55results about How to "Reduce centrifugal force" patented technology

The invention discloses an annular magnetic crushing system for wood fiber micro-nano crushing, which comprises an annular crushing cavity, a breathing device and an emission recovery device, the annular crushing cavity is a closed structure, and the annular crushing cavity is filled with conductive particles; a circle of electromagnetic driving device and a circle of attraction device are arranged in the annular crushing cavity, the electromagnetic driving device is located on the outer circle, the attraction device is located on the inner circle, the attraction device and the electromagnetic driving device exist in a mutual accompanying mode, and the outer portion of the annular crushing cavity is connected with a conductive particle emission and recovery device; and breathing openings are formed in the top and the bottom of the annular crushing cavity and are connected with a breathing device. The wood fiber powder regularly moves up and down under the action of the breathing device, collides with the conductive particles moving at a high speed in the annular cavity and is broken down and broken. The problems that the diameter of existing professional corollary equipment is limited, the initial velocity of conductive particles cannot be obtained, and the machining efficiency is insufficient due to the lack of a breathing device are solved.

The invention discloses a renewable self-cleaning type pipe-free ventilation cabinet, and belongs to the technical field of ventilation cabinets, the renewable self-cleaning type pipe-free ventilation cabinet comprises a cabinet body and a cleaning mechanism, air inlet holes are formed in the two sides of the cabinet body, filter screens are fixedly mounted in the air inlet holes, a fan is arranged at the top of the cabinet body, the fan comprises an air duct, fan blades and a driving motor, the driving motor is fixedly mounted in the air duct, and the fan blades are fixedly mounted in the air duct. The fan blades are fixedly connected to an output shaft of the driving motor; a linkage mechanism is arranged in the air duct and comprises a linkage blade and two transverse shafts, a linkage shaft is fixedly installed in the linkage blade, and a driving bevel gear is fixedly connected to the linkage shaft. According to the ventilation cabinet, the fan power can be adjusted according to the ventilation quantity in the ventilation cabinet through the adjusting mechanism, the ventilation quantity is dynamically balanced, the heat exchange effect is guaranteed, automatic cleaning and alarming work can be achieved through the linkage mechanism and the cleaning mechanism when dust in the ventilation cabinet is too much, and the working efficiency is improved. Therefore, dust is prevented from continuously accumulating to influence the operation stability of the fume hood.

The invention relates to the technical field of lignite humic acid fertilizer preparation, in particular to a technology and equipment for producing lignite humic acid fertilizer through spraying granulation, the equipment comprises a bottom plate, a temperature rise detection mechanism is arranged above the bottom plate, the temperature rise detection mechanism comprises a cylinder, the cylinder is fixedly installed at the top of the bottom plate, and a temperature rise detection mechanism is arranged above the cylinder. A round rod is rotatably connected to the inner wall of the top of the cylinder, a plurality of stirring blades are rotatably connected to the outer side of the round rod at equal intervals, the section of each stirring blade is a parallelogram, and a plurality of first limiting blocks and second limiting blocks are fixedly connected to the outer side of the round rod at equal intervals; and the outer sides of the first limiting blocks can abut against the outer sides of the corresponding stirring blades. In the heating process, the heating mixing mechanism and the viscosity detection mechanism are integrated together, so that on one hand, the mixing effect is improved, on the other hand, the viscosity of slurry at the temperature can reach a set range after the slurry reaches the set temperature, and the production efficiency and quality are further ensured.

The invention discloses an impact type rotating wheel hollow water bucket structure and a manufacturing method thereof, and relates to the technical field of hydroelectric power generation, in particular to the manufacturing method of the impact type rotating wheel hollow water bucket structure, which comprises the following steps: S1, preparing an impact type rotating wheel hub and a water bucket root solid area through forging, milling, polishing and other process means; s2, calculating a water bucket hollow part model through the working stress of the rotating wheel; and S3, the prepared rotating wheel hub is clamped to a positioner, and according to the model calculated in the above steps, the additive manufacturing of the rotating wheel hollow water bucket is achieved by continuously and cooperatively adjusting the spatial position of the rotating wheel and the posture of a welding gun. The invention has the advantages of reducing the weight, improving the stability, reducing the inertia, prolonging the service life, saving the cost, promoting the sustainable development, optimizing the structural design, improving the performance, improving the efficiency, reducing the energy consumption, being convenient to manufacture and maintain and enhancing the adaptability.

