DE2052079A1 - Axial plain bearings for high-speed shafts - Google Patents

Description

Axial plain bearings for high-speed shafts

The invention relates to an axial sliding bearing for high-speed Shafts, in particular turbo rotors, consisting of a sliding washer fastened on the rotor shaft, which is pressed against a Bearing carrier side arranged, stationary bearing disk starts up.

In order to compensate for imbalances and to dampen vibrations in rotors that rotate at high speed, they are stored in Radial plain bearings with floating bushings, i.e. the high-speed rotor rotates in a sliding bush, which in turn is absorbed by an oil cushion in the bearing bracket. There is lubricant in the two sliding fits. Such Bearing is to be regarded as a flexible bearing in the radial direction and gives the rotor a correspondingly large amount of freedom to deal with the imbalances due to its suspension and damping properties and to compensate for vibrations at high speeds. In the case of a rotor received in radially flexible bearings of this type

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the design of the AxMlager causes difficulties, than through possible wobbling movements of the rotor, the axial running disk rigidly attached to this opposite the the thrust on the housing transmitting stationary axial bearing washer staggers. This results in running gaps in the axial bearing that differ in terms of location and time on the circumference as a result, edge wear and local overloading of the bearing.

The object of the present invention is to address these disadvantages while taking into account a justifiable economic To avoid effort.

To solve this problem it is proposed according to the invention that the stationary bearing washer in the bearing bracket be cardanic is hung. Through this cardanic suspension, the stationary bearing disc can always adjust so that their The sliding surface is exactly parallel to the rotating sliding washer, causing excessive stress on the bearing washers and premature destruction caused thereby is avoided will.

In an advantageous embodiment of the invention, the cardanic suspension should take place in such a way that the stationary bearing washer on its rear side via two diametrically opposite balls with respect to the rotor axis on an intermediate ring.

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which in turn is supported against the bearing carrier on two balls which are diametrically opposite with respect to the rotor axis iäb, whereby the four balls against each other by 90 are arranged offset. This simple, reliable and maintenance-free device results in two perpendiculars standing axes around which the stationary bearing disk can be tilted in all directions.

In a further embodiment of the invention, the stationary bearing disk is to be acted upon by a pressure medium on its rear side be. As a result, the pressure load on the bearing balls is significantly reduced, since the pressure medium on the entire Attacks the annular surface of the stationary bearing disk and generates a compressive force which counteracts the axial thrust of the rotor is. A piston ring which is arranged on the outer circumference of the axial bearing disk and rests against the bearing carrier bore prevents it a pressure equalization and is therefore a guarantee that the pressure relief force will take effect.

According to a further feature of the invention, the stationary Bearing disk and / or the rotating sliding disk on their sliding surfaces with one another with hydrodynamically more effective Profiling be provided. Such a profiling, also referred to as a multi-slide surface profile, and further details of the invention are described using a drawing.

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In the drawing shows

1 shows a longitudinal section of a turbo rotor bearing with an axial sliding bearing according to the invention

2 shows a meridional section through a sliding pairing according to the invention with a sliding disk has a hydrodynamically effective profile.

A turbo rotor consisting of a shaft J> and a turbine wheel 2 connected to it in a rotationally fixed manner is supported in radial plain bearings 4 and 5 in a housing 1. In the direction of the arrow, an axial thrust S resulting, for example, from the gas forces acts on the turbo rotor, which is supported in an axial sliding bearing 12. The radial plain bearings 4 and 5 are equipped with floating bushings (4a, 5 &, 5b), ie there are two lubrication gaps between the bearing carrier and the rotor, namely one between the shaft and the floating bush, the other between the floating bush and the bearing housing. The two lubrication gaps in each bearing result in a bearing that is radially flexible to a limited extent and is particularly suitable for high-speed turbo rotors. To achieve better lubrication and cooling, the radial sliding bearing 5 should be subdivided in such a way that two floating bushings (5a, 5b) are axially adjacent to one another, with

