WO2012080095A2

WO2012080095A2 - Axial bearing washer segment, axial bearing washer and method of production

Info

Publication number: WO2012080095A2
Application number: PCT/EP2011/072253
Authority: WO
Inventors: Johannes Goetz; Fred Menig
Original assignee: Aktiebolaget Skf
Priority date: 2010-12-16
Filing date: 2011-12-09
Publication date: 2012-06-21
Also published as: EP2652345A2; DE102010063278A1; WO2012080095A3

Abstract

The invention relates to a design for an axial bearing washer segment (100) and an axial bearing washer (105) comprising a fastening facility (110) for fastening to a structural component to be mounted axially, the side of the axial bearing washer segment (100) or of the axial bearing washer (105) facing the structural component to be mounted comprising a coating (120; 125) that increases a frictional force between the axial bearing washer segment (100) or the axial bearing washer (105) and the structural component to be mounted.

Description

Thrust washer segment, thrust washer and

production method

The present invention is in the field of low-maintenance storage of drive shafts, in particular drive shafts in underwater power plants.

Submarine power plants are already known from the field of conventional technology. In the following, well-known storage concepts for underwater power plants are briefly summarized. DE102009005556A1 discloses a concept for flushing underwater power plants, which consciously dispenses with encapsulation of the bearings used. In such constructions, the area in direct contact with the surrounding water is to be protected against excessive sediment. Furthermore, the growth in this area must be limited. One of the measures involved is to rinse the flooded area and, in particular, the bearings and the components associated therewith, such as sealing elements and the like.

One concept provides for applying at least one flushing connection to an underwater power station, by means of which a flushing medium can be supplied to the system from outside. Accordingly, in the plant itself lies between the ex- Rinse connection and the area to be washed no conveyor system, such as a pump or the like, before for the flushing medium. Furthermore, an additional filter system is dispensed with. Instead, the flushing medium is supplied at such an overpressure at the external flushing connection that there is a sufficiently strong flow through the area to be flushed and an outflow to the outside area, whereby sediments and preferably an originally present growth are transported to the outside.

A concept for optimized power control and control of underwater power plants is disclosed in DE102008053732B3. The

DE102008031615A1 shows a generator unit which can be handled as a whole and can be mounted as a unit, which can be transported and mounted separately from the actual drive shaft of an underwater power plant. This includes a generator rotor and a generator stator, the basic components of an electric generator. In addition, a generator housing is part of the generator unit. The control and power components of the electric generator can be additionally included in the generator assembly.

DE102008061912A1 deals with bearing pads, for example for seawater suitable slide bearings. For a hydrodynamically building up lubricating film and the associated parabolic pressure development for soft or elastic sliding linings, a concave deflection occurs in the central area. This leads to a Lagerpalterweiterung and a collapse of the pressure distribution in the central region of the sliding surface. This is counteracted by the fact that the material thickness of the sliding lining in the direction of the surface normal of the sliding surface is adapted to the lubricant film pressure occurring during operation. In the areas of high pressure around the surface center of the sliding surface, a reduced material used strength, while the edge regions have a high material thickness. In this case, the profile of the sliding surface is obtained, which typically corresponds to that of the mating surface. The adjustment of the material thickness of the sliding lining is carried out by a corresponding profiling of the bearing surface on the base body, which is opposite to the back of the sliding lining. In the simplest case, a raised base is provided in the central region of the support surface of the base body. A more accurate adjustment can be effected by a multiple stepped or convex course of the support surface.

DE102008006899A1 discloses a concept for supporting a drive shaft of an underwater power plant. Here, a bearing arrangement is provided, for supporting a shaft of a device for generating energy from a water flow, wherein the bearing arrangement comprises at least one radial sliding bearing and at least one axial sliding bearing and wherein the bearing assembly is lubricated by externally penetrating water.

FIG. 3 shows a schematic structure of an underwater power plant. FIG. 3 shows a machine nacelle 300 with a segmented structure. The nacelle 300 is followed by a hood 305 and a propeller-shaped water turbine 310 in the front area. The nacelle 300 includes two segments 315 and 320 that contain the drive shaft 325. In another segment 330 is a generator 335 which is coupled to the drive shaft 325. Another hood 340 terminates the underwater power plant after the generator 335.

