CN110578782A

CN110578782A - Transmission shaft of differential mechanism and differential mechanism

Info

Publication number: CN110578782A
Application number: CN201810589812.2A
Authority: CN
Inventors: 于胜华; 龙金星
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2018-06-08
Filing date: 2018-06-08
Publication date: 2019-12-17

Abstract

The invention relates to a propeller shaft for a differential and a differential, wherein the propeller shaft is used for connecting planetary gears of the differential and transmitting torque between the planetary gears. According to the technical scheme of the invention, the transmission shaft is provided with a groove for guiding lubricating oil to the planetary gear.

Description

Transmission shaft of differential mechanism and differential mechanism

Technical Field

The invention relates to a propeller shaft, preferably a straight shaft, for a differential, wherein the propeller shaft is used to connect planetary gears of the differential and to transmit torque between the planetary gears.

Background

Differentials are very important devices in vehicle drivelines. Because many rotating parts are provided in the differential, the requirement for lubrication is relatively high. CN 206092869U discloses a drive axle assembly using an integral differential case, in which a straight shaft is provided as a transmission shaft for connecting planetary gears and driving the planetary gears to rotate. One end of the straight shaft is transversely provided with a pin shaft hole, the integral differential shell corresponding to the pin shaft hole is transversely provided with a through hole in a penetrating way, and the straight shaft passes through the pin shaft hole and the through hole through a lock pin to be connected with the integral differential shell and rotates along with the rotation of the differential shell.

Since no guide groove for guiding the lubricating fluid is provided in the in-line shaft, the lubricating effect between the planetary gear and the propeller shaft is not ideal in the known differential.

Disclosure of Invention

The present invention is therefore based on the object of providing an improved propeller shaft and differential, which allow better lubrication of the planet gears of the differential at lower costs, thus resulting in better transmission and increased service life of the differential.

The object of the invention is achieved by a drive shaft for a differential, wherein the drive shaft is used for connecting planetary gears of the differential and transmitting torque between the planetary gears, and according to the invention, a groove for guiding lubricating fluid to the planetary gears is arranged on the drive shaft, and more lubricating fluid can be guided to the planetary gears through the groove, so that relative rotation between the planetary gears and the drive shaft can be lubricated better.

According to a preferred embodiment of the invention, the groove has a helical shape, so that the lubrication fluid is better guided, since the propeller shaft is in operation in a rotational movement about the differential axis. The helical groove enables better guidance of the lubricating liquid to prevent it from being thrown out of the groove. Preferably, the groove extends from the centre of the propeller shaft, in particular from the axis of rotation of the differential, to the end of the propeller shaft. Since the propeller shaft always performs a rotational motion about the axis (rotation axis) of the output shaft of the differential when the differential is in operation, the lubricating fluid flows from the middle of the propeller shaft to both ends under the influence of centrifugal force. The groove for guiding the lubricating liquid should also be designed to extend from the middle of the drive shaft to both ends of the drive shaft. It is also advantageous if the helical groove has a helix angle of 30 °.

according to a further preferred embodiment of the invention, the drive shaft can be a straight shaft or a cross shaft. If the propeller shaft is a straight shaft, at least one through-opening, preferably two such through-openings, extending in the radial direction of the propeller shaft, i.e. parallel to the half-shafts of the differential, may be provided in the middle of the propeller shaft, in order to reduce vibrations of the propeller shaft during operation. Preferably, the recess of the drive shaft passes through the through hole. A large amount of lubricating fluid is present between the axle shafts and the side gears of the differential, and therefore, a large amount of lubricating fluid is also stored in the through-holes of the propeller shaft between the two side gears. The groove extending on the surface of the transmission shaft passes through the through hole, so that lubricating liquid in the through hole can be better guided to the planetary gear, and the lubricating effect is improved. It is further advantageous if two recesses are provided, which extend from the through-opening towards the two ends of the drive shaft, respectively.

According to a further preferred embodiment of the present invention, a square groove is provided at a junction of the transmission shaft and the planetary gear such that the groove of the transmission shaft passes through the square groove. During operation of the differential, for example when the vehicle is turning, the planet gears will rotate relative to the propeller shaft, and therefore better lubrication is required at the junction of the planet gears and the propeller shaft. Set up the square groove on the junction of planetary gear and transmission shaft and let as above the recess pass through this square groove, can guide lubricated liquid on the one hand, on the other hand also can save the lubricated liquid through the recess leading-in to can make the relative rotation between planetary gear and the transmission shaft more steady, reduce the friction, improve the life of the relevant rotation piece.

The object of the invention is also achieved by a differential having a propeller shaft which is designed according to one of the features described above.

Drawings

The invention is schematically illustrated in the following with reference to the accompanying drawings. The attached drawings are as follows:

FIG. 1 shows a cross-sectional view of a differential according to the present invention;

Fig. 2 shows a front view of a propeller shaft according to a first preferred embodiment of the present invention;

Fig. 3 shows a front view of a propeller shaft according to a second preferred embodiment of the present invention.

In the figures, identical reference numerals have been used for functionally identical or similar parts.

