This thesis deals with the issue of hydrostatic bearings. The aim was to design a test rig for an axial hydrostatic bearing. The axial hydrostatic bearing was calculated and designed with respect to the function of the tester. The construction of the test equipment was further supported by calculations of the main parts together with FEM analyses. The design was also accompanied by an introduction to the hydraulic parts of the hydrostatic bearing, which took place in consultation with Bosch Rexroth. The aim of the work, the design of a test device in a scale of 1:10, was completed. The following results from hydrostatic bearing tests will allow the introduction of new procedures in the production of turntables mounted on a hydrostatic bearing. Examination of operating conditions and permissible assembly inaccuracies will make it possible to reduce the production requirements for bearing mounting.

Three flexure pivot pad bearings (FPBs) with different preloads are evaluated for use in high performance applications by comparing them to a hybrid hydrostatic bearing (HHB). One application of these bearings is in turbopumps for liquid rocket engines. To evaluate bearing performance, the lift-off speed of the shaft from the bearing surface is experimentally determined. Experimental data of lift-off are collected using a circuit running through the shaft and the designed bearing. Other methods for measuring liftoff speeds were attempted but did not yield consistent results. Water is used as a lubricant to simulate a low viscosity medium. In comparison to load-capacity-based predictions for FPBs, the experimental results showed lower lift-off speeds, higher load capacities, higher eccentricity ratios, and lower attitude angles. The bearings’ predicted load capacity determined lift-off speed predictions, but the experimental results show no clear trend relating lift-off speed to load capacity. This was for a range of running speeds, with the design speed defined as the final speed in a particular test case. At 0.689 bar supply pressure and for a design speed of 3000 rpm, the HHB showed greater load capacities and lower eccentricities than the FPBs, but the FPBs had lower lift-off speeds and attitude angles. In fact, the FPBs in the load-between-pad orientation outperformed the HHB in the load-on-pocket orientation with lower lift-off speeds for the shaft weight-only case. An increased supply pressure lowered the lift-off speeds in the HHB tests. If the load in the bearing application remains relatively small, a FPB could be substituted for an HHB.

No description available.

This diploma deals is occupied with design of the heavy rotary table with hydrostatic bearing of table. In introductory part of deals the design part are described, for exampel. tipes of bearings, drive and etc. In other parts the design of rotary table with hydrostatic bearings is described.

A novel electric machine design, similar to an axial flux machine, incorporates hydrostatic bearings to increase efficiency and stability of said machine. In this thesis, the feasibility of a hydrostatic solution is explored and evaluated by development, manufacturing, and assembly of a test rig, as well as running experimental tests with it. The experiments are designed to measure viscous losses in the contact area between a rotor disc and stator bearing pads, where the oil fil thickness is below 0.1 mm, simulating low rpm (50-150 rpm) working condition of a 1:1 scale simplified model of the novel machine. The effects on the viscous losses by the hydraulic oil film thickness, rotor disc speed and oil pump pressure are analyzed and compared with an analytical model provided by the inventing startup company. A regression analysis model based on the experimental data is also presented. / En ny elektrisk maskinkonstruktion, lik en axialflödesmaskin i design, innefattar hydrostatiska lager för att öka verkningsgraden och stabiliteten hos den nämnda maskinen. I detta examensarbete undersöks och utvärderas genomförbarheten av en hydrostatisk lösning genom utveckling, tillverkning och ihopmontering av en testrigg, samt genom att köra experimentella test med riggen. Experimenten är utformade för att mäta viskösa förluster i kontaktområdet mellan en rotorskiva och statorlager, där oiljefilmstjockleken är under 0.1mm, genom att simulera ett arbetstillstånd i modell skala 1:1 av för en förenklad variant av den nya maskinen, under lågt varvtal (50–150 rpm). Effekterna på de viskösa förlusterna av den hydrauliska oljefilmens tjocklek, rotorskivans hastighet och oljepumpens tryck analyseras och jämförs med en analytisk modell given av det uppfinnande startupföretaget.

In industrial practice greases are mainly used as lubricants in hydrodynamic plain bearings and roller bearings. The use in hydrostatic bearings is avoided due to the difficult controllability. One reason is the complex non-Newtonian flow behavior of greases. The motivation for this paper is the use of greases to increase the efficiency of hydrostatic bearings. The assumption is that the so-called yield stress of consistent greases can lead to self-sealing behavior in the bearing under stationary operation conditions. Assuming a volume-flow-free operation of the bearing, a concept for the active control of the sealing gap height and thus the bearing stiffness was developed. The concept idea is the use of a second medium with Newtonian characteristic for pressure transfer. The grease and the pressure control fluid are structurally separated. The grease is induced in the shortest possible way into the bearing pocket to keep the pressure losses as low as possible. The results of test bench investigations indicate the feasibility of a gap height control with very high bearing stiffness under use of highly consistent greases and initiate further investigation on non-stationary operation.

No description available.