3954results about How to "Reduce stress concentration" patented technology

A double shouldered high torque resistance threaded connection for drill stem components having enhanced resistance to torque forces, tensile loads and material stress and fatigue is disclosed. The tool joint is provided with threads having a 75 DEG included angle between the thread flanks thereof and with generally elliptical root surfaces to minimize material stress and fatigue during operation under high torque and high tensile loads. When made up, the double intrerengaging shoulders of the threaded tool joint are in firm face to face engagement permitting torque forces and tensile loads to propagate through the tool joint in a manner that minimizes bending forces and minimizes high stress concentration so that the resulting service life of the tool joint is significantly enhanced.

A flexible prosthetic tissue-type heart valve having commissures that are substantially decoupled from a cusp support structure. The valve includes three leaflets having arcuate cusp edges and opposed concave shaped free edges, with outwardly-directed attachment tabs therebetween. A cusp support structure in either one or more pieces attaches to the leaflet cusp edges. Three commissures are each formed partly with an axially-extending insert member to which two adjacent leaflet tabs attach. An inverted V-shaped clip maintains close contact between the adjacent leaflet tabs and provides a stress-relieving clamping action in conjunction with the insert member. The insert member attaches about its lower end to base sections of the cusp support structure, or to an intermediate sewing ring, so that the commissures may pivot about the cusp support structure.

A multilayer wiring board assembly component comprises: an insulating substrate component (the insulating resin layer 111); a conductive layer 112 formed on one surface of said insulating substrate component 111 in the form of an electrode pattern; an adhesive layer 113 formed on the other surface of said insulating substrate component 111; and a conductive resin composition 115 with which is filled a through hole passing through said insulating substrate component 111, said adhesive layer and said conductive layer in order to make interlayer interconnection. The bore diameter of the conductive layer portion 114b of the through hole 114 is smaller than the bore diameter of the insulating resin layer portion and the adhesive layer portion 114a to establish electrical connection between the conductive resin composition 115 and the conductive layer 112 by the rare surface 112a of the conductive layer 112.

A valve body and seal assembly comprising a valve body having one or more peripheral integral seal retention grooves and one or more peripheral single-durometer and/or dual-durometer elastomeric seals, each seal being cast-in-place in an integral seal retention groove having adhesion-inhibiting surfaces and offset circular serrations of predetermined height on opposing groove walls. Adhesion-inhibiting surfaces reduce or eliminate internal elastomer stress due to curing of cast-in-place elastomeric seals. Serrations on each of the opposing groove walls are offset to accommodate differing stress concentrations in the walls. Opposing groove walls diverge peripherally. Offset serrations result in decreased metal fatigue from impact and bending stress. Offset serrations also improve valve sealing and increase valve service life by maintaining correct seal position on the valve body while minimizing background stress in the seal elastomer(s). Valve service life is also increased by appropriate choice of differing elastomer compositions for dual-durometer seals.

Threaded and coupled pipe connections are provided with a number of design features that increase resistance of the connection to fatigue failure from cyclical side loading. The features acting alone or in combination include the provision of a pin thread that is formed along a single taper and that vanishes at the surface of the pipe. The coupling engages the pin such that the threaded area of the coupling engages all of the pin threads and extends beyond the vanish point of the pin threads at the optimum coupling makeup position. The threads of the coupling and pipe may engage along both the stab and load flanks to distribute the side loading. The external surface of the coupling may be tapered from the center toward each coupling end to reduce the stiffness ratio of the connection, and the ends or faces of the coupling may be reduced in radial thickness to prevent coupling splitting. The coupling length may be extended to exceed standard coupling lengths to provide the additional threaded area and/or taper areas and/or reduced stiffness ratios.

A magnetic disk apparatus of the present invention is equipped with a microactuator for micro motion using piezoelectric elements in addition to a coarse adjustment actuator such as a voice coil motor or the like, eliminates parts that slide between the microactuator and surrounding members, and alleviates stress on the piezoelectric elements even if an impact is given to the magnetic disk apparatus. Thus, a first actuator fixing portion on a carriage side and a second actuator fixing portion on a magnetic head side of a microactuator mounting portion are coupled with a plurality of flexible coupling portions and coupling portions are placed outside the microactuator in substantially symmetric with respect to a centerline in a longitudinal direction of a suspension.

A surgical saw blade operatively couples to an oscillatory power tool for oscillation about an oscillation axis (OA). The saw blade includes a plurality of cutting teeth separated from one another by a clean out opening along a distal end. The clean out opening comprises an arcuate closed end and straight side walls extending from the closed end. Each tooth comprises first and second rake surfaces and first and second relief surfaces intersecting to define first and second cutting edges, respectively. The first and second cutting edges are oppositely disposed from one another. One cutting tooth protrudes a distance (de) from one side face of the blade and the next adjacent cutting tooth protrudes the same distance (de) from the other side face of the blade to cut a groove having a width (dg) wider than the thickness (t) of the blade.

A composite frame includes a plurality of truss elements covered by a cap. The truss elements are flexibly coupled with each other and with the cap. The frame flexes to conform to a contoured surface to which it is attached. Once attached, the installed frame provides the required rigidity to the structure.

