On-line condition monitoring and evaluation of remaining useful lifetimes for mineral hydraulic and turbine oils

Tič, Vito; Lovrec, Darko

doi:10.18690/978-961-286-130-8

Cited by 3 publications

(7 citation statements)

References 7 publications

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“…Furthermore, oils change their polarity during the ageing process. Thus, it is also possible to monitor the course of ageing (Tič and Lovrec, 2017).…”

Section: Dielectric Constant and Fluid Condition Monitoringmentioning

confidence: 99%

“…Therefore, they can only reach the thin surface layers of the fluid. Besides, they are very sensitive to surface contamination and deposits’ formation (Tič and Lovrec, 2017).…”

Section: Dielectric Constant and Fluid Condition Monitoringmentioning

confidence: 99%

“…The measuring range and resolution can be taken from the general technical specifications. As the relative dielectric constant is dependent on the temperature, the sensor performs a conversion to an internal reference temperature of 40°C (Tič and Lovrec, 2017; Meindorf, 2005). An additional parameter results from this conversion: The temperature gradient of the characteristic size, which can also be used for the characterisation of the oil.…”

Section: Dielectric Constant and Fluid Condition Monitoringmentioning

confidence: 99%

“…Roughly, we found for some popular ILs ε S ≅ 10. According to the opinion expressed in most papers (Tič and Lovrec, 2017; Meindorf, 2005; Wakai et al , 2005; Tejwant and Kumar, 2008), ε S should fall into the range between 20 and 40. Note that, from a practical point of view, the determination of reliable physico-chemical parameters crucially depends on the preparation of samples.…”

Section: Dielectric Constant and Fluid Condition Monitoringmentioning

confidence: 99%

“…These tests somehow include knowledge of the characteristic electrical parameters of a fluid – its characteristic initial values and the course of their change. On the basis of known electrical values, we can decide on the design of the hydraulic unit, or on the basis of changing electrical values, we can conclude on the state of the installed fluid (Tič and Lovrec, 2017; Carey and Hayzen, 2001).…”

Section: Introductionmentioning

confidence: 99%

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The importance of the electrical properties of hydraulic fluids

Lovrec

Tič

2021

ILT

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Purpose Apart from the basic material properties of liquid lubricants, such as, e.g., the viscosity and density of the hydraulic fluid, it is also important to have information regarding the electrical properties of the fluid used. The latter is closely related to the purpose, type, structure, and conditions of use of a hydraulic system, especially the powertrain design and fluid condition monitoring. The insulating capacity of the hydraulic fluid is important in cases where the electric motor of the pump is immersed in the fluid. In other cases, on the basis of changing the electrical conductive properties of the hydraulic fluid, we can refer its condition, and, on this basis, the degree of degradation. Design/methodology/approach The paper first highlights the importance of knowing the electrical properties of hydraulic fluids and then aims to compare these properties, such as the breakdown voltage of commonly used hydraulic mineral oils and newer ionic fluids suitable for use as hydraulic fluids. Findings Knowledge of this property is crucial for the design approach of modern hydraulic compact power packs. In the following, the emphasis is on the more advanced use of known electrical quantities, such as electrical conductivity and the dielectric constant of a liquid. Originality/value Based on the changes in these quantities, we have the possibility of real-time monitoring the hydraulic fluid condition, on the basis of which we judge the degree of fluid degradation and its suitability for further use.

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“…Furthermore, oils change their polarity during the ageing process. Thus, it is also possible to monitor the course of ageing (Tič and Lovrec, 2017).…”

Section: Dielectric Constant and Fluid Condition Monitoringmentioning

confidence: 99%

“…Therefore, they can only reach the thin surface layers of the fluid. Besides, they are very sensitive to surface contamination and deposits’ formation (Tič and Lovrec, 2017).…”

Section: Dielectric Constant and Fluid Condition Monitoringmentioning

confidence: 99%

Section: Dielectric Constant and Fluid Condition Monitoringmentioning

confidence: 99%

Section: Dielectric Constant and Fluid Condition Monitoringmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The importance of the electrical properties of hydraulic fluids

Lovrec

Tič

2021

ILT

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An Embedded Online Hydraulic Fluid CM and RUL-System for Industry 4.0 Manufacturing Machines

Tič

Lovrec

2020

Advances in Business Information Systems and Analytics

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Production machines and devices, especially those that operate continuously in multi-shift operation or are critical for the production process, must be equipped with an intelligent condition monitoring system for critical machine components. This is the only way to ensure high availability and prevent downtimes in critical phases of the production processes, affecting customer delivery times. This has become especially important in the context of the strategy Industry 4.0, wherein information technology, telecommunications, and manufacturing are united when the means of production are becoming more independent. This also applies to hydraulic fluid, an important component of most heavy machinery. The chapter presents the design and advantages to be achieved by the implementation of a comprehensive online condition monitoring (OCM) and remaining useful lifetime (RUL) system of built-in hydraulic fluid. The presented OCM-RUL system is designed conceptually for Industry 4.0 and focuses on the remote monitoring and self-diagnosis function of health condition for the fluid.

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