JPH0544855A - Air seal device - Google Patents

Abstract

PURPOSE:To provide an air seal device in which the setting of a clearance is easy and the leakage of gas can be prevented and also biting or scuffing due to thermal shrinkage is not caused. CONSTITUTION:In an air seal device by which the clearance between a turning shaft 1 and a casing 4 surrounding the shaft is sealed, on either one side of the casing 4 and the turning shaft 1 a brush 10 consisting of closely gathered wires 9 is provided so that the ends of the wires 9 are closely in contact with the other side thereof.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air seal device having a novel structure for sealing a gap between a rotary shaft and a casing surrounding the rotary shaft.

[0002]

2. Description of the Related Art Labyrinth packing is widely used as a device for preventing gas from leaking from a gap between a rotary shaft and a casing surrounding the rotary shaft. This is configured by providing a casing, which is a stationary part, with fins surrounding the rotating shaft in multiple stages in the axial direction of the rotating shaft and with a gap between the rotating shaft and the rotating shaft as small as possible. It is designed to prevent gas leakage by utilizing the decompression effect when passing through the slit.

[0003]

However, in the above labyrinth packing, when the labyrinth packing is used in a portion that undergoes a rapid temperature change, such as a turbine portion of a jet engine, a gap between the fin and the rotating shaft is not provided. If it is small, heat shrinkage causes gazing, and if the gap is large, there are problems such as insufficient sealing, and it is difficult to set the gap.

Therefore, an object of the present invention is to provide an air seal device which can easily set a gap, prevent gas from leaking, and prevent galling due to thermal contraction.

[0005]

In order to achieve the above object, the present invention provides an air seal device for sealing a gap between a rotating shaft and a casing surrounding the rotating shaft. It is characterized in that a brush having a densely packed wire is provided so that the tip of the wire is close to the other.

[0006]

The function of the present invention is to prevent the leakage of gas from the gap between the casing and the rotating shaft by the pressure reducing effect of the gap between the wires of the brush, and to absorb the thermal contraction due to the rapid temperature change by the elastic force of the wire. It does not cause galling.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a rotary shaft connecting a compressor of a jet engine and a turbine, and a portion of the turbine portion 2 side thereof is supported by a casing 4 via a ball bearing 3. An oil chamber 5 is formed on the turbine portion 2 side of the ball bearing 3 in the casing 4,
An oil injection nozzle 6 for supplying lubricating oil to the ball bearing 3 is provided in the oil chamber 5, and a circulation pump (not shown) for sucking and circulating the oil in the oil chamber 5 is provided.

At the portion surrounding the rotating shaft 1 of the casing 4 that defines the outer side of the oil chamber 5, the air suction port 2 side becomes higher in pressure than the inside of the oil chamber 5 during flight, so that air is separated. An air seal device 7 is provided to prevent the oil from leaking into the oil chamber. In the embodiment, the rotary shaft 1 is integrally provided with the flange member 8.
The air seal device 7 is arranged in the gap between the outer peripheral portion of the casing and the inner peripheral portion of the casing 4 surrounding the casing.

The air seal device 7 comprises a brush 10 in which wires 9 are closely packed. Specifically, the brush 10 is an annular base 11 attached to the inner peripheral portion of the casing 4, and the inner periphery of the base 11. It is mainly composed of a large number of wires 9 which are planted in a dense state. The base 11 is halved as shown in FIG. 2 for easy assembly and disassembly.

In order to facilitate the implantation of the brush 10 on the base 11, for example, as shown in FIG. 3, the wire 9 is densely formed on the thin substrate 12 to form the brush member 13 having the base end portion brazed. This may be attached to the inner peripheral surface of the base 11.

As the wire 9 constituting the brush 10,
A stainless steel wire having a diameter of 0.5 mm or more is preferable, and its cross-sectional shape is a circle (a), a semicircle (b), a square (c), a rhombus (d), an ellipse, an oval, etc., as shown in FIG. May be

In the embodiment, in order to improve the sealing performance, the annular projection 14 and the annular groove 1 are provided on the outer peripheral portion of the flange member 8.
5 and 5 are formed in multiple stages, and the tip of the wire 9 of the brush 10 is cut according to these shapes. The tip of the wire 9 is provided as close as possible to the outer peripheral portion of the flange member 8. In some cases, a honeycomb-shaped contact surface is formed on the outer peripheral portion of the flange member 8, and the tip of the wire 9 is brought into contact with this contact surface. It may be allowed to.

According to the above construction, a pressure reducing effect is produced by the gap between the wires 9 of the brush 10, so that air leakage from the high pressure air suction port 2 side to the low pressure oil chamber 5 is prevented by the pressure reducing effect. be able to. Further, since the thermal contraction due to the abrupt temperature change can be absorbed by the elastic force of the wire 9, there will be no galling unlike the labyrinth packing, and the gap between the tip of the wire 9 and the outer peripheral portion of the flange member 8 will not be generated. Easy to set up.

In the above embodiment, the brush 10 is provided on the casing 4 side, but the brush 10 may be provided on the rotary shaft 1 side, on the contrary.

[0016]

In summary, according to the present invention, it is possible to prevent gas from leaking from the gap between the casing and the rotating shaft by the pressure reducing effect of the gap between the wires of the brush, and to prevent the heat generated by the rapid temperature change. The contraction can be absorbed by the elastic force of the wire without causing galling.

[Brief description of drawings]

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

FIG. 2 is a front view of the air seal device.

FIG. 3 is a perspective view of a wire brush that constitutes an air seal device.

FIG. 4 is a cross-sectional view of a wire forming a wire brush.

[Explanation of symbols]

 1 rotating shaft 4 casing 9 wire 10 brush

Claims (1)

[Claims] 1. An air seal device for sealing a gap between a rotating shaft and a casing surrounding the rotating shaft, wherein a wire tip of a brush formed by densely packing the wire on one of the casing and the rotating shaft is close to the other. An air seal device characterized by being provided as described above.