CN106015586A - Stepped end face type magnetic fluid sealing device - Google Patents

Abstract

The invention relates to the field of mechanical engineering seals, in particular to a stepped end-face magnetic fluid sealing device, which includes a housing, a left pole piece, a middle pole piece, a right pole piece, and a permanent magnet. The middle pole piece is installed on a shaft The left and right sides of the middle pole shoe are radially symmetrically provided with stepped structures; the left pole shoe is installed on the left side of the middle pole shoe, the right pole shoe is installed on the right side of the middle pole shoe, and the right end surface of the left pole shoe is provided with a pole Teeth I and annular groove I, pole tooth I corresponds to the stepped side of the left end of the middle pole piece, and there is an annular groove I between pole teeth I; pole teeth II and annular groove II are set on the left end face of the right pole piece, pole Teeth II correspond to the stepped side of the right end of the middle pole shoe, and there is an annular groove II between the pole teeth II; permanent magnets are installed in the annular groove I and the annular groove II. The sealing device of the present invention has good sealing performance, and can meet the use requirements of working conditions such as large gaps, high speeds, and heavy loads.

Description

A stepped end face magnetic fluid sealing device

technical field

The invention belongs to the field of mechanical engineering seals, in particular to a stepped end face magnetic fluid seal device.

Background technique

The pressure resistance performance of the magnetic fluid seal decreases significantly with the increase of the seal gap. Therefore, improving the pressure resistance performance of large-gap magnetic fluid seals is one of the hot issues in current research. One of the methods to improve the pressure resistance performance of magnetic fluid seals under large gaps is to improve the structure of magnetic fluid seals. Compared with the traditional sealing structure, the sealing performance of the existing magnetic fluid sealing device has been greatly improved by setting the labyrinth sealing structure. In addition, due to the defects in the sealing structure, the leakage of magnetic fluid is large when the seal fails, and the pressure resistance is low, which cannot meet the requirements of large gaps and high-speed working conditions.

Contents of the invention

The invention aims to solve the requirement that the existing sealing device cannot achieve high sealing performance under working conditions such as high speed or large gap, and provides a stepped end face magnetic fluid sealing device.

The technical scheme of the present invention is as follows: a stepped end-face magnetic fluid sealing device, including a housing, a left pole piece, a middle pole piece, a right pole piece, and a permanent magnet. The middle pole piece is installed in the middle of the shaft, and the middle pole piece The left end face and the right end face of the shoe are both stepped structures, and the steps on the left end face and the right end face are arranged along the radial axis respectively; the left pole shoe is installed on the left side of the middle pole shoe, and the right pole shoe is installed on the middle pole shoe the right side of

A pole tooth I and an annular groove I are arranged on the right end surface of the left pole shoe, the number of steps of the pole tooth I is equal to that of the left end surface of the middle pole shoe, and an annular groove is arranged between adjacent pole teeth I I; the pole teeth I are arranged in the axial direction of the shaft, respectively extending to the side of each step on the left end face of the middle pole piece, and there is a gap between the right end face of each pole tooth I and the side of each step. The right end surface of the tooth I is injected with magnetic fluid, and under the action of the magnetic field force, the magnetic fluid is adsorbed on the right end surface of the pole tooth, and the height of the pole tooth I in the axial direction is smaller than the height of the side surface of the corresponding step; A permanent magnet is set in the annular groove 1 described above;

A pole tooth II and an annular groove II are arranged on the left end surface of the right pole piece, the number of steps of the pole tooth II is equal to that of the right end surface of the middle pole piece, and an annular groove is arranged between adjacent pole teeth II II; the pole teeth II are arranged along the axial direction of the shaft, extending to the side of each step on the right end face of the middle pole piece respectively, and there is a gap between the left end face of each pole tooth II and the side of each step, Magnetic fluid is injected into the left end surface of the tooth II, and under the action of the magnetic field force, the magnetic fluid is adsorbed on the left end surface of the pole tooth II, and the height of the pole tooth II in the axial direction is smaller than the height of the side of the corresponding step; A permanent magnet is arranged in the annular groove II.

The axial depths of each annular groove I are different, and the axial depth of each annular groove I gradually becomes shallower in the direction from the shaft to the shell, and the difference between the axial depths of two adjacent annular grooves I is equal to the middle The axial length of any step at the left end of the pole piece; the axial depth of each annular groove II is different, and the axial depth of each annular groove II gradually becomes shallower in the direction from the shaft to the shell, and two adjacent The difference in the axial depth of the annular groove II is equal to the axial length of any step at the right end of the middle pole piece.

The stepped structures of the left end face and the right end face of the middle pole shoe are mirror images of each other, and the axial length of each step is equal.

