JPH0483957A - Lubrication structure for differential device - Google Patents

Abstract

PURPOSE:To ensure efficient circulation of lubricating oil and to reduce the size and the weight of a device by forming an opening part, communicated with the hollow part on the small end side of a taper roller bearing, in a lubricating oil passage running from a pinion gear to an oil seal. CONSTITUTION:When a drive pinion shaft 13 is rotated, taper roller bearings 14 and 15 are rotated, the first chamber 20 side is brought into a negative pressure state through the action of a pump with the aid of which liquid is delivered from the small end side toward the large end side, and lubricating oil in a lubricating oil passage 16 flows through a second opening 18 to the first chamber 20 side. A part of inflow lubricating oil lubricates the large taper roller bearing 14 and flows in a ring gear part. After the lubricating oil lubricates a ring gear 12 and a pinion gear 13a, it is returned through a first opening 17 to the lubricating oil passage 16. Meanwhile, after the rest of the lubricating oil flowing to the first chamber 20 lubricates the small taper roller bearing 15, it flows to a second chamber 22, and after it lubricates an oil seal 21, it is returned to the lubricating oil passage 16 again.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a differential device for a vehicle, and particularly to a differential device that is compact and lightweight.

In the conventional technology differential device, as shown in FIG. The oil seal portion 4 where the drive pinion shaft 2 extends from (the right end in the figure), the ring gear 5 and the pinion gear 6
It lubricates each part of the shaft to prevent rotational failure and heat generation due to friction. In particular, the oil that has lubricated the bearing parts 3a and 3b of the drive pinion shaft 2, which is one of the high heat generating parts in the differential carrier 1, is sent to the parts that lubricate the ring gear 5 etc., which generate relatively little heat, to lower the oil temperature. In order to prevent the oil from degrading and causing the oil to deteriorate, it is necessary to actively circulate the oil between the two parts to prevent the oil from overheating.

Therefore, in the past, the oil was scraped up by the rotation of the ring gear 5 and the oil was removed from the ring gear 5 and the pinion gear 6.
At the same time, the bearing parts 3a and 3b of the drive pinion shaft 2 and the oil seal part 4 are
lubrication. That is, an oil forward hole 8 is provided in the upper part of the differential carrier 1 to serve as a passage for oil that scatters in the tangential direction. is returned to the lower oil return hole 7 by gravity.

As described above, the conventional differential device requires two lubricating oil passages, the oil return hole 8 and the oil return hole 7.

Problems to be Solved by the Invention Therefore, as described above, in the conventional differential device, the two lubricating oil passages, the oil forward hole 8 and the oil return hole 7, ensure that each part in the differential carrier 1 is sufficiently supplied with lubricating oil. Although the lubricating oil is formed so as to spread and circulate, there are problems in that the apparatus becomes large and heavy because two lubricating oil passages are required. In particular, the oil forward hole 8 formed in the upper part of the differential carrier 1 is designed to have a shape that allows the oil splashing in the tangential direction from the ring gear 5 to pass through efficiently, so it occupies a large space and increases the size of the device. This was one of the reasons why.

This invention was made in view of the above circumstances, and instead of scattering the oil using a ring gear, the lubricating oil is circulated by the pumping action of a tapered roller bearing, which is a bearing of a drive pinion shaft. The purpose of this invention is to provide a lubrication structure for a differential device that allows the device to be made smaller and lighter.

Means for Solving the Problems As a means for solving the above problems, a lubrication structure for a differential device of the present invention includes a ring gear portion housing a ring gear, and a drive pinion shaft having a pinion gear meshing with the ring gear. Lubrication is formed in the axial direction of the drive pinion shaft on the outer peripheral side of the drive pinion part of the differential carrier consisting of a drive pinion part, and communicates from a position facing the pinion gear to a position facing the oil seal at the end of the drive pinion shaft. It is characterized by having an oil passage and an opening that opens in the middle of the lubricating oil passage and communicates with a hollow portion facing the small diameter end side of the Taper roller bearing that rotatably supports the drive pinion shaft.

Operation With the above structure, first, when the drive pinion shaft rotates, the Tabor roller bearing rotates accordingly, and the bearing part is self-lubricated by the pump action of the Tabor roller bearing, and the Tabor roller bearing also rotates. Negative pressure is generated in the hollow portion facing the small diameter end of the tube. When negative pressure is generated in the hollow part, the lubricating oil in the lubricating oil passage is sucked in through the opening.

As a result, the lubricating oil in the differential carrier is sucked into the hollow part from the lubricating oil passage through the opening, and then flows from the small diameter side of the Taper roller bearing in the bearing section to the large diameter side, and is then transferred to the pinion gear and ring gear. A circulating flow is formed in which the lubricating oil is sent to the lubricating oil passage or the oil seal portion, lubricates each part, and then returns to the lubricating oil passage.

