JPH0469308B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a rotary sealing ring fixed on a rotating shaft and having a sealing surface perpendicular to the axis, and a non-rotating sealing ring having a sealing surface opposite the sealing surface and also perpendicular to the axis; and a tube surrounding the shaft and flexible in the radial and axial directions and connecting the non-rotating sealing ring to the sealing device housing. A shaft sealing device having a flexible sealing element and an arcuate distribution pocket formed in the sealing surface of the non-rotating sealing ring or the rotating sealing ring and communicating with or facing a sealing medium supply hole in the non-rotating sealing ring. .

[Conventional technology]

Shaft sealing devices are already known which reduce the flow rate of the sealing medium required for sealing a rotating part with respect to a non-rotating part at the wall separating two spaces from each other (Deutsche Bundeslichungschaftungschaft) 2134964 specification). Here the non-rotating sealing ring is free to move in all directions relative to the non-rotating part and is connected to this part by one or more deformable walls.

This arrangement has the disadvantage that if the narrow feed hole becomes clogged, there will be no restoring force and the rotating ring will therefore rub against the stationary ring.

According to German Patent Application No. 24 44 544, in order to avoid this disadvantage, the sealing gas is routed radially outwardly or inwardly into the sealing gap through a spiral groove in the rotating sealing ring and the non-rotating sealing ring. is supplied from the air, creating an aerodynamic restoring force. In this case, this restoring force is related to the rotation speed, so
A disadvantage is that at low rotational speeds a static gas cylinder must be present which is generated via the throttle hole.

In order to reduce leakage losses of the working medium in shaft seals of turbomachines, it has been proposed, in patent application No.
It is proposed in specification No. 2515316. However, nothing is disclosed regarding the configuration of the shaft sealing device as a radial gap sealing device in connection with its concentric position relative to the shaft.

In addition, the Federal Republic of Germany Patent Application Publication No.
The specification of No. 1675354 hints at the idea of forming a sealing gap between the aperture holes by a permanent magnet that is embedded in a sealing ring and acts repulsively, but there is no suggestion as to its structural configuration.

The configurations known so far are not suitable for very small sealing gaps in radial shaft sealing systems, where in addition to the sealing medium there is also an elastic restoring force acting on the non-rotating sealing ring. This is because if a force directed axially towards the sealing gap is superimposed, the necessary uniformity of the gap is not maintained and there is a risk that the rings rotating with the shaft will come into contact.

[Problem to be solved by the invention]

The object of the invention is to match the forces acting on the radial sealing gap in a shaft sealing device to one another so that the ability of the shaft sealing device to maintain a defined sealing gap is always guaranteed.

[Means to solve the problem]

According to the first invention to solve this problem,
The non-rotating sealing ring has a radially outwardly extending shoulder, and on each axially opposite side of the shoulder an electromagnet is provided in the sealing device housing and acting in opposite directions on the shoulder to activate the non-rotating sealing ring. A sensor is provided on the sealing surface, by means of which the magnetic force of the electromagnet, which is controlled via an electronic control unit, is superimposed on the pressure of the sealing medium applied to the sealing gap and acting in the axial direction and on the restoring force of the flexible sealing element. to maintain a predetermined gap width of the sealing gap.

Furthermore, according to the second invention, means are provided around the non-rotating sealing ring for guiding it in the radial direction.

〔Effect of the invention〕

A common advantage of the first and second inventions is that, in addition to the magnetic force of the electromagnet acting on the shoulder of the non-rotating sealing ring, the pressure of the sealing medium supplied to the sealing gap and the restoring force of the flexible sealing element are , acts on the non-rotating sealing ring in the axial direction, so the electromagnetic force required to generate magnetic force can be reduced, and the excitation energy of the electromagnet can also be reduced. In addition, since the electromagnet is controlled by a sensor, even if the sealing medium is not supplied to the sealing gap for some reason during operation, contact between the non-rotating sealing ring and the rotating sealing ring is reliably avoided, and the specified sealing gap is maintained. Width can be maintained.
Furthermore, during transport and assembly of machines with shaft sealing devices, as long as the sealing medium has not yet been fed into the sealing gap,
Electromagnets may also be utilized to maintain the gap between the non-rotating and rotating seal rings.

A particular advantage of the second invention is that the radial guide means ensure that the axis of the non-rotating sealing ring always coincides with the axis of the rotating shaft, and the flexible sealing element only has to exert an axial restoring force.

