WO2018033289A1 - Thrust bearing arrangement for mounting a turbine rotor - Google Patents

Abstract

The invention relates to a thrust bearing arrangement (1) for mounting a turbine rotor (2), wherein the thrust bearing arrangement (1) has a track disk (3), which is connected to the turbine rotor (2) for conjoint rotation and which is arranged in an axially movable manner between two thrust bearings (4, 5), which are fixedly fastened in a housing, and wherein lubricant can be admitted into the respective gaps (6, 7) between the track disk (3) and the thrust bearings (4, 5). The amount of lubricant that is fed to each of the respective gaps (6, 7) between the track disk (3) and the thrust bearings (4, 5) is a function of the axial position of the track disk.

Description

description

Thrust bearing arrangement for mounting a turbine rotor

The invention relates to a thrust bearing assembly for supporting a turbine rotor according to the preamble of independent claim 1. Furthermore, the invention relates to a method for operating such a thrust bearing assembly according to claim 6 and a turbomachine with such a thrust bearing assembly according to claim 8.

Turbines, for example gas or steam turbines, have egg ^NEN nen equipped with turbine blades and rotatably mounted rotor. The turbine blades are traversed by a flow ^¬ medium, in this case the kinetic energy of the flowing medium is converted into rotational energy. Due to the flow of the flow medium, an axial force is exerted on the rotor. The resulting axial forces acting on the rotor are called axial thrust. The ^¬ ser axial thrust causes the rotor with respect to the vice ^¬ reproduced turbine housing is shifted. In order to avoid tarnishing of the turbine blade on the turbine housing and thus a possible destruction of essential turbine parts, the axial thrust or caused by this larger off ^¬ steering of the rotor must be counteracted. For this purpose, the turbine has a thrust bearing arrangement for axial bearing of the rotor.

The thrust bearing assembly comprises a non-rotatably connected to the rotor track disc, which is arranged axially movable between two in the axial direction left and right next to the track disc fixedly mounted in a housing radial bearings and thereby form a first and a second bearing ^¬ side. Between the respective radial bearings and the track disc, a bearing gap is present, with a

Lubricant can be acted upon. As a lubricant übli ^¬ cherweise a bearing oil is used. As camp find usual ^¬ segment bearings application. The track wheel is then positioned as centrally as possible between the at ^¬ the radial bearings, ie, the first or the second bearing side depending on the load point be charged. The Lagersei ^¬ th are therefore designed symmetrically with respect to segment and lubricant supply geometry. The power supplied to the respective bearing ^¬ cleave amount of lubricant is distributed to 50% on the loaded bearing side and 50% on the unloaded La ^¬ gerseite, regardless of the track wheel position. Consequently, the unloaded bearing side is applied amount of substance with a high lubrication, causing increased consumption ^¬ lubricant used as well as larger frictional losses in the bearings.

The object of the present invention is therefore to provide an axial ^¬ bearing arrangement for mounting a turbine rotor bereitzu- having a reduced lubricant consumption, and in which the friction losses are re ^¬ duced in the bearings. It is another object of the present OF INVENTION ^¬ dung provide a method for operating such Axiallageran ^¬ order.

The object is achieved with respect to the axial bearing arrangement by the features of independent claim 1 and Lich ^¬ respect to the method by the features of independent Pa ^¬ tentanspruchs. 6

Further embodiments of the invention, which are used individually or in combination with each other, are the subject of the dependent claims. The axial bearing arrangement according to the invention for supporting a turbine rotor, wherein the thrust bearing assembly has a non-rotatably connected to the turbine rotor disc, which is arranged axially movable between two fixed in a housing ^¬ th thrust bearing and wherein the respective gaps between the track disc and the respective thrust bearing

Lubricant can be acted upon, is characterized in that the respective amount of lubricant, which the respective gap between the track disc and the respective thrust bearing is supplied, is a function of the axial Scheibenscheibenpositi ^¬ on.