Detailed Description

Fig. 1 shows a differential according to the invention, which, as shown, comprises: the differential comprises a differential shell 1, a driven bevel gear 6, two planet gears 4, two side gears 3 and a transmission shaft 2 for connecting the planet gears. In the present embodiment, the transmission shaft 2 is a straight shaft, but is not limited to a straight shaft, and may be a cross shaft, for example. The vehicle's driveline transfers torque from the drive train to the driven bevel gear 6, and the driven bevel gear 6 rotates the differential housing 1 because the driven bevel gear 6 is fixedly coupled to the differential housing 1 by fasteners, such as bolts. In the differential of the present embodiment, a propeller shaft 2 is used to transmit torque between two planetary gears 4. A through-hole is provided at one end of the propeller shaft, and the propeller shaft 2 can be fixedly connected to the differential case 1 by means of a bolt 5. Thus, the differential case 1 can drive the propeller shaft 2, thereby driving the planetary gears 4, and then the planetary gears 4 transmit the torque to the side gears 3, and finally the output shaft (half shaft) is driven to rotate thereby.

The transmission shaft 2 designed according to the present embodiment is provided with two through holes 7 in the middle, and grooves 8 extending to both ends of the transmission shaft are provided on the outer surface of the transmission shaft 2 respectively starting from the two through holes 7. The groove guides the lubricating fluid to the planetary gear 4. The arrows in fig. 1 indicate the direction of flow of the lubricating fluid in the differential. The axial arrows indicate the lubricating fluid between the axle half shaft and the side gear, which, after being collected in the center of the differential, flows by centrifugal force through the through-hole 7 and the groove 8 towards the two ends of the propeller shaft 2, respectively, so that the lubricating fluid flows better into the planetary gears.

Fig. 2 shows a first preferred embodiment of a propeller shaft 2 according to the present invention. In the present embodiment, the propeller shaft 2 is a straight shaft having a cylindrical shape. Two through holes 7 are provided in the middle of the drive shaft 2. As shown, a groove 8, preferably a helical groove, is provided on the outer surface of the drive shaft 2, the helical groove passing through the through hole 7. Preferably, two spiral grooves are provided on the outer surface of the drive shaft 2, each starting from a respective through hole 7 and then extending towards a respective end of the drive shaft 2. According to the present preferred embodiment, the helical groove has a helix angle of 30 °. Of course other sizes of helix angles and other shapes of grooves are contemplated as long as the lubrication fluid is better directed to the planet gears.

Fig. 3 shows a second preferred embodiment of a propeller shaft 2 according to the present invention. This second preferred embodiment differs from the first preferred embodiment in that: between the through-hole 7 and the end of the respective transmission shaft 2, i.e. at the connection of the transmission shaft 2 and the planetary gear 4, a square groove 9 is provided for storing and guiding the lubricating fluid. Advantageously, a groove 8, preferably a helical groove, is also provided on the outer surface of the drive shaft 2, which passes through the through-hole 7 and the square groove 9.

Although possible embodiments have been described by way of example in the above description, it should be understood that numerous embodiment variations exist, still by way of combination of all technical features and embodiments that are known and that are obvious to a person skilled in the art. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. From the foregoing description, one of ordinary skill in the art will more particularly provide a technical guide to convert at least one exemplary embodiment, wherein various changes may be made, particularly in matters of function and structure of the components described, without departing from the scope of the following claims.

List of reference numerals

1 differential case

2 drive shaft

3 half axle gear

4 planetary gear

5 bolt

6 driven bevel gear

7 through hole

8 grooves

9 square groove

Claims

1. A propeller shaft (2) for a differential, wherein the propeller shaft (2) is intended to connect planet gears (4) of the differential and to transmit torque between the planet gears (4),

it is characterized in that the preparation method is characterized in that,

A recess (8) for conducting lubricating fluid to the planetary gear (4) is provided on the drive shaft (2).

2. A propeller shaft (2) according to claim 1, wherein the propeller shaft (2) is a straight shaft or a cross shaft.

3. A propeller shaft (2) as claimed in claim 1, characterised in that the groove (8) has a helical shape.

4. A propeller shaft (2) according to claim 3, wherein the grooves (8) extend from the centre of the propeller shaft towards the ends of the propeller shaft (2), respectively.

5. A propeller shaft (2) as claimed in claim 3 or 4, characterised in that the grooves (8) have a helix angle of 30 °.

6. A propeller shaft (2) according to claim 2, characterised in that if the propeller shaft (2) is a straight shaft, at least one through hole (7) is provided in the middle of the propeller shaft (2) extending in the radial direction of the propeller shaft (2).

7. Transmission shaft (2) according to claim 6, characterized in that said groove (8) passes through said through hole (7).

8. transmission shaft (2) according to claim 7, characterized in that two grooves (8) are provided, which extend from the through hole (7) towards the two ends of the transmission shaft (2), respectively.

9. A propeller shaft (2) according to claim 3, characterised in that a square groove (9) is provided at the connection of the propeller shaft (2) and the planet gear (4), and that the recess (8) passes through the square groove (9).

10. Differential, characterized in that it has a propeller shaft (2) according to any one of claims 1 to 9.