DE102014221814B4 - Shaft assembly for operation in a liquid medium and hydroelectric power plant with the shaft assembly - Google Patents

Abstract

Shaft arrangement (1) for operation in a liquid medium (5) with a housing (6), with a shaft (2), wherein the shaft (2) is arranged in sections in a shaft space (11) of the housing (6), wherein a liquid lubricant (12) is arranged in the shaft space (11), with a sealing device (7) for sealing the shaft (2) relative to the housing (6) and for separating a surrounding area (U) with the liquid medium (5) of the housing Shaft space (11) with the liquid lubricant (12), and with a separator device (14) for the deposition of in the shaft space (11) penetrated medium (5) from the lubricant (12), wherein the separator means (14) fluidly with the shaft space (11), characterized in that the shaft space (11) has at least one outlet (18) for fluid communication with the separator device (14), wherein the outlet (18): - either in a bottom region (B) of the wave space ( 11) is arranged t, wherein the lubricant (12) has a lower specific gravity than the medium (5), - or in a ceiling region (D) of the wave space (11) is arranged, wherein the lubricant (12) has a higher specific gravity than the medium ( 5).

Description

The invention relates to a shaft assembly for operation in a liquid medium with a housing, with a shaft, wherein the shaft is arranged in sections in a shaft space of the housing, wherein in the shaft space a liquid lubricant is arranged, and with a sealing device for sealing the shaft opposite the housing and for the separation of a surrounding area with the liquid medium from the shaft space with the liquid lubricant. The invention further relates to a hydroelectric power plant with the shaft arrangement.

In hydroelectric plants, turbines are driven by flowing waters to produce electricity. For the implementation of the kinetic energy of water such hydroelectric power plants usually have a turbine, which is arranged in the water and is driven by the water. The rotational movement of the turbine is transmitted via a shaft in the direction of a generator, wherein the shaft is guided, starting from the externally applied medium water in a transmission interior. In the transmission interior are other functional elements, such. As bearings arranged, which must be lubricated during operation and in particular must not run in the medium water, so as not to wear prematurely. Thus, the shaft leads from an environmental area to an interior area of the hydroelectric plant, the passage being secured by one or more seals.

In such and other underwater applications, it is often envisaged that the transmission interior is completely filled with a lubricant to prevent ingress of water into the transmission interior.

An exemplary embodiment of such an underwater wave, for example, in the document DE 692 388 A , which is probably the closest prior art, shown. This document describes a device for sealing waves that run in different fluids, wherein it is provided that the shaft is sealed by a labyrinth seal and the transmission interior is subjected to a barrier medium.

The DE 37 21 145 A1 shows a lubrication system for the rear stern tube seal on propeller driven marine vessels and the DE 32 13 392 A1 further shows a sealing system for such a stern tube seal. DE 37 21 145 A1 and DE 32 13 392 A1 each show the features of the preamble of claim 1.

The US Pat. No. 1,323,474 A shows a tubular housing for a propeller shaft for ships. In particular, it concerns US Pat. No. 1,323,474 A Means for lubricating the propeller shaft bearings disposed in the housing.

It is an object of the present invention to provide a shaft assembly for operation in a liquid medium, which can be operated safely and optionally supplementary environmentally conscious. This object is achieved by a shaft assembly having the features of claim 1 and by a hydroelectric power plant having the features of claim 7. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims, the following description and the accompanying drawings.

In the context of the invention, a shaft arrangement is thus proposed which is suitable and / or designed for operation in a liquid medium. The shaft arrangement can, for. As in the storage of underwater turbines of tidal power plants, river water turbines, industrial pumps, in the food industry, and for machines and conveyors of offshore and marine engineering, in particular for marine propulsion. In particular, the shaft assembly is suitable and / or designed for underwater operation, wherein the liquid medium is formed by the water. The shaft arrangement is preferably arranged at least temporarily, preferably permanently in the medium region, in particular underwater region. In other embodiments of the invention, the shaft assembly can also be operated in a different medium except water.

The shaft assembly comprises a housing, wherein the housing may be formed in one or more parts. Further, the shaft assembly has a shaft which is rotatably disposed in the housing. It can be provided that at a free end of the shaft, a turbine or other fluidic element is seated, which is designed to convert a medium flow, in particular water flow, in a rotational movement of the shaft. Between the shaft and the housing, a sealing device for sealing the shaft relative to the housing is arranged. Particularly preferably, the sealing device is realized as at least one radial seal. For example, the sealing device, in particular the radial seal, arranged stationary in the housing and is sealingly on the shaft. Particularly preferably, the sealing device is designed as at least one lip seal and / or contacting seal. It can be provided that the sealing device comprises a plurality of individual seals, but with a compromise between the sealing effect and the sealing device generated friction and production costs is to be implemented. The sealing device separates a surrounding area from a wave space. The surrounding area has the outer liquid medium, in particular water, in particular salt water or fresh water as the medium is arranged in the surrounding area.

