73results about How to "Increase shear area" patented technology

A speed limiting mechanisms for turbine-driven fluid distribution apparatus usable with compressible fluid such as compressed air and incompressible fluid such as water. Dynamic viscous damping of the turbine output power train is used to control the rotational speed of the turbine. This prevents overspeeding when the turbine is air driven, and also when the turbine is water driven, under abnormal conditions such as blockage of a bypass area designed to control the turbine speed by limiting flow to the turbine. The same mechanism can be used to impose a lower rotational speed in the turbine during normal operation in conjunction with a turbine optimized for lower speed operation to reduce the required gear reduction in the power train.

A recess-projection fitting structure includes projections extending in an axial direction on an outer diameter surface of a shaft section of an outer joint member or an inner diameter surface of a hole of a hub wheel, press-fitting the projections in another of the outer diameter surface and the inner diameter surface along the axial direction, and forming recesses brought into contact and fitted with the projections by press fitting in the other of the outer diameter surface and the inner diameter surface, the projections and the recesses being held in contact with each other through intermediation. An outer member is fitted in a hole of a knuckle of a vehicle. Annular grooves are formed respectively in an outer peripheral surface of the outer member and an inner peripheral surface of the hole of the knuckle, and a snap ring is engaged with both the annular grooves.

A valve is used for continuous regulating and / or cutting-off magnetic rheological fluid. It has an annular drag channel and a circular drag channel. The external magnetic path is formed by a cylinder, a magnet-conducting disc and the said both channels. The core of the said valve is used as the internal magnetic path. The gap of the annular drag channel depends on precise transition fit of the cylinder and the positioning block, which is connected with the magnet-conducting disc by a pin. The thickness of the circular drag channel depends on cushions on a connecting pin of the said core. Neither pin nor cushions are of magnet-conducting material. A strong resistance of flow can be generated by a little electric current. The valve has a larger range of control, little energy consumption, small size and is light and simple, easy to mass production.

The invention discloses a domestic vertical type noodle maker which comprises a base, a stirring cup, a stirring rod, a dough extrusion cylinder, a screw rod, a mold head and a control unit, wherein the base is provided with motors; the stirring cup is connected with the base; the stirring rod comprises a rod body as well as upper stirring teeth and lower stirring teeth which are arranged on the rod body; a dough inlet is formed in the communicating part of the stirring cup and the dough extrusion cylinder; a dough cutting rod is arranged on the inner wall of the stirring cup; the dough cutting rod is positioned between the upper stirring teeth and the lower stirring teeth; the stirring rod rotates to drive the upper stirring teeth and the lower stirring teeth to rotate and mix and stir flour with water to make dough; the dough cutting rod cooperates with the upper stirring teeth and the lower stirring teeth to cut off or tear and deform the dough into dough pieces which are smaller than the dough inlet; when the upper stirring teeth and / or the lower stirring teeth rotate to the dough cutting rod, the projects of the dough cutting rod and the upper stirring teeth and / or the lower stirring teeth in the horizontal direction are at least partially overlapped. By adopting the mode, the effects of no residue, high possibility of dough feeding and high processing efficiency can be achieved.

The invention discloses a traveling chassis of a submarine mining vehicle. The traveling chassis comprises a vehicle body bracket, a crawler bracket and two traveling crawlers, wherein the two traveling crawlers are arranged at the two sides of the crawler bracket; a plurality of long toothed plates are arranged on the traveling crawlers at intervals; a plurality of short toothed plates are arranged between the adjacent long toothed plates at intervals; each long toothed plate is higher than the corresponding short toothed plate; each long toothed plate is vertical to the grounding surface of the traveling crawler, and an acute angle is formed between each long toothed plate and the traveling direction of the corresponding traveling crawler. The traveling chassis of the submarine mining vehicle has the advantages that the pushing property is good, the slippage rate is low, the energy consumption is low, the traveling chassis is suitable for deep-sea thin and soft bottom environments, and the like.

