86results about How to "Reduce the amplitude" patented technology

The invention discloses equipment and a method for detecting the strength of an annular section of a large-diameter TA31 pipe, and relates to the technical field of pipes. According to the annular section strength detection equipment for the large-diameter TA31 pipe, through the design of a composite mechanism, the pipe is placed in the processing mechanism, the pipe space is restrained through the limiting mechanism, the pipe is prevented from moving in the inspection process, danger to workers is avoided, and therefore normal operation of the equipment is kept; the fixing mechanism controls the pipe to rotate and rub with the processing mechanism, so that the effect of cleaning the surface of the pipe is achieved, the situation that stains on the surface of the pipe affect the detection effect is avoided, a hydraulic rod controls a pressing plate to extrude the surface of the pipe, and the detection effect on the annular section strength of the pipe is achieved; therefore, the friction force on the surface of the pipe is increased, the pipe is prevented from shaking in the downward pressing process, and the operation stability is improved.

The invention discloses rock core drilling sampling equipment for geological disaster investigation, and relates to the technical field of sampling, and the rock core drilling sampling equipment comprises a composite mechanism. According to the rock core drilling and sampling equipment for geological disaster investigation, through the design of a composite mechanism, the motor is connected with the butt joint block, and the drill rod is inserted into the inner side of the butt joint block, so that drilling and sampling are conducted on rocks, in the drilling process, the movable frame slides on the outer side of the sliding column so as to ascend and descend, and therefore the work requirement is met; a drill bit mechanism is arranged on the outer side of the drill rod, large rocks are crushed through the drill bit mechanism in the drilling process, meanwhile, rock blocks are guided to enter the inner side of the drill rod, so that a sample is taken out when the movable frame body is lifted subsequently, subsequent treatment is facilitated, and after sampling is finished, the drill bit mechanism is used for crushing the large rocks and guiding the rock blocks to enter the drill rod. When the sample is taken out from the inner side of the drill rod, the sample is taken out more cumbersomely and difficultly, the pushing and pressing mechanism is pressed by the electric push rod, so that the effect of discharging the sample is achieved, and normal operation of equipment is kept.

The invention relates to the technical field of air rail transportation, in particular to a power type bogie based on a box girder type base and an induction gap adjusting method. The power type bogie comprises a box girder type base, the box girder type base comprises a suspension gap located at the bottom and communicated with an inner cavity, first rails located on the two sides of the suspension gap are arranged at the bottom of the box girder type base, and an induction magnetic stator is fixedly arranged on the inner side of the top of the box girder type base. The bogie assembly comprises a bottom frame, a motor support arranged on the bottom frame and walking wheels arranged on the bottom frame; the top of the motor support is provided with a motor rotor having an induction gap with the induction magnetic stator, and the motor rotor is used for driving the bogie assembly to move under the action of magnetic force generated by the motor rotor and the induction magnetic stator. And the gap adjusting device is used for adjusting the size of the induction gap. A semi-closed base can be formed through the box girder type base, a bogie and other components are arranged in a box girder cavity, maintenance is convenient, the influence of weather is small, and the service life can be prolonged.

The invention relates to a multifunctional multi-axis linkage numerical control internal and external circle and thread grinding machine which comprises a base, a grinding head and a grinding head. The N grinding spindles are symmetrically arranged on the machining table; the cross-shaped moving assembly is arranged on the base and located above the grinding main shaft; the lifting assembly is arranged on the cross-shaped moving assembly; the machining base is arranged on the cross-shaped moving assembly in a sliding mode and connected with the lifting assembly; the N machining spindles are symmetrically arranged on the machining base and correspond to the grinding spindles one to one. According to the multifunctional multi-shaft linkage numerical control internal and external circle and thread grinding machine, the grinding main shaft and the machining main shaft are symmetrically arranged to reduce vibration, and then the machining precision is improved. The N main shafts are symmetrically and uniformly distributed and can be vertically, horizontally and obliquely arranged. The overall rigidity is improved by 4 times, the amplitude is reduced by 4 times, the precision is improved by 16 times, and the machining rhythm speed is improved by 4 times. Different grinding wheel tools can be replaced so as to be widely applied to grinding machining of inner holes, outer circles and threads. The whole weight is light, the occupied area is small, and energy consumption is low.

