JPH0220868B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention a. Field of Industrial Application The present invention is directed to an improvement of a lubricating device for a differential limiting device, that is, a lubricating device for a differential device with a differential limiting mechanism used in automobiles and other vehicles. It is related to.

b. Prior Art Differential limiting devices for automobiles and other vehicles rotate both wheels at the same rate when the vehicle is traveling straight, and when turning, the angular velocity of both wheels is changed by the differential to ensure smooth turning. If the vehicle enters an area with a low coefficient of friction, such as a muddy ground or frozen road surface,
The differential is limited by external means or other means to transmit sufficient torque to the other wheels, making it possible to escape.

Recently, a friction clutch is often used as a differential limiting means. This allows for smooth switching between normal differential and limited differential even when stationary.
Although this method has the advantage that excessive stress is not generated in the device, it is necessary to supply lubricating oil to cool the friction surfaces.

Therefore, as a conventional lubricating device for this differential limiting device, there is a device as disclosed in Japanese Patent Publication No. 50-22766, for example. The lubricating oil in the axle box is scooped up with a scraper and sent into the differential gear, and through the oil passage formed on the side surface of the differential case to the inner diameter side of the friction clutch, the lubricant oil is scooped up from inside the axle box and passed between the inner diameter of each friction plate and the spline teeth of the differential side gear. It leads to each friction gap through a long gap and provides a lubricating effect.

c. Problems to be solved by the invention As mentioned above, the conventional lubricating device for the differential limiting device is
Oil is supplied between each friction plate through the space between the inner diameter of the friction plate and the spline teeth of the differential side gear. At this time, the lubricating oil passes between the inner diameter part of the first friction plate near the oil passage on the side surface of the differential case and the spline teeth, and a part of it lubricates the first friction plate,
The remaining lubricating oil passes between the inner diameter of the second friction plate and the spline teeth. Then, a part of this lubricating oil lubricates the second friction plate, and the remaining lubricating oil is supplied to the third friction plate in the same manner as described above, and so on, and the amount of oil is gradually reduced.

However, since the distance between the inner diameter part of the friction plate and the spline teeth of the differential side gear boss part is not very large,
When the number of friction plates in a friction clutch increases due to an increase in the differential restriction due to vehicle specifications, even if the first number of friction plates are lubricated, it is difficult for the lubricating oil to be guided to between the friction plates closer to the back. In severe cases, the friction surface becomes unlubricated and heats up and wears out, leading to the problem of having to be repaired or replaced sooner.

The present invention relates to a lubricating device for a differential limiting device, and is an object of the present invention to solve the above-mentioned problems of the conventional lubricating device. That is, the first object of the present invention is to enable a constant and sufficient supply of lubricating oil between each friction plate of a friction clutch. The second purpose is to uniformly and sufficiently supply lubricating oil between each friction plate even when switching from a limited differential state to a normal differential state, so that the heat accumulated in each friction plate is quickly cooled down. Further, it is possible to uniformly and sufficiently supply lubricating oil between the respective friction plates immediately after switching from the normal differential state to the limited differential state. The third purpose is to form a positive flow of lubricating oil from the annular oil passage in the piston to the annular oil passage in the boss portion of the differential side gear, thereby increasing the amount of oil flowing into the friction clutch.
The fourth purpose is to form a positive flow of lubricating oil from the inner diameter side to the outer diameter side between each friction plate to reliably lubricate the space between each friction plate.

B. Structure of the Invention (a) Means for Solving Problems A piston 4, which has an input pinion 1, a ring gear 2, and a gear type differential mechanism 3 and is operated by external fluid pressure, connects a friction clutch 6 via a slide sleeve 5. In a differential limiting device that normally switches between differential and limiting differential, an axle box 8 is placed between the axle 7 on the slide sleeve 5 side and the piston 4 on the outer periphery.
An annular oil passage 9 within the piston into which lubricating oil can flow is provided, and an annular oil passage 10 within the sleeve is formed between the axle 7 and the slide sleeve 5 following the annular oil passage 9 within the piston. Following the sleeve inner annular oil passage 10, a boss inner annular oil passage 13 is provided between the axle 7 and the boss 12 of the differential side gear 11 on that side, and the piston inner annular oil passage 9 and the sleeve inner annular oil passage 10. The boss inner annular oil passage 13 is formed with a larger diameter toward the back, and the slide sleeve 5
The rear end is extended into the boss portion 12 of the differential side gear 11, and the boss portion 12 is provided with an oil passage hole 14 from the inner circumference to the outer circumference, and each of the meshing friction plates 15 is provided on the outer circumference of the boss portion 12.
An oil groove 16 is formed on the friction surface of the clutch case 17 toward the outer diameter side, and an oil drain hole 18 that communicates with the outer axle box 8 is provided in the clutch case 17.

