48results about How to "Reduce working temperature rise" patented technology

The invention relates to the electric field, in particular to a circumferential radial multipath oil cooling system for a high-speed motor. An oil inlet which is connected with an oil inlet channel of the oil cooling system is formed in the axial middle of a stator frame. Axial cooling passages are formed at positions at certain distance from an excircle of each stator yoke iron core. Each stator yoke iron core is provided with circumferential arc cooling passages. Each stator yoke iron core is provided with radial cooling passages. End circumferential arc cooling passages are formed at two ends of each stator yoke iron core. Comb-shaped guide plates are disposed at two ends of each stator yoke iron core. The circumferential radial multipath oil cooling system has the advantages that different cooling passages combine a three-dimensional cooling path network, working temperature rising of the high-speed motor is lowered effectively, system stability of the motor is increased, axial temperature difference of a rotor is reduced evidently, and influence, caused by unbalanced heat stress distribution, on the motor is weakened.

The invention discloses a high-power density motor with a water cooling structure and belongs to the field of high-power density motors. The high-power density motor with the water cooling structure is characterized in that a stator winding is annularly sheathed on a stator iron core by adopting a back winding way, an inner side winding is placed in an internal slot in the stator iron core, an outer side winding is placed in an external slot in the stator iron core, and an end winding is placed on an end supporting frame; the axial lengths of an internal-layer machine case and an external-layer machine case are the same, seamless welding is adopted, dimension of the outer surface of the internal-layer machine case and the dimension of the inner surface of the external-layer machine case are in tight fit, and supporting ribs are arranged at intervals for forming a continuous water channel; projected gear teeth in the inner circle of the internal-layer machine case and an external slot in the stator iron core are assembled in tight fit; copper loss and iron loss during operation of a motor can be transmitted to a water cooling machine case. The high-power density motor with the water cooling structure has the advantages that the structure is simple, the effect is obvious, the defects of the existing airtight oil cooling system that the sealing degree is high and auxiliary equipment is complex are overcome, and the problem that the cooling effect of an open-type air cooling system is poor is solved; a cooling system of the high-density motor is effectively improved, the working temperature rise of the motor is reduced, and the system stability of the motor is improved.

The invention discloses a gas-liquid interlaced cooling high power density motor, and belongs to the field of high power density motors. An armature winding of the motor is wrapped by an insulating bushing, supported by a non-metal T-type support, and fixed through a slot wedge, and an axial cooling medium channel inside a stator core is formed. A space defined by a non-metal airtight cylinder, a housing case inner wall, the stator core, a first annular sealing plate and a second annular sealing plate in an enclosed mode constitutes a stator side airtight cooling cavity. Liquid-state cooling media flow from a liquid inflow guiding tube into the axial cooling medium channel inside the stator core, trickle down onto a rotor through first to Nth trickling holes, flow out from a liquid outflow guiding tube and a second liquid outflow guiding tube, and are cooled through a liquid cooling device. Gas-state cooling media enter from a gas inflow guiding tube and flow out from a gas medium outlet hole. Different cooling channels are combined into an interlaced multi-dimensional space cooling system, working temperature rise of the motor is effectively reduced, stability is improved, and unbalanced thermal stress influences caused by axial temperature difference are reduced.

The present invention discloses an electrical push device, comprising a motor (1), a housing (2), and an axially movable push rod (3) provided in the housing (2). A lead screw (4) whose helix rise angle is larger than the locking angle is provided in the push rod (3). A screw nut (5) is provided in the inner end of the push rod (3), and the screw nut and the lead screw (4) constitute a screw pair. The inner segment of the lead screw is provided with a supporting bearing (8). The inner end of the lead screw (4) is connected with the shaft of the motor (1). The electrical push device includes an electromagnet (6) and a brake pair (7). A spring (6b) acting on the moving core (6a) of the electromagnet (6) is provided in the stationary core (6c) of the electromagnet (6). The brake pair (7) includes a rotating brake disc (7a) and a translational movement brake disc (7b). The rotating brake disc (7a) is connected with the shaft of the motor (1). The translational movement brake disc (7b) is connected with the moving core (6a) of the electromagnet (6) and axially moves in a straight line along with the moving core (6a).

