CN103115152B - Magnetic fluid and maze alternated type combined sealing - Google Patents

Abstract

The utility model relates to an alternating combination seal of magnetic liquid and labyrinth, which belongs to the sealing device of a rotating shaft. The leakage problem of the rotating shaft with large clearance is solved. The shaft of the alternate combined seal is a stepped shaft, using the magnetic force generated by the first to Nth permanent magnets, injecting magnetic liquid between the first to Nth pole pieces and the first to Nth steps of the stepped shaft to achieve the first From the Nth-level magnetic liquid seal, the space surrounded by the stepped shaft, the first to the Nth permanent magnets and the pole pieces on both sides is designed as the first to the N-1th expansion seal cavity of the labyrinth seal, realizing the magnetic liquid and Labyrinth alternate combination seal. The invention overcomes the defect that the labyrinth seal cannot realize zero leakage, reduces the loss of magnetic liquid when the seal fails, improves the pressure resistance of the magnetic liquid seal under the condition of a large gap, and expands the safe working range. The alternating combined seal has a compact structure and is easy to install, and is an ideal sealing method for solving the leakage problem of the rotating shaft under the condition of large gap.

Description

A magnetic liquid and labyrinth alternate combined seal

technical field

The invention belongs to the field of mechanical engineering seals, in particular to an alternate combined seal of magnetic liquid and labyrinth.

Background technique

In many occasions, such as the seal of a 500mm large-diameter rotating shaft machine, the radial runout of the rotating shaft is usually not less than 0.4mm due to the rotating large-diameter main shaft, and too small a seal gap will cause wear and tear on the rotating shaft and the housing and lead to seal failure. Failure, so in general, the unilateral sealing gap is not less than 0.4mm. Although the magnetic liquid seal has the advantages of zero leakage, high reliability and long life, the larger the gap, the smaller the pressure resistance of the magnetic liquid seal. Therefore, it is of great significance to improve the performance of the magnetic liquid seal under the condition of a large gap.

Contents of the invention

The technical problem to be solved by the present invention is to provide an alternating combination seal of magnetic liquid and labyrinth, which is used to solve the leakage problem of the rotating shaft with large gap.

Technical scheme of the present invention is:

An alternate combined seal of magnetic liquid and labyrinth, the alternate combined seal includes:

Shaft, casing, first and second magnetic isolation rings, first to Nth pole shoes, first to Nth rubber rings, first to N-1th permanent magnets, first and second bearings, end caps, first , the second snap ring.

The shaft is a stepped shaft.

The first to Nth rubber rings are respectively installed in the grooves on the outer circles of the first to Nth pole pieces.

Between the first and second magnetic isolation rings, install the first pole piece, the first permanent magnet, the second pole piece, the second permanent magnet, the third pole piece,

So on and so forth

The N-1th permanent magnet and the Nth pole shoe;

Injecting magnetic liquid into the inner circular surfaces of the first to Nth pole pieces to form an N-level seal assembly, which is sleeved on the shaft;

Install the first and second bearings on the shafts outside the first and second magnetic isolation rings respectively, and install the first and second retaining springs in the grooves at the left end and the right end of the shaft respectively; The N-level seal assembly installed on the shaft is installed in the housing, and the second bearing outer ring is pressed through the threaded connection between the end cover and the housing;

The first pole piece of the N-level seal assembly is installed on the outer circle of the first step of the stepped shaft;

The second pole piece of the N-level seal assembly is installed on the outer circle of the second step of the stepped shaft;

The third pole piece of the N-level seal assembly is installed on the outer circle of the third step of the stepped shaft;

So on and so forth

The Nth pole piece of the N-level seal assembly is installed on the outer circle of the Nth step of the stepped shaft;

The space enclosed by the first pole piece, the first permanent magnet, the second pole piece and the second step is the first expansion sealing chamber;

The space surrounded by the second pole piece, the second permanent magnet, the third pole piece and the third step is the second expansion sealing cavity;

So on and so forth

The space enclosed by the N-1 pole shoe, the N-1 permanent magnet, the N pole shoe and the N step is the N-1 expansion seal chamber;

The magnetic liquid seal between the first pole piece and the first step of the stepped shaft and the first expansion seal cavity form a combined seal of the magnetic liquid and the first stage of the labyrinth; the magnetic liquid between the second pole piece and the second step of the stepped shaft The seal and the second expansion seal chamber form a magnetic fluid and labyrinth second-level combined seal;

So on and so forth

The magnetic liquid seal between the N-1 pole piece and the N-1 step of the stepped shaft and the N-1 expansion seal cavity form a combined seal of the magnetic liquid and the N-1 labyrinth;

N is 2-20.

Through the above assembly, the alternating combination seal of magnetic liquid and labyrinth can be realized.

Beneficial effects of the present invention:

By designing the shaft in the magnetic liquid seal as a stepped shaft, the shape between the pole piece and the inner diameter of the pole piece is designed as a stepped shape, and the permanent magnet, the pole pieces on both sides of the permanent magnet, and the space between the stepped shaft are designed The labyrinth-sealed expansion seal cavity structure realizes the alternating combined seal of magnetic liquid and labyrinth. The invention overcomes the defect that the labyrinth seal cannot realize zero leakage, reduces the loss of magnetic liquid when the seal fails, improves the pressure resistance of the magnetic liquid seal under the condition of a large gap, and expands its safe working range. Therefore, it is an ideal sealing method for solving the leakage problem of the rotating shaft under the condition of large gap. The magnetic liquid and labyrinth alternate combined seal has a compact structure and is easy to install.