The hood 305 forms with the water turbine 310, a circumferential unit which is coupled to the drive shaft 325. For storage of the drive shaft 325 a plurality of plain bearings are provided. In the water turbine 310 facing the front portion of the drive shaft 325 is a radial sliding bearing 345. In the rear region of the drive shaft 325 facing the generator 335, there is another radial slide bearing 350. Axial forces of the drive shaft are absorbed by the two axial slide bearings 355 and 360 which axially support a track disc 365 connected to the drive shaft 325.

The plain bearings 345, 350, 355 and 360 can be carried out seawater resistant, in particular water lubricated. This makes it possible to flood the entire interior of the nacelle 300 and to dispense with elaborate seals, especially the bearings.

The sliding bearings used 345, 350, 355 and 360 are partially realized directly on the drive shaft 325. The shaft 325 may typically have a continuous outer diameter of about 100-6000 mm, with a maximum power of the entire system of about 50 kW - 15 MW. At one point there is a shaft shoulder or a track disc 365 with a diameter of about 150-9000 mm. The resulting end faces of the paragraph serve as a surface for the thrust bearings 355,360 of the shaft. A very hard coating is applied to these two surfaces and this then represents one slice of the axial sliding bearing.

For example, high-speed flame spraying can be used as the coating process (also HVOF, derived from high-velocity oxygen-fuel) or another thermal coating process for surface treatment, such as plasma coating, nano-coating, PVD coating (physical vapor deposition, English, physical vapor deposition) etc. It is also possible initially to attach a steel disc by welding at these locations and then to machine the surface thereof. layers. The bearing is used directly in the water / seawater, the surfaces of the thrust bearing 355,360 are directly surrounded by the water.

A problem now is that the very large and heavy shaft handled, transported, clamped on a machine, coated and then the bearing or the welded bearing ring must be ground, which is costly. In the variant which provides for a fixed welding of at least one bearing disk, material distortion may occur due to the fixed welding of the bearing disk on the end faces of the shaft shoulder.

Furthermore, it is problematic that the maintenance of the storage is difficult. If such a bearing fails in the application, the entire shaft must be brought for repair or replaced. This results in long machine downtimes.

Conventional concepts provide a large one-piece wave. There then takes place a coating of the bare shaft outlet front side, or only an attachment of bearing washers on the end faces of the shaft shoulder by welding and then a coating of these discs. When coating the bearings handling the entire shaft is necessary. The coated areas must also be post-processed, e.g. by grinding. It is not possible to replace the plain bearing in the event of damage; the complete shaft must be repaired or replaced.

It is therefore an object of the present invention to provide an improved concept for a thrust bearing of a drive shaft, in particular for an underwater power plant. The object is achieved by a thrust washer segment, a thrust washer and a manufacturing method according to the independent claims.

A core idea of the present invention lies in the realization that, in particular in underwater power plants, a mechanical decoupling of thrust bearing and drive shaft can take place. This can be achieved by a thrust washer, which in turn can be divided into individual Axiallagerscheiben- segments. For example, the axial bearing disc can be segmented into n parts. The segments or the bearing plate can or can then be fixed, for example, by screws, rivets, gluing, plugging, etc. on the front sides of the shaft shoulder, a welding of the disc is not necessary. Advantages can also be achieved by the fact that the thrust bearing can be coated arbitrarily.

The present invention is further based on the finding that after the mechanical decoupling of thrust bearing and drive shaft of the mounting effort of the decoupled bearing can be reduced by a friction coating to increase the frictional force on the mounting side. The fastening means can be reduced accordingly, if the friction between thrust washer or Axiallagerscheibensegment on the mounting side can be increased accordingly. Accordingly, less fasteners, such as screws, rivets, etc. are necessary to ensure a secure attachment. In order to ensure a secure attachment of the Axial- Lagerscheiben segments or the thrust washer, a rotation or Mitwandern the disc in the circumferential direction must be prevented. This should also be ensured once it has become a reality. clock should come between the bearing disc on the shaft and the bearing disc in the housing.

