Sensor Integrating Machine Elements - Revision history

MartinKliemank: /* Gas foil bearing */

2024-10-14T18:58:20Z

Gas foil bearing

← Older revision		Revision as of 20:58, 14 October 2024
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	==== Gas foil bearing ====		==== Gas foil bearing ====
			[[File:SiGFB.png\|thumb\|Design of the second prototype of the sensor integrating gas foil bearing (SiGFB), enabling in situ measurement of acceleration, sound, acoustic emission and temperature, dataprocessing, and BLE communication (with temporary USB for redundancy)]]
	Gas foil bearings (GFBs) are an advanced class of fluid dynamic bearings that utilize a thin layer of gas, typically air, as a lubricant in a gap between a rotating journal and an elastic metal foil structure, consisting typically of a supporting bump foil and a smooth top foil. This design allows for the creation of a load-bearing gas film at operational speeds, effectively minimizing friction and wear by maintaining separation between the rotor and bearing surfaces through dynamic pressure in the lubrication film. The compliant foil structure enables adaptability to varying operational conditions without the need for tight radial clearances. GFBs are thus able to function at large rotating speeds with high efficiency, low maintenance and without oil and related problems. GFBs are thus particularly suited for applications in high-speed rotating machinery where oil lubrication is undesirable or impractical, including but not limited to fuel cell blowers, air cycle machines, microturbines, and compact compressors.		Gas foil bearings (GFBs) are an advanced class of fluid dynamic bearings that utilize a thin layer of gas, typically air, as a lubricant in a gap between a rotating journal and an elastic metal foil structure, consisting typically of a supporting bump foil and a smooth top foil. This design allows for the creation of a load-bearing gas film at operational speeds, effectively minimizing friction and wear by maintaining separation between the rotor and bearing surfaces through dynamic pressure in the lubrication film. The compliant foil structure enables adaptability to varying operational conditions without the need for tight radial clearances. GFBs are thus able to function at large rotating speeds with high efficiency, low maintenance and without oil and related problems. GFBs are thus particularly suited for applications in high-speed rotating machinery where oil lubrication is undesirable or impractical, including but not limited to fuel cell blowers, air cycle machines, microturbines, and compact compressors.
	[[File:Sketch GFB.png\|thumb\|Schematic representation of bump-type gas foil bearing of generation I, top foil (1), bump foil (2), bearing sleeve (3), bearing journal (4)]]		[[File:Sketch GFB.png\|thumb\|Schematic representation of bump-type gas foil bearing of generation I, top foil (1), bump foil (2), bearing sleeve (3), bearing journal (4)]]

MariusFuerst: /* Gear */

2024-09-03T16:17:04Z

Gear

← Older revision		Revision as of 18:17, 3 September 2024
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	Other relevant physical quantities include:		Other relevant physical quantities include:

	* lubrication quality		* type of lubrication
			* lubrication quality
	* gear material		* gear material
	* gear geometry		* gear geometry

MariusFuerst: /* Exemplary measurement tasks in machine elements */

2024-09-03T16:14:51Z

Exemplary measurement tasks in machine elements

← Older revision		Revision as of 18:14, 3 September 2024
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	Other relevant physical quantities include:		Other relevant physical quantities include:

	* type of lubrication
	* lubrication quality		* lubrication quality
	* gear material		* gear material

AlexanderNowak: /* Feather keys */

2024-08-26T08:04:07Z

Feather keys

← Older revision		Revision as of 10:04, 26 August 2024
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	==== Feather keys ====		==== Feather keys ====
	The ~~feather keys are made~~ of ~~C45 N steel with~~ a ~~yield~~ strength ~~<math>\sigma_y</math> = 490MPa according to~~ DIN 743 ~~part 3~~, the ~~shaft~~ and ~~hub are made of 42CrMo4+QT with a yield strength of <math>\sigma_y</math> = 849MPa for~~ the shaft and ~~<math>\sigma_y</math> = 592 MPa for~~ the ~~hub, respectively. The shaft~~ and hub ~~yield strengths are determined by quasi-static tensile tests~~. ~~Considering~~ the feather key as the ~~weakest part~~ of ~~this feather~~ key ~~connection~~, the ~~transmittable~~ torque ~~moment is calculated according to DIN 6892 method C~~ as ~~follows~~:		[[File:FeatherKeyTest.jpg\|thumb\|Quasi-static test to identify plastic deformation of the feather key which occurs as failure criterion]]
			The fatigue strength of a feather key connection can be calculated by different concepts. On the one hand, the fatigue strength of the notched shaft can be carried out by the German national standard DIN 743 and on the other hand, the transmittable torque can be calculated by the German national standard DIN 6892, which addresses the pressure distribution between the feather key and the shaft notch and the pressure distribution between the feather key and the hub notch. This standard is divided in three methods, of which method C is relevant in the context of sensor-integrating feather key connections. In the elastic deformation range, there is a linear relationship between torque and angle of twist. When the key is plastically deformed, the relationship between torque and angle becomes non-linear, as shown by the evaluation of a quasi-static test in the [[:File:FeatherKeyTest.jpg\|right-hand side figure]].