[Embodiment]

By feeding the sealing medium through a distribution pocket of the sealing ring or from the edge, for example via a spiral groove, some margin for gap retention can be obtained, but this margin alone is not sufficient. If a large number of electromagnets are arranged in parallel, additional margins are obtained in the electromagnetic arrangement itself.

The flexible sealing element is configured to exert a force that separates the non-rotating sealing ring from the rotating sealing ring, thereby preventing contact with the rotating sealing ring in the event of a failure of the electronic control unit.

It is also possible to grade the pressure in the shaft sealing device or to use two different sealing media. For this purpose, the rotary sealing ring can define a sealing gap in each case with the non-rotating sealing ring which faces it on both sides in the axial direction.

A sensor on the sealing surface of the unsealed ring also measures the temperature in the sealing gap, so that the temperature measured at a specific time interval forms a temperature gradient which, via the electronic control unit, triggers the electromagnet. It is also possible to vary the target value of the sealing gap, which is to be kept constant, in a controlled manner. It is advantageous to provide at least three sensors distributed around the non-rotating sealing ring. As a result, the temperature occurring in the area of the sealing gap is also fed as an additional parameter to the electronic control unit, so that an optimal adaptation of the respective electrical running conditions is carried out and the operational reliability of the shaft seal is significantly increased.

〔Example〕

An embodiment of the invention is shown in the drawing and will be explained below.

In the figure, the sealing gap 1 includes a rotating sealing ring 2 that rotates with the shaft and has a sealing surface perpendicular to the axis;
It is defined by a non-rotating sealing ring 5 which faces this sealing ring and also has a sealing surface perpendicular to the axis. A non-rotating sealing ring 5 is connected to the sealing device housing 4 by a cylindrical flexible sealing element 3 which can be deflected radially and axially around the shaft. This sealing element 3, for example a bellows, exerts an axially directed force on the non-rotating sealing ring 5.

According to FIGS. 1 and 2, the supply of the sealing medium is provided by an arcuate distribution pocket 7 in the non-rotating sealing ring 5.
Supply hole 6 with constriction-like constriction at the connection to
It is done through. A sealing medium is thus supplied to the sealing gap 1. In this example, the non-rotating sealing ring 5
Dynamic pressure compression of the sealing medium additionally occurs at high rotational speeds in the spiral groove 12 provided on the inner edge of the rotor.

The sensor 8 provided in the non-rotating sealing ring 5 and the insert piece 11 embedded in the rotating sealing ring 2 control electromagnets 9 in the sealing device housing 4 via an electronic control device, these electromagnets 9 It acts on the sealing gap 1 in conjunction with a magnetizable counterbody 10 on the radially outwardly extending shoulder 5a of the non-rotating ring 5.

The electromagnets 9 in the sealing device housing 4 are arranged so as to act in opposite directions on both sides in the axial direction of a magnetizable counterbody 10 provided on the shoulder 5a of the non-rotating sealing ring 5 and configured as a laminated iron plate. ing. The forces acting on the sealing medium and sealing element 3 on the non-rotating sealing ring 5 are thereby superimposed by an electromagnetic force, which is adjusted via the sensor 8 in the sealing gap 1 independently of other forces to a predetermined value. Maintain a sealing gap of 1.

Non-rotating seal ring 5 relative to seal housing 4
According to FIG. 3, an electromagnet 13 provided on the inner peripheral surface of the sealing device housing 4 and a laminated iron plate 14 located on the non-rotating sealing ring 5 opposite to this electromagnet 13 are used to guide the electromagnet 13 in the radial direction. It's useful. According to FIG. 4, this radial guidance is also provided by a radial gas bearing 15, which is connected to a radial gas supply hole 16 in the sealing device housing.
A gas exhaust hole 17 is provided in the annular gap between the non-rotating sealing ring 5 and the housing 4.

FIG. 5 shows an embodiment in which the sealing device shown in FIG. 1 is used as a so-called double sealing device, corresponding parts being labeled with the same numerals and dashes. In this case, different sealing media can be supplied to the sealing gaps 1 and 1'.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view passing through the central axis of the shaft sealing device according to the present invention, Fig. 2 is a front view of the non-rotating sealing ring as seen in the - line direction of Fig. 1, and Fig. 3 is a non-rotating sealing ring of the present invention. A vertical cross-sectional view of a shaft sealing device with a device for radially guiding a rotating sealing ring, FIG. 4 is a vertical cross-sectional view of a shaft sealing device with a device for radially guiding a rotating seal ring, and FIG. 5 is a vertical cross-sectional view of a shaft sealing device with a device for radially guiding a rotating seal ring. FIG. 2 is a longitudinal cross-sectional view of a shaft sealing device configured as an apparatus. DESCRIPTION OF SYMBOLS 1... Sealing gap, 2... Rotating sealing ring, 3... Flexible sealing element, 4... Sealing device housing, 5... Non-rotating sealing ring, 5a... Shoulder, 6... Sealing medium supply hole, 7... Distribution pocket, 8... Sensor , 9... Electromagnet, 10... Opposing body, 12... Spiral groove, 13, 14, 15... Radial guide means.

