Showing papers on "Bearing (mechanical) published in 1976"

Scroll-type apparatus with hydrodynamic thrust bearing

Abstract: A flat plate hydrodynamic thrust bearing for orbiting machinery and scroll-type apparatus embodying the thrust bearing are disclosed. The thrust bearing exerts an axial force on the orbiting scroll member to ensure efficient radial sealing of the scroll assembly; and one of the contacting surfaces of the bearing and or of the orbiting scroll member, serving as a journal, has a plurality of intersecting groovings to ensure continuous lubrication of the surfaces. The scroll apparatus is particularly suited for incorporation in a closed cycle refrigeration system wherein minimum wear over extended periods and quiet and reliable operation are required.

Friction and end bearing tests on bedrock for high capacity socket design

Abstract: Rock sockets are used to transfer axial loads to bedrock by a combination of periferal contact bond and end bearing. The load distribution with embedded depth in relation to rock properties actuall...

Convertible filling machine

Abstract: A filling machine which in its original construction includes a first number of filling units and which is adapted to be converted into a filling machine with a second number of filling units greater than the first number; to that end the actuating drives of two filling units on the same side of the machine are interconnected by the use of a linking bar detachably mounted over the eccentrics thereof while bearing sleeve housings and bearing bushings are detachably secured on the linking bar in a predetermined number and at predetermined locations for installing thereon the lower ends of the filling units; the pump post mounting members for the upper ends of the respective filling units are removed and in lieu thereof an upper mounting bar is fastened to the filling machine by the use of the same threaded holes in the filling machine which were originally used for fastening the pump post mounting members; the upper mounting bar is provided with a number of pump post members detachably secured thereto which correspond in number to the predetermined number and which are so located on the mounting bar that the upper ends of the filling units can be pivotally secured thereon.

Bearing and drive structure for spinning turbine

Abstract: A bearing and drive structure for the funnel-shaped spinning element of an open-end spinning turbine, composed of a stator with a projecting portion carrying an elastically mounted bearing and a rotor with a cup-shaped portion into which the projecting portion of the stator extends, the rotor being carried by the bearing and having its center of gravity at least approximately in the region defined between the axial ends of the flexible bearing, the stator carrying electrical windings cooperating with the cup-shaped rotor portion to form an electrical drive for the rotor

Dynamic Capacity and Surface Fatigue Life for Spur and Helical Gears

Abstract: A mathematical model for surface fatigue life of gear, pinion, or entire meshing gear train is given. The theory is based on the statistical approach used by Lundberg and Palmgren for rolling-element bearings. Also equations are presented which give the dynamic capacity of the gear set. The dynamic capacity is the transmitted tangential load which gives a 90 percent probability of survival of the gear set for one million pinion revolutions. The analytical results were compared with test data for a set of AISI 9310 spur gears operating at a maximum Hertz stress of 1.71 billion N per sq m (248,000 psi) and 10,000 rpm. The theoretical life predictions were very good when material constants obtained from rolling-element bearing tests were used in the gear life model.

Plural probe circuit card fixture using a vacuum collapsed membrane to hold the card against the probes

Abstract: A test fixture for circuit cards comprising a probe board bearing electrical test probes in a fixed position with respect to the overlying test surface. A flexible sheet is supported by the probes and serves to stabilize their relative positions. The circuit card is held against the probes by vacuum force applied utilizing a thin plastic layer overlying the circuit card. The test probe utilized in the test fixture has a conductive shaft tapering to a cylindrical tip on which a conductive spring and a conductive contact cap are slidably mountable. The cap is tapered down to the tip, and the spring is designed to engage both the tapered portions of the cap and of the shaft. A twisting motion of the cap causes the spring to electrically and physically connect the cap and the shaft. The cap also an indentation for interlocking with the flexible sheet of the test fixture.

Francis-type hydraulic machine

Abstract: The disclosure concerns a Francis-type hydraulic machine, i.e., a turbine, pump-turbine or pump, having a bladed wheel of large diameter, and in which bearing apparatus for supporting the rotor is arranged in a peripheral region of the bladed wheel spaced radially from the axis.