The invention discloses a two-stroke heavy oil aviation piston engine, and belongs to the technical field of unmanned aerial vehicle engines, the two-stroke heavy oil aviation piston engine comprises an engine body, a spark plug, an exhaust pipe, a fuel oil supply system, a crank connecting rod mechanism, two pistons and an auxiliary heating system, the engine body is composed of a crankcase and two piston cylinders, and the two piston cylinders are horizontally and oppositely distributed on the two sides of the crankcase; the two sides of the crankcase are connected with the short output shaft and the long output shaft in a penetrating and coupling mode, and a rotating cavity opposite to the crankshaft connecting disc is formed in the crankcase. The opposed crankshaft connecting disc is provided with two crank throws in an opposed 180-degree working phase, and the structure of the opposed crankshaft connecting disc without a central shaft neck can reduce the centrifugal force of rotation and improve the operation stability; the crank throw is connected with the piston through a connecting rod, and the joint can rotate; the two pistons are respectively positioned in the two piston cylinders; and the auxiliary heating system is dispersedly arranged on the engine body, consists of a temperature switch and a heating rod, and is used for heating the purified oil-gas mixture provided by the fuel oil supply system.

The invention provides a built-in permanent magnet synchronous motorized spindle optimization design method for a high-precision numerical control machine tool, and aims to solve the problem that a conventional motorized spindle structure cannot adjust an axial preload and a radial external load in real time. The structure of the motorized spindle is optimally designed from three aspects of high-speed ceramic ball mixed bearing materials, axial preload real-time compensation and radial external load real-time compensation. The dynamic characteristics of the rotor system can be improved, and shafting vibration can be actively inhibited.

The utility model relates to a rotary rectifier, and belongs to the technical field of motor control, the rotary rectifier comprises a rectification disc, one side of the rectification disc is provided with a plurality of diode modules and overvoltage absorption modules, the rectification disc is fixedly connected with a plurality of installation teeth uniformly distributed along the edge of the rectification disc, and an installation groove is formed between every two adjacent installation teeth. And one ends, close to the center of the rectifying disc, of the diode module and the overvoltage absorption module are inserted into the mounting grooves and are fixedly connected with the rectifying disc through bolts. The rotary rectifier has the effect of improving the applicability of the rotary rectifier to the high rotating speed.

The present application relates to a vertical mill for processing polytetrafluoroethylene for Teflon tubes, which includes a machine body, a plum blossom frame, a scraper assembly and a material tray, wherein the plum blossom frame is circumferentially connected with a plurality of grinding roller devices, wherein the grinding roller device includes a rotatable first grinding roller and a second grinding roller, wherein the first grinding roller and the second grinding roller are close to each other, wherein a first grinding ring and a second grinding ring are arranged in the machine body, wherein the first grinding ring is arranged in the inner wall of the machine body and is in contact with the side wall of the first grinding roller, and the second grinding ring is arranged on the plum blossom frame and is in contact with the side wall of the second grinding roller. The present application has the effect of increasing the contact surface of the grinding powder and thus improving the grinding efficiency.

The application discloses a damping head and damping mechanism, and belongs to the technical field of damping devices such as vehicle-mounted shooting equipment. The damping head comprises a connecting piece, a movable piece, a supporting piece and a damping structure, the damping structure is movably connected with the connecting piece and the movable piece respectively, one end of the movable piece is movably connected with the connecting piece, the other end of the movable piece is movably connected with the supporting piece, and one end of the damping structure, which is away from the connecting piece, is movably connected with the supporting piece. The damping head of the damping mechanism can drive the supporting piece to swing forward and backward or left and right through the telescopic movement of the damping head when the supporting piece tends to swing, so that the centrifugal force of the camera swinging is buffered, the camera is prevented from falling off the damping arm, the camera is prevented from shaking, and the stability of a shooting picture is ensured.