A bearing device for a wheel, in which circumferential play is minimized, a hub ring and an outer joint member of a constant velocity universal joint can be connected to each other with good workability, and the hub ring and the outer joint member are adapted to be separable from each other to provide the device with good maintainability. In the bearing device, the outer joint member of the constant velocity universal joint (3) has a shaft section (12) fitted into a hole (22) of the hub ring (1), and the hub ring (1) and the shaft section (12) are separably joined to each other by a ridge-groove fit structure (M). Axially extending ridges are formed on either of the outer diameter surface of the shaft section of the outer joint member and the inner diameter surface of the hole of the hub ring. The ridges are axially press-fitted into the other. As a result, grooves fitting on the ridges are formed in the other to form the ridge-groove fit structure in which the entire areas of fit and contact portions of the ridges and grooves are in intimate contact with each other. The ridge-groove fit structure (M) allows separation between the hub and the outer joint member by axially applied pulling force.

Provided are a bearing device for a wheel, in which circumferential play is reduced, which provides excellent workability in connection between a hub ring and an outer joint member of a constant velocity universal joint, in which fitting between the hub ring and the outer joint member of the constant velocity universal joint is stable, and which has excellent strength, and an axle module using the bearing device. An axially extending projection is formed on either of the outer diameter surface of a shaft section of the outer joint member and the inner diameter surface of a hole of the hub ring. The projection is press-fitted to the other in the axial direction to form a recess in the other by the press-fitting. By this, a recess / projection fit structure is formed, in which the entire regions of those portions of the projection and the recess at which they are fitted to each other are in intimate contact with each other. The hardness of at least that portion of the projection at which the press-fit starts is higher than that of a portion where the recess is formed. The difference in hardness in HRC is 20 or more.

A bearing device for a wheel, in which circumferential play is suppressed, which facilitates connection between a hub ring and an outer coupling member, in which a reduction in NVH characteristics due to play at a joint between the hub ring and the constant velocity universal joint and by play between a bearing outer member and a knuckle is prevented, and which performs highly accurate transmission of rotational torque. The bearing device has a groove-ridge fitting structure (M) by which the hub ring (1) and a shaft section (12) of the outer coupling member of the constant velocity universal joint (3) are integrated together, and the shaft section (12) is fitted in a hole (22) of the hub ring (1). In the groove-ridge fitting structure (M), ridges (35) on the outer diameter surface of the shaft section (12) and grooves (36) in the inner diameter surface (37) of the hub ring (1) are fitted to each other in a fitting contact portion (38), and the ridges (35) and the grooves (36) are in intimate contact with each other in the entire fitting contact portion (38).

The invention discloses a mixed flow magnetorheological valve which comprises a left end cover, a valve spool, a valve body, a guide disk, a magnetic disk, a positioning disk, a gasket, a coil, a sealing ring, a screw and a right end cover. A flow passage between the magnetic disk and the valve body forms an axial damping gap, and flow passages among the magnetic disk, the valve body and the valve spool form radial damping gaps. When current is inputted into the coil, magnetic lines vertically penetrate the axial and radial damping gaps, and the magnetic induction intensity is generated under the action of a magnetic field. The pressure difference in the axial and radial damping gaps can be controlled by adjusting the strength of the current. By the aid of the structure, the magnetorheological valve has enough pressure difference, clogging of the valve is avoided, the performance of the valve is more stable, the adjustable range of the pressure difference is wider, and the magnetorheological valve is accurate in damping gap positioning, compact in structure, small in size, convenient to assemble, particularly suitable for serving as a damper bypass valve and applied to damping systems of industries such as a railway and a traffic.

Provided is a bearing device for a wheel that can realize prevention of a backlash in a circumferential direction and is excellent in workability of connection of a hub wheel and an outer joint member of a constant velocity universal joint. Further, provided is a bearing device for a wheel that can prevent deterioration in NVH characteristics, which is caused by the backlash occurring in a joint section between the hub wheel and the constant velocity universal joint or between an outer member and a knuckle, and can perform rotation torque transmission with high accuracy. The bearing device includes a recess-projection fitting structure (M) in which the hub wheel (1) and a shaft section (12), which is fitted in a hole (22) of the hub wheel (1) of the outer joint member of the constant velocity universal joint (3) are unitized together. In the recess-projection fitting structure (M), entire fitting regions among projections (35) on the outer surface of the shaft section (12) of the outer joint member and recesses (36), which fit on the projections, are brought into intimate contact with each other.