The present invention belongs to the technical field of lightning prevention and control, and discloses a lightning arrester and a lightning protection device using the positioning pin. By arranging a collector wheel around the upper needle rod and arranging an adjustable capacitor below, the lightning arrester eliminates corona, can form a sufficiently long upward leader discharge, actively search for lightning and eliminate it, expand the protection range of the lightning arrester, reduce the damage of lightning strikes to buildings and electrical equipment, and is particularly suitable for application in summer lightning protection scenarios of various high-rise buildings.

The invention provides a damping device for a steel hollow floor slab and the steel hollow floor slab, and relates to the technical field of floor slab damping, the damping device comprises a prestressed inhaul cable, a stiffening beam, a connecting short beam and a first friction damper; the stiffening beam is arranged at the bottom of the floor slab and used for supporting the floor slab and transmitting vertical vibration of the floor slab; the two ends of the stiffening beam are connected with the two connecting short beams correspondingly, and the stiffening beam is connected with the main beams on the two sides through the connecting short beams. One end of the connecting short beam is connected with the main beam, and the other end is connected with the end part of the stiffening beam; the upper surface of the connecting short beam is connected with the lower surface of the floor; the two first friction dampers are connected between the two ends of the stiffening beam and the two connecting short beams correspondingly and used for dissipating floor vibration energy. The two ends of the prestress inhaul cable are connected to the main beams on the two sides respectively and used for vibration reduction of the floor slab. The prestressed inhaul cables and the stiffening beams are arranged in parallel, and the prestressed inhaul cables are arranged on the two sides of the stiffening beams. Resonance of the floor slab under the action of pedestrian load is reduced, and living comfort and safety are improved.

The invention discloses container shell welding equipment for chemical pressure container machining, and relates to the technical field of shell welding, and the container shell welding equipment comprises a composite mechanism. According to the container shell welding equipment for chemical pressure container machining, through the design of a composite mechanism, the telescopic rod is used for controlling the welding frame to conduct lifting operation, so that welding materials can be attached conveniently, the application range is expanded, and the operation efficiency is improved; and when the telescopic rod controls the welding frame to ascend and descend, the protection mechanism is attached to the top of the material, so that the effect of presetting a welding spot is achieved, deviation during welding is prevented, the welding quality is improved, and the welding efficiency is improved. Materials are welded in a mechanical rotating mode, and normal operation of material welding is guaranteed.

The utility model provides a centrifugal fan, including volute still include: impeller, the impeller is provided with at least two groups, and at least two groups impeller follow the axial direction of volute, the middle disc is arranged between two groups of adjacent impeller, two groups of adjacent impeller are separated through the middle disc, and the import of middle disc is linked together with the import of volute, each group impeller is provided with several blades, and several blades are arrayed around the axial direction of volute, and the blade of two groups of adjacent impeller is staggered along the projection direction of blade. Through the mode for increasing the number of blade, increase the times of cutting the airflow that enters the volute, thereby improved the frequency of rotation noise, namely BPF noise, make BPF noise frequency far away from the hearing range of human ear, and then reduce the situation that the user hears the rotation noise. In addition, the blade that interlaces can break the shedding vortex that the blade tail edge produces, reduces the broadband noise of fan.

