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Showing papers on "Bearing (mechanical) published in 1972"


Patent
30 May 1972
TL;DR: In this article, a femoral component in the form of a shell member having two condylar portions with major convex bearing surfaces areas, which portions are bridged at one end by a portion defining a trough between the convex areas.
Abstract: A prosthetic knee joint device comprises a femoral component in the form of a shell member having two condylar portions with major convex bearing surfaces areas, which portions are bridged at one end by a portion defining a trough between the convex areas. An associated tibial component has similar portions in a platform bearing member defining major concave bearing surface areas and a ridge therebetween. The convex bearing areas are longer than the concave bearing areas and generally U-shaped longitudinally to simulate the corresponding shaping in the natural joint from which the shell member can in fact be derived. The concave bearing areas however simulate the menisci of the natural joint different phases of rotation to provide an optimized congruity between the bearing surfaces during rotation of the predetermined geometry of the prosthesis as compared to the variable geometry in the natural joint.

113 citations


Patent
04 Apr 1972
TL;DR: In this paper, a bearing assembly comprises two engaging members movable relative to one another, one of which is a bearing surface made of metal or ceramic coated with a thin film of a parting agent, and the other bearing surface is a cured mixture of a curable acrylate composition and particulate polytetrafluoroethylene.
Abstract: A bearing assembly comprises two engaging members movable relative to one another. One of said members has a bearing surface made of metal or ceramic coated with a thin film of a parting agent, and the other bearing surface is a cured mixture of a curable acrylate composition and particulate polytetrafluoroethylene.

92 citations


Journal ArticleDOI
TL;DR: In this article, it has been shown that the existing pile driving formulas yield bearing capacities which usually do not stand in good correlation to the actual bearing capacities of the vehicles, and it has often been shown by previous investigators that these bearing capacities are not correlated with the actual vehicle bearing capacities.
Abstract: It has often been shown by previous investigators that the existing pile driving formulas yield bearing capacities which usually do not stand in good correlation to the actual bearing capacities of...

71 citations


Journal ArticleDOI
H. Christensen1
01 Jun 1972
TL;DR: In this paper, the phenomena observed when a lubricated contact or bearing is operating under mixed lubrication conditions are assumed to arise from an interaction of the surface asperities or roughness as well as a...
Abstract: The phenomena observed when a lubricated contact or bearing is operating under mixed lubrication conditions are assumed to arise from an interaction of the surface asperities or roughness as well a...

62 citations


Patent
11 Dec 1972
TL;DR: In this article, a gyroscope including a rotating member which is supported by a pair of magnetic bearings has two detectors for providing signals representative of the relative position of the member with respect to a common axis of the two bearings along first and second directions perpendicular to the axis and to each other.
Abstract: A gyroscope including a rotating member which is supported by a pair of magnetic bearings. Each bearing has two detectors for providing signals representative of the relative position of the member with respect to a common axis of the two bearings along first and second directions perpendicular to the axis and to each other. A feed-back loop controls biasing means in each bearing assembly and includes, for each direction, a summation circuit which sums the signals from the detectors corresponding to that direction in the two bearings and applies correction signals increasing with the summed signals to the biasing means corresponding to the directions in the two bearings. A subtracting circuit subtracts the signals from the detectors corresponding to the considered direction in the two bearings and applied correction signals to the biasing means, but through a polarity inverter in one of the bearings.

57 citations


Patent
01 Dec 1972
TL;DR: In this paper, a transducer is used to detect defects in rotating and/or reciprocating components, such as gears or bearings, and a demodulator converts the resulting signal into a series of pulses in which each pulse represents an individual impact.
Abstract: An apparatus for detecting defects or flaws in mechanical systems with rotating and/or reciprocating components, such as gears or bearings. The scheme utilizes a transducer, which is excited at its mounted natural frequency by the vibrations caused by the impacting of components of a device across a flaw in a bearing or the like, a filter to eliminate background noise and signals other than the natural resonant frequency of the transducer, and a demodulator which converts the resulting signal into a series of pulses in which each pulse represents an individual impact. A spectral analysis is then performed on the series of pulses to obtain the location and nature of the surface defect in the bearing or other rotating and/or reciprocating component.

