9results about How to "Small pulsation" patented technology

The utility model relates to three screw rod pump technical field, concretely relates to three screw rod pump for conveying high temperature lubricating grease, including double -deck heat preservation pump body, shaft seal, screw rod to be used for double -deck heat preservation pump body's double -deck welding type heat preservation mechanism, be used for shaft seal's mechanical seal flushing mechanism, be used for screw rod's axial thrust mechanism. The three screw rod pump for conveying high temperature lubricating grease, through having the double -deck welding type with heat preservation function's double -deck heat preservation pump body design, make it in the conveying high temperature lubricating grease pumping process, realize high pressure material in low pressure chamber when in overpressure is introduced, through having the shaft seal design with mechanical seal flushing system, reliably realized the shaft seal problem of high temperature lubricating grease, through the combination use under double -deck welding type heat preservation mechanism, mechanical seal flushing mechanism, axial thrust mechanism, can completely realize the safe long -life pumping of high temperature lubricating grease, pulsation is low, no shear, and this method is simple, economic, continuous, is suitable for the conveying process of high temperature lubricating grease.

The application discloses a Sepic type power correction circuit based on a switched inductor, which comprises switching tubes S1-S3, diodes D1-D5, inductors L1-L5, capacitors C1 and C o The diodes D3-D5 and the inductors L4 and L5 form a switched inductor structure, and the voltage gain of the converter is D / (2-D). Compared with a conventional Sepic PFC converter, the Sepic type power correction circuit based on the switched inductor improves the step-down gain, ensures that the whole duty cycle range is in a step-down state, and has a larger duty cycle than the conventional Sepic PFC converter in the case of a high step-down ratio, thereby effectively avoiding the emergence of a limit duty cycle. The no-bridge structure can realize lower conduction loss. The original output diode is replaced by the switched inductor structure, so that the output current is continuous, and the output current can be filtered. All the switching tubes are common ground, and a lower-cost driving circuit can be used.

The application discloses a bridgeless Cuk PFC converter based on a switched-inductor-capacitor structure, which comprises switching tubes S1-S3, diodes D1-D4, inductors L1-L5, capacitors C1, C2 and C o The diodes D3 and D4, the capacitor C2 and the inductors L3 and L4 form a switched-inductor-capacitor structure. The original freewheeling diode is replaced by the switched-inductor-capacitor structure, so that the voltage gain of the converter is D / 2(1-D), compared with a traditional Cuk PFC converter, the converter realizes positive voltage output and improves the voltage reduction gain, and the duty cycle range in the voltage reduction mode is wider. Meanwhile, the bridgeless structure is adopted, so that lower on-state loss can be realized. The converter has continuous input and output currents, high power factor and high efficiency, and has rich application.

This invention discloses an exhaust muffler assembly, a compressor, and a refrigeration appliance, relating to the field of compressor technology. It solves the problem of poor noise reduction effect of existing exhaust mufflers and improves the ability and effect of reducing exhaust noise and pulsation. The specific solution is as follows: the axis of the air inlet is perpendicular to that of the exhaust outlet. A first inner tube is fixedly installed at one end of the first exhaust pipe and passes through the air inlet and is inserted into the muffler mechanism. The end connection between the first inner tube and the first exhaust pipe is a constricted section with a size smaller than the diameter of the first exhaust pipe. The outlet end of the first inner tube faces away from the exhaust outlet. A buffer platform for buffering airflow is fixedly provided on the side wall of the muffler mechanism adjacent to the outlet end of the first inner tube.

This invention relates to the field of reciprocating pump technology, specifically to a low-pulse steady-flow reciprocating pump. The reciprocating pump includes a pump body, a gearbox, and a pump head, with the gearbox and pump head respectively located at both ends of the pump body. The reciprocating pump includes a cylindrical cam reciprocating mechanism and a protection mechanism. The cylindrical cam reciprocating mechanism reduces the pulsation of the reciprocating pump, achieving uniform and stable flow delivery. The protection mechanism works in conjunction with the cylindrical cam reciprocating mechanism to cool the pump body. This invention utilizes a differential mechanism in conjunction with the cylindrical cam reciprocating mechanism. The specially designed cylindrical cam in the cylindrical cam reciprocating mechanism reduces the pulsation of the reciprocating pump, achieving uniform and stable flow delivery. Furthermore, the structure is simple and compact, occupying little space. The rotational connection between the limiting roller and the slide bar allows the limiting roller to roll along the cylindrical cam during reciprocating motion, reducing the friction between the cylindrical cam and the limiting roller, thereby reducing wear and extending their service life.