Description of drawings

Fig. 1 is a schematic diagram of an N-level magnetic liquid and labyrinth alternate combination seal.

Fig. 2 is a schematic diagram of a secondary magnetic liquid and labyrinth alternate combination seal.

Fig. 3 is a schematic diagram of a three-stage magnetic liquid and labyrinth alternate combined seal.

Fig. 4 is a schematic diagram of a three-stage magnetic liquid and labyrinth alternately combined sealing shaft.

Fig. 5 is a partial enlarged view of Fig. 3a.

Fig. 6 is a schematic diagram of a three-stage magnetic liquid and labyrinth alternate combined seal with pole teeth.

Fig. 7 is a schematic diagram of a three-stage magnetic liquid and labyrinth alternate combined seal with tapered holes on the pole shoe.

Fig. 8 is a schematic diagram of a three-stage magnetic liquid and labyrinth alternate combined seal with pole teeth on the tapered hole of the pole shoe.

Fig. 9 is a schematic diagram of a four-stage magnetic liquid and labyrinth alternate combination seal.

Fig. 10 is a schematic diagram of a ten-stage magnetic liquid and labyrinth alternate combination seal.

Fig. 11 is a schematic diagram of a twenty-stage magnetic liquid and labyrinth alternate combination seal.

Detailed ways

The present invention will be further described in conjunction with accompanying drawings.

Implementation Mode 1

An alternate combination seal of magnetic liquid and labyrinth, as shown in Figure 1, the alternate combination seal includes: shaft 1, housing 2, first and second magnetic isolation rings 6, 10, first to Nth pole pieces 7 -1, 7-2, ... 7-N, the first to the Nth rubber ring 8-1, 8-2, ..., 8-N, the first to the N-1th permanent magnet 9-1, 9- 2, ..., 9-(N-1), the first and second bearings 5 and 11, end caps 12, the first and second snap springs 4 and 13.

The shaft 1 is a stepped shaft, and the material of the stepped shaft is 2cr13 stainless steel.

The material of the shell 2 is non-magnetic stainless steel.

The first to Nth pole pieces 7-1, 7-2, ... 7-N are made of 2cr13 stainless steel.

The materials of the first to N-1th permanent magnets 9-1, 9-2, ..., 9-(N-1) are all NdFeB materials.

Install the first to Nth rubber rings 8-1, 8-2, ..., 8-N on the outer circles of the first to Nth pole pieces 7-1, 7-2, ..., 7-N respectively inside the groove.

Between the first and second magnetic isolation rings 6 and 10, the first pole shoe 7-1, the first permanent magnet 9-1, the second pole shoe 7-2, the second permanent magnet 9-2, the Three-pole shoe 7-3,

So on and so forth

The N-1th permanent magnet 9-(N-1), the Nth pole shoe 7-N;

Inject magnetic liquid into the inner surface of the first to Nth pole pieces to form an N-level seal assembly, which is set on the shaft 1; the magnetic liquid is oil-based magnetic liquid, ester-based magnetic liquid or silicone oil-based magnetic liquid. Liquid, which magnetic liquid to choose is determined by the sealed medium and its pressure, but this is not the focus of the present invention.

Then install the first and second bearings 5 and 11 on the shafts outside the first and second magnetic isolation rings 6 and 10 respectively, and install the first and second snap springs 4 and 13 in the grooves at the left end of the shaft 1 respectively 4-1 and the groove 4-2 at the right end; then install the N-level seal assembly installed on the shaft 1 in the casing 2, and press the outer ring of the second bearing 11 through the threaded connection between the end cover 12 and the casing 2;

The first pole piece 7-1 of the N-level seal assembly is installed on the outer circle of the first step 1-1 of the stepped shaft;

The second pole piece 7-2 of the N-level seal assembly is installed on the outer circle of the second step 1-2 of the stepped shaft;

The third pole piece 7-3 of the N-level seal assembly is installed on the outer circle of the third step 1-3 of the stepped shaft;

So on and so forth

The Nth pole piece 7-N of the N-level seal assembly is installed on the outer circle of the Nth step 1-N of the stepped shaft;

The space surrounded by the first pole piece 7-1, the first permanent magnet 9-1, the second pole piece 7-2 and the second step 1-2 is the first expansion sealing cavity 14-1;

The space surrounded by the second pole piece 7-2, the second permanent magnet 9-2, the third pole piece 7-3 and the third step 1-3 is the second expansion sealing cavity 14-2;

So on and so forth

The space enclosed by the N-1 pole piece 7-(N-1), the N-1 permanent magnet 9-(N-1), the N-th pole piece 7-N and the N-th step 1-N is the N-th 1 expansion sealing cavity 14-(N-1);

The magnetic fluid seal between the first pole piece 7-1 and the first step 1-1 of the stepped shaft and the first expansion seal chamber 14-1 form a combined seal of the magnetic fluid and the first level of the labyrinth; the second pole piece 7-2 The magnetic liquid seal between the second step 1-2 of the stepped shaft and the second expansion seal cavity 14-2 form a combined seal of the magnetic liquid and the second stage of the labyrinth;

So on and so forth

Magnetic liquid seal between the N-1th pole shoe 7-(N-1) and the N-1st step 1-(N-1) of the stepped shaft and the N-1th expansion seal cavity 14-(N-1) Form the magnetic liquid and labyrinth level N-1 combined seal;

N is 2 to 20;

Through the above assembly, the alternating combination seal of magnetic liquid and labyrinth can be realized.

