JP2551599B2 - Lubricating oil feeding device for transfer gear in power transmission device for four-wheel drive vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a power transmission device for a four-wheel drive vehicle, particularly a four-wheel drive based on a front engine / front wheel drive (hereinafter referred to as FF) for horizontal mounting. The present invention relates to a lubricating oil feeding device for a transfer gear part in a power transmission device for a vehicle, specifically, an oil pump drive gear fixed to a ring gear mount case, an oil pump driven gear meshing with the drive gear, and driven by rotation of the driven gear. Oil pump,
Further, the present invention relates to a lubricating oil feeding device for a transfer gear portion including a strainer arranged on the suction side of the oil pump.

(B) Conventional technology In general, a power transmission device for a four-wheel drive vehicle based on FF is a transfer gear for transmitting engine power to rear wheels in both a part-time system and a full-time system. And a hypoid gear is used for the gear part. For this reason, since the lubricating oil to which the extreme pressure additive is added is used for the gear portion, the gear portion is housed in a closed chamber which is separated from other portions where the same lubricating oil as that of the automatic transmission is used. There is.

Then, the applicant of the present invention has found that in the closed chamber, an oil pump drive gear fixed to a ring gear mount case to which power from the engine is transmitted, an oil pump driven gear meshing with the drive gear, and a two-part split surrounding the ring gear mount case. A lubricating oil feeding device including an oil pump main body fixed to one divided piece of the transfer case of the structure and driven by rotation of the oil pump driven gear, and a strainer arranged on the suction side of the oil pump is installed. A gear rig and a bearing of a pinion shaft housed in the closed chamber are lubricated efficiently with a small amount of lubricating oil containing an extreme pressure additive. We have proposed a lubrication device for the transfer gear.

(C) Problems to be Solved by the Invention By the way, when assembling the above-mentioned lubricating oil feeding device in a closed chamber, the above-mentioned proposed example is fixed by fitting the oil pump main body to one split piece on one side of the transfer case. Then, the tip of the discharge pipe of the strainer is attached to the opening formed in the main body by fitting or the like, and the oil pump driven gear is attached to the drive shaft of the oil pump by press fitting or the like. With the large-diameter opening side of the split piece on one side facing downward, the ring gear mount case and other parts were aligned from above the split piece on the other side of the completed transfer case, and then tightened with bolts to assemble. .

However, according to the above assembling structure of the lubricating oil feeder, when the transfer case is assembled, when the opening of the split piece on one side of the transfer case is directed downward, the fitting direction of the strainer and the driven gear is vertical. The strainer and the oil pump driven gear easily fall off from the opening part of the body of the oil pump or the drive shaft.Therefore, the worker must assemble with sufficient caution to prevent the dropout. It took a lot of time and effort. Also, when assembling, the teeth of the driven gear may interfere with the teeth of the oil pump drive gear.In this state, tightening one end and the other end of the transfer case with bolts will cause the teeth of the gear to be lost. It may end up.

Therefore, in the present invention, the oil pump main body, the oil pump driven gear, and the strainer are subassemblies, and the subassemblies can be assembled after the transfer case is assembled.
An object of the present invention is to provide a lubricating oil feeding device for a transfer gear portion in a power transmission device for a wheel drive vehicle.

(D) Means for Solving the Problem The present invention has been made in view of the above circumstances, and for example, as shown with reference to FIG. 1, a ring gear mount case (16) to which power is transmitted from an engine is provided. The fixed oil pump drive gear (52) and the drive gear (5
2) which is meshed with the oil pump driven gear (55), the oil pump main body (53) driven by the rotation of the driven gear (55), and the strainer (56 disposed on the suction side of the oil pump main body (53). ) And a lubricating oil feeding device (57) of a transfer gear part (15) in a power transmission device (U) for a four-wheel drive vehicle, the pump drive shaft (53b) arranged in the oil pump body (53). ), The oil pump driven gear (55) is non-rotatably attached, the strainer (56) is attached to the oil pump main body (53), and the oil pump driven gear (55) and the strainer (56) are attached. The oil pump body (53) is fixed to a base (54) having an oil passage (for example, a suction port (54a) and a discharge port (54b)) to form a sub-assembly (S), and the sub-assembly (S) is It is characterized in that it is oil-tightly attached to the opening (13b ') formed in the transfer case (13).

