Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C17/00—Sliding-contact bearings for exclusively rotary movement
  • F16C17/12—Sliding-contact bearings for exclusively rotary movement characterised by features not related to the direction of the load
  • F16C17/24—Sliding-contact bearings for exclusively rotary movement characterised by features not related to the direction of the load with devices affected by abnormal or undesired positions, e.g. for preventing overheating, for safety
  • F16C17/246—Sliding-contact bearings for exclusively rotary movement characterised by features not related to the direction of the load with devices affected by abnormal or undesired positions, e.g. for preventing overheating, for safety related to wear, e.g. sensors for measuring wear
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M13/00—Testing of machine parts
  • G01M13/04—Bearings
  • G01M13/045—Acoustic or vibration analysis
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C2233/00—Monitoring condition, e.g. temperature, load, vibration
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C2360/00—Engines or pumps
  • F16C2360/31—Wind motors

Definitions

• the invention relates to a method according to claim 1 and a control device according to claim 3.
• Hydrodynamic plain bearings can be operated in different lubrication states. Possible lubrication conditions are: boundary friction, mixed friction or sliding friction. The transition between the friction states is fluid. Ideally, hydrodynamic plain bearings are operated exclusively with sliding friction. The sliding surfaces are completely separated by a stable lubricating film. In this operating state, there is no wear. However, an exclusive operation with sliding friction is not possible in many applications, for example in wind power transmissions. If boundary friction or mixed friction occurs, the bearing wears and ultimately fails in the advanced stage of wear.
• a so-called self-healing wear effect is known from the prior art.
• Self-healing wear effects are described, for example, in “Fast running de combustion engines” (H. Ricardo; Springer-Verlag, Berlin, 1926).
• the self-healing wear effect makes it possible to smooth the running surfaces of a damaged plain bearing.
• suitable operating points are approached in which mixed friction is present.
• the mixed friction means that the previously created roughness is smoothed out again. So far, self-healing wear effects can only be achieved under laboratory conditions.
• the lubrication condition of a plain bearing can be determined on the basis of structure-borne noise signals that are recorded with one or more acoustic emission sensors.
• Corresponding procedures are described in "Classification of Journal Bearing Friction States based on Acoustic Emission Signals” (N. Mokhtari, C. Guhmann; TM-Technisches Messen, Vol. 85, Issue 6, 2018) and “Approach for the Migration of Hydrodynamic Journal Bearings based on Acoustic Emission Feature Change "(N. Mokhtari, C. Guhmann, S. Novolski; IEEE International Conference on Prognostics and Health Management (ICPHM), 2018). From “Vibra- tion Signal Analysis for the Lifetime Prediction and Failure Detection of Future Turbofan Components "(N. Mokhtari, M. Riskowski, C. Guhmann; Technische Mechanik 37, 2017) is a method for deriving a Stribeck curve from the Signals from acoustic emission sensors known.
• the invention is based on the object of improving the operational safety of a plain bearing and preventing premature failures caused by damage. This object is achieved by a method according to claim 1 and a control device according to claim 3. Preferred developments result from claim 2 and the following description.
• the method according to the invention enables the targeted use of self-healing wear effects in a sliding bearing that is in operation.
• the invention is based on the knowledge that in order to use self-healing wear effects in a transmission that is in operation, valid knowledge about the current state of a plain bearing is required. As an indicator of the status, a speed is used, which is applied when the lubrication state of the plain bearing changes. Accordingly, the method according to the invention provides, as one of two alternatives, a first speed of the plain bearing to be determined at which a transition of the lubrication state takes place in the plain bearing or in a bearing gap of the plain bearing.
• a relative speed of two relatively rotatable sliding surfaces of the plain bearing is referred to.
• a bearing gap runs between the sliding surfaces in which, depending on the operating point, boundary friction, mixed friction or fluid friction occurs.
• boundary friction mixed friction or fluid friction occurs.
• a transition in the lubrication state is equivalent to a transition between boundary friction and mixed friction or between mixed friction and fluid friction.