	<math>M_{t,~~zul}~~=p_{~~zul~~}~~\cdot (h-t_1)\cdot~~ l_{~~tr}~~\~~cdot \frac~~{d}{2} ~~\cdot~~ i~~\cdot~~\varphi</math>		Since the concept of calculating circumferential forces is based on the theory of linear elasticity, the sensor-integrating feather key must not show any plastic deformation. The corresponding threshold value for the transmittable torque can be estimated using method C of DIN 6892, where a critical pressure <math display="inline">p_{\rm{crit}}</math>, the height of the feather key <math display="inline">h</math> and the supporting height in the “critical” notch <math>t_{1,\rm{sup}}</math>, the supporting length <math display="inline">l_{\rm{sup}}</math>, the number of feather keys <math display="inline">i</math>, the supporting factor <math display="inline">\varphi</math> and the shaft diameter <math display="inline">d</math> are taken into account. The transmittable torque is given by

	~~The allowable pressure~~ <math>p_{~~zul~~}~~</math> = 441MPa, the height ''~~h~~'' = 8mm and the width of the feather key ''b'' = 12mm. The support depth in the shaft is <math>t_1</math> = 5mm~~, ~~the support length <math>~~l_{tr}~~</math> = 28mm and the support factor is <math>~~\~~varphi</math> = 0.75 due to two keys (i = 2) in the feather key connection. The joint diameter of the shaft-hub connection is ''~~d~~'' = 40mm. This leads to a nominal load of <math>M_t</math> = 1111 Nm. To protect the topology optimised key and the electronics, the test moment is carried out at <math>M_~~{~~test~~}</math> ~~= 300 Nm, which is reached ten seconds after the start of the test. Due to low frequency of the quasistatic test, temperature effects are not taken into account.<ref>C~~. Chen, B. Muhammedi, D. Bäcker, W-G. Drossel, S. Seltmann, A. Norwak, A. Hasse, Development of a measurement system to determine the circumferential force on a feather key. Forschung im Ingenieurwesen (2024) 88:24, June 2024</ref>		<math>M_{\rm{trans}}=p_{\rm{crit}} \cdot (h-t_{1,\rm{sup}}) \cdot l_{\rm{sup}}\cdot \frac{d}{2} \cdot i \cdot \varphi</math>.

	=== Mechanical integration ===		=== Mechanical integration ===

ErichKnoll: /* Gear */

2024-08-14T17:00:47Z

Gear

← Older revision		Revision as of 19:00, 14 August 2024
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	==== Gear ====		==== Gear ====
	Gears are usually subject to a standardized design process (ISO 6336<ref>International Organization for Standardization (2019, November 1). ''Calculation of load capacity of spur and helical gears'' (ISO 6336). Beuth.</ref>), with a variety of power levels (e.g., wrist watches to wind turbines). Since gears are relevant for the functionality of the overall system, detecting gear faults as early as possible is benefitial. A measurement at or in the gear is of interest because of the damping of the elements from the gear to the housing, which is the typical measurement position.		Gears are usually subject to a standardized design process (ISO 6336<ref>International Organization for Standardization (2019, November 1). ''Calculation of load capacity of spur and helical gears'' (ISO 6336). Beuth.</ref>), with a variety of power levels (e.g., wrist watches to wind turbines). Since gears are relevant for the functionality of the overall system, detecting gear faults as early as possible is benefitial. A measurement at or in the gear is of interest because of the damping of the elements from the gear to the housing, which is the typical measurement position.
			[[File:DMK-SIZA.jpg\|thumb\|Sensor integrating gear wheel according to Knoll et al.<ref>Knoll, E., Rothemund, M., Otto, M., Rupprecht, B., Ochs, M., Vogel-Heuser, B., Brederlow, R., & Stahl, K. (2024). Evaluation of vibration behavior at different sensing positions on gearboxes. ''Forschung Im Ingenieurwesen'', ''88''(1). <nowiki>https://doi.org/10.1007/s10010-024-00750-6</nowiki></ref> - CC BY 4.0]]
	The physical quantities relevant for the primary function of the gear operation are:		The physical quantities relevant for the primary function of the gear operation are:

ErichKnoll: /* Gear */

2024-08-14T16:54:20Z

Gear

← Older revision		Revision as of 18:54, 14 August 2024
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	==== Gear ====		==== Gear ====
	Gears are usually subject to a standardized design process (ISO 6336), with a variety of power levels (e.g., wrist watches to wind turbines). Since gears are relevant for the functionality of the overall system, detecting gear faults as early as possible is benefitial. A measurement at or in the gear is of interest because of the damping of the elements from the gear to the housing, which is the typical measurement position.		Gears are usually subject to a standardized design process (ISO 6336<ref>International Organization for Standardization (2019, November 1). ''Calculation of load capacity of spur and helical gears'' (ISO 6336). Beuth.</ref>), with a variety of power levels (e.g., wrist watches to wind turbines). Since gears are relevant for the functionality of the overall system, detecting gear faults as early as possible is benefitial. A measurement at or in the gear is of interest because of the damping of the elements from the gear to the housing, which is the typical measurement position.