Claims (1)

[Claims] 1. A rotating sealing ring fixed on a rotating shaft and having a sealing surface perpendicular to the axis, and a rotating sealing ring fixed on a rotating shaft and having a sealing surface perpendicular to the axis, and a rotating sealing ring fixed on a rotating shaft and facing the sealing surface of the rotating sealing ring through a sealing gap and also with respect to the axis. a non-rotating sealing ring having a sealing surface perpendicular to the shaft; a cylindrical flexible sealing element that surrounds the shaft and is radially and axially deflectable and connects the non-rotating sealing ring to the sealing device housing; and a non-rotating sealing ring or and an arcuate distribution pocket formed in the sealing surface of the rotating sealing ring and communicating with or opposing a sealing medium supply hole in the non-rotating sealing ring, in which the non-rotating sealing ring 5 has a radially outwardly extending shoulder. Electromagnets 9 are provided in the sealing device housing 4 on both sides of the shoulder 5a in the axial direction, and act on the shoulder 5a in opposite directions, and a sensor 8 is mounted on the sealing surface of the non-rotating sealing ring 5. The magnetic force of the electromagnet 9 which is provided and controlled by this sensor 8 via an electronic control device is
A shaft sealing device characterized in that the pressure of the sealing medium supplied to the sealing gap 1 and acting in the axial direction and the restoring force of the flexible sealing element 3 are superimposed to maintain a predetermined gap width of the sealing gap 1. 2. The shaft sealing device according to claim 1, characterized in that multiple electromagnets 9 are provided in parallel. 3. Shaft sealing device according to claim 1, characterized in that the flexible sealing element (3) is configured to generate a force that separates the non-rotating sealing ring (5) from the rotating sealing ring (2). 4. Claims characterized in that the rotating sealing ring 2, together with the non-rotating sealing rings 5, 5', which oppose it on both sides in the axial direction, respectively define sealing gaps 1, 1'. The shaft sealing device according to item 1. 5 A sensor on the sealing surface of the non-rotating sealing ring 5 also measures the temperature in the sealing gap 1, so that the temperatures measured at specific time intervals form a temperature gradient over time, which gradient controls the electronic control unit. The shaft sealing device according to claim 1, characterized in that the target value of the sealing gap 1 to be kept constant is changed by controlling the electromagnet 9 through the shaft sealing device. 6. The shaft sealing device according to claim 5, wherein at least three sensors for measuring the temperature of the sealing gap 1 are provided distributed around the non-rotating sealing ring 5. 7. A rotating sealing ring fixed on a rotating shaft and having a sealing surface perpendicular to the axis, and a sealing surface facing the sealing surface of the rotating sealing ring through a sealing gap and also perpendicular to the axis. a non-rotating sealing ring having a cylindrical flexible sealing element which is radially and axially deflectable surrounding the shaft and coupling the non-rotating sealing ring to the sealing device housing; and a sealing surface of the non-rotating sealing ring or the rotating sealing ring. having an arcuate distribution pocket formed in the non-rotating sealing ring and communicating with or opposing the sealing medium supply hole in the non-rotating sealing ring 5, the non-rotating sealing ring 5 has a shoulder 5a extending radially outwardly; Sealing device housing 4 on both sides of section 5a in the axial direction
are each provided with an electromagnet 9 acting in opposite directions on the shoulder 5a, and a sensor 8 is provided on the sealing surface of the non-rotating sealing ring 5, the electromagnet 9 being controlled by the sensor 8 via an electronic control unit. The magnetic force supplied to the sealing gap 1 is superimposed on the pressure of the sealing medium acting in the axial direction and the restoring force of the flexible sealing element 3 to maintain the predetermined gap width of the sealing gap 1 and also to maintain the non-rotating sealing ring. A shaft sealing device characterized in that means 13, 14, 15 for radially guiding the shaft are provided around the shaft.