(E) Action Based on the above configuration, first, the drive shaft (53a) of the oil pump main body (53) is mounted with the oil pump driven gear (55) so as not to rotate, and the strainer (56) is attached to the main body (53).
, And the oil pump body (53) equipped with these, the predetermined oil passage (suction port (54a), discharge port (54b)
Etc.) to a base (54) having a bolt (59) and the like to assemble as a sub-assembly (A). At this time, the driven gear (55) and the strainer (56) may be in a temporarily held state such as loosely fitted. Then, after assembling the transfer cases (13a) and (13b), the pump side of the sub-assembly (S) is turned inward, and the case (13b) is placed.
The driven gear (55) with the drive gear (55), and the drive shaft (53b) and the tip of the strainer (56) are fixed to the fixing members (13c) and (24).
The base (54) is fixed to the case (13b) in an oil-tight manner by bolts (60) or the like in this state.

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

As shown in FIG. 2, a power transmission device U for a full-time front engine front four-wheel drive vehicle of a full-time type has an input gear 1 to which power is transmitted from an engine (not shown) via a torque converter and an automatic transmission. The input gear 1 is fixed to the gear mount case 2. The mount case 2 is formed of a divided case piece, is fastened together with the input gear 1 by a bolt 12, is supported by a support case 9 by tapered roller bearings 9a and 9b, and has a front differential device 3 and The differential control device 10 is housed. Further, the front differential device 3 has a front differential case 3c rotatably supported by two needle bearings 11a and 11b in the mount case 2, and the differential case
3c supports a plurality of pinion shafts 3d supporting the pinion 3p in the vertical direction to form a carrier, and left and right side gears 3a and 3b extend in the left and right direction and are rotatably supported, and each side gear 3a , 3b are connected to left and right front axles 8l, 8r, respectively, so that power can be transmitted.

Also, on the right side of the input gear mount case 2, that is,
A transfer case 13, which is composed of a left-side split piece 13a and a right-side split piece 13b, is separable into left and right parts, and the input gear mount case 2 and the front differential device 3 are mounted in the transfer case 13.
The transfer gear unit 15 is assembled coaxially with the. The transfer gear portion 15 has a ring gear mount case 16, the ring gear mount case 16 can be divided into two parts, left and right, and integrally supports a transfer drive gear 17 for driving rear wheels, which is a hypoid gear. At the same time, the transfer case 13 is rotatably supported by a pair of tapered roller bearings 19, 19. A transfer driven gear 21, which is a hypoid gear formed on the pinion shaft 20, is constantly meshed with the gear 17, and the pinion shaft 20
Is rotatably supported by an extension case 24 extending rearward via tapered roller bearings 24a, 24b, is transmitted to a universal joint 25 via a spline portion 20a, and is not shown in the drawing, a propeller shaft and a rear differential device. Power is connected to the left and right rear axle shafts via the.
On the other hand, a center differential device 18 is arranged in the ring gear mount case 16, and the center differential device 18 is provided with a differential carrier 18c having an open end. In addition, the diff carrier 1
8c is connected to the sleeve portion 2b extending from the input gear mount case 2, and the opposite side of the connecting boss portion 18c 'is opened to form an open end, and the open end portion and the connecting boss portion 18c' are formed. Is rotatably supported by the ring gear mount case 16 with needle bearings 23, 23 interposed therebetween. Further, a pinion shaft 18d for supporting the pinion 18p is attached to the diff carrier 18c, the right side gear 18b is directly spline-coupled to the ring gear mount case 16, and the left side gear 18a is a diff carrier connection. linked to the differential case 3c of the front differential 3 through a boss portion 18c 'fitted within and sleeve portion 3c which is fitted on the right front axle shafts 8r _1'.