The invention relates to the technical field of bearing assembly, and particularly discloses a rapid ball distributing device applied to bearing machining, the rapid ball distributing device comprises a mounting bottom plate and a mounting stand column, the upper end of the mounting stand column is slidably sleeved with a sliding sleeve, the sliding sleeve is fixedly sleeved with a movable plate, and the top of the mounting stand column is fixedly connected with a fixed top plate; a pressing and inserting air cylinder is installed at one end of the fixed top plate, a fixed shaft rod is installed at the end, away from the sliding sleeve, of the movable plate, an installation base is installed at the lower end of the fixed shaft rod, an installation sleeve is installed on the bottom face of the installation base, and a plurality of ball inserting needles are evenly arranged in the installation sleeve. According to the device, the automatic reset capacity after the movable plate is pressed down can be improved, it is ensured that after one-time pressing and inserting operation is completed, the ball inserting needle can be rapidly restored to the original position and rapidly put into the next-time pressing and inserting preparation operation, and therefore the ball distributing efficiency of the device on steel balls in a bearing is greatly improved, and the assembling speed of the bearing is increased.

The utility model relates to the technical field of equipment for glass tube production, and discloses a transfer device for glass tube production, which comprises a bottom plate, a first cylinder machine is fixedly connected inside a cylinder box, a driven fluted disc is fixedly connected outside a rotating rod, a driving rack is arranged inside a column tube, and a second cylinder machine is fixedly connected outside the column tube. And the upper surface of the transverse plate is fixedly connected with a second air cylinder machine, and the interior of the hopper box is fixedly connected with a hydraulic machine. The utility model has the following advantages and effects: the driving rack is meshed with the driven fluted disc, so that the driven fluted disc rotates, and the transverse plate rotates by 90 degrees, so that one end of the transverse plate is butted with the processing platform, and meanwhile, the second cylinder machine and the hydraulic machine are quickly started; and the output end of the hydraulic machine pushes the push plate to move so as to push the storage plate placed in the hopper box to the upper surface of the machining platform, and through the operation, manpower is saved, and the effect that the glass tube transfer effect is good is achieved.

This utility model discloses a vibrating screen for nicotinamide production, comprising a support frame, four fixed seats (first type) fixed to the support frame, springs fixed to the fixed seats (first type), and fixed seats (second type) fixed to the springs. A vibrating screen body is fixed between the four fixed seats (second type). A dual-shaft motor is fixed to the lower side of the vibrating screen body. Eccentric wheels are fixed to the output shafts of the dual-shaft motors. Fixed columns are fixed to the output shafts of the dual-shaft motors. Connecting shells are fixed to the fixed columns. Sealing covers are fixed to the connecting shells. Connecting pipes are embedded within the fixed columns and communicate with the connecting shells. Through its control structure, this utility model allows the device to dynamically adjust the amplitude of the vibrating screen body according to screening requirements. When a water pump is started to inject water into the connecting shells, the centrifugal force of the connecting shells increases, causing the dual-shaft motors to drive the vibrating screen to produce a larger amplitude, suitable for processing materials that are difficult to screen. Conversely, pumping water reduces the amplitude, suitable for fine screening.

The invention relates to the technical field of motors, in particular to a stator punching sheet, a stator iron core comprising the stator punching sheet and an external rotor motor comprising the stator iron core. The stator punching sheet is annular, twelve stator tooth grooves used for winding stator windings are evenly formed in the outer periphery of the stator punching sheet at intervals in the circumferential direction, the diameter of the outer circle of the stator punching sheet is D1, the diameter of a virtual circle concentric with the outer circle on the stator punching sheet is D2, D2 / D1 is equal to 0.45-0.5, the area of an annular area between the outer circle and the virtual circle is the effective magnetic circuit area, and D1 is larger than D1 and smaller than D2. The stator tooth grooves are located in the annular area, and the proportion of the total area of the 12 stator tooth grooves to the effective magnetic circuit area is 0.45-0.5. The effective size of the motor can be reduced, the torque ripple of the motor is reduced, and the operation efficiency of the motor is improved.