The invention relates to the related technical field of anti-collision guardrail prefabrication, and discloses a construction device for concrete pouring of an anti-collision guardrail through an inverted method, the construction device comprises a shell, two semi-ring plates are symmetrically and fixedly arranged on one side of the shell, an operation table is arranged on the other side of the shell, a mold is arranged in the shell, and a vibrating assembly is arranged in the shell; one side of the movable block slides on the inclined surface of the outer side of the lower part of the mold, so that the distance between the shell and the frame body is reduced, the position of the eccentric wheel in the two semi-conical plates is changed, and the vibration frequency of the shell and the movable block is conveniently changed; the two ejector rods get close to each other to drive the two semicircular cylinders and the two semi-conical plates to get close to each other, so that the distance between the two semi-conical plates is reduced, the rolling path of the eccentric wheel is shortened, the vibration output frequency of the shell and the movable block to the mold is changed, and finally the continuously changing vibration output frequency is obtained; therefore, richer vibration waves can be output, and the vibration effect can be improved.

The utility model relates to the technical field of scroll compressors, in particular to a scroll compression structure for a scroll compressor and the scroll compressor, the scroll compression structure for the scroll compressor comprises a movable scroll plate, the movable scroll plate is made of aluminum alloy, and the surface of the movable scroll plate is coated with a nano graphene coating; and the static scroll plate is meshed with the movable scroll plate. According to the scroll compression structure for the scroll compressor and the scroll compressor, the problem that an existing scroll compression structure for the scroll compressor is seriously abraded can be solved.

The utility model relates to the field of analytical instruments, and discloses a urine specimen centrifugal device which comprises a centrifugal tube containing a urine specimen, the centrifugal tube comprises a tube body with the upper diameter identical to the lower diameter, and a separation plug is connected in the tube body in the length direction. The separating plug divides the pipe body into a first cavity and a second cavity and seals the first cavity and the second cavity. The centrifugal tube is divided into the first chamber and the second chamber through the separation plug, during use, a patient puts urine into the first chamber, and even if the patient fills the first chamber, an analyst can move the separation plug towards the second chamber, so that the accommodating volume of the first chamber is enlarged, the liquid level in the first chamber is reduced, and the urine in the first chamber is separated from the urine in the second chamber. The urine is prevented from splashing when an analyst opens the cover.

The invention discloses a vegetable stuffing machine with a meat-mincing function, comprising a base; a driving motor, which is arranged in the base; a first container, which is arranged on the base and has an opening at one end; a rotating shaft, which is arranged in the first container and driven to rotate by the driving motor; a second container, which has an opening at one end and is detachably arranged in the first container; a meat-mincing knife group, which is arranged in the second container, and one end of the meat-mincing knife group is detachably plugged with the rotating shaft and can be driven to rotate by the rotating shaft; a vegetable-mincing knife group, which is plugged with the rotating shaft at one end in the first container after the second container is taken out and the meat-mincing knife group is disassembled from the rotating shaft; and a cover body, which is arranged on the first container and covers the openings of the first container and the second container. When mincing meat, the meat is put into the second container, and the meat-mincing knife group in the second container is used to mince the meat. When mincing vegetables, the second container and the meat-mincing knife group are taken out, the mincing knife group is inserted into the first container, plugged with the rotating shaft, and the vegetables are put into the first container to mince the vegetables.

