Operating Behavior of Sliding Planet Gear Bearings for Wind Turbine Gearbox Applications—Part II: Impact of Structure Deformation

The use of planetary gear stages intends to increase power density in drive trains of rotating machinery. Due to lightweight requirements on this type of machine elements, structures are comparably flexible while mechanical loads are high. This study investigates the impact of structure deformation on sliding planet gear bearings applied in the planetary stages of wind turbine gearboxes with helical gears. It focuses on three main objectives: (i) development of a procedure for the time-efficient thermo-elasto-hydrodynamic (TEHD) analysis of sliding planet gear bearing; (ii) understanding of the specific deformation characteristics of this application; (iii) investigation of the planet gear bearing’s modified operating behavior, caused by the deformation of the sliding surfaces. Generally, results indicate an improvement of predicted operating conditions by consideration of structure deformation in the bearing analysis for this application. Peak load in the bearing decreases because the loaded proportion of the sliding surface increases. Moreover, tendencies of single design measures, determined for rigid geometries, keep valid but exhibit significantly different magnitudes under consideration of structure deformation. Results show that consideration of structure flexibility is essential for sliding planet gear bearing analysis if quantitative assertions on load distributions, wear phenomena, and interaction of the bearing with other components are required.

DETERMINAN PROFITABILITAS: KAJIAN PENGELOLAAN FAKTOR INTERNAL DAN EKSTERNAL PERUSAHAAN TEKSTIL DAN PRODUK TEKSTIL (TPT) YANG TERDAFTAR DI BURSA EFEK INDONESIA

This research looks at the effect of internal factors or microeconomics and external factors or macroeconomic factors on profitability of textiles and textiles products companies. The result showed that partially, only current ratio and the interest rates which have significant impact on ROA. simultanously, internal and external factors have significant impact on ROA. Managerial implication based on this research are, the companies should apply liquidity risk management like mitigation on liquidity crisis and liquidity risk bearing analysis also look for another fund resources to decrease interest rates expenses.

Structural analysis of cross-laminated timber slabs subjected to bending – state of the art

Compared to solid or laminated timber, the main point of the design of cross-laminated timber (CLT) is very low resistance and stiffness of the CLT cross layers. For the modeling and analyzing of the load distribution in CLT, various methods are available. The aim of this paper is to present the possible ways for load-bearing analysis of structural members subjected to uniaxial and biaxial bending in various software products and using various methods. A parametric analysis was performed with the aim to compare the results obtained by the analytical method, the model of the orthotropic slab, the grillage model and using the software based on the finite element method. The values of maximum deflection obtained by selected methods were compared. The mid-span deflection of beams subjected to uniaxial bending differs only slightly. In the case of slabs subjected to biaxial bending, more visible differences in results occurred. The simplified methods give the highest values on the safe side.

ANALYSIS OF BEARING CLEARANCE AND WIDTH OF AN OIL GROOVE ON THE CHARACTERISTIC OF FLUID FILM IN HYDRODYNAMIC MAIN CRANKSHAFT BEARINGS

Paper represents an analysis of the influence of oil groove width and bearing clearance on the characteristics of oil film in a hydrodynamic journal main crankshaft bearing. Analysis was performed to define the influence of bearing clearance and dimensions of oil grooves on static characteristics and manufacturability of half-shelf bearings in industrial high-volume production. Computer simulations were made using an ARTbear program, which was developed in Department of Machine Construction and Vehicle Design in Gdańsk Technical University. The analysis allowed defining the correlation between groove geometry and load capacity and working conditions of bearings. Potential opportunities of possible shortening of production time in high-volume production were also indicated.