Tsinghua University

Other

Beijing Jiaotong University

Decai Li

Xiao Xi Liu

Qian Li

Zhenghao Li

Siyu Chen

Rui Sun

Zhibin Wang

Yanwen Li

Sijie Ren

Pengdong Han

Xinzhi He

Ying Liu

Fei Guo

XiaoHong Jia

Weifeng Huang

Yongjian Li

Yuan Yin

ShuangFu Suo

Zepeng Li

Jixian Yang

Xiangfeng Liu

Zixi Wang

Yingsong Li

Sijia Liu

Xiaolong Yang

Zhi Gao

Fan Chen

Peng Yun Sun

Zulong Yang

Meili He

Fuxiang Hao

Nuo Chen

Zixian Li

Shilin Nie

Provided is a device sealed with a magnetic liquid. The device includes: a rotary shaft, a tank body, a control unit, a first module, a second module, a magnetic liquid, and a pole-tooth. The first module and the second module are in the same configuration, each consists of an outer shell, a left pole-shoe, an electromagnet, a control wiring, a right pole-shoe, and a circlip. The device includes at least two modular structures; the control unit controls a first electromagnet and a second electromagnet to be magnetized to alternately bear a sealing role.

Device sealed with magnetic liquid

Provided is a self-cooling device sealed with a magnetic liquid, related to the field of mechanical engineering sealing technology. The device includes: a tank body, a pole-tooth, a rotary shaft, a magnetic liquid, a first gasket ring, a second gasket ring, a first pole-shoe, a permanent magnet, a third gasket ring, a second pole-shoe, a fourth gasket ring, a fan, a bolt, an end cover, a second U-shape soaking rod, and a first U-shape soaking rod.

Self-cooling device sealed with magnetic liquid

A preparation method of a perfluoropolyether-based magnetic liquid includes dispersing magnetic nanoparticles coated with graphene oxide into a solution of N,N-dimethylformamide to obtain solution A; dispersing a surfactant into dichloromethane, and adding triethylamine as a cosolvent to obtain solution B; mixing the solution A and the solution B uniformly, heating them under reflux and stirring them for a modification reaction; and after the modification reaction is completed, washing and drying a reaction product to obtain the modified magnetic nanoparticles coated with the graphene oxide; dispersing the modified magnetic nanoparticles coated with the graphene oxide into a base carrier liquid to prepare the perfluoropolyether-based magnetic liquid. The surfactant is a perfluoroalkylamine. The base carrier liquid is a perfluoropolyether oil. The modification reaction is performed at a temperature of 50 to 120° C. for a time period of 20 to 50 hours.

Low-temperature resistant perfluoropolyether-based magnetic liquid and preparation method thereof

The present disclosure relates to a magnetic liquid sealing device. When a rotating shaft of the device axially vibrates, an outer ring of a bearing may not be provided with a rim, and a J-shaped bush and U-shaped sleeve ring can have relative displacement in an axial direction. When the rotating shaft radially vibrates, the U-shaped sleeve ring may deviate radially to allow sealing gaps, so as to prevent a bump between a pole shoe and J-shaped bush. Under action of a support spring and axial spring, sealing rings can be pressed to allow for sealing, and the U-shaped sleeve ring may not be in direct contact with an end cap, so as to avoid face friction.

Magnetic liquid sealing device resistible to axial and radial vibration

A magnetic liquid sealing device includes a housing, a rotating shaft, a first pole shoe, a second pole shoe, a plurality of permanent magnets, a rotation ring, and a sealing block. A chamber is defined in the housing including a first housing and a second housing. The rotating shaft passes through and is rotatable. The first pole shoe and the second pole shoe surround the rotating shaft and are spaced apart. The plurality of permanent magnets between the first pole shoe and the second pole shoe are spaced apart. The rotation ring surrounds the rotating shaft and is rotatable. The first housing, the rotation ring, and the second housing define the chamber. The rotation ring on outer sides of the plurality of permanent magnets is defined with a through hole running through the rotation ring. The sealing block in the through hole is detachably connected to the rotation ring.

Magnetic liquid sealing device

A magnetic liquid sealing device is provided. The magnetic liquid sealing device includes a housing, a rotating shaft, a pole shoe, a permanent magnet, and a first sealing ring. The rotating shaft is provided with an annular first stop portion, the pole shoe has a first end face and a second end face opposite to each other in an axial direction of the rotating shaft, and the permanent magnet is fitted over the rotating shaft. The first sealing ring is fitted over the rotating shaft, and includes a first part and a second part. The first part is sealedly fitted with at least one of the first end face and an inner peripheral surface of the housing, and an inner end of the second part is a first free end movably arranged along the axial direction of the rotating shaft.

A magnetic fluid sealing device for an oscillating shaft includes a housing, the oscillating shaft, a first seal, a second seal, and a magnetic source. The housing includes a ball head, and a ball hinge is arranged within the housing. The oscillating shaft is swingable with the ball hinge as a center. The first seal and the second seal are arranged on both sides of the ball head. The first seal includes a first toothed ring, and the second seal includes a second toothed ring. Magnetic fluid is filled at sealing gaps between the first and second toothed rings and the ball head. The magnetic source generates a magnetic field along an axial direction of the oscillating shaft.