The present invention is therefore further based on the core idea of providing a coating of the axial bearing disk or its segments in such a way that a frictional connection between the respective axial bearing disk and the housing or the drive shaft shoulder is increased or reduced on the opposite side. Embodiments may therefore provide for providing a surface of the bearing disc segments with a coating. This coating may have various properties, e.g. an extremely large friction coefficient. The opposite side can also be coated, this coating can e.g. have a high hardness, good sliding properties, etc.

In embodiments, the segments can be mounted on the shaft in such a way that the side with the friction coating lies on the end face of the shaft shoulder or on the shaft shoulder and / or on the shaft axis. The attachment can be done eg by means of screws, bolts, pins, rivets, gluing, plugging, etc. Due to the friction coating, the resistance of the segments against co-rotation in the circumferential direction can be greatly increased. This may result in embodiments that significantly fewer fasteners are required for the attachment of the segment pieces to the shaft shoulder. As a result, the shaft is less strongly weakened and the side of the segments with the sliding coating has a much larger sliding surface, since it can be interrupted less frequently due to the reduced number of fastening elements. Further advantageous embodiments are specified by the dependent claims and explained in the following with reference to the accompanying drawings in detail in the context of embodiments of the present invention. Show it

1 shows an embodiment of a Axiallagerscheibensegments or a section of a thrust washer;

Figure 2a shows another embodiment of a Axiallagerscheibensegments or a thrust washer;

Figure 2b shows an embodiment of a manufacturing process for an axial bearing disc segment or a thrust washer; and

Figure 3 is a conventional underwater power plant.

FIG. 1 shows an exemplary embodiment of an axial bearing disk segment 100 or an axial bearing disk 105. The axial bearing disk segment 100 of an axial bearing disk has an attachment option 110 for attachment to a component to be axially supported, wherein the side of the axial bearing disk segment 100 facing the component to be supported comprises a coating 120, 125 which increases a frictional force between the thrust washer segment 100 and the component to be supported. The attachment option 110 may include attachment means, thereby, for example, holes / recesses or bolts of any geometry (round, square, triangular, oval, T-shaped cross section, etc.) occur. The fastening means 110 may also include grooves or webs, for example, dovetailed guides or grooves may be provided. Accordingly, the axial bearing disk segment 100 may, for example, comprise a certain angular range of an axial bearing disk 105, as shown by way of example in FIG. In exemplary embodiments, a plurality of geometrically identical or unequal axial bearing disk segments 100 may form an axial bearing disk 105. Embodiments are not limited to a specific subdivision of a thrust washer 105 in Axiallagerscheibensegmente 100, there are any axial and radial segmentation conceivable.

As an example, the coating 120 in the figure is running the local underside of the Axiallagerscheibensegments 105 indicated by the arrow, i. in the local embodiment, it is assumed that the side facing the component to be stored is located below in the plane of the drawing. In exemplary embodiments, however, a side 125 of the axial bearing disk segment 100 facing an axial bearing center or the axis of rotation of the axial bearing, which is then designed as an axial bearing disk ring segment, can have the coating 120, 125 and thus the frictional force between the axial bearing disk segment 100 and the component to be supported increased.

This is indicated in the figure 1 by the reference numeral 120.125, in other words, a frictional force between the Axiallagerscheibenringsegment 100 and the component to be supported on the axis of the component can be increased, ie on an axial contact surface (contact surface with axial extent) with the component. In further exemplary embodiments, for example those in which the drive shaft shoulder has an edge, the coating 120 can also be present on the outside of the edge of the segment 100 or the disk 105. Embodiments also include an entire thrust washer 105, the attachment means or a mounting option 110 for attachment to an axially to be stored component, wherein the component to be stored facing side of the thrust bearing 105 has a coating having a frictional force between the thrust washer 105 and to be stored Component increased. The thrust washer 105 may be formed in several pieces and / or, as shown in FIG. 1, may be composed of a plurality of bearing disk segments 105. In other embodiments, the thrust washer 105 may also be integrally formed.

