Magnetic liquid sealing device

Patent metadata

Field	Value
Publication number	US-11525514-B2
Application number	US-202117313391-A
Country	US
Kind code	B2
Filing date	May 6, 2021
Priority date	Dec 29, 2020
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

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.

First claim

What is claimed is:

1. A magnetic liquid sealing device, comprising
a housing, a chamber being defined in the housing, the housing comprising a first housing and a second housing;
a rotating shaft passing through the housing and rotatable relative to the housing, at least a part of the rotating shaft being located in the chamber, and the first housing and the second housing being opposite to each other in an axial direction of the rotating shaft;
a first pole shoe and a second pole shoe both located in the chamber and surrounding the rotating shaft, respectively, the first pole shoe and the second pole shoe being spaced apart in the axial direction of the rotating shaft, magnetic liquid being filled between the first pole shoe and the rotating shaft, and magnetic liquid being filled between the second pole shoe and the rotating shaft;
a plurality of permanent magnets located in the chamber, located between the first pole shoe and the second pole shoe, and spaced apart in a circumferential direction of the rotating shaft, the permanent magnet being provided with a first magnetic pole and a second magnetic pole opposite to each other in the axial direction of the rotating shaft;
a rotation ring surrounding the rotating shaft and rotatable relative to the housing, the first housing, the rotation ring, and the second housing being successively connected in the axial direction of the rotating shaft, the first housing, the rotation ring, and the second housing defining the chamber, the rotation ring being located on outer sides of the plurality of permanent magnets, and the rotation ring being defined with a through hole running through the rotation ring along a radial direction of the rotating shaft; and
a sealing block configured to detachably connect to the rotation ring in the through hole, such that the plurality of permanent magnets are removable from the chamber via the through hole;
wherein a dimension of the through hole in the axial direction of the rotating shaft is D 1 , a deminsion of the permanent magnet in the axial direction of the rotating shaft is D 2 , D 1 >D 2 , and a dimension of the through hole in the circumferential direciton of the rotating shaft is greater than or equal to diameter of the permanent magnet.

2. The magnetic liquid sealing device according to claim 1 , wherein one side of the first housing adjacent to the second housing is provided with a first annular groove, and one side of the second housing adjacent to the first housing is provided with a second annular groove, and
one side of the rotation ring adjacent to the first housing is provided with a first annular projection, one side of the rotation ring adjacent to the second housing is provided with a second annular projection, the first annular projection is fitted with the first annular groove, and the second annular projection is fitted with the second annular groove.

3. The magnetic liquid sealing device according to claim 1 , wherein one side of the first pole shoe adjacent to the second pole shoe is provided with a third annular projection, one side of the second pole shoe adjacent to the first pole shoe is provided with a fourth annular projection, and an outer circumferential surface of the permanent magnet is in contact with outer circumferential surfaces of the third annular projection and the fourth annular projection, respectively.

4. The magnetic liquid sealing device according to claim 1 , further comprising a first sealing ring and a second sealing ring, the first sealing ring being arranged between the rotation ring and the first housing, and the second sealing ring being arranged between the rotation ring and the second housing.

5. The magnetic liquid sealing device according to claim 1 , further comprising a third sealing ring arranged between the sealing block and the rotation ring.

6. The magnetic liquid sealing device according to claim 1 , further comprising a first bearing and a second bearing both located in the chamber, the first bearing and the second bearing being fitted over the rotating shaft, respectively, and being spaced apart in the axial direction of the rotating shaft, the first pole shoe, the second pole shoe, and the permanent magnets being all located between the first bearing and the second bearing.

7. The magnetic liquid sealing device according to claim 6 , further comprising a first positioning member, a second positioning member, and a third positioning member all located in the chamber, the first positioning member, the second positioning member, and the third positioning member being fitted over the rotating shaft, respectively, the first bearing being located between the first positioning member and the second positioning member, and the third positioning member being located between the second pole shoe and the second bearing.

8. The magnetic liquid sealing device according to claim 1 , wherein an outer circumferential surface of the first pole shoe and an outer circumferential surface of the second pole shoe are both provided with a groove, and
the magnetic liquid sealing device further comprises a fourth sealing ring and a fifth sealing ring, the fourth sealing ring is arranged in the groove on the outer circumferential surface of the first pole shoe, and the fifth sealing ring is arranged in the groove on the outer circumferential surface of the second pole shoe.

9. The magnetic liquid sealing device according to claim 1 , further comprising an end cover arranged on one side of the housing, the rotating shaft passing through the end cover, and the end cover being configured to seal the chamber.

Assignees

• Univ Tsinghua

Inventors

• Li Decai
• Li Yingsong
• Liu Xiao
• Ren Sijie
• Han Pengdong

Classifications

• F16J15/43 Primary

  kept in sealing position by magnetic force · CPC title

• F16J15/40

  by means of fluid · CPC title

• F16C33/765

  by a magnetic field · CPC title