A spline joint 22 is slidably fitted to a spline formed at the tip of the sleeve portion 2b of the input gear mount case 2, and the spline joint 22 is axially operated by an operating lever (not shown). The lock position (see the upper half of FIG. 2) that engages with the spline formed in the sleeve portion of the ring gear mount case 16 and the release position (see the lower half of FIG. 2) that does not engage the mechanism are switched. It constitutes a diff lock mechanism. The mechanical differential lock mechanism is normally in a release position, but is switched to a lock position when a tire is placed on a roller at a service factory or the like to perform various inspections.

The differential control device 10 is disposed in the input gear mount case 2 provided so as to cover the front differential device 3 and coaxially with the device 3. The differential control device 10 includes a wet friction multi-plate clutch 26 and a hydraulic actuator thereof. Consists of 27. The clutch 26 has its outer friction plate connected to the mount case 2 and its inner friction plate connected to the differential case 3c, and these friction plates are pressed and controlled by the hydraulic actuator 27. Further, the hydraulic actuator 27 includes a first piston 28 and a second piston 29, which are oil-tightly housed in a cylinder formed in the mount case 2, and an oil-tight arrangement which is located between both pistons. It has a force plate 30 in which the first piston 28 is the second
The outer peripheral flange portion of the piston 29 abuts, and the reaction force plate 30 abuts the cylinder end surface to form a double piston. The transfer case 13 is provided with a valve unit 31 for the differential control device 10. The control oil pressure from the unit 31 is supplied to the first piston 28 of the hydraulic actuator 27 through a pipe 32 and oil passages 33 and 35. And the second piston 29.

On the other hand, oil seals 50, 51 are installed between both ends of the gear mount case 16, that is, the transfer case 13 on the outer side of the tapered roller bearings 19, 19 and the gear mount case 16. 51
The oil seal 54 at the tip of the extension 24 constitutes a sealed chamber D which is separated from the above-mentioned lubricating system by the inner surfaces of the transfer case 13 and the extension case 24 and the outer surface of the gear mount case 16. The transfer drive gear 17 and the transfer driven gear 21 meshing with the transfer drive gear 17 are housed in the closed chamber D. Further, as shown in detail in FIG. 1, an oil pump drive gear 52 is fixedly installed on the outer peripheral surface of the gear mount case 16, and the sealing between the extension case 24 and the transfer case 13 is performed. In the chamber D, a base 54 integral with the oil pump main body 53 is installed so as to close the opening 13b 'formed in the right divided piece 13b of the transfer case 13.
The drive shaft 53b of the pump body 53 has an oil pump driven gear that meshes with the oil pump drive gear 52.
55 is fitted and inserted so as to transmit rotation to the drive shaft 53b but to be movable in the axial direction. Further, a cylindrical strainer 56 is disposed adjacent to the oil pump 53, and the strainer 56 has a filter body portion 56 having an elliptical cross section.
a and the elliptical upper part is flatly cut off to form a body 56b having a cross-sectional shape, a cylindrical discharge pipe 56c, and a fitting boss 56d arranged at the end of the filter body 56a. It has moderate flexibility as a whole. Further, a concave portion 56f is formed on the side of the body portion 56b so as to surround a portion of the oil pump driven gear 55 facing the strainer 56 from three sides. Then, the above-mentioned oil pump drive gear 52, oil pump driven gear 55, oil pump
53 and a strainer 56 constitutes a lubricating oil feeding device 57, and the feeding device 57 sucks the lubricating oil containing the decompression additive enclosed in the closed chamber D from the strainer 56, and causes the oil pump 53 to An oil passage formed on the base 54, an inlet 54a, an outlet 54b, and a right split piece 13b of the transfer case 13, an oil passage b formed on the left split 13a, and an oil passage formed on the extension case 24. c, an orifice hole f, an oil passage g, and a strainer e provided in the oil passage d, then ejected from the orifice hole g, respectively, and transferred to a transfer drive gear 17 and a driven gear.
The meshing portion A with 21 and the bearing 24b are lubricated.

 Next, the operation based on the above structure will be described.