As already explained above with reference to the axial bearing disk ring segment 100, the axial bearing disk 105 can also be designed as an axial bearing disk ring and the coating 120, 125 can then also be present on a side facing a bearing center point. In other embodiments, e.g. those in which the drive shaft shoulder has an edge, the coating 120 may also be present on the outside of the edge of the segment 100 or the disk 105. That Again, the coating 120 may be located on a contact surface with axial extension. The fastening means 110 may in embodiments z. B. holes for screwing with the component to be stored.

The thrust washer segment 100 or the thrust washer 105 may be adapted for use in a sliding bearing of a drive shaft of an underwater power plant. However, embodiments may also generally provide for use in axial sliding or rolling bearings. The thrust washer segment 100 may be a ring segment of a ring, the thrust washer 105 may be a ring having an inside diameter greater than or equal to 50, 500, 1000, 1500, 2000, 3000, 5000 or 10000 mm and an outside diameter greater than or equal to 75, 750, 1500, 2250 , 3000, 4500, 7500 or 15000 mm correspond. The axial bearing disk segment 100 or the axial bearing disk 105 can have an edge thickness 115, cf. Figure 1, of about 650mmm have. In embodiments, edge strengths 115 greater than or equal to 25, 50, 100, 250, 500, 750, 1000, 1500, 2000, 2500 or 5000 mm may also occur. An axial bearing disk segment 100 may have a weight of about 1kg to 1 liter, a thrust washer 105 may have a weight of about 2kg - 5 tonnes. The thickness of a thrust washer segment 100 or a thrust washer 105 may be about 1 to 100 mm.

FIG. 2 a shows a further exemplary embodiment of an axial bearing disk segment 105 or an axial bearing disk 100 in a sectional view. FIG. 2a shows two coatings 120 and 130, of which the coating 120, which represents the side / coating facing the component to be stored, is also referred to below as the friction coating 120. The coating carrier 140, i. the uncoated thrust washer segment 100 or the uncoated thrust washer 105 is also shown in FIG. 2a. In embodiments, the coating carrier 140 may comprise a metallic, a ceramic or a mixed material or a partially ceramic material.

The coating 120 serves to increase a frictional force and thus the adhesion to the component to be stored. In addition, an axially extended contact surface 125 is indicated in FIG. 2a, such as a side facing the bearing center or the axis of rotation of the bearing, which may also be coated. Axiallagerscheibensegment 100 and the thrust washer 105 may be formed for attachment to a housing or a drive shaft of an underwater power plant, ie, in embodiments, the component to be stored, for example, a Ge housing or a drive shaft, in particular those of an underwater power plant.

The friction coating 120 of the axial bearing disk segment 105 or of the axial bearing disk 100 can have a high-strength, tough and hard metal as the main component, the coating 120 being provided in at least one surface region with a square-like base surface having a side length in the region of one millimeter, by a profile many pointed mountains and valleys can be characterized. In this surface area, a proportion of those peaks and valleys which project beyond a plane plane-parallel to the ground plane, which has a distance in the range between 15 and 30 μm from the highest mountain, can be greater than approximately 20%.

The topography of the friction coating 120, in particular when the coating is formed as a flame-sprayed molybdenum coating, can have a high surface carrying ratio, for example greater than 20%, and high static friction coefficients, for example greater than 0.6 or even greater than 0.65, based on a pairing of said coating with a steel counterpart , or with the end face of the drive shaft, the wave washer or the shaft shoulder, have.

In exemplary embodiments, the friction coating 120 may have particles having a Mohs hardness greater than or equal to 9 and / or a predeterminable average grain size. In embodiments, however, particles having a Mohs hardness greater than or equal to 6, 7 or 8 may also occur. Furthermore, the coating may have a thickness approximately equal to half the mean grain size. The coating carrier 140, ie the uncoated axial bearing disk 105 or its uncoated segment 100, can have a surface comprising recesses. A share of approx. 85% or more of the fimgen may be formed with respect to a surface surrounding the respective depression with a depth of less than about 10% and / or an opening width less than or equal to about 15% of the coating thickness. The coating 120 may be applied to the surface of the coating carrier 140 and enclose the particles at least in a lower region oriented toward the coating carrier 140.