The supply of lubricant is thus for the first time no longer independent of the position of the track disc within the Axial ^¬ bearing arrangement divided into 50% each on first and 50% on the second bearing side. The lubricant supply is rather distributed as needed to the respective bearing side. This can save considerable amounts of lubricant. In addition, due to the reduction of

Lubricant quantities friction losses within the Radallageran ^¬ order significantly reduced.

An embodiment of the invention provides that with decreasing gap width, between the track disc and the respec ^¬ radial bearing, the supplied amount of lubricant increases and with increasing gap width, between the track disc and the respective radial bearing, the supplied lubricant quantity ver ^{¬ is} reduced. If the track disc is in its center position, the lubricant is distributed 50% to the first and 50% to the second bearing side. If, on ^¬ due to axial thrust in a shift of the track ticket ^¬ be, so the gap which decreases due to the Radialver ^¬ shift is a higher amount of lubricant leads conces-, as the gap increases due to the axial displacement of the thrust collar. Due to the higher lubricating ^¬ molar feed in the narrow gap a compensation of the axial thrust is achieved and the track plate moves back towards its central position. By this demand supply of lubricant to the respective gap, a Re ^¬ production of the lubricant flow within the axial bearing ^¬ arrangement results in comparison to conventional thrust bearing assembly of up to 40%. With large thrust bearing arrangements, it is thus possible to save up to 200 liters per minute and more. Due to the lower supply of lubricant in each larger

Gap can also friction losses was reduced considerably, ^¬. Preliminary calculations have shown that the total loss ^¬ performance of the thrust bearing assembly by up to 40% over conventional thrust bearing arrangements can be reduced. With larger thrust bearing arrangements, it is thus possible to save up to 100 kilowatts and more. An embodiment of the invention provides that there is a linear function between the supplied amount of lubricant and the gap width between the track disc and the respective radi ^¬ allager. This means that with a decreasing gap ^¬ wide increases the fed quantity of lubricant and linear, the quantity of lubricant for the opposite ^¬ the flared gap is decreased linearly in return. Overall, so that the total amount of lubricant supplied remains the same, this total amount of lubricant is significantly reduced compared to a conventional thrust bearing ^¬ arrangement.

A further embodiment of the invention provides that the track disc position is determined by means of an axial monitor. The axial vector is used as standard for most turbines, eliminating the need for additional sensors to determine the position of the pulley. Here ^¬ by the cost of such Axiallageranord ^¬ tion can be kept low.

A further embodiment of the invention provides that bearing oil is used as the lubricant. Bearing oil has a good lubricating property and a high temperature resistance.

The inventive method for operating a Axialla ^¬ geranordnung is characterized by the following procedural rensschritte:

- Determining the pulley position within the Axial ^¬ bearing assembly;

 - Determination of the axial deflection of the track disc from its center position;

 - Supply of lubricant between the respective

Gap, between the track disc and the respective radi ^¬ allager, wherein the supplied amount of lubricant is a function of the track disc position. The inventive method thus ge ^¬ genüber the prior art differs in that the lubricant ^¬ amount of feed to the respective gaps between the track ^¬ disc and the respective radial bearings from the corresponding position or axial design of the track wheel dependent and not, as previously, independently this is done.

The inventive method thus allows a targeted supply of lubricant to the respective gap, which can save considerable amounts of lubricant and friction ^¬ losses can be reduced within the radial bearing assembly.

An embodiment of the method for operating the Axialla- geranordnung is characterized in that the amount of lubricant ^¬ increases on the side with decreasing gap width and is reduced on the opposite side with increasing gap ^¬ wide. This achieves a particularly high level of lubricant savings and minimizes friction losses.

Furthermore, the invention comprises a turbomachine with egg ^¬ ner corresponding thrust bearing assembly. The invention and further advantages of He ^¬ invention will be described with reference to the figures.