The sealing device of the present invention also includes a circlip, a magnetic isolation ring, and a bearing. The circlip is installed on the shaft and is located on the left and right sides of the middle pole piece; the left side of the left pole piece and the right side of the right pole piece Install the magnetic isolation ring and the bearing in sequence.

The magnetic isolation ring includes an outer magnetic isolation ring and an inner magnetic isolation ring, the outer magnetic isolation ring is installed on the inner wall of the shell, the inner magnetic isolation ring is installed on the shaft, and the inner wall of the outer magnetic isolation ring and the outer wall of the inner magnetic isolation ring There is a gap between them, and the axial lengths of the outer magnetic ring and the inner magnetic ring are equal.

The permanent magnets are radially magnetized permanent magnets, the polarities of the two adjacent permanent magnets on the left pole shoe are opposite, and the polarities of the two adjacent permanent magnets on the right pole shoe are opposite.

The number of steps at the left and right ends of the middle pole shoe is 2-7 respectively, and the height of the steps is 1-5mm.

The distance between the end faces of the upper pole teeth I on the left pole piece and the upper pole teeth II on the right pole piece and the side of the step on the middle pole piece is 0.1-5mm.

Annular grooves III are respectively arranged on the outer ring surfaces of the left pole piece and the right pole piece for installing rubber sealing rings.

The installation process of the sealing device of the present invention is as follows: the middle pole piece is installed in the middle of the shaft; the rubber ring is respectively installed in the annular groove III of the outer ring surface of the left pole piece and the right pole piece, A permanent magnet is installed in the annular groove I, so that the polarities of the permanent magnets in each annular groove I are opposite, and a permanent magnet is installed in the annular groove II of the right pole shoe, so that the polarity of the permanent magnets in the annular groove II is opposite; Inject the magnetic fluid into the end faces of pole tooth I and pole tooth II respectively; install the circlip, left pole shoe, magnetic isolation ring and bearing in sequence on the left side of the middle pole piece, and install the circlip, right Pole shoe, magnetic isolation ring, bearing; install the shell on the shaft so that the shell covers the above-mentioned parts installed on the shaft, the inner wall of the left end of the shell is close to the bearing on the left side, and the end cover is pressed through the threaded connection with the right end of the shell The outer ring of the bearing on the right.

In the stepped end face magnetic fluid sealing device of the present invention, the left and right ends of the middle pole piece are symmetrically arranged with radial stepped structures, and the left pole piece and the right pole piece are provided with poles corresponding to the steps on the middle pole piece. The ring grooves between the pole teeth and the pole teeth form a stepped structure, so that the middle pole piece, the left pole piece and the right pole piece form a radially stepped sealing structure. The stepped sealing structure has good magnetic gathering performance, thereby enhancing the The pressure resistance of the sealing structure reduces the loss of magnetic fluid when the seal fails; in addition, the radial stepped sealing structure prevents the sealing gap from being affected by the radial runout of the rotating shaft. The axial positioning of the sealing structure is realized by cooperating with the function of the shell and the end cover, which is beneficial to ensure that the fluctuation of the sealing gap is within a reliable range, and the sealing performance of the sealing device is stable and reliable; due to the reasonable structure design, the sealing device of the present invention It is used in rotating machinery that requires special working conditions such as large clearances, and its pressure resistance meets the requirements, thus expanding the safe working range.

Description of drawings

Fig. 1 is the structural representation of sealing device of the present invention

The serial numbers and corresponding names in the figure are as follows: 1-shaft, 2-housing, 3-bearing, 4-inner spacer magnetic ring, 5-outer spacer magnetic ring, 6-left pole shoe, 61-pole tooth I, 62 -Annular groove I, 7-Permanent magnet, 8-Middle pole piece, 9-Right pole piece, 91-Polar tooth II, 92-Annular groove II, 10-Circlip, 11-End cover, 12-Annular concave Slot III.

detailed description

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

As shown in Figure 1, a stepped end-face magnetic fluid sealing device includes a housing 2, a left pole piece 6, a middle pole piece 8, a right pole piece 9, and a permanent magnet 7. The middle pole piece 8 is installed on the shaft 1, the left end face and right end face of the middle pole piece 8 are stepped structures, and the steps on the left end face and the right end face are respectively set along the radial direction of the shaft 1; the left pole piece 6 is installed on the left side of the middle pole piece 8 side, the right pole piece 9 is installed on the right side of the middle pole piece 8;