The utility model relates to the technical field of absorption circuits, and discloses a protection circuit which comprises a power switch tube Q1, a first absorption unit and a second absorption unit are connected between a drain electrode and a source electrode of the power switch tube Q1, the source electrode of the power switch tube Q1 is connected with the ground, and the first absorption unit and the second absorption unit are connected in parallel; according to the utility model, a more efficient peak voltage absorption effect can be achieved, the power loss of the circuit can be effectively reduced, and the reliability of the circuit can be improved at the same time.

The invention discloses a micro electro mechanical system (MEMS) ultrasonic transducer, which comprises a transmitting unit, a receiving unit, a transmitting unit and a receiving unit, the decoupling space is positioned between the transmitting unit and the receiving unit; wherein the surface, opposite to the receiving unit, of the transmitting unit is a curved surface. According to the invention, the surface, opposite to the receiving unit, of the transmitting unit is set to be the curved surface, so that the transmitting performance is improved on the premise that the receiving performance is not reduced.

The invention discloses a flexible mechanical arm main resonance control method based on nonlinear feedback and time delay feedback, and the method mainly comprises the steps: carrying out the discretization of the transverse deformation of a flexible mechanical arm through employing a hypothesis modal method, and obtaining a vibration equation of the flexible mechanical arm; a linear feedback control item, a nonlinear feedback control item and a time-delay feedback control item are introduced to form a control signal model of the vibration absorber. Constructing a vibration absorber control signal model; a Kane equation is used for establishing a flexible mechanical arm system vibration control model including the vibration absorber; solving an approximate analytic solution of the system vibration equation by applying a multi-scale method to obtain a single-mode solution and a dual-mode solution of the system steady-state response; and finally, under the coexistence state of the internal resonance condition and the main resonance condition of the flexible mechanical arm system in which the vibration absorber is included, the main resonance of the flexible mechanical arm is controlled, and the modal amplitude of the first-order modal of the main resonance of the flexible mechanical arm is well inhibited.

The invention discloses a double-layer structure noise reduction liquid storage device and a compressor, and relates to the technical field of compressors, the double-layer structure noise reduction liquid storage device comprises a liquid storage body, a guide pipe is fixedly installed on the top face of the liquid storage body, a double-ring frame is fixed to the outer wall of the liquid storage body, and double-layer noise reduction assemblies are arranged on the left side and the right side of the double-ring frame; the double-layer noise reduction assembly comprises two L-shaped plates, the two L-shaped plates are fixedly installed on the left side and the right side of the double-ring frame, the telescopic ends of electric telescopic rods are fixed to the bottom faces of the two L-shaped plates, and two amplitude sensors are fixedly installed at the bottoms of the sides, away from each other, of the two electric telescopic rods correspondingly. According to the invention, the spring is driven by the frame plate to move downwards, and the spring is compressed, so that the problem of too high noise generated by the compression main machine and the liquid storage main body due to too fast amplitude frequency of the compression main machine and the liquid storage main body in a high-power state is avoided.

The invention discloses a claw-shaped stator and a motor thereof; the stator tooth shoe is optimized to form a claw-shaped stator tooth shoe shape which is symmetrical about the tooth neutral line; under the premise of not affecting the fundamental wave amplitude of the air gap magnetic density and ensuring the output torque, the frequency of the tooth slot torque pulsation is increased, the amplitude is reduced, and the torque fluctuation is further reduced.

The invention belongs to the technical field of vibration reduction metamaterial structure design, and aims to solve the problem of poor vibration reduction effect in metamaterial structure design. The invention provides a dual-mass resonator structure, a design method and a shape and function fused metamaterial structure, the dual-mass resonator structure comprises a plurality of connected cell structures, and two adjacent cell structures are connected through a cell outer frame; the double-bridge-arm structure comprises two bridge arms which are led out from the inner frame of the cell element outer frame to the inner side; the dual-mass structure comprises two groups of local resonant columns, and one group of local resonant columns is arranged at one end, far away from the cell outer frame, of any bridge arm; and meanwhile, a shape and function fused metamaterial with a customizable vibration isolation belt is designed and prototype, and various metamaterial shapes are integrated into different functional frames by the structure, so that the coherent design of forms and functions is realized. By utilizing the characteristics of the metamaterial, the vibration and noise reduction performance of the structure is effectively improved.

