduction gear 17 and the side wall 61b.

Thus, the three first and second pinions 52, 54 of the center differential device 50 are assembled in the same arrangement by utilizing the carrier 55 integrated with the reduction gear 17 and the drum 61 of the hydraulic multi-plate clutch 60. It is attached.

In the hydraulic multi-plate clutch 60, the drum 61 is rotatably mounted by fitting the boss portion 61c to the bearing 25 of the rear drive shaft 20, and the hub 62 is integrally spline-coupled to the rear drive shaft 20. Here, the retaining plate 63 and the driven plate 64 on the drum 61 side are the fitting grooves 61d of the drum 61.
Is fitted and attached. Also, drive plate 65
Are connected to the hub 62 by splines on the inner periphery and are alternately arranged with the retaining plate 63 and the driven plate 64, and are retained by the clip 66 on the outer peripheral portion 61a of the drum 61.

On the other hand, immediately after the hub 62, the boss portion of the transfer case 4 is provided.
4a is provided, and the rear drive shaft 20 is rotatably supported by the bearing 27 inside the boss portion 4a.
Piston 67 has a hydraulic chamber 68 between the
It is fitted and installed by stopping rotation at 67a. The piston 67 has
The pressing plate 70 is connected via a release bearing 69 so as to face the driven plate 64, and the pressing plate 70 is also guided by fitting the outer peripheral spline 70a into the drum fitting groove 61d. Further, a retainer 72 is attached to the boss portion 4a of the transfer case 4 by a snap ring 71,
A return spring 73 is biased between the retainer 72 and the piston 67.

In this way, the hydraulic multi-plate clutch 60 is provided between the carrier 55, which is one output element of the center differential device 50, and the second sun gear 53, which is the other output element, by both-side support by-passing. If the hydraulic pressure in the hydraulic chamber 68 is zero,
The return spring 73 causes the piston 67 and the like to retreat and separate the plates 63 to 65, so that the differential limiting torque is not generated. On the other hand, when hydraulic pressure is generated in the hydraulic chamber 68, the pressing plate 70 moves together with the piston 67 and the bearing 69 to move the plates.
63 to 65 are pressed into contact with each other, and a predetermined differential limiting torque is generated to perform torque movement and differential limiting action.

Further, a pulse gear 82 is attached to the rear drive shaft 20,
A rear wheel rotation speed sensor 83 is installed in close proximity to the pulse gear 82 to detect the rear wheel rotation speed. A sleeve yoke 84 is spline-coupled to the rear end of the rear drive shaft 20.
On the other hand, the oil seal 85 is supported between the transfer case 4 and the sleeve yoke 84 via the bush 23.

Next, the lubricating system for the center differential device 50 and the hydraulic multi-plate clutch 60 will be described.

First, the lubrication circuit 90 from the control valve body 43 is transmitted through the oil cooler 103 to the transmission case 3
Of the transmission output shaft 15 through this passage 91.
It communicates with the passage 93 of the center through 92. A passage 94 is provided in the axial direction between the front end of the center of the rear drive shaft 20 and the portion of the pulse gear 82, and an orifice 95 is provided at the front end of the passage 94. The part is branched, and the flow rate is controlled by the orifice 95 to be introduced into the passage 94.

Therefore, the oil in the passage 94 is transferred to the bush 23 between the transmission output shaft 15 and the rear drive shaft 20 by the radial hole 96,
The thrust washer 28 is supplied through the hole 97. Further, the oil is guided to the inside of the reduction gear 17 by the holes 98a and 98b of the rear drive shaft 20 and the transmission output shaft 15, and the holes 98c of the reduction gear 17 and the carrier 55 and the hole 98d of the pinion shaft 56.
Is supplied to the needle bearing 26 and the washer 58 through the. On the other hand, the oil flows through the hole 99a and the groove 99 at the end of the hub 62.
It is supplied to a portion such as each plate 63 to 65 between the drum 61 and the hub 62 via b. Furthermore, the end of the passage 94 is at the end of the hole 10.
The oil is opened to the inside of the transfer case 4 through 0, and the oil flows in the transfer case 4 immediately behind the ball bearing 27.