The axial length of the first step 1-1 of the stepped shaft is the axial length of the first magnetic isolation ring 6, the axial length of the first pole piece 7-1, and the right side of the first pole piece 7-1. The sum of the distances between 16 and the left side of the shoulder of the second ladder 15;

The axial length of the second step 1-2 of the stepped shaft is the sum of the axial length of the first permanent magnet 9-1 and the axial length of the second pole piece 7-2;

The axial length of the third step 1-3 of the stepped shaft is the sum of the axial length of the second permanent magnet 9-2 and the axial length of the third pole piece 7-3;

So on and so forth

The axial length of the Nth step 1-N of the stepped shaft is the sum of the axial length of the N-1th permanent magnet 9-(N-1) and the axial length of the Nth pole piece 7-N;

The difference between the shaft diameters of two adjacent steps is 2-12 mm.

The distance Lg between the right side 16 of the first pole shoe 7-1 and the left side 15 of the second step shoulder is 0.1-2.0 mm.

The inner circular surfaces of the first to Nth pole pieces 7-1, 7-2, ..., 7-N and the first to Nth steps 1-1, 1-2, . .....The fit clearance of the outer circular surface of 1-N is 0.4~2.0mm.

The outer diameters of the first to N-1th permanent magnets 9-1, 9-2, ... 9-(N-1) are all equal;

The radial lengths of the first to N-1 expansion sealing chambers 14-1, 14-2, ..., 14-(N-1) are equal, and are all 6-30 mm.

The inner holes of the first to Nth pole shoes 7-1, 7-2, ..., 7-N are machined with pole teeth, and the number of pole teeth is 2-10.

The inner holes of the first to Nth pole pieces 7-1, 7-2, ..., 7-N are tapered holes with a taper of 1:10-1:0.25.

In the tapered holes of the first to Nth pole shoes 7-1, 7-2, ..., 7-N, pole teeth are machined, and the number of pole teeth is 2-10.

The axial length of the first step 1-1 is the axial length of the first magnetic isolation ring 6, the axial length of the first pole piece 7-1, the right side 16 of the first pole piece 7-1 and the The sum of 15 distances from the left side of the shoulder of the second step;

The axial length of the second step 1-2 is the sum of the axial length of the first permanent magnet 9-1 and the axial length of the second pole piece 7-2;

The axial length of the third step 1-3 is the sum of the axial length of the second permanent magnet 9-2 and the axial length of the third pole piece 7-3;

So on and so forth

The axial length of the Nth step 1-N is the sum of the axial length of the N-1th permanent magnet 9-(N-1) and the axial length of the Nth pole piece 7-N;

The difference between the shaft diameters of two adjacent steps is 2-12 mm.

The distance Lg between the right side 16 of the first pole shoe 7-1 and the left side 15 of the second step shoulder is 0.1-2.0 mm.

The inner circular surfaces of the first to Nth pole pieces 7-1, 7-2, ..., 7-N and the first to Nth steps 1-1, 1-2, . .....The fit clearance of the outer circular surface of 1-N is 0.4~2.0mm.

The outer diameters of the first to N-1th permanent magnets 9-1, 9-2, ... 9-(N-1) are all equal;

The radial lengths of the first to N-1 expansion sealing chambers 14-1, 14-2, ..., 14-(N-1) are equal, and are all 6-30 mm.

Implementation mode two

The difference between the second embodiment and the first embodiment: pole teeth are processed on the inner holes of the first to Nth pole shoes 7-1, 7-2, ..., 7-N, and the number of pole teeth is 2-10 indivual.

Implementation Mode Three

The difference between Embodiment 3 and Embodiment 1: the inner holes of the first to Nth pole pieces 7-1, 7-2, ..., 7-N are tapered holes with a taper of 1:10 to 1:0.25 .

Implementation Mode Four

The difference between Embodiment 4 and Embodiment 3: In the taper holes of the first to Nth pole pieces 7-1, 7-2, ..., 7-N, pole teeth are processed, and the number of pole teeth is 2- 10.

Implementation Mode Five

An alternate combination seal of magnetic liquid and labyrinth, as shown in Figure 2, the alternate combination seal includes: shaft 1, housing 2, first and second magnetic isolation rings 6, 10, first and second pole pieces 7 -1, 7-2, the first and second rubber rings 8-1, 8-2, the first permanent magnet 9-1, the first and second bearings 5, 11, end cap 12, the first and second snap rings 4, 13. The shaft 1 is a stepped shaft.

Install the first and second rubber rings 8-1 and 8-2 respectively in the grooves on the outer circles of the first and second pole pieces 7-1 and 7-2.

Between the first and second magnetic isolation rings 6 and 10, the first pole piece 7-1, the first permanent magnet 9-1, and the second pole piece 7-2 are sequentially installed.