It shows: - Fig.l the basic structure of an inventive

Radial arrangement;

- Figure 2 the supply of the quantities of lubricant in Depending ^¬ speed of the axial position of the thrust collar within the radial bearing arrangement.

The same or functionally identical components are cross-figurative provided with the same reference numerals. The illustrations in the figures are schematic and not necessarily dimensioning true to scale ^¬ right.

Fig.l shows the basic structure of an inventive thrust bearing assembly for supporting a turbine rotor. The thrust bearing assembly 1 comprises a track disc 3 which is rotatably connected to the turbine rotor 2. The track ^¬ disc 3 may be formed for this purpose, for example, integral with the door ^¬ binenrotor 2 or by means of a bond Schrumpfver- be shrunk onto the turbine rotor. The

Track disc 3 is arranged axially movable between two fixedly mounted in a housing radial bearings 4,5. The radial ^bearing 4,5 are formed as a segment bearing. The radial bearings 4, 5 have axial blocks 8, 9 which consist of white metal and wear or removal of the radial bearing in the case of

To prevent the track disc 3 rubbing. Between the respective radial bearing 4.5 and the track disc 3, a gap 6.7 is present. The column 6.7 are usually supplied with a lubricating material ^¬ a bearing oil, so that a possible liehst low friction between the moving and the ^¬ is available to the components. The position of the track disc 3 is monitored by a Axialwächter, not shown in Fig.l. The Axialwächter is a sensor which can determine the posi tion of the track ^¬ disk 3 accurately. The track disc 3 should preferably be located in ih ^¬ rer center position during the storage operation. The maximum axial displacement of the thrust collar between the two thrust bearings 4,5 is referred to as Axi ^¬ alspiel. The center position of the track disc 3 is because ^¬ characterized in that the columns are 6.7 each equal. As soon as the track disc 3 moves away from its center position, measures must be taken to bring the track disc 3 back into its central position in order to prevent the track disc 3 from rubbing against one of the axial bearings 4, 5.

To this end, lubricant is in the gaps 6,7 between the radi- allagern 4.5 and the lane plate 3 is introduced and thus produces an axial force that opposes the axial thrust, which is responsible for the axial displacement ^¬ Lich. The jewei ^¬ lige amount of lubricant which the respective gap 6.7 between see the track disc 3 and the respective radial bearing is fed to 4.5 is a function of the track position ^¬ tion. In central track wheel position is gerseiten the two La ^¬ and thus the respective columns 6,7 respectively supplied with the same amount of lubricant. Moves the track ^¬ disc 3 due to an axial thrust in the direction of the first bearing side and thus reduces the first gap 7, 1 more lubricant is supplied to this side of the thrust bearing assembly and simultaneously reduced the supplied amount of lubricant to the second gap 6. As a result, an axial force is generated, which counteracts the axial thrust and brings the track disc 3 back into its center position. By be ^¬ may just supply of lubricant resulting from ^¬ over the prior art in which two columns, the left and right of the lane plate 3 each have the same lubricant is supplied fuel quantity considerable advantages. On the one hand, due to the reduction in the amount of lubricant on the unloaded side (larger gap) a significant amount of lubricant can be saved. The lubricant throughput can be reduced by up to 40% compared to conventional designs. With a larger thrust bearing can thus be saved 200 liters per minute and more. At the same time, the friction losses in the axial bearing arrangement are also reduced due to the smaller filling of the gap of the unloaded bearing side. Initial calculations have shown that the Gesamtver ^¬ loss performance of the thrust bearing assembly can be reduced by up to 40% by the thrust bearing assembly according to the invention, which can make up 100 kilowatts and more for larger thrust bearings.