By contrast, the shaft space is preferably designed as a transmission interior, with the shaft extending at least in sections and / or in rotation in the shaft space. The wave space is surrounded by the housing. In the wave space, a liquid lubricant, in particular a hydrophobic lubricant, lubricating oil, oil, fresh water, salt water, filtered dirty water, process liquid except water, cooling liquid, in particular water, hydraulic fluid, liquefied petroleum gas, aqueous solutions are arranged. Particularly preferably, the shaft space is completely filled with the liquid lubricant. In particular, there is a pressure balance between the wave space and the surrounding area. In possible developments of the invention, the pressure in the shaft space is greater than the pressure in the surrounding area, so that the liquid lubricant tries to get out of the shaft space into the outer liquid medium. Particularly preferably, however, the shaft arrangement is adjusted so that at least in the stationary and / or stationary state of the shaft, a pressure equilibrium is present in order to minimize the loss of lubricant through the sealing device.

For longer operating times, however, an exchange between the outer liquid medium and the liquid lubricant takes place due to dynamic effects in the sealing device and / or due to any sealing inaccuracies. Optionally, it is provided that the shaft arrangement has a refilling device, so that liquid lubricant, which passes from the shaft space into the surrounding area via the sealing device, can be replaced. For example, such a refilling device has a volume of more than 100 l, preferably more than 500 l in order to obtain sufficient liquid lubricant for a period of, for. B. 1 year to provide.

In the operation of the shaft assembly, however, boundary conditions arise: the greater the lubricant loss through the sealing device, the smaller the amount of penetrating outer liquid medium in the shaft space, since the outer liquid medium has to overcome virtually a counterflow of the lubricant during penetration. On the other hand, even if biodegradable lubricant is used, the loss of lubricant through the seal means pollutes the environment and also adds cost and maintenance to the consumption of the liquid lubricant. This results in a field of tension, which should be lost on the one hand as little lubricant and on the other hand may enter as little liquid medium from the surrounding area in the wave space.

In the context of the invention, it is proposed that the shaft arrangement has a separator device for separating media which has penetrated into the shaft space and / or located in the shaft space from the lubricant, wherein the separator device is fluidically connected to the shaft space. In particular, the separator device is designed to deposit the medium during operation of the shaft arrangement and / or during operation from the lubricant.

It is a consideration of the invention that, on the one hand, attempts can be made to largely or completely avoid the penetration of liquid medium into the wave space. However, the approach according to the invention provides that a certain penetration of the medium into the shaft space is tolerated, but this penetrated medium is withdrawn from the lubricant in the wave space by means of the separator device. By the separator thus the stress field described above is mitigated, since on the one hand, the shaft assembly may be designed so that only very little liquid lubricant from the wave space may pass into the surrounding area, the associated, possibly higher amount of medium, which from the surrounding area enters the wave space, is discharged through the separator from the wave space again. With this measure, the balancing act thus succeeds in providing a lubricant atmosphere in the wave space with little contamination through the medium and at the same time creating a wave arrangement which works in an environmentally conscious manner.

In a preferred embodiment of the invention, the shaft arrangement has at least one bearing device, wherein the bearing device is arranged in the shaft space and supports the shaft relative to the housing. For example, the bearing device is designed as a roller bearing device. The storage facility operates in the liquid lubricant, so that the storage facility is always well lubricated. By the separator device ensures that the applied amount of penetrated medium is kept low on the storage device.

It is preferably provided that the separator device is permanently and / or stationarily arranged in the shaft arrangement. For example, the separator device can be integrated in a wall of the housing or forms a integral part of the shaft arrangement. However, it is also possible that the separator device is connected to the housing, for example via a detachable or non-detachable connection. In particular, the separator device is rigidly connected to the housing. This aspect again emphasizes the idea that the removal of the liquid medium from the wave space and / or the cleaning of the liquid lubricant from the medium in the wave space should be performed in parallel to the operation of the wave arrangement and / or during pauses in the operation of the wave arrangement.