The magnetic liquid is injected into the inner circular surfaces of the first and second pole pieces to form a secondary sealing assembly, which is sleeved on the shaft 1 .

Install the first and second bearings 5 and 11 on the shafts at both ends of the first and second magnetic isolation rings 6 and 10 respectively, and install the first and second snap springs 4 and 13 in the grooves at the left end of the shaft 1 4-1 and the groove 4-2 at the right end; then install the sealing assembly installed on the shaft 1 in the housing 2, and press the outer ring of the second bearing 11 through the threaded connection between the end cover 12 and the housing 2.

The first pole piece 7-1 of the secondary seal assembly is installed on the outer circle of the first step 1-1 of the stepped shaft;

The second pole shoe 7-2 of the secondary seal assembly is installed on the outer circle of the second step 1-2 of the stepped shaft.

The space enclosed by the first pole piece 7-1, the first permanent magnet 9-1, the second pole piece 7-2 and the second step 1-1 is the first expansion sealing cavity 14-1.

The magnetic fluid seal between the first pole piece 7-1 and the first step 1-1 of the stepped shaft and the first expansion seal cavity 14-1 form a combined seal of the magnetic fluid and the first stage of the labyrinth.

The difference between the shaft diameters of two adjacent steps is 2 mm. The distance Lg between the right side 16 of the first pole shoe 7-1 and the left side 15 of the shoulder of the second step is 0.1mm. The fit clearances between the inner circular surfaces of the first and second pole pieces 7-1, 7-2 and the outer circular surfaces of the first and second steps 1-1, 1-2 of the stepped shaft are both 0.4 mm.

The radial lengths of the first expansion sealing chambers 14-1 are equal to 6 mm.

Through the above assembly, the alternating combination seal of magnetic liquid and labyrinth can be realized.

Embodiment Six

An alternate combination seal of magnetic liquid and labyrinth, as shown in Figure 3, the alternate combination seal includes: shaft 1, housing 2, first and second magnetic isolation rings 6, 10, first to third pole pieces 7 -1, 7-2, 7-3, first to third rubber rings 8-1, 8-2, 8-3, first and second permanent magnets 9-1, 9-2, first and second bearings 5, 11, end cap 12, first and second retaining springs 4, 13. The shaft 1 is a stepped shaft.

The first to third rubber rings 8-1, 8-2, 8-3 are respectively installed in the grooves on the outer circles of the first to third pole shoes 7-1, 7-2, 7-3.

Between the first and second magnetic isolation rings 6 and 10, the first pole shoe 7-1, the first permanent magnet 9-1, the second pole shoe 7-2, the second permanent magnet 9-2, the Three pole boots 7-3.

The magnetic liquid is injected into the inner circular surfaces of the first to third pole pieces to form a three-stage seal assembly, which is sleeved on the shaft 1 .

Install the first and second bearings 5 and 11 on the shafts at the two ends of the first and second magnetic isolation rings 6 and 10 respectively, and install the first and second snap springs 4 and 13 on the concave holes at the left end of the shaft 1 respectively. In the groove 4-1 and the groove 4-2 at the right end; then install the sealing assembly installed on the shaft 1 in the housing 2, and press the outer ring of the second bearing 11 through the threaded connection between the end cover 12 and the housing 2.

The first pole piece 7-1 of the three-stage seal assembly is installed on the outer circle of the first step 1-1 of the stepped shaft;

The second pole piece 7-2 of the three-stage seal assembly is installed on the outer circle of the second step 1-2 of the stepped shaft;

The third pole shoe 7-3 of the three-stage seal assembly is installed on the outer circle of the third step 1-3 of the stepped shaft.

The space enclosed by the first pole piece 7-1, the first permanent magnet 9-1, the second pole piece 7-2 and the second step 1-1 is the first expansion sealing cavity 14-1.

The space surrounded by the second pole piece 7-2, the second permanent magnet 9-2, the third pole piece 7-3 and the third step 1-3 is the second expansion sealing chamber 14-2.

The magnetic liquid seal between the first pole piece 7-1 and the first step 1-1 of the stepped shaft and the first expansion seal cavity 14-1 form a combined seal of the magnetic liquid and the labyrinth at the first level;

The magnetic liquid seal between the second pole piece 7-2 and the second step 1-2 of the stepped shaft and the second expansion seal chamber 14-2 form a second-stage combination seal of the magnetic liquid and the labyrinth.

The difference between the shaft diameters of two adjacent steps is 4mm. The distance Lg between the right side 16 of the first pole shoe 7-1 and the left side 15 of the shoulder of the second step is 1 mm. The inner circular surfaces of the first to third pole shoes 7-1, 7-2, 7-3 are in contact with the outer surfaces of the first to third steps 1-1, 1-2, 1-3 of the stepped shaft. The matching clearance of the round surface is 0.6mm.

The radial lengths of the first and second expansion sealing chambers 14-1 and 14-2 are equal, both being 8mm.

Through the above assembly, the alternate combination seal of the third-level magnetic liquid and the second-level labyrinth is realized.

Implementation Mode Seven

An alternate combination seal of magnetic liquid and labyrinth, as shown in Figure 9, the alternate combination seal includes: shaft 1, housing 2, first and second magnetic isolation rings 6, 10, first to fourth pole pieces 7 -1,7-2,7-3,7-4, the first to the fourth rubber ring 8-1,8-2,8-3,8-4, the first to the third permanent magnet 9-1,9 -2,9-3, the first and second bearings 5,11, the end cover 12, the first and the second snap springs 4,13. The shaft 1 is a stepped shaft.