Systems and methods for a rugged hand held mobile terminal design are provided. The mobile terminal design includes a monocoque enclosure for housing electronic components. The electronic components are mounted on a rail system, which is positioned within an interior portion of the enclosure through an open end of the enclosure. The mobile terminal design also includes a display bezel. The display bezel and the rail system have mating parts for securing the assembly together.

The invention described herein provides a non-pneumatic deformable structure having a variable stiffness spoke assembly that provides a method of adjusting the vertical stiffness. The structure comprises an outer annular band having a predetermined stiffness, a set of spoke elements having an outer end and an inner end, where the outer end is connected to the outer band, with the spoke element extending inward and having its inner end connected to a hub, the hub being configured to attach the structure to a vehicle axle or other apparatus capable of rotation about an axis. Each of the spoke elements has a curvilinear length greater than the length of a straight line segment extending from a point of connection of the outer end of the spoke element with the outer annular band to a point of connection of the inner end of the spoke element to the hub. The outer end of said spoke element is tangent to the straight line segment, and the inner end of said spoke element is tangent to the straight line segment.

The invention relates to a combined type rubber shock absorber and belongs to the technical field of rubber vibration isolators. The combined type rubber shock absorber is mainly used for vibration and buffering processing of electronic equipment or instruments. The combined type rubber shock absorber comprises a rubber anti-vibration pad, a rubber anti-vibration column, a metal limiting lining and a metal limiting gasket. According to the combined type rubber shock absorber, vibration and impact energy is translated into heat energy and deformation energy of rubber materials through the deformation of rubber parts by means of a combined shock absorber structure, the rubber anti-vibration pad is capable of reducing dynamic energy of an instrument with vibration to be isolated in the axial direction, the rubber anti-vibration column is capable of reducing dynamic energy of the instrument with the vibration to be isolated in the radial direction, the metal limiting lining and the metal limiting gasket are used in a matching mode, dynamic displacement of the shock absorber is limited due to the fact that the shock absorber is installed on a base plate of the instrument through bolts, and then an installation function and a limiting function are achieved.

The invention provides a spring steel used for an automobile suspension. the spring steel comprises the following ingredients in percentage by weight: 0.46-0.56% of C, 0.90-1.20% of Si, 0.80-1.20% of Mn, less than or equal to 0.020% of P, less than or equal to 0.020% of S, 0.70-1.0% of Cr, 0.90-1.50% of Ni, 0.60-0.90% of Mo, 0.50-0.80% of Cu, 0.02-0.07% of RE and the balance of Fe and inevitable impurities. The invention also provides a preparation method for the spring steel and a method for preparing a spring steel wire by using the spring steel. According to the invention, the chemical components of the spring steel are reasonably designed, and the smelting rolling and steel wire preparation method and the auxiliary material adding method and proportion are improved. Compared with the existing 55SiCr steel, the tensile strength of the spring steel disclosed by the invention is improved by 400MPa, the working stress is improved by 200MPa, and the fatigue life is improved by 200 thousand times.

A wind turbine blade has a load carrying structure including at least a first spar cap and an aerodynamic shell having an outer surface forming at least part of an exterior surface of the wind turbine blade and an inner surface. The aerodynamic shell includes a first recess at the inner surface of the blade shell with a first thickened part at a first side of the first recess and a second thickened part at a second side of the first recess. The first recess is tapered towards the first side of the recess and tapered towards the second side of the recess, and the first spar cap is arranged in the first recess of the aerodynamic shell. The first spar cap is tapered towards a first side of the spar cap and further is tapered towards a second side of the spar cap.

The invention belongs to the technical field of metal plastic processing, and aims at providing a superplastic forming/diffusion bonding forming method for a heat-resistant titanium alloy envelope with high material utilization ratio, high dimension control precision and high product performance. As a mould is adopted to control the appearance and dimension of a workpiece, the forming of a titanium alloy workpiece provided with a complex profile is completed, the production process of the heat-resistant envelope workpiece is shortened, and production cost is lowered; as the process of diffusion bonding followed by superplastic forming is adopted, the diffusion bonding is realized at the contact part of an inner envelope and an outer envelope, and the superplastic forming is realized at a separated part, the once-formed heat-resistant envelope with the complex profile and a hollow structure has the advantages of greatly improved structural integrity of a component, enhanced specific strength and specific stiffness of the component and increased welding rate of the diffusion bonding; the processed workpiece has the advantages of high dimension accuracy, high integral performance, light weight and the like; and the method disclosed by the invention has the advantages of shortened processing period, high material utilization ratio and lowered production cost.

A connection between a shaft and a coupling that preferably involves involute shaped splines is designed to reduce stress from torque applied to the shaft by a drive motor. To avoid stress concentration at the mouth of the coupling on startup, the shaft splines are made to taper from the shaft end down to the spline end. As a result, the initial contact with the coupling splines occurs within the coupling and removed from it mouth. The shaft is allowed to elastically twist in response to the applied torque as the contact area increases with shaft twisting and the contact line moves toward the mouth of the coupling. Stress concentration that formerly occurred at the coupling mouth is alleviated as some shaft elastic twist occurs without adding stress to the shaft splines until coupling contact is made.