Abstract: A pull-down lock, may include a top cover, wherein the bottom end of the top cover is fixedly connected with the pull rod, and the bottom end of the pull rod is fixedly connected with the lock head; besides, the lock bolt component for limiting and fixing the lock head is arranged in the movable part upper cover, and the movable part base is slidably inserted into the bottom end of the movable part upper cover; the movable part base is internally provided with the pull-down component which is adapted to and penetrates through the lock bolt component. When the movable part base is pulled to move downwards, the lock bolt component could be pushed to move under the cooperation of the pull-down component, so that the limiting and fixation of the lock head is released.

Abstract: The present application discloses a testing device and a testing method for multiple piston assembly of a cam-lobe hydraulic motor. N cylinder blocks are installed on the cylinder block base, and piston assemblies to be tested are installed on the cylinder blocks. A driving plate is installed on the cylinder block base, and N uniformly-distributed driving plate clamping grooves are formed in the driving plate. A cylinder block protrusion is arranged at the bottom of each cylinder block, and the cylinder block protrusions are clamped in the driving plate clamping grooves. When the driving plate is rotated, the N driving plate clamping grooves drive the N cylinder blocks to rotate synchronously through the cylinder block protrusions, to synchronously change the pressure angle between a driving shaft and each piston assembly.

Abstract: Disclosed are a motor, an electric drive device, an electric drive system, and an electric apparatus. The motor includes a casing and a stator. The casing has a first accommodation cavity configured to accommodate a cooling medium. The stator is disposed in the first accommodation cavity. At least part of the stator is immersed in the cooling medium.

Abstract: Disclosed are an electric drive assembly and an electric device. The electric drive assembly includes a motor, a speed shifting mechanism connected to the motor, and a cooling system configured to supply lubricating oil to the motor and the speed shifting mechanism in sequence. With the cooling system provided, lubricating oil is sequentially supplied to the motor and the speed shifting mechanism, reducing the loss of the cooling capacity of lubricating oil in the speed shifting mechanism, improving the cooling efficiency and the utilization rate of the cooling capacity, and reducing the loss.

Abstract: A constant value method for detecting and evaluating internal leakage in a hydraulic cylinder and a detection device. The method comprises: step (1) measuring an accurate pressure drop value ?p of the internal leakage in the hydraulic cylinder; step (2), determining whether the detected hydraulic cylinder meets a standard: if the product of the accurate pressure drop value ?p of the internal leakage in the hydraulic cylinder and a corresponding hydraulic stroke L, is less than a standard parameter C for evaluating the internal leakage in the hydraulic cylinder, C = 4 ? QtK ? ? D 2 , the internal leakage in me hydraulic cylinder meets the standard. Otherwise, the internal leakage in the hydraulic cylinder does not meet the standard. The detection device comprises a motor, a hydraulic pump, a directional valve, a detected part, a pipeline disassembly joint and a pressure sensor.

Abstract: The present application discloses a testing device and a testing method for multiple piston assembly of a cam-lobe hydraulic motor. N cylinder blocks are installed on the cylinder block base, and piston assemblies to be tested are installed on the cylinder blocks. A driving plate is installed on the cylinder block base, and N uniformly-distributed driving plate clamping grooves are formed in the driving plate. A cylinder block protrusion is arranged at the bottom of each cylinder block, and the cylinder block protrusions are clamped in the driving plate clamping grooves. When the driving plate is rotated, the N driving plate clamping grooves drive the N cylinder blocks to rotate synchronously through the cylinder block protrusions, to synchronously change the pressure angle between a driving shaft and each piston assembly.

Abstract: Provided is a design method for a self-compensation structure of a cam-lobe hydraulic motor plate distribution system, which comprises that follow steps: firstly, establishing a force balance equation, a pressure distribution equation and a flow balance equation for each balance chamber, setting a boundary condition, and setting an expected nominal clearance; selecting a fit clearance for simultaneous solutions, and obtaining a set of solutions of areas; taking a maximum value in this set of solutions as the median, and setting a set of area values in the optimization design; further solving changing curves of the nominal clearance and the total leakage of the distribution system with the rotation angle of the cylinder block, and calculating the average value of various curves after the operation is smooth, and designing the self-compensation structure based on selection of the optimal combination of the fit clearance and area.

Abstract: A method for preparing polymer includes the steps of enabling olefin and unsaturated carboxylate be subjected to a polymerization reaction in the presence of a catalyst to generate an olefin-unsaturated carboxylate polymer. The catalyst has a primary catalyst and optionally a cocatalyst. The primary catalyst has at least one complex represented by formula I, formula I?, or formula I?. By selecting a reacted unsaturated carboxylate monomer, catalysts, and a suitable polymerization process, a spherical and/or sphere-like polymer having good shape is directly prepared without subsequent processing steps such as granulation, and the obtained polymer product is not prone to fouling in a reactor and is convenient for transportation.

Abstract: A constant value method for detecting and evaluating internal leakage in a hydraulic cylinder and a detection device. The method comprises: step (1) measuring an accurate pressure drop value ?p of the internal leakage in the hydraulic cylinder; step (2), determining whether the detected hydraulic cylinder meets a standard: if the product of the accurate pressure drop value ?p of the internal leakage in the hydraulic cylinder and a corresponding hydraulic stroke L, is less than a standard parameter C for evaluating the internal leakage in the hydraulic cylinder, C = 4 ? QtK ? ? D 2 , the internal leakage in me hydraulic cylinder meets the standard. Otherwise, the internal leakage in the hydraulic cylinder does not meet the standard. The detection device comprises a motor, a hydraulic pump, a directional valve, a detected part, a pipeline disassembly joint and a pressure sensor.

