JPH0621630B2 - Lubrication device for four-wheel drive transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a four-wheel drive transmission, and more particularly to a horizontal four-wheel drive automatic transmission based on FF (front engine / front drive). More specifically, the present invention relates to a lubricating device for a transfer portion of the transmission.

(B) Conventional Technology Conventionally, in a horizontal automatic transmission for F / F, the differential portion thereof is forcibly lubricated through an oil passage formed in the case.

In addition, based on the F / F automatic transmission, a transfer unit constituted by fitting a front wheel axle with a rear wheel drive shaft is attached, and an automatic transmission for four-wheel drive has been devised. . The four-wheel drive automatic transmission has a double shaft composed of a front-wheel axle and a rear-wheel drive shaft, and a long front-wheel axle is supported by bearings. However, if the structure is such that the transfer portion is simply communicated with the differential portion, it is installed away from the differential portion,
In addition, the lubricating oil is not supplied to the bearing portion at the tip, which is arranged with a narrow gap between the double shafts, and the transfer portion may be inferior in lubrication.

(C) Problems to be solved by the inventionTherefore, it is necessary to forcibly lubricate the transfer portion, but since the transfer portion, especially the tip bearing portion is separated from the transmission main body and separates a narrow gap,
It is difficult to circulate the lubricating oil. Therefore, in general, as shown in FIG.
It is conceivable that the transfer portion 7 communicates with the tip bearing 30 portion.

However, the tube method has a problem in that the tube may or may not leak even if the tube does not come off, and leaks from the connecting portion, resulting in lack of reliability.

On the other hand, it is conceivable to form an oil passage in the case 7 part, but this method requires major modification of the control unit, casing, etc., and may leak from the mating part of the case, resulting in a significant cost increase and This causes problems such as deterioration of reliability.

Therefore, the present invention uses the gap between the front wheel axle and the drive shaft and the inside of the ring gear mount case as a lubricating oil passage, and thus does not require a tube, but does not require a major modification of the control unit and the casing. SUMMARY OF THE INVENTION It is an object of the present invention to provide an inexpensive and highly reliable lubrication device for a transfer portion in a four-wheel drive transmission.

(D) Means for Solving the Problems The present invention has been made in view of the above circumstances, and as shown in FIG. 1, for example, the transfer portion 7 of the four-wheel drive transmission is a front wheel differential. The drive shaft 26 (for rear wheels) is attached to the front wheel axle 22r extending from the portion 6 (right).
The ring gear mount case 29 is connected to the tip of the drive shaft 26, and the transfer case rotatably supports both end bosses 29a, 29a of the mount case 29 and the tip of the front wheel axle 22r. The portion is supported via a bearing 30.

Then, both end boss portions 2 of the ring gear mount case 29
The oil seals 41, 41 are provided between the transfer cases 11 and 9a, 29a to form an oil passage 40 that passes through the inside of the mount case 29. Further, from the front wheel differential portion 6 side to the front wheel axle 22r and the drive shaft. 26, a lubricating oil is supplied to a clearance c between the mounting case 29 and the drive shaft 26, and the lubricating oil is supplied to the bearing 30 portion at the front end of the front wheel axle through the clearance c.
It is configured such that it is sent to the oil passage 40 inside the mount case through the passage 62a formed in 2, and is discharged to the drain oil passage 60 formed in the vicinity of the front wheel differential portion 6.

(E) Operation Based on the above configuration, the lubricating oil that is pressure-fed from the oil pump to the lubricating oil supply oil passage on the front wheel differential portion 6 side through the control unit passes through the clearance c and the front wheel axle 22r and the drive shaft 26. The oil is sent to the oil sump chamber 43 including the bearing 30 while lubricating the space between them. Then, the bearing 30 is lubricated in the chamber 43, and then the passage 62a is formed.
Through the oil passage (oil sump chamber) 40 in the mount case 29
And is discharged from the drain oil passage 60.

(F) Example Hereinafter, an example according to the present invention will be described with reference to the drawings.

First, a part-time automatic transmission for four-wheel drive to which the lubricating device according to the present invention is applied will be described with reference to FIG.