• a transition can therefore take place from boundary friction to mixed friction, from mixed friction to boundary friction, from mixed friction to fluid friction and / or from fluid friction to mixed friction.
• the lubrication state or a transition of the lubrication state can, as mentioned above, be determined by methods known from the prior art. In particular, acoustic emission sensors can be used for this purpose.
• the first speed indicates an operating point at which the friction in the plain bearing, i.e. in its bearing gap, is minimal. This means that the friction in the plain bearing is greater at any other speed than at the first speed. Friction denotes a moment of friction which the plain bearing opposes a relative rotation of the sliding surfaces due to the friction arising in the bearing gap
• the said operating point is preferably determined using a Stribeck curve.
• a Stribeck curve assigns the corresponding friction arising in the bearing to each speed of the Gleitla gers. Using the Stribeck curve, a speed can be determined at which the friction is minimal.
• the first speed is higher, the worse the condition of the plain bearing is. In particular, roughened sliding surfaces lead to a higher first speed.
• the first speed is therefore an indicator of any wear or damage to the plain bearing. According to the invention, the first speed is therefore used as an indicator for et waigen wear or damage to the plain bearing.
• a threshold value with which the first speed is compared is used as a criterion for assessing the condition of the plain bearing.
• the inventive method provides to regenerate the plain bearing through self-healing wear.
• the bearing is thus operated in such a way that a self-healing wear effect occurs, ie the bearing is exposed to operating states in which a self-healing wear effect occurs. Other operating states are avoided. Typical of such operating conditions is the occurrence of mixed friction in the bearing gap.
• a second speed is determined. This is preferably done following the method steps described above.
• the second speed like the first speed, is characterized in that the lubrication state of the sliding bearing changes or the friction in the sliding bearing is minimal.
• the first speed and the second speed are therefore determined in the same way. The above statements regarding the determination of the first speed apply mutatis mutandis to the second speed.
• the second speed is used to check the self-healing effect. The lower the second speed, the more successful the self-healing process.
• the second speed is preferably compared with the first speed. For example, the difference between the first speed and the second speed can be calculated. The greater this difference, the more successful the self-healing process.
• the reference speed can be a speed at which a transition of the lubrication state of an undamaged reference bearing takes place, or at which the friction in the reference bearing is minimal.
• a sliding bearing when new is preferably used as the reference bearing.
• it can be the above-mentioned plain bearing when new. The reference speed is then determined before the plain bearing is installed.
• a control device implements the method according to the invention or a preferred development.
• a data processing device is referred to as a control unit.
• FIG. 1 A preferred embodiment of the invention is shown in FIG. 1 in detail shows:
• Fig. 1 shows two Stribeck curves.
• a first Stribeck curve 101 and a second Stribeck curve 103 are provided.
• the three operating states boundary friction 105, mixed friction 107 and fluid friction 109 are assigned to the first Stribeck curve 101.
• release point B a transition from mixed friction 107 to fluid friction 109 takes place.
• point A the friction is minimal.
• the first Stribeck curve 101 merges into the second Stribeck curve.
• the second Stribeck curve 103 is shifted compared to the first Stribeck curve in the direction of lower speeds or to the left. Points A and B have been shifted accordingly.
• the distance between the corresponding points A, B of the two Stribeck curves 101, 103 can therefore be used as an indicator of the success of self-healing.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• General Physics & Mathematics (AREA)
• Sliding-Contact Bearings (AREA)
• Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=73013393

Family Applications (1)

Country Status (5)

Family Cites Families (11)

• 2019
  • 2019-11-25 DE DE102019218117.1A patent/DE102019218117A1/de active Pending
• 2020
  • 2020-10-19 EP EP20796736.5A patent/EP4065852A1/de active Pending
  • 2020-10-19 CN CN202080078079.3A patent/CN114667401A/zh active Pending
  • 2020-10-19 US US17/778,010 patent/US20220412401A1/en active Pending
  • 2020-10-19 WO PCT/EP2020/079361 patent/WO2021104748A1/de active Search and Examination

Also Published As

Similar Documents

Legal Events