Abstract: A tilting pad bearing comprises a piston carrier ring that may include a plurality of voids spaced around the piston carrier ring, wherein a channel may be formed in a surface of the piston carrier ring opposite the plurality of voids. A carrier end plate may be positioned in the channel and secured to the piston carrier ring, wherein a recess may be formed in a top surface of the carrier end plate. A piston may be positioned in each void, wherein a bottom face of each piston is positioned adjacent the recess. The pistons may be substantially secured in the voids using a plurality of membranes, wherein one membrane corresponds to one piston and one void. Alternatively, the pistons may be formed in two pieces secured via a membrane. Each piston may be engaged with a bearing pad and/or interface member in a bearing pad carrier ring.

Abstract: A tilting pad bearing comprises a piston carrier ring that may include a plurality of voids spaced around the piston carrier ring, wherein a channel may be formed in a surface of the piston carrier ring opposite the plurality of voids. A carrier end plate may be positioned in the channel and secured to the piston carrier ring, wherein a recess may be formed in a top surface of the carrier end plate. A piston may be positioned in each void, wherein a bottom face of each piston is positioned adjacent the recess. The pistons may be substantially secured in the voids using a plurality of membranes, wherein one membrane corresponds to one piston and one void. Alternatively, the pistons may be formed in two pieces secured via a membrane. Each piston may be engaged with a bearing pad and/or interface member in a bearing pad carrier ring.

Abstract: A tilting pad thrust bearing arrangement (30), comprises a circular array of pads (351, 352, . . . ) having tilt pivots (381, 382, . . . ) and supported spaced from a carrier surface (33) by supporting springs (40) in the form of a stack of at least two annular, axially deflectable spring members (41, 42). Each spring member (41 and 42) is spaced from an adjacent surface, the carrier surface (33) and spring member (41) respectively, by an array of deflection pivots (411, 412, . . . , 421, 422, . . . ) disposed one pivot each between the tilt pivots of adjacent pads and acting as a fulcrum for spring deflection. The spring deflection pivots are in line axially so that upon axial loading of the bearing pads the spring (42) closest to the pads deflects at a first rate to contact the next spring (41) and the spring combination deflects at a second rate, at least until it contacts the carrier surface (33). Any number of springs may be stacked to give appropriate overall progressive deflection characterising.

Abstract: A tilting pad thrust bearing assembly comprises an annular body which carries an array of bearing pads either as discrete pads or in an integral ring. The pads are manufactured with opposite faces flat, that is, without the usual radially extending fulcrum ridges, such ridges being provided by a shim member disposed between the pads and a correspondingly flat surface of the carrier body. The fulcrum ridges are defined by folded back tabs displacing the shim material or by pleating the shim material. This construction permits the consumable bearing pads to be made profitable more easily and cheaply.

Abstract: This invention relates to vertical bearing assemblies employed to support vertically extending rotatable shafts and provide thrust and/or journal bearing support therefor, and in particular relates to lubricant arrangements therefor.

Abstract: A back-up bearing arrangement (25) for a magnetic bearing (12, 13) includes a stationary dry running bearing material (30) and a rotable collar (26) which runs in abutment where with upon failure of the magnetic bearing. To avoid adhesive wear due to localised welding or melting of bearing material at surface asperities because of the inability of collar material (chosen to withstand centrifugal stresses at high rotation rates) to remove it adequately, the contact-making face of the collar is plated with a layer of copper on which is deposited a thin layer of titanium nitride.

Abstract: An electromagnetic axial shaft bearing 50 (FIG. 2 ) reduces rotational stresses on a ferromagnetic rotor 14' by reducing its radius and displacing inwardly the radially outer, axially extending part 51 of the stator core 15 containing an axial groove 18 and electromagnet coil 19 so that the outer stator pole 22 overlies the stator electromagnet coil.

Abstract: A back-up bearing (50, FIG. 1) is provided for a magnetic journal or thrust bearing by a source of pressurized fluid 52 (such as gas), channels 51 supplying the fluid to the suspension gap 30 between moving bearing armature 25 and stationary armature pole faces 28.sub.1, 29.sub.1, and magnet control means 56 responsive to a decrease in gap width at any point below an acceptable minimum to supply the fluid by way of the channel(s) to the gap to form a hydrostatic bearing between stationary and movable armatures to aid or replace the magnetic bearing support. In a journal bearing, (FIG. 3) in which coil-containing spaces (62) exist between radially extending armature limbs the spaces may be closed by an apertured bridging piece (64) extending between pole faces and fluid supplied via that space to provide both increased hydrostatic bearing area and a way of cooling the coil by a low pressure fluid bleed at all times.

Abstract: A magnetic bearing arrangement for a rotatable shaft 11 including electromagnetic journal bearings 20, 21 and electromagnetic thrust bearings 22, 23, is provided with back-up bearings provided as hydrostatic journal bearings 50, 51 and thrust bearings 52, 53. The hydrostatic bearings are energized by controls 63 responsive to detected failure of the magnetic bearing to support the shaft in any particular direction within a permitted range of displacements and supplied with fluid at such pressure to support the shaft on a fluid film at all speeds down to rest. Preferably the fluid is a gas.

Abstract: Laminated stator and rotor components for a magnetic thrust bearing each include a plurality of generally radially directed laminations (10) whose roots lie along the axis of rotation of a shaft located by the bearing and whose distal portions are progressively twisted relative to the axis such that the width of any lamination (t, t') at any given radial distance from the root corresponds to at least the circumferential separation between adjacent laminations at that distance.

