Showing papers on "Bearing (mechanical) published in 1985"

Ball and Roller Bearings : Theory, Design and Application

Abstract: General Fundamentals. Principles of Bearing Calculation. Load Carrying Capacity and Service Life. Friction, Temperature and Lubrication. Principles of Bearing Design. Design of Bearing Locations. Rolling Bearing Damage. Examples of Calculation and Design of Roller Bearing Arrangements. References. Index. Explanation of Symbols.

The Elastohydrodynamic Solution of Journal Bearings Under Dynamic Loading

Abstract: The Newton-Raphson algorithm was used in conjunction with Murty’s algorithm and the finite-element method to analyze the elastohydrodynamic lubrication of a journal bearing under dynamic loading. Cavitation boundary conditions were used. A realistic compliance matrix and load schedule were used in the illustrative example. Solutions for the film pressure, the film thickness and its rate of change with time were obtained as functions of the crank angle.

Method of making a split bearing assembly

Abstract: Split bearing assemblies are disclosed having separable bearing caps for both single applications, such as connecting rods, and multiple applications, such as engine crankshaft supports, together with methods and apparatus for making such assemblies by integrally forming the caps with the main body and separating them by fracture separation. A two step separation method is disclosed with bore starter notches and semicircular die expanders that minimize split plane and bore distortion.

Water-lubricated rubber bearings, history and new developments

Abstract: Rubber bearings are simple, robust and highly reliable devices, able to perform over long periods and under adverse operating conditions; the Authors review their historical development and describe some recent designs for reducing friction and wear, especially at low journal velocities. These improved characteristics mean that length/diameter ratios can be reduced, or existing lengths can be used to support much larger radial loads. Other developments discussed are a self-aligning mounting ring of rubber around the bearing housing, and using rubber bearings with oil as the lubricant.

Vehicle wheel end assembly

Abstract: A vehicle wheel end assembly (10) is adaptable for use with an on-board central tire inflation system. The assembly provides a passage for the routing of air between the on-board system and the vehicle tire. The assembly comprises a stationary spindle (12) and a rotational hub (14) mounted thereon. The hub is supported for rotation by first and second axially spaced bearing sets (16, 18), each having an inner race (20, 26) and an outer race (22, 28) associated with the spindle and hub, respectively. The inner race of the inboard bearing set (18) is formed with an axial air passage (46) which communicates with an internal chamber (36) in the hub to form a portion of the air passage between the tire and on-board system. In another feature, rotary seals (60, 62) are seated in opposed faces of the bearing sets and include sealing lips (72) which have a sealed contact with the upper surface of the inner bearing races. An inboard spindle collar (100) may also be employed to facilitate the continuation of the air passage (98) in the bearing race (90) to the on-board system.

Vibration characteristics of the HPOTP (High-Pressure Oxygen Turbopump) of the SSME (Space Shuttle Main Engine)

Abstract: Attention is given to rotor dynamic problems that have been encountered and eliminated in the course of Space Shuttle Main Engine (SSME) development, as well as continuing, subsynchronous problems which are being encountered in the development of a 109-percent power level engine. The basic model for the SSME's High Pressure Oxygen Turbopump (HPOTP) encompasses a structural dynamic model for the rotor and housing, and component models for the liquid and gas seals, turbine clearance excitation forces, and impeller diffuser forces. Linear model results are used to examine the synchronous response and stability characteristics of the HPOTP, with attention to bearing load and stability problems associated with the second critical speed. Differences between linear and nonlinear model results are discussed and explained in terms of simple models. Simulation results indicate that while synchronous bearing loads can be reduced, subsynchronous motion is not eliminated by seal modifications.

Control yoke apparatus for computerized aircraft simulation

Abstract: An aircraft control yoke apparatus includes an inexpensive mechanism for manipulating a two axis variable transducer and is especially adaptable for use with microcomputers. The apparatus includes a control wheel attached at one end to a shaft which is in turn supported by a linear bearing. The linear bearing permits the shaft to rotate and simultaneously move back and forth. A crank mechanism is attached to the other end of the shaft and serves to amplify the rotational movement of the steering wheel. A resilient, elastic material like natural isoprene rubber connects the crank to a two axis variable transducer. The elastic material causes the two axis transducer to follow the motion of the rotational and back and forth movement of the steering wheel. A return-to-center mechanism causes the wheel to return to a neutral position when no force is applied to it. A very life-like simulation of airplane flight is achieved with a minimum of expense and a high degree of realism.

Helical Gears With Circular Arc Teeth: Simulation of Conditions of Meshing and Bearing Contact

Abstract: Engrenages helicoidaux avec denture en arc de cercle. Simulation du contact et de l'engrenement

Device for the reciprocating linear drive of a part

Abstract: A device for the reciprocating linear drive of a part, especially of a scraper at a calender cylinder, comprises a driver connected to the scraper and having two mutually parallel oppositely disposed abutments and an eccentric disposed between the abutments. The eccentric has an outside diameter which is smaller than the distance between the abutments. The eccentric is designed as a double eccentric with a driven inner eccentric fixed to a rotary drive shaft and with a freely movable outer eccentric floatingly mounted to the inner eccentric via an antifriction bearing.

