JPS6231734Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a lubrication structure for an interaxle differential device, and more specifically, the present invention relates to a lubrication structure for an interaxle differential device. The present invention relates to a lubrication structure for an interaxle differential device provided to allow a difference in rotational speed between the two.

A conventional interaxle differential device will be explained with reference to FIG.

In the figure, the first casing 1, the lowest gear 2
The interaxle differential device includes a gear train including the highest gear 3, a first shaft 4, a second shaft 5, a second casing 6, a bearing 7, and the like.

The first casing 1 constitutes a part of the differential carrier of the front rear axle, and oil A is stored in the bottom part. The lowest gear 2 is rotated while its lower part is immersed in oil, and is mounted on a shaft 8 that inputs input to a differential device (not shown) of the front rear axle. The oil pumped up by the lowest gear 2 is conveyed to the highest gear 3 via an idler (not shown). Top gear 3
The oil transported is injected into the second casing 6 and stored through holes bored at appropriate locations in the bearing housing 10 that supports the tapered roller bearing 9. The second casing 6 is the first casing 1
is fixed to the second shaft 5 via a bolt 11.
The swollen portion 5a is housed therein. The bulging portion 5a is formed in a bowl shape at the right end of the second shaft 5 in the figure.
Furthermore, a similar bowl-shaped member 12 is arranged opposite to this bowl-shaped end.
is substantially integrally formed with the second shaft by the bolt 13. Inside the bulging portion 5a, although not shown, there is a first shaft fixed to the tip of the first shaft 4.
A bevel gear, a second bevel gear arranged opposite to the first bevel gear and fixed to the uppermost gear 3, and a gear 4 which is meshed with these bevel gears and is loosely attached to a member called a cross-shaped spider. Contains several bevel gears. Hole 30 (only one hole is shown in FIG. 1) drilled on the outer periphery of the bulging portion 5a
is for inserting the above spider. The second shaft 5 projects from the second casing 6 and is connected to a drive shaft connected to the engine side. Further, a ball bearing 7 is interposed between the second shaft 5 and the second casing 6 to support the second shaft 5. Further, an oil seal 14 is arranged near the ball bearing 7 to prevent the oil B stored in the second casing 6 from leaking to the outside.

To explain the operation of the interaxle differential device configured as above, the rotational force from the drive shaft is transmitted to the second shaft 5, and if the rotational resistance is equal to the front rear axle and the rear rear axle, the rotational force is transmitted to the top gear 3. It rotates at the same rotational speed as the first shaft 4. However, if the rotational resistance or wheel radius is different between the front rear axle and the rear rear axle, the top gear 3 and the first shaft 4 will rotate at different speeds. As a result, a differential operation is performed between the front and rear wheels, and the vehicle rotates smoothly.

Incidentally, the oil B stored at the bottom of the second casing 6 adheres to the outer periphery of the bulging portion 5a, and a part of it is scattered by centrifugal force and transmitted through the wall inside the second casing 6 to the ball bearing 7. However, when the rotational speed is low, the centrifugal force is small and the amount of oil splashed is small, resulting in insufficient lubrication of the ball bearing 7. Particularly when climbing a long slope, rotational force is required, the load on the ball bearing 7 becomes large, and lubricating oil is required, but there is a risk of oil shortage for the above reasons.

The present invention was devised to solve the above-mentioned problems, and its purpose is to provide a lubrication structure for an interaxle differential device that can reliably supply oil to the bearings even when the rotational speed decreases.

In order to achieve the above object, the present invention includes a spiral groove formed on the outer periphery of the bulge of the shaft connected to the drive shaft so that the lagging side in the rotational direction is close to the bearing to be lubricated. The lubrication structure of the interaxle differential device is characterized in that the interaxle differential device is configured to be bored on the outer periphery of the protruding portion and to transfer oil to the bearing through the groove to lubricate the bearing.

Hereinafter, embodiments of the present invention will be described based on the drawings.

In FIG. 2, the same reference numerals as in FIG. 1 indicate the same items or items with the same function.

As shown in FIG. 2, the second shaft 25 has a bowl-shaped end on the side of the first casing 1, and a similar bowl-shaped member 26 is disposed opposite to the bowl-shaped end 25a. The portion 25a and the bowl-shaped member 26 are substantially integrally formed by a bolt 27.
The contact portion between the bowl-shaped end portion 25a and the bowl-shaped member 26 is shaped into a cylindrical shape, so that a large area is immersed in the oil stored at the bottom of the second casing 6. In this case, the bulging portion 28 includes a conical portion 25b that expands conically from the portion of the second shaft 25 that is fitted into the inner ring portion of the ball bearing 7, a bowl-shaped end portion 25a that forms the maximum outer diameter portion of the cylindrical shape, and A known differential gear (not shown) is housed inside the bowl-shaped member 26. Further, the cylindrical bowl-shaped end portion 2 of this bulging portion 28
5a, the bowl-shaped member 26, and the conical portion 26b are provided with a plurality of grooves 29. The groove 29 is formed in a spiral shape up to the vicinity of the ball bearing 7, and the twisting direction is from a point M on the outer circumference of the bulge 28 to a point N on the rotational direction delay side of this point M to a point P close to the ball bearing 7. It is formed to draw a trajectory.
The groove 29 is bored avoiding the hole 30 for holding the spider, the bolt 27, an opening (not shown), etc., and is desirably formed as deep as possible.

Next, the functions and effects of this embodiment will be explained.

The maximum outer circumferential portion of the bulging portion 28 is always immersed in oil B, and oil intervenes in the groove 28. When the bulging portion 28 rotates in the direction of the arrow R, the oil moves toward the ball bearing 7 while being pushed by the rotation direction lag side wall 29a of the groove 29, and is finally injected into the ball bearing 7. become. Moreover, since the groove 29 is also formed on the outer periphery of the conical portion 25b, even if the rotational speed decreases, the oil will not flow into the groove 29.
The ball bearing 7 can be reached along this line. Since the grooves 29 are deeply bored, a large amount of oil can naturally be transferred and sufficient lubrication can be achieved.

The groove 29 is not limited to a single groove, but may be multiple grooves.

As is clear from the above description, according to the present invention, it is possible to reliably supply oil to the bearing portion and provide sufficient lubrication regardless of the decrease in rotational speed.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a conventional interaxle differential device, and FIG. 2 is a side view showing an embodiment of the present invention. 1...First casing, 2...Lowest gear, 3
...Top gear, 4...1st shaft, 5,25
...Second shaft, 5a, 28...Bulging portion, 6...
...Second casing, 7...Ball bearing.

Claims (1)

[Scope of utility model registration request] a first casing that stores oil at the bottom;
a gear train disposed within the first casing, the lower part of the lowest gear of which is immersed in oil; The shaft is coaxially connected to the first shaft and the uppermost gear via a differential gear, and its end on the first shaft side bulges to hold the differential gear. a second shaft forming a bulge and protruding from the second casing, the other end of which will be described later; and a second shaft attached to the first casing so as to be able to store oil pumped up through the gear train; a second casing that accommodates the bulge of the second shaft whose lower part is immersed in oil; and a bearing interposed between the second casing and the second shaft that protrudes from the second casing. In an interaxle differential device having
A lubrication structure for an interaxle differential device, characterized in that a spiral groove is formed on the outer periphery of the bulge of the second shaft, the lag side of the groove in the rotational direction being close to the bearing.