The invention discloses a new ball-type single-shear experimental device for anchor rods and anchor cables, and the device comprises upper and lower shear devices, left and right fixed cylinders, front and rear fixed guide grooves, and samples, wherein the shear devices comprise a loading flat plate, a fixed support plate, a vertical guide rail plate and a hollow shear ball table; the fixed cylinders comprise a long hollow cylinder and a hollow ball table coupled with one side of the hollow shear ball table; the fixed guide grooves comprise a concave steel block with three bolt holes; the samples comprise a left and right symmetric long cylinder, a middle spherical protrusion, and anchor rods or anchor cables built in the centers of the long cylinder and the middle spherical protrusion. The new ball-type single-shear experimental device has a simple structure, is easy to operate and convenient to control variables by loading through a common uniaxial compression tester, can achieve theshearing at any space angle with the shearing surface, overcomes the defect that the traditional single-shear experiment for anchor rods cannot change the installation angle, and increases the sheararea at the same time, thereby not only adapting to the conditions of large shear displacement, but also considering the impact of the shear surface on shear engineering.

The invention discloses an integrated thermal insulation structure of an existing building exterior wall. The integrated thermal insulation structure comprises an existing wall body, a thermal insulation board and a surface layer. The inner side of the thermal insulation board adheres to the outer side of the existing wall body. The outer side of the thermal insulation board is connected with thesurface layer. A gridded mesh reinforcement is longitudinally arranged in the surface layer. Communicating round holes are reserved in the existing wall body, the thermal insulation board and the surface layer. Connecting pipes are horizontally laid inside the round holes. Small seams are evenly formed in the end faces, laid in the existing wall body, of the connecting pipes. Pipe cushions are arranged at the ends, where the small seams are formed, of the connecting pipes. The ends, laid in the surface layer, of the connecting pipes penetrate through the mesh reinforcement and are longitudinally provided with fixing reinforcements. The invention also provides a construction method of the integrated thermal insulation structure of the existing building exterior wall. The method comprises the following procedures of drilling holes, installing the connecting pipes and the pipe cushions, expanding the connecting pipes, grouting, pasting the thermal insulation board and binding the mesh reinforcement, and painting and maintaining the surface layer. The integrated thermal insulation structure of the existing building exterior wall realizes the integration of existing building exterior wall thermal insulation and the structure, so that the same serviceable life of the exterior wall external thermal insulation and the structure is ensured.

The invention discloses a detachable steel-concrete composite beam adopting conical nut and bolt connectors. The detachable steel-concrete composite beam comprises the bolt shear force connectors, a steel beam and precast concrete slabs. According to the detachable steel-concrete composite beam, the prefabricating rate of components is increased, site construction wet operation can be reduced, andthus pollution caused by construction flying dust to the atmospheric environment is avoided; shear surface areas of the shear force connectors at the steel-concrete interface can be effectively enlarged through conical hexagonal locking nuts, and the risk that roots of the shear force connectors are shorn off is lowered; the bonding effect between grout and the precast concrete slabs can be enhanced through corrugated pipes; dismantling and repairing are convenient; and the components can be recycled, generation of building waste is reduced to a certain extent, and resources are saved.