Comparison of Dynamic Behavior of Elastic Connecting-Rod Bearing in Both Petrol and Diesel Engines

Abstract: The method developed in an earlier work describing the dynamic behavior of an elastic connecting-rod bearing was used to compare the performance (minimum film thickness, torque and flow rate) of two different bearings which belong respectively to a petrol and a diesel engine Results show that of all the mechanical factors considered (load, speed, viscosity ), the most significant parameter is the load diagrams, which through the elastic deformation governs the film thickness distribution

Electric motor with ferrofluid bearing

Abstract: An electric motor including an integral ferrofluid bearing provides significant reduction in non-repeatable runout, stray flux, and audible noise over conventional motors using ball bearings. The motor includes a hub and a base, with the base attached to a tapered magnetically permeable shaft which defines an inner bearing race, and the hub attached to an internally tapered, magnetically permeable sleeve which defines an outer bearing race. Permanent magnets surround and are rotatable with the sleeve to provide mangetic fields which interact with the stator winding to cause rotation of the hub and sleeve. In addition, the permanent magnets form magnetic flux paths with the shaft and the sleeve to maintain ferrofluid lubricant between the inner and outer bearing races.

Split bearing assemblies

Abstract: Split bearing assemblies are disclosed having separable bearing caps for both single applications, such as connecting rods, and multiple applications, such as engine crankshaft supports, together with methods and apparatus for making such assemblies by integrally forming the caps with the main body and separating them by fracture separation. A two step separation method is disclosed with bore starter notches and semicircular die expanders that minimize split plane and bore distortion.

Magnetic bearing having triaxial position stabilization

Abstract: A magnetic bearing having contactless position stabilization of a supported body which includes a damping and aligning arrangement. This arrangement includes two spaced rotating annular permanent magnets which form a gap therebetween and which are attached to a rotor supported by the bearing. A stationary plate having good electrical conductivity and extending into the gap between the permanent magnets, is cut by their rotating magnetic flux. Mechanical disturbances of the rotor generate eddy-currents in the conductive plate which currents damp out these disturbances. A portion of the plate outside the gap is much thicker than the portion in the gap and provides a very low resistance path for the eddy-currents.

Fatigue life analysis of a turboprop reduction gearbox

Abstract: A fatigue life analysis of the Allison T56/501 turboprop reduction gearbox was developed. The life and reliability of the gearbox was based on the lives and reliabilities of the main power train bearings and gears. The bearing and gear lives were determined using the Lundberg-Palmgren theory and a mission profile. The five planet bearing set had the shortest calculated life among the various gearbox components, which agreed with field experience where the planet bearing had the greatest incidences of failure. The analytical predictions of relative lives among the various bearings were in reasonable agreement with field experience. The predicted gearbox life was in excellent agreement with field data when the material life adjustment factors alone were used. The gearbox had a lower predicted life in comparison with field data when no life adjustment factors were used or when lubrication life adjustment factors were used either alone or in combination with the material factors.

Diagnostic monitoring of rolling-element bearings by high-frequency resonance technique©

Abstract: In the present work, investigations by high-frequency resonance technique for diagnosis of defect frequencies of rolling-element bearings are reported. Raw vibration signature of the bearings at different speeds of operation has been demodulated. Envelope detected spectrum is analyzed to evaluate various defect frequencies and their energy levels. Experimentally evaluated frequencies are compared with theoretically determined defect frequencies. These frequency values and their energy levels are used to monitor intrinsic condition of bearings as well as to establish severity of existing/developed defects in the bearings. Relative comparison of bearings of the same type are made at various operating speeds under identical conditions of operation on the basis of identified defect frequencies and severity of defects. The paper gives a realistic approach to monitor intrinsic condition of a bearing. Investigations given in the paper may have a potential for performance evaluation and may act as a reliable tool...

Structurally lightened piston utilizable especially in an internal combustion engine

Abstract: The piston for an internal combustion engine, consisting of a piston head (1) and a body (2) of monobloc or two-piece construction, the head bearing upon the body (2) via at least two circular bearing surfaces (4, 5), the body (2) having a bearing part (6) receiving an articulation part (10) rigidly attached to the end of a connecting rod (3) and said bearing part (6) having on its piston head side a wall (7) forming a bearing whose bearing surface (8) is continuous, is structurally lighter in that the portion of its body (2) connecting the wall (7) to the bearing surfaces (4, 5) is formed of at least two thin, truncated conical partitions (11, 12) whose center lines (13, 14, 15, 16) are rectilinear, each of said partitions bearing upon a separate one of the circular bearing surfaces (4, 5).

Collapsible vertical wind mill

Abstract: A collapsible vertical wind mill is disclosed, which comprises four main wings arranged in a rhombic form having a pair of opposed corners fitted on a shaft and auxiliary wings each provided on each of the main wings. The upper one of the pair corners on the shaft is fitted via a bearing capable of movement along the shaft. The other pair of opposed corners of the rhombic structure each have a hinged structure capable of variation of the angle.

