160results about How to "Reduce stress concentration" patented technology

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.

The invention relates to a novel large-span tunnel excavating construction method, namely, an excavating method for jump-digging of a double-side wall guide pit combined arch part. After the construction of a double-side wall guide pit and side wall secondary lining is completed, a large-span tunnel arch soil body is excavated by blocks. During the excavation of the arch part of the tunnel, a middle guide pit of the arch part is excavated first, then two side guide pits of the arch part of the tunnel are excavated from the excavation surface of the middle guide pit to the two sides by departing from an opening, a primary supporting structure and the secondary lining of the arch part at the position are constructed, and then the excavation of a arch part structure of the tunnel with large span is completed gradually from inside to outside. The method considers the space effect of tunnel excavation and support, reduces stress concentration at the opening during the excavation of the arch part, and has remarkable effects in ensuring the stability of excavating surrounding rocks at the section of the tunnel with large span and controlling the settlement of a larger area caused by the tunnel excavation.

A valve seal assembly comprising a valve body having one or more peripheral integral seal retention grooves and one or more peripheral 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 preferably 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. In representative valve applications, serration height is preferably predetermined so that the cured elastomeric seal remains interdigitated with the serrations for greater than half of the predetermined serration height.

A fiber reinforced composite shaft bearing a metallic flanged end coupling (Fl) attached to the outside diameter through a concentric cylindrical torsional joint, comprising:

• • a) a cylindrical end region comprising a wedge shaped inner layer of fiber (Hp) composite;
  • b) a layer of outer helical composite plies (He) forming the shaft and extending over the wedge shaped inner layer, wherein the layer of outer helical plies has a tapered end part overlying wedge shaped inner layer to form the cylindrical end portion, wherein all helical plies of fibre layers are exposed on an outer surface; and
  • c) a metallic flanged end coupling attached to the outer surface of the cylindrical end region through a primary mechanically interface (Sp) which may be splined.

The joint may be strengthened by internally reinforcing the main shaft with an interference fit tubular plug (Pg) and protected from environmental degradation by inboard secondary adhesive bond (Ad).

A crank arm assembly (1) for a bicycle, comprising a crank arm (2) and an element (3,3a) for transferring torque from the crank arm (2) to a bicycle chain. The crank arm (2) and the element (3,3a) for transferring torque respectively comprise first (25) and second (34) front coupling means provided with respective matching profiles adapted to be coupled together to transfer torque from the crank arm (2) to the element (3,3a) for transferring torque. In particular, the first and second means for transferring torque comprise respective front toothings, preferably Hirth toothings. The crank arm assembly (1) is very light and is stronger in structure than crank arm assembly known.

A structural member of a motor vehicle, e.g., a “B” pillar, comprises a reinforcing member having an elongate core of ultra high strength steel and a casing of aluminum alloy, the casing having a constant section profile with a closed section cavity. The core is encased within the casing and the core and the casing bonded together by co-drawing the core and the casing through a die. The casing has a pair of spaced flanges which connect the reinforcing member to aluminum alloy pressings to form the structural member. The reinforcing member has considerable yield strength from the use of the ultra high strength steel in the core while the flanges, being of aluminum alloy, are readily joined by self-piercing rivets.

The invention discloses a water plugging device for petroleum pipeline maintenance. The water plugging device comprises a gasbag body and an exhaust pipe which is arranged at the end of the gasbag body. A plurality of grooves are formed in the outer circumferential wall of the middle of the gasbag body. Two elastic metal sheets are arranged in each groove in a spaced mode, and the bent part in each elastic metal sheet is fixedly provided with a reinforcing pad. When the gasbag body is inflated, the two elastic metal sheets in each groove deform to expand outwards in the radial direction of the gasbag body. Pressure in a gasbag is gradually increased, elastic deformation is made to occur to the elastic metal sheets, and the elastic metal sheets expand outwards in the radial direction of the gasbag body until the elastic metal sheets make contact with the inner wall of a pipeline. In the outward expansion process, elastic force generated by the deformation of the elastic metal sheets directly acts on scale on the inner wall of the pipeline and crushes the scale; the reinforcing pads fixed on the elastic metal sheets can weaken the impact strength between the scale and the elastic metal sheets, and the problem of stress concentration of the elastic metal sheets is solved.