The application discloses a processing method of a cage type inner gear ring and relates to the technical field of gear pumps. The processing method comprises the following steps: S1, rough machining is performed on a workpiece of a bar-shaped metal raw material, a rotating shaft is processed at a first end of the workpiece, and an outline of the inner gear ring and a reinforcing ring sleeved outside the inner gear ring are processed at a second end of the workpiece; S2, an inner cavity of the inner gear ring is rough machined at the second end of the workpiece, a tool rotates and moves along a set track to rough machine the inner teeth, and a root of the inner teeth forms a rounded corner area; S3, an electric spark processing device is used to eliminate the rounded corner area of the inner tooth root; and S4, the inner gear ring and the rotating shaft are finished machined to obtain a cage type inner gear ring product. The application can meet the demand of integrally processing and forming the cage type inner gear ring and guarantee the structural strength of the cage type inner gear ring.

This invention belongs to the field of building material testing technology, specifically relating to a mechanical sensing-type asphalt admixture preparation shear strength testing device. It includes a fixed frame with a test chamber fixedly connected inside. A drive unit is fixedly connected to the upper end of the test chamber, providing driving force for the device. A mixing unit is fixedly connected to the middle of the drive unit, used for mixing asphalt and admixtures. A shearing unit is fixedly connected to the lower end of the drive unit, used for testing the shear strength of the mixture formed by the asphalt and admixtures. The shearing unit includes a mounting base, shear blades, a separating ring, and a layering block. The mounting base is fixedly connected to the drive unit, and multiple shear blades are provided, with each shear blade fixedly connected to the outer edge of the mounting base. This invention ensures stable high-speed operation through a three-blade symmetrical inclined design, integrating mixing and shearing functions, effectively improving the uniformity of material mixing and the accuracy and reliability of shear testing.

The utility model discloses a kind of low vibration bearing with optimized retainer structure belong to bearing technical field, including inner ring and outer ring, evenly be provided with rolling element between inner ring and outer ring, rolling element outside is provided with retainer, retainer includes first side plate and second side plate, there is array distribution in between first side plate and second side plate pocket, pocket and first side plate and second side plate between fixed connection, pocket and pocket between fixed connection there is pocket crossbeam.The utility model uses above-mentioned a kind of low vibration bearing with optimized retainer structure, reduce the collision of rolling element and retainer, inner ring and outer ring, enhance the overall rigidity of retainer, avoid rolling element position deviation, inhibit bearing vibration;Oil reservoir can store lubricating oil, reduce the friction and abrasion of rolling element and pocket, raceway, prolong the service life of bearing;Retainer uses aluminium alloy material, reduce centrifugal force when high speed operation, reduce the additional load to bearing overall, indirectly reduce vibration.

The present application provides a washing machine motor control method and a washing machine. When the real-time current of the motor reaches the starting current, the motor is controlled to drive the drum to rotate at a first rotation amplitude. During the dehydration process, if water is stored in the gap between the inner and outer barrels, the current will increase. Therefore, when the real-time current is greater than the overload current, the motor is controlled to drive the drum to rotate at a second rotation amplitude. Since the second rotation amplitude is less than the first rotation amplitude, the centrifugal force corresponding to the water storage is reduced at this time, so that the water storage can be removed from the gap between the inner and outer barrels, which plays a role in reducing the motor load. Correspondingly, the real-time current of the motor is also reduced. When the real-time current is greater than the starting current and less than the overload current, the motor is controlled to drive the drum to rotate at a third rotation amplitude greater than the second rotation amplitude to perform clothing dehydration. Therefore, the present application can prevent the occurrence of thermal protection caused by water storage, ensure the normal operation of the motor, and then ensure the dehydration effect.

The present invention relates to a crown-type retainer for a ball bearing. A column portion (12) is formed such that the outer peripheral surface of the terminal portion side including a pair of claw portions is located at a position closer to the inner diameter side than the outer peripheral surface of the main portion (11). On the inner diameter side of the retainer (10), a plurality of weight-reducing portions are formed separately at the positions of each column portion in the circumferential direction, which are cut in the axial direction from the axial side surface of the main portion to each column portion. Each weight-reducing portion (20) is formed as a surface away from a pocket (13) and an axial outer side surface of the column portion formed between a pair of claw portions (14). When the axial dimension of a wall portion (22) formed between the axial outer side surface of the column portion and the inner wall surface of the weight-reducing portion is set to T1, and the axial dimension of the main portion at the bottom of the pocket is set to T2, T2>T1. As a result, even if the retainer is deformed by centrifugal force during high-speed rotation, it is not easy to contact other components, and the centrifugal force during high-speed rotation can be reduced by reducing the weight while ensuring the rigidity at a specified position to suppress deformation during high-speed rotation.