Abstract: Laminated stator (15, 16) and rotor components (11) of a magnetic thrust bearing comprise a plurality of generally radially disposed laminations (2) fixed at their inner end to a cylindrical hub (3), the laminations all being curved in the same direction so that their outer tips lie in a common cylindrical plane (6) which is concentric with said hub (3).

Abstract: An assembly in which a rotating shaft is supported by a magnetic bearing has a back-up bearing to support the shaft in the event of failure of the magnetic bearing, the back-up bearing comprising one or more coaxial bearing parts each including cylindrical rolling elements supported on a single raceway, or each part comprising a ball race with radially inner and outer raceways. If a radially outer raceway is provided it is secured to an anchorage, such as a housing. A layer of dry bearing material is secured to rotate with each raceway to be rotated by the shaft, the dry bearing material having a surface opposite to the shaft. After any failure of the magnetic bearing the shaft is contacted by the layer of dry bearing material, and the rolling elements are brought up to speed at a slower rate than otherwise would be the case, because of slipping of the shaft relative to the dry bearing material.

Abstract: An assembly in which a rotating shaft is supported by a magnetic bearing has a backup bearing to support the shaft in the event of failure of the magnetic bearing. If the bearing portion of the backup bearing comprises a ball race, the radially outer raceway thereof is secured to an anchorage, such as a housing for the assembly. A low stiffness damper member in the form of an annular shaped body of resilient material also is included in the backup bearing, between the bearing portion thereof and the anchorage. Advantageously, when the magnetic bearing has failed, and the shaft is being brought to rest by being in contact with the backup bearing, the resilient body is in shear, and the body has a lower stiffness than otherwise would be the case. Thus, any tendency for the backup bearing, and/or the anchorage, to be damaged while the shaft is being brought to rest, is reduced, because the provision of the low stiffness damper causes the shaft to have a low natural frequency of oscillation.

Abstract: An assembly in which a rotating shaft is supported by a magnetic bearing has a back-up bearing to support the shaft in the event of failure of the magnetic bearing, the back-up bearing comprising a first layer of a dry bearing material, and with a surface opposite to a wear-resistant surface portion of a second layer. One layer is provided on a stationary part of the assembly, such as a housing, and the other layer is provided on the shaft. When the coefficient of friction between the first and second layers is either relatively low, or relatively high, heat can be dissipated from the back-up bearing at a low rate; or at a high rate. Heat dissipation may be enhanced by providing fins in good thermal contact with at least one of the two layers of the back-up bearing; and each such layer, advantageously, has a high thermal conductivity.

Abstract: A magnetic bearing assembly includes at least one electromagnet with a coil at least partially enclosed by a ferrogmagnetic core. Because of this arrangement, heat, inevitably generated within the coil in a conventional bearing, may cause the temperatures of the coil and adjacent parts of the electromagnet to rise to unacceptable values. These temperatures are reduced by placing a heat conducting member, say of copper, contiguous with the coil, and possibly inserted into the coil. Heat is conducted at a high rate to an exposed portion of the member, and is extracted efficiently therefrom by windage, or air flow, created within the apparatus having the magnetic bearing. Advantageously, the exposed portion of the heat conducting member has an extensive surface.

Abstract: A machine tool includes an elongate tool holder which is mounted by a pair of spring strips for pivotal movement on a mounting. One end of the tool holder carries the tool while the other end of the tool holder is moved by an actuator via a rod. Tool positioning signals are fed to the actuator in digital form and are converted to analogue form by a digital-to-analogue converter before being applied to the actuator. The tool holder is of light-weight and low inertia and can thus effect rapid changes of tool position, so exploiting to the full the high rates of positioning signal production of modern machine tool control systems.

Abstract: A machine tool has a workpiece which is rotated by a motor. The tool is moved by a tool drive to machine a required surface profile on the workpiece and is also indexed on a carriage. The stepping signals for the workpiece motor are produced by a control system and, for each workpiece step, the control system also produces from a data store, a signal which moves the tool to the required tool position for machining the workpiece profile at the angular position corresponding to the stepped position of the workpiece motor. After each revolution of the workpiece motor, the carriage is indexed. Thus, the control system also controls the rotation of the workpiece and so no feedback of the workpiece position is required. This means that, during the machining cycle, the control system is involved solely with the supply of data from the store and does not conduct any calculation.

Abstract: Thrust bearings are described comprising a substantially planar thrust accepting member having at least one locating portion substantially at a right angle thereto and which is adapted to co-operate with a recess formed in the bearing housing. In a preferred embodiment there are two locating portions and the co-operating recesses in the bearing housing have re-entrant geometry to prevent accidental displacement of the thrust bearing during installation of the shaft.

Abstract: Flanged bearings are described which are amenable to reliable installation by robotics and which do not require such fine engineering manufacturing tolerances on the flanges as has hitherto been the case. A flanged bearing comprises a journal bearing element and at least one thrust bearing element constituting a flange and wherein the thrust bearing element is attached to the journal bearing element by flexible attachment means. Flanged bearings are described wherein flexible attachment portions are formed from the steel backing material of a thrust bearing, slots are also provided to enhance flexibility. The thrust bearing is attached to a journal half bearing by, for example, electron beam welds.

Abstract: A tilting pad thrust bearing comprising a bearing ring, a number of spaced, circumferentially mounted thrust pads, and a series of oil nozzles located in the spaces between the pads. The pads are mounted to pivot on the ring by means of two pins arranged to fit slackly into corresponding holes in the pad.