JPH0426661Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is applied to an exhaust turbine supercharger.

BACKGROUND ART FIG. 3 shows the structure of the rotor disk portion of a conventional supercharger, in which the rotor 20 is rotated at high speed by the force of exhaust gas A30 from the engine.

At this time, to prevent oil and gas leaks, the compressed air discharged from the blower (not shown) is transferred to the passage 4.
5 to the space 16 of the disk portion as seal air. In the disk part of the rotor 20,
An oil labyrinth 80 is attached to the bearing case 40 of the bearing 50 to prevent leakage of discharged lubricating oil. Furthermore, gas labyrinths 60 and 70 are attached to the bearing case 40 to prevent exhaust gas A30 from leaking inside.

To explain the gas labyrinth in detail, a shelf 18 and a shelf 15 are provided on the rotor 20 that rotates to seal the exhaust gas A30, and gas labyrinths 60 and 70 are provided opposite to these. Several fins 62, 64 and 72 are arranged in parallel in the axial direction of the gas labyrinths 60 and 70, respectively.
These gas labyrinth fins 62, 64, 7
The gap between the rotor 2 and the shelves 15 and 18 provided on the disk portion of the rotating rotor 20 is extremely small, and gas leakage is prevented by the sealing effect of the fins of the gas labyrinth and the seal air.

Problems to be Solved by the Invention In the conventional structure as described above, the gas labyrinth fins 62, 64, and 72 are arranged in three stages, and the space between the fins 72 and fins 62 is too narrow to process. It is divided into two parts: a gas labyrinth 70 having fins 72 and a gas labyrinth 60 having fins 62 and 64.

However, by dividing only the fin portion, the bearing case 40
If the gas labyrinth 70 were to be installed in a common place, the size of the gas labyrinth 70 would be reduced, but the fin shape shown in FIG. 3 would make the structure more complicated and would not work well. For this reason, each of the gas labyrinths 60 and 70 shown in FIG.
0.70 is large in size and high in cost.

Means for Solving the Problems In order to solve the above problems, the present invention provides a turbocharger in which an oil labyrinth part is provided on the inner circumferential edge of the rotor shaft and a gas labyrinth part is provided on the outer circumferential edge. The part is provided with a plurality of radial labyrinth fins extending toward the disk part of the rotor shaft in one gas labyrinth part in the radial direction of the rotor shaft, and a plurality of radial labyrinth fins extending toward the disk part of the rotor shaft in the radial direction of the rotor shaft. directional labyrinth fins are provided, and the disk portion of the rotor shaft is provided with a plurality of shelves that individually face each of the radial labyrinth fins and whose surfaces facing the radial labyrinth fins are parallel to the axis of the rotor shaft. At the same time, a shelf is provided opposite the inner peripheral edge of each axial labyrinth fin, and the radial labyrinth fin and axial labyrinth fin are set so that the minimum clearance between them and the shelf is approximately the same amount of clearance in the radial direction. The present invention provides a gas leak prevention device for a supercharger, which is characterized by:

Embodiments The present invention will be explained with reference to embodiments shown in FIGS. 1 and 2 of the accompanying drawings. The turbine blades 11 fixed to the rotor 20 rotate at high speed in a direction perpendicular to the drawing due to the force of the exhaust gas A30.

The disk portion of the rotor 20 has a large shelf 15 that extends relatively long in the axial direction, that is, in the direction parallel to the axial center line of the rotor shaft (horizontal direction in the drawing) at approximately half of the radial direction. Radially outward and adjacent to this, several stages of small shelves 12 (four stages in the illustrated embodiment) extend relatively short in a direction parallel to the axis of the rotor shaft (horizontal direction in the drawing).
is provided. In Figure 2 these small shelves 12
The upper surface extending in a direction parallel to the axis of is denoted by 12a.
It is shown.

The gas labyrinth 75 consists of a single block with a substantially square cross section (toroidal shape as a whole),
Its inner circumferential surface (bottom surface in the drawing) faces the large shelf 15, and its side wall surface (left side wall surface in the drawing) faces the disk portion forming the small shelf 12. Several stages of axial labyrinth fins 74 extending in the axial direction are protruded from the inner peripheral surface of the gas labyrinth 75 (four stages in the illustrated embodiment). Therefore, the radial clearance a (FIG. 3) between these axial labyrinth fins 74 and the large shelf 15 extending in the axial direction of the rotor 20 is the minimum clearance between them and the rotor 20.