The invention discloses a self-adaptive buckling-preventing support which comprises a sealing cylinder cavity. The top face of the sealing cylinder cavity is open. An upper sealing end cylinder is installed on the top face. A hole matched with a piston rod in radial size is formed in the center of the upper sealing end cylinder. The piston rod penetrates through the center hole of the upper sealing end cylinder and is partially installed in the sealing cylinder cavity. An energy consumption partition plate is installed on the piston rod. The energy consumption partition plate is transversely arranged on the piston rod in a sleeving manner, and moves in the sealing cylinder cavity along with moving of the piston rod. The sealing cylinder cavity is filled with damping liquid. Springs are further installed in the sealing cylinder cavity. The self-adaptive buckling-preventing support has the beneficial effects that the energy consumption partition plate can move along with the piston, an upper oil storing box cylinder, a lower oil storing box limiting cylinder and the energy consumption partition plate arranged internally have shearing and extruding effects on the damping liquid, the first-level spring and the second-level spring deform in an extruding manner to generate restoring force, after external force disappears, the piston rod is driven to carry out self restoring, and selfperformance can be adjusted automatically according to the change of the affected external excitation effect.

The invention discloses a temperature-dependent phase alternation surface shear plasticization method. According to the method, a surface shear grinding device is formed by connecting an inner sleeve with annular comb teeth and an outer sleeve with annular comb teeth in a butt-joint manner, and in combination with the fast heating and fast refrigeration of materials, materials with different melting points or softening points in at least two components are treated through a mixing plasticization method; the materials with the low melting point or the low softening point in the components are always in the molten state in the plasticization process, the materials with the high melting point or the high softening point are subjected to fast temperature control, the phase state of the materials with the high melting point or the high softening point is alternately changed among the solid state, the semi-solid state and the molten state, in cooperation with the mechanical grinding function of the full plane shear, solid particles and melt fragments of the materials are refined, homogenized, micro-fibered and plasticized under the function of repeatedly and alternately conducting fracture, fragmentation, friction and the like, the plasticization effect can be improved greatly, and the mixed materials are dispersed to the great extent.

The invention discloses a magnetorheological damper with a complex liquid flow passage structure. The magnetorheological damper is mainly composed of a piston rod, damper end covers, a damper cylinderbody, a magnet exciting coil, a piston head left end cover, a piston head right end cover, a piston head and the like. A complex liquid flow passage is formed by gaps defined by the piston head leftend cover, the piston head right end cover and the piston head in an enclosed mode, wherein four effective damping gaps are composed of the axial ring type damping gap I, the axial ring type damping gap V, the radial disc type damping gap II and the radial disc type damping gap III. When the magnet exciting coil is powered on, a definite-size magnetic field is generated in the four effective damping gaps, so that the shearing area and the effective damping length of the damping passage are increased. By the adoption of the complex flowing type liquid flow passage structure, the output dampingforce and the damping force adjustable range of the damper are further improved on the premise of not changing the radial and axial sizes of the damper, and the damper is particularly suitable for vibration isolation systems in the industries of railway, traffic and the like.

The invention discloses a drying device, a garbage treatment device and a material machining method. The drying device comprises a bin body with a feed port and a discharge port and further comprisestwo rotating shafts, a drying device and a heating device, wherein the two rotating shafts are arranged in the bin body in parallel, each rotating shaft is provided with a spiral conveying blade, thedistance between the two rotating shafts is larger than the linear distance between the edge of any spiral conveying blade and the rotating shaft where the spiral conveying blade is located and smaller than the sum of the linear distances between the two spiral conveying blades and the respective rotating shafts where the spiral conveying blades are located, the driving device drives the two rotating shafts to rotate around own axes, the rotating directions of the two rotating shafts are opposite, and the heating device is used for heating the interior of the bin body. According to the scheme,the two mutually-engaged spiral conveying blades are adopted for synchronous conveying, the driving force during conveying is effectively increased, the stable conveying requirement of crushed solidwaste with certain humidity and viscosity can be met, and the drying stability can be guaranteed beneficially.