The invention relates to an intelligent controller of a frame circuit breaker with high reliability and security and low production cost. The intelligent controller of the frame circuit breaker comprises a microcontroller, a current signal conditioning module connected with the microcontroller, a voltage signal conditioning module, a transformer off-line detection module, a frequency detection module, a keyboard, a display module, an execution mechanism driving module and a relay output module, wherein the current signal conditioning module and the voltage signal conditioning module are connected with the output ends of a current transformer and a voltage transformer respectively. The intelligent controller of the frame circuit breaker realizes the functions realized by hardware in like products by using a digital method, greatly simplifies circuit hardware, and reduces the number of components so as to improve the reliability of the system and reduce the production cost. In the design aspect of a power supply circuit, the adoption of a DC / DC voltage-stabilizing circuit with hysteresis property remarkably improves the efficiency of the power supply so as to obviously reduce the temperature rise of a product.

The invention relates to a parallel voltage stabilizing circuit which has large output power, low operation power, simple structure and low cost. The parallel voltage stabilizing circuit comprises a voltage detection and control unit M1, a regulating tube Q1 and an isolated diode D1; wherein the output voltage end VIN is connected with the anode of the isolated diode D1 and the current input end of the regulating tube Q1, the cathode of the isolated diode D1 is connected with the power input end of the voltage detection and control unit M1, and the power output end of the voltage detection and control unit M1 is connected with the output voltage end VDD; the control output end of the voltage detection and control unit M1 is connected with the control end of the regulating tube Q1; the current output end of the regulating tube Q1 is connected with a system ground GND; and the regulating tube Q1 is correspondingly controlled to switch on or off when the voltage detection and control unit M1 detects that the voltage at the output voltage end VDD is higher or lower than a preset value so as to ensure that the output voltage end VDD is stabilized.

The invention discloses a control method for a DC contactor for rail transit, and the method specifically comprises the steps: outputting a broad pulse voltage to a coil of the DC contactor at the attraction stage of the DC contactor, so as to enable a coil current to reach an attracting current; and outputting a narrow pulse voltage to the coil at the closing maintaining stage of the DC contactor, so as to enable the coil current to be reduced to a holding current from the attracting current. The method provided by the invention is characterized in that the method comprises the steps: outputting a broad pulse voltage to a coil of the DC contactor at the attraction stage of the DC contactor, so as to enable a coil current to reach an attracting current; and outputting a narrow pulse voltage to the coil at the closing maintaining stage of the DC contactor, so as to enable the coil current to be reduced to a holding current from the attracting current. The method and device are simple in operation, and are safe and reliable.

The present invention provides a motor dual-bearing structure with a dual-lubricating system. The motor dual-bearing structure is characterized in that an inner bearing, a grease regulator and an outer bearing sleeve on a rotating shaft, the grease regulator is located between the inner bearing and the outer bearing, an outer bearing chamber sleeves the outer bearing, and an inner bearing chamber sleeves the inner bearing; the end parts of the inner bearing and the inner bearing chamber are equipped with the inner bearing covers, and an inner oil seal is arranged between the inner bearing covers and the rotating shaft; the end parts of the outer bearing and the outer bearing chamber are equipped with the outer bearing covers, and an outer oil seal is arranged between the outer bearing covers and the rotating shaft; the inner bearing chamber, the inner bearing covers, the inner oil seal and the inner bearing form an inner grease storage cavity, and an inner grease injection channel is arranged inside the outer bearing chamber; the outer bearing chamber, the outer bearing covers, the outer oil seal and the outer bearing form an outer grease storage cavity, and an outer grease injection channel is arranged in the outer bearing chamber; the inner bearing chamber, the inner bearing and the grease regulator form an inner grease discharging cavity, and the outer bearing chamber, the outer bearing and the grease regulator form an outer grease discharging cavity; the grease discharging holes are arranged at the lateral bottom of the outer bearing chamber and are communicated with the inner grease discharging cavity and the outer grease discharging cavity separately.