In the invention it is provided that the shaft arrangement comprises the liquid lubricant, wherein the liquid lubricant has a lower specific gravity than the medium, in particular as water. Due to the lower, specific density, the medium and the liquid lubricant separate, with the medium sinking into a bottom area of the wave space and the liquid lubricant, however, rising into a ceiling area. The situation is exemplary and simplified as "oil floats on water" represent. In particular, the lubricant is hydrophobic in order to simplify the separation.

In order to be able to purposely discharge the medium from the wave space into the separator device, an outlet for the fluidic connection of the shaft space with the separator device is provided in the invention, wherein the outlet is arranged in the bottom region. Particularly preferably, the outlet forms the lowest point in the wave space, so that the medium, which is heavier in comparison to the lubricant, automatically runs to and / or into the outlet and / or sinks.

If in the present case reference is made to lower or higher positions, the height indication is related to a vertical direction and / or to an immersion depth.

In a preferred embodiment, the separator device has a demixing reservoir and a connecting device, wherein the demixing reservoir is fluidically connected via the connecting device to the shaft space, in particular to the outlet in the shaft space. The demixing reservoir is preferably arranged deeper than the shaft space, so that the heavier medium or the medium with the higher specific gravity, in particular starting from the outlet, can sink through the connecting device into the demixing reservoir. The demixing reservoir is designed, for example, as a stationary cylinder. Particularly preferably, the demixing reservoir is completely filled, at least in the beginning of operation, with liquid lubricant, wherein in operation it is achieved by the arrangement of the demixing reservoir and the connecting device that the medium can sink via the connecting device into the demixing reservoir and into the latter at the bottom of the demixing reservoir. On the other hand, the comparatively lighter lubricant increases, so that via the connecting means an exchange of lubricant and medium can take place.

In a preferred embodiment of the invention, the demixing reservoir has a discharge device, for. B. a drain plug or a drain line. The draining device is positioned at a bottom portion of the segregation reservoir and allows the segregation reservoir to be emptied from the bottom so that fluid is first drained from the bottom of the segregation reservoir. This makes it possible to drain the medium which has settled on the bottom of the demixing reservoir and thereby permanently remove it from the shaft arrangement.

In possible developments of the invention can be filled with the lubricant during commissioning on the discharge device and the shaft space. For this purpose, however, it is preferably provided that the shaft arrangement, in particular the shaft space, has a ventilation device in a ceiling area.

In a preferred embodiment of the invention, the connecting device is designed as a constriction and / or as a fluidic throttle. As a result of this configuration, during operation of the shaft arrangement, the medium arranged in the demixing reservoir is not mixed again with the lubricant, in particular forms an emulsion and is returned to the wave space.

Alternatively or additionally, it may be provided that the connecting device is designed as a labyrinth connection and / or a helical connection, in order to artificially increase the flow resistance and thereby avoid a backflow of the medium into the wave space. However, it is particularly preferred that the connecting device is monotonically or even strictly monotonically decreasing, in particular starting from the outlet to the demixing reservoir, in order to prevent accumulation of the medium during the transition from the wave space into the demixing reservoir. In the same way, it is preferred that starting from the demixing reservoir and in the direction of the wave space, the connecting device is monotonically or even strictly monotonously rising in order to allow the lubricant to rise.

However, if the specific gravity of the medium is less than the specific gravity of the lubricant, so that penetrated medium collects in a ceiling region of the wave space, then it is provided according to the invention that the outlet is arranged in the ceiling region of the wave space. In a development of this embodiment, it is preferred that the demixing reservoir is arranged higher than the outlet and / or the ceiling area and / or as the wave space.

Another object of the invention relates to a hydroelectric power plant with a shaft arrangement according to one of the preceding claims and / or according to the preceding description. In particular, sits on the shaft, a turbine and the shaft performs the rotational movement in the direction of a generator of the hydroelectric power plant.

Further features, advantages and effects of the invention will become apparent from the following description of preferred embodiments of the invention and from the accompanying figures. Showing:

1 a schematic schematic diagram of a shaft assembly as a first embodiment of the invention;

2a , b, c in the same representation as the 1 the shaft arrangement in different operating states;

3 an alternative embodiment of the shaft assembly as a further embodiment of the invention.

The 1 shows a schematic diagram of a shaft arrangement 1 a hydroelectric power station 13 as an embodiment of the invention. The wave arrangement 1 has a wave 2 on which at a free end a turbine 3 carries and the other end with a generator 4 is actively connected. The turbine 3 as well as the wave 2 are located in an underwater area, so the wave 2 in a liquid medium formed as water 5 as surrounding area U is running. The turbine 3 gets through the liquid medium 5 driven. For example, the wave 2 at least 1 m, preferably at least 3 m below a water level.