The application provides an optimization design method of an internal permanent magnet synchronous electric spindle for a high-precision numerical control machine tool, and aims at the problem that a conventional electric spindle structure cannot perform real-time adjustment on axial pre-load and radial external load, and performs optimization design on the electric spindle structure from three aspects of high-speed ceramic ball hybrid bearing material, axial pre-load real-time compensation and radial external load real-time compensation. The application can improve dynamic characteristics of a rotor system and can actively inhibit shafting vibration.

The utility model relates to the technical field of transmissions, in particular to a CVT (continuously variable transmission) with a deceleration brake function, which comprises a primary assembly, the primary assembly is provided with a driving shaft, and a driving fixed disc component and a driving movable disc component are sleeved on the driving shaft. An isolator and bearings are installed on the driving shaft and located between the driving fixed disc assembly and the driving movable disc assembly, the two bearings are located on the two sides of the isolator, the bearings and the isolator are sleeved with a transmission belt, and the other end of the transmission belt is connected with a secondary assembly. According to the utility model, after the accelerator of the vehicle is released and the vehicle is decelerated and braked, the wheels can be decelerated and braked through the anti-dragging force of the engine, so that the dependence, the abrasion and the driving jerking feeling on a braking system are reduced, the oil consumption is reduced, and the durability and the reliability of the CVT gearbox and the operation performance of the vehicle are improved.

The invention relates to the technical field of engineering construction, in particular to a foundation construction earth ramming device which comprises a machine base, a ramming frame, an eccentric hammer and an adjusting mechanism, the ramming frame is provided with an earth ramming end and a connecting end, the connecting end is hinged to the machine base, and a first rotating shaft is arranged at the earth ramming end; a vertical plane rectangular coordinate system is established by taking any point on the axis of the first rotating shaft as an original point, the vertical plane rectangular coordinate system is provided with a first quadrant, a second quadrant, a third quadrant and a fourth quadrant, the eccentric hammer comprises a mounting disc and a balancing weight, and the mounting disc sleeves the first rotating shaft and can synchronously rotate along with the first rotating shaft; the mounting disc can slide in the radial direction of the first rotating shaft; the balancing weight is fixedly arranged on the mounting disc; and the adjusting mechanism is configured to inversely adjust the distance between the balancing weight and the first rotating shaft according to the soil hardness of the to-be-tamped foundation when the balancing weight is located in the third quadrant, so that the hitting force of the tamping frame to the ground is increased, and the tamping device can adapt to the foundations with different soil properties.

The invention provides a high-damping mute bearing and an assembly production line thereof, the high-damping mute bearing comprises a retainer, solid balls and hollow balls, the solid balls and the hollow balls are mounted on the retainer in a staggered manner, and the high-damping mute bearing comprises a jacking mechanism for driving the retainer on the jacking mechanism to mount the solid balls and the hollow balls in the staggered manner; the ball feeding mechanism is arranged on one side of the jacking and supporting mechanism and used for providing the solid balls and the hollow balls and assisting the jacking and supporting mechanism in installing the solid balls and the hollow balls in a staggered mode; the detection mechanism is arranged on the jacking mechanism and is used for detecting whether the retainer leaks balls or not and pressing the balls on the retainer; the holding frame is driven by the jacking mechanism to distribute balls in a staggered mode to reduce centrifugal force, then abrasion and noise are reduced, the ball feeding mechanism automatically and continuously feeds the balls, and the detecting mechanism detects whether the balls leak or not, presses the balls on the holding frame and cooperates with the ball supplementing assembly to conduct ball supplementing operation.