Fig. 2 shows a diagram which the

Lubricant flow rate through the respective bearing side as a function of the pulley position represents. Bearing ^¬ page 1 indicates the located in the axial direction right of the track disc bearing side and bearing side 2 located on the left of the track disc bearing side. When egg ^¬ ner central track disc position, the gap to the left and right sides is the same size. When shifting the Track disc to the left reduces the gap on the left ^¬ side and at the same time increases the gap on the right side. When the track disc is shifted to the right, the gap on the right side decreases while the gap on the left side increases. If the Axialrichter an axial displacement of the track Schei ^¬ benposition found from the middle position, then in From ^¬ pendence from the direction of the axial displacement, the

Quantity of lubricant which is supplied to the respective gap, changed accordingly. In a displacement of the track Schei ^¬ be to the left side, for example, the bearing gap on the left bearing side more lubricant supplied, while reducing the amount of lubricant on the ^{opposite ¬} right bearing side. In this way an axial force is produced which moves the disk track again in the direction ih ^¬ rer center position. If the track disc is in its center position, then 50% of the total lubricant quantity is supplied to both sides of the bearing. In order to ensure a sufficient lubrication of the respective bearing side, each side bearing must always have a minimum amount of lubricant to be supplied ^¬ leads that even with a maximum displacement of the track wheel in a direction of a certain amount of lubricant to be supplied to the opposite gap. This should preferably not be below 10% of the total

Lubricant quantity lie.

The illustrated in Fig. 2 linear control of the lubricant supply quantity ^¬ has shown a good controllability of the axial position of the disk track. In principle, however, the invention is not limited to a linear function. It is also conceivable any other function of the amount of lubricant as a function of the pulley position within the thrust bearing assembly.

In summary, it can be stated that the fiction ^¬ contemporary thrust bearing assembly due to their needs-based supply of lubricant to the respective bearing sides a significant saving of Öldurchsat zes on the Axiallageran ^¬ order allows, whereby large amounts of lubricant can be saved, at the same time a reduction the frictional losses can be realized, which contributes to a significant reduction in the total power loss.

Claims

claims 1. Axiallageranordnung (1) for supporting a turbine rotor (2), wherein the thrust bearing assembly (1) rotatably with the turbine rotor (2) connected track disc (3) which axially movable between two fixedly mounted in a housing thrust bearings (4, 5) is arranged and wherein the respective column (6, 7) between the track disc (3) and the respective thrust bearing (4, 5) can be acted upon with lubricant,  characterized in that is a function of the axial position of disc track the respective quantity of lubricant, which (3) and the jeweili ^¬ gen thrust bearing (4, 5) is supplied to the respective gap (6.7) between the track wheel. 2. thrust bearing assembly (1) according to claim 1,  characterized in that  with decreasing gap (6, 7), between the track disc (3) and the respective thrust bearing (4, 5), the supplied  Increased lubricant quantity and with increasing gap (6, 7), between the track disc (3) and the respective thrust bearing (4, 5), the amount of lubricant supplied is reduced. 3. thrust bearing assembly (1) according to claim 1 or 2,  characterized in that a linear function between the supplied lubricant amount ^¬ substance and the gap width between the track disc (3) and the respective thrust bearing (4, 5). 4. thrust bearing assembly (1) according to one of the preceding Ansprü ^¬ che,  characterized in that the track wheel position by means of a Axialwächters he ^¬ is averages. 5. thrust bearing arrangement (1) according to one of the preceding Ansprü ^¬ che, characterized in that  as a bearing oil storage oil is used. 6. A method for operating a thrust bearing assembly (1) according to any one of claims 1 to 5,  characterized by the following method steps:  Determine the track disc position  Determining the axial deflection of the track disc (3) from its center position Supplying lubricant between the respective gap (6, 7), between the track disc (3) and the respective thrust bearing (4, 5), wherein the supplied lubricant ^¬ quantity is a function of the track disc position. 7. A method for operating a thrust bearing assembly (1) according to claim 6,  characterized in that the amount of lubricant is increased on the side with decreasing gap ^¬ wide and reduced on the opposite side with too ^¬ participating gap width. 8. Turbomachine  characterized in that  the turbomachine has a thrust bearing assembly (1) according to one of claims 1 to 5.