JPH05187558A - Seal of body of revolution and process of seal action - Google Patents

Abstract

PURPOSE: To provide a seal for castings for high-speed rotors and large-diameter rotors. CONSTITUTION: A seal ring 8 is pressed against a casing 11 by limited spring tension at the circumference surface, and is made immovable by the pressure of the medium to be sealed. However, the seal ring 8 can laterally move to the center of the narrow groove 7 by direct contact with the side walls 13, 14 of the groove 7 surrounding the seal ring 8, and friction loss and abrasion at the seal part are prevented. The narrowest gaps 15, 16 prevent any loss of the medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal between a rotating body and a casing that houses the rotating body. The seal has a seal ring housed in the rotating body or the casing, and the inner or outer circumference of the seal ring. Engages with the rotating body or casing to make the space surrounding the seal ring wider than the seal ring so that the seal ring can move in the axial direction in the accommodating space. It is movably held by the rotating body or the casing by the static friction force on the surface.

[0002]

2. Description of the Prior Art Known seals of the type described above, such as disclosed in U.S. Pat. No. 4,714,417 and shown in FIG. 6, located on the outer rotor of a single rotating machine, have a seal ring or packing ring sealed. It has the disadvantage that it is compressed against the mating sealing surfaces by the pressure of the gaseous medium to be applied, resulting in friction losses and a high level of wear on the non-smooth or minimally smooth sealing surfaces. This drawback is especially problematic for a rotating body that rotates very fast such that the peripheral speed is 20 m / sec or more. Therefore, the sealing action of the rotating body that rotates very fast is normally performed in a non-contact manner by the seal gap or the labyrinth packing. A narrow sealing gap that results in a good seal, however, requires high manufacturing costs and causes thermal expansion and manufacturing tolerances that must be taken into account, especially when the outer circumference to be sealed has a large diameter The thickness cannot be made small enough to provide a suitable gap seal. The known labyrinth packing consequently has several sealing ribs arranged side by side in the axial direction, said sealing ribs projecting into the space surrounding the sealing ribs. Separation carbon rings are known for the sealing action of gas turbines on oil-lubricated bearings that rotate together and are slightly axially displaceable because the axial displacement of the rotating parts is taken into account. In order to prevent premature wear of the carbon ring due to compression against the mating sealing surface by the pressure of the medium to be sealed, according to French patent 2,602,847,
Significantly compensates the pressure of the sealed medium against the seal ring and also exerts fluid pressure on either side of the seal ring so that the seal ring is compressed to and held in a central position , Was proposed.
This fluid pressure is obtained by surface grinding of a suitable, for example fast rotating, rotating surface, which contains a seal ring with a space between the rotating surfaces. However, the sealing action of the seal is incomplete, despite the high manufacturing costs, and loss of pressure gas and smoothness cannot be prevented.

[0003]

SUMMARY OF THE INVENTION The object of the invention is to find a seal for a rotor, which seal allows a narrow seal gap without significant wear and is made at a low manufacturing cost. Moreover, it is advantageously constructed for large diameters and works well and increases the efficiency of the machine when the space required is limited.

[0004]

According to the invention, this task is based on the fact that the static friction force is greater than the axial force resulting from the pressure exerted on the side of the sealing ring of the medium to be sealed, Between the flanks and the surrounding space facing the flanks, there is always an annular gap space and the medium to be sealed flows around the sealing ring in the manner of a labyrinth packing, the sealing ring A short mechanical contact with the surface between the surfaces automatically results in a central, non-contact position.

The method of solving the problem according to the invention is such that the axial force of the resulting static friction at the outer or inner circumference of the seal ring is always greater than the pressure of the sealing medium acting axially on the seal ring. When large, but abutting on the casing surface, the sealing ring overcomes the bond and is axially displaceable so that the seal is non-contacting like a labyrinth packing in the sealing gap between the sealing band and the casing. So that the radial spring tension acting on the seal ring is determined.

As a result of the present invention, the seal ring is provided with an ideal location of the center and an abutting surface of the receiving space due to the brief abutment of the direct mechanical contact, which would not be obtained by measurement and precision assembly. Automatically move to an ideal position in the center between adjacent surfaces due to relative rotation between. The relatively large static friction forces on the adhesive circumference of the seal ring are overcome, but not by the pressure of the sealing medium.
Therefore, the space surrounding the seal ring can be made narrower than in the prior art, and contact due to manufacturing tolerances and / or thermal expansion due to deformation of the seal ring alone, or both, does not risk any immobilization of the seal ring. Alternatively, it easily occurs without permanent wear. Thus, the seal can be described as for a self-regulating packing or a dynamic labyrinth packing, and as a result the seal ring forms a labyrinth element.