	The physical quantities relevant for the primary function of the gear operation are:		The physical quantities relevant for the primary function of the gear operation are:
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	Thus, for an efficient monitoring of gears the following physical quantities are beneficial to be measured:		Thus, for an efficient monitoring of gears the following physical quantities are beneficial to be measured:

	* torsional acceleration		* torsional acceleration<ref>Binder, M., Stapff, V., Heinig, A., Schmitt, M., Seidel, C., & Reinhart, G. (2022). Additive manufacturing of a passive, sensor-monitored 16MnCr5 steel gear incorporating a wireless signal transmission system. ''Procedia CIRP'', ''107'', 505–510. <nowiki>https://doi.org/10.1016/j.procir.2022.05.016</nowiki> </ref><ref name=":1">Hasenoehrl, S., Peters, J., & Matthiesen, S. (2024). Integration of Sensors for Enhanced Condition Monitoring in Polymer Gears: A Comparative Study of Acceleration and Temperature Sensors. ''Applied Sciences'', ''14''(6), 2240. <nowiki>https://doi.org/10.3390/app14062240</nowiki></ref><ref name=":3">Knoll, E., Rupprecht, B., Groppo, E., Otto, M., Vogel-Heuser, B., Brederlow, R., & Stahl, K. (2023). MODULAR EXTENSION OF FZG-GEAR TEST RIG FOR IN-SITU MEASUREMENT POSSIBILITIES. In IIAV CZECH s.r.o. (Chair), ''29th International Congress on Sound and Vibration.'' Symposium conducted at the meeting of IIAV CZECH s.r.o., Prag.</ref><ref>Peters, J., Ott, L., Dörr, M., Gwosch, T., & Matthiesen, S. (2021a). Design of sensor integrating gears: methodical development, integration and verification of an in-Situ MEMS sensor system. ''Procedia CIRP'', ''100'', 672–677. <nowiki>https://doi.org/10.1016/j.procir.2021.05.142</nowiki></ref><ref>Peters, J., Ott, L., Dörr, M., Gwosch, T., & Matthiesen, S. (2021b). Sensor-integrating gears: wear detection by in-situ MEMS acceleration sensors. ''Forschung Im Ingenieurwesen.'' Advance online publication. <nowiki>https://doi.org/10.1007/s10010-021-00575-7</nowiki></ref>
	* lubrication thickness in the loaded contact		* lubrication thickness in the loaded contact
	* instantaneous rotational speed		* instantaneous rotational speed
	* gear temperature		* gear temperature<ref name=":1" /><ref name=":3" />
	* structure borne noise		* structure borne noise
	Depending on the assembly into the gearbox and the type of gear (spur gear or helical gear) different designs are possible which are also depending on classical designs of microelectronic circuits. So, for gears the following two designs are most relevant:		Depending on the assembly into the gearbox and the type of gear (spur gear or helical gear) different designs are possible which are also depending on classical designs of microelectronic circuits. So, for gears the following two designs are most relevant:

PeterWelzbacher: /* Processors (in situ) */

2024-08-14T15:33:20Z

Processors (in situ)

← Older revision		Revision as of 17:33, 14 August 2024
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	=== Energy storages ===		=== Energy storages ===
			Examples for energy storages that were integrated into SiME within the SPP 2305 are:
	* 7.4 V Li-Ion 3000 mAh (50h continuous high speed measurement, > 250 h discontinuous measurements)		* 7.4 V Li-Ion 3000 mAh (50h continuous high speed measurement, > 250 h discontinuous measurements)
	* ET1210C-H 4mAh (12.5x1.3mm, deep discharge, constant voltage charging, reflow solderable, up to 105℃ operating temperature		* ET1210C-H 4mAh (12.5x1.3mm, deep discharge, constant voltage charging, reflow solderable, up to 105℃ operating temperature

	=== Processors (in situ) ===		=== Processors (in situ) ===
			Examples for processors used for in-situ measurements in SiME within the SPP 2305 are:
	* STM32U5xxx~~, relatively~~ low power, but offers high processing power (Cortex M33); fast, efficient ADC (2.5 MSPS at 1 mA)		* STM32U5xxx (Relatively low power, but offers high processing power (Cortex M33); fast, efficient ADC (2.5 MSPS at 1 mA))
	* PSOC 6 CY8C63xxx: Low Power MCU, dual ARM CPU (M0+ for controlling, M4 for data processing), BT LE 5.0 subsystem, multi-channel ADC (1 mA @ 1 MSPS), programmable analog subsystems		* PSOC 6 CY8C63xxx (Low Power MCU, dual ARM CPU (M0+ for controlling, M4 for data processing), BT LE 5.0 subsystem, multi-channel ADC (1 mA @ 1 MSPS), programmable analog subsystems)
	* BGM220S, Low Power MCU (<200nA Deep Sleep), Cortex M33, BLE 5.2, Integrated RF-Frontend+Antenna, Wakeup through RF Signal in Deep Sleep)		* BGM220S (Low Power MCU (<200nA Deep Sleep), Cortex M33, BLE 5.2, Integrated RF-Frontend+Antenna, Wakeup through RF Signal in Deep Sleep)

	=== Methodology for design of SiME ===		=== Methodology for design of SiME ===
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	In SysML, individual diagrams can be created separately, which are arranged along the V-model as shown here. Different diagram types can be used in SysML, such as requirement or block diagrams, in which the product properties, components, modules and module variants can be mapped. The individual diagrams can be linked by dependency matrices. In this case, requirements are linked to product properties, properties to components, components to modules and modules to module variants. An exemplary hierarchical requirements diagram is shown [[Index.php?title=Media:Anforderungsdiagramm hierarchisch.png\|here]].		In SysML, individual diagrams can be created separately, which are arranged along the V-model as shown here. Different diagram types can be used in SysML, such as requirement or block diagrams, in which the product properties, components, modules and module variants can be mapped. The individual diagrams can be linked by dependency matrices. In this case, requirements are linked to product properties, properties to components, components to modules and modules to module variants. An exemplary hierarchical requirements diagram is shown [[Index.php?title=Media:Anforderungsdiagramm hierarchisch.png\|here]].