The wave arrangement 1 has a housing 6 on, which is shown in one piece in the schematic diagram shown, which, however, can also be realized as an assembly of several parts. The wave 2 is in the case 6 rotatably arranged and passes through the housing 6 at least in sections.

The wave arrangement 1 has a sealing device 7 on, which is designed as a radial seal and which is radially on the outside of a recording 8th of the housing 6 supports and is arranged there sealing. At the radial inside, the sealing device 7 at least or exactly one sealing lip 9 on which sealing to the shaft 2 is applied. This seals the sealing device 7 the wave 2 opposite the housing 6 from. On the surrounding area U with the medium 5 opposite side is a storage facility 10 arranged, wherein the outer ring in the housing 6 sits and the inner ring with the shaft 2 connected is. The storage facility 10 is designed as a rolling bearing device.

In the case 6 is a wave space 11 formed by the shaft 2 runs. The wave space 11 is through the sealing device 7 from the surrounding area U with the medium 5 separated. The storage facility 10 is inside the wave space 11 , The wave space 11 is especially complete with a liquid lubricant 12 filled, so the storage facility 10 through the lubricant 12 is lubricated.

In operation of the shaft arrangement 1 occurs due to minor leaks, pump action of the sealing device 7 and other influences on the one hand lubricant 12 from the wave space 11 in the surrounding area U out. In return, medium occurs 5 from the surrounding area U into the wave space 11 one. In the first embodiment shown, the lubricant 12 a lower specific gravity than the medium 5 on. The lubricant 12 is formed hydrqophobic, so that although in a mixture between medium 5 and lubricant 12 can form an emulsion, but this automatically separates again. Thus, during operation of the shaft assembly 1 in the wave space 11 a mixture or emulsion of lubricant 12 and medium 5 available. However, the mixture or the emulsion is selbstentmischend because the lubricant 12 , z. As oil, a lower specific gravity than the medium 5 having. In other words, the lubricant floats 12 on the medium 5 , Related to the wave space 11 In a ceiling area D, the lubricant becomes 12 and in a bottom area B, the medium 5 collect.

The wave arrangement 1 has a separator device fourteen on, which via a connecting device 15 , a segregation reservoir 16 and a discharge device 17 having. The separator device fourteen is below the wave-space in terms of depth or geographic depth 11 arranged. The separator device fourteen is over an outlet 18 fluidically via the connecting device 15 with the wave space 11 connected. The outlet 18 is especially in the Bottom area B formed and forms again in relation to the depth of a deepest region in the wave space 11 , For example, the outlet 18 be funnel-shaped, with the funnel-shaped extension below the shaft space 11 located. The outlet 18 is directly with the connection device 15 connected or forms part of this. The connection device 15 is designed as a throttle or constriction and flows into the segregation reservoir 16 , The demixing reservoir 16 has a larger cross-section perpendicular to the depth extension, as the connecting device 15 , At the bottom of the segregation reservoir 16 is the discharge device 17 arranged. For example, outlet 18 , Connecting device 15 , Segregation reservoir 16 and discharge device 17 along a line extending in the depth direction, be lined up linearly or serially.

To describe the operation of the separator fourteen will be on the 2 a, b, c representing the shaft arrangement 1 in the same representation, but in different operating states show referenced. The 2a shows an operating condition, where both the wave space 11 as well as the separator device fourteen completely with the lubricant 12 is filled. This operating state takes the shaft arrangement 1 for example, during initial filling, initial filling or refilling with lubricant 12 one.

In operation, medium penetrates 5 in the wave space 11 one. Optionally during operation or during short downtimes of the shaft arrangement 1 the medium sinks 5 in the bottom area B of the wave space 11 , There, the medium seeps 5 in the outlet 18 because this is the lowest point in the wave space 11 represents. Starting from the outlet 18 the medium sinks 5 continue via the connection device 15 into the segregation reservoir 16 and sits down there on the ground. To a negative pressure in the wave space 11 and an overpressure in the separator fourteen to avoid rises in parallel to the sinking of the medium 5 lubricant 12 from the first filling from the demixing reservoir 16 via the connection device 15 in the wave space 11 on.

The 2 B shows an operating state, wherein the segregation reservoir 16 Half with medium 5 and the other half with the lubricant 12 is filled, which is the medium 5 and the lubricant 12 have arranged as two separate layer areas.

The 2c on the other hand shows an operating state, the demixing reservoir 16 completely with the medium 5 is filled. In this operating condition, the demixing reservoir 16 be emptied, as this is no further medium 5 can record.