The invention discloses an evaporated liquor flooded type phase-change heat transfer device for an oil-immersed transformer and belongs to the technical field of electric power supply and distribution facilities. The device comprises a main oil inlet pipe, a main oil return pipe and at least one evaporator, wherein each evaporator comprises a tank body, an evaporating pipe, an upper partition board and a lower partition board. The device is characterized by further comprising a cooling liquid storage tank used for storing cooling liquid, the cooling liquid storage tank is matched with the evaporators, a cooling liquid inlet port communicated with a cavity of the cooling liquid storage tank is formed in the top or the upper lateral portion of the cooling liquid storage tank, a cooling liquid outlet port also communicated with the cavity of the cooling liquid storage tank is formed in the lower lateral portion of the cooling liquid storage tank, the cooling liquid inlet port is connected with a liquid outlet of a radiator of the transformer when in use, and the cooling liquid outlet port is connected with a tank body and communicated with a liquid cavity. According to the device, it can be guaranteed that the cavity of the evaporating pipe is in a flooded state, effective heat exchange can be conducted by the evaporating pipe on high-temperature oil introduced by the transformer, working temperature rise of the transformer is reduced, and the service life of the transformer is guaranteed.

The invention particularly relates to a permanent magnet synchronous motor device with a closed self-circulation cooling system for a stator, and belongs to the field of electrical technologies. The permanent magnet synchronous motor device comprises a motor shaft and a rotor core. The rotor core sleeves the motor shaft, a non-magnetic ring is arranged between the motor shaft and the rotor core, a stator core sleeves the rotor core, a vacuum jacket is arranged between the rotor core and the stator core, a housing case sleeves the stator core, and cooling pipes are respectively arranged on the inner side and the outer side of the housing case. The permanent magnet synchronous motor device has the advantages that the permanent magnet synchronous motor device is provided with the vacuum jacket of a rotor, so that heat generated due to eddy-current loss on the surface of the rotor can be effectively stopped against being transmitted to permanent magnets; heat inside a motor can be quickly carried away by the closed self-circulation cooling system for the stator, so that temperature rise of the motor can be reduced, influence of high temperature rise on demagnetization of the permanent magnets can be decreased, the service lives of the permanent magnets and the service life of the motor can be prolonged, and the overload capacity of the motor can be improved.

The invention discloses an organic light-emitting diode and a preparation method thereof. The organic light-emitting diode comprises an anode, a cathode and an organic electroluminescence unit clamped between the anode and the cathode; and the cathode is made of a metal material, the cathode is provided with a metal-insulator-metal plasma nano waveguide filter reflector, and light, emitted to the cathode, of the organic electroluminescence unit reversely irradiates to the anode direction. The preparation method of the organic light-emitting diode is used to manufacture the organic light-emitting diode, and to prepare the metal-insulator-metal plasma nano waveguide filter reflector on the cathode of the organic light-emitting diode through adoption of a nano imprint method. The light irradiated to the cathode is reflected to the anode direction through the metal-insulator-metal plasma nano waveguide filter reflector, light-extraction efficiency of the organic light-emitting diode is improved, a work temperature rise is reduced at the same time, and a working current is improved.

The invention discloses a low-frequency inner-coupled electrodeless fluorescent lamp, which belongs to the field of illuminating apparatuses. The low-frequency inner-coupled electrodeless fluorescent lamp is characterized by mainly comprising a glass bubble casing, an inner power coupler, a lamp holder, a heat conducting base, a low-frequency ballast, and the like, wherein heat dissipating holes for dissipating the heat of the inner power coupler are arranged on the lamp holder, and the inner power coupler adopts the design of fanned solid ferrites and V-shaped grooves. The bottoms of the fanned solid ferrites are flat, and the bottoms of the V-shaped grooves are triangular; therefore, the bottom of each V-shaped groove forms an air convection hole when embedded, the heat in the inner power coupler can be dissipated quickly and effectively through the lamp base with heat dissipating holes, and meanwhile, the ballast with a low-frequency drive device improves the electromagnetic compatibility and solves the problem of the temperature rise of coils. The invention has the advantages of high electromagnetic compatibility, quick heat dissipation, good heat dissipating effect and prolonged service life of electrodeless fluorescent lamps.