	~~''Schraube (Ka)''~~

	In the project sensor-integrating bolt for multi-axial force measurement a modular electronics architecture realized as a flex pcb with interfaces to swap the module for data and energy transfer was developed. This enables an adaptation to different environmental settings, e.g. bright and dark environments (solar panels) or electromagnetic interferences (HF-technology).[[File:Hierarchy levels.png\|thumb\|Hierarchical modeling levels of the model-based ''Modular Building Kit'' \|406x406px]]		In the project sensor-integrating bolt for multi-axial force measurement a modular electronics architecture realized as a flex pcb with interfaces to swap the module for data and energy transfer was developed. This enables an adaptation to different environmental settings, e.g. bright and dark environments (solar panels) or electromagnetic interferences (HF-technology).[[File:Hierarchy levels.png\|thumb\|Hierarchical modeling levels of the model-based ''Modular Building Kit'' \|406x406px]]

PeterWelzbacher: /* Bolt */

2024-08-14T15:27:49Z

Bolt

← Older revision		Revision as of 17:27, 14 August 2024
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	* [https://consenses.de/produkte/sensoren/kraft-und-vibrationssensoren/piezobolt-pb20/produkt PiezoBolt] from ConSenses		* [https://consenses.de/produkte/sensoren/kraft-und-vibrationssensoren/piezobolt-pb20/produkt PiezoBolt] from ConSenses
	* [https://sensorise.de/solutions/smartscrew/ SmartScrew] from sensorise		* [https://sensorise.de/solutions/smartscrew/ SmartScrew] from sensorise
			* [https://www.cit.fraunhofer.de/en/tech-hubs/iot-comms/q-bo.html Q-Bo] from Fraunhofer IIS

	Most of the existing solutions however do not fulfill the requirements of this SPP 2305. Sensors and electronics need to be fully integrated into the bolt and self-sufficient in order to maintain usability as the conventional bolt.		Most of the existing solutions however do not fulfill the requirements of this SPP 2305. Sensors and electronics need to be fully integrated into the bolt and self-sufficient in order to maintain usability as the conventional bolt.
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	==== Plain bearing ====		==== Plain bearing ====
	Besides roller bearings, plain bearings are the most frequently used machine elements in mechanical engineering, which enable the relative movements of machine parts to each other. A ~~'''~~plain bearing~~'''~~, or more commonly ~~'''~~sliding contact bearing~~'''~~ and ~~'''~~slide bearing~~'''~~, is the simplest type of bearing, comprising just a bearing surface and no rolling elements. Therefore, the journal (i.e., the part of the shaft in contact with the bearing) slides over the bearing surface. The simplest example of a plain bearing is a shaft rotating in a hole. The effects of bearing damage are serious in economic terms as well as in terms of safety. Consequently, condition monitoring of bearings is becoming increasingly important to minimize downtime. Plain bearings are characterized by having a longer service lifetime and higher load capacity at equivalent dimensioning compared to roller bearings<ref name=":0">Lau, H. Y.; Liu, K. P.; Wong, P. L.; Wang, Wen (2012): A new design of smart journal bearing based on GMM actuators. In: ''Industrial Lubrication and Tribology'' 64 (3), S. 147–151. DOI: 10.1108/00368791211218678.</ref>. Therefore, plain bearings are especially suitable for long-term and heavy-duty applications. Accordingly, roller bearings are increasingly being replaced by plain bearings in the planetary stages of wind turbine gearboxes<ref>Ni, Sen (2022): Study on Mixed Lubrication Property of Planetary Gear Journal Bearing in Wind Turbine Gearbox. In: 2022 International Conference on Manufacturing, Industrial Automation and Electronics (ICMIAE). Rimini, Italy, 26.08.2022 - 28.08.2022: IEEE, S. 24–32.</ref>. Additionally, first concepts of main drive trains with plain bearings in wind turbines have been published<ref>Jonuschies, Ingo (2015): Hydrodynamisch wirkende zylindrische Radialgleitlager für die Rotorwellenlagerung in Windenergieanlagen. Dissertation.</ref><sup>,</sup><ref>Rolink, Amadeus; Schröder, Tim; Jacobs, Georg; Bosse, Dennis; Hölzl, Johannes; Bergmann, Philipp (2020): Feasibility study for the use of hydrodynamic plain bearings with balancing support characteristics as main bearing in wind turbines. In: ''J. Phys.: Conf. Ser.'' 1618 (5), S. 52002. DOI: 10.1088/1742-6596/1618/5/052002.</ref>. In summary, significant challenges for the safe and economical operation of a drive train can be identified: The severe effects of bearing damage in drive train systems and the current development trends leading to higher loads and increased use of plain bearings in drive trains.		Besides roller bearings, plain bearings are the most frequently used machine elements in mechanical engineering, which enable the relative movements of machine parts to each other. A plain bearing, or more commonly sliding contact bearing and slide bearing, is the simplest type of bearing, comprising just a bearing surface and no rolling elements. Therefore, the journal (i.e., the part of the shaft in contact with the bearing) slides over the bearing surface. The simplest example of a plain bearing is a shaft rotating in a hole. The effects of bearing damage are serious in economic terms as well as in terms of safety. Consequently, condition monitoring of bearings is becoming increasingly important to minimize downtime. Plain bearings are characterized by having a longer service lifetime and higher load capacity at equivalent dimensioning compared to roller bearings<ref name=":0">Lau, H. Y.; Liu, K. P.; Wong, P. L.; Wang, Wen (2012): A new design of smart journal bearing based on GMM actuators. In: ''Industrial Lubrication and Tribology'' 64 (3), S. 147–151. DOI: 10.1108/00368791211218678.</ref>. Therefore, plain bearings are especially suitable for long-term and heavy-duty applications. Accordingly, roller bearings are increasingly being replaced by plain bearings in the planetary stages of wind turbine gearboxes<ref>Ni, Sen (2022): Study on Mixed Lubrication Property of Planetary Gear Journal Bearing in Wind Turbine Gearbox. In: 2022 International Conference on Manufacturing, Industrial Automation and Electronics (ICMIAE). Rimini, Italy, 26.08.2022 - 28.08.2022: IEEE, S. 24–32.</ref>. Additionally, first concepts of main drive trains with plain bearings in wind turbines have been published<ref>Jonuschies, Ingo (2015): Hydrodynamisch wirkende zylindrische Radialgleitlager für die Rotorwellenlagerung in Windenergieanlagen. Dissertation.</ref><sup>,</sup><ref>Rolink, Amadeus; Schröder, Tim; Jacobs, Georg; Bosse, Dennis; Hölzl, Johannes; Bergmann, Philipp (2020): Feasibility study for the use of hydrodynamic plain bearings with balancing support characteristics as main bearing in wind turbines. In: ''J. Phys.: Conf. Ser.'' 1618 (5), S. 52002. DOI: 10.1088/1742-6596/1618/5/052002.</ref>. In summary, significant challenges for the safe and economical operation of a drive train can be identified: The severe effects of bearing damage in drive train systems and the current development trends leading to higher loads and increased use of plain bearings in drive trains.

