JP3126910B2 - Gear device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear unit for driving a vehicle, and more particularly to a structure of an oil drain hole of a shaft sealing device.

[0002]

2. Description of the Related Art An example of a conventional oil bath lubricated gear device will be described with reference to the drawings. FIG. 3 is a sectional view of an essential part showing an example of a conventional oil bath lubrication type gear device, wherein 1 is a small gear, 2 is a large gear,
Is a gear box that seals the large gear 2 and the small gear 1 therein, and stores the lubricating oil 4 at the bottom thereof until a part of the large gear 2 is immersed. Reference numerals 5 and 6 denote bearings. The small gear 1 and the large gear 2 are supported by the gear box 3 via bearings 5 and 6, respectively, and rotate. The lubricating oil 4 is scraped up by the rotation of the large gear 2 to lubricate the meshing surfaces of the small gear 1 and the large gear 2 and the bearings 5 and 6. Here, when the rotation speed is high, the lubricating oil 4 is disturbed in the gear box 3 and the temperature rise of the gear device becomes excessive. As a countermeasure, as shown in FIGS. 3 and 4, there is a gear device in which a ring 3a is formed on the inner wall of the gear box 3 near the rim side surface 2a of the large gear 2.

FIG. 4 is a cross-sectional view of a main part at the center of the large gear shaft in FIG. 3, and the same reference numerals as those in FIG. 3 indicate the same parts. FIG.
In this case, the lubricating oil (not shown) scooped up by the large gear 2 smoothly flows through the inner peripheral wall surface of the gear box 3, the rim side surface 2 a of the large gear 2, and the path 7 surrounded by the ring 3 a, causing excessive disturbance. Is suppressed. Here, a shaft sealing device using a labyrinth will be described with reference to FIG. The axle 9 is rotatably supported on the gear box 3 by the lid 8 via the bearing 6. A labyrinth that forms a shaft sealing device is formed on the lid 8 together with an oil drain 10 fitted to the axle 9, and lubricating oil (not shown) that accumulates in the labyrinth is returned to the inside of the gear box 3 by a lower oil drain hole 11.
This gear device is used for driving a vehicle, and the outside of the gear device, that is, the outside of the labyrinth receives a traveling wind, and thereby a negative pressure acts.

[0004]

The pressure at the outlet of the oil drain hole by the conventional labyrinth structure is equal to the internal pressure of the gear box, and is substantially atmospheric pressure. Here, in a situation where the outside of the labyrinth has a negative pressure due to the traveling wind, the lubricating oil accumulated in the labyrinth does not return to the inside of the gear box from the oil drain hole, but may be sucked by the outside air and leak from the labyrinth. The present invention has been made in view of the above points, and an object of the present invention is to provide a gear device that prevents oil leakage from a labyrinth.

[0005]

Means for achieving the object is to provide a gear box in which an annular ring protruding from the inner wall surface of the gear box protrudes from an inner wall surface of the gear box, the ring being close to the rim side surface of the large gear having a horizontal rotation axis. In the gear device using the present invention, a recess is provided at a lower portion of the ring so as to make a hole in the axial direction from the inside of the gear box. A waste oil hole outlet of a labyrinth formed on a lid rotatably supporting the axle to the gear box via a bearing is provided on a spigot surface of the lid and the gear box. A hole penetrates through the inside of the gear box wall from a contact portion of the spigot surface of the gear box with the oil drain hole outlet to the concave portion, and a hole is formed, and the concave portion serves as an outlet of the oil drain hole. In this manner, an oil discharge hole outlet of the labyrinth of the gear device is formed near the rim side surface of the rotating large gear.