The utility model relates to a built-in type tilt U-shaped permanent magnet rotor of displacement, and relates to the motor technical field, and the rotor includes rotor core, be equipped with a plurality of permanent magnet unit on rotor core, permanent magnet unit includes first middle part horizontal magnetic steel group, middle part oblique magnetic steel group and two first side part magnetic steel, first middle part horizontal magnetic steel group and middle part oblique magnetic steel group all include at least two width different one -word type magnetic steel, and the one -word type magnetic steel of first middle part horizontal magnetic steel group is perpendicular to d axle, and the one -word type magnetic steel of middle part oblique magnetic steel group is inclined to set up relative to the one -word type magnetic steel of first middle part horizontal magnetic steel group, and first middle part horizontal magnetic steel group and two first side part magnetic steel form first U-shaped magnetic steel group, and middle part oblique magnetic steel group is arranged at the radial outer side of first middle part horizontal magnetic steel group, and the rotor of the utility model can reduce motor noise and torque fluctuation.

The utility model discloses a sand mulling device for casting processing, which relates to the technical field of casting processing, and comprises a base, the top of the base is fixedly connected with a sand mulling cylinder, and the outer ring surface of the sand mulling cylinder is fixedly connected with a discharge port. The magnetic shaft is used for driving the scraper to rotate, then the auxiliary part is driven to rotate, rotation of the stirring shaft and the supporting rod is achieved, centrifugal force generated during rotation is reduced, sand in the sand mixing cylinder is stirred, the layering phenomenon generated during sand stirring is reduced, sand mixing is more uniform, the magnetic shaft is used for driving the scraper to rotate, the inner wall of the sand mixing cylinder can be scraped, and the sand mixing efficiency is improved. And magnetic substances in the sand can be selected out through a magnetic suction cup and a magnetic suction strip, use interference of the magnetic substances to the magnetic force shaft is reduced, overturning of the sand can be accelerated through the overturning shaft, and therefore time consumed for magnetic separation of the sand in the hopper is shortened.

The present application relates to the technical field of polymer processing equipment, and in particular to a modified plastic processing extrusion device, comprising a fixed plate, a barrel connected to the fixed plate, and an extrusion nozzle on the side of the barrel away from the fixed plate; a frame, the frame is connected to the fixed plate; a conical centrifugal cylinder with a feed inlet, the conical centrifugal cylinder is located in an installation cavity, and the conical centrifugal cylinder is rotatably connected to the fixed plate and the frame; a conical follower core, the conical follower core is coaxially arranged in the inner cavity of the conical centrifugal cylinder, and the conical follower core reciprocates along the axial direction of the barrel; an extrusion column head, the extrusion column head is coaxially connected to the conical follower core, the extrusion column head can extend into and be slidably connected to the inner wall of the barrel; a material heating unit, the material heating unit is connected to the conical centrifugal cylinder and / or the conical follower core; the present application has the effect of reducing the possibility of melt fracture of the material and reducing the time the material stays in the barrel to improve the molding quality of the product.

The invention relates to the technical field of rice dust removal, in particular to an intermittent transposition ejection type rice dust removal treatment device and a treatment method thereof.The intermittent transposition ejection type rice dust removal treatment device comprises a support, symmetrically-arranged fixing plates are fixedly installed on the support, a storage tank used for containing rice needing to be treated is further fixed to the support, and supporting plates are fixed to the fixing plates; the feeding hopper is arranged on the support, a dust removal assembly connected with the feeding hopper and the storage tank is arranged on the fixing plate, a driving mechanism connected with the feeding hopper is further arranged on the fixing plate, and the driving mechanism can drive the feeding hopper to rotate; the lifting feeding mechanism is arranged on the supporting plate and connected with the driving mechanism and the storage tank, and the supporting plate is further provided with a Maltese cross movement assembly connected with the lifting feeding mechanism and the driving mechanism; the centrifugal regulation and control assembly is arranged on the support and connected with the driving mechanism and the lifting feeding mechanism.