Install the first to fourth rubber rings 8-1, 8-2, 8-3, 8-4 on the outer circles of the first to fourth pole shoes 7-1, 7-2, 7-3, 7-4 respectively in the groove on the

Between the first and second magnetic isolation rings 6 and 10, the first pole shoe 7-1, the first permanent magnet 9-1, the second pole shoe 7-2, the second permanent magnet 9-2, the Three pole pieces 7-3, the third permanent magnet 9-3, and the fourth pole piece 7-4.

The magnetic liquid is injected into the inner circular surfaces of the first to fourth pole pieces to form a four-stage sealing assembly, which is sleeved on the shaft 1 .

Install the first and second bearings 5 and 11 on the shafts at the two ends of the first and second magnetic isolation rings 6 and 10 respectively, and install the first and second snap springs 4 and 13 on the concave holes at the left end of the shaft 1 respectively. In the groove 4-1 and the groove 4-2 at the right end; then install the sealing assembly installed on the shaft 1 in the housing 2, and press the outer ring of the second bearing 11 through the threaded connection between the end cover 12 and the housing 2.

The first pole piece 7-1 of the four-stage seal assembly is installed on the outer circle of the first step 1-1 of the stepped shaft;

The second pole piece 7-2 of the four-stage seal assembly is installed on the outer circle of the second step 1-2 of the stepped shaft;

The third pole piece 7-3 of the four-stage seal assembly is installed on the outer circle of the third step 1-3 of the stepped shaft;

The fourth pole piece 7-4 of the four-stage seal assembly is installed on the outer circle of the fourth step 1-4 of the stepped shaft.

The space enclosed by the first pole piece 7-1, the first permanent magnet 9-1, the second pole piece 7-2 and the second step 1-1 is the first expansion sealing cavity 14-1.

The space surrounded by the second pole piece 7-2, the second permanent magnet 9-2, the third pole piece 7-3 and the third step 1-3 is the second expansion sealing cavity 14-2.

The space surrounded by the third pole piece 7-3, the third permanent magnet 9-3, the fourth pole piece 7-4 and the fourth step 1-4 is the third expansion sealing cavity 14-3.

The magnetic liquid seal between the first pole piece 7-1 and the first step 1-1 of the stepped shaft and the first expansion seal cavity 14-1 form a combined seal of the magnetic liquid and the labyrinth at the first level;

The magnetic liquid seal between the second pole piece 7-2 and the second step 1-2 of the stepped shaft and the second expansion seal cavity 14-2 form a second-stage combination seal of the magnetic liquid and the labyrinth;

The magnetic liquid seal between the third pole piece 7-3 and the third step 1-3 of the stepped shaft and the third expansion seal cavity 14-3 form a third-level combined seal of the magnetic liquid and the labyrinth;

The difference between the shaft diameters of two adjacent steps is 6mm. The distance Lg between the right side 16 of the first pole shoe 7-1 and the left side 15 of the shoulder of the second step is 1.2 mm. The inner circular surfaces of the first to fourth pole shoes 7-1, 7-2, 7-3, 7-4 and the first to fourth steps 1-1, 1-2, The fit clearance of the outer circular surfaces of 1-3 and 1-4 is 0.8mm.

The radial lengths of the first to third expansion and sealing chambers 14-1, 14-2, 14-3 are equal to 15 mm.

Through the above assembly, the four-stage magnetic liquid and labyrinth alternate combination seal can be realized.

Embodiment eight

An alternating combined seal of magnetic liquid and labyrinth, as shown in Figure 6, the difference between the eighth embodiment and the sixth embodiment: the inner parts of the first to third pole pieces 7-1, 7-2, 7-3 Pole teeth are processed on the hole, and the number of pole teeth is 2 or 10 or any number between 2 and 10.

Implementation Mode Nine

An alternating combined seal of magnetic liquid and labyrinth, as shown in Figure 7, the difference between the ninth embodiment and the sixth embodiment: the inner parts of the first to third pole pieces 7-1, 7-2, 7-3 The hole is a tapered hole, and the taper is 1:10 or 1:0.25 or any number between 1:10 and 1:0.25.

Embodiment ten

An alternating combined seal of magnetic liquid and labyrinth, as shown in Figure 8, the difference between the tenth embodiment and the ninth embodiment: the cones of the first to third pole pieces 7-1, 7-2, 7-3 In the hole, pole teeth are processed, the number of pole teeth is 2-10, and the number of pole teeth is 2 or 10 or any number between 2-10.

Embodiment Eleven

An alternate combination seal of magnetic liquid and labyrinth, as shown in Figure 10, the alternate combination seal includes: shaft 1, housing 2, first and second magnetic isolation rings 6, 10, first to tenth pole shoes 7 -1,7-2,7-3,...,7-9,7-10, the first to tenth rubber rings 8-1,8-2,8-3,...,8-9,8- 10. The first to ninth permanent magnets 9-1, 9-2, ..., 9-9, the first and second bearings 5, 11, end caps 12, first and second snap springs 4, 13. The shaft 1 is a stepped shaft.