The invention discloses an ultra-rapid recovered diode, the insulating shell of which is provided with a diode chip; the invention is characterized in that: the cathode of the diode chip is welded on an insulating plate and a copper bottom plate sequentially after being welded on a copper electrode plate, and the anode thereof is conducted out by a conductive strip; the cooper electrode plate is conducted out by the cathode conductive strip. The ultra-rapid recovered diode of the invention, which adopts the module-type encapsulating structure, has the advantages of freely combining two or more chips by common-cathode connection according to the need of the circuit structure, increasing the working electric flow, ensuring the short time of the reverse-recovery, and facilitating the installation owing to the insulating bottom plate. Meanwhile, the invention has compact structure, can reduce circuit connection and improve operation security, and the copper bottom plate can be both a heat conduction component and a heat dissipation component, which can lower working temperature-rising, and increase working electric flow.

The invention relates to the technical field of stepping motors, in particular to an eight-pole stepping motor with a large stepping angle being 3 degrees. The eight-pole stepping motor with the large stepping angle being 3 degrees consists of a stator punching and a rotor punching, the stator punching consists of eight stator poles and a stator yoke, wherein the eight stator poles are distributed uniformly, and three stator teeth are arranged on each pole of a stator, so that 24 stator teeth are arranged; and the rotor punching consists of 30 rotor teeth and a rotor yoke, and the 30 rotor teeth are distributed uniformly, so that the stepping motor with the large stepping angle being 3 degrees is formed. The eight-pole stepping motor with the large stepping angle being 3 degrees has the advantages that the design is reasonable, the structure is simple, the work stepping frequency property is good, the effective running efficiency is high, the load rotating speed of the motor is increased greatly, the loss when the motor is in high-frequency running is small, the efficiency is high, the work is stable, the work temperature rising is low and the like and is novel in structure and high in performance.

The invention relates to a roller type ultramicro grinding pump, which is the main working mainframe used in an ultramicro grinder for the ultramicro refined processing for colloidal materials and can be applied for ultra-fine crushing and grinding of fluids with solid particles in the technical fields of food, chemical industry, and pharmacy. The roller type ultramicro grinding pump comprises a plurality of stator shells, a plurality of rotors, a plurality of rollers, a port plate, a plurality of pump covers and a drive shaft, which is characterized in that: a plurality of rotors with rollers on the circumference are sleeved on the drive shaft, each rotor is positioned in a stator shell with the eccentric magnitude size of e; a port plate is arranged between the two sets of rotors and stator shells; the sets of stator shells, the sets of rotors, the port plate, the front pump cover and rear pump cover are connected and assembled in series to form the roller type ultramicro grinding pump; and a plurality of cooling water channels communicated with each other are arranged on the pump covers, the stator shells and the port plate used for water-cooling the temperature rise when the pump is grinding.

The invention relates to the field of modular LED (light emitting diode) street lamp lighting, in particular to an LED lighting module which is composed of ceramic radiating fins, a power box, a superconductive base and a light source chamber, wherein a plurality of ceramic radiating fin connecting grooves are arranged on the superconductive base with a plurality of vertically thorough heat dissipation holes, the ceramic radiating fin cavity forms into an whole through an epoxy resin heat conducting layer, and meanwhile, the power box, in which a driving power supply is arranged, is arranged on the superconductive base; and a plurality of LED wafers are arrayed on the bottom part of the superconductive base, and the LED wafers are covered by a light distribution lens to form the light source chamber. Therefore, the light source chamber and power box of the LED lighting module are separated, a radiator and a lamp cover are designed integrally, so that the radiating links are reduced, the heat conduction and heat dissipation performances are improved greatly, and the LED lighting module has the characteristics of improved luminous efficiency, prolonged service life, compact structure, low cost, and the like.