The surface of the coating carrier 140, i. of the uncoated axial bearing disk segment 100 or of the uncoated axial bearing disk 105, can accordingly be designed such that the groove-like depressions face a surface surrounding the respective depression, have a depth of less than about 10% of the coating thickness and / or an opening width of less than about 15 % of the coating thickness. Thus, an optimal adhesion for the coating 120 can be ensured and at the same time it can be prevented that particles disappear into depressions in such a way that they do not contribute to increasing the friction of the coating arrangement.

The friction coating 120 may comprise, for example, nickel, tungsten, cobalt, chromium, aluminum, diamond or a ceramic material. For example, the coating 120 may be formed of electroplated nickel, such that for the coating carrier 140, i. the uncoated axial bearing disk 105 or the uncoated segment 100, at the same time a protective layer against corrosion-causing and other environmental influences is generated.

In addition, the coating or the coatings hard particles, in particular particles with the degree of hardness of diamond or cubic boron nitrate (CBN) or of corundum or carbide, have. Such coating The fact that the friction-enhancing coatings improve the detachable connection between the components can be distinguished.

In embodiments, the coating may comprise zinc silicate or the particles may be e.g. be formed by spray-galvanizing or the like according to a friction-increasing coating. Because the connection is hot-dip galvanized, a reliable, friction-increasing coating can also be provided.

In embodiments, as particles, hard particles, such as e.g. Diamond may be used, wherein the particle size may be greater than 30 pm, preferably more than 35 pm. For example, For example, a nickel-based nickel plating 120 for diamond coating with a mean particle size of 46 pm (D46 diamond) can be produced.

In exemplary embodiments, the axial bearing disk 105 or the axial disk segment 100, having a greater Mohs hardness and / or a greater tensile strength than the wave spur disk or even a housing, ie the component to be supported, against which the coating arrangement is provided for counterpressing, can be formed. Therefore, the regions of the particles protruding beyond the coating 120 can press into the wave spur disk. The coating 120 below the particles as well as the regions of the coating carrier 140 underneath the particles can only be slightly deformed compared with the impressions into the counterelement / component.

In embodiments, 120 particles can be applied in one or a few layers with the eib coating, with subsequent fixing of the particles by means of an electrodeposited metal, in particular nickel, so that a particle layer is fixed, wherein when applying several layers, the excess layers can be removed, for example by brushing after fixing. For example, a coating 120 is conceivable in which the particle area protruding out of the nickel layer accounts for more than 25%, or up to 40%, of the surface of the coating, thus ultimately achieving very high static friction coefficients of greater than 0.7 and also greater than 0.8. Here, by a single layer is meant that in a majority of the coated surface, in particular greater than 75%, actually only one layer of particles is fixed, and only in smaller areas of the coated surface, the particles can also adhere in multiple layers, in particular two-ply.

In addition, the Axiallagerscheibensegment 100 or the Axiallagerscheibe 105 on the side facing away from the component to be stored, ie, on the side facing the bearing gap, a further coating 130 having a frictional force between the Axiallagerscheibensegment 100 and the thrust washer 105 and a reduced other thrust washer segment or another thrust washer. The coating 130 may also be referred to as a sliding coating, it may help to allow easy bearing operation. Suitable coating materials are, for example, Teflon or Teflon-based coatings. In embodiments, all coatings which are suitable for reducing the frictional force can be used as a lubricious coating. These include, for example, thermoplastic polymer coating, nanocoating, plasma coating, carbide coating, PVD, CVD (chemical vapor deposition), TiC coating, TiCN, TiN, AlTiN, DLC (diamond-like carbon coating). like carbon), HVOF, etc. Embodiments also include a method of manufacturing an axial bearing disk segment 100 or a thrust bearing disk 105, which is schematically illustrated in FIG. 2b by a flowchart. The manufacturing method comprises a step of coating 210 a side of the thrust washer segment 100 or the thrust bearing disk 105 facing a component to be stored with a coating 120 which increases a frictional force between the thrust washer segment 100 or the thrust washer 105 and the component to be supported. This can be followed in embodiments by a step of mounting 220 of the coated axial bearing disk segment 100 or of the coated axial bearing disk 105 to the component to be supported.