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A lubricating oil supply 7 is arranged between the bushes. The axial sliding bearing 12, which absorbs the axial thrust, consists of a sliding disk 11 fastened to the rotor shaft 3 and a stationary bearing disk 6, which is in the bearing carrier 1. danish is hung up. This cardanic suspension takes place in such a way that the axial bearing disk 6 is supported on an intermediate ring 14 via two diametrically opposite balls with respect to the rotor axis J> o , which in turn is supported on two diametrically opposite balls 15 against a housing sleeve 16. The balls 13 and 15 are offset from one another by 9 ° with respect to the machine axis. In this way, two mutually perpendicular tilting axes are created which each run through the center of the sphere and about which the stationary axial bearing disk 6 can tilt in the desired manner in all directions. As a result, the axial bearing disk 6 can adapt itself to a wobbling movement of the shaft 3 and thus the sliding disk 11 so that a parallel sliding gap between the disks 6 and 11 is always present.

The bearing disk 6 forms a piston in the bore 2o of the housing 1. That through a hole 17 in the annular space between the housing sleeve 16 and thrust bearing disk 6 entering, pressurized lubricating oil acts on the rear side 6a of the thrust bearing disk 6 and thereby partially relieves the cardanic suspension from the axial thrust S of the rotor to be transmitted. At the

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Outer circumference 6b of the axial bearing disk 6 prevents a piston ring 18, which rests against the bearing carrier bore 2o, the outlet of the lubricating oil. On the inner diameter of the discs 6 and lA, the lubricating oil can on both sides The lubrication gaps of the axial and radial bearings flow in. To improve the sliding properties of the axial plain bearing is either the rotating sliding disk 11 or the stationary axial bearing disk 6 with a hydrodynamically effective one Profiling provided. Such a contour Io is on the disk 6 in Pig. 2 attached.

During the operation of the turbo runner, the sliding disk 11 is clearly in contact with the axial bearing disk 6. When the rotor starts up, when the thrust S is not yet fully effective, the oil pressure acting on the axial bearing disk 6 will initially press the rotor via the sliding disk 11 in the direction opposite to the axial thrust S. Therefore, a thrust washer 19 is arranged in the housing 1, which in order to improve the sliding properties if necessary with a hydrodynamically effective profile as in Pig. 2 may be provided.

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Claims (7)

ba / kn ^ 9 Π ζ "7 Π 7 Q MOTORS AND TURBINES UNION <£ U 3 ^ U / MUNICH GMBH. Munich, October 19, 1970 Claims / 1.! Axial plain bearings for high-speed shafts, especially turbo rotors, with a sliding washer fastened on the rotor shaft, which is arranged against a bearing support side, stationary bearing disk starts up, characterized in that the stationary bearing disk (6) in the bearing bracket (l) is gimbaled. 2. Axial plain bearing according to claim 1, characterized in that the stationary bearing washer (6) is located on its rear side (6a) via two balls (13) diametrically opposite with respect to the rotor axis (3o) onto an intermediate ring (l4) supported, which in turn on two with respect to the rotor axis (Jo) diametrically opposite balls (15) against the bearing bracket is supported, the four balls (13, 15) being offset from one another by 90 °. 3. Axial plain bearing according to claim 1 or claim 2, characterized T-3o9 - 2 - 209818/0354 characterized in that the stationary bearing disk (6) is acted upon by pressure medium on its rear side (6a). 4. Axial plain bearing according to claim 2 or claim j5, characterized characterized in that a piston ring (l8) is arranged on the outer circumference (6b) of the axial bearing disk (6), which is connected to the bearing bracket bore (2o) is in contact. 5 · Axial plain bearings according to one or more of the preceding Claims, characterized in that the axial bearing washer (6) and / or the sliding washer (11) on their running surfaces sliding on each other are provided with hydrodynamically effective profiling. 6. Axial plain bearing according to claim 1 or one or more of the preceding claims, characterized in that an im Bearing bracket (£) attached thrust washer (19) provided is. 7. Axial plain bearing according to claim 6, characterized in that the contact surfaces between the sliding washer (ll) and the thrust washer (19) are provided with hydrodynamically effective profiles. T-309
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