The invention relates to an under-voltage tripper circuit for a miniature circuit breaker. The under-voltage tripper circuit for the miniature circuit breaker comprises a power supply circuit, and is characterized by also comprising an under-voltage detection and control circuit and a tripping circuit, wherein the power supply circuit, the under-voltage detection and control circuit and the tripping circuit are connected in sequence. The under-voltage detection and control circuit consists of a voltage detector U1, a resistor R4, a resistor R5, a resistor R6 and a capacitor C2; the voltage detector U1 is connected with the resistor R5 in series after being connected with the resistor R4 in parallel; the resistor R6 and the resistor R5 are connected in series; the anode of the capacitor C2 is connected with one end of the resistor R6; the cathode of the capacitor C2 is connected with the negative electrode of silicon controlled D6 in the tripping circuit; the other end of the resistor R6 is connected with a control electrode of the silicon controlled D6 in the tripping circuit. The under-voltage tripper circuit for the miniature circuit breaker provided by the invention has the advantages that the working temperature rise of a tripper is reduced, the fluctuation range of an under-voltage protection threshold value is small, the power consumption is low, the operating characteristic is stable, the circuit design is simple, the EMC (electromagnetic compatibility) resistance is strong, and the reliability is high, and more meets the actual demand of the under-voltage tripper for the miniature circuit breaker.

The invention provides an oil-oil lubrication design method for a high-speed electric spindle rolling bearing, belonging to the technical field of rolling bearing cooling and lubrication. The design technology includes the following steps: 1, the configuration design of the oil-gas lubrication system of the high-speed electric spindle rolling bearing; 2, structural design of the oil-gas nozzle ofthe high-speed rolling bear; 3, designing the oil and gas parameters of the high-speed roll bearing. The design technology puts forward a basic configuration scheme of oil-air lubrication system, andprovides a technical method for structural design of oil-air nozzle and selection of oil-air parameters. The oil-oil lubrication design technology of the high-speed electric spindle rolling bearing provided by the invention can effectively improve the lubrication effect of the oil-oil lubrication system of the high-speed electric spindle rolling bearing, greatly reduce the working temperature riseof the high-speed electric spindle rolling bearing, and prolong the service life of the high-speed electric spindle rolling bearing.

The invention discloses a stacking-type lithium battery system. The stacking-type lithium battery system comprises a plurality of lithium battery units which are connected in parallel; each lithium battery unit is formed by serial connection of a plurality of lithium battery modules with functions of current balancing, backflow protection, shirt circuit protection, temperature protection as well as signal transmission; each lithium battery unit is respectively connected with a controller by a corresponding magnetic maintaining relay. According to the stacking-type lithium battery system provided by the invention, not only is volume small and peripheral control circuit simple, but also the operation is stable and reliable, the discharge capacity resistance is high, and the existing cost can be directly reduced by more than 40%. According to the lithium battery system, lithium battery modules with required amount can be connected in series and parallel within a certain range so as to achieve a lithium battery system with different voltages and capacities, so that the lithium battery is applied simply, the traditional and complex using mode of the lithium battery pack can be overturned completely, and the stacking-type lithium battery system is extremely important in the application fields of electric tools, electric bicycles, electric mobiles and minitype energy storage and the like.

The invention discloses a shielded coil module and a preparation method thereof. The shielded coil module comprises a base material, a coil on the surface of the base surface, an insulating layer on the coil, and a shielding material layer and a heat dissipating layer which are arranged on the surface of the insulating layer in a covered manner, wherein the base material comprises a PI base material and an EMI microwave absorbing material or a PI single-faced adhesive; if the base material comprises the PI base material and the EMI microwave absorbing material, the coil and the insulating layer are distributed on two sides of the base material to form a double-faced plate, the shielding material layer and the heat dissipating layer are arranged on one face of the double-faced plate and arepositioned below a battery panel; if the base material comprises the PI single-faced adhesive, the coil and the insulating layer are positioned on the side without adhesive to form a single-faced plate, and the shielding material layer and the heat dissipating layer are positioned below the battery panel. The shielded coil module is high in integration level, thin in thickness, good in magnetismisolating capacity and relatively low in working temperature, so that the cost is greatly saved.

