JPH10196769A - Gear device for rolling stock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the leakage of lubricating oil by providing a through-hole in a gear box so as to set equal the pressures of two internal space parts partitioned by a gear in the gear box and a breather in its middle part in a rolling stock gear device for discharging into atmosphere expansion air in the gear box by the breather. SOLUTION: In a rolling stock gear device for discharging into atmosphere expansion air in a gear box 1 having a gear 2, a through-hole is provided as an air passage in the gear box 1 opposite the gear 2 such that the pressures of internal space parts A and B formed by both side faces of the gear 2 and the gear box 1 are set equal to each other, and a breather 7 is provided in the middle way of this air passage 6. During the rotation of the helical gear 2, an air flow is produced along a tooth space by the fan effect of the gear 2. A pressure difference between the pressures of both internal space parts A and B and an atmospheric pressure is suppressed to a low pressure difference almost equal to a residual pressure produced by the resistance of the breather 7, a load applied to a shaft seal device 5 is reduced and thereby lubricating oil is prevented from being leaked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear device for a railway vehicle, and more particularly to a gear box for a high-speed rotating gear device using a helical gear.

[0002]

2. Description of the Related Art FIG. 3 shows a gear box of a conventional gear unit for a railway vehicle, and FIG. In FIG. 3, a bearing 3 and a shaft sealing device 5 are mounted on a bearing lid 4 fixed to the gear box 1, and the gear 2 is pressed into a shaft 8 supported by the bearing 3. The inner spaces A and B formed by both side surfaces of the gear 2 and the gear box 1 are kept airtight by a shaft sealing device 5. In this conventional gear box 1, the internal spaces A and B are in the same space, and when the rotation is stopped, the pressures in both spaces are the same. However, when the gear 2 rotates at a high speed, particularly when the gear 2 is a helical gear, the torsion of the teeth causes the gear to act as a fan, and a wind flow is generated from one side of the gear to the other side. As a result, a pressure difference at the boundary of the gear 2 is generated inside the gear box as shown in the pressure distribution diagram of FIG.

[0003]

However, in such a structure of the gear box 1, the space on the side where the pressure rises is:
During the rotation of the gear 2, it always rises, and due to the difference between this rise and the pressure difference between the outside of the gear box 2 and the shaft sealing device 5.
Lubricating oil leaks often occur. In some cases, a breather or the like is mounted as a mechanism for releasing the increased pressure to the outside. The breather reduces the pressure difference between the inside of the gear box 1 and the outside. However, it was necessary to attach a breather to each part where the pressure increased. The present invention has been made in view of the above points, and an object of the present invention is to provide a railway vehicle gear device that solves these drawbacks.

[0004]

Means for achieving the above object is to provide a gear device for a railway vehicle in which a gear is provided in a gear box and the expanded air in the gear box is released into the atmosphere by a breather. A through hole is formed in a gear box facing the gear so that the pressure in both internal spaces formed by both side surfaces of the gear and the gear box is equal, and the breather is provided in the middle of the air passage. Is installed. In addition, although the through-hole is provided in the gear box, providing a breather to have a similar function is also included.

With such a configuration, as shown in FIG. 2, the air passage provided in the gear box 1 changes from A to B when the pressure in the internal space A is high, and B when the pressure in the internal space B is high.
→ Air flows to A. Ideally, the pressure difference between the outside of the gear box 1 and the pressure difference between the outside of the gear box 1 is small even during high-speed rotation, and the pressure difference between the outside and the outside is small from the breather 7 provided in the middle of the air passage. Gearbox is realized. Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0006]

FIG. 1 is a cross-sectional view of a main part of a vehicle gear box showing an embodiment of the present invention, and FIG. 2 is an explanatory view showing pressure distribution inside and outside a gear box according to the present invention. 3 have the same configuration and function. FIG.
In the gear device for a railway vehicle in which the gear 2 is provided in the gear box 1 and the expanded air in the gear box is released into the atmosphere by the breather 7, both internal spaces formed by the both sides of the gear 2 and the gear box 1 are provided. A through hole is formed in the gear box 1 facing the gear 2 so that the pressures of the parts A and B are equal, and a breather 7 is provided in the middle of the air passage 6.

In FIG. 2, if all pressures are expressed as gauge pressures, the external pressure of the gear box 1 and the pressures in the internal spaces A and B of the gear box 1 are shown as follows. Pat = 0------------(1) Pa = P1 + P0---------Pb = P2 + P0-------------------------------------------Here External pressure 1 (= atmospheric pressure) P0: Gearbox internal residual pressure due to resistance of breather 7 when gear 2 is not rotating Pa: Pressure in gearbox internal space A Pb: Pressure in gearbox internal space B P1: Gear2 Is the pressure increase in the internal space A of the gear box 1 due to the fan effect of the gear 2 when the gear 2 is rotating. (Note that the gear 2 may be described as a helical gear 2 for convenience of explanation.)