The invention provides a hot and cold composite precision forging forming method applied to a great-modulus high-thickness straight-tooth cylindrical gear, and belongs to the technical field of metal plastic processing. The hot and cold composite precision forging forming method adopts the following steps of: baiting, upsetting after heating, hot die forging, annealing middle treatment, cold forward extrusion, center hole processing, annealing middle treatment and cold finishing, wherein the deformation quantity is reasonably distributed in three forming work procedures, certain tooth shapes are formed by the hot die forging work procedure, then, the cold forward extrusion process is adopted for further forming complete tooth shapes, and better surface quality is formed through radial and axial material flowing. Through the center hole processing work procedures, the stress concentration phenomenon during the closed cold finishing can be effectively reduced, and the service life of a mold is improved. Through the cold finishing work procedure, the tooth surface precision can be further improved, simultaneously, the defect of imperfect gear sectional surface filling generated in the cold extrusion work procedure is eliminated, and finally, the tooth-shaped surface of a forge element can directly reach gear hobbing and gear milling precision.

A method of welding together the parts of a boiler tube wall panel includes placing at least two parts of the panel to be welded together along a weld line and adjacent each other, and forming a weld along the weld line using a laser beam. The method can advantageously be used to weld boiler tube wall panels solely from one side of the panel. A GMAW process can also be used in combination with the laser beam to form the weld. Where the boiler tube wall panel includes a membrane between tubes, the membrane may be beveled.

The invention relates to a floating clamp. The floating clamp comprises a pressure box, wherein a plurality of jacking rods floating along an axial direction and used for jacking a specially-shaped part are assembled on at least one side surface except a reference surface, of the pressure box in a manner of guide sealing; one end of each jacking rod is located in the pressure box, and the other end of the jacking rod stretches out of the pressure box; working mediums used for pushing the jacking rods to axially float are arranged in the pressure box; and a space adjustment mechanism used for adjusting the size of a space where the working mediums are located is arranged on the pressure box. The space where the working mediums are located is reduced through the space adjustment mechanism, so that the working mediums push the jacking rods to axially float to jack the specially-shaped part; acting forces on the jacking rods are the same according to a hydraulic principle; the plurality of jacking rods form a plurality of equal-force fulcrums and the equal-force fulcrums act on different parts of the specially-shaped part, thus the acting forces acting on the specially-shaped part are effectively dispersed, the stress concentration of the specially-shaped part is reduced, and the deformation amount of the specially-shaped part is reduced.

An improvement is realized in mutual assembly strength between a swing bearing member and right and left longitudinal ribs, and welds are subjected to a reduced stress concentration. A backhoe comprises a swivel deck (10); a first longitudinal rib (19L) disposed on the swivel deck, the first longitudinal rib extending in a fore and aft direction, and having a front portion (19La) extending in a transverse direction; a second longitudinal rib (19R) disposed on said swivel deck, the second longitudinal rib extending in the fore and aft direction, and having a front end thereof connected to the front portion of the first longitudinal rib; and a swing bearing member (20) attached to a front surface of the front portion of the first longitudinal rib for supporting a ground working implement through a swing shaft.