	Regarding the type and direction of the forces occurring between the moving machine elements, a distinction is drawn between statically or dynamically loaded radial and axial plain bearings<ref>Sauer, Bernd (2018): Konstruktionselemente des Maschinenbaus 2. Berlin, Heidelberg: Springer Berlin Heidelberg.</ref>. Furthermore, a distinction between plain bearings without the use of an intermediate medium, which are permanently subject to wear, and those with a separating medium (typically oil) can be made. Plain bearings using a separating medium are advantageous in terms of their friction behavior, which can be optimized to the extent of no wear occurring during operation. However, the wear-free state can only be ensured if solid contact between the two contact partners, the bearing bush and the shaft, is completely avoided. Plain bearings, which are operated using a separating medium and therefore can enable wear-free operation, are classified into hydrostatic and hydrodynamic plain bearings<ref>Hinzen, Hubert (2022): Hubert Hinzen: Maschinenelemente/Lager, Welle-Nabe-Verbindungen, Getriebe. 5., aktualisierte Auflage. Berlin: De Gruyter Oldenbourg (De Gruyter Studium, 2).</ref>. In case of hydrostatic plain bearings, the wear-free state is achieved by applying pressure to the lubricating film externally by a pump. Therefore, the state of motion created, does not influence the separation of the surfaces relative to each other. In the case of hydrostatic plain bearings, the lubrication gap height can be controlled by using active hydraulic chamber systems <ref>Althaus, Josef (1991): Eine aktive hydraulische Lagerung für Rotorsysteme (Fortschritt-Berichte VDI, Series 11, N154).</ref><sup>,</sup><ref>Kurth, R.; Tehel, R.; Päßler, T.; Putz, M.; Wehmeyer, K.; Kraft, C.; Schwarze, H. (2019): Forming 4.0: Smart machine components applied as a hybrid plain bearing and a tool clamping system. In: ''Procedia Manufacturing'' 27, S. 65–71. DOI: 10.1016/j.promfg.2018.12.045.</ref><sup>,</sup><ref>Santos, Ilmar F. (2011): Trends in Controllable Oil Film Bearings. In: K. Gupta (Hg.): IUTAM Symposium on Emerging Trends in Rotor Dynamics, Bd. 1011. Dordrecht: Springer Netherlands (IUTAM Bookseries), S. 185–199.</ref>. Due to active separation of the wear surfaces, sensor-integrated condition monitoring is of secondary relevance for hydrostatic plain bearings. The friction and wear behavior of the surfaces moving relative to each other in hydrodynamic plain bearing is decisively dependent on their relative speed. Wear-free conditions are only achieved at sufficient relative speed. Hydrodynamic axial plain bearings, which primarily support axial forces in the direction of the shaft, are used less frequently compared to radial hydrodynamic plain bearings. Accordingly, the following section will focus primarily on hydrodynamic radial plain bearings and the possibilities for condition monitoring.		Regarding the type and direction of the forces occurring between the moving machine elements, a distinction is drawn between statically or dynamically loaded radial and axial plain bearings<ref>Sauer, Bernd (2018): Konstruktionselemente des Maschinenbaus 2. Berlin, Heidelberg: Springer Berlin Heidelberg.</ref>. Furthermore, a distinction between plain bearings without the use of an intermediate medium, which are permanently subject to wear, and those with a separating medium (typically oil) can be made. Plain bearings using a separating medium are advantageous in terms of their friction behavior, which can be optimized to the extent of no wear occurring during operation. However, the wear-free state can only be ensured if solid contact between the two contact partners, the bearing bush and the shaft, is completely avoided. Plain bearings, which are operated using a separating medium and therefore can enable wear-free operation, are classified into hydrostatic and hydrodynamic plain bearings<ref>Hinzen, Hubert (2022): Hubert Hinzen: Maschinenelemente/Lager, Welle-Nabe-Verbindungen, Getriebe. 5., aktualisierte Auflage. Berlin: De Gruyter Oldenbourg (De Gruyter Studium, 2).</ref>. In case of hydrostatic plain bearings, the wear-free state is achieved by applying pressure to the lubricating film externally by a pump. Therefore, the state of motion created, does not influence the separation of the surfaces relative to each other. In the case of hydrostatic plain bearings, the lubrication gap height can be controlled by using active hydraulic chamber systems <ref>Althaus, Josef (1991): Eine aktive hydraulische Lagerung für Rotorsysteme (Fortschritt-Berichte VDI, Series 11, N154).</ref><sup>,</sup><ref>Kurth, R.; Tehel, R.; Päßler, T.; Putz, M.; Wehmeyer, K.; Kraft, C.; Schwarze, H. (2019): Forming 4.0: Smart machine components applied as a hybrid plain bearing and a tool clamping system. In: ''Procedia Manufacturing'' 27, S. 65–71. DOI: 10.1016/j.promfg.2018.12.045.</ref><sup>,</sup><ref>Santos, Ilmar F. (2011): Trends in Controllable Oil Film Bearings. In: K. Gupta (Hg.): IUTAM Symposium on Emerging Trends in Rotor Dynamics, Bd. 1011. Dordrecht: Springer Netherlands (IUTAM Bookseries), S. 185–199.</ref>. Due to active separation of the wear surfaces, sensor-integrated condition monitoring is of secondary relevance for hydrostatic plain bearings. The friction and wear behavior of the surfaces moving relative to each other in hydrodynamic plain bearing is decisively dependent on their relative speed. Wear-free conditions are only achieved at sufficient relative speed. Hydrodynamic axial plain bearings, which primarily support axial forces in the direction of the shaft, are used less frequently compared to radial hydrodynamic plain bearings. Accordingly, the following section will focus primarily on hydrodynamic radial plain bearings and the possibilities for condition monitoring.
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	Testing includes the question how the SiME performs under developing damages. This poses several challenges: Not only have the sensors to be robust enough to resist often harsh conditions for damaging the machine elements. Also several SiMe have to be available for testing and potential destruction by the test. Furthermore an adequate test rig to apply realistic operating conditions to the specimens has to be available. All this leads to the fact that the first tests of the campaign are mostly measurement tests and only later in the project test conditions will become more challenging and related to real operation of the SiME.		Testing includes the question how the SiME performs under developing damages. This poses several challenges: Not only have the sensors to be robust enough to resist often harsh conditions for damaging the machine elements. Also several SiMe have to be available for testing and potential destruction by the test. Furthermore an adequate test rig to apply realistic operating conditions to the specimens has to be available. All this leads to the fact that the first tests of the campaign are mostly measurement tests and only later in the project test conditions will become more challenging and related to real operation of the SiME.