When the helical gear 2 rotates, the gear 2 causes a fan effect due to the torsion of the teeth, so that one side of the gear 2 (hereinafter referred to as a side surface of the gear box internal space B) is connected to the other side of the gear. An air flow is generated on the side surface (hereinafter referred to as a side surface on the side of the gear box internal space A) along the tooth grooves. Assuming that the volumes of the gear box internal spaces A and B are the same, the volume of air flowing into the gear box internal space A due to the fan effect of the gear 2 and the volume of air flowing out of the gear box internal space B are the same. , The pressure increments in the gearbox interior spaces A and B have opposite signs and equal absolute values. That is, P2 = -P1-----------(4)

Further, the air flow rate Q from the gear box internal space B to the gear box internal space A due to the fan effect of the gear 2 described above.
Can flow from the gear box internal space A to the gear box internal space B by the air passage 6 connecting the gear box internal spaces A and B, the pressure increase and decrease of the gear box internal spaces A and B can be reduced. . Assuming that the air passage 6 has a tubular shape, the relationship between the flow rate and the pressure is generally expressed by the following equation. Pa−Pb = λ (γ / 2g) (ι / d) v · v −−− (5) v = (Q / A) = (4 / π) (Q / dd ·) − (6) Here, Q: air flow rate due to the fan effect of the gear 2 v: air flow velocity in the air passage 6 A: cross-sectional area of the air passage 6 d: diameter of the air passage 6 ι: length of the air passage 6 λ: air passage The flow path friction coefficient of No. 6 is γ: specific weight of air g: gravitational acceleration.

From the equations (2) to (6), the gear box internal space A
And B pressure increments are: P1 = −P2 = λ (4γ / π · πg) (5th power of ι / d) Q · Q-(7) From the equation (7), the pressures in the gear box internal spaces A and B indicate that the pressure of the gear Negligible pressure compared to the gearbox internal residual pressure P0 due to the resistance of the breather during non-rotation, ie, | P1 | = | P2 | ≪ | P0 | −−−−−−−−−−−− (8) If the diameter d and the length l of the air passage 6 are determined with respect to the air flow rate due to the fan effect of the gear 2, the pressures in the gear box internal spaces A and B become (2) and (3). From equation (8) and from equation (8), Pa = P1 + P0 ≒ P0 ----- (9) Pb = P2 + P0 ≒ P0 -------------- (10 ). Here, since the pressure is expressed as a gauge pressure, the equations (9) and (10) are the pressure differences between the gear box internal spaces A and B with respect to the external pressure of the gear box 1 (= atmospheric pressure).

As a result, the pressure difference between the pressures in the gear box internal spaces A and B generated by the fan effect of the gears and the external pressure of the gear box 1, that is, the atmospheric pressure, is reduced to a pressure as low as the residual pressure generated by the resistance of the breather. The difference can be suppressed. Further, when the railway vehicle travels, the gear box 1, the gear 2, the lubricating oil and the like are heated by the power loss due to the transmission efficiency of the gear device, and the temperature rises. Due to this temperature rise, the air in the gear box internal spaces A and B expands, and the pressure in the gear box internal spaces A and B tends to increase, but the air expanded by the breather 7 installed in the air passage 6 Is discharged to the outside of the gear box 1. Therefore, the pressure rise due to the temperature rise of the gear box 1 in the gear box internal spaces A and B can be suppressed to a level as low as the residual pressure due to the resistance of the breather 7. As described above, according to the present invention, (1) the pressure rise due to the fan effect of the gear 2 and (2) the pressure rise due to the temperature rise of the gear box 1 in the gear box internal spaces A and B are determined. The pressure can be suppressed to a low pressure such as the residual pressure due to the resistance of the breather 7. That is, the pressure difference between the inside and outside of the gear box 1 can be suppressed to a pressure difference as low as the above-described residual pressure. The smaller the pressure difference between the inside and outside of the gear box 1 is, the smaller the load applied to the shaft sealing device 5 is.

[0012]

As described above, according to the present invention,
(A) Gear box inner space A caused by the fan effect of gear 1
The pressure rise of the gear box 1 and the space inside the gear box internal space A and (B) caused by the temperature rise of the gear box 1 can be suppressed by installing the space passage 6 connecting the gear box internal spaces A and B to the residual pressure of the breather. By installing the breather 7 in the middle of the air passage 6, it is possible to suppress the pressure increase of B to about the residual pressure of the breather, and it is possible to provide a gearbox for a railway vehicle in which lubricating oil leakage hardly occurs. Also, as the speed of a railway vehicle increases, the present invention can provide a gearbox for a railway vehicle in which lubricating oil leakage does not easily occur, even if the gear device is required to rotate at a higher speed than before. Can contribute to

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part structure of a gear device for a railway vehicle showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a pressure distribution inside and outside a gear box according to the present invention.

FIG. 3 is a cross-sectional view of a main part structure of a gear device for a railway vehicle, showing an example of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Gear box 2 Gear 3 Bearing 4 Bearing lid 5 Shaft sealing device 6 Air passage 7 Breather 8 Axis A Gear box internal space B Gear box internal space

Claims (1)

[Claims] 1. A railway vehicle gear device in which gears are provided in a gear box, and the expanded air in the gear box is released into the atmosphere by a breather, wherein both sides of the gear and both internal spaces formed by the gear box are formed. A gear device for a railway vehicle, wherein a through-hole for forming an air passage is provided in a gear box facing the gear so that the pressure becomes equal, and the breather is provided in the middle of the air passage.