Install the first to tenth rubber rings 8-1, 8-2, 8-3, ..., 8-9, 8-10 on the first to tenth pole shoes 7-1, 7-2, 7- 3, ..., 7-9, 7-10 in the groove on the outer circle.

Between the first and second magnetic isolation rings 6 and 10, the first pole shoe 7-1, the first permanent magnet 9-1, the second pole shoe 7-2, the second permanent magnet 9-2, the Three-pole shoe 7-3, and so on

The ninth pole piece 7-9, the ninth permanent magnet 9-9, and the tenth pole piece 7-10.

The magnetic liquid is injected into the inner circular surfaces of the first to tenth pole shoes to form a tenth stage seal assembly, which is sleeved on the shaft 1 .

Install the first and second bearings 5 and 11 on the shafts at the two ends of the first and second magnetic isolation rings 6 and 10 respectively, and install the first and second snap springs 4 and 13 on the concave holes at the left end of the shaft 1 respectively. In the groove 4-1 and the groove 4-2 at the right end; then install the sealing assembly installed on the shaft 1 in the housing 2, and press the outer ring of the second bearing 11 through the threaded connection between the end cover 12 and the housing 2.

The first pole shoe 7-1 of the ten-stage seal assembly is installed on the outer circle of the first step 1-1 of the stepped shaft;

The second pole piece 7-2 of the tenth seal assembly is installed on the outer circle of the second step 1-2 of the stepped shaft;

The third pole piece 7-3 of the tenth seal assembly is installed on the outer circle of the third step 1-3 of the stepped shaft;

So on and so forth

The ninth pole piece 7-9 of the tenth seal assembly is installed on the outer circle of the ninth step 1-9 of the stepped shaft;

The tenth pole piece 7-10 of the tenth seal assembly is installed on the outer circle of the tenth step 1-10 of the stepped shaft.

The space surrounded by the first pole piece 7-1, the first permanent magnet 9-1, the second pole piece 7-2 and the second step 1-2 is the first expansion sealing cavity 14-1;

The space surrounded by the second pole piece 7-2, the second permanent magnet 9-2, the third pole piece 7-3 and the third step 1-3 is the second expansion sealing cavity 14-2;

So on and so forth

The space enclosed by the ninth pole shoe 7-9, the ninth permanent magnet 9-9, the tenth pole shoe 7-10 and the tenth step 1-10 is the ninth expansion sealing cavity 14-9.

The magnetic liquid seal between the first pole piece 7-1 and the first step 1-1 of the stepped shaft and the first expansion seal cavity 14-1 form a combined seal of the magnetic liquid and the labyrinth at the first stage;

The magnetic liquid seal between the second pole piece 7-2 and the second step 1-2 of the stepped shaft and the second expansion seal cavity 14-2 form a second-stage combination seal of the magnetic liquid and the labyrinth;

The magnetic liquid seal between the third pole piece 7-3 and the third step 1-3 of the stepped shaft and the third expansion seal cavity 14-3 form a third-level combined seal of the magnetic liquid and the labyrinth;

So on and so forth

The magnetic liquid seal between the ninth pole shoe 7-9 and the ninth step 1-9 of the stepped shaft and the ninth expansion sealing chamber 14-9 form a magnetic liquid and labyrinth ninth-level combined seal;

The magnetic liquid seal between the tenth pole piece 7-10 and the tenth step 1-10 of the stepped shaft is a tenth-stage magnetic liquid seal.

The difference between the shaft diameters of two adjacent steps is 3mm. The distance Lg between the right side 16 of the first pole shoe 7-1 and the left side 15 of the shoulder of the second step is 1.5mm. The inner circular surfaces of the first to tenth pole shoes 7-1, 7-2, ..., 7-10 and the first to tenth steps 1-1, 1-2, . ... and the fit clearance of the outer circular surface of 1-10 is 1.2mm.

The radial lengths of the first to ninth expansion and sealing chambers 14-1, 14-2, ..., 14-9 are equal to 20 mm.

Through the above assembly, the alternate combined seal of ten-stage magnetic liquid and nine-stage labyrinth can be realized.

Embodiment 12

An alternate combination seal of magnetic liquid and labyrinth, as shown in Figure 11, the alternate combination seal includes: shaft 1, housing 2, first and second magnetic isolation rings 6, 10, first to twentieth pole shoes 7-1,7-2,7-3,...,7-19,7-20, the first to the twentieth rubber ring 8-1,8-2,8-3,...,8-19, 8-20, the first to nineteenth permanent magnets 9-1, 9-2, ..., 9-19, the first and second bearings 5, 11, end caps 12, the first and second retaining springs 4, 13 . The shaft 1 is a stepped shaft.

Install the first to twentieth rubber rings 8-1, 8-2, 8-3, ..., 8-19, 8-20 on the first to twentieth pole pieces 7-1, 7-2, In the groove on 7-3, ..., 7-19, 7-20 outer circle.

Between the first and second magnetic isolation rings 6 and 10, the first pole shoe 7-1, the first permanent magnet 9-1, the second pole shoe 7-2, the second permanent magnet 9-2, the Three-pole shoe 7-3, and so on

The nineteenth pole piece 7-19, the nineteenth permanent magnet 9-19, and the twentieth pole piece 7-20.