Once the segregation reservoir 16 completely with the medium 5 filled, this can be done via the discharge device 17 be drained. It can be provided on the one hand that the wave space 11 a ventilation device, so temporarily air into the shaft space 11 penetrates. After removal of the medium 5 from the separator fourteen This can be done from the side of the discharge device 17 again with lubricant 12 be filled, the penetrated air can be pushed out through the venting again. Alternatively, at another location in the wave space 11 a lubricant supply provided so that the discharge device 17 the medium 5 is deducted and at the same time the lubricant 12 in the wave space 11 is replaced. In all three operating states, the medium becomes 5 from the wave space 11 in the separator fourteen convicted and the wave space 11 with lubricant 12 refilled. The demixing reservoir 16 forms in particular an oil-water separator.

To prevent operation of the shaft assembly 1 medium 5 from the separator fourteen , in particular from the demixing reservoir 16 , again in the wave space 11 is pulled, is the connecting device 15 formed as a throttle or as a constriction. Optionally, the fluidic path between the outlet 18 and the demixing reservoir 16 can also be extended by a labyrinth compound such. As a helix is used. It is preferred that the fluidic path from the outlet 18 to the segregation reservoir 16 monotonous or even monotonically decreasing to avoid congestion.

In the 3 is another embodiment of the shaft assembly 1 illustrated, wherein provided in comparison to the preceding embodiments that the lubricant 12 a higher specific gravity than the medium 5 having. As a result, it turns out that the medium 5 not in the floor area B, but in the ceiling area D settles. Consequently, the outlet 18 in the ceiling area D, in particular in relation to the depth of the highest point of the wave space 11 arranged. The separator device fourteen is higher in relation to the depth than the wave space 11 , Otherwise, reference is made to the previous description with regard to the mode of operation.

LIST OF REFERENCE NUMBERS

1

shaft assembly

2

wave

3

turbine

4

generator

5

medium

6

casing

7

seal means

8th

admission

9

sealing lip

10

Storage facility

11

wave room

12

lubricant

13

Hydroelectric power station

14

trap structure

15

connecting device

16

Entmischungsreservoir

17

discharge device

18

outlet

19

inlet

B

floor area

D

ceiling area

S

flow direction

U

surrounding area

Claims (7)

Shaft arrangement ( 1 ) for operation in a liquid medium ( 5 ) with a housing ( 6 ), with a wave ( 2 ), where the wave ( 2 ) in sections in a wave space ( 11 ) of the housing ( 6 ), wherein in the wave space ( 11 ) a liquid lubricant ( 12 ) is arranged with a sealing device ( 7 ) for sealing the shaft ( 2 ) opposite the housing ( 6 ) and the separation of a surrounding area (U) with the liquid medium ( 5 ) of the wave space ( 11 ) with the liquid lubricant ( 12 ), and with a separator device ( fourteen ) for the separation of into the wave space ( 11 ) penetrated medium ( 5 ) from the lubricant ( 12 ), wherein the separator device ( fourteen ) fluidically with the shaft space ( 11 ), characterized in that the wave space ( 11 ) at least one outlet ( 18 ) for the fluidic connection with the separator device ( fourteen ), wherein the outlet ( 18 ): Either in a bottom region (B) of the wave space ( 11 ), wherein the lubricant ( 12 ) has a lower specific gravity than the medium ( 5 ), or in a ceiling region (D) of the wave space ( 11 ), wherein the lubricant ( 12 ) has a higher specific gravity than the medium ( 5 ) having. Shaft arrangement ( 1 ) according to claim 1, characterized by a storage device ( 10 ), the storage facility ( 10 ) in the wave space ( 11 ) and the shaft ( 2 ) relative to the housing ( 6 ) stores. Shaft arrangement ( 1 ) according to claim 1 or 2, characterized in that the separator device ( fourteen ) permanently and / or stationary in the shaft arrangement ( 1 ) is arranged. Shaft arrangement ( 1 ) according to one of the preceding claims, characterized in that the separator device ( fourteen ) a demixing reservoir ( 16 ) and a connection device ( 15 ), wherein the demixing reservoir ( 16 ) via the connection device ( 15 ) with the wave space ( 11 ) is fluidically connected. Shaft arrangement ( 1 ) according to claim 4, characterized in that the connecting device ( 15 ) is designed as a constriction and / or as a fluidic throttle. Shaft arrangement ( 1 ) according to claim 4 or 5, characterized in that the connecting device ( 15 ) is formed as a labyrinth connection. Hydroelectric power plant ( 13 ), characterized by a wave arrangement ( 1 ) according to any one of the preceding claims.

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