Influence of recess shape on the performance of a capillary compensated circular thrust pad hydrostatic bearing

The steady state and dynamic characteristics including whirl instability of water-lubricated journal bearings having three axial grooves are obtained theoretically. The Reynolds equation is solved numerically by the finite difference method satisfying the appropriate boundary conditions. The dynamic behaviour in terms of stiffness and damping coefficients of film and stability are found using a first-order perturbation method. It has been shown that both load capacity and stability improve when smaller groove angles are used.

Analysis of water-lubricated journal bearings with multiple axial grooves:

Static characteristics of a water-lubricated hydrostatic thrust bearing using a membrane restrictor

In this paper, the stability of water-lubricated, hydrostatic, conical bearings with spiral grooves for high-speed spindles is investigated theoretically and experimentally. In these bearing types, pressurized water is first fed to the inside of the rotating shaft and then introduced into spiral grooves through feeding holes located at one end of each spiral groove. Therefore, water pressure is increased due to the effect of the centrifugal force at the outlets of the feeding holes, which results from shaft rotation. In addition, water pressure is also increased by the viscous pumping effect of the spiral grooves. The stability of the proposed bearing is theoretically predicted using the perturbation method, and calculated results are compared with experimental results. It was consequently found that the proposed bearing is very stable at high speeds and theoretical predictions show good agreement with experimental data.

Stability of water-lubricated, hydrostatic, conical bearings with spiral grooves for high-speed spindles

High-speed stability of a rigid rotor supported by aerostatic journal bearings with compound restrictors

This paper describes the static characteristics of water-lubricated hydrostatic conical bearings with spiral grooves. Hydrostatic conical bearings treated here have been designed for high speed spindles and are intended to apply to spindles for drilling small holes of printed circuit-boards. Pressurized water is first fed to the inside of the rotating shaft and supplied to spiral grooves on the shaft surface through feeding holes. Therefore, water pressure is greatly increased at outlets of feeding holes due to the centrifugal force by shaft rotation. Furthermore, water pressure is also increased by the viscous pump effect of spiral grooves. Water pressures in the bearings under concentric condition are numerically obtained by using the finite element method and calculated results are compared with experimental ones. It is consequently found that this water-lubricated hydrostatic conical bearings with spiral grooves are very suitable for precision high speed spindles.

Axial Load Capacity of Water-Lubricated Hydrostatic Conical Bearings With Spiral Grooves (On the Case of Rigid Surface Bearings)

This paper proposes a new type of a self-controlled restrictor which can achieve a very high bearing stiffness in hydrostatic bearings. This self-controlled restrictor employs a floating disk to control the mass flow rate of the oil entering the bearing clearance according to changes of the applied load. Furthermore, a hydrostatic bearing with this restrictor can theoretically achieve an infinite stiffness when the mass of a floating disk is assumed to be zero. The static characteristics of a rectangular hydrostatic thrust bearing with this self-controlled restrictor are theoretically and experimentally investigated

Static Characteristics of a Rectangular Hydrostatic Thrust Bearing With a Self-Controlled Restrictor Employing a Floating Disk

This paper describes the step response of a hydrostatic thrust bearing with a selfcontrolled restrictor employing a floating disk. This type of bearing can achieve a very high static bearing stiffness by controlling the mass flow rate of the fluid entering the bearing clearance, using the floating disk. Many parameters affect the step-response characteristics of this type of bearings. Influences of each parameter on the step response are theoretically investigated, and theoretical and experimental results are compared in order to verify the theoretical predictions. It was consequently found that the step response of this hydrostatic thrust bearing with the self-controlled restrictor was stable over a wide range of values of design parameters

Step Response of Hydrostatic Thrust Bearings With a Self-Controlled Restrictor Employing a Floating Disk

Etude de la stabilite d'un rotor rigide monte dans des paliers aerostatiques avec une double alimentation en lubrifiant par des rainures circulaires

Y. Anno

Papers

Axial Load Capacity of Water-Lubricated Hydrostatic Conical Bearings With Spiral Grooves (On the Case of Rigid Surface Bearings)

Static Characteristics of a Rectangular Hydrostatic Thrust Bearing With a Self-Controlled Restrictor Employing a Floating Disk

Step Response of Hydrostatic Thrust Bearings With a Self-Controlled Restrictor Employing a Floating Disk

Stability of a Rigid Rotor Supported by Aerostatic Journal Bearings With Circular Slot Restrictors (On the Double-Row Admission Bearing)