JP3166547B2 - Bearing lubrication structure - Google Patents

Abstract

PURPOSE: To achieve excellent lubrication of a bearing by causing a stream along the axial direction of a lubricating oil toward the bearing positively. CONSTITUTION: A rotary shaft 4 is supported on a bearing 6 which is fitted in an inner face of a bearing case 3, and a lubricating oil O is poured and supplied into one end in the axial direction of the bearing 6 to form a lubricating structure of the bearing 6. A cylindrical section 10 of which central axis almost coincides with the bearing 6 is formed at one end in the axial direction of the bearing 6 in the bearing case 3. A guide wall face section 24 which protrudes toward the central part, is continuous circumferentially, and whose a part is inclined circumferentially in the direction in which it approaches the bearing 6 is formed on an inner face of the cylindrical section 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubrication structure for a bearing in a differential device for a vehicle such as an automobile.

[0002]

2. Description of the Related Art As a lubrication system for a bearing, there are known a splash lubrication system in which lubricating oil is scraped up by a rotating member and the splash is supplied to the bearing, and a forced lubrication system in which lubricating oil is supplied by an oil pump. I have. The differential device used as the final reduction gear in the above vehicle cannot incorporate an oil pump in itself, and since it is difficult to provide a lubricating oil passage, splash lubrication is generally adopted. ing.

[0003] This type of differential device is
In addition to the bearings supporting the left and right axles connected to the side gears, a drive pinion or a bearing supporting the drive shaft connected to the drive pinion is provided. The bearing supporting the pinion or the drive shaft is provided on a portion of the differential carrier (differential carrier) that protrudes in the front-rear direction of the vehicle. This part is located radially outward of the ring gear that lubricates the lubricating oil, but if the front and rear bearings are provided, the lubricating oil is Is difficult to supply. In such a case, for example, JP-A-4-3
As described in Japanese Patent Publication No. 02756, a lubricating oil guide is formed on an inner surface of a differential carrier or the like, and lubricating oil scraped up by a ring gear or the like is guided to a target bearing or oil seal by the lubricating oil guide. It is effective.

[0004]

In a bearing in which rolling elements such as balls and rollers are arranged between an inner ring and an outer ring,
It is necessary to supply the lubricating oil between the inner ring and the outer ring, but when the lubricating oil is supplied by the above-described lubricating oil guide to the bearing mainly receiving the radial load, the lubricating oil is not pressurized. Therefore, lubricating oil is supplied by gravity to one end of the bearing in the axial direction. The lubricating oil supplied in this way receives centrifugal force when it comes into contact with bearings and rotating shafts, and receives rotational force due to viscosity, so it rotates along the inner surface of the part that houses the bearings and rotating shaft. It flows and partly flows to places other than the bearing. In particular, in a structure such as a tapered roller bearing in which the centrifugal force generated by rotation increases at one end side in the axial direction, lubricating oil is positively pushed out, and lubrication shortage is likely to occur.

That is, in the conventional lubricating structure, the lubricating oil that has been scooped up can be guided to the vicinity of the bearing, but has no effect on the lubricating oil swirled by the bearing and the rotating shaft. Insufficient lubrication may occur. In particular, in the differential device described above, when a part of the lubricating oil in the differential carrier flows into the axle housing as the vehicle turns at a high speed, when the amount of lubricating oil lifted up by the ring gear decreases, the differential oil is guided by the lubricating oil guide. Since the amount of lubricating oil to be reduced is small, the lubricating oil in the vicinity of the bearing swirls and becomes difficult to be supplied to the bearing, and there is a high possibility that the lubrication of the bearing will be insufficient.

The present invention has been made in view of the above circumstances, and has as its object to provide a lubricating structure excellent in a function of supplying lubricating oil to a bearing.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a rotary shaft supported by a bearing fitted on the inner surface of a bearing case, and the bearing is provided at one end in the axial direction of the bearing. In the lubricating structure of a bearing that supplies lubricating oil, a cylindrical part having a center axis substantially aligned with the bearing is formed in a bearing case at one end in the axial direction of the bearing, and an inner surface of the cylindrical part is formed in a circumferential direction. to together and continuing to, the times
Toward the rotation direction of the rotation axis, to near gradually contact first portion is the bearing
It is characterized in that the guide wall portion which is tilted with respect to the circular circumferential direction so that is formed.