The present application relates to the field of motor technology, and discloses a direct-drive permanent magnet synchronous motor for mining, including a vibration isolation shaft, one end of the vibration isolation shaft close to the rotor shaft is movably connected to a buffer cylinder through a ball seat, the vibration isolation shaft can rotate in any direction around the center of the buffer cylinder, the center of the buffer cylinder is on the axis of the rotor shaft, the position of the vibration isolation shaft close to the end of the buffer cylinder is connected to the buffer cylinder through a buffer seat, and the distance between the end of the vibration isolation shaft close to the rotor shaft and the center of the buffer cylinder is smaller than the distance between the other end and the center of the buffer cylinder. A direct-drive permanent magnet synchronous motor for mining provided by the present invention is connected to the input shaft of the load through the vibration isolation shaft, when the vibration of the load is transmitted to the vibration isolation shaft, one end of the vibration isolation shaft is used to absorb the vibration energy, and the other end constrains the vibration of the vibration isolation shaft to reduce the amplitude of the vibration isolation shaft, and at the same time, the vibration isolation shaft is connected to the rotor shaft through a buffer sleeve, which effectively isolates the transmission of vibration.

The invention belongs to the technical field of machining tools, and particularly relates to a thin-wall workpiece clamping tool. The thin-wall workpiece clamping tool comprises a bottom plate, a locking assembly, a plurality of clamping assemblies, a plurality of first steering assemblies, a headless traction rope, an adjusting assembly and an adjusting traction rope. The locking assembly is connected to the bottom plate and used for fixing the bottom of the thin-wall workpiece and the bottom plate. The first steering assembly is connected to the bottom plate and comprises a first steering wheel; the headless traction rope penetrates through the wire passing piece and the first steering wheel, and the ends of the headless traction rope are connected to form a closed loop. The adjusting assembly is arranged on the bottom plate and comprises a wiring piece, and the wiring piece can move relative to the bottom plate; one end of the adjusting traction rope is connected with the headless traction rope, and the other end of the adjusting traction rope is connected with the wiring piece. According to the technical scheme, the thin-wall workpiece clamping tool can effectively reduce vibration in the machining process of the thin-wall workpiece, and structural deformation of the workpiece cannot be caused.

The application provides a multi-frequency transducer, and belongs to the technical field of part cleaning. The multi-frequency transducer solves the problem that the connecting position of an electrode sheet and a wire of an existing transducer is prone to loosening and falling off. The multi-frequency transducer comprises a wire, a front cover, a rear cover arranged behind the front cover, and an electrode sheet and a piezoelectric ceramic sheet fixed between the front cover and the rear cover. The outer circumferential surface of the electrode sheet is provided with a radially protruding lug in a strip shape. One end of the lug is fixedly connected with the electrode sheet or integrated with the electrode sheet. One end of the wire is welded with the lug. The other end of the lug is bent and forms a limiting cover, and the limiting cover is covered outside the welding point of the wire and the lug. The outer side of the limiting cover is further covered with an insulating layer made of insulating material. The multi-frequency transducer has the advantage of good connection stability.

The invention relates to the technical field of drilling machines, in particular to a radial drilling machine for zinc-aluminum-silicon-magnesium-chromium alloy machining, which comprises an L-shaped rocker arm and a spindle box mounted on the L-shaped rocker arm, the spindle box is matched with the L-shaped rocker arm to adjust the drilling position, and a rotatable assembled drill bit is mounted on the lower portion of the spindle box. An axial flow channel and a forking flow channel are formed in the assembled drill bit; the forking runner directly sprays the gas-liquid mixed medium, and compared with an external cutting fluid spraying mode in the traditional technology, the gas-liquid mixed medium can directly reach the end of the drill bit and take away cutting powder.