The invention provides a spring damping synergistic vibration / shock isolating and reducing device. The spring damping synergistic vibration / shock isolating and reducing device includes an upper steelplate, a lower steel plate, a spiral spring clamped and installed between the steel plates and a barbed-type viscoelastic cylinder damper placed in the spiral spring. The barbed-type viscoelastic cylindrical damper includes an upper inner sleeve, a lower inner sleeve, a lower outer sleeve, a viscoelastic damping layer and a position controlling plate, wherein the upper inner sleeve is fixed to theupper steel plate, the lower inner sleeve and the lower outer sleeve are installed in a sleeved mode coaxially, the viscoelastic damping layer is arranged between the lower inner sleeve and the lowerouter sleeve in a clamped mode, and the position controlling plate is hooped in the lower inner sleeve in the clamped mode along the section. The outer diameter of the upper inner sleeve is less thanthe inner diameter of the lower inner sleeve, and the inner periphery of the bottom end of the upper inner sleeve is provided with upwards-arranged barbs extending upwards obliquely. The outer periphery of the top end of the lower inner sleeve is provided with downwards-arranged barbs extending downwards obliquely. After the upper inner sleeve slides to the lower inner sleeve, the upwards-arranged barbs and the downwards-arranged barbs are engaged and locked, the bottom surfaces of the inner sleeves abut against the position controlling plate. According to the spring damping synergistic vibration / shock isolating and reducing device, a complete spring damping synergistic working system suitable for vertical excitation bearing of a vertical load bearing structure is designed, the problem oflow damping of the system is solved, and excellent vibration isolating and reducing effects are played.

The invention discloses an efficient energy-consumption self-resetting anti-buckling support. The key points of the technical scheme are that the efficient energy-consumption self-resetting anti-buckling support includes a piston rod, an upper sealing cylinder, a sealing cylinder body and a lower sealing connection part; the piston rod penetrates through the upper sealing cylinder, the sealing cylinder body is filled with damping material, the piston rod sleeves a lower oil storage tank limiting energy-consumption end cylinder and an upper oil storage tank sealing energy-consumption end plate,the end, oriented towards the lower sealing connection part, of the piston rod is provided with a fixing energy-consumption end plate, the lateral wall, away from the lower sealing connection part, of the piston rod is provided with an extruding part which penetrates through the upper sealing cylinder and abuts against the upper oil storage tank sealing energy-consumption end plate, a damping reset mechanism is arranged between the upper oil storage tank sealing energy-consumption end plate and the lower oil storage tank limiting energy-consumption end cylinder. The efficient energy-consumption self-resetting anti-buckling support has a self- reset ability and stable and reliable efficient energy-consumption ability.

The invention discloses a safe landing device adopting permanent magnets variable in magnetic field and magnetorheological fluids variable in area. The safe landing device is characterized by comprising a base, a worm, a worm wheel, winding drums and a deceleration descending device, the worm wheel and the worm are meshed together, the right end of the worm is connected with the winding drums, thedeceleration descending device is located on one side of the worm, and comprises a first shell, a second shell, a screw, a rotating disc and a moving disc, the two ends of the screw are connected with the first shell and the second shell correspondingly, moreover, the screw is connected with the worm wheel, the rotating disc is close to the second shell, the moving disc and the screw are meshed together, a sealing ring is arranged between the rotating disc and the moving disc, the portion among the first shell, the second shell, the rotating disc, the moving disc and the sealing ring is filled with the magnetorheological fluids, and one permanent magnet is arranged on each of the sides, deviating from each other, of the rotating disc and the moving disc. The safe landing device has the advantages that the structure is simple, the landing distance is large, moreover, adjustment can be performed according to actual conditions, the adaptability is higher, the comfort is good, moreover, the safety is higher, and the stability is better.