The invention provides lubricating oil for engineering machinery and a preparation method thereof. The lubricating oil is prepared from the following components: modified calcium carbonate, modified titanium dioxide, modified nano copper powder, an ethanol solution, linseed oil, polyurethane, a natural gum extract, paraffin, basic oil, a dispersing agent, a viscosity index improver, an antioxidant, polyalcohol, a defoaming agent, an extreme pressure antiwear agent and an oiliness agent. The lubricating oil prepared by the preparation method provided by the invention can substantially reduce the friction power consumption and wear of the engineering machinery and heavy machinery equipment; meanwhile, the working temperature rise of the equipment is obviously reduced; pollution of waste andleaking engine oil to the environment is relieved; the consumption of the lubricating oil is reduced; nonrenewable petroleum resources are saved.

The invention belongs to the cooling technical field of a power circuit system, and discloses a comprehensive cooling housing of a power circuit. The comprehensive cooling housing of a power circuit comprises a lower housing. The lower housing is filled with transformer oil. Sectional material radiators are arranged on the four sidewalls of the housing. A bottom circulation block is arranged at the bottom of the housing, and is connected with the housing through standard pieces. An intelligent cooling fan is fixed on each sectional material radiator. The problem of low cooling efficiency caused by dependency upon metal heat conduction and cooling of fans is overcome, and the problem of abnormal operations caused by overheating of power devices is overcome. The housing also solves the problem of a single way only relying on water or oil cooling. Conventional single water or oil cooling structures and manufacturing processes are simplified. Multiple cooling ways are combined as one way, and work temperature rises of the power circuit are reduced to ensure that the power circuit functions reliably and stably. Through a comprehensive cooling technique, the housing has the technical advantages of being higher in environment adaptability and long in service life, being reliable and stable, etc.

The invention discloses a preparation method of lubricant oil for mechanical equipment. The preparation method comprises the following steps: a, mixing modified copper nanopowder, a clearing agent, a dispersing agent, a preservative, an extreme pressure anti-wear agent and an oily agent, and stirring at high speed to obtain a mixture 1; b, uniformly mixing an antioxidant, a viscosity index improver, an antirust agent, a pour point depressant, an anti-foaming agent and base oil, mixing in a reaction kettle, and cooling to room temperature to obtain a mixture 2; c, mixing the mixture 1 and the mixture 2, heating, and then concentrating to obtain a finished product. The lubricant oil prepared by the preparation method provided by the invention can greatly reduce the frictional power consumption and the abrasion of the mechanical equipment, especially heavy mechanical equipment; pollution of waste and leaked engine oil to the environment is reduced; the consumption of the lubricant oil is reduced; non-renewable petroleum resources are saved.

The invention relates to an intelligent controller of a frame circuit breaker with high reliability and security and low production cost. The intelligent controller of the frame circuit breaker comprises a microcontroller, a current signal conditioning module connected with the microcontroller, a voltage signal conditioning module, a transformer off-line detection module, a frequency detection module, a keyboard, a display module, an execution mechanism driving module and a relay output module, wherein the current signal conditioning module and the voltage signal conditioning module are connected with the output ends of a current transformer and a voltage transformer respectively. The intelligent controller of the frame circuit breaker realizes the functions realized by hardware in like products by using a digital method, greatly simplifies circuit hardware, and reduces the number of components so as to improve the reliability of the system and reduce the production cost. In the design aspect of a power supply circuit, the adoption of a DC / DC voltage-stabilizing circuit with hysteresis property remarkably improves the efficiency of the power supply so as to obviously reduce the temperature rise of a product.