FIG. 2b shows an optional step 215 in dotted lines. In exemplary embodiments, the manufacturing method may include an optional step of coating 215 a side of the thrust washer segment 100 facing away from the component to be stored, or the thrust washer 105 with a coating 130 that generates a frictional force between the thrust washer segment 100 or the thrust washer 105 and another thrust washer segment 100 or another thrust washer 105 is reduced.

Accordingly, exemplary embodiments also include a drive shaft with a thrust bearing, wherein the thrust bearing comprises an axial bearing disk 105 or an axial bearing disk segment 100. The drive shaft can have a shaft shoulder, a shaft shoulder or a shaft track rod, which is mounted relative to a housing by means of the axial bearing. The thrust bearing can be designed as a sliding bearing. Finally, embodiments also include an underwater power plant with such a slide-mounted drive shaft. LIST OF REFERENCE NUMBERS

100 thrust washer segment

105 thrust washer

110 fasteners

115 ring width

120 friction coating

125 Side facing the bearing center

130 slip coating

140 coating carrier

210, a coating of a component to be stored facing side of the Axiallagerscheibensegments 100 or the thrust washer 105 with a coating 120th

215 Coating a side of the axial bearing disk segment 100 or the axial bearing disk 105 facing away from a component to be supported with a coating 130

220 Mount the coated thrust washer segment 100 or the coated thrust washer 105 to the component to be stored

300 nacelle

305 hood

310 water turbine

315 segment

320 segment _{1 0}

lo

drive shaft

segment

generator

Hood

radial bearings

axial plain

track disc

Claims

P atentansprü che thrust washer segment, thrust washer and manufacturing process

1. A Axiallagerscheibensegment (100) of a thrust washer (105) having a mounting option (110) for attachment to an axially supported component, wherein the component to be stored facing side of the Axiallagerscheibensegments (100) a coating (120; ) which increases a frictional force between the thrust washer segment (100) and the component to be supported.

2. The thrust washer segment (100) of claim 1 formed as an axial bearing disc ring segment and a thrust bearing center side of the thrust washer ring segment (100) includes a coating (120; 125) that provides a frictional force between the thrust washer segment (100) and stored component increases.

3. The Axiallagerscheibensegment (100) according to one of the preceding claims, which has on a side facing away from the component to be stored a coating (130), which reduces a frictional force between the Axiagerageribebeteil (100) and another Axiallagerscheibe segment or other thrust washer.

4. The Axiallagerscheibensegment (110) according to any one of the preceding claims, wherein the fastening means (110) includes bores for screwing to the component to be stored and / or is designed for attachment to a housing or a drive shaft of an underwater power plant.

5. The thrust washer segment (100) according to one of the preceding claims, wherein the side facing the component to be supported has a coating (120; 125) comprising nickel, tungsten, cobalt, chromium, aluminum, diamond or a ceramic material and / or in which the coating (120; 125) has particles with a Mohs hardness greater than or equal to 9.

6. An axial bearing washer (105), which has a fastening possibility (110) for attachment to an axially to be supported component, wherein the component to be stored facing side of the thrust washer (105) has a coating (120, 125) which has a frictional force between the thrust washer (105) and the component to be stored increased.

7. The thrust washer (105) according to claim 6, which is formed as Axiallagerschei- benring and a Axiallagermeldpunkt side facing the Axiallagerscheibenrings (105) has a coating (120; 125), the frictional force between the Axiallagerscheibe segment (100) and the zu stored component increases.

8. The thrust bearing (105) according to any one of claims 6 or 7, which on a side facing away from the component to be stored on a coating (130) which has a frictional force between the thrust washer (105) and another thrust washer segment or other thrust washer.

9. A manufacturing method for a thrust washer segment (100) or an axial bearing washer (105), comprising the following step:

Coating a side of the axial bearing disk segment (100) facing the component to be supported or the axial bearing disk (105) with a coating (120; 125) which increases a frictional force between the axial bearing disk segment (100) or the axial bearing disk (105) and the component to be supported.

10. The manufacturing method according to claim 9, with the following further step:

Coating a side of the thrust washer segment (100) facing away from the component to be supported or the thrust washer (105) with a coating (130) which reduces a frictional force between the thrust washer segment (100) or the thrust washer (105) and another thrust washer segment or other thrust washer ,