A built-in multilayer arc-shaped mixed magnetic steel magnetism gathering type permanent magnet rotor relates to the technical field of motors, the rotor comprises a rotor iron core, a plurality of permanent magnet units are arranged on the rotor iron core, the permanent magnet units are symmetrically arranged around the axis of the rotor iron core, and the permanent magnet rotor is characterized in that each permanent magnet unit comprises three arc-shaped magnetic steel groups, the three arc-shaped magnetic steel groups are sequentially arranged from inside to outside in the radial direction of the rotor, the two ends of each arc-shaped magnetic steel group face outwards, first air permanent magnet grooves are formed in the two ends of each arc-shaped magnetic steel group, and each arc-shaped magnetic steel group is divided into left magnetic steel, middle magnetic steel and right magnetic steel from left to right; second air permanent magnet grooves are formed between the middle magnetic steel and the left magnetic steel and between the middle magnetic steel and the right magnetic steel; the coercive force of the left magnetic steel and the right magnetic steel is larger than the coercive force of the middle magnetic steel. The rotor provided by the invention can reduce motor noise and torque ripple.

A ventilator impeller device belongs to the technical field of centrifugal ventilators and comprises a wheel disc and a wheel cover, a shaft disc is arranged at the axis of the wheel disc, and blades are arranged between the wheel disc and the wheel cover. The wheel cover is of an unequal-thickness structure, and the thickness of the part, close to the air inlet, of the wheel cover is larger than that of the remaining part. An air opening reinforcing part is arranged on the wheel cover close to the air inlet, and an edge reinforcing part is arranged on the outer edge of the wheel cover. The impeller device of the ventilator is reasonable in design and simple and ingenious in structure, the impeller cover is light in weight, the centrifugal force of the impeller is small, the manufacturing cost can be reduced, and the situation that the motor is difficult to start can be prevented.

The application provides a multi-stage sludge screening device and a sewage treatment system. The device is used for screening sludge of a sewage treatment unit, and comprises a first number of first cyclones, a second number of second cyclones and a third number of third cyclones. The specification parameters of the first cyclones, the second cyclones and the third cyclones gradually decrease. The feed inlet of each first cyclone is used to receive sludge of the sewage treatment unit. The overflow outlets of the first cyclones are in communication with the feed inlets of the second cyclones. The underflow outlets of the first cyclones are in communication with a first pipeline. The other end of the first pipeline is in communication with a main pipeline. The overflow outlets of each second cyclone are in communication with the feed inlets of the third cyclones. The underflow outlets of each second cyclone are in communication with a second pipeline. The underflow outlets of each third cyclone are in communication with a third pipeline. The overflow outlets of each third cyclone are in communication with the main pipeline through a fourth pipeline. The multi-stage sludge screening device and the sewage treatment system can improve the performance of sludge and effectively improve the sewage treatment efficiency.

The utility model discloses a frameless motor testing tool, and particularly relates to the technical field of motor testing, which comprises a base, the top end of the base is fixedly connected with a support frame, the front side of the support frame is provided with a motor stator, the inner side of the motor stator is provided with a motor rotor, the front side of the support frame is provided with a limiting assembly, and an auxiliary mechanism is arranged above the base; the limiting assembly comprises a fixed column, a plurality of first guide grooves are formed in the fixed column, guide columns are slidably connected into the first guide grooves, one ends of the guide columns are fixedly connected with movable columns, and threaded rods are in threaded connection with the interiors of the movable columns. According to the utility model, by arranging the limiting assembly and the auxiliary mechanism, a rigid supporting structure can be formed on the inner side of the motor rotor, displacement caused by centrifugal force or torque fluctuation in the testing process is reduced, and the motor rotor can be kept stable in the testing process; and meanwhile, centrifugal force or vibration generated by uneven mass distribution of the motor stator during high-speed rotation can be reduced, so that the test precision is improved.