Abstract: Provided is a dynamic characteristic measurement method for a cylinder block of a non-intrusive axial piston pump. The cylinder block is the main rotating component of the axial piston pump, and the dynamic characteristic of the cylinder block is more capable of reflecting the health condition of the pump than an external characteristic. A non-contact type measurement scheme is provided so as to reduce the influence of a measurement device on the motion of the cylinder block. Cylinder block contour signals and radial displacement signals are obtained by measuring the radial displacement of two sections of the surface of the cylinder block under different working conditions in the perpendicular directions, and then the cylinder block contour signals are accurately removed from the radial displacement signals to obtain the translational and tilting motion characteristics of the cylinder block.

Abstract: A loading module includes a test vehicle, a servo cylinder is mounted on the test vehicle, a piston rod of the servo cylinder is connected with a bearing plate acting on a subgrade surface, an annular loading plate is disposed around the bearing plate, and the loading plate is connected, through a force transmission rod, with a bearing tray on which a counterweight block is placed; a data collecting module includes a second high precision displacement sensor and a plurality of first high precision displacement sensors; a data processing module includes a computer, the computer is connected with a signal input end of the servo cylinder, an output end of the first high precision displacement sensor and an output end of the second high precision displacement sensor respectively, and performs inverse calculation for a dynamic resilient modulus value of a subgrade using a software.

Abstract: An air conditioner and control method therefor to solve the problem that an existing air conditioner stops operation upon detection of an operation parameter abnormality situation, causing the user experience to be significantly influenced. For this reason, the air conditioner includes a compressor. The control method includes: obtaining an outdoor ambient temperature; determining a first preset time period according to the outdoor ambient temperature; obtaining operation parameters of the compressor after the first preset time period; and selectively stopping operation of the air conditioner according to the operation parameters of the compressor, so that the air conditioner can be automatically repaired within the first preset time period. If the air conditioner can be automatically repaired within the first preset time period, the air conditioner does not need to stop operation, so as to guarantee a continuous heat exchange capability of the air conditioner and not to cause an operation failure.

Abstract: A catalyst system for olefin polymerization contains a main catalyst and a cocatalyst. The cocatalyst contains a twelve-membered ring compound represented by formula (M). The catalyst system is suitable for preparing polypropylene products having high stereoregularity and low ash, and can regulate the melt index of the products within a wide range by adjusting the amount of hydrogenation. It is also suitable for copolymerization systems to improve the copolymerization yield.

Abstract: A magnesium-based solid, by means of determination based on a nitrogen adsorption method, has a multimodal pore distribution and a specific surface area of not less than 50 m2/g, and the pore size distribution of the solid is in a range of 1 nm to 300 nm. There is at least one peak within a pore size range of less than 10 nm, and there is at least another peak within a pore size range of not less than 10 nm. A catalyst is formed using the solid catalyst component is used for propylene polymerization.

Abstract: An amino-imine metal complex represented by Formula I, its preparation method and an application thereof are provided. The complex is used as a main catalyst in catalysts for olefin polymerization, and can catalyze the polymerization of ethylene at a relatively high temperature to prepare branched polyethylene having high molecular weight.

Abstract: A method for preparing an olefin-olefinic alcohol copolymer and an olefin-olefinic alcohol copolymer prepared by the method are provided. The catalyst used in the method for preparing the olefin-olefinic alcohol copolymer has a diimine metal complex as shown in Formula I.

Abstract: A loading module includes a test vehicle, a servo cylinder is mounted on the test vehicle, a piston rod of the servo cylinder is connected with a bearing plate acting on a subgrade surface, an annular loading plate is disposed around the bearing plate, and the loading plate is connected, through a force transmission rod, with a bearing tray on which a counterweight block is placed; a data collecting module includes a second high precision displacement sensor and a plurality of first high precision displacement sensors; a data processing module includes a computer, the computer is connected with a signal input end of the servo cylinder, an output end of the first high precision displacement sensor and an output end of the second high precision displacement sensor respectively, and performs inverse calculation for a dynamic resilient modulus value of a subgrade using a software.

Abstract: A diimine metal complex represented by Formula I, a preparation method therefor, and application thereof are provided. The complex is used as a main catalyst in catalysts for olefin polymerization, and can achieve catalytic ethylene polymerization at a high temperature to prepare high molecular weight branched polyethylene.

Abstract: A catalyst system for olefin polymerization contains a main catalyst and a cocatalyst. The cocatalyst contains a twelve-membered ring compound represented by formula (M). The catalyst system is suitable for preparing polypropylene products having high stereoregularity and low ash, and can regulate the melt index of the products within a wide range by adjusting the amount of hydrogenation. It is also suitable for copolymerization systems to improve the copolymerization yield.

Abstract: An endoscope, including: a handle, a sheath tube, an endoscopic cannula, and a tensioning mechanism. The sheath tube includes a first axial guide hole and a first joint pin disposed in the first axial guide hole. The handle includes a second axial guide hole and a second joint pin disposed in the second axial guide hole. The first joint pin matches and is directly connected to the second joint pin. The sheath tube matches and connects to the handle. The handle includes a cavity and the tensioning mechanism is disposed in the cavity. The endoscopic cannula includes a flexible part extending out of the sheath tube and a rigid part fixed in the sheath tube. The flexible part includes a steering wire. The first joint pin is connected to the steering wire. The tensioning mechanism is connected to the second joint pin.