44 citations


01 Oct 1972
TL;DR: In this paper, the distance between the ball center and the outer raceway groove curvature center (V and W) was evaluated using the Newton-Raphson method of iteration.
Abstract: A Newton-Raphson method of iteration was used in evaluating the radial and axial projection of the distance between the ball center and the outer raceway groove curvature center (V and W). Fatigue life evaluations were made. The similar analysis of a conventional bearing can be directly obtained from the arched bearing analysis by simply letting the amount of arching be zero (g = 0) and not considering equations related to the unloaded half of the outer race. The analysis was applied to a 150-mm angular contact ball bearing. Results for life, contact loads, and angles are shown for a conventional bearing (g = 0) and two arched bearings (g = 0.127 mm (0.005 in.), and 0.254 mm (0.010 in.)). The results indicate that an arched bearing is highly desirable for high speed applications. In particular, for a DN value of 3 million (20,000 rpm) and an applied axial load of 4448 N (1000 lb), an arched bearing shows an improvement in life of 306 percent over that of a conventional bearing. At 4.2 million DN (28,000 rpm), the corresponding improvement is 340 percent. It was also found for low speeds, the arched bearing does not offer the advantages that it does for high speed applications.

37 citations



Patent
13 Dec 1972
TL;DR: In this article, a self-pressurizing hydrodynamic foil bearing with resilient foils provides support between a movable and stationary bearing member and further has resilient foil supports for supporting and stiffening the foils.
Abstract: A self-pressurizing hydrodynamic foil bearing having resilient foils providing support between a movable and stationary bearing member and further having resilient foil supports for supporting and stiffening the foils. The foil supports additionally generate Coulomb friction with another bearing member for enhancing the damping characteristics of the bearing.

35 citations


Patent
R Gleichman1
25 Apr 1972
TL;DR: In this paper, a totally enclosed, inert gas filled vertical dynamoelectric machine is described wherein liquid lubricant in the lower bearing housing is employed to seal the machine output shaft against the loss of inert gas.
Abstract: A totally enclosed, inert gas filled vertical dynamoelectric machine is described wherein liquid lubricant in the lower bearing housing is employed to seal the machine output shaft against the loss of inert gas. To inhibit loss of lubricant from the seal, a stationary oil sleeve concentrically disposed within a zone between the rotor shaft and shaft sleeve protrudes to a height in excess of the oil level within the housing by an amount at least equal to the change in level produced by the pressure of the inert gas within the machine. The lower bearing preferably is enclosed by a selectively notched bearing cover which serves in conjunction with annular grooves upon the shaft sleeve to prevent oil creepage along the exterior of the shaft while blow-out of oil from the seal by excessive gas pressure within the machine is inhibited by a liquid filled, generally U-shaped tube communicating the motor interior with the ambient. To prevent turbulence produced by rotation of the rotor from breaking the seal, the lubricant should extend to a level above the bearing or a selectively apertured partition could be inserted between the lower end of the shaft sleeve and the bearing.

34 citations


Patent
15 Nov 1972
TL;DR: In this article, a swing bearing in combination with a swing gear for the slewing platform of hydraulic excavators and the like is disclosed. But the combination is constructed so that individual segments of the gearing can be removed and replaced without removing the sle wing platform.
Abstract: There is disclosed a swing bearing in combination with a swing gear for the slewing platform of hydraulic excavators and the like. The swing gear comprises a plurality of gear segments detachably secured to one race member of the bearing assembly in a manner to form a continuous annular gear element or member. The combination is constructed so that individual segments of the gearing can be removed and replaced without removing the slewing platform.

Patent
Matto Lawrence Robert1
01 Dec 1972
TL;DR: In this article, the inner periphery of the annular plate defines the entrance of a passageway for the flow of cooling air from the entry chamber to and through the blades to cool them.
Abstract: A gas turbine engine is described, particularly the turbine rotor portion thereof and the bearing for journaling this rotor. Cooling air is directed along passageways extending through the bearing mounting and discharged into an entry chamber at the inner portion of the rotor. The rotor includes an annular plate spaced from a disc on which the rotor blades are mounted. The inner periphery of the plate defines the entrance of a passageway means for the flow of cooling air from the entry chamber to and through the blades to cool them. Cooling air as it is directed into the entry chamber at an angle such that its tangential vector approximates the peripheral speed of the cooling air passageway entrances. Further, vanes are provided on the blades to facilitate flow of cooling air through the rotor passageway means.