The present application belongs to the technical field of motor design, and more particularly relates to an alternating pole vernier permanent magnet motor based on a harmonic modified rotor and a magnetic barrier stator. Specifically, it comprises a rotor and a stator, the rotor is coaxially arranged in the stator, the pole of the rotor core adopts a harmonic modified directional design, the air gap permeance distribution is optimized to suppress non-working harmonics, and at the same time, the inter-pole leakage is reduced and the permanent magnet flux density fundamental amplitude is improved; and the magnetic barrier embedded in the stator tooth is used to block the low-order non-working harmonic path in the armature flux density, so as to weaken the amplitude. The present application solves the problem that the current motor simply applies the Halbach permanent magnet array to only realize the enhancement of working harmonics, ignores the non-working harmonics existing in the air gap, and fails to realize the full utilization of permanent magnets, resulting in the problems of low torque density and high manufacturing cost of the current alternating pole vernier permanent magnet motor.

The invention relates to the technical field of stacking machine stand column structures, and discloses a high-position stacking machine stand column structure which is characterized in that a centrifugal assembly and a counterweight assembly are installed on the outer wall of the top of a stand column and used for counteracting inertia force, and the centrifugal assembly pushes hydraulic pressure to adjust the counterweight assembly in the centrifugal process; a movable table is slidably connected between the two stand columns, hydraulic balance assemblies with balanced stress are installed at the tops of the stand columns, and the movable table ascends to push the hydraulic balance assemblies to operate. Through the arrangement of the balancing weight, when hydraulic oil is pushed, the hydraulic oil pushes the movable block to move towards one end of the balancing weight, so that the balance weight of the balancing weight is increased, at the moment, the balance weights on the two sides of the two stand columns are increased, certain downward pressure is applied to the stand columns, and therefore swing caused by inertia is reduced.

The utility model relates to the technical field of fan damping and buffering, in particular to a fan damping and buffering device which is characterized by comprising a damper, the damper comprises a first damping cylinder and a second damping cylinder, a first connecting piece is connected between the first damping cylinder and the second damping cylinder in a sliding mode, and a second connecting piece is connected between the second damping cylinder and the first connecting piece. The side, away from the first damping cylinder, of the second damping cylinder is slidably connected with a second connecting piece. The first damping cylinder, the second damping cylinder, the first connecting piece and the second connecting piece are arranged, so that the vibration amplitude of the fan can be reduced, and the influence caused by vibration of the fan is reduced; springs are arranged in the first damping cylinder and the second damping cylinder, so that the moving stroke of the guide plate in the damper is reduced through the characteristics of the springs, and the amplitude of the fan is reduced; by arranging the guide groove and the clamping block which are clamped with each other, the guide plate can only move along the guide groove, the function of absorbing vibration and impact energy of the spring can be fully played, and the damping effect of the damper is improved.

The invention relates to a compressor which comprises a crankshaft, a rotor and an oil-gas separation piece. The rotor is connected to the crankshaft and comprises a fluid through hole. The oil-gas separation part comprises an oil-gas separation part, a first oil collecting part and a first valve, the oil-gas separation part comprises a fluid inlet, a first cavity, a first flow channel, a second flow channel, a second cavity, a fluid outlet, a first oil catching structure and a second oil catching structure, and the first cavity comprises a first sub-cavity and a second sub-cavity which are communicated through the first flow channel; the fluid inlet is communicated with the first sub-cavity, the second runner is communicated with the second sub-cavity and the second cavity, the fluid outlet is communicated with the second cavity, the first runner is arranged away from the crankshaft in the radial direction of the rotor, and the second runner is arranged close to the crankshaft; the first oil catching structure is arranged in the second sub-cavity, the second oil catching structure is arranged in the second cavity, a first oil collecting part is arranged on the bottom wall of the oil-gas separation part, the first valve is connected to the bottom wall of the oil-gas separation part, and the first valve controls the first oil collecting part to be opened or closed.