The application discloses a kind of liquid piston pump systems and working methods of multiple hydraulic cylinder phase difference arrangement, including drive motor, transmission mechanism, first hydraulic cylinder unit, flow convergence pipeline, high-pressure liquid outlet main pipeline and low-pressure liquid inlet main pipeline.First hydraulic cylinder unit includes first hydraulic cylinder and second hydraulic cylinder, two pistons movement phase difference half movement cycle, so that two hydraulic cylinders alternate execution liquid suction and liquid discharge stroke.System further includes at least one same structure hydraulic cylinder unit, each unit is arranged according to preset phase difference, and the output fluid is converged and output after passing through flow convergence pipeline.The application is arranged by pure mechanical structure phase difference, without sensor and controller, can effectively inhibit output flow pulsation, with the advantages of simple structure, high reliability, low cost.

This invention relates to a pulsation reduction device installed in a vehicle's hydraulic braking system. The pulsation reduction device includes: a first chamber (A) into which brake hydraulic fluid is input from a brake hydraulic circuit (2); a second chamber (B) into which brake hydraulic fluid is output to the brake hydraulic circuit (2); and a connecting portion (80a) connecting the first chamber (A) and the second chamber (B); the connecting portion (80a) includes: a first valve body (86) movable to a non-connected position seated on a first valve seat (85b) without connecting the first chamber (A) and the second chamber (B), and a connected position dismounted from the first valve seat (85b) and connecting the first chamber (A) and the second chamber (B); and a force-applying member for applying force to the first valve body (86) towards the first valve seat (85b). b) Lateral force application; the force application components include a second force application component (89) and a third force application component (90) different from the second force application component (89); the second force application component (89) has a hysteresis characteristic that the recovery force (p) in the loading process and the recovery force (p) in the unloading process are different magnitudes when the displacement (s) is the same in the loading process and the unloading process; the third force application component (90) has a characteristic that the recovery force (p) in the unloading process when the displacement (s) is the same as that of the second force application component (89) is larger than the recovery force in the unloading process of the second force application component (89) when the displacement (s) is the same.

The application provides a kind of weak magnetic control method based on permanent magnet synchronous motor adaptive parameter identification, it is related to motor control technical field, the method is by fusing the improved particle swarm optimization algorithm (CIPSO) of chaos inertia weight and Gaussian disturbance online identification stator resistance, cross-axis inductance and permanent magnet flux linkage, solve the problem of control performance decline caused by parameter time-varying;Below rated speed, maximum torque current ratio (MTPA) control based on real-time parameters is used, the convex pole effect is used to reduce the amplitude of stator current, improve the efficiency and dynamic response of low speed operation;Above rated speed, the voltage saturation criterion triggers the lead angle weak magnetic control, dynamically introduces the phase of lead angle correction current vector, makes the operating point move along the voltage limit ellipse boundary, breaks through the voltage constraint of inverter, while combining the parameter identification result carries out feedforward decoupling compensation, realizes the smooth switching from MTPA to weak magnetic and high speed area stable operation.

The application discloses a Cuk type power factor correction circuit based on a switching inductor, which comprises switching tubes S1-S3, diodes D1-D5, inductors L1-L5, capacitors C1 and C o Among them, diodes D3-D5 and inductors L3 and L4 form a switching inductor structure.The converter voltage gain is D / (2-D), compared with a traditional Cuk PFC converter, the power factor correction circuit realizes positive voltage output, improves the step-down gain, ensures that the whole duty cycle range is in a step-down state, and the duty cycle is larger than that of the traditional Cuk PFC converter in the case of high step-down ratio, and the emergence of the limit duty cycle condition is effectively avoided.The application of the bridgeless structure can realize lower on-state loss.The power factor correction circuit has the advantages of continuous input and output current, high power factor and high efficiency, and has great practical value.