Patent
18 Dec 1972
TL;DR: A composite article having a body of at least one layer of glass fibers includes a pair of opposed outer bearing portions connected with the body, at least a outer bearing portion including ingredients of graphite, carbon or their mixtures, such as in fiber form, to provide improved bearing characteristics.
Abstract: A composite article having a body of at least one layer of glass fibers includes a pair of opposed outer bearing portions connected with the body, at least one outer bearing portion including ingredients of graphite, carbon or their mixtures, such as in fiber form, to provide improved bearing characteristics. The article is bonded together through a polymer resin. In one form, the article includes a low coefficient of friction material at least as a coating on the bearing portion, especially for very thin, lightweight bearing designs.

Patent
02 Oct 1972
TL;DR: In this paper, the main drive bearing of a refrigerant compressor of the type having a casing wherein lubricant normally stands at a level and wherein the refrigerant compressing mechanism and a motor for driving it are mounted in the casing above that level, is illustrated.
Abstract: Means for lubricating a bearing in a mechanism which is operated intermittently, the illustrated example of which is the main drive bearing of a refrigerant compressor of the type having a casing wherein lubricant normally stands at a level and wherein the refrigerant compressing mechanism and a motor for driving it are mounted in the casing above that level, the means comprising a generally vertically disposed drive shaft having a portion journaled in the bearing, means supporting the drive shaft with the drive shaft portion journaled in the bearing disposed above said level, means for rotating the drive shaft, means defining a recess within the drive shaft adjacent the bearing and defining a passage through which lubricant may flow from the recess to the bearing, lubricant pump means extending into the lubricant reservoir below said level and extending into the recess and effective to pump lubricant from the reservoir into the recess, the means defining the recess including means retaining lubricant in the recess when rotation of the pump stops and the lubricant pump means stops so that such retained lubricant may flow from the recess through the passage to lubricate the bearing when rotation of the drive shaft resumes.

Journal ArticleDOI
TL;DR: Stability characteristics and general transient motion of vertical finite width three lobe journal bearing, assuming incompressible fluid with cavitation, were analyzed in this paper. But they did not consider the effect of cavitation on the bearing.
Abstract: Stability characteristics and general transient motion of vertical finite width three lobe journal bearing, assuming incompressible fluid with cavitation

Journal ArticleDOI
TL;DR: In this paper, a theoretical analysis of a slider bearing using an electrically conducting lubricant in the presence of a non-uniform magnetic field applied perpendicularly to the bearing surfaces is made.
Abstract: A theoretical analysis is made of a slider bearing using an electrically conducting lubricant in the presence of a nonuniform magnetic field applied perpendicularly to the bearing surfaces. In the differential equations inertia terms are retained and the solution is obtained numerically for low Hartmann numbers. The results indicate that the contribution of inertia terms decreases with the increase of Hartmann number and that the nonuniform magnetic field gives higher load capacity than the comparable uniform magnetic field.

Patent
21 Dec 1972
TL;DR: In this paper, yarns of Teflon filaments and yarn of bondable filaments are woven in a 1 x 1 plain weave so that the filaments were just sufficiently loose to allow the capillary action of the liquid resin to thoroughly impregnate the fabric in the manufacture of the bearing and anchor the teflon filament to prevent their being worked loose from the resin by the reversing loads.
Abstract: Unblended yarns are constructed and woven with other yarns to form a mixed fabric which is particularly suitable for use as the liner for resin bodied annular bearings which are subject to reversing loads, that is where one bearing element oscillates relative to the other or relative rotation or movement of the bearing elements regularly reverses in direction. More particularly, yarn of Teflon filaments and yarn of bondable filaments are woven in a 1 x 1 plain weave so that the filaments are just sufficiently loose to allow the capillary action of the liquid resin to thoroughly impregnate the fabric in the manufacture of the bearing and anchor the Teflon filaments to prevent their being worked loose from the resin by the reversing loads.

Patent
24 May 1972
TL;DR: In this article, the imbalance vibration of two concentric rotating shafts is damped simultaneously by a single damped bearing by supporting one of the shafts on a fixed bearing which is fixed to ground, and by transmitting imbalance vibration from the other shaft into the first shaft by means of a nondamped intershaft bearing.
Abstract: Imbalance vibration of each of two concentric rotating shafts is damped simultaneously by a single damped bearing. By supporting one of the shafts on a damped bearing which is fixed to ground, and by transmitting imbalance vibration from the other shaft into the first shaft by means of a nondamped intershaft bearing, the imbalance vibration of both shafts is damped by the single damped bearing.