The invention belongs to the technical field of metallurgy, and particularly relates to a control method for corner cracks of boron-containing steel plate slabs. The production procedure of a boron-containing steel plate sequentially comprises molten iron pre-treatment, converter smelting, secondary refining and plate slab continuous casting. In the continuous casting process, the ratio of the water amount of a crystallizer to the product of the casting blank section size and the pulling speed is controlled to be 0.02-0.03; meanwhile, the ratio of the wide face water amount/wide face size of the crystallizer to the narrow face water amount/narrow face size is controlled to be 1-1.5; a full-width coverage spraying manner is adopted as a secondary cooling manner, and the ratio of the total water amount of secondary cooling to the product of the casting blank section size and the pulling speed is controlled to be smaller than or equal to 0.0075; and according to the proportion of the water amount of each segment in the total water amount, the foot roller area accounts for 10%-15%, the zero segment area accounts for 35%-45%, the arc-shaped segment area accounts for 25%-35%, and the straightening area accounts for 5%-10%. According to the control method for the corner cracks of the boron-containing steel plate slabs, the straightening temperature rises, the corner cross cracks are eliminated, and the hot-rolled coiled plate edge portion surface warping defect occurrence rate caused by the corner cross cracks of the plate slabs is reduced to 0.2% or below from 3%.

The invention relates to a turbine rotor, of a low-pressure turbine of a turbine engine for example, comprising:

• • a first disk,
  • a second disk,
  • an annular seal ring comprising a radial flange on which is formed a scalloping defined by a plurality of scallops offering a locally increased surface, circularly distributed, said radial flange being attached to the rotor between the first disk and the second disk, and
  • a flow circuit including at least one lunule, suitable to place into fluid communication a radially inner cavity and a radially outer cavity, the lunule being formed on the radial flange of the seal ring, said lunule being provided on at least one scallop.

A multi-arc specially-shaped hole comprises a largest lengthwise outline a and a largest crosswise outline b, wherein the largest lengthwise outline a is smaller than or equal to the largest crosswise outline b. The geometric outline of the multi-arc specially-shaped hole is formed by eight arcs which are tangent smoothly. The eight arcs comprise a top portion main arc with radius R1, a bottom main arc with radius R2, two side main arcs with radius R3 which are symmetrical about the Y axis, two upper transition arcs with radius R4 which are symmetrical about the Y-axis and two lower transition arcs with radius R5 which are symmetrical about Y-axis. The multi-arc specially-shaped hole effectively solves the problems of stress concentration of hole structures such as bolt holes and pressure equalizing holes in an existing engine turbine disc and an existing compressor disc, and the service life of the structure can be prolonged.

A gas turbine engine component having shaped cooling holes that further enhances the cooling of a desired region while reducing stress levels in and around the cooling holes is disclosed. The cooling holes are generally elliptically-shaped and diffuse from a cooling fluid supply side to a discharge side and are oriented on the turbine component to reduce stress concentrations while directing the cooling fluid to a desired surface or location. The elliptical cooling holes have openings in the surface that have high points that are concentric and planar.

A rotor for a rotary electric machine includes a rotor core which is formed by crimping laminated steel plates so as to be opposed to a stator, and has pairs of magnet housing holes disposed in a V shape, and pairs of magnets housed in the magnet housing holes. The rotor core has a crimped portion formed in a q axis core portion positioned between the two magnet poles, which are adjacent to each other in a circumferential direction, a first flux barrier formed between the q axis core portion and the magnet, and a pair of second flux barriers which enlarges from an end positioned at a center side of the magnet pole of the magnet housing holes toward a central axis of the rotor core. The crimped portion is formed so that distances between the crimped portion and both the first and second flux barriers are equal.

The invention relates to a laser welding method for ultrasonic vibration along with welding, and belongs to the field of welding. According to the method, preheating is applied in the welding process,and ultrasonic vibration is applied to the front side of a weld joint at a certain distance behind a molten pool; a corresponding relation exists between the preheating temperature T and the distanced from the top end of an ultrasonic head to the welding position, wherein the relation expression is as follows: T is equal to 30d-40, the unit T is DEG C, and the unit d is mm; and the position, thepower and the force of ultrasonic application are adjusted according to the mechanical property of materials under the preheating temperature. According to the laser welding method, the welding residual stress can be effectively reduced, pores and cracks are reduced, and thus the fatigue performance of the weld joint is improved, and the welding deformation is reduced. By adopting the method, thetemperature gradient in the cooling process can be effectively reduced, and the residual stress is reduced; and the plasticity of the ultrasonic application area can be improved, and the ultrasonic effect is better. The ultrasonic impact can effectively reduce residual stress, refine crystal grains and reduce pores and cracks, and thus the fatigue performance of the weld joint is improved; and the metal plastic extension of the weld joint can effectively reduce the welding deformation.