In a manner similar to conventional labyrinth packings, several sealing rings are axially continuous with each other,
It is also clear that each seal ring is provided with a surrounding space. It is also clear that the components according to the casing additionally rotate at different rotational speeds, since the seal according to the invention is generally suitable for the sealing action of rotating bodies which rotate with respect to each other.

In the conventional piston ring method, the seal ring may or may not have an overlapping joint,
Alternatively, it can be made from cast iron, steel or similar other metallic or non-metallic materials without joints. In order to obtain sufficient spring tension, as a sealing ring with a coupling, preferably a larger radial cross section and pressure compensation means are provided on the two ring sides. The sealing ring is also slightly larger compared to the surrounding space or casing, i.e. it is held by a slight compression fit. When fitted in this way, for example by means of a separate casing of the surrounding space, the sealing ring is
In addition, the rotating body can be surrounded so as to be movable in a state with an initial tension.

Further sealing embodiments are described in the claims which describe the embodiments.

[0010]

The present invention relates to non-limiting embodiments
It is described in further detail below. In the accompanying drawings, only a diagrammatic view of the cross section of the seal ring is shown, not the side border of the ring.

The internal rotating single-spindle machine shown in FIG.
West German Patent Publication (Publication Registration) No. 3329915 (US Pat. No. 4,714,417 or US Pat. No. 48012)
55) and is considered part of this invention. By mounting the inner rotor 1 and the outer rotor 2 of a single rotating machine around a fixed geometric axis,
Single rotating machine is suitable for high speed rotation, eg 20 to 50m / se
The outer peripheral velocity of c is large in the outer rotor 2. The invention provides a non-contacting seal, for example on the side members 3, 4 of the outer rotor. The seals 5, 6 provided for this purpose have a seal ring or packing ring 8 surrounded by a space 7 shaped as a groove in the side members 3, 4, and also an outer peripheral surface 9 of the seal ring 8.
Tightly engages the inner surface 10 of the circular cylinder of the machine casing 11 with a friction grip.

A radial annular space 1 on the side of a space 7 surrounding a seal ring or another ring surface which is likewise arranged to form a corresponding surrounding space 7 of the seal ring 8.
3, 14 have a distance from each other that is just sufficient to be out of contact with the rotational movement of the seal ring 8 at the ideal center position and the positioning of the tumbling movement between the annular spaces 13, 14. There should be a corresponding minimum gap space for the gap seal. This position of the sealing ring 8 is not obtained by its exact assembly, but instead the surrounding groove surface 1 at the beginning of the relative rotary movement.
Achieved automatically by the abutment of the two sides at 3, 14 when the surfaces 9, 10 at the outer circumference of the seal ring
A friction grip or a press fit between the two is easily achieved by corresponding mechanical forces.

In order to limit the different pressures of the gas acting on the sealing ring 8, the ring surfaces 17, 18 which define the sealing gaps 15, 16 are preferably confined to a narrow area and the rest of the sides of the sealing ring. In the section (1), there is a free space 20, 21 for pressure compensation between the sides of the two sealing rings.

In the embodiment according to FIGS. 2 to 5, the free spaces 20, 21 are formed by a notch in the side of the seal ring forming a step 19 on each side. In the embodiment according to FIG. 6, the free space 21 is only on one side of the seal ring 8 and on the low pressure side.

Instead of being formed by notches that form the step 19, according to FIG. 7, free spaces 20 ', 21'.
Is the inclined surface 2 on one or both sides of the seal ring 8.
2, 23 or a conical surface.

According to the embodiment of FIG. 8, in the surface 24 retained by the static frictional force, a groove 25 of full circumference in radial cross section is provided, said groove 25 being a contact surface for static frictional force. To increase the surface pressure. Also, it becomes more difficult to form a lubricating oil film that reduces static friction forces, and the lubricating oil film reaches the seal ring 8 through, for example, the bearing and gear lubrication of the machine of FIG. Suitably, the discharge opening 26 leads outwardly from the groove space towards the low pressure side of the seal ring 8 into the groove space,
Make sure there is no lubricating oil or gas pressure.

FIG. 9 shows an embodiment of the seal in which a seal ring 8 is used, said seal ring 8 having no profile cuts on its side surface forming a free space, which is a free space 20 ″. , 21 '' is the side surface 31 of the enclosed space,
This is because it is formed by 32.