Journal ArticleDOI
TL;DR: In this paper, it was shown that properly preloaded fasteners loosen as a result of rotation as soon as relative motion occurs between the mating threads and between the bearing surfaces of the fastener and the clamped material.
Abstract: A UNIQUE TEST method and apparatus now make it possible to reproduce conditions of vibration that are not only certain to loosen bolted joints but which also closely simulate actual conditions. It can be shown that properly preloaded fasteners loosen as a result of rotation as soon as relative motion occurs between the mating threads and between the bearing surfaces of the fastener and the clamped material.

Patent
25 Jan 1972
TL;DR: A self-aligning bearing assembly has a single piece, stamped housing of general cup-shaped configuration, an opening in the bottom of the housing for seating a spherical bearing ball and spring fingers extending from the bottom to engage the diametrically opposite side of the ball and retaining it in the housing.
Abstract: A self-aligning bearing assembly having a single piece, stamped housing of general cup-shaped configuration, an opening in the bottom of the housing for seating a spherical bearing ball and spring fingers extending from the bottom of the housing for engaging the diametrically opposite side of the ball and retaining it in the housing.

Journal ArticleDOI
Steve M. Rohde1
TL;DR: In this article, the bearing profile which maximizes the load carrying capacity of an infinite length journal bearing is obtained by the use of a new variational technique, and the solution obtained is a concentric step bearing with a film thickness ratio of 1.812 and a ridge to pad ratio of 0.328.
Abstract: By the use of a new variational technique, the bearing profile which maximizes the load carrying capacity of an infinite length journal bearing is obtained. The lubricant is assumed to be incompressible and of constant viscosity. The flow is assumed to be laminar and the optimization is based upon a minimum film thickness. The solution obtained is a concentric step bearing with a film thickness ratio of 1.812 and a ridge to pad ratio of 0.328. It is mathematically shown by the use of the “nonlocal” formulation that this step profile does yield a maximum among all profiles sufficiently “close.”

Patent
17 Aug 1972
TL;DR: In this paper, an arrangement for mounting a bearing to the surface of a machine part in which the bearing has an inner and an outer race ring is presented, where the race ring opposed to the machine part is formed with a conically tapered surface forming a corresponding space therebetween.
Abstract: An arrangement for mounting a bearing to the surface of a machine part in which the bearing has an inner and an outer race ring. The race ring opposed to the machine part is formed with a conically tapered surface forming a corresponding space therebetween. A radially extending annular flange is provided along the edge of the conically formed ring and a wedge block is located within the space. The arrangement is provided with screw means by which the block is securely pressed and forced into engagement with both the conical surface and the surface of the machine part.

Patent
11 Jul 1972
TL;DR: An ear muff assembly for use with a headband including an ear cup, a circumferentially extending first bearing, the ear cup being mounted in the first bearing for rotation about a first axis, a yoke, the circum-differentially extending bearing being mounted on a second axis which extends laterally of the first axis and the yoke being mountable on the headband as mentioned in this paper.
Abstract: An ear muff assembly for use with a headband including an ear cup, a circumferentially extending first bearing, the ear cup being mounted in the first bearing for rotation about a first axis, a yoke, the circumferentially extending bearing being mounted in the yoke for rotation about a second axis which extends laterally of the first axis, the yoke being mountable on the headband.

Patent
G Johnson1
10 Oct 1972
TL;DR: The helicopter main rotor is mounted on a rotating support mast by feathering bearings and flapping bearings to provide pitch change control and to tilt the rotation plane of the rotor Rotor tilting is provided by the flapping bearing coupling a blade yoke to the mast as discussed by the authors.
Abstract: The helicopter main rotor is mounted on a rotating support mast by feathering bearings and flapping bearings to provide pitch change control and to tilt the rotation plane of the rotor Rotor tilting is provided by the flapping bearings coupling a blade yoke to the mast The flapping bearings are elastomeric elements fitted onto pivot shafts on a trunnion mounted on the mast These elastomeric elements also mount in bearing blocks bolted to the rotor yoke To increase the control power about the pitch and roll axis of the aircraft, particularly at rotor loadings of less than one ''''G,'''' a concentric tube torsion spring interconnects pivot shafts of the trunnion to respective bearing blocks Each of the concentric tube torsion springs includes an inner tube mounted within an outer tube and joined together at the outboard ends The inboard end of the inner tube connects to the pivot shaft and the inboard end of the outer tube connects to the bearing block