The horizontal four-wheel drive automatic transmission 1 includes a torque converter section 2, an automatic transmission mechanism section 3, a front wheel differential section 5, a rear wheel operation switching section 6 and a transfer section 7, and these are joined together. It is housed in a transaxle housing 8, a transaxle case 9, and a transfer case 11. The torque converter unit 2 includes a torque converter 12 and a lockup clutch 13, and the rotation of the engine output shaft 14 is transmitted to the input shaft 15 via these components. Further, the automatic transmission mechanism unit 3 is a three-stage planetary gear unit (not shown) that is appropriately controlled by a clutch or a brake.
The output of the input shaft 15 is rotatably supported by the counter shaft 16 by appropriately converting the rotation of the input shaft 15 into each of the first speed, the second speed, the third speed, the overdrive speed and the reverse speed through these gear units. It is transmitted to the gear 17. The front wheel differential portion 5 is composed of a ring gear 19 meshing with the gear 17, a mount case 20 fixing the ring gear 19 and a front wheel differential unit 21 arranged in the case 20. The rotation of 19 causes the left and right front wheel axles 22l via the gear unit 21,
22r is differentially rotated. The rear wheel operation switching unit 6 is composed of a hydraulic multi-plate clutch 23 fixed to the mount case 20 together with the ring gear 19, the clutch 23 being controlled by the double pistons 25a and 25b, and the output unit 23a thereof being right. The front wheel axle 22r is connected to a rear wheel drive shaft 26, which is a sleeve shaft. The transfer unit 7 has a transfer case 11 and a hypoid ring gear 27, and a ring gear mount case 29 spline-coupled to the tip of the rear wheel drive shaft 26. The transfer case 11 has a tip. Front right wheel axle 2
2r is rotatably supported by a ball bearing 30, and the mount case 29 is rotatably supported by roller bearings 31 and 31 at an intermediate portion thereof. Further, the gear 27 meshes with a hypoid gear 33 fixed to the tip of a connecting shaft 32 extending rearward, and the rotation of the rear wheel drive shaft 26 is transmitted to the connecting shaft 32 via the hypoid gears 27 and 33. An oil pump 35 is installed in the portion of the transaxle housing 8 that is joined to the case 9 so as to surround the input shaft 15. The pump 35 is driven by the engine output shaft 14 and the torque is transmitted via the control unit. Converter 1
2. Oil is supplied to control devices such as the pistons 25a and 25b of the clutch 23, and each lubrication point.

As a result, the rotation of the engine is controlled by the torque converter 12
Alternatively, it is transmitted to the automatic transmission mechanism section 3 via the lockup clutch 13, and further transmitted from the output gear 17 thereof to the left and right front wheel axles 22l, 22r via the front wheel differential gear unit 21 to drive the front wheels. On the other hand, the hydraulic multi-plate clutch 23 is switched manually or automatically, and is connected only when four-wheel drive is required, such as during climbing. When the clutch 23 is connected, the rotation of the output gear 17 of the automatic transmission mechanism 3 is transmitted to the rear wheel drive shaft 26 via the clutch 23 and further via the hypoid gears 27, 33 and the connecting shaft 32. The rear wheels are also driven, resulting in four-wheel drive.

Next, the lubricating device according to the present invention will be described with reference to FIG.