The rotation of the engine is appropriately shifted by the automatic transmission and transmitted to the input gear mount case 2 via the input gear 1. During normal driving, the valve unit
31 is connected and the hydraulic pressure based on the line pressure is
Acting on both pistons 28 and 29 of the hydraulic actuator 27 via the oil passages 32 and the oil passages 33 and 35, the wet multi-plate clutch 26 is connected at a predetermined pressure. Therefore, in the center differential device 18, the differential carrier 18c and the left side gear 18a are coupled with each other with a predetermined coupling force, and the differential is limited by the predetermined regulation force. Accordingly, when the frictional force between the road surface and the tire is smaller than the above-described regulation force, for example, on a road surface having a small friction coefficient such as a snowy road or a dirt road, the center differential device is determined based on the pressing force of the clutch 26.
18 is close to direct connection, input gear mount case 2
Is transmitted to the differential case 3c of the front differential device 3 through the friction clutch 26 and the center differential device 18 that rotates integrally, and the torque is distributed to the left and right side gears 3a and 3b through the pinion 3p to drive the left and right front wheels. At the same time, it is transmitted to the pinion shaft 20 via the ring gear 17 and the gear 21 fixed to the center differential device 18, and the rear differential device further distributes torque to drive the left and right rear wheels. Further, when the frictional force between the road surface and the tire is substantially balanced with the regulating force by the clutch 26, for example, when traveling on a paved road at a relatively high speed, the tire slip is reduced in relation to the road surface friction coefficient. The clutch 26 is pressed while sliding so as not to occur. That is, the center differential device 18 distributes the torque to the front and rear wheels while absorbing the rotation difference between the front and rear wheels in a state where the torque distribution to the front and rear wheels is biased to approach 50:50.

When the steering angle is greatly reduced at low speeds such as when the vehicle is put in a garage, a difference in rotation occurs between the front and rear wheels. In this case, however, the throttle opening is small and the hydraulic pressure based on the line pressure is also low. The pressure is also weak, and the engaging force of the friction clutch 26 of the differential control device 10 is also weak. Therefore, in order to allow the relative rotation of the left and right side gears 18a and 18b of the center differential device 18 based on the rotation difference between the front wheels and the rear wheels, the friction clutch 26 slips to allow the differential of the center differential device 2 and the tight corners. The torque is transmitted to the front and rear wheels while preventing the occurrence of the braking phenomenon.

When the power transmission device U is operated, the oil pump 53 is driven through the gears 52 and 55 based on the rotation of the gear mount case 16, and the lubricating oil in the sealed chamber D is strained by the strainer 56.
And is discharged from the orifice hole g to the outside of the bearing 24b through the oil passages a, b, c, d and the strainer e, and the lubricating oil passing through the orifice hole f is transferred to the transfer drive and driven gear. It is ejected toward the meshing part A of 17,21. The lubricating oil discharged in the vicinity of the bearing 24b lubricates the bearing 24b and the pinion shaft 20 and the universal joint 25
Lubricate the sliding spline in 20a, and lubricate the bearing 24a when returning to the pump direction. Further, the lubricating oil passing through the orifice hole f is regulated to a substantially constant amount based on the hole diameter and the length, and the lubricating oil of a predetermined flow rate is always supplied to the gear meshing portion A regardless of the pump rotation speed and accordingly the traveling speed. As a result, the transfer drive and driven gears 17 and 21 are reliably lubricated by being supplied with the above-mentioned predetermined amount of lubricating oil in addition to the oil bath lubrication.