In addition, on the side wall surface of the gas labyrinth 75, several stages of radial labyrinth fins 76 (four stages in the figure) are arranged in the radial direction toward the upper surface 12a of the small shelf 12 extending relatively short in the axial direction of the several stages. They are arranged side by side and project diagonally. Therefore, for these diagonally projecting radial labyrinth fins 76, the radial clearance a (FIG. 3) between the small shelves 12 is the minimum clearance between them and the rotor 20.

The gas labyrinth 75 is attached to the labyrinth support 65, and the labyrinth support 65 is the bearing case 4.
It is attached to 0.

As shown in FIG. 2, there is a radial gap a between several stages of axial labyrinth fins 74 and a large shelf 15 extending in the axial direction, and a small shelf arranged in parallel with the radial labyrinth fin 76 in the radial direction. The gap a in the radial direction with 12 is set to have substantially the same length.

In FIG. 1, 16 is a space where compressed air for sealing is stored, 45 is a passage for compressed air for sealing, and 5 is a space for storing compressed air for sealing.
0 is a bearing, and 80 is an oil labyrinth that seals lubricating oil from the bearing 50 side.

Operation Compressed air for sealing extracted from a compressor (not shown) of the supercharger is introduced into the space 16 through the passage 45. The compressed air in the space 16 is
As shown by the arrows in the figure, the exhaust gas and lubricating oil are guided into 75 parts of the gas labyrinth and 80 parts of the oil labyrinth to seal them.

Effects of the invention The invention has the above structure, and has an oil labyrinth of 80
Separately, one gas labyrinth 75 is provided with an axial labyrinth fin 74 and a radial labyrinth fin 76, and each fin 74, 76 is connected to the shelf 1.
Since the gas is sealed in two stages by facing the parts 5 and 12, sufficient sealing is achieved on both the gas side and the lubricating oil side, and no oil leakage occurs. Further, since the axial labyrinth fins 74 and the radial labyrinth fins 76 are provided on the inner peripheral surface and side wall surface of the gas labyrinth 75, which is a single block with a substantially square cross section, the structure can be integrated and miniaturized.
Furthermore, since only one gas labyrinth 75 is attached to the bearing case 40, the attachment structure is also simple. Furthermore, since the minimum gaps between the labyrinth fins 74 and 76 and the shelves 15 and 12 of the rotor 20 are both radial gaps, the gaps can be easily adjusted, and the minimum gaps between the gas labyrinth fins 75 and the disk portion of the rotor 20 are easy to adjust. Even if the relative position shifts slightly in the axial direction (1 to
2 mm), characterized in that the radial clearance remains substantially constant.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of a gas leakage prevention device for a supercharger according to the present invention, FIG. 2 is an enlarged view of a gas labyrinth fin, and FIG. 3 is a longitudinal sectional front view of a conventional example. 10... Rotor shaft, 11... Turbine blade, 12... Small shelf, 15... Large shelf, 16
... Space, 18 ... Shelf, 20 ... Rotor, A30
... Exhaust gas, 40 ... Bearing case, 45 ... Passage, 50 ... Bearing, 60 ... Gas labyrinth, 6
2...Fin, 64...Fin, 65...Labyrinth support, 70...Gas labyrinth, 72...Fin, 74...Axial labyrinth fin, 75...
...Gas labyrinth, 76...Radial labyrinth fin, 80...Oil labyrinth.

Claims (1)

[Scope of utility model registration request] In a supercharger in which an oil labyrinth portion is provided on the inner circumferential side of the rotor shaft and a gas labyrinth portion is provided on the outer circumferential side, the gas labyrinth portion is provided in one gas labyrinth portion 75 facing toward the disk portion of the rotor shaft 10. A plurality of previously extending radial labyrinth fins 76 are provided in the radial direction of the rotor shaft 10, and
A plurality of axial labyrinth fins 74 are provided along the axial direction of the rotor shaft 10, and a plurality of axial labyrinth fins 74 are provided on the disc portion of the rotor shaft, each facing each of the radial labyrinth fins 76 individually.
A plurality of shelves 12 are provided whose surfaces facing the rotor shaft are parallel to the axial center line of the rotor shaft, and a shelf 15 is provided opposite the inner peripheral edge of each axial labyrinth fin, and the radial labyrinth fin and axial labyrinth fin are A gas leak prevention device for a supercharger, characterized in that a minimum gap between these and the shelf is set to be a gap of approximately the same amount in a radial direction.