The invention discloses a low-frequency inner-coupled electrodeless fluorescent lamp, which belongs to the field of illuminating apparatuses. The low-frequency inner-coupled electrodeless fluorescent lamp is characterized by mainly comprising a glass bubble casing, an inner power coupler, a lamp holder, a heat conducting base, a low-frequency ballast, and the like, wherein heat dissipating holes for dissipating the heat of the inner power coupler are arranged on the lamp holder, and the inner power coupler adopts the design of fanned solid ferrites and V-shaped grooves. The bottoms of the fanned solid ferrites are flat, and the bottoms of the V-shaped grooves are triangular; therefore, the bottom of each V-shaped groove forms an air convection hole when embedded, the heat in the inner power coupler can be dissipated quickly and effectively through the lamp base with heat dissipating holes, and meanwhile, the ballast with a low-frequency drive device improves the electromagnetic compatibility and solves the problem of the temperature rise of coils. The invention has the advantages of high electromagnetic compatibility, quick heat dissipation, good heat dissipating effect and prolonged service life of electrodeless fluorescent lamps.

The invention belongs to the cooling technical field of a power circuit system, and discloses a comprehensive cooling housing of a power circuit. The comprehensive cooling housing of a power circuit comprises a lower housing. The lower housing is filled with transformer oil. Sectional material radiators are arranged on the four sidewalls of the housing. A bottom circulation block is arranged at the bottom of the housing, and is connected with the housing through standard pieces. An intelligent cooling fan is fixed on each sectional material radiator. The problem of low cooling efficiency caused by dependency upon metal heat conduction and cooling of fans is overcome, and the problem of abnormal operations caused by overheating of power devices is overcome. The housing also solves the problem of a single way only relying on water or oil cooling. Conventional single water or oil cooling structures and manufacturing processes are simplified. Multiple cooling ways are combined as one way, and work temperature rises of the power circuit are reduced to ensure that the power circuit functions reliably and stably. Through a comprehensive cooling technique, the housing has the technical advantages of being higher in environment adaptability and long in service life, being reliable and stable, etc.

The invention discloses a control method for a DC contactor for rail transit, and the method specifically comprises the steps: outputting a broad pulse voltage to a coil of the DC contactor at the attraction stage of the DC contactor, so as to enable a coil current to reach an attracting current; and outputting a narrow pulse voltage to the coil at the closing maintaining stage of the DC contactor, so as to enable the coil current to be reduced to a holding current from the attracting current. The method provided by the invention is characterized in that the method comprises the steps: outputting a broad pulse voltage to a coil of the DC contactor at the attraction stage of the DC contactor, so as to enable a coil current to reach an attracting current; and outputting a narrow pulse voltage to the coil at the closing maintaining stage of the DC contactor, so as to enable the coil current to be reduced to a holding current from the attracting current. The method and device are simple in operation, and are safe and reliable.

The invention belongs to the field of electromagnets, and relates to an efficient high-speed permanent magnet direct current electromagnetic device. An efficient high-speed permanent magnet direct current electromagnetic yoke (3) is connected with end plate magnetic poles (6) of stop iron (2), permanent magnets (5), push rods (pull rods) (1) and magnetism stop gaskets (4) are fixed to an armature (9), a coil and a coil holder (8) are fixed in the electromagnetic yoke (3), and push rods (pull rods) (1) are arranged in guide holes (10).

The invention relates to a thin-film capacitor element with a middle heat dissipation through hole structure, which comprises a capacitor element core and a shell for accommodating the capacitor element core, a central through hole is formed in the shell, and a core rod through hole in the capacitor element core is communicated with the central through hole, so that part of heat generated when the capacitor element core works is diffused out through the central through hole. The capacitor element with the radial middle through hole has good natural ventilation and heat dissipation capability, so that the working temperature rise of the capacitor element is obviously reduced, the possibility of thermal stress and thermal damage is greatly reduced, the service life of the capacitor element is prolonged, and the cost of enterprises and society is reduced under lower enterprise cost and social cost. Enterprises and society are benefited at the same time through improvement of product quality and service life.