Patent
26 May 1972
TL;DR: In this paper, a self-contained, full film hydrodynamic bearing is provided having a ferrofluid (colloidal suspension of magnetic particles) with magnetic properties which facilitates retention of the fluid within the bearing.
Abstract: A self-contained, full film hydrodynamic bearing is provided having a ferrofluid (colloidal suspension of magnetic particles) with magnetic properties which facilitates retention of the fluid within the bearing where the bearing retains the ferrofluid over a wide temperature range and concomitantly compensates for ferrofluid expansion and contraction.


01 Apr 1972
TL;DR: In this article, four groups of 12.7 millimeter diameter vacuum-degassed AISI 52100 balls were tested, each at a maximum Hertz stress in the range of 4.5 times 10-to-9th power to 6.0 times 10 to 9th power N/m2.
Abstract: Four groups of 12.7 millimeter diameter vacuum-degassed AISI 52100 balls were tested, each at a maximum Hertz stress in the range of 4.5 times 10 to 9th power to 6.0 times 10 to 9th power N/m2. Tests were run in the five-ball fatigue tester at a contact angle of 30 deg and a shaft speed of 10,000 rpm. The 10 percent fatigue lives at the four stress levels indicated that fatigue life is inversely proportional to maximum Hertz stress raised to the power of 12. This result agrees with a survey of the literature which suggests that a stress-life exponent of approximately 12 is typical of vacuum-processed bearing steels rather than the exponent of 9 which has been generally accepted by the bearing industry.

Patent
04 Aug 1972
TL;DR: In this paper, a variable-speed, multi-rotor asynchronous motor with a hollow cup-shaped intermediate rotor arranged adjacent the main rotor radially between the stator and an independently rotating ventilator rotor, where the intermediate rotor is removably and/or axially adjustably mounted on the main drive shaft.
Abstract: A variable-speed, multi-rotor asynchronous motor with a hollow cup-shaped intermediate rotor arranged adjacent the main rotor radially between the stator and an independently rotating ventilator rotor, where the intermediate rotor is removably and/or axially adjustably mounted on the main drive shaft. The rotors and the stator have air passages and air lobes for the internal cross-circulation of air; the bearing plates have openings for the entry and exit of cooling air from the ventilator.

Journal ArticleDOI
TL;DR: In this paper, the authors run rolling-element fatigue tests with eight through-hardened bearing materials at 150 F. The results of these tests correlate well with the results of the five-ball fatigue data at 150F.
Abstract: Rolling-element fatigue tests were run with eight through-hardened bearing materials at 150 F. One-half in. dia balls of each material were run in five-ball fatigue testers. Care was taken to maintain constant all variables known to affect rolling-element fatigue life. The longest lives at 150 F were obtained with AISI 52100. Ten-percent lives of the other materials ranged from 7 to 78 percent of that obtained with 52100. A trend is indicated toward decreased rolling-element fatigue life with increased total weight percent of alloying elements. Three groups of 120-mm bore ball bearings made from AISI M-1, AISI M-50, and WB-49 were fatigue tested at an outer-race temperature of 600 F. The 10-percent lives of the M-50 and M-1 bearings exceeded the calculated AFBMA life by factors of 13 and 6, respectively. The bearings with WB-49 races showed lives less than AFBMA life. The results of the bearing tests at 600 F correlate well with the results of the five-ball fatigue data at 150 F.

Patent
20 Dec 1972
TL;DR: In this article, a structural bearing element is formed by winding on a bondable surface of the element a thread impregnated with a bonding resin, and the element and thread are then treated to cause the resin to bond the thread turns to each other and to the element.
Abstract: A structural bearing element having a low friction surface is formed by winding on a bondable surface of the element a bondable low friction thread impregnated with a bonding resin, and the element and thread are then treated to cause the resin to bond the thread turns to each other and to the element. A representative application of the bearing is shown in an automotive type ball joint and an improved sealing means is shown on the joint.