The invention provides an upper bracket of a tower crane and the tower crane. The tower crane comprises crane arms (200) and a balanced arm (300), wherein the crane arms (200) comprise a first crane arm (210) and a second crane arm (220) which are impendent from each other and are arranged in parallel; the upper bracket comprises an upper bracket body, a crane arm connecting part (120) and a balanced arm connecting part (13), wherein the upper bracket body comprises a first side end and a second side end in opposite arrangement; the crane arm connecting part (120) is used for being connected with the crane arm (200), is arranged on the first side end of the first crane arm connecting part, and comprises a first crane arm connecting part connected with the first crane arm (210) and a second crane arm connecting part connected with the second crane arm (220); and the balanced arm connecting part (130) is used for being connected with a balanced arm (300), and is arranged on the second side end of the upper bracket body. According to the invention, the stress state of the upper bracket can be improved, and the stress concentration phenomenon is released.

The invention discloses a riveting pressing forming device for a cover plate of an automobile clutch booster. The riveting pressing forming device for the cover plate of the automobile clutch booster comprises a base plate, wherein a positioning base is arranged on the base plate; a positioning cylinder is arranged rightly opposite to the positioning base; a pressing block is arranged on the positioning cylinder; a riveting cylinder is arranged on the base plate; the output end of the riveting cylinder is connected with the riveting assembly; a pressing cylinder is arranged below the base plate of the corresponding riveting cylinder; the output end of the pressing cylinder is connected with the pressing assembly; the riveting assembly comprises an installing base and a hinging pressing head; the installing base is fixedly installed on the base plate; the hinging pressing head are hinged with the installing base and the output end of the riveting cylinder; an installing plate is fixedly arranged on the base plate; the end part of the riveting cylinder is hinged with the installing plate; the pressing assembly comprises a pressing plate; the pressing plate is fixedly connected with the output end of the pressing cylinder vertically; and the pressing cylinder is fixed below the base plate through a fixing plate. The riveting pressing forming device for the cover plate of the automobile clutch booster has good riveting quality; in the riveting process, the damage to an electrophoretic paint layer at a cover plate forming position is avoided; the consistency of products is good; and the production efficiency is high.

A stack chip package structure is provided. One principal feature of the structure is the formation of a few peripheral surfaces (e.g. ladder or lead-angle surfaces) at the bottom peripheral sections of a stack structure. When the stack structure is attached to a surface of a die through an adhesive layer, the thickness of the adhesive layer under a peripheral section of the stack structure is greater than a central region. Therefore, as the chip package is subjected to a thermal stress test, the adhesive layer under the peripheral sections of the stack structure is able to provide some buffering against thermal stress so that the stress concentration around the stack structure is reduced. Consequently, damages of the die surface due to stress are prevented and the average working life of the chip package is extended.

The invention relates to a truck-frame side beam and crossbeam connecting joint totally-butted structure which is characterized in that the totally-butted connection of a side beam and a crossbeam is realized through a connecting seat, a plate-plate butt-joint structure is formed by a side beam connecting end and a side beam inner vertical plate, and a pipe-pipe butt-joint structure is formed by a crossbeam connecting end and the crossbeam. A assembly-welding process method comprises the assembly welding of the connecting seat and a crossbeam pipe, the assembly welding of crossbeam composition, the assembly welding of the connecting seat and the side beam inner vertical plate as well as a guide pole, the assembly welding of a side beam reinforcing baffle plate and an upper cover plate and the assembly welding of a whole frame. ,The invention realizes the totally-butted connection of the side beam and the crossbeam of the frame through a new connecting joint of the side beam and the crossbeam, breaks through a traditional process of forming the frame after both the side beam and the crossbeam become finished products, and has the advantage superior to the angle connecting structure or the angle-connecting and butting combined structure of a traditional structure and greatly superior to an overlapping structure. A welding joint has the minimum stress concentration, the minimum welding filling quantity and the minimum welding residual stress and deformation; the structural shape is continuous and attractive; and the bearing capacity and the anti-fatigue capacity are strong.