In the embodiment according to FIGS. 10 and 11, the sealing ring 8 has a larger cross-sectional area 31 laterally defined by the abutting surfaces 29, 30 and the surface 13 of the enclosing groove space 7, Seal gap 15 on 14,
It is intended to prevent abutting contact of the narrow ring surfaces 17, 18 defining 16 and damage thereto. In order to ensure that the abutting surfaces 29, 30 do not contribute to the sealing action which results in uncontrolled movement of the medium against the surfaces 13, 14 of the enclosing groove space, the two sides of the seal ring 8 are provided with flow channels 32. , 33 or channel 3
4 are interconnected by either one or both.

According to FIG. 12, the abutting surfaces 29, 30 are shown.
Can be provided with a wedge-shaped sliding shoe-shaped projection 35, and the projection 35 assists the formation of a sliding film when the surfaces 13 and 14 of the surrounding space 7 are butted.
And as a result, it facilitates the automatic centering of the sealing ring 8 in the surrounding space 7 without any significant wear or even pitting.

In the embodiment according to FIGS. 13 to 15, the side surfaces 36, 37 of the sealing ring are substantially provided by a rotator 38 having a radially oriented groove 39 of limited depth, said groove 39 being provided. Is produced by, for example, a pot-shaped wheel 38 shown by a circle in FIG. 14 or a milling machine. These grooves 39 allow, for example, FIG.
The pressure can be compensated in the same manner as the free spaces 20 and 21 according to. The seal is again obtained in the manner of a labyrinth packing with a narrow clearance between the seal ring 8 and the surrounding groove space 7. Preventing the side surfaces of the seal ring 8 from flattening in the narrow groove space 12 eliminates the risk of the seal ring 8 becoming stuck at the abutments at the side surfaces 13, 14 of the groove space 7. ..

In the embodiment shown in FIGS. 16-18, a slightly curved variant of the seal ring 8, such as the exaggerated deflecting portions 40, 41, 42, in FIGS. 13-15. An effect similar to that of the embodiment is obtained. Such a corrugated seal ring 8
Also provides an improved sealing action in the circumferential direction of the ring 8.

As shown by the embodiment, the seal rings 8 are rubbed against each other by static friction with respect to the body to be sealed, either on their outer peripheral surface 9 according to FIGS. 2 and 3 and 6 to 18, or on FIG. The seal ring 8 is preferably stationary, i.e. the machine casing in the embodiment of FIG. 1, although it may be provided according to FIG. 5 to engage with any of its inner peripheral surfaces 12 and also to bond the seal ring 8 to the rotating body. It adheres to the body which is 11. However, when the seal ring 8 is provided by being adhered to the rotating body, centrifugal force must be explained in order to ensure that the seal ring 8 can move to the center position at high speed rotation. To form the space 7, a seal ring 8
It is immaterial to the functioning of the invention whether it surrounds or is surrounded by a rotating body, or whether the seal ring 8 adheres to or is surrounded by a rotating body.

[0023]

The attached drawings show only some possible limited embodiments of the seal according to the invention, and the molding of the seal ring 8 and the associated surrounding space 7
Obviously, various changes can be made.

[Brief description of drawings]

1 is an axial cross-section through the inner mandrel of a known type single-spindle machine.

FIG. 2 shows the seal ring held in the casing, FIG.
Figure 3 is an enlarged cross-sectional view of the seal of the present invention for a single rotating machine according to

FIG. 3 is a side view of a peripheral area of the seal according to FIG.

FIG. 4 is an enlarged cross-sectional view of a seal having a seal ring held by a rotating body.

5 is a side view of the peripheral area of the seal according to FIG. 4;

FIG. 6 is a cross-sectional view showing a further embodiment of the seal of the present invention.

FIG. 7 shows a further embodiment of the seal of the present invention.
It is a figure similar to.

FIG. 8 shows a further embodiment of the seal of the present invention.
It is a figure similar to.

FIG. 9 shows a further embodiment of the seal of the present invention.
It is a figure similar to.

FIG. 10 is a cross-sectional view showing a further embodiment of the seal of the present invention.

11 is a side view of the peripheral area of the seal according to FIG.

12 shows a butt surface of the seal according to FIG.

FIG. 13 is a cross-sectional view showing a further embodiment of the seal of the present invention.

14 is a side view of the peripheral area of the seal according to FIG.

FIG. 15 shows a narrowly defined portion of the seal ring, showing an embodiment of profile cutting of the lateral surface of the seal ring.

FIG. 16 is a cross-sectional view showing a further embodiment of the seal of the present invention.

17 is a side view of the peripheral area of the seal according to FIG. 16;

18 is a cross-sectional view of a peripheral area of the seal according to FIG.