The magnetic liquid is injected into the inner circular surfaces of the first to twentieth pole pieces to form a twentieth-level sealing assembly, which is sleeved on the shaft 1 .

Install the first and second bearings 5 and 11 on the shafts at the two ends of the first and second magnetic isolation rings 6 and 10 respectively, and install the first and second snap springs 4 and 13 on the concave holes at the left end of the shaft 1 respectively. In the groove 4-1 and the groove 4-2 at the right end; then install the sealing assembly installed on the shaft 1 in the housing 2, and press the outer ring of the second bearing 11 through the threaded connection between the end cover 12 and the housing 2.

The first pole shoe 7-1 of the twentieth-level seal assembly is installed on the outer circle of the first step 1-1 of the stepped shaft;

The second pole piece 7-2 of the twenty-stage seal assembly is installed on the outer circle of the second step 1-2 of the stepped shaft;

The third pole shoe 7-3 of the twenty-stage seal assembly is installed on the outer circle of the third step 1-3 of the stepped shaft;

So on and so forth

The nineteenth pole piece 7-19 of the twenty-level seal assembly is installed on the outer circle of the nineteenth step 1-19 of the stepped shaft;

The twentieth pole shoe 7-20 of the twentieth-level seal assembly is installed on the outer circle of the twentieth step 1-20 of the stepped shaft.

The space surrounded by the first pole piece 7-1, the first permanent magnet 9-1, the second pole piece 7-2 and the second step 1-2 is the first expansion sealing cavity 14-1;

The space surrounded by the second pole piece 7-2, the second permanent magnet 9-2, the third pole piece 7-3 and the third step 1-3 is the second expansion sealing cavity 14-2;

So on and so forth

The space surrounded by the nineteenth pole piece 7-19, the nineteenth permanent magnet 9-19, the twentieth pole piece 7-20 and the twentieth step 1-20 is the nineteenth expansion sealing cavity 14-19.

The magnetic liquid seal between the first pole piece 7-1 and the first step 1-1 of the stepped shaft and the first expansion seal cavity 14-1 form a combined seal of the magnetic liquid and the labyrinth at the first level;

The magnetic liquid seal between the second pole piece 7-2 and the second step 1-2 of the stepped shaft and the second expansion seal cavity 14-2 form a second-stage combination seal of the magnetic liquid and the labyrinth;

The magnetic liquid seal between the third pole piece 7-3 and the third step 1-3 of the stepped shaft and the third expansion seal cavity 14-3 form a third-level combined seal of the magnetic liquid and the labyrinth;

So on and so forth

The magnetic liquid seal between the nineteenth pole piece 7-19 and the nineteenth step 1-19 of the stepped shaft and the nineteenth expansion seal cavity 14-19 form a combined seal of the nineteenth stage of the magnetic liquid and the labyrinth;

The magnetic liquid seal between the twentieth pole shoe 7-20 and the twentieth step 1-20 of the stepped shaft is a twentieth-level magnetic liquid seal.

The difference between the shaft diameters of two adjacent steps is 12mm. The distance Lg between the right side 16 of the first pole shoe 7-1 and the left side 15 of the shoulder of the second step is 2.0 mm. The inner circular surfaces of the first to twentieth pole shoes 7-1, 7-2, ..., 7-20 and the first to twentieth steps 1-1, 1-2 of the stepped shaft ,...,1-20 The fit clearance of the outer circular surface is 2.0mm.

The radial lengths of the first to nineteenth expansion and sealing chambers 14-1, 14-2, ..., 14-19 are equal to 30mm.

Through the above assembly, the alternate combination seal of 20-level magnetic liquid and 19-level labyrinth can be realized.

The sealing ring 3 is embedded in the groove on the flange of the casing 2, and is fixed on the casing of the sealed medium through the threaded connection between the casing 2 and the casing of the sealed medium.

Claims (8)

1. magnetic liquid and a labyrinth alternate type combination seal, this alternate type combination seal comprises: axle (1), shell (2), the first magnetism resistent ring (6), the second magnetism resistent ring (10), the first pole shoe (7-1), the second pole shoe (7-2), the first permanent magnet (9-1), the first rubber ring (8-1), the second rubber ring (8-2), clutch shaft bearing (5), the second bearing (11), end cap (12), the first jump ring (4), the second jump ring (13);

First rubber ring (8-1), the second rubber ring (8-2) are arranged in the groove on the first pole shoe (7-1), the second pole shoe (7-2) cylindrical respectively;

Between the first magnetism resistent ring (6), the second magnetism resistent ring (10), order installs the first pole shoe (7-1), the first permanent magnet (9-1), the second pole shoe (7-2), by on the first pole shoe described in magnetic liquid injection and the second pole shoe inner headed face, form black box, be enclosed within axle (1);

Again clutch shaft bearing (5), the second bearing (11) are arranged on the axle in the first magnetism resistent ring (6), the second magnetism resistent ring (10) outside respectively, the first jump ring (4), the second jump ring (13) are arranged in the groove (4-1) of axle (1) left end and the groove (4-2) of right-hand member respectively; Again the black box be arranged on axle (1) is arranged in shell (2), by be threaded compression second bearing (11) outer ring of end cap (12) with shell (2);

It is characterized in that:

Described axle (1) is a multidiameter shaft;