This invention discloses an automatic correction and feeding mechanism for a flexible vibratory feeder, belonging to the field of vibratory feeding technology. It includes a fixed box, a vibratory feeder seat above the fixed box, a feed tray on the top surface of the vibratory feeder seat, and a camera assembly on one side above the feed tray. It also includes a flexible vibration assembly, comprising a connecting seat fixedly connected to the bottom surface inside the fixed box, an eccentric vibration motor fixedly connected to the top of the connecting seat, and one end of the output shaft of the eccentric vibration motor fixedly connected to the center of the bottom of the vibratory feeder seat. In this invention, a single eccentric vibration motor combined with four sets of obliquely symmetrical elastic support structures decomposes the rotational excitation force output by the motor into two orthogonal simple harmonic vibration components in the X and Y directions. The two components are superimposed to synthesize a stable and controllable horizontal elliptical motion trajectory. This trajectory causes the pins inside the feed tray to produce continuous, low-impact flexible sliding under the action of friction and inertia, preventing deformation, bending, or peeling of the surface coating of the parts.

The present invention provides a circular steel tube concrete combined wind turbine tower structure, the tower structure includes an upper steel tower and a lower steel tube concrete tower, the steel tube concrete tower is composed of multiple circular steel tube concrete tower sections; the steel tube concrete tower section includes an inner and outer double-layer steel tube, the inner and outer steel tubes are connected at the upper and lower ends of the tower section, a grouting space is formed between the two, and concrete is poured and filled. The present invention meets the requirements of high-altitude and large-scale wind turbines, the total height of the upper steel tower and the lower steel tube concrete tower can reach no less than 150m, and it is easy to manufacture, transport and install, can be reused, and reduces costs.

The embodiment of the utility model provides a battery pack. The battery pack comprises battery monomers and a box body, the box body comprises a frame body, a first brace and a second brace, the frame body comprises a first side and a second side which are oppositely arranged along a first direction, an accommodating space is arranged in the frame body, and the battery monomers are arranged in the accommodating space; the first brace extends along the second direction, is connected to the first side of the frame body and is connected with the battery monomers; and the second brace extends along the second direction, is connected to the second side of the frame body and is connected with the battery monomer. The first brace and the second brace can press the single batteries, and the amplitude of the single batteries under the vibration working condition is reduced, so that the risk of damage to the battery pack is reduced; when the bottom of the battery pack is impacted, the second brace can provide buffering for deformation of the bottom of the battery pack; in addition, when the battery monomers are expanded, the first brace and the second brace can limit the outward displacement of the frame body, so that the safety of the battery pack is improved.

The application discloses a 4MV modulation method for inhibiting common-mode current of a photovoltaic ANPC type three-level inverter, and steps of the method comprise the following steps: 1. applying Kirchhoff's law to deduce a relationship formula of common-mode voltage and a parasitic capacitance of a photovoltaic array, and establishing a common-mode equivalent circuit; 2. deducing a functional relationship formula of instantaneous values of a neutral current, three-phase currents and a switch state; 3. according to a relationship between a basic vector diagram and a midpoint current expression and a principle that the common-mode voltage is 0, selecting six middle vectors as basic vectors, and using four middle vectors to synthesize a reference voltage vector in each sector, wherein two middle vectors are used for synthesizing the reference voltage vector, and the other two middle vectors are used as equivalent zero vectors and are used for introducing the neutral current to effectively reduce fluctuation of a midpoint potential. The application replaces the zero vectors with a pair of equal-amplitude and opposite-phase middle vectors, can reduce deviation of the midpoint potential, further reduces common-mode voltage caused by the deviation of the midpoint potential, and thus can reduce the common-mode current of the system.