[0008]

In the lubricating structure of the present invention, when lubricating oil is supplied to the bearing, the lubricating oil flows into a cylindrical portion formed at one end of the bearing. The lubricating oil swirls and flows along the inner surface of the cylindrical portion by receiving a circumferential force from a bearing or a rotating shaft supported by the bearing. As a result, the flow direction of the lubricating oil is changed by the guide wall portion formed on the inner surface of the cylindrical portion, and a part of the lubricating oil flows toward the bearing along the guide wall portion. That is, the lubricating oil is forcibly supplied to the bearing while swirling and flowing inside the cylindrical portion, and the bearing is lubricated well.

[0009]

Next, the present invention will be described in detail based on embodiments. 1 to 3 show an example in which the present invention is applied to a banjo type differential device. A differential device 1 has a differential carrier 2 having a circular cross section.
And a conical bearing case 3 is integrally provided in front of the differential carrier 2. An axle housing (not shown) is connected to both left and right sides of the differential carrier 2. And the whole is configured in a sealed structure. A drive shaft 4 is inserted into the bearing case 3 along the front-rear direction of the vehicle, and power output from the engine via a transmission is input via the drive shaft 4. .

As shown in FIGS. 1 and 2, the bearing case 3 has a cylindrical receiving portion 5, and tapered roller-type bearings 6, 7 are fitted and fixed to two front and rear portions inside the receiving portion 5. I have. The distance between the bearings 6 and 7 is maintained at a constant distance by the spacer 8. The drive shaft 4 integral with the drive pinion 9 is rotatably supported by these two bearings 6 and 7. In front of the front bearing 6 of the receiving portion 5, an opening end 11 is sandwiched by a predetermined cylindrical portion 10.
The opening end 11 is sealed in a liquid-tight state by an oil seal 12. A flange 13 connected to, for example, a propeller shaft (not shown) is attached to one end of the drive shaft 4 protruding from the bearing case 3 by a bolt.

The drive pinion 9 meshes with a ring gear 15 integrated with the outer peripheral portion of the differential case 14.
Inside the differential case 14, two pairs of pinions 16 are rotatably held, and these pinions 16 mesh with left and right side gears (not shown) to allow differential rotation of left and right wheels. It has become.

A predetermined amount of oil O is contained in the bottom of the differential carrier 2, and a part of the ring gear 15 is immersed in the oil O. Since the ring gear 15 rotates in the direction of the arrow in FIG. 1, the oil O is scraped up by the ring gear 15 and scatters in the tangential direction. For this reason, an oil supply passage 17 surrounded by the outer peripheral surface 5a and the case inner wall surface 3a is formed above the receiving portion 5 of the bearing case 3, and one end thereof is formed above the ring gear 15. The oil O scattered from the ring gear 15 is guided toward the opening.

The oil supply passage 17 extends forward in the axial direction of the receiving portion 5 while gradually reducing the opening cross section. The height of the oil supply passage 17 increases as the outer peripheral surface 5a of the receiving portion 5 forming the bottom portion moves forward. It gradually lowers, so that the oil can be guided forward. A communication port 18 in the middle of the oil supply passage 17 opens between the two bearings 6 and 7, and a supply port 19 on the distal end side opens in the cylindrical portion 10.

An oil return port 20 is opened in the cylindrical portion 10, and a guide groove 21 is formed in the inner peripheral surface 10a of the cylindrical portion 10. The return port 20 is the supply port 1
The oil return passage 22 is formed at a position rotated by, for example, 90 degrees in the rotation direction of the drive shaft 4 with respect to the drive shaft 9 and displaced slightly forward from the supply port 19.
Are formed along the longitudinal direction of the bearing case 3 in a state of being isolated from the hollow portion accommodating the drive shaft 4.
The oil return passage 22 communicates with a portion of the differential carrier 2 that houses the ring gear 15.