The invention relates to a method for assembling a rubber dam in a slope-shaped river channel. The method solves the long-existing problem of water leaking at the design height of the conventional slope-shaped rubber dam at present, improves unreasonable stress of dam bags and improves appearance of dam shapes. The method comprises the following steps of: 1) opening an upstream anchoring tank, a downstream anchoring tank and a top anchoring tank; 2) installing the bag edges of a downstream dam of the dam bag of the rubber dam; 3) installing the bag edges of an upstream dam of the dam bag of the rubber dam; 4) sealing both ends of the dam bag of the rubber dam, flatly overlaying ports on both ends of the dam bag, and placing the ports into the top anchoring tank; and 5) injecting water to the dam bag of the rubber dam from a water injection port to install the rubber dam. The method changes the structural form in the river channel after the rubber dam is installed, the slope part of the dam bag of the rubber dam extends downstream, cockles are formed at the positions of the horizontal section of the dam bottom and the slope section after the dam bag is aerated, and the cockles exist in downstream instead of the top of the dam bag in the conventional structure (the cockles are formed in the vertical direction).

The invention discloses a gas testing system suitable for tests of a low-thrust engine. The gas testing system comprises a fixed module and a movable module, the fixed module comprises manual stop valves, filters, pressure reducers and pressure meters, and the movable module comprises sonic nozzles, electromagnetic valves, one-way valves and pressure sensors. The gas testing system is subjected to modularized designing, and corresponding hoses are adopted for connection, so that the requirement that a valve is closest to the engine is guaranteed to be met, stress concentration in the process when hard stainless steel pipes are adopted for connection is reduced, and unnecessary modifying operation on a connecting pipeline of the engine during multiple tests is reduced.

The invention relates to the field of tool storage, in particular to a drawer type tool cabinet. The drawer type tool cabinet has the advantages that support mechanisms used for supporting drawers after the drawers are completely drawn out are arranged between a cabinet body and the drawers; the support mechanisms act and further support the drawers after the drawers are completely drawn out, so that stress concentrated at joints of the drawers and the cabinet body after the drawers are drawn out can be reduced, the drawers and the cabinet body cannot be damaged easily, and the service life of the drawer type tool cabinet can be prolonged.

The invention provides a frame. The frame comprises a rear frame section (13), wherein the end part of the rear frame section (13) is connected with a fixed supporting leg (11); the fixed supporting leg (11) comprises an outer vertical plate (111), a middle vertical plate (113) and an inner vertical plate (113) which are arranged in parallel; grooves (114) are formed on the outer vertical plate (111), the middle vertical plate (113) and the inner vertical plate (113); vertical plate cover boards (115) are arranged among the grooves (114); the rear frame section (13) is embedded into the grooves (114); the top ends of the grooves (114) are level with an upper cover board (134) of the rear frame section (13); and a lower cover board of the rear frame section (13) is in butt joint with the vertical plate cover boards (115). The frame has the advantages of high carrying capacity and high stability. In addition, the invention also provides a crane with the frame.

A capacitor (1) using a flexible substrate (2) includes a hole portion (6a) formed in a dielectric (6) to connect an upper electrode (7) to an external leader electrode (4). At least part of the hole portion ( 6a) extends from its lower end to upper end at an inclination between 0.1 and 20 DEG with respect to a top surface of the external leader electrode (4). Then, an upper end corner of an inclined wall surface of the upper electrode (7), which inclines along the hole portion (6a) of the dielectric (6), has a downward inclination between 0.1 and 20 DEG . A lower end corner of the inclined wall surface of the upper electrode (7), which inclines along the hole portion of the dielectric (6), has an upward inclination between 0.1 and 20 DEG . As a result, stress concentration on the corners of the upper electrode (7) is drastically reduced to prevent the upper electrode (7) from cracking.

