JP2001065670A - Gear transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an oil leakage from an air breather by providing a gear box, gears, a gear shaft, a lubricating oil and the air breather, and connecting the air breather for exhausting air in the gear box, to the part, facing the end face center of the gear shaft, of the gear box. SOLUTION: When an input flange 8 is rotated by an engine or the like to drive an upper pump 9 through a gear shaft 4, a lower pump 9 is simultaneously driven through a gear train 3. At this time, a lubricating oil 5 stored at the bottom part in the gear box 2 is splashed by the lower gear train 3 to lubricate a sliding part. When temperature in the gear box 2 rises due to this operation to expand air in the gear box 2, the air is exhausted from the air breather 6 through a through-hole 11. At this time, since the part, facing the end face center of the gear shaft 4, of the gear box 2 is evacuated due to the lubricating oil being blown off by centrifugal force, an oil leakage from the air breather 6 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a gear transmission device such as a pump drive gear box and a transmission applied to a working vehicle such as a dump truck.

[0002]

2. Description of the Related Art Conventionally, as a gear transmission of this type,
For example, a pump drive gear box shown in FIGS. 3 and 4 is known. The gear transmission device 50 is basically provided with a gear box 51, a plurality of gears 52 provided in the gear box 51 and engaged with each other, and provided at the center of each gear 52 and rotatable with the gear box 51. A lubricating oil 54 stored at the bottom of the gear box 51 and scraped up by the gear 52;
Connected to the upper part of the gearbox 51
And an air breather 55 for discharging air from the inside. A gear 52 and a gear shaft 53 are provided at an upper part and two at a lower part on the left and right sides.
Are provided, and the rear of the upper gear shaft 52 and the front of the lower gear shaft 52 are output sides, to which pumps 57 are respectively connected. The air breather 55 includes a relatively long pipe 58 connected to an upper part of the gear box 51,
An oil sump pot 59 is connected to the tip of the oil sump and stores the lubricating oil 54. In such a case, the power from the input side is transmitted to the output side by the gear, and the pump is driven to rotate. The lubricating oil stored in the bottom of the gear box is swept up and scattered by the lower gear immersed therein, and each gear is lubricated. When the temperature in the gear box rises, the air in the gear box expands and is discharged from the upper portion of the gear box from the air breather via the piping and the oil reservoir.

[0003]

However, in such a case, even if there is an oil sump, if the inside of the gear box becomes hot, the lubricating oil becomes mist and leaks from the air breather. Had occurred. The present invention
In view of the above-mentioned problems, the present invention has been made to solve the above problems, and an object of the present invention is to provide a gear transmission device that prevents oil leakage from an air breather.

[0004]

The gear transmission of the present invention basically includes a gear box, a plurality of gears provided in the gear box and engaged with each other, and provided at the center of each gear. A gear shaft rotatably supported by the gear box, lubricating oil stored at the bottom of the gear box and lifted up by the gear, and a portion of the gear box connected to a portion of the gear box facing the center of the end face of the gear shaft. The air breather that discharges air is characterized by the fact that it is composed of an air breather.

[0005] Power from the input side is transmitted to the output side by a gear shaft and gears. The lubricating oil stored in the bottom of the gear box is swept up by the gears and scattered, and each gear is lubricated. When the temperature inside the gear box rises, the air inside the gear box expands and is discharged from the air breather. The portion of the gear box facing the center of the end face of the gear shaft has a negative pressure due to the lubricating oil being blown outward by centrifugal force due to the rotation of the gear shaft. Therefore, since the air breather is connected to this negative pressure point, even if the inside of the gear box becomes hot,
Lubricating oil does not leak from the air breather to cause so-called oil leakage.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional side view showing a gear transmission of the present invention. FIG. 2 is a longitudinal rear view of FIG.

The main part of the gear transmission 1 is composed of a gear box 2, a gear 3, a gear shaft 4, a lubricating oil 5, and an air breather 6, and in this example, is a pump drive gear box.

The gear box 2 forms a basic part of the gear transmission device 1. In this example, a substantially hexagonal front face having a small width in the front-rear direction (left in FIG. It is shaped like a box.