Lightweight high performance titanium sliding contact bearing

Abstract: A combination of a sliding-contact race (12) and bearing (10) in which a generally ring-shaped race member (12) and a generally ring-shaped bearing member (10) are fitted for relative sliding-rotation, the bearing member being within the race member. One of the members is comprised substantially of copper and the other of the members is comprised substantially of titanium. The members (10, 12) have lubricated contact surfaces (16, 18) for sliding-rotation, the member being comprised substantially of titanium having its lubricated contact surface being coated with chromium oxide (16).

Friction losses in rolling piston type rotary compressors. III

Abstract: This paper is concerned with rolling piston type rotary compressors for air conditioners. Friction losses at the vane tip and sides and at the rolling piston bearing are analysed taking account of the kinematics of the compressor. Characteristics of the losses and the influences of design parameters on them are investigated. It is indicated that the short length/diameter configuration of the cylinder is favourable to decrease total loss but the reverse is desirable to achieve maximum reliability of the compressor.

Conveyor roller and bearing assembly

Abstract: A conveyor roller and bearing assembly designed to rotate around a fixed shaft in a conveyor frame is disclosed having a polymeric roller constructed and arranged to minimize the generation of production noise and static electricity, a polymeric spherical bearing capable of freely rotating within a shaft subjected to more than the normal degree of deflectional rotation while generating a minimum of friction and heat, and a spring loaded shaft designed for easy installation in a conveyor frame.

Downhole progressive cavity type drilling motor with flexible connecting rod

Abstract: A downhole motor has a rotor and a stator, of the progressive cavity type, inside a housing A bearing shaft is mounted within the housing, with a bearing between the housing and the bearing shaft, and the bearing shaft is rotatable about the longitudinal axis of the bearing shaft and the housing A flexible rod, with a connection on each end, extends between the rotor and the bearing shaft, for translating the rotation and gyration of the rotor to the true rotation of the bearing shaft A cylindrical overload sub is located concentrically around the rod A plurality of splines and slots on the connections engage a plurality of splines and slots on the sub to allow the connections to rotate axially a limited amount in relation to one another Teeth may be used instead of splines and slots

Constant velocity elastomeric bearing joint

Abstract: A constant velocity joint (200) for interconnecting a first shaft (202) to a second shaft (204) for bidirectional drive is provided. The constant velocity joint employs a carrier (218) which is formed with a series of apertures for receiving elastomeric bearing assemblies (220). The elastomeric bearing assemblies are provided with a spherical elastomeric bearing (60) and a cylindrical elastomeric bearing (48). Certain of the elastomeric bearing assemblies connect the carrier to one of the rotated members while the remaining elastomeric bearing assemblies connect the other rotating member to the carrier. The axis of symmetry of the carrier (218) will always bisect the angle of misalignment between the two rotating shafts to assure that a constant velocity joint is achieved.

Copper-based spinodal alloy bearings

Abstract: This invention relates to the use of spinodal alloys consisting essentially of copper-nickel-tin for bearing surfaces formed between roller cutter cones of sealed bearing rock bits.

Earth boring bit with improved rigid face seal assembly

Abstract: An earth boring bit having a cantilevered bearing shaft and a compensator system to equalize the pressure of the lubricant with the hydrostatic pressure of the drilling fluid surrounding the bit. A rigid face seal assembly, positioned between the cutter and bearing shaft of the bit, moves axially in response to, and to compensate for, dynamic pressure changes in the lubricant adjacent the seal. The positioning of the seal groove and seal assembly in relation to the bearing surface is such that rigid face seal movement is decreased relative to axial cutter movement during drilling to enhance seal life. Preferably the ratio of rigid ring movement to axial cutter movement is substantially one half to one.

Method and apparatus for swing gear and bearing assembly for power mining shovel

Abstract: An improved swing gear for a power mining shovel which can be removed and replaced simply by partially separating the upper rotatable frame assembly from the lower stationary frame assembly and including upper and lower bearing rails formed of a plurality of arcuate segments and a plurality of arcuate bearing segments removably coupled to each other to form a circular bearing arrangement positioned between the upper and lower bearing rails whereby the bearing segments and bearing rail segments may be removed and replaced in an area exposed by the upper frame assembly without any separation of the upper rotatable frame assembly from the lower stationary assembly.

Self-aligning bearing and oil cap mount for an electric motor

Abstract: A self-aligning bearing and end shield mount for an electric motor or the like. The bearing mount has a spacer with a hub through which the rotor shaft extends and fingers that seat within an annular locating groove of the rotor shaft for securing the spacer to the shaft. The spacer also has a thrust surface. A spring has a hub portion through which the rotor shaft extends and a ring surrounding the hub with resilient arms therebetween. The spring also has a bearing seat and a thrust plate seat. A self-aligning bearing is seated in a bearing socket in the end shield of the motor housing and in the bearing seat of the spring. A thrust plate is seated within the thrust plate seat of the spring with the thrust surface of the spacer running against a surface portion of the thrust plate. The oil cap mount inlcudes circumferentially spaced protrusions extending out of the surface of the end shield and formed integrally therewith to define an oil cap seat. The protrusions are deformed to engage and overlie side surfaces of the oil cap to secure the oil cap to the end shield.