Self-lubricating auxiliary bearing with a main bearing failure indicator

Abstract: An auxiliary bearing structure having a selflubricating sleeve which is, upon main bearing failure, engaged by a shaft mounted runner which also actuates a main bearing failure indicator. A portion of the runner also provides a debris shield between the main bearing and auxiliary bearing. Main bearing failure annunciation is accomplished by the runner abrading insulation from an insulated electrical probe during main bearing failure.

Rim-type hydroelectric machine

Abstract: The disclosure concerns a hydroelectric machine including a tube-type hydraulic machine having a bladed wheel which carries adjustable blades, rotates about a horizontal axis and is connected with a shaft which extends into a guide blade lattice hub, and an electrical machine which surrounds the bladed wheel and has a rotor secured to an annular rim in which the external ends of the adjustable wheel blades are pivotably mounted. The rotating set is provided with three radial bearing arrangements, one being associated with the rotating unit formed by the rotor and the rim, providing sole radial support for that unit, and consisting exclusively of hydrostatic devices which support without physical contact. The other bearing arrangements are associated with the shaft at its free and bladed wheel ends, respectively. The bearing arrangement at the free shaft end and one of the other bearing arrangements center the rotating set with respect to the axis of rotation and are the only bearings which perform this function. The remaining radial bearings provide a constant supporting force when there are slow radial movements of the rotating set and a progressively increasing supporting force when there are sudden radial movements of that set.

Device for compensating synchronous disturbances in the magnetic suspension of a rotor

Abstract: A device is disclosed for compensating synchronous disturbances in the magnetic suspension system of a rotor which is supported by a radial electromagnetic bearing and which has means associated therewith for detecting the radial position of the rotor, comprising a servo-circuit for connection between the detecting means and windings of the electromagnetic bearing and including a circuit for the control of the current supply to the windings in response to signals from the detecting means to keep the rotor in a pre-determined radial position. The servo-circuit is provided with means for filtering the signals supplied by the detecting means between the latter and the control circuit, the filtering means having at least one band rejection filter centered on a frequency which is a direct function of the speed of rotation of the rotor.

Endurance and Failure Characteristic of Main-Shaft Jet Engine Bearing at 3 × 106 DN

Abstract: Groups of thirty 120-mm bore angular-contact ball bearings were endurance tested at a speed of 12,000 and 25,000 rpm (1.44 million and 3.0 million DN, where DN is the product of the bearing bore in mm and the shaft speed in rpm) and a thrust load of 66,721 N. The bearings were manufactured from a single heat of VIM-VAR AISI M-50 steel. At 1.44 million and 3.0 million DN, 84,483 and 74,800 bearing test hours were accumulated, respectively. Test results were compared with similar bearings made from CVM AISI M-50 steel run under the same conditions. Bearing lives at speeds of 3 million DN with the VIM-VAR AISI M-50 steel were nearly equivalent to those obtained at lower speeds. A combined processing and material life factor of 44 was found for VIM-VAR AISI M-50 steel. Continuous running after a spall has occurred at 3.0 million DN can result in a destructive fracture of the bearing inner race.

Permanent magnetic centrifugal pump

Abstract: A glandless permanent magnetic centrifugal pump designed for a power input of about 10kW or more and a delivery head of between 2 and 10 bars having a pump casing containing an impeller assembly connected to an inner rotor journalled in the pump casing and carrying permanent bar magnets disposed parallel to the rotor axis via which it is driven magnetically by an outer motor-driven rotor generating a rotating magnetic field passing through an air gap which circumferentially surrounds the inner rotor and in which a gap tube extends around the inner rotor and is fixed to the pump housing to glandlessly close the interior thereof in a fluid-tight manner. All components which come in direct contact with the pumped fluid, particularly the pump casing, the impeller assembly including its shaft, and the inner rotor, and the gap tube, are made entirely of a temperature -- and/or acid-resistant synthetic plastics material, in which the permanent bar magnets of the inner rotor are completely embedded and have trapezoidal cross section, their side faces and end faces are tapered and inclined towards each other in the radially outward direction. Bearing material which imparts the hardness and frictional properties of ordinary bearings to the bearing surfaces is incorporated in the synthetic plastics material forming the bearing surfaces of the bearings of the impeller assembly and inner driven rotor.