The invention provides a cross tenon type vertical bolt connecting joint of a fabricated concrete frame structure. The cross tenon type vertical bolt connecting joint comprises an upper concrete column and a lower concrete column; a cross tenon is arranged at the bottom of the upper concrete column and is in matched inserted connection with a cross mortise formed in the top of the lower concrete column; bolt connecting grooves are formed in the four corners of the upper concrete column and above the cross tenon. Bolts vertically penetrate the four corners of the bottom of the upper concrete column from the four corners of the lower concrete column, stretch into the bolt connecting grooves and are fastened through nuts; the vertical bearing force of the upper concrete column and the lower concrete column is transmitted through cross mortise and tenon joint, and the force transmission section is the same as the section area of the concrete columns; meanwhile, integral stirrups are arranged at the joint so as to enhance the axial bearing force, the core position of the joint is in a three-direction pressed state under the axial pressure state exceeding the bearing force, ductility damage is generated, and the vertical bearing force is guaranteed; and bolt connection only bears the vertical loads of the columns, bears part of axial force in the normal state, bears pull force under the earthquake action and is clear in stress. The cross tenon type vertical bolt connecting joint has the beneficial effects of being simple in structure, convenient to construct, efficient in assembly and high in shear bearing capacity.

A bearing device for a wheel, in which circumferential play is suppressed and which has excellent workability of connection between a hub ring and an outer joint member of a constant velocity universal joint. In the bearing device for a wheel, a stem shaft (12), which is fitted in a hole (22) of the hub ring (1), of the outer joint member of the constant velocity universal joint (3) is integrated with a hub ring (1) via a depression / projection fitting structure (M). In the depression / projection fitting structure (M), the entire part of a portion (38) of a projection (35), which portion is to be fitted to a depression, is in intimate contact with a corresponding depression section (36).

The invention discloses a crushing and solid-liquid separation device and a garbage treatment device. The crushing and solid-liquid separation device comprises a box, wherein the box is provided witha feeding port, a discharging port located in the upper end of the box and a liquid discharging port located in the lower end of the box, and a spiral conveying shaft is longitudinally arranged in thebox and connected with a driving device for driving the spiral conveying shaft to rotate; and spiral blades of the spiral conveying shaft are located in a solid-liquid separation barrel, the solid-liquid separation barrel is located in the box body and communicated with the feeding port, the discharging port and the liquid discharging port, and cutters which form a cutter forming shearing force with the spiral blades on the spiral conveying shaft is arranged on the inner wall of the solid-liquid separation barrel. According to the scheme, solid moves upwards, and liquid moves downwards, so that solid-liquid separation is achieved; and the spiral blades and the cutters are matched to generate shearing force, conveying and smashing are synchronous, the whole equipment can achieve garbage smashing and solid-liquid separation only through one power source, and the equipment is high in integration degree, small in size, convenient to machine and low in equipment cost and use cost, and facilitates application to occasions such as families, dining halls and restaurants.

The invention provides a hair trimmer, and relates to the field of hair trimmers. The hair trimmer comprises a main machine shell, a tool bit assembly and a driving motor. The tool bit assembly comprises a first movable blade and a second movable blade which are stacked in a sliding mode. An output shaft of the driving motor is provided with a first incomplete gear structure and a second incomplete gear structure, the first movable blade is provided with two first rack structures, the two first rack structures are distributed on the two sides of the first incomplete gear structure, and the two first rack structures are engaged and matched with tooth parts of the first incomplete gear structure correspondingly; the first movable blade is driven to intermittently reciprocate; the tooth portion of the first incomplete gear structure and the tooth portion of the second incomplete gear structure are distributed in a staggered mode in the circumferential direction, so that the cutter teeth of the first movable blade and the cutter teeth of the second movable blade move in a staggered mode to cut hair. The transmission design is similar to a gear and rack transmission mode, the moving blades are high in motion linearity and large in cutting stroke, the shearing area can be remarkably increased by combining the double moving blades, and the shearing efficiency is higher.

A sawtooth interface constraint damping track bed applied to vibration and noise reduction of a subway comprises a concrete base layer, a constraint layer and a middle layer located between the layers, wherein the concrete base layer, the constraint layer and the middle layer are shaped like sawteeth, and sawteeth of the two adjacent layers are matched; the middle layer is a multi-layer constraint damping layer, and the middle layer is composed of a damping material layer I, a hard interlayer and a damping material layer II which are successively arranged; the damping material layer I is located on the side close to the concrete base layer, and the damping material layer II is located on the side close to the constraint layer; and the damping material layer is made of a polyurethane-urea damping material. According to the invention, a track bed constraint interface is designed into a sawtooth shape. Hence, on one side, hidden dangers in relative slippage of the track bed are avoided; and on the other side, the specific area of the structure is increased, namely the shear area is increased, so that non-linear characteristics of the damping material could be manifested better. Shear energy consumption of the damping material is applied, and the loss factor increases by 0.3-0.5, so that vibration reduction effects are also improved obviously.