In the above configuration, if the diameters of the piston inner annular oil passage 9, the sleeve inner annular oil passage 10, and the boss inner annular oil passage 13 are to be made larger toward the back, that is, toward the friction clutch 6, it may be done in stages, for example, as in the illustrated example. However, the diameter is not limited to this, and the diameter may be increased smoothly. It is desirable to provide an inner flange portion 19 on the opening side of the boss portion 12 of the differential side gear 11 so that lubricating oil can easily accumulate in the annular oil passage 13 inside the boss portion. Boss part 12
and each friction plate 15 are engaged with each other through spline teeth 20, and the oil passage hole 14 formed therein is formed into a long diameter hole in the axial direction of the boss portion 12, that is, in the direction in which the friction plates 15 are lined up. , or several round holes in parallel. Connect the back end of the slide sleeve 5 to the boss portion 12
Extending it to the inside means that the annular oil passage 1 inside the sleeve
This means that 0 and the boss inner annular oil passage 13 communicate directly without any delay.

The oil passage hole 14 of the boss portion 12, the oil groove 16 of each friction plate 15, and the oil drain hole 18 of the clutch case 17 are as follows:
Each lubricating oil is formed in such a number that it can be uniformly and sufficiently lubricated.

As shown in the illustrated example, it is desirable to form a short space 21 between the piston 4 and the slide sleeve 5 so that a portion of the lubricating oil can pass therethrough.

In the figure, 22 is an operating box, 23 is a pressure plate, 24 is a rolling bearing, and l is the center line of the axle.

b. Operation The operating state of the lubricating device of the differential limiting device is as follows.

Lubricating oil is contained in the axle box 8, usually to a level around the centerline l of the axle 7. Therefore, in this lubrication mechanism, lubricating oil flows from the side end of the piston 4 into the internal piston annular oil passage 9 between the piston 4 and the axle 7, as shown by the arrow a in FIG. Subsequently, the lubricating oil is transferred from the sleeve internal annular oil passage 10 between the slide sleeve 5 and the axle 7 to the differential side gear 11.
An annular oil passage 13 in the boss part between the boss part 12 and the axle 7
Head to.

In the above case, since the three oil passages 9, 10, and 13 are formed to have larger diameters toward the back, the operating box 22
The lubricating oil is sucked by the centrifugal force caused by the rotation of the lubricating oil, and the lubricating oil does not flow backward, but actively flows toward the annular oil passage 13 inside the boss portion at the back. Also slide sleeve 5
The inner end of the sleeve is extended into the boss portion 12 of the differential side gear 11, and the sleeve inner annular oil passage 10 is directly connected to the boss inner annular oil passage 13, so that all the lubricating oil in the sleeve inner annular oil passage 10 is inside the boss portion. Annular oilway 1
We will move on to 3.

Since the rear end of the lubricating oil that has entered the annular oil passage 13 in the boss part is closed by the differential side gear 11, the pressure of the lubricating oil is equalized here, and the oil passes through the oil passage hole 14 of the boss part 12, and is absorbed by each friction of the friction clutch 6. It is evenly and sufficiently supplied directly between the plates 15. Furthermore, operation box 2
Due to the centrifugal force caused by the rotation of 2, a positive flow of lubricating oil is formed in the oil groove 16 on the friction surface from the inner diameter side toward the outer diameter side, sufficiently lubricating the friction surface and reducing heat generation and wear. . Thereafter, the lubricating oil exits from the outer diameter side of each friction plate 15 and returns to the original axle box 8 through an oil drain hole 18 formed in the clutch case 17.

In addition, in the case where a small gap 21 is formed between the piston 4 and the slide sleeve 5 as shown in the illustrated example, a small portion of the lubricating oil that has passed through the piston inner annular oil passage 9 passes through the gap 21 as shown by arrow b. It lubricates the rolling bearing 24 through the shaft, eliminates abnormal heat generation and wear there, and returns to the axle box 8.

C. Effects of the Invention As is clear from the above, the present invention has the following effects.

According to the present invention, even when the number of friction plates of a friction clutch is large, lubricating oil can always be uniformly and sufficiently supplied to each friction surface. In other words, in the conventional friction clutch lubricating device, the lubricating oil led to the inner diameter side of the friction clutch passes between the inner diameter part of each friction plate and the spline teeth of the differential side gear boss part, and then sequentially reaches the inner part of the friction clutch. It is sent to Itama.
However, the distance between them is small and cannot be made very large, and if the number of friction plates increases due to the increase in differential limiting force due to vehicle specifications, the lubricating oil will not be able to spread between the friction plates located further back.