	~~=== Cost aspects ===~~
	Sensors need to be added to established machine elements. This will increase cost and and maybe decrease performance. To keep this aspect under control turning to mass produced sensors is helpful. Finally, additional costs may be small and balanced by gaining less unexpected downtime of the whole system.

	== Operating strategy ==		== Operating strategy ==
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	==== Eventbased ====		==== Eventbased ====
	The processor operates after an event has happened. This can be realisrealizeded using interrupt signals from either internal hardware like comparators or external hardware, like additional sensors.		The processor operates after an event has happened. This can be realisrealizeded using interrupt signals from either internal hardware like comparators or external hardware, like additional sensors.

	~~==== Validation strategy ====~~
	A crucial step for the evaluation of an operating strategy is the assessment of algorithm execution time, especially when using low-power embedded microcontrollers. If the execution time of selected algorithms cannot meet the timing requirements of a specific use-case considering them in the operating strategy is not feasible. Thus, it is important to consider algorithm execution time right from the beginning of the system design. Thereby, performance benchmarking methods provide tools to effectively measure and predict algorithm execution time within the design process <ref name="Rupprecht2022" />. For early design states, early-stage execution time prediction approaches, for example, based on sparse measurements can give a first estimate about algorithm execution times on different hardware devices by simultaneously minimizing measurement effort <ref name="Rupprecht2024" />. Challenges in measuring software execution time on heterogeneous devices can be mitigated by a systematic selection of execution time measurement methods within the benchmarking setup <ref name="Rupprecht2023b" />.
	=== Data transfer ===		=== Data transfer ===

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	==== Protocols ====		==== Protocols ====

	* Bluetooth Low Energy
	* Zigbee
	* LoRaWan
	Long Range Wide Area Network (LoRaWAN) is a low-power wireless network protocol operating at the network layer. It is defined by the LoRa Alliance and provides specifications that are freely available. Additionally, software building blocks are accessible as open-source software.		Long Range Wide Area Network (LoRaWAN) is a low-power wireless network protocol operating at the network layer. It is defined by the LoRa Alliance and provides specifications that are freely available. Additionally, software building blocks are accessible as open-source software.