A plurality of gears 3 are provided in the gear box 2 and meshed with each other. In this example, there are one gear at the upper part and two at the lower part on the left and right, and the same number of gears are meshed with each other. It has gears.

The gear shaft 4 is provided at the center of each gear 3 and rotatably supported by the gear box 2.
In this example, there is one upper part and two lower parts left and right corresponding to the gear 3, both ends of which are rotatably supported by the gear box 2 via bearings 7. An input flange 8 is provided in which the front is an input side and is connected to a prime mover (not shown) such as an engine, and the rear of the upper gear shaft 4 and the front of the lower gear shaft 4 are the output side. Each of them is connected to a pump (hydraulic pump) 8. The rear of the lower gear shaft 4 is closed by a pump bearing cover 10 attached to the gear box 2.

The lubricating oil 5 is stored in the bottom of the gear box 2 and is scraped up by the gear 3. In this example, the lower part of the lower gear 3 is immersed.

The air breather 6 is connected to a position facing the center of the end face of the gear shaft 4 of the gear box 2 and discharges the air in the gear box 2. A through hole 11 is formed in the center of the pump bearing cover 10 located on the opposite side, and is connected to this through an elbow 12.

Next, the operation will be described based on such a configuration. When the input flange 8 is rotated by a prime mover such as an engine, the upper gear shaft 4 is rotated and the upper pump 9 connected thereto is driven to rotate, and the lower gear shaft 4 is rotated via the gear 3 meshing with the lower gear shaft. The gear shaft 4 is rotated in a direction opposite to that of the upper gear shaft 4, and the lower pump 9 connected thereto is driven to rotate. The lubricating oil 5 stored in the bottom of the gear box 2 is raked up and scattered by the lower gear 3 immersed therein, and each gear 3 is lubricated. When the temperature inside the gear box 2 rises, the air inside the gear box 2 expands and is discharged from the air breather 6 through the through hole 11 and the elbow 12. The portion of the gear box 2 that faces the center of the end face of the gear shaft 4, that is, the portion of the pump bearing cover 10 where the through hole 11 is formed, causes the lubricating oil 5 to fly outward due to centrifugal force due to the rotation of the gear shaft 4. Has been under negative pressure. Therefore, the air breather 6
Is connected, the lubricating oil 5 does not leak from the air breather 6 and so-called oil leakage does not occur even if the inside of the gear box 2 becomes hot.

The gear transmission 1 is a pump drive gear box in the above example, but is not limited to this, and may be, for example, a transmission. The number of the gears 3 and the gear shafts 4 is three in the above example, but is not limited thereto, and may be two or four or more.

[0015]

As described above, according to the present invention, as described above,
The following excellent effects can be obtained. (1) Gear box, gear, gear shaft, lubricating oil,
The air breather, which is configured with an air breather, is connected to a portion facing the center of the end face of the gear shaft of the gear box, in particular, for discharging the air in the gear box. Therefore, oil leakage from the air breather can be prevented. (2) Since the air breather that discharges air from the gear box is simply connected to the part facing the center of the end face of the gear shaft of the gear box, relatively long piping and oil sump pots as in the past are not required, and costs are reduced. Can be planned.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing a gear transmission of the present invention.

FIG. 2 is a longitudinal rear view of FIG.

FIG. 3 is a vertical side view showing a conventional gear transmission.

FIG. 4 is a longitudinal rear view of FIG. 3;

[Explanation of symbols]

1,50 ... gear transmission device, 2,51 ... gear box,
3, 52 ... gear, 4, 53 ... gear shaft, 5, 54 ...
Lubricating oil, 6,55 ... air breather, 7 ... bearing,
8, 56 ... input flange, 9, 57 ... pump, 1
0: pump bearing cover, 11: through hole, 12: elbow, 58: piping, 59: oil reservoir pot.

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Claims (1)

[Claims] A gear box, a plurality of gears provided in the gear box and engaged with each other, a gear shaft provided at the center of each gear and rotatably supported by a gear box, A gear characterized by comprising lubricating oil stored at the bottom and scooped up by the gear, and an air breather connected to a portion facing the center of the end face of the gear shaft of the gear box and discharging air from the gear box. Transmission device.