However, in the present invention, the lubricating oil that flows from the piston inner annular oil passage through the sleeve inner annular oil passage and into the boss inner annular oil passage is equalized there, passes through the oil passage hole in the boss part, and is directly directed to each oil passage. Supplied between the friction plates. Therefore, even if there are a large number of friction plates, lubricating oil is not supplied sequentially like in the past, so lubricating oil can be uniformly and sufficiently supplied even between the friction plates located at the back, and each friction Abnormal heat generation and wear on surfaces can be eliminated.

b In normal differential state and differential limited state,
Lubricating oil can be uniformly and sufficiently supplied between each friction plate. In other words, in the conventional type, there is a gap between the rear end of the slide sleeve and the boss of the differential side gear, and the lubricating oil guided into the annular oil passage inside the sleeve is sucked by the centrifugal force caused by the rotation of the differential box. If this happens, it will pass through the clutch case and return to the axle box through the exhaust hole in the clutch case. Therefore, after switching from the limited differential state to the normal differential state, lubricating oil is not sufficiently supplied between each friction plate, and the heat accumulated between each friction plate cannot be quickly cooled down.
Also, after switching from the normal differential state to the limited differential state, lubricating oil will not flow into the annular oil passage inside the boss unless the space between the friction clutch and the pressure plate is filled with lubricating oil. During this time, lubricating oil was not distributed between the friction plates, resulting in intense heat generation and wear on the friction surfaces.

In contrast, in the present invention, the slide sleeve extends into the boss portion, and the annular oil passage within the sleeve and the annular oil passage within the boss portion extend straight. Therefore, all the lubricating oil that has flowed into the sleeve internal annular oil passage is guided to the boss internal annular oil passage. Therefore, regardless of the normal differential state or differential limited state, lubricating oil can be uniformly and sufficiently supplied between each friction plate, and abnormal heat generation and wear on each friction surface can be eliminated.

c. Lubricating oil can be actively supplied to the friction surfaces of each friction plate of the friction clutch. That is, the lubricating oil in the present invention passes through the piston inner annular oil passage, the sleeve inner annular oil passage, and the boss inner annular oil passage, and then flows into the inner diameter side of each friction plate through the oil passage hole in the boss, and The centrifugal force generated by the rotation of the box is used to form a flow toward the outer diameter side of the friction plate through the oil grooves on each friction surface. Therefore, lubricating oil can be actively supplied to each friction surface, and abnormal heat generation and wear of each friction surface can be eliminated from this surface as well.

d) The amount of lubricant to the friction clutch can be increased. That is, in the present invention, the lubricant oil passage from the axle box to the friction clutch is replaced by an annular oil passage inside the piston.
It consists of an annular oil passage inside the sleeve and an annular oil passage inside the boss, and the diameter increases gradually or smoothly toward the back. Therefore, due to the centrifugal force caused by the rotation of the differential box, the lubricating oil flows smoothly without backflowing, and the amount of lubricating oil to the friction clutch can be increased.

e) The structure of the lubricating device can be simplified, making it easier to manufacture, suppressing the temperature rise of the lubricating oil, and preventing dust from getting mixed in. That is,
Conventional lubrication equipment requires a separate scraper,
Requires special processing such as drilling holes in the differential box,
Additionally, since the lubricating oil passes through the differential box, the oil temperature rises during that time, and dirt can also get mixed in due to wear on the differential pinion and side gear.

However, in the present invention, the lubricating oil is configured to pass through each annular oil passage between the piston/slide sleeve, the boss of the differential side gear, and the axle, so drilling or other special processing in the differential box is not necessary. It is not necessary and manufacturing is easy. In addition, the lubricating oil does not pass through the differential gear as in conventional systems, but instead is supplied to the friction clutch through each annular oil passage and oil hole, which prevents oil temperature from rising and dirt from entering. Can be done.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional front view thereof, and FIG. 2 is a partially enlarged longitudinal sectional front view. Drawing code 1...Input pinion, 2...Ring gear, 3...Gear differential mechanism, 4...Piston, 5...
...Slide sleeve, 6...Friction clutch, 7...
...Axle, 8... Axle box, 9... Piston inner annular oil passage, 10... Sleeve inner annular oil passage, 11... Differential side gear, 12... Boss part, 13... Boss part inner annular oil passage, 14... ...Oil hole, 15...Friction plate, 1
6... Oil groove, 17... Clutch case, 18...
Oil drain hole.

Claims (1)

[Claims] 1 It has an input pinion 1, a ring gear 2, and a gear type differential mechanism 3, and uses a piston 4 operated by external fluid pressure to switch between normal differential and differential limited by a friction clutch 6 via a slide sleeve 5. In the differential limiting device, an axle box 8 is installed between the axle 7 on the slide sleeve 5 side and the piston 4 on the outer periphery.
An annular oil passage 9 inside the piston into which lubricating oil can flow is provided, followed by an annular oil passage 10 inside the sleeve between the axle 7 and the slide sleeve 5, and an annular oil passage 10 inside the sleeve. continue,
A boss inner annular oil passage 13 is provided between the axle 7 and the boss 12 of the differential side gear 11 on that side, and the piston inner annular oil passage 9 and the sleeve inner annular oil passage 1 are provided.
0. The boss inner annular oil passage 13 is formed to have a larger diameter toward the rear, and the rear end of the slide sleeve 5 extends into the boss 12 of the differential side gear 11. A through hole 14 is provided, and an oil groove 16 is formed toward the outer diameter side on the friction surface of each friction plate 15 meshing with the outer periphery of the through hole 14.
A lubricating device in a differential limiting device, which is provided with an oil drain hole 18 leading to an outer axle box 8.