Described black box is N level sealing configuration, and this structure comprises: first to N pole shoe (7-1,7-2 ... 7-N), first to N rubber ring (8-1,8-2 ..., 8-N), first to N-1 permanent magnet (9-1,9-2 ..., 9-(N-1));

By the 3rd to N rubber ring (8-3 ..., 8-N) be arranged on respectively the 3rd to N pole shoe (7-3 ..., 7-N) in groove on cylindrical;

After the second pole shoe (7-2), order install the second permanent magnet (9-2), the 3rd pole shoe (7-3) ..., N-1 permanent magnet (9-(N-1)), N pole shoe (7-N), described in being injected by magnetic liquid first on N pole shoe inner headed face, be enclosed within described axle (1), form N level black box, realize N level magnetic fluid sealing;

First pole shoe (7-1) of N level black box is arranged on the cylindrical of the first ladder (1-1) of multidiameter shaft;

Second pole shoe (7-2) of N level black box is arranged on the cylindrical of the second ladder (1-2) of multidiameter shaft;

3rd pole shoe (7-3) of N level black box is arranged on the cylindrical of the 3rd ladder (1-3) of multidiameter shaft;

The rest may be inferred

The N pole shoe (7-N) of N level black box is arranged on the cylindrical of N ladder (1-N) of multidiameter shaft;

The space that first pole shoe (7-1), the first permanent magnet (9-1), the second pole shoe (7-2) and the second ladder (1-2) surround is the first Expansion sealing chamber (14-1);

The space that second pole shoe (7-2), the second permanent magnet (9-2), the 3rd pole shoe (7-3) and the 3rd ladder (1-3) surround is the second Expansion sealing chamber (14-2);

The rest may be inferred

The space that N-1 pole shoe (7-(N-1)), N-1 permanent magnet (9-(N-1)), N pole shoe (7-N) and N ladder (1-N) surround is N-1 Expansion sealing chamber (14-(N-1));

Magnetic fluid sealing between first ladder (1-1) of the first pole shoe (7-1) and multidiameter shaft and the first Expansion sealing chamber (14-1) form magnetic liquid and labyrinth first order combination seal; Magnetic fluid sealing between second ladder (1-2) of the second pole shoe (7-2) and multidiameter shaft and the second Expansion sealing chamber (14-2) form magnetic liquid and the second level, labyrinth combination seal;

The rest may be inferred

Magnetic fluid sealing between N-1 pole shoe (7-(N-1)) and the N-1 ladder (1-(N-1)) of multidiameter shaft and N-1 Expansion sealing chamber (14-(N-1)) form magnetic liquid and labyrinth N-1 level combination seal; N is 2 ~ 20;

Magnetic liquid and labyrinth alternate type combination seal is realized by assembling above.

2. a kind of magnetic liquid according to claim 1 and labyrinth alternate type combination seal, is characterized in that:

First ladder (1-1) axial length of described multidiameter shaft is the distance sum of the axial length of the first magnetism resistent ring (6), the axial length of the first pole shoe (7-1), the right flank (16) of the first pole shoe (7-1) and the shaft shoulder left surface (15) of the second ladder;

Second ladder (1-2) axial length of multidiameter shaft is the axial length of the first permanent magnet (9-1) and the axial length sum of the second pole shoe (7-2);

3rd ladder (1-3) axial length of multidiameter shaft is the axial length of the second permanent magnet (9-2) and the axial length sum of the 3rd pole shoe (7-3);

The rest may be inferred

N ladder (1-N) axial length of multidiameter shaft is the axial length of N-1 permanent magnet (9-(N-1)) and the axial length sum of N pole shoe (7-N);

The difference of the diameter of axle of adjacent two ladders is equal, is 2 ~ 12mm.

3. a kind of magnetic liquid according to claim 2 and labyrinth alternate type combination seal, is characterized in that:

The right flank (16) of described the first pole shoe (7-1) and shaft shoulder left surface (15) the distance Lg of the second ladder are 0.1 ~ 2.0mm.

4. a kind of magnetic liquid according to claim 1 and labyrinth alternate type combination seal, is characterized in that:

Described first to N pole shoe (7-1,7-2 ..., 7-N) inner headed face and described multidiameter shaft first equal to the matching gap of N ladder (1-1,1-2 ... 1-N) periphery, be 0.4 ~ 2.0mm.

5. a kind of magnetic liquid according to claim 1 and labyrinth alternate type combination seal, is characterized in that:

First to N-1 Expansion sealing chamber (14-1,14-2 ..., 14-(N-1)) radial length equal, be 6 ~ 30mm.

6. a kind of magnetic liquid according to claim 1 and labyrinth alternate type combination seal, is characterized in that:

Described first to N pole shoe (7-1,7-2 ..., 7-N) endoporus on process pole tooth, pole number of teeth amount is 2 ~ 10.

7. a kind of magnetic liquid according to claim 1 and labyrinth alternate type combination seal, is characterized in that:

Described first to N pole shoe (7-1,7-2 ..., 7-N) endoporus be taper hole, tapering size is 1:10 ~ 1:0.25.

8. a kind of magnetic liquid according to claim 7 and labyrinth alternate type combination seal, is characterized in that:

Described first to N pole shoe (7-1,7-2 ..., 7-N) taper hole in, process pole tooth, pole number of teeth amount is 2 ~ 10.