Magnetic fluid sealing device for oscillating shaft

A magnetic fluid sealing device includes a housing, a shaft, a magnetic fluid sealing assembly, a thermal conductive gasket and a resistance wire. The housing has a cavity. The shaft is pivotally arranged in the cavity, and at least one end of the shaft extends out of the cavity. The magnetic fluid sealing assembly is arranged in the cavity and fitted over the shaft. The thermal conductive gasket is arranged in the cavity and fitted over the shaft, an inner peripheral surface of the thermal conductive gasket is spaced apart from the shaft along a radial direction of the shaft, and the magnetic fluid sealing assembly is spaced apart from the thermal conductive gasket along an axial direction of the shaft. The resistance wire is arranged in the thermal conductive gasket and configured to vaporize a sealed fluid medium between the thermal conductive gasket and the shaft.

Magnetic fluid sealing device for sealing fluid medium

A magnetic fluid sealing device, includes first pole teeth and a first magnetic fluid adsorbed on the first pole teeth functioning as a first line of defense for sealing, as well as second pole teeth and a second magnetic fluid adsorbed on the second pole teeth functioning as a second line of defense for sealing. The second pole teeth of the magnetic fluid sealing device are arranged on the permanent magnet or the flux sleeve. Since the flux sleeve is fitted over the permanent magnet, the arrangement of the second pole teeth can ensure the ability of the pole shoe to absorb the magnetic fluid, and also can make full use of a length of the permanent magnet in the axial direction of the rotating shaft. Therefore, the magnetic fluid sealing device is effectively improved in the sealing effect and the pressure resistance without increasing its axial length.

Magnetic fluid sealing device

A magnetic liquid damping shock absorber includes a housing, a thermal insulating material layer, a mass block and a magnetic liquid. The housing defines a sealed cavity, the sealed cavity has a first wall face and a second wall face opposite in a first direction and a circumferential wall face located between the first wall face and the second wall face in the first direction. The thermal insulating material layer is provided on an outer surface of the housing, on a wall face of the sealed cavity or in a housing wall of the housing. The mass block is located in the sealed cavity, and the mass block and the housing define a magnetic liquid cavity therebetween. The magnetic liquid is filled in the magnetic liquid cavity.

Magnetic liquid damping shock absorber

A chain unit lubricated and sealed with magnetic fluid includes a pin shaft, a magnetic sleeve, a first pole piece and a second pole piece. The sleeve is fitted over an outer periphery of the pin shaft. Both ends of the pin shaft protrude from the sleeve. A first gap exists between an inner peripheral surface of the sleeve and an outer peripheral surface of the pin shaft. The first pole piece is arranged at one of the sleeve and has a first mating hole. A second gap exists between an inner wall surface of the first mating hole and the outer peripheral surface of the pin shaft. The second pole piece is arranged at the other end of the sleeve and has a second mating hole. A third gap exists between an inner wall surface of the second mating hole and the outer peripheral surface of the pin shaft.

Chain unit sealed and lubricated with magnetic fluid and chain having same

A magnetic fluid damper includes a housing defining a cavity; a plurality of mass blocks located in the cavity and spaced from each other in a first direction; at least one energy dissipating assembly, in which the plurality of mass blocks and the at least one energy dissipating assembly are arranged alternately along the first direction in the cavity, in which each energy dissipating assembly includes a first permanent magnet and a first porous medium member, pores of each first porous medium member being filled with first magnetic fluid; and a plurality of reset parts cooperating with the plurality of mass blocks in one-to-one correspondence to apply restoring forces in a second direction to the mass blocks, in which restoring forces received by two mass blocks adjacent in the first direction are not equal.

Magnetic fluid damper

A capillary magnetic-liquid sealing device includes: a housing having a shaft chamber; a rotating shaft arranged in the shaft chamber; a first pole shoe and a second pole shoe fitted over the rotating shaft and spaced apart in an axial direction of the rotating shaft; a permanent magnet fitted over the rotating shaft and located between the first pole shoe and the second pole shoe; a first magnetically nonconductive capillary block and a second magnetically nonconductive capillary block fitted over the rotating shaft and spaced apart in the axial direction of the rotating shaft. A first capillary cavity is formed among the first magnetically nonconductive capillary block, the first pole shoe and the rotating shaft; and a second capillary cavity is formed among the second magnetically nonconductive capillary block, the second pole shoe and the rotating shaft.

Capillary magnetic-liquid sealing device

The present disclosure provides a detection system and method for a distribution state of magnetic fluid in a sealing gap. The detection system includes: a detection assembly including a first capacitor plate, a second capacitor plate and a capacitance meter. The first capacitor plate is arranged at an inner circumferential surface of a pole piece in a sealing device, and the second capacitor plate is arranged at an outer circumferential surface of a rotating shaft in the sealing device. The first capacitor plate and the second capacitor plate are annular and opposite to each other in a radial direction of the rotating shaft, the sealing gap being formed between the first capacitor plate and the second capacitor plate. The capacitance meter is electrically connected with the first capacitor plate and the second capacitor plate to measure capacitance between the first capacitor plate and the second capacitor plate.

Detection system and method for distribution state of magnetic fluid in sealing gap

A combined sealing device with magnetic fluid includes a housing having a chamber; a rotating shaft rotatably arranged in the chamber; a seal assembly fitted over the rotating shaft and located in the chamber, in which the seal assembly includes a brush seal part, a magnetic fluid seal part, and a labyrinth seal part all fitted over the rotating shaft and spaced apart from one another in an axial direction of the rotating shaft, the brush seal part being arranged adjacent to the sealing cavity, and the magnetic fluid seal part being arranged between the brush seal part and the labyrinth seal part; and an absorption part arranged in the brush seal part and configured to adsorb a sealing medium spilled from the sealing cavity.

Growing community of inventors

Beijing, China

Decai Li