The transfer case 11 is made up of case halves 11a and 11b that are joined together at a bulging portion at the center, and
The left side surface is joined to the transaxle housing 8, and the rear side surface is a longitudinally extending gear case 3.
It is joined to 7. Further, the ring gear mount case 29 is arranged at the bulging portion of the transfer case 11, the ring gear 27 is fixed to the outer peripheral side thereof with bolts 39, and the inner peripheral portion of the ring gear mount case 29 is widened to expand the oil sump chamber 4.
0 and the boss portions 29a, 29a at both ends thereof are formed.
Tapered roller bearings 31, 31 are interposed between the outer peripheral surface and the case 11, and oil seals 41, 41 are fitted in an oil-tight manner with the case 11 on the outer side thereof. An oil seal 42 is interposed between the case 11 and the drive shaft 22r in an oil-tight manner on the outer side of the ball bearing 30 supporting the right front wheel axle 22r. A small oil sump chamber 43 including the ball bearing 30 is formed between the oil seal 41 and the boss end oil seal 41. On the other hand, a boss portion 23c extending from the clutch housing 23b of the hydraulic multi-plate clutch 23 is in sliding contact with the inner peripheral surface of the transfer case 11, and a sleeve 45 is press-fitted to the inner peripheral surface of the boss portion 23c, and The inner peripheral surface of the sleeve 45 is in sliding contact with the sleeve-shaped rear wheel drive shaft 26. Then, two annular grooves 47, 49 separated by a seal ring 46 are formed in the boss portion 23c, and one annular groove 47 is formed in the boss portion 2c.
It communicates with the piston 25a portion of the clutch 23 via an axial groove 50 and a hole 51 formed on the inner peripheral surface of 3c. Further, an axial groove 54 is formed on the inner peripheral surface of the boss portion 23c on the opposite side (lower side) to the axial groove 50, and at the same portion, the inner peripheral surface of the sleeve 45 is also axially predetermined. An annular groove 52 having a width is formed, and the other annular groove 49 communicates with the axial groove 54 through a hole 55, further communicates with the annular groove 52 through a hole, and further for rear wheel drive. Through a hole 56 formed in the shaft 26, it communicates with a gap c between the front wheel axle 22r and the rear wheel drive shaft 26 that form a double shaft. Further, the transfer case 11 is formed with a clutch control oil passage 57 communicating with the oil pump 35 via a control unit, and the oil passage 57 communicates with the one annular groove 47. Further, the clutch control oil passage 57 of the transfer case 11 is used.
A lubricating supply oil passage 59 which is also communicated with the oil pump 35 is formed on the opposite side of the oil pump 35, and the oil passage 59 is communicated with the other annular groove 49. Further, a drain oil passage 60 is formed in the case 11 near the lubrication supply oil passage 59, and the oil passage 60 is partitioned by the mount case boss proximal oil seal 41 and inside the mount case 29. The chamber 61 communicates with the oil sump chamber 40, and the other end communicates with the oil sump inside the transaxle case. Further, the front end of the rear wheel drive shaft 26 and the mount case 29 are connected to each other via a spline 62, and a part of the spline 62 has a missing tooth 62a.
The small oil sump chamber 43 and the oil sump chamber 40 in the mount case 29 communicate with each other through the toothless portion 62a. The boss 23c of the multi-plate clutch 23 is also rotatably supported by the housing 8 by the differential side roller bearing 63, and the boss 23c has a small hole 65 communicating with the axial groove 51. The lubricating oil is also supplied to the bearing 63 through the small hole 65.

Based on the above configuration, the lubricating oil supplied from the oil pump 35 to the lubricating oil supply oil passage 59 via the control unit is sent to the axial groove 51 via the annular groove 49 and the hole 55 of the clutch boss portion 23c, Further, it is supplied to the differential side bearing 63 through the small hole 65, and is also supplied to the clearance c through the axial groove 52 of the sleeve 45 and the hole 56 of the rear wheel drive shaft 26. The lubricating oil in the gap c is directed toward the differential portion 5 and the small oil reservoir 4 at the tip.
3 and thereby lubricates between the front wheel axle 22r and the rear wheel drive shaft 26. Further, the lubricating oil sent to the small oil sump chamber 43 receives the ball bearing 30 at the tip.
And the oil seal 41 prevents the oil from flowing out toward the hypoid gears 27 and 37.
It is guided to the oil sump chamber 40 in the mount case 29 through a. Further, the lubricating oil in the oil sump chamber 40 is discharged from the drain oil passage 60 via the chamber 61 and returned to the oil sump in the axle case 9. This allows the differential side bearing 6
By using the lubricating oil supply oil passage 59 ′ for lubricating 3, the respective lubrication necessary portions of the transfer portion 7 are forcibly lubricated.

In the above-described embodiment, the four-wheel drive transmission of the part-time system including the rear wheel operation switching clutch 23 has been described. However, the intermediate differential gear unit is housed in the ring gear mount case 29, and the automatic transmission mechanism unit. A so-called full-time system four-wheel system in which the output gear 17 of 3 is transmitted to the intermediate differential gear unit via a drive shaft, and the transmission force to the front wheels and the rear wheels is branched by the gear unit. The present lubricating device can be similarly applied to the drive transmission.