Here, in the boss portion 4a of the transfer case 4, as shown in FIGS. 3 (a) and 3 (b), the center hole 4b and the bearing fitting hole 4c are formed.
Is formed in a stepped manner, and an oil groove 101 is provided axially and in the tip direction in the lower center of these holes 4b, 4c, and the oil is branched to the ball bearing 27 and the release bearing 69 on the back side thereof. It is supposed to be supplied. On the other hand, the release bearing 69 is installed between the inner race 69a and the outer race 69b with the ball 69c supported by the retainer 69d, and the inner race 69a is supported by the piston 6
The outer race 69b is press-fitted to the pressing plate 70, and the outer race 69b is press-fitted to the pressing plate 70 so as to rotatably support the pressing plate 70. Further, a retainer 102 as shown in FIG. 3C is attached to the tip of the piston 67 in the vicinity of the release bearing 69. The retainer 102 has a pawl 102a that bends substantially at a right angle from the inner circumference of a ring-shaped portion that abuts the tip end surface of the piston 67 and projects rearward. By being inserted into the formed engagement groove (not shown), it is prevented from rotating in the circumferential direction. A plurality of small-diameter coil-shaped springs 73 are circumferentially arranged between the retainer 102 and the retainer 72 and are biased.

Therefore, the retainer 102 is used to project an oil guide 102b in one radial direction on the circumference thereof. The oil guide 102b is located immediately below the tip of the oil groove 101 by bulging from the ring-shaped portion of the retainer 102 to the side opposite to the claw 102a, and has a large opening at the top and a release bearing 69 at the bottom. By opening in the vicinity
The oil flowing down from the tip of the oil groove 101 is guided between the inner race 69a and the outer race 69b of the release bearing 69.

Next, the operation of the four-wheel drive vehicle thus configured will be described.

First, the power of the engine 10 is the torque converter 13, the input shaft 1
Input to the automatic transmission 30 via 4 and the transmission power automatically changed by the automatic transmission 30 is input from the transmission output shaft 15 to the first sun gear 51 of the center differential device 50. Here, by setting, for example, TF: TR≈38: 62 according to the specifications of each gear element of the center differential device 50, 38% of the shifting power torque is applied to the reduction gear 17 integrated with the carrier 55. , 62% of the torque is distributed to the second sun gear 53 and output.

And the 38% torque output to the reduction gear 17 is
It is transmitted to the front wheels as it is through the reduction gear 18, the front drive shaft 16, and the front differential device 19. Further, 62% of the torque output to the second sun gear 23 is transmitted to the rear wheels via the rear drive shaft 20, the propeller shaft 21, and the rear differential device 22, and the four-wheel drive traveling with rear wheel bias is performed. Then, with this torque distribution, there is a slight tendency to understeer, which ensures good maneuverability. Further, at the time of turning, the center differential device 50 completely rotates and revolves the first and second pinions 52 and 54 in accordance with the difference in rotation speed between the front and rear wheels to completely absorb the difference in rotation speed.
It becomes possible to freely turn.

Next, when the vehicle travels on slippery roads, the rear wheels always slip first due to the torque distribution of the rear wheel bias, the clutch pressure is set according to the slip state, hydraulic pressure acts on the hydraulic multi-plate clutch 60, and a predetermined difference is generated. The dynamic limiting torque Tc is generated. Therefore, in the center differential device 50, a transmission system path via the hydraulic multi-plate clutch 60 is formed by bypass between the carrier 55 of the two output elements and the second sun gear 53, and the high-speed side is formed. The torque is bypassed and transmitted from the second sun gear 53 to the low rotation speed carrier 55 by the differential limiting torque Tc. As a result, the torque distribution changes toward the front wheels, the rear wheel torque is reduced, and slip does not occur,
Driving performance is increased and maneuverability is also maintained.

When the above-mentioned slip ratio S becomes equal to or less than the set value SI, the differential limiting torque becomes maximum together with the hydraulic pressure of the hydraulic multi-plate clutch 60, and the carrier of the center differential device 50.
55 and the second sun gear 53 are directly connected. For this reason, the center differential device 50 is differentially locked, and it becomes a direct-coupled four-wheel drive traveling with a torque distribution corresponding to the axial load distribution of the front and rear wheels, and the running performance is maximized. In this way, according to the slip state, the torque distribution is widely controlled to the front and rear wheels to avoid it.