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	LoRa end devices and gateways in LoRaWAN utilize a proprietary and patented transmission method based on a chirp spread spectrum modulation technique called “LoRa". LoRa operates at the physical layer and is asymmetrically designed for energy efficiency, achieving uplink communication ranges of over 10 km. Data rates range from 292 bit/s to 50 kbit/s. Various operational modes, including quasi-continuous downlink communication, are possible, although the latter affects energy efficiency. The LoRa Alliance also refers to this technology as Low Power Wide Area Networks (LPWANs). LoRa uses different regional frequency bands in the ISM and SRD bands. For example, in Europe, the frequency band ranges from 433.05 to 434.79 MHz (ISM Band Region 1) and from 863 to 870 MHz (SRD Band Europe). The coverage extends from 2 km in urban areas to 40 km in rural regions. Notably, LoRa’s penetration capabilities allow it to reach even basement areas <ref>https://www.lora-wan.de/</ref>.		LoRa end devices and gateways in LoRaWAN utilize a proprietary and patented transmission method based on a chirp spread spectrum modulation technique called “LoRa". LoRa operates at the physical layer and is asymmetrically designed for energy efficiency, achieving uplink communication ranges of over 10 km. Data rates range from 292 bit/s to 50 kbit/s. Various operational modes, including quasi-continuous downlink communication, are possible, although the latter affects energy efficiency. The LoRa Alliance also refers to this technology as Low Power Wide Area Networks (LPWANs). LoRa uses different regional frequency bands in the ISM and SRD bands. For example, in Europe, the frequency band ranges from 433.05 to 434.79 MHz (ISM Band Region 1) and from 863 to 870 MHz (SRD Band Europe). The coverage extends from 2 km in urban areas to 40 km in rural regions. Notably, LoRa’s penetration capabilities allow it to reach even basement areas <ref>https://www.lora-wan.de/</ref>.

			Other protocols that can be used in the context of SiME are:
			* Bluetooth Low Energy
			* Zigbee
	* Mioty		* Mioty
	* Sigfox		* Sigfox
	* NB-IOT		* NB-IOT

			=== Validation strategy ===
			A crucial step for the evaluation of an operating strategy is the assessment of algorithm execution time, especially when using low-power embedded microcontrollers. If the execution time of selected algorithms cannot meet the timing requirements of a specific use-case considering them in the operating strategy is not feasible. Thus, it is important to consider algorithm execution time right from the beginning of the system design. Thereby, performance benchmarking methods provide tools to effectively measure and predict algorithm execution time within the design process <ref name="Rupprecht2022" />. For early design states, early-stage execution time prediction approaches, for example, based on sparse measurements can give a first estimate about algorithm execution times on different hardware devices by simultaneously minimizing measurement effort <ref name="Rupprecht2024" />. Challenges in measuring software execution time on heterogeneous devices can be mitigated by a systematic selection of execution time measurement methods within the benchmarking setup <ref name="Rupprecht2023b" />.
	== Microsystem technology ==		== Microsystem technology ==

PeterWelzbacher: /* Introduction */

2024-08-14T15:19:21Z

Introduction

ArthurEwert: /* Shaft coupling */ Removed quotation marks

2024-08-05T11:06:47Z

Shaft coupling: Removed quotation marks

← Older revision		Revision as of 13:06, 5 August 2024
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	==== Shaft coupling ====		==== Shaft coupling ====
	"Couplings are mechanical elements that connect two shafts in order to transmit mechanical power from one to the other. Furthermore, they i) can compensate for shaft misalignment, ii) have a switching function to interrupt or limit the power flow, and iii) compensate for shocks. The industry provides a variety of application-specific designs, which satisfy diverse requirement profiles. VDI 2240 provides a suitable basis for selecting and classifying couplings according to their requirements. A subdivision is made according to switchable (clutch) and non-switchable (couplings) couplings. Based on this classification, different possible measurement quantities result. For couplings, the measured variables of a torque and rotational speed are particularly relevant. Furthermore, temperature, wear, shaft misalignments, restoring and reaction forces, and vibrations can be significant. For clutches, which also includes brakes, the measurement of the same parameters is desirable. Additionally, relevant parameters are clutch engagement and slip between the two hubs." <ref name="Kirchner2024" />		Couplings are mechanical elements that connect two shafts in order to transmit mechanical power from one to the other. Furthermore, they i) can compensate for shaft misalignment, ii) have a switching function to interrupt or limit the power flow, and iii) compensate for shocks. The industry provides a variety of application-specific designs, which satisfy diverse requirement profiles. VDI 2240 provides a suitable basis for selecting and classifying couplings according to their requirements. A subdivision is made according to switchable (clutch) and non-switchable (couplings) couplings. Based on this classification, different possible measurement quantities result. For couplings, the measured variables of a torque and rotational speed are particularly relevant. Furthermore, temperature, wear, shaft misalignments, restoring and reaction forces, and vibrations can be significant. For clutches, which also includes brakes, the measurement of the same parameters is desirable. Additionally, relevant parameters are clutch engagement and slip between the two hubs. <ref name="Kirchner2024" />
	[[File:Types of sensor-integrating couplings.png\|thumb\|Sensor-integrating gearbox, focusing on sensor-integrating couplings and their measuring task, exemplified by a sleeve coupling (1), a bellow coupling (2), and an elastic jaw coupling (3).]]		[[File:Types of sensor-integrating couplings.png\|thumb\|Sensor-integrating gearbox, focusing on sensor-integrating couplings and their measuring task, exemplified by a sleeve coupling (1), a bellow coupling (2), and an elastic jaw coupling (3).]]