A pole tooth I61 and an annular groove I62 are arranged on the right end surface of the left pole piece 6, the number of steps of the pole tooth I61 and the left end surface of the middle pole piece 8 are equal, and an annular groove I61 is arranged between adjacent pole teeth I61. Groove I62; the pole teeth I61 are arranged along the axial direction of the shaft 1, respectively extending to the side of each step on the left end surface of the middle pole piece 8, leaving a gap between the right end surface of each pole tooth I61 and the side of each step Clearance, the height of the pole tooth I61 in the radial direction of the shaft 1 is smaller than the height of the side of the corresponding step; the permanent magnet 7 is set in the annular groove I62;

A pole tooth II91 and an annular groove II92 are arranged on the left end surface of the right pole piece 9, the number of steps of the pole tooth II91 and the right end surface of the middle pole piece 8 are equal, and an annular groove is arranged between adjacent pole teeth II91. Groove II92; the pole teeth II91 are arranged along the axial direction of the shaft 1, respectively extending to the side of each step on the right end surface of the middle pole piece 8, leaving a gap between the left end surface of each pole tooth II91 and the side of each step The gap, the height of the pole tooth II91 in the radial direction of the shaft 1 is smaller than the height of the side of the corresponding step; the permanent magnet 7 is arranged in the annular groove II92.

The axial depth of each annular groove I62 is different, the axial depth of each annular groove I62 gradually becomes shallower in the direction from the shaft 1 to the shell 2, and the difference in the axial depth of two adjacent annular grooves I62 It is equal to the axial length of any step at the left end of the middle pole shoe 8; the axial depth of each annular groove II92 is different, and the axial depth of each annular groove II92 gradually becomes shallower in the direction from the shaft 1 to the shell 2, And the difference between the axial depths of two adjacent annular grooves II92 is equal to the axial length of any step at the right end of the middle pole piece 8 .

The stepped structures of the left end surface and the right end surface of the middle pole shoe 8 are mirror images of each other, and the axial length of each step is equal.

The sealing device of the present invention also includes a circlip 10, a magnetic isolation ring, and a bearing 3. The circlip 10 is installed on the shaft 1 and is located on the left and right sides of the middle pole piece 8; the left side of the left pole piece 6 and the The right side of the right pole shoe 9 is respectively installed with a magnetic isolation ring and a bearing 3 in sequence.

The magnetic isolation ring includes an outer magnetic isolation ring 5 and an inner magnetic isolation ring 4, the outer magnetic isolation ring 5 is installed on the inner wall of the housing 2, the inner magnetic isolation ring 4 is installed on the shaft 1, the inner wall of the outer magnetic isolation ring 5 and There is a gap between the outer walls of the inner magnetic isolation ring 4 , and the axial lengths of the outer magnetic isolation ring 5 and the inner magnetic isolation ring 4 are equal.

The permanent magnets 7 are radially magnetized permanent magnets. The polarities of the two adjacent permanent magnets 7 on the left pole shoe 6 are opposite, and the polarities of the two adjacent permanent magnets 7 on the right pole shoe 9 are opposite.

The number of steps at the left and right ends of the middle pole piece 8 is 2-7 respectively, and the height of the steps is 1-5 mm.

The distances between the end surfaces of the pole tooth I61 on the left pole piece 6 and the pole tooth II91 on the right pole piece 9 and the side of the step on the middle pole piece 8 are all 0.1-5mm.

Annular grooves III12 are respectively provided on the outer ring surfaces of the left pole piece 6 and the right pole piece 9 for installing rubber sealing rings.

The installation process of the sealing device of the present invention is as follows: the middle pole piece 8 is installed in the middle of the shaft 1; the rubber ring is respectively installed in the annular groove III12 of the outer ring surface of the left pole piece 6 and the right pole piece 9, and the Install permanent magnet 7 in the annular groove I62 of left pole shoe 6, make the permanent magnet 7 polarities in each annular groove I62 opposite, install permanent magnet 7 in the annular groove II92 of right pole shoe 9, make annular groove The polarity of the permanent magnet 7 in II92 is opposite; the magnetic fluid is injected into the end faces of the pole tooth I61 and the pole tooth II91 respectively; on the left side of the middle pole shoe 8, the circlip 10, the left pole shoe 6, the magnetic isolation ring and the bearing 3 are installed in sequence , on the right side of the middle pole shoe 8, install the circlip 10, the right pole shoe 9, the magnetic isolation ring, and the bearing 3 in sequence; install the shell 2 on the shaft 1, so that the shell 2 covers the above-mentioned parts installed on the shaft 1, and the shell 2. The inner wall of the left end is close to the bearing 3 on the left side, and the end cover 11 presses the outer ring of the bearing 3 on the right side through the screw connection with the right end of the housing 2.