The invention aims to provide a constant volume bomb window with a glass window protection structure to solve the problems of uneven stress and bumping damage to a traditional volume bomb glass window. When the constant volume bomb window is impacted, impact force can be effectively buffered, and volume bomb sealing is ensured. The constant volume bomb window comprises a constant volume bomb body, a circular glass window, an O-shaped sealing ring, a first metal washer, a second metal washer, a pressing plate, bolts and nuts, the first metal washer and the second metal washer are the same in structure and positioned on two sides of the glass window respectively, annular bosses are arranged at the edges of the first metal washer and the second metal washer and face one side of the glass window, bolt holes are formed in the periphery of the pressing plate, one end of the bolt is fixed to the constant volume bomb body, and the other end of the bolt penetrates the bolt hole of the pressing plate and is connected with the nut, so that the O-shaped sealing ring, the first metal washer, the glass window, the second metal washer are fixedly compressed between the constant volume bomb body and the pressing plate.

A cushion plate is provided, for example, between a piston of a hydraulic servo and an adjacent friction plate in a frictional engagement element of an automatic transmission. The cushion plate is deflected by a pressing force of the piston to absorb an engagement shock. The cushion plate includes a main body portion formed into a belleville-spring shape, and a plurality of pawls that extend from the outer periphery of the main body for spline engagement with a member that is splined to, for example, the friction plate. A side wall of each pawl is formed with a curved recess extending circumferentially of the cushion plate and located adjacent the juncture (base) of the pawl at the outer periphery of the main body.

The invention discloses a three-dimensional stranding, untwisting and cabling machine for a large-length great-section high-voltage photoelectric composite submarine cable, which comprises a stranding rotating plate and a mechanical untwisting device of a supporting plate on the stranding rotating plate, the rotation of the stranding rotating plate is transmitted to the supporting plate through gears, and the supporting plate rotates by means of a mechanical swing bearing. The cabling machine also comprises a variable frequency motor, a PLC (Programmable Logic Controller) control system and an electrical untwisting device of an untwisting system, wherein the PLC control system controls the variable frequency motor to drive the supporting plate to rotate, the untwisting system is arranged above the supporting plate and detects the cable, the detection data is fed back to the PLC control system, the PLC control system compares the detection data with the set untwisting rate, the actual untwisting rate is obtained through comparison, and the deviation value is calculation so as to perform closed loop regulation to the variable frequency motor. The sufficient untwisting of each supporting plate untwisting device before cabling is realized through mechanical untwisting and electrical untwisting.

The invention discloses an assembled semi-rigid wood structure joint. The assembled semi-rigid wood structure joint comprises a component I, a component II, a bending connecting piece, a shear connecting piece, an assembling piece, a steel cushion plate and connecting bolts, wherein the component I is a wood component, the bending connecting piece and the shear connecting piece are fixedly arranged at the end portion of the component I by adopting a steel plate implanting manner, the bending connecting piece and the shear connecting piece are T-shaped steel, the surfaces of the parts thereof implanted into the wood member are vulcanized with rubber layers, the end portion of the component I is pre-grooved at a steel plate implanting position, and the bending connecting piece and the shear connecting piece are connected through the connecting bolts and the assembling piece; the end portion of the component I can be connected with the side surfaces and the end portion of the component II or can be connected with a concrete foundation. The joint disclosed by the invention has higher bending capacity, joint rigidity, energy dissipation capacity and ductility performance. The joint not only can guarantee the structure stability under small earthquakes, but also can realize the prevention of large deformation of the structure under large earthquakes and control structure damages, and realizes ideal effects of high bearing capacity, high energy dissipation capacity and high ductility.