[0006]

In the labyrinth oil drain hole according to the present invention, since the outlet is located near the rim side surface of the large gear, the position of the outlet can be lowered as compared with the prior art, and the pressure near the outlet can be reduced by rotating the large gear. It can be a negative pressure. For example, 30
Under the floor of a railway car running at 0 km / h, v1 = 30 m
/ S is measured, which acts as a negative pressure outside the labyrinth of the gear train. Here, the peripheral speed of the rim portion of the gear device is v2 = 45 m / S, which is assumed to be the speed of the liquid at the outlet of the oil drain hole, and the fluid is also air (density ρ = 1.2
(Kg / cubic meter), the pressures p1 and p2 at the outside of the labyrinth and at the outlet of the oil drain hole are: p1 (v1 = 30 m / S) =） ρ · v1 · v1 = 54 mmAq p2 (v2 = 45 m / S) = (1/2) ρ · v2 · v2 = 122 mmAq, and the pressure is lower than that in the atmosphere. Accordingly, the pressure at the outlet of the oil drain hole is 6 times greater than the pressure p1 outside the labyrinth.
It becomes 8 mmAq negative pressure. The speed of the liquid at the outlet of the oil drain hole is v2
= 45 m / S, but the liquid is an oil mist with a higher density than air, and this value is a rough value. As described above, it is possible to make the oil discharge hole outlet a relatively negative pressure from the outside of the labyrinth, the oil in the oil discharge hole easily returns to the inside of the gear box, and oil leakage from the labyrinth can be prevented.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention similar to FIG. 4, and FIG. 2 is a side view thereof. In FIG. 1, in a gear device using a gear box 3 in which a ring 3a close to a rim side surface 2a of a large gear 2 protrudes from an inner wall surface of the gear box, a lower portion of the ring 3a A recess 12 is provided to receive the hole in the axial direction. While the oil drain hole 11 of the labyrinth formed in the lid 8 that rotatably supports the axle 9 on the gear box 3 via the bearing 6 is stopped by the stopper 13 on the inner surface of the gear box,
A notch 14 is provided in a spigot portion of the cover 8 with the gear 3, and an outlet of the oil drain hole 11 is provided on a spigot surface of the cover 8 with the gear box 3. A similar notch 15 is also provided in a contact portion of the spigot surface of the gear box 3 with the outlet of the oil drain hole 11, and a hole 16 is formed by penetrating the inside of the wall of the gear box 3 from the notch 15 to the recess 12. In this way, an oil discharge hole outlet of the labyrinth of the gear device is formed near the rim side surface of the rotating large gear. In FIG. 2, a drain hole 11 formed in the lid 8, a cutout 14 formed in the spigot portion, a recess 12 formed in the ring 3 a of the gear box 3, a cutout 15 in the spigot portion, and a hole passing through the wall. 16 is shown.

[0008]

As described above, according to the present invention, the pressure at the outlet of the oil drain hole of the labyrinth can be made negative by the rotation of the large gear. As a result, even if the pressure outside the labyrinth becomes negative due to the traveling wind as in a vehicle drive gear device, the oil remaining in the labyrinth can be smoothly returned to the inside of the gear box through the oil drain hole, preventing oil leakage. It has a great effect. In addition, since the outlet of the oil drain hole can be set near the rim of the large gear by using the ring along the rim side surface of the large gear, there is no new protrusion for the rotation of the large gear, and the gear device has It is possible to prevent a new heat source.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a gear device according to the present invention.

FIG. 2 is a side view of the main part.

FIG. 3 is a sectional view of a main part showing an example of a conventional oil bath lubrication type gear device.

FIG. 4 is a cross-sectional view of a main part at the center of the large gear shaft.

[Explanation of symbols]

 Reference Signs List 1 small gear 2 large gear 2a rim side surface 3 gear box 3a ring 4 lubricating oil 5 bearing 6 bearing 7 path 8 lid 9 axle 10 oil drain 11 oil drain hole 12 dent 13 plug 14 notch 15 notch 16 hole

Claims (1)

(57) [Claims] 1. A gear device using a gear box projecting an annular proximate to the rim side of the gear wheel from the inner wall surface of the gearbox, is provided a recess on a surface proximate to the rim side of the gear wheel of said circular ring By drilling a hole in the axial direction from this dent via the inner side wall of the gear box , the dent portion can be
A gear device characterized in that it is an outlet portion of a labyrinth oil drain hole of a gear device having a cover that rotatably supports an axle on a gear box .