Claims (10)

1. A stepped end-face magnetic fluid sealing device, including a housing (2), a left pole piece (6), a permanent magnet (7), a middle pole piece (8), and a right pole piece (9), characterized in that: The middle pole shoe (8) is installed in the middle of the shaft (1), the left end face and the right end face of the middle pole shoe (8) are both stepped structures, and the steps on the left end face and the right end face are respectively along the diameter of the shaft (1). The left pole piece (6) is installed on the left side of the middle pole piece (8), and the right pole piece (9) is installed on the right side of the middle pole piece (8); The pole tooth I (61) and the annular groove I (62) are arranged on the right end surface of the left pole piece (6), and the step between the pole tooth I (61) and the left end surface of the middle pole piece (8) The numbers are equal, and an annular groove I (62) is set between adjacent pole teeth I (61); said pole teeth I (61) are arranged The side of each step on the left end face of the pole tooth I (61) has a gap between the right end face of each step and the side of each step, and the height of the pole tooth I (61) in the radial direction of the shaft (1) is less than The height of the side of the corresponding ladder; the permanent magnet (7) is set in the annular groove I (62); The pole tooth II (91) and the annular groove II (92) are arranged on the left end surface of the right pole piece (9), and the step between the pole tooth II (91) and the right end surface of the middle pole piece (8) The numbers are equal, and an annular groove II (92) is set between adjacent pole teeth II (91); said pole teeth II (91) are arranged The side of each step on the right end face of the pole tooth II (91) has a gap between the left end face of each step and the side of each step, and the height of the pole tooth II (91) in the radial direction of the shaft (1) is less than It corresponds to the height of the side of the ladder; the permanent magnet (7) is set in the annular groove II (92). 2. The stepped end-face magnetic fluid sealing device according to claim 1, characterized in that: the axial depths of each annular groove I (62) are different, and the axial depth of each annular groove I (62) The shaft (1) gradually becomes shallower in the direction of the shell (2), and the difference between the axial depths of two adjacent annular grooves I (62) is equal to the axial depth of any step at the left end of the middle pole shoe (8) length; the axial depths of each annular groove II (92) are different, and the axial depth of each annular groove II (92) gradually becomes shallower in the direction from the shaft (1) to the shell (2), and adjacent The difference between the axial depths of the two annular grooves II (92) is equal to the axial length of any step at the right end of the middle pole piece (8). 3. The stepped end face magnetic fluid sealing device according to claim 1 or 2, characterized in that: the stepped structures of the left end face and the right end face of the middle pole shoe (8) are mirror images of each other, and each The axial lengths of the steps are equal. 4. The stepped end-face magnetic fluid seal device according to claim 1, characterized in that it further comprises a circlip (10), and the circlip (10) is installed on the shaft (1) and is located in the middle pole shoe (8) on the left and right sides. 5. The stepped end-face magnetic fluid sealing device according to claim 1, characterized in that it also includes a magnetic isolation ring, a bearing (3), the left side of the left pole piece (6) and the right pole piece (9) Install the magnetic isolation ring and the bearing (3) in sequence on the right side respectively. 6. The stepped end-face magnetic fluid sealing device according to claim 5, characterized in that: the magnetic isolation ring includes an outer magnetic isolation ring (5) and an inner magnetic isolation ring (4), and the outer magnetic isolation ring ( 5) Installed on the inner wall of the shell (2), the inner magnetic ring (4) is installed on the shaft (1), there is a gap between the inner wall of the outer magnetic ring (5) and the outer wall of the inner magnetic ring (4), The axial lengths of the outer magnetic ring (5) and the inner magnetic ring (4) are equal. 7. The stepped end-face magnetic fluid sealing device according to claim 1, characterized in that: the permanent magnet (7) is a radially magnetized permanent magnet, and there are two adjacent pole pieces on the left pole shoe (6). The polarities of the permanent magnets (7) are opposite, and the polarities of two adjacent permanent magnets (7) on the right pole piece (9) are opposite. 8. The stepped end face magnetic fluid sealing device according to claim 1, characterized in that: the number of steps at the left and right ends of the middle pole piece (8) is 2-7 respectively, and the step height is 1-5mm. 9. The stepped end face magnetic fluid sealing device according to claim 1, characterized in that: the upper pole teeth I (61) of the left pole piece (6) and the upper pole teeth II ( The distance between the end face of 91) and the side of the step on the middle pole piece (8) is 0.1-5mm. 10. The stepped end-face magnetic fluid sealing device according to claim 1, characterized in that: ring grooves III (12) are respectively provided on the outer ring surfaces of the left pole piece (6) and the right pole piece (9), For installing rubber seals.