Therefore, compared to the conventional lubricating structure of a differential device, the oil forward hole 8, which is formed largely in the tangential direction of the ring gear, is not required, and the device can be made smaller and lighter by that amount. In addition, the lubricating oil that lubricates and cools the drive pinion, which is one of the heat generating parts, flows into the lubricating oil passage and mixes with the lubricating oil that has circulated in the ring gear, which has a relatively low temperature, and the oil temperature decreases. This prevents lubricating oil from deteriorating due to an increase in temperature.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

This differential device houses a ring gear 12 in a ring gear part (the left half in FIG. 1) A of a differential carrier 11, and a drive pinion shaft 13 in a drive pinion part B, which has one set of large and small tapered roller bearings. 14 and 15, and is rotatably accommodated while being restricted from moving in the axial direction. The drive pinion shaft 13 has one large, large-diameter taper roller bearing 14 on the pinion gear 13a side, which is subjected to a large load, and the other small taper roller bearing 15, which is placed on the oil seal side, which is subject to a small load. are provided so that the small diameter ends of the two are opposite to each other.

Further, a lubricating oil passage 16 is provided on the outer circumferential side of the drive pinion portion B of the differential carrier 11.
It is formed in a direction parallel to the axis of 3. In addition, the lubricating oil passage 16 has three openings 17, 18, 19, first to third openings.
The lubricating oil passage 16 communicates with the ring gear part A through the first opening 17, and is formed between the tapered roller bearings 14 and 15 bearing the drive pinion shaft 13 through the second opening 18. 1st room 20
The third opening 19 further communicates with a second chamber 22 formed facing the oil seal 21 .

Next, the operation of this embodiment configured as described above will be explained.

First, when the drive pinion shaft 13 rotates within the differential carrier 11, the tapered roller bearings 14 and 15 that rotatably support the drive pinion shaft 13 rotate, directing the liquid from the small diameter end to the large diameter end. Due to the pumping action, the first chamber 20 side becomes negative pressure, and the lubricating oil in the lubricating oil passage 16 flows to the first chamber 20 side via the second opening 18. A part of the lubricating oil that has flowed into the first chamber 20 lubricates the large tapered roller bearing 14 and flows into the ring gear part A, and after lubricating the ring gear 12 and pinion gear 13a,
The lubricating oil flows back into the lubricating oil passage 16 from the first opening 17 . On the other hand, the remainder of the lubricating oil that has flowed into the first chamber 20 lubricates the small tapered roller bearing 15 and then flows into the second chamber 22.
After lubricating the oil seal 21 arranged facing this second chamber 22, the oil flows back into the lubricating oil passage 16, and the lubricating oil passage 16
After being mixed with the lubricating oil that has returned from the ring gear section A side, the lubricating oil flows back into the first chamber 20 through the second opening 18 and lubricates each section.

Therefore, compared to conventional lubrication structures, the apparatus can be made smaller and lighter by eliminating the need for an oil return hole. Furthermore, the high-temperature lubricating oil that has cooled and lubricated the drive pinion part B, which is one of the heat-generating parts, flows into the lubricating oil passage 16 and is mixed with the lubricating oil that has circulated in the relatively low-temperature ring gear part A. This lowers the oil temperature and prevents deterioration of the lubricating oil due to overheating.

Effects of the Invention As described above, the lubrication structure of the differential gear according to the present invention includes a ring gear section that accommodates a ring gear, a drive pinion section that accommodates a drive pinion shaft that includes a pinion gear that meshes with the ring gear. a lubricating oil passage formed in the axial direction of the drive pinion shaft on the outer circumferential side of the drive pinion portion of the differential carrier, which communicates from a position facing the pinion gear to a position facing the oil sill at the end of the drive pinion shaft; The lubricating oil passage has an opening that opens in the middle and communicates with the hollow part facing the small diameter end of the tapered roller bearing that rotatably supports the drive pinion shaft, thereby ensuring efficient circulation of the lubricating oil. In addition, the device can be made smaller and lighter. In addition, the volume is reduced due to the miniaturization of the device.
This has effects such as being able to reduce the amount of lubricating oil used.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention, in which FIG. 1 is a partially sectional side view of a differential device;
FIG. 2 is a sectional plan view of FIG. 1, and FIG. 3 is an explanatory diagram showing a conventional example. 11... Differential carrier, 12... Ring gear,
13... Drive pinion shaft, 14.15.
...Taper roller bearing, 16...Lubricating oil path, 17...First opening, 18...Second opening, 19
...Third opening, 20...First chamber, 21...Oil seal, 22...Second chamber, A...Ring gear section, B...Drive pinion section.

Claims (1)

[Claims] A differential carrier comprising a ring gear part that accommodates a ring gear and a drive pinion part that accommodates a drive pinion shaft having a pinion gear meshing with the ring gear is provided on the outer circumferential side within the drive pinion part in the axial direction of the drive pinion shaft. a lubricating oil passage that is formed and communicates from a position facing the pinion gear to a position facing the oil seal at the end of the drive pinion shaft; and a taper roller that opens in the middle of this lubricating oil passage and rotatably supports the drive pinion shaft. A lubrication structure for a differential device, comprising an opening communicating with a hollow portion facing a small diameter end of a bearing.