On the optimization of fluid film bearings

Abstract: In a classical paper slightly after the turn of the century, Lord Rayleigh obtained the optimum one dimensional slider bearing profile, the Rayleigh step. His criteria for optimality was that the load capacity per unit length of the bearing be maximum among all profiles having a given minimum film thickness. Since Rayleigh, an open question has been the determina­tion of the optimum two dimensional bearing profile based on the same criteria as above. In this paper we propose a method for answering that question using algorithms which we have recently developed for this class of problems.

Holder for magnetic discs

Abstract: A container for a magnetic data recording disc includes a flat cassette shaped for insertion into a receptacle of disc memory of a data processing apparatus. A normally closed opening in a sidewall of the cassette provides access to the disc for recording and/or reading heads of the data processing apparatus. The cassette includes a pair of generally parallel walls that extend in a direction generally parallel to faces of the disc. One of the opposing walls includes an opening for enabling rotary drive means of the apparatus to be coupled to an annular hub of the disc. The opposed walls are rigid, but elastically deformable. In a free state, the opposed walls are outwardly convex. An internal projection extends from the center of the other opposed wall. The projection has an annular bearing surface facing the inside face of the other wall. The one opposing wall has an opening coaxial with the projection. The opening is surrounded by an annular bearing surface on the outside face of the one wall. The disc includes an annular hub carrying two axially displaced flanges. The flanges respectively extend internally and externally of the hub and are arranged to engage the bearing surfaces of the projection and the other wall. The flanges are axially spaced from each other by a smaller distance than the bearing surfaces in the free state of the cassette opposing walls. Thereby, when the disc is not engaged by the drive means of the apparatus, an elastic restoring force from the opposed walls, while they are in a flattened state, mechanically holds the disc in position. The disc is released from the bearing surfaces in response to the opposed walls being moved closer together by a pressure member and stops of the apparatus.

Device for damping the critical frequencies of a rotor suspended by a radial electromagnetic bearing

Abstract: A device is disclosed for damping the critical frequencies of a rotor suspended by a radial electromagnetic bearing which has means associated therewith for detecting the radial position of the rotor, comprising a servo-circuit for connection between the detecting means and windings of the electromagnetic bearing and including a circuit for controlling the current supply to the windings in response to signals from the detecting means to keep the rotor in a predetermined radial position. The servo-circuit is provided with means for the selective amplification of the phase advance gain of said circuit in a frequency equal to the speed of rotation of the rotor for damping said critical frequencies.

Journal bearing assembly with flexible support and viscous damping

Abstract: A plurality of arcuate, vibration cushioning, spring beams are positioned in endwise relationship in the interior of an annular bearing housing to resiliently support an annular journal bearing therewithin which, in turn, rotatably supports a shaft. An annular clearance is provided between the bearing housing and the bearing elements, and oil is introduced to the clearance to provide viscous damping of vibrations.

Bearing assembly and liner

Abstract: A bearing liner adapted for extreme temperature applications comprising polybutadiene resin matrix having included therein a random dispersion of polytetrafluoroethylene particles, the resin matrix adhered to a backing material.