Further, not only the automatic transmission but also a manual type four-wheel drive transmission in which the gear train is manually changed can be similarly applied.

(G) Effect of the Invention As described above, according to the present invention, the clearance c between the front wheel axle 22r and the driving time 26 and the oil passage 40 in the ring gear mount case 29 are used as a lubricating oil circulation passage. While forcibly lubricating the entire part 7, especially the bearing 30 at the front end of the front wheel axle,
There is no need to use a tube or to form a special oil passage in the case 11, and it is possible to prevent the tube from coming off or leaking from the mating surface of the case, improve reliability, and configure inexpensively. Also, for example, oil seals 41, 4
Even if the lubricating oil leaks from No. 1, it does not leak out of the cases 11 and 37, which is safe.

Further, the oil passage 59 for supplying the lubricating oil to the clearance c between the front wheel axle 22r and the drive shaft 26 is provided with the differential side bearing 63.
If it is also used as an oil passage for supplying lubricating oil to the transfer portion 7, the transfer portion 7 can be forcibly lubricated by only slightly changing the oil passage of the differential portion 6 originally provided.
A lubrication device for an automatic transmission for four-wheel drive can be configured based on the automatic transmission for F without major changes to the control unit and casing.

[Brief description of drawings]

FIG. 1 is a sectional view showing a transfer portion provided with a lubricating device according to the present invention, FIG. 2 is a sectional view showing an automatic transmission for four-wheel drive to which the present invention is applied, and FIG. 3 is for four-wheel drive. FIG. 6 is a cross-sectional view of a transfer portion showing an example that can be naturally considered when designing an automatic transmission. 1 ... Four-wheel drive (automatic) transmission, 2 ... Torque converter (part), 3 ... Automatic transmission mechanism (part), 5 ... Differential part, 6 ... Rear wheel operation switching part, 7 ... Transfer part, 8 ... Transaxle housing, 1
1 ... Transfer case, 22r ... (right) front wheel axle, 23 ... Clutch, 23c ... Boss part, 26
... (for rear wheels) drive shaft, 29 ... ring gear mount case, 29a, 29a ... boss, 30 ... bearing, 40 ... oil passage (oil sump), 43 ... small oil sump,
45 ... Sleeve, 49 ... Annular groove, 51, 52 ... Axial groove, 55, 56, 65 ... Hole, 59 ... Lubricating oil supply oil passage, 60 ... Drain oil passage, 62 ... Connecting portion (Spline), 62a ... passage (missing tooth), 65 ... differential side bearing, c ... gap.

Claims (4)

[Claims] 1. A drive shaft is fitted to a front wheel axle extending from a front wheel differential portion, a ring gear mount case is connected to the tip end portion of the drive shaft, and both end boss portions of the mount case are rotated to a transfer case. It has a transfer part that freely supports and supports the front end of the front wheel axle via a bearing.
In a wheel drive transmission, an oil seal is provided between both end bosses of the ring gear mount case and a transfer case to form an oil passage passing through the mount case, and further from the differential portion side for the front wheel, Lubricating oil is supplied to the gap between the front wheel axle and the drive shaft, the lubricating oil is supplied to the bearing portion of the front wheel axle tip through the gap, and the connecting portion between the mount case and the drive shaft is further provided. Lubrication device for a four-wheel drive transmission, which is configured to be sent to an oil passage inside the mount case through a passage formed in the front case and discharged to a drain oil passage formed near the differential portion for the front wheels. . 2. The lubricating apparatus according to claim 1, wherein the four-wheel drive transmission is a horizontal four-wheel drive automatic transmission having an automatic transmission mechanism including a torque converter and a planetary gear unit. 3. The drive shaft is a rear-wheel drive shaft that is interlocked with an automatic transmission mechanism via a clutch, and the gear mount case forms an oil reservoir inside the drive shaft.
The lubricating device according to claim 2, wherein the automatic transmission for wheel drive is a part-time system. 4. An oil passage for supplying lubricating oil to a gap between the front wheel axle and the drive shaft also serves as an oil passage for supplying lubricating oil to a differential side bearing installed at an end of the differential portion on the transfer portion side. The lubricating device according to claim 1, wherein