On the other hand, in assembling the power transmission device U, the oil pump driven gear 55 is used as the drive shaft of the oil pump body 53.
53b and the strainer 56 is attached to the body 5 of the main body 53.
3a, the oil pump main body 53 is further fixed to the base plate 54 by the bolt 59, thereby forming the sub-assembly S, and the divided pieces 13a and 13b of the transfer case are joined by the bolt 62. And transfer section 1
After the 5 is assembled, the sub-assembly S is assembled. That is, the sub-assembly S is inserted into the opening 13b 'formed in the transfer case piece 13b with its pump 53 side facing inward, whereby the driven gear 55 is meshed with the drive gear 52 and the drive shaft 53b of the drive shaft 53b. The tip end contacts the positioning boss portion 13c of the transfer case 13a, and the fitting boss portion 56d of the strainer 56 fits into the positioning hole 24c formed in the side portion of the extension case 24. In this state, the base 54 is brought into close contact with the transfer 13b 'with the oil seal 61 sandwiched therebetween and fixed by the bolt 60, whereby the assembling of the lubricating oil feeder 57 is completed.
In the assembly described above, even if the tooth flanks of the oil pump drive gear 52 and the oil pump driven gear 55 interfere with each other, if the sub-assemblies S are slightly rotated while pressing the tooth flanks lightly, the interference will be removed. The meshing of the gears 52 and 55 is achieved very smoothly, and the sub-assembly S only needs to be inserted sideways. The fitting of the driven gear 55 to the drive shaft 53b and the fitting of the body 53a of the strainer 56 are temporarily performed. It can be stopped and loose fitting is sufficient. When the assembly is completed, the end portion of the oil pump driven gear 55 is brought into contact with the positioning boss portion 13c projecting from the left divided piece 13a and positioned at an appropriate position, and the strainer 56 is also fitted to the end portion. Boss 56d
Is fitted and positioned in the positioning hole 24c formed in the side portion of the extension case 24, and does not fall off.

In the above-described embodiment, the differential control device 10 is described as being used in the constantly operating state, but it may be used as a so-called diff lock mechanism that is normally in the non-operating state and operates only when necessary. Of course. Further, although the full-time four-wheel drive device having the center differential device has been described, the present invention is also applicable to a part-time four-wheel drive device in which a clutch is interposed in the power transmission system at the rear wheels, and has a viscous coupling. It can also be applied to a four-wheel drive system.

(G) Effect of the Invention As described above, according to the present invention, the oil pump driven gear (55), the oil pump body (53), and the strainer (56) are attached to the base (54), and the sub-assembly (S) is attached.
Then, the sub-assembly (S) may be incorporated into the opening (13b ') of the transfer case (13b) that has been assembled, and the assembly work of the transfer part lubricating oil feeding device (57) can be simplified. Can be done efficiently. Also, when assembling, the oil pump drive gear (52)
The teeth of the driven gear (55) and the teeth of the driven gear (55) interfere with each other to prevent defects such as missing teeth, and prevent the occurrence of defective products.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view showing a lubricating oil feeding device according to the present invention, and FIG. 2 is an application of the lubricating oil feeding device according to the present invention.
It is sectional drawing which shows the power transmission device for wheel drive vehicles. 13 …… Transfer case, 13b …… One side split piece (right split piece), 13b ′ …… Opening part, 15 …… Transfer gear part, 16 …… Ring gear mount case, 52 ……
Oil pump drive gear, 53 …… Oil pump body,
53a …… Body, 53b …… Drive shaft, 54 …… Base, 54a, 54b
...... Oil passage (suction port, discharge port), 55 …… Oil pump driven gear, 56 …… Strainer, 57 …… Lubricating oil feeding device,
U: Power transmission device for 4-wheel drive vehicle.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Fumitomo Yokoyama 10 Takane, Fujii-cho, Anjo-shi, Aichi Aisin Warner Co., Ltd. (72) Inventor Masaharu Tanaka 1-cho, Toyota-cho, Aichi Prefecture Toyota Motor Corporation In-house (72) Inventor Kojiro Kuramochi 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (1)

(57) [Claims] 1. An oil pump drive gear fixed to a ring gear mount case to which power from an engine is transmitted, an oil pump driven gear meshing with the oil pump drive gear, and oil driven by rotation of the oil pump driven gear. A lubricating oil feeding device for a transfer gear in a power transmission device for a four-wheel drive vehicle, comprising: a pump main body; and a strainer arranged on the suction side of the oil pump main body. The oil pump driven gear is attached to the pump drive shaft so that it cannot rotate, and
The strainer was attached to the oil pump body, and the oil pump body equipped with the oil pump driven gear and the strainer was fixed to a base having an oil passage to form a sub-assembly, and the sub-assembly was formed in a transfer case. A lubricating oil feeding device for a transfer gear part in a power transmission device for a four-wheel drive vehicle, in which an opening is attached in an oiltight manner.