Gas turbine plant

Abstract: A stationary gas turbine plant in which a bearing for the bladed rotor is located at the exhaust end of the casing where the flow passage for the exhaust gas merges into an annular diffusor ring surrounding the bearing housing and which is established by radially spaced circular walls interconnected by means of an array of circumferentially spaced radially extending aero-foil shaped ribs. Two of these ribs extending divergently in a generally downward direction toward the foundation for the turbine are made hollow for the purpose of passing support struts through them, the upper ends of these struts being secured to the bearing housing and the lower ends of the struts being secured to the foundation. Additional supports are provided at opposite sides of the casing at the exhaust end, these supports also being secured to the foundation. The two downwardly directed hollow ribs and the two additional supports for the casing incorporate ducts through which a fluid coolant is circulated, and the coolant which passes through the two hollow ribs enters the bearing casing. The coolant can be ambient air, or gland sealing air, or the bearing lubricant and it can also be the same fluid as is used for cooling the rotor.

Damped intershaft bearing and stabilizer

Abstract: A viscous damper for a bearing mounted between coaxially mounted shafts rotating at relative speeds is stabilized by mounting a spring in parallel with the damper so as to raise the natural frequency of one of the shafts.

Web guide apparatus

Abstract: A web steering frame having parallel entering and exiting rollers is supported for pivotal movement on a stationary support frame in a web guide apparatus by a system of pivoted, linear bearings. Each bearing includes a bushing which is movable along a linear guide rod. The bushings are fixed near the rollers where any loads are transmitted to the support frame thereby minimizing steering frame racking. The guide rods are pivotally connected to the support frame. The bearings are oriented so that the direction of linear freedom of each is orthogonal to a line passing through the bearing pivot and the desired steering frame pivot. The linear bearings effectively constrain the steering frame to pivotal motion about the steering frame pivot. Their use gives rise to significant reductions in cost and complexity over conventional web guide apparatus using precision arcuate guides, links or flexures.

Web tension monitor

Abstract: A web tension monitor in which the tension of a moving web passing over a guide roll is monitored by a sensing device positioned upon a cantilever-mounted support which is coupled to a shaft which carries the roll. Forces applied to the roll by the tensioned web passing over it are coupled to a fixed frame through the cantilever-mounted support by means of a pair of concentric rings between which bearing balls are disposed in confronting openings formed in both members at diametrically opposed points. Misalignment and expansion of machine components can be tolerated to a large degree without causing pre-loading of the sensing device.

Temperature and failure indicating probe for a bearing

Abstract: The disclosed invention relates to a combination temperature and failure indicating probe for use in a bearing. In the preferred embodiment, a negative coefficient thermistor is disposed within a tubular, electrically conductive, enclosure. The enclosure is surrounded by an electrically insulating sleeve for mounting within a bearing. Electrical conductors connected to the thermistor and to the enclosure itself lead to a resistance sensor which detects an abnormal resistance due to either: 1. an excess temperature at the bearing; or 2. contact by a metallic portion of the bearing with the enclosure due to bearing wear or failure.

Load-sensing and adjusting method for operable machines

Abstract: A vibration isolator of the type used for mounting industrial equipment, having the capability of measuring forces exerted upon the isolator to adjust the support provided by each of the isolators upon which the equipment is mounted so as to provide the most suitable distribution of support and to reduce the transmission of dynamic forces created by the operation of the equipment The isolator comprises a resilient base, a bearing plate on the base and a sensing device cooperating therewith, with or without means for attaching the isolator to the equipment A force applied to the isolator exerts pressure on the bearing plate which is transmitted therethrough to the resilient base causing each of them to experience some deformation The sensing device detects the pressure or deformation caused by the force applied to the isolator and generates a signal corresponding to said force The signal is transmitted to indicating instruments suitably calibrated to show the static and dynamic forces to which both the equipment and foundation are subjected, as well as the weight and center of gravity of the equipment

Zahnradmaschine (pumpe oder motor)

Abstract: The pump-motor has two externally meshing gears (13,14) with journals in sleeve-shaped bearings (19,20). Sealing plates (26,27) between the gear side and bearing, engage for sealing on the gear side, due to a pressure zone (30,31) which is limited by a further seat (28,29). A circumferential narrow groove (32,33) is formed in the outer circumference of the bearing at a small distance to the sealing plate. The groove is connected to the low pressure side, resp. the intake side.