On the other hand, during the above-described four-wheel drive traveling, the lubricating oil from the control valve body 43 is guided to the oil cooler 103 by the circuit 90 and cooled, and then pumped to the passage 93 of the transmission output shaft 15 through the passages 91 and 92. And supplied to each lubrication unit such as the automatic transmission 30. Also, the oil in the passage 93 is
Through the passageway 94 of the rear drive shaft 20, and through the radial holes 96, 97, 98a to 98d, the bush 23, the thrust washer 28, and the thrust washer 28 between the transmission output shaft 15 and the rear drive shaft 20,
The thrust bearing 24 between the reduction gear 17 and the transmission output shaft 15 and further the center differential device 5
Zero first and second sun gears 51 and 53 and first and second pinions 52 and 5
It is supplied to the meshing part with 4, the needle bearing 26, and the washer 58 for lubrication. Next, the oil in the passage 94 is cooled by the holes 99a,
It is supplied to the ball bearing 25 by the groove 99b, further enters the inside of the drum 61 of the hydraulic multi-plate clutch 60 and scatters, and each plate 63 to 65, 70, spline fitting portion, spring 73
Etc. to be lubricated. Excess oil inside the drum 61 collects in the fitting groove 61d by centrifugal force,
A hole or the like in the outer peripheral portion 61a of the drum comes out.

The oil in the passage 94 flows down into the inside of the transfer case 4 through the hole 100 at the terminal end, bypasses the pulse gear 82, and bosses.
It is supplied to the ball bearing 27 by the hole 4b of 4a and lubricated. On the other hand, the oil in the hole 4b gathers in the oil groove 101, bypasses the ball bearing 27, and is guided again to the piston 67 attached to the boss portion 4a of the hydraulic multi-plate clutch 60.
The oil flowing down from the oil groove 101 is retained by the retainer 102.
The oil guide 102b collects the oil, directly supplies it between the inner race 69a and the outer race 69b of the release bearing 69 regardless of whether or not the piston moves, and discharges it through a gap with the piston 67 on the opposite side.

As a result, with release bearing 69, inner race 69
A large amount of oil always passes through the ball 69c and the cage 69d between the a and the outer race 69b. Therefore, when the piston 67, the release bearing 69, and the pressing plate 70 move to press the plates 63 to 65, and the differential limiting torque is generated, the inner race 69a on the fixed side of the release bearing 69 and the rotating side A large rotational speed difference and thrust force are generated between the outer race 69b and the ball 69c.
By positively supplying oil to the rolling contact parts of the inner race 69a and the outer race 69b and the sliding contact parts of the retainer 69d, the oil quickly passes through the contact parts one after another and is well lubricated. Become.

The embodiment of the present invention has been described above, but the same can be applied to the case where the center differential device 50 and the hydraulic multi-plate clutch 60 are mounted on a manual transmission or a horizontal transaxle. Further, it is needless to say that the present invention can be applied to the case where the structure of the center differential device 50 is different.

[Effect of device]

As described above, according to the present invention, in the hydraulic multiple disc clutch for the differential limiting torque of the four-wheel drive vehicle with the center differential device, the pressing plate is connected to the fixed side piston via the release bearing. In the case of the method described above, since a large amount of oil is positively supplied between the inner race and the outer race of the release bearing, good lubrication is achieved and durability and reliability are improved.

Furthermore, due to good lubrication of the release bearing part,
The generation and variable control of the differential limiting torque by the pressing plate can be performed smoothly and reliably.

Further, since the oil inside the transfer case is guided by the groove and the guide of the spring retainer of the piston and the bearing portion, the structure is simple and a large amount of oil can be surely supplied when the piston moves.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing an embodiment of a lubricating oil supply device for a four-wheel drive vehicle according to the present invention, and FIG. 2 is an enlarged sectional view of a center differential device and a hydraulic multi-plate clutch, FIG. (C) is an enlarged sectional view and a perspective view of each part. 4 ... Transfer case, 4a ... Boss part, 50 ... Center differential device, 67 ... Piston, 69 ... Release bearing, 69a ... Inner race, 69b ... Outer race, 70
... Pressing plate, 73 ... Spring, 101 ... Oil groove, 102
… Retainer, 102b… Oil guide

Claims (1)

[Scope of utility model registration request] 1. A four-wheel drive vehicle in which a hydraulic multi-plate clutch for limiting operation is arranged coaxially adjacent to a center differential device, wherein the hydraulic multi-plate clutch has an outer periphery of a boss portion of a case which is a stationary member. Installed on the side and movable along the axial direction of the boss by control hydraulic pressure, a release bearing that rotatably supports and connects a pressing plate that presses each clutch plate to the piston, and this release bearing. Closely attached to the tip of the piston,
A retainer that supports one end of the return spring of the piston, and an oil groove that guides the oil introduced to the inner peripheral side to the outer peripheral side is provided in the lower part of the boss near the retainer. A lubricating oil supply device for a four-wheel drive vehicle, wherein the retainer is integrally formed with an oil guide for guiding the oil flowing down from the oil groove between the inner race and the outer race of the release bearing.