[Explanation of symbols]

 2 ... Rotating body 7 ... Enclosing space 8 ... Seal ring 9 ... Outer peripheral surface 11 ... Casing 13, 14 ... Side surface 15, 16 ... Annular gap space 17, 18 ... Seal gap surface 19; 19 ″ ... Steps 20, 21; 20 ″, 21 ″ ... Free space 24 ... Contact surface 25 ... Groove of entire circumference 26 ... Outflow opening 29, 30 ... Butting surface 31 ... Section area 32 ... Recession 34 ... Flow path 35 ... Protrusion 36, 37 ... Side surface 39 ... Grooves 40, 41, 42 ... Deflection part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Frank O'Bleist Austria, Dornbirn, Hristofstraße 24

Claims (11)

[Claims] 1. A seal between a rotating body and a casing that houses the rotating body, comprising a seal ring (8) housed in the rotating body (2) or the casing (11), and the inner circumference of the seal ring or The outer periphery is engaged with the rotating body or the casing, and the space (7) surrounding the seal ring (8) is made wider than the seal ring (8), so that the seal ring (8)
Can be moved in the housing space (7) in the axial direction, and can be moved to the rotating body (2) or the casing (11) by the static friction force on the inner peripheral surface or the outer peripheral surface of the seal ring (8). In the seal of the rotating body intended to be held at a higher level, the static friction force is greater than the axial force resulting from the pressure acting on the side surfaces (13, 14) of the seal ring (8) of the medium to be sealed There is always an annular gap space (15, 16) between the two side surfaces and the surrounding space (7) facing the side surface, and the medium to be sealed has a sealing ring (8) in the manner of a labyrinth packing. ) Around the seal ring (8)
But enclosing space (7) between said surfaces (13, 14)
A seal of a rotating body which, by means of a brief mechanical abutment contact with the surface (13, 14) of the rotor, automatically places it in a central, non-contact position. 2. An outer peripheral surface (9) of the seal ring (8) engaged at least on one of the side surfaces of the seal ring (8) or of the space (7) surrounding the seal ring (8) and by static friction. A free space (20, 21; 20 ″ ″ ″) provided for pressure compensation and formed by a notch, said notch being separated by a step (19; 19 ″). Space (1
5, 16) defining an annular seal gap space (17, 1, 1)
The seal for a rotating body according to claim 1, wherein the seal is connected to 8) and the width of the notch matches the space. 3. Abutment surface (29) in which the sides of the sealing ring enclose an annular shape for centering in the enclosing space (7) of the sealing ring (8) and for protection of the sealing gap surfaces (17, 18). , 30), said abutting surface (2
A rotary seal according to claim 1, wherein the 9, 30) laterally defines a cross-sectional area (31) of the wider seal ring (8). 4. A flow path (34) or a seal ring (34) which passes through the seal ring (8) with two axially facing ring sides of the seal ring (8) provided for pressure compensation. 8. The rotor seal according to claim 1, wherein the seals are interconnected by recesses (32) extending radially over the sides of (8). 5. Wedge-shaped projections (35) are formed on the abutment surface (29) for the formation of a sliding oil film.
The seal for a rotating body according to claim 3. 6. A side surface (36, 3) of the seal ring (8).
Rotor seal according to claim 1, wherein 7) is oriented radially through the groove (39). 7. Sealing ring (8) is a continuous deflection portion (4) on the outer circumference to form individual abutting surfaces.
0, 41, 42), wherein the seal of the rotating body according to claim 1. 8. The seal ring (8) engages at least one annular inner or outer peripheral surface in the rotating body or casing, the annular inner or outer peripheral surface being narrower than the seal ring (8). The seal of the rotating body according to 1. 9. The contact surface (24) of the seal ring (8)
For holding the seal ring (8) by static friction,
Rotor seal according to claim 8, reduced by a groove (25) around the entire circumference. 10. The space of the groove (25) is the outlet opening (2).
6) is connected to the outside of the seal ring (8) by
The seal for a rotating body according to claim 9. 11. A step of sealing action in a rotor housed in a casing, in particular in an outer rotor (2) of an internal-axis single rotating machine, which is carried out by a sealing action (8) surrounding the rotor (2). In the step of the sealing action in which the inner circumference or the outer circumference of the seal ring (8) engages with a part of the rotating body (2) by the elasticity in the radial direction, the radial spring tension acting on the seal ring (8). However, the axial force resulting from static frictional forces on the outer or inner circumference of the seal ring is always greater than the pressure acting axially on the seal ring (8) of the medium to be sealed, but on the casing surface (13). , 14)
At the abutment at, the seal ring is axially displaceable to overcome the adhesive force and the seal is such that the seal gap (15, 16) between the seal band (8) and the casing (7, 11). ), The step of sealing action of the rotating body so as to be non-contact like labyrinth packing.