The invention provides a vertical coordinated vibration isolation or reduction device and an application method thereof. The device comprises an upper support and a lower steel plate which are horizontally arranged, a spiral spring which is vertically clamped between the upper support and the lower steel plate and a combined viscous-elastic cylinder damper which is coaxially installed in the spiral spring; the upper support comprises a circumferential side wing plate and a support top board and a support base board which are respectively fixed at an upper end and a lower end of the side wing plate; the combined viscous-elastic cylinder damper comprises an inner sleeve and an outer sleeve which are coaxially arranged and a viscous-elastic damping layer which is between the inner sleeve andthe outer sleeve by high temperature vulcanization; the combined viscous-elastic cylinder damper passes through and is fixed on the support base plate through a bolt at the top of the inner sleeve; abottom of the outer sleeve is fixed on the lower steel plate. Based on the spring vibration isolation system, the invention adopts a viscous-elastic damping material to increase the energy consumptionability of the device system with large damping ratio, stable performance, good sealing property and suitable for engineering application, and designs a complete spring damping cooperative working system suitable for vertical load-bearing structure to withstand vertical excitation, which plays an excellent role in vibration isolation and vibration reduction.

The invention relates to a surface hole structure in a dam body of a high concrete dam. The surface hole structure in the dam body of the high concrete dam is simple, stable, firm, high in applicability, and simple and convenient to construct and can achieve the purposes of reducing the impact of outflowing water jet of a surface hole on an energy dissipation area at the back of the dam, ensuring the construction safety and decreasing the workload of energy dissipation and impact treatment at a downstream. According to the technical scheme, the dam body of the high concrete dam comprises a surface hole capable of releasing flood water. The surface hole structure in the dam body of the high concrete dam is characterized in that a wedge-shaped body which can contract to the middle is arranged close to each of the two sidewalls and an outlet of a flowing channel of the surface hole; a hollow part with the length of L1 is arranged at the outlet end of a bottom plate of the flowing channel of the surface hole. The surface hole structure in the dam body of the high concrete dam is applicable to narrow-river-valley, high-waterhead and large-discharge concrete dam engineering.

The invention provides a grinding medium. The grinding medium comprises a main ball body; multiple sections are arranged on the surface of the main ball body; and the sections are generally circular, and are uniformly distributed on the surface of the main ball body. The grinding medium can be manufactured by at least one material of zirconium oxide and composite zirconium thereof, aluminum oxide, zirconium silicate, silicon carbide, silicon nitride or aluminum nitride. The grinding medium takes the shape of a football, and is novel in shape. Compared with a traditional grinding medium, the grinding medium is high in strength, is uniform, largely increases the shearing area, effectively improves the grinding efficiency, is not limited by grinding equipment, and is suitable for multiple grinding devices.

Provided are a bearing device for a wheel, in which circumferential play is reduced, which provides excellent workability in connection between a hub ring and an outer joint member of a constant velocity universal joint, in which fitting between the hub ring and the outer joint member of the constant velocity universal joint is stable, and which has excellent strength, and an axle module using the bearing device. An axially extending projection is formed on either of the outer diameter surface of a shaft section of the outer joint member and the inner diameter surface of a hole of the hub ring. The projection is press-fitted to the other in the axial direction to form a recess in the other by the press-fitting. By this, a recess / projection fit structure is formed, in which the entire regions of those portions of the projection and the recess at which they are fitted to each other are in intimate contact with each other. The hardness of at least that portion of the projection at which the press-fit starts is higher than that of a portion where the recess is formed. The difference in hardness in HRC is 20 or more.