← Older revision		Revision as of 17:19, 14 August 2024
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	== Introduction ==		== Introduction ==
	Caused by Industry 4.0 and the implementation of cyber-physical systems, a significant ~~need~~ for high-quality and reliable information about relevant state and process variables of technical systems arises. Sensor-integrating machine elements (SiME) offer great potential in this context since they enable the measurement of these variables directly at or close to their point of origin, so-called in-situ measurement. SiME build upon the primary mechanical functions of conventional machine elements and extend them by sensory functions. For SiME, the measurand - the quantity to be measured - is directly affected by the primary mechanical function of the machine element. Since the interfaces of the conventional machine elements are maintained and almost no additional installation space is required, SiME can easily be retrofitted into technical systems that were not developed against today's background. This means that also older technical systems can be made usable and continue to be operated in the context of Industry 4.0, which is particularly advantageous from an ecological point of view.<ref name="Kirchner2024" /><ref name="Welzbacher2021" />		Caused by Industry 4.0 and the implementation of cyber-physical systems, a significant demand for high-quality and reliable information about relevant state and process variables of technical systems arises. Sensor-integrating machine elements (SiME) offer great potential in this context since they enable the measurement of these variables directly at or close to their point of origin, so-called in-situ measurement. SiME build upon the primary mechanical functions of conventional machine elements and extend them by sensory functions. For SiME, the measurand - the quantity to be measured - is directly affected by the primary mechanical function of the machine element and measured by integrated sensors. Since the interfaces of the conventional machine elements are maintained and almost no additional installation space is required, SiME can easily be retrofitted into technical systems that were not developed against today's background. This means that also older technical systems can be made usable and continue to be operated in the context of Industry 4.0, which is particularly advantageous from an ecological point of view.<ref name="Kirchner2024" /><ref name="Welzbacher2021" />

	Consequently, SiME can pave the way for widespread digitalization. However, to fulfill this vision, a varity of new and innovative SiME are needed. Therefore, the German Research Foundation (dt. Deutsche Forschungsgemeinschaft, DFG) funded the priority program (dt. Schwerpunktprogramm, SPP) 2305. The goal of the SPP is the development of various SiME. In the following, the results and findings of the ten projects conducted within the SPP 2305 are outlined in the form of a wiki. The projects of the SPP 2305 are:		Consequently, SiME can pave the way for widespread digitalization. However, to fulfill this vision, a varity of new and innovative SiME are needed. Therefore, the German Research Foundation (dt. Deutsche Forschungsgemeinschaft, DFG) funded the priority program (dt. Schwerpunktprogramm, SPP) 2305. The goal of the SPP is the development of various SiME. In the following, the results and findings of the ten projects conducted within the SPP 2305 are outlined in the form of a wiki. The projects of the SPP 2305 are:

	* Auto-informative plain bearings		* [https://gepris.dfg.de/gepris/projekt/466775494?language=en Auto-informative plain bearings]
	* Elastic couplings with integrated flexible dielectric elastomer sensors		* [https://gepris.dfg.de/gepris/projekt/466661922 Elastic couplings with integrated flexible dielectric elastomer sensors]
	* Integrated sensors for intelligent large-size bearings		* [https://gepris.dfg.de/gepris/projekt/466778958 Integrated sensors for intelligent large-size bearings]
	* Load sensitive splined shaft with sensory material		* [https://gepris.dfg.de/gepris/projekt/466760574 Load sensitive splined shaft with sensory material]
	* Microelectronic modular system for sensor-integrating machine elements		* [https://gepris.dfg.de/gepris/projekt/466493340 Microelectronic modular system for sensor-integrating machine elements]
	* Sensor-integrating machine element radial shaft seal for monitoring of operation conditions and lubricant quality		* [https://gepris.dfg.de/gepris/projekt/466192751 Sensor-integrating machine element radial shaft seal for monitoring of operation conditions and lubricant quality]
	* Sensor-integrating feather keys for the detection of torques		* [https://gepris.dfg.de/gepris/projekt/466657550 Sensor-integrating feather keys for the detection of torques]
	* Sensor-integrating gear		* [https://gepris.dfg.de/gepris/projekt/466653706 Sensor-integrating gear]
	* Sensor-integrating bolts for multiaxial force measurement and derivation of a design methodology for sensor integration in closed cylindrical machine elements		* [https://gepris.dfg.de/gepris/projekt/466650813 Sensor-integrating bolts for multiaxial force measurement and derivation of a design methodology for sensor integration in closed cylindrical machine elements]
	* Standardized integral instrumentation of gas foil bearings for condition and operation monitoring		* [https://gepris.dfg.de/gepris/projekt/466782279 Standardized integral instrumentation of gas foil bearings for condition and operation monitoring]

	== Exemplary measurement tasks in machine elements ==		== Exemplary measurement tasks in machine elements ==