The guide groove 21 will be described with reference to FIGS. (A) is a perspective view of the guide groove portion viewed from the right side of the opening end of the receiving portion, (B) is a perspective view similarly viewed from the front, and (C) is a perspective view similarly viewed from the left side. As shown in these figures, the guide groove 21 is
The drive shaft 4 is connected to the supply port 19 almost all around the inner peripheral surface
Are formed along the rotation direction. This guide groove 21
Is a groove defined by a side wall surface (temporarily assumed to be an inner wall surface) 23 close to the front bearing 6 and a side wall surface (temporarily assumed to be an outer wall surface) 24 close to the open end 11. It can be divided into parts 21a, 21b, 21c.

That is, the inner wall surface 23 is a simple wall surface along the rotation direction of the drive shaft 4, while the outer wall surface 2 is
Numeral 4 is inclined in the spiral direction in each of the portions 21a and 21c. More specifically, each part 21a of the guide groove 21
21c, the outer wall portion 24 in the direction of rotation of the drive shaft 4 is inclined in the circumferential direction so as to approach the inner wall surface 23 to form the guide wall portion in the present invention. The groove width at each of the portions 21a, 21c is gradually reduced in the rotation direction. FIG. 5 is an expanded view of the shape of the guide groove 21.

Next, the operation of the above lubricating structure will be described. The power transmitted to the drive shaft 4 is transmitted from the drive pinion 9 to the ring gear 15, and the ring gear 15 and the differential case 14 integrated therewith are rotated. Further, power is transmitted from the differential case 14 to the left and right wheels via a pinion 16 and left and right side gears. In that case, the rotation of the pinion 16 causes a differential between the left and right wheels. Since a part of the ring gear 15 is immersed in the oil O of the differential carrier 2, the ring gear 1
5 is lubricated, and the oil O is scraped up with the rotation of the ring gear 15 in the direction of the arrow in the figure, and is scattered throughout the inside of the differential carrier 2. Lubricated.

The ring gear 1 is provided in front of the differential carrier 2.
The oil O scattered in the tangential direction of 5 flows into the oil supply passage 17 of the bearing case 3 and is collected. This oil O
Is guided by the passage 17 and flows forward of the drive shaft 4.
It flows into the space between the two bearings 6 and 7 from the communication port 18 on the way. In this case, since the nose angle is usually set so that the opening end 11 side of the differential carrier 2 is higher, the oil O supplied from the communication port 18 is mainly
Then, it is supplied to a rear bearing (the left bearing in FIG. 1) 7. The oil O in the oil supply passage 17 further flows from the supply port 19 on the distal end side toward the cylindrical portion 10 forward of the front bearing 6.

The oil O flowing into the cylindrical portion 10 is rotated by contacting the bearing 6 and the drive shaft 4,
The fluid flows in the same direction as the rotating shaft 4 along the inner peripheral surface 10 a of the cylindrical portion 10. The oil O attached to the inner peripheral surface 10a of the cylindrical portion 10 flows into the guide groove 21 formed on the inner peripheral surface 10a of the cylindrical portion 10 and flows along the guide groove 21. As described above, the outer wall surface 24 of the guide groove 21 is formed in a spiral shape so as to approach the front bearing 6 on the front side in the oil flow direction in each of the portions 21a to 21c. Wall 24
And flowed to the front bearing 6 side. As a result, the oil O flowing along the inner peripheral surface 10a of the cylindrical portion 10 is positively flown toward the front bearing 6 for each of the portions 21a and 21c of the guide groove 21, and as a result, lubrication of the front bearing 6 is achieved. Is performed well.

The oil O overflowing from the third portion 21c of the guide groove 21 flows through a portion of the inner peripheral surface 10a of the cylindrical portion 10 where the guide groove 21 is not formed, and again flows into the first portion 21a. Or returned to the inside of the differential carrier 2 from the return port 20 through the oil return passage 22. When a large amount of oil O is scooped up by the high-speed rotation of the ring gear 15 and the amount of oil O flowing into the cylindrical portion 10 from the oil supply passage 17 increases, the oil O that cannot be collected by the guide groove 21 returns as appropriate. Mouth 2
Reflux from 0 toward the differential carrier 2. As a result, it is possible to prevent the oil from being supplied to the front bearing 6 more than necessary, and to thereby prevent an increase in stirring loss.

The guide groove 21 is formed on the inner peripheral surface 10 of the cylindrical portion 10.
The oil O is held in the guide groove 21 to some extent because it is formed to be more depressed than a. Therefore, even when the oil level of the differential carrier 2 is low and the amount of oil O scraped up by the ring gear 15 is reduced, for example, when the vehicle is traveling at high speed turning or traveling on an inclined ground, the guide groove is provided to the front bearing 6. Since the oil O inside 21 is continuously supplied, even when the amount of oil O scraped up by the ring gear 15 decreases, the front bearing 6 can be sufficiently lubricated.

Further, even in a case where the oil 0 is not sufficiently fed from the supply port 19, the oil O once supplied to the bearing from the guide groove 21 lubricates the bearing and then re-enters the guide groove 21. I can go back,
Insufficient lubrication is less likely to occur, and in this respect, the lubrication is excellent.

The present invention is not limited to the embodiment described above, and the guide surface for forcibly flowing the lubricating oil toward the bearing is not limited to the outer wall surface 24 of the guide groove 21 described above. In short, it is only necessary that the lubricating oil flowing along the circumferential direction is forcibly guided toward one side in the axial direction. A weir may be formed, and the protrusion or one of the side walls of the weir may be used as the guide wall.
The guide wall may not be formed in the cylindrical portion but may be formed by fitting another member. Further, when forming the guide groove, the guide groove may be formed by a pair of circumferentially continuous projections. Further, the lubricating structure of the present invention is not limited to the differential device described above, but can be applied to a lubricating structure of a bearing of another general mechanical device.

[0024]

As described above, according to the lubricating structure of the present invention, the guide wall portion for flowing the lubricating oil supplied in the vicinity of the bearing in the axial direction while rotating and flowing together with the bearing and the rotating shaft. Is provided, it is possible to positively generate the flow of lubricating oil in the axial direction toward the bearing, and as a result, a sufficient amount of lubricating oil to be supplied to the bearing is ensured and the lubrication of the bearing is improved. The burning can be prevented beforehand.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a differential device equipped with a lubrication device of the present invention.

FIG. 2 is a sectional view of a part of a bearing case.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is a perspective view of the guide groove as viewed from a case opening end.

FIG. 5 is a development view of a cylindrical portion for explaining the shape of a guide groove.

[Explanation of symbols]

 Reference Signs List 2 differential carrier 3 bearing case 4 drive shaft 6, 7 bearing 9 drive pinion 10 cylindrical portion 10a inner peripheral surface 15 ring gear (large-diameter gear) 19 supply port 21 guide groove 24 outer wall surface

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-199352 (JP, A) JP-A-3-89220 (JP, U) JP-A-55-7476 (JP, U) JP-A-1 156353 (JP, U) Hira 3-123150 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F16H 57/00-57/04 F16H 48/08

Claims (1)

(57) [Claims] 1. A lubrication structure for a bearing in which a rotating shaft is supported by a bearing fitted to an inner surface of a bearing case and lubricating oil is supplied to one end of the bearing in the axial direction. on one end, a cylindrical portion which substantially coincide with the bearing and the center axis is formed in the bearing casing, the inner surface of the cylindrical portion, to together for continuous in a circumferential direction, said rotary shaft
Toward the rotation direction, one part close progressively against the bearing
Lubrication structure for the bearing, characterized in that